1 /* Reload pseudo regs into hard regs for insns that require hard regs.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 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))
1177 replace_pseudos_in (& CALL_INSN_FUNCTION_USAGE (insn),
1178 VOIDmode, CALL_INSN_FUNCTION_USAGE (insn));
1180 if ((GET_CODE (PATTERN (insn)) == USE
1181 /* We mark with QImode USEs introduced by reload itself. */
1182 && (GET_MODE (insn) == QImode
1183 || find_reg_note (insn, REG_EQUAL, NULL_RTX)))
1184 || (GET_CODE (PATTERN (insn)) == CLOBBER
1185 && (!MEM_P (XEXP (PATTERN (insn), 0))
1186 || GET_MODE (XEXP (PATTERN (insn), 0)) != BLKmode
1187 || (GET_CODE (XEXP (XEXP (PATTERN (insn), 0), 0)) != SCRATCH
1188 && XEXP (XEXP (PATTERN (insn), 0), 0)
1189 != stack_pointer_rtx))
1190 && (!REG_P (XEXP (PATTERN (insn), 0))
1191 || ! REG_FUNCTION_VALUE_P (XEXP (PATTERN (insn), 0)))))
1197 /* Some CLOBBERs may survive until here and still reference unassigned
1198 pseudos with const equivalent, which may in turn cause ICE in later
1199 passes if the reference remains in place. */
1200 if (GET_CODE (PATTERN (insn)) == CLOBBER)
1201 replace_pseudos_in (& XEXP (PATTERN (insn), 0),
1202 VOIDmode, PATTERN (insn));
1204 /* Discard obvious no-ops, even without -O. This optimization
1205 is fast and doesn't interfere with debugging. */
1206 if (NONJUMP_INSN_P (insn)
1207 && GET_CODE (PATTERN (insn)) == SET
1208 && REG_P (SET_SRC (PATTERN (insn)))
1209 && REG_P (SET_DEST (PATTERN (insn)))
1210 && (REGNO (SET_SRC (PATTERN (insn)))
1211 == REGNO (SET_DEST (PATTERN (insn)))))
1217 pnote = ®_NOTES (insn);
1220 if (REG_NOTE_KIND (*pnote) == REG_DEAD
1221 || REG_NOTE_KIND (*pnote) == REG_UNUSED
1222 || REG_NOTE_KIND (*pnote) == REG_INC
1223 || REG_NOTE_KIND (*pnote) == REG_RETVAL
1224 || REG_NOTE_KIND (*pnote) == REG_LIBCALL)
1225 *pnote = XEXP (*pnote, 1);
1227 pnote = &XEXP (*pnote, 1);
1231 add_auto_inc_notes (insn, PATTERN (insn));
1234 /* Simplify (subreg (reg)) if it appears as an operand. */
1235 cleanup_subreg_operands (insn);
1237 /* Clean up invalid ASMs so that they don't confuse later passes.
1239 if (asm_noperands (PATTERN (insn)) >= 0)
1241 extract_insn (insn);
1242 if (!constrain_operands (1))
1244 error_for_asm (insn,
1245 "%<asm%> operand has impossible constraints");
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, NULL);
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 /* We do not support elimination of a register that is modified.
2552 elimination_effects has already make sure that this does not
2558 /* We do not support elimination of a register that is modified.
2559 elimination_effects has already make sure that this does not
2560 happen. The only remaining case we need to consider here is
2561 that the increment value may be an eliminable register. */
2562 if (GET_CODE (XEXP (x, 1)) == PLUS
2563 && XEXP (XEXP (x, 1), 0) == XEXP (x, 0))
2565 rtx new = eliminate_regs_1 (XEXP (XEXP (x, 1), 1), mem_mode,
2568 if (new != XEXP (XEXP (x, 1), 1))
2569 return gen_rtx_fmt_ee (code, GET_MODE (x), XEXP (x, 0),
2570 gen_rtx_PLUS (GET_MODE (x),
2575 case STRICT_LOW_PART:
2577 case SIGN_EXTEND: case ZERO_EXTEND:
2578 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
2579 case FLOAT: case FIX:
2580 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
2589 new = eliminate_regs_1 (XEXP (x, 0), mem_mode, insn, false);
2590 if (new != XEXP (x, 0))
2591 return gen_rtx_fmt_e (code, GET_MODE (x), new);
2595 /* Similar to above processing, but preserve SUBREG_BYTE.
2596 Convert (subreg (mem)) to (mem) if not paradoxical.
2597 Also, if we have a non-paradoxical (subreg (pseudo)) and the
2598 pseudo didn't get a hard reg, we must replace this with the
2599 eliminated version of the memory location because push_reload
2600 may do the replacement in certain circumstances. */
2601 if (REG_P (SUBREG_REG (x))
2602 && (GET_MODE_SIZE (GET_MODE (x))
2603 <= GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
2604 && reg_equiv_memory_loc != 0
2605 && reg_equiv_memory_loc[REGNO (SUBREG_REG (x))] != 0)
2607 new = SUBREG_REG (x);
2610 new = eliminate_regs_1 (SUBREG_REG (x), mem_mode, insn, false);
2612 if (new != SUBREG_REG (x))
2614 int x_size = GET_MODE_SIZE (GET_MODE (x));
2615 int new_size = GET_MODE_SIZE (GET_MODE (new));
2618 && ((x_size < new_size
2619 #ifdef WORD_REGISTER_OPERATIONS
2620 /* On these machines, combine can create rtl of the form
2621 (set (subreg:m1 (reg:m2 R) 0) ...)
2622 where m1 < m2, and expects something interesting to
2623 happen to the entire word. Moreover, it will use the
2624 (reg:m2 R) later, expecting all bits to be preserved.
2625 So if the number of words is the same, preserve the
2626 subreg so that push_reload can see it. */
2627 && ! ((x_size - 1) / UNITS_PER_WORD
2628 == (new_size -1 ) / UNITS_PER_WORD)
2631 || x_size == new_size)
2633 return adjust_address_nv (new, GET_MODE (x), SUBREG_BYTE (x));
2635 return gen_rtx_SUBREG (GET_MODE (x), new, SUBREG_BYTE (x));
2641 /* Our only special processing is to pass the mode of the MEM to our
2642 recursive call and copy the flags. While we are here, handle this
2643 case more efficiently. */
2645 replace_equiv_address_nv (x,
2646 eliminate_regs_1 (XEXP (x, 0), GET_MODE (x),
2650 /* Handle insn_list USE that a call to a pure function may generate. */
2651 new = eliminate_regs_1 (XEXP (x, 0), 0, insn, false);
2652 if (new != XEXP (x, 0))
2653 return gen_rtx_USE (GET_MODE (x), new);
2665 /* Process each of our operands recursively. If any have changed, make a
2667 fmt = GET_RTX_FORMAT (code);
2668 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2672 new = eliminate_regs_1 (XEXP (x, i), mem_mode, insn, false);
2673 if (new != XEXP (x, i) && ! copied)
2675 x = shallow_copy_rtx (x);
2680 else if (*fmt == 'E')
2683 for (j = 0; j < XVECLEN (x, i); j++)
2685 new = eliminate_regs_1 (XVECEXP (x, i, j), mem_mode, insn, false);
2686 if (new != XVECEXP (x, i, j) && ! copied_vec)
2688 rtvec new_v = gen_rtvec_v (XVECLEN (x, i),
2692 x = shallow_copy_rtx (x);
2695 XVEC (x, i) = new_v;
2698 XVECEXP (x, i, j) = new;
2707 eliminate_regs (rtx x, enum machine_mode mem_mode, rtx insn)
2709 return eliminate_regs_1 (x, mem_mode, insn, false);
2712 /* Scan rtx X for modifications of elimination target registers. Update
2713 the table of eliminables to reflect the changed state. MEM_MODE is
2714 the mode of an enclosing MEM rtx, or VOIDmode if not within a MEM. */
2717 elimination_effects (rtx x, enum machine_mode mem_mode)
2719 enum rtx_code code = GET_CODE (x);
2720 struct elim_table *ep;
2744 /* First handle the case where we encounter a bare register that
2745 is eliminable. Replace it with a PLUS. */
2746 if (regno < FIRST_PSEUDO_REGISTER)
2748 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
2750 if (ep->from_rtx == x && ep->can_eliminate)
2753 ep->ref_outside_mem = 1;
2758 else if (reg_renumber[regno] < 0 && reg_equiv_constant
2759 && reg_equiv_constant[regno]
2760 && ! function_invariant_p (reg_equiv_constant[regno]))
2761 elimination_effects (reg_equiv_constant[regno], mem_mode);
2770 /* If we modify the source of an elimination rule, disable it. */
2771 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2772 if (ep->from_rtx == XEXP (x, 0))
2773 ep->can_eliminate = 0;
2775 /* If we modify the target of an elimination rule by adding a constant,
2776 update its offset. If we modify the target in any other way, we'll
2777 have to disable the rule as well. */
2778 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2779 if (ep->to_rtx == XEXP (x, 0))
2781 int size = GET_MODE_SIZE (mem_mode);
