1 /* Reload pseudo regs into hard regs for insns that require hard regs.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
28 #include "hard-reg-set.h"
32 #include "insn-config.h"
38 #include "addresses.h"
39 #include "basic-block.h"
52 /* This file contains the reload pass of the compiler, which is
53 run after register allocation has been done. It checks that
54 each insn is valid (operands required to be in registers really
55 are in registers of the proper class) and fixes up invalid ones
56 by copying values temporarily into registers for the insns
59 The results of register allocation are described by the vector
60 reg_renumber; the insns still contain pseudo regs, but reg_renumber
61 can be used to find which hard reg, if any, a pseudo reg is in.
63 The technique we always use is to free up a few hard regs that are
64 called ``reload regs'', and for each place where a pseudo reg
65 must be in a hard reg, copy it temporarily into one of the reload regs.
67 Reload regs are allocated locally for every instruction that needs
68 reloads. When there are pseudos which are allocated to a register that
69 has been chosen as a reload reg, such pseudos must be ``spilled''.
70 This means that they go to other hard regs, or to stack slots if no other
71 available hard regs can be found. Spilling can invalidate more
72 insns, requiring additional need for reloads, so we must keep checking
73 until the process stabilizes.
75 For machines with different classes of registers, we must keep track
76 of the register class needed for each reload, and make sure that
77 we allocate enough reload registers of each class.
79 The file reload.c contains the code that checks one insn for
80 validity and reports the reloads that it needs. This file
81 is in charge of scanning the entire rtl code, accumulating the
82 reload needs, spilling, assigning reload registers to use for
83 fixing up each insn, and generating the new insns to copy values
84 into the reload registers. */
86 /* During reload_as_needed, element N contains a REG rtx for the hard reg
87 into which reg N has been reloaded (perhaps for a previous insn). */
88 static rtx *reg_last_reload_reg;
90 /* Elt N nonzero if reg_last_reload_reg[N] has been set in this insn
91 for an output reload that stores into reg N. */
92 static regset_head reg_has_output_reload;
94 /* Indicates which hard regs are reload-registers for an output reload
95 in the current insn. */
96 static HARD_REG_SET reg_is_output_reload;
98 /* Element N is the constant value to which pseudo reg N is equivalent,
99 or zero if pseudo reg N is not equivalent to a constant.
100 find_reloads looks at this in order to replace pseudo reg N
101 with the constant it stands for. */
102 rtx *reg_equiv_constant;
104 /* Element N is an invariant value to which pseudo reg N is equivalent.
105 eliminate_regs_in_insn uses this to replace pseudos in particular
107 rtx *reg_equiv_invariant;
109 /* Element N is a memory location to which pseudo reg N is equivalent,
110 prior to any register elimination (such as frame pointer to stack
111 pointer). Depending on whether or not it is a valid address, this value
112 is transferred to either reg_equiv_address or reg_equiv_mem. */
113 rtx *reg_equiv_memory_loc;
115 /* We allocate reg_equiv_memory_loc inside a varray so that the garbage
116 collector can keep track of what is inside. */
117 VEC(rtx,gc) *reg_equiv_memory_loc_vec;
119 /* Element N is the address of stack slot to which pseudo reg N is equivalent.
120 This is used when the address is not valid as a memory address
121 (because its displacement is too big for the machine.) */
122 rtx *reg_equiv_address;
124 /* Element N is the memory slot to which pseudo reg N is equivalent,
125 or zero if pseudo reg N is not equivalent to a memory slot. */
128 /* Element N is an EXPR_LIST of REG_EQUIVs containing MEMs with
129 alternate representations of the location of pseudo reg N. */
130 rtx *reg_equiv_alt_mem_list;
132 /* Widest width in which each pseudo reg is referred to (via subreg). */
133 static unsigned int *reg_max_ref_width;
135 /* Element N is the list of insns that initialized reg N from its equivalent
136 constant or memory slot. */
138 int reg_equiv_init_size;
140 /* Vector to remember old contents of reg_renumber before spilling. */
141 static short *reg_old_renumber;
143 /* During reload_as_needed, element N contains the last pseudo regno reloaded
144 into hard register N. If that pseudo reg occupied more than one register,
145 reg_reloaded_contents points to that pseudo for each spill register in
146 use; all of these must remain set for an inheritance to occur. */
147 static int reg_reloaded_contents[FIRST_PSEUDO_REGISTER];
149 /* During reload_as_needed, element N contains the insn for which
150 hard register N was last used. Its contents are significant only
151 when reg_reloaded_valid is set for this register. */
152 static rtx reg_reloaded_insn[FIRST_PSEUDO_REGISTER];
154 /* Indicate if reg_reloaded_insn / reg_reloaded_contents is valid. */
155 static HARD_REG_SET reg_reloaded_valid;
156 /* Indicate if the register was dead at the end of the reload.
157 This is only valid if reg_reloaded_contents is set and valid. */
158 static HARD_REG_SET reg_reloaded_dead;
160 /* Indicate whether the register's current value is one that is not
161 safe to retain across a call, even for registers that are normally
162 call-saved. This is only meaningful for members of reg_reloaded_valid. */
163 static HARD_REG_SET reg_reloaded_call_part_clobbered;
165 /* Number of spill-regs so far; number of valid elements of spill_regs. */
168 /* In parallel with spill_regs, contains REG rtx's for those regs.
169 Holds the last rtx used for any given reg, or 0 if it has never
170 been used for spilling yet. This rtx is reused, provided it has
172 static rtx spill_reg_rtx[FIRST_PSEUDO_REGISTER];
174 /* In parallel with spill_regs, contains nonzero for a spill reg
175 that was stored after the last time it was used.
176 The precise value is the insn generated to do the store. */
177 static rtx spill_reg_store[FIRST_PSEUDO_REGISTER];
179 /* This is the register that was stored with spill_reg_store. This is a
180 copy of reload_out / reload_out_reg when the value was stored; if
181 reload_out is a MEM, spill_reg_stored_to will be set to reload_out_reg. */
182 static rtx spill_reg_stored_to[FIRST_PSEUDO_REGISTER];
184 /* This table is the inverse mapping of spill_regs:
185 indexed by hard reg number,
186 it contains the position of that reg in spill_regs,
187 or -1 for something that is not in spill_regs.
189 ?!? This is no longer accurate. */
190 static short spill_reg_order[FIRST_PSEUDO_REGISTER];
192 /* This reg set indicates registers that can't be used as spill registers for
193 the currently processed insn. These are the hard registers which are live
194 during the insn, but not allocated to pseudos, as well as fixed
196 static HARD_REG_SET bad_spill_regs;
198 /* These are the hard registers that can't be used as spill register for any
199 insn. This includes registers used for user variables and registers that
200 we can't eliminate. A register that appears in this set also can't be used
201 to retry register allocation. */
202 static HARD_REG_SET bad_spill_regs_global;
204 /* Describes order of use of registers for reloading
205 of spilled pseudo-registers. `n_spills' is the number of
206 elements that are actually valid; new ones are added at the end.
208 Both spill_regs and spill_reg_order are used on two occasions:
209 once during find_reload_regs, where they keep track of the spill registers
210 for a single insn, but also during reload_as_needed where they show all
211 the registers ever used by reload. For the latter case, the information
212 is calculated during finish_spills. */
213 static short spill_regs[FIRST_PSEUDO_REGISTER];
215 /* This vector of reg sets indicates, for each pseudo, which hard registers
216 may not be used for retrying global allocation because the register was
217 formerly spilled from one of them. If we allowed reallocating a pseudo to
218 a register that it was already allocated to, reload might not
220 static HARD_REG_SET *pseudo_previous_regs;
222 /* This vector of reg sets indicates, for each pseudo, which hard
223 registers may not be used for retrying global allocation because they
224 are used as spill registers during one of the insns in which the
226 static HARD_REG_SET *pseudo_forbidden_regs;
228 /* All hard regs that have been used as spill registers for any insn are
229 marked in this set. */
230 static HARD_REG_SET used_spill_regs;
232 /* Index of last register assigned as a spill register. We allocate in
233 a round-robin fashion. */
234 static int last_spill_reg;
236 /* Nonzero if indirect addressing is supported on the machine; this means
237 that spilling (REG n) does not require reloading it into a register in
238 order to do (MEM (REG n)) or (MEM (PLUS (REG n) (CONST_INT c))). The
239 value indicates the level of indirect addressing supported, e.g., two
240 means that (MEM (MEM (REG n))) is also valid if (REG n) does not get
242 static char spill_indirect_levels;
244 /* Nonzero if indirect addressing is supported when the innermost MEM is
245 of the form (MEM (SYMBOL_REF sym)). It is assumed that the level to
246 which these are valid is the same as spill_indirect_levels, above. */
247 char indirect_symref_ok;
249 /* Nonzero if an address (plus (reg frame_pointer) (reg ...)) is valid. */
250 char double_reg_address_ok;
252 /* Record the stack slot for each spilled hard register. */
253 static rtx spill_stack_slot[FIRST_PSEUDO_REGISTER];
255 /* Width allocated so far for that stack slot. */
256 static unsigned int spill_stack_slot_width[FIRST_PSEUDO_REGISTER];
258 /* Record which pseudos needed to be spilled. */
259 static regset_head spilled_pseudos;
261 /* Record which pseudos changed their allocation in finish_spills. */
262 static regset_head changed_allocation_pseudos;
264 /* Used for communication between order_regs_for_reload and count_pseudo.
265 Used to avoid counting one pseudo twice. */
266 static regset_head pseudos_counted;
268 /* First uid used by insns created by reload in this function.
269 Used in find_equiv_reg. */
270 int reload_first_uid;
272 /* Flag set by local-alloc or global-alloc if anything is live in
273 a call-clobbered reg across calls. */
274 int caller_save_needed;
276 /* Set to 1 while reload_as_needed is operating.
277 Required by some machines to handle any generated moves differently. */
278 int reload_in_progress = 0;
280 /* These arrays record the insn_code of insns that may be needed to
281 perform input and output reloads of special objects. They provide a
282 place to pass a scratch register. */
283 enum insn_code reload_in_optab[NUM_MACHINE_MODES];
284 enum insn_code reload_out_optab[NUM_MACHINE_MODES];
286 /* This obstack is used for allocation of rtl during register elimination.
287 The allocated storage can be freed once find_reloads has processed the
289 static struct obstack reload_obstack;
291 /* Points to the beginning of the reload_obstack. All insn_chain structures
292 are allocated first. */
293 static char *reload_startobj;
295 /* The point after all insn_chain structures. Used to quickly deallocate
296 memory allocated in copy_reloads during calculate_needs_all_insns. */
297 static char *reload_firstobj;
299 /* This points before all local rtl generated by register elimination.
300 Used to quickly free all memory after processing one insn. */
301 static char *reload_insn_firstobj;
303 /* List of insn_chain instructions, one for every insn that reload needs to
305 struct insn_chain *reload_insn_chain;
307 /* List of all insns needing reloads. */
308 static struct insn_chain *insns_need_reload;
310 /* This structure is used to record information about register eliminations.
311 Each array entry describes one possible way of eliminating a register
312 in favor of another. If there is more than one way of eliminating a
313 particular register, the most preferred should be specified first. */
317 int from; /* Register number to be eliminated. */
318 int to; /* Register number used as replacement. */
319 HOST_WIDE_INT initial_offset; /* Initial difference between values. */
320 int can_eliminate; /* Nonzero if this elimination can be done. */
321 int can_eliminate_previous; /* Value of CAN_ELIMINATE in previous scan over
322 insns made by reload. */
323 HOST_WIDE_INT offset; /* Current offset between the two regs. */
324 HOST_WIDE_INT previous_offset;/* Offset at end of previous insn. */
325 int ref_outside_mem; /* "to" has been referenced outside a MEM. */
326 rtx from_rtx; /* REG rtx for the register to be eliminated.
327 We cannot simply compare the number since
328 we might then spuriously replace a hard
329 register corresponding to a pseudo
330 assigned to the reg to be eliminated. */
331 rtx to_rtx; /* REG rtx for the replacement. */
334 static struct elim_table *reg_eliminate = 0;
336 /* This is an intermediate structure to initialize the table. It has
337 exactly the members provided by ELIMINABLE_REGS. */
338 static const struct elim_table_1
342 } reg_eliminate_1[] =
344 /* If a set of eliminable registers was specified, define the table from it.
345 Otherwise, default to the normal case of the frame pointer being
346 replaced by the stack pointer. */
348 #ifdef ELIMINABLE_REGS
351 {{ FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM}};
354 #define NUM_ELIMINABLE_REGS ARRAY_SIZE (reg_eliminate_1)
356 /* Record the number of pending eliminations that have an offset not equal
357 to their initial offset. If nonzero, we use a new copy of each
358 replacement result in any insns encountered. */
359 int num_not_at_initial_offset;
361 /* Count the number of registers that we may be able to eliminate. */
362 static int num_eliminable;
363 /* And the number of registers that are equivalent to a constant that
364 can be eliminated to frame_pointer / arg_pointer + constant. */
365 static int num_eliminable_invariants;
367 /* For each label, we record the offset of each elimination. If we reach
368 a label by more than one path and an offset differs, we cannot do the
369 elimination. This information is indexed by the difference of the
370 number of the label and the first label number. We can't offset the
371 pointer itself as this can cause problems on machines with segmented
372 memory. The first table is an array of flags that records whether we
373 have yet encountered a label and the second table is an array of arrays,
374 one entry in the latter array for each elimination. */
376 static int first_label_num;
377 static char *offsets_known_at;
378 static HOST_WIDE_INT (*offsets_at)[NUM_ELIMINABLE_REGS];
380 /* Number of labels in the current function. */
382 static int num_labels;
384 static void replace_pseudos_in (rtx *, enum machine_mode, rtx);
385 static void maybe_fix_stack_asms (void);
386 static void copy_reloads (struct insn_chain *);
387 static void calculate_needs_all_insns (int);
388 static int find_reg (struct insn_chain *, int);
389 static void find_reload_regs (struct insn_chain *);
390 static void select_reload_regs (void);
391 static void delete_caller_save_insns (void);
393 static void spill_failure (rtx, enum reg_class);
394 static void count_spilled_pseudo (int, int, int);
395 static void delete_dead_insn (rtx);
396 static void alter_reg (int, int, bool);
397 static void set_label_offsets (rtx, rtx, int);
398 static void check_eliminable_occurrences (rtx);
399 static void elimination_effects (rtx, enum machine_mode);
400 static int eliminate_regs_in_insn (rtx, int);
401 static void update_eliminable_offsets (void);
402 static void mark_not_eliminable (rtx, const_rtx, void *);
403 static void set_initial_elim_offsets (void);
404 static bool verify_initial_elim_offsets (void);
405 static void set_initial_label_offsets (void);
406 static void set_offsets_for_label (rtx);
407 static void init_elim_table (void);
408 static void update_eliminables (HARD_REG_SET *);
409 static void spill_hard_reg (unsigned int, int);
410 static int finish_spills (int);
411 static void scan_paradoxical_subregs (rtx);
412 static void count_pseudo (int);
413 static void order_regs_for_reload (struct insn_chain *);
414 static void reload_as_needed (int);
415 static void forget_old_reloads_1 (rtx, const_rtx, void *);
416 static void forget_marked_reloads (regset);
417 static int reload_reg_class_lower (const void *, const void *);
418 static void mark_reload_reg_in_use (unsigned int, int, enum reload_type,
420 static void clear_reload_reg_in_use (unsigned int, int, enum reload_type,
422 static int reload_reg_free_p (unsigned int, int, enum reload_type);
423 static int reload_reg_free_for_value_p (int, int, int, enum reload_type,
425 static int free_for_value_p (int, enum machine_mode, int, enum reload_type,
427 static int reload_reg_reaches_end_p (unsigned int, int, enum reload_type);
428 static int allocate_reload_reg (struct insn_chain *, int, int);
429 static int conflicts_with_override (rtx);
430 static void failed_reload (rtx, int);
431 static int set_reload_reg (int, int);
432 static void choose_reload_regs_init (struct insn_chain *, rtx *);
433 static void choose_reload_regs (struct insn_chain *);
434 static void merge_assigned_reloads (rtx);
435 static void emit_input_reload_insns (struct insn_chain *, struct reload *,
437 static void emit_output_reload_insns (struct insn_chain *, struct reload *,
439 static void do_input_reload (struct insn_chain *, struct reload *, int);
440 static void do_output_reload (struct insn_chain *, struct reload *, int);
441 static void emit_reload_insns (struct insn_chain *);
442 static void delete_output_reload (rtx, int, int, rtx);
443 static void delete_address_reloads (rtx, rtx);
444 static void delete_address_reloads_1 (rtx, rtx, rtx);
445 static rtx inc_for_reload (rtx, rtx, rtx, int);
447 static void add_auto_inc_notes (rtx, rtx);
449 static void copy_eh_notes (rtx, rtx);
450 static void substitute (rtx *, const_rtx, rtx);
451 static bool gen_reload_chain_without_interm_reg_p (int, int);
452 static int reloads_conflict (int, int);
453 static rtx gen_reload (rtx, rtx, int, enum reload_type);
454 static rtx emit_insn_if_valid_for_reload (rtx);
456 /* Initialize the reload pass. This is called at the beginning of compilation
457 and may be called again if the target is reinitialized. */
464 /* Often (MEM (REG n)) is still valid even if (REG n) is put on the stack.
465 Set spill_indirect_levels to the number of levels such addressing is
466 permitted, zero if it is not permitted at all. */
469 = gen_rtx_MEM (Pmode,
472 LAST_VIRTUAL_REGISTER + 1),
474 spill_indirect_levels = 0;
476 while (memory_address_p (QImode, tem))
478 spill_indirect_levels++;
479 tem = gen_rtx_MEM (Pmode, tem);
482 /* See if indirect addressing is valid for (MEM (SYMBOL_REF ...)). */
484 tem = gen_rtx_MEM (Pmode, gen_rtx_SYMBOL_REF (Pmode, "foo"));
485 indirect_symref_ok = memory_address_p (QImode, tem);
487 /* See if reg+reg is a valid (and offsettable) address. */
489 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
491 tem = gen_rtx_PLUS (Pmode,
492 gen_rtx_REG (Pmode, HARD_FRAME_POINTER_REGNUM),
493 gen_rtx_REG (Pmode, i));
495 /* This way, we make sure that reg+reg is an offsettable address. */
496 tem = plus_constant (tem, 4);
498 if (memory_address_p (QImode, tem))
500 double_reg_address_ok = 1;
505 /* Initialize obstack for our rtl allocation. */
506 gcc_obstack_init (&reload_obstack);
507 reload_startobj = XOBNEWVAR (&reload_obstack, char, 0);
509 INIT_REG_SET (&spilled_pseudos);
510 INIT_REG_SET (&changed_allocation_pseudos);
511 INIT_REG_SET (&pseudos_counted);
514 /* List of insn chains that are currently unused. */
515 static struct insn_chain *unused_insn_chains = 0;
517 /* Allocate an empty insn_chain structure. */
519 new_insn_chain (void)
521 struct insn_chain *c;
523 if (unused_insn_chains == 0)
525 c = XOBNEW (&reload_obstack, struct insn_chain);
526 INIT_REG_SET (&c->live_throughout);
527 INIT_REG_SET (&c->dead_or_set);
531 c = unused_insn_chains;
532 unused_insn_chains = c->next;
534 c->is_caller_save_insn = 0;
535 c->need_operand_change = 0;
541 /* Small utility function to set all regs in hard reg set TO which are
542 allocated to pseudos in regset FROM. */
545 compute_use_by_pseudos (HARD_REG_SET *to, regset from)
548 reg_set_iterator rsi;
550 EXECUTE_IF_SET_IN_REG_SET (from, FIRST_PSEUDO_REGISTER, regno, rsi)
552 int r = reg_renumber[regno];
556 /* reload_combine uses the information from DF_LIVE_IN,
557 which might still contain registers that have not
558 actually been allocated since they have an
560 gcc_assert ((flag_ira && optimize) || reload_completed);
563 add_to_hard_reg_set (to, PSEUDO_REGNO_MODE (regno), r);
567 /* Replace all pseudos found in LOC with their corresponding
571 replace_pseudos_in (rtx *loc, enum machine_mode mem_mode, rtx usage)
584 unsigned int regno = REGNO (x);
586 if (regno < FIRST_PSEUDO_REGISTER)
589 x = eliminate_regs (x, mem_mode, usage);
593 replace_pseudos_in (loc, mem_mode, usage);
597 if (reg_equiv_constant[regno])
598 *loc = reg_equiv_constant[regno];
599 else if (reg_equiv_mem[regno])
600 *loc = reg_equiv_mem[regno];
601 else if (reg_equiv_address[regno])
602 *loc = gen_rtx_MEM (GET_MODE (x), reg_equiv_address[regno]);
605 gcc_assert (!REG_P (regno_reg_rtx[regno])
606 || REGNO (regno_reg_rtx[regno]) != regno);
607 *loc = regno_reg_rtx[regno];
612 else if (code == MEM)
614 replace_pseudos_in (& XEXP (x, 0), GET_MODE (x), usage);
618 /* Process each of our operands recursively. */
619 fmt = GET_RTX_FORMAT (code);
620 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
622 replace_pseudos_in (&XEXP (x, i), mem_mode, usage);
623 else if (*fmt == 'E')
624 for (j = 0; j < XVECLEN (x, i); j++)
625 replace_pseudos_in (& XVECEXP (x, i, j), mem_mode, usage);
628 /* Determine if the current function has an exception receiver block
629 that reaches the exit block via non-exceptional edges */
632 has_nonexceptional_receiver (void)
636 basic_block *tos, *worklist, bb;
638 /* If we're not optimizing, then just err on the safe side. */
642 /* First determine which blocks can reach exit via normal paths. */
643 tos = worklist = XNEWVEC (basic_block, n_basic_blocks + 1);
646 bb->flags &= ~BB_REACHABLE;
648 /* Place the exit block on our worklist. */
649 EXIT_BLOCK_PTR->flags |= BB_REACHABLE;
650 *tos++ = EXIT_BLOCK_PTR;
652 /* Iterate: find everything reachable from what we've already seen. */
653 while (tos != worklist)
657 FOR_EACH_EDGE (e, ei, bb->preds)
658 if (!(e->flags & EDGE_ABNORMAL))
660 basic_block src = e->src;
662 if (!(src->flags & BB_REACHABLE))
664 src->flags |= BB_REACHABLE;
671 /* Now see if there's a reachable block with an exceptional incoming
674 if (bb->flags & BB_REACHABLE)
675 FOR_EACH_EDGE (e, ei, bb->preds)
676 if (e->flags & EDGE_ABNORMAL)
679 /* No exceptional block reached exit unexceptionally. */
684 /* Global variables used by reload and its subroutines. */
686 /* Set during calculate_needs if an insn needs register elimination. */
687 static int something_needs_elimination;
688 /* Set during calculate_needs if an insn needs an operand changed. */
689 static int something_needs_operands_changed;
691 /* Nonzero means we couldn't get enough spill regs. */
694 /* Temporary array of pseudo-register number. */
695 static int *temp_pseudo_reg_arr;
697 /* Main entry point for the reload pass.
699 FIRST is the first insn of the function being compiled.
701 GLOBAL nonzero means we were called from global_alloc
702 and should attempt to reallocate any pseudoregs that we
703 displace from hard regs we will use for reloads.
704 If GLOBAL is zero, we do not have enough information to do that,
705 so any pseudo reg that is spilled must go to the stack.
707 Return value is nonzero if reload failed
708 and we must not do any more for this function. */
711 reload (rtx first, int global)
715 struct elim_table *ep;
718 /* Make sure even insns with volatile mem refs are recognizable. */
723 reload_firstobj = XOBNEWVAR (&reload_obstack, char, 0);
725 /* Make sure that the last insn in the chain
726 is not something that needs reloading. */
727 emit_note (NOTE_INSN_DELETED);
729 /* Enable find_equiv_reg to distinguish insns made by reload. */
730 reload_first_uid = get_max_uid ();
732 #ifdef SECONDARY_MEMORY_NEEDED
733 /* Initialize the secondary memory table. */
734 clear_secondary_mem ();
737 /* We don't have a stack slot for any spill reg yet. */
738 memset (spill_stack_slot, 0, sizeof spill_stack_slot);
739 memset (spill_stack_slot_width, 0, sizeof spill_stack_slot_width);
741 /* Initialize the save area information for caller-save, in case some
745 /* Compute which hard registers are now in use
746 as homes for pseudo registers.
747 This is done here rather than (eg) in global_alloc
748 because this point is reached even if not optimizing. */
749 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
752 /* A function that has a nonlocal label that can reach the exit
753 block via non-exceptional paths must save all call-saved
755 if (cfun->has_nonlocal_label
756 && has_nonexceptional_receiver ())
757 crtl->saves_all_registers = 1;
759 if (crtl->saves_all_registers)
760 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
761 if (! call_used_regs[i] && ! fixed_regs[i] && ! LOCAL_REGNO (i))
762 df_set_regs_ever_live (i, true);
764 /* Find all the pseudo registers that didn't get hard regs
765 but do have known equivalent constants or memory slots.
766 These include parameters (known equivalent to parameter slots)
767 and cse'd or loop-moved constant memory addresses.
769 Record constant equivalents in reg_equiv_constant
770 so they will be substituted by find_reloads.
771 Record memory equivalents in reg_mem_equiv so they can
772 be substituted eventually by altering the REG-rtx's. */
774 reg_equiv_constant = XCNEWVEC (rtx, max_regno);
775 reg_equiv_invariant = XCNEWVEC (rtx, max_regno);
776 reg_equiv_mem = XCNEWVEC (rtx, max_regno);
777 reg_equiv_alt_mem_list = XCNEWVEC (rtx, max_regno);
778 reg_equiv_address = XCNEWVEC (rtx, max_regno);
779 reg_max_ref_width = XCNEWVEC (unsigned int, max_regno);
780 reg_old_renumber = XCNEWVEC (short, max_regno);
781 memcpy (reg_old_renumber, reg_renumber, max_regno * sizeof (short));
782 pseudo_forbidden_regs = XNEWVEC (HARD_REG_SET, max_regno);
783 pseudo_previous_regs = XCNEWVEC (HARD_REG_SET, max_regno);
785 CLEAR_HARD_REG_SET (bad_spill_regs_global);
787 /* Look for REG_EQUIV notes; record what each pseudo is equivalent
788 to. Also find all paradoxical subregs and find largest such for
791 num_eliminable_invariants = 0;
792 for (insn = first; insn; insn = NEXT_INSN (insn))
794 rtx set = single_set (insn);
796 /* We may introduce USEs that we want to remove at the end, so
797 we'll mark them with QImode. Make sure there are no
798 previously-marked insns left by say regmove. */
799 if (INSN_P (insn) && GET_CODE (PATTERN (insn)) == USE
800 && GET_MODE (insn) != VOIDmode)
801 PUT_MODE (insn, VOIDmode);
804 scan_paradoxical_subregs (PATTERN (insn));
806 if (set != 0 && REG_P (SET_DEST (set)))
808 rtx note = find_reg_note (insn, REG_EQUIV, NULL_RTX);
814 i = REGNO (SET_DEST (set));
817 if (i <= LAST_VIRTUAL_REGISTER)
820 if (! function_invariant_p (x)
822 /* A function invariant is often CONSTANT_P but may
823 include a register. We promise to only pass
824 CONSTANT_P objects to LEGITIMATE_PIC_OPERAND_P. */
826 && LEGITIMATE_PIC_OPERAND_P (x)))
828 /* It can happen that a REG_EQUIV note contains a MEM
829 that is not a legitimate memory operand. As later
830 stages of reload assume that all addresses found
831 in the reg_equiv_* arrays were originally legitimate,
832 we ignore such REG_EQUIV notes. */
833 if (memory_operand (x, VOIDmode))
835 /* Always unshare the equivalence, so we can
836 substitute into this insn without touching the
838 reg_equiv_memory_loc[i] = copy_rtx (x);
840 else if (function_invariant_p (x))
842 if (GET_CODE (x) == PLUS)
844 /* This is PLUS of frame pointer and a constant,
845 and might be shared. Unshare it. */
846 reg_equiv_invariant[i] = copy_rtx (x);
847 num_eliminable_invariants++;
849 else if (x == frame_pointer_rtx || x == arg_pointer_rtx)
851 reg_equiv_invariant[i] = x;
852 num_eliminable_invariants++;
854 else if (LEGITIMATE_CONSTANT_P (x))
855 reg_equiv_constant[i] = x;
858 reg_equiv_memory_loc[i]
859 = force_const_mem (GET_MODE (SET_DEST (set)), x);
860 if (! reg_equiv_memory_loc[i])
861 reg_equiv_init[i] = NULL_RTX;
866 reg_equiv_init[i] = NULL_RTX;
871 reg_equiv_init[i] = NULL_RTX;
876 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
877 if (reg_equiv_init[i])
879 fprintf (dump_file, "init_insns for %u: ", i);
880 print_inline_rtx (dump_file, reg_equiv_init[i], 20);
881 fprintf (dump_file, "\n");
886 first_label_num = get_first_label_num ();
887 num_labels = max_label_num () - first_label_num;
889 /* Allocate the tables used to store offset information at labels. */
890 /* We used to use alloca here, but the size of what it would try to
891 allocate would occasionally cause it to exceed the stack limit and
892 cause a core dump. */
893 offsets_known_at = XNEWVEC (char, num_labels);
894 offsets_at = (HOST_WIDE_INT (*)[NUM_ELIMINABLE_REGS]) xmalloc (num_labels * NUM_ELIMINABLE_REGS * sizeof (HOST_WIDE_INT));
896 /* Alter each pseudo-reg rtx to contain its hard reg number. Assign
897 stack slots to the pseudos that lack hard regs or equivalents.
898 Do not touch virtual registers. */
900 temp_pseudo_reg_arr = XNEWVEC (int, max_regno - LAST_VIRTUAL_REGISTER - 1);
901 for (n = 0, i = LAST_VIRTUAL_REGISTER + 1; i < max_regno; i++)
902 temp_pseudo_reg_arr[n++] = i;
904 if (flag_ira && optimize)
905 /* Ask IRA to order pseudo-registers for better stack slot
907 ira_sort_regnos_for_alter_reg (temp_pseudo_reg_arr, n, reg_max_ref_width);
909 for (i = 0; i < n; i++)
910 alter_reg (temp_pseudo_reg_arr[i], -1, false);
912 /* If we have some registers we think can be eliminated, scan all insns to
913 see if there is an insn that sets one of these registers to something
914 other than itself plus a constant. If so, the register cannot be
915 eliminated. Doing this scan here eliminates an extra pass through the
916 main reload loop in the most common case where register elimination
918 for (insn = first; insn && num_eliminable; insn = NEXT_INSN (insn))
920 note_stores (PATTERN (insn), mark_not_eliminable, NULL);
922 maybe_fix_stack_asms ();
924 insns_need_reload = 0;
925 something_needs_elimination = 0;
927 /* Initialize to -1, which means take the first spill register. */
930 /* Spill any hard regs that we know we can't eliminate. */
931 CLEAR_HARD_REG_SET (used_spill_regs);
932 /* There can be multiple ways to eliminate a register;
933 they should be listed adjacently.
934 Elimination for any register fails only if all possible ways fail. */
935 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; )
938 int can_eliminate = 0;
941 can_eliminate |= ep->can_eliminate;
944 while (ep < ®_eliminate[NUM_ELIMINABLE_REGS] && ep->from == from);
946 spill_hard_reg (from, 1);
949 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
950 if (frame_pointer_needed)
951 spill_hard_reg (HARD_FRAME_POINTER_REGNUM, 1);
953 finish_spills (global);
955 /* From now on, we may need to generate moves differently. We may also
956 allow modifications of insns which cause them to not be recognized.
957 Any such modifications will be cleaned up during reload itself. */
958 reload_in_progress = 1;
960 /* This loop scans the entire function each go-round
961 and repeats until one repetition spills no additional hard regs. */
964 int something_changed;
966 HOST_WIDE_INT starting_frame_size;
968 starting_frame_size = get_frame_size ();
970 set_initial_elim_offsets ();
971 set_initial_label_offsets ();
973 /* For each pseudo register that has an equivalent location defined,
974 try to eliminate any eliminable registers (such as the frame pointer)
975 assuming initial offsets for the replacement register, which
978 If the resulting location is directly addressable, substitute
979 the MEM we just got directly for the old REG.
981 If it is not addressable but is a constant or the sum of a hard reg
982 and constant, it is probably not addressable because the constant is
983 out of range, in that case record the address; we will generate
984 hairy code to compute the address in a register each time it is
985 needed. Similarly if it is a hard register, but one that is not
986 valid as an address register.
988 If the location is not addressable, but does not have one of the
989 above forms, assign a stack slot. We have to do this to avoid the
990 potential of producing lots of reloads if, e.g., a location involves
991 a pseudo that didn't get a hard register and has an equivalent memory
992 location that also involves a pseudo that didn't get a hard register.
994 Perhaps at some point we will improve reload_when_needed handling
995 so this problem goes away. But that's very hairy. */
997 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
998 if (reg_renumber[i] < 0 && reg_equiv_memory_loc[i])
1000 rtx x = eliminate_regs (reg_equiv_memory_loc[i], 0, NULL_RTX);
1002 if (strict_memory_address_p (GET_MODE (regno_reg_rtx[i]),
1004 reg_equiv_mem[i] = x, reg_equiv_address[i] = 0;
1005 else if (CONSTANT_P (XEXP (x, 0))
1006 || (REG_P (XEXP (x, 0))
1007 && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER)
1008 || (GET_CODE (XEXP (x, 0)) == PLUS
1009 && REG_P (XEXP (XEXP (x, 0), 0))
1010 && (REGNO (XEXP (XEXP (x, 0), 0))
1011 < FIRST_PSEUDO_REGISTER)
1012 && CONSTANT_P (XEXP (XEXP (x, 0), 1))))
1013 reg_equiv_address[i] = XEXP (x, 0), reg_equiv_mem[i] = 0;
1016 /* Make a new stack slot. Then indicate that something
1017 changed so we go back and recompute offsets for
1018 eliminable registers because the allocation of memory
1019 below might change some offset. reg_equiv_{mem,address}
1020 will be set up for this pseudo on the next pass around
1022 reg_equiv_memory_loc[i] = 0;
1023 reg_equiv_init[i] = 0;
1024 alter_reg (i, -1, true);
1028 if (caller_save_needed)
1029 setup_save_areas ();
1031 /* If we allocated another stack slot, redo elimination bookkeeping. */
1032 if (starting_frame_size != get_frame_size ())
1034 if (starting_frame_size && crtl->stack_alignment_needed)
1036 /* If we have a stack frame, we must align it now. The
1037 stack size may be a part of the offset computation for
1038 register elimination. So if this changes the stack size,
1039 then repeat the elimination bookkeeping. We don't
1040 realign when there is no stack, as that will cause a
1041 stack frame when none is needed should
1042 STARTING_FRAME_OFFSET not be already aligned to
1044 assign_stack_local (BLKmode, 0, crtl->stack_alignment_needed);
1045 if (starting_frame_size != get_frame_size ())
1049 if (caller_save_needed)
1051 save_call_clobbered_regs ();
1052 /* That might have allocated new insn_chain structures. */
1053 reload_firstobj = XOBNEWVAR (&reload_obstack, char, 0);
1056 calculate_needs_all_insns (global);
1058 if (! flag_ira || ! optimize)
1059 /* Don't do it for IRA. We need this info because we don't
1060 change live_throughout and dead_or_set for chains when IRA
1062 CLEAR_REG_SET (&spilled_pseudos);
1066 something_changed = 0;
1068 /* If we allocated any new memory locations, make another pass
1069 since it might have changed elimination offsets. */
1070 if (starting_frame_size != get_frame_size ())
1071 something_changed = 1;
1073 /* Even if the frame size remained the same, we might still have
1074 changed elimination offsets, e.g. if find_reloads called
1075 force_const_mem requiring the back end to allocate a constant
1076 pool base register that needs to be saved on the stack. */
1077 else if (!verify_initial_elim_offsets ())
1078 something_changed = 1;
1081 HARD_REG_SET to_spill;
1082 CLEAR_HARD_REG_SET (to_spill);
1083 update_eliminables (&to_spill);
1084 AND_COMPL_HARD_REG_SET (used_spill_regs, to_spill);
1086 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1087 if (TEST_HARD_REG_BIT (to_spill, i))
1089 spill_hard_reg (i, 1);
1092 /* Regardless of the state of spills, if we previously had
1093 a register that we thought we could eliminate, but now can
1094 not eliminate, we must run another pass.
1096 Consider pseudos which have an entry in reg_equiv_* which
1097 reference an eliminable register. We must make another pass
1098 to update reg_equiv_* so that we do not substitute in the
1099 old value from when we thought the elimination could be
1101 something_changed = 1;
1105 select_reload_regs ();
1109 if (insns_need_reload != 0 || did_spill)
1110 something_changed |= finish_spills (global);
1112 if (! something_changed)
1115 if (caller_save_needed)
1116 delete_caller_save_insns ();
1118 obstack_free (&reload_obstack, reload_firstobj);
1121 /* If global-alloc was run, notify it of any register eliminations we have
1124 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
1125 if (ep->can_eliminate)
1126 mark_elimination (ep->from, ep->to);
1128 /* If a pseudo has no hard reg, delete the insns that made the equivalence.
