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 Free Software Foundation,
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 2, 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 COPYING. If not, write to the Free
20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
25 #include "coretypes.h"
29 #include "hard-reg-set.h"
33 #include "insn-config.h"
39 #include "addresses.h"
40 #include "basic-block.h"
50 /* This file contains the reload pass of the compiler, which is
51 run after register allocation has been done. It checks that
52 each insn is valid (operands required to be in registers really
53 are in registers of the proper class) and fixes up invalid ones
54 by copying values temporarily into registers for the insns
57 The results of register allocation are described by the vector
58 reg_renumber; the insns still contain pseudo regs, but reg_renumber
59 can be used to find which hard reg, if any, a pseudo reg is in.
61 The technique we always use is to free up a few hard regs that are
62 called ``reload regs'', and for each place where a pseudo reg
63 must be in a hard reg, copy it temporarily into one of the reload regs.
65 Reload regs are allocated locally for every instruction that needs
66 reloads. When there are pseudos which are allocated to a register that
67 has been chosen as a reload reg, such pseudos must be ``spilled''.
68 This means that they go to other hard regs, or to stack slots if no other
69 available hard regs can be found. Spilling can invalidate more
70 insns, requiring additional need for reloads, so we must keep checking
71 until the process stabilizes.
73 For machines with different classes of registers, we must keep track
74 of the register class needed for each reload, and make sure that
75 we allocate enough reload registers of each class.
77 The file reload.c contains the code that checks one insn for
78 validity and reports the reloads that it needs. This file
79 is in charge of scanning the entire rtl code, accumulating the
80 reload needs, spilling, assigning reload registers to use for
81 fixing up each insn, and generating the new insns to copy values
82 into the reload registers. */
84 /* During reload_as_needed, element N contains a REG rtx for the hard reg
85 into which reg N has been reloaded (perhaps for a previous insn). */
86 static rtx *reg_last_reload_reg;
88 /* Elt N nonzero if reg_last_reload_reg[N] has been set in this insn
89 for an output reload that stores into reg N. */
90 static regset_head reg_has_output_reload;
92 /* Indicates which hard regs are reload-registers for an output reload
93 in the current insn. */
94 static HARD_REG_SET reg_is_output_reload;
96 /* Element N is the constant value to which pseudo reg N is equivalent,
97 or zero if pseudo reg N is not equivalent to a constant.
98 find_reloads looks at this in order to replace pseudo reg N
99 with the constant it stands for. */
100 rtx *reg_equiv_constant;
102 /* Element N is an invariant value to which pseudo reg N is equivalent.
103 eliminate_regs_in_insn uses this to replace pseudos in particular
105 rtx *reg_equiv_invariant;
107 /* Element N is a memory location to which pseudo reg N is equivalent,
108 prior to any register elimination (such as frame pointer to stack
109 pointer). Depending on whether or not it is a valid address, this value
110 is transferred to either reg_equiv_address or reg_equiv_mem. */
111 rtx *reg_equiv_memory_loc;
113 /* We allocate reg_equiv_memory_loc inside a varray so that the garbage
114 collector can keep track of what is inside. */
115 VEC(rtx,gc) *reg_equiv_memory_loc_vec;
117 /* Element N is the address of stack slot to which pseudo reg N is equivalent.
118 This is used when the address is not valid as a memory address
119 (because its displacement is too big for the machine.) */
120 rtx *reg_equiv_address;
122 /* Element N is the memory slot to which pseudo reg N is equivalent,
123 or zero if pseudo reg N is not equivalent to a memory slot. */
126 /* Element N is an EXPR_LIST of REG_EQUIVs containing MEMs with
127 alternate representations of the location of pseudo reg N. */
128 rtx *reg_equiv_alt_mem_list;
130 /* Widest width in which each pseudo reg is referred to (via subreg). */
131 static unsigned int *reg_max_ref_width;
133 /* Element N is the list of insns that initialized reg N from its equivalent
134 constant or memory slot. */
136 int reg_equiv_init_size;
138 /* Vector to remember old contents of reg_renumber before spilling. */
139 static short *reg_old_renumber;
141 /* During reload_as_needed, element N contains the last pseudo regno reloaded
142 into hard register N. If that pseudo reg occupied more than one register,
143 reg_reloaded_contents points to that pseudo for each spill register in
144 use; all of these must remain set for an inheritance to occur. */
145 static int reg_reloaded_contents[FIRST_PSEUDO_REGISTER];
147 /* During reload_as_needed, element N contains the insn for which
148 hard register N was last used. Its contents are significant only
149 when reg_reloaded_valid is set for this register. */
150 static rtx reg_reloaded_insn[FIRST_PSEUDO_REGISTER];
152 /* Indicate if reg_reloaded_insn / reg_reloaded_contents is valid. */
153 static HARD_REG_SET reg_reloaded_valid;
154 /* Indicate if the register was dead at the end of the reload.
155 This is only valid if reg_reloaded_contents is set and valid. */
156 static HARD_REG_SET reg_reloaded_dead;
158 /* Indicate whether the register's current value is one that is not
159 safe to retain across a call, even for registers that are normally
161 static HARD_REG_SET reg_reloaded_call_part_clobbered;
163 /* Number of spill-regs so far; number of valid elements of spill_regs. */
166 /* In parallel with spill_regs, contains REG rtx's for those regs.
167 Holds the last rtx used for any given reg, or 0 if it has never
168 been used for spilling yet. This rtx is reused, provided it has
170 static rtx spill_reg_rtx[FIRST_PSEUDO_REGISTER];
172 /* In parallel with spill_regs, contains nonzero for a spill reg
173 that was stored after the last time it was used.
174 The precise value is the insn generated to do the store. */
175 static rtx spill_reg_store[FIRST_PSEUDO_REGISTER];
177 /* This is the register that was stored with spill_reg_store. This is a
178 copy of reload_out / reload_out_reg when the value was stored; if
179 reload_out is a MEM, spill_reg_stored_to will be set to reload_out_reg. */
180 static rtx spill_reg_stored_to[FIRST_PSEUDO_REGISTER];
182 /* This table is the inverse mapping of spill_regs:
183 indexed by hard reg number,
184 it contains the position of that reg in spill_regs,
185 or -1 for something that is not in spill_regs.
187 ?!? This is no longer accurate. */
188 static short spill_reg_order[FIRST_PSEUDO_REGISTER];
190 /* This reg set indicates registers that can't be used as spill registers for
191 the currently processed insn. These are the hard registers which are live
192 during the insn, but not allocated to pseudos, as well as fixed
194 static HARD_REG_SET bad_spill_regs;
196 /* These are the hard registers that can't be used as spill register for any
197 insn. This includes registers used for user variables and registers that
198 we can't eliminate. A register that appears in this set also can't be used
199 to retry register allocation. */
200 static HARD_REG_SET bad_spill_regs_global;
202 /* Describes order of use of registers for reloading
203 of spilled pseudo-registers. `n_spills' is the number of
204 elements that are actually valid; new ones are added at the end.
206 Both spill_regs and spill_reg_order are used on two occasions:
207 once during find_reload_regs, where they keep track of the spill registers
208 for a single insn, but also during reload_as_needed where they show all
209 the registers ever used by reload. For the latter case, the information
210 is calculated during finish_spills. */
211 static short spill_regs[FIRST_PSEUDO_REGISTER];
213 /* This vector of reg sets indicates, for each pseudo, which hard registers
214 may not be used for retrying global allocation because the register was
215 formerly spilled from one of them. If we allowed reallocating a pseudo to
216 a register that it was already allocated to, reload might not
218 static HARD_REG_SET *pseudo_previous_regs;
220 /* This vector of reg sets indicates, for each pseudo, which hard
221 registers may not be used for retrying global allocation because they
222 are used as spill registers during one of the insns in which the
224 static HARD_REG_SET *pseudo_forbidden_regs;
226 /* All hard regs that have been used as spill registers for any insn are
227 marked in this set. */
228 static HARD_REG_SET used_spill_regs;
230 /* Index of last register assigned as a spill register. We allocate in
231 a round-robin fashion. */
232 static int last_spill_reg;
234 /* Nonzero if indirect addressing is supported on the machine; this means
235 that spilling (REG n) does not require reloading it into a register in
236 order to do (MEM (REG n)) or (MEM (PLUS (REG n) (CONST_INT c))). The
237 value indicates the level of indirect addressing supported, e.g., two
238 means that (MEM (MEM (REG n))) is also valid if (REG n) does not get
240 static char spill_indirect_levels;
242 /* Nonzero if indirect addressing is supported when the innermost MEM is
243 of the form (MEM (SYMBOL_REF sym)). It is assumed that the level to
244 which these are valid is the same as spill_indirect_levels, above. */
245 char indirect_symref_ok;
247 /* Nonzero if an address (plus (reg frame_pointer) (reg ...)) is valid. */
248 char double_reg_address_ok;
250 /* Record the stack slot for each spilled hard register. */
251 static rtx spill_stack_slot[FIRST_PSEUDO_REGISTER];
253 /* Width allocated so far for that stack slot. */
254 static unsigned int spill_stack_slot_width[FIRST_PSEUDO_REGISTER];
256 /* Record which pseudos needed to be spilled. */
257 static regset_head spilled_pseudos;
259 /* Used for communication between order_regs_for_reload and count_pseudo.
260 Used to avoid counting one pseudo twice. */
261 static regset_head pseudos_counted;
263 /* First uid used by insns created by reload in this function.
264 Used in find_equiv_reg. */
265 int reload_first_uid;
267 /* Flag set by local-alloc or global-alloc if anything is live in
268 a call-clobbered reg across calls. */
269 int caller_save_needed;
271 /* Set to 1 while reload_as_needed is operating.
272 Required by some machines to handle any generated moves differently. */
273 int reload_in_progress = 0;
275 /* These arrays record the insn_code of insns that may be needed to
276 perform input and output reloads of special objects. They provide a
277 place to pass a scratch register. */
278 enum insn_code reload_in_optab[NUM_MACHINE_MODES];
279 enum insn_code reload_out_optab[NUM_MACHINE_MODES];
281 /* This obstack is used for allocation of rtl during register elimination.
282 The allocated storage can be freed once find_reloads has processed the
284 static struct obstack reload_obstack;
286 /* Points to the beginning of the reload_obstack. All insn_chain structures
287 are allocated first. */
288 static char *reload_startobj;
290 /* The point after all insn_chain structures. Used to quickly deallocate
291 memory allocated in copy_reloads during calculate_needs_all_insns. */
292 static char *reload_firstobj;
294 /* This points before all local rtl generated by register elimination.
295 Used to quickly free all memory after processing one insn. */
296 static char *reload_insn_firstobj;
298 /* List of insn_chain instructions, one for every insn that reload needs to
300 struct insn_chain *reload_insn_chain;
302 /* List of all insns needing reloads. */
303 static struct insn_chain *insns_need_reload;
305 /* This structure is used to record information about register eliminations.
306 Each array entry describes one possible way of eliminating a register
307 in favor of another. If there is more than one way of eliminating a
308 particular register, the most preferred should be specified first. */
312 int from; /* Register number to be eliminated. */
313 int to; /* Register number used as replacement. */
314 HOST_WIDE_INT initial_offset; /* Initial difference between values. */
315 int can_eliminate; /* Nonzero if this elimination can be done. */
316 int can_eliminate_previous; /* Value of CAN_ELIMINATE in previous scan over
317 insns made by reload. */
318 HOST_WIDE_INT offset; /* Current offset between the two regs. */
319 HOST_WIDE_INT previous_offset;/* Offset at end of previous insn. */
320 int ref_outside_mem; /* "to" has been referenced outside a MEM. */
321 rtx from_rtx; /* REG rtx for the register to be eliminated.
322 We cannot simply compare the number since
323 we might then spuriously replace a hard
324 register corresponding to a pseudo
325 assigned to the reg to be eliminated. */
326 rtx to_rtx; /* REG rtx for the replacement. */
329 static struct elim_table *reg_eliminate = 0;
331 /* This is an intermediate structure to initialize the table. It has
332 exactly the members provided by ELIMINABLE_REGS. */
333 static const struct elim_table_1
337 } reg_eliminate_1[] =
339 /* If a set of eliminable registers was specified, define the table from it.
340 Otherwise, default to the normal case of the frame pointer being
341 replaced by the stack pointer. */
343 #ifdef ELIMINABLE_REGS
346 {{ FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM}};
349 #define NUM_ELIMINABLE_REGS ARRAY_SIZE (reg_eliminate_1)
351 /* Record the number of pending eliminations that have an offset not equal
352 to their initial offset. If nonzero, we use a new copy of each
353 replacement result in any insns encountered. */
354 int num_not_at_initial_offset;
356 /* Count the number of registers that we may be able to eliminate. */
357 static int num_eliminable;
358 /* And the number of registers that are equivalent to a constant that
359 can be eliminated to frame_pointer / arg_pointer + constant. */
360 static int num_eliminable_invariants;
362 /* For each label, we record the offset of each elimination. If we reach
363 a label by more than one path and an offset differs, we cannot do the
364 elimination. This information is indexed by the difference of the
365 number of the label and the first label number. We can't offset the
366 pointer itself as this can cause problems on machines with segmented
367 memory. The first table is an array of flags that records whether we
368 have yet encountered a label and the second table is an array of arrays,
369 one entry in the latter array for each elimination. */
371 static int first_label_num;
372 static char *offsets_known_at;
373 static HOST_WIDE_INT (*offsets_at)[NUM_ELIMINABLE_REGS];
375 /* Number of labels in the current function. */
377 static int num_labels;
379 static void replace_pseudos_in (rtx *, enum machine_mode, rtx);
380 static void maybe_fix_stack_asms (void);
381 static void copy_reloads (struct insn_chain *);
382 static void calculate_needs_all_insns (int);
383 static int find_reg (struct insn_chain *, int);
384 static void find_reload_regs (struct insn_chain *);
385 static void select_reload_regs (void);
386 static void delete_caller_save_insns (void);
388 static void spill_failure (rtx, enum reg_class);
389 static void count_spilled_pseudo (int, int, int);
390 static void delete_dead_insn (rtx);
391 static void alter_reg (int, int);
392 static void set_label_offsets (rtx, rtx, int);
393 static void check_eliminable_occurrences (rtx);
394 static void elimination_effects (rtx, enum machine_mode);
395 static int eliminate_regs_in_insn (rtx, int);
396 static void update_eliminable_offsets (void);
397 static void mark_not_eliminable (rtx, rtx, void *);
398 static void set_initial_elim_offsets (void);
399 static bool verify_initial_elim_offsets (void);
400 static void set_initial_label_offsets (void);
401 static void set_offsets_for_label (rtx);
402 static void init_elim_table (void);
403 static void update_eliminables (HARD_REG_SET *);
404 static void spill_hard_reg (unsigned int, int);
405 static int finish_spills (int);
406 static void scan_paradoxical_subregs (rtx);
407 static void count_pseudo (int);
408 static void order_regs_for_reload (struct insn_chain *);
409 static void reload_as_needed (int);
410 static void forget_old_reloads_1 (rtx, rtx, void *);
411 static void forget_marked_reloads (regset);
412 static int reload_reg_class_lower (const void *, const void *);
413 static void mark_reload_reg_in_use (unsigned int, int, enum reload_type,
415 static void clear_reload_reg_in_use (unsigned int, int, enum reload_type,
417 static int reload_reg_free_p (unsigned int, int, enum reload_type);
418 static int reload_reg_free_for_value_p (int, int, int, enum reload_type,
420 static int free_for_value_p (int, enum machine_mode, int, enum reload_type,
422 static int reload_reg_reaches_end_p (unsigned int, int, enum reload_type);
423 static int allocate_reload_reg (struct insn_chain *, int, int);
424 static int conflicts_with_override (rtx);
425 static void failed_reload (rtx, int);
426 static int set_reload_reg (int, int);
427 static void choose_reload_regs_init (struct insn_chain *, rtx *);
428 static void choose_reload_regs (struct insn_chain *);
429 static void merge_assigned_reloads (rtx);
430 static void emit_input_reload_insns (struct insn_chain *, struct reload *,
432 static void emit_output_reload_insns (struct insn_chain *, struct reload *,
434 static void do_input_reload (struct insn_chain *, struct reload *, int);
435 static void do_output_reload (struct insn_chain *, struct reload *, int);
436 static bool inherit_piecemeal_p (int, int);
437 static void emit_reload_insns (struct insn_chain *);
438 static void delete_output_reload (rtx, int, int);
439 static void delete_address_reloads (rtx, rtx);
440 static void delete_address_reloads_1 (rtx, rtx, rtx);
441 static rtx inc_for_reload (rtx, rtx, rtx, int);
443 static void add_auto_inc_notes (rtx, rtx);
445 static void copy_eh_notes (rtx, rtx);
446 static int reloads_conflict (int, int);
447 static rtx gen_reload (rtx, rtx, int, enum reload_type);
448 static rtx emit_insn_if_valid_for_reload (rtx);
450 /* Initialize the reload pass once per compilation. */
457 /* Often (MEM (REG n)) is still valid even if (REG n) is put on the stack.
458 Set spill_indirect_levels to the number of levels such addressing is
459 permitted, zero if it is not permitted at all. */
462 = gen_rtx_MEM (Pmode,
465 LAST_VIRTUAL_REGISTER + 1),
467 spill_indirect_levels = 0;
469 while (memory_address_p (QImode, tem))
471 spill_indirect_levels++;
472 tem = gen_rtx_MEM (Pmode, tem);
475 /* See if indirect addressing is valid for (MEM (SYMBOL_REF ...)). */
477 tem = gen_rtx_MEM (Pmode, gen_rtx_SYMBOL_REF (Pmode, "foo"));
478 indirect_symref_ok = memory_address_p (QImode, tem);
480 /* See if reg+reg is a valid (and offsettable) address. */
482 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
484 tem = gen_rtx_PLUS (Pmode,
485 gen_rtx_REG (Pmode, HARD_FRAME_POINTER_REGNUM),
486 gen_rtx_REG (Pmode, i));
488 /* This way, we make sure that reg+reg is an offsettable address. */
489 tem = plus_constant (tem, 4);
491 if (memory_address_p (QImode, tem))
493 double_reg_address_ok = 1;
498 /* Initialize obstack for our rtl allocation. */
499 gcc_obstack_init (&reload_obstack);
500 reload_startobj = obstack_alloc (&reload_obstack, 0);
502 INIT_REG_SET (&spilled_pseudos);
503 INIT_REG_SET (&pseudos_counted);
506 /* List of insn chains that are currently unused. */
507 static struct insn_chain *unused_insn_chains = 0;
509 /* Allocate an empty insn_chain structure. */
511 new_insn_chain (void)
513 struct insn_chain *c;
515 if (unused_insn_chains == 0)
517 c = obstack_alloc (&reload_obstack, sizeof (struct insn_chain));
518 INIT_REG_SET (&c->live_throughout);
519 INIT_REG_SET (&c->dead_or_set);
523 c = unused_insn_chains;
524 unused_insn_chains = c->next;
526 c->is_caller_save_insn = 0;
527 c->need_operand_change = 0;
533 /* Small utility function to set all regs in hard reg set TO which are
534 allocated to pseudos in regset FROM. */
537 compute_use_by_pseudos (HARD_REG_SET *to, regset from)
540 reg_set_iterator rsi;
542 EXECUTE_IF_SET_IN_REG_SET (from, FIRST_PSEUDO_REGISTER, regno, rsi)
544 int r = reg_renumber[regno];
549 /* reload_combine uses the information from
550 BASIC_BLOCK->global_live_at_start, which might still
551 contain registers that have not actually been allocated
552 since they have an equivalence. */
553 gcc_assert (reload_completed);
557 nregs = hard_regno_nregs[r][PSEUDO_REGNO_MODE (regno)];
559 SET_HARD_REG_BIT (*to, r + nregs);
564 /* Replace all pseudos found in LOC with their corresponding
568 replace_pseudos_in (rtx *loc, enum machine_mode mem_mode, rtx usage)
581 unsigned int regno = REGNO (x);
583 if (regno < FIRST_PSEUDO_REGISTER)
586 x = eliminate_regs (x, mem_mode, usage);
590 replace_pseudos_in (loc, mem_mode, usage);
594 if (reg_equiv_constant[regno])
595 *loc = reg_equiv_constant[regno];
596 else if (reg_equiv_mem[regno])
597 *loc = reg_equiv_mem[regno];
598 else if (reg_equiv_address[regno])
599 *loc = gen_rtx_MEM (GET_MODE (x), reg_equiv_address[regno]);
602 gcc_assert (!REG_P (regno_reg_rtx[regno])
603 || REGNO (regno_reg_rtx[regno]) != regno);
604 *loc = regno_reg_rtx[regno];
609 else if (code == MEM)
611 replace_pseudos_in (& XEXP (x, 0), GET_MODE (x), usage);
615 /* Process each of our operands recursively. */
616 fmt = GET_RTX_FORMAT (code);
617 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
619 replace_pseudos_in (&XEXP (x, i), mem_mode, usage);
620 else if (*fmt == 'E')
621 for (j = 0; j < XVECLEN (x, i); j++)
622 replace_pseudos_in (& XVECEXP (x, i, j), mem_mode, usage);
626 /* Global variables used by reload and its subroutines. */
628 /* Set during calculate_needs if an insn needs register elimination. */
629 static int something_needs_elimination;
630 /* Set during calculate_needs if an insn needs an operand changed. */
631 static int something_needs_operands_changed;
633 /* Nonzero means we couldn't get enough spill regs. */
636 /* Main entry point for the reload pass.
638 FIRST is the first insn of the function being compiled.
640 GLOBAL nonzero means we were called from global_alloc
641 and should attempt to reallocate any pseudoregs that we
642 displace from hard regs we will use for reloads.
643 If GLOBAL is zero, we do not have enough information to do that,
644 so any pseudo reg that is spilled must go to the stack.
646 Return value is nonzero if reload failed
647 and we must not do any more for this function. */
650 reload (rtx first, int global)
654 struct elim_table *ep;
657 /* Make sure even insns with volatile mem refs are recognizable. */
662 reload_firstobj = obstack_alloc (&reload_obstack, 0);
664 /* Make sure that the last insn in the chain
665 is not something that needs reloading. */
666 emit_note (NOTE_INSN_DELETED);
668 /* Enable find_equiv_reg to distinguish insns made by reload. */
669 reload_first_uid = get_max_uid ();
671 #ifdef SECONDARY_MEMORY_NEEDED
672 /* Initialize the secondary memory table. */
673 clear_secondary_mem ();
676 /* We don't have a stack slot for any spill reg yet. */
677 memset (spill_stack_slot, 0, sizeof spill_stack_slot);
678 memset (spill_stack_slot_width, 0, sizeof spill_stack_slot_width);
680 /* Initialize the save area information for caller-save, in case some
684 /* Compute which hard registers are now in use
685 as homes for pseudo registers.
686 This is done here rather than (eg) in global_alloc
687 because this point is reached even if not optimizing. */
688 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
691 /* A function that receives a nonlocal goto must save all call-saved
693 if (current_function_has_nonlocal_label)
694 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
695 if (! call_used_regs[i] && ! fixed_regs[i] && ! LOCAL_REGNO (i))
696 regs_ever_live[i] = 1;
698 /* Find all the pseudo registers that didn't get hard regs
699 but do have known equivalent constants or memory slots.
700 These include parameters (known equivalent to parameter slots)
701 and cse'd or loop-moved constant memory addresses.
703 Record constant equivalents in reg_equiv_constant
704 so they will be substituted by find_reloads.
705 Record memory equivalents in reg_mem_equiv so they can
706 be substituted eventually by altering the REG-rtx's. */
708 reg_equiv_constant = XCNEWVEC (rtx, max_regno);
709 reg_equiv_invariant = XCNEWVEC (rtx, max_regno);
710 reg_equiv_mem = XCNEWVEC (rtx, max_regno);
711 reg_equiv_alt_mem_list = XCNEWVEC (rtx, max_regno);
712 reg_equiv_address = XCNEWVEC (rtx, max_regno);
713 reg_max_ref_width = XCNEWVEC (unsigned int, max_regno);
714 reg_old_renumber = XCNEWVEC (short, max_regno);
715 memcpy (reg_old_renumber, reg_renumber, max_regno * sizeof (short));
716 pseudo_forbidden_regs = XNEWVEC (HARD_REG_SET, max_regno);
717 pseudo_previous_regs = XCNEWVEC (HARD_REG_SET, max_regno);
719 CLEAR_HARD_REG_SET (bad_spill_regs_global);
721 /* Look for REG_EQUIV notes; record what each pseudo is equivalent
722 to. Also find all paradoxical subregs and find largest such for
725 num_eliminable_invariants = 0;
726 for (insn = first; insn; insn = NEXT_INSN (insn))
728 rtx set = single_set (insn);
730 /* We may introduce USEs that we want to remove at the end, so
731 we'll mark them with QImode. Make sure there are no
732 previously-marked insns left by say regmove. */
733 if (INSN_P (insn) && GET_CODE (PATTERN (insn)) == USE
734 && GET_MODE (insn) != VOIDmode)
735 PUT_MODE (insn, VOIDmode);
738 scan_paradoxical_subregs (PATTERN (insn));
740 if (set != 0 && REG_P (SET_DEST (set)))
742 rtx note = find_reg_note (insn, REG_EQUIV, NULL_RTX);
748 i = REGNO (SET_DEST (set));
751 if (i <= LAST_VIRTUAL_REGISTER)
754 if (! function_invariant_p (x)
756 /* A function invariant is often CONSTANT_P but may
757 include a register. We promise to only pass
758 CONSTANT_P objects to LEGITIMATE_PIC_OPERAND_P. */
760 && LEGITIMATE_PIC_OPERAND_P (x)))
762 /* It can happen that a REG_EQUIV note contains a MEM
763 that is not a legitimate memory operand. As later
764 stages of reload assume that all addresses found
765 in the reg_equiv_* arrays were originally legitimate,
766 we ignore such REG_EQUIV notes. */
767 if (memory_operand (x, VOIDmode))
769 /* Always unshare the equivalence, so we can
770 substitute into this insn without touching the
772 reg_equiv_memory_loc[i] = copy_rtx (x);
774 else if (function_invariant_p (x))
776 if (GET_CODE (x) == PLUS)
778 /* This is PLUS of frame pointer and a constant,
779 and might be shared. Unshare it. */
780 reg_equiv_invariant[i] = copy_rtx (x);
781 num_eliminable_invariants++;
783 else if (x == frame_pointer_rtx || x == arg_pointer_rtx)
785 reg_equiv_invariant[i] = x;
786 num_eliminable_invariants++;
788 else if (LEGITIMATE_CONSTANT_P (x))
789 reg_equiv_constant[i] = x;
792 reg_equiv_memory_loc[i]
793 = force_const_mem (GET_MODE (SET_DEST (set)), x);
794 if (! reg_equiv_memory_loc[i])
795 reg_equiv_init[i] = NULL_RTX;
800 reg_equiv_init[i] = NULL_RTX;
805 reg_equiv_init[i] = NULL_RTX;
810 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
811 if (reg_equiv_init[i])
813 fprintf (dump_file, "init_insns for %u: ", i);
814 print_inline_rtx (dump_file, reg_equiv_init[i], 20);
815 fprintf (dump_file, "\n");
820 first_label_num = get_first_label_num ();
821 num_labels = max_label_num () - first_label_num;
823 /* Allocate the tables used to store offset information at labels. */
824 /* We used to use alloca here, but the size of what it would try to
825 allocate would occasionally cause it to exceed the stack limit and
826 cause a core dump. */
827 offsets_known_at = XNEWVEC (char, num_labels);
828 offsets_at = (HOST_WIDE_INT (*)[NUM_ELIMINABLE_REGS]) xmalloc (num_labels * NUM_ELIMINABLE_REGS * sizeof (HOST_WIDE_INT));
830 /* Alter each pseudo-reg rtx to contain its hard reg number.
831 Assign stack slots to the pseudos that lack hard regs or equivalents.
832 Do not touch virtual registers. */
834 for (i = LAST_VIRTUAL_REGISTER + 1; i < max_regno; i++)
837 /* If we have some registers we think can be eliminated, scan all insns to
838 see if there is an insn that sets one of these registers to something
839 other than itself plus a constant. If so, the register cannot be
840 eliminated. Doing this scan here eliminates an extra pass through the
841 main reload loop in the most common case where register elimination
843 for (insn = first; insn && num_eliminable; insn = NEXT_INSN (insn))
845 note_stores (PATTERN (insn), mark_not_eliminable, NULL);
847 maybe_fix_stack_asms ();
849 insns_need_reload = 0;
850 something_needs_elimination = 0;
852 /* Initialize to -1, which means take the first spill register. */
855 /* Spill any hard regs that we know we can't eliminate. */
856 CLEAR_HARD_REG_SET (used_spill_regs);
857 /* There can be multiple ways to eliminate a register;
858 they should be listed adjacently.
859 Elimination for any register fails only if all possible ways fail. */
860 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; )
863 int can_eliminate = 0;
866 can_eliminate |= ep->can_eliminate;
869 while (ep < ®_eliminate[NUM_ELIMINABLE_REGS] && ep->from == from);
871 spill_hard_reg (from, 1);
874 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
875 if (frame_pointer_needed)
876 spill_hard_reg (HARD_FRAME_POINTER_REGNUM, 1);
878 finish_spills (global);
880 /* From now on, we may need to generate moves differently. We may also
881 allow modifications of insns which cause them to not be recognized.
882 Any such modifications will be cleaned up during reload itself. */
883 reload_in_progress = 1;
885 /* This loop scans the entire function each go-round
886 and repeats until one repetition spills no additional hard regs. */
889 int something_changed;
891 HOST_WIDE_INT starting_frame_size;
893 starting_frame_size = get_frame_size ();
895 set_initial_elim_offsets ();
896 set_initial_label_offsets ();
898 /* For each pseudo register that has an equivalent location defined,
899 try to eliminate any eliminable registers (such as the frame pointer)
900 assuming initial offsets for the replacement register, which
903 If the resulting location is directly addressable, substitute
904 the MEM we just got directly for the old REG.
906 If it is not addressable but is a constant or the sum of a hard reg
907 and constant, it is probably not addressable because the constant is
908 out of range, in that case record the address; we will generate
909 hairy code to compute the address in a register each time it is
910 needed. Similarly if it is a hard register, but one that is not
911 valid as an address register.
913 If the location is not addressable, but does not have one of the
914 above forms, assign a stack slot. We have to do this to avoid the
915 potential of producing lots of reloads if, e.g., a location involves
916 a pseudo that didn't get a hard register and has an equivalent memory
917 location that also involves a pseudo that didn't get a hard register.
919 Perhaps at some point we will improve reload_when_needed handling
920 so this problem goes away. But that's very hairy. */
922 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
923 if (reg_renumber[i] < 0 && reg_equiv_memory_loc[i])
925 rtx x = eliminate_regs (reg_equiv_memory_loc[i], 0, NULL_RTX);
927 if (strict_memory_address_p (GET_MODE (regno_reg_rtx[i]),
929 reg_equiv_mem[i] = x, reg_equiv_address[i] = 0;
930 else if (CONSTANT_P (XEXP (x, 0))
931 || (REG_P (XEXP (x, 0))
932 && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER)
933 || (GET_CODE (XEXP (x, 0)) == PLUS
934 && REG_P (XEXP (XEXP (x, 0), 0))
935 && (REGNO (XEXP (XEXP (x, 0), 0))
936 < FIRST_PSEUDO_REGISTER)
937 && CONSTANT_P (XEXP (XEXP (x, 0), 1))))
938 reg_equiv_address[i] = XEXP (x, 0), reg_equiv_mem[i] = 0;
941 /* Make a new stack slot. Then indicate that something
942 changed so we go back and recompute offsets for
943 eliminable registers because the allocation of memory
944 below might change some offset. reg_equiv_{mem,address}
945 will be set up for this pseudo on the next pass around
947 reg_equiv_memory_loc[i] = 0;
948 reg_equiv_init[i] = 0;
953 if (caller_save_needed)
956 /* If we allocated another stack slot, redo elimination bookkeeping. */
957 if (starting_frame_size != get_frame_size ())
959 if (starting_frame_size && cfun->stack_alignment_needed)
961 /* If we have a stack frame, we must align it now. The
962 stack size may be a part of the offset computation for
963 register elimination. So if this changes the stack size,
964 then repeat the elimination bookkeeping. We don't
965 realign when there is no stack, as that will cause a
966 stack frame when none is needed should
967 STARTING_FRAME_OFFSET not be already aligned to
969 assign_stack_local (BLKmode, 0, cfun->stack_alignment_needed);
970 if (starting_frame_size != get_frame_size ())
974 if (caller_save_needed)
976 save_call_clobbered_regs ();
977 /* That might have allocated new insn_chain structures. */
978 reload_firstobj = obstack_alloc (&reload_obstack, 0);
981 calculate_needs_all_insns (global);
983 CLEAR_REG_SET (&spilled_pseudos);
986 something_changed = 0;
988 /* If we allocated any new memory locations, make another pass
989 since it might have changed elimination offsets. */
990 if (starting_frame_size != get_frame_size ())
991 something_changed = 1;
993 /* Even if the frame size remained the same, we might still have
994 changed elimination offsets, e.g. if find_reloads called
995 force_const_mem requiring the back end to allocate a constant
996 pool base register that needs to be saved on the stack. */
997 else if (!verify_initial_elim_offsets ())
998 something_changed = 1;
1001 HARD_REG_SET to_spill;
1002 CLEAR_HARD_REG_SET (to_spill);
1003 update_eliminables (&to_spill);
1004 AND_COMPL_HARD_REG_SET (used_spill_regs, to_spill);
1006 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1007 if (TEST_HARD_REG_BIT (to_spill, i))
1009 spill_hard_reg (i, 1);
1012 /* Regardless of the state of spills, if we previously had
1013 a register that we thought we could eliminate, but now can
1014 not eliminate, we must run another pass.
1016 Consider pseudos which have an entry in reg_equiv_* which
1017 reference an eliminable register. We must make another pass
1018 to update reg_equiv_* so that we do not substitute in the
1019 old value from when we thought the elimination could be
1021 something_changed = 1;
1025 select_reload_regs ();
1029 if (insns_need_reload != 0 || did_spill)
1030 something_changed |= finish_spills (global);
1032 if (! something_changed)
1035 if (caller_save_needed)
1036 delete_caller_save_insns ();
1038 obstack_free (&reload_obstack, reload_firstobj);
1041 /* If global-alloc was run, notify it of any register eliminations we have
1044 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
1045 if (ep->can_eliminate)
1046 mark_elimination (ep->from, ep->to);
1048 /* If a pseudo has no hard reg, delete the insns that made the equivalence.