2783 /* If more bytes than MEM_MODE are pushed, account for them. */
2784 #ifdef PUSH_ROUNDING
2785 if (ep->to_rtx == stack_pointer_rtx)
2786 size = PUSH_ROUNDING (size);
2788 if (code == PRE_DEC || code == POST_DEC)
2790 else if (code == PRE_INC || code == POST_INC)
2792 else if (code == PRE_MODIFY || code == POST_MODIFY)
2794 if (GET_CODE (XEXP (x, 1)) == PLUS
2795 && XEXP (x, 0) == XEXP (XEXP (x, 1), 0)
2796 && CONST_INT_P (XEXP (XEXP (x, 1), 1)))
2797 ep->offset -= INTVAL (XEXP (XEXP (x, 1), 1));
2799 ep->can_eliminate = 0;
2803 /* These two aren't unary operators. */
2804 if (code == POST_MODIFY || code == PRE_MODIFY)
2807 /* Fall through to generic unary operation case. */
2808 case STRICT_LOW_PART:
2810 case SIGN_EXTEND: case ZERO_EXTEND:
2811 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
2812 case FLOAT: case FIX:
2813 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
2822 elimination_effects (XEXP (x, 0), mem_mode);
2826 if (REG_P (SUBREG_REG (x))
2827 && (GET_MODE_SIZE (GET_MODE (x))
2828 <= GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
2829 && reg_equiv_memory_loc != 0
2830 && reg_equiv_memory_loc[REGNO (SUBREG_REG (x))] != 0)
2833 elimination_effects (SUBREG_REG (x), mem_mode);
2837 /* If using a register that is the source of an eliminate we still
2838 think can be performed, note it cannot be performed since we don't
2839 know how this register is used. */
2840 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2841 if (ep->from_rtx == XEXP (x, 0))
2842 ep->can_eliminate = 0;
2844 elimination_effects (XEXP (x, 0), mem_mode);
2848 /* If clobbering a register that is the replacement register for an
2849 elimination we still think can be performed, note that it cannot
2850 be performed. Otherwise, we need not be concerned about it. */
2851 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2852 if (ep->to_rtx == XEXP (x, 0))
2853 ep->can_eliminate = 0;
2855 elimination_effects (XEXP (x, 0), mem_mode);
2859 /* Check for setting a register that we know about. */
2860 if (REG_P (SET_DEST (x)))
2862 /* See if this is setting the replacement register for an
2865 If DEST is the hard frame pointer, we do nothing because we
2866 assume that all assignments to the frame pointer are for
2867 non-local gotos and are being done at a time when they are valid
2868 and do not disturb anything else. Some machines want to
2869 eliminate a fake argument pointer (or even a fake frame pointer)
2870 with either the real frame or the stack pointer. Assignments to
2871 the hard frame pointer must not prevent this elimination. */
2873 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
2875 if (ep->to_rtx == SET_DEST (x)
2876 && SET_DEST (x) != hard_frame_pointer_rtx)
2878 /* If it is being incremented, adjust the offset. Otherwise,
2879 this elimination can't be done. */
2880 rtx src = SET_SRC (x);
2882 if (GET_CODE (src) == PLUS
2883 && XEXP (src, 0) == SET_DEST (x)
2884 && GET_CODE (XEXP (src, 1)) == CONST_INT)
2885 ep->offset -= INTVAL (XEXP (src, 1));
2887 ep->can_eliminate = 0;
2891 elimination_effects (SET_DEST (x), 0);
2892 elimination_effects (SET_SRC (x), 0);
2896 /* Our only special processing is to pass the mode of the MEM to our
2898 elimination_effects (XEXP (x, 0), GET_MODE (x));
2905 fmt = GET_RTX_FORMAT (code);
2906 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2909 elimination_effects (XEXP (x, i), mem_mode);
2910 else if (*fmt == 'E')
2911 for (j = 0; j < XVECLEN (x, i); j++)
2912 elimination_effects (XVECEXP (x, i, j), mem_mode);
2916 /* Descend through rtx X and verify that no references to eliminable registers
2917 remain. If any do remain, mark the involved register as not
2921 check_eliminable_occurrences (rtx x)
2930 code = GET_CODE (x);
2932 if (code == REG && REGNO (x) < FIRST_PSEUDO_REGISTER)
2934 struct elim_table *ep;
2936 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2937 if (ep->from_rtx == x)
2938 ep->can_eliminate = 0;
2942 fmt = GET_RTX_FORMAT (code);
2943 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2946 check_eliminable_occurrences (XEXP (x, i));
2947 else if (*fmt == 'E')
2950 for (j = 0; j < XVECLEN (x, i); j++)
2951 check_eliminable_occurrences (XVECEXP (x, i, j));
2956 /* Scan INSN and eliminate all eliminable registers in it.
2958 If REPLACE is nonzero, do the replacement destructively. Also
2959 delete the insn as dead it if it is setting an eliminable register.
2961 If REPLACE is zero, do all our allocations in reload_obstack.
2963 If no eliminations were done and this insn doesn't require any elimination
2964 processing (these are not identical conditions: it might be updating sp,
2965 but not referencing fp; this needs to be seen during reload_as_needed so
2966 that the offset between fp and sp can be taken into consideration), zero
2967 is returned. Otherwise, 1 is returned. */
2970 eliminate_regs_in_insn (rtx insn, int replace)
2972 int icode = recog_memoized (insn);
2973 rtx old_body = PATTERN (insn);
2974 int insn_is_asm = asm_noperands (old_body) >= 0;
2975 rtx old_set = single_set (insn);
2979 rtx substed_operand[MAX_RECOG_OPERANDS];
2980 rtx orig_operand[MAX_RECOG_OPERANDS];
2981 struct elim_table *ep;
2982 rtx plus_src, plus_cst_src;
2984 if (! insn_is_asm && icode < 0)
2986 gcc_assert (GET_CODE (PATTERN (insn)) == USE
2987 || GET_CODE (PATTERN (insn)) == CLOBBER
2988 || GET_CODE (PATTERN (insn)) == ADDR_VEC
2989 || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
2990 || GET_CODE (PATTERN (insn)) == ASM_INPUT);
2994 if (old_set != 0 && REG_P (SET_DEST (old_set))
2995 && REGNO (SET_DEST (old_set)) < FIRST_PSEUDO_REGISTER)
2997 /* Check for setting an eliminable register. */
2998 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2999 if (ep->from_rtx == SET_DEST (old_set) && ep->can_eliminate)
3001 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
3002 /* If this is setting the frame pointer register to the
3003 hardware frame pointer register and this is an elimination
3004 that will be done (tested above), this insn is really
3005 adjusting the frame pointer downward to compensate for
3006 the adjustment done before a nonlocal goto. */
3007 if (ep->from == FRAME_POINTER_REGNUM
3008 && ep->to == HARD_FRAME_POINTER_REGNUM)
3010 rtx base = SET_SRC (old_set);
3011 rtx base_insn = insn;
3012 HOST_WIDE_INT offset = 0;
3014 while (base != ep->to_rtx)
3016 rtx prev_insn, prev_set;
3018 if (GET_CODE (base) == PLUS
3019 && GET_CODE (XEXP (base, 1)) == CONST_INT)
3021 offset += INTVAL (XEXP (base, 1));
3022 base = XEXP (base, 0);
3024 else if ((prev_insn = prev_nonnote_insn (base_insn)) != 0
3025 && (prev_set = single_set (prev_insn)) != 0
3026 && rtx_equal_p (SET_DEST (prev_set), base))
3028 base = SET_SRC (prev_set);
3029 base_insn = prev_insn;
3035 if (base == ep->to_rtx)
3038 = plus_constant (ep->to_rtx, offset - ep->offset);
3040 new_body = old_body;
3043 new_body = copy_insn (old_body);
3044 if (REG_NOTES (insn))
3045 REG_NOTES (insn) = copy_insn_1 (REG_NOTES (insn));
3047 PATTERN (insn) = new_body;
3048 old_set = single_set (insn);
3050 /* First see if this insn remains valid when we
3051 make the change. If not, keep the INSN_CODE
3052 the same and let reload fit it up. */
3053 validate_change (insn, &SET_SRC (old_set), src, 1);
3054 validate_change (insn, &SET_DEST (old_set),
3056 if (! apply_change_group ())
3058 SET_SRC (old_set) = src;
3059 SET_DEST (old_set) = ep->to_rtx;
3068 /* In this case this insn isn't serving a useful purpose. We
3069 will delete it in reload_as_needed once we know that this
3070 elimination is, in fact, being done.