1129 If that insn didn't set the register (i.e., it copied the register to
1130 memory), just delete that insn instead of the equivalencing insn plus
1131 anything now dead. If we call delete_dead_insn on that insn, we may
1132 delete the insn that actually sets the register if the register dies
1133 there and that is incorrect. */
1135 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
1137 if (reg_renumber[i] < 0 && reg_equiv_init[i] != 0)
1140 for (list = reg_equiv_init[i]; list; list = XEXP (list, 1))
1142 rtx equiv_insn = XEXP (list, 0);
1144 /* If we already deleted the insn or if it may trap, we can't
1145 delete it. The latter case shouldn't happen, but can
1146 if an insn has a variable address, gets a REG_EH_REGION
1147 note added to it, and then gets converted into a load
1148 from a constant address. */
1149 if (NOTE_P (equiv_insn)
1150 || can_throw_internal (equiv_insn))
1152 else if (reg_set_p (regno_reg_rtx[i], PATTERN (equiv_insn)))
1153 delete_dead_insn (equiv_insn);
1155 SET_INSN_DELETED (equiv_insn);
1160 /* Use the reload registers where necessary
1161 by generating move instructions to move the must-be-register
1162 values into or out of the reload registers. */
1164 if (insns_need_reload != 0 || something_needs_elimination
1165 || something_needs_operands_changed)
1167 HOST_WIDE_INT old_frame_size = get_frame_size ();
1169 reload_as_needed (global);
1171 gcc_assert (old_frame_size == get_frame_size ());
1173 gcc_assert (verify_initial_elim_offsets ());
1176 /* If we were able to eliminate the frame pointer, show that it is no
1177 longer live at the start of any basic block. If it ls live by
1178 virtue of being in a pseudo, that pseudo will be marked live
1179 and hence the frame pointer will be known to be live via that
1182 if (! frame_pointer_needed)
1184 bitmap_clear_bit (df_get_live_in (bb), HARD_FRAME_POINTER_REGNUM);
1186 /* Come here (with failure set nonzero) if we can't get enough spill
1190 CLEAR_REG_SET (&changed_allocation_pseudos);
1191 CLEAR_REG_SET (&spilled_pseudos);
1192 reload_in_progress = 0;
1194 /* Now eliminate all pseudo regs by modifying them into
1195 their equivalent memory references.
1196 The REG-rtx's for the pseudos are modified in place,
1197 so all insns that used to refer to them now refer to memory.
1199 For a reg that has a reg_equiv_address, all those insns
1200 were changed by reloading so that no insns refer to it any longer;
1201 but the DECL_RTL of a variable decl may refer to it,
1202 and if so this causes the debugging info to mention the variable. */
1204 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
1208 if (reg_equiv_mem[i])
1209 addr = XEXP (reg_equiv_mem[i], 0);
1211 if (reg_equiv_address[i])
1212 addr = reg_equiv_address[i];
1216 if (reg_renumber[i] < 0)
1218 rtx reg = regno_reg_rtx[i];
1220 REG_USERVAR_P (reg) = 0;
1221 PUT_CODE (reg, MEM);
1222 XEXP (reg, 0) = addr;
1223 if (reg_equiv_memory_loc[i])
1224 MEM_COPY_ATTRIBUTES (reg, reg_equiv_memory_loc[i]);
1227 MEM_IN_STRUCT_P (reg) = MEM_SCALAR_P (reg) = 0;
1228 MEM_ATTRS (reg) = 0;
1230 MEM_NOTRAP_P (reg) = 1;
1232 else if (reg_equiv_mem[i])
1233 XEXP (reg_equiv_mem[i], 0) = addr;
1237 /* We must set reload_completed now since the cleanup_subreg_operands call
1238 below will re-recognize each insn and reload may have generated insns
1239 which are only valid during and after reload. */
1240 reload_completed = 1;
1242 /* Make a pass over all the insns and delete all USEs which we inserted
1243 only to tag a REG_EQUAL note on them. Remove all REG_DEAD and REG_UNUSED
1244 notes. Delete all CLOBBER insns, except those that refer to the return
1245 value and the special mem:BLK CLOBBERs added to prevent the scheduler
1246 from misarranging variable-array code, and simplify (subreg (reg))
1247 operands. Strip and regenerate REG_INC notes that may have been moved
1250 for (insn = first; insn; insn = NEXT_INSN (insn))
1256 replace_pseudos_in (& CALL_INSN_FUNCTION_USAGE (insn),
1257 VOIDmode, CALL_INSN_FUNCTION_USAGE (insn));
1259 if ((GET_CODE (PATTERN (insn)) == USE
1260 /* We mark with QImode USEs introduced by reload itself. */
1261 && (GET_MODE (insn) == QImode
1262 || find_reg_note (insn, REG_EQUAL, NULL_RTX)))
1263 || (GET_CODE (PATTERN (insn)) == CLOBBER
1264 && (!MEM_P (XEXP (PATTERN (insn), 0))
1265 || GET_MODE (XEXP (PATTERN (insn), 0)) != BLKmode
1266 || (GET_CODE (XEXP (XEXP (PATTERN (insn), 0), 0)) != SCRATCH
1267 && XEXP (XEXP (PATTERN (insn), 0), 0)
1268 != stack_pointer_rtx))
1269 && (!REG_P (XEXP (PATTERN (insn), 0))
1270 || ! REG_FUNCTION_VALUE_P (XEXP (PATTERN (insn), 0)))))
1276 /* Some CLOBBERs may survive until here and still reference unassigned
1277 pseudos with const equivalent, which may in turn cause ICE in later
1278 passes if the reference remains in place. */
1279 if (GET_CODE (PATTERN (insn)) == CLOBBER)
1280 replace_pseudos_in (& XEXP (PATTERN (insn), 0),
1281 VOIDmode, PATTERN (insn));
1283 /* Discard obvious no-ops, even without -O. This optimization
1284 is fast and doesn't interfere with debugging. */
1285 if (NONJUMP_INSN_P (insn)
1286 && GET_CODE (PATTERN (insn)) == SET
1287 && REG_P (SET_SRC (PATTERN (insn)))
1288 && REG_P (SET_DEST (PATTERN (insn)))
1289 && (REGNO (SET_SRC (PATTERN (insn)))
1290 == REGNO (SET_DEST (PATTERN (insn)))))
1296 pnote = ®_NOTES (insn);
1299 if (REG_NOTE_KIND (*pnote) == REG_DEAD
1300 || REG_NOTE_KIND (*pnote) == REG_UNUSED
1301 || REG_NOTE_KIND (*pnote) == REG_INC)
1302 *pnote = XEXP (*pnote, 1);
1304 pnote = &XEXP (*pnote, 1);
1308 add_auto_inc_notes (insn, PATTERN (insn));
1311 /* Simplify (subreg (reg)) if it appears as an operand. */
1312 cleanup_subreg_operands (insn);
1314 /* Clean up invalid ASMs so that they don't confuse later passes.
1316 if (asm_noperands (PATTERN (insn)) >= 0)
1318 extract_insn (insn);
1319 if (!constrain_operands (1))
1321 error_for_asm (insn,
1322 "%<asm%> operand has impossible constraints");
1329 /* If we are doing generic stack checking, give a warning if this
1330 function's frame size is larger than we expect. */
1331 if (flag_stack_check == GENERIC_STACK_CHECK)
1333 HOST_WIDE_INT size = get_frame_size () + STACK_CHECK_FIXED_FRAME_SIZE;
1334 static int verbose_warned = 0;
1336 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1337 if (df_regs_ever_live_p (i) && ! fixed_regs[i] && call_used_regs[i])
1338 size += UNITS_PER_WORD;
1340 if (size > STACK_CHECK_MAX_FRAME_SIZE)
1342 warning (0, "frame size too large for reliable stack checking");
1343 if (! verbose_warned)
1345 warning (0, "try reducing the number of local variables");
1351 /* Indicate that we no longer have known memory locations or constants. */
1352 if (reg_equiv_constant)
1353 free (reg_equiv_constant);
1354 if (reg_equiv_invariant)
1355 free (reg_equiv_invariant);
1356 reg_equiv_constant = 0;
1357 reg_equiv_invariant = 0;
1358 VEC_free (rtx, gc, reg_equiv_memory_loc_vec);
1359 reg_equiv_memory_loc = 0;
1361 free (temp_pseudo_reg_arr);
1363 if (offsets_known_at)
1364 free (offsets_known_at);
1368 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1369 if (reg_equiv_alt_mem_list[i])
1370 free_EXPR_LIST_list (®_equiv_alt_mem_list[i]);
1371 free (reg_equiv_alt_mem_list);
1373 free (reg_equiv_mem);
1375 free (reg_equiv_address);
1376 free (reg_max_ref_width);
1377 free (reg_old_renumber);
1378 free (pseudo_previous_regs);
1379 free (pseudo_forbidden_regs);
1381 CLEAR_HARD_REG_SET (used_spill_regs);
1382 for (i = 0; i < n_spills; i++)
1383 SET_HARD_REG_BIT (used_spill_regs, spill_regs[i]);
1385 /* Free all the insn_chain structures at once. */
1386 obstack_free (&reload_obstack, reload_startobj);
1387 unused_insn_chains = 0;
1388 fixup_abnormal_edges ();
1390 /* Replacing pseudos with their memory equivalents might have
1391 created shared rtx. Subsequent passes would get confused
1392 by this, so unshare everything here. */
1393 unshare_all_rtl_again (first);
1395 #ifdef STACK_BOUNDARY
1396 /* init_emit has set the alignment of the hard frame pointer
1397 to STACK_BOUNDARY. It is very likely no longer valid if
1398 the hard frame pointer was used for register allocation. */
1399 if (!frame_pointer_needed)
1400 REGNO_POINTER_ALIGN (HARD_FRAME_POINTER_REGNUM) = BITS_PER_UNIT;
1406 /* Yet another special case. Unfortunately, reg-stack forces people to
1407 write incorrect clobbers in asm statements. These clobbers must not
1408 cause the register to appear in bad_spill_regs, otherwise we'll call
1409 fatal_insn later. We clear the corresponding regnos in the live
1410 register sets to avoid this.
1411 The whole thing is rather sick, I'm afraid. */
1414 maybe_fix_stack_asms (void)
1417 const char *constraints[MAX_RECOG_OPERANDS];
1418 enum machine_mode operand_mode[MAX_RECOG_OPERANDS];
1419 struct insn_chain *chain;
1421 for (chain = reload_insn_chain; chain != 0; chain = chain->next)
1424 HARD_REG_SET clobbered, allowed;
1427 if (! INSN_P (chain->insn)
1428 || (noperands = asm_noperands (PATTERN (chain->insn))) < 0)
1430 pat = PATTERN (chain->insn);
1431 if (GET_CODE (pat) != PARALLEL)
1434 CLEAR_HARD_REG_SET (clobbered);
1435 CLEAR_HARD_REG_SET (allowed);
1437 /* First, make a mask of all stack regs that are clobbered. */
1438 for (i = 0; i < XVECLEN (pat, 0); i++)
1440 rtx t = XVECEXP (pat, 0, i);
1441 if (GET_CODE (t) == CLOBBER && STACK_REG_P (XEXP (t, 0)))
1442 SET_HARD_REG_BIT (clobbered, REGNO (XEXP (t, 0)));
1445 /* Get the operand values and constraints out of the insn. */
1446 decode_asm_operands (pat, recog_data.operand, recog_data.operand_loc,
1447 constraints, operand_mode, NULL);
1449 /* For every operand, see what registers are allowed. */
1450 for (i = 0; i < noperands; i++)
1452 const char *p = constraints[i];
1453 /* For every alternative, we compute the class of registers allowed
1454 for reloading in CLS, and merge its contents into the reg set
1456 int cls = (int) NO_REGS;
1462 if (c == '\0' || c == ',' || c == '#')
1464 /* End of one alternative - mark the regs in the current
1465 class, and reset the class. */
1466 IOR_HARD_REG_SET (allowed, reg_class_contents[cls]);
1472 } while (c != '\0' && c != ',');
1480 case '=': case '+': case '*': case '%': case '?': case '!':
1481 case '0': case '1': case '2': case '3': case '4': case '<':
1482 case '>': case 'V': case 'o': case '&': case 'E': case 'F':
1483 case 's': case 'i': case 'n': case 'X': case 'I': case 'J':
1484 case 'K': case 'L': case 'M': case 'N': case 'O': case 'P':
1485 case TARGET_MEM_CONSTRAINT:
1489 cls = (int) reg_class_subunion[cls]
1490 [(int) base_reg_class (VOIDmode, ADDRESS, SCRATCH)];
1495 cls = (int) reg_class_subunion[cls][(int) GENERAL_REGS];
1499 if (EXTRA_ADDRESS_CONSTRAINT (c, p))
1500 cls = (int) reg_class_subunion[cls]
1501 [(int) base_reg_class (VOIDmode, ADDRESS, SCRATCH)];
1503 cls = (int) reg_class_subunion[cls]
1504 [(int) REG_CLASS_FROM_CONSTRAINT (c, p)];
1506 p += CONSTRAINT_LEN (c, p);
1509 /* Those of the registers which are clobbered, but allowed by the
1510 constraints, must be usable as reload registers. So clear them
1511 out of the life information. */
1512 AND_HARD_REG_SET (allowed, clobbered);
1513 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1514 if (TEST_HARD_REG_BIT (allowed, i))
1516 CLEAR_REGNO_REG_SET (&chain->live_throughout, i);
1517 CLEAR_REGNO_REG_SET (&chain->dead_or_set, i);
1524 /* Copy the global variables n_reloads and rld into the corresponding elts
1527 copy_reloads (struct insn_chain *chain)
1529 chain->n_reloads = n_reloads;
1530 chain->rld = XOBNEWVEC (&reload_obstack, struct reload, n_reloads);
1531 memcpy (chain->rld, rld, n_reloads * sizeof (struct reload));
1532 reload_insn_firstobj = XOBNEWVAR (&reload_obstack, char, 0);
1535 /* Walk the chain of insns, and determine for each whether it needs reloads
1536 and/or eliminations. Build the corresponding insns_need_reload list, and
1537 set something_needs_elimination as appropriate. */
1539 calculate_needs_all_insns (int global)
1541 struct insn_chain **pprev_reload = &insns_need_reload;
1542 struct insn_chain *chain, *next = 0;
1544 something_needs_elimination = 0;
1546 reload_insn_firstobj = XOBNEWVAR (&reload_obstack, char, 0);
1547 for (chain = reload_insn_chain; chain != 0; chain = next)
1549 rtx insn = chain->insn;
1553 /* Clear out the shortcuts. */
1554 chain->n_reloads = 0;
1555 chain->need_elim = 0;
1556 chain->need_reload = 0;
1557 chain->need_operand_change = 0;
1559 /* If this is a label, a JUMP_INSN, or has REG_NOTES (which might
1560 include REG_LABEL_OPERAND and REG_LABEL_TARGET), we need to see
1561 what effects this has on the known offsets at labels. */
1563 if (LABEL_P (insn) || JUMP_P (insn)
1564 || (INSN_P (insn) && REG_NOTES (insn) != 0))
1565 set_label_offsets (insn, insn, 0);
1569 rtx old_body = PATTERN (insn);
1570 int old_code = INSN_CODE (insn);
1571 rtx old_notes = REG_NOTES (insn);
1572 int did_elimination = 0;
1573 int operands_changed = 0;
1574 rtx set = single_set (insn);
1576 /* Skip insns that only set an equivalence. */
1577 if (set && REG_P (SET_DEST (set))
1578 && reg_renumber[REGNO (SET_DEST (set))] < 0
1579 && (reg_equiv_constant[REGNO (SET_DEST (set))]
1580 || (reg_equiv_invariant[REGNO (SET_DEST (set))]))
1581 && reg_equiv_init[REGNO (SET_DEST (set))])
1584 /* If needed, eliminate any eliminable registers. */
1585 if (num_eliminable || num_eliminable_invariants)
1586 did_elimination = eliminate_regs_in_insn (insn, 0);
1588 /* Analyze the instruction. */
1589 operands_changed = find_reloads (insn, 0, spill_indirect_levels,
1590 global, spill_reg_order);
1592 /* If a no-op set needs more than one reload, this is likely
1593 to be something that needs input address reloads. We
1594 can't get rid of this cleanly later, and it is of no use
1595 anyway, so discard it now.
1596 We only do this when expensive_optimizations is enabled,
1597 since this complements reload inheritance / output
1598 reload deletion, and it can make debugging harder. */
1599 if (flag_expensive_optimizations && n_reloads > 1)
1601 rtx set = single_set (insn);
1604 ((SET_SRC (set) == SET_DEST (set)
1605 && REG_P (SET_SRC (set))
1606 && REGNO (SET_SRC (set)) >= FIRST_PSEUDO_REGISTER)
1607 || (REG_P (SET_SRC (set)) && REG_P (SET_DEST (set))
1608 && reg_renumber[REGNO (SET_SRC (set))] < 0
1609 && reg_renumber[REGNO (SET_DEST (set))] < 0
1610 && reg_equiv_memory_loc[REGNO (SET_SRC (set))] != NULL
1611 && reg_equiv_memory_loc[REGNO (SET_DEST (set))] != NULL
1612 && rtx_equal_p (reg_equiv_memory_loc
1613 [REGNO (SET_SRC (set))],
1614 reg_equiv_memory_loc
1615 [REGNO (SET_DEST (set))]))))
1617 if (flag_ira && optimize)
1618 /* Inform IRA about the insn deletion. */
1619 ira_mark_memory_move_deletion (REGNO (SET_DEST (set)),
1620 REGNO (SET_SRC (set)));
1622 /* Delete it from the reload chain. */
1624 chain->prev->next = next;
1626 reload_insn_chain = next;
1628 next->prev = chain->prev;
1629 chain->next = unused_insn_chains;
1630 unused_insn_chains = chain;
1635 update_eliminable_offsets ();
1637 /* Remember for later shortcuts which insns had any reloads or
1638 register eliminations. */
1639 chain->need_elim = did_elimination;
1640 chain->need_reload = n_reloads > 0;
1641 chain->need_operand_change = operands_changed;
1643 /* Discard any register replacements done. */
1644 if (did_elimination)
1646 obstack_free (&reload_obstack, reload_insn_firstobj);
1647 PATTERN (insn) = old_body;
1648 INSN_CODE (insn) = old_code;
1649 REG_NOTES (insn) = old_notes;
1650 something_needs_elimination = 1;
1653 something_needs_operands_changed |= operands_changed;
1657 copy_reloads (chain);
1658 *pprev_reload = chain;
1659 pprev_reload = &chain->next_need_reload;
1666 /* Comparison function for qsort to decide which of two reloads
1667 should be handled first. *P1 and *P2 are the reload numbers. */
1670 reload_reg_class_lower (const void *r1p, const void *r2p)
1672 int r1 = *(const short *) r1p, r2 = *(const short *) r2p;
1675 /* Consider required reloads before optional ones. */
1676 t = rld[r1].optional - rld[r2].optional;
1680 /* Count all solitary classes before non-solitary ones. */
1681 t = ((reg_class_size[(int) rld[r2].rclass] == 1)
1682 - (reg_class_size[(int) rld[r1].rclass] == 1));
1686 /* Aside from solitaires, consider all multi-reg groups first. */
1687 t = rld[r2].nregs - rld[r1].nregs;
1691 /* Consider reloads in order of increasing reg-class number. */
1692 t = (int) rld[r1].rclass - (int) rld[r2].rclass;
1696 /* If reloads are equally urgent, sort by reload number,
1697 so that the results of qsort leave nothing to chance. */
1701 /* The cost of spilling each hard reg. */
1702 static int spill_cost[FIRST_PSEUDO_REGISTER];
1704 /* When spilling multiple hard registers, we use SPILL_COST for the first
1705 spilled hard reg and SPILL_ADD_COST for subsequent regs. SPILL_ADD_COST
1706 only the first hard reg for a multi-reg pseudo. */
1707 static int spill_add_cost[FIRST_PSEUDO_REGISTER];
1709 /* Map of hard regno to pseudo regno currently occupying the hard
1711 static int hard_regno_to_pseudo_regno[FIRST_PSEUDO_REGISTER];
1713 /* Update the spill cost arrays, considering that pseudo REG is live. */
1716 count_pseudo (int reg)
1718 int freq = REG_FREQ (reg);
1719 int r = reg_renumber[reg];
1722 if (REGNO_REG_SET_P (&pseudos_counted, reg)
1723 || REGNO_REG_SET_P (&spilled_pseudos, reg)
1724 /* Ignore spilled pseudo-registers which can be here only if IRA
1726 || (flag_ira && optimize && r < 0))
1729 SET_REGNO_REG_SET (&pseudos_counted, reg);
1731 gcc_assert (r >= 0);
1733 spill_add_cost[r] += freq;
1734 nregs = hard_regno_nregs[r][PSEUDO_REGNO_MODE (reg)];
1737 hard_regno_to_pseudo_regno[r + nregs] = reg;
1738 spill_cost[r + nregs] += freq;
1742 /* Calculate the SPILL_COST and SPILL_ADD_COST arrays and determine the
1743 contents of BAD_SPILL_REGS for the insn described by CHAIN. */
1746 order_regs_for_reload (struct insn_chain *chain)
1749 HARD_REG_SET used_by_pseudos;
1750 HARD_REG_SET used_by_pseudos2;
1751 reg_set_iterator rsi;
1753 COPY_HARD_REG_SET (bad_spill_regs, fixed_reg_set);
1755 memset (spill_cost, 0, sizeof spill_cost);
1756 memset (spill_add_cost, 0, sizeof spill_add_cost);
1757 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1758 hard_regno_to_pseudo_regno[i] = -1;
1760 /* Count number of uses of each hard reg by pseudo regs allocated to it
1761 and then order them by decreasing use. First exclude hard registers
1762 that are live in or across this insn. */
1764 REG_SET_TO_HARD_REG_SET (used_by_pseudos, &chain->live_throughout);
1765 REG_SET_TO_HARD_REG_SET (used_by_pseudos2, &chain->dead_or_set);
1766 IOR_HARD_REG_SET (bad_spill_regs, used_by_pseudos);
1767 IOR_HARD_REG_SET (bad_spill_regs, used_by_pseudos2);
1769 /* Now find out which pseudos are allocated to it, and update
1771 CLEAR_REG_SET (&pseudos_counted);
1773 EXECUTE_IF_SET_IN_REG_SET
1774 (&chain->live_throughout, FIRST_PSEUDO_REGISTER, i, rsi)
1778 EXECUTE_IF_SET_IN_REG_SET
1779 (&chain->dead_or_set, FIRST_PSEUDO_REGISTER, i, rsi)
1783 CLEAR_REG_SET (&pseudos_counted);
1786 /* Vector of reload-numbers showing the order in which the reloads should
1788 static short reload_order[MAX_RELOADS];
1790 /* This is used to keep track of the spill regs used in one insn. */
1791 static HARD_REG_SET used_spill_regs_local;
1793 /* We decided to spill hard register SPILLED, which has a size of
1794 SPILLED_NREGS. Determine how pseudo REG, which is live during the insn,
1795 is affected. We will add it to SPILLED_PSEUDOS if necessary, and we will
1796 update SPILL_COST/SPILL_ADD_COST. */
1799 count_spilled_pseudo (int spilled, int spilled_nregs, int reg)
1801 int freq = REG_FREQ (reg);
1802 int r = reg_renumber[reg];
1803 int nregs = hard_regno_nregs[r][PSEUDO_REGNO_MODE (reg)];
1805 /* Ignore spilled pseudo-registers which can be here only if IRA is
1807 if ((flag_ira && optimize && r < 0)
1808 || REGNO_REG_SET_P (&spilled_pseudos, reg)
1809 || spilled + spilled_nregs <= r || r + nregs <= spilled)
1812 SET_REGNO_REG_SET (&spilled_pseudos, reg);
1814 spill_add_cost[r] -= freq;
1817 hard_regno_to_pseudo_regno[r + nregs] = -1;
1818 spill_cost[r + nregs] -= freq;
1822 /* Find reload register to use for reload number ORDER. */
1825 find_reg (struct insn_chain *chain, int order)
1827 int rnum = reload_order[order];
1828 struct reload *rl = rld + rnum;
1829 int best_cost = INT_MAX;
1831 unsigned int i, j, n;
1833 HARD_REG_SET not_usable;
1834 HARD_REG_SET used_by_other_reload;
1835 reg_set_iterator rsi;
1836 static int regno_pseudo_regs[FIRST_PSEUDO_REGISTER];
1837 static int best_regno_pseudo_regs[FIRST_PSEUDO_REGISTER];
1839 COPY_HARD_REG_SET (not_usable, bad_spill_regs);
1840 IOR_HARD_REG_SET (not_usable, bad_spill_regs_global);
1841 IOR_COMPL_HARD_REG_SET (not_usable, reg_class_contents[rl->rclass]);
1843 CLEAR_HARD_REG_SET (used_by_other_reload);
1844 for (k = 0; k < order; k++)
1846 int other = reload_order[k];
1848 if (rld[other].regno >= 0 && reloads_conflict (other, rnum))
1849 for (j = 0; j < rld[other].nregs; j++)
1850 SET_HARD_REG_BIT (used_by_other_reload, rld[other].regno + j);
1853 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1855 #ifdef REG_ALLOC_ORDER
1856 unsigned int regno = reg_alloc_order[i];
1858 unsigned int regno = i;
1861 if (! TEST_HARD_REG_BIT (not_usable, regno)
1862 && ! TEST_HARD_REG_BIT (used_by_other_reload, regno)
1863 && HARD_REGNO_MODE_OK (regno, rl->mode))
1865 int this_cost = spill_cost[regno];
1867 unsigned int this_nregs = hard_regno_nregs[regno][rl->mode];
1869 for (j = 1; j < this_nregs; j++)
1871 this_cost += spill_add_cost[regno + j];
1872 if ((TEST_HARD_REG_BIT (not_usable, regno + j))
1873 || TEST_HARD_REG_BIT (used_by_other_reload, regno + j))
1879 if (flag_ira && optimize)
1881 /* Ask IRA to find a better pseudo-register for
1883 for (n = j = 0; j < this_nregs; j++)
1885 int r = hard_regno_to_pseudo_regno[regno + j];
1889 if (n == 0 || regno_pseudo_regs[n - 1] != r)
1890 regno_pseudo_regs[n++] = r;
1892 regno_pseudo_regs[n++] = -1;
1894 || ira_better_spill_reload_regno_p (regno_pseudo_regs,
1895 best_regno_pseudo_regs,
1902 best_regno_pseudo_regs[j] = regno_pseudo_regs[j];
1903 if (regno_pseudo_regs[j] < 0)
1910 if (rl->in && REG_P (rl->in) && REGNO (rl->in) == regno)
1912 if (rl->out && REG_P (rl->out) && REGNO (rl->out) == regno)
1914 if (this_cost < best_cost
1915 /* Among registers with equal cost, prefer caller-saved ones, or
1916 use REG_ALLOC_ORDER if it is defined. */
1917 || (this_cost == best_cost
1918 #ifdef REG_ALLOC_ORDER
1919 && (inv_reg_alloc_order[regno]
1920 < inv_reg_alloc_order[best_reg])
1922 && call_used_regs[regno]
1923 && ! call_used_regs[best_reg]
1928 best_cost = this_cost;
1936 fprintf (dump_file, "Using reg %d for reload %d\n", best_reg, rnum);
1938 rl->nregs = hard_regno_nregs[best_reg][rl->mode];
1939 rl->regno = best_reg;
1941 EXECUTE_IF_SET_IN_REG_SET
1942 (&chain->live_throughout, FIRST_PSEUDO_REGISTER, j, rsi)
1944 count_spilled_pseudo (best_reg, rl->nregs, j);
1947 EXECUTE_IF_SET_IN_REG_SET
1948 (&chain->dead_or_set, FIRST_PSEUDO_REGISTER, j, rsi)
1950 count_spilled_pseudo (best_reg, rl->nregs, j);
1953 for (i = 0; i < rl->nregs; i++)
1955 gcc_assert (spill_cost[best_reg + i] == 0);
1956 gcc_assert (spill_add_cost[best_reg + i] == 0);
1957 gcc_assert (hard_regno_to_pseudo_regno[best_reg + i] == -1);
1958 SET_HARD_REG_BIT (used_spill_regs_local, best_reg + i);
1963 /* Find more reload regs to satisfy the remaining need of an insn, which
1965 Do it by ascending class number, since otherwise a reg
1966 might be spilled for a big class and might fail to count
1967 for a smaller class even though it belongs to that class. */
1970 find_reload_regs (struct insn_chain *chain)
1974 /* In order to be certain of getting the registers we need,
1975 we must sort the reloads into order of increasing register class.
1976 Then our grabbing of reload registers will parallel the process
1977 that provided the reload registers. */
1978 for (i = 0; i < chain->n_reloads; i++)
1980 /* Show whether this reload already has a hard reg. */
1981 if (chain->rld[i].reg_rtx)
1983 int regno = REGNO (chain->rld[i].reg_rtx);
1984 chain->rld[i].regno = regno;
1986 = hard_regno_nregs[regno][GET_MODE (chain->rld[i].reg_rtx)];
1989 chain->rld[i].regno = -1;
1990 reload_order[i] = i;
1993 n_reloads = chain->n_reloads;
1994 memcpy (rld, chain->rld, n_reloads * sizeof (struct reload));
1996 CLEAR_HARD_REG_SET (used_spill_regs_local);
1999 fprintf (dump_file, "Spilling for insn %d.\n", INSN_UID (chain->insn));
2001 qsort (reload_order, n_reloads, sizeof (short), reload_reg_class_lower);
2003 /* Compute the order of preference for hard registers to spill. */
2005 order_regs_for_reload (chain);
2007 for (i = 0; i < n_reloads; i++)
2009 int r = reload_order[i];
2011 /* Ignore reloads that got marked inoperative. */
2012 if ((rld[r].out != 0 || rld[r].in != 0 || rld[r].secondary_p)
2013 && ! rld[r].optional
2014 && rld[r].regno == -1)
2015 if (! find_reg (chain, i))
2018 fprintf (dump_file, "reload failure for reload %d\n", r);
2019 spill_failure (chain->insn, rld[r].rclass);
2025 COPY_HARD_REG_SET (chain->used_spill_regs, used_spill_regs_local);
2026 IOR_HARD_REG_SET (used_spill_regs, used_spill_regs_local);
2028 memcpy (chain->rld, rld, n_reloads * sizeof (struct reload));
2032 select_reload_regs (void)
2034 struct insn_chain *chain;
2036 /* Try to satisfy the needs for each insn. */
2037 for (chain = insns_need_reload; chain != 0;
2038 chain = chain->next_need_reload)
2039 find_reload_regs (chain);
2042 /* Delete all insns that were inserted by emit_caller_save_insns during
2045 delete_caller_save_insns (void)
2047 struct insn_chain *c = reload_insn_chain;
2051 while (c != 0 && c->is_caller_save_insn)
2053 struct insn_chain *next = c->next;
2056 if (c == reload_insn_chain)
2057 reload_insn_chain = next;
2061 next->prev = c->prev;
2063 c->prev->next = next;
2064 c->next = unused_insn_chains;
2065 unused_insn_chains = c;
2073 /* Handle the failure to find a register to spill.
2074 INSN should be one of the insns which needed this particular spill reg. */
2077 spill_failure (rtx insn, enum reg_class rclass)
2079 if (asm_noperands (PATTERN (insn)) >= 0)
2080 error_for_asm (insn, "can't find a register in class %qs while "
2081 "reloading %<asm%>",
2082 reg_class_names[rclass]);
2085 error ("unable to find a register to spill in class %qs",
2086 reg_class_names[rclass]);
2090 fprintf (dump_file, "\nReloads for insn # %d\n", INSN_UID (insn));
2091 debug_reload_to_stream (dump_file);
2093 fatal_insn ("this is the insn:", insn);
2097 /* Delete an unneeded INSN and any previous insns who sole purpose is loading
2098 data that is dead in INSN. */
2101 delete_dead_insn (rtx insn)
2103 rtx prev = prev_real_insn (insn);
2106 /* If the previous insn sets a register that dies in our insn, delete it
2108 if (prev && GET_CODE (PATTERN (prev)) == SET
2109 && (prev_dest = SET_DEST (PATTERN (prev)), REG_P (prev_dest))
2110 && reg_mentioned_p (prev_dest, PATTERN (insn))
2111 && find_regno_note (insn, REG_DEAD, REGNO (prev_dest))
2112 && ! side_effects_p (SET_SRC (PATTERN (prev))))
2113 delete_dead_insn (prev);
2115 SET_INSN_DELETED (insn);
2118 /* Modify the home of pseudo-reg I.
2119 The new home is present in reg_renumber[I].
2121 FROM_REG may be the hard reg that the pseudo-reg is being spilled from;
2122 or it may be -1, meaning there is none or it is not relevant.
2123 This is used so that all pseudos spilled from a given hard reg
2124 can share one stack slot. */
2127 alter_reg (int i, int from_reg, bool dont_share_p)
2129 /* When outputting an inline function, this can happen
2130 for a reg that isn't actually used. */
2131 if (regno_reg_rtx[i] == 0)
2134 /* If the reg got changed to a MEM at rtl-generation time,
2136 if (!REG_P (regno_reg_rtx[i]))
2139 /* Modify the reg-rtx to contain the new hard reg
2140 number or else to contain its pseudo reg number. */
2141 SET_REGNO (regno_reg_rtx[i],
2142 reg_renumber[i] >= 0 ? reg_renumber[i] : i);
2144 /* If we have a pseudo that is needed but has no hard reg or equivalent,
2145 allocate a stack slot for it. */
2147 if (reg_renumber[i] < 0
2148 && REG_N_REFS (i) > 0
2149 && reg_equiv_constant[i] == 0
2150 && (reg_equiv_invariant[i] == 0 || reg_equiv_init[i] == 0)
2151 && reg_equiv_memory_loc[i] == 0)
2154 enum machine_mode mode = GET_MODE (regno_reg_rtx[i]);
2155 unsigned int inherent_size = PSEUDO_REGNO_BYTES (i);
2156 unsigned int inherent_align = GET_MODE_ALIGNMENT (mode);
2157 unsigned int total_size = MAX (inherent_size, reg_max_ref_width[i]);
2158 unsigned int min_align = reg_max_ref_width[i] * BITS_PER_UNIT;
2161 if (flag_ira && optimize)
2163 /* Mark the spill for IRA. */
2164 SET_REGNO_REG_SET (&spilled_pseudos, i);
2166 x = ira_reuse_stack_slot (i, inherent_size, total_size);
2172 /* Each pseudo reg has an inherent size which comes from its own mode,
2173 and a total size which provides room for paradoxical subregs
2174 which refer to the pseudo reg in wider modes.
2176 We can use a slot already allocated if it provides both
2177 enough inherent space and enough total space.
2178 Otherwise, we allocate a new slot, making sure that it has no less
2179 inherent space, and no less total space, then the previous slot. */
2180 else if (from_reg == -1 || (!dont_share_p && flag_ira && optimize))
2184 /* No known place to spill from => no slot to reuse. */
2185 x = assign_stack_local (mode, total_size,
2186 min_align > inherent_align
2187 || total_size > inherent_size ? -1 : 0);
2191 /* Cancel the big-endian correction done in assign_stack_local.
2192 Get the address of the beginning of the slot. This is so we
2193 can do a big-endian correction unconditionally below. */
2194 if (BYTES_BIG_ENDIAN)
2196 adjust = inherent_size - total_size;
2199 = adjust_address_nv (x, mode_for_size (total_size
2205 if (! dont_share_p && flag_ira && optimize)
2206 /* Inform IRA about allocation a new stack slot. */
2207 ira_mark_new_stack_slot (stack_slot, i, total_size);
2210 /* Reuse a stack slot if possible. */
2211 else if (spill_stack_slot[from_reg] != 0
2212 && spill_stack_slot_width[from_reg] >= total_size
2213 && (GET_MODE_SIZE (GET_MODE (spill_stack_slot[from_reg]))
2215 && MEM_ALIGN (spill_stack_slot[from_reg]) >= min_align)
2216 x = spill_stack_slot[from_reg];
2218 /* Allocate a bigger slot. */
2221 /* Compute maximum size needed, both for inherent size
2222 and for total size. */
2225 if (spill_stack_slot[from_reg])
2227 if (GET_MODE_SIZE (GET_MODE (spill_stack_slot[from_reg]))
2229 mode = GET_MODE (spill_stack_slot[from_reg]);
2230 if (spill_stack_slot_width[from_reg] > total_size)
2231 total_size = spill_stack_slot_width[from_reg];
2232 if (MEM_ALIGN (spill_stack_slot[from_reg]) > min_align)
2233 min_align = MEM_ALIGN (spill_stack_slot[from_reg]);
2236 /* Make a slot with that size. */
2237 x = assign_stack_local (mode, total_size,
2238 min_align > inherent_align
2239 || total_size > inherent_size ? -1 : 0);
2242 /* Cancel the big-endian correction done in assign_stack_local.