1049 If that insn didn't set the register (i.e., it copied the register to
1050 memory), just delete that insn instead of the equivalencing insn plus
1051 anything now dead. If we call delete_dead_insn on that insn, we may
1052 delete the insn that actually sets the register if the register dies
1053 there and that is incorrect. */
1055 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
1057 if (reg_renumber[i] < 0 && reg_equiv_init[i] != 0)
1060 for (list = reg_equiv_init[i]; list; list = XEXP (list, 1))
1062 rtx equiv_insn = XEXP (list, 0);
1064 /* If we already deleted the insn or if it may trap, we can't
1065 delete it. The latter case shouldn't happen, but can
1066 if an insn has a variable address, gets a REG_EH_REGION
1067 note added to it, and then gets converted into a load
1068 from a constant address. */
1069 if (NOTE_P (equiv_insn)
1070 || can_throw_internal (equiv_insn))
1072 else if (reg_set_p (regno_reg_rtx[i], PATTERN (equiv_insn)))
1073 delete_dead_insn (equiv_insn);
1075 SET_INSN_DELETED (equiv_insn);
1080 /* Use the reload registers where necessary
1081 by generating move instructions to move the must-be-register
1082 values into or out of the reload registers. */
1084 if (insns_need_reload != 0 || something_needs_elimination
1085 || something_needs_operands_changed)
1087 HOST_WIDE_INT old_frame_size = get_frame_size ();
1089 reload_as_needed (global);
1091 gcc_assert (old_frame_size == get_frame_size ());
1093 gcc_assert (verify_initial_elim_offsets ());
1096 /* If we were able to eliminate the frame pointer, show that it is no
1097 longer live at the start of any basic block. If it ls live by
1098 virtue of being in a pseudo, that pseudo will be marked live
1099 and hence the frame pointer will be known to be live via that
1102 if (! frame_pointer_needed)
1104 CLEAR_REGNO_REG_SET (bb->il.rtl->global_live_at_start,
1105 HARD_FRAME_POINTER_REGNUM);
1107 /* Come here (with failure set nonzero) if we can't get enough spill
1111 CLEAR_REG_SET (&spilled_pseudos);
1112 reload_in_progress = 0;
1114 /* Now eliminate all pseudo regs by modifying them into
1115 their equivalent memory references.
1116 The REG-rtx's for the pseudos are modified in place,
1117 so all insns that used to refer to them now refer to memory.
1119 For a reg that has a reg_equiv_address, all those insns
1120 were changed by reloading so that no insns refer to it any longer;
1121 but the DECL_RTL of a variable decl may refer to it,
1122 and if so this causes the debugging info to mention the variable. */
1124 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
1128 if (reg_equiv_mem[i])
1129 addr = XEXP (reg_equiv_mem[i], 0);
1131 if (reg_equiv_address[i])
1132 addr = reg_equiv_address[i];
1136 if (reg_renumber[i] < 0)
1138 rtx reg = regno_reg_rtx[i];
1140 REG_USERVAR_P (reg) = 0;
1141 PUT_CODE (reg, MEM);
1142 XEXP (reg, 0) = addr;
1143 if (reg_equiv_memory_loc[i])
1144 MEM_COPY_ATTRIBUTES (reg, reg_equiv_memory_loc[i]);
1147 MEM_IN_STRUCT_P (reg) = MEM_SCALAR_P (reg) = 0;
1148 MEM_ATTRS (reg) = 0;
1150 MEM_NOTRAP_P (reg) = 1;
1152 else if (reg_equiv_mem[i])
1153 XEXP (reg_equiv_mem[i], 0) = addr;
1157 /* We must set reload_completed now since the cleanup_subreg_operands call
1158 below will re-recognize each insn and reload may have generated insns
1159 which are only valid during and after reload. */
1160 reload_completed = 1;
1162 /* Make a pass over all the insns and delete all USEs which we inserted
1163 only to tag a REG_EQUAL note on them. Remove all REG_DEAD and REG_UNUSED
1164 notes. Delete all CLOBBER insns, except those that refer to the return
1165 value and the special mem:BLK CLOBBERs added to prevent the scheduler
1166 from misarranging variable-array code, and simplify (subreg (reg))
1167 operands. Also remove all REG_RETVAL and REG_LIBCALL notes since they
1168 are no longer useful or accurate. Strip and regenerate REG_INC notes
1169 that may have been moved around. */
1171 for (insn = first; insn; insn = NEXT_INSN (insn))
1176 /* Clean up invalid ASMs so that they don't confuse later passes.
1178 if (asm_noperands (PATTERN (insn)) >= 0)
1180 extract_insn (insn);
1181 if (!constrain_operands (1))
1183 error_for_asm (insn,
1184 "%<asm%> operand has impossible constraints");
1191 replace_pseudos_in (& CALL_INSN_FUNCTION_USAGE (insn),
1192 VOIDmode, CALL_INSN_FUNCTION_USAGE (insn));
1194 if ((GET_CODE (PATTERN (insn)) == USE
1195 /* We mark with QImode USEs introduced by reload itself. */
1196 && (GET_MODE (insn) == QImode
1197 || find_reg_note (insn, REG_EQUAL, NULL_RTX)))
1198 || (GET_CODE (PATTERN (insn)) == CLOBBER
1199 && (!MEM_P (XEXP (PATTERN (insn), 0))
1200 || GET_MODE (XEXP (PATTERN (insn), 0)) != BLKmode
1201 || (GET_CODE (XEXP (XEXP (PATTERN (insn), 0), 0)) != SCRATCH
1202 && XEXP (XEXP (PATTERN (insn), 0), 0)
1203 != stack_pointer_rtx))
1204 && (!REG_P (XEXP (PATTERN (insn), 0))
1205 || ! REG_FUNCTION_VALUE_P (XEXP (PATTERN (insn), 0)))))
1211 /* Some CLOBBERs may survive until here and still reference unassigned
1212 pseudos with const equivalent, which may in turn cause ICE in later
1213 passes if the reference remains in place. */
1214 if (GET_CODE (PATTERN (insn)) == CLOBBER)
1215 replace_pseudos_in (& XEXP (PATTERN (insn), 0),
1216 VOIDmode, PATTERN (insn));
1218 /* Discard obvious no-ops, even without -O. This optimization
1219 is fast and doesn't interfere with debugging. */
1220 if (NONJUMP_INSN_P (insn)
1221 && GET_CODE (PATTERN (insn)) == SET
1222 && REG_P (SET_SRC (PATTERN (insn)))
1223 && REG_P (SET_DEST (PATTERN (insn)))
1224 && (REGNO (SET_SRC (PATTERN (insn)))
1225 == REGNO (SET_DEST (PATTERN (insn)))))
1231 pnote = ®_NOTES (insn);
1234 if (REG_NOTE_KIND (*pnote) == REG_DEAD
1235 || REG_NOTE_KIND (*pnote) == REG_UNUSED
1236 || REG_NOTE_KIND (*pnote) == REG_INC
1237 || REG_NOTE_KIND (*pnote) == REG_RETVAL
1238 || REG_NOTE_KIND (*pnote) == REG_LIBCALL)
1239 *pnote = XEXP (*pnote, 1);
1241 pnote = &XEXP (*pnote, 1);
1245 add_auto_inc_notes (insn, PATTERN (insn));
1248 /* And simplify (subreg (reg)) if it appears as an operand. */
1249 cleanup_subreg_operands (insn);
1252 /* If we are doing stack checking, give a warning if this function's
1253 frame size is larger than we expect. */
1254 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
1256 HOST_WIDE_INT size = get_frame_size () + STACK_CHECK_FIXED_FRAME_SIZE;
1257 static int verbose_warned = 0;
1259 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1260 if (regs_ever_live[i] && ! fixed_regs[i] && call_used_regs[i])
1261 size += UNITS_PER_WORD;
1263 if (size > STACK_CHECK_MAX_FRAME_SIZE)
1265 warning (0, "frame size too large for reliable stack checking");
1266 if (! verbose_warned)
1268 warning (0, "try reducing the number of local variables");
1274 /* Indicate that we no longer have known memory locations or constants. */
1275 if (reg_equiv_constant)
1276 free (reg_equiv_constant);
1277 if (reg_equiv_invariant)
1278 free (reg_equiv_invariant);
1279 reg_equiv_constant = 0;
1280 reg_equiv_invariant = 0;
1281 VEC_free (rtx, gc, reg_equiv_memory_loc_vec);
1282 reg_equiv_memory_loc = 0;
1284 if (offsets_known_at)
1285 free (offsets_known_at);
1289 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1290 if (reg_equiv_alt_mem_list[i])
1291 free_EXPR_LIST_list (®_equiv_alt_mem_list[i]);
1292 free (reg_equiv_alt_mem_list);
1294 free (reg_equiv_mem);
1296 free (reg_equiv_address);
1297 free (reg_max_ref_width);
1298 free (reg_old_renumber);
1299 free (pseudo_previous_regs);
1300 free (pseudo_forbidden_regs);
1302 CLEAR_HARD_REG_SET (used_spill_regs);
1303 for (i = 0; i < n_spills; i++)
1304 SET_HARD_REG_BIT (used_spill_regs, spill_regs[i]);
1306 /* Free all the insn_chain structures at once. */
1307 obstack_free (&reload_obstack, reload_startobj);
1308 unused_insn_chains = 0;
1309 fixup_abnormal_edges ();
1311 /* Replacing pseudos with their memory equivalents might have
1312 created shared rtx. Subsequent passes would get confused
1313 by this, so unshare everything here. */
1314 unshare_all_rtl_again (first);
1316 #ifdef STACK_BOUNDARY
1317 /* init_emit has set the alignment of the hard frame pointer
1318 to STACK_BOUNDARY. It is very likely no longer valid if
1319 the hard frame pointer was used for register allocation. */
1320 if (!frame_pointer_needed)
1321 REGNO_POINTER_ALIGN (HARD_FRAME_POINTER_REGNUM) = BITS_PER_UNIT;
1327 /* Yet another special case. Unfortunately, reg-stack forces people to
1328 write incorrect clobbers in asm statements. These clobbers must not
1329 cause the register to appear in bad_spill_regs, otherwise we'll call
1330 fatal_insn later. We clear the corresponding regnos in the live
1331 register sets to avoid this.
1332 The whole thing is rather sick, I'm afraid. */
1335 maybe_fix_stack_asms (void)
1338 const char *constraints[MAX_RECOG_OPERANDS];
1339 enum machine_mode operand_mode[MAX_RECOG_OPERANDS];
1340 struct insn_chain *chain;
1342 for (chain = reload_insn_chain; chain != 0; chain = chain->next)
1345 HARD_REG_SET clobbered, allowed;
1348 if (! INSN_P (chain->insn)
1349 || (noperands = asm_noperands (PATTERN (chain->insn))) < 0)
1351 pat = PATTERN (chain->insn);
1352 if (GET_CODE (pat) != PARALLEL)
1355 CLEAR_HARD_REG_SET (clobbered);
1356 CLEAR_HARD_REG_SET (allowed);
1358 /* First, make a mask of all stack regs that are clobbered. */
1359 for (i = 0; i < XVECLEN (pat, 0); i++)
1361 rtx t = XVECEXP (pat, 0, i);
1362 if (GET_CODE (t) == CLOBBER && STACK_REG_P (XEXP (t, 0)))
1363 SET_HARD_REG_BIT (clobbered, REGNO (XEXP (t, 0)));
1366 /* Get the operand values and constraints out of the insn. */
1367 decode_asm_operands (pat, recog_data.operand, recog_data.operand_loc,
1368 constraints, operand_mode);
1370 /* For every operand, see what registers are allowed. */
1371 for (i = 0; i < noperands; i++)
1373 const char *p = constraints[i];
1374 /* For every alternative, we compute the class of registers allowed
1375 for reloading in CLS, and merge its contents into the reg set
1377 int cls = (int) NO_REGS;
1383 if (c == '\0' || c == ',' || c == '#')
1385 /* End of one alternative - mark the regs in the current
1386 class, and reset the class. */
1387 IOR_HARD_REG_SET (allowed, reg_class_contents[cls]);
1393 } while (c != '\0' && c != ',');
1401 case '=': case '+': case '*': case '%': case '?': case '!':
1402 case '0': case '1': case '2': case '3': case '4': case 'm':
1403 case '<': case '>': case 'V': case 'o': case '&': case 'E':
1404 case 'F': case 's': case 'i': case 'n': case 'X': case 'I':
1405 case 'J': case 'K': case 'L': case 'M': case 'N': case 'O':
1410 cls = (int) reg_class_subunion[cls]
1411 [(int) base_reg_class (VOIDmode, ADDRESS, SCRATCH)];
1416 cls = (int) reg_class_subunion[cls][(int) GENERAL_REGS];
1420 if (EXTRA_ADDRESS_CONSTRAINT (c, p))
1421 cls = (int) reg_class_subunion[cls]
1422 [(int) base_reg_class (VOIDmode, ADDRESS, SCRATCH)];
1424 cls = (int) reg_class_subunion[cls]
1425 [(int) REG_CLASS_FROM_CONSTRAINT (c, p)];
1427 p += CONSTRAINT_LEN (c, p);
1430 /* Those of the registers which are clobbered, but allowed by the
1431 constraints, must be usable as reload registers. So clear them
1432 out of the life information. */
1433 AND_HARD_REG_SET (allowed, clobbered);
1434 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1435 if (TEST_HARD_REG_BIT (allowed, i))
1437 CLEAR_REGNO_REG_SET (&chain->live_throughout, i);
1438 CLEAR_REGNO_REG_SET (&chain->dead_or_set, i);
1445 /* Copy the global variables n_reloads and rld into the corresponding elts
1448 copy_reloads (struct insn_chain *chain)
1450 chain->n_reloads = n_reloads;
1451 chain->rld = obstack_alloc (&reload_obstack,
1452 n_reloads * sizeof (struct reload));
1453 memcpy (chain->rld, rld, n_reloads * sizeof (struct reload));
1454 reload_insn_firstobj = obstack_alloc (&reload_obstack, 0);
1457 /* Walk the chain of insns, and determine for each whether it needs reloads
1458 and/or eliminations. Build the corresponding insns_need_reload list, and
1459 set something_needs_elimination as appropriate. */
1461 calculate_needs_all_insns (int global)
1463 struct insn_chain **pprev_reload = &insns_need_reload;
1464 struct insn_chain *chain, *next = 0;
1466 something_needs_elimination = 0;
1468 reload_insn_firstobj = obstack_alloc (&reload_obstack, 0);
1469 for (chain = reload_insn_chain; chain != 0; chain = next)
1471 rtx insn = chain->insn;
1475 /* Clear out the shortcuts. */
1476 chain->n_reloads = 0;
1477 chain->need_elim = 0;
1478 chain->need_reload = 0;
1479 chain->need_operand_change = 0;
1481 /* If this is a label, a JUMP_INSN, or has REG_NOTES (which might
1482 include REG_LABEL), we need to see what effects this has on the
1483 known offsets at labels. */
1485 if (LABEL_P (insn) || JUMP_P (insn)
1486 || (INSN_P (insn) && REG_NOTES (insn) != 0))
1487 set_label_offsets (insn, insn, 0);
1491 rtx old_body = PATTERN (insn);
1492 int old_code = INSN_CODE (insn);
1493 rtx old_notes = REG_NOTES (insn);
1494 int did_elimination = 0;
1495 int operands_changed = 0;
1496 rtx set = single_set (insn);
1498 /* Skip insns that only set an equivalence. */
1499 if (set && REG_P (SET_DEST (set))
1500 && reg_renumber[REGNO (SET_DEST (set))] < 0
1501 && (reg_equiv_constant[REGNO (SET_DEST (set))]
1502 || (reg_equiv_invariant[REGNO (SET_DEST (set))]))
1503 && reg_equiv_init[REGNO (SET_DEST (set))])
1506 /* If needed, eliminate any eliminable registers. */
1507 if (num_eliminable || num_eliminable_invariants)
1508 did_elimination = eliminate_regs_in_insn (insn, 0);
1510 /* Analyze the instruction. */
1511 operands_changed = find_reloads (insn, 0, spill_indirect_levels,
1512 global, spill_reg_order);
1514 /* If a no-op set needs more than one reload, this is likely
1515 to be something that needs input address reloads. We
1516 can't get rid of this cleanly later, and it is of no use
1517 anyway, so discard it now.
1518 We only do this when expensive_optimizations is enabled,
1519 since this complements reload inheritance / output
1520 reload deletion, and it can make debugging harder. */
1521 if (flag_expensive_optimizations && n_reloads > 1)
1523 rtx set = single_set (insn);
1525 && SET_SRC (set) == SET_DEST (set)
1526 && REG_P (SET_SRC (set))
1527 && REGNO (SET_SRC (set)) >= FIRST_PSEUDO_REGISTER)
1530 /* Delete it from the reload chain. */
1532 chain->prev->next = next;
1534 reload_insn_chain = next;
1536 next->prev = chain->prev;
1537 chain->next = unused_insn_chains;
1538 unused_insn_chains = chain;
1543 update_eliminable_offsets ();
1545 /* Remember for later shortcuts which insns had any reloads or
1546 register eliminations. */
1547 chain->need_elim = did_elimination;
1548 chain->need_reload = n_reloads > 0;
1549 chain->need_operand_change = operands_changed;
1551 /* Discard any register replacements done. */
1552 if (did_elimination)
1554 obstack_free (&reload_obstack, reload_insn_firstobj);
1555 PATTERN (insn) = old_body;
1556 INSN_CODE (insn) = old_code;
1557 REG_NOTES (insn) = old_notes;
1558 something_needs_elimination = 1;
1561 something_needs_operands_changed |= operands_changed;
1565 copy_reloads (chain);
1566 *pprev_reload = chain;
1567 pprev_reload = &chain->next_need_reload;
1574 /* Comparison function for qsort to decide which of two reloads
1575 should be handled first. *P1 and *P2 are the reload numbers. */
1578 reload_reg_class_lower (const void *r1p, const void *r2p)
1580 int r1 = *(const short *) r1p, r2 = *(const short *) r2p;
1583 /* Consider required reloads before optional ones. */
1584 t = rld[r1].optional - rld[r2].optional;
1588 /* Count all solitary classes before non-solitary ones. */
1589 t = ((reg_class_size[(int) rld[r2].class] == 1)
1590 - (reg_class_size[(int) rld[r1].class] == 1));
1594 /* Aside from solitaires, consider all multi-reg groups first. */
1595 t = rld[r2].nregs - rld[r1].nregs;
1599 /* Consider reloads in order of increasing reg-class number. */
1600 t = (int) rld[r1].class - (int) rld[r2].class;
1604 /* If reloads are equally urgent, sort by reload number,
1605 so that the results of qsort leave nothing to chance. */
1609 /* The cost of spilling each hard reg. */
1610 static int spill_cost[FIRST_PSEUDO_REGISTER];
1612 /* When spilling multiple hard registers, we use SPILL_COST for the first
1613 spilled hard reg and SPILL_ADD_COST for subsequent regs. SPILL_ADD_COST
1614 only the first hard reg for a multi-reg pseudo. */
1615 static int spill_add_cost[FIRST_PSEUDO_REGISTER];
1617 /* Update the spill cost arrays, considering that pseudo REG is live. */
1620 count_pseudo (int reg)
1622 int freq = REG_FREQ (reg);
1623 int r = reg_renumber[reg];
1626 if (REGNO_REG_SET_P (&pseudos_counted, reg)
1627 || REGNO_REG_SET_P (&spilled_pseudos, reg))
1630 SET_REGNO_REG_SET (&pseudos_counted, reg);
1632 gcc_assert (r >= 0);
1634 spill_add_cost[r] += freq;
1636 nregs = hard_regno_nregs[r][PSEUDO_REGNO_MODE (reg)];
1638 spill_cost[r + nregs] += freq;
1641 /* Calculate the SPILL_COST and SPILL_ADD_COST arrays and determine the
1642 contents of BAD_SPILL_REGS for the insn described by CHAIN. */
1645 order_regs_for_reload (struct insn_chain *chain)
1648 HARD_REG_SET used_by_pseudos;
1649 HARD_REG_SET used_by_pseudos2;
1650 reg_set_iterator rsi;
1652 COPY_HARD_REG_SET (bad_spill_regs, fixed_reg_set);
1654 memset (spill_cost, 0, sizeof spill_cost);
1655 memset (spill_add_cost, 0, sizeof spill_add_cost);
1657 /* Count number of uses of each hard reg by pseudo regs allocated to it
1658 and then order them by decreasing use. First exclude hard registers
1659 that are live in or across this insn. */
1661 REG_SET_TO_HARD_REG_SET (used_by_pseudos, &chain->live_throughout);
1662 REG_SET_TO_HARD_REG_SET (used_by_pseudos2, &chain->dead_or_set);
1663 IOR_HARD_REG_SET (bad_spill_regs, used_by_pseudos);
1664 IOR_HARD_REG_SET (bad_spill_regs, used_by_pseudos2);
1666 /* Now find out which pseudos are allocated to it, and update
1668 CLEAR_REG_SET (&pseudos_counted);
1670 EXECUTE_IF_SET_IN_REG_SET
1671 (&chain->live_throughout, FIRST_PSEUDO_REGISTER, i, rsi)
1675 EXECUTE_IF_SET_IN_REG_SET
1676 (&chain->dead_or_set, FIRST_PSEUDO_REGISTER, i, rsi)
1680 CLEAR_REG_SET (&pseudos_counted);
1683 /* Vector of reload-numbers showing the order in which the reloads should
1685 static short reload_order[MAX_RELOADS];
1687 /* This is used to keep track of the spill regs used in one insn. */
1688 static HARD_REG_SET used_spill_regs_local;
1690 /* We decided to spill hard register SPILLED, which has a size of
1691 SPILLED_NREGS. Determine how pseudo REG, which is live during the insn,
1692 is affected. We will add it to SPILLED_PSEUDOS if necessary, and we will
1693 update SPILL_COST/SPILL_ADD_COST. */
1696 count_spilled_pseudo (int spilled, int spilled_nregs, int reg)
1698 int r = reg_renumber[reg];
1699 int nregs = hard_regno_nregs[r][PSEUDO_REGNO_MODE (reg)];
1701 if (REGNO_REG_SET_P (&spilled_pseudos, reg)
1702 || spilled + spilled_nregs <= r || r + nregs <= spilled)
1705 SET_REGNO_REG_SET (&spilled_pseudos, reg);
1707 spill_add_cost[r] -= REG_FREQ (reg);
1709 spill_cost[r + nregs] -= REG_FREQ (reg);
1712 /* Find reload register to use for reload number ORDER. */
1715 find_reg (struct insn_chain *chain, int order)
1717 int rnum = reload_order[order];
1718 struct reload *rl = rld + rnum;
1719 int best_cost = INT_MAX;
1723 HARD_REG_SET not_usable;
1724 HARD_REG_SET used_by_other_reload;
1725 reg_set_iterator rsi;
1727 COPY_HARD_REG_SET (not_usable, bad_spill_regs);
1728 IOR_HARD_REG_SET (not_usable, bad_spill_regs_global);
1729 IOR_COMPL_HARD_REG_SET (not_usable, reg_class_contents[rl->class]);
1731 CLEAR_HARD_REG_SET (used_by_other_reload);
1732 for (k = 0; k < order; k++)
1734 int other = reload_order[k];
1736 if (rld[other].regno >= 0 && reloads_conflict (other, rnum))
1737 for (j = 0; j < rld[other].nregs; j++)
1738 SET_HARD_REG_BIT (used_by_other_reload, rld[other].regno + j);
1741 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1743 unsigned int regno = i;
1745 if (! TEST_HARD_REG_BIT (not_usable, regno)
1746 && ! TEST_HARD_REG_BIT (used_by_other_reload, regno)
1747 && HARD_REGNO_MODE_OK (regno, rl->mode))
1749 int this_cost = spill_cost[regno];
1751 unsigned int this_nregs = hard_regno_nregs[regno][rl->mode];
1753 for (j = 1; j < this_nregs; j++)
1755 this_cost += spill_add_cost[regno + j];
1756 if ((TEST_HARD_REG_BIT (not_usable, regno + j))
1757 || TEST_HARD_REG_BIT (used_by_other_reload, regno + j))
1762 if (rl->in && REG_P (rl->in) && REGNO (rl->in) == regno)
1764 if (rl->out && REG_P (rl->out) && REGNO (rl->out) == regno)
1766 if (this_cost < best_cost
1767 /* Among registers with equal cost, prefer caller-saved ones, or
1768 use REG_ALLOC_ORDER if it is defined. */
1769 || (this_cost == best_cost
1770 #ifdef REG_ALLOC_ORDER
1771 && (inv_reg_alloc_order[regno]
1772 < inv_reg_alloc_order[best_reg])
1774 && call_used_regs[regno]
1775 && ! call_used_regs[best_reg]
1780 best_cost = this_cost;
1788 fprintf (dump_file, "Using reg %d for reload %d\n", best_reg, rnum);
1790 rl->nregs = hard_regno_nregs[best_reg][rl->mode];
1791 rl->regno = best_reg;
1793 EXECUTE_IF_SET_IN_REG_SET
1794 (&chain->live_throughout, FIRST_PSEUDO_REGISTER, j, rsi)
1796 count_spilled_pseudo (best_reg, rl->nregs, j);
1799 EXECUTE_IF_SET_IN_REG_SET
1800 (&chain->dead_or_set, FIRST_PSEUDO_REGISTER, j, rsi)
1802 count_spilled_pseudo (best_reg, rl->nregs, j);
1805 for (i = 0; i < rl->nregs; i++)
1807 gcc_assert (spill_cost[best_reg + i] == 0);
1808 gcc_assert (spill_add_cost[best_reg + i] == 0);
1809 SET_HARD_REG_BIT (used_spill_regs_local, best_reg + i);
1814 /* Find more reload regs to satisfy the remaining need of an insn, which
1816 Do it by ascending class number, since otherwise a reg
1817 might be spilled for a big class and might fail to count
1818 for a smaller class even though it belongs to that class. */
1821 find_reload_regs (struct insn_chain *chain)
1825 /* In order to be certain of getting the registers we need,
1826 we must sort the reloads into order of increasing register class.
1827 Then our grabbing of reload registers will parallel the process
1828 that provided the reload registers. */
1829 for (i = 0; i < chain->n_reloads; i++)
1831 /* Show whether this reload already has a hard reg. */
1832 if (chain->rld[i].reg_rtx)
1834 int regno = REGNO (chain->rld[i].reg_rtx);
1835 chain->rld[i].regno = regno;
1837 = hard_regno_nregs[regno][GET_MODE (chain->rld[i].reg_rtx)];
1840 chain->rld[i].regno = -1;
1841 reload_order[i] = i;
1844 n_reloads = chain->n_reloads;
1845 memcpy (rld, chain->rld, n_reloads * sizeof (struct reload));
1847 CLEAR_HARD_REG_SET (used_spill_regs_local);
1850 fprintf (dump_file, "Spilling for insn %d.\n", INSN_UID (chain->insn));
1852 qsort (reload_order, n_reloads, sizeof (short), reload_reg_class_lower);
1854 /* Compute the order of preference for hard registers to spill. */
1856 order_regs_for_reload (chain);
1858 for (i = 0; i < n_reloads; i++)
1860 int r = reload_order[i];
1862 /* Ignore reloads that got marked inoperative. */
1863 if ((rld[r].out != 0 || rld[r].in != 0 || rld[r].secondary_p)
1864 && ! rld[r].optional
1865 && rld[r].regno == -1)
1866 if (! find_reg (chain, i))
1869 fprintf (dump_file, "reload failure for reload %d\n", r);
1870 spill_failure (chain->insn, rld[r].class);
1876 COPY_HARD_REG_SET (chain->used_spill_regs, used_spill_regs_local);
1877 IOR_HARD_REG_SET (used_spill_regs, used_spill_regs_local);
1879 memcpy (chain->rld, rld, n_reloads * sizeof (struct reload));
1883 select_reload_regs (void)
1885 struct insn_chain *chain;
1887 /* Try to satisfy the needs for each insn. */
1888 for (chain = insns_need_reload; chain != 0;
1889 chain = chain->next_need_reload)
1890 find_reload_regs (chain);
1893 /* Delete all insns that were inserted by emit_caller_save_insns during
1896 delete_caller_save_insns (void)
1898 struct insn_chain *c = reload_insn_chain;
1902 while (c != 0 && c->is_caller_save_insn)
1904 struct insn_chain *next = c->next;
1907 if (c == reload_insn_chain)
1908 reload_insn_chain = next;
1912 next->prev = c->prev;
1914 c->prev->next = next;
1915 c->next = unused_insn_chains;
1916 unused_insn_chains = c;
1924 /* Handle the failure to find a register to spill.
1925 INSN should be one of the insns which needed this particular spill reg. */
1928 spill_failure (rtx insn, enum reg_class class)
1930 if (asm_noperands (PATTERN (insn)) >= 0)
1931 error_for_asm (insn, "can't find a register in class %qs while "
1932 "reloading %<asm%>",
1933 reg_class_names[class]);
1936 error ("unable to find a register to spill in class %qs",
1937 reg_class_names[class]);
1941 fprintf (dump_file, "\nReloads for insn # %d\n", INSN_UID (insn));
1942 debug_reload_to_stream (dump_file);
1944 fatal_insn ("this is the insn:", insn);
1948 /* Delete an unneeded INSN and any previous insns who sole purpose is loading
1949 data that is dead in INSN. */
1952 delete_dead_insn (rtx insn)
1954 rtx prev = prev_real_insn (insn);
1957 /* If the previous insn sets a register that dies in our insn, delete it
1959 if (prev && GET_CODE (PATTERN (prev)) == SET
1960 && (prev_dest = SET_DEST (PATTERN (prev)), REG_P (prev_dest))
1961 && reg_mentioned_p (prev_dest, PATTERN (insn))
1962 && find_regno_note (insn, REG_DEAD, REGNO (prev_dest))
1963 && ! side_effects_p (SET_SRC (PATTERN (prev))))
1964 delete_dead_insn (prev);
1966 SET_INSN_DELETED (insn);
1969 /* Modify the home of pseudo-reg I.
1970 The new home is present in reg_renumber[I].
1972 FROM_REG may be the hard reg that the pseudo-reg is being spilled from;
1973 or it may be -1, meaning there is none or it is not relevant.
1974 This is used so that all pseudos spilled from a given hard reg
1975 can share one stack slot. */
1978 alter_reg (int i, int from_reg)
1980 /* When outputting an inline function, this can happen
1981 for a reg that isn't actually used. */
1982 if (regno_reg_rtx[i] == 0)
1985 /* If the reg got changed to a MEM at rtl-generation time,
1987 if (!REG_P (regno_reg_rtx[i]))
1990 /* Modify the reg-rtx to contain the new hard reg
1991 number or else to contain its pseudo reg number. */
1992 REGNO (regno_reg_rtx[i])
1993 = reg_renumber[i] >= 0 ? reg_renumber[i] : i;
1995 /* If we have a pseudo that is needed but has no hard reg or equivalent,
1996 allocate a stack slot for it. */
1998 if (reg_renumber[i] < 0
1999 && REG_N_REFS (i) > 0
2000 && reg_equiv_constant[i] == 0
2001 && (reg_equiv_invariant[i] == 0 || reg_equiv_init[i] == 0)
2002 && reg_equiv_memory_loc[i] == 0)
2005 enum machine_mode mode = GET_MODE (regno_reg_rtx[i]);
2006 unsigned int inherent_size = PSEUDO_REGNO_BYTES (i);
2007 unsigned int inherent_align = GET_MODE_ALIGNMENT (mode);
2008 unsigned int total_size = MAX (inherent_size, reg_max_ref_width[i]);
2009 unsigned int min_align = reg_max_ref_width[i] * BITS_PER_UNIT;
2012 /* Each pseudo reg has an inherent size which comes from its own mode,
2013 and a total size which provides room for paradoxical subregs
2014 which refer to the pseudo reg in wider modes.
2016 We can use a slot already allocated if it provides both
2017 enough inherent space and enough total space.
2018 Otherwise, we allocate a new slot, making sure that it has no less
2019 inherent space, and no less total space, then the previous slot. */
2022 /* No known place to spill from => no slot to reuse. */
2023 x = assign_stack_local (mode, total_size,
2024 min_align > inherent_align
2025 || total_size > inherent_size ? -1 : 0);
2026 if (BYTES_BIG_ENDIAN)
2027 /* Cancel the big-endian correction done in assign_stack_local.
2028 Get the address of the beginning of the slot.
2029 This is so we can do a big-endian correction unconditionally
2031 adjust = inherent_size - total_size;
2033 /* Nothing can alias this slot except this pseudo. */
2034 set_mem_alias_set (x, new_alias_set ());
2037 /* Reuse a stack slot if possible. */
2038 else if (spill_stack_slot[from_reg] != 0
2039 && spill_stack_slot_width[from_reg] >= total_size
2040 && (GET_MODE_SIZE (GET_MODE (spill_stack_slot[from_reg]))
2042 && MEM_ALIGN (spill_stack_slot[from_reg]) >= min_align)
2043 x = spill_stack_slot[from_reg];
2045 /* Allocate a bigger slot. */
2048 /* Compute maximum size needed, both for inherent size
2049 and for total size. */
2052 if (spill_stack_slot[from_reg])
2054 if (GET_MODE_SIZE (GET_MODE (spill_stack_slot[from_reg]))
2056 mode = GET_MODE (spill_stack_slot[from_reg]);
2057 if (spill_stack_slot_width[from_reg] > total_size)
2058 total_size = spill_stack_slot_width[from_reg];
2059 if (MEM_ALIGN (spill_stack_slot[from_reg]) > min_align)
2060 min_align = MEM_ALIGN (spill_stack_slot[from_reg]);
2063 /* Make a slot with that size. */
2064 x = assign_stack_local (mode, total_size,
2065 min_align > inherent_align
2066 || total_size > inherent_size ? -1 : 0);
2069 /* All pseudos mapped to this slot can alias each other. */
2070 if (spill_stack_slot[from_reg])
2071 set_mem_alias_set (x, MEM_ALIAS_SET (spill_stack_slot[from_reg]));
2073 set_mem_alias_set (x, new_alias_set ());
2075 if (BYTES_BIG_ENDIAN)
2077 /* Cancel the big-endian correction done in assign_stack_local.
2078 Get the address of the beginning of the slot.
2079 This is so we can do a big-endian correction unconditionally
2081 adjust = GET_MODE_SIZE (mode) - total_size;
2084 = adjust_address_nv (x, mode_for_size (total_size
2090 spill_stack_slot[from_reg] = stack_slot;
2091 spill_stack_slot_width[from_reg] = total_size;
2094 /* On a big endian machine, the "address" of the slot
2095 is the address of the low part that fits its inherent mode. */
2096 if (BYTES_BIG_ENDIAN && inherent_size < total_size)
2097 adjust += (total_size - inherent_size);
2099 /* If we have any adjustment to make, or if the stack slot is the
2100 wrong mode, make a new stack slot. */
2101 x = adjust_address_nv (x, GET_MODE (regno_reg_rtx[i]), adjust);
2103 /* If we have a decl for the original register, set it for the
2104 memory. If this is a shared MEM, make a copy. */
2105 if (REG_EXPR (regno_reg_rtx[i])
2106 && DECL_P (REG_EXPR (regno_reg_rtx[i])))
2108 rtx decl = DECL_RTL_IF_SET (REG_EXPR (regno_reg_rtx[i]));
2110 /* We can do this only for the DECLs home pseudo, not for
2111 any copies of it, since otherwise when the stack slot
2112 is reused, nonoverlapping_memrefs_p might think they
2114 if (decl && REG_P (decl) && REGNO (decl) == (unsigned) i)
2116 if (from_reg != -1 && spill_stack_slot[from_reg] == x)
2119 set_mem_attrs_from_reg (x, regno_reg_rtx[i]);
2123 /* Save the stack slot for later. */
2124 reg_equiv_memory_loc[i] = x;
2128 /* Mark the slots in regs_ever_live for the hard regs
2129 used by pseudo-reg number REGNO. */
2132 mark_home_live (int regno)
2136 i = reg_renumber[regno];
2139 lim = i + hard_regno_nregs[i][PSEUDO_REGNO_MODE (regno)];
2141 regs_ever_live[i++] = 1;
2144 /* This function handles the tracking of elimination offsets around branches.