3072 If REPLACE isn't set, we can't delete this insn, but needn't
3073 process it since it won't be used unless something changes. */
3076 delete_dead_insn (insn);
3084 /* We allow one special case which happens to work on all machines we
3085 currently support: a single set with the source or a REG_EQUAL
3086 note being a PLUS of an eliminable register and a constant. */
3087 plus_src = plus_cst_src = 0;
3088 if (old_set && REG_P (SET_DEST (old_set)))
3090 if (GET_CODE (SET_SRC (old_set)) == PLUS)
3091 plus_src = SET_SRC (old_set);
3092 /* First see if the source is of the form (plus (...) CST). */
3094 && GET_CODE (XEXP (plus_src, 1)) == CONST_INT)
3095 plus_cst_src = plus_src;
3096 else if (REG_P (SET_SRC (old_set))
3099 /* Otherwise, see if we have a REG_EQUAL note of the form
3100 (plus (...) CST). */
3102 for (links = REG_NOTES (insn); links; links = XEXP (links, 1))
3104 if ((REG_NOTE_KIND (links) == REG_EQUAL
3105 || REG_NOTE_KIND (links) == REG_EQUIV)
3106 && GET_CODE (XEXP (links, 0)) == PLUS
3107 && GET_CODE (XEXP (XEXP (links, 0), 1)) == CONST_INT)
3109 plus_cst_src = XEXP (links, 0);
3115 /* Check that the first operand of the PLUS is a hard reg or
3116 the lowpart subreg of one. */
3119 rtx reg = XEXP (plus_cst_src, 0);
3120 if (GET_CODE (reg) == SUBREG && subreg_lowpart_p (reg))
3121 reg = SUBREG_REG (reg);
3123 if (!REG_P (reg) || REGNO (reg) >= FIRST_PSEUDO_REGISTER)
3129 rtx reg = XEXP (plus_cst_src, 0);
3130 HOST_WIDE_INT offset = INTVAL (XEXP (plus_cst_src, 1));
3132 if (GET_CODE (reg) == SUBREG)
3133 reg = SUBREG_REG (reg);
3135 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3136 if (ep->from_rtx == reg && ep->can_eliminate)
3138 rtx to_rtx = ep->to_rtx;
3139 offset += ep->offset;
3140 offset = trunc_int_for_mode (offset, GET_MODE (reg));
3142 if (GET_CODE (XEXP (plus_cst_src, 0)) == SUBREG)
3143 to_rtx = gen_lowpart (GET_MODE (XEXP (plus_cst_src, 0)),
3145 /* If we have a nonzero offset, and the source is already
3146 a simple REG, the following transformation would
3147 increase the cost of the insn by replacing a simple REG
3148 with (plus (reg sp) CST). So try only when we already
3149 had a PLUS before. */
3150 if (offset == 0 || plus_src)
3152 rtx new_src = plus_constant (to_rtx, offset);
3154 new_body = old_body;
3157 new_body = copy_insn (old_body);
3158 if (REG_NOTES (insn))
3159 REG_NOTES (insn) = copy_insn_1 (REG_NOTES (insn));
3161 PATTERN (insn) = new_body;
3162 old_set = single_set (insn);
3164 /* First see if this insn remains valid when we make the
3165 change. If not, try to replace the whole pattern with
3166 a simple set (this may help if the original insn was a
3167 PARALLEL that was only recognized as single_set due to
3168 REG_UNUSED notes). If this isn't valid either, keep
3169 the INSN_CODE the same and let reload fix it up. */
3170 if (!validate_change (insn, &SET_SRC (old_set), new_src, 0))
3172 rtx new_pat = gen_rtx_SET (VOIDmode,
3173 SET_DEST (old_set), new_src);
3175 if (!validate_change (insn, &PATTERN (insn), new_pat, 0))
3176 SET_SRC (old_set) = new_src;
3183 /* This can't have an effect on elimination offsets, so skip right
3189 /* Determine the effects of this insn on elimination offsets. */
3190 elimination_effects (old_body, 0);
3192 /* Eliminate all eliminable registers occurring in operands that
3193 can be handled by reload. */
3194 extract_insn (insn);
3195 for (i = 0; i < recog_data.n_operands; i++)
3197 orig_operand[i] = recog_data.operand[i];
3198 substed_operand[i] = recog_data.operand[i];
3200 /* For an asm statement, every operand is eliminable. */
3201 if (insn_is_asm || insn_data[icode].operand[i].eliminable)
3203 bool is_set_src, in_plus;
3205 /* Check for setting a register that we know about. */
3206 if (recog_data.operand_type[i] != OP_IN
3207 && REG_P (orig_operand[i]))
3209 /* If we are assigning to a register that can be eliminated, it
3210 must be as part of a PARALLEL, since the code above handles
3211 single SETs. We must indicate that we can no longer
3212 eliminate this reg. */
3213 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
3215 if (ep->from_rtx == orig_operand[i])
3216 ep->can_eliminate = 0;
3219 /* Companion to the above plus substitution, we can allow
3220 invariants as the source of a plain move. */
3222 if (old_set && recog_data.operand_loc[i] == &SET_SRC (old_set))
3226 && (recog_data.operand_loc[i] == &XEXP (plus_src, 0)
3227 || recog_data.operand_loc[i] == &XEXP (plus_src, 1)))
3231 = eliminate_regs_1 (recog_data.operand[i], 0,
3232 replace ? insn : NULL_RTX,
3233 is_set_src || in_plus);
3234 if (substed_operand[i] != orig_operand[i])
3236 /* Terminate the search in check_eliminable_occurrences at
3238 *recog_data.operand_loc[i] = 0;
3240 /* If an output operand changed from a REG to a MEM and INSN is an
3241 insn, write a CLOBBER insn. */
3242 if (recog_data.operand_type[i] != OP_IN
3243 && REG_P (orig_operand[i])
3244 && MEM_P (substed_operand[i])
3246 emit_insn_after (gen_rtx_CLOBBER (VOIDmode, orig_operand[i]),
3251 for (i = 0; i < recog_data.n_dups; i++)
3252 *recog_data.dup_loc[i]
3253 = *recog_data.operand_loc[(int) recog_data.dup_num[i]];
3255 /* If any eliminable remain, they aren't eliminable anymore. */
3256 check_eliminable_occurrences (old_body);
3258 /* Substitute the operands; the new values are in the substed_operand
3260 for (i = 0; i < recog_data.n_operands; i++)
3261 *recog_data.operand_loc[i] = substed_operand[i];
3262 for (i = 0; i < recog_data.n_dups; i++)
3263 *recog_data.dup_loc[i] = substed_operand[(int) recog_data.dup_num[i]];
3265 /* If we are replacing a body that was a (set X (plus Y Z)), try to
3266 re-recognize the insn. We do this in case we had a simple addition
3267 but now can do this as a load-address. This saves an insn in this
3269 If re-recognition fails, the old insn code number will still be used,
3270 and some register operands may have changed into PLUS expressions.
3271 These will be handled by find_reloads by loading them into a register
3276 /* If we aren't replacing things permanently and we changed something,
3277 make another copy to ensure that all the RTL is new. Otherwise
3278 things can go wrong if find_reload swaps commutative operands
3279 and one is inside RTL that has been copied while the other is not. */
3280 new_body = old_body;
3283 new_body = copy_insn (old_body);
3284 if (REG_NOTES (insn))
3285 REG_NOTES (insn) = copy_insn_1 (REG_NOTES (insn));
3287 PATTERN (insn) = new_body;
3289 /* If we had a move insn but now we don't, rerecognize it. This will
3290 cause spurious re-recognition if the old move had a PARALLEL since
3291 the new one still will, but we can't call single_set without
3292 having put NEW_BODY into the insn and the re-recognition won't
3293 hurt in this rare case. */
3294 /* ??? Why this huge if statement - why don't we just rerecognize the
3298 && ((REG_P (SET_SRC (old_set))
3299 && (GET_CODE (new_body) != SET
3300 || !REG_P (SET_SRC (new_body))))
3301 /* If this was a load from or store to memory, compare
3302 the MEM in recog_data.operand to the one in the insn.
3303 If they are not equal, then rerecognize the insn. */
3305 && ((MEM_P (SET_SRC (old_set))
3306 && SET_SRC (old_set) != recog_data.operand[1])
3307 || (MEM_P (SET_DEST (old_set))
3308 && SET_DEST (old_set) != recog_data.operand[0])))
3309 /* If this was an add insn before, rerecognize. */
3310 || GET_CODE (SET_SRC (old_set)) == PLUS))
3312 int new_icode = recog (PATTERN (insn), insn, 0);
3314 INSN_CODE (insn) = new_icode;
3318 /* Restore the old body. If there were any changes to it, we made a copy
3319 of it while the changes were still in place, so we'll correctly return
3320 a modified insn below. */
3323 /* Restore the old body. */
3324 for (i = 0; i < recog_data.n_operands; i++)
3325 *recog_data.operand_loc[i] = orig_operand[i];
3326 for (i = 0; i < recog_data.n_dups; i++)
3327 *recog_data.dup_loc[i] = orig_operand[(int) recog_data.dup_num[i]];
3330 /* Update all elimination pairs to reflect the status after the current
3331 insn. The changes we make were determined by the earlier call to
3332 elimination_effects.
3334 We also detect cases where register elimination cannot be done,
3335 namely, if a register would be both changed and referenced outside a MEM
3336 in the resulting insn since such an insn is often undefined and, even if
3337 not, we cannot know what meaning will be given to it. Note that it is
3338 valid to have a register used in an address in an insn that changes it
3339 (presumably with a pre- or post-increment or decrement).
3341 If anything changes, return nonzero. */
3343 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3345 if (ep->previous_offset != ep->offset && ep->ref_outside_mem)
3346 ep->can_eliminate = 0;
3348 ep->ref_outside_mem = 0;
3350 if (ep->previous_offset != ep->offset)
3355 /* If we changed something, perform elimination in REG_NOTES. This is
3356 needed even when REPLACE is zero because a REG_DEAD note might refer
3357 to a register that we eliminate and could cause a different number
3358 of spill registers to be needed in the final reload pass than in
3360 if (val && REG_NOTES (insn) != 0)
3362 = eliminate_regs_1 (REG_NOTES (insn), 0, REG_NOTES (insn), true);
3367 /* Loop through all elimination pairs.
3368 Recalculate the number not at initial offset.
3370 Compute the maximum offset (minimum offset if the stack does not
3371 grow downward) for each elimination pair. */
3374 update_eliminable_offsets (void)
3376 struct elim_table *ep;
3378 num_not_at_initial_offset = 0;
3379 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3381 ep->previous_offset = ep->offset;
3382 if (ep->can_eliminate && ep->offset != ep->initial_offset)
3383 num_not_at_initial_offset++;
3387 /* Given X, a SET or CLOBBER of DEST, if DEST is the target of a register
3388 replacement we currently believe is valid, mark it as not eliminable if X
3389 modifies DEST in any way other than by adding a constant integer to it.
3391 If DEST is the frame pointer, we do nothing because we assume that
3392 all assignments to the hard frame pointer are nonlocal gotos and are being
3393 done at a time when they are valid and do not disturb anything else.
3394 Some machines want to eliminate a fake argument pointer with either the
3395 frame or stack pointer. Assignments to the hard frame pointer must not
3396 prevent this elimination.
3398 Called via note_stores from reload before starting its passes to scan
3399 the insns of the function. */
3402 mark_not_eliminable (rtx dest, rtx x, void *data ATTRIBUTE_UNUSED)
3406 /* A SUBREG of a hard register here is just changing its mode. We should
3407 not see a SUBREG of an eliminable hard register, but check just in
3409 if (GET_CODE (dest) == SUBREG)
3410 dest = SUBREG_REG (dest);
3412 if (dest == hard_frame_pointer_rtx)
3415 for (i = 0; i < NUM_ELIMINABLE_REGS; i++)
3416 if (reg_eliminate[i].can_eliminate && dest == reg_eliminate[i].to_rtx
3417 && (GET_CODE (x) != SET
3418 || GET_CODE (SET_SRC (x)) != PLUS
3419 || XEXP (SET_SRC (x), 0) != dest
3420 || GET_CODE (XEXP (SET_SRC (x), 1)) != CONST_INT))
3422 reg_eliminate[i].can_eliminate_previous
3423 = reg_eliminate[i].can_eliminate = 0;
3428 /* Verify that the initial elimination offsets did not change since the
3429 last call to set_initial_elim_offsets. This is used to catch cases
3430 where something illegal happened during reload_as_needed that could
3431 cause incorrect code to be generated if we did not check for it. */
3434 verify_initial_elim_offsets (void)
3438 if (!num_eliminable)
3441 #ifdef ELIMINABLE_REGS
3443 struct elim_table *ep;
3445 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3447 INITIAL_ELIMINATION_OFFSET (ep->from, ep->to, t);
3448 if (t != ep->initial_offset)
3453 INITIAL_FRAME_POINTER_OFFSET (t);
3454 if (t != reg_eliminate[0].initial_offset)
3461 /* Reset all offsets on eliminable registers to their initial values. */
3464 set_initial_elim_offsets (void)
3466 struct elim_table *ep = reg_eliminate;
3468 #ifdef ELIMINABLE_REGS
3469 for (; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3471 INITIAL_ELIMINATION_OFFSET (ep->from, ep->to, ep->initial_offset);
3472 ep->previous_offset = ep->offset = ep->initial_offset;
3475 INITIAL_FRAME_POINTER_OFFSET (ep->initial_offset);
3476 ep->previous_offset = ep->offset = ep->initial_offset;
3479 num_not_at_initial_offset = 0;
3482 /* Subroutine of set_initial_label_offsets called via for_each_eh_label. */
3485 set_initial_eh_label_offset (rtx label)
3487 set_label_offsets (label, NULL_RTX, 1);
3490 /* Initialize the known label offsets.