2243 Get the address of the beginning of the slot. This is so we
2244 can do a big-endian correction unconditionally below. */
2245 if (BYTES_BIG_ENDIAN)
2247 adjust = GET_MODE_SIZE (mode) - total_size;
2250 = adjust_address_nv (x, mode_for_size (total_size
2256 spill_stack_slot[from_reg] = stack_slot;
2257 spill_stack_slot_width[from_reg] = total_size;
2260 /* On a big endian machine, the "address" of the slot
2261 is the address of the low part that fits its inherent mode. */
2262 if (BYTES_BIG_ENDIAN && inherent_size < total_size)
2263 adjust += (total_size - inherent_size);
2265 /* If we have any adjustment to make, or if the stack slot is the
2266 wrong mode, make a new stack slot. */
2267 x = adjust_address_nv (x, GET_MODE (regno_reg_rtx[i]), adjust);
2269 /* Set all of the memory attributes as appropriate for a spill. */
2270 set_mem_attrs_for_spill (x);
2272 /* Save the stack slot for later. */
2273 reg_equiv_memory_loc[i] = x;
2277 /* Mark the slots in regs_ever_live for the hard regs used by
2278 pseudo-reg number REGNO, accessed in MODE. */
2281 mark_home_live_1 (int regno, enum machine_mode mode)
2285 i = reg_renumber[regno];
2288 lim = end_hard_regno (mode, i);
2290 df_set_regs_ever_live(i++, true);
2293 /* Mark the slots in regs_ever_live for the hard regs
2294 used by pseudo-reg number REGNO. */
2297 mark_home_live (int regno)
2299 if (reg_renumber[regno] >= 0)
2300 mark_home_live_1 (regno, PSEUDO_REGNO_MODE (regno));
2303 /* This function handles the tracking of elimination offsets around branches.
2305 X is a piece of RTL being scanned.
2307 INSN is the insn that it came from, if any.
2309 INITIAL_P is nonzero if we are to set the offset to be the initial
2310 offset and zero if we are setting the offset of the label to be the
2314 set_label_offsets (rtx x, rtx insn, int initial_p)
2316 enum rtx_code code = GET_CODE (x);
2319 struct elim_table *p;
2324 if (LABEL_REF_NONLOCAL_P (x))
2329 /* ... fall through ... */
2332 /* If we know nothing about this label, set the desired offsets. Note
2333 that this sets the offset at a label to be the offset before a label
2334 if we don't know anything about the label. This is not correct for
2335 the label after a BARRIER, but is the best guess we can make. If
2336 we guessed wrong, we will suppress an elimination that might have
2337 been possible had we been able to guess correctly. */
2339 if (! offsets_known_at[CODE_LABEL_NUMBER (x) - first_label_num])
2341 for (i = 0; i < NUM_ELIMINABLE_REGS; i++)
2342 offsets_at[CODE_LABEL_NUMBER (x) - first_label_num][i]
2343 = (initial_p ? reg_eliminate[i].initial_offset
2344 : reg_eliminate[i].offset);
2345 offsets_known_at[CODE_LABEL_NUMBER (x) - first_label_num] = 1;
2348 /* Otherwise, if this is the definition of a label and it is
2349 preceded by a BARRIER, set our offsets to the known offset of
2353 && (tem = prev_nonnote_insn (insn)) != 0
2355 set_offsets_for_label (insn);
2357 /* If neither of the above cases is true, compare each offset
2358 with those previously recorded and suppress any eliminations
2359 where the offsets disagree. */
2361 for (i = 0; i < NUM_ELIMINABLE_REGS; i++)
2362 if (offsets_at[CODE_LABEL_NUMBER (x) - first_label_num][i]
2363 != (initial_p ? reg_eliminate[i].initial_offset
2364 : reg_eliminate[i].offset))
2365 reg_eliminate[i].can_eliminate = 0;
2370 set_label_offsets (PATTERN (insn), insn, initial_p);
2372 /* ... fall through ... */
2376 /* Any labels mentioned in REG_LABEL_OPERAND notes can be branched
2377 to indirectly and hence must have all eliminations at their
2379 for (tem = REG_NOTES (x); tem; tem = XEXP (tem, 1))
2380 if (REG_NOTE_KIND (tem) == REG_LABEL_OPERAND)
2381 set_label_offsets (XEXP (tem, 0), insn, 1);
2387 /* Each of the labels in the parallel or address vector must be
2388 at their initial offsets. We want the first field for PARALLEL
2389 and ADDR_VEC and the second field for ADDR_DIFF_VEC. */
2391 for (i = 0; i < (unsigned) XVECLEN (x, code == ADDR_DIFF_VEC); i++)
2392 set_label_offsets (XVECEXP (x, code == ADDR_DIFF_VEC, i),
2397 /* We only care about setting PC. If the source is not RETURN,
2398 IF_THEN_ELSE, or a label, disable any eliminations not at
2399 their initial offsets. Similarly if any arm of the IF_THEN_ELSE
2400 isn't one of those possibilities. For branches to a label,
2401 call ourselves recursively.
2403 Note that this can disable elimination unnecessarily when we have
2404 a non-local goto since it will look like a non-constant jump to
2405 someplace in the current function. This isn't a significant
2406 problem since such jumps will normally be when all elimination
2407 pairs are back to their initial offsets. */
2409 if (SET_DEST (x) != pc_rtx)
2412 switch (GET_CODE (SET_SRC (x)))
2419 set_label_offsets (SET_SRC (x), insn, initial_p);
2423 tem = XEXP (SET_SRC (x), 1);
2424 if (GET_CODE (tem) == LABEL_REF)
2425 set_label_offsets (XEXP (tem, 0), insn, initial_p);
2426 else if (GET_CODE (tem) != PC && GET_CODE (tem) != RETURN)
2429 tem = XEXP (SET_SRC (x), 2);
2430 if (GET_CODE (tem) == LABEL_REF)
2431 set_label_offsets (XEXP (tem, 0), insn, initial_p);
2432 else if (GET_CODE (tem) != PC && GET_CODE (tem) != RETURN)
2440 /* If we reach here, all eliminations must be at their initial
2441 offset because we are doing a jump to a variable address. */
2442 for (p = reg_eliminate; p < ®_eliminate[NUM_ELIMINABLE_REGS]; p++)
2443 if (p->offset != p->initial_offset)
2444 p->can_eliminate = 0;
2452 /* Scan X and replace any eliminable registers (such as fp) with a
2453 replacement (such as sp), plus an offset.
2455 MEM_MODE is the mode of an enclosing MEM. We need this to know how
2456 much to adjust a register for, e.g., PRE_DEC. Also, if we are inside a
2457 MEM, we are allowed to replace a sum of a register and the constant zero
2458 with the register, which we cannot do outside a MEM. In addition, we need
2459 to record the fact that a register is referenced outside a MEM.
2461 If INSN is an insn, it is the insn containing X. If we replace a REG
2462 in a SET_DEST with an equivalent MEM and INSN is nonzero, write a
2463 CLOBBER of the pseudo after INSN so find_equiv_regs will know that
2464 the REG is being modified.
2466 Alternatively, INSN may be a note (an EXPR_LIST or INSN_LIST).
2467 That's used when we eliminate in expressions stored in notes.
2468 This means, do not set ref_outside_mem even if the reference
2471 REG_EQUIV_MEM and REG_EQUIV_ADDRESS contain address that have had
2472 replacements done assuming all offsets are at their initial values. If
2473 they are not, or if REG_EQUIV_ADDRESS is nonzero for a pseudo we
2474 encounter, return the actual location so that find_reloads will do
2475 the proper thing. */
2478 eliminate_regs_1 (rtx x, enum machine_mode mem_mode, rtx insn,
2479 bool may_use_invariant)
2481 enum rtx_code code = GET_CODE (x);
2482 struct elim_table *ep;
2489 if (! current_function_decl)
2512 /* First handle the case where we encounter a bare register that
2513 is eliminable. Replace it with a PLUS. */
2514 if (regno < FIRST_PSEUDO_REGISTER)
2516 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
2518 if (ep->from_rtx == x && ep->can_eliminate)
2519 return plus_constant (ep->to_rtx, ep->previous_offset);
2522 else if (reg_renumber && reg_renumber[regno] < 0
2523 && reg_equiv_invariant && reg_equiv_invariant[regno])
2525 if (may_use_invariant)
2526 return eliminate_regs_1 (copy_rtx (reg_equiv_invariant[regno]),
2527 mem_mode, insn, true);
2528 /* There exists at least one use of REGNO that cannot be
2529 eliminated. Prevent the defining insn from being deleted. */
2530 reg_equiv_init[regno] = NULL_RTX;
2531 alter_reg (regno, -1, true);
2535 /* You might think handling MINUS in a manner similar to PLUS is a
2536 good idea. It is not. It has been tried multiple times and every
2537 time the change has had to have been reverted.
2539 Other parts of reload know a PLUS is special (gen_reload for example)
2540 and require special code to handle code a reloaded PLUS operand.
2542 Also consider backends where the flags register is clobbered by a
2543 MINUS, but we can emit a PLUS that does not clobber flags (IA-32,
2544 lea instruction comes to mind). If we try to reload a MINUS, we
2545 may kill the flags register that was holding a useful value.
2547 So, please before trying to handle MINUS, consider reload as a
2548 whole instead of this little section as well as the backend issues. */
2550 /* If this is the sum of an eliminable register and a constant, rework
2552 if (REG_P (XEXP (x, 0))
2553 && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER
2554 && CONSTANT_P (XEXP (x, 1)))
2556 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
2558 if (ep->from_rtx == XEXP (x, 0) && ep->can_eliminate)
2560 /* The only time we want to replace a PLUS with a REG (this
2561 occurs when the constant operand of the PLUS is the negative
2562 of the offset) is when we are inside a MEM. We won't want
2563 to do so at other times because that would change the
2564 structure of the insn in a way that reload can't handle.
2565 We special-case the commonest situation in
2566 eliminate_regs_in_insn, so just replace a PLUS with a
2567 PLUS here, unless inside a MEM. */
2568 if (mem_mode != 0 && GET_CODE (XEXP (x, 1)) == CONST_INT
2569 && INTVAL (XEXP (x, 1)) == - ep->previous_offset)
2572 return gen_rtx_PLUS (Pmode, ep->to_rtx,
2573 plus_constant (XEXP (x, 1),
2574 ep->previous_offset));
2577 /* If the register is not eliminable, we are done since the other
2578 operand is a constant. */
2582 /* If this is part of an address, we want to bring any constant to the
2583 outermost PLUS. We will do this by doing register replacement in
2584 our operands and seeing if a constant shows up in one of them.
2586 Note that there is no risk of modifying the structure of the insn,
2587 since we only get called for its operands, thus we are either
2588 modifying the address inside a MEM, or something like an address
2589 operand of a load-address insn. */
2592 rtx new0 = eliminate_regs_1 (XEXP (x, 0), mem_mode, insn, true);
2593 rtx new1 = eliminate_regs_1 (XEXP (x, 1), mem_mode, insn, true);
2595 if (reg_renumber && (new0 != XEXP (x, 0) || new1 != XEXP (x, 1)))
2597 /* If one side is a PLUS and the other side is a pseudo that
2598 didn't get a hard register but has a reg_equiv_constant,
2599 we must replace the constant here since it may no longer
2600 be in the position of any operand. */
2601 if (GET_CODE (new0) == PLUS && REG_P (new1)
2602 && REGNO (new1) >= FIRST_PSEUDO_REGISTER
2603 && reg_renumber[REGNO (new1)] < 0
2604 && reg_equiv_constant != 0
2605 && reg_equiv_constant[REGNO (new1)] != 0)
2606 new1 = reg_equiv_constant[REGNO (new1)];
2607 else if (GET_CODE (new1) == PLUS && REG_P (new0)
2608 && REGNO (new0) >= FIRST_PSEUDO_REGISTER
2609 && reg_renumber[REGNO (new0)] < 0
2610 && reg_equiv_constant[REGNO (new0)] != 0)
2611 new0 = reg_equiv_constant[REGNO (new0)];
2613 new_rtx = form_sum (new0, new1);
2615 /* As above, if we are not inside a MEM we do not want to
2616 turn a PLUS into something else. We might try to do so here
2617 for an addition of 0 if we aren't optimizing. */
2618 if (! mem_mode && GET_CODE (new_rtx) != PLUS)
2619 return gen_rtx_PLUS (GET_MODE (x), new_rtx, const0_rtx);
2627 /* If this is the product of an eliminable register and a
2628 constant, apply the distribute law and move the constant out
2629 so that we have (plus (mult ..) ..). This is needed in order
2630 to keep load-address insns valid. This case is pathological.
2631 We ignore the possibility of overflow here. */
2632 if (REG_P (XEXP (x, 0))
2633 && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER
2634 && GET_CODE (XEXP (x, 1)) == CONST_INT)
2635 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
2637 if (ep->from_rtx == XEXP (x, 0) && ep->can_eliminate)
2640 /* Refs inside notes don't count for this purpose. */
2641 && ! (insn != 0 && (GET_CODE (insn) == EXPR_LIST
2642 || GET_CODE (insn) == INSN_LIST)))
2643 ep->ref_outside_mem = 1;
2646 plus_constant (gen_rtx_MULT (Pmode, ep->to_rtx, XEXP (x, 1)),
2647 ep->previous_offset * INTVAL (XEXP (x, 1)));
2650 /* ... fall through ... */
2654 /* See comments before PLUS about handling MINUS. */
2656 case DIV: case UDIV:
2657 case MOD: case UMOD:
2658 case AND: case IOR: case XOR:
2659 case ROTATERT: case ROTATE:
2660 case ASHIFTRT: case LSHIFTRT: case ASHIFT:
2662 case GE: case GT: case GEU: case GTU:
2663 case LE: case LT: case LEU: case LTU:
2665 rtx new0 = eliminate_regs_1 (XEXP (x, 0), mem_mode, insn, false);
2666 rtx new1 = XEXP (x, 1)
2667 ? eliminate_regs_1 (XEXP (x, 1), mem_mode, insn, false) : 0;
2669 if (new0 != XEXP (x, 0) || new1 != XEXP (x, 1))
2670 return gen_rtx_fmt_ee (code, GET_MODE (x), new0, new1);
2675 /* If we have something in XEXP (x, 0), the usual case, eliminate it. */
2678 new_rtx = eliminate_regs_1 (XEXP (x, 0), mem_mode, insn, true);
2679 if (new_rtx != XEXP (x, 0))
2681 /* If this is a REG_DEAD note, it is not valid anymore.
2682 Using the eliminated version could result in creating a
2683 REG_DEAD note for the stack or frame pointer. */
2684 if (REG_NOTE_KIND (x) == REG_DEAD)
2686 ? eliminate_regs_1 (XEXP (x, 1), mem_mode, insn, true)
2689 x = gen_rtx_EXPR_LIST (REG_NOTE_KIND (x), new_rtx, XEXP (x, 1));
2693 /* ... fall through ... */
2696 /* Now do eliminations in the rest of the chain. If this was
2697 an EXPR_LIST, this might result in allocating more memory than is
2698 strictly needed, but it simplifies the code. */
2701 new_rtx = eliminate_regs_1 (XEXP (x, 1), mem_mode, insn, true);
2702 if (new_rtx != XEXP (x, 1))
2704 gen_rtx_fmt_ee (GET_CODE (x), GET_MODE (x), XEXP (x, 0), new_rtx);
2712 /* We do not support elimination of a register that is modified.
2713 elimination_effects has already make sure that this does not
2719 /* We do not support elimination of a register that is modified.
2720 elimination_effects has already make sure that this does not
2721 happen. The only remaining case we need to consider here is
2722 that the increment value may be an eliminable register. */
2723 if (GET_CODE (XEXP (x, 1)) == PLUS
2724 && XEXP (XEXP (x, 1), 0) == XEXP (x, 0))
2726 rtx new_rtx = eliminate_regs_1 (XEXP (XEXP (x, 1), 1), mem_mode,
2729 if (new_rtx != XEXP (XEXP (x, 1), 1))
2730 return gen_rtx_fmt_ee (code, GET_MODE (x), XEXP (x, 0),
2731 gen_rtx_PLUS (GET_MODE (x),
2732 XEXP (x, 0), new_rtx));
2736 case STRICT_LOW_PART:
2738 case SIGN_EXTEND: case ZERO_EXTEND:
2739 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
2740 case FLOAT: case FIX:
2741 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
2750 new_rtx = eliminate_regs_1 (XEXP (x, 0), mem_mode, insn, false);
2751 if (new_rtx != XEXP (x, 0))
2752 return gen_rtx_fmt_e (code, GET_MODE (x), new_rtx);
2756 /* Similar to above processing, but preserve SUBREG_BYTE.
2757 Convert (subreg (mem)) to (mem) if not paradoxical.
2758 Also, if we have a non-paradoxical (subreg (pseudo)) and the
2759 pseudo didn't get a hard reg, we must replace this with the
2760 eliminated version of the memory location because push_reload
2761 may do the replacement in certain circumstances. */
2762 if (REG_P (SUBREG_REG (x))
2763 && (GET_MODE_SIZE (GET_MODE (x))
2764 <= GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
2765 && reg_equiv_memory_loc != 0
2766 && reg_equiv_memory_loc[REGNO (SUBREG_REG (x))] != 0)
2768 new_rtx = SUBREG_REG (x);
2771 new_rtx = eliminate_regs_1 (SUBREG_REG (x), mem_mode, insn, false);
2773 if (new_rtx != SUBREG_REG (x))
2775 int x_size = GET_MODE_SIZE (GET_MODE (x));
2776 int new_size = GET_MODE_SIZE (GET_MODE (new_rtx));
2779 && ((x_size < new_size
2780 #ifdef WORD_REGISTER_OPERATIONS
2781 /* On these machines, combine can create rtl of the form
2782 (set (subreg:m1 (reg:m2 R) 0) ...)
2783 where m1 < m2, and expects something interesting to
2784 happen to the entire word. Moreover, it will use the
2785 (reg:m2 R) later, expecting all bits to be preserved.
2786 So if the number of words is the same, preserve the
2787 subreg so that push_reload can see it. */
2788 && ! ((x_size - 1) / UNITS_PER_WORD
2789 == (new_size -1 ) / UNITS_PER_WORD)
2792 || x_size == new_size)
2794 return adjust_address_nv (new_rtx, GET_MODE (x), SUBREG_BYTE (x));
2796 return gen_rtx_SUBREG (GET_MODE (x), new_rtx, SUBREG_BYTE (x));
2802 /* Our only special processing is to pass the mode of the MEM to our
2803 recursive call and copy the flags. While we are here, handle this
2804 case more efficiently. */
2806 replace_equiv_address_nv (x,
2807 eliminate_regs_1 (XEXP (x, 0), GET_MODE (x),
2811 /* Handle insn_list USE that a call to a pure function may generate. */
2812 new_rtx = eliminate_regs_1 (XEXP (x, 0), 0, insn, false);
2813 if (new_rtx != XEXP (x, 0))
2814 return gen_rtx_USE (GET_MODE (x), new_rtx);
2826 /* Process each of our operands recursively. If any have changed, make a
2828 fmt = GET_RTX_FORMAT (code);
2829 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2833 new_rtx = eliminate_regs_1 (XEXP (x, i), mem_mode, insn, false);
2834 if (new_rtx != XEXP (x, i) && ! copied)
2836 x = shallow_copy_rtx (x);
2839 XEXP (x, i) = new_rtx;
2841 else if (*fmt == 'E')
2844 for (j = 0; j < XVECLEN (x, i); j++)
2846 new_rtx = eliminate_regs_1 (XVECEXP (x, i, j), mem_mode, insn, false);
2847 if (new_rtx != XVECEXP (x, i, j) && ! copied_vec)
2849 rtvec new_v = gen_rtvec_v (XVECLEN (x, i),
2853 x = shallow_copy_rtx (x);
2856 XVEC (x, i) = new_v;
2859 XVECEXP (x, i, j) = new_rtx;
2868 eliminate_regs (rtx x, enum machine_mode mem_mode, rtx insn)
2870 return eliminate_regs_1 (x, mem_mode, insn, false);
2873 /* Scan rtx X for modifications of elimination target registers. Update
2874 the table of eliminables to reflect the changed state. MEM_MODE is
2875 the mode of an enclosing MEM rtx, or VOIDmode if not within a MEM. */
2878 elimination_effects (rtx x, enum machine_mode mem_mode)
2880 enum rtx_code code = GET_CODE (x);
2881 struct elim_table *ep;
2906 /* First handle the case where we encounter a bare register that
2907 is eliminable. Replace it with a PLUS. */
2908 if (regno < FIRST_PSEUDO_REGISTER)
2910 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
2912 if (ep->from_rtx == x && ep->can_eliminate)
2915 ep->ref_outside_mem = 1;
2920 else if (reg_renumber[regno] < 0 && reg_equiv_constant
2921 && reg_equiv_constant[regno]
2922 && ! function_invariant_p (reg_equiv_constant[regno]))
2923 elimination_effects (reg_equiv_constant[regno], mem_mode);
2932 /* If we modify the source of an elimination rule, disable it. */
2933 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2934 if (ep->from_rtx == XEXP (x, 0))
2935 ep->can_eliminate = 0;
2937 /* If we modify the target of an elimination rule by adding a constant,
2938 update its offset. If we modify the target in any other way, we'll
2939 have to disable the rule as well. */
2940 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2941 if (ep->to_rtx == XEXP (x, 0))
2943 int size = GET_MODE_SIZE (mem_mode);
2945 /* If more bytes than MEM_MODE are pushed, account for them. */
2946 #ifdef PUSH_ROUNDING
2947 if (ep->to_rtx == stack_pointer_rtx)
2948 size = PUSH_ROUNDING (size);
2950 if (code == PRE_DEC || code == POST_DEC)
2952 else if (code == PRE_INC || code == POST_INC)
2954 else if (code == PRE_MODIFY || code == POST_MODIFY)
2956 if (GET_CODE (XEXP (x, 1)) == PLUS
2957 && XEXP (x, 0) == XEXP (XEXP (x, 1), 0)
2958 && CONST_INT_P (XEXP (XEXP (x, 1), 1)))
2959 ep->offset -= INTVAL (XEXP (XEXP (x, 1), 1));
2961 ep->can_eliminate = 0;
2965 /* These two aren't unary operators. */
2966 if (code == POST_MODIFY || code == PRE_MODIFY)
2969 /* Fall through to generic unary operation case. */
2970 case STRICT_LOW_PART:
2972 case SIGN_EXTEND: case ZERO_EXTEND:
2973 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
2974 case FLOAT: case FIX:
2975 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
2984 elimination_effects (XEXP (x, 0), mem_mode);
2988 if (REG_P (SUBREG_REG (x))
2989 && (GET_MODE_SIZE (GET_MODE (x))
2990 <= GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
2991 && reg_equiv_memory_loc != 0
2992 && reg_equiv_memory_loc[REGNO (SUBREG_REG (x))] != 0)
2995 elimination_effects (SUBREG_REG (x), mem_mode);
2999 /* If using a register that is the source of an eliminate we still
3000 think can be performed, note it cannot be performed since we don't
3001 know how this register is used. */
3002 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3003 if (ep->from_rtx == XEXP (x, 0))
3004 ep->can_eliminate = 0;
3006 elimination_effects (XEXP (x, 0), mem_mode);
3010 /* If clobbering a register that is the replacement register for an
3011 elimination we still think can be performed, note that it cannot
3012 be performed. Otherwise, we need not be concerned about it. */
3013 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3014 if (ep->to_rtx == XEXP (x, 0))
3015 ep->can_eliminate = 0;
3017 elimination_effects (XEXP (x, 0), mem_mode);
3021 /* Check for setting a register that we know about. */
3022 if (REG_P (SET_DEST (x)))
3024 /* See if this is setting the replacement register for an
3027 If DEST is the hard frame pointer, we do nothing because we
3028 assume that all assignments to the frame pointer are for
3029 non-local gotos and are being done at a time when they are valid
3030 and do not disturb anything else. Some machines want to
3031 eliminate a fake argument pointer (or even a fake frame pointer)
3032 with either the real frame or the stack pointer. Assignments to
3033 the hard frame pointer must not prevent this elimination. */
3035 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
3037 if (ep->to_rtx == SET_DEST (x)
3038 && SET_DEST (x) != hard_frame_pointer_rtx)
3040 /* If it is being incremented, adjust the offset. Otherwise,
3041 this elimination can't be done. */
3042 rtx src = SET_SRC (x);
3044 if (GET_CODE (src) == PLUS
3045 && XEXP (src, 0) == SET_DEST (x)
3046 && GET_CODE (XEXP (src, 1)) == CONST_INT)
3047 ep->offset -= INTVAL (XEXP (src, 1));
3049 ep->can_eliminate = 0;
3053 elimination_effects (SET_DEST (x), 0);
3054 elimination_effects (SET_SRC (x), 0);
3058 /* Our only special processing is to pass the mode of the MEM to our
3060 elimination_effects (XEXP (x, 0), GET_MODE (x));
3067 fmt = GET_RTX_FORMAT (code);
3068 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
3071 elimination_effects (XEXP (x, i), mem_mode);
3072 else if (*fmt == 'E')
3073 for (j = 0; j < XVECLEN (x, i); j++)
3074 elimination_effects (XVECEXP (x, i, j), mem_mode);
3078 /* Descend through rtx X and verify that no references to eliminable registers
3079 remain. If any do remain, mark the involved register as not
3083 check_eliminable_occurrences (rtx x)
3092 code = GET_CODE (x);
3094 if (code == REG && REGNO (x) < FIRST_PSEUDO_REGISTER)
3096 struct elim_table *ep;
3098 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3099 if (ep->from_rtx == x)
3100 ep->can_eliminate = 0;
3104 fmt = GET_RTX_FORMAT (code);
3105 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
3108 check_eliminable_occurrences (XEXP (x, i));
3109 else if (*fmt == 'E')
3112 for (j = 0; j < XVECLEN (x, i); j++)
3113 check_eliminable_occurrences (XVECEXP (x, i, j));
3118 /* Scan INSN and eliminate all eliminable registers in it.
3120 If REPLACE is nonzero, do the replacement destructively. Also
3121 delete the insn as dead it if it is setting an eliminable register.
3123 If REPLACE is zero, do all our allocations in reload_obstack.
3125 If no eliminations were done and this insn doesn't require any elimination
3126 processing (these are not identical conditions: it might be updating sp,
3127 but not referencing fp; this needs to be seen during reload_as_needed so
3128 that the offset between fp and sp can be taken into consideration), zero
3129 is returned. Otherwise, 1 is returned. */
3132 eliminate_regs_in_insn (rtx insn, int replace)
3134 int icode = recog_memoized (insn);
3135 rtx old_body = PATTERN (insn);
3136 int insn_is_asm = asm_noperands (old_body) >= 0;
3137 rtx old_set = single_set (insn);
3141 rtx substed_operand[MAX_RECOG_OPERANDS];
3142 rtx orig_operand[MAX_RECOG_OPERANDS];
3143 struct elim_table *ep;
3144 rtx plus_src, plus_cst_src;
3146 if (! insn_is_asm && icode < 0)
3148 gcc_assert (GET_CODE (PATTERN (insn)) == USE
3149 || GET_CODE (PATTERN (insn)) == CLOBBER
3150 || GET_CODE (PATTERN (insn)) == ADDR_VEC
3151 || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
3152 || GET_CODE (PATTERN (insn)) == ASM_INPUT);
3156 if (old_set != 0 && REG_P (SET_DEST (old_set))
3157 && REGNO (SET_DEST (old_set)) < FIRST_PSEUDO_REGISTER)
3159 /* Check for setting an eliminable register. */
3160 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3161 if (ep->from_rtx == SET_DEST (old_set) && ep->can_eliminate)
3163 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
3164 /* If this is setting the frame pointer register to the
3165 hardware frame pointer register and this is an elimination
3166 that will be done (tested above), this insn is really
3167 adjusting the frame pointer downward to compensate for
3168 the adjustment done before a nonlocal goto. */
3169 if (ep->from == FRAME_POINTER_REGNUM
3170 && ep->to == HARD_FRAME_POINTER_REGNUM)
3172 rtx base = SET_SRC (old_set);
3173 rtx base_insn = insn;
3174 HOST_WIDE_INT offset = 0;
3176 while (base != ep->to_rtx)
3178 rtx prev_insn, prev_set;
3180 if (GET_CODE (base) == PLUS
3181 && GET_CODE (XEXP (base, 1)) == CONST_INT)
3183 offset += INTVAL (XEXP (base, 1));
3184 base = XEXP (base, 0);
3186 else if ((prev_insn = prev_nonnote_insn (base_insn)) != 0
3187 && (prev_set = single_set (prev_insn)) != 0
3188 && rtx_equal_p (SET_DEST (prev_set), base))
3190 base = SET_SRC (prev_set);
3191 base_insn = prev_insn;
3197 if (base == ep->to_rtx)
3200 = plus_constant (ep->to_rtx, offset - ep->offset);
3202 new_body = old_body;
3205 new_body = copy_insn (old_body);
3206 if (REG_NOTES (insn))
3207 REG_NOTES (insn) = copy_insn_1 (REG_NOTES (insn));
3209 PATTERN (insn) = new_body;
3210 old_set = single_set (insn);
3212 /* First see if this insn remains valid when we
3213 make the change. If not, keep the INSN_CODE
3214 the same and let reload fit it up. */
3215 validate_change (insn, &SET_SRC (old_set), src, 1);
3216 validate_change (insn, &SET_DEST (old_set),
3218 if (! apply_change_group ())
3220 SET_SRC (old_set) = src;
3221 SET_DEST (old_set) = ep->to_rtx;
3230 /* In this case this insn isn't serving a useful purpose. We
3231 will delete it in reload_as_needed once we know that this
3232 elimination is, in fact, being done.
3234 If REPLACE isn't set, we can't delete this insn, but needn't
3235 process it since it won't be used unless something changes. */
3238 delete_dead_insn (insn);
3246 /* We allow one special case which happens to work on all machines we
3247 currently support: a single set with the source or a REG_EQUAL
3248 note being a PLUS of an eliminable register and a constant. */
3249 plus_src = plus_cst_src = 0;
3250 if (old_set && REG_P (SET_DEST (old_set)))
3252 if (GET_CODE (SET_SRC (old_set)) == PLUS)
3253 plus_src = SET_SRC (old_set);
3254 /* First see if the source is of the form (plus (...) CST). */
3256 && GET_CODE (XEXP (plus_src, 1)) == CONST_INT)
3257 plus_cst_src = plus_src;
3258 else if (REG_P (SET_SRC (old_set))
3261 /* Otherwise, see if we have a REG_EQUAL note of the form
3262 (plus (...) CST). */
3264 for (links = REG_NOTES (insn); links; links = XEXP (links, 1))
3266 if ((REG_NOTE_KIND (links) == REG_EQUAL
3267 || REG_NOTE_KIND (links) == REG_EQUIV)
3268 && GET_CODE (XEXP (links, 0)) == PLUS
3269 && GET_CODE (XEXP (XEXP (links, 0), 1)) == CONST_INT)
3271 plus_cst_src = XEXP (links, 0);
3277 /* Check that the first operand of the PLUS is a hard reg or
3278 the lowpart subreg of one. */
3281 rtx reg = XEXP (plus_cst_src, 0);
3282 if (GET_CODE (reg) == SUBREG && subreg_lowpart_p (reg))
3283 reg = SUBREG_REG (reg);
3285 if (!REG_P (reg) || REGNO (reg) >= FIRST_PSEUDO_REGISTER)
3291 rtx reg = XEXP (plus_cst_src, 0);
3292 HOST_WIDE_INT offset = INTVAL (XEXP (plus_cst_src, 1));
3294 if (GET_CODE (reg) == SUBREG)
3295 reg = SUBREG_REG (reg);
3297 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3298 if (ep->from_rtx == reg && ep->can_eliminate)
3300 rtx to_rtx = ep->to_rtx;
3301 offset += ep->offset;
3302 offset = trunc_int_for_mode (offset, GET_MODE (plus_cst_src));
3304 if (GET_CODE (XEXP (plus_cst_src, 0)) == SUBREG)
3305 to_rtx = gen_lowpart (GET_MODE (XEXP (plus_cst_src, 0)),
3307 /* If we have a nonzero offset, and the source is already
3308 a simple REG, the following transformation would
3309 increase the cost of the insn by replacing a simple REG
3310 with (plus (reg sp) CST). So try only when we already
3311 had a PLUS before. */
3312 if (offset == 0 || plus_src)
3314 rtx new_src = plus_constant (to_rtx, offset);
3316 new_body = old_body;
3319 new_body = copy_insn (old_body);
3320 if (REG_NOTES (insn))
3321 REG_NOTES (insn) = copy_insn_1 (REG_NOTES (insn));
3323 PATTERN (insn) = new_body;
3324 old_set = single_set (insn);
3326 /* First see if this insn remains valid when we make the
3327 change. If not, try to replace the whole pattern with
3328 a simple set (this may help if the original insn was a
3329 PARALLEL that was only recognized as single_set due to
3330 REG_UNUSED notes). If this isn't valid either, keep
3331 the INSN_CODE the same and let reload fix it up. */
3332 if (!validate_change (insn, &SET_SRC (old_set), new_src, 0))
3334 rtx new_pat = gen_rtx_SET (VOIDmode,
3335 SET_DEST (old_set), new_src);
3337 if (!validate_change (insn, &PATTERN (insn), new_pat, 0))
3338 SET_SRC (old_set) = new_src;
3345 /* This can't have an effect on elimination offsets, so skip right
3351 /* Determine the effects of this insn on elimination offsets. */
3352 elimination_effects (old_body, 0);
3354 /* Eliminate all eliminable registers occurring in operands that
3355 can be handled by reload. */
3356 extract_insn (insn);
3357 for (i = 0; i < recog_data.n_operands; i++)
3359 orig_operand[i] = recog_data.operand[i];
3360 substed_operand[i] = recog_data.operand[i];
3362 /* For an asm statement, every operand is eliminable. */
3363 if (insn_is_asm || insn_data[icode].operand[i].eliminable)
3365 bool is_set_src, in_plus;
3367 /* Check for setting a register that we know about. */
3368 if (recog_data.operand_type[i] != OP_IN
3369 && REG_P (orig_operand[i]))
3371 /* If we are assigning to a register that can be eliminated, it
3372 must be as part of a PARALLEL, since the code above handles
3373 single SETs. We must indicate that we can no longer
3374 eliminate this reg. */
3375 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
3377 if (ep->from_rtx == orig_operand[i])
3378 ep->can_eliminate = 0;
3381 /* Companion to the above plus substitution, we can allow
3382 invariants as the source of a plain move. */
3384 if (old_set && recog_data.operand_loc[i] == &SET_SRC (old_set))
3388 && (recog_data.operand_loc[i] == &XEXP (plus_src, 0)
3389 || recog_data.operand_loc[i] == &XEXP (plus_src, 1)))
3393 = eliminate_regs_1 (recog_data.operand[i], 0,
3394 replace ? insn : NULL_RTX,
3395 is_set_src || in_plus);
3396 if (substed_operand[i] != orig_operand[i])
3398 /* Terminate the search in check_eliminable_occurrences at
3400 *recog_data.operand_loc[i] = 0;
3402 /* If an output operand changed from a REG to a MEM and INSN is an
3403 insn, write a CLOBBER insn. */
3404 if (recog_data.operand_type[i] != OP_IN
3405 && REG_P (orig_operand[i])
3406 && MEM_P (substed_operand[i])
3408 emit_insn_after (gen_clobber (orig_operand[i]), insn);
3412 for (i = 0; i < recog_data.n_dups; i++)
3413 *recog_data.dup_loc[i]
3414 = *recog_data.operand_loc[(int) recog_data.dup_num[i]];
3416 /* If any eliminable remain, they aren't eliminable anymore. */
3417 check_eliminable_occurrences (old_body);
3419 /* Substitute the operands; the new values are in the substed_operand
3421 for (i = 0; i < recog_data.n_operands; i++)
3422 *recog_data.operand_loc[i] = substed_operand[i];
3423 for (i = 0; i < recog_data.n_dups; i++)
3424 *recog_data.dup_loc[i] = substed_operand[(int) recog_data.dup_num[i]];
3426 /* If we are replacing a body that was a (set X (plus Y Z)), try to
3427 re-recognize the insn. We do this in case we had a simple addition
3428 but now can do this as a load-address. This saves an insn in this
3430 If re-recognition fails, the old insn code number will still be used,
3431 and some register operands may have changed into PLUS expressions.
3432 These will be handled by find_reloads by loading them into a register
3437 /* If we aren't replacing things permanently and we changed something,
3438 make another copy to ensure that all the RTL is new. Otherwise
3439 things can go wrong if find_reload swaps commutative operands
3440 and one is inside RTL that has been copied while the other is not. */
3441 new_body = old_body;
3444 new_body = copy_insn (old_body);
3445 if (REG_NOTES (insn))
3446 REG_NOTES (insn) = copy_insn_1 (REG_NOTES (insn));
3448 PATTERN (insn) = new_body;
3450 /* If we had a move insn but now we don't, rerecognize it. This will
3451 cause spurious re-recognition if the old move had a PARALLEL since
3452 the new one still will, but we can't call single_set without
3453 having put NEW_BODY into the insn and the re-recognition won't
3454 hurt in this rare case. */
3455 /* ??? Why this huge if statement - why don't we just rerecognize the
3459 && ((REG_P (SET_SRC (old_set))
3460 && (GET_CODE (new_body) != SET
3461 || !REG_P (SET_SRC (new_body))))
3462 /* If this was a load from or store to memory, compare
3463 the MEM in recog_data.operand to the one in the insn.