2146 X is a piece of RTL being scanned.
2148 INSN is the insn that it came from, if any.
2150 INITIAL_P is nonzero if we are to set the offset to be the initial
2151 offset and zero if we are setting the offset of the label to be the
2155 set_label_offsets (rtx x, rtx insn, int initial_p)
2157 enum rtx_code code = GET_CODE (x);
2160 struct elim_table *p;
2165 if (LABEL_REF_NONLOCAL_P (x))
2170 /* ... fall through ... */
2173 /* If we know nothing about this label, set the desired offsets. Note
2174 that this sets the offset at a label to be the offset before a label
2175 if we don't know anything about the label. This is not correct for
2176 the label after a BARRIER, but is the best guess we can make. If
2177 we guessed wrong, we will suppress an elimination that might have
2178 been possible had we been able to guess correctly. */
2180 if (! offsets_known_at[CODE_LABEL_NUMBER (x) - first_label_num])
2182 for (i = 0; i < NUM_ELIMINABLE_REGS; i++)
2183 offsets_at[CODE_LABEL_NUMBER (x) - first_label_num][i]
2184 = (initial_p ? reg_eliminate[i].initial_offset
2185 : reg_eliminate[i].offset);
2186 offsets_known_at[CODE_LABEL_NUMBER (x) - first_label_num] = 1;
2189 /* Otherwise, if this is the definition of a label and it is
2190 preceded by a BARRIER, set our offsets to the known offset of
2194 && (tem = prev_nonnote_insn (insn)) != 0
2196 set_offsets_for_label (insn);
2198 /* If neither of the above cases is true, compare each offset
2199 with those previously recorded and suppress any eliminations
2200 where the offsets disagree. */
2202 for (i = 0; i < NUM_ELIMINABLE_REGS; i++)
2203 if (offsets_at[CODE_LABEL_NUMBER (x) - first_label_num][i]
2204 != (initial_p ? reg_eliminate[i].initial_offset
2205 : reg_eliminate[i].offset))
2206 reg_eliminate[i].can_eliminate = 0;
2211 set_label_offsets (PATTERN (insn), insn, initial_p);
2213 /* ... fall through ... */
2217 /* Any labels mentioned in REG_LABEL notes can be branched to indirectly
2218 and hence must have all eliminations at their initial offsets. */
2219 for (tem = REG_NOTES (x); tem; tem = XEXP (tem, 1))
2220 if (REG_NOTE_KIND (tem) == REG_LABEL)
2221 set_label_offsets (XEXP (tem, 0), insn, 1);
2227 /* Each of the labels in the parallel or address vector must be
2228 at their initial offsets. We want the first field for PARALLEL
2229 and ADDR_VEC and the second field for ADDR_DIFF_VEC. */
2231 for (i = 0; i < (unsigned) XVECLEN (x, code == ADDR_DIFF_VEC); i++)
2232 set_label_offsets (XVECEXP (x, code == ADDR_DIFF_VEC, i),
2237 /* We only care about setting PC. If the source is not RETURN,
2238 IF_THEN_ELSE, or a label, disable any eliminations not at
2239 their initial offsets. Similarly if any arm of the IF_THEN_ELSE
2240 isn't one of those possibilities. For branches to a label,
2241 call ourselves recursively.
2243 Note that this can disable elimination unnecessarily when we have
2244 a non-local goto since it will look like a non-constant jump to
2245 someplace in the current function. This isn't a significant
2246 problem since such jumps will normally be when all elimination
2247 pairs are back to their initial offsets. */
2249 if (SET_DEST (x) != pc_rtx)
2252 switch (GET_CODE (SET_SRC (x)))
2259 set_label_offsets (SET_SRC (x), insn, initial_p);
2263 tem = XEXP (SET_SRC (x), 1);
2264 if (GET_CODE (tem) == LABEL_REF)
2265 set_label_offsets (XEXP (tem, 0), insn, initial_p);
2266 else if (GET_CODE (tem) != PC && GET_CODE (tem) != RETURN)
2269 tem = XEXP (SET_SRC (x), 2);
2270 if (GET_CODE (tem) == LABEL_REF)
2271 set_label_offsets (XEXP (tem, 0), insn, initial_p);
2272 else if (GET_CODE (tem) != PC && GET_CODE (tem) != RETURN)
2280 /* If we reach here, all eliminations must be at their initial
2281 offset because we are doing a jump to a variable address. */
2282 for (p = reg_eliminate; p < ®_eliminate[NUM_ELIMINABLE_REGS]; p++)
2283 if (p->offset != p->initial_offset)
2284 p->can_eliminate = 0;
2292 /* Scan X and replace any eliminable registers (such as fp) with a
2293 replacement (such as sp), plus an offset.
2295 MEM_MODE is the mode of an enclosing MEM. We need this to know how
2296 much to adjust a register for, e.g., PRE_DEC. Also, if we are inside a
2297 MEM, we are allowed to replace a sum of a register and the constant zero
2298 with the register, which we cannot do outside a MEM. In addition, we need
2299 to record the fact that a register is referenced outside a MEM.
2301 If INSN is an insn, it is the insn containing X. If we replace a REG
2302 in a SET_DEST with an equivalent MEM and INSN is nonzero, write a
2303 CLOBBER of the pseudo after INSN so find_equiv_regs will know that
2304 the REG is being modified.
2306 Alternatively, INSN may be a note (an EXPR_LIST or INSN_LIST).
2307 That's used when we eliminate in expressions stored in notes.
2308 This means, do not set ref_outside_mem even if the reference
2311 REG_EQUIV_MEM and REG_EQUIV_ADDRESS contain address that have had
2312 replacements done assuming all offsets are at their initial values. If
2313 they are not, or if REG_EQUIV_ADDRESS is nonzero for a pseudo we
2314 encounter, return the actual location so that find_reloads will do
2315 the proper thing. */
2318 eliminate_regs_1 (rtx x, enum machine_mode mem_mode, rtx insn,
2319 bool may_use_invariant)
2321 enum rtx_code code = GET_CODE (x);
2322 struct elim_table *ep;
2329 if (! current_function_decl)
2351 /* First handle the case where we encounter a bare register that
2352 is eliminable. Replace it with a PLUS. */
2353 if (regno < FIRST_PSEUDO_REGISTER)
2355 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
2357 if (ep->from_rtx == x && ep->can_eliminate)
2358 return plus_constant (ep->to_rtx, ep->previous_offset);
2361 else if (reg_renumber && reg_renumber[regno] < 0
2362 && reg_equiv_invariant && reg_equiv_invariant[regno])
2364 if (may_use_invariant)
2365 return eliminate_regs_1 (copy_rtx (reg_equiv_invariant[regno]),
2366 mem_mode, insn, true);
2367 /* There exists at least one use of REGNO that cannot be
2368 eliminated. Prevent the defining insn from being deleted. */
2369 reg_equiv_init[regno] = NULL_RTX;
2370 alter_reg (regno, -1);
2374 /* You might think handling MINUS in a manner similar to PLUS is a
2375 good idea. It is not. It has been tried multiple times and every
2376 time the change has had to have been reverted.
2378 Other parts of reload know a PLUS is special (gen_reload for example)
2379 and require special code to handle code a reloaded PLUS operand.
2381 Also consider backends where the flags register is clobbered by a
2382 MINUS, but we can emit a PLUS that does not clobber flags (IA-32,
2383 lea instruction comes to mind). If we try to reload a MINUS, we
2384 may kill the flags register that was holding a useful value.
2386 So, please before trying to handle MINUS, consider reload as a
2387 whole instead of this little section as well as the backend issues. */
2389 /* If this is the sum of an eliminable register and a constant, rework
2391 if (REG_P (XEXP (x, 0))
2392 && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER
2393 && CONSTANT_P (XEXP (x, 1)))
2395 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
2397 if (ep->from_rtx == XEXP (x, 0) && ep->can_eliminate)
2399 /* The only time we want to replace a PLUS with a REG (this
2400 occurs when the constant operand of the PLUS is the negative
2401 of the offset) is when we are inside a MEM. We won't want
2402 to do so at other times because that would change the
2403 structure of the insn in a way that reload can't handle.
2404 We special-case the commonest situation in
2405 eliminate_regs_in_insn, so just replace a PLUS with a
2406 PLUS here, unless inside a MEM. */
2407 if (mem_mode != 0 && GET_CODE (XEXP (x, 1)) == CONST_INT
2408 && INTVAL (XEXP (x, 1)) == - ep->previous_offset)
2411 return gen_rtx_PLUS (Pmode, ep->to_rtx,
2412 plus_constant (XEXP (x, 1),
2413 ep->previous_offset));
2416 /* If the register is not eliminable, we are done since the other
2417 operand is a constant. */
2421 /* If this is part of an address, we want to bring any constant to the
2422 outermost PLUS. We will do this by doing register replacement in
2423 our operands and seeing if a constant shows up in one of them.
2425 Note that there is no risk of modifying the structure of the insn,
2426 since we only get called for its operands, thus we are either
2427 modifying the address inside a MEM, or something like an address
2428 operand of a load-address insn. */
2431 rtx new0 = eliminate_regs_1 (XEXP (x, 0), mem_mode, insn, true);
2432 rtx new1 = eliminate_regs_1 (XEXP (x, 1), mem_mode, insn, true);
2434 if (reg_renumber && (new0 != XEXP (x, 0) || new1 != XEXP (x, 1)))
2436 /* If one side is a PLUS and the other side is a pseudo that
2437 didn't get a hard register but has a reg_equiv_constant,
2438 we must replace the constant here since it may no longer
2439 be in the position of any operand. */
2440 if (GET_CODE (new0) == PLUS && REG_P (new1)
2441 && REGNO (new1) >= FIRST_PSEUDO_REGISTER
2442 && reg_renumber[REGNO (new1)] < 0
2443 && reg_equiv_constant != 0
2444 && reg_equiv_constant[REGNO (new1)] != 0)
2445 new1 = reg_equiv_constant[REGNO (new1)];
2446 else if (GET_CODE (new1) == PLUS && REG_P (new0)
2447 && REGNO (new0) >= FIRST_PSEUDO_REGISTER
2448 && reg_renumber[REGNO (new0)] < 0
2449 && reg_equiv_constant[REGNO (new0)] != 0)
2450 new0 = reg_equiv_constant[REGNO (new0)];
2452 new = form_sum (new0, new1);
2454 /* As above, if we are not inside a MEM we do not want to
2455 turn a PLUS into something else. We might try to do so here
2456 for an addition of 0 if we aren't optimizing. */
2457 if (! mem_mode && GET_CODE (new) != PLUS)
2458 return gen_rtx_PLUS (GET_MODE (x), new, const0_rtx);
2466 /* If this is the product of an eliminable register and a
2467 constant, apply the distribute law and move the constant out
2468 so that we have (plus (mult ..) ..). This is needed in order
2469 to keep load-address insns valid. This case is pathological.
2470 We ignore the possibility of overflow here. */
2471 if (REG_P (XEXP (x, 0))
2472 && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER
2473 && GET_CODE (XEXP (x, 1)) == CONST_INT)
2474 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
2476 if (ep->from_rtx == XEXP (x, 0) && ep->can_eliminate)
2479 /* Refs inside notes don't count for this purpose. */
2480 && ! (insn != 0 && (GET_CODE (insn) == EXPR_LIST
2481 || GET_CODE (insn) == INSN_LIST)))
2482 ep->ref_outside_mem = 1;
2485 plus_constant (gen_rtx_MULT (Pmode, ep->to_rtx, XEXP (x, 1)),
2486 ep->previous_offset * INTVAL (XEXP (x, 1)));
2489 /* ... fall through ... */
2493 /* See comments before PLUS about handling MINUS. */
2495 case DIV: case UDIV:
2496 case MOD: case UMOD:
2497 case AND: case IOR: case XOR:
2498 case ROTATERT: case ROTATE:
2499 case ASHIFTRT: case LSHIFTRT: case ASHIFT:
2501 case GE: case GT: case GEU: case GTU:
2502 case LE: case LT: case LEU: case LTU:
2504 rtx new0 = eliminate_regs_1 (XEXP (x, 0), mem_mode, insn, false);
2505 rtx new1 = XEXP (x, 1)
2506 ? eliminate_regs_1 (XEXP (x, 1), mem_mode, insn, false) : 0;
2508 if (new0 != XEXP (x, 0) || new1 != XEXP (x, 1))
2509 return gen_rtx_fmt_ee (code, GET_MODE (x), new0, new1);
2514 /* If we have something in XEXP (x, 0), the usual case, eliminate it. */
2517 new = eliminate_regs_1 (XEXP (x, 0), mem_mode, insn, true);
2518 if (new != XEXP (x, 0))
2520 /* If this is a REG_DEAD note, it is not valid anymore.
2521 Using the eliminated version could result in creating a
2522 REG_DEAD note for the stack or frame pointer. */
2523 if (GET_MODE (x) == REG_DEAD)
2525 ? eliminate_regs_1 (XEXP (x, 1), mem_mode, insn, true)
2528 x = gen_rtx_EXPR_LIST (REG_NOTE_KIND (x), new, XEXP (x, 1));
2532 /* ... fall through ... */
2535 /* Now do eliminations in the rest of the chain. If this was
2536 an EXPR_LIST, this might result in allocating more memory than is
2537 strictly needed, but it simplifies the code. */
2540 new = eliminate_regs_1 (XEXP (x, 1), mem_mode, insn, true);
2541 if (new != XEXP (x, 1))
2543 gen_rtx_fmt_ee (GET_CODE (x), GET_MODE (x), XEXP (x, 0), new);
2551 case STRICT_LOW_PART:
2553 case SIGN_EXTEND: case ZERO_EXTEND:
2554 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
2555 case FLOAT: case FIX:
2556 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
2565 new = eliminate_regs_1 (XEXP (x, 0), mem_mode, insn, false);
2566 if (new != XEXP (x, 0))
2567 return gen_rtx_fmt_e (code, GET_MODE (x), new);
2571 /* Similar to above processing, but preserve SUBREG_BYTE.
2572 Convert (subreg (mem)) to (mem) if not paradoxical.
2573 Also, if we have a non-paradoxical (subreg (pseudo)) and the
2574 pseudo didn't get a hard reg, we must replace this with the
2575 eliminated version of the memory location because push_reload
2576 may do the replacement in certain circumstances. */
2577 if (REG_P (SUBREG_REG (x))
2578 && (GET_MODE_SIZE (GET_MODE (x))
2579 <= GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
2580 && reg_equiv_memory_loc != 0
2581 && reg_equiv_memory_loc[REGNO (SUBREG_REG (x))] != 0)
2583 new = SUBREG_REG (x);
2586 new = eliminate_regs_1 (SUBREG_REG (x), mem_mode, insn, false);
2588 if (new != SUBREG_REG (x))
2590 int x_size = GET_MODE_SIZE (GET_MODE (x));
2591 int new_size = GET_MODE_SIZE (GET_MODE (new));
2594 && ((x_size < new_size
2595 #ifdef WORD_REGISTER_OPERATIONS
2596 /* On these machines, combine can create rtl of the form
2597 (set (subreg:m1 (reg:m2 R) 0) ...)
2598 where m1 < m2, and expects something interesting to
2599 happen to the entire word. Moreover, it will use the
2600 (reg:m2 R) later, expecting all bits to be preserved.
2601 So if the number of words is the same, preserve the
2602 subreg so that push_reload can see it. */
2603 && ! ((x_size - 1) / UNITS_PER_WORD
2604 == (new_size -1 ) / UNITS_PER_WORD)
2607 || x_size == new_size)
2609 return adjust_address_nv (new, GET_MODE (x), SUBREG_BYTE (x));
2611 return gen_rtx_SUBREG (GET_MODE (x), new, SUBREG_BYTE (x));
2617 /* Our only special processing is to pass the mode of the MEM to our
2618 recursive call and copy the flags. While we are here, handle this
2619 case more efficiently. */
2621 replace_equiv_address_nv (x,
2622 eliminate_regs_1 (XEXP (x, 0), GET_MODE (x),
2626 /* Handle insn_list USE that a call to a pure function may generate. */
2627 new = eliminate_regs_1 (XEXP (x, 0), 0, insn, false);
2628 if (new != XEXP (x, 0))
2629 return gen_rtx_USE (GET_MODE (x), new);
2641 /* Process each of our operands recursively. If any have changed, make a
2643 fmt = GET_RTX_FORMAT (code);
2644 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2648 new = eliminate_regs_1 (XEXP (x, i), mem_mode, insn, false);
2649 if (new != XEXP (x, i) && ! copied)
2651 x = shallow_copy_rtx (x);
2656 else if (*fmt == 'E')
2659 for (j = 0; j < XVECLEN (x, i); j++)
2661 new = eliminate_regs_1 (XVECEXP (x, i, j), mem_mode, insn, false);
2662 if (new != XVECEXP (x, i, j) && ! copied_vec)
2664 rtvec new_v = gen_rtvec_v (XVECLEN (x, i),
2668 x = shallow_copy_rtx (x);
2671 XVEC (x, i) = new_v;
2674 XVECEXP (x, i, j) = new;
2683 eliminate_regs (rtx x, enum machine_mode mem_mode, rtx insn)
2685 return eliminate_regs_1 (x, mem_mode, insn, false);
2688 /* Scan rtx X for modifications of elimination target registers. Update
2689 the table of eliminables to reflect the changed state. MEM_MODE is
2690 the mode of an enclosing MEM rtx, or VOIDmode if not within a MEM. */
2693 elimination_effects (rtx x, enum machine_mode mem_mode)
2695 enum rtx_code code = GET_CODE (x);
2696 struct elim_table *ep;
2720 /* First handle the case where we encounter a bare register that
2721 is eliminable. Replace it with a PLUS. */
2722 if (regno < FIRST_PSEUDO_REGISTER)
2724 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
2726 if (ep->from_rtx == x && ep->can_eliminate)
2729 ep->ref_outside_mem = 1;
2734 else if (reg_renumber[regno] < 0 && reg_equiv_constant
2735 && reg_equiv_constant[regno]
2736 && ! function_invariant_p (reg_equiv_constant[regno]))
2737 elimination_effects (reg_equiv_constant[regno], mem_mode);
2746 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2747 if (ep->to_rtx == XEXP (x, 0))
2749 int size = GET_MODE_SIZE (mem_mode);
2751 /* If more bytes than MEM_MODE are pushed, account for them. */
2752 #ifdef PUSH_ROUNDING
2753 if (ep->to_rtx == stack_pointer_rtx)
2754 size = PUSH_ROUNDING (size);
2756 if (code == PRE_DEC || code == POST_DEC)
2758 else if (code == PRE_INC || code == POST_INC)
2760 else if ((code == PRE_MODIFY || code == POST_MODIFY)
2761 && GET_CODE (XEXP (x, 1)) == PLUS
2762 && XEXP (x, 0) == XEXP (XEXP (x, 1), 0)
2763 && CONSTANT_P (XEXP (XEXP (x, 1), 1)))
2764 ep->offset -= INTVAL (XEXP (XEXP (x, 1), 1));
2767 /* These two aren't unary operators. */
2768 if (code == POST_MODIFY || code == PRE_MODIFY)
2771 /* Fall through to generic unary operation case. */
2772 case STRICT_LOW_PART:
2774 case SIGN_EXTEND: case ZERO_EXTEND:
2775 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
2776 case FLOAT: case FIX:
2777 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
2786 elimination_effects (XEXP (x, 0), mem_mode);
2790 if (REG_P (SUBREG_REG (x))
2791 && (GET_MODE_SIZE (GET_MODE (x))
2792 <= GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
2793 && reg_equiv_memory_loc != 0
2794 && reg_equiv_memory_loc[REGNO (SUBREG_REG (x))] != 0)
2797 elimination_effects (SUBREG_REG (x), mem_mode);
2801 /* If using a register that is the source of an eliminate we still
2802 think can be performed, note it cannot be performed since we don't
2803 know how this register is used. */
2804 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2805 if (ep->from_rtx == XEXP (x, 0))
2806 ep->can_eliminate = 0;
2808 elimination_effects (XEXP (x, 0), mem_mode);
2812 /* If clobbering a register that is the replacement register for an
2813 elimination we still think can be performed, note that it cannot
2814 be performed. Otherwise, we need not be concerned about it. */
2815 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2816 if (ep->to_rtx == XEXP (x, 0))
2817 ep->can_eliminate = 0;
2819 elimination_effects (XEXP (x, 0), mem_mode);
2823 /* Check for setting a register that we know about. */
2824 if (REG_P (SET_DEST (x)))
2826 /* See if this is setting the replacement register for an
2829 If DEST is the hard frame pointer, we do nothing because we
2830 assume that all assignments to the frame pointer are for
2831 non-local gotos and are being done at a time when they are valid
2832 and do not disturb anything else. Some machines want to
2833 eliminate a fake argument pointer (or even a fake frame pointer)
2834 with either the real frame or the stack pointer. Assignments to
2835 the hard frame pointer must not prevent this elimination. */
2837 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
2839 if (ep->to_rtx == SET_DEST (x)
2840 && SET_DEST (x) != hard_frame_pointer_rtx)
2842 /* If it is being incremented, adjust the offset. Otherwise,
2843 this elimination can't be done. */
2844 rtx src = SET_SRC (x);
2846 if (GET_CODE (src) == PLUS
2847 && XEXP (src, 0) == SET_DEST (x)
2848 && GET_CODE (XEXP (src, 1)) == CONST_INT)
2849 ep->offset -= INTVAL (XEXP (src, 1));
2851 ep->can_eliminate = 0;
2855 elimination_effects (SET_DEST (x), 0);
2856 elimination_effects (SET_SRC (x), 0);
2860 /* Our only special processing is to pass the mode of the MEM to our
2862 elimination_effects (XEXP (x, 0), GET_MODE (x));
2869 fmt = GET_RTX_FORMAT (code);
2870 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2873 elimination_effects (XEXP (x, i), mem_mode);
2874 else if (*fmt == 'E')
2875 for (j = 0; j < XVECLEN (x, i); j++)
2876 elimination_effects (XVECEXP (x, i, j), mem_mode);
2880 /* Descend through rtx X and verify that no references to eliminable registers
2881 remain. If any do remain, mark the involved register as not
2885 check_eliminable_occurrences (rtx x)
2894 code = GET_CODE (x);
2896 if (code == REG && REGNO (x) < FIRST_PSEUDO_REGISTER)
2898 struct elim_table *ep;
2900 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2901 if (ep->from_rtx == x)
2902 ep->can_eliminate = 0;
2906 fmt = GET_RTX_FORMAT (code);
2907 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2910 check_eliminable_occurrences (XEXP (x, i));
2911 else if (*fmt == 'E')
2914 for (j = 0; j < XVECLEN (x, i); j++)
2915 check_eliminable_occurrences (XVECEXP (x, i, j));
2920 /* Scan INSN and eliminate all eliminable registers in it.
2922 If REPLACE is nonzero, do the replacement destructively. Also
2923 delete the insn as dead it if it is setting an eliminable register.
2925 If REPLACE is zero, do all our allocations in reload_obstack.
2927 If no eliminations were done and this insn doesn't require any elimination
2928 processing (these are not identical conditions: it might be updating sp,
2929 but not referencing fp; this needs to be seen during reload_as_needed so
2930 that the offset between fp and sp can be taken into consideration), zero
2931 is returned. Otherwise, 1 is returned. */
2934 eliminate_regs_in_insn (rtx insn, int replace)
2936 int icode = recog_memoized (insn);
2937 rtx old_body = PATTERN (insn);
2938 int insn_is_asm = asm_noperands (old_body) >= 0;
2939 rtx old_set = single_set (insn);
2943 rtx substed_operand[MAX_RECOG_OPERANDS];
2944 rtx orig_operand[MAX_RECOG_OPERANDS];
2945 struct elim_table *ep;
2946 rtx plus_src, plus_cst_src;
2948 if (! insn_is_asm && icode < 0)
2950 gcc_assert (GET_CODE (PATTERN (insn)) == USE
2951 || GET_CODE (PATTERN (insn)) == CLOBBER
2952 || GET_CODE (PATTERN (insn)) == ADDR_VEC
2953 || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
2954 || GET_CODE (PATTERN (insn)) == ASM_INPUT);
2958 if (old_set != 0 && REG_P (SET_DEST (old_set))
2959 && REGNO (SET_DEST (old_set)) < FIRST_PSEUDO_REGISTER)
2961 /* Check for setting an eliminable register. */
2962 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2963 if (ep->from_rtx == SET_DEST (old_set) && ep->can_eliminate)
2965 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
2966 /* If this is setting the frame pointer register to the
2967 hardware frame pointer register and this is an elimination
2968 that will be done (tested above), this insn is really
2969 adjusting the frame pointer downward to compensate for
2970 the adjustment done before a nonlocal goto. */
2971 if (ep->from == FRAME_POINTER_REGNUM
2972 && ep->to == HARD_FRAME_POINTER_REGNUM)
2974 rtx base = SET_SRC (old_set);
2975 rtx base_insn = insn;
2976 HOST_WIDE_INT offset = 0;
2978 while (base != ep->to_rtx)
2980 rtx prev_insn, prev_set;
2982 if (GET_CODE (base) == PLUS
2983 && GET_CODE (XEXP (base, 1)) == CONST_INT)
2985 offset += INTVAL (XEXP (base, 1));
2986 base = XEXP (base, 0);
2988 else if ((prev_insn = prev_nonnote_insn (base_insn)) != 0
2989 && (prev_set = single_set (prev_insn)) != 0
2990 && rtx_equal_p (SET_DEST (prev_set), base))
2992 base = SET_SRC (prev_set);
2993 base_insn = prev_insn;
2999 if (base == ep->to_rtx)
3002 = plus_constant (ep->to_rtx, offset - ep->offset);
3004 new_body = old_body;
3007 new_body = copy_insn (old_body);
3008 if (REG_NOTES (insn))
3009 REG_NOTES (insn) = copy_insn_1 (REG_NOTES (insn));
3011 PATTERN (insn) = new_body;
3012 old_set = single_set (insn);
3014 /* First see if this insn remains valid when we
3015 make the change. If not, keep the INSN_CODE
3016 the same and let reload fit it up. */
3017 validate_change (insn, &SET_SRC (old_set), src, 1);
3018 validate_change (insn, &SET_DEST (old_set),
3020 if (! apply_change_group ())
3022 SET_SRC (old_set) = src;
3023 SET_DEST (old_set) = ep->to_rtx;
3032 /* In this case this insn isn't serving a useful purpose. We
3033 will delete it in reload_as_needed once we know that this
3034 elimination is, in fact, being done.
3036 If REPLACE isn't set, we can't delete this insn, but needn't
3037 process it since it won't be used unless something changes. */
3040 delete_dead_insn (insn);
3048 /* We allow one special case which happens to work on all machines we
3049 currently support: a single set with the source or a REG_EQUAL
3050 note being a PLUS of an eliminable register and a constant. */
3051 plus_src = plus_cst_src = 0;
3052 if (old_set && REG_P (SET_DEST (old_set)))
3054 if (GET_CODE (SET_SRC (old_set)) == PLUS)
3055 plus_src = SET_SRC (old_set);
3056 /* First see if the source is of the form (plus (...) CST). */
3058 && GET_CODE (XEXP (plus_src, 1)) == CONST_INT)
3059 plus_cst_src = plus_src;
3060 else if (REG_P (SET_SRC (old_set))
3063 /* Otherwise, see if we have a REG_EQUAL note of the form
3064 (plus (...) CST). */
3066 for (links = REG_NOTES (insn); links; links = XEXP (links, 1))
3068 if (REG_NOTE_KIND (links) == REG_EQUAL
3069 && GET_CODE (XEXP (links, 0)) == PLUS
3070 && GET_CODE (XEXP (XEXP (links, 0), 1)) == CONST_INT)
3072 plus_cst_src = XEXP (links, 0);
3078 /* Check that the first operand of the PLUS is a hard reg or
3079 the lowpart subreg of one. */
3082 rtx reg = XEXP (plus_cst_src, 0);
3083 if (GET_CODE (reg) == SUBREG && subreg_lowpart_p (reg))
3084 reg = SUBREG_REG (reg);
3086 if (!REG_P (reg) || REGNO (reg) >= FIRST_PSEUDO_REGISTER)
3092 rtx reg = XEXP (plus_cst_src, 0);
3093 HOST_WIDE_INT offset = INTVAL (XEXP (plus_cst_src, 1));
3095 if (GET_CODE (reg) == SUBREG)
3096 reg = SUBREG_REG (reg);
3098 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3099 if (ep->from_rtx == reg && ep->can_eliminate)
3101 rtx to_rtx = ep->to_rtx;
3102 offset += ep->offset;
3104 if (GET_CODE (XEXP (plus_cst_src, 0)) == SUBREG)
3105 to_rtx = gen_lowpart (GET_MODE (XEXP (plus_cst_src, 0)),
3110 /* We assume here that if we need a PARALLEL with
3111 CLOBBERs for this assignment, we can do with the
3112 MATCH_SCRATCHes that add_clobbers allocates.
3113 There's not much we can do if that doesn't work. */
3114 PATTERN (insn) = gen_rtx_SET (VOIDmode,
3118 INSN_CODE (insn) = recog (PATTERN (insn), insn, &num_clobbers);
3121 rtvec vec = rtvec_alloc (num_clobbers + 1);
3123 vec->elem[0] = PATTERN (insn);
3124 PATTERN (insn) = gen_rtx_PARALLEL (VOIDmode, vec);
3125 add_clobbers (PATTERN (insn), INSN_CODE (insn));
3127 gcc_assert (INSN_CODE (insn) >= 0);
3129 /* If we have a nonzero offset, and the source is already
3130 a simple REG, the following transformation would
3131 increase the cost of the insn by replacing a simple REG
3132 with (plus (reg sp) CST). So try only when we already
3133 had a PLUS before. */
3136 new_body = old_body;
3139 new_body = copy_insn (old_body);
3140 if (REG_NOTES (insn))
3141 REG_NOTES (insn) = copy_insn_1 (REG_NOTES (insn));
3143 PATTERN (insn) = new_body;
3144 old_set = single_set (insn);
3146 XEXP (SET_SRC (old_set), 0) = to_rtx;
3147 XEXP (SET_SRC (old_set), 1) = GEN_INT (offset);
3153 /* This can't have an effect on elimination offsets, so skip right
3159 /* Determine the effects of this insn on elimination offsets. */
3160 elimination_effects (old_body, 0);
3162 /* Eliminate all eliminable registers occurring in operands that
3163 can be handled by reload. */
3164 extract_insn (insn);
3165 for (i = 0; i < recog_data.n_operands; i++)
3167 orig_operand[i] = recog_data.operand[i];
3168 substed_operand[i] = recog_data.operand[i];
3170 /* For an asm statement, every operand is eliminable. */
3171 if (insn_is_asm || insn_data[icode].operand[i].eliminable)
3173 bool is_set_src, in_plus;
3175 /* Check for setting a register that we know about. */
3176 if (recog_data.operand_type[i] != OP_IN
3177 && REG_P (orig_operand[i]))
3179 /* If we are assigning to a register that can be eliminated, it
3180 must be as part of a PARALLEL, since the code above handles
3181 single SETs. We must indicate that we can no longer
3182 eliminate this reg. */
3183 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
3185 if (ep->from_rtx == orig_operand[i])
3186 ep->can_eliminate = 0;
3189 /* Companion to the above plus substitution, we can allow
3190 invariants as the source of a plain move. */
3192 if (old_set && recog_data.operand_loc[i] == &SET_SRC (old_set))
3196 && (recog_data.operand_loc[i] == &XEXP (plus_src, 0)
3197 || recog_data.operand_loc[i] == &XEXP (plus_src, 1)))
3201 = eliminate_regs_1 (recog_data.operand[i], 0,
3202 replace ? insn : NULL_RTX,
3203 is_set_src || in_plus);
3204 if (substed_operand[i] != orig_operand[i])
3206 /* Terminate the search in check_eliminable_occurrences at
3208 *recog_data.operand_loc[i] = 0;
3210 /* If an output operand changed from a REG to a MEM and INSN is an
3211 insn, write a CLOBBER insn. */
3212 if (recog_data.operand_type[i] != OP_IN
3213 && REG_P (orig_operand[i])
3214 && MEM_P (substed_operand[i])
3216 emit_insn_after (gen_rtx_CLOBBER (VOIDmode, orig_operand[i]),
3221 for (i = 0; i < recog_data.n_dups; i++)
3222 *recog_data.dup_loc[i]
3223 = *recog_data.operand_loc[(int) recog_data.dup_num[i]];
3225 /* If any eliminable remain, they aren't eliminable anymore. */
3226 check_eliminable_occurrences (old_body);
3228 /* Substitute the operands; the new values are in the substed_operand
3230 for (i = 0; i < recog_data.n_operands; i++)
3231 *recog_data.operand_loc[i] = substed_operand[i];
3232 for (i = 0; i < recog_data.n_dups; i++)
3233 *recog_data.dup_loc[i] = substed_operand[(int) recog_data.dup_num[i]];
3235 /* If we are replacing a body that was a (set X (plus Y Z)), try to
3236 re-recognize the insn. We do this in case we had a simple addition
3237 but now can do this as a load-address. This saves an insn in this
3239 If re-recognition fails, the old insn code number will still be used,
3240 and some register operands may have changed into PLUS expressions.
3241 These will be handled by find_reloads by loading them into a register
3246 /* If we aren't replacing things permanently and we changed something,
3247 make another copy to ensure that all the RTL is new. Otherwise
3248 things can go wrong if find_reload swaps commutative operands
3249 and one is inside RTL that has been copied while the other is not. */
3250 new_body = old_body;
3253 new_body = copy_insn (old_body);
3254 if (REG_NOTES (insn))
3255 REG_NOTES (insn) = copy_insn_1 (REG_NOTES (insn));
3257 PATTERN (insn) = new_body;
3259 /* If we had a move insn but now we don't, rerecognize it. This will
3260 cause spurious re-recognition if the old move had a PARALLEL since
3261 the new one still will, but we can't call single_set without
3262 having put NEW_BODY into the insn and the re-recognition won't
3263 hurt in this rare case. */
3264 /* ??? Why this huge if statement - why don't we just rerecognize the
3268 && ((REG_P (SET_SRC (old_set))
3269 && (GET_CODE (new_body) != SET
3270 || !REG_P (SET_SRC (new_body))))
3271 /* If this was a load from or store to memory, compare
3272 the MEM in recog_data.operand to the one in the insn.
3273 If they are not equal, then rerecognize the insn. */
3275 && ((MEM_P (SET_SRC (old_set))
3276 && SET_SRC (old_set) != recog_data.operand[1])
3277 || (MEM_P (SET_DEST (old_set))
3278 && SET_DEST (old_set) != recog_data.operand[0])))
3279 /* If this was an add insn before, rerecognize. */
3280 || GET_CODE (SET_SRC (old_set)) == PLUS))
3282 int new_icode = recog (PATTERN (insn), insn, 0);
3284 INSN_CODE (insn) = new_icode;
3288 /* Restore the old body. If there were any changes to it, we made a copy
3289 of it while the changes were still in place, so we'll correctly return
3290 a modified insn below. */
3293 /* Restore the old body. */
3294 for (i = 0; i < recog_data.n_operands; i++)
3295 *recog_data.operand_loc[i] = orig_operand[i];
3296 for (i = 0; i < recog_data.n_dups; i++)
3297 *recog_data.dup_loc[i] = orig_operand[(int) recog_data.dup_num[i]];
3300 /* Update all elimination pairs to reflect the status after the current
3301 insn. The changes we make were determined by the earlier call to
3302 elimination_effects.
3304 We also detect cases where register elimination cannot be done,
3305 namely, if a register would be both changed and referenced outside a MEM
3306 in the resulting insn since such an insn is often undefined and, even if
3307 not, we cannot know what meaning will be given to it. Note that it is
3308 valid to have a register used in an address in an insn that changes it
3309 (presumably with a pre- or post-increment or decrement).