3491 Set a known offset for each forced label to be at the initial offset
3492 of each elimination. We do this because we assume that all
3493 computed jumps occur from a location where each elimination is
3494 at its initial offset.
3495 For all other labels, show that we don't know the offsets. */
3498 set_initial_label_offsets (void)
3501 memset (offsets_known_at, 0, num_labels);
3503 for (x = forced_labels; x; x = XEXP (x, 1))
3505 set_label_offsets (XEXP (x, 0), NULL_RTX, 1);
3507 for_each_eh_label (set_initial_eh_label_offset);
3510 /* Set all elimination offsets to the known values for the code label given
3514 set_offsets_for_label (rtx insn)
3517 int label_nr = CODE_LABEL_NUMBER (insn);
3518 struct elim_table *ep;
3520 num_not_at_initial_offset = 0;
3521 for (i = 0, ep = reg_eliminate; i < NUM_ELIMINABLE_REGS; ep++, i++)
3523 ep->offset = ep->previous_offset
3524 = offsets_at[label_nr - first_label_num][i];
3525 if (ep->can_eliminate && ep->offset != ep->initial_offset)
3526 num_not_at_initial_offset++;
3530 /* See if anything that happened changes which eliminations are valid.
3531 For example, on the SPARC, whether or not the frame pointer can
3532 be eliminated can depend on what registers have been used. We need
3533 not check some conditions again (such as flag_omit_frame_pointer)
3534 since they can't have changed. */
3537 update_eliminables (HARD_REG_SET *pset)
3539 int previous_frame_pointer_needed = frame_pointer_needed;
3540 struct elim_table *ep;
3542 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3543 if ((ep->from == HARD_FRAME_POINTER_REGNUM && FRAME_POINTER_REQUIRED)
3544 #ifdef ELIMINABLE_REGS
3545 || ! CAN_ELIMINATE (ep->from, ep->to)
3548 ep->can_eliminate = 0;
3550 /* Look for the case where we have discovered that we can't replace
3551 register A with register B and that means that we will now be
3552 trying to replace register A with register C. This means we can
3553 no longer replace register C with register B and we need to disable
3554 such an elimination, if it exists. This occurs often with A == ap,
3555 B == sp, and C == fp. */
3557 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3559 struct elim_table *op;
3562 if (! ep->can_eliminate && ep->can_eliminate_previous)
3564 /* Find the current elimination for ep->from, if there is a
3566 for (op = reg_eliminate;
3567 op < ®_eliminate[NUM_ELIMINABLE_REGS]; op++)
3568 if (op->from == ep->from && op->can_eliminate)
3574 /* See if there is an elimination of NEW_TO -> EP->TO. If so,
3576 for (op = reg_eliminate;
3577 op < ®_eliminate[NUM_ELIMINABLE_REGS]; op++)
3578 if (op->from == new_to && op->to == ep->to)
3579 op->can_eliminate = 0;
3583 /* See if any registers that we thought we could eliminate the previous
3584 time are no longer eliminable. If so, something has changed and we
3585 must spill the register. Also, recompute the number of eliminable
3586 registers and see if the frame pointer is needed; it is if there is
3587 no elimination of the frame pointer that we can perform. */
3589 frame_pointer_needed = 1;
3590 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3592 if (ep->can_eliminate && ep->from == FRAME_POINTER_REGNUM
3593 && ep->to != HARD_FRAME_POINTER_REGNUM)
3594 frame_pointer_needed = 0;
3596 if (! ep->can_eliminate && ep->can_eliminate_previous)
3598 ep->can_eliminate_previous = 0;
3599 SET_HARD_REG_BIT (*pset, ep->from);
3604 /* If we didn't need a frame pointer last time, but we do now, spill
3605 the hard frame pointer. */
3606 if (frame_pointer_needed && ! previous_frame_pointer_needed)
3607 SET_HARD_REG_BIT (*pset, HARD_FRAME_POINTER_REGNUM);
3610 /* Initialize the table of registers to eliminate. */
3613 init_elim_table (void)
3615 struct elim_table *ep;
3616 #ifdef ELIMINABLE_REGS
3617 const struct elim_table_1 *ep1;
3621 reg_eliminate = xcalloc (sizeof (struct elim_table), NUM_ELIMINABLE_REGS);
3623 /* Does this function require a frame pointer? */
3625 frame_pointer_needed = (! flag_omit_frame_pointer
3626 /* ?? If EXIT_IGNORE_STACK is set, we will not save
3627 and restore sp for alloca. So we can't eliminate
3628 the frame pointer in that case. At some point,
3629 we should improve this by emitting the
3630 sp-adjusting insns for this case. */
3631 || (current_function_calls_alloca
3632 && EXIT_IGNORE_STACK)
3633 || current_function_accesses_prior_frames
3634 || FRAME_POINTER_REQUIRED);
3638 #ifdef ELIMINABLE_REGS
3639 for (ep = reg_eliminate, ep1 = reg_eliminate_1;
3640 ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++, ep1++)
3642 ep->from = ep1->from;
3644 ep->can_eliminate = ep->can_eliminate_previous
3645 = (CAN_ELIMINATE (ep->from, ep->to)
3646 && ! (ep->to == STACK_POINTER_REGNUM && frame_pointer_needed));
3649 reg_eliminate[0].from = reg_eliminate_1[0].from;
3650 reg_eliminate[0].to = reg_eliminate_1[0].to;
3651 reg_eliminate[0].can_eliminate = reg_eliminate[0].can_eliminate_previous
3652 = ! frame_pointer_needed;
3655 /* Count the number of eliminable registers and build the FROM and TO
3656 REG rtx's. Note that code in gen_rtx_REG will cause, e.g.,
3657 gen_rtx_REG (Pmode, STACK_POINTER_REGNUM) to equal stack_pointer_rtx.
3658 We depend on this. */
3659 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3661 num_eliminable += ep->can_eliminate;
3662 ep->from_rtx = gen_rtx_REG (Pmode, ep->from);
3663 ep->to_rtx = gen_rtx_REG (Pmode, ep->to);
3667 /* Kick all pseudos out of hard register REGNO.
3669 If CANT_ELIMINATE is nonzero, it means that we are doing this spill
3670 because we found we can't eliminate some register. In the case, no pseudos
3671 are allowed to be in the register, even if they are only in a block that
3672 doesn't require spill registers, unlike the case when we are spilling this
3673 hard reg to produce another spill register.
3675 Return nonzero if any pseudos needed to be kicked out. */
3678 spill_hard_reg (unsigned int regno, int cant_eliminate)
3684 SET_HARD_REG_BIT (bad_spill_regs_global, regno);
3685 regs_ever_live[regno] = 1;
3688 /* Spill every pseudo reg that was allocated to this reg
3689 or to something that overlaps this reg. */
3691 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
3692 if (reg_renumber[i] >= 0
3693 && (unsigned int) reg_renumber[i] <= regno
3694 && ((unsigned int) reg_renumber[i]
3695 + hard_regno_nregs[(unsigned int) reg_renumber[i]]
3696 [PSEUDO_REGNO_MODE (i)]
3698 SET_REGNO_REG_SET (&spilled_pseudos, i);
3701 /* After find_reload_regs has been run for all insn that need reloads,
3702 and/or spill_hard_regs was called, this function is used to actually
3703 spill pseudo registers and try to reallocate them. It also sets up the
3704 spill_regs array for use by choose_reload_regs. */
3707 finish_spills (int global)
3709 struct insn_chain *chain;
3710 int something_changed = 0;
3712 reg_set_iterator rsi;
3714 /* Build the spill_regs array for the function. */
3715 /* If there are some registers still to eliminate and one of the spill regs
3716 wasn't ever used before, additional stack space may have to be
3717 allocated to store this register. Thus, we may have changed the offset
3718 between the stack and frame pointers, so mark that something has changed.
3720 One might think that we need only set VAL to 1 if this is a call-used
3721 register. However, the set of registers that must be saved by the
3722 prologue is not identical to the call-used set. For example, the
3723 register used by the call insn for the return PC is a call-used register,
3724 but must be saved by the prologue. */
3727 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3728 if (TEST_HARD_REG_BIT (used_spill_regs, i))
3730 spill_reg_order[i] = n_spills;
3731 spill_regs[n_spills++] = i;
3732 if (num_eliminable && ! regs_ever_live[i])
3733 something_changed = 1;
3734 regs_ever_live[i] = 1;
3737 spill_reg_order[i] = -1;
3739 EXECUTE_IF_SET_IN_REG_SET (&spilled_pseudos, FIRST_PSEUDO_REGISTER, i, rsi)
3741 /* Record the current hard register the pseudo is allocated to in
3742 pseudo_previous_regs so we avoid reallocating it to the same
3743 hard reg in a later pass. */
3744 gcc_assert (reg_renumber[i] >= 0);
3746 SET_HARD_REG_BIT (pseudo_previous_regs[i], reg_renumber[i]);
3747 /* Mark it as no longer having a hard register home. */
3748 reg_renumber[i] = -1;
3749 /* We will need to scan everything again. */
3750 something_changed = 1;
3753 /* Retry global register allocation if possible. */
3756 memset (pseudo_forbidden_regs, 0, max_regno * sizeof (HARD_REG_SET));
3757 /* For every insn that needs reloads, set the registers used as spill
3758 regs in pseudo_forbidden_regs for every pseudo live across the
3760 for (chain = insns_need_reload; chain; chain = chain->next_need_reload)
3762 EXECUTE_IF_SET_IN_REG_SET
3763 (&chain->live_throughout, FIRST_PSEUDO_REGISTER, i, rsi)
3765 IOR_HARD_REG_SET (pseudo_forbidden_regs[i],
3766 chain->used_spill_regs);
3768 EXECUTE_IF_SET_IN_REG_SET
3769 (&chain->dead_or_set, FIRST_PSEUDO_REGISTER, i, rsi)
3771 IOR_HARD_REG_SET (pseudo_forbidden_regs[i],
3772 chain->used_spill_regs);
3776 /* Retry allocating the spilled pseudos. For each reg, merge the
3777 various reg sets that indicate which hard regs can't be used,
3778 and call retry_global_alloc.