3464 If they are not equal, then rerecognize the insn. */
3466 && ((MEM_P (SET_SRC (old_set))
3467 && SET_SRC (old_set) != recog_data.operand[1])
3468 || (MEM_P (SET_DEST (old_set))
3469 && SET_DEST (old_set) != recog_data.operand[0])))
3470 /* If this was an add insn before, rerecognize. */
3471 || GET_CODE (SET_SRC (old_set)) == PLUS))
3473 int new_icode = recog (PATTERN (insn), insn, 0);
3475 INSN_CODE (insn) = new_icode;
3479 /* Restore the old body. If there were any changes to it, we made a copy
3480 of it while the changes were still in place, so we'll correctly return
3481 a modified insn below. */
3484 /* Restore the old body. */
3485 for (i = 0; i < recog_data.n_operands; i++)
3486 *recog_data.operand_loc[i] = orig_operand[i];
3487 for (i = 0; i < recog_data.n_dups; i++)
3488 *recog_data.dup_loc[i] = orig_operand[(int) recog_data.dup_num[i]];
3491 /* Update all elimination pairs to reflect the status after the current
3492 insn. The changes we make were determined by the earlier call to
3493 elimination_effects.
3495 We also detect cases where register elimination cannot be done,
3496 namely, if a register would be both changed and referenced outside a MEM
3497 in the resulting insn since such an insn is often undefined and, even if
3498 not, we cannot know what meaning will be given to it. Note that it is
3499 valid to have a register used in an address in an insn that changes it
3500 (presumably with a pre- or post-increment or decrement).
3502 If anything changes, return nonzero. */
3504 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3506 if (ep->previous_offset != ep->offset && ep->ref_outside_mem)
3507 ep->can_eliminate = 0;
3509 ep->ref_outside_mem = 0;
3511 if (ep->previous_offset != ep->offset)
3516 /* If we changed something, perform elimination in REG_NOTES. This is
3517 needed even when REPLACE is zero because a REG_DEAD note might refer
3518 to a register that we eliminate and could cause a different number
3519 of spill registers to be needed in the final reload pass than in
3521 if (val && REG_NOTES (insn) != 0)
3523 = eliminate_regs_1 (REG_NOTES (insn), 0, REG_NOTES (insn), true);
3528 /* Loop through all elimination pairs.
3529 Recalculate the number not at initial offset.
3531 Compute the maximum offset (minimum offset if the stack does not
3532 grow downward) for each elimination pair. */
3535 update_eliminable_offsets (void)
3537 struct elim_table *ep;
3539 num_not_at_initial_offset = 0;
3540 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3542 ep->previous_offset = ep->offset;
3543 if (ep->can_eliminate && ep->offset != ep->initial_offset)
3544 num_not_at_initial_offset++;
3548 /* Given X, a SET or CLOBBER of DEST, if DEST is the target of a register
3549 replacement we currently believe is valid, mark it as not eliminable if X
3550 modifies DEST in any way other than by adding a constant integer to it.
3552 If DEST is the frame pointer, we do nothing because we assume that
3553 all assignments to the hard frame pointer are nonlocal gotos and are being
3554 done at a time when they are valid and do not disturb anything else.
3555 Some machines want to eliminate a fake argument pointer with either the
3556 frame or stack pointer. Assignments to the hard frame pointer must not
3557 prevent this elimination.
3559 Called via note_stores from reload before starting its passes to scan
3560 the insns of the function. */
3563 mark_not_eliminable (rtx dest, const_rtx x, void *data ATTRIBUTE_UNUSED)
3567 /* A SUBREG of a hard register here is just changing its mode. We should
3568 not see a SUBREG of an eliminable hard register, but check just in
3570 if (GET_CODE (dest) == SUBREG)
3571 dest = SUBREG_REG (dest);
3573 if (dest == hard_frame_pointer_rtx)
3576 for (i = 0; i < NUM_ELIMINABLE_REGS; i++)
3577 if (reg_eliminate[i].can_eliminate && dest == reg_eliminate[i].to_rtx
3578 && (GET_CODE (x) != SET
3579 || GET_CODE (SET_SRC (x)) != PLUS
3580 || XEXP (SET_SRC (x), 0) != dest
3581 || GET_CODE (XEXP (SET_SRC (x), 1)) != CONST_INT))
3583 reg_eliminate[i].can_eliminate_previous
3584 = reg_eliminate[i].can_eliminate = 0;
3589 /* Verify that the initial elimination offsets did not change since the
3590 last call to set_initial_elim_offsets. This is used to catch cases
3591 where something illegal happened during reload_as_needed that could
3592 cause incorrect code to be generated if we did not check for it. */
3595 verify_initial_elim_offsets (void)
3599 if (!num_eliminable)
3602 #ifdef ELIMINABLE_REGS
3604 struct elim_table *ep;
3606 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3608 INITIAL_ELIMINATION_OFFSET (ep->from, ep->to, t);
3609 if (t != ep->initial_offset)
3614 INITIAL_FRAME_POINTER_OFFSET (t);
3615 if (t != reg_eliminate[0].initial_offset)
3622 /* Reset all offsets on eliminable registers to their initial values. */
3625 set_initial_elim_offsets (void)
3627 struct elim_table *ep = reg_eliminate;
3629 #ifdef ELIMINABLE_REGS
3630 for (; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3632 INITIAL_ELIMINATION_OFFSET (ep->from, ep->to, ep->initial_offset);
3633 ep->previous_offset = ep->offset = ep->initial_offset;
3636 INITIAL_FRAME_POINTER_OFFSET (ep->initial_offset);
3637 ep->previous_offset = ep->offset = ep->initial_offset;
3640 num_not_at_initial_offset = 0;
3643 /* Subroutine of set_initial_label_offsets called via for_each_eh_label. */
3646 set_initial_eh_label_offset (rtx label)
3648 set_label_offsets (label, NULL_RTX, 1);
3651 /* Initialize the known label offsets.
3652 Set a known offset for each forced label to be at the initial offset
3653 of each elimination. We do this because we assume that all
3654 computed jumps occur from a location where each elimination is
3655 at its initial offset.
3656 For all other labels, show that we don't know the offsets. */
3659 set_initial_label_offsets (void)
3662 memset (offsets_known_at, 0, num_labels);
3664 for (x = forced_labels; x; x = XEXP (x, 1))
3666 set_label_offsets (XEXP (x, 0), NULL_RTX, 1);
3668 for_each_eh_label (set_initial_eh_label_offset);
3671 /* Set all elimination offsets to the known values for the code label given
3675 set_offsets_for_label (rtx insn)
3678 int label_nr = CODE_LABEL_NUMBER (insn);
3679 struct elim_table *ep;
3681 num_not_at_initial_offset = 0;
3682 for (i = 0, ep = reg_eliminate; i < NUM_ELIMINABLE_REGS; ep++, i++)
3684 ep->offset = ep->previous_offset
3685 = offsets_at[label_nr - first_label_num][i];
3686 if (ep->can_eliminate && ep->offset != ep->initial_offset)
3687 num_not_at_initial_offset++;
3691 /* See if anything that happened changes which eliminations are valid.
3692 For example, on the SPARC, whether or not the frame pointer can
3693 be eliminated can depend on what registers have been used. We need
3694 not check some conditions again (such as flag_omit_frame_pointer)
3695 since they can't have changed. */
3698 update_eliminables (HARD_REG_SET *pset)
3700 int previous_frame_pointer_needed = frame_pointer_needed;
3701 struct elim_table *ep;
3703 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3704 if ((ep->from == HARD_FRAME_POINTER_REGNUM && FRAME_POINTER_REQUIRED)
3705 #ifdef ELIMINABLE_REGS
3706 || ! CAN_ELIMINATE (ep->from, ep->to)
3709 ep->can_eliminate = 0;
3711 /* Look for the case where we have discovered that we can't replace
3712 register A with register B and that means that we will now be
3713 trying to replace register A with register C. This means we can
3714 no longer replace register C with register B and we need to disable
3715 such an elimination, if it exists. This occurs often with A == ap,
3716 B == sp, and C == fp. */
3718 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3720 struct elim_table *op;
3723 if (! ep->can_eliminate && ep->can_eliminate_previous)
3725 /* Find the current elimination for ep->from, if there is a
3727 for (op = reg_eliminate;
3728 op < ®_eliminate[NUM_ELIMINABLE_REGS]; op++)
3729 if (op->from == ep->from && op->can_eliminate)
3735 /* See if there is an elimination of NEW_TO -> EP->TO. If so,
3737 for (op = reg_eliminate;
3738 op < ®_eliminate[NUM_ELIMINABLE_REGS]; op++)
3739 if (op->from == new_to && op->to == ep->to)
3740 op->can_eliminate = 0;
3744 /* See if any registers that we thought we could eliminate the previous
3745 time are no longer eliminable. If so, something has changed and we
3746 must spill the register. Also, recompute the number of eliminable
3747 registers and see if the frame pointer is needed; it is if there is
3748 no elimination of the frame pointer that we can perform. */
3750 frame_pointer_needed = 1;
3751 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3753 if (ep->can_eliminate
3754 && ep->from == FRAME_POINTER_REGNUM
3755 && ep->to != HARD_FRAME_POINTER_REGNUM
3756 && (! SUPPORTS_STACK_ALIGNMENT
3757 || ! crtl->stack_realign_needed))
3758 frame_pointer_needed = 0;
3760 if (! ep->can_eliminate && ep->can_eliminate_previous)
3762 ep->can_eliminate_previous = 0;
3763 SET_HARD_REG_BIT (*pset, ep->from);
3768 /* If we didn't need a frame pointer last time, but we do now, spill
3769 the hard frame pointer. */
3770 if (frame_pointer_needed && ! previous_frame_pointer_needed)
3771 SET_HARD_REG_BIT (*pset, HARD_FRAME_POINTER_REGNUM);
3774 /* Return true if X is used as the target register of an elimination. */
3777 elimination_target_reg_p (rtx x)
3779 struct elim_table *ep;
3781 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3782 if (ep->to_rtx == x && ep->can_eliminate)
3788 /* Initialize the table of registers to eliminate.
3789 Pre-condition: global flag frame_pointer_needed has been set before
3790 calling this function. */
3793 init_elim_table (void)
3795 struct elim_table *ep;
3796 #ifdef ELIMINABLE_REGS
3797 const struct elim_table_1 *ep1;
3801 reg_eliminate = XCNEWVEC (struct elim_table, NUM_ELIMINABLE_REGS);
3805 #ifdef ELIMINABLE_REGS
3806 for (ep = reg_eliminate, ep1 = reg_eliminate_1;
3807 ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++, ep1++)
3809 ep->from = ep1->from;
3811 ep->can_eliminate = ep->can_eliminate_previous
3812 = (CAN_ELIMINATE (ep->from, ep->to)
3813 && ! (ep->to == STACK_POINTER_REGNUM
3814 && frame_pointer_needed
3815 && (! SUPPORTS_STACK_ALIGNMENT
3816 || ! stack_realign_fp)));
3819 reg_eliminate[0].from = reg_eliminate_1[0].from;
3820 reg_eliminate[0].to = reg_eliminate_1[0].to;
3821 reg_eliminate[0].can_eliminate = reg_eliminate[0].can_eliminate_previous
3822 = ! frame_pointer_needed;
3825 /* Count the number of eliminable registers and build the FROM and TO
3826 REG rtx's. Note that code in gen_rtx_REG will cause, e.g.,
3827 gen_rtx_REG (Pmode, STACK_POINTER_REGNUM) to equal stack_pointer_rtx.
3828 We depend on this. */
3829 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3831 num_eliminable += ep->can_eliminate;
3832 ep->from_rtx = gen_rtx_REG (Pmode, ep->from);
3833 ep->to_rtx = gen_rtx_REG (Pmode, ep->to);
3837 /* Kick all pseudos out of hard register REGNO.
3839 If CANT_ELIMINATE is nonzero, it means that we are doing this spill
3840 because we found we can't eliminate some register. In the case, no pseudos
3841 are allowed to be in the register, even if they are only in a block that
3842 doesn't require spill registers, unlike the case when we are spilling this
3843 hard reg to produce another spill register.
3845 Return nonzero if any pseudos needed to be kicked out. */
3848 spill_hard_reg (unsigned int regno, int cant_eliminate)
3854 SET_HARD_REG_BIT (bad_spill_regs_global, regno);
3855 df_set_regs_ever_live (regno, true);
3858 /* Spill every pseudo reg that was allocated to this reg
3859 or to something that overlaps this reg. */
3861 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
3862 if (reg_renumber[i] >= 0
3863 && (unsigned int) reg_renumber[i] <= regno
3864 && end_hard_regno (PSEUDO_REGNO_MODE (i), reg_renumber[i]) > regno)
3865 SET_REGNO_REG_SET (&spilled_pseudos, i);
3868 /* After find_reload_regs has been run for all insn that need reloads,
3869 and/or spill_hard_regs was called, this function is used to actually
3870 spill pseudo registers and try to reallocate them. It also sets up the
3871 spill_regs array for use by choose_reload_regs. */
3874 finish_spills (int global)
3876 struct insn_chain *chain;
3877 int something_changed = 0;
3879 reg_set_iterator rsi;
3881 /* Build the spill_regs array for the function. */
3882 /* If there are some registers still to eliminate and one of the spill regs
3883 wasn't ever used before, additional stack space may have to be
3884 allocated to store this register. Thus, we may have changed the offset
3885 between the stack and frame pointers, so mark that something has changed.
3887 One might think that we need only set VAL to 1 if this is a call-used
3888 register. However, the set of registers that must be saved by the
3889 prologue is not identical to the call-used set. For example, the
3890 register used by the call insn for the return PC is a call-used register,
3891 but must be saved by the prologue. */
3894 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3895 if (TEST_HARD_REG_BIT (used_spill_regs, i))
3897 spill_reg_order[i] = n_spills;
3898 spill_regs[n_spills++] = i;
3899 if (num_eliminable && ! df_regs_ever_live_p (i))
3900 something_changed = 1;
3901 df_set_regs_ever_live (i, true);
3904 spill_reg_order[i] = -1;
3906 EXECUTE_IF_SET_IN_REG_SET (&spilled_pseudos, FIRST_PSEUDO_REGISTER, i, rsi)
3907 if (! flag_ira || ! optimize || reg_renumber[i] >= 0)
3909 /* Record the current hard register the pseudo is allocated to
3910 in pseudo_previous_regs so we avoid reallocating it to the
3911 same hard reg in a later pass. */
3912 gcc_assert (reg_renumber[i] >= 0);
3914 SET_HARD_REG_BIT (pseudo_previous_regs[i], reg_renumber[i]);
3915 /* Mark it as no longer having a hard register home. */
3916 reg_renumber[i] = -1;
3917 if (flag_ira && optimize)
3918 /* Inform IRA about the change. */
3919 ira_mark_allocation_change (i);
3920 /* We will need to scan everything again. */
3921 something_changed = 1;
3924 /* Retry global register allocation if possible. */
3927 memset (pseudo_forbidden_regs, 0, max_regno * sizeof (HARD_REG_SET));
3928 /* For every insn that needs reloads, set the registers used as spill
3929 regs in pseudo_forbidden_regs for every pseudo live across the
3931 for (chain = insns_need_reload; chain; chain = chain->next_need_reload)
3933 EXECUTE_IF_SET_IN_REG_SET
3934 (&chain->live_throughout, FIRST_PSEUDO_REGISTER, i, rsi)
3936 IOR_HARD_REG_SET (pseudo_forbidden_regs[i],
3937 chain->used_spill_regs);
3939 EXECUTE_IF_SET_IN_REG_SET
3940 (&chain->dead_or_set, FIRST_PSEUDO_REGISTER, i, rsi)
3942 IOR_HARD_REG_SET (pseudo_forbidden_regs[i],
3943 chain->used_spill_regs);
3947 if (! flag_ira || ! optimize)
3949 /* Retry allocating the spilled pseudos. For each reg,
3950 merge the various reg sets that indicate which hard regs
3951 can't be used, and call retry_global_alloc. We change
3952 spill_pseudos here to only contain pseudos that did not
3953 get a new hard register. */
3954 for (i = FIRST_PSEUDO_REGISTER; i < (unsigned)max_regno; i++)
3955 if (reg_old_renumber[i] != reg_renumber[i])
3957 HARD_REG_SET forbidden;
3959 COPY_HARD_REG_SET (forbidden, bad_spill_regs_global);
3960 IOR_HARD_REG_SET (forbidden, pseudo_forbidden_regs[i]);
3961 IOR_HARD_REG_SET (forbidden, pseudo_previous_regs[i]);
3962 retry_global_alloc (i, forbidden);
3963 if (reg_renumber[i] >= 0)
3964 CLEAR_REGNO_REG_SET (&spilled_pseudos, i);
3969 /* Retry allocating the pseudos spilled in IRA and the
3970 reload. For each reg, merge the various reg sets that
3971 indicate which hard regs can't be used, and call
3972 ira_reassign_pseudos. */
3975 for (n = 0, i = FIRST_PSEUDO_REGISTER; i < (unsigned) max_regno; i++)
3976 if (reg_old_renumber[i] != reg_renumber[i])
3978 if (reg_renumber[i] < 0)
3979 temp_pseudo_reg_arr[n++] = i;
3981 CLEAR_REGNO_REG_SET (&spilled_pseudos, i);
3983 if (ira_reassign_pseudos (temp_pseudo_reg_arr, n,
3984 bad_spill_regs_global,
3985 pseudo_forbidden_regs, pseudo_previous_regs,
3987 something_changed = 1;
3991 /* Fix up the register information in the insn chain.
3992 This involves deleting those of the spilled pseudos which did not get
3993 a new hard register home from the live_{before,after} sets. */
3994 for (chain = reload_insn_chain; chain; chain = chain->next)
3996 HARD_REG_SET used_by_pseudos;
3997 HARD_REG_SET used_by_pseudos2;
3999 if (! flag_ira || ! optimize)
4001 /* Don't do it for IRA because IRA and the reload still can
4002 assign hard registers to the spilled pseudos on next
4003 reload iterations. */
4004 AND_COMPL_REG_SET (&chain->live_throughout, &spilled_pseudos);
4005 AND_COMPL_REG_SET (&chain->dead_or_set, &spilled_pseudos);
4007 /* Mark any unallocated hard regs as available for spills. That
4008 makes inheritance work somewhat better. */
4009 if (chain->need_reload)
4011 REG_SET_TO_HARD_REG_SET (used_by_pseudos, &chain->live_throughout);
4012 REG_SET_TO_HARD_REG_SET (used_by_pseudos2, &chain->dead_or_set);
4013 IOR_HARD_REG_SET (used_by_pseudos, used_by_pseudos2);
4015 compute_use_by_pseudos (&used_by_pseudos, &chain->live_throughout);
4016 compute_use_by_pseudos (&used_by_pseudos, &chain->dead_or_set);
4017 /* Value of chain->used_spill_regs from previous iteration
4018 may be not included in the value calculated here because
4019 of possible removing caller-saves insns (see function
4020 delete_caller_save_insns. */
4021 COMPL_HARD_REG_SET (chain->used_spill_regs, used_by_pseudos);
4022 AND_HARD_REG_SET (chain->used_spill_regs, used_spill_regs);
4026 CLEAR_REG_SET (&changed_allocation_pseudos);
4027 /* Let alter_reg modify the reg rtx's for the modified pseudos. */
4028 for (i = FIRST_PSEUDO_REGISTER; i < (unsigned)max_regno; i++)
4030 int regno = reg_renumber[i];
4031 if (reg_old_renumber[i] == regno)
4034 SET_REGNO_REG_SET (&changed_allocation_pseudos, i);
4036 alter_reg (i, reg_old_renumber[i], false);
4037 reg_old_renumber[i] = regno;
4041 fprintf (dump_file, " Register %d now on stack.\n\n", i);
4043 fprintf (dump_file, " Register %d now in %d.\n\n",
4044 i, reg_renumber[i]);
4048 return something_changed;
4051 /* Find all paradoxical subregs within X and update reg_max_ref_width. */
4054 scan_paradoxical_subregs (rtx x)
4058 enum rtx_code code = GET_CODE (x);
4069 case CONST_VECTOR: /* shouldn't happen, but just in case. */
4077 if (REG_P (SUBREG_REG (x))
4078 && (GET_MODE_SIZE (GET_MODE (x))
4079 > reg_max_ref_width[REGNO (SUBREG_REG (x))]))
4081 reg_max_ref_width[REGNO (SUBREG_REG (x))]
4082 = GET_MODE_SIZE (GET_MODE (x));
4083 mark_home_live_1 (REGNO (SUBREG_REG (x)), GET_MODE (x));
4091 fmt = GET_RTX_FORMAT (code);
4092 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
4095 scan_paradoxical_subregs (XEXP (x, i));
4096 else if (fmt[i] == 'E')
4099 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
4100 scan_paradoxical_subregs (XVECEXP (x, i, j));
4105 /* A subroutine of reload_as_needed. If INSN has a REG_EH_REGION note,
4106 examine all of the reload insns between PREV and NEXT exclusive, and
4107 annotate all that may trap. */
4110 fixup_eh_region_note (rtx insn, rtx prev, rtx next)
4112 rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
4113 unsigned int trap_count;
4119 if (may_trap_p (PATTERN (insn)))
4123 remove_note (insn, note);
4127 for (i = NEXT_INSN (prev); i != next; i = NEXT_INSN (i))
4128 if (INSN_P (i) && i != insn && may_trap_p (PATTERN (i)))
4131 add_reg_note (i, REG_EH_REGION, XEXP (note, 0));
4135 /* Reload pseudo-registers into hard regs around each insn as needed.
4136 Additional register load insns are output before the insn that needs it
4137 and perhaps store insns after insns that modify the reloaded pseudo reg.
4139 reg_last_reload_reg and reg_reloaded_contents keep track of
4140 which registers are already available in reload registers.
4141 We update these for the reloads that we perform,
4142 as the insns are scanned. */
4145 reload_as_needed (int live_known)
4147 struct insn_chain *chain;
4148 #if defined (AUTO_INC_DEC)
4153 memset (spill_reg_rtx, 0, sizeof spill_reg_rtx);
4154 memset (spill_reg_store, 0, sizeof spill_reg_store);
4155 reg_last_reload_reg = XCNEWVEC (rtx, max_regno);
4156 INIT_REG_SET (®_has_output_reload);
4157 CLEAR_HARD_REG_SET (reg_reloaded_valid);
4158 CLEAR_HARD_REG_SET (reg_reloaded_call_part_clobbered);
4160 set_initial_elim_offsets ();
4162 for (chain = reload_insn_chain; chain; chain = chain->next)
4165 rtx insn = chain->insn;
4166 rtx old_next = NEXT_INSN (insn);
4168 rtx old_prev = PREV_INSN (insn);
4171 /* If we pass a label, copy the offsets from the label information
4172 into the current offsets of each elimination. */
4174 set_offsets_for_label (insn);
4176 else if (INSN_P (insn))
4178 regset_head regs_to_forget;
4179 INIT_REG_SET (®s_to_forget);
4180 note_stores (PATTERN (insn), forget_old_reloads_1, ®s_to_forget);
4182 /* If this is a USE and CLOBBER of a MEM, ensure that any
4183 references to eliminable registers have been removed. */
4185 if ((GET_CODE (PATTERN (insn)) == USE
4186 || GET_CODE (PATTERN (insn)) == CLOBBER)
4187 && MEM_P (XEXP (PATTERN (insn), 0)))
4188 XEXP (XEXP (PATTERN (insn), 0), 0)
4189 = eliminate_regs (XEXP (XEXP (PATTERN (insn), 0), 0),
4190 GET_MODE (XEXP (PATTERN (insn), 0)),
4193 /* If we need to do register elimination processing, do so.
4194 This might delete the insn, in which case we are done. */
4195 if ((num_eliminable || num_eliminable_invariants) && chain->need_elim)
4197 eliminate_regs_in_insn (insn, 1);
4200 update_eliminable_offsets ();
4201 CLEAR_REG_SET (®s_to_forget);
4206 /* If need_elim is nonzero but need_reload is zero, one might think
4207 that we could simply set n_reloads to 0. However, find_reloads
4208 could have done some manipulation of the insn (such as swapping
4209 commutative operands), and these manipulations are lost during
4210 the first pass for every insn that needs register elimination.
4211 So the actions of find_reloads must be redone here. */
4213 if (! chain->need_elim && ! chain->need_reload
4214 && ! chain->need_operand_change)
4216 /* First find the pseudo regs that must be reloaded for this insn.
4217 This info is returned in the tables reload_... (see reload.h).
4218 Also modify the body of INSN by substituting RELOAD
4219 rtx's for those pseudo regs. */
4222 CLEAR_REG_SET (®_has_output_reload);
4223 CLEAR_HARD_REG_SET (reg_is_output_reload);
4225 find_reloads (insn, 1, spill_indirect_levels, live_known,
4231 rtx next = NEXT_INSN (insn);
4234 prev = PREV_INSN (insn);
4236 /* Now compute which reload regs to reload them into. Perhaps
4237 reusing reload regs from previous insns, or else output
4238 load insns to reload them. Maybe output store insns too.
4239 Record the choices of reload reg in reload_reg_rtx. */
4240 choose_reload_regs (chain);
4242 /* Merge any reloads that we didn't combine for fear of
4243 increasing the number of spill registers needed but now
4244 discover can be safely merged. */
4245 if (SMALL_REGISTER_CLASSES)
4246 merge_assigned_reloads (insn);
4248 /* Generate the insns to reload operands into or out of
4249 their reload regs. */
4250 emit_reload_insns (chain);
4252 /* Substitute the chosen reload regs from reload_reg_rtx
4253 into the insn's body (or perhaps into the bodies of other
4254 load and store insn that we just made for reloading
4255 and that we moved the structure into). */
4256 subst_reloads (insn);
4258 /* Adjust the exception region notes for loads and stores. */
4259 if (flag_non_call_exceptions && !CALL_P (insn))
4260 fixup_eh_region_note (insn, prev, next);
4262 /* If this was an ASM, make sure that all the reload insns
4263 we have generated are valid. If not, give an error
4265 if (asm_noperands (PATTERN (insn)) >= 0)
4266 for (p = NEXT_INSN (prev); p != next; p = NEXT_INSN (p))
4267 if (p != insn && INSN_P (p)
4268 && GET_CODE (PATTERN (p)) != USE
4269 && (recog_memoized (p) < 0
4270 || (extract_insn (p), ! constrain_operands (1))))
4272 error_for_asm (insn,
4273 "%<asm%> operand requires "
4274 "impossible reload");
4279 if (num_eliminable && chain->need_elim)
4280 update_eliminable_offsets ();
4282 /* Any previously reloaded spilled pseudo reg, stored in this insn,
4283 is no longer validly lying around to save a future reload.
4284 Note that this does not detect pseudos that were reloaded
4285 for this insn in order to be stored in
4286 (obeying register constraints). That is correct; such reload
4287 registers ARE still valid. */
4288 forget_marked_reloads (®s_to_forget);
4289 CLEAR_REG_SET (®s_to_forget);
4291 /* There may have been CLOBBER insns placed after INSN. So scan
4292 between INSN and NEXT and use them to forget old reloads. */
4293 for (x = NEXT_INSN (insn); x != old_next; x = NEXT_INSN (x))
4294 if (NONJUMP_INSN_P (x) && GET_CODE (PATTERN (x)) == CLOBBER)
4295 note_stores (PATTERN (x), forget_old_reloads_1, NULL);
4298 /* Likewise for regs altered by auto-increment in this insn.
4299 REG_INC notes have been changed by reloading:
4300 find_reloads_address_1 records substitutions for them,
4301 which have been performed by subst_reloads above. */
4302 for (i = n_reloads - 1; i >= 0; i--)
4304 rtx in_reg = rld[i].in_reg;
4307 enum rtx_code code = GET_CODE (in_reg);
4308 /* PRE_INC / PRE_DEC will have the reload register ending up
4309 with the same value as the stack slot, but that doesn't
4310 hold true for POST_INC / POST_DEC. Either we have to
4311 convert the memory access to a true POST_INC / POST_DEC,
4312 or we can't use the reload register for inheritance. */
4313 if ((code == POST_INC || code == POST_DEC)
4314 && TEST_HARD_REG_BIT (reg_reloaded_valid,
4315 REGNO (rld[i].reg_rtx))
4316 /* Make sure it is the inc/dec pseudo, and not
4317 some other (e.g. output operand) pseudo. */
4318 && ((unsigned) reg_reloaded_contents[REGNO (rld[i].reg_rtx)]
4319 == REGNO (XEXP (in_reg, 0))))
4322 rtx reload_reg = rld[i].reg_rtx;
4323 enum machine_mode mode = GET_MODE (reload_reg);
4327 for (p = PREV_INSN (old_next); p != prev; p = PREV_INSN (p))
4329 /* We really want to ignore REG_INC notes here, so
4330 use PATTERN (p) as argument to reg_set_p . */
4331 if (reg_set_p (reload_reg, PATTERN (p)))
4333 n = count_occurrences (PATTERN (p), reload_reg, 0);
4338 n = validate_replace_rtx (reload_reg,
4339 gen_rtx_fmt_e (code,
4344 /* We must also verify that the constraints
4345 are met after the replacement. */
4348 n = constrain_operands (1);
4352 /* If the constraints were not met, then
4353 undo the replacement. */
4356 validate_replace_rtx (gen_rtx_fmt_e (code,
4368 add_reg_note (p, REG_INC, reload_reg);
4369 /* Mark this as having an output reload so that the
4370 REG_INC processing code below won't invalidate
4371 the reload for inheritance. */
4372 SET_HARD_REG_BIT (reg_is_output_reload,
4373 REGNO (reload_reg));
4374 SET_REGNO_REG_SET (®_has_output_reload,
4375 REGNO (XEXP (in_reg, 0)));
4378 forget_old_reloads_1 (XEXP (in_reg, 0), NULL_RTX,
4381 else if ((code == PRE_INC || code == PRE_DEC)
4382 && TEST_HARD_REG_BIT (reg_reloaded_valid,
4383 REGNO (rld[i].reg_rtx))
4384 /* Make sure it is the inc/dec pseudo, and not
4385 some other (e.g. output operand) pseudo. */
4386 && ((unsigned) reg_reloaded_contents[REGNO (rld[i].reg_rtx)]
4387 == REGNO (XEXP (in_reg, 0))))
4389 SET_HARD_REG_BIT (reg_is_output_reload,
4390 REGNO (rld[i].reg_rtx));
4391 SET_REGNO_REG_SET (®_has_output_reload,
4392 REGNO (XEXP (in_reg, 0)));
4394 else if ((code == PRE_INC || code == PRE_DEC
4395 || code == POST_INC || code == POST_DEC))
4398 int in_regno = REGNO (XEXP (in_reg, 0));
4400 if (reg_last_reload_reg[in_regno] != NULL_RTX)
4402 in_hard_regno = REGNO (reg_last_reload_reg[in_regno]);
4403 gcc_assert (TEST_HARD_REG_BIT (reg_reloaded_valid,
4405 for (x = old_prev ? NEXT_INSN (old_prev) : insn;
4408 if (x == reg_reloaded_insn[in_hard_regno])
4410 /* If for some reasons, we didn't set up
4411 reg_last_reload_reg in this insn,
4412 invalidate inheritance from previous
4413 insns for the incremented/decremented
4414 register. Such registers will be not in
4415 reg_has_output_reload. */
4417 forget_old_reloads_1 (XEXP (in_reg, 0),
4423 /* If a pseudo that got a hard register is auto-incremented,
4424 we must purge records of copying it into pseudos without
4426 for (x = REG_NOTES (insn); x; x = XEXP (x, 1))
4427 if (REG_NOTE_KIND (x) == REG_INC)
4429 /* See if this pseudo reg was reloaded in this insn.
4430 If so, its last-reload info is still valid
4431 because it is based on this insn's reload. */
4432 for (i = 0; i < n_reloads; i++)
4433 if (rld[i].out == XEXP (x, 0))
4437 forget_old_reloads_1 (XEXP (x, 0), NULL_RTX, NULL);
4441 /* A reload reg's contents are unknown after a label. */
4443 CLEAR_HARD_REG_SET (reg_reloaded_valid);
4445 /* Don't assume a reload reg is still good after a call insn
4446 if it is a call-used reg, or if it contains a value that will
4447 be partially clobbered by the call. */
4448 else if (CALL_P (insn))
4450 AND_COMPL_HARD_REG_SET (reg_reloaded_valid, call_used_reg_set);
4451 AND_COMPL_HARD_REG_SET (reg_reloaded_valid, reg_reloaded_call_part_clobbered);
4456 free (reg_last_reload_reg);
4457 CLEAR_REG_SET (®_has_output_reload);
4460 /* Discard all record of any value reloaded from X,
4461 or reloaded in X from someplace else;
4462 unless X is an output reload reg of the current insn.
4464 X may be a hard reg (the reload reg)
4465 or it may be a pseudo reg that was reloaded from.
4467 When DATA is non-NULL just mark the registers in regset
4468 to be forgotten later. */
4471 forget_old_reloads_1 (rtx x, const_rtx ignored ATTRIBUTE_UNUSED,
4476 regset regs = (regset) data;
4478 /* note_stores does give us subregs of hard regs,
4479 subreg_regno_offset requires a hard reg. */
4480 while (GET_CODE (x) == SUBREG)
4482 /* We ignore the subreg offset when calculating the regno,
4483 because we are using the entire underlying hard register
4493 if (regno >= FIRST_PSEUDO_REGISTER)
4499 nr = hard_regno_nregs[regno][GET_MODE (x)];
4500 /* Storing into a spilled-reg invalidates its contents.
4501 This can happen if a block-local pseudo is allocated to that reg
4502 and it wasn't spilled because this block's total need is 0.
4503 Then some insn might have an optional reload and use this reg. */
4505 for (i = 0; i < nr; i++)
4506 /* But don't do this if the reg actually serves as an output
4507 reload reg in the current instruction. */
4509 || ! TEST_HARD_REG_BIT (reg_is_output_reload, regno + i))
4511 CLEAR_HARD_REG_BIT (reg_reloaded_valid, regno + i);
4512 spill_reg_store[regno + i] = 0;
4518 SET_REGNO_REG_SET (regs, regno + nr);
4521 /* Since value of X has changed,
4522 forget any value previously copied from it. */
4525 /* But don't forget a copy if this is the output reload
4526 that establishes the copy's validity. */
4528 || !REGNO_REG_SET_P (®_has_output_reload, regno + nr))
4529 reg_last_reload_reg[regno + nr] = 0;
4533 /* Forget the reloads marked in regset by previous function. */
4535 forget_marked_reloads (regset regs)
4538 reg_set_iterator rsi;
4539 EXECUTE_IF_SET_IN_REG_SET (regs, 0, reg, rsi)
4541 if (reg < FIRST_PSEUDO_REGISTER
4542 /* But don't do this if the reg actually serves as an output
4543 reload reg in the current instruction. */
4545 || ! TEST_HARD_REG_BIT (reg_is_output_reload, reg)))
4547 CLEAR_HARD_REG_BIT (reg_reloaded_valid, reg);
4548 spill_reg_store[reg] = 0;
4551 || !REGNO_REG_SET_P (®_has_output_reload, reg))
4552 reg_last_reload_reg[reg] = 0;
4556 /* The following HARD_REG_SETs indicate when each hard register is
4557 used for a reload of various parts of the current insn. */
4559 /* If reg is unavailable for all reloads. */
4560 static HARD_REG_SET reload_reg_unavailable;
4561 /* If reg is in use as a reload reg for a RELOAD_OTHER reload. */
4562 static HARD_REG_SET reload_reg_used;
4563 /* If reg is in use for a RELOAD_FOR_INPUT_ADDRESS reload for operand I. */
4564 static HARD_REG_SET reload_reg_used_in_input_addr[MAX_RECOG_OPERANDS];
4565 /* If reg is in use for a RELOAD_FOR_INPADDR_ADDRESS reload for operand I. */
4566 static HARD_REG_SET reload_reg_used_in_inpaddr_addr[MAX_RECOG_OPERANDS];
4567 /* If reg is in use for a RELOAD_FOR_OUTPUT_ADDRESS reload for operand I. */
4568 static HARD_REG_SET reload_reg_used_in_output_addr[MAX_RECOG_OPERANDS];
4569 /* If reg is in use for a RELOAD_FOR_OUTADDR_ADDRESS reload for operand I. */
4570 static HARD_REG_SET reload_reg_used_in_outaddr_addr[MAX_RECOG_OPERANDS];
4571 /* If reg is in use for a RELOAD_FOR_INPUT reload for operand I. */
4572 static HARD_REG_SET reload_reg_used_in_input[MAX_RECOG_OPERANDS];
4573 /* If reg is in use for a RELOAD_FOR_OUTPUT reload for operand I. */
4574 static HARD_REG_SET reload_reg_used_in_output[MAX_RECOG_OPERANDS];
4575 /* If reg is in use for a RELOAD_FOR_OPERAND_ADDRESS reload. */
4576 static HARD_REG_SET reload_reg_used_in_op_addr;
4577 /* If reg is in use for a RELOAD_FOR_OPADDR_ADDR reload. */
4578 static HARD_REG_SET reload_reg_used_in_op_addr_reload;
4579 /* If reg is in use for a RELOAD_FOR_INSN reload. */
4580 static HARD_REG_SET reload_reg_used_in_insn;
4581 /* If reg is in use for a RELOAD_FOR_OTHER_ADDRESS reload. */
4582 static HARD_REG_SET reload_reg_used_in_other_addr;
4584 /* If reg is in use as a reload reg for any sort of reload. */
4585 static HARD_REG_SET reload_reg_used_at_all;
4587 /* If reg is use as an inherited reload. We just mark the first register
4589 static HARD_REG_SET reload_reg_used_for_inherit;
4591 /* Records which hard regs are used in any way, either as explicit use or
4592 by being allocated to a pseudo during any point of the current insn. */
4593 static HARD_REG_SET reg_used_in_insn;
4595 /* Mark reg REGNO as in use for a reload of the sort spec'd by OPNUM and
4596 TYPE. MODE is used to indicate how many consecutive regs are
4600 mark_reload_reg_in_use (unsigned int regno, int opnum, enum reload_type type,
4601 enum machine_mode mode)
4603 unsigned int nregs = hard_regno_nregs[regno][mode];
4606 for (i = regno; i < nregs + regno; i++)
4611 SET_HARD_REG_BIT (reload_reg_used, i);
4614 case RELOAD_FOR_INPUT_ADDRESS:
4615 SET_HARD_REG_BIT (reload_reg_used_in_input_addr[opnum], i);
4618 case RELOAD_FOR_INPADDR_ADDRESS:
4619 SET_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[opnum], i);
4622 case RELOAD_FOR_OUTPUT_ADDRESS:
4623 SET_HARD_REG_BIT (reload_reg_used_in_output_addr[opnum], i);
4626 case RELOAD_FOR_OUTADDR_ADDRESS:
4627 SET_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[opnum], i);
4630 case RELOAD_FOR_OPERAND_ADDRESS:
4631 SET_HARD_REG_BIT (reload_reg_used_in_op_addr, i);
4634 case RELOAD_FOR_OPADDR_ADDR:
4635 SET_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, i);
4638 case RELOAD_FOR_OTHER_ADDRESS:
4639 SET_HARD_REG_BIT (reload_reg_used_in_other_addr, i);
4642 case RELOAD_FOR_INPUT:
4643 SET_HARD_REG_BIT (reload_reg_used_in_input[opnum], i);
4646 case RELOAD_FOR_OUTPUT:
4647 SET_HARD_REG_BIT (reload_reg_used_in_output[opnum], i);
4650 case RELOAD_FOR_INSN:
4651 SET_HARD_REG_BIT (reload_reg_used_in_insn, i);
4655 SET_HARD_REG_BIT (reload_reg_used_at_all, i);
4659 /* Similarly, but show REGNO is no longer in use for a reload. */
4662 clear_reload_reg_in_use (unsigned int regno, int opnum,
4663 enum reload_type type, enum machine_mode mode)
4665 unsigned int nregs = hard_regno_nregs[regno][mode];
4666 unsigned int start_regno, end_regno, r;
4668 /* A complication is that for some reload types, inheritance might
4669 allow multiple reloads of the same types to share a reload register.