3311 If anything changes, return nonzero. */
3313 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3315 if (ep->previous_offset != ep->offset && ep->ref_outside_mem)
3316 ep->can_eliminate = 0;
3318 ep->ref_outside_mem = 0;
3320 if (ep->previous_offset != ep->offset)
3325 /* If we changed something, perform elimination in REG_NOTES. This is
3326 needed even when REPLACE is zero because a REG_DEAD note might refer
3327 to a register that we eliminate and could cause a different number
3328 of spill registers to be needed in the final reload pass than in
3330 if (val && REG_NOTES (insn) != 0)
3332 = eliminate_regs_1 (REG_NOTES (insn), 0, REG_NOTES (insn), true);
3337 /* Loop through all elimination pairs.
3338 Recalculate the number not at initial offset.
3340 Compute the maximum offset (minimum offset if the stack does not
3341 grow downward) for each elimination pair. */
3344 update_eliminable_offsets (void)
3346 struct elim_table *ep;
3348 num_not_at_initial_offset = 0;
3349 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3351 ep->previous_offset = ep->offset;
3352 if (ep->can_eliminate && ep->offset != ep->initial_offset)
3353 num_not_at_initial_offset++;
3357 /* Given X, a SET or CLOBBER of DEST, if DEST is the target of a register
3358 replacement we currently believe is valid, mark it as not eliminable if X
3359 modifies DEST in any way other than by adding a constant integer to it.
3361 If DEST is the frame pointer, we do nothing because we assume that
3362 all assignments to the hard frame pointer are nonlocal gotos and are being
3363 done at a time when they are valid and do not disturb anything else.
3364 Some machines want to eliminate a fake argument pointer with either the
3365 frame or stack pointer. Assignments to the hard frame pointer must not
3366 prevent this elimination.
3368 Called via note_stores from reload before starting its passes to scan
3369 the insns of the function. */
3372 mark_not_eliminable (rtx dest, rtx x, void *data ATTRIBUTE_UNUSED)
3376 /* A SUBREG of a hard register here is just changing its mode. We should
3377 not see a SUBREG of an eliminable hard register, but check just in
3379 if (GET_CODE (dest) == SUBREG)
3380 dest = SUBREG_REG (dest);
3382 if (dest == hard_frame_pointer_rtx)
3385 for (i = 0; i < NUM_ELIMINABLE_REGS; i++)
3386 if (reg_eliminate[i].can_eliminate && dest == reg_eliminate[i].to_rtx
3387 && (GET_CODE (x) != SET
3388 || GET_CODE (SET_SRC (x)) != PLUS
3389 || XEXP (SET_SRC (x), 0) != dest
3390 || GET_CODE (XEXP (SET_SRC (x), 1)) != CONST_INT))
3392 reg_eliminate[i].can_eliminate_previous
3393 = reg_eliminate[i].can_eliminate = 0;
3398 /* Verify that the initial elimination offsets did not change since the
3399 last call to set_initial_elim_offsets. This is used to catch cases
3400 where something illegal happened during reload_as_needed that could
3401 cause incorrect code to be generated if we did not check for it. */
3404 verify_initial_elim_offsets (void)
3408 if (!num_eliminable)
3411 #ifdef ELIMINABLE_REGS
3413 struct elim_table *ep;
3415 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3417 INITIAL_ELIMINATION_OFFSET (ep->from, ep->to, t);
3418 if (t != ep->initial_offset)
3423 INITIAL_FRAME_POINTER_OFFSET (t);
3424 if (t != reg_eliminate[0].initial_offset)
3431 /* Reset all offsets on eliminable registers to their initial values. */
3434 set_initial_elim_offsets (void)
3436 struct elim_table *ep = reg_eliminate;
3438 #ifdef ELIMINABLE_REGS
3439 for (; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3441 INITIAL_ELIMINATION_OFFSET (ep->from, ep->to, ep->initial_offset);
3442 ep->previous_offset = ep->offset = ep->initial_offset;
3445 INITIAL_FRAME_POINTER_OFFSET (ep->initial_offset);
3446 ep->previous_offset = ep->offset = ep->initial_offset;
3449 num_not_at_initial_offset = 0;
3452 /* Subroutine of set_initial_label_offsets called via for_each_eh_label. */
3455 set_initial_eh_label_offset (rtx label)
3457 set_label_offsets (label, NULL_RTX, 1);
3460 /* Initialize the known label offsets.
3461 Set a known offset for each forced label to be at the initial offset
3462 of each elimination. We do this because we assume that all
3463 computed jumps occur from a location where each elimination is
3464 at its initial offset.
3465 For all other labels, show that we don't know the offsets. */
3468 set_initial_label_offsets (void)
3471 memset (offsets_known_at, 0, num_labels);
3473 for (x = forced_labels; x; x = XEXP (x, 1))
3475 set_label_offsets (XEXP (x, 0), NULL_RTX, 1);
3477 for_each_eh_label (set_initial_eh_label_offset);
3480 /* Set all elimination offsets to the known values for the code label given
3484 set_offsets_for_label (rtx insn)
3487 int label_nr = CODE_LABEL_NUMBER (insn);
3488 struct elim_table *ep;
3490 num_not_at_initial_offset = 0;
3491 for (i = 0, ep = reg_eliminate; i < NUM_ELIMINABLE_REGS; ep++, i++)
3493 ep->offset = ep->previous_offset
3494 = offsets_at[label_nr - first_label_num][i];
3495 if (ep->can_eliminate && ep->offset != ep->initial_offset)
3496 num_not_at_initial_offset++;
3500 /* See if anything that happened changes which eliminations are valid.
3501 For example, on the SPARC, whether or not the frame pointer can
3502 be eliminated can depend on what registers have been used. We need
3503 not check some conditions again (such as flag_omit_frame_pointer)
3504 since they can't have changed. */
3507 update_eliminables (HARD_REG_SET *pset)
3509 int previous_frame_pointer_needed = frame_pointer_needed;
3510 struct elim_table *ep;
3512 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3513 if ((ep->from == HARD_FRAME_POINTER_REGNUM && FRAME_POINTER_REQUIRED)
3514 #ifdef ELIMINABLE_REGS
3515 || ! CAN_ELIMINATE (ep->from, ep->to)
3518 ep->can_eliminate = 0;
3520 /* Look for the case where we have discovered that we can't replace
3521 register A with register B and that means that we will now be
3522 trying to replace register A with register C. This means we can
3523 no longer replace register C with register B and we need to disable
3524 such an elimination, if it exists. This occurs often with A == ap,
3525 B == sp, and C == fp. */
3527 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3529 struct elim_table *op;
3532 if (! ep->can_eliminate && ep->can_eliminate_previous)
3534 /* Find the current elimination for ep->from, if there is a
3536 for (op = reg_eliminate;
3537 op < ®_eliminate[NUM_ELIMINABLE_REGS]; op++)
3538 if (op->from == ep->from && op->can_eliminate)
3544 /* See if there is an elimination of NEW_TO -> EP->TO. If so,
3546 for (op = reg_eliminate;
3547 op < ®_eliminate[NUM_ELIMINABLE_REGS]; op++)
3548 if (op->from == new_to && op->to == ep->to)
3549 op->can_eliminate = 0;
3553 /* See if any registers that we thought we could eliminate the previous
3554 time are no longer eliminable. If so, something has changed and we
3555 must spill the register. Also, recompute the number of eliminable
3556 registers and see if the frame pointer is needed; it is if there is
3557 no elimination of the frame pointer that we can perform. */
3559 frame_pointer_needed = 1;
3560 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3562 if (ep->can_eliminate && ep->from == FRAME_POINTER_REGNUM
3563 && ep->to != HARD_FRAME_POINTER_REGNUM)
3564 frame_pointer_needed = 0;
3566 if (! ep->can_eliminate && ep->can_eliminate_previous)
3568 ep->can_eliminate_previous = 0;
3569 SET_HARD_REG_BIT (*pset, ep->from);
3574 /* If we didn't need a frame pointer last time, but we do now, spill
3575 the hard frame pointer. */
3576 if (frame_pointer_needed && ! previous_frame_pointer_needed)
3577 SET_HARD_REG_BIT (*pset, HARD_FRAME_POINTER_REGNUM);
3580 /* Initialize the table of registers to eliminate. */
3583 init_elim_table (void)
3585 struct elim_table *ep;
3586 #ifdef ELIMINABLE_REGS
3587 const struct elim_table_1 *ep1;
3591 reg_eliminate = xcalloc (sizeof (struct elim_table), NUM_ELIMINABLE_REGS);
3593 /* Does this function require a frame pointer? */
3595 frame_pointer_needed = (! flag_omit_frame_pointer
3596 /* ?? If EXIT_IGNORE_STACK is set, we will not save
3597 and restore sp for alloca. So we can't eliminate
3598 the frame pointer in that case. At some point,
3599 we should improve this by emitting the
3600 sp-adjusting insns for this case. */
3601 || (current_function_calls_alloca
3602 && EXIT_IGNORE_STACK)
3603 || current_function_accesses_prior_frames
3604 || FRAME_POINTER_REQUIRED);
3608 #ifdef ELIMINABLE_REGS
3609 for (ep = reg_eliminate, ep1 = reg_eliminate_1;
3610 ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++, ep1++)
3612 ep->from = ep1->from;
3614 ep->can_eliminate = ep->can_eliminate_previous
3615 = (CAN_ELIMINATE (ep->from, ep->to)
3616 && ! (ep->to == STACK_POINTER_REGNUM && frame_pointer_needed));
3619 reg_eliminate[0].from = reg_eliminate_1[0].from;
3620 reg_eliminate[0].to = reg_eliminate_1[0].to;
3621 reg_eliminate[0].can_eliminate = reg_eliminate[0].can_eliminate_previous
3622 = ! frame_pointer_needed;
3625 /* Count the number of eliminable registers and build the FROM and TO
3626 REG rtx's. Note that code in gen_rtx_REG will cause, e.g.,
3627 gen_rtx_REG (Pmode, STACK_POINTER_REGNUM) to equal stack_pointer_rtx.
3628 We depend on this. */
3629 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3631 num_eliminable += ep->can_eliminate;
3632 ep->from_rtx = gen_rtx_REG (Pmode, ep->from);
3633 ep->to_rtx = gen_rtx_REG (Pmode, ep->to);
3637 /* Kick all pseudos out of hard register REGNO.
3639 If CANT_ELIMINATE is nonzero, it means that we are doing this spill
3640 because we found we can't eliminate some register. In the case, no pseudos
3641 are allowed to be in the register, even if they are only in a block that
3642 doesn't require spill registers, unlike the case when we are spilling this
3643 hard reg to produce another spill register.
3645 Return nonzero if any pseudos needed to be kicked out. */
3648 spill_hard_reg (unsigned int regno, int cant_eliminate)
3654 SET_HARD_REG_BIT (bad_spill_regs_global, regno);
3655 regs_ever_live[regno] = 1;
3658 /* Spill every pseudo reg that was allocated to this reg
3659 or to something that overlaps this reg. */
3661 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
3662 if (reg_renumber[i] >= 0
3663 && (unsigned int) reg_renumber[i] <= regno
3664 && ((unsigned int) reg_renumber[i]
3665 + hard_regno_nregs[(unsigned int) reg_renumber[i]]
3666 [PSEUDO_REGNO_MODE (i)]
3668 SET_REGNO_REG_SET (&spilled_pseudos, i);
3671 /* After find_reload_regs has been run for all insn that need reloads,
3672 and/or spill_hard_regs was called, this function is used to actually
3673 spill pseudo registers and try to reallocate them. It also sets up the
3674 spill_regs array for use by choose_reload_regs. */
3677 finish_spills (int global)
3679 struct insn_chain *chain;
3680 int something_changed = 0;
3682 reg_set_iterator rsi;
3684 /* Build the spill_regs array for the function. */
3685 /* If there are some registers still to eliminate and one of the spill regs
3686 wasn't ever used before, additional stack space may have to be
3687 allocated to store this register. Thus, we may have changed the offset
3688 between the stack and frame pointers, so mark that something has changed.
3690 One might think that we need only set VAL to 1 if this is a call-used
3691 register. However, the set of registers that must be saved by the
3692 prologue is not identical to the call-used set. For example, the
3693 register used by the call insn for the return PC is a call-used register,
3694 but must be saved by the prologue. */
3697 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3698 if (TEST_HARD_REG_BIT (used_spill_regs, i))
3700 spill_reg_order[i] = n_spills;
3701 spill_regs[n_spills++] = i;
3702 if (num_eliminable && ! regs_ever_live[i])
3703 something_changed = 1;
3704 regs_ever_live[i] = 1;
3707 spill_reg_order[i] = -1;
3709 EXECUTE_IF_SET_IN_REG_SET (&spilled_pseudos, FIRST_PSEUDO_REGISTER, i, rsi)
3711 /* Record the current hard register the pseudo is allocated to in
3712 pseudo_previous_regs so we avoid reallocating it to the same
3713 hard reg in a later pass. */
3714 gcc_assert (reg_renumber[i] >= 0);
3716 SET_HARD_REG_BIT (pseudo_previous_regs[i], reg_renumber[i]);
3717 /* Mark it as no longer having a hard register home. */
3718 reg_renumber[i] = -1;
3719 /* We will need to scan everything again. */
3720 something_changed = 1;
3723 /* Retry global register allocation if possible. */
3726 memset (pseudo_forbidden_regs, 0, max_regno * sizeof (HARD_REG_SET));
3727 /* For every insn that needs reloads, set the registers used as spill
3728 regs in pseudo_forbidden_regs for every pseudo live across the
3730 for (chain = insns_need_reload; chain; chain = chain->next_need_reload)
3732 EXECUTE_IF_SET_IN_REG_SET
3733 (&chain->live_throughout, FIRST_PSEUDO_REGISTER, i, rsi)
3735 IOR_HARD_REG_SET (pseudo_forbidden_regs[i],
3736 chain->used_spill_regs);
3738 EXECUTE_IF_SET_IN_REG_SET
3739 (&chain->dead_or_set, FIRST_PSEUDO_REGISTER, i, rsi)
3741 IOR_HARD_REG_SET (pseudo_forbidden_regs[i],
3742 chain->used_spill_regs);
3746 /* Retry allocating the spilled pseudos. For each reg, merge the
3747 various reg sets that indicate which hard regs can't be used,
3748 and call retry_global_alloc.
3749 We change spill_pseudos here to only contain pseudos that did not
3750 get a new hard register. */
3751 for (i = FIRST_PSEUDO_REGISTER; i < (unsigned)max_regno; i++)
3752 if (reg_old_renumber[i] != reg_renumber[i])
3754 HARD_REG_SET forbidden;
3755 COPY_HARD_REG_SET (forbidden, bad_spill_regs_global);
3756 IOR_HARD_REG_SET (forbidden, pseudo_forbidden_regs[i]);
3757 IOR_HARD_REG_SET (forbidden, pseudo_previous_regs[i]);
3758 retry_global_alloc (i, forbidden);
3759 if (reg_renumber[i] >= 0)
3760 CLEAR_REGNO_REG_SET (&spilled_pseudos, i);
3764 /* Fix up the register information in the insn chain.
3765 This involves deleting those of the spilled pseudos which did not get
3766 a new hard register home from the live_{before,after} sets. */
3767 for (chain = reload_insn_chain; chain; chain = chain->next)
3769 HARD_REG_SET used_by_pseudos;
3770 HARD_REG_SET used_by_pseudos2;
3772 AND_COMPL_REG_SET (&chain->live_throughout, &spilled_pseudos);
3773 AND_COMPL_REG_SET (&chain->dead_or_set, &spilled_pseudos);
3775 /* Mark any unallocated hard regs as available for spills. That
3776 makes inheritance work somewhat better. */
3777 if (chain->need_reload)
3779 REG_SET_TO_HARD_REG_SET (used_by_pseudos, &chain->live_throughout);
3780 REG_SET_TO_HARD_REG_SET (used_by_pseudos2, &chain->dead_or_set);
3781 IOR_HARD_REG_SET (used_by_pseudos, used_by_pseudos2);
3783 /* Save the old value for the sanity test below. */
3784 COPY_HARD_REG_SET (used_by_pseudos2, chain->used_spill_regs);
3786 compute_use_by_pseudos (&used_by_pseudos, &chain->live_throughout);
3787 compute_use_by_pseudos (&used_by_pseudos, &chain->dead_or_set);
3788 COMPL_HARD_REG_SET (chain->used_spill_regs, used_by_pseudos);
3789 AND_HARD_REG_SET (chain->used_spill_regs, used_spill_regs);
3791 /* Make sure we only enlarge the set. */
3792 GO_IF_HARD_REG_SUBSET (used_by_pseudos2, chain->used_spill_regs, ok);
3798 /* Let alter_reg modify the reg rtx's for the modified pseudos. */
3799 for (i = FIRST_PSEUDO_REGISTER; i < (unsigned)max_regno; i++)
3801 int regno = reg_renumber[i];
3802 if (reg_old_renumber[i] == regno)
3805 alter_reg (i, reg_old_renumber[i]);
3806 reg_old_renumber[i] = regno;
3810 fprintf (dump_file, " Register %d now on stack.\n\n", i);
3812 fprintf (dump_file, " Register %d now in %d.\n\n",
3813 i, reg_renumber[i]);
3817 return something_changed;
3820 /* Find all paradoxical subregs within X and update reg_max_ref_width. */
3823 scan_paradoxical_subregs (rtx x)
3827 enum rtx_code code = GET_CODE (x);
3837 case CONST_VECTOR: /* shouldn't happen, but just in case. */
3845 if (REG_P (SUBREG_REG (x))
3846 && (GET_MODE_SIZE (GET_MODE (x))
3847 > reg_max_ref_width[REGNO (SUBREG_REG (x))]))
3848 reg_max_ref_width[REGNO (SUBREG_REG (x))]
3849 = GET_MODE_SIZE (GET_MODE (x));
3856 fmt = GET_RTX_FORMAT (code);
3857 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
3860 scan_paradoxical_subregs (XEXP (x, i));
3861 else if (fmt[i] == 'E')
3864 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
3865 scan_paradoxical_subregs (XVECEXP (x, i, j));
3870 /* A subroutine of reload_as_needed. If INSN has a REG_EH_REGION note,
3871 examine all of the reload insns between PREV and NEXT exclusive, and
3872 annotate all that may trap. */
3875 fixup_eh_region_note (rtx insn, rtx prev, rtx next)
3877 rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
3878 unsigned int trap_count;
3884 if (may_trap_p (PATTERN (insn)))
3888 remove_note (insn, note);
3892 for (i = NEXT_INSN (prev); i != next; i = NEXT_INSN (i))
3893 if (INSN_P (i) && i != insn && may_trap_p (PATTERN (i)))
3897 = gen_rtx_EXPR_LIST (REG_EH_REGION, XEXP (note, 0), REG_NOTES (i));
3901 /* Reload pseudo-registers into hard regs around each insn as needed.
3902 Additional register load insns are output before the insn that needs it
3903 and perhaps store insns after insns that modify the reloaded pseudo reg.
3905 reg_last_reload_reg and reg_reloaded_contents keep track of
3906 which registers are already available in reload registers.
3907 We update these for the reloads that we perform,
3908 as the insns are scanned. */
3911 reload_as_needed (int live_known)
3913 struct insn_chain *chain;
3914 #if defined (AUTO_INC_DEC)
3919 memset (spill_reg_rtx, 0, sizeof spill_reg_rtx);
3920 memset (spill_reg_store, 0, sizeof spill_reg_store);
3921 reg_last_reload_reg = XCNEWVEC (rtx, max_regno);
3922 INIT_REG_SET (®_has_output_reload);
3923 CLEAR_HARD_REG_SET (reg_reloaded_valid);
3924 CLEAR_HARD_REG_SET (reg_reloaded_call_part_clobbered);
3926 set_initial_elim_offsets ();
3928 for (chain = reload_insn_chain; chain; chain = chain->next)
3931 rtx insn = chain->insn;
3932 rtx old_next = NEXT_INSN (insn);
3934 /* If we pass a label, copy the offsets from the label information
3935 into the current offsets of each elimination. */
3937 set_offsets_for_label (insn);
3939 else if (INSN_P (insn))
3941 regset_head regs_to_forget;
3942 INIT_REG_SET (®s_to_forget);
3943 note_stores (PATTERN (insn), forget_old_reloads_1, ®s_to_forget);
3945 /* If this is a USE and CLOBBER of a MEM, ensure that any
3946 references to eliminable registers have been removed. */
3948 if ((GET_CODE (PATTERN (insn)) == USE
3949 || GET_CODE (PATTERN (insn)) == CLOBBER)
3950 && MEM_P (XEXP (PATTERN (insn), 0)))
3951 XEXP (XEXP (PATTERN (insn), 0), 0)
3952 = eliminate_regs (XEXP (XEXP (PATTERN (insn), 0), 0),
3953 GET_MODE (XEXP (PATTERN (insn), 0)),
3956 /* If we need to do register elimination processing, do so.
3957 This might delete the insn, in which case we are done. */
3958 if ((num_eliminable || num_eliminable_invariants) && chain->need_elim)
3960 eliminate_regs_in_insn (insn, 1);
3963 update_eliminable_offsets ();
3964 CLEAR_REG_SET (®s_to_forget);
3969 /* If need_elim is nonzero but need_reload is zero, one might think
3970 that we could simply set n_reloads to 0. However, find_reloads
3971 could have done some manipulation of the insn (such as swapping
3972 commutative operands), and these manipulations are lost during
3973 the first pass for every insn that needs register elimination.
3974 So the actions of find_reloads must be redone here. */
3976 if (! chain->need_elim && ! chain->need_reload
3977 && ! chain->need_operand_change)
3979 /* First find the pseudo regs that must be reloaded for this insn.
3980 This info is returned in the tables reload_... (see reload.h).
3981 Also modify the body of INSN by substituting RELOAD
3982 rtx's for those pseudo regs. */
3985 CLEAR_REG_SET (®_has_output_reload);
3986 CLEAR_HARD_REG_SET (reg_is_output_reload);
3988 find_reloads (insn, 1, spill_indirect_levels, live_known,
3994 rtx next = NEXT_INSN (insn);
3997 prev = PREV_INSN (insn);
3999 /* Now compute which reload regs to reload them into. Perhaps
4000 reusing reload regs from previous insns, or else output
4001 load insns to reload them. Maybe output store insns too.
4002 Record the choices of reload reg in reload_reg_rtx. */
4003 choose_reload_regs (chain);
4005 /* Merge any reloads that we didn't combine for fear of
4006 increasing the number of spill registers needed but now
4007 discover can be safely merged. */
4008 if (SMALL_REGISTER_CLASSES)
4009 merge_assigned_reloads (insn);
4011 /* Generate the insns to reload operands into or out of
4012 their reload regs. */
4013 emit_reload_insns (chain);
4015 /* Substitute the chosen reload regs from reload_reg_rtx
4016 into the insn's body (or perhaps into the bodies of other
4017 load and store insn that we just made for reloading
4018 and that we moved the structure into). */
4019 subst_reloads (insn);
4021 /* Adjust the exception region notes for loads and stores. */
4022 if (flag_non_call_exceptions && !CALL_P (insn))
4023 fixup_eh_region_note (insn, prev, next);
4025 /* If this was an ASM, make sure that all the reload insns
4026 we have generated are valid. If not, give an error
4028 if (asm_noperands (PATTERN (insn)) >= 0)
4029 for (p = NEXT_INSN (prev); p != next; p = NEXT_INSN (p))
4030 if (p != insn && INSN_P (p)
4031 && GET_CODE (PATTERN (p)) != USE
4032 && (recog_memoized (p) < 0
4033 || (extract_insn (p), ! constrain_operands (1))))
4035 error_for_asm (insn,
4036 "%<asm%> operand requires "
4037 "impossible reload");
4042 if (num_eliminable && chain->need_elim)
4043 update_eliminable_offsets ();
4045 /* Any previously reloaded spilled pseudo reg, stored in this insn,
4046 is no longer validly lying around to save a future reload.
4047 Note that this does not detect pseudos that were reloaded
4048 for this insn in order to be stored in
4049 (obeying register constraints). That is correct; such reload
4050 registers ARE still valid. */
4051 forget_marked_reloads (®s_to_forget);
4052 CLEAR_REG_SET (®s_to_forget);
4054 /* There may have been CLOBBER insns placed after INSN. So scan
4055 between INSN and NEXT and use them to forget old reloads. */
4056 for (x = NEXT_INSN (insn); x != old_next; x = NEXT_INSN (x))
4057 if (NONJUMP_INSN_P (x) && GET_CODE (PATTERN (x)) == CLOBBER)
4058 note_stores (PATTERN (x), forget_old_reloads_1, NULL);
4061 /* Likewise for regs altered by auto-increment in this insn.
4062 REG_INC notes have been changed by reloading:
4063 find_reloads_address_1 records substitutions for them,
4064 which have been performed by subst_reloads above. */
4065 for (i = n_reloads - 1; i >= 0; i--)
4067 rtx in_reg = rld[i].in_reg;
4070 enum rtx_code code = GET_CODE (in_reg);
4071 /* PRE_INC / PRE_DEC will have the reload register ending up
4072 with the same value as the stack slot, but that doesn't
4073 hold true for POST_INC / POST_DEC. Either we have to
4074 convert the memory access to a true POST_INC / POST_DEC,
4075 or we can't use the reload register for inheritance. */
4076 if ((code == POST_INC || code == POST_DEC)
4077 && TEST_HARD_REG_BIT (reg_reloaded_valid,
4078 REGNO (rld[i].reg_rtx))
4079 /* Make sure it is the inc/dec pseudo, and not
4080 some other (e.g. output operand) pseudo. */
4081 && ((unsigned) reg_reloaded_contents[REGNO (rld[i].reg_rtx)]
4082 == REGNO (XEXP (in_reg, 0))))
4085 rtx reload_reg = rld[i].reg_rtx;
4086 enum machine_mode mode = GET_MODE (reload_reg);
4090 for (p = PREV_INSN (old_next); p != prev; p = PREV_INSN (p))
4092 /* We really want to ignore REG_INC notes here, so
4093 use PATTERN (p) as argument to reg_set_p . */
4094 if (reg_set_p (reload_reg, PATTERN (p)))
4096 n = count_occurrences (PATTERN (p), reload_reg, 0);
4101 n = validate_replace_rtx (reload_reg,
4102 gen_rtx_fmt_e (code,
4107 /* We must also verify that the constraints
4108 are met after the replacement. */
4111 n = constrain_operands (1);
4115 /* If the constraints were not met, then
4116 undo the replacement. */
4119 validate_replace_rtx (gen_rtx_fmt_e (code,
4132 = gen_rtx_EXPR_LIST (REG_INC, reload_reg,
4134 /* Mark this as having an output reload so that the
4135 REG_INC processing code below won't invalidate
4136 the reload for inheritance. */
4137 SET_HARD_REG_BIT (reg_is_output_reload,
4138 REGNO (reload_reg));
4139 SET_REGNO_REG_SET (®_has_output_reload,
4140 REGNO (XEXP (in_reg, 0)));
4143 forget_old_reloads_1 (XEXP (in_reg, 0), NULL_RTX,
4146 else if ((code == PRE_INC || code == PRE_DEC)
4147 && TEST_HARD_REG_BIT (reg_reloaded_valid,
4148 REGNO (rld[i].reg_rtx))
4149 /* Make sure it is the inc/dec pseudo, and not
4150 some other (e.g. output operand) pseudo. */
4151 && ((unsigned) reg_reloaded_contents[REGNO (rld[i].reg_rtx)]
4152 == REGNO (XEXP (in_reg, 0))))
4154 SET_HARD_REG_BIT (reg_is_output_reload,
4155 REGNO (rld[i].reg_rtx));
4156 SET_REGNO_REG_SET (®_has_output_reload,
4157 REGNO (XEXP (in_reg, 0)));
4161 /* If a pseudo that got a hard register is auto-incremented,
4162 we must purge records of copying it into pseudos without
4164 for (x = REG_NOTES (insn); x; x = XEXP (x, 1))
4165 if (REG_NOTE_KIND (x) == REG_INC)
4167 /* See if this pseudo reg was reloaded in this insn.
4168 If so, its last-reload info is still valid
4169 because it is based on this insn's reload. */
4170 for (i = 0; i < n_reloads; i++)
4171 if (rld[i].out == XEXP (x, 0))
4175 forget_old_reloads_1 (XEXP (x, 0), NULL_RTX, NULL);
4179 /* A reload reg's contents are unknown after a label. */
4181 CLEAR_HARD_REG_SET (reg_reloaded_valid);
4183 /* Don't assume a reload reg is still good after a call insn
4184 if it is a call-used reg, or if it contains a value that will
4185 be partially clobbered by the call. */
4186 else if (CALL_P (insn))
4188 AND_COMPL_HARD_REG_SET (reg_reloaded_valid, call_used_reg_set);
4189 AND_COMPL_HARD_REG_SET (reg_reloaded_valid, reg_reloaded_call_part_clobbered);
4194 free (reg_last_reload_reg);
4195 CLEAR_REG_SET (®_has_output_reload);
4198 /* Discard all record of any value reloaded from X,
4199 or reloaded in X from someplace else;
4200 unless X is an output reload reg of the current insn.
4202 X may be a hard reg (the reload reg)
4203 or it may be a pseudo reg that was reloaded from.
4205 When DATA is non-NULL just mark the registers in regset
4206 to be forgotten later. */
4209 forget_old_reloads_1 (rtx x, rtx ignored ATTRIBUTE_UNUSED,
4214 regset regs = (regset) data;
4216 /* note_stores does give us subregs of hard regs,
4217 subreg_regno_offset requires a hard reg. */
4218 while (GET_CODE (x) == SUBREG)
4220 /* We ignore the subreg offset when calculating the regno,
4221 because we are using the entire underlying hard register
4231 if (regno >= FIRST_PSEUDO_REGISTER)
4237 nr = hard_regno_nregs[regno][GET_MODE (x)];
4238 /* Storing into a spilled-reg invalidates its contents.
4239 This can happen if a block-local pseudo is allocated to that reg
4240 and it wasn't spilled because this block's total need is 0.
4241 Then some insn might have an optional reload and use this reg. */
4243 for (i = 0; i < nr; i++)
4244 /* But don't do this if the reg actually serves as an output
4245 reload reg in the current instruction. */
4247 || ! TEST_HARD_REG_BIT (reg_is_output_reload, regno + i))
4249 CLEAR_HARD_REG_BIT (reg_reloaded_valid, regno + i);
4250 CLEAR_HARD_REG_BIT (reg_reloaded_call_part_clobbered, regno + i);
4251 spill_reg_store[regno + i] = 0;
4257 SET_REGNO_REG_SET (regs, regno + nr);
4260 /* Since value of X has changed,
4261 forget any value previously copied from it. */
4264 /* But don't forget a copy if this is the output reload
4265 that establishes the copy's validity. */
4267 || !REGNO_REG_SET_P (®_has_output_reload, regno + nr))
4268 reg_last_reload_reg[regno + nr] = 0;
4272 /* Forget the reloads marked in regset by previous function. */
4274 forget_marked_reloads (regset regs)
4277 reg_set_iterator rsi;
4278 EXECUTE_IF_SET_IN_REG_SET (regs, 0, reg, rsi)
4280 if (reg < FIRST_PSEUDO_REGISTER
4281 /* But don't do this if the reg actually serves as an output
4282 reload reg in the current instruction. */
4284 || ! TEST_HARD_REG_BIT (reg_is_output_reload, reg)))
4286 CLEAR_HARD_REG_BIT (reg_reloaded_valid, reg);
4287 CLEAR_HARD_REG_BIT (reg_reloaded_call_part_clobbered, reg);
4288 spill_reg_store[reg] = 0;
4291 || !REGNO_REG_SET_P (®_has_output_reload, reg))
4292 reg_last_reload_reg[reg] = 0;
4296 /* The following HARD_REG_SETs indicate when each hard register is
4297 used for a reload of various parts of the current insn. */
4299 /* If reg is unavailable for all reloads. */
4300 static HARD_REG_SET reload_reg_unavailable;
4301 /* If reg is in use as a reload reg for a RELOAD_OTHER reload. */
4302 static HARD_REG_SET reload_reg_used;
4303 /* If reg is in use for a RELOAD_FOR_INPUT_ADDRESS reload for operand I. */
4304 static HARD_REG_SET reload_reg_used_in_input_addr[MAX_RECOG_OPERANDS];
4305 /* If reg is in use for a RELOAD_FOR_INPADDR_ADDRESS reload for operand I. */
4306 static HARD_REG_SET reload_reg_used_in_inpaddr_addr[MAX_RECOG_OPERANDS];
4307 /* If reg is in use for a RELOAD_FOR_OUTPUT_ADDRESS reload for operand I. */
4308 static HARD_REG_SET reload_reg_used_in_output_addr[MAX_RECOG_OPERANDS];
4309 /* If reg is in use for a RELOAD_FOR_OUTADDR_ADDRESS reload for operand I. */
4310 static HARD_REG_SET reload_reg_used_in_outaddr_addr[MAX_RECOG_OPERANDS];
4311 /* If reg is in use for a RELOAD_FOR_INPUT reload for operand I. */
4312 static HARD_REG_SET reload_reg_used_in_input[MAX_RECOG_OPERANDS];
4313 /* If reg is in use for a RELOAD_FOR_OUTPUT reload for operand I. */
4314 static HARD_REG_SET reload_reg_used_in_output[MAX_RECOG_OPERANDS];
4315 /* If reg is in use for a RELOAD_FOR_OPERAND_ADDRESS reload. */
4316 static HARD_REG_SET reload_reg_used_in_op_addr;
4317 /* If reg is in use for a RELOAD_FOR_OPADDR_ADDR reload. */
4318 static HARD_REG_SET reload_reg_used_in_op_addr_reload;
4319 /* If reg is in use for a RELOAD_FOR_INSN reload. */
4320 static HARD_REG_SET reload_reg_used_in_insn;
4321 /* If reg is in use for a RELOAD_FOR_OTHER_ADDRESS reload. */
4322 static HARD_REG_SET reload_reg_used_in_other_addr;
4324 /* If reg is in use as a reload reg for any sort of reload. */
4325 static HARD_REG_SET reload_reg_used_at_all;
4327 /* If reg is use as an inherited reload. We just mark the first register
4329 static HARD_REG_SET reload_reg_used_for_inherit;
4331 /* Records which hard regs are used in any way, either as explicit use or
4332 by being allocated to a pseudo during any point of the current insn. */
4333 static HARD_REG_SET reg_used_in_insn;
4335 /* Mark reg REGNO as in use for a reload of the sort spec'd by OPNUM and
4336 TYPE. MODE is used to indicate how many consecutive regs are
4340 mark_reload_reg_in_use (unsigned int regno, int opnum, enum reload_type type,
4341 enum machine_mode mode)
4343 unsigned int nregs = hard_regno_nregs[regno][mode];
4346 for (i = regno; i < nregs + regno; i++)
4351 SET_HARD_REG_BIT (reload_reg_used, i);
4354 case RELOAD_FOR_INPUT_ADDRESS:
4355 SET_HARD_REG_BIT (reload_reg_used_in_input_addr[opnum], i);
4358 case RELOAD_FOR_INPADDR_ADDRESS:
4359 SET_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[opnum], i);
4362 case RELOAD_FOR_OUTPUT_ADDRESS:
4363 SET_HARD_REG_BIT (reload_reg_used_in_output_addr[opnum], i);
4366 case RELOAD_FOR_OUTADDR_ADDRESS:
4367 SET_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[opnum], i);
4370 case RELOAD_FOR_OPERAND_ADDRESS:
4371 SET_HARD_REG_BIT (reload_reg_used_in_op_addr, i);
4374 case RELOAD_FOR_OPADDR_ADDR:
4375 SET_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, i);
4378 case RELOAD_FOR_OTHER_ADDRESS:
4379 SET_HARD_REG_BIT (reload_reg_used_in_other_addr, i);
4382 case RELOAD_FOR_INPUT:
4383 SET_HARD_REG_BIT (reload_reg_used_in_input[opnum], i);
4386 case RELOAD_FOR_OUTPUT:
4387 SET_HARD_REG_BIT (reload_reg_used_in_output[opnum], i);
4390 case RELOAD_FOR_INSN:
4391 SET_HARD_REG_BIT (reload_reg_used_in_insn, i);
4395 SET_HARD_REG_BIT (reload_reg_used_at_all, i);
4399 /* Similarly, but show REGNO is no longer in use for a reload. */
4402 clear_reload_reg_in_use (unsigned int regno, int opnum,
4403 enum reload_type type, enum machine_mode mode)
4405 unsigned int nregs = hard_regno_nregs[regno][mode];
4406 unsigned int start_regno, end_regno, r;
4408 /* A complication is that for some reload types, inheritance might
4409 allow multiple reloads of the same types to share a reload register.