3779 We change spill_pseudos here to only contain pseudos that did not
3780 get a new hard register. */
3781 for (i = FIRST_PSEUDO_REGISTER; i < (unsigned)max_regno; i++)
3782 if (reg_old_renumber[i] != reg_renumber[i])
3784 HARD_REG_SET forbidden;
3785 COPY_HARD_REG_SET (forbidden, bad_spill_regs_global);
3786 IOR_HARD_REG_SET (forbidden, pseudo_forbidden_regs[i]);
3787 IOR_HARD_REG_SET (forbidden, pseudo_previous_regs[i]);
3788 retry_global_alloc (i, forbidden);
3789 if (reg_renumber[i] >= 0)
3790 CLEAR_REGNO_REG_SET (&spilled_pseudos, i);
3794 /* Fix up the register information in the insn chain.
3795 This involves deleting those of the spilled pseudos which did not get
3796 a new hard register home from the live_{before,after} sets. */
3797 for (chain = reload_insn_chain; chain; chain = chain->next)
3799 HARD_REG_SET used_by_pseudos;
3800 HARD_REG_SET used_by_pseudos2;
3802 AND_COMPL_REG_SET (&chain->live_throughout, &spilled_pseudos);
3803 AND_COMPL_REG_SET (&chain->dead_or_set, &spilled_pseudos);
3805 /* Mark any unallocated hard regs as available for spills. That
3806 makes inheritance work somewhat better. */
3807 if (chain->need_reload)
3809 REG_SET_TO_HARD_REG_SET (used_by_pseudos, &chain->live_throughout);
3810 REG_SET_TO_HARD_REG_SET (used_by_pseudos2, &chain->dead_or_set);
3811 IOR_HARD_REG_SET (used_by_pseudos, used_by_pseudos2);
3813 /* Save the old value for the sanity test below. */
3814 COPY_HARD_REG_SET (used_by_pseudos2, chain->used_spill_regs);
3816 compute_use_by_pseudos (&used_by_pseudos, &chain->live_throughout);
3817 compute_use_by_pseudos (&used_by_pseudos, &chain->dead_or_set);
3818 COMPL_HARD_REG_SET (chain->used_spill_regs, used_by_pseudos);
3819 AND_HARD_REG_SET (chain->used_spill_regs, used_spill_regs);
3821 /* Make sure we only enlarge the set. */
3822 GO_IF_HARD_REG_SUBSET (used_by_pseudos2, chain->used_spill_regs, ok);
3828 /* Let alter_reg modify the reg rtx's for the modified pseudos. */
3829 for (i = FIRST_PSEUDO_REGISTER; i < (unsigned)max_regno; i++)
3831 int regno = reg_renumber[i];
3832 if (reg_old_renumber[i] == regno)
3835 alter_reg (i, reg_old_renumber[i]);
3836 reg_old_renumber[i] = regno;
3840 fprintf (dump_file, " Register %d now on stack.\n\n", i);
3842 fprintf (dump_file, " Register %d now in %d.\n\n",
3843 i, reg_renumber[i]);
3847 return something_changed;
3850 /* Find all paradoxical subregs within X and update reg_max_ref_width. */
3853 scan_paradoxical_subregs (rtx x)
3857 enum rtx_code code = GET_CODE (x);
3867 case CONST_VECTOR: /* shouldn't happen, but just in case. */
3875 if (REG_P (SUBREG_REG (x))
3876 && (GET_MODE_SIZE (GET_MODE (x))
3877 > reg_max_ref_width[REGNO (SUBREG_REG (x))]))
3878 reg_max_ref_width[REGNO (SUBREG_REG (x))]
3879 = GET_MODE_SIZE (GET_MODE (x));
3886 fmt = GET_RTX_FORMAT (code);
3887 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
3890 scan_paradoxical_subregs (XEXP (x, i));
3891 else if (fmt[i] == 'E')
3894 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
3895 scan_paradoxical_subregs (XVECEXP (x, i, j));
3900 /* A subroutine of reload_as_needed. If INSN has a REG_EH_REGION note,
3901 examine all of the reload insns between PREV and NEXT exclusive, and
3902 annotate all that may trap. */
3905 fixup_eh_region_note (rtx insn, rtx prev, rtx next)
3907 rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
3908 unsigned int trap_count;
3914 if (may_trap_p (PATTERN (insn)))
3918 remove_note (insn, note);
3922 for (i = NEXT_INSN (prev); i != next; i = NEXT_INSN (i))
3923 if (INSN_P (i) && i != insn && may_trap_p (PATTERN (i)))
3927 = gen_rtx_EXPR_LIST (REG_EH_REGION, XEXP (note, 0), REG_NOTES (i));
3931 /* Reload pseudo-registers into hard regs around each insn as needed.
3932 Additional register load insns are output before the insn that needs it
3933 and perhaps store insns after insns that modify the reloaded pseudo reg.
3935 reg_last_reload_reg and reg_reloaded_contents keep track of
3936 which registers are already available in reload registers.
3937 We update these for the reloads that we perform,
3938 as the insns are scanned. */
3941 reload_as_needed (int live_known)
3943 struct insn_chain *chain;
3944 #if defined (AUTO_INC_DEC)
3949 memset (spill_reg_rtx, 0, sizeof spill_reg_rtx);
3950 memset (spill_reg_store, 0, sizeof spill_reg_store);
3951 reg_last_reload_reg = XCNEWVEC (rtx, max_regno);
3952 INIT_REG_SET (®_has_output_reload);
3953 CLEAR_HARD_REG_SET (reg_reloaded_valid);
3954 CLEAR_HARD_REG_SET (reg_reloaded_call_part_clobbered);
3956 set_initial_elim_offsets ();
3958 for (chain = reload_insn_chain; chain; chain = chain->next)
3961 rtx insn = chain->insn;
3962 rtx old_next = NEXT_INSN (insn);
3964 /* If we pass a label, copy the offsets from the label information
3965 into the current offsets of each elimination. */
3967 set_offsets_for_label (insn);
3969 else if (INSN_P (insn))
3971 regset_head regs_to_forget;
3972 INIT_REG_SET (®s_to_forget);
3973 note_stores (PATTERN (insn), forget_old_reloads_1, ®s_to_forget);
3975 /* If this is a USE and CLOBBER of a MEM, ensure that any
3976 references to eliminable registers have been removed. */
3978 if ((GET_CODE (PATTERN (insn)) == USE
3979 || GET_CODE (PATTERN (insn)) == CLOBBER)
3980 && MEM_P (XEXP (PATTERN (insn), 0)))
3981 XEXP (XEXP (PATTERN (insn), 0), 0)
3982 = eliminate_regs (XEXP (XEXP (PATTERN (insn), 0), 0),
3983 GET_MODE (XEXP (PATTERN (insn), 0)),
3986 /* If we need to do register elimination processing, do so.
3987 This might delete the insn, in which case we are done. */
3988 if ((num_eliminable || num_eliminable_invariants) && chain->need_elim)
3990 eliminate_regs_in_insn (insn, 1);
3993 update_eliminable_offsets ();
3994 CLEAR_REG_SET (®s_to_forget);
3999 /* If need_elim is nonzero but need_reload is zero, one might think
4000 that we could simply set n_reloads to 0. However, find_reloads
4001 could have done some manipulation of the insn (such as swapping
4002 commutative operands), and these manipulations are lost during
4003 the first pass for every insn that needs register elimination.
4004 So the actions of find_reloads must be redone here. */
4006 if (! chain->need_elim && ! chain->need_reload
4007 && ! chain->need_operand_change)
4009 /* First find the pseudo regs that must be reloaded for this insn.
4010 This info is returned in the tables reload_... (see reload.h).
4011 Also modify the body of INSN by substituting RELOAD
4012 rtx's for those pseudo regs. */
4015 CLEAR_REG_SET (®_has_output_reload);
4016 CLEAR_HARD_REG_SET (reg_is_output_reload);
4018 find_reloads (insn, 1, spill_indirect_levels, live_known,
4024 rtx next = NEXT_INSN (insn);
4027 prev = PREV_INSN (insn);
4029 /* Now compute which reload regs to reload them into. Perhaps
4030 reusing reload regs from previous insns, or else output
4031 load insns to reload them. Maybe output store insns too.
4032 Record the choices of reload reg in reload_reg_rtx. */
4033 choose_reload_regs (chain);
4035 /* Merge any reloads that we didn't combine for fear of
4036 increasing the number of spill registers needed but now
4037 discover can be safely merged. */
4038 if (SMALL_REGISTER_CLASSES)
4039 merge_assigned_reloads (insn);
4041 /* Generate the insns to reload operands into or out of
4042 their reload regs. */
4043 emit_reload_insns (chain);
4045 /* Substitute the chosen reload regs from reload_reg_rtx
4046 into the insn's body (or perhaps into the bodies of other
4047 load and store insn that we just made for reloading
4048 and that we moved the structure into). */
4049 subst_reloads (insn);
4051 /* Adjust the exception region notes for loads and stores. */
4052 if (flag_non_call_exceptions && !CALL_P (insn))
4053 fixup_eh_region_note (insn, prev, next);
4055 /* If this was an ASM, make sure that all the reload insns
4056 we have generated are valid. If not, give an error
4058 if (asm_noperands (PATTERN (insn)) >= 0)
4059 for (p = NEXT_INSN (prev); p != next; p = NEXT_INSN (p))
4060 if (p != insn && INSN_P (p)
4061 && GET_CODE (PATTERN (p)) != USE
4062 && (recog_memoized (p) < 0
4063 || (extract_insn (p), ! constrain_operands (1))))
4065 error_for_asm (insn,
4066 "%<asm%> operand requires "
4067 "impossible reload");
4072 if (num_eliminable && chain->need_elim)
4073 update_eliminable_offsets ();
4075 /* Any previously reloaded spilled pseudo reg, stored in this insn,
4076 is no longer validly lying around to save a future reload.