4670 We set check_opnum if we have to check only reloads with the same
4671 operand number, and check_any if we have to check all reloads. */
4672 int check_opnum = 0;
4674 HARD_REG_SET *used_in_set;
4679 used_in_set = &reload_reg_used;
4682 case RELOAD_FOR_INPUT_ADDRESS:
4683 used_in_set = &reload_reg_used_in_input_addr[opnum];
4686 case RELOAD_FOR_INPADDR_ADDRESS:
4688 used_in_set = &reload_reg_used_in_inpaddr_addr[opnum];
4691 case RELOAD_FOR_OUTPUT_ADDRESS:
4692 used_in_set = &reload_reg_used_in_output_addr[opnum];
4695 case RELOAD_FOR_OUTADDR_ADDRESS:
4697 used_in_set = &reload_reg_used_in_outaddr_addr[opnum];
4700 case RELOAD_FOR_OPERAND_ADDRESS:
4701 used_in_set = &reload_reg_used_in_op_addr;
4704 case RELOAD_FOR_OPADDR_ADDR:
4706 used_in_set = &reload_reg_used_in_op_addr_reload;
4709 case RELOAD_FOR_OTHER_ADDRESS:
4710 used_in_set = &reload_reg_used_in_other_addr;
4714 case RELOAD_FOR_INPUT:
4715 used_in_set = &reload_reg_used_in_input[opnum];
4718 case RELOAD_FOR_OUTPUT:
4719 used_in_set = &reload_reg_used_in_output[opnum];
4722 case RELOAD_FOR_INSN:
4723 used_in_set = &reload_reg_used_in_insn;
4728 /* We resolve conflicts with remaining reloads of the same type by
4729 excluding the intervals of reload registers by them from the
4730 interval of freed reload registers. Since we only keep track of
4731 one set of interval bounds, we might have to exclude somewhat
4732 more than what would be necessary if we used a HARD_REG_SET here.
4733 But this should only happen very infrequently, so there should
4734 be no reason to worry about it. */
4736 start_regno = regno;
4737 end_regno = regno + nregs;
4738 if (check_opnum || check_any)
4740 for (i = n_reloads - 1; i >= 0; i--)
4742 if (rld[i].when_needed == type
4743 && (check_any || rld[i].opnum == opnum)
4746 unsigned int conflict_start = true_regnum (rld[i].reg_rtx);
4747 unsigned int conflict_end
4748 = end_hard_regno (rld[i].mode, conflict_start);
4750 /* If there is an overlap with the first to-be-freed register,
4751 adjust the interval start. */
4752 if (conflict_start <= start_regno && conflict_end > start_regno)
4753 start_regno = conflict_end;
4754 /* Otherwise, if there is a conflict with one of the other
4755 to-be-freed registers, adjust the interval end. */
4756 if (conflict_start > start_regno && conflict_start < end_regno)
4757 end_regno = conflict_start;
4762 for (r = start_regno; r < end_regno; r++)
4763 CLEAR_HARD_REG_BIT (*used_in_set, r);
4766 /* 1 if reg REGNO is free as a reload reg for a reload of the sort
4767 specified by OPNUM and TYPE. */
4770 reload_reg_free_p (unsigned int regno, int opnum, enum reload_type type)
4774 /* In use for a RELOAD_OTHER means it's not available for anything. */
4775 if (TEST_HARD_REG_BIT (reload_reg_used, regno)
4776 || TEST_HARD_REG_BIT (reload_reg_unavailable, regno))
4782 /* In use for anything means we can't use it for RELOAD_OTHER. */
4783 if (TEST_HARD_REG_BIT (reload_reg_used_in_other_addr, regno)
4784 || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)
4785 || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno)
4786 || TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno))
4789 for (i = 0; i < reload_n_operands; i++)
4790 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4791 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno)
4792 || TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4793 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
4794 || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)
4795 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4800 case RELOAD_FOR_INPUT:
4801 if (TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4802 || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno))
4805 if (TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno))
4808 /* If it is used for some other input, can't use it. */
4809 for (i = 0; i < reload_n_operands; i++)
4810 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4813 /* If it is used in a later operand's address, can't use it. */
4814 for (i = opnum + 1; i < reload_n_operands; i++)
4815 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4816 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno))
4821 case RELOAD_FOR_INPUT_ADDRESS:
4822 /* Can't use a register if it is used for an input address for this
4823 operand or used as an input in an earlier one. */
4824 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[opnum], regno)
4825 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[opnum], regno))
4828 for (i = 0; i < opnum; i++)
4829 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4834 case RELOAD_FOR_INPADDR_ADDRESS:
4835 /* Can't use a register if it is used for an input address
4836 for this operand or used as an input in an earlier
4838 if (TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[opnum], regno))
4841 for (i = 0; i < opnum; i++)
4842 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4847 case RELOAD_FOR_OUTPUT_ADDRESS:
4848 /* Can't use a register if it is used for an output address for this
4849 operand or used as an output in this or a later operand. Note
4850 that multiple output operands are emitted in reverse order, so
4851 the conflicting ones are those with lower indices. */
4852 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[opnum], regno))
4855 for (i = 0; i <= opnum; i++)
4856 if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4861 case RELOAD_FOR_OUTADDR_ADDRESS:
4862 /* Can't use a register if it is used for an output address
4863 for this operand or used as an output in this or a
4864 later operand. Note that multiple output operands are
4865 emitted in reverse order, so the conflicting ones are
4866 those with lower indices. */
4867 if (TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[opnum], regno))
4870 for (i = 0; i <= opnum; i++)
4871 if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4876 case RELOAD_FOR_OPERAND_ADDRESS:
4877 for (i = 0; i < reload_n_operands; i++)
4878 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4881 return (! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4882 && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno));
4884 case RELOAD_FOR_OPADDR_ADDR:
4885 for (i = 0; i < reload_n_operands; i++)
4886 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4889 return (!TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno));
4891 case RELOAD_FOR_OUTPUT:
4892 /* This cannot share a register with RELOAD_FOR_INSN reloads, other
4893 outputs, or an operand address for this or an earlier output.
4894 Note that multiple output operands are emitted in reverse order,
4895 so the conflicting ones are those with higher indices. */
4896 if (TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno))
4899 for (i = 0; i < reload_n_operands; i++)
4900 if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4903 for (i = opnum; i < reload_n_operands; i++)
4904 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4905 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno))
4910 case RELOAD_FOR_INSN:
4911 for (i = 0; i < reload_n_operands; i++)
4912 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)
4913 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4916 return (! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4917 && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno));
4919 case RELOAD_FOR_OTHER_ADDRESS:
4920 return ! TEST_HARD_REG_BIT (reload_reg_used_in_other_addr, regno);
4927 /* Return 1 if the value in reload reg REGNO, as used by a reload
4928 needed for the part of the insn specified by OPNUM and TYPE,
4929 is still available in REGNO at the end of the insn.
4931 We can assume that the reload reg was already tested for availability
4932 at the time it is needed, and we should not check this again,
4933 in case the reg has already been marked in use. */
4936 reload_reg_reaches_end_p (unsigned int regno, int opnum, enum reload_type type)
4943 /* Since a RELOAD_OTHER reload claims the reg for the entire insn,
4944 its value must reach the end. */
4947 /* If this use is for part of the insn,
4948 its value reaches if no subsequent part uses the same register.
4949 Just like the above function, don't try to do this with lots
4952 case RELOAD_FOR_OTHER_ADDRESS:
4953 /* Here we check for everything else, since these don't conflict
4954 with anything else and everything comes later. */
4956 for (i = 0; i < reload_n_operands; i++)
4957 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4958 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
4959 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)
4960 || TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4961 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno)
4962 || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4965 return (! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)
4966 && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno)
4967 && ! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4968 && ! TEST_HARD_REG_BIT (reload_reg_used, regno));
4970 case RELOAD_FOR_INPUT_ADDRESS:
4971 case RELOAD_FOR_INPADDR_ADDRESS:
4972 /* Similar, except that we check only for this and subsequent inputs
4973 and the address of only subsequent inputs and we do not need
4974 to check for RELOAD_OTHER objects since they are known not to
4977 for (i = opnum; i < reload_n_operands; i++)
4978 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4981 for (i = opnum + 1; i < reload_n_operands; i++)
4982 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4983 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno))
4986 for (i = 0; i < reload_n_operands; i++)
4987 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4988 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
4989 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4992 if (TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno))
4995 return (!TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)
4996 && !TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4997 && !TEST_HARD_REG_BIT (reload_reg_used, regno));
4999 case RELOAD_FOR_INPUT:
5000 /* Similar to input address, except we start at the next operand for
5001 both input and input address and we do not check for
5002 RELOAD_FOR_OPERAND_ADDRESS and RELOAD_FOR_INSN since these
5005 for (i = opnum + 1; i < reload_n_operands; i++)
5006 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
5007 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno)
5008 || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
5011 /* ... fall through ... */
5013 case RELOAD_FOR_OPERAND_ADDRESS:
5014 /* Check outputs and their addresses. */
5016 for (i = 0; i < reload_n_operands; i++)
5017 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
5018 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
5019 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
5022 return (!TEST_HARD_REG_BIT (reload_reg_used, regno));
5024 case RELOAD_FOR_OPADDR_ADDR:
5025 for (i = 0; i < reload_n_operands; i++)
5026 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
5027 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
5028 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
5031 return (!TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)
5032 && !TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
5033 && !TEST_HARD_REG_BIT (reload_reg_used, regno));
5035 case RELOAD_FOR_INSN:
5036 /* These conflict with other outputs with RELOAD_OTHER. So
5037 we need only check for output addresses. */
5039 opnum = reload_n_operands;
5041 /* ... fall through ... */
5043 case RELOAD_FOR_OUTPUT:
5044 case RELOAD_FOR_OUTPUT_ADDRESS:
5045 case RELOAD_FOR_OUTADDR_ADDRESS:
5046 /* We already know these can't conflict with a later output. So the
5047 only thing to check are later output addresses.
5048 Note that multiple output operands are emitted in reverse order,
5049 so the conflicting ones are those with lower indices. */
5050 for (i = 0; i < opnum; i++)
5051 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
5052 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno))
5062 /* Like reload_reg_reaches_end_p, but check that the condition holds for
5063 every register in the range [REGNO, REGNO + NREGS). */
5066 reload_regs_reach_end_p (unsigned int regno, int nregs,
5067 int opnum, enum reload_type type)
5071 for (i = 0; i < nregs; i++)
5072 if (!reload_reg_reaches_end_p (regno + i, opnum, type))
5078 /* Returns whether R1 and R2 are uniquely chained: the value of one
5079 is used by the other, and that value is not used by any other
5080 reload for this insn. This is used to partially undo the decision
5081 made in find_reloads when in the case of multiple
5082 RELOAD_FOR_OPERAND_ADDRESS reloads it converts all
5083 RELOAD_FOR_OPADDR_ADDR reloads into RELOAD_FOR_OPERAND_ADDRESS
5084 reloads. This code tries to avoid the conflict created by that
5085 change. It might be cleaner to explicitly keep track of which
5086 RELOAD_FOR_OPADDR_ADDR reload is associated with which
5087 RELOAD_FOR_OPERAND_ADDRESS reload, rather than to try to detect
5088 this after the fact. */
5090 reloads_unique_chain_p (int r1, int r2)
5094 /* We only check input reloads. */
5095 if (! rld[r1].in || ! rld[r2].in)
5098 /* Avoid anything with output reloads. */
5099 if (rld[r1].out || rld[r2].out)
5102 /* "chained" means one reload is a component of the other reload,
5103 not the same as the other reload. */
5104 if (rld[r1].opnum != rld[r2].opnum
5105 || rtx_equal_p (rld[r1].in, rld[r2].in)
5106 || rld[r1].optional || rld[r2].optional
5107 || ! (reg_mentioned_p (rld[r1].in, rld[r2].in)
5108 || reg_mentioned_p (rld[r2].in, rld[r1].in)))
5111 for (i = 0; i < n_reloads; i ++)
5112 /* Look for input reloads that aren't our two */
5113 if (i != r1 && i != r2 && rld[i].in)
5115 /* If our reload is mentioned at all, it isn't a simple chain. */
5116 if (reg_mentioned_p (rld[r1].in, rld[i].in))
5123 /* The recursive function change all occurrences of WHAT in *WHERE
5126 substitute (rtx *where, const_rtx what, rtx repl)
5135 if (*where == what || rtx_equal_p (*where, what))
5141 code = GET_CODE (*where);
5142 fmt = GET_RTX_FORMAT (code);
5143 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
5149 for (j = XVECLEN (*where, i) - 1; j >= 0; j--)
5150 substitute (&XVECEXP (*where, i, j), what, repl);
5152 else if (fmt[i] == 'e')
5153 substitute (&XEXP (*where, i), what, repl);
5157 /* The function returns TRUE if chain of reload R1 and R2 (in any
5158 order) can be evaluated without usage of intermediate register for
5159 the reload containing another reload. It is important to see
5160 gen_reload to understand what the function is trying to do. As an
5161 example, let us have reload chain
5164 r1: <something> + const
5166 and reload R2 got reload reg HR. The function returns true if
5167 there is a correct insn HR = HR + <something>. Otherwise,
5168 gen_reload will use intermediate register (and this is the reload
5169 reg for R1) to reload <something>.
5171 We need this function to find a conflict for chain reloads. In our
5172 example, if HR = HR + <something> is incorrect insn, then we cannot
5173 use HR as a reload register for R2. If we do use it then we get a
5182 gen_reload_chain_without_interm_reg_p (int r1, int r2)
5186 rtx out, in, tem, insn;
5187 rtx last = get_last_insn ();
5189 /* Make r2 a component of r1. */
5190 if (reg_mentioned_p (rld[r1].in, rld[r2].in))
5196 gcc_assert (reg_mentioned_p (rld[r2].in, rld[r1].in));
5197 regno = rld[r1].regno >= 0 ? rld[r1].regno : rld[r2].regno;
5198 gcc_assert (regno >= 0);
5199 out = gen_rtx_REG (rld[r1].mode, regno);
5200 in = copy_rtx (rld[r1].in);
5201 substitute (&in, rld[r2].in, gen_rtx_REG (rld[r2].mode, regno));
5203 /* If IN is a paradoxical SUBREG, remove it and try to put the
5204 opposite SUBREG on OUT. Likewise for a paradoxical SUBREG on OUT. */
5205 if (GET_CODE (in) == SUBREG
5206 && (GET_MODE_SIZE (GET_MODE (in))
5207 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))))
5208 && (tem = gen_lowpart_common (GET_MODE (SUBREG_REG (in)), out)) != 0)
5209 in = SUBREG_REG (in), out = tem;
5211 if (GET_CODE (in) == PLUS
5212 && (REG_P (XEXP (in, 0))
5213 || GET_CODE (XEXP (in, 0)) == SUBREG
5214 || MEM_P (XEXP (in, 0)))
5215 && (REG_P (XEXP (in, 1))
5216 || GET_CODE (XEXP (in, 1)) == SUBREG
5217 || CONSTANT_P (XEXP (in, 1))
5218 || MEM_P (XEXP (in, 1))))
5220 insn = emit_insn (gen_rtx_SET (VOIDmode, out, in));
5221 code = recog_memoized (insn);
5226 extract_insn (insn);
5227 /* We want constrain operands to treat this insn strictly in
5228 its validity determination, i.e., the way it would after
5229 reload has completed. */
5230 result = constrain_operands (1);
5233 delete_insns_since (last);
5237 /* It looks like other cases in gen_reload are not possible for
5238 chain reloads or do need an intermediate hard registers. */
5242 /* Return 1 if the reloads denoted by R1 and R2 cannot share a register.
5245 This function uses the same algorithm as reload_reg_free_p above. */
5248 reloads_conflict (int r1, int r2)
5250 enum reload_type r1_type = rld[r1].when_needed;
5251 enum reload_type r2_type = rld[r2].when_needed;
5252 int r1_opnum = rld[r1].opnum;
5253 int r2_opnum = rld[r2].opnum;
5255 /* RELOAD_OTHER conflicts with everything. */
5256 if (r2_type == RELOAD_OTHER)
5259 /* Otherwise, check conflicts differently for each type. */
5263 case RELOAD_FOR_INPUT:
5264 return (r2_type == RELOAD_FOR_INSN
5265 || r2_type == RELOAD_FOR_OPERAND_ADDRESS
5266 || r2_type == RELOAD_FOR_OPADDR_ADDR
5267 || r2_type == RELOAD_FOR_INPUT
5268 || ((r2_type == RELOAD_FOR_INPUT_ADDRESS
5269 || r2_type == RELOAD_FOR_INPADDR_ADDRESS)
5270 && r2_opnum > r1_opnum));
5272 case RELOAD_FOR_INPUT_ADDRESS:
5273 return ((r2_type == RELOAD_FOR_INPUT_ADDRESS && r1_opnum == r2_opnum)
5274 || (r2_type == RELOAD_FOR_INPUT && r2_opnum < r1_opnum));
5276 case RELOAD_FOR_INPADDR_ADDRESS:
5277 return ((r2_type == RELOAD_FOR_INPADDR_ADDRESS && r1_opnum == r2_opnum)
5278 || (r2_type == RELOAD_FOR_INPUT && r2_opnum < r1_opnum));
5280 case RELOAD_FOR_OUTPUT_ADDRESS:
5281 return ((r2_type == RELOAD_FOR_OUTPUT_ADDRESS && r2_opnum == r1_opnum)
5282 || (r2_type == RELOAD_FOR_OUTPUT && r2_opnum <= r1_opnum));
5284 case RELOAD_FOR_OUTADDR_ADDRESS:
5285 return ((r2_type == RELOAD_FOR_OUTADDR_ADDRESS && r2_opnum == r1_opnum)
5286 || (r2_type == RELOAD_FOR_OUTPUT && r2_opnum <= r1_opnum));
5288 case RELOAD_FOR_OPERAND_ADDRESS:
5289 return (r2_type == RELOAD_FOR_INPUT || r2_type == RELOAD_FOR_INSN
5290 || (r2_type == RELOAD_FOR_OPERAND_ADDRESS
5291 && (!reloads_unique_chain_p (r1, r2)
5292 || !gen_reload_chain_without_interm_reg_p (r1, r2))));
5294 case RELOAD_FOR_OPADDR_ADDR:
5295 return (r2_type == RELOAD_FOR_INPUT
5296 || r2_type == RELOAD_FOR_OPADDR_ADDR);
5298 case RELOAD_FOR_OUTPUT:
5299 return (r2_type == RELOAD_FOR_INSN || r2_type == RELOAD_FOR_OUTPUT
5300 || ((r2_type == RELOAD_FOR_OUTPUT_ADDRESS
5301 || r2_type == RELOAD_FOR_OUTADDR_ADDRESS)
5302 && r2_opnum >= r1_opnum));
5304 case RELOAD_FOR_INSN:
5305 return (r2_type == RELOAD_FOR_INPUT || r2_type == RELOAD_FOR_OUTPUT
5306 || r2_type == RELOAD_FOR_INSN
5307 || r2_type == RELOAD_FOR_OPERAND_ADDRESS);
5309 case RELOAD_FOR_OTHER_ADDRESS:
5310 return r2_type == RELOAD_FOR_OTHER_ADDRESS;
5320 /* Indexed by reload number, 1 if incoming value
5321 inherited from previous insns. */
5322 static char reload_inherited[MAX_RELOADS];
5324 /* For an inherited reload, this is the insn the reload was inherited from,
5325 if we know it. Otherwise, this is 0. */
5326 static rtx reload_inheritance_insn[MAX_RELOADS];
5328 /* If nonzero, this is a place to get the value of the reload,
5329 rather than using reload_in. */
5330 static rtx reload_override_in[MAX_RELOADS];
5332 /* For each reload, the hard register number of the register used,
5333 or -1 if we did not need a register for this reload. */
5334 static int reload_spill_index[MAX_RELOADS];
5336 /* Index X is the value of rld[X].reg_rtx, adjusted for the input mode. */
5337 static rtx reload_reg_rtx_for_input[MAX_RELOADS];
5339 /* Index X is the value of rld[X].reg_rtx, adjusted for the output mode. */
5340 static rtx reload_reg_rtx_for_output[MAX_RELOADS];
5342 /* Subroutine of free_for_value_p, used to check a single register.
5343 START_REGNO is the starting regno of the full reload register
5344 (possibly comprising multiple hard registers) that we are considering. */
5347 reload_reg_free_for_value_p (int start_regno, int regno, int opnum,
5348 enum reload_type type, rtx value, rtx out,
5349 int reloadnum, int ignore_address_reloads)
5352 /* Set if we see an input reload that must not share its reload register
5353 with any new earlyclobber, but might otherwise share the reload
5354 register with an output or input-output reload. */
5355 int check_earlyclobber = 0;
5359 if (TEST_HARD_REG_BIT (reload_reg_unavailable, regno))
5362 if (out == const0_rtx)
5368 /* We use some pseudo 'time' value to check if the lifetimes of the
5369 new register use would overlap with the one of a previous reload
5370 that is not read-only or uses a different value.
5371 The 'time' used doesn't have to be linear in any shape or form, just
5373 Some reload types use different 'buckets' for each operand.
5374 So there are MAX_RECOG_OPERANDS different time values for each
5376 We compute TIME1 as the time when the register for the prospective
5377 new reload ceases to be live, and TIME2 for each existing
5378 reload as the time when that the reload register of that reload
5380 Where there is little to be gained by exact lifetime calculations,
5381 we just make conservative assumptions, i.e. a longer lifetime;
5382 this is done in the 'default:' cases. */
5385 case RELOAD_FOR_OTHER_ADDRESS:
5386 /* RELOAD_FOR_OTHER_ADDRESS conflicts with RELOAD_OTHER reloads. */
5387 time1 = copy ? 0 : 1;
5390 time1 = copy ? 1 : MAX_RECOG_OPERANDS * 5 + 5;
5392 /* For each input, we may have a sequence of RELOAD_FOR_INPADDR_ADDRESS,
5393 RELOAD_FOR_INPUT_ADDRESS and RELOAD_FOR_INPUT. By adding 0 / 1 / 2 ,
5394 respectively, to the time values for these, we get distinct time
5395 values. To get distinct time values for each operand, we have to
5396 multiply opnum by at least three. We round that up to four because
5397 multiply by four is often cheaper. */
5398 case RELOAD_FOR_INPADDR_ADDRESS:
5399 time1 = opnum * 4 + 2;
5401 case RELOAD_FOR_INPUT_ADDRESS:
5402 time1 = opnum * 4 + 3;
5404 case RELOAD_FOR_INPUT:
5405 /* All RELOAD_FOR_INPUT reloads remain live till the instruction
5406 executes (inclusive). */
5407 time1 = copy ? opnum * 4 + 4 : MAX_RECOG_OPERANDS * 4 + 3;
5409 case RELOAD_FOR_OPADDR_ADDR:
5411 <= (MAX_RECOG_OPERANDS - 1) * 4 + 4 == MAX_RECOG_OPERANDS * 4 */
5412 time1 = MAX_RECOG_OPERANDS * 4 + 1;
5414 case RELOAD_FOR_OPERAND_ADDRESS:
5415 /* RELOAD_FOR_OPERAND_ADDRESS reloads are live even while the insn
5417 time1 = copy ? MAX_RECOG_OPERANDS * 4 + 2 : MAX_RECOG_OPERANDS * 4 + 3;
5419 case RELOAD_FOR_OUTADDR_ADDRESS:
5420 time1 = MAX_RECOG_OPERANDS * 4 + 4 + opnum;
5422 case RELOAD_FOR_OUTPUT_ADDRESS:
5423 time1 = MAX_RECOG_OPERANDS * 4 + 5 + opnum;
5426 time1 = MAX_RECOG_OPERANDS * 5 + 5;
5429 for (i = 0; i < n_reloads; i++)
5431 rtx reg = rld[i].reg_rtx;
5432 if (reg && REG_P (reg)
5433 && ((unsigned) regno - true_regnum (reg)
5434 <= hard_regno_nregs[REGNO (reg)][GET_MODE (reg)] - (unsigned) 1)
5437 rtx other_input = rld[i].in;
5439 /* If the other reload loads the same input value, that
5440 will not cause a conflict only if it's loading it into
5441 the same register. */
5442 if (true_regnum (reg) != start_regno)
5443 other_input = NULL_RTX;
5444 if (! other_input || ! rtx_equal_p (other_input, value)
5445 || rld[i].out || out)
5448 switch (rld[i].when_needed)
5450 case RELOAD_FOR_OTHER_ADDRESS:
5453 case RELOAD_FOR_INPADDR_ADDRESS:
5454 /* find_reloads makes sure that a
5455 RELOAD_FOR_{INP,OP,OUT}ADDR_ADDRESS reload is only used
5456 by at most one - the first -
5457 RELOAD_FOR_{INPUT,OPERAND,OUTPUT}_ADDRESS . If the
5458 address reload is inherited, the address address reload
5459 goes away, so we can ignore this conflict. */
5460 if (type == RELOAD_FOR_INPUT_ADDRESS && reloadnum == i + 1
5461 && ignore_address_reloads
5462 /* Unless the RELOAD_FOR_INPUT is an auto_inc expression.
5463 Then the address address is still needed to store
5464 back the new address. */
5465 && ! rld[reloadnum].out)
5467 /* Likewise, if a RELOAD_FOR_INPUT can inherit a value, its
5468 RELOAD_FOR_INPUT_ADDRESS / RELOAD_FOR_INPADDR_ADDRESS
5470 if (type == RELOAD_FOR_INPUT && opnum == rld[i].opnum
5471 && ignore_address_reloads
5472 /* Unless we are reloading an auto_inc expression. */
5473 && ! rld[reloadnum].out)
5475 time2 = rld[i].opnum * 4 + 2;
5477 case RELOAD_FOR_INPUT_ADDRESS:
5478 if (type == RELOAD_FOR_INPUT && opnum == rld[i].opnum
5479 && ignore_address_reloads
5480 && ! rld[reloadnum].out)
5482 time2 = rld[i].opnum * 4 + 3;
5484 case RELOAD_FOR_INPUT:
5485 time2 = rld[i].opnum * 4 + 4;
5486 check_earlyclobber = 1;
5488 /* rld[i].opnum * 4 + 4 <= (MAX_RECOG_OPERAND - 1) * 4 + 4
5489 == MAX_RECOG_OPERAND * 4 */
5490 case RELOAD_FOR_OPADDR_ADDR:
5491 if (type == RELOAD_FOR_OPERAND_ADDRESS && reloadnum == i + 1
5492 && ignore_address_reloads
5493 && ! rld[reloadnum].out)
5495 time2 = MAX_RECOG_OPERANDS * 4 + 1;
5497 case RELOAD_FOR_OPERAND_ADDRESS:
5498 time2 = MAX_RECOG_OPERANDS * 4 + 2;
5499 check_earlyclobber = 1;
5501 case RELOAD_FOR_INSN:
5502 time2 = MAX_RECOG_OPERANDS * 4 + 3;
5504 case RELOAD_FOR_OUTPUT:
5505 /* All RELOAD_FOR_OUTPUT reloads become live just after the
5506 instruction is executed. */
5507 time2 = MAX_RECOG_OPERANDS * 4 + 4;
5509 /* The first RELOAD_FOR_OUTADDR_ADDRESS reload conflicts with
5510 the RELOAD_FOR_OUTPUT reloads, so assign it the same time
5512 case RELOAD_FOR_OUTADDR_ADDRESS:
5513 if (type == RELOAD_FOR_OUTPUT_ADDRESS && reloadnum == i + 1
5514 && ignore_address_reloads
5515 && ! rld[reloadnum].out)
5517 time2 = MAX_RECOG_OPERANDS * 4 + 4 + rld[i].opnum;
5519 case RELOAD_FOR_OUTPUT_ADDRESS:
5520 time2 = MAX_RECOG_OPERANDS * 4 + 5 + rld[i].opnum;
5523 /* If there is no conflict in the input part, handle this
5524 like an output reload. */
5525 if (! rld[i].in || rtx_equal_p (other_input, value))
5527 time2 = MAX_RECOG_OPERANDS * 4 + 4;
5528 /* Earlyclobbered outputs must conflict with inputs. */
5529 if (earlyclobber_operand_p (rld[i].out))
5530 time2 = MAX_RECOG_OPERANDS * 4 + 3;
5535 /* RELOAD_OTHER might be live beyond instruction execution,
5536 but this is not obvious when we set time2 = 1. So check
5537 here if there might be a problem with the new reload
5538 clobbering the register used by the RELOAD_OTHER. */
5546 && (! rld[i].in || rld[i].out
5547 || ! rtx_equal_p (other_input, value)))
5548 || (out && rld[reloadnum].out_reg
5549 && time2 >= MAX_RECOG_OPERANDS * 4 + 3))
5555 /* Earlyclobbered outputs must conflict with inputs. */
5556 if (check_earlyclobber && out && earlyclobber_operand_p (out))
5562 /* Return 1 if the value in reload reg REGNO, as used by a reload
5563 needed for the part of the insn specified by OPNUM and TYPE,
5564 may be used to load VALUE into it.
5566 MODE is the mode in which the register is used, this is needed to
5567 determine how many hard regs to test.
5569 Other read-only reloads with the same value do not conflict
5570 unless OUT is nonzero and these other reloads have to live while
5571 output reloads live.
5572 If OUT is CONST0_RTX, this is a special case: it means that the
5573 test should not be for using register REGNO as reload register, but
5574 for copying from register REGNO into the reload register.
5576 RELOADNUM is the number of the reload we want to load this value for;
5577 a reload does not conflict with itself.
5579 When IGNORE_ADDRESS_RELOADS is set, we can not have conflicts with
5580 reloads that load an address for the very reload we are considering.
5582 The caller has to make sure that there is no conflict with the return
5586 free_for_value_p (int regno, enum machine_mode mode, int opnum,
5587 enum reload_type type, rtx value, rtx out, int reloadnum,
5588 int ignore_address_reloads)
5590 int nregs = hard_regno_nregs[regno][mode];
5592 if (! reload_reg_free_for_value_p (regno, regno + nregs, opnum, type,
5593 value, out, reloadnum,
5594 ignore_address_reloads))
5599 /* Return nonzero if the rtx X is invariant over the current function. */
5600 /* ??? Actually, the places where we use this expect exactly what is
5601 tested here, and not everything that is function invariant. In
5602 particular, the frame pointer and arg pointer are special cased;
5603 pic_offset_table_rtx is not, and we must not spill these things to
5607 function_invariant_p (const_rtx x)
5611 if (x == frame_pointer_rtx || x == arg_pointer_rtx)
5613 if (GET_CODE (x) == PLUS
5614 && (XEXP (x, 0) == frame_pointer_rtx || XEXP (x, 0) == arg_pointer_rtx)
5615 && CONSTANT_P (XEXP (x, 1)))
5620 /* Determine whether the reload reg X overlaps any rtx'es used for
5621 overriding inheritance. Return nonzero if so. */
5624 conflicts_with_override (rtx x)
5627 for (i = 0; i < n_reloads; i++)
5628 if (reload_override_in[i]
5629 && reg_overlap_mentioned_p (x, reload_override_in[i]))
5634 /* Give an error message saying we failed to find a reload for INSN,
5635 and clear out reload R. */
5637 failed_reload (rtx insn, int r)
5639 if (asm_noperands (PATTERN (insn)) < 0)
5640 /* It's the compiler's fault. */
5641 fatal_insn ("could not find a spill register", insn);
5643 /* It's the user's fault; the operand's mode and constraint
5644 don't match. Disable this reload so we don't crash in final. */
5645 error_for_asm (insn,
5646 "%<asm%> operand constraint incompatible with operand size");
5650 rld[r].optional = 1;
5651 rld[r].secondary_p = 1;
5654 /* I is the index in SPILL_REG_RTX of the reload register we are to allocate
5655 for reload R. If it's valid, get an rtx for it. Return nonzero if
5658 set_reload_reg (int i, int r)
5661 rtx reg = spill_reg_rtx[i];
5663 if (reg == 0 || GET_MODE (reg) != rld[r].mode)
5664 spill_reg_rtx[i] = reg
5665 = gen_rtx_REG (rld[r].mode, spill_regs[i]);
5667 regno = true_regnum (reg);
5669 /* Detect when the reload reg can't hold the reload mode.
5670 This used to be one `if', but Sequent compiler can't handle that. */
5671 if (HARD_REGNO_MODE_OK (regno, rld[r].mode))
5673 enum machine_mode test_mode = VOIDmode;
5675 test_mode = GET_MODE (rld[r].in);
5676 /* If rld[r].in has VOIDmode, it means we will load it
5677 in whatever mode the reload reg has: to wit, rld[r].mode.
5678 We have already tested that for validity. */
5679 /* Aside from that, we need to test that the expressions
5680 to reload from or into have modes which are valid for this
5681 reload register. Otherwise the reload insns would be invalid. */
5682 if (! (rld[r].in != 0 && test_mode != VOIDmode
5683 && ! HARD_REGNO_MODE_OK (regno, test_mode)))
5684 if (! (rld[r].out != 0
5685 && ! HARD_REGNO_MODE_OK (regno, GET_MODE (rld[r].out))))
5687 /* The reg is OK. */
5690 /* Mark as in use for this insn the reload regs we use
5692 mark_reload_reg_in_use (spill_regs[i], rld[r].opnum,
5693 rld[r].when_needed, rld[r].mode);
5695 rld[r].reg_rtx = reg;
5696 reload_spill_index[r] = spill_regs[i];
5703 /* Find a spill register to use as a reload register for reload R.
5704 LAST_RELOAD is nonzero if this is the last reload for the insn being
5707 Set rld[R].reg_rtx to the register allocated.
5709 We return 1 if successful, or 0 if we couldn't find a spill reg and
5710 we didn't change anything. */
5713 allocate_reload_reg (struct insn_chain *chain ATTRIBUTE_UNUSED, int r,
5718 /* If we put this reload ahead, thinking it is a group,
5719 then insist on finding a group. Otherwise we can grab a
5720 reg that some other reload needs.
5721 (That can happen when we have a 68000 DATA_OR_FP_REG
5722 which is a group of data regs or one fp reg.)
5723 We need not be so restrictive if there are no more reloads
5726 ??? Really it would be nicer to have smarter handling
5727 for that kind of reg class, where a problem like this is normal.
5728 Perhaps those classes should be avoided for reloading
5729 by use of more alternatives. */
5731 int force_group = rld[r].nregs > 1 && ! last_reload;
5733 /* If we want a single register and haven't yet found one,
5734 take any reg in the right class and not in use.
5735 If we want a consecutive group, here is where we look for it.
5737 We use two passes so we can first look for reload regs to
5738 reuse, which are already in use for other reloads in this insn,
5739 and only then use additional registers.