4410 We set check_opnum if we have to check only reloads with the same
4411 operand number, and check_any if we have to check all reloads. */
4412 int check_opnum = 0;
4414 HARD_REG_SET *used_in_set;
4419 used_in_set = &reload_reg_used;
4422 case RELOAD_FOR_INPUT_ADDRESS:
4423 used_in_set = &reload_reg_used_in_input_addr[opnum];
4426 case RELOAD_FOR_INPADDR_ADDRESS:
4428 used_in_set = &reload_reg_used_in_inpaddr_addr[opnum];
4431 case RELOAD_FOR_OUTPUT_ADDRESS:
4432 used_in_set = &reload_reg_used_in_output_addr[opnum];
4435 case RELOAD_FOR_OUTADDR_ADDRESS:
4437 used_in_set = &reload_reg_used_in_outaddr_addr[opnum];
4440 case RELOAD_FOR_OPERAND_ADDRESS:
4441 used_in_set = &reload_reg_used_in_op_addr;
4444 case RELOAD_FOR_OPADDR_ADDR:
4446 used_in_set = &reload_reg_used_in_op_addr_reload;
4449 case RELOAD_FOR_OTHER_ADDRESS:
4450 used_in_set = &reload_reg_used_in_other_addr;
4454 case RELOAD_FOR_INPUT:
4455 used_in_set = &reload_reg_used_in_input[opnum];
4458 case RELOAD_FOR_OUTPUT:
4459 used_in_set = &reload_reg_used_in_output[opnum];
4462 case RELOAD_FOR_INSN:
4463 used_in_set = &reload_reg_used_in_insn;
4468 /* We resolve conflicts with remaining reloads of the same type by
4469 excluding the intervals of reload registers by them from the
4470 interval of freed reload registers. Since we only keep track of
4471 one set of interval bounds, we might have to exclude somewhat
4472 more than what would be necessary if we used a HARD_REG_SET here.
4473 But this should only happen very infrequently, so there should
4474 be no reason to worry about it. */
4476 start_regno = regno;
4477 end_regno = regno + nregs;
4478 if (check_opnum || check_any)
4480 for (i = n_reloads - 1; i >= 0; i--)
4482 if (rld[i].when_needed == type
4483 && (check_any || rld[i].opnum == opnum)
4486 unsigned int conflict_start = true_regnum (rld[i].reg_rtx);
4487 unsigned int conflict_end
4489 + hard_regno_nregs[conflict_start][rld[i].mode]);
4491 /* If there is an overlap with the first to-be-freed register,
4492 adjust the interval start. */
4493 if (conflict_start <= start_regno && conflict_end > start_regno)
4494 start_regno = conflict_end;
4495 /* Otherwise, if there is a conflict with one of the other
4496 to-be-freed registers, adjust the interval end. */
4497 if (conflict_start > start_regno && conflict_start < end_regno)
4498 end_regno = conflict_start;
4503 for (r = start_regno; r < end_regno; r++)
4504 CLEAR_HARD_REG_BIT (*used_in_set, r);
4507 /* 1 if reg REGNO is free as a reload reg for a reload of the sort
4508 specified by OPNUM and TYPE. */
4511 reload_reg_free_p (unsigned int regno, int opnum, enum reload_type type)
4515 /* In use for a RELOAD_OTHER means it's not available for anything. */
4516 if (TEST_HARD_REG_BIT (reload_reg_used, regno)
4517 || TEST_HARD_REG_BIT (reload_reg_unavailable, regno))
4523 /* In use for anything means we can't use it for RELOAD_OTHER. */
4524 if (TEST_HARD_REG_BIT (reload_reg_used_in_other_addr, regno)
4525 || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)
4526 || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno)
4527 || TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno))
4530 for (i = 0; i < reload_n_operands; i++)
4531 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4532 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno)
4533 || TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4534 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
4535 || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)
4536 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4541 case RELOAD_FOR_INPUT:
4542 if (TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4543 || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno))
4546 if (TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno))
4549 /* If it is used for some other input, can't use it. */
4550 for (i = 0; i < reload_n_operands; i++)
4551 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4554 /* If it is used in a later operand's address, can't use it. */
4555 for (i = opnum + 1; i < reload_n_operands; i++)
4556 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4557 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno))
4562 case RELOAD_FOR_INPUT_ADDRESS:
4563 /* Can't use a register if it is used for an input address for this
4564 operand or used as an input in an earlier one. */
4565 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[opnum], regno)
4566 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[opnum], regno))
4569 for (i = 0; i < opnum; i++)
4570 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4575 case RELOAD_FOR_INPADDR_ADDRESS:
4576 /* Can't use a register if it is used for an input address
4577 for this operand or used as an input in an earlier
4579 if (TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[opnum], regno))
4582 for (i = 0; i < opnum; i++)
4583 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4588 case RELOAD_FOR_OUTPUT_ADDRESS:
4589 /* Can't use a register if it is used for an output address for this
4590 operand or used as an output in this or a later operand. Note
4591 that multiple output operands are emitted in reverse order, so
4592 the conflicting ones are those with lower indices. */
4593 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[opnum], regno))
4596 for (i = 0; i <= opnum; i++)
4597 if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4602 case RELOAD_FOR_OUTADDR_ADDRESS:
4603 /* Can't use a register if it is used for an output address
4604 for this operand or used as an output in this or a
4605 later operand. Note that multiple output operands are
4606 emitted in reverse order, so the conflicting ones are
4607 those with lower indices. */
4608 if (TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[opnum], regno))
4611 for (i = 0; i <= opnum; i++)
4612 if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4617 case RELOAD_FOR_OPERAND_ADDRESS:
4618 for (i = 0; i < reload_n_operands; i++)
4619 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4622 return (! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4623 && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno));
4625 case RELOAD_FOR_OPADDR_ADDR:
4626 for (i = 0; i < reload_n_operands; i++)
4627 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4630 return (!TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno));
4632 case RELOAD_FOR_OUTPUT:
4633 /* This cannot share a register with RELOAD_FOR_INSN reloads, other
4634 outputs, or an operand address for this or an earlier output.
4635 Note that multiple output operands are emitted in reverse order,
4636 so the conflicting ones are those with higher indices. */
4637 if (TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno))
4640 for (i = 0; i < reload_n_operands; i++)
4641 if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4644 for (i = opnum; i < reload_n_operands; i++)
4645 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4646 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno))
4651 case RELOAD_FOR_INSN:
4652 for (i = 0; i < reload_n_operands; i++)
4653 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)
4654 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4657 return (! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4658 && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno));
4660 case RELOAD_FOR_OTHER_ADDRESS:
4661 return ! TEST_HARD_REG_BIT (reload_reg_used_in_other_addr, regno);
4668 /* Return 1 if the value in reload reg REGNO, as used by a reload
4669 needed for the part of the insn specified by OPNUM and TYPE,
4670 is still available in REGNO at the end of the insn.
4672 We can assume that the reload reg was already tested for availability
4673 at the time it is needed, and we should not check this again,
4674 in case the reg has already been marked in use. */
4677 reload_reg_reaches_end_p (unsigned int regno, int opnum, enum reload_type type)
4684 /* Since a RELOAD_OTHER reload claims the reg for the entire insn,
4685 its value must reach the end. */
4688 /* If this use is for part of the insn,
4689 its value reaches if no subsequent part uses the same register.
4690 Just like the above function, don't try to do this with lots
4693 case RELOAD_FOR_OTHER_ADDRESS:
4694 /* Here we check for everything else, since these don't conflict
4695 with anything else and everything comes later. */
4697 for (i = 0; i < reload_n_operands; i++)
4698 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4699 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
4700 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)
4701 || TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4702 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno)
4703 || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4706 return (! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)
4707 && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno)
4708 && ! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4709 && ! TEST_HARD_REG_BIT (reload_reg_used, regno));
4711 case RELOAD_FOR_INPUT_ADDRESS:
4712 case RELOAD_FOR_INPADDR_ADDRESS:
4713 /* Similar, except that we check only for this and subsequent inputs
4714 and the address of only subsequent inputs and we do not need
4715 to check for RELOAD_OTHER objects since they are known not to
4718 for (i = opnum; i < reload_n_operands; i++)
4719 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4722 for (i = opnum + 1; i < reload_n_operands; i++)
4723 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4724 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno))
4727 for (i = 0; i < reload_n_operands; i++)
4728 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4729 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
4730 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4733 if (TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno))
4736 return (!TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)
4737 && !TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4738 && !TEST_HARD_REG_BIT (reload_reg_used, regno));
4740 case RELOAD_FOR_INPUT:
4741 /* Similar to input address, except we start at the next operand for
4742 both input and input address and we do not check for
4743 RELOAD_FOR_OPERAND_ADDRESS and RELOAD_FOR_INSN since these
4746 for (i = opnum + 1; i < reload_n_operands; i++)
4747 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4748 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno)
4749 || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4752 /* ... fall through ... */
4754 case RELOAD_FOR_OPERAND_ADDRESS:
4755 /* Check outputs and their addresses. */
4757 for (i = 0; i < reload_n_operands; i++)
4758 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4759 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
4760 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4763 return (!TEST_HARD_REG_BIT (reload_reg_used, regno));
4765 case RELOAD_FOR_OPADDR_ADDR:
4766 for (i = 0; i < reload_n_operands; i++)
4767 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4768 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
4769 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4772 return (!TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)
4773 && !TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4774 && !TEST_HARD_REG_BIT (reload_reg_used, regno));
4776 case RELOAD_FOR_INSN:
4777 /* These conflict with other outputs with RELOAD_OTHER. So
4778 we need only check for output addresses. */
4780 opnum = reload_n_operands;
4782 /* ... fall through ... */
4784 case RELOAD_FOR_OUTPUT:
4785 case RELOAD_FOR_OUTPUT_ADDRESS:
4786 case RELOAD_FOR_OUTADDR_ADDRESS:
4787 /* We already know these can't conflict with a later output. So the
4788 only thing to check are later output addresses.
4789 Note that multiple output operands are emitted in reverse order,
4790 so the conflicting ones are those with lower indices. */
4791 for (i = 0; i < opnum; i++)
4792 if (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))
4804 /* Returns whether R1 and R2 are uniquely chained: the value of one
4805 is used by the other, and that value is not used by any other
4806 reload for this insn. This is used to partially undo the decision
4807 made in find_reloads when in the case of multiple
4808 RELOAD_FOR_OPERAND_ADDRESS reloads it converts all
4809 RELOAD_FOR_OPADDR_ADDR reloads into RELOAD_FOR_OPERAND_ADDRESS
4810 reloads. This code tries to avoid the conflict created by that
4811 change. It might be cleaner to explicitly keep track of which
4812 RELOAD_FOR_OPADDR_ADDR reload is associated with which
4813 RELOAD_FOR_OPERAND_ADDRESS reload, rather than to try to detect
4814 this after the fact. */
4816 reloads_unique_chain_p (int r1, int r2)
4820 /* We only check input reloads. */
4821 if (! rld[r1].in || ! rld[r2].in)
4824 /* Avoid anything with output reloads. */
4825 if (rld[r1].out || rld[r2].out)
4828 /* "chained" means one reload is a component of the other reload,
4829 not the same as the other reload. */
4830 if (rld[r1].opnum != rld[r2].opnum
4831 || rtx_equal_p (rld[r1].in, rld[r2].in)
4832 || rld[r1].optional || rld[r2].optional
4833 || ! (reg_mentioned_p (rld[r1].in, rld[r2].in)
4834 || reg_mentioned_p (rld[r2].in, rld[r1].in)))
4837 for (i = 0; i < n_reloads; i ++)
4838 /* Look for input reloads that aren't our two */
4839 if (i != r1 && i != r2 && rld[i].in)
4841 /* If our reload is mentioned at all, it isn't a simple chain. */
4842 if (reg_mentioned_p (rld[r1].in, rld[i].in))
4848 /* Return 1 if the reloads denoted by R1 and R2 cannot share a register.
4851 This function uses the same algorithm as reload_reg_free_p above. */
4854 reloads_conflict (int r1, int r2)
4856 enum reload_type r1_type = rld[r1].when_needed;
4857 enum reload_type r2_type = rld[r2].when_needed;
4858 int r1_opnum = rld[r1].opnum;
4859 int r2_opnum = rld[r2].opnum;
4861 /* RELOAD_OTHER conflicts with everything. */
4862 if (r2_type == RELOAD_OTHER)
4865 /* Otherwise, check conflicts differently for each type. */
4869 case RELOAD_FOR_INPUT:
4870 return (r2_type == RELOAD_FOR_INSN
4871 || r2_type == RELOAD_FOR_OPERAND_ADDRESS
4872 || r2_type == RELOAD_FOR_OPADDR_ADDR
4873 || r2_type == RELOAD_FOR_INPUT
4874 || ((r2_type == RELOAD_FOR_INPUT_ADDRESS
4875 || r2_type == RELOAD_FOR_INPADDR_ADDRESS)
4876 && r2_opnum > r1_opnum));
4878 case RELOAD_FOR_INPUT_ADDRESS:
4879 return ((r2_type == RELOAD_FOR_INPUT_ADDRESS && r1_opnum == r2_opnum)
4880 || (r2_type == RELOAD_FOR_INPUT && r2_opnum < r1_opnum));
4882 case RELOAD_FOR_INPADDR_ADDRESS:
4883 return ((r2_type == RELOAD_FOR_INPADDR_ADDRESS && r1_opnum == r2_opnum)
4884 || (r2_type == RELOAD_FOR_INPUT && r2_opnum < r1_opnum));
4886 case RELOAD_FOR_OUTPUT_ADDRESS:
4887 return ((r2_type == RELOAD_FOR_OUTPUT_ADDRESS && r2_opnum == r1_opnum)
4888 || (r2_type == RELOAD_FOR_OUTPUT && r2_opnum <= r1_opnum));
4890 case RELOAD_FOR_OUTADDR_ADDRESS:
4891 return ((r2_type == RELOAD_FOR_OUTADDR_ADDRESS && r2_opnum == r1_opnum)
4892 || (r2_type == RELOAD_FOR_OUTPUT && r2_opnum <= r1_opnum));
4894 case RELOAD_FOR_OPERAND_ADDRESS:
4895 return (r2_type == RELOAD_FOR_INPUT || r2_type == RELOAD_FOR_INSN
4896 || (r2_type == RELOAD_FOR_OPERAND_ADDRESS
4897 && !reloads_unique_chain_p (r1, r2)));
4899 case RELOAD_FOR_OPADDR_ADDR:
4900 return (r2_type == RELOAD_FOR_INPUT
4901 || r2_type == RELOAD_FOR_OPADDR_ADDR);
4903 case RELOAD_FOR_OUTPUT:
4904 return (r2_type == RELOAD_FOR_INSN || r2_type == RELOAD_FOR_OUTPUT
4905 || ((r2_type == RELOAD_FOR_OUTPUT_ADDRESS
4906 || r2_type == RELOAD_FOR_OUTADDR_ADDRESS)
4907 && r2_opnum >= r1_opnum));
4909 case RELOAD_FOR_INSN:
4910 return (r2_type == RELOAD_FOR_INPUT || r2_type == RELOAD_FOR_OUTPUT
4911 || r2_type == RELOAD_FOR_INSN
4912 || r2_type == RELOAD_FOR_OPERAND_ADDRESS);
4914 case RELOAD_FOR_OTHER_ADDRESS:
4915 return r2_type == RELOAD_FOR_OTHER_ADDRESS;
4925 /* Indexed by reload number, 1 if incoming value
4926 inherited from previous insns. */
4927 static char reload_inherited[MAX_RELOADS];
4929 /* For an inherited reload, this is the insn the reload was inherited from,
4930 if we know it. Otherwise, this is 0. */
4931 static rtx reload_inheritance_insn[MAX_RELOADS];
4933 /* If nonzero, this is a place to get the value of the reload,
4934 rather than using reload_in. */
4935 static rtx reload_override_in[MAX_RELOADS];
4937 /* For each reload, the hard register number of the register used,
4938 or -1 if we did not need a register for this reload. */
4939 static int reload_spill_index[MAX_RELOADS];
4941 /* Subroutine of free_for_value_p, used to check a single register.
4942 START_REGNO is the starting regno of the full reload register
4943 (possibly comprising multiple hard registers) that we are considering. */
4946 reload_reg_free_for_value_p (int start_regno, int regno, int opnum,
4947 enum reload_type type, rtx value, rtx out,
4948 int reloadnum, int ignore_address_reloads)
4951 /* Set if we see an input reload that must not share its reload register
4952 with any new earlyclobber, but might otherwise share the reload
4953 register with an output or input-output reload. */
4954 int check_earlyclobber = 0;
4958 if (TEST_HARD_REG_BIT (reload_reg_unavailable, regno))
4961 if (out == const0_rtx)
4967 /* We use some pseudo 'time' value to check if the lifetimes of the
4968 new register use would overlap with the one of a previous reload
4969 that is not read-only or uses a different value.
4970 The 'time' used doesn't have to be linear in any shape or form, just
4972 Some reload types use different 'buckets' for each operand.
4973 So there are MAX_RECOG_OPERANDS different time values for each
4975 We compute TIME1 as the time when the register for the prospective
4976 new reload ceases to be live, and TIME2 for each existing
4977 reload as the time when that the reload register of that reload
4979 Where there is little to be gained by exact lifetime calculations,
4980 we just make conservative assumptions, i.e. a longer lifetime;
4981 this is done in the 'default:' cases. */
4984 case RELOAD_FOR_OTHER_ADDRESS:
4985 /* RELOAD_FOR_OTHER_ADDRESS conflicts with RELOAD_OTHER reloads. */
4986 time1 = copy ? 0 : 1;
4989 time1 = copy ? 1 : MAX_RECOG_OPERANDS * 5 + 5;
4991 /* For each input, we may have a sequence of RELOAD_FOR_INPADDR_ADDRESS,
4992 RELOAD_FOR_INPUT_ADDRESS and RELOAD_FOR_INPUT. By adding 0 / 1 / 2 ,
4993 respectively, to the time values for these, we get distinct time
4994 values. To get distinct time values for each operand, we have to
4995 multiply opnum by at least three. We round that up to four because
4996 multiply by four is often cheaper. */
4997 case RELOAD_FOR_INPADDR_ADDRESS:
4998 time1 = opnum * 4 + 2;
5000 case RELOAD_FOR_INPUT_ADDRESS:
5001 time1 = opnum * 4 + 3;
5003 case RELOAD_FOR_INPUT:
5004 /* All RELOAD_FOR_INPUT reloads remain live till the instruction
5005 executes (inclusive). */
5006 time1 = copy ? opnum * 4 + 4 : MAX_RECOG_OPERANDS * 4 + 3;
5008 case RELOAD_FOR_OPADDR_ADDR:
5010 <= (MAX_RECOG_OPERANDS - 1) * 4 + 4 == MAX_RECOG_OPERANDS * 4 */
5011 time1 = MAX_RECOG_OPERANDS * 4 + 1;
5013 case RELOAD_FOR_OPERAND_ADDRESS:
5014 /* RELOAD_FOR_OPERAND_ADDRESS reloads are live even while the insn
5016 time1 = copy ? MAX_RECOG_OPERANDS * 4 + 2 : MAX_RECOG_OPERANDS * 4 + 3;
5018 case RELOAD_FOR_OUTADDR_ADDRESS:
5019 time1 = MAX_RECOG_OPERANDS * 4 + 4 + opnum;
5021 case RELOAD_FOR_OUTPUT_ADDRESS:
5022 time1 = MAX_RECOG_OPERANDS * 4 + 5 + opnum;
5025 time1 = MAX_RECOG_OPERANDS * 5 + 5;
5028 for (i = 0; i < n_reloads; i++)
5030 rtx reg = rld[i].reg_rtx;
5031 if (reg && REG_P (reg)
5032 && ((unsigned) regno - true_regnum (reg)
5033 <= hard_regno_nregs[REGNO (reg)][GET_MODE (reg)] - (unsigned) 1)
5036 rtx other_input = rld[i].in;
5038 /* If the other reload loads the same input value, that
5039 will not cause a conflict only if it's loading it into
5040 the same register. */
5041 if (true_regnum (reg) != start_regno)
5042 other_input = NULL_RTX;
5043 if (! other_input || ! rtx_equal_p (other_input, value)
5044 || rld[i].out || out)
5047 switch (rld[i].when_needed)
5049 case RELOAD_FOR_OTHER_ADDRESS:
5052 case RELOAD_FOR_INPADDR_ADDRESS:
5053 /* find_reloads makes sure that a
5054 RELOAD_FOR_{INP,OP,OUT}ADDR_ADDRESS reload is only used
5055 by at most one - the first -
5056 RELOAD_FOR_{INPUT,OPERAND,OUTPUT}_ADDRESS . If the
5057 address reload is inherited, the address address reload
5058 goes away, so we can ignore this conflict. */
5059 if (type == RELOAD_FOR_INPUT_ADDRESS && reloadnum == i + 1
5060 && ignore_address_reloads
5061 /* Unless the RELOAD_FOR_INPUT is an auto_inc expression.
5062 Then the address address is still needed to store
5063 back the new address. */
5064 && ! rld[reloadnum].out)
5066 /* Likewise, if a RELOAD_FOR_INPUT can inherit a value, its
5067 RELOAD_FOR_INPUT_ADDRESS / RELOAD_FOR_INPADDR_ADDRESS
5069 if (type == RELOAD_FOR_INPUT && opnum == rld[i].opnum
5070 && ignore_address_reloads
5071 /* Unless we are reloading an auto_inc expression. */
5072 && ! rld[reloadnum].out)
5074 time2 = rld[i].opnum * 4 + 2;
5076 case RELOAD_FOR_INPUT_ADDRESS:
5077 if (type == RELOAD_FOR_INPUT && opnum == rld[i].opnum
5078 && ignore_address_reloads
5079 && ! rld[reloadnum].out)
5081 time2 = rld[i].opnum * 4 + 3;
5083 case RELOAD_FOR_INPUT:
5084 time2 = rld[i].opnum * 4 + 4;
5085 check_earlyclobber = 1;
5087 /* rld[i].opnum * 4 + 4 <= (MAX_RECOG_OPERAND - 1) * 4 + 4
5088 == MAX_RECOG_OPERAND * 4 */
5089 case RELOAD_FOR_OPADDR_ADDR:
5090 if (type == RELOAD_FOR_OPERAND_ADDRESS && reloadnum == i + 1
5091 && ignore_address_reloads
5092 && ! rld[reloadnum].out)
5094 time2 = MAX_RECOG_OPERANDS * 4 + 1;
5096 case RELOAD_FOR_OPERAND_ADDRESS:
5097 time2 = MAX_RECOG_OPERANDS * 4 + 2;
5098 check_earlyclobber = 1;
5100 case RELOAD_FOR_INSN:
5101 time2 = MAX_RECOG_OPERANDS * 4 + 3;
5103 case RELOAD_FOR_OUTPUT:
5104 /* All RELOAD_FOR_OUTPUT reloads become live just after the
5105 instruction is executed. */
5106 time2 = MAX_RECOG_OPERANDS * 4 + 4;
5108 /* The first RELOAD_FOR_OUTADDR_ADDRESS reload conflicts with
5109 the RELOAD_FOR_OUTPUT reloads, so assign it the same time
5111 case RELOAD_FOR_OUTADDR_ADDRESS:
5112 if (type == RELOAD_FOR_OUTPUT_ADDRESS && reloadnum == i + 1
5113 && ignore_address_reloads
5114 && ! rld[reloadnum].out)
5116 time2 = MAX_RECOG_OPERANDS * 4 + 4 + rld[i].opnum;
5118 case RELOAD_FOR_OUTPUT_ADDRESS:
5119 time2 = MAX_RECOG_OPERANDS * 4 + 5 + rld[i].opnum;
5122 /* If there is no conflict in the input part, handle this
5123 like an output reload. */
5124 if (! rld[i].in || rtx_equal_p (other_input, value))
5126 time2 = MAX_RECOG_OPERANDS * 4 + 4;
5127 /* Earlyclobbered outputs must conflict with inputs. */
5128 if (earlyclobber_operand_p (rld[i].out))
5129 time2 = MAX_RECOG_OPERANDS * 4 + 3;
5134 /* RELOAD_OTHER might be live beyond instruction execution,
5135 but this is not obvious when we set time2 = 1. So check
5136 here if there might be a problem with the new reload
5137 clobbering the register used by the RELOAD_OTHER. */
5145 && (! rld[i].in || rld[i].out
5146 || ! rtx_equal_p (other_input, value)))
5147 || (out && rld[reloadnum].out_reg
5148 && time2 >= MAX_RECOG_OPERANDS * 4 + 3))
5154 /* Earlyclobbered outputs must conflict with inputs. */
5155 if (check_earlyclobber && out && earlyclobber_operand_p (out))
5161 /* Return 1 if the value in reload reg REGNO, as used by a reload
5162 needed for the part of the insn specified by OPNUM and TYPE,
5163 may be used to load VALUE into it.
5165 MODE is the mode in which the register is used, this is needed to
5166 determine how many hard regs to test.
5168 Other read-only reloads with the same value do not conflict
5169 unless OUT is nonzero and these other reloads have to live while
5170 output reloads live.
5171 If OUT is CONST0_RTX, this is a special case: it means that the
5172 test should not be for using register REGNO as reload register, but
5173 for copying from register REGNO into the reload register.
5175 RELOADNUM is the number of the reload we want to load this value for;
5176 a reload does not conflict with itself.
5178 When IGNORE_ADDRESS_RELOADS is set, we can not have conflicts with
5179 reloads that load an address for the very reload we are considering.
5181 The caller has to make sure that there is no conflict with the return
5185 free_for_value_p (int regno, enum machine_mode mode, int opnum,
5186 enum reload_type type, rtx value, rtx out, int reloadnum,
5187 int ignore_address_reloads)
5189 int nregs = hard_regno_nregs[regno][mode];
5191 if (! reload_reg_free_for_value_p (regno, regno + nregs, opnum, type,
5192 value, out, reloadnum,
5193 ignore_address_reloads))
5198 /* Return nonzero if the rtx X is invariant over the current function. */
5199 /* ??? Actually, the places where we use this expect exactly what is
5200 tested here, and not everything that is function invariant. In
5201 particular, the frame pointer and arg pointer are special cased;
5202 pic_offset_table_rtx is not, and we must not spill these things to
5206 function_invariant_p (rtx x)
5210 if (x == frame_pointer_rtx || x == arg_pointer_rtx)
5212 if (GET_CODE (x) == PLUS
5213 && (XEXP (x, 0) == frame_pointer_rtx || XEXP (x, 0) == arg_pointer_rtx)
5214 && CONSTANT_P (XEXP (x, 1)))
5219 /* Determine whether the reload reg X overlaps any rtx'es used for
5220 overriding inheritance. Return nonzero if so. */
5223 conflicts_with_override (rtx x)
5226 for (i = 0; i < n_reloads; i++)
5227 if (reload_override_in[i]
5228 && reg_overlap_mentioned_p (x, reload_override_in[i]))
5233 /* Give an error message saying we failed to find a reload for INSN,
5234 and clear out reload R. */
5236 failed_reload (rtx insn, int r)
5238 if (asm_noperands (PATTERN (insn)) < 0)
5239 /* It's the compiler's fault. */
5240 fatal_insn ("could not find a spill register", insn);
5242 /* It's the user's fault; the operand's mode and constraint
5243 don't match. Disable this reload so we don't crash in final. */
5244 error_for_asm (insn,
5245 "%<asm%> operand constraint incompatible with operand size");
5249 rld[r].optional = 1;
5250 rld[r].secondary_p = 1;
5253 /* I is the index in SPILL_REG_RTX of the reload register we are to allocate
5254 for reload R. If it's valid, get an rtx for it. Return nonzero if
5257 set_reload_reg (int i, int r)
5260 rtx reg = spill_reg_rtx[i];
5262 if (reg == 0 || GET_MODE (reg) != rld[r].mode)
5263 spill_reg_rtx[i] = reg
5264 = gen_rtx_REG (rld[r].mode, spill_regs[i]);
5266 regno = true_regnum (reg);
5268 /* Detect when the reload reg can't hold the reload mode.
5269 This used to be one `if', but Sequent compiler can't handle that. */
5270 if (HARD_REGNO_MODE_OK (regno, rld[r].mode))
5272 enum machine_mode test_mode = VOIDmode;
5274 test_mode = GET_MODE (rld[r].in);
5275 /* If rld[r].in has VOIDmode, it means we will load it
5276 in whatever mode the reload reg has: to wit, rld[r].mode.
5277 We have already tested that for validity. */
5278 /* Aside from that, we need to test that the expressions
5279 to reload from or into have modes which are valid for this
5280 reload register. Otherwise the reload insns would be invalid. */
5281 if (! (rld[r].in != 0 && test_mode != VOIDmode
5282 && ! HARD_REGNO_MODE_OK (regno, test_mode)))
5283 if (! (rld[r].out != 0
5284 && ! HARD_REGNO_MODE_OK (regno, GET_MODE (rld[r].out))))
5286 /* The reg is OK. */
5289 /* Mark as in use for this insn the reload regs we use
5291 mark_reload_reg_in_use (spill_regs[i], rld[r].opnum,
5292 rld[r].when_needed, rld[r].mode);
5294 rld[r].reg_rtx = reg;
5295 reload_spill_index[r] = spill_regs[i];
5302 /* Find a spill register to use as a reload register for reload R.
5303 LAST_RELOAD is nonzero if this is the last reload for the insn being
5306 Set rld[R].reg_rtx to the register allocated.
5308 We return 1 if successful, or 0 if we couldn't find a spill reg and
5309 we didn't change anything. */
5312 allocate_reload_reg (struct insn_chain *chain ATTRIBUTE_UNUSED, int r,
5317 /* If we put this reload ahead, thinking it is a group,
5318 then insist on finding a group. Otherwise we can grab a
5319 reg that some other reload needs.
5320 (That can happen when we have a 68000 DATA_OR_FP_REG
5321 which is a group of data regs or one fp reg.)
5322 We need not be so restrictive if there are no more reloads
5325 ??? Really it would be nicer to have smarter handling
5326 for that kind of reg class, where a problem like this is normal.
5327 Perhaps those classes should be avoided for reloading
5328 by use of more alternatives. */
5330 int force_group = rld[r].nregs > 1 && ! last_reload;
5332 /* If we want a single register and haven't yet found one,
5333 take any reg in the right class and not in use.
5334 If we want a consecutive group, here is where we look for it.
5336 We use two passes so we can first look for reload regs to
5337 reuse, which are already in use for other reloads in this insn,
5338 and only then use additional registers.
5339 I think that maximizing reuse is needed to make sure we don't
5340 run out of reload regs. Suppose we have three reloads, and
5341 reloads A and B can share regs. These need two regs.
5342 Suppose A and B are given different regs.
5343 That leaves none for C. */
5344 for (pass = 0; pass < 2; pass++)
5346 /* I is the index in spill_regs.
5347 We advance it round-robin between insns to use all spill regs
5348 equally, so that inherited reloads have a chance
5349 of leapfrogging each other. */
5353 for (count = 0; count < n_spills; count++)
5355 int class = (int) rld[r].class;
5361 regnum = spill_regs[i];
5363 if ((reload_reg_free_p (regnum, rld[r].opnum,
5366 /* We check reload_reg_used to make sure we
5367 don't clobber the return register. */
5368 && ! TEST_HARD_REG_BIT (reload_reg_used, regnum)
5369 && free_for_value_p (regnum, rld[r].mode, rld[r].opnum,
5370 rld[r].when_needed, rld[r].in,
5372 && TEST_HARD_REG_BIT (reg_class_contents[class], regnum)
5373 && HARD_REGNO_MODE_OK (regnum, rld[r].mode)
5374 /* Look first for regs to share, then for unshared. But
5375 don't share regs used for inherited reloads; they are
5376 the ones we want to preserve. */
5378 || (TEST_HARD_REG_BIT (reload_reg_used_at_all,
5380 && ! TEST_HARD_REG_BIT (reload_reg_used_for_inherit,
5383 int nr = hard_regno_nregs[regnum][rld[r].mode];
5384 /* Avoid the problem where spilling a GENERAL_OR_FP_REG
5385 (on 68000) got us two FP regs. If NR is 1,
5386 we would reject both of them. */
5389 /* If we need only one reg, we have already won. */
5392 /* But reject a single reg if we demand a group. */
5397 /* Otherwise check that as many consecutive regs as we need
5398 are available here. */
5401 int regno = regnum + nr - 1;
5402 if (!(TEST_HARD_REG_BIT (reg_class_contents[class], regno)
5403 && spill_reg_order[regno] >= 0
5404 && reload_reg_free_p (regno, rld[r].opnum,
5405 rld[r].when_needed)))
5414 /* If we found something on pass 1, omit pass 2. */
5415 if (count < n_spills)
5419 /* We should have found a spill register by now. */
5420 if (count >= n_spills)
5423 /* I is the index in SPILL_REG_RTX of the reload register we are to
5424 allocate. Get an rtx for it and find its register number. */
5426 return set_reload_reg (i, r);
5429 /* Initialize all the tables needed to allocate reload registers.