4077 Note that this does not detect pseudos that were reloaded
4078 for this insn in order to be stored in
4079 (obeying register constraints). That is correct; such reload
4080 registers ARE still valid. */
4081 forget_marked_reloads (®s_to_forget);
4082 CLEAR_REG_SET (®s_to_forget);
4084 /* There may have been CLOBBER insns placed after INSN. So scan
4085 between INSN and NEXT and use them to forget old reloads. */
4086 for (x = NEXT_INSN (insn); x != old_next; x = NEXT_INSN (x))
4087 if (NONJUMP_INSN_P (x) && GET_CODE (PATTERN (x)) == CLOBBER)
4088 note_stores (PATTERN (x), forget_old_reloads_1, NULL);
4091 /* Likewise for regs altered by auto-increment in this insn.
4092 REG_INC notes have been changed by reloading:
4093 find_reloads_address_1 records substitutions for them,
4094 which have been performed by subst_reloads above. */
4095 for (i = n_reloads - 1; i >= 0; i--)
4097 rtx in_reg = rld[i].in_reg;
4100 enum rtx_code code = GET_CODE (in_reg);
4101 /* PRE_INC / PRE_DEC will have the reload register ending up
4102 with the same value as the stack slot, but that doesn't
4103 hold true for POST_INC / POST_DEC. Either we have to
4104 convert the memory access to a true POST_INC / POST_DEC,
4105 or we can't use the reload register for inheritance. */
4106 if ((code == POST_INC || code == POST_DEC)
4107 && TEST_HARD_REG_BIT (reg_reloaded_valid,
4108 REGNO (rld[i].reg_rtx))
4109 /* Make sure it is the inc/dec pseudo, and not
4110 some other (e.g. output operand) pseudo. */
4111 && ((unsigned) reg_reloaded_contents[REGNO (rld[i].reg_rtx)]
4112 == REGNO (XEXP (in_reg, 0))))
4115 rtx reload_reg = rld[i].reg_rtx;
4116 enum machine_mode mode = GET_MODE (reload_reg);
4120 for (p = PREV_INSN (old_next); p != prev; p = PREV_INSN (p))
4122 /* We really want to ignore REG_INC notes here, so
4123 use PATTERN (p) as argument to reg_set_p . */
4124 if (reg_set_p (reload_reg, PATTERN (p)))
4126 n = count_occurrences (PATTERN (p), reload_reg, 0);
4131 n = validate_replace_rtx (reload_reg,
4132 gen_rtx_fmt_e (code,
4137 /* We must also verify that the constraints
4138 are met after the replacement. */
4141 n = constrain_operands (1);
4145 /* If the constraints were not met, then
4146 undo the replacement. */
4149 validate_replace_rtx (gen_rtx_fmt_e (code,
4162 = gen_rtx_EXPR_LIST (REG_INC, reload_reg,
4164 /* Mark this as having an output reload so that the
4165 REG_INC processing code below won't invalidate
4166 the reload for inheritance. */
4167 SET_HARD_REG_BIT (reg_is_output_reload,
4168 REGNO (reload_reg));
4169 SET_REGNO_REG_SET (®_has_output_reload,
4170 REGNO (XEXP (in_reg, 0)));
4173 forget_old_reloads_1 (XEXP (in_reg, 0), NULL_RTX,
4176 else if ((code == PRE_INC || code == PRE_DEC)
4177 && TEST_HARD_REG_BIT (reg_reloaded_valid,
4178 REGNO (rld[i].reg_rtx))
4179 /* Make sure it is the inc/dec pseudo, and not
4180 some other (e.g. output operand) pseudo. */
4181 && ((unsigned) reg_reloaded_contents[REGNO (rld[i].reg_rtx)]
4182 == REGNO (XEXP (in_reg, 0))))
4184 SET_HARD_REG_BIT (reg_is_output_reload,
4185 REGNO (rld[i].reg_rtx));
4186 SET_REGNO_REG_SET (®_has_output_reload,
4187 REGNO (XEXP (in_reg, 0)));
4191 /* If a pseudo that got a hard register is auto-incremented,
4192 we must purge records of copying it into pseudos without
4194 for (x = REG_NOTES (insn); x; x = XEXP (x, 1))
4195 if (REG_NOTE_KIND (x) == REG_INC)
4197 /* See if this pseudo reg was reloaded in this insn.
4198 If so, its last-reload info is still valid
4199 because it is based on this insn's reload. */
4200 for (i = 0; i < n_reloads; i++)
4201 if (rld[i].out == XEXP (x, 0))
4205 forget_old_reloads_1 (XEXP (x, 0), NULL_RTX, NULL);
4209 /* A reload reg's contents are unknown after a label. */
4211 CLEAR_HARD_REG_SET (reg_reloaded_valid);
4213 /* Don't assume a reload reg is still good after a call insn
4214 if it is a call-used reg, or if it contains a value that will
4215 be partially clobbered by the call. */
4216 else if (CALL_P (insn))
4218 AND_COMPL_HARD_REG_SET (reg_reloaded_valid, call_used_reg_set);
4219 AND_COMPL_HARD_REG_SET (reg_reloaded_valid, reg_reloaded_call_part_clobbered);
4224 free (reg_last_reload_reg);
4225 CLEAR_REG_SET (®_has_output_reload);
4228 /* Discard all record of any value reloaded from X,
4229 or reloaded in X from someplace else;
4230 unless X is an output reload reg of the current insn.
4232 X may be a hard reg (the reload reg)
4233 or it may be a pseudo reg that was reloaded from.
4235 When DATA is non-NULL just mark the registers in regset
4236 to be forgotten later. */
4239 forget_old_reloads_1 (rtx x, rtx ignored ATTRIBUTE_UNUSED,
4244 regset regs = (regset) data;
4246 /* note_stores does give us subregs of hard regs,
4247 subreg_regno_offset requires a hard reg. */
4248 while (GET_CODE (x) == SUBREG)
4250 /* We ignore the subreg offset when calculating the regno,
4251 because we are using the entire underlying hard register
4261 if (regno >= FIRST_PSEUDO_REGISTER)
4267 nr = hard_regno_nregs[regno][GET_MODE (x)];
4268 /* Storing into a spilled-reg invalidates its contents.
4269 This can happen if a block-local pseudo is allocated to that reg
4270 and it wasn't spilled because this block's total need is 0.
4271 Then some insn might have an optional reload and use this reg. */
4273 for (i = 0; i < nr; i++)
4274 /* But don't do this if the reg actually serves as an output
4275 reload reg in the current instruction. */
4277 || ! TEST_HARD_REG_BIT (reg_is_output_reload, regno + i))
4279 CLEAR_HARD_REG_BIT (reg_reloaded_valid, regno + i);
4280 CLEAR_HARD_REG_BIT (reg_reloaded_call_part_clobbered, regno + i);
4281 spill_reg_store[regno + i] = 0;
4287 SET_REGNO_REG_SET (regs, regno + nr);
4290 /* Since value of X has changed,
4291 forget any value previously copied from it. */
4294 /* But don't forget a copy if this is the output reload
4295 that establishes the copy's validity. */
4297 || !REGNO_REG_SET_P (®_has_output_reload, regno + nr))
4298 reg_last_reload_reg[regno + nr] = 0;
4302 /* Forget the reloads marked in regset by previous function. */
4304 forget_marked_reloads (regset regs)
4307 reg_set_iterator rsi;
4308 EXECUTE_IF_SET_IN_REG_SET (regs, 0, reg, rsi)
4310 if (reg < FIRST_PSEUDO_REGISTER
4311 /* But don't do this if the reg actually serves as an output
4312 reload reg in the current instruction. */
4314 || ! TEST_HARD_REG_BIT (reg_is_output_reload, reg)))
4316 CLEAR_HARD_REG_BIT (reg_reloaded_valid, reg);
4317 CLEAR_HARD_REG_BIT (reg_reloaded_call_part_clobbered, reg);
4318 spill_reg_store[reg] = 0;
4321 || !REGNO_REG_SET_P (®_has_output_reload, reg))
4322 reg_last_reload_reg[reg] = 0;
4326 /* The following HARD_REG_SETs indicate when each hard register is
4327 used for a reload of various parts of the current insn. */
4329 /* If reg is unavailable for all reloads. */
4330 static HARD_REG_SET reload_reg_unavailable;
4331 /* If reg is in use as a reload reg for a RELOAD_OTHER reload. */
4332 static HARD_REG_SET reload_reg_used;
4333 /* If reg is in use for a RELOAD_FOR_INPUT_ADDRESS reload for operand I. */
4334 static HARD_REG_SET reload_reg_used_in_input_addr[MAX_RECOG_OPERANDS];
4335 /* If reg is in use for a RELOAD_FOR_INPADDR_ADDRESS reload for operand I. */
4336 static HARD_REG_SET reload_reg_used_in_inpaddr_addr[MAX_RECOG_OPERANDS];
4337 /* If reg is in use for a RELOAD_FOR_OUTPUT_ADDRESS reload for operand I. */
4338 static HARD_REG_SET reload_reg_used_in_output_addr[MAX_RECOG_OPERANDS];
4339 /* If reg is in use for a RELOAD_FOR_OUTADDR_ADDRESS reload for operand I. */
4340 static HARD_REG_SET reload_reg_used_in_outaddr_addr[MAX_RECOG_OPERANDS];
4341 /* If reg is in use for a RELOAD_FOR_INPUT reload for operand I. */
4342 static HARD_REG_SET reload_reg_used_in_input[MAX_RECOG_OPERANDS];
4343 /* If reg is in use for a RELOAD_FOR_OUTPUT reload for operand I. */
4344 static HARD_REG_SET reload_reg_used_in_output[MAX_RECOG_OPERANDS];
4345 /* If reg is in use for a RELOAD_FOR_OPERAND_ADDRESS reload. */
4346 static HARD_REG_SET reload_reg_used_in_op_addr;
4347 /* If reg is in use for a RELOAD_FOR_OPADDR_ADDR reload. */
4348 static HARD_REG_SET reload_reg_used_in_op_addr_reload;
4349 /* If reg is in use for a RELOAD_FOR_INSN reload. */
4350 static HARD_REG_SET reload_reg_used_in_insn;
4351 /* If reg is in use for a RELOAD_FOR_OTHER_ADDRESS reload. */
4352 static HARD_REG_SET reload_reg_used_in_other_addr;
4354 /* If reg is in use as a reload reg for any sort of reload. */
4355 static HARD_REG_SET reload_reg_used_at_all;
4357 /* If reg is use as an inherited reload. We just mark the first register
4359 static HARD_REG_SET reload_reg_used_for_inherit;