5740 I think that maximizing reuse is needed to make sure we don't
5741 run out of reload regs. Suppose we have three reloads, and
5742 reloads A and B can share regs. These need two regs.
5743 Suppose A and B are given different regs.
5744 That leaves none for C. */
5745 for (pass = 0; pass < 2; pass++)
5747 /* I is the index in spill_regs.
5748 We advance it round-robin between insns to use all spill regs
5749 equally, so that inherited reloads have a chance
5750 of leapfrogging each other. */
5754 for (count = 0; count < n_spills; count++)
5756 int rclass = (int) rld[r].rclass;
5762 regnum = spill_regs[i];
5764 if ((reload_reg_free_p (regnum, rld[r].opnum,
5767 /* We check reload_reg_used to make sure we
5768 don't clobber the return register. */
5769 && ! TEST_HARD_REG_BIT (reload_reg_used, regnum)
5770 && free_for_value_p (regnum, rld[r].mode, rld[r].opnum,
5771 rld[r].when_needed, rld[r].in,
5773 && TEST_HARD_REG_BIT (reg_class_contents[rclass], regnum)
5774 && HARD_REGNO_MODE_OK (regnum, rld[r].mode)
5775 /* Look first for regs to share, then for unshared. But
5776 don't share regs used for inherited reloads; they are
5777 the ones we want to preserve. */
5779 || (TEST_HARD_REG_BIT (reload_reg_used_at_all,
5781 && ! TEST_HARD_REG_BIT (reload_reg_used_for_inherit,
5784 int nr = hard_regno_nregs[regnum][rld[r].mode];
5785 /* Avoid the problem where spilling a GENERAL_OR_FP_REG
5786 (on 68000) got us two FP regs. If NR is 1,
5787 we would reject both of them. */
5790 /* If we need only one reg, we have already won. */
5793 /* But reject a single reg if we demand a group. */
5798 /* Otherwise check that as many consecutive regs as we need
5799 are available here. */
5802 int regno = regnum + nr - 1;
5803 if (!(TEST_HARD_REG_BIT (reg_class_contents[rclass], regno)
5804 && spill_reg_order[regno] >= 0
5805 && reload_reg_free_p (regno, rld[r].opnum,
5806 rld[r].when_needed)))
5815 /* If we found something on pass 1, omit pass 2. */
5816 if (count < n_spills)
5820 /* We should have found a spill register by now. */
5821 if (count >= n_spills)
5824 /* I is the index in SPILL_REG_RTX of the reload register we are to
5825 allocate. Get an rtx for it and find its register number. */
5827 return set_reload_reg (i, r);
5830 /* Initialize all the tables needed to allocate reload registers.
5831 CHAIN is the insn currently being processed; SAVE_RELOAD_REG_RTX
5832 is the array we use to restore the reg_rtx field for every reload. */
5835 choose_reload_regs_init (struct insn_chain *chain, rtx *save_reload_reg_rtx)
5839 for (i = 0; i < n_reloads; i++)
5840 rld[i].reg_rtx = save_reload_reg_rtx[i];
5842 memset (reload_inherited, 0, MAX_RELOADS);
5843 memset (reload_inheritance_insn, 0, MAX_RELOADS * sizeof (rtx));
5844 memset (reload_override_in, 0, MAX_RELOADS * sizeof (rtx));
5846 CLEAR_HARD_REG_SET (reload_reg_used);
5847 CLEAR_HARD_REG_SET (reload_reg_used_at_all);
5848 CLEAR_HARD_REG_SET (reload_reg_used_in_op_addr);
5849 CLEAR_HARD_REG_SET (reload_reg_used_in_op_addr_reload);
5850 CLEAR_HARD_REG_SET (reload_reg_used_in_insn);
5851 CLEAR_HARD_REG_SET (reload_reg_used_in_other_addr);
5853 CLEAR_HARD_REG_SET (reg_used_in_insn);
5856 REG_SET_TO_HARD_REG_SET (tmp, &chain->live_throughout);
5857 IOR_HARD_REG_SET (reg_used_in_insn, tmp);
5858 REG_SET_TO_HARD_REG_SET (tmp, &chain->dead_or_set);
5859 IOR_HARD_REG_SET (reg_used_in_insn, tmp);
5860 compute_use_by_pseudos (®_used_in_insn, &chain->live_throughout);
5861 compute_use_by_pseudos (®_used_in_insn, &chain->dead_or_set);
5864 for (i = 0; i < reload_n_operands; i++)
5866 CLEAR_HARD_REG_SET (reload_reg_used_in_output[i]);
5867 CLEAR_HARD_REG_SET (reload_reg_used_in_input[i]);
5868 CLEAR_HARD_REG_SET (reload_reg_used_in_input_addr[i]);
5869 CLEAR_HARD_REG_SET (reload_reg_used_in_inpaddr_addr[i]);
5870 CLEAR_HARD_REG_SET (reload_reg_used_in_output_addr[i]);
5871 CLEAR_HARD_REG_SET (reload_reg_used_in_outaddr_addr[i]);
5874 COMPL_HARD_REG_SET (reload_reg_unavailable, chain->used_spill_regs);
5876 CLEAR_HARD_REG_SET (reload_reg_used_for_inherit);
5878 for (i = 0; i < n_reloads; i++)
5879 /* If we have already decided to use a certain register,
5880 don't use it in another way. */
5882 mark_reload_reg_in_use (REGNO (rld[i].reg_rtx), rld[i].opnum,
5883 rld[i].when_needed, rld[i].mode);
5886 /* Assign hard reg targets for the pseudo-registers we must reload
5887 into hard regs for this insn.
5888 Also output the instructions to copy them in and out of the hard regs.
5890 For machines with register classes, we are responsible for
5891 finding a reload reg in the proper class. */
5894 choose_reload_regs (struct insn_chain *chain)
5896 rtx insn = chain->insn;
5898 unsigned int max_group_size = 1;
5899 enum reg_class group_class = NO_REGS;
5900 int pass, win, inheritance;
5902 rtx save_reload_reg_rtx[MAX_RELOADS];
5904 /* In order to be certain of getting the registers we need,
5905 we must sort the reloads into order of increasing register class.
5906 Then our grabbing of reload registers will parallel the process
5907 that provided the reload registers.
5909 Also note whether any of the reloads wants a consecutive group of regs.
5910 If so, record the maximum size of the group desired and what
5911 register class contains all the groups needed by this insn. */
5913 for (j = 0; j < n_reloads; j++)
5915 reload_order[j] = j;
5916 if (rld[j].reg_rtx != NULL_RTX)
5918 gcc_assert (REG_P (rld[j].reg_rtx)
5919 && HARD_REGISTER_P (rld[j].reg_rtx));
5920 reload_spill_index[j] = REGNO (rld[j].reg_rtx);
5923 reload_spill_index[j] = -1;
5925 if (rld[j].nregs > 1)
5927 max_group_size = MAX (rld[j].nregs, max_group_size);
5929 = reg_class_superunion[(int) rld[j].rclass][(int) group_class];
5932 save_reload_reg_rtx[j] = rld[j].reg_rtx;
5936 qsort (reload_order, n_reloads, sizeof (short), reload_reg_class_lower);
5938 /* If -O, try first with inheritance, then turning it off.
5939 If not -O, don't do inheritance.
5940 Using inheritance when not optimizing leads to paradoxes
5941 with fp on the 68k: fp numbers (not NaNs) fail to be equal to themselves
5942 because one side of the comparison might be inherited. */
5944 for (inheritance = optimize > 0; inheritance >= 0; inheritance--)
5946 choose_reload_regs_init (chain, save_reload_reg_rtx);
5948 /* Process the reloads in order of preference just found.
5949 Beyond this point, subregs can be found in reload_reg_rtx.
5951 This used to look for an existing reloaded home for all of the
5952 reloads, and only then perform any new reloads. But that could lose
5953 if the reloads were done out of reg-class order because a later
5954 reload with a looser constraint might have an old home in a register
5955 needed by an earlier reload with a tighter constraint.
5957 To solve this, we make two passes over the reloads, in the order
5958 described above. In the first pass we try to inherit a reload
5959 from a previous insn. If there is a later reload that needs a
5960 class that is a proper subset of the class being processed, we must
5961 also allocate a spill register during the first pass.
5963 Then make a second pass over the reloads to allocate any reloads
5964 that haven't been given registers yet. */
5966 for (j = 0; j < n_reloads; j++)
5968 int r = reload_order[j];
5969 rtx search_equiv = NULL_RTX;
5971 /* Ignore reloads that got marked inoperative. */
5972 if (rld[r].out == 0 && rld[r].in == 0
5973 && ! rld[r].secondary_p)
5976 /* If find_reloads chose to use reload_in or reload_out as a reload
5977 register, we don't need to chose one. Otherwise, try even if it
5978 found one since we might save an insn if we find the value lying
5980 Try also when reload_in is a pseudo without a hard reg. */
5981 if (rld[r].in != 0 && rld[r].reg_rtx != 0
5982 && (rtx_equal_p (rld[r].in, rld[r].reg_rtx)
5983 || (rtx_equal_p (rld[r].out, rld[r].reg_rtx)
5984 && !MEM_P (rld[r].in)
5985 && true_regnum (rld[r].in) < FIRST_PSEUDO_REGISTER)))
5988 #if 0 /* No longer needed for correct operation.
5989 It might give better code, or might not; worth an experiment? */
5990 /* If this is an optional reload, we can't inherit from earlier insns
5991 until we are sure that any non-optional reloads have been allocated.
5992 The following code takes advantage of the fact that optional reloads
5993 are at the end of reload_order. */
5994 if (rld[r].optional != 0)
5995 for (i = 0; i < j; i++)
5996 if ((rld[reload_order[i]].out != 0
5997 || rld[reload_order[i]].in != 0
5998 || rld[reload_order[i]].secondary_p)
5999 && ! rld[reload_order[i]].optional
6000 && rld[reload_order[i]].reg_rtx == 0)
6001 allocate_reload_reg (chain, reload_order[i], 0);
6004 /* First see if this pseudo is already available as reloaded
6005 for a previous insn. We cannot try to inherit for reloads
6006 that are smaller than the maximum number of registers needed
6007 for groups unless the register we would allocate cannot be used
6010 We could check here to see if this is a secondary reload for
6011 an object that is already in a register of the desired class.
6012 This would avoid the need for the secondary reload register.
6013 But this is complex because we can't easily determine what
6014 objects might want to be loaded via this reload. So let a
6015 register be allocated here. In `emit_reload_insns' we suppress
6016 one of the loads in the case described above. */
6022 enum machine_mode mode = VOIDmode;
6026 else if (REG_P (rld[r].in))
6028 regno = REGNO (rld[r].in);
6029 mode = GET_MODE (rld[r].in);
6031 else if (REG_P (rld[r].in_reg))
6033 regno = REGNO (rld[r].in_reg);
6034 mode = GET_MODE (rld[r].in_reg);
6036 else if (GET_CODE (rld[r].in_reg) == SUBREG
6037 && REG_P (SUBREG_REG (rld[r].in_reg)))
6039 regno = REGNO (SUBREG_REG (rld[r].in_reg));
6040 if (regno < FIRST_PSEUDO_REGISTER)
6041 regno = subreg_regno (rld[r].in_reg);
6043 byte = SUBREG_BYTE (rld[r].in_reg);
6044 mode = GET_MODE (rld[r].in_reg);
6047 else if (GET_RTX_CLASS (GET_CODE (rld[r].in_reg)) == RTX_AUTOINC
6048 && REG_P (XEXP (rld[r].in_reg, 0)))
6050 regno = REGNO (XEXP (rld[r].in_reg, 0));
6051 mode = GET_MODE (XEXP (rld[r].in_reg, 0));
6052 rld[r].out = rld[r].in;
6056 /* This won't work, since REGNO can be a pseudo reg number.
6057 Also, it takes much more hair to keep track of all the things
6058 that can invalidate an inherited reload of part of a pseudoreg. */
6059 else if (GET_CODE (rld[r].in) == SUBREG
6060 && REG_P (SUBREG_REG (rld[r].in)))
6061 regno = subreg_regno (rld[r].in);
6065 && reg_last_reload_reg[regno] != 0
6066 #ifdef CANNOT_CHANGE_MODE_CLASS
6067 /* Verify that the register it's in can be used in
6069 && !REG_CANNOT_CHANGE_MODE_P (REGNO (reg_last_reload_reg[regno]),
6070 GET_MODE (reg_last_reload_reg[regno]),
6075 enum reg_class rclass = rld[r].rclass, last_class;
6076 rtx last_reg = reg_last_reload_reg[regno];
6077 enum machine_mode need_mode;
6079 i = REGNO (last_reg);
6080 i += subreg_regno_offset (i, GET_MODE (last_reg), byte, mode);
6081 last_class = REGNO_REG_CLASS (i);
6087 = smallest_mode_for_size
6088 (GET_MODE_BITSIZE (mode) + byte * BITS_PER_UNIT,
6089 GET_MODE_CLASS (mode) == MODE_PARTIAL_INT
6090 ? MODE_INT : GET_MODE_CLASS (mode));
6092 if ((GET_MODE_SIZE (GET_MODE (last_reg))
6093 >= GET_MODE_SIZE (need_mode))
6094 && reg_reloaded_contents[i] == regno
6095 && TEST_HARD_REG_BIT (reg_reloaded_valid, i)
6096 && HARD_REGNO_MODE_OK (i, rld[r].mode)
6097 && (TEST_HARD_REG_BIT (reg_class_contents[(int) rclass], i)
6098 /* Even if we can't use this register as a reload
6099 register, we might use it for reload_override_in,
6100 if copying it to the desired class is cheap
6102 || ((REGISTER_MOVE_COST (mode, last_class, rclass)
6103 < MEMORY_MOVE_COST (mode, rclass, 1))
6104 && (secondary_reload_class (1, rclass, mode,
6107 #ifdef SECONDARY_MEMORY_NEEDED
6108 && ! SECONDARY_MEMORY_NEEDED (last_class, rclass,
6113 && (rld[r].nregs == max_group_size
6114 || ! TEST_HARD_REG_BIT (reg_class_contents[(int) group_class],
6116 && free_for_value_p (i, rld[r].mode, rld[r].opnum,
6117 rld[r].when_needed, rld[r].in,
6120 /* If a group is needed, verify that all the subsequent
6121 registers still have their values intact. */
6122 int nr = hard_regno_nregs[i][rld[r].mode];
6125 for (k = 1; k < nr; k++)
6126 if (reg_reloaded_contents[i + k] != regno
6127 || ! TEST_HARD_REG_BIT (reg_reloaded_valid, i + k))
6135 last_reg = (GET_MODE (last_reg) == mode
6136 ? last_reg : gen_rtx_REG (mode, i));
6139 for (k = 0; k < nr; k++)
6140 bad_for_class |= ! TEST_HARD_REG_BIT (reg_class_contents[(int) rld[r].rclass],
6143 /* We found a register that contains the
6144 value we need. If this register is the
6145 same as an `earlyclobber' operand of the
6146 current insn, just mark it as a place to
6147 reload from since we can't use it as the
6148 reload register itself. */
6150 for (i1 = 0; i1 < n_earlyclobbers; i1++)
6151 if (reg_overlap_mentioned_for_reload_p
6152 (reg_last_reload_reg[regno],
6153 reload_earlyclobbers[i1]))
6156 if (i1 != n_earlyclobbers
6157 || ! (free_for_value_p (i, rld[r].mode,
6159 rld[r].when_needed, rld[r].in,
6161 /* Don't use it if we'd clobber a pseudo reg. */
6162 || (TEST_HARD_REG_BIT (reg_used_in_insn, i)
6164 && ! TEST_HARD_REG_BIT (reg_reloaded_dead, i))
6165 /* Don't clobber the frame pointer. */
6166 || (i == HARD_FRAME_POINTER_REGNUM
6167 && frame_pointer_needed
6169 /* Don't really use the inherited spill reg
6170 if we need it wider than we've got it. */
6171 || (GET_MODE_SIZE (rld[r].mode)
6172 > GET_MODE_SIZE (mode))
6175 /* If find_reloads chose reload_out as reload
6176 register, stay with it - that leaves the
6177 inherited register for subsequent reloads. */
6178 || (rld[r].out && rld[r].reg_rtx
6179 && rtx_equal_p (rld[r].out, rld[r].reg_rtx)))
6181 if (! rld[r].optional)
6183 reload_override_in[r] = last_reg;
6184 reload_inheritance_insn[r]
6185 = reg_reloaded_insn[i];
6191 /* We can use this as a reload reg. */
6192 /* Mark the register as in use for this part of
6194 mark_reload_reg_in_use (i,
6198 rld[r].reg_rtx = last_reg;
6199 reload_inherited[r] = 1;
6200 reload_inheritance_insn[r]
6201 = reg_reloaded_insn[i];
6202 reload_spill_index[r] = i;
6203 for (k = 0; k < nr; k++)
6204 SET_HARD_REG_BIT (reload_reg_used_for_inherit,
6212 /* Here's another way to see if the value is already lying around. */
6215 && ! reload_inherited[r]
6217 && (CONSTANT_P (rld[r].in)
6218 || GET_CODE (rld[r].in) == PLUS
6219 || REG_P (rld[r].in)
6220 || MEM_P (rld[r].in))
6221 && (rld[r].nregs == max_group_size
6222 || ! reg_classes_intersect_p (rld[r].rclass, group_class)))
6223 search_equiv = rld[r].in;
6224 /* If this is an output reload from a simple move insn, look
6225 if an equivalence for the input is available. */
6226 else if (inheritance && rld[r].in == 0 && rld[r].out != 0)
6228 rtx set = single_set (insn);
6231 && rtx_equal_p (rld[r].out, SET_DEST (set))
6232 && CONSTANT_P (SET_SRC (set)))
6233 search_equiv = SET_SRC (set);
6239 = find_equiv_reg (search_equiv, insn, rld[r].rclass,
6240 -1, NULL, 0, rld[r].mode);
6246 regno = REGNO (equiv);
6249 /* This must be a SUBREG of a hard register.
6250 Make a new REG since this might be used in an
6251 address and not all machines support SUBREGs
6253 gcc_assert (GET_CODE (equiv) == SUBREG);
6254 regno = subreg_regno (equiv);
6255 equiv = gen_rtx_REG (rld[r].mode, regno);
6256 /* If we choose EQUIV as the reload register, but the
6257 loop below decides to cancel the inheritance, we'll
6258 end up reloading EQUIV in rld[r].mode, not the mode
6259 it had originally. That isn't safe when EQUIV isn't
6260 available as a spill register since its value might
6261 still be live at this point. */
6262 for (i = regno; i < regno + (int) rld[r].nregs; i++)
6263 if (TEST_HARD_REG_BIT (reload_reg_unavailable, i))
6268 /* If we found a spill reg, reject it unless it is free
6269 and of the desired class. */
6273 int bad_for_class = 0;
6274 int max_regno = regno + rld[r].nregs;
6276 for (i = regno; i < max_regno; i++)
6278 regs_used |= TEST_HARD_REG_BIT (reload_reg_used_at_all,
6280 bad_for_class |= ! TEST_HARD_REG_BIT (reg_class_contents[(int) rld[r].rclass],
6285 && ! free_for_value_p (regno, rld[r].mode,
6286 rld[r].opnum, rld[r].when_needed,
6287 rld[r].in, rld[r].out, r, 1))
6292 if (equiv != 0 && ! HARD_REGNO_MODE_OK (regno, rld[r].mode))
6295 /* We found a register that contains the value we need.
6296 If this register is the same as an `earlyclobber' operand
6297 of the current insn, just mark it as a place to reload from
6298 since we can't use it as the reload register itself. */
6301 for (i = 0; i < n_earlyclobbers; i++)
6302 if (reg_overlap_mentioned_for_reload_p (equiv,
6303 reload_earlyclobbers[i]))
6305 if (! rld[r].optional)
6306 reload_override_in[r] = equiv;
6311 /* If the equiv register we have found is explicitly clobbered
6312 in the current insn, it depends on the reload type if we
6313 can use it, use it for reload_override_in, or not at all.
6314 In particular, we then can't use EQUIV for a
6315 RELOAD_FOR_OUTPUT_ADDRESS reload. */
6319 if (regno_clobbered_p (regno, insn, rld[r].mode, 2))
6320 switch (rld[r].when_needed)
6322 case RELOAD_FOR_OTHER_ADDRESS:
6323 case RELOAD_FOR_INPADDR_ADDRESS:
6324 case RELOAD_FOR_INPUT_ADDRESS:
6325 case RELOAD_FOR_OPADDR_ADDR:
6328 case RELOAD_FOR_INPUT:
6329 case RELOAD_FOR_OPERAND_ADDRESS:
6330 if (! rld[r].optional)
6331 reload_override_in[r] = equiv;
6337 else if (regno_clobbered_p (regno, insn, rld[r].mode, 1))
6338 switch (rld[r].when_needed)
6340 case RELOAD_FOR_OTHER_ADDRESS:
6341 case RELOAD_FOR_INPADDR_ADDRESS:
6342 case RELOAD_FOR_INPUT_ADDRESS:
6343 case RELOAD_FOR_OPADDR_ADDR:
6344 case RELOAD_FOR_OPERAND_ADDRESS:
6345 case RELOAD_FOR_INPUT:
6348 if (! rld[r].optional)
6349 reload_override_in[r] = equiv;
6357 /* If we found an equivalent reg, say no code need be generated
6358 to load it, and use it as our reload reg. */
6360 && (regno != HARD_FRAME_POINTER_REGNUM
6361 || !frame_pointer_needed))
6363 int nr = hard_regno_nregs[regno][rld[r].mode];
6365 rld[r].reg_rtx = equiv;
6366 reload_spill_index[r] = regno;
6367 reload_inherited[r] = 1;
6369 /* If reg_reloaded_valid is not set for this register,
6370 there might be a stale spill_reg_store lying around.
6371 We must clear it, since otherwise emit_reload_insns
6372 might delete the store. */
6373 if (! TEST_HARD_REG_BIT (reg_reloaded_valid, regno))
6374 spill_reg_store[regno] = NULL_RTX;
6375 /* If any of the hard registers in EQUIV are spill
6376 registers, mark them as in use for this insn. */
6377 for (k = 0; k < nr; k++)
6379 i = spill_reg_order[regno + k];
6382 mark_reload_reg_in_use (regno, rld[r].opnum,
6385 SET_HARD_REG_BIT (reload_reg_used_for_inherit,
6392 /* If we found a register to use already, or if this is an optional
6393 reload, we are done. */
6394 if (rld[r].reg_rtx != 0 || rld[r].optional != 0)
6398 /* No longer needed for correct operation. Might or might
6399 not give better code on the average. Want to experiment? */
6401 /* See if there is a later reload that has a class different from our
6402 class that intersects our class or that requires less register
6403 than our reload. If so, we must allocate a register to this
6404 reload now, since that reload might inherit a previous reload
6405 and take the only available register in our class. Don't do this
6406 for optional reloads since they will force all previous reloads
6407 to be allocated. Also don't do this for reloads that have been
6410 for (i = j + 1; i < n_reloads; i++)
6412 int s = reload_order[i];
6414 if ((rld[s].in == 0 && rld[s].out == 0
6415 && ! rld[s].secondary_p)
6419 if ((rld[s].rclass != rld[r].rclass
6420 && reg_classes_intersect_p (rld[r].rclass,
6422 || rld[s].nregs < rld[r].nregs)
6429 allocate_reload_reg (chain, r, j == n_reloads - 1);
6433 /* Now allocate reload registers for anything non-optional that
6434 didn't get one yet. */
6435 for (j = 0; j < n_reloads; j++)
6437 int r = reload_order[j];
6439 /* Ignore reloads that got marked inoperative. */
6440 if (rld[r].out == 0 && rld[r].in == 0 && ! rld[r].secondary_p)
6443 /* Skip reloads that already have a register allocated or are
6445 if (rld[r].reg_rtx != 0 || rld[r].optional)
6448 if (! allocate_reload_reg (chain, r, j == n_reloads - 1))
6452 /* If that loop got all the way, we have won. */
6459 /* Loop around and try without any inheritance. */
6464 /* First undo everything done by the failed attempt
6465 to allocate with inheritance. */
6466 choose_reload_regs_init (chain, save_reload_reg_rtx);
6468 /* Some sanity tests to verify that the reloads found in the first
6469 pass are identical to the ones we have now. */
6470 gcc_assert (chain->n_reloads == n_reloads);
6472 for (i = 0; i < n_reloads; i++)
6474 if (chain->rld[i].regno < 0 || chain->rld[i].reg_rtx != 0)
6476 gcc_assert (chain->rld[i].when_needed == rld[i].when_needed);
6477 for (j = 0; j < n_spills; j++)
6478 if (spill_regs[j] == chain->rld[i].regno)
6479 if (! set_reload_reg (j, i))
6480 failed_reload (chain->insn, i);
6484 /* If we thought we could inherit a reload, because it seemed that
6485 nothing else wanted the same reload register earlier in the insn,
6486 verify that assumption, now that all reloads have been assigned.
6487 Likewise for reloads where reload_override_in has been set. */
6489 /* If doing expensive optimizations, do one preliminary pass that doesn't
6490 cancel any inheritance, but removes reloads that have been needed only
6491 for reloads that we know can be inherited. */
6492 for (pass = flag_expensive_optimizations; pass >= 0; pass--)
6494 for (j = 0; j < n_reloads; j++)
6496 int r = reload_order[j];
6498 if (reload_inherited[r] && rld[r].reg_rtx)
6499 check_reg = rld[r].reg_rtx;
6500 else if (reload_override_in[r]
6501 && (REG_P (reload_override_in[r])
6502 || GET_CODE (reload_override_in[r]) == SUBREG))
6503 check_reg = reload_override_in[r];
6506 if (! free_for_value_p (true_regnum (check_reg), rld[r].mode,
6507 rld[r].opnum, rld[r].when_needed, rld[r].in,
6508 (reload_inherited[r]
6509 ? rld[r].out : const0_rtx),
6514 reload_inherited[r] = 0;
6515 reload_override_in[r] = 0;
6517 /* If we can inherit a RELOAD_FOR_INPUT, or can use a
6518 reload_override_in, then we do not need its related
6519 RELOAD_FOR_INPUT_ADDRESS / RELOAD_FOR_INPADDR_ADDRESS reloads;
6520 likewise for other reload types.
6521 We handle this by removing a reload when its only replacement
6522 is mentioned in reload_in of the reload we are going to inherit.
6523 A special case are auto_inc expressions; even if the input is
6524 inherited, we still need the address for the output. We can
6525 recognize them because they have RELOAD_OUT set to RELOAD_IN.
6526 If we succeeded removing some reload and we are doing a preliminary
6527 pass just to remove such reloads, make another pass, since the
6528 removal of one reload might allow us to inherit another one. */
6530 && rld[r].out != rld[r].in
6531 && remove_address_replacements (rld[r].in) && pass)
6536 /* Now that reload_override_in is known valid,
6537 actually override reload_in. */
6538 for (j = 0; j < n_reloads; j++)
6539 if (reload_override_in[j])
6540 rld[j].in = reload_override_in[j];
6542 /* If this reload won't be done because it has been canceled or is
6543 optional and not inherited, clear reload_reg_rtx so other
6544 routines (such as subst_reloads) don't get confused. */
6545 for (j = 0; j < n_reloads; j++)
6546 if (rld[j].reg_rtx != 0
6547 && ((rld[j].optional && ! reload_inherited[j])
6548 || (rld[j].in == 0 && rld[j].out == 0
6549 && ! rld[j].secondary_p)))
6551 int regno = true_regnum (rld[j].reg_rtx);
6553 if (spill_reg_order[regno] >= 0)
6554 clear_reload_reg_in_use (regno, rld[j].opnum,
6555 rld[j].when_needed, rld[j].mode);
6557 reload_spill_index[j] = -1;
6560 /* Record which pseudos and which spill regs have output reloads. */
6561 for (j = 0; j < n_reloads; j++)
6563 int r = reload_order[j];
6565 i = reload_spill_index[r];
6567 /* I is nonneg if this reload uses a register.
6568 If rld[r].reg_rtx is 0, this is an optional reload
6569 that we opted to ignore. */
6570 if (rld[r].out_reg != 0 && REG_P (rld[r].out_reg)
6571 && rld[r].reg_rtx != 0)
6573 int nregno = REGNO (rld[r].out_reg);
6576 if (nregno < FIRST_PSEUDO_REGISTER)
6577 nr = hard_regno_nregs[nregno][rld[r].mode];
6580 SET_REGNO_REG_SET (®_has_output_reload,
6585 nr = hard_regno_nregs[i][rld[r].mode];
6587 SET_HARD_REG_BIT (reg_is_output_reload, i + nr);
6590 gcc_assert (rld[r].when_needed == RELOAD_OTHER
6591 || rld[r].when_needed == RELOAD_FOR_OUTPUT
6592 || rld[r].when_needed == RELOAD_FOR_INSN);
6597 /* Deallocate the reload register for reload R. This is called from
6598 remove_address_replacements. */
6601 deallocate_reload_reg (int r)
6605 if (! rld[r].reg_rtx)
6607 regno = true_regnum (rld[r].reg_rtx);
6609 if (spill_reg_order[regno] >= 0)
6610 clear_reload_reg_in_use (regno, rld[r].opnum, rld[r].when_needed,
6612 reload_spill_index[r] = -1;
6615 /* If SMALL_REGISTER_CLASSES is nonzero, we may not have merged two
6616 reloads of the same item for fear that we might not have enough reload
6617 registers. However, normally they will get the same reload register
6618 and hence actually need not be loaded twice.
6620 Here we check for the most common case of this phenomenon: when we have
6621 a number of reloads for the same object, each of which were allocated
6622 the same reload_reg_rtx, that reload_reg_rtx is not used for any other
6623 reload, and is not modified in the insn itself. If we find such,
6624 merge all the reloads and set the resulting reload to RELOAD_OTHER.
6625 This will not increase the number of spill registers needed and will
6626 prevent redundant code. */
6629 merge_assigned_reloads (rtx insn)
6633 /* Scan all the reloads looking for ones that only load values and
6634 are not already RELOAD_OTHER and ones whose reload_reg_rtx are
6635 assigned and not modified by INSN. */
6637 for (i = 0; i < n_reloads; i++)
6639 int conflicting_input = 0;
6640 int max_input_address_opnum = -1;
6641 int min_conflicting_input_opnum = MAX_RECOG_OPERANDS;
6643 if (rld[i].in == 0 || rld[i].when_needed == RELOAD_OTHER
6644 || rld[i].out != 0 || rld[i].reg_rtx == 0
6645 || reg_set_p (rld[i].reg_rtx, insn))
6648 /* Look at all other reloads. Ensure that the only use of this
6649 reload_reg_rtx is in a reload that just loads the same value
6650 as we do. Note that any secondary reloads must be of the identical
6651 class since the values, modes, and result registers are the
6652 same, so we need not do anything with any secondary reloads. */
6654 for (j = 0; j < n_reloads; j++)
6656 if (i == j || rld[j].reg_rtx == 0
6657 || ! reg_overlap_mentioned_p (rld[j].reg_rtx,
6661 if (rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
6662 && rld[j].opnum > max_input_address_opnum)
6663 max_input_address_opnum = rld[j].opnum;
6665 /* If the reload regs aren't exactly the same (e.g, different modes)
6666 or if the values are different, we can't merge this reload.
6667 But if it is an input reload, we might still merge
6668 RELOAD_FOR_INPUT_ADDRESS and RELOAD_FOR_OTHER_ADDRESS reloads. */
6670 if (! rtx_equal_p (rld[i].reg_rtx, rld[j].reg_rtx)
6671 || rld[j].out != 0 || rld[j].in == 0
6672 || ! rtx_equal_p (rld[i].in, rld[j].in))
6674 if (rld[j].when_needed != RELOAD_FOR_INPUT
6675 || ((rld[i].when_needed != RELOAD_FOR_INPUT_ADDRESS
6676 || rld[i].opnum > rld[j].opnum)
6677 && rld[i].when_needed != RELOAD_FOR_OTHER_ADDRESS))
6679 conflicting_input = 1;
6680 if (min_conflicting_input_opnum > rld[j].opnum)
6681 min_conflicting_input_opnum = rld[j].opnum;
6685 /* If all is OK, merge the reloads. Only set this to RELOAD_OTHER if
6686 we, in fact, found any matching reloads. */
6689 && max_input_address_opnum <= min_conflicting_input_opnum)
6691 gcc_assert (rld[i].when_needed != RELOAD_FOR_OUTPUT);
6693 for (j = 0; j < n_reloads; j++)
6694 if (i != j && rld[j].reg_rtx != 0
6695 && rtx_equal_p (rld[i].reg_rtx, rld[j].reg_rtx)
6696 && (! conflicting_input
6697 || rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
6698 || rld[j].when_needed == RELOAD_FOR_OTHER_ADDRESS))
6700 rld[i].when_needed = RELOAD_OTHER;
6702 reload_spill_index[j] = -1;
6703 transfer_replacements (i, j);
6706 /* If this is now RELOAD_OTHER, look for any reloads that
6707 load parts of this operand and set them to
6708 RELOAD_FOR_OTHER_ADDRESS if they were for inputs,
6709 RELOAD_OTHER for outputs. Note that this test is
6710 equivalent to looking for reloads for this operand
6713 We must take special care with RELOAD_FOR_OUTPUT_ADDRESS;
6714 it may share registers with a RELOAD_FOR_INPUT, so we can
6715 not change it to RELOAD_FOR_OTHER_ADDRESS. We should
6716 never need to, since we do not modify RELOAD_FOR_OUTPUT.