5430 CHAIN is the insn currently being processed; SAVE_RELOAD_REG_RTX
5431 is the array we use to restore the reg_rtx field for every reload. */
5434 choose_reload_regs_init (struct insn_chain *chain, rtx *save_reload_reg_rtx)
5438 for (i = 0; i < n_reloads; i++)
5439 rld[i].reg_rtx = save_reload_reg_rtx[i];
5441 memset (reload_inherited, 0, MAX_RELOADS);
5442 memset (reload_inheritance_insn, 0, MAX_RELOADS * sizeof (rtx));
5443 memset (reload_override_in, 0, MAX_RELOADS * sizeof (rtx));
5445 CLEAR_HARD_REG_SET (reload_reg_used);
5446 CLEAR_HARD_REG_SET (reload_reg_used_at_all);
5447 CLEAR_HARD_REG_SET (reload_reg_used_in_op_addr);
5448 CLEAR_HARD_REG_SET (reload_reg_used_in_op_addr_reload);
5449 CLEAR_HARD_REG_SET (reload_reg_used_in_insn);
5450 CLEAR_HARD_REG_SET (reload_reg_used_in_other_addr);
5452 CLEAR_HARD_REG_SET (reg_used_in_insn);
5455 REG_SET_TO_HARD_REG_SET (tmp, &chain->live_throughout);
5456 IOR_HARD_REG_SET (reg_used_in_insn, tmp);
5457 REG_SET_TO_HARD_REG_SET (tmp, &chain->dead_or_set);
5458 IOR_HARD_REG_SET (reg_used_in_insn, tmp);
5459 compute_use_by_pseudos (®_used_in_insn, &chain->live_throughout);
5460 compute_use_by_pseudos (®_used_in_insn, &chain->dead_or_set);
5463 for (i = 0; i < reload_n_operands; i++)
5465 CLEAR_HARD_REG_SET (reload_reg_used_in_output[i]);
5466 CLEAR_HARD_REG_SET (reload_reg_used_in_input[i]);
5467 CLEAR_HARD_REG_SET (reload_reg_used_in_input_addr[i]);
5468 CLEAR_HARD_REG_SET (reload_reg_used_in_inpaddr_addr[i]);
5469 CLEAR_HARD_REG_SET (reload_reg_used_in_output_addr[i]);
5470 CLEAR_HARD_REG_SET (reload_reg_used_in_outaddr_addr[i]);
5473 COMPL_HARD_REG_SET (reload_reg_unavailable, chain->used_spill_regs);
5475 CLEAR_HARD_REG_SET (reload_reg_used_for_inherit);
5477 for (i = 0; i < n_reloads; i++)
5478 /* If we have already decided to use a certain register,
5479 don't use it in another way. */
5481 mark_reload_reg_in_use (REGNO (rld[i].reg_rtx), rld[i].opnum,
5482 rld[i].when_needed, rld[i].mode);
5485 /* Assign hard reg targets for the pseudo-registers we must reload
5486 into hard regs for this insn.
5487 Also output the instructions to copy them in and out of the hard regs.
5489 For machines with register classes, we are responsible for
5490 finding a reload reg in the proper class. */
5493 choose_reload_regs (struct insn_chain *chain)
5495 rtx insn = chain->insn;
5497 unsigned int max_group_size = 1;
5498 enum reg_class group_class = NO_REGS;
5499 int pass, win, inheritance;
5501 rtx save_reload_reg_rtx[MAX_RELOADS];
5503 /* In order to be certain of getting the registers we need,
5504 we must sort the reloads into order of increasing register class.
5505 Then our grabbing of reload registers will parallel the process
5506 that provided the reload registers.
5508 Also note whether any of the reloads wants a consecutive group of regs.
5509 If so, record the maximum size of the group desired and what
5510 register class contains all the groups needed by this insn. */
5512 for (j = 0; j < n_reloads; j++)
5514 reload_order[j] = j;
5515 reload_spill_index[j] = -1;
5517 if (rld[j].nregs > 1)
5519 max_group_size = MAX (rld[j].nregs, max_group_size);
5521 = reg_class_superunion[(int) rld[j].class][(int) group_class];
5524 save_reload_reg_rtx[j] = rld[j].reg_rtx;
5528 qsort (reload_order, n_reloads, sizeof (short), reload_reg_class_lower);
5530 /* If -O, try first with inheritance, then turning it off.
5531 If not -O, don't do inheritance.
5532 Using inheritance when not optimizing leads to paradoxes
5533 with fp on the 68k: fp numbers (not NaNs) fail to be equal to themselves
5534 because one side of the comparison might be inherited. */
5536 for (inheritance = optimize > 0; inheritance >= 0; inheritance--)
5538 choose_reload_regs_init (chain, save_reload_reg_rtx);
5540 /* Process the reloads in order of preference just found.
5541 Beyond this point, subregs can be found in reload_reg_rtx.
5543 This used to look for an existing reloaded home for all of the
5544 reloads, and only then perform any new reloads. But that could lose
5545 if the reloads were done out of reg-class order because a later
5546 reload with a looser constraint might have an old home in a register
5547 needed by an earlier reload with a tighter constraint.
5549 To solve this, we make two passes over the reloads, in the order
5550 described above. In the first pass we try to inherit a reload
5551 from a previous insn. If there is a later reload that needs a
5552 class that is a proper subset of the class being processed, we must
5553 also allocate a spill register during the first pass.
5555 Then make a second pass over the reloads to allocate any reloads
5556 that haven't been given registers yet. */
5558 for (j = 0; j < n_reloads; j++)
5560 int r = reload_order[j];
5561 rtx search_equiv = NULL_RTX;
5563 /* Ignore reloads that got marked inoperative. */
5564 if (rld[r].out == 0 && rld[r].in == 0
5565 && ! rld[r].secondary_p)
5568 /* If find_reloads chose to use reload_in or reload_out as a reload
5569 register, we don't need to chose one. Otherwise, try even if it
5570 found one since we might save an insn if we find the value lying
5572 Try also when reload_in is a pseudo without a hard reg. */
5573 if (rld[r].in != 0 && rld[r].reg_rtx != 0
5574 && (rtx_equal_p (rld[r].in, rld[r].reg_rtx)
5575 || (rtx_equal_p (rld[r].out, rld[r].reg_rtx)
5576 && !MEM_P (rld[r].in)
5577 && true_regnum (rld[r].in) < FIRST_PSEUDO_REGISTER)))
5580 #if 0 /* No longer needed for correct operation.
5581 It might give better code, or might not; worth an experiment? */
5582 /* If this is an optional reload, we can't inherit from earlier insns
5583 until we are sure that any non-optional reloads have been allocated.
5584 The following code takes advantage of the fact that optional reloads
5585 are at the end of reload_order. */
5586 if (rld[r].optional != 0)
5587 for (i = 0; i < j; i++)
5588 if ((rld[reload_order[i]].out != 0
5589 || rld[reload_order[i]].in != 0
5590 || rld[reload_order[i]].secondary_p)
5591 && ! rld[reload_order[i]].optional
5592 && rld[reload_order[i]].reg_rtx == 0)
5593 allocate_reload_reg (chain, reload_order[i], 0);
5596 /* First see if this pseudo is already available as reloaded
5597 for a previous insn. We cannot try to inherit for reloads
5598 that are smaller than the maximum number of registers needed
5599 for groups unless the register we would allocate cannot be used
5602 We could check here to see if this is a secondary reload for
5603 an object that is already in a register of the desired class.
5604 This would avoid the need for the secondary reload register.
5605 But this is complex because we can't easily determine what
5606 objects might want to be loaded via this reload. So let a
5607 register be allocated here. In `emit_reload_insns' we suppress
5608 one of the loads in the case described above. */
5614 enum machine_mode mode = VOIDmode;
5618 else if (REG_P (rld[r].in))
5620 regno = REGNO (rld[r].in);
5621 mode = GET_MODE (rld[r].in);
5623 else if (REG_P (rld[r].in_reg))
5625 regno = REGNO (rld[r].in_reg);
5626 mode = GET_MODE (rld[r].in_reg);
5628 else if (GET_CODE (rld[r].in_reg) == SUBREG
5629 && REG_P (SUBREG_REG (rld[r].in_reg)))
5631 regno = REGNO (SUBREG_REG (rld[r].in_reg));
5632 if (regno < FIRST_PSEUDO_REGISTER)
5633 regno = subreg_regno (rld[r].in_reg);
5635 byte = SUBREG_BYTE (rld[r].in_reg);
5636 mode = GET_MODE (rld[r].in_reg);
5639 else if (GET_RTX_CLASS (GET_CODE (rld[r].in_reg)) == RTX_AUTOINC
5640 && REG_P (XEXP (rld[r].in_reg, 0)))
5642 regno = REGNO (XEXP (rld[r].in_reg, 0));
5643 mode = GET_MODE (XEXP (rld[r].in_reg, 0));
5644 rld[r].out = rld[r].in;
5648 /* This won't work, since REGNO can be a pseudo reg number.
5649 Also, it takes much more hair to keep track of all the things
5650 that can invalidate an inherited reload of part of a pseudoreg. */
5651 else if (GET_CODE (rld[r].in) == SUBREG
5652 && REG_P (SUBREG_REG (rld[r].in)))
5653 regno = subreg_regno (rld[r].in);
5657 && reg_last_reload_reg[regno] != 0
5658 #ifdef CANNOT_CHANGE_MODE_CLASS
5659 /* Verify that the register it's in can be used in
5661 && !REG_CANNOT_CHANGE_MODE_P (REGNO (reg_last_reload_reg[regno]),
5662 GET_MODE (reg_last_reload_reg[regno]),
5667 enum reg_class class = rld[r].class, last_class;
5668 rtx last_reg = reg_last_reload_reg[regno];
5669 enum machine_mode need_mode;
5671 i = REGNO (last_reg);
5672 i += subreg_regno_offset (i, GET_MODE (last_reg), byte, mode);
5673 last_class = REGNO_REG_CLASS (i);
5679 = smallest_mode_for_size (GET_MODE_BITSIZE (mode)
5680 + byte * BITS_PER_UNIT,
5681 GET_MODE_CLASS (mode));
5683 if ((GET_MODE_SIZE (GET_MODE (last_reg))
5684 >= GET_MODE_SIZE (need_mode))
5685 && reg_reloaded_contents[i] == regno
5686 && TEST_HARD_REG_BIT (reg_reloaded_valid, i)
5687 && HARD_REGNO_MODE_OK (i, rld[r].mode)
5688 && (TEST_HARD_REG_BIT (reg_class_contents[(int) class], i)
5689 /* Even if we can't use this register as a reload
5690 register, we might use it for reload_override_in,
5691 if copying it to the desired class is cheap
5693 || ((REGISTER_MOVE_COST (mode, last_class, class)
5694 < MEMORY_MOVE_COST (mode, class, 1))
5695 && (secondary_reload_class (1, class, mode,
5698 #ifdef SECONDARY_MEMORY_NEEDED
5699 && ! SECONDARY_MEMORY_NEEDED (last_class, class,
5704 && (rld[r].nregs == max_group_size
5705 || ! TEST_HARD_REG_BIT (reg_class_contents[(int) group_class],
5707 && free_for_value_p (i, rld[r].mode, rld[r].opnum,
5708 rld[r].when_needed, rld[r].in,
5711 /* If a group is needed, verify that all the subsequent
5712 registers still have their values intact. */
5713 int nr = hard_regno_nregs[i][rld[r].mode];
5716 for (k = 1; k < nr; k++)
5717 if (reg_reloaded_contents[i + k] != regno
5718 || ! TEST_HARD_REG_BIT (reg_reloaded_valid, i + k))
5726 last_reg = (GET_MODE (last_reg) == mode
5727 ? last_reg : gen_rtx_REG (mode, i));
5730 for (k = 0; k < nr; k++)
5731 bad_for_class |= ! TEST_HARD_REG_BIT (reg_class_contents[(int) rld[r].class],
5734 /* We found a register that contains the
5735 value we need. If this register is the
5736 same as an `earlyclobber' operand of the
5737 current insn, just mark it as a place to
5738 reload from since we can't use it as the
5739 reload register itself. */
5741 for (i1 = 0; i1 < n_earlyclobbers; i1++)
5742 if (reg_overlap_mentioned_for_reload_p
5743 (reg_last_reload_reg[regno],
5744 reload_earlyclobbers[i1]))
5747 if (i1 != n_earlyclobbers
5748 || ! (free_for_value_p (i, rld[r].mode,
5750 rld[r].when_needed, rld[r].in,
5752 /* Don't use it if we'd clobber a pseudo reg. */
5753 || (TEST_HARD_REG_BIT (reg_used_in_insn, i)
5755 && ! TEST_HARD_REG_BIT (reg_reloaded_dead, i))
5756 /* Don't clobber the frame pointer. */
5757 || (i == HARD_FRAME_POINTER_REGNUM
5758 && frame_pointer_needed
5760 /* Don't really use the inherited spill reg
5761 if we need it wider than we've got it. */
5762 || (GET_MODE_SIZE (rld[r].mode)
5763 > GET_MODE_SIZE (mode))
5766 /* If find_reloads chose reload_out as reload
5767 register, stay with it - that leaves the
5768 inherited register for subsequent reloads. */
5769 || (rld[r].out && rld[r].reg_rtx
5770 && rtx_equal_p (rld[r].out, rld[r].reg_rtx)))
5772 if (! rld[r].optional)
5774 reload_override_in[r] = last_reg;
5775 reload_inheritance_insn[r]
5776 = reg_reloaded_insn[i];
5782 /* We can use this as a reload reg. */
5783 /* Mark the register as in use for this part of
5785 mark_reload_reg_in_use (i,
5789 rld[r].reg_rtx = last_reg;
5790 reload_inherited[r] = 1;
5791 reload_inheritance_insn[r]
5792 = reg_reloaded_insn[i];
5793 reload_spill_index[r] = i;
5794 for (k = 0; k < nr; k++)
5795 SET_HARD_REG_BIT (reload_reg_used_for_inherit,
5803 /* Here's another way to see if the value is already lying around. */
5806 && ! reload_inherited[r]
5808 && (CONSTANT_P (rld[r].in)
5809 || GET_CODE (rld[r].in) == PLUS
5810 || REG_P (rld[r].in)
5811 || MEM_P (rld[r].in))
5812 && (rld[r].nregs == max_group_size
5813 || ! reg_classes_intersect_p (rld[r].class, group_class)))
5814 search_equiv = rld[r].in;
5815 /* If this is an output reload from a simple move insn, look
5816 if an equivalence for the input is available. */
5817 else if (inheritance && rld[r].in == 0 && rld[r].out != 0)
5819 rtx set = single_set (insn);
5822 && rtx_equal_p (rld[r].out, SET_DEST (set))
5823 && CONSTANT_P (SET_SRC (set)))
5824 search_equiv = SET_SRC (set);
5830 = find_equiv_reg (search_equiv, insn, rld[r].class,
5831 -1, NULL, 0, rld[r].mode);
5837 regno = REGNO (equiv);
5840 /* This must be a SUBREG of a hard register.
5841 Make a new REG since this might be used in an
5842 address and not all machines support SUBREGs
5844 gcc_assert (GET_CODE (equiv) == SUBREG);
5845 regno = subreg_regno (equiv);
5846 equiv = gen_rtx_REG (rld[r].mode, regno);
5847 /* If we choose EQUIV as the reload register, but the
5848 loop below decides to cancel the inheritance, we'll
5849 end up reloading EQUIV in rld[r].mode, not the mode
5850 it had originally. That isn't safe when EQUIV isn't
5851 available as a spill register since its value might
5852 still be live at this point. */
5853 for (i = regno; i < regno + (int) rld[r].nregs; i++)
5854 if (TEST_HARD_REG_BIT (reload_reg_unavailable, i))
5859 /* If we found a spill reg, reject it unless it is free
5860 and of the desired class. */
5864 int bad_for_class = 0;
5865 int max_regno = regno + rld[r].nregs;
5867 for (i = regno; i < max_regno; i++)
5869 regs_used |= TEST_HARD_REG_BIT (reload_reg_used_at_all,
5871 bad_for_class |= ! TEST_HARD_REG_BIT (reg_class_contents[(int) rld[r].class],
5876 && ! free_for_value_p (regno, rld[r].mode,
5877 rld[r].opnum, rld[r].when_needed,
5878 rld[r].in, rld[r].out, r, 1))
5883 if (equiv != 0 && ! HARD_REGNO_MODE_OK (regno, rld[r].mode))
5886 /* We found a register that contains the value we need.
5887 If this register is the same as an `earlyclobber' operand
5888 of the current insn, just mark it as a place to reload from
5889 since we can't use it as the reload register itself. */
5892 for (i = 0; i < n_earlyclobbers; i++)
5893 if (reg_overlap_mentioned_for_reload_p (equiv,
5894 reload_earlyclobbers[i]))
5896 if (! rld[r].optional)
5897 reload_override_in[r] = equiv;
5902 /* If the equiv register we have found is explicitly clobbered
5903 in the current insn, it depends on the reload type if we
5904 can use it, use it for reload_override_in, or not at all.
5905 In particular, we then can't use EQUIV for a
5906 RELOAD_FOR_OUTPUT_ADDRESS reload. */
5910 if (regno_clobbered_p (regno, insn, rld[r].mode, 2))
5911 switch (rld[r].when_needed)
5913 case RELOAD_FOR_OTHER_ADDRESS:
5914 case RELOAD_FOR_INPADDR_ADDRESS:
5915 case RELOAD_FOR_INPUT_ADDRESS:
5916 case RELOAD_FOR_OPADDR_ADDR:
5919 case RELOAD_FOR_INPUT:
5920 case RELOAD_FOR_OPERAND_ADDRESS:
5921 if (! rld[r].optional)
5922 reload_override_in[r] = equiv;
5928 else if (regno_clobbered_p (regno, insn, rld[r].mode, 1))
5929 switch (rld[r].when_needed)
5931 case RELOAD_FOR_OTHER_ADDRESS:
5932 case RELOAD_FOR_INPADDR_ADDRESS:
5933 case RELOAD_FOR_INPUT_ADDRESS:
5934 case RELOAD_FOR_OPADDR_ADDR:
5935 case RELOAD_FOR_OPERAND_ADDRESS:
5936 case RELOAD_FOR_INPUT:
5939 if (! rld[r].optional)
5940 reload_override_in[r] = equiv;
5948 /* If we found an equivalent reg, say no code need be generated
5949 to load it, and use it as our reload reg. */
5951 && (regno != HARD_FRAME_POINTER_REGNUM
5952 || !frame_pointer_needed))
5954 int nr = hard_regno_nregs[regno][rld[r].mode];
5956 rld[r].reg_rtx = equiv;
5957 reload_inherited[r] = 1;
5959 /* If reg_reloaded_valid is not set for this register,
5960 there might be a stale spill_reg_store lying around.
5961 We must clear it, since otherwise emit_reload_insns
5962 might delete the store. */
5963 if (! TEST_HARD_REG_BIT (reg_reloaded_valid, regno))
5964 spill_reg_store[regno] = NULL_RTX;
5965 /* If any of the hard registers in EQUIV are spill
5966 registers, mark them as in use for this insn. */
5967 for (k = 0; k < nr; k++)
5969 i = spill_reg_order[regno + k];
5972 mark_reload_reg_in_use (regno, rld[r].opnum,
5975 SET_HARD_REG_BIT (reload_reg_used_for_inherit,
5982 /* If we found a register to use already, or if this is an optional
5983 reload, we are done. */
5984 if (rld[r].reg_rtx != 0 || rld[r].optional != 0)
5988 /* No longer needed for correct operation. Might or might
5989 not give better code on the average. Want to experiment? */
5991 /* See if there is a later reload that has a class different from our
5992 class that intersects our class or that requires less register
5993 than our reload. If so, we must allocate a register to this
5994 reload now, since that reload might inherit a previous reload
5995 and take the only available register in our class. Don't do this
5996 for optional reloads since they will force all previous reloads
5997 to be allocated. Also don't do this for reloads that have been
6000 for (i = j + 1; i < n_reloads; i++)
6002 int s = reload_order[i];
6004 if ((rld[s].in == 0 && rld[s].out == 0
6005 && ! rld[s].secondary_p)
6009 if ((rld[s].class != rld[r].class
6010 && reg_classes_intersect_p (rld[r].class,
6012 || rld[s].nregs < rld[r].nregs)
6019 allocate_reload_reg (chain, r, j == n_reloads - 1);
6023 /* Now allocate reload registers for anything non-optional that
6024 didn't get one yet. */
6025 for (j = 0; j < n_reloads; j++)
6027 int r = reload_order[j];
6029 /* Ignore reloads that got marked inoperative. */
6030 if (rld[r].out == 0 && rld[r].in == 0 && ! rld[r].secondary_p)
6033 /* Skip reloads that already have a register allocated or are
6035 if (rld[r].reg_rtx != 0 || rld[r].optional)
6038 if (! allocate_reload_reg (chain, r, j == n_reloads - 1))
6042 /* If that loop got all the way, we have won. */
6049 /* Loop around and try without any inheritance. */
6054 /* First undo everything done by the failed attempt
6055 to allocate with inheritance. */
6056 choose_reload_regs_init (chain, save_reload_reg_rtx);
6058 /* Some sanity tests to verify that the reloads found in the first
6059 pass are identical to the ones we have now. */
6060 gcc_assert (chain->n_reloads == n_reloads);
6062 for (i = 0; i < n_reloads; i++)
6064 if (chain->rld[i].regno < 0 || chain->rld[i].reg_rtx != 0)
6066 gcc_assert (chain->rld[i].when_needed == rld[i].when_needed);
6067 for (j = 0; j < n_spills; j++)
6068 if (spill_regs[j] == chain->rld[i].regno)
6069 if (! set_reload_reg (j, i))
6070 failed_reload (chain->insn, i);
6074 /* If we thought we could inherit a reload, because it seemed that
6075 nothing else wanted the same reload register earlier in the insn,
6076 verify that assumption, now that all reloads have been assigned.
6077 Likewise for reloads where reload_override_in has been set. */
6079 /* If doing expensive optimizations, do one preliminary pass that doesn't
6080 cancel any inheritance, but removes reloads that have been needed only
6081 for reloads that we know can be inherited. */
6082 for (pass = flag_expensive_optimizations; pass >= 0; pass--)
6084 for (j = 0; j < n_reloads; j++)
6086 int r = reload_order[j];
6088 if (reload_inherited[r] && rld[r].reg_rtx)
6089 check_reg = rld[r].reg_rtx;
6090 else if (reload_override_in[r]
6091 && (REG_P (reload_override_in[r])
6092 || GET_CODE (reload_override_in[r]) == SUBREG))
6093 check_reg = reload_override_in[r];
6096 if (! free_for_value_p (true_regnum (check_reg), rld[r].mode,
6097 rld[r].opnum, rld[r].when_needed, rld[r].in,
6098 (reload_inherited[r]
6099 ? rld[r].out : const0_rtx),
6104 reload_inherited[r] = 0;
6105 reload_override_in[r] = 0;
6107 /* If we can inherit a RELOAD_FOR_INPUT, or can use a
6108 reload_override_in, then we do not need its related
6109 RELOAD_FOR_INPUT_ADDRESS / RELOAD_FOR_INPADDR_ADDRESS reloads;
6110 likewise for other reload types.
6111 We handle this by removing a reload when its only replacement
6112 is mentioned in reload_in of the reload we are going to inherit.
6113 A special case are auto_inc expressions; even if the input is
6114 inherited, we still need the address for the output. We can
6115 recognize them because they have RELOAD_OUT set to RELOAD_IN.
6116 If we succeeded removing some reload and we are doing a preliminary
6117 pass just to remove such reloads, make another pass, since the
6118 removal of one reload might allow us to inherit another one. */
6120 && rld[r].out != rld[r].in
6121 && remove_address_replacements (rld[r].in) && pass)
6126 /* Now that reload_override_in is known valid,
6127 actually override reload_in. */
6128 for (j = 0; j < n_reloads; j++)
6129 if (reload_override_in[j])
6130 rld[j].in = reload_override_in[j];
6132 /* If this reload won't be done because it has been canceled or is
6133 optional and not inherited, clear reload_reg_rtx so other
6134 routines (such as subst_reloads) don't get confused. */
6135 for (j = 0; j < n_reloads; j++)
6136 if (rld[j].reg_rtx != 0
6137 && ((rld[j].optional && ! reload_inherited[j])
6138 || (rld[j].in == 0 && rld[j].out == 0
6139 && ! rld[j].secondary_p)))
6141 int regno = true_regnum (rld[j].reg_rtx);
6143 if (spill_reg_order[regno] >= 0)
6144 clear_reload_reg_in_use (regno, rld[j].opnum,
6145 rld[j].when_needed, rld[j].mode);
6147 reload_spill_index[j] = -1;
6150 /* Record which pseudos and which spill regs have output reloads. */
6151 for (j = 0; j < n_reloads; j++)
6153 int r = reload_order[j];
6155 i = reload_spill_index[r];
6157 /* I is nonneg if this reload uses a register.
6158 If rld[r].reg_rtx is 0, this is an optional reload
6159 that we opted to ignore. */
6160 if (rld[r].out_reg != 0 && REG_P (rld[r].out_reg)
6161 && rld[r].reg_rtx != 0)
6163 int nregno = REGNO (rld[r].out_reg);
6166 if (nregno < FIRST_PSEUDO_REGISTER)
6167 nr = hard_regno_nregs[nregno][rld[r].mode];
6170 SET_REGNO_REG_SET (®_has_output_reload,
6175 nr = hard_regno_nregs[i][rld[r].mode];
6177 SET_HARD_REG_BIT (reg_is_output_reload, i + nr);
6180 gcc_assert (rld[r].when_needed == RELOAD_OTHER
6181 || rld[r].when_needed == RELOAD_FOR_OUTPUT
6182 || rld[r].when_needed == RELOAD_FOR_INSN);
6187 /* Deallocate the reload register for reload R. This is called from
6188 remove_address_replacements. */
6191 deallocate_reload_reg (int r)
6195 if (! rld[r].reg_rtx)
6197 regno = true_regnum (rld[r].reg_rtx);
6199 if (spill_reg_order[regno] >= 0)
6200 clear_reload_reg_in_use (regno, rld[r].opnum, rld[r].when_needed,
6202 reload_spill_index[r] = -1;
6205 /* If SMALL_REGISTER_CLASSES is nonzero, we may not have merged two
6206 reloads of the same item for fear that we might not have enough reload
6207 registers. However, normally they will get the same reload register
6208 and hence actually need not be loaded twice.
6210 Here we check for the most common case of this phenomenon: when we have
6211 a number of reloads for the same object, each of which were allocated
6212 the same reload_reg_rtx, that reload_reg_rtx is not used for any other
6213 reload, and is not modified in the insn itself. If we find such,
6214 merge all the reloads and set the resulting reload to RELOAD_OTHER.
6215 This will not increase the number of spill registers needed and will
6216 prevent redundant code. */
6219 merge_assigned_reloads (rtx insn)
6223 /* Scan all the reloads looking for ones that only load values and
6224 are not already RELOAD_OTHER and ones whose reload_reg_rtx are
6225 assigned and not modified by INSN. */
6227 for (i = 0; i < n_reloads; i++)
6229 int conflicting_input = 0;
6230 int max_input_address_opnum = -1;
6231 int min_conflicting_input_opnum = MAX_RECOG_OPERANDS;
6233 if (rld[i].in == 0 || rld[i].when_needed == RELOAD_OTHER
6234 || rld[i].out != 0 || rld[i].reg_rtx == 0
6235 || reg_set_p (rld[i].reg_rtx, insn))
6238 /* Look at all other reloads. Ensure that the only use of this
6239 reload_reg_rtx is in a reload that just loads the same value
6240 as we do. Note that any secondary reloads must be of the identical
6241 class since the values, modes, and result registers are the
6242 same, so we need not do anything with any secondary reloads. */
6244 for (j = 0; j < n_reloads; j++)
6246 if (i == j || rld[j].reg_rtx == 0
6247 || ! reg_overlap_mentioned_p (rld[j].reg_rtx,
6251 if (rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
6252 && rld[j].opnum > max_input_address_opnum)
6253 max_input_address_opnum = rld[j].opnum;
6255 /* If the reload regs aren't exactly the same (e.g, different modes)
6256 or if the values are different, we can't merge this reload.
6257 But if it is an input reload, we might still merge
6258 RELOAD_FOR_INPUT_ADDRESS and RELOAD_FOR_OTHER_ADDRESS reloads. */
6260 if (! rtx_equal_p (rld[i].reg_rtx, rld[j].reg_rtx)
6261 || rld[j].out != 0 || rld[j].in == 0
6262 || ! rtx_equal_p (rld[i].in, rld[j].in))
6264 if (rld[j].when_needed != RELOAD_FOR_INPUT
6265 || ((rld[i].when_needed != RELOAD_FOR_INPUT_ADDRESS
6266 || rld[i].opnum > rld[j].opnum)
6267 && rld[i].when_needed != RELOAD_FOR_OTHER_ADDRESS))
6269 conflicting_input = 1;
6270 if (min_conflicting_input_opnum > rld[j].opnum)
6271 min_conflicting_input_opnum = rld[j].opnum;
6275 /* If all is OK, merge the reloads. Only set this to RELOAD_OTHER if
6276 we, in fact, found any matching reloads. */
6279 && max_input_address_opnum <= min_conflicting_input_opnum)
6281 gcc_assert (rld[i].when_needed != RELOAD_FOR_OUTPUT);
6283 for (j = 0; j < n_reloads; j++)
6284 if (i != j && rld[j].reg_rtx != 0
6285 && rtx_equal_p (rld[i].reg_rtx, rld[j].reg_rtx)
6286 && (! conflicting_input
6287 || rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
6288 || rld[j].when_needed == RELOAD_FOR_OTHER_ADDRESS))
6290 rld[i].when_needed = RELOAD_OTHER;
6292 reload_spill_index[j] = -1;
6293 transfer_replacements (i, j);
6296 /* If this is now RELOAD_OTHER, look for any reloads that load
6297 parts of this operand and set them to RELOAD_FOR_OTHER_ADDRESS
6298 if they were for inputs, RELOAD_OTHER for outputs. Note that
6299 this test is equivalent to looking for reloads for this operand
6301 /* We must take special care with RELOAD_FOR_OUTPUT_ADDRESS; it may
6302 share registers with a RELOAD_FOR_INPUT, so we can not change it
6303 to RELOAD_FOR_OTHER_ADDRESS. We should never need to, since we
6304 do not modify RELOAD_FOR_OUTPUT. */
6306 if (rld[i].when_needed == RELOAD_OTHER)
6307 for (j = 0; j < n_reloads; j++)
6309 && rld[j].when_needed != RELOAD_OTHER
6310 && rld[j].when_needed != RELOAD_FOR_OTHER_ADDRESS
6311 && rld[j].when_needed != RELOAD_FOR_OUTPUT_ADDRESS
6312 && (! conflicting_input
6313 || rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
6314 || rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
6315 && reg_overlap_mentioned_for_reload_p (rld[j].in,
6321 = ((rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
6322 || rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
6323 ? RELOAD_FOR_OTHER_ADDRESS : RELOAD_OTHER);
6325 /* Check to see if we accidentally converted two
6326 reloads that use the same reload register with
6327 different inputs to the same type. If so, the
6328 resulting code won't work. */
6330 for (k = 0; k < j; k++)
6331 gcc_assert (rld[k].in == 0 || rld[k].reg_rtx == 0
6332 || rld[k].when_needed != rld[j].when_needed
6333 || !rtx_equal_p (rld[k].reg_rtx,
6335 || rtx_equal_p (rld[k].in,
6342 /* These arrays are filled by emit_reload_insns and its subroutines. */
6343 static rtx input_reload_insns[MAX_RECOG_OPERANDS];
6344 static rtx other_input_address_reload_insns = 0;
6345 static rtx other_input_reload_insns = 0;
6346 static rtx input_address_reload_insns[MAX_RECOG_OPERANDS];
6347 static rtx inpaddr_address_reload_insns[MAX_RECOG_OPERANDS];
6348 static rtx output_reload_insns[MAX_RECOG_OPERANDS];
6349 static rtx output_address_reload_insns[MAX_RECOG_OPERANDS];
6350 static rtx outaddr_address_reload_insns[MAX_RECOG_OPERANDS];
6351 static rtx operand_reload_insns = 0;
6352 static rtx other_operand_reload_insns = 0;
6353 static rtx other_output_reload_insns[MAX_RECOG_OPERANDS];
6355 /* Values to be put in spill_reg_store are put here first. */
6356 static rtx new_spill_reg_store[FIRST_PSEUDO_REGISTER];
6357 static HARD_REG_SET reg_reloaded_died;
6359 /* Check if *RELOAD_REG is suitable as an intermediate or scratch register
6360 of class NEW_CLASS with mode NEW_MODE. Or alternatively, if alt_reload_reg
6361 is nonzero, if that is suitable. On success, change *RELOAD_REG to the
6362 adjusted register, and return true. Otherwise, return false. */
6364 reload_adjust_reg_for_temp (rtx *reload_reg, rtx alt_reload_reg,
6365 enum reg_class new_class,
6366 enum machine_mode new_mode)
6371 for (reg = *reload_reg; reg; reg = alt_reload_reg, alt_reload_reg = 0)
6373 unsigned regno = REGNO (reg);
6375 if (!TEST_HARD_REG_BIT (reg_class_contents[(int) new_class], regno))
6377 if (GET_MODE (reg) != new_mode)
6379 if (!HARD_REGNO_MODE_OK (regno, new_mode))
6381 if (hard_regno_nregs[regno][new_mode]
6382 > hard_regno_nregs[regno][GET_MODE (reg)])
6384 reg = reload_adjust_reg_for_mode (reg, new_mode);
6392 /* Check if *RELOAD_REG is suitable as a scratch register for the reload
6393 pattern with insn_code ICODE, or alternatively, if alt_reload_reg is
6394 nonzero, if that is suitable. On success, change *RELOAD_REG to the
6395 adjusted register, and return true. Otherwise, return false. */
6397 reload_adjust_reg_for_icode (rtx *reload_reg, rtx alt_reload_reg,
6398 enum insn_code icode)
6401 enum reg_class new_class = scratch_reload_class (icode);
6402 enum machine_mode new_mode = insn_data[(int) icode].operand[2].mode;
6404 return reload_adjust_reg_for_temp (reload_reg, alt_reload_reg,
6405 new_class, new_mode);
6408 /* Generate insns to perform reload RL, which is for the insn in CHAIN and
6409 has the number J. OLD contains the value to be used as input. */
6412 emit_input_reload_insns (struct insn_chain *chain, struct reload *rl,
6415 rtx insn = chain->insn;
6416 rtx reloadreg = rl->reg_rtx;
6417 rtx oldequiv_reg = 0;
6420 enum machine_mode mode;
6423 /* Determine the mode to reload in.
6424 This is very tricky because we have three to choose from.
6425 There is the mode the insn operand wants (rl->inmode).
6426 There is the mode of the reload register RELOADREG.
6427 There is the intrinsic mode of the operand, which we could find
6428 by stripping some SUBREGs.
6429 It turns out that RELOADREG's mode is irrelevant:
6430 we can change that arbitrarily.
6432 Consider (SUBREG:SI foo:QI) as an operand that must be SImode;
6433 then the reload reg may not support QImode moves, so use SImode.
6434 If foo is in memory due to spilling a pseudo reg, this is safe,
6435 because the QImode value is in the least significant part of a
6436 slot big enough for a SImode. If foo is some other sort of
6437 memory reference, then it is impossible to reload this case,
6438 so previous passes had better make sure this never happens.
6440 Then consider a one-word union which has SImode and one of its
6441 members is a float, being fetched as (SUBREG:SF union:SI).
6442 We must fetch that as SFmode because we could be loading into
6443 a float-only register. In this case OLD's mode is correct.
6445 Consider an immediate integer: it has VOIDmode. Here we need
6446 to get a mode from something else.
6448 In some cases, there is a fourth mode, the operand's
6449 containing mode. If the insn specifies a containing mode for
6450 this operand, it overrides all others.