4361 /* Records which hard regs are used in any way, either as explicit use or
4362 by being allocated to a pseudo during any point of the current insn. */
4363 static HARD_REG_SET reg_used_in_insn;
4365 /* Mark reg REGNO as in use for a reload of the sort spec'd by OPNUM and
4366 TYPE. MODE is used to indicate how many consecutive regs are
4370 mark_reload_reg_in_use (unsigned int regno, int opnum, enum reload_type type,
4371 enum machine_mode mode)
4373 unsigned int nregs = hard_regno_nregs[regno][mode];
4376 for (i = regno; i < nregs + regno; i++)
4381 SET_HARD_REG_BIT (reload_reg_used, i);
4384 case RELOAD_FOR_INPUT_ADDRESS:
4385 SET_HARD_REG_BIT (reload_reg_used_in_input_addr[opnum], i);
4388 case RELOAD_FOR_INPADDR_ADDRESS:
4389 SET_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[opnum], i);
4392 case RELOAD_FOR_OUTPUT_ADDRESS:
4393 SET_HARD_REG_BIT (reload_reg_used_in_output_addr[opnum], i);
4396 case RELOAD_FOR_OUTADDR_ADDRESS:
4397 SET_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[opnum], i);
4400 case RELOAD_FOR_OPERAND_ADDRESS:
4401 SET_HARD_REG_BIT (reload_reg_used_in_op_addr, i);
4404 case RELOAD_FOR_OPADDR_ADDR:
4405 SET_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, i);
4408 case RELOAD_FOR_OTHER_ADDRESS:
4409 SET_HARD_REG_BIT (reload_reg_used_in_other_addr, i);
4412 case RELOAD_FOR_INPUT:
4413 SET_HARD_REG_BIT (reload_reg_used_in_input[opnum], i);
4416 case RELOAD_FOR_OUTPUT:
4417 SET_HARD_REG_BIT (reload_reg_used_in_output[opnum], i);
4420 case RELOAD_FOR_INSN:
4421 SET_HARD_REG_BIT (reload_reg_used_in_insn, i);
4425 SET_HARD_REG_BIT (reload_reg_used_at_all, i);
4429 /* Similarly, but show REGNO is no longer in use for a reload. */
4432 clear_reload_reg_in_use (unsigned int regno, int opnum,
4433 enum reload_type type, enum machine_mode mode)
4435 unsigned int nregs = hard_regno_nregs[regno][mode];
4436 unsigned int start_regno, end_regno, r;
4438 /* A complication is that for some reload types, inheritance might
4439 allow multiple reloads of the same types to share a reload register.
4440 We set check_opnum if we have to check only reloads with the same
4441 operand number, and check_any if we have to check all reloads. */
4442 int check_opnum = 0;
4444 HARD_REG_SET *used_in_set;
4449 used_in_set = &reload_reg_used;
4452 case RELOAD_FOR_INPUT_ADDRESS:
4453 used_in_set = &reload_reg_used_in_input_addr[opnum];
4456 case RELOAD_FOR_INPADDR_ADDRESS:
4458 used_in_set = &reload_reg_used_in_inpaddr_addr[opnum];
4461 case RELOAD_FOR_OUTPUT_ADDRESS:
4462 used_in_set = &reload_reg_used_in_output_addr[opnum];
4465 case RELOAD_FOR_OUTADDR_ADDRESS:
4467 used_in_set = &reload_reg_used_in_outaddr_addr[opnum];
4470 case RELOAD_FOR_OPERAND_ADDRESS:
4471 used_in_set = &reload_reg_used_in_op_addr;
4474 case RELOAD_FOR_OPADDR_ADDR:
4476 used_in_set = &reload_reg_used_in_op_addr_reload;
4479 case RELOAD_FOR_OTHER_ADDRESS:
4480 used_in_set = &reload_reg_used_in_other_addr;
4484 case RELOAD_FOR_INPUT:
4485 used_in_set = &reload_reg_used_in_input[opnum];
4488 case RELOAD_FOR_OUTPUT:
4489 used_in_set = &reload_reg_used_in_output[opnum];
4492 case RELOAD_FOR_INSN:
4493 used_in_set = &reload_reg_used_in_insn;
4498 /* We resolve conflicts with remaining reloads of the same type by
4499 excluding the intervals of reload registers by them from the
4500 interval of freed reload registers. Since we only keep track of
4501 one set of interval bounds, we might have to exclude somewhat
4502 more than what would be necessary if we used a HARD_REG_SET here.
4503 But this should only happen very infrequently, so there should
4504 be no reason to worry about it. */
4506 start_regno = regno;
4507 end_regno = regno + nregs;
4508 if (check_opnum || check_any)
4510 for (i = n_reloads - 1; i >= 0; i--)
4512 if (rld[i].when_needed == type
4513 && (check_any || rld[i].opnum == opnum)
4516 unsigned int conflict_start = true_regnum (rld[i].reg_rtx);
4517 unsigned int conflict_end
4519 + hard_regno_nregs[conflict_start][rld[i].mode]);
4521 /* If there is an overlap with the first to-be-freed register,
4522 adjust the interval start. */
4523 if (conflict_start <= start_regno && conflict_end > start_regno)
4524 start_regno = conflict_end;
4525 /* Otherwise, if there is a conflict with one of the other
4526 to-be-freed registers, adjust the interval end. */
4527 if (conflict_start > start_regno && conflict_start < end_regno)
4528 end_regno = conflict_start;
4533 for (r = start_regno; r < end_regno; r++)
4534 CLEAR_HARD_REG_BIT (*used_in_set, r);
4537 /* 1 if reg REGNO is free as a reload reg for a reload of the sort
4538 specified by OPNUM and TYPE. */
4541 reload_reg_free_p (unsigned int regno, int opnum, enum reload_type type)
4545 /* In use for a RELOAD_OTHER means it's not available for anything. */
4546 if (TEST_HARD_REG_BIT (reload_reg_used, regno)
4547 || TEST_HARD_REG_BIT (reload_reg_unavailable, regno))
4553 /* In use for anything means we can't use it for RELOAD_OTHER. */
4554 if (TEST_HARD_REG_BIT (reload_reg_used_in_other_addr, regno)
4555 || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)
4556 || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno)
4557 || TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno))
4560 for (i = 0; i < reload_n_operands; i++)
4561 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4562 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno)
4563 || TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4564 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
4565 || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)
4566 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4571 case RELOAD_FOR_INPUT:
4572 if (TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4573 || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno))
4576 if (TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno))
4579 /* If it is used for some other input, can't use it. */
4580 for (i = 0; i < reload_n_operands; i++)
4581 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4584 /* If it is used in a later operand's address, can't use it. */
4585 for (i = opnum + 1; i < reload_n_operands; i++)
4586 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4587 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno))
4592 case RELOAD_FOR_INPUT_ADDRESS:
4593 /* Can't use a register if it is used for an input address for this
4594 operand or used as an input in an earlier one. */
4595 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[opnum], regno)
4596 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[opnum], regno))
4599 for (i = 0; i < opnum; i++)
4600 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4605 case RELOAD_FOR_INPADDR_ADDRESS:
4606 /* Can't use a register if it is used for an input address
4607 for this operand or used as an input in an earlier
4609 if (TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[opnum], regno))
4612 for (i = 0; i < opnum; i++)
4613 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4618 case RELOAD_FOR_OUTPUT_ADDRESS:
4619 /* Can't use a register if it is used for an output address for this
4620 operand or used as an output in this or a later operand. Note
4621 that multiple output operands are emitted in reverse order, so
4622 the conflicting ones are those with lower indices. */
4623 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[opnum], regno))
4626 for (i = 0; i <= opnum; i++)
4627 if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4632 case RELOAD_FOR_OUTADDR_ADDRESS:
4633 /* Can't use a register if it is used for an output address
4634 for this operand or used as an output in this or a
4635 later operand. Note that multiple output operands are
4636 emitted in reverse order, so the conflicting ones are
4637 those with lower indices. */
4638 if (TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[opnum], regno))
4641 for (i = 0; i <= opnum; i++)
4642 if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4647 case RELOAD_FOR_OPERAND_ADDRESS:
4648 for (i = 0; i < reload_n_operands; i++)
4649 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4652 return (! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4653 && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno));
4655 case RELOAD_FOR_OPADDR_ADDR:
4656 for (i = 0; i < reload_n_operands; i++)
4657 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4660 return (!TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno));
4662 case RELOAD_FOR_OUTPUT:
4663 /* This cannot share a register with RELOAD_FOR_INSN reloads, other
4664 outputs, or an operand address for this or an earlier output.