6718 It is possible that the RELOAD_FOR_OPERAND_ADDRESS
6719 instruction is assigned the same register as the earlier
6720 RELOAD_FOR_OTHER_ADDRESS instruction. Merging these two
6721 instructions will cause the RELOAD_FOR_OTHER_ADDRESS
6722 instruction to be deleted later on. */
6724 if (rld[i].when_needed == RELOAD_OTHER)
6725 for (j = 0; j < n_reloads; j++)
6727 && rld[j].when_needed != RELOAD_OTHER
6728 && rld[j].when_needed != RELOAD_FOR_OTHER_ADDRESS
6729 && rld[j].when_needed != RELOAD_FOR_OUTPUT_ADDRESS
6730 && rld[j].when_needed != RELOAD_FOR_OPERAND_ADDRESS
6731 && (! conflicting_input
6732 || rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
6733 || rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
6734 && reg_overlap_mentioned_for_reload_p (rld[j].in,
6740 = ((rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
6741 || rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
6742 ? RELOAD_FOR_OTHER_ADDRESS : RELOAD_OTHER);
6744 /* Check to see if we accidentally converted two
6745 reloads that use the same reload register with
6746 different inputs to the same type. If so, the
6747 resulting code won't work. */
6749 for (k = 0; k < j; k++)
6750 gcc_assert (rld[k].in == 0 || rld[k].reg_rtx == 0
6751 || rld[k].when_needed != rld[j].when_needed
6752 || !rtx_equal_p (rld[k].reg_rtx,
6754 || rtx_equal_p (rld[k].in,
6761 /* These arrays are filled by emit_reload_insns and its subroutines. */
6762 static rtx input_reload_insns[MAX_RECOG_OPERANDS];
6763 static rtx other_input_address_reload_insns = 0;
6764 static rtx other_input_reload_insns = 0;
6765 static rtx input_address_reload_insns[MAX_RECOG_OPERANDS];
6766 static rtx inpaddr_address_reload_insns[MAX_RECOG_OPERANDS];
6767 static rtx output_reload_insns[MAX_RECOG_OPERANDS];
6768 static rtx output_address_reload_insns[MAX_RECOG_OPERANDS];
6769 static rtx outaddr_address_reload_insns[MAX_RECOG_OPERANDS];
6770 static rtx operand_reload_insns = 0;
6771 static rtx other_operand_reload_insns = 0;
6772 static rtx other_output_reload_insns[MAX_RECOG_OPERANDS];
6774 /* Values to be put in spill_reg_store are put here first. */
6775 static rtx new_spill_reg_store[FIRST_PSEUDO_REGISTER];
6776 static HARD_REG_SET reg_reloaded_died;
6778 /* Check if *RELOAD_REG is suitable as an intermediate or scratch register
6779 of class NEW_CLASS with mode NEW_MODE. Or alternatively, if alt_reload_reg
6780 is nonzero, if that is suitable. On success, change *RELOAD_REG to the
6781 adjusted register, and return true. Otherwise, return false. */
6783 reload_adjust_reg_for_temp (rtx *reload_reg, rtx alt_reload_reg,
6784 enum reg_class new_class,
6785 enum machine_mode new_mode)
6790 for (reg = *reload_reg; reg; reg = alt_reload_reg, alt_reload_reg = 0)
6792 unsigned regno = REGNO (reg);
6794 if (!TEST_HARD_REG_BIT (reg_class_contents[(int) new_class], regno))
6796 if (GET_MODE (reg) != new_mode)
6798 if (!HARD_REGNO_MODE_OK (regno, new_mode))
6800 if (hard_regno_nregs[regno][new_mode]
6801 > hard_regno_nregs[regno][GET_MODE (reg)])
6803 reg = reload_adjust_reg_for_mode (reg, new_mode);
6811 /* Check if *RELOAD_REG is suitable as a scratch register for the reload
6812 pattern with insn_code ICODE, or alternatively, if alt_reload_reg is
6813 nonzero, if that is suitable. On success, change *RELOAD_REG to the
6814 adjusted register, and return true. Otherwise, return false. */
6816 reload_adjust_reg_for_icode (rtx *reload_reg, rtx alt_reload_reg,
6817 enum insn_code icode)
6820 enum reg_class new_class = scratch_reload_class (icode);
6821 enum machine_mode new_mode = insn_data[(int) icode].operand[2].mode;
6823 return reload_adjust_reg_for_temp (reload_reg, alt_reload_reg,
6824 new_class, new_mode);
6827 /* Generate insns to perform reload RL, which is for the insn in CHAIN and
6828 has the number J. OLD contains the value to be used as input. */
6831 emit_input_reload_insns (struct insn_chain *chain, struct reload *rl,
6834 rtx insn = chain->insn;
6836 rtx oldequiv_reg = 0;
6839 enum machine_mode mode;
6842 /* delete_output_reload is only invoked properly if old contains
6843 the original pseudo register. Since this is replaced with a
6844 hard reg when RELOAD_OVERRIDE_IN is set, see if we can
6845 find the pseudo in RELOAD_IN_REG. */
6846 if (reload_override_in[j]
6847 && REG_P (rl->in_reg))
6854 else if (REG_P (oldequiv))
6855 oldequiv_reg = oldequiv;
6856 else if (GET_CODE (oldequiv) == SUBREG)
6857 oldequiv_reg = SUBREG_REG (oldequiv);
6859 reloadreg = reload_reg_rtx_for_input[j];
6860 mode = GET_MODE (reloadreg);
6862 /* If we are reloading from a register that was recently stored in
6863 with an output-reload, see if we can prove there was
6864 actually no need to store the old value in it. */
6866 if (optimize && REG_P (oldequiv)
6867 && REGNO (oldequiv) < FIRST_PSEUDO_REGISTER
6868 && spill_reg_store[REGNO (oldequiv)]
6870 && (dead_or_set_p (insn, spill_reg_stored_to[REGNO (oldequiv)])
6871 || rtx_equal_p (spill_reg_stored_to[REGNO (oldequiv)],
6873 delete_output_reload (insn, j, REGNO (oldequiv), reloadreg);
6875 /* Encapsulate OLDEQUIV into the reload mode, then load RELOADREG from
6878 while (GET_CODE (oldequiv) == SUBREG && GET_MODE (oldequiv) != mode)
6879 oldequiv = SUBREG_REG (oldequiv);
6880 if (GET_MODE (oldequiv) != VOIDmode
6881 && mode != GET_MODE (oldequiv))
6882 oldequiv = gen_lowpart_SUBREG (mode, oldequiv);
6884 /* Switch to the right place to emit the reload insns. */
6885 switch (rl->when_needed)
6888 where = &other_input_reload_insns;
6890 case RELOAD_FOR_INPUT:
6891 where = &input_reload_insns[rl->opnum];
6893 case RELOAD_FOR_INPUT_ADDRESS:
6894 where = &input_address_reload_insns[rl->opnum];
6896 case RELOAD_FOR_INPADDR_ADDRESS:
6897 where = &inpaddr_address_reload_insns[rl->opnum];
6899 case RELOAD_FOR_OUTPUT_ADDRESS:
6900 where = &output_address_reload_insns[rl->opnum];
6902 case RELOAD_FOR_OUTADDR_ADDRESS:
6903 where = &outaddr_address_reload_insns[rl->opnum];
6905 case RELOAD_FOR_OPERAND_ADDRESS:
6906 where = &operand_reload_insns;
6908 case RELOAD_FOR_OPADDR_ADDR:
6909 where = &other_operand_reload_insns;
6911 case RELOAD_FOR_OTHER_ADDRESS:
6912 where = &other_input_address_reload_insns;
6918 push_to_sequence (*where);
6920 /* Auto-increment addresses must be reloaded in a special way. */
6921 if (rl->out && ! rl->out_reg)
6923 /* We are not going to bother supporting the case where a
6924 incremented register can't be copied directly from
6925 OLDEQUIV since this seems highly unlikely. */
6926 gcc_assert (rl->secondary_in_reload < 0);
6928 if (reload_inherited[j])
6929 oldequiv = reloadreg;
6931 old = XEXP (rl->in_reg, 0);
6933 if (optimize && REG_P (oldequiv)
6934 && REGNO (oldequiv) < FIRST_PSEUDO_REGISTER
6935 && spill_reg_store[REGNO (oldequiv)]
6937 && (dead_or_set_p (insn,
6938 spill_reg_stored_to[REGNO (oldequiv)])
6939 || rtx_equal_p (spill_reg_stored_to[REGNO (oldequiv)],
6941 delete_output_reload (insn, j, REGNO (oldequiv), reloadreg);
6943 /* Prevent normal processing of this reload. */
6945 /* Output a special code sequence for this case. */
6946 new_spill_reg_store[REGNO (reloadreg)]
6947 = inc_for_reload (reloadreg, oldequiv, rl->out,
6951 /* If we are reloading a pseudo-register that was set by the previous
6952 insn, see if we can get rid of that pseudo-register entirely
6953 by redirecting the previous insn into our reload register. */
6955 else if (optimize && REG_P (old)
6956 && REGNO (old) >= FIRST_PSEUDO_REGISTER
6957 && dead_or_set_p (insn, old)
6958 /* This is unsafe if some other reload
6959 uses the same reg first. */
6960 && ! conflicts_with_override (reloadreg)
6961 && free_for_value_p (REGNO (reloadreg), rl->mode, rl->opnum,
6962 rl->when_needed, old, rl->out, j, 0))
6964 rtx temp = PREV_INSN (insn);
6965 while (temp && NOTE_P (temp))
6966 temp = PREV_INSN (temp);
6968 && NONJUMP_INSN_P (temp)
6969 && GET_CODE (PATTERN (temp)) == SET
6970 && SET_DEST (PATTERN (temp)) == old
6971 /* Make sure we can access insn_operand_constraint. */
6972 && asm_noperands (PATTERN (temp)) < 0
6973 /* This is unsafe if operand occurs more than once in current
6974 insn. Perhaps some occurrences aren't reloaded. */
6975 && count_occurrences (PATTERN (insn), old, 0) == 1)
6977 rtx old = SET_DEST (PATTERN (temp));
6978 /* Store into the reload register instead of the pseudo. */
6979 SET_DEST (PATTERN (temp)) = reloadreg;
6981 /* Verify that resulting insn is valid. */
6982 extract_insn (temp);
6983 if (constrain_operands (1))
6985 /* If the previous insn is an output reload, the source is
6986 a reload register, and its spill_reg_store entry will
6987 contain the previous destination. This is now
6989 if (REG_P (SET_SRC (PATTERN (temp)))
6990 && REGNO (SET_SRC (PATTERN (temp))) < FIRST_PSEUDO_REGISTER)
6992 spill_reg_store[REGNO (SET_SRC (PATTERN (temp)))] = 0;
6993 spill_reg_stored_to[REGNO (SET_SRC (PATTERN (temp)))] = 0;
6996 /* If these are the only uses of the pseudo reg,
6997 pretend for GDB it lives in the reload reg we used. */
6998 if (REG_N_DEATHS (REGNO (old)) == 1
6999 && REG_N_SETS (REGNO (old)) == 1)
7001 reg_renumber[REGNO (old)] = REGNO (reloadreg);
7002 if (flag_ira && optimize)
7003 /* Inform IRA about the change. */
7004 ira_mark_allocation_change (REGNO (old));
7005 alter_reg (REGNO (old), -1, false);
7011 SET_DEST (PATTERN (temp)) = old;
7016 /* We can't do that, so output an insn to load RELOADREG. */
7018 /* If we have a secondary reload, pick up the secondary register
7019 and icode, if any. If OLDEQUIV and OLD are different or
7020 if this is an in-out reload, recompute whether or not we
7021 still need a secondary register and what the icode should
7022 be. If we still need a secondary register and the class or
7023 icode is different, go back to reloading from OLD if using
7024 OLDEQUIV means that we got the wrong type of register. We
7025 cannot have different class or icode due to an in-out reload
7026 because we don't make such reloads when both the input and
7027 output need secondary reload registers. */
7029 if (! special && rl->secondary_in_reload >= 0)
7031 rtx second_reload_reg = 0;
7032 rtx third_reload_reg = 0;
7033 int secondary_reload = rl->secondary_in_reload;
7034 rtx real_oldequiv = oldequiv;
7037 enum insn_code icode;
7038 enum insn_code tertiary_icode = CODE_FOR_nothing;
7040 /* If OLDEQUIV is a pseudo with a MEM, get the real MEM
7041 and similarly for OLD.
7042 See comments in get_secondary_reload in reload.c. */
7043 /* If it is a pseudo that cannot be replaced with its
7044 equivalent MEM, we must fall back to reload_in, which
7045 will have all the necessary substitutions registered.
7046 Likewise for a pseudo that can't be replaced with its
7047 equivalent constant.
7049 Take extra care for subregs of such pseudos. Note that
7050 we cannot use reg_equiv_mem in this case because it is
7051 not in the right mode. */
7054 if (GET_CODE (tmp) == SUBREG)
7055 tmp = SUBREG_REG (tmp);
7057 && REGNO (tmp) >= FIRST_PSEUDO_REGISTER
7058 && (reg_equiv_memory_loc[REGNO (tmp)] != 0
7059 || reg_equiv_constant[REGNO (tmp)] != 0))
7061 if (! reg_equiv_mem[REGNO (tmp)]
7062 || num_not_at_initial_offset
7063 || GET_CODE (oldequiv) == SUBREG)
7064 real_oldequiv = rl->in;
7066 real_oldequiv = reg_equiv_mem[REGNO (tmp)];
7070 if (GET_CODE (tmp) == SUBREG)
7071 tmp = SUBREG_REG (tmp);
7073 && REGNO (tmp) >= FIRST_PSEUDO_REGISTER
7074 && (reg_equiv_memory_loc[REGNO (tmp)] != 0
7075 || reg_equiv_constant[REGNO (tmp)] != 0))
7077 if (! reg_equiv_mem[REGNO (tmp)]
7078 || num_not_at_initial_offset
7079 || GET_CODE (old) == SUBREG)
7082 real_old = reg_equiv_mem[REGNO (tmp)];
7085 second_reload_reg = rld[secondary_reload].reg_rtx;
7086 if (rld[secondary_reload].secondary_in_reload >= 0)
7088 int tertiary_reload = rld[secondary_reload].secondary_in_reload;
7090 third_reload_reg = rld[tertiary_reload].reg_rtx;
7091 tertiary_icode = rld[secondary_reload].secondary_in_icode;
7092 /* We'd have to add more code for quartary reloads. */
7093 gcc_assert (rld[tertiary_reload].secondary_in_reload < 0);
7095 icode = rl->secondary_in_icode;
7097 if ((old != oldequiv && ! rtx_equal_p (old, oldequiv))
7098 || (rl->in != 0 && rl->out != 0))
7100 secondary_reload_info sri, sri2;
7101 enum reg_class new_class, new_t_class;
7103 sri.icode = CODE_FOR_nothing;
7104 sri.prev_sri = NULL;
7105 new_class = targetm.secondary_reload (1, real_oldequiv, rl->rclass,
7108 if (new_class == NO_REGS && sri.icode == CODE_FOR_nothing)
7109 second_reload_reg = 0;
7110 else if (new_class == NO_REGS)
7112 if (reload_adjust_reg_for_icode (&second_reload_reg,
7113 third_reload_reg, sri.icode))
7114 icode = sri.icode, third_reload_reg = 0;
7116 oldequiv = old, real_oldequiv = real_old;
7118 else if (sri.icode != CODE_FOR_nothing)
7119 /* We currently lack a way to express this in reloads. */
7123 sri2.icode = CODE_FOR_nothing;
7124 sri2.prev_sri = &sri;
7125 new_t_class = targetm.secondary_reload (1, real_oldequiv,
7126 new_class, mode, &sri);
7127 if (new_t_class == NO_REGS && sri2.icode == CODE_FOR_nothing)
7129 if (reload_adjust_reg_for_temp (&second_reload_reg,
7132 third_reload_reg = 0, tertiary_icode = sri2.icode;
7134 oldequiv = old, real_oldequiv = real_old;
7136 else if (new_t_class == NO_REGS && sri2.icode != CODE_FOR_nothing)
7138 rtx intermediate = second_reload_reg;
7140 if (reload_adjust_reg_for_temp (&intermediate, NULL,
7142 && reload_adjust_reg_for_icode (&third_reload_reg, NULL,
7145 second_reload_reg = intermediate;
7146 tertiary_icode = sri2.icode;
7149 oldequiv = old, real_oldequiv = real_old;
7151 else if (new_t_class != NO_REGS && sri2.icode == CODE_FOR_nothing)
7153 rtx intermediate = second_reload_reg;
7155 if (reload_adjust_reg_for_temp (&intermediate, NULL,
7157 && reload_adjust_reg_for_temp (&third_reload_reg, NULL,
7160 second_reload_reg = intermediate;
7161 tertiary_icode = sri2.icode;
7164 oldequiv = old, real_oldequiv = real_old;
7167 /* This could be handled more intelligently too. */
7168 oldequiv = old, real_oldequiv = real_old;
7172 /* If we still need a secondary reload register, check
7173 to see if it is being used as a scratch or intermediate
7174 register and generate code appropriately. If we need
7175 a scratch register, use REAL_OLDEQUIV since the form of
7176 the insn may depend on the actual address if it is
7179 if (second_reload_reg)
7181 if (icode != CODE_FOR_nothing)
7183 /* We'd have to add extra code to handle this case. */
7184 gcc_assert (!third_reload_reg);
7186 emit_insn (GEN_FCN (icode) (reloadreg, real_oldequiv,
7187 second_reload_reg));
7192 /* See if we need a scratch register to load the
7193 intermediate register (a tertiary reload). */
7194 if (tertiary_icode != CODE_FOR_nothing)
7196 emit_insn ((GEN_FCN (tertiary_icode)
7197 (second_reload_reg, real_oldequiv,
7198 third_reload_reg)));
7200 else if (third_reload_reg)
7202 gen_reload (third_reload_reg, real_oldequiv,
7205 gen_reload (second_reload_reg, third_reload_reg,
7210 gen_reload (second_reload_reg, real_oldequiv,
7214 oldequiv = second_reload_reg;
7219 if (! special && ! rtx_equal_p (reloadreg, oldequiv))
7221 rtx real_oldequiv = oldequiv;
7223 if ((REG_P (oldequiv)
7224 && REGNO (oldequiv) >= FIRST_PSEUDO_REGISTER
7225 && (reg_equiv_memory_loc[REGNO (oldequiv)] != 0
7226 || reg_equiv_constant[REGNO (oldequiv)] != 0))
7227 || (GET_CODE (oldequiv) == SUBREG
7228 && REG_P (SUBREG_REG (oldequiv))
7229 && (REGNO (SUBREG_REG (oldequiv))
7230 >= FIRST_PSEUDO_REGISTER)
7231 && ((reg_equiv_memory_loc
7232 [REGNO (SUBREG_REG (oldequiv))] != 0)
7233 || (reg_equiv_constant
7234 [REGNO (SUBREG_REG (oldequiv))] != 0)))
7235 || (CONSTANT_P (oldequiv)
7236 && (PREFERRED_RELOAD_CLASS (oldequiv,
7237 REGNO_REG_CLASS (REGNO (reloadreg)))
7239 real_oldequiv = rl->in;
7240 gen_reload (reloadreg, real_oldequiv, rl->opnum,
7244 if (flag_non_call_exceptions)
7245 copy_eh_notes (insn, get_insns ());
7247 /* End this sequence. */
7248 *where = get_insns ();
7251 /* Update reload_override_in so that delete_address_reloads_1
7252 can see the actual register usage. */
7254 reload_override_in[j] = oldequiv;
7257 /* Generate insns to for the output reload RL, which is for the insn described
7258 by CHAIN and has the number J. */
7260 emit_output_reload_insns (struct insn_chain *chain, struct reload *rl,
7264 rtx insn = chain->insn;
7267 enum machine_mode mode;
7271 if (rl->when_needed == RELOAD_OTHER)
7274 push_to_sequence (output_reload_insns[rl->opnum]);
7276 rl_reg_rtx = reload_reg_rtx_for_output[j];
7277 mode = GET_MODE (rl_reg_rtx);
7279 reloadreg = rl_reg_rtx;
7281 /* If we need two reload regs, set RELOADREG to the intermediate
7282 one, since it will be stored into OLD. We might need a secondary
7283 register only for an input reload, so check again here. */
7285 if (rl->secondary_out_reload >= 0)
7288 int secondary_reload = rl->secondary_out_reload;
7289 int tertiary_reload = rld[secondary_reload].secondary_out_reload;
7291 if (REG_P (old) && REGNO (old) >= FIRST_PSEUDO_REGISTER
7292 && reg_equiv_mem[REGNO (old)] != 0)
7293 real_old = reg_equiv_mem[REGNO (old)];
7295 if (secondary_reload_class (0, rl->rclass, mode, real_old) != NO_REGS)
7297 rtx second_reloadreg = reloadreg;
7298 reloadreg = rld[secondary_reload].reg_rtx;
7300 /* See if RELOADREG is to be used as a scratch register
7301 or as an intermediate register. */
7302 if (rl->secondary_out_icode != CODE_FOR_nothing)
7304 /* We'd have to add extra code to handle this case. */
7305 gcc_assert (tertiary_reload < 0);
7307 emit_insn ((GEN_FCN (rl->secondary_out_icode)
7308 (real_old, second_reloadreg, reloadreg)));
7313 /* See if we need both a scratch and intermediate reload
7316 enum insn_code tertiary_icode
7317 = rld[secondary_reload].secondary_out_icode;
7319 /* We'd have to add more code for quartary reloads. */
7320 gcc_assert (tertiary_reload < 0
7321 || rld[tertiary_reload].secondary_out_reload < 0);
7323 if (GET_MODE (reloadreg) != mode)
7324 reloadreg = reload_adjust_reg_for_mode (reloadreg, mode);
7326 if (tertiary_icode != CODE_FOR_nothing)
7328 rtx third_reloadreg = rld[tertiary_reload].reg_rtx;
7331 /* Copy primary reload reg to secondary reload reg.
7332 (Note that these have been swapped above, then
7333 secondary reload reg to OLD using our insn.) */
7335 /* If REAL_OLD is a paradoxical SUBREG, remove it
7336 and try to put the opposite SUBREG on
7338 if (GET_CODE (real_old) == SUBREG
7339 && (GET_MODE_SIZE (GET_MODE (real_old))
7340 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (real_old))))
7341 && 0 != (tem = gen_lowpart_common
7342 (GET_MODE (SUBREG_REG (real_old)),
7344 real_old = SUBREG_REG (real_old), reloadreg = tem;
7346 gen_reload (reloadreg, second_reloadreg,
7347 rl->opnum, rl->when_needed);
7348 emit_insn ((GEN_FCN (tertiary_icode)
7349 (real_old, reloadreg, third_reloadreg)));
7355 /* Copy between the reload regs here and then to
7358 gen_reload (reloadreg, second_reloadreg,
7359 rl->opnum, rl->when_needed);
7360 if (tertiary_reload >= 0)
7362 rtx third_reloadreg = rld[tertiary_reload].reg_rtx;
7364 gen_reload (third_reloadreg, reloadreg,
7365 rl->opnum, rl->when_needed);
7366 reloadreg = third_reloadreg;
7373 /* Output the last reload insn. */
7378 /* Don't output the last reload if OLD is not the dest of
7379 INSN and is in the src and is clobbered by INSN. */
7380 if (! flag_expensive_optimizations
7382 || !(set = single_set (insn))
7383 || rtx_equal_p (old, SET_DEST (set))
7384 || !reg_mentioned_p (old, SET_SRC (set))
7385 || !((REGNO (old) < FIRST_PSEUDO_REGISTER)
7386 && regno_clobbered_p (REGNO (old), insn, rl->mode, 0)))
7387 gen_reload (old, reloadreg, rl->opnum,
7391 /* Look at all insns we emitted, just to be safe. */
7392 for (p = get_insns (); p; p = NEXT_INSN (p))
7395 rtx pat = PATTERN (p);
7397 /* If this output reload doesn't come from a spill reg,
7398 clear any memory of reloaded copies of the pseudo reg.
7399 If this output reload comes from a spill reg,
7400 reg_has_output_reload will make this do nothing. */
7401 note_stores (pat, forget_old_reloads_1, NULL);
7403 if (reg_mentioned_p (rl_reg_rtx, pat))
7405 rtx set = single_set (insn);
7406 if (reload_spill_index[j] < 0
7408 && SET_SRC (set) == rl_reg_rtx)
7410 int src = REGNO (SET_SRC (set));
7412 reload_spill_index[j] = src;
7413 SET_HARD_REG_BIT (reg_is_output_reload, src);
7414 if (find_regno_note (insn, REG_DEAD, src))
7415 SET_HARD_REG_BIT (reg_reloaded_died, src);
7417 if (HARD_REGISTER_P (rl_reg_rtx))
7419 int s = rl->secondary_out_reload;
7420 set = single_set (p);
7421 /* If this reload copies only to the secondary reload
7422 register, the secondary reload does the actual
7424 if (s >= 0 && set == NULL_RTX)
7425 /* We can't tell what function the secondary reload
7426 has and where the actual store to the pseudo is
7427 made; leave new_spill_reg_store alone. */
7430 && SET_SRC (set) == rl_reg_rtx
7431 && SET_DEST (set) == rld[s].reg_rtx)
7433 /* Usually the next instruction will be the
7434 secondary reload insn; if we can confirm
7435 that it is, setting new_spill_reg_store to
7436 that insn will allow an extra optimization. */
7437 rtx s_reg = rld[s].reg_rtx;
7438 rtx next = NEXT_INSN (p);
7439 rld[s].out = rl->out;
7440 rld[s].out_reg = rl->out_reg;
7441 set = single_set (next);
7442 if (set && SET_SRC (set) == s_reg
7443 && ! new_spill_reg_store[REGNO (s_reg)])
7445 SET_HARD_REG_BIT (reg_is_output_reload,
7447 new_spill_reg_store[REGNO (s_reg)] = next;
7451 new_spill_reg_store[REGNO (rl_reg_rtx)] = p;
7456 if (rl->when_needed == RELOAD_OTHER)
7458 emit_insn (other_output_reload_insns[rl->opnum]);
7459 other_output_reload_insns[rl->opnum] = get_insns ();
7462 output_reload_insns[rl->opnum] = get_insns ();
7464 if (flag_non_call_exceptions)
7465 copy_eh_notes (insn, get_insns ());
7470 /* Do input reloading for reload RL, which is for the insn described by CHAIN
7471 and has the number J. */
7473 do_input_reload (struct insn_chain *chain, struct reload *rl, int j)
7475 rtx insn = chain->insn;
7476 rtx old = (rl->in && MEM_P (rl->in)
7477 ? rl->in_reg : rl->in);
7478 rtx reg_rtx = rl->reg_rtx;
7482 enum machine_mode mode;
7484 /* Determine the mode to reload in.
7485 This is very tricky because we have three to choose from.
7486 There is the mode the insn operand wants (rl->inmode).
7487 There is the mode of the reload register RELOADREG.
7488 There is the intrinsic mode of the operand, which we could find
7489 by stripping some SUBREGs.
7490 It turns out that RELOADREG's mode is irrelevant:
7491 we can change that arbitrarily.
7493 Consider (SUBREG:SI foo:QI) as an operand that must be SImode;
7494 then the reload reg may not support QImode moves, so use SImode.
7495 If foo is in memory due to spilling a pseudo reg, this is safe,
7496 because the QImode value is in the least significant part of a
7497 slot big enough for a SImode. If foo is some other sort of
7498 memory reference, then it is impossible to reload this case,
7499 so previous passes had better make sure this never happens.
7501 Then consider a one-word union which has SImode and one of its
7502 members is a float, being fetched as (SUBREG:SF union:SI).
7503 We must fetch that as SFmode because we could be loading into
7504 a float-only register. In this case OLD's mode is correct.
7506 Consider an immediate integer: it has VOIDmode. Here we need
7507 to get a mode from something else.
7509 In some cases, there is a fourth mode, the operand's
7510 containing mode. If the insn specifies a containing mode for
7511 this operand, it overrides all others.
7513 I am not sure whether the algorithm here is always right,
7514 but it does the right things in those cases. */
7516 mode = GET_MODE (old);
7517 if (mode == VOIDmode)
7520 /* We cannot use gen_lowpart_common since it can do the wrong thing
7521 when REG_RTX has a multi-word mode. Note that REG_RTX must
7522 always be a REG here. */
7523 if (GET_MODE (reg_rtx) != mode)
7524 reg_rtx = reload_adjust_reg_for_mode (reg_rtx, mode);
7526 reload_reg_rtx_for_input[j] = reg_rtx;
7529 /* AUTO_INC reloads need to be handled even if inherited. We got an
7530 AUTO_INC reload if reload_out is set but reload_out_reg isn't. */
7531 && (! reload_inherited[j] || (rl->out && ! rl->out_reg))
7532 && ! rtx_equal_p (reg_rtx, old)
7534 emit_input_reload_insns (chain, rld + j, old, j);
7536 /* When inheriting a wider reload, we have a MEM in rl->in,
7537 e.g. inheriting a SImode output reload for
7538 (mem:HI (plus:SI (reg:SI 14 fp) (const_int 10))) */
7539 if (optimize && reload_inherited[j] && rl->in
7541 && MEM_P (rl->in_reg)
7542 && reload_spill_index[j] >= 0
7543 && TEST_HARD_REG_BIT (reg_reloaded_valid, reload_spill_index[j]))
7544 rl->in = regno_reg_rtx[reg_reloaded_contents[reload_spill_index[j]]];
7546 /* If we are reloading a register that was recently stored in with an
7547 output-reload, see if we can prove there was
7548 actually no need to store the old value in it. */
7551 && (reload_inherited[j] || reload_override_in[j])
7554 && spill_reg_store[REGNO (reg_rtx)] != 0
7556 /* There doesn't seem to be any reason to restrict this to pseudos
7557 and doing so loses in the case where we are copying from a
7558 register of the wrong class. */
7559 && !HARD_REGISTER_P (spill_reg_stored_to[REGNO (reg_rtx)])
7561 /* The insn might have already some references to stackslots
7562 replaced by MEMs, while reload_out_reg still names the
7564 && (dead_or_set_p (insn, spill_reg_stored_to[REGNO (reg_rtx)])
7565 || rtx_equal_p (spill_reg_stored_to[REGNO (reg_rtx)], rl->out_reg)))
7566 delete_output_reload (insn, j, REGNO (reg_rtx), reg_rtx);
7569 /* Do output reloading for reload RL, which is for the insn described by
7570 CHAIN and has the number J.
7571 ??? At some point we need to support handling output reloads of
7572 JUMP_INSNs or insns that set cc0. */
7574 do_output_reload (struct insn_chain *chain, struct reload *rl, int j)
7577 rtx insn = chain->insn;
7578 /* If this is an output reload that stores something that is
7579 not loaded in this same reload, see if we can eliminate a previous
7581 rtx pseudo = rl->out_reg;
7582 rtx reg_rtx = rl->reg_rtx;
7584 if (rl->out && reg_rtx)
7586 enum machine_mode mode;
7588 /* Determine the mode to reload in.
7589 See comments above (for input reloading). */
7590 mode = GET_MODE (rl->out);
7591 if (mode == VOIDmode)
7593 /* VOIDmode should never happen for an output. */
7594 if (asm_noperands (PATTERN (insn)) < 0)
7595 /* It's the compiler's fault. */
7596 fatal_insn ("VOIDmode on an output", insn);
7597 error_for_asm (insn, "output operand is constant in %<asm%>");
7598 /* Prevent crash--use something we know is valid. */
7600 rl->out = gen_rtx_REG (mode, REGNO (reg_rtx));
7602 if (GET_MODE (reg_rtx) != mode)
7603 reg_rtx = reload_adjust_reg_for_mode (reg_rtx, mode);
7605 reload_reg_rtx_for_output[j] = reg_rtx;
7610 && ! rtx_equal_p (rl->in_reg, pseudo)
7611 && REGNO (pseudo) >= FIRST_PSEUDO_REGISTER
7612 && reg_last_reload_reg[REGNO (pseudo)])
7614 int pseudo_no = REGNO (pseudo);
7615 int last_regno = REGNO (reg_last_reload_reg[pseudo_no]);
7617 /* We don't need to test full validity of last_regno for
7618 inherit here; we only want to know if the store actually
7619 matches the pseudo. */
7620 if (TEST_HARD_REG_BIT (reg_reloaded_valid, last_regno)
7621 && reg_reloaded_contents[last_regno] == pseudo_no
7622 && spill_reg_store[last_regno]
7623 && rtx_equal_p (pseudo, spill_reg_stored_to[last_regno]))
7624 delete_output_reload (insn, j, last_regno, reg_rtx);
7630 || rtx_equal_p (old, reg_rtx))
7633 /* An output operand that dies right away does need a reload,
7634 but need not be copied from it. Show the new location in the
7636 if ((REG_P (old) || GET_CODE (old) == SCRATCH)
7637 && (note = find_reg_note (insn, REG_UNUSED, old)) != 0)
7639 XEXP (note, 0) = reg_rtx;
7642 /* Likewise for a SUBREG of an operand that dies. */
7643 else if (GET_CODE (old) == SUBREG
7644 && REG_P (SUBREG_REG (old))
7645 && 0 != (note = find_reg_note (insn, REG_UNUSED,
7648 XEXP (note, 0) = gen_lowpart_common (GET_MODE (old), reg_rtx);
7651 else if (GET_CODE (old) == SCRATCH)
7652 /* If we aren't optimizing, there won't be a REG_UNUSED note,
7653 but we don't want to make an output reload. */
7656 /* If is a JUMP_INSN, we can't support output reloads yet. */
7657 gcc_assert (NONJUMP_INSN_P (insn));
7659 emit_output_reload_insns (chain, rld + j, j);
7662 /* A reload copies values of MODE from register SRC to register DEST.
7663 Return true if it can be treated for inheritance purposes like a
7664 group of reloads, each one reloading a single hard register. The
7665 caller has already checked that (reg:MODE SRC) and (reg:MODE DEST)
7666 occupy the same number of hard registers. */
7669 inherit_piecemeal_p (int dest ATTRIBUTE_UNUSED,
7670 int src ATTRIBUTE_UNUSED,
7671 enum machine_mode mode ATTRIBUTE_UNUSED)
7673 #ifdef CANNOT_CHANGE_MODE_CLASS
7674 return (!REG_CANNOT_CHANGE_MODE_P (dest, mode, reg_raw_mode[dest])
7675 && !REG_CANNOT_CHANGE_MODE_P (src, mode, reg_raw_mode[src]));
7681 /* Output insns to reload values in and out of the chosen reload regs. */
7684 emit_reload_insns (struct insn_chain *chain)
7686 rtx insn = chain->insn;
7690 CLEAR_HARD_REG_SET (reg_reloaded_died);
7692 for (j = 0; j < reload_n_operands; j++)
7693 input_reload_insns[j] = input_address_reload_insns[j]
7694 = inpaddr_address_reload_insns[j]
7695 = output_reload_insns[j] = output_address_reload_insns[j]
7696 = outaddr_address_reload_insns[j]
7697 = other_output_reload_insns[j] = 0;
7698 other_input_address_reload_insns = 0;
7699 other_input_reload_insns = 0;
7700 operand_reload_insns = 0;
7701 other_operand_reload_insns = 0;
7703 /* Dump reloads into the dump file. */
7706 fprintf (dump_file, "\nReloads for insn # %d\n", INSN_UID (insn));
7707 debug_reload_to_stream (dump_file);
7710 /* Now output the instructions to copy the data into and out of the
7711 reload registers. Do these in the order that the reloads were reported,
7712 since reloads of base and index registers precede reloads of operands
7713 and the operands may need the base and index registers reloaded. */
7715 for (j = 0; j < n_reloads; j++)
7717 if (rld[j].reg_rtx && HARD_REGISTER_P (rld[j].reg_rtx))
7721 for (i = REGNO (rld[j].reg_rtx); i < END_REGNO (rld[j].reg_rtx); i++)
7722 new_spill_reg_store[i] = 0;
7725 do_input_reload (chain, rld + j, j);
7726 do_output_reload (chain, rld + j, j);
7729 /* Now write all the insns we made for reloads in the order expected by
7730 the allocation functions. Prior to the insn being reloaded, we write
7731 the following reloads:
7733 RELOAD_FOR_OTHER_ADDRESS reloads for input addresses.
7735 RELOAD_OTHER reloads.
7737 For each operand, any RELOAD_FOR_INPADDR_ADDRESS reloads followed
7738 by any RELOAD_FOR_INPUT_ADDRESS reloads followed by the
7739 RELOAD_FOR_INPUT reload for the operand.
7741 RELOAD_FOR_OPADDR_ADDRS reloads.
7743 RELOAD_FOR_OPERAND_ADDRESS reloads.
7745 After the insn being reloaded, we write the following:
7747 For each operand, any RELOAD_FOR_OUTADDR_ADDRESS reloads followed
7748 by any RELOAD_FOR_OUTPUT_ADDRESS reload followed by the
7749 RELOAD_FOR_OUTPUT reload, followed by any RELOAD_OTHER output
7750 reloads for the operand. The RELOAD_OTHER output reloads are
7751 output in descending order by reload number. */
7753 emit_insn_before (other_input_address_reload_insns, insn);
7754 emit_insn_before (other_input_reload_insns, insn);
7756 for (j = 0; j < reload_n_operands; j++)
7758 emit_insn_before (inpaddr_address_reload_insns[j], insn);
7759 emit_insn_before (input_address_reload_insns[j], insn);
7760 emit_insn_before (input_reload_insns[j], insn);
7763 emit_insn_before (other_operand_reload_insns, insn);
7764 emit_insn_before (operand_reload_insns, insn);
7766 for (j = 0; j < reload_n_operands; j++)
7768 rtx x = emit_insn_after (outaddr_address_reload_insns[j], insn);
7769 x = emit_insn_after (output_address_reload_insns[j], x);
7770 x = emit_insn_after (output_reload_insns[j], x);
7771 emit_insn_after (other_output_reload_insns[j], x);
7774 /* For all the spill regs newly reloaded in this instruction,
7775 record what they were reloaded from, so subsequent instructions
7776 can inherit the reloads.
7778 Update spill_reg_store for the reloads of this insn.
7779 Copy the elements that were updated in the loop above. */
7781 for (j = 0; j < n_reloads; j++)
7783 int r = reload_order[j];
7784 int i = reload_spill_index[r];
7786 /* If this is a non-inherited input reload from a pseudo, we must
7787 clear any memory of a previous store to the same pseudo. Only do
7788 something if there will not be an output reload for the pseudo
7790 if (rld[r].in_reg != 0
7791 && ! (reload_inherited[r] || reload_override_in[r]))
7793 rtx reg = rld[r].in_reg;
7795 if (GET_CODE (reg) == SUBREG)
7796 reg = SUBREG_REG (reg);
7799 && REGNO (reg) >= FIRST_PSEUDO_REGISTER
7800 && !REGNO_REG_SET_P (®_has_output_reload, REGNO (reg)))
7802 int nregno = REGNO (reg);
7804 if (reg_last_reload_reg[nregno])
7806 int last_regno = REGNO (reg_last_reload_reg[nregno]);
7808 if (reg_reloaded_contents[last_regno] == nregno)
7809 spill_reg_store[last_regno] = 0;
7814 /* I is nonneg if this reload used a register.