6452 I am not sure whether the algorithm here is always right,
6453 but it does the right things in those cases. */
6455 mode = GET_MODE (old);
6456 if (mode == VOIDmode)
6459 /* delete_output_reload is only invoked properly if old contains
6460 the original pseudo register. Since this is replaced with a
6461 hard reg when RELOAD_OVERRIDE_IN is set, see if we can
6462 find the pseudo in RELOAD_IN_REG. */
6463 if (reload_override_in[j]
6464 && REG_P (rl->in_reg))
6471 else if (REG_P (oldequiv))
6472 oldequiv_reg = oldequiv;
6473 else if (GET_CODE (oldequiv) == SUBREG)
6474 oldequiv_reg = SUBREG_REG (oldequiv);
6476 /* If we are reloading from a register that was recently stored in
6477 with an output-reload, see if we can prove there was
6478 actually no need to store the old value in it. */
6480 if (optimize && REG_P (oldequiv)
6481 && REGNO (oldequiv) < FIRST_PSEUDO_REGISTER
6482 && spill_reg_store[REGNO (oldequiv)]
6484 && (dead_or_set_p (insn, spill_reg_stored_to[REGNO (oldequiv)])
6485 || rtx_equal_p (spill_reg_stored_to[REGNO (oldequiv)],
6487 delete_output_reload (insn, j, REGNO (oldequiv));
6489 /* Encapsulate both RELOADREG and OLDEQUIV into that mode,
6490 then load RELOADREG from OLDEQUIV. Note that we cannot use
6491 gen_lowpart_common since it can do the wrong thing when
6492 RELOADREG has a multi-word mode. Note that RELOADREG
6493 must always be a REG here. */
6495 if (GET_MODE (reloadreg) != mode)
6496 reloadreg = reload_adjust_reg_for_mode (reloadreg, mode);
6497 while (GET_CODE (oldequiv) == SUBREG && GET_MODE (oldequiv) != mode)
6498 oldequiv = SUBREG_REG (oldequiv);
6499 if (GET_MODE (oldequiv) != VOIDmode
6500 && mode != GET_MODE (oldequiv))
6501 oldequiv = gen_lowpart_SUBREG (mode, oldequiv);
6503 /* Switch to the right place to emit the reload insns. */
6504 switch (rl->when_needed)
6507 where = &other_input_reload_insns;
6509 case RELOAD_FOR_INPUT:
6510 where = &input_reload_insns[rl->opnum];
6512 case RELOAD_FOR_INPUT_ADDRESS:
6513 where = &input_address_reload_insns[rl->opnum];
6515 case RELOAD_FOR_INPADDR_ADDRESS:
6516 where = &inpaddr_address_reload_insns[rl->opnum];
6518 case RELOAD_FOR_OUTPUT_ADDRESS:
6519 where = &output_address_reload_insns[rl->opnum];
6521 case RELOAD_FOR_OUTADDR_ADDRESS:
6522 where = &outaddr_address_reload_insns[rl->opnum];
6524 case RELOAD_FOR_OPERAND_ADDRESS:
6525 where = &operand_reload_insns;
6527 case RELOAD_FOR_OPADDR_ADDR:
6528 where = &other_operand_reload_insns;
6530 case RELOAD_FOR_OTHER_ADDRESS:
6531 where = &other_input_address_reload_insns;
6537 push_to_sequence (*where);
6539 /* Auto-increment addresses must be reloaded in a special way. */
6540 if (rl->out && ! rl->out_reg)
6542 /* We are not going to bother supporting the case where a
6543 incremented register can't be copied directly from
6544 OLDEQUIV since this seems highly unlikely. */
6545 gcc_assert (rl->secondary_in_reload < 0);
6547 if (reload_inherited[j])
6548 oldequiv = reloadreg;
6550 old = XEXP (rl->in_reg, 0);
6552 if (optimize && REG_P (oldequiv)
6553 && REGNO (oldequiv) < FIRST_PSEUDO_REGISTER
6554 && spill_reg_store[REGNO (oldequiv)]
6556 && (dead_or_set_p (insn,
6557 spill_reg_stored_to[REGNO (oldequiv)])
6558 || rtx_equal_p (spill_reg_stored_to[REGNO (oldequiv)],
6560 delete_output_reload (insn, j, REGNO (oldequiv));
6562 /* Prevent normal processing of this reload. */
6564 /* Output a special code sequence for this case. */
6565 new_spill_reg_store[REGNO (reloadreg)]
6566 = inc_for_reload (reloadreg, oldequiv, rl->out,
6570 /* If we are reloading a pseudo-register that was set by the previous
6571 insn, see if we can get rid of that pseudo-register entirely
6572 by redirecting the previous insn into our reload register. */
6574 else if (optimize && REG_P (old)
6575 && REGNO (old) >= FIRST_PSEUDO_REGISTER
6576 && dead_or_set_p (insn, old)
6577 /* This is unsafe if some other reload
6578 uses the same reg first. */
6579 && ! conflicts_with_override (reloadreg)
6580 && free_for_value_p (REGNO (reloadreg), rl->mode, rl->opnum,
6581 rl->when_needed, old, rl->out, j, 0))
6583 rtx temp = PREV_INSN (insn);
6584 while (temp && NOTE_P (temp))
6585 temp = PREV_INSN (temp);
6587 && NONJUMP_INSN_P (temp)
6588 && GET_CODE (PATTERN (temp)) == SET
6589 && SET_DEST (PATTERN (temp)) == old
6590 /* Make sure we can access insn_operand_constraint. */
6591 && asm_noperands (PATTERN (temp)) < 0
6592 /* This is unsafe if operand occurs more than once in current
6593 insn. Perhaps some occurrences aren't reloaded. */
6594 && count_occurrences (PATTERN (insn), old, 0) == 1)
6596 rtx old = SET_DEST (PATTERN (temp));
6597 /* Store into the reload register instead of the pseudo. */
6598 SET_DEST (PATTERN (temp)) = reloadreg;
6600 /* Verify that resulting insn is valid. */
6601 extract_insn (temp);
6602 if (constrain_operands (1))
6604 /* If the previous insn is an output reload, the source is
6605 a reload register, and its spill_reg_store entry will
6606 contain the previous destination. This is now
6608 if (REG_P (SET_SRC (PATTERN (temp)))
6609 && REGNO (SET_SRC (PATTERN (temp))) < FIRST_PSEUDO_REGISTER)
6611 spill_reg_store[REGNO (SET_SRC (PATTERN (temp)))] = 0;
6612 spill_reg_stored_to[REGNO (SET_SRC (PATTERN (temp)))] = 0;
6615 /* If these are the only uses of the pseudo reg,
6616 pretend for GDB it lives in the reload reg we used. */
6617 if (REG_N_DEATHS (REGNO (old)) == 1
6618 && REG_N_SETS (REGNO (old)) == 1)
6620 reg_renumber[REGNO (old)] = REGNO (rl->reg_rtx);
6621 alter_reg (REGNO (old), -1);
6627 SET_DEST (PATTERN (temp)) = old;
6632 /* We can't do that, so output an insn to load RELOADREG. */
6634 /* If we have a secondary reload, pick up the secondary register
6635 and icode, if any. If OLDEQUIV and OLD are different or
6636 if this is an in-out reload, recompute whether or not we
6637 still need a secondary register and what the icode should
6638 be. If we still need a secondary register and the class or
6639 icode is different, go back to reloading from OLD if using
6640 OLDEQUIV means that we got the wrong type of register. We
6641 cannot have different class or icode due to an in-out reload
6642 because we don't make such reloads when both the input and
6643 output need secondary reload registers. */
6645 if (! special && rl->secondary_in_reload >= 0)
6647 rtx second_reload_reg = 0;
6648 rtx third_reload_reg = 0;
6649 int secondary_reload = rl->secondary_in_reload;
6650 rtx real_oldequiv = oldequiv;
6653 enum insn_code icode;
6654 enum insn_code tertiary_icode = CODE_FOR_nothing;
6656 /* If OLDEQUIV is a pseudo with a MEM, get the real MEM
6657 and similarly for OLD.
6658 See comments in get_secondary_reload in reload.c. */
6659 /* If it is a pseudo that cannot be replaced with its
6660 equivalent MEM, we must fall back to reload_in, which
6661 will have all the necessary substitutions registered.
6662 Likewise for a pseudo that can't be replaced with its
6663 equivalent constant.
6665 Take extra care for subregs of such pseudos. Note that
6666 we cannot use reg_equiv_mem in this case because it is
6667 not in the right mode. */
6670 if (GET_CODE (tmp) == SUBREG)
6671 tmp = SUBREG_REG (tmp);
6673 && REGNO (tmp) >= FIRST_PSEUDO_REGISTER
6674 && (reg_equiv_memory_loc[REGNO (tmp)] != 0
6675 || reg_equiv_constant[REGNO (tmp)] != 0))
6677 if (! reg_equiv_mem[REGNO (tmp)]
6678 || num_not_at_initial_offset
6679 || GET_CODE (oldequiv) == SUBREG)
6680 real_oldequiv = rl->in;
6682 real_oldequiv = reg_equiv_mem[REGNO (tmp)];
6686 if (GET_CODE (tmp) == SUBREG)
6687 tmp = SUBREG_REG (tmp);
6689 && REGNO (tmp) >= FIRST_PSEUDO_REGISTER
6690 && (reg_equiv_memory_loc[REGNO (tmp)] != 0
6691 || reg_equiv_constant[REGNO (tmp)] != 0))
6693 if (! reg_equiv_mem[REGNO (tmp)]
6694 || num_not_at_initial_offset
6695 || GET_CODE (old) == SUBREG)
6698 real_old = reg_equiv_mem[REGNO (tmp)];
6701 second_reload_reg = rld[secondary_reload].reg_rtx;
6702 if (rld[secondary_reload].secondary_in_reload >= 0)
6704 int tertiary_reload = rld[secondary_reload].secondary_in_reload;
6706 third_reload_reg = rld[tertiary_reload].reg_rtx;
6707 tertiary_icode = rld[secondary_reload].secondary_in_icode;
6708 /* We'd have to add more code for quartary reloads. */
6709 gcc_assert (rld[tertiary_reload].secondary_in_reload < 0);
6711 icode = rl->secondary_in_icode;
6713 if ((old != oldequiv && ! rtx_equal_p (old, oldequiv))
6714 || (rl->in != 0 && rl->out != 0))
6716 secondary_reload_info sri, sri2;
6717 enum reg_class new_class, new_t_class;
6719 sri.icode = CODE_FOR_nothing;
6720 sri.prev_sri = NULL;
6721 new_class = targetm.secondary_reload (1, real_oldequiv, rl->class,
6724 if (new_class == NO_REGS && sri.icode == CODE_FOR_nothing)
6725 second_reload_reg = 0;
6726 else if (new_class == NO_REGS)
6728 if (reload_adjust_reg_for_icode (&second_reload_reg,
6729 third_reload_reg, sri.icode))
6730 icode = sri.icode, third_reload_reg = 0;
6732 oldequiv = old, real_oldequiv = real_old;
6734 else if (sri.icode != CODE_FOR_nothing)
6735 /* We currently lack a way to express this in reloads. */
6739 sri2.icode = CODE_FOR_nothing;
6740 sri2.prev_sri = &sri;
6741 new_t_class = targetm.secondary_reload (1, real_oldequiv,
6742 new_class, mode, &sri);
6743 if (new_t_class == NO_REGS && sri2.icode == CODE_FOR_nothing)
6745 if (reload_adjust_reg_for_temp (&second_reload_reg,
6748 third_reload_reg = 0, tertiary_icode = sri2.icode;
6750 oldequiv = old, real_oldequiv = real_old;
6752 else if (new_t_class == NO_REGS && sri2.icode != CODE_FOR_nothing)
6754 rtx intermediate = second_reload_reg;
6756 if (reload_adjust_reg_for_temp (&intermediate, NULL,
6758 && reload_adjust_reg_for_icode (&third_reload_reg, NULL,
6761 second_reload_reg = intermediate;
6762 tertiary_icode = sri2.icode;
6765 oldequiv = old, real_oldequiv = real_old;
6767 else if (new_t_class != NO_REGS && sri2.icode == CODE_FOR_nothing)
6769 rtx intermediate = second_reload_reg;
6771 if (reload_adjust_reg_for_temp (&intermediate, NULL,
6773 && reload_adjust_reg_for_temp (&third_reload_reg, NULL,
6776 second_reload_reg = intermediate;
6777 tertiary_icode = sri2.icode;
6780 oldequiv = old, real_oldequiv = real_old;
6783 /* This could be handled more intelligently too. */
6784 oldequiv = old, real_oldequiv = real_old;
6788 /* If we still need a secondary reload register, check
6789 to see if it is being used as a scratch or intermediate
6790 register and generate code appropriately. If we need
6791 a scratch register, use REAL_OLDEQUIV since the form of
6792 the insn may depend on the actual address if it is
6795 if (second_reload_reg)
6797 if (icode != CODE_FOR_nothing)
6799 /* We'd have to add extra code to handle this case. */
6800 gcc_assert (!third_reload_reg);
6802 emit_insn (GEN_FCN (icode) (reloadreg, real_oldequiv,
6803 second_reload_reg));
6808 /* See if we need a scratch register to load the
6809 intermediate register (a tertiary reload). */
6810 if (tertiary_icode != CODE_FOR_nothing)
6812 emit_insn ((GEN_FCN (tertiary_icode)
6813 (second_reload_reg, real_oldequiv,
6814 third_reload_reg)));
6816 else if (third_reload_reg)
6818 gen_reload (third_reload_reg, real_oldequiv,
6821 gen_reload (second_reload_reg, third_reload_reg,
6826 gen_reload (second_reload_reg, real_oldequiv,
6830 oldequiv = second_reload_reg;
6835 if (! special && ! rtx_equal_p (reloadreg, oldequiv))
6837 rtx real_oldequiv = oldequiv;
6839 if ((REG_P (oldequiv)
6840 && REGNO (oldequiv) >= FIRST_PSEUDO_REGISTER
6841 && (reg_equiv_memory_loc[REGNO (oldequiv)] != 0
6842 || reg_equiv_constant[REGNO (oldequiv)] != 0))
6843 || (GET_CODE (oldequiv) == SUBREG
6844 && REG_P (SUBREG_REG (oldequiv))
6845 && (REGNO (SUBREG_REG (oldequiv))
6846 >= FIRST_PSEUDO_REGISTER)
6847 && ((reg_equiv_memory_loc
6848 [REGNO (SUBREG_REG (oldequiv))] != 0)
6849 || (reg_equiv_constant
6850 [REGNO (SUBREG_REG (oldequiv))] != 0)))
6851 || (CONSTANT_P (oldequiv)
6852 && (PREFERRED_RELOAD_CLASS (oldequiv,
6853 REGNO_REG_CLASS (REGNO (reloadreg)))
6855 real_oldequiv = rl->in;
6856 gen_reload (reloadreg, real_oldequiv, rl->opnum,
6860 if (flag_non_call_exceptions)
6861 copy_eh_notes (insn, get_insns ());
6863 /* End this sequence. */
6864 *where = get_insns ();
6867 /* Update reload_override_in so that delete_address_reloads_1
6868 can see the actual register usage. */
6870 reload_override_in[j] = oldequiv;
6873 /* Generate insns to for the output reload RL, which is for the insn described
6874 by CHAIN and has the number J. */
6876 emit_output_reload_insns (struct insn_chain *chain, struct reload *rl,
6879 rtx reloadreg = rl->reg_rtx;
6880 rtx insn = chain->insn;
6883 enum machine_mode mode = GET_MODE (old);
6886 if (rl->when_needed == RELOAD_OTHER)
6889 push_to_sequence (output_reload_insns[rl->opnum]);
6891 /* Determine the mode to reload in.
6892 See comments above (for input reloading). */
6894 if (mode == VOIDmode)
6896 /* VOIDmode should never happen for an output. */
6897 if (asm_noperands (PATTERN (insn)) < 0)
6898 /* It's the compiler's fault. */
6899 fatal_insn ("VOIDmode on an output", insn);
6900 error_for_asm (insn, "output operand is constant in %<asm%>");
6901 /* Prevent crash--use something we know is valid. */
6903 old = gen_rtx_REG (mode, REGNO (reloadreg));
6906 if (GET_MODE (reloadreg) != mode)
6907 reloadreg = reload_adjust_reg_for_mode (reloadreg, mode);
6909 /* If we need two reload regs, set RELOADREG to the intermediate
6910 one, since it will be stored into OLD. We might need a secondary
6911 register only for an input reload, so check again here. */
6913 if (rl->secondary_out_reload >= 0)
6916 int secondary_reload = rl->secondary_out_reload;
6917 int tertiary_reload = rld[secondary_reload].secondary_out_reload;
6919 if (REG_P (old) && REGNO (old) >= FIRST_PSEUDO_REGISTER
6920 && reg_equiv_mem[REGNO (old)] != 0)
6921 real_old = reg_equiv_mem[REGNO (old)];
6923 if (secondary_reload_class (0, rl->class, mode, real_old) != NO_REGS)
6925 rtx second_reloadreg = reloadreg;
6926 reloadreg = rld[secondary_reload].reg_rtx;
6928 /* See if RELOADREG is to be used as a scratch register
6929 or as an intermediate register. */
6930 if (rl->secondary_out_icode != CODE_FOR_nothing)
6932 /* We'd have to add extra code to handle this case. */
6933 gcc_assert (tertiary_reload < 0);
6935 emit_insn ((GEN_FCN (rl->secondary_out_icode)
6936 (real_old, second_reloadreg, reloadreg)));
6941 /* See if we need both a scratch and intermediate reload
6944 enum insn_code tertiary_icode
6945 = rld[secondary_reload].secondary_out_icode;
6947 /* We'd have to add more code for quartary reloads. */
6948 gcc_assert (tertiary_reload < 0
6949 || rld[tertiary_reload].secondary_out_reload < 0);
6951 if (GET_MODE (reloadreg) != mode)
6952 reloadreg = reload_adjust_reg_for_mode (reloadreg, mode);
6954 if (tertiary_icode != CODE_FOR_nothing)
6956 rtx third_reloadreg = rld[tertiary_reload].reg_rtx;
6959 /* Copy primary reload reg to secondary reload reg.
6960 (Note that these have been swapped above, then
6961 secondary reload reg to OLD using our insn.) */
6963 /* If REAL_OLD is a paradoxical SUBREG, remove it
6964 and try to put the opposite SUBREG on
6966 if (GET_CODE (real_old) == SUBREG
6967 && (GET_MODE_SIZE (GET_MODE (real_old))
6968 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (real_old))))
6969 && 0 != (tem = gen_lowpart_common
6970 (GET_MODE (SUBREG_REG (real_old)),
6972 real_old = SUBREG_REG (real_old), reloadreg = tem;
6974 gen_reload (reloadreg, second_reloadreg,
6975 rl->opnum, rl->when_needed);
6976 emit_insn ((GEN_FCN (tertiary_icode)
6977 (real_old, reloadreg, third_reloadreg)));
6983 /* Copy between the reload regs here and then to
6986 gen_reload (reloadreg, second_reloadreg,
6987 rl->opnum, rl->when_needed);
6988 if (tertiary_reload >= 0)
6990 rtx third_reloadreg = rld[tertiary_reload].reg_rtx;
6992 gen_reload (third_reloadreg, reloadreg,
6993 rl->opnum, rl->when_needed);
6994 reloadreg = third_reloadreg;
7001 /* Output the last reload insn. */
7006 /* Don't output the last reload if OLD is not the dest of
7007 INSN and is in the src and is clobbered by INSN. */
7008 if (! flag_expensive_optimizations
7010 || !(set = single_set (insn))
7011 || rtx_equal_p (old, SET_DEST (set))
7012 || !reg_mentioned_p (old, SET_SRC (set))
7013 || !((REGNO (old) < FIRST_PSEUDO_REGISTER)
7014 && regno_clobbered_p (REGNO (old), insn, rl->mode, 0)))
7015 gen_reload (old, reloadreg, rl->opnum,
7019 /* Look at all insns we emitted, just to be safe. */
7020 for (p = get_insns (); p; p = NEXT_INSN (p))
7023 rtx pat = PATTERN (p);
7025 /* If this output reload doesn't come from a spill reg,
7026 clear any memory of reloaded copies of the pseudo reg.
7027 If this output reload comes from a spill reg,
7028 reg_has_output_reload will make this do nothing. */
7029 note_stores (pat, forget_old_reloads_1, NULL);
7031 if (reg_mentioned_p (rl->reg_rtx, pat))
7033 rtx set = single_set (insn);
7034 if (reload_spill_index[j] < 0
7036 && SET_SRC (set) == rl->reg_rtx)
7038 int src = REGNO (SET_SRC (set));
7040 reload_spill_index[j] = src;
7041 SET_HARD_REG_BIT (reg_is_output_reload, src);
7042 if (find_regno_note (insn, REG_DEAD, src))
7043 SET_HARD_REG_BIT (reg_reloaded_died, src);
7045 if (REGNO (rl->reg_rtx) < FIRST_PSEUDO_REGISTER)
7047 int s = rl->secondary_out_reload;
7048 set = single_set (p);
7049 /* If this reload copies only to the secondary reload
7050 register, the secondary reload does the actual
7052 if (s >= 0 && set == NULL_RTX)
7053 /* We can't tell what function the secondary reload
7054 has and where the actual store to the pseudo is
7055 made; leave new_spill_reg_store alone. */
7058 && SET_SRC (set) == rl->reg_rtx
7059 && SET_DEST (set) == rld[s].reg_rtx)
7061 /* Usually the next instruction will be the
7062 secondary reload insn; if we can confirm
7063 that it is, setting new_spill_reg_store to
7064 that insn will allow an extra optimization. */
7065 rtx s_reg = rld[s].reg_rtx;
7066 rtx next = NEXT_INSN (p);
7067 rld[s].out = rl->out;
7068 rld[s].out_reg = rl->out_reg;
7069 set = single_set (next);
7070 if (set && SET_SRC (set) == s_reg
7071 && ! new_spill_reg_store[REGNO (s_reg)])
7073 SET_HARD_REG_BIT (reg_is_output_reload,
7075 new_spill_reg_store[REGNO (s_reg)] = next;
7079 new_spill_reg_store[REGNO (rl->reg_rtx)] = p;
7084 if (rl->when_needed == RELOAD_OTHER)
7086 emit_insn (other_output_reload_insns[rl->opnum]);
7087 other_output_reload_insns[rl->opnum] = get_insns ();
7090 output_reload_insns[rl->opnum] = get_insns ();
7092 if (flag_non_call_exceptions)
7093 copy_eh_notes (insn, get_insns ());
7098 /* Do input reloading for reload RL, which is for the insn described by CHAIN
7099 and has the number J. */
7101 do_input_reload (struct insn_chain *chain, struct reload *rl, int j)
7103 rtx insn = chain->insn;
7104 rtx old = (rl->in && MEM_P (rl->in)
7105 ? rl->in_reg : rl->in);
7108 /* AUTO_INC reloads need to be handled even if inherited. We got an
7109 AUTO_INC reload if reload_out is set but reload_out_reg isn't. */
7110 && (! reload_inherited[j] || (rl->out && ! rl->out_reg))
7111 && ! rtx_equal_p (rl->reg_rtx, old)
7112 && rl->reg_rtx != 0)
7113 emit_input_reload_insns (chain, rld + j, old, j);
7115 /* When inheriting a wider reload, we have a MEM in rl->in,
7116 e.g. inheriting a SImode output reload for
7117 (mem:HI (plus:SI (reg:SI 14 fp) (const_int 10))) */
7118 if (optimize && reload_inherited[j] && rl->in
7120 && MEM_P (rl->in_reg)
7121 && reload_spill_index[j] >= 0
7122 && TEST_HARD_REG_BIT (reg_reloaded_valid, reload_spill_index[j]))
7123 rl->in = regno_reg_rtx[reg_reloaded_contents[reload_spill_index[j]]];
7125 /* If we are reloading a register that was recently stored in with an
7126 output-reload, see if we can prove there was
7127 actually no need to store the old value in it. */
7130 /* Only attempt this for input reloads; for RELOAD_OTHER we miss
7131 that there may be multiple uses of the previous output reload.
7132 Restricting to RELOAD_FOR_INPUT is mostly paranoia. */
7133 && rl->when_needed == RELOAD_FOR_INPUT
7134 && (reload_inherited[j] || reload_override_in[j])
7136 && REG_P (rl->reg_rtx)
7137 && spill_reg_store[REGNO (rl->reg_rtx)] != 0
7139 /* There doesn't seem to be any reason to restrict this to pseudos
7140 and doing so loses in the case where we are copying from a
7141 register of the wrong class. */
7142 && (REGNO (spill_reg_stored_to[REGNO (rl->reg_rtx)])
7143 >= FIRST_PSEUDO_REGISTER)
7145 /* The insn might have already some references to stackslots
7146 replaced by MEMs, while reload_out_reg still names the
7148 && (dead_or_set_p (insn,
7149 spill_reg_stored_to[REGNO (rl->reg_rtx)])
7150 || rtx_equal_p (spill_reg_stored_to[REGNO (rl->reg_rtx)],
7152 delete_output_reload (insn, j, REGNO (rl->reg_rtx));
7155 /* Do output reloading for reload RL, which is for the insn described by
7156 CHAIN and has the number J.
7157 ??? At some point we need to support handling output reloads of
7158 JUMP_INSNs or insns that set cc0. */
7160 do_output_reload (struct insn_chain *chain, struct reload *rl, int j)
7163 rtx insn = chain->insn;
7164 /* If this is an output reload that stores something that is
7165 not loaded in this same reload, see if we can eliminate a previous
7167 rtx pseudo = rl->out_reg;
7172 && ! rtx_equal_p (rl->in_reg, pseudo)
7173 && REGNO (pseudo) >= FIRST_PSEUDO_REGISTER
7174 && reg_last_reload_reg[REGNO (pseudo)])
7176 int pseudo_no = REGNO (pseudo);
7177 int last_regno = REGNO (reg_last_reload_reg[pseudo_no]);
7179 /* We don't need to test full validity of last_regno for
7180 inherit here; we only want to know if the store actually
7181 matches the pseudo. */
7182 if (TEST_HARD_REG_BIT (reg_reloaded_valid, last_regno)
7183 && reg_reloaded_contents[last_regno] == pseudo_no
7184 && spill_reg_store[last_regno]
7185 && rtx_equal_p (pseudo, spill_reg_stored_to[last_regno]))
7186 delete_output_reload (insn, j, last_regno);
7191 || rl->reg_rtx == old
7192 || rl->reg_rtx == 0)
7195 /* An output operand that dies right away does need a reload,
7196 but need not be copied from it. Show the new location in the
7198 if ((REG_P (old) || GET_CODE (old) == SCRATCH)
7199 && (note = find_reg_note (insn, REG_UNUSED, old)) != 0)
7201 XEXP (note, 0) = rl->reg_rtx;
7204 /* Likewise for a SUBREG of an operand that dies. */
7205 else if (GET_CODE (old) == SUBREG
7206 && REG_P (SUBREG_REG (old))
7207 && 0 != (note = find_reg_note (insn, REG_UNUSED,
7210 XEXP (note, 0) = gen_lowpart_common (GET_MODE (old),
7214 else if (GET_CODE (old) == SCRATCH)
7215 /* If we aren't optimizing, there won't be a REG_UNUSED note,
7216 but we don't want to make an output reload. */
7219 /* If is a JUMP_INSN, we can't support output reloads yet. */
7220 gcc_assert (NONJUMP_INSN_P (insn));
7222 emit_output_reload_insns (chain, rld + j, j);
7225 /* Reload number R reloads from or to a group of hard registers starting at
7226 register REGNO. Return true if it can be treated for inheritance purposes
7227 like a group of reloads, each one reloading a single hard register.
7228 The caller has already checked that the spill register and REGNO use
7229 the same number of registers to store the reload value. */
7232 inherit_piecemeal_p (int r ATTRIBUTE_UNUSED, int regno ATTRIBUTE_UNUSED)
7234 #ifdef CANNOT_CHANGE_MODE_CLASS
7235 return (!REG_CANNOT_CHANGE_MODE_P (reload_spill_index[r],
7236 GET_MODE (rld[r].reg_rtx),
7237 reg_raw_mode[reload_spill_index[r]])
7238 && !REG_CANNOT_CHANGE_MODE_P (regno,
7239 GET_MODE (rld[r].reg_rtx),
7240 reg_raw_mode[regno]));
7246 /* Output insns to reload values in and out of the chosen reload regs. */
7249 emit_reload_insns (struct insn_chain *chain)
7251 rtx insn = chain->insn;
7255 CLEAR_HARD_REG_SET (reg_reloaded_died);
7257 for (j = 0; j < reload_n_operands; j++)
7258 input_reload_insns[j] = input_address_reload_insns[j]
7259 = inpaddr_address_reload_insns[j]
7260 = output_reload_insns[j] = output_address_reload_insns[j]
7261 = outaddr_address_reload_insns[j]
7262 = other_output_reload_insns[j] = 0;
7263 other_input_address_reload_insns = 0;
7264 other_input_reload_insns = 0;
7265 operand_reload_insns = 0;
7266 other_operand_reload_insns = 0;
7268 /* Dump reloads into the dump file. */
7271 fprintf (dump_file, "\nReloads for insn # %d\n", INSN_UID (insn));
7272 debug_reload_to_stream (dump_file);
7275 /* Now output the instructions to copy the data into and out of the
7276 reload registers. Do these in the order that the reloads were reported,
7277 since reloads of base and index registers precede reloads of operands
7278 and the operands may need the base and index registers reloaded. */
7280 for (j = 0; j < n_reloads; j++)
7283 && REGNO (rld[j].reg_rtx) < FIRST_PSEUDO_REGISTER)
7284 new_spill_reg_store[REGNO (rld[j].reg_rtx)] = 0;
7286 do_input_reload (chain, rld + j, j);
7287 do_output_reload (chain, rld + j, j);
7290 /* Now write all the insns we made for reloads in the order expected by
7291 the allocation functions. Prior to the insn being reloaded, we write
7292 the following reloads:
7294 RELOAD_FOR_OTHER_ADDRESS reloads for input addresses.
7296 RELOAD_OTHER reloads.
7298 For each operand, any RELOAD_FOR_INPADDR_ADDRESS reloads followed
7299 by any RELOAD_FOR_INPUT_ADDRESS reloads followed by the
7300 RELOAD_FOR_INPUT reload for the operand.
7302 RELOAD_FOR_OPADDR_ADDRS reloads.
7304 RELOAD_FOR_OPERAND_ADDRESS reloads.
7306 After the insn being reloaded, we write the following:
7308 For each operand, any RELOAD_FOR_OUTADDR_ADDRESS reloads followed
7309 by any RELOAD_FOR_OUTPUT_ADDRESS reload followed by the
7310 RELOAD_FOR_OUTPUT reload, followed by any RELOAD_OTHER output
7311 reloads for the operand. The RELOAD_OTHER output reloads are
7312 output in descending order by reload number. */
7314 emit_insn_before (other_input_address_reload_insns, insn);
7315 emit_insn_before (other_input_reload_insns, insn);
7317 for (j = 0; j < reload_n_operands; j++)
7319 emit_insn_before (inpaddr_address_reload_insns[j], insn);
7320 emit_insn_before (input_address_reload_insns[j], insn);
7321 emit_insn_before (input_reload_insns[j], insn);
7324 emit_insn_before (other_operand_reload_insns, insn);
7325 emit_insn_before (operand_reload_insns, insn);
7327 for (j = 0; j < reload_n_operands; j++)
7329 rtx x = emit_insn_after (outaddr_address_reload_insns[j], insn);
7330 x = emit_insn_after (output_address_reload_insns[j], x);
7331 x = emit_insn_after (output_reload_insns[j], x);
7332 emit_insn_after (other_output_reload_insns[j], x);
7335 /* For all the spill regs newly reloaded in this instruction,
7336 record what they were reloaded from, so subsequent instructions
7337 can inherit the reloads.
7339 Update spill_reg_store for the reloads of this insn.
7340 Copy the elements that were updated in the loop above. */
7342 for (j = 0; j < n_reloads; j++)
7344 int r = reload_order[j];
7345 int i = reload_spill_index[r];
7347 /* If this is a non-inherited input reload from a pseudo, we must
7348 clear any memory of a previous store to the same pseudo. Only do
7349 something if there will not be an output reload for the pseudo
7351 if (rld[r].in_reg != 0
7352 && ! (reload_inherited[r] || reload_override_in[r]))
7354 rtx reg = rld[r].in_reg;
7356 if (GET_CODE (reg) == SUBREG)
7357 reg = SUBREG_REG (reg);
7360 && REGNO (reg) >= FIRST_PSEUDO_REGISTER
7361 && !REGNO_REG_SET_P (®_has_output_reload, REGNO (reg)))
7363 int nregno = REGNO (reg);
7365 if (reg_last_reload_reg[nregno])
7367 int last_regno = REGNO (reg_last_reload_reg[nregno]);
7369 if (reg_reloaded_contents[last_regno] == nregno)
7370 spill_reg_store[last_regno] = 0;
7375 /* I is nonneg if this reload used a register.
7376 If rld[r].reg_rtx is 0, this is an optional reload
7377 that we opted to ignore. */
7379 if (i >= 0 && rld[r].reg_rtx != 0)
7381 int nr = hard_regno_nregs[i][GET_MODE (rld[r].reg_rtx)];
7383 int part_reaches_end = 0;
7384 int all_reaches_end = 1;
7386 /* For a multi register reload, we need to check if all or part
7387 of the value lives to the end. */
7388 for (k = 0; k < nr; k++)
7390 if (reload_reg_reaches_end_p (i + k, rld[r].opnum,
7391 rld[r].when_needed))
7392 part_reaches_end = 1;
7394 all_reaches_end = 0;
7397 /* Ignore reloads that don't reach the end of the insn in
7399 if (all_reaches_end)
7401 /* First, clear out memory of what used to be in this spill reg.
7402 If consecutive registers are used, clear them all. */
7404 for (k = 0; k < nr; k++)
7406 CLEAR_HARD_REG_BIT (reg_reloaded_valid, i + k);
7407 CLEAR_HARD_REG_BIT (reg_reloaded_call_part_clobbered, i + k);
7410 /* Maybe the spill reg contains a copy of reload_out. */
7412 && (REG_P (rld[r].out)
7416 || REG_P (rld[r].out_reg)))
7418 rtx out = (REG_P (rld[r].out)
7422 /* AUTO_INC */ : XEXP (rld[r].in_reg, 0));
7423 int nregno = REGNO (out);
7424 int nnr = (nregno >= FIRST_PSEUDO_REGISTER ? 1
7425 : hard_regno_nregs[nregno]
7426 [GET_MODE (rld[r].reg_rtx)]);
7429 spill_reg_store[i] = new_spill_reg_store[i];
7430 spill_reg_stored_to[i] = out;
7431 reg_last_reload_reg[nregno] = rld[r].reg_rtx;
7433 piecemeal = (nregno < FIRST_PSEUDO_REGISTER
7435 && inherit_piecemeal_p (r, nregno));
7437 /* If NREGNO is a hard register, it may occupy more than
7438 one register. If it does, say what is in the
7439 rest of the registers assuming that both registers
7440 agree on how many words the object takes. If not,
7441 invalidate the subsequent registers. */
7443 if (nregno < FIRST_PSEUDO_REGISTER)
7444 for (k = 1; k < nnr; k++)
7445 reg_last_reload_reg[nregno + k]
7447 ? regno_reg_rtx[REGNO (rld[r].reg_rtx) + k]
7450 /* Now do the inverse operation. */
7451 for (k = 0; k < nr; k++)
7453 CLEAR_HARD_REG_BIT (reg_reloaded_dead, i + k);
7454 reg_reloaded_contents[i + k]
7455 = (nregno >= FIRST_PSEUDO_REGISTER || !piecemeal
7458 reg_reloaded_insn[i + k] = insn;
7459 SET_HARD_REG_BIT (reg_reloaded_valid, i + k);
7460 if (HARD_REGNO_CALL_PART_CLOBBERED (i + k, GET_MODE (out)))
7461 SET_HARD_REG_BIT (reg_reloaded_call_part_clobbered, i + k);
7465 /* Maybe the spill reg contains a copy of reload_in. Only do
7466 something if there will not be an output reload for
7467 the register being reloaded. */
7468 else if (rld[r].out_reg == 0
7470 && ((REG_P (rld[r].in)
7471 && REGNO (rld[r].in) >= FIRST_PSEUDO_REGISTER
7472 && !REGNO_REG_SET_P (®_has_output_reload,
7474 || (REG_P (rld[r].in_reg)
7475 && !REGNO_REG_SET_P (®_has_output_reload,
7476 REGNO (rld[r].in_reg))))
7477 && ! reg_set_p (rld[r].reg_rtx, PATTERN (insn)))
7484 if (REG_P (rld[r].in)
7485 && REGNO (rld[r].in) >= FIRST_PSEUDO_REGISTER)
7487 else if (REG_P (rld[r].in_reg))
7490 in = XEXP (rld[r].in_reg, 0);
7491 nregno = REGNO (in);
7493 nnr = (nregno >= FIRST_PSEUDO_REGISTER ? 1
7494 : hard_regno_nregs[nregno]
7495 [GET_MODE (rld[r].reg_rtx)]);
7497 reg_last_reload_reg[nregno] = rld[r].reg_rtx;
7499 piecemeal = (nregno < FIRST_PSEUDO_REGISTER
7501 && inherit_piecemeal_p (r, nregno));
7503 if (nregno < FIRST_PSEUDO_REGISTER)
7504 for (k = 1; k < nnr; k++)
7505 reg_last_reload_reg[nregno + k]
7507 ? regno_reg_rtx[REGNO (rld[r].reg_rtx) + k]
7510 /* Unless we inherited this reload, show we haven't
7511 recently done a store.
7512 Previous stores of inherited auto_inc expressions
7513 also have to be discarded. */
7514 if (! reload_inherited[r]
7515 || (rld[r].out && ! rld[r].out_reg))
7516 spill_reg_store[i] = 0;
7518 for (k = 0; k < nr; k++)
7520 CLEAR_HARD_REG_BIT (reg_reloaded_dead, i + k);
7521 reg_reloaded_contents[i + k]
7522 = (nregno >= FIRST_PSEUDO_REGISTER || !piecemeal
7525 reg_reloaded_insn[i + k] = insn;
7526 SET_HARD_REG_BIT (reg_reloaded_valid, i + k);
7527 if (HARD_REGNO_CALL_PART_CLOBBERED (i + k, GET_MODE (in)))
7528 SET_HARD_REG_BIT (reg_reloaded_call_part_clobbered, i + k);
7533 /* However, if part of the reload reaches the end, then we must
7534 invalidate the old info for the part that survives to the end. */
7535 else if (part_reaches_end)
7537 for (k = 0; k < nr; k++)
7538 if (reload_reg_reaches_end_p (i + k,
7540 rld[r].when_needed))
7541 CLEAR_HARD_REG_BIT (reg_reloaded_valid, i + k);
7545 /* The following if-statement was #if 0'd in 1.34 (or before...).
7546 It's reenabled in 1.35 because supposedly nothing else
7547 deals with this problem. */
7549 /* If a register gets output-reloaded from a non-spill register,
7550 that invalidates any previous reloaded copy of it.
7551 But forget_old_reloads_1 won't get to see it, because
7552 it thinks only about the original insn. So invalidate it here.
7553 Also do the same thing for RELOAD_OTHER constraints where the
7554 output is discarded. */
7556 && ((rld[r].out != 0
7557 && (REG_P (rld[r].out)
7558 || (MEM_P (rld[r].out)
7559 && REG_P (rld[r].out_reg))))
7560 || (rld[r].out == 0 && rld[r].out_reg
7561 && REG_P (rld[r].out_reg))))
7563 rtx out = ((rld[r].out && REG_P (rld[r].out))
7564 ? rld[r].out : rld[r].out_reg);
7565 int nregno = REGNO (out);
7567 /* REG_RTX is now set or clobbered by the main instruction.
7568 As the comment above explains, forget_old_reloads_1 only
7569 sees the original instruction, and there is no guarantee
7570 that the original instruction also clobbered REG_RTX.
7571 For example, if find_reloads sees that the input side of
7572 a matched operand pair dies in this instruction, it may
7573 use the input register as the reload register.
7575 Calling forget_old_reloads_1 is a waste of effort if
7576 REG_RTX is also the output register.
7578 If we know that REG_RTX holds the value of a pseudo
7579 register, the code after the call will record that fact. */
7580 if (rld[r].reg_rtx && rld[r].reg_rtx != out)
7581 forget_old_reloads_1 (rld[r].reg_rtx, NULL_RTX, NULL);
7583 if (nregno >= FIRST_PSEUDO_REGISTER)
7585 rtx src_reg, store_insn = NULL_RTX;
7587 reg_last_reload_reg[nregno] = 0;
7589 /* If we can find a hard register that is stored, record
7590 the storing insn so that we may delete this insn with
7591 delete_output_reload. */
7592 src_reg = rld[r].reg_rtx;
7594 /* If this is an optional reload, try to find the source reg
7595 from an input reload. */
7598 rtx set = single_set (insn);
7599 if (set && SET_DEST (set) == rld[r].out)
7603 src_reg = SET_SRC (set);
7605 for (k = 0; k < n_reloads; k++)
7607 if (rld[k].in == src_reg)
7609 src_reg = rld[k].reg_rtx;
7616 store_insn = new_spill_reg_store[REGNO (src_reg)];
7617 if (src_reg && REG_P (src_reg)
7618 && REGNO (src_reg) < FIRST_PSEUDO_REGISTER)
7620 int src_regno = REGNO (src_reg);
7621 int nr = hard_regno_nregs[src_regno][rld[r].mode];
7622 /* The place where to find a death note varies with
7623 PRESERVE_DEATH_INFO_REGNO_P . The condition is not
7624 necessarily checked exactly in the code that moves
7625 notes, so just check both locations. */
7626 rtx note = find_regno_note (insn, REG_DEAD, src_regno);
7627 if (! note && store_insn)
7628 note = find_regno_note (store_insn, REG_DEAD, src_regno);
7631 spill_reg_store[src_regno + nr] = store_insn;
7632 spill_reg_stored_to[src_regno + nr] = out;
7633 reg_reloaded_contents[src_regno + nr] = nregno;
7634 reg_reloaded_insn[src_regno + nr] = store_insn;
7635 CLEAR_HARD_REG_BIT (reg_reloaded_dead, src_regno + nr);
7636 SET_HARD_REG_BIT (reg_reloaded_valid, src_regno + nr);
7637 if (HARD_REGNO_CALL_PART_CLOBBERED (src_regno + nr,
7638 GET_MODE (src_reg)))
7639 SET_HARD_REG_BIT (reg_reloaded_call_part_clobbered,
7641 SET_HARD_REG_BIT (reg_is_output_reload, src_regno + nr);
7643 SET_HARD_REG_BIT (reg_reloaded_died, src_regno);
7645 CLEAR_HARD_REG_BIT (reg_reloaded_died, src_regno);
7647 reg_last_reload_reg[nregno] = src_reg;
7648 /* We have to set reg_has_output_reload here, or else
7649 forget_old_reloads_1 will clear reg_last_reload_reg
7651 SET_REGNO_REG_SET (®_has_output_reload,
7657 int num_regs = hard_regno_nregs[nregno][GET_MODE (out)];
7659 while (num_regs-- > 0)
7660 reg_last_reload_reg[nregno + num_regs] = 0;
7664 IOR_HARD_REG_SET (reg_reloaded_dead, reg_reloaded_died);
7667 /* Go through the motions to emit INSN and test if it is strictly valid.
7668 Return the emitted insn if valid, else return NULL. */
7671 emit_insn_if_valid_for_reload (rtx insn)
7673 rtx last = get_last_insn ();
7676 insn = emit_insn (insn);
7677 code = recog_memoized (insn);
7681 extract_insn (insn);
7682 /* We want constrain operands to treat this insn strictly in its
7683 validity determination, i.e., the way it would after reload has
7685 if (constrain_operands (1))
7689 delete_insns_since (last);
7693 /* Emit code to perform a reload from IN (which may be a reload register) to
7694 OUT (which may also be a reload register). IN or OUT is from operand
7695 OPNUM with reload type TYPE.
7697 Returns first insn emitted. */
7700 gen_reload (rtx out, rtx in, int opnum, enum reload_type type)
7702 rtx last = get_last_insn ();
7705 /* If IN is a paradoxical SUBREG, remove it and try to put the
7706 opposite SUBREG on OUT. Likewise for a paradoxical SUBREG on OUT. */
7707 if (GET_CODE (in) == SUBREG
7708 && (GET_MODE_SIZE (GET_MODE (in))
7709 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))))
7710 && (tem = gen_lowpart_common (GET_MODE (SUBREG_REG (in)), out)) != 0)
7711 in = SUBREG_REG (in), out = tem;
7712 else if (GET_CODE (out) == SUBREG
7713 && (GET_MODE_SIZE (GET_MODE (out))
7714 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))))
7715 && (tem = gen_lowpart_common (GET_MODE (SUBREG_REG (out)), in)) != 0)
7716 out = SUBREG_REG (out), in = tem;
7718 /* How to do this reload can get quite tricky. Normally, we are being
7719 asked to reload a simple operand, such as a MEM, a constant, or a pseudo
7720 register that didn't get a hard register. In that case we can just
7721 call emit_move_insn.
7723 We can also be asked to reload a PLUS that adds a register or a MEM to
7724 another register, constant or MEM. This can occur during frame pointer
7725 elimination and while reloading addresses. This case is handled by
7726 trying to emit a single insn to perform the add. If it is not valid,
7727 we use a two insn sequence.
7729 Or we can be asked to reload an unary operand that was a fragment of
7730 an addressing mode, into a register. If it isn't recognized as-is,
7731 we try making the unop operand and the reload-register the same:
7732 (set reg:X (unop:X expr:Y))
7733 -> (set reg:Y expr:Y) (set reg:X (unop:X reg:Y)).
7735 Finally, we could be called to handle an 'o' constraint by putting
7736 an address into a register. In that case, we first try to do this
7737 with a named pattern of "reload_load_address". If no such pattern
7738 exists, we just emit a SET insn and hope for the best (it will normally
7739 be valid on machines that use 'o').
7741 This entire process is made complex because reload will never
7742 process the insns we generate here and so we must ensure that
7743 they will fit their constraints and also by the fact that parts of
7744 IN might be being reloaded separately and replaced with spill registers.
7745 Because of this, we are, in some sense, just guessing the right approach
7746 here. The one listed above seems to work.
7748 ??? At some point, this whole thing needs to be rethought. */
7750 if (GET_CODE (in) == PLUS
7751 && (REG_P (XEXP (in, 0))
7752 || GET_CODE (XEXP (in, 0)) == SUBREG
7753 || MEM_P (XEXP (in, 0)))
7754 && (REG_P (XEXP (in, 1))
7755 || GET_CODE (XEXP (in, 1)) == SUBREG
7756 || CONSTANT_P (XEXP (in, 1))
7757 || MEM_P (XEXP (in, 1))))
7759 /* We need to compute the sum of a register or a MEM and another
7760 register, constant, or MEM, and put it into the reload
7761 register. The best possible way of doing this is if the machine
7762 has a three-operand ADD insn that accepts the required operands.
7764 The simplest approach is to try to generate such an insn and see if it
7765 is recognized and matches its constraints. If so, it can be used.
7767 It might be better not to actually emit the insn unless it is valid,
7768 but we need to pass the insn as an operand to `recog' and
7769 `extract_insn' and it is simpler to emit and then delete the insn if
7770 not valid than to dummy things up. */
7772 rtx op0, op1, tem, insn;
7775 op0 = find_replacement (&XEXP (in, 0));
7776 op1 = find_replacement (&XEXP (in, 1));
7778 /* Since constraint checking is strict, commutativity won't be
7779 checked, so we need to do that here to avoid spurious failure
7780 if the add instruction is two-address and the second operand
7781 of the add is the same as the reload reg, which is frequently
7782 the case. If the insn would be A = B + A, rearrange it so
7783 it will be A = A + B as constrain_operands expects. */
7785 if (REG_P (XEXP (in, 1))
7786 && REGNO (out) == REGNO (XEXP (in, 1)))
7787 tem = op0, op0 = op1, op1 = tem;
7789 if (op0 != XEXP (in, 0) || op1 != XEXP (in, 1))
7790 in = gen_rtx_PLUS (GET_MODE (in), op0, op1);
7792 insn = emit_insn_if_valid_for_reload (gen_rtx_SET (VOIDmode, out, in));
7796 /* If that failed, we must use a conservative two-insn sequence.
7798 Use a move to copy one operand into the reload register. Prefer
7799 to reload a constant, MEM or pseudo since the move patterns can
7800 handle an arbitrary operand. If OP1 is not a constant, MEM or
7801 pseudo and OP1 is not a valid operand for an add instruction, then
7804 After reloading one of the operands into the reload register, add
7805 the reload register to the output register.
7807 If there is another way to do this for a specific machine, a
7808 DEFINE_PEEPHOLE should be specified that recognizes the sequence
7811 code = (int) add_optab->handlers[(int) GET_MODE (out)].insn_code;
7813 if (CONSTANT_P (op1) || MEM_P (op1) || GET_CODE (op1) == SUBREG
7815 && REGNO (op1) >= FIRST_PSEUDO_REGISTER)
7816 || (code != CODE_FOR_nothing
7817 && ! ((*insn_data[code].operand[2].predicate)
7818 (op1, insn_data[code].operand[2].mode))))
7819 tem = op0, op0 = op1, op1 = tem;
7821 gen_reload (out, op0, opnum, type);
7823 /* If OP0 and OP1 are the same, we can use OUT for OP1.
7824 This fixes a problem on the 32K where the stack pointer cannot
7825 be used as an operand of an add insn. */
7827 if (rtx_equal_p (op0, op1))
7830 insn = emit_insn_if_valid_for_reload (gen_add2_insn (out, op1));
7833 /* Add a REG_EQUIV note so that find_equiv_reg can find it. */
7835 = gen_rtx_EXPR_LIST (REG_EQUIV, in, REG_NOTES (insn));
7839 /* If that failed, copy the address register to the reload register.
7840 Then add the constant to the reload register. */
7842 gen_reload (out, op1, opnum, type);
7843 insn = emit_insn (gen_add2_insn (out, op0));
7844 REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_EQUIV, in, REG_NOTES (insn));
7847 #ifdef SECONDARY_MEMORY_NEEDED
7848 /* If we need a memory location to do the move, do it that way. */
7849 else if ((REG_P (in) || GET_CODE (in) == SUBREG)
7850 && reg_or_subregno (in) < FIRST_PSEUDO_REGISTER
7851 && (REG_P (out) || GET_CODE (out) == SUBREG)
7852 && reg_or_subregno (out) < FIRST_PSEUDO_REGISTER
7853 && SECONDARY_MEMORY_NEEDED (REGNO_REG_CLASS (reg_or_subregno (in)),
7854 REGNO_REG_CLASS (reg_or_subregno (out)),
7857 /* Get the memory to use and rewrite both registers to its mode. */
7858 rtx loc = get_secondary_mem (in, GET_MODE (out), opnum, type);
7860 if (GET_MODE (loc) != GET_MODE (out))
7861 out = gen_rtx_REG (GET_MODE (loc), REGNO (out));
7863 if (GET_MODE (loc) != GET_MODE (in))
7864 in = gen_rtx_REG (GET_MODE (loc), REGNO (in));
7866 gen_reload (loc, in, opnum, type);
7867 gen_reload (out, loc, opnum, type);
7870 else if (REG_P (out) && UNARY_P (in))
7877 op1 = find_replacement (&XEXP (in, 0));
7878 if (op1 != XEXP (in, 0))
7879 in = gen_rtx_fmt_e (GET_CODE (in), GET_MODE (in), op1);
7881 /* First, try a plain SET. */
7882 set = emit_insn_if_valid_for_reload (gen_rtx_SET (VOIDmode, out, in));
7886 /* If that failed, move the inner operand to the reload
7887 register, and try the same unop with the inner expression
7888 replaced with the reload register. */
7890 if (GET_MODE (op1) != GET_MODE (out))
7891 out_moded = gen_rtx_REG (GET_MODE (op1), REGNO (out));
7895 gen_reload (out_moded, op1, opnum, type);
7898 = gen_rtx_SET (VOIDmode, out,
7899 gen_rtx_fmt_e (GET_CODE (in), GET_MODE (in),
7901 insn = emit_insn_if_valid_for_reload (insn);
7905 = gen_rtx_EXPR_LIST (REG_EQUIV, in, REG_NOTES (insn));
7909 fatal_insn ("Failure trying to reload:", set);
7911 /* If IN is a simple operand, use gen_move_insn. */
7912 else if (OBJECT_P (in) || GET_CODE (in) == SUBREG)
7914 tem = emit_insn (gen_move_insn (out, in));
7915 /* IN may contain a LABEL_REF, if so add a REG_LABEL note. */
7916 mark_jump_label (in, tem, 0);
7919 #ifdef HAVE_reload_load_address
7920 else if (HAVE_reload_load_address)
7921 emit_insn (gen_reload_load_address (out, in));
7924 /* Otherwise, just write (set OUT IN) and hope for the best. */
7926 emit_insn (gen_rtx_SET (VOIDmode, out, in));
7928 /* Return the first insn emitted.
7929 We can not just return get_last_insn, because there may have
7930 been multiple instructions emitted. Also note that gen_move_insn may
7931 emit more than one insn itself, so we can not assume that there is one
7932 insn emitted per emit_insn_before call. */
7934 return last ? NEXT_INSN (last) : get_insns ();
7937 /* Delete a previously made output-reload whose result we now believe
7938 is not needed. First we double-check.
7940 INSN is the insn now being processed.
7941 LAST_RELOAD_REG is the hard register number for which we want to delete
7942 the last output reload.
7943 J is the reload-number that originally used REG. The caller has made
7944 certain that reload J doesn't use REG any longer for input. */
7947 delete_output_reload (rtx insn, int j, int last_reload_reg)
7949 rtx output_reload_insn = spill_reg_store[last_reload_reg];
7950 rtx reg = spill_reg_stored_to[last_reload_reg];
7953 int n_inherited = 0;
7957 /* It is possible that this reload has been only used to set another reload
7958 we eliminated earlier and thus deleted this instruction too. */
7959 if (INSN_DELETED_P (output_reload_insn))
7962 /* Get the raw pseudo-register referred to. */
7964 while (GET_CODE (reg) == SUBREG)
7965 reg = SUBREG_REG (reg);
7966 substed = reg_equiv_memory_loc[REGNO (reg)];
7968 /* This is unsafe if the operand occurs more often in the current
7969 insn than it is inherited. */
7970 for (k = n_reloads - 1; k >= 0; k--)
7972 rtx reg2 = rld[k].in;
7975 if (MEM_P (reg2) || reload_override_in[k])
7976 reg2 = rld[k].in_reg;
7978 if (rld[k].out && ! rld[k].out_reg)
7979 reg2 = XEXP (rld[k].in_reg, 0);
7981 while (GET_CODE (reg2) == SUBREG)
7982 reg2 = SUBREG_REG (reg2);
7983 if (rtx_equal_p (reg2, reg))
7985 if (reload_inherited[k] || reload_override_in[k] || k == j)
7988 reg2 = rld[k].out_reg;
7991 while (GET_CODE (reg2) == SUBREG)
7992 reg2 = XEXP (reg2, 0);
7993 if (rtx_equal_p (reg2, reg))
8000 n_occurrences = count_occurrences (PATTERN (insn), reg, 0);
8001 if (CALL_P (insn) && CALL_INSN_FUNCTION_USAGE (insn))
8002 n_occurrences += count_occurrences (CALL_INSN_FUNCTION_USAGE (insn),
8005 n_occurrences += count_occurrences (PATTERN (insn),
8006 eliminate_regs (substed, 0,
8008 for (i1 = reg_equiv_alt_mem_list [REGNO (reg)]; i1; i1 = XEXP (i1, 1))
8010 gcc_assert (!rtx_equal_p (XEXP (i1, 0), substed));
8011 n_occurrences += count_occurrences (PATTERN (insn), XEXP (i1, 0), 0);
8013 if (n_occurrences > n_inherited)
8016 /* If the pseudo-reg we are reloading is no longer referenced
8017 anywhere between the store into it and here,
8018 and we're within the same basic block, then the value can only
8019 pass through the reload reg and end up here.
8020 Otherwise, give up--return. */
8021 for (i1 = NEXT_INSN (output_reload_insn);
8022 i1 != insn; i1 = NEXT_INSN (i1))
8024 if (NOTE_INSN_BASIC_BLOCK_P (i1))
8026 if ((NONJUMP_INSN_P (i1) || CALL_P (i1))
8027 && reg_mentioned_p (reg, PATTERN (i1)))
8029 /* If this is USE in front of INSN, we only have to check that
8030 there are no more references than accounted for by inheritance. */
8031 while (NONJUMP_INSN_P (i1) && GET_CODE (PATTERN (i1)) == USE)
8033 n_occurrences += rtx_equal_p (reg, XEXP (PATTERN (i1), 0)) != 0;
8034 i1 = NEXT_INSN (i1);
8036 if (n_occurrences <= n_inherited && i1 == insn)
8042 /* We will be deleting the insn. Remove the spill reg information. */
8043 for (k = hard_regno_nregs[last_reload_reg][GET_MODE (reg)]; k-- > 0; )
8045 spill_reg_store[last_reload_reg + k] = 0;
8046 spill_reg_stored_to[last_reload_reg + k] = 0;
8049 /* The caller has already checked that REG dies or is set in INSN.
8050 It has also checked that we are optimizing, and thus some
8051 inaccuracies in the debugging information are acceptable.
8052 So we could just delete output_reload_insn. But in some cases
8053 we can improve the debugging information without sacrificing
8054 optimization - maybe even improving the code: See if the pseudo
8055 reg has been completely replaced with reload regs. If so, delete
8056 the store insn and forget we had a stack slot for the pseudo. */
8057 if (rld[j].out != rld[j].in
8058 && REG_N_DEATHS (REGNO (reg)) == 1
8059 && REG_N_SETS (REGNO (reg)) == 1
8060 && REG_BASIC_BLOCK (REGNO (reg)) >= 0
8061 && find_regno_note (insn, REG_DEAD, REGNO (reg)))
8065 /* We know that it was used only between here and the beginning of
8066 the current basic block. (We also know that the last use before
8067 INSN was the output reload we are thinking of deleting, but never
8068 mind that.) Search that range; see if any ref remains. */
8069 for (i2 = PREV_INSN (insn); i2; i2 = PREV_INSN (i2))
8071 rtx set = single_set (i2);
8073 /* Uses which just store in the pseudo don't count,
8074 since if they are the only uses, they are dead. */
8075 if (set != 0 && SET_DEST (set) == reg)
8080 if ((NONJUMP_INSN_P (i2) || CALL_P (i2))
8081 && reg_mentioned_p (reg, PATTERN (i2)))
8083 /* Some other ref remains; just delete the output reload we
8085 delete_address_reloads (output_reload_insn, insn);
8086 delete_insn (output_reload_insn);
8091 /* Delete the now-dead stores into this pseudo. Note that this
8092 loop also takes care of deleting output_reload_insn. */
8093 for (i2 = PREV_INSN (insn); i2; i2 = PREV_INSN (i2))
8095 rtx set = single_set (i2);
8097 if (set != 0 && SET_DEST (set) == reg)
8099 delete_address_reloads (i2, insn);
8107 /* For the debugging info, say the pseudo lives in this reload reg. */
8108 reg_renumber[REGNO (reg)] = REGNO (rld[j].reg_rtx);
8109 alter_reg (REGNO (reg), -1);
8113 delete_address_reloads (output_reload_insn, insn);
8114 delete_insn (output_reload_insn);
8118 /* We are going to delete DEAD_INSN. Recursively delete loads of
8119 reload registers used in DEAD_INSN that are not used till CURRENT_INSN.
8120 CURRENT_INSN is being reloaded, so we have to check its reloads too. */
8122 delete_address_reloads (rtx dead_insn, rtx current_insn)
8124 rtx set = single_set (dead_insn);
8125 rtx set2, dst, prev, next;
8128 rtx dst = SET_DEST (set);
8130 delete_address_reloads_1 (dead_insn, XEXP (dst, 0), current_insn);
8132 /* If we deleted the store from a reloaded post_{in,de}c expression,
8133 we can delete the matching adds. */
8134 prev = PREV_INSN (dead_insn);
8135 next = NEXT_INSN (dead_insn);
8136 if (! prev || ! next)
8138 set = single_set (next);
8139 set2 = single_set (prev);
8141 || GET_CODE (SET_SRC (set)) != PLUS || GET_CODE (SET_SRC (set2)) != PLUS
8142 || GET_CODE (XEXP (SET_SRC (set), 1)) != CONST_INT
8143 || GET_CODE (XEXP (SET_SRC (set2), 1)) != CONST_INT)
8145 dst = SET_DEST (set);
8146 if (! rtx_equal_p (dst, SET_DEST (set2))
8147 || ! rtx_equal_p (dst, XEXP (SET_SRC (set), 0))
8148 || ! rtx_equal_p (dst, XEXP (SET_SRC (set2), 0))
8149 || (INTVAL (XEXP (SET_SRC (set), 1))
8150 != -INTVAL (XEXP (SET_SRC (set2), 1))))
8152 delete_related_insns (prev);
8153 delete_related_insns (next);
8156 /* Subfunction of delete_address_reloads: process registers found in X. */
8158 delete_address_reloads_1 (rtx dead_insn, rtx x, rtx current_insn)
8160 rtx prev, set, dst, i2;
8162 enum rtx_code code = GET_CODE (x);
8166 const char *fmt = GET_RTX_FORMAT (code);
8167 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
8170 delete_address_reloads_1 (dead_insn, XEXP (x, i), current_insn);
8171 else if (fmt[i] == 'E')
8173 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
8174 delete_address_reloads_1 (dead_insn, XVECEXP (x, i, j),
8181 if (spill_reg_order[REGNO (x)] < 0)
8184 /* Scan backwards for the insn that sets x. This might be a way back due
8186 for (prev = PREV_INSN (dead_insn); prev; prev = PREV_INSN (prev))
8188 code = GET_CODE (prev);
8189 if (code == CODE_LABEL || code == JUMP_INSN)
8193 if (reg_set_p (x, PATTERN (prev)))
8195 if (reg_referenced_p (x, PATTERN (prev)))
8198 if (! prev || INSN_UID (prev) < reload_first_uid)
8200 /* Check that PREV only sets the reload register. */
8201 set = single_set (prev);
8204 dst = SET_DEST (set);
8206 || ! rtx_equal_p (dst, x))
8208 if (! reg_set_p (dst, PATTERN (dead_insn)))
8210 /* Check if DST was used in a later insn -
8211 it might have been inherited. */
8212 for (i2 = NEXT_INSN (dead_insn); i2; i2 = NEXT_INSN (i2))
8218 if (reg_referenced_p (dst, PATTERN (i2)))
8220 /* If there is a reference to the register in the current insn,
8221 it might be loaded in a non-inherited reload. If no other
8222 reload uses it, that means the register is set before
8224 if (i2 == current_insn)
8226 for (j = n_reloads - 1; j >= 0; j--)
8227 if ((rld[j].reg_rtx == dst && reload_inherited[j])
8228 || reload_override_in[j] == dst)
8230 for (j = n_reloads - 1; j >= 0; j--)
8231 if (rld[j].in && rld[j].reg_rtx == dst)
8240 /* If DST is still live at CURRENT_INSN, check if it is used for
8241 any reload. Note that even if CURRENT_INSN sets DST, we still
8242 have to check the reloads. */
8243 if (i2 == current_insn)
8245 for (j = n_reloads - 1; j >= 0; j--)
8246 if ((rld[j].reg_rtx == dst && reload_inherited[j])
8247 || reload_override_in[j] == dst)
8249 /* ??? We can't finish the loop here, because dst might be
8250 allocated to a pseudo in this block if no reload in this
8251 block needs any of the classes containing DST - see
8252 spill_hard_reg. There is no easy way to tell this, so we
8253 have to scan till the end of the basic block. */
8255 if (reg_set_p (dst, PATTERN (i2)))
8259 delete_address_reloads_1 (prev, SET_SRC (set), current_insn);
8260 reg_reloaded_contents[REGNO (dst)] = -1;
8264 /* Output reload-insns to reload VALUE into RELOADREG.
8265 VALUE is an autoincrement or autodecrement RTX whose operand
8266 is a register or memory location;
8267 so reloading involves incrementing that location.
8268 IN is either identical to VALUE, or some cheaper place to reload from.
8270 INC_AMOUNT is the number to increment or decrement by (always positive).
8271 This cannot be deduced from VALUE.
8273 Return the instruction that stores into RELOADREG. */
8276 inc_for_reload (rtx reloadreg, rtx in, rtx value, int inc_amount)
8278 /* REG or MEM to be copied and incremented. */
8279 rtx incloc = find_replacement (&XEXP (value, 0));
8280 /* Nonzero if increment after copying. */
8281 int post = (GET_CODE (value) == POST_DEC || GET_CODE (value) == POST_INC
8282 || GET_CODE (value) == POST_MODIFY);
8288 rtx real_in = in == value ? incloc : in;
8290 /* No hard register is equivalent to this register after
8291 inc/dec operation. If REG_LAST_RELOAD_REG were nonzero,
8292 we could inc/dec that register as well (maybe even using it for
8293 the source), but I'm not sure it's worth worrying about. */
8295 reg_last_reload_reg[REGNO (incloc)] = 0;
8297 if (GET_CODE (value) == PRE_MODIFY || GET_CODE (value) == POST_MODIFY)
8299 gcc_assert (GET_CODE (XEXP (value, 1)) == PLUS);
8300 inc = find_replacement (&XEXP (XEXP (value, 1), 1));
8304 if (GET_CODE (value) == PRE_DEC || GET_CODE (value) == POST_DEC)
8305 inc_amount = -inc_amount;
8307 inc = GEN_INT (inc_amount);
8310 /* If this is post-increment, first copy the location to the reload reg. */
8311 if (post && real_in != reloadreg)
8312 emit_insn (gen_move_insn (reloadreg, real_in));
8316 /* See if we can directly increment INCLOC. Use a method similar to
8317 that in gen_reload. */
8319 last = get_last_insn ();
8320 add_insn = emit_insn (gen_rtx_SET (VOIDmode, incloc,
8321 gen_rtx_PLUS (GET_MODE (incloc),
8324 code = recog_memoized (add_insn);
8327 extract_insn (add_insn);
8328 if (constrain_operands (1))
8330 /* If this is a pre-increment and we have incremented the value
8331 where it lives, copy the incremented value to RELOADREG to
8332 be used as an address. */
8335 emit_insn (gen_move_insn (reloadreg, incloc));
8340 delete_insns_since (last);
8343 /* If couldn't do the increment directly, must increment in RELOADREG.
8344 The way we do this depends on whether this is pre- or post-increment.
8345 For pre-increment, copy INCLOC to the reload register, increment it
8346 there, then save back. */
8350 if (in != reloadreg)
8351 emit_insn (gen_move_insn (reloadreg, real_in));
8352 emit_insn (gen_add2_insn (reloadreg, inc));
8353 store = emit_insn (gen_move_insn (incloc, reloadreg));
8358 Because this might be a jump insn or a compare, and because RELOADREG
8359 may not be available after the insn in an input reload, we must do
8360 the incrementation before the insn being reloaded for.
8362 We have already copied IN to RELOADREG. Increment the copy in
8363 RELOADREG, save that back, then decrement RELOADREG so it has
8364 the original value. */
8366 emit_insn (gen_add2_insn (reloadreg, inc));
8367 store = emit_insn (gen_move_insn (incloc, reloadreg));
8368 if (GET_CODE (inc) == CONST_INT)
8369 emit_insn (gen_add2_insn (reloadreg, GEN_INT (-INTVAL (inc))));
8371 emit_insn (gen_sub2_insn (reloadreg, inc));
8379 add_auto_inc_notes (rtx insn, rtx x)
8381 enum rtx_code code = GET_CODE (x);
8385 if (code == MEM && auto_inc_p (XEXP (x, 0)))
8388 = gen_rtx_EXPR_LIST (REG_INC, XEXP (XEXP (x, 0), 0), REG_NOTES (insn));
8392 /* Scan all the operand sub-expressions. */
8393 fmt = GET_RTX_FORMAT (code);
8394 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
8397 add_auto_inc_notes (insn, XEXP (x, i));
8398 else if (fmt[i] == 'E')
8399 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
8400 add_auto_inc_notes (insn, XVECEXP (x, i, j));
8405 /* Copy EH notes from an insn to its reloads. */
8407 copy_eh_notes (rtx insn, rtx x)
8409 rtx eh_note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
8412 for (; x != 0; x = NEXT_INSN (x))
8414 if (may_trap_p (PATTERN (x)))
8416 = gen_rtx_EXPR_LIST (REG_EH_REGION, XEXP (eh_note, 0),
8422 /* This is used by reload pass, that does emit some instructions after
8423 abnormal calls moving basic block end, but in fact it wants to emit
8424 them on the edge. Looks for abnormal call edges, find backward the
8425 proper call and fix the damage.
8427 Similar handle instructions throwing exceptions internally. */
8429 fixup_abnormal_edges (void)
8431 bool inserted = false;
8439 /* Look for cases we are interested in - calls or instructions causing
8441 FOR_EACH_EDGE (e, ei, bb->succs)
8443 if (e->flags & EDGE_ABNORMAL_CALL)
8445 if ((e->flags & (EDGE_ABNORMAL | EDGE_EH))
8446 == (EDGE_ABNORMAL | EDGE_EH))
8449 if (e && !CALL_P (BB_END (bb))
8450 && !can_throw_internal (BB_END (bb)))
8454 /* Get past the new insns generated. Allow notes, as the insns
8455 may be already deleted. */
8457 while ((NONJUMP_INSN_P (insn) || NOTE_P (insn))
8458 && !can_throw_internal (insn)
8459 && insn != BB_HEAD (bb))
8460 insn = PREV_INSN (insn);
8462 if (CALL_P (insn) || can_throw_internal (insn))
8466 stop = NEXT_INSN (BB_END (bb));
8468 insn = NEXT_INSN (insn);
8470 FOR_EACH_EDGE (e, ei, bb->succs)
8471 if (e->flags & EDGE_FALLTHRU)
8474 while (insn && insn != stop)
8476 next = NEXT_INSN (insn);
8481 /* Sometimes there's still the return value USE.
8482 If it's placed after a trapping call (i.e. that
8483 call is the last insn anyway), we have no fallthru
8484 edge. Simply delete this use and don't try to insert
8485 on the non-existent edge. */
8486 if (GET_CODE (PATTERN (insn)) != USE)
8488 /* We're not deleting it, we're moving it. */
8489 INSN_DELETED_P (insn) = 0;
8490 PREV_INSN (insn) = NULL_RTX;
8491 NEXT_INSN (insn) = NULL_RTX;
8493 insert_insn_on_edge (insn, e);
8501 /* It may be that we don't find any such trapping insn. In this
8502 case we discovered quite late that the insn that had been
8503 marked as can_throw_internal in fact couldn't trap at all.
8504 So we should in fact delete the EH edges out of the block. */
8506 purge_dead_edges (bb);
8510 /* We've possibly turned single trapping insn into multiple ones. */
8511 if (flag_non_call_exceptions)
8514 blocks = sbitmap_alloc (last_basic_block);
8515 sbitmap_ones (blocks);
8516 find_many_sub_basic_blocks (blocks);
8520 commit_edge_insertions ();
8522 #ifdef ENABLE_CHECKING
8523 /* Verify that we didn't turn one trapping insn into many, and that
8524 we found and corrected all of the problems wrt fixups on the
8526 verify_flow_info ();
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