7815 If rld[r].reg_rtx is 0, this is an optional reload
7816 that we opted to ignore. */
7818 if (i >= 0 && rld[r].reg_rtx != 0)
7820 int nr = hard_regno_nregs[i][GET_MODE (rld[r].reg_rtx)];
7823 /* For a multi register reload, we need to check if all or part
7824 of the value lives to the end. */
7825 for (k = 0; k < nr; k++)
7826 if (reload_reg_reaches_end_p (i + k, rld[r].opnum,
7827 rld[r].when_needed))
7828 CLEAR_HARD_REG_BIT (reg_reloaded_valid, i + k);
7830 /* Maybe the spill reg contains a copy of reload_out. */
7832 && (REG_P (rld[r].out)
7836 || REG_P (rld[r].out_reg)))
7839 enum machine_mode mode;
7842 reg = reload_reg_rtx_for_output[r];
7843 mode = GET_MODE (reg);
7844 regno = REGNO (reg);
7845 nregs = hard_regno_nregs[regno][mode];
7846 if (reload_regs_reach_end_p (regno, nregs, rld[r].opnum,
7847 rld[r].when_needed))
7849 rtx out = (REG_P (rld[r].out)
7853 /* AUTO_INC */ : XEXP (rld[r].in_reg, 0));
7854 int out_regno = REGNO (out);
7855 int out_nregs = (!HARD_REGISTER_NUM_P (out_regno) ? 1
7856 : hard_regno_nregs[out_regno][mode]);
7859 spill_reg_store[regno] = new_spill_reg_store[regno];
7860 spill_reg_stored_to[regno] = out;
7861 reg_last_reload_reg[out_regno] = reg;
7863 piecemeal = (HARD_REGISTER_NUM_P (out_regno)
7864 && nregs == out_nregs
7865 && inherit_piecemeal_p (out_regno, regno, mode));
7867 /* If OUT_REGNO is a hard register, it may occupy more than
7868 one register. If it does, say what is in the
7869 rest of the registers assuming that both registers
7870 agree on how many words the object takes. If not,
7871 invalidate the subsequent registers. */
7873 if (HARD_REGISTER_NUM_P (out_regno))
7874 for (k = 1; k < out_nregs; k++)
7875 reg_last_reload_reg[out_regno + k]
7876 = (piecemeal ? regno_reg_rtx[regno + k] : 0);
7878 /* Now do the inverse operation. */
7879 for (k = 0; k < nregs; k++)
7881 CLEAR_HARD_REG_BIT (reg_reloaded_dead, regno + k);
7882 reg_reloaded_contents[regno + k]
7883 = (!HARD_REGISTER_NUM_P (out_regno) || !piecemeal
7886 reg_reloaded_insn[regno + k] = insn;
7887 SET_HARD_REG_BIT (reg_reloaded_valid, regno + k);
7888 if (HARD_REGNO_CALL_PART_CLOBBERED (regno + k, mode))
7889 SET_HARD_REG_BIT (reg_reloaded_call_part_clobbered,
7892 CLEAR_HARD_REG_BIT (reg_reloaded_call_part_clobbered,
7897 /* Maybe the spill reg contains a copy of reload_in. Only do
7898 something if there will not be an output reload for
7899 the register being reloaded. */
7900 else if (rld[r].out_reg == 0
7902 && ((REG_P (rld[r].in)
7903 && !HARD_REGISTER_P (rld[r].in)
7904 && !REGNO_REG_SET_P (®_has_output_reload,
7906 || (REG_P (rld[r].in_reg)
7907 && !REGNO_REG_SET_P (®_has_output_reload,
7908 REGNO (rld[r].in_reg))))
7909 && !reg_set_p (reload_reg_rtx_for_input[r], PATTERN (insn)))
7912 enum machine_mode mode;
7915 reg = reload_reg_rtx_for_input[r];
7916 mode = GET_MODE (reg);
7917 regno = REGNO (reg);
7918 nregs = hard_regno_nregs[regno][mode];
7919 if (reload_regs_reach_end_p (regno, nregs, rld[r].opnum,
7920 rld[r].when_needed))
7927 if (REG_P (rld[r].in)
7928 && REGNO (rld[r].in) >= FIRST_PSEUDO_REGISTER)
7930 else if (REG_P (rld[r].in_reg))
7933 in = XEXP (rld[r].in_reg, 0);
7934 in_regno = REGNO (in);
7936 in_nregs = (!HARD_REGISTER_NUM_P (in_regno) ? 1
7937 : hard_regno_nregs[in_regno][mode]);
7939 reg_last_reload_reg[in_regno] = reg;
7941 piecemeal = (HARD_REGISTER_NUM_P (in_regno)
7942 && nregs == in_nregs
7943 && inherit_piecemeal_p (regno, in_regno, mode));
7945 if (HARD_REGISTER_NUM_P (in_regno))
7946 for (k = 1; k < in_nregs; k++)
7947 reg_last_reload_reg[in_regno + k]
7948 = (piecemeal ? regno_reg_rtx[regno + k] : 0);
7950 /* Unless we inherited this reload, show we haven't
7951 recently done a store.
7952 Previous stores of inherited auto_inc expressions
7953 also have to be discarded. */
7954 if (! reload_inherited[r]
7955 || (rld[r].out && ! rld[r].out_reg))
7956 spill_reg_store[regno] = 0;
7958 for (k = 0; k < nregs; k++)
7960 CLEAR_HARD_REG_BIT (reg_reloaded_dead, regno + k);
7961 reg_reloaded_contents[regno + k]
7962 = (!HARD_REGISTER_NUM_P (in_regno) || !piecemeal
7965 reg_reloaded_insn[regno + k] = insn;
7966 SET_HARD_REG_BIT (reg_reloaded_valid, regno + k);
7967 if (HARD_REGNO_CALL_PART_CLOBBERED (regno + k, mode))
7968 SET_HARD_REG_BIT (reg_reloaded_call_part_clobbered,
7971 CLEAR_HARD_REG_BIT (reg_reloaded_call_part_clobbered,
7978 /* The following if-statement was #if 0'd in 1.34 (or before...).
7979 It's reenabled in 1.35 because supposedly nothing else
7980 deals with this problem. */
7982 /* If a register gets output-reloaded from a non-spill register,
7983 that invalidates any previous reloaded copy of it.
7984 But forget_old_reloads_1 won't get to see it, because
7985 it thinks only about the original insn. So invalidate it here.
7986 Also do the same thing for RELOAD_OTHER constraints where the
7987 output is discarded. */
7989 && ((rld[r].out != 0
7990 && (REG_P (rld[r].out)
7991 || (MEM_P (rld[r].out)
7992 && REG_P (rld[r].out_reg))))
7993 || (rld[r].out == 0 && rld[r].out_reg
7994 && REG_P (rld[r].out_reg))))
7996 rtx out = ((rld[r].out && REG_P (rld[r].out))
7997 ? rld[r].out : rld[r].out_reg);
7998 int out_regno = REGNO (out);
7999 enum machine_mode mode = GET_MODE (out);
8001 /* REG_RTX is now set or clobbered by the main instruction.
8002 As the comment above explains, forget_old_reloads_1 only
8003 sees the original instruction, and there is no guarantee
8004 that the original instruction also clobbered REG_RTX.
8005 For example, if find_reloads sees that the input side of
8006 a matched operand pair dies in this instruction, it may
8007 use the input register as the reload register.
8009 Calling forget_old_reloads_1 is a waste of effort if
8010 REG_RTX is also the output register.
8012 If we know that REG_RTX holds the value of a pseudo
8013 register, the code after the call will record that fact. */
8014 if (rld[r].reg_rtx && rld[r].reg_rtx != out)
8015 forget_old_reloads_1 (rld[r].reg_rtx, NULL_RTX, NULL);
8017 if (!HARD_REGISTER_NUM_P (out_regno))
8019 rtx src_reg, store_insn = NULL_RTX;
8021 reg_last_reload_reg[out_regno] = 0;
8023 /* If we can find a hard register that is stored, record
8024 the storing insn so that we may delete this insn with
8025 delete_output_reload. */
8026 src_reg = reload_reg_rtx_for_output[r];
8028 /* If this is an optional reload, try to find the source reg
8029 from an input reload. */
8032 rtx set = single_set (insn);
8033 if (set && SET_DEST (set) == rld[r].out)
8037 src_reg = SET_SRC (set);
8039 for (k = 0; k < n_reloads; k++)
8041 if (rld[k].in == src_reg)
8043 src_reg = reload_reg_rtx_for_input[k];
8050 store_insn = new_spill_reg_store[REGNO (src_reg)];
8051 if (src_reg && REG_P (src_reg)
8052 && REGNO (src_reg) < FIRST_PSEUDO_REGISTER)
8054 int src_regno, src_nregs, k;
8057 gcc_assert (GET_MODE (src_reg) == mode);
8058 src_regno = REGNO (src_reg);
8059 src_nregs = hard_regno_nregs[src_regno][mode];
8060 /* The place where to find a death note varies with
8061 PRESERVE_DEATH_INFO_REGNO_P . The condition is not
8062 necessarily checked exactly in the code that moves
8063 notes, so just check both locations. */
8064 note = find_regno_note (insn, REG_DEAD, src_regno);
8065 if (! note && store_insn)
8066 note = find_regno_note (store_insn, REG_DEAD, src_regno);
8067 for (k = 0; k < src_nregs; k++)
8069 spill_reg_store[src_regno + k] = store_insn;
8070 spill_reg_stored_to[src_regno + k] = out;
8071 reg_reloaded_contents[src_regno + k] = out_regno;
8072 reg_reloaded_insn[src_regno + k] = store_insn;
8073 CLEAR_HARD_REG_BIT (reg_reloaded_dead, src_regno + k);
8074 SET_HARD_REG_BIT (reg_reloaded_valid, src_regno + k);
8075 if (HARD_REGNO_CALL_PART_CLOBBERED (src_regno + k,
8077 SET_HARD_REG_BIT (reg_reloaded_call_part_clobbered,
8080 CLEAR_HARD_REG_BIT (reg_reloaded_call_part_clobbered,
8082 SET_HARD_REG_BIT (reg_is_output_reload, src_regno + k);
8084 SET_HARD_REG_BIT (reg_reloaded_died, src_regno);
8086 CLEAR_HARD_REG_BIT (reg_reloaded_died, src_regno);
8088 reg_last_reload_reg[out_regno] = src_reg;
8089 /* We have to set reg_has_output_reload here, or else
8090 forget_old_reloads_1 will clear reg_last_reload_reg
8092 SET_REGNO_REG_SET (®_has_output_reload,
8098 int k, out_nregs = hard_regno_nregs[out_regno][mode];
8100 for (k = 0; k < out_nregs; k++)
8101 reg_last_reload_reg[out_regno + k] = 0;
8105 IOR_HARD_REG_SET (reg_reloaded_dead, reg_reloaded_died);
8108 /* Go through the motions to emit INSN and test if it is strictly valid.
8109 Return the emitted insn if valid, else return NULL. */
8112 emit_insn_if_valid_for_reload (rtx insn)
8114 rtx last = get_last_insn ();
8117 insn = emit_insn (insn);
8118 code = recog_memoized (insn);
8122 extract_insn (insn);
8123 /* We want constrain operands to treat this insn strictly in its
8124 validity determination, i.e., the way it would after reload has
8126 if (constrain_operands (1))
8130 delete_insns_since (last);
8134 /* Emit code to perform a reload from IN (which may be a reload register) to
8135 OUT (which may also be a reload register). IN or OUT is from operand
8136 OPNUM with reload type TYPE.
8138 Returns first insn emitted. */
8141 gen_reload (rtx out, rtx in, int opnum, enum reload_type type)
8143 rtx last = get_last_insn ();
8146 /* If IN is a paradoxical SUBREG, remove it and try to put the
8147 opposite SUBREG on OUT. Likewise for a paradoxical SUBREG on OUT. */
8148 if (GET_CODE (in) == SUBREG
8149 && (GET_MODE_SIZE (GET_MODE (in))
8150 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))))
8151 && (tem = gen_lowpart_common (GET_MODE (SUBREG_REG (in)), out)) != 0)
8152 in = SUBREG_REG (in), out = tem;
8153 else if (GET_CODE (out) == SUBREG
8154 && (GET_MODE_SIZE (GET_MODE (out))
8155 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))))
8156 && (tem = gen_lowpart_common (GET_MODE (SUBREG_REG (out)), in)) != 0)
8157 out = SUBREG_REG (out), in = tem;
8159 /* How to do this reload can get quite tricky. Normally, we are being
8160 asked to reload a simple operand, such as a MEM, a constant, or a pseudo
8161 register that didn't get a hard register. In that case we can just
8162 call emit_move_insn.
8164 We can also be asked to reload a PLUS that adds a register or a MEM to
8165 another register, constant or MEM. This can occur during frame pointer
8166 elimination and while reloading addresses. This case is handled by
8167 trying to emit a single insn to perform the add. If it is not valid,
8168 we use a two insn sequence.
8170 Or we can be asked to reload an unary operand that was a fragment of
8171 an addressing mode, into a register. If it isn't recognized as-is,
8172 we try making the unop operand and the reload-register the same:
8173 (set reg:X (unop:X expr:Y))
8174 -> (set reg:Y expr:Y) (set reg:X (unop:X reg:Y)).
8176 Finally, we could be called to handle an 'o' constraint by putting
8177 an address into a register. In that case, we first try to do this
8178 with a named pattern of "reload_load_address". If no such pattern
8179 exists, we just emit a SET insn and hope for the best (it will normally
8180 be valid on machines that use 'o').
8182 This entire process is made complex because reload will never
8183 process the insns we generate here and so we must ensure that
8184 they will fit their constraints and also by the fact that parts of
8185 IN might be being reloaded separately and replaced with spill registers.
8186 Because of this, we are, in some sense, just guessing the right approach
8187 here. The one listed above seems to work.
8189 ??? At some point, this whole thing needs to be rethought. */
8191 if (GET_CODE (in) == PLUS
8192 && (REG_P (XEXP (in, 0))
8193 || GET_CODE (XEXP (in, 0)) == SUBREG
8194 || MEM_P (XEXP (in, 0)))
8195 && (REG_P (XEXP (in, 1))
8196 || GET_CODE (XEXP (in, 1)) == SUBREG
8197 || CONSTANT_P (XEXP (in, 1))
8198 || MEM_P (XEXP (in, 1))))
8200 /* We need to compute the sum of a register or a MEM and another
8201 register, constant, or MEM, and put it into the reload
8202 register. The best possible way of doing this is if the machine
8203 has a three-operand ADD insn that accepts the required operands.
8205 The simplest approach is to try to generate such an insn and see if it
8206 is recognized and matches its constraints. If so, it can be used.
8208 It might be better not to actually emit the insn unless it is valid,
8209 but we need to pass the insn as an operand to `recog' and
8210 `extract_insn' and it is simpler to emit and then delete the insn if
8211 not valid than to dummy things up. */
8213 rtx op0, op1, tem, insn;
8216 op0 = find_replacement (&XEXP (in, 0));
8217 op1 = find_replacement (&XEXP (in, 1));
8219 /* Since constraint checking is strict, commutativity won't be
8220 checked, so we need to do that here to avoid spurious failure
8221 if the add instruction is two-address and the second operand
8222 of the add is the same as the reload reg, which is frequently
8223 the case. If the insn would be A = B + A, rearrange it so
8224 it will be A = A + B as constrain_operands expects. */
8226 if (REG_P (XEXP (in, 1))
8227 && REGNO (out) == REGNO (XEXP (in, 1)))
8228 tem = op0, op0 = op1, op1 = tem;
8230 if (op0 != XEXP (in, 0) || op1 != XEXP (in, 1))
8231 in = gen_rtx_PLUS (GET_MODE (in), op0, op1);
8233 insn = emit_insn_if_valid_for_reload (gen_rtx_SET (VOIDmode, out, in));
8237 /* If that failed, we must use a conservative two-insn sequence.
8239 Use a move to copy one operand into the reload register. Prefer
8240 to reload a constant, MEM or pseudo since the move patterns can
8241 handle an arbitrary operand. If OP1 is not a constant, MEM or
8242 pseudo and OP1 is not a valid operand for an add instruction, then
8245 After reloading one of the operands into the reload register, add
8246 the reload register to the output register.
8248 If there is another way to do this for a specific machine, a
8249 DEFINE_PEEPHOLE should be specified that recognizes the sequence
8252 code = (int) optab_handler (add_optab, GET_MODE (out))->insn_code;
8254 if (CONSTANT_P (op1) || MEM_P (op1) || GET_CODE (op1) == SUBREG
8256 && REGNO (op1) >= FIRST_PSEUDO_REGISTER)
8257 || (code != CODE_FOR_nothing
8258 && ! ((*insn_data[code].operand[2].predicate)
8259 (op1, insn_data[code].operand[2].mode))))
8260 tem = op0, op0 = op1, op1 = tem;
8262 gen_reload (out, op0, opnum, type);
8264 /* If OP0 and OP1 are the same, we can use OUT for OP1.
8265 This fixes a problem on the 32K where the stack pointer cannot
8266 be used as an operand of an add insn. */
8268 if (rtx_equal_p (op0, op1))
8271 insn = emit_insn_if_valid_for_reload (gen_add2_insn (out, op1));
8274 /* Add a REG_EQUIV note so that find_equiv_reg can find it. */
8275 set_unique_reg_note (insn, REG_EQUIV, in);
8279 /* If that failed, copy the address register to the reload register.
8280 Then add the constant to the reload register. */
8282 gcc_assert (!reg_overlap_mentioned_p (out, op0));
8283 gen_reload (out, op1, opnum, type);
8284 insn = emit_insn (gen_add2_insn (out, op0));
8285 set_unique_reg_note (insn, REG_EQUIV, in);
8288 #ifdef SECONDARY_MEMORY_NEEDED
8289 /* If we need a memory location to do the move, do it that way. */
8290 else if ((REG_P (in)
8291 || (GET_CODE (in) == SUBREG && REG_P (SUBREG_REG (in))))
8292 && reg_or_subregno (in) < FIRST_PSEUDO_REGISTER
8294 || (GET_CODE (out) == SUBREG && REG_P (SUBREG_REG (out))))
8295 && reg_or_subregno (out) < FIRST_PSEUDO_REGISTER
8296 && SECONDARY_MEMORY_NEEDED (REGNO_REG_CLASS (reg_or_subregno (in)),
8297 REGNO_REG_CLASS (reg_or_subregno (out)),
8300 /* Get the memory to use and rewrite both registers to its mode. */
8301 rtx loc = get_secondary_mem (in, GET_MODE (out), opnum, type);
8303 if (GET_MODE (loc) != GET_MODE (out))
8304 out = gen_rtx_REG (GET_MODE (loc), REGNO (out));
8306 if (GET_MODE (loc) != GET_MODE (in))
8307 in = gen_rtx_REG (GET_MODE (loc), REGNO (in));
8309 gen_reload (loc, in, opnum, type);
8310 gen_reload (out, loc, opnum, type);
8313 else if (REG_P (out) && UNARY_P (in))
8320 op1 = find_replacement (&XEXP (in, 0));
8321 if (op1 != XEXP (in, 0))
8322 in = gen_rtx_fmt_e (GET_CODE (in), GET_MODE (in), op1);
8324 /* First, try a plain SET. */
8325 set = emit_insn_if_valid_for_reload (gen_rtx_SET (VOIDmode, out, in));
8329 /* If that failed, move the inner operand to the reload
8330 register, and try the same unop with the inner expression
8331 replaced with the reload register. */
8333 if (GET_MODE (op1) != GET_MODE (out))
8334 out_moded = gen_rtx_REG (GET_MODE (op1), REGNO (out));
8338 gen_reload (out_moded, op1, opnum, type);
8341 = gen_rtx_SET (VOIDmode, out,
8342 gen_rtx_fmt_e (GET_CODE (in), GET_MODE (in),
8344 insn = emit_insn_if_valid_for_reload (insn);
8347 set_unique_reg_note (insn, REG_EQUIV, in);
8351 fatal_insn ("Failure trying to reload:", set);
8353 /* If IN is a simple operand, use gen_move_insn. */
8354 else if (OBJECT_P (in) || GET_CODE (in) == SUBREG)
8356 tem = emit_insn (gen_move_insn (out, in));
8357 /* IN may contain a LABEL_REF, if so add a REG_LABEL_OPERAND note. */
8358 mark_jump_label (in, tem, 0);
8361 #ifdef HAVE_reload_load_address
8362 else if (HAVE_reload_load_address)
8363 emit_insn (gen_reload_load_address (out, in));
8366 /* Otherwise, just write (set OUT IN) and hope for the best. */
8368 emit_insn (gen_rtx_SET (VOIDmode, out, in));
8370 /* Return the first insn emitted.
8371 We can not just return get_last_insn, because there may have
8372 been multiple instructions emitted. Also note that gen_move_insn may
8373 emit more than one insn itself, so we can not assume that there is one
8374 insn emitted per emit_insn_before call. */
8376 return last ? NEXT_INSN (last) : get_insns ();
8379 /* Delete a previously made output-reload whose result we now believe
8380 is not needed. First we double-check.
8382 INSN is the insn now being processed.
8383 LAST_RELOAD_REG is the hard register number for which we want to delete
8384 the last output reload.
8385 J is the reload-number that originally used REG. The caller has made
8386 certain that reload J doesn't use REG any longer for input.
8387 NEW_RELOAD_REG is reload register that reload J is using for REG. */
8390 delete_output_reload (rtx insn, int j, int last_reload_reg, rtx new_reload_reg)
8392 rtx output_reload_insn = spill_reg_store[last_reload_reg];
8393 rtx reg = spill_reg_stored_to[last_reload_reg];
8396 int n_inherited = 0;
8400 /* It is possible that this reload has been only used to set another reload
8401 we eliminated earlier and thus deleted this instruction too. */
8402 if (INSN_DELETED_P (output_reload_insn))
8405 /* Get the raw pseudo-register referred to. */
8407 while (GET_CODE (reg) == SUBREG)
8408 reg = SUBREG_REG (reg);
8409 substed = reg_equiv_memory_loc[REGNO (reg)];
8411 /* This is unsafe if the operand occurs more often in the current
8412 insn than it is inherited. */
8413 for (k = n_reloads - 1; k >= 0; k--)
8415 rtx reg2 = rld[k].in;
8418 if (MEM_P (reg2) || reload_override_in[k])
8419 reg2 = rld[k].in_reg;
8421 if (rld[k].out && ! rld[k].out_reg)
8422 reg2 = XEXP (rld[k].in_reg, 0);
8424 while (GET_CODE (reg2) == SUBREG)
8425 reg2 = SUBREG_REG (reg2);
8426 if (rtx_equal_p (reg2, reg))
8428 if (reload_inherited[k] || reload_override_in[k] || k == j)
8434 n_occurrences = count_occurrences (PATTERN (insn), reg, 0);
8435 if (CALL_P (insn) && CALL_INSN_FUNCTION_USAGE (insn))
8436 n_occurrences += count_occurrences (CALL_INSN_FUNCTION_USAGE (insn),
8439 n_occurrences += count_occurrences (PATTERN (insn),
8440 eliminate_regs (substed, 0,
8442 for (i1 = reg_equiv_alt_mem_list[REGNO (reg)]; i1; i1 = XEXP (i1, 1))
8444 gcc_assert (!rtx_equal_p (XEXP (i1, 0), substed));
8445 n_occurrences += count_occurrences (PATTERN (insn), XEXP (i1, 0), 0);
8447 if (n_occurrences > n_inherited)
8450 /* If the pseudo-reg we are reloading is no longer referenced
8451 anywhere between the store into it and here,
8452 and we're within the same basic block, then the value can only
8453 pass through the reload reg and end up here.
8454 Otherwise, give up--return. */
8455 for (i1 = NEXT_INSN (output_reload_insn);
8456 i1 != insn; i1 = NEXT_INSN (i1))
8458 if (NOTE_INSN_BASIC_BLOCK_P (i1))
8460 if ((NONJUMP_INSN_P (i1) || CALL_P (i1))
8461 && reg_mentioned_p (reg, PATTERN (i1)))
8463 /* If this is USE in front of INSN, we only have to check that
8464 there are no more references than accounted for by inheritance. */
8465 while (NONJUMP_INSN_P (i1) && GET_CODE (PATTERN (i1)) == USE)
8467 n_occurrences += rtx_equal_p (reg, XEXP (PATTERN (i1), 0)) != 0;
8468 i1 = NEXT_INSN (i1);
8470 if (n_occurrences <= n_inherited && i1 == insn)
8476 /* We will be deleting the insn. Remove the spill reg information. */
8477 for (k = hard_regno_nregs[last_reload_reg][GET_MODE (reg)]; k-- > 0; )
8479 spill_reg_store[last_reload_reg + k] = 0;
8480 spill_reg_stored_to[last_reload_reg + k] = 0;
8483 /* The caller has already checked that REG dies or is set in INSN.
8484 It has also checked that we are optimizing, and thus some
8485 inaccuracies in the debugging information are acceptable.
8486 So we could just delete output_reload_insn. But in some cases
8487 we can improve the debugging information without sacrificing
8488 optimization - maybe even improving the code: See if the pseudo
8489 reg has been completely replaced with reload regs. If so, delete
8490 the store insn and forget we had a stack slot for the pseudo. */
8491 if (rld[j].out != rld[j].in
8492 && REG_N_DEATHS (REGNO (reg)) == 1
8493 && REG_N_SETS (REGNO (reg)) == 1
8494 && REG_BASIC_BLOCK (REGNO (reg)) >= NUM_FIXED_BLOCKS
8495 && find_regno_note (insn, REG_DEAD, REGNO (reg)))
8499 /* We know that it was used only between here and the beginning of
8500 the current basic block. (We also know that the last use before
8501 INSN was the output reload we are thinking of deleting, but never
8502 mind that.) Search that range; see if any ref remains. */
8503 for (i2 = PREV_INSN (insn); i2; i2 = PREV_INSN (i2))
8505 rtx set = single_set (i2);
8507 /* Uses which just store in the pseudo don't count,
8508 since if they are the only uses, they are dead. */
8509 if (set != 0 && SET_DEST (set) == reg)
8514 if ((NONJUMP_INSN_P (i2) || CALL_P (i2))
8515 && reg_mentioned_p (reg, PATTERN (i2)))
8517 /* Some other ref remains; just delete the output reload we
8519 delete_address_reloads (output_reload_insn, insn);
8520 delete_insn (output_reload_insn);
8525 /* Delete the now-dead stores into this pseudo. Note that this
8526 loop also takes care of deleting output_reload_insn. */
8527 for (i2 = PREV_INSN (insn); i2; i2 = PREV_INSN (i2))
8529 rtx set = single_set (i2);
8531 if (set != 0 && SET_DEST (set) == reg)
8533 delete_address_reloads (i2, insn);
8541 /* For the debugging info, say the pseudo lives in this reload reg. */
8542 reg_renumber[REGNO (reg)] = REGNO (new_reload_reg);
8543 if (flag_ira && optimize)
8544 /* Inform IRA about the change. */
8545 ira_mark_allocation_change (REGNO (reg));
8546 alter_reg (REGNO (reg), -1, false);
8550 delete_address_reloads (output_reload_insn, insn);
8551 delete_insn (output_reload_insn);
8555 /* We are going to delete DEAD_INSN. Recursively delete loads of
8556 reload registers used in DEAD_INSN that are not used till CURRENT_INSN.
8557 CURRENT_INSN is being reloaded, so we have to check its reloads too. */
8559 delete_address_reloads (rtx dead_insn, rtx current_insn)
8561 rtx set = single_set (dead_insn);
8562 rtx set2, dst, prev, next;
8565 rtx dst = SET_DEST (set);
8567 delete_address_reloads_1 (dead_insn, XEXP (dst, 0), current_insn);
8569 /* If we deleted the store from a reloaded post_{in,de}c expression,
8570 we can delete the matching adds. */
8571 prev = PREV_INSN (dead_insn);
8572 next = NEXT_INSN (dead_insn);
8573 if (! prev || ! next)
8575 set = single_set (next);
8576 set2 = single_set (prev);
8578 || GET_CODE (SET_SRC (set)) != PLUS || GET_CODE (SET_SRC (set2)) != PLUS
8579 || GET_CODE (XEXP (SET_SRC (set), 1)) != CONST_INT
8580 || GET_CODE (XEXP (SET_SRC (set2), 1)) != CONST_INT)
8582 dst = SET_DEST (set);
8583 if (! rtx_equal_p (dst, SET_DEST (set2))
8584 || ! rtx_equal_p (dst, XEXP (SET_SRC (set), 0))
8585 || ! rtx_equal_p (dst, XEXP (SET_SRC (set2), 0))
8586 || (INTVAL (XEXP (SET_SRC (set), 1))
8587 != -INTVAL (XEXP (SET_SRC (set2), 1))))
8589 delete_related_insns (prev);
8590 delete_related_insns (next);
8593 /* Subfunction of delete_address_reloads: process registers found in X. */
8595 delete_address_reloads_1 (rtx dead_insn, rtx x, rtx current_insn)
8597 rtx prev, set, dst, i2;
8599 enum rtx_code code = GET_CODE (x);
8603 const char *fmt = GET_RTX_FORMAT (code);
8604 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
8607 delete_address_reloads_1 (dead_insn, XEXP (x, i), current_insn);
8608 else if (fmt[i] == 'E')
8610 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
8611 delete_address_reloads_1 (dead_insn, XVECEXP (x, i, j),
8618 if (spill_reg_order[REGNO (x)] < 0)
8621 /* Scan backwards for the insn that sets x. This might be a way back due
8623 for (prev = PREV_INSN (dead_insn); prev; prev = PREV_INSN (prev))
8625 code = GET_CODE (prev);
8626 if (code == CODE_LABEL || code == JUMP_INSN)
8630 if (reg_set_p (x, PATTERN (prev)))
8632 if (reg_referenced_p (x, PATTERN (prev)))
8635 if (! prev || INSN_UID (prev) < reload_first_uid)
8637 /* Check that PREV only sets the reload register. */
8638 set = single_set (prev);
8641 dst = SET_DEST (set);
8643 || ! rtx_equal_p (dst, x))
8645 if (! reg_set_p (dst, PATTERN (dead_insn)))
8647 /* Check if DST was used in a later insn -
8648 it might have been inherited. */
8649 for (i2 = NEXT_INSN (dead_insn); i2; i2 = NEXT_INSN (i2))
8655 if (reg_referenced_p (dst, PATTERN (i2)))
8657 /* If there is a reference to the register in the current insn,
8658 it might be loaded in a non-inherited reload. If no other
8659 reload uses it, that means the register is set before
8661 if (i2 == current_insn)
8663 for (j = n_reloads - 1; j >= 0; j--)
8664 if ((rld[j].reg_rtx == dst && reload_inherited[j])
8665 || reload_override_in[j] == dst)
8667 for (j = n_reloads - 1; j >= 0; j--)
8668 if (rld[j].in && rld[j].reg_rtx == dst)
8677 /* If DST is still live at CURRENT_INSN, check if it is used for
8678 any reload. Note that even if CURRENT_INSN sets DST, we still
8679 have to check the reloads. */
8680 if (i2 == current_insn)
8682 for (j = n_reloads - 1; j >= 0; j--)
8683 if ((rld[j].reg_rtx == dst && reload_inherited[j])
8684 || reload_override_in[j] == dst)
8686 /* ??? We can't finish the loop here, because dst might be
8687 allocated to a pseudo in this block if no reload in this
8688 block needs any of the classes containing DST - see
8689 spill_hard_reg. There is no easy way to tell this, so we
8690 have to scan till the end of the basic block. */
8692 if (reg_set_p (dst, PATTERN (i2)))
8696 delete_address_reloads_1 (prev, SET_SRC (set), current_insn);
8697 reg_reloaded_contents[REGNO (dst)] = -1;
8701 /* Output reload-insns to reload VALUE into RELOADREG.
8702 VALUE is an autoincrement or autodecrement RTX whose operand
8703 is a register or memory location;
8704 so reloading involves incrementing that location.
8705 IN is either identical to VALUE, or some cheaper place to reload from.
8707 INC_AMOUNT is the number to increment or decrement by (always positive).
8708 This cannot be deduced from VALUE.
8710 Return the instruction that stores into RELOADREG. */
8713 inc_for_reload (rtx reloadreg, rtx in, rtx value, int inc_amount)
8715 /* REG or MEM to be copied and incremented. */
8716 rtx incloc = find_replacement (&XEXP (value, 0));
8717 /* Nonzero if increment after copying. */
8718 int post = (GET_CODE (value) == POST_DEC || GET_CODE (value) == POST_INC
8719 || GET_CODE (value) == POST_MODIFY);
8725 rtx real_in = in == value ? incloc : in;
8727 /* No hard register is equivalent to this register after
8728 inc/dec operation. If REG_LAST_RELOAD_REG were nonzero,
8729 we could inc/dec that register as well (maybe even using it for
8730 the source), but I'm not sure it's worth worrying about. */
8732 reg_last_reload_reg[REGNO (incloc)] = 0;
8734 if (GET_CODE (value) == PRE_MODIFY || GET_CODE (value) == POST_MODIFY)
8736 gcc_assert (GET_CODE (XEXP (value, 1)) == PLUS);
8737 inc = find_replacement (&XEXP (XEXP (value, 1), 1));
8741 if (GET_CODE (value) == PRE_DEC || GET_CODE (value) == POST_DEC)
8742 inc_amount = -inc_amount;
8744 inc = GEN_INT (inc_amount);
8747 /* If this is post-increment, first copy the location to the reload reg. */
8748 if (post && real_in != reloadreg)
8749 emit_insn (gen_move_insn (reloadreg, real_in));
8753 /* See if we can directly increment INCLOC. Use a method similar to
8754 that in gen_reload. */
8756 last = get_last_insn ();
8757 add_insn = emit_insn (gen_rtx_SET (VOIDmode, incloc,
8758 gen_rtx_PLUS (GET_MODE (incloc),
8761 code = recog_memoized (add_insn);
8764 extract_insn (add_insn);
8765 if (constrain_operands (1))
8767 /* If this is a pre-increment and we have incremented the value
8768 where it lives, copy the incremented value to RELOADREG to
8769 be used as an address. */
8772 emit_insn (gen_move_insn (reloadreg, incloc));
8777 delete_insns_since (last);
8780 /* If couldn't do the increment directly, must increment in RELOADREG.
8781 The way we do this depends on whether this is pre- or post-increment.
8782 For pre-increment, copy INCLOC to the reload register, increment it
8783 there, then save back. */
8787 if (in != reloadreg)
8788 emit_insn (gen_move_insn (reloadreg, real_in));
8789 emit_insn (gen_add2_insn (reloadreg, inc));
8790 store = emit_insn (gen_move_insn (incloc, reloadreg));
8795 Because this might be a jump insn or a compare, and because RELOADREG
8796 may not be available after the insn in an input reload, we must do
8797 the incrementation before the insn being reloaded for.
8799 We have already copied IN to RELOADREG. Increment the copy in
8800 RELOADREG, save that back, then decrement RELOADREG so it has
8801 the original value. */
8803 emit_insn (gen_add2_insn (reloadreg, inc));
8804 store = emit_insn (gen_move_insn (incloc, reloadreg));
8805 if (GET_CODE (inc) == CONST_INT)
8806 emit_insn (gen_add2_insn (reloadreg, GEN_INT (-INTVAL (inc))));
8808 emit_insn (gen_sub2_insn (reloadreg, inc));
8816 add_auto_inc_notes (rtx insn, rtx x)
8818 enum rtx_code code = GET_CODE (x);
8822 if (code == MEM && auto_inc_p (XEXP (x, 0)))
8824 add_reg_note (insn, REG_INC, XEXP (XEXP (x, 0), 0));
8828 /* Scan all the operand sub-expressions. */
8829 fmt = GET_RTX_FORMAT (code);
8830 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
8833 add_auto_inc_notes (insn, XEXP (x, i));
8834 else if (fmt[i] == 'E')
8835 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
8836 add_auto_inc_notes (insn, XVECEXP (x, i, j));
8841 /* Copy EH notes from an insn to its reloads. */
8843 copy_eh_notes (rtx insn, rtx x)
8845 rtx eh_note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
8848 for (; x != 0; x = NEXT_INSN (x))
8850 if (may_trap_p (PATTERN (x)))
8851 add_reg_note (x, REG_EH_REGION, XEXP (eh_note, 0));
8856 /* This is used by reload pass, that does emit some instructions after
8857 abnormal calls moving basic block end, but in fact it wants to emit
8858 them on the edge. Looks for abnormal call edges, find backward the
8859 proper call and fix the damage.
8861 Similar handle instructions throwing exceptions internally. */
8863 fixup_abnormal_edges (void)
8865 bool inserted = false;
8873 /* Look for cases we are interested in - calls or instructions causing
8875 FOR_EACH_EDGE (e, ei, bb->succs)
8877 if (e->flags & EDGE_ABNORMAL_CALL)
8879 if ((e->flags & (EDGE_ABNORMAL | EDGE_EH))
8880 == (EDGE_ABNORMAL | EDGE_EH))
8883 if (e && !CALL_P (BB_END (bb))
8884 && !can_throw_internal (BB_END (bb)))
8888 /* Get past the new insns generated. Allow notes, as the insns
8889 may be already deleted. */
8891 while ((NONJUMP_INSN_P (insn) || NOTE_P (insn))
8892 && !can_throw_internal (insn)
8893 && insn != BB_HEAD (bb))
8894 insn = PREV_INSN (insn);
8896 if (CALL_P (insn) || can_throw_internal (insn))
8900 stop = NEXT_INSN (BB_END (bb));
8902 insn = NEXT_INSN (insn);
8904 FOR_EACH_EDGE (e, ei, bb->succs)
8905 if (e->flags & EDGE_FALLTHRU)
8908 while (insn && insn != stop)
8910 next = NEXT_INSN (insn);
8915 /* Sometimes there's still the return value USE.
8916 If it's placed after a trapping call (i.e. that
8917 call is the last insn anyway), we have no fallthru
8918 edge. Simply delete this use and don't try to insert
8919 on the non-existent edge. */
8920 if (GET_CODE (PATTERN (insn)) != USE)
8922 /* We're not deleting it, we're moving it. */
8923 INSN_DELETED_P (insn) = 0;
8924 PREV_INSN (insn) = NULL_RTX;
8925 NEXT_INSN (insn) = NULL_RTX;
8927 insert_insn_on_edge (insn, e);
8931 else if (!BARRIER_P (insn))
8932 set_block_for_insn (insn, NULL);
8937 /* It may be that we don't find any such trapping insn. In this
8938 case we discovered quite late that the insn that had been
8939 marked as can_throw_internal in fact couldn't trap at all.
8940 So we should in fact delete the EH edges out of the block. */
8942 purge_dead_edges (bb);
8946 /* We've possibly turned single trapping insn into multiple ones. */
8947 if (flag_non_call_exceptions)
8950 blocks = sbitmap_alloc (last_basic_block);
8951 sbitmap_ones (blocks);
8952 find_many_sub_basic_blocks (blocks);
8953 sbitmap_free (blocks);
8957 commit_edge_insertions ();
8959 #ifdef ENABLE_CHECKING
8960 /* Verify that we didn't turn one trapping insn into many, and that
8961 we found and corrected all of the problems wrt fixups on the
8963 verify_flow_info ();
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