4665 Note that multiple output operands are emitted in reverse order,
4666 so the conflicting ones are those with higher indices. */
4667 if (TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno))
4670 for (i = 0; i < reload_n_operands; i++)
4671 if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4674 for (i = opnum; i < reload_n_operands; i++)
4675 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4676 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno))
4681 case RELOAD_FOR_INSN:
4682 for (i = 0; i < reload_n_operands; i++)
4683 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)
4684 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4687 return (! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4688 && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno));
4690 case RELOAD_FOR_OTHER_ADDRESS:
4691 return ! TEST_HARD_REG_BIT (reload_reg_used_in_other_addr, regno);
4698 /* Return 1 if the value in reload reg REGNO, as used by a reload
4699 needed for the part of the insn specified by OPNUM and TYPE,
4700 is still available in REGNO at the end of the insn.
4702 We can assume that the reload reg was already tested for availability
4703 at the time it is needed, and we should not check this again,
4704 in case the reg has already been marked in use. */
4707 reload_reg_reaches_end_p (unsigned int regno, int opnum, enum reload_type type)
4714 /* Since a RELOAD_OTHER reload claims the reg for the entire insn,
4715 its value must reach the end. */
4718 /* If this use is for part of the insn,
4719 its value reaches if no subsequent part uses the same register.
4720 Just like the above function, don't try to do this with lots
4723 case RELOAD_FOR_OTHER_ADDRESS:
4724 /* Here we check for everything else, since these don't conflict
4725 with anything else and everything comes later. */
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)
4731 || TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4732 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno)
4733 || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4736 return (! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)
4737 && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno)
4738 && ! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4739 && ! TEST_HARD_REG_BIT (reload_reg_used, regno));
4741 case RELOAD_FOR_INPUT_ADDRESS:
4742 case RELOAD_FOR_INPADDR_ADDRESS:
4743 /* Similar, except that we check only for this and subsequent inputs
4744 and the address of only subsequent inputs and we do not need
4745 to check for RELOAD_OTHER objects since they are known not to
4748 for (i = opnum; i < reload_n_operands; i++)
4749 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4752 for (i = opnum + 1; i < reload_n_operands; i++)
4753 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4754 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno))
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 if (TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno))
4766 return (!TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)
4767 && !TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4768 && !TEST_HARD_REG_BIT (reload_reg_used, regno));
4770 case RELOAD_FOR_INPUT:
4771 /* Similar to input address, except we start at the next operand for
4772 both input and input address and we do not check for
4773 RELOAD_FOR_OPERAND_ADDRESS and RELOAD_FOR_INSN since these
4776 for (i = opnum + 1; i < reload_n_operands; i++)
4777 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4778 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno)
4779 || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4782 /* ... fall through ... */
4784 case RELOAD_FOR_OPERAND_ADDRESS:
4785 /* Check outputs and their addresses. */
4787 for (i = 0; i < reload_n_operands; i++)
4788 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4789 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
4790 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4793 return (!TEST_HARD_REG_BIT (reload_reg_used, regno));
4795 case RELOAD_FOR_OPADDR_ADDR:
4796 for (i = 0; i < reload_n_operands; i++)
4797 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4798 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
4799 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4802 return (!TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)
4803 && !TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4804 && !TEST_HARD_REG_BIT (reload_reg_used, regno));
4806 case RELOAD_FOR_INSN:
4807 /* These conflict with other outputs with RELOAD_OTHER. So
4808 we need only check for output addresses. */
4810 opnum = reload_n_operands;
4812 /* ... fall through ... */
4814 case RELOAD_FOR_OUTPUT:
4815 case RELOAD_FOR_OUTPUT_ADDRESS:
4816 case RELOAD_FOR_OUTADDR_ADDRESS:
4817 /* We already know these can't conflict with a later output. So the
4818 only thing to check are later output addresses.
4819 Note that multiple output operands are emitted in reverse order,
4820 so the conflicting ones are those with lower indices. */
4821 for (i = 0; i < opnum; i++)
4822 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4823 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno))
4834 /* Returns whether R1 and R2 are uniquely chained: the value of one
4835 is used by the other, and that value is not used by any other
4836 reload for this insn. This is used to partially undo the decision
4837 made in find_reloads when in the case of multiple
4838 RELOAD_FOR_OPERAND_ADDRESS reloads it converts all
4839 RELOAD_FOR_OPADDR_ADDR reloads into RELOAD_FOR_OPERAND_ADDRESS
4840 reloads. This code tries to avoid the conflict created by that
4841 change. It might be cleaner to explicitly keep track of which
4842 RELOAD_FOR_OPADDR_ADDR reload is associated with which
4843 RELOAD_FOR_OPERAND_ADDRESS reload, rather than to try to detect
4844 this after the fact. */
4846 reloads_unique_chain_p (int r1, int r2)
4850 /* We only check input reloads. */
4851 if (! rld[r1].in || ! rld[r2].in)
4854 /* Avoid anything with output reloads. */
4855 if (rld[r1].out || rld[r2].out)
4858 /* "chained" means one reload is a component of the other reload,
4859 not the same as the other reload. */
4860 if (rld[r1].opnum != rld[r2].opnum
4861 || rtx_equal_p (rld[r1].in, rld[r2].in)
4862 || rld[r1].optional || rld[r2].optional
4863 || ! (reg_mentioned_p (rld[r1].in, rld[r2].in)
4864 || reg_mentioned_p (rld[r2].in, rld[r1].in)))
4867 for (i = 0; i < n_reloads; i ++)
4868 /* Look for input reloads that aren't our two */
4869 if (i != r1 && i != r2 && rld[i].in)
4871 /* If our reload is mentioned at all, it isn't a simple chain. */
4872 if (reg_mentioned_p (rld[r1].in, rld[i].in))
4878 /* Return 1 if the reloads denoted by R1 and R2 cannot share a register.
4881 This function uses the same algorithm as reload_reg_free_p above. */
4884 reloads_conflict (int r1, int r2)
4886 enum reload_type r1_type = rld[r1].when_needed;
4887 enum reload_type r2_type = rld[r2].when_needed;
4888 int r1_opnum = rld[r1].opnum;
4889 int r2_opnum = rld[r2].opnum;
4891 /* RELOAD_OTHER conflicts with everything. */
4892 if (r2_type == RELOAD_OTHER)
4895 /* Otherwise, check conflicts differently for each type. */
4899 case RELOAD_FOR_INPUT:
4900 return (r2_type == RELOAD_FOR_INSN
4901 || r2_type == RELOAD_FOR_OPERAND_ADDRESS
4902 || r2_type == RELOAD_FOR_OPADDR_ADDR
4903 || r2_type == RELOAD_FOR_INPUT
4904 || ((r2_type == RELOAD_FOR_INPUT_ADDRESS
4905 || r2_type == RELOAD_FOR_INPADDR_ADDRESS)
4906 && r2_opnum > r1_opnum));
4908 case RELOAD_FOR_INPUT_ADDRESS:
4909 return ((r2_type == RELOAD_FOR_INPUT_ADDRESS && r1_opnum == r2_opnum)
4910 || (r2_type == RELOAD_FOR_INPUT && r2_opnum < r1_opnum));
4912 case RELOAD_FOR_INPADDR_ADDRESS:
4913 return ((r2_type == RELOAD_FOR_INPADDR_ADDRESS && r1_opnum == r2_opnum)
4914 || (r2_type == RELOAD_FOR_INPUT && r2_opnum < r1_opnum));
4916 case RELOAD_FOR_OUTPUT_ADDRESS:
4917 return ((r2_type == RELOAD_FOR_OUTPUT_ADDRESS && r2_opnum == r1_opnum)
4918 || (r2_type == RELOAD_FOR_OUTPUT && r2_opnum <= r1_opnum));
4920 case RELOAD_FOR_OUTADDR_ADDRESS:
4921 return ((r2_type == RELOAD_FOR_OUTADDR_ADDRESS && r2_opnum == r1_opnum)
4922 || (r2_type == RELOAD_FOR_OUTPUT && r2_opnum <= r1_opnum));
4924 case RELOAD_FOR_OPERAND_ADDRESS:
4925 return (r2_type == RELOAD_FOR_INPUT || r2_type == RELOAD_FOR_INSN
4926 || (r2_type == RELOAD_FOR_OPERAND_ADDRESS
4927 && !reloads_unique_chain_p (r1, r2)));
4929 case RELOAD_FOR_OPADDR_ADDR:
4930 return (r2_type == RELOAD_FOR_INPUT
4931 || r2_type == RELOAD_FOR_OPADDR_ADDR);
4933 case RELOAD_FOR_OUTPUT:
4934 return (r2_type == RELOAD_FOR_INSN || r2_type == RELOAD_FOR_OUTPUT
4935 || ((r2_type == RELOAD_FOR_OUTPUT_ADDRESS
4936 || r2_type == RELOAD_FOR_OUTADDR_ADDRESS)
4937 && r2_opnum >= r1_opnum));
4939 case RELOAD_FOR_INSN:
4940 return (r2_type == RELOAD_FOR_INPUT || r2_type == RELOAD_FOR_OUTPUT
4941 || r2_type == RELOAD_FOR_INSN
4942 || r2_type == RELOAD_FOR_OPERAND_ADDRESS);
4944 case RELOAD_FOR_OTHER_ADDRESS:
4945 return r2_type == RELOAD_FOR_OTHER_ADDRESS;
4955 /* Indexed by reload number, 1 if incoming value
4956 inherited from previous insns. */
4957 static char reload_inherited[MAX_RELOADS];
4959 /* For an inherited reload, this is the insn the reload was inherited from,
4960 if we know it. Otherwise, this is 0. */
4961 static rtx reload_inheritance_insn[MAX_RELOADS];
4963 /* If nonzero, this is a place to get the value of the reload,
4964 rather than using reload_in. */
4965 static rtx reload_override_in[MAX_RELOADS];
4967 /* For each reload, the hard register number of the register used,
4968 or -1 if we did not need a register for this reload. */
4969 static int reload_spill_index[MAX_RELOADS];
4971 /* Subroutine of free_for_value_p, used to check a single register.
4972 START_REGNO is the starting regno of the full reload register
4973 (possibly comprising multiple hard registers) that we are considering. */
4976 reload_reg_free_for_value_p (int start_regno, int regno, int opnum,
4977 enum reload_type type, rtx value, rtx out,
4978 int reloadnum, int ignore_address_reloads)
4981 /* Set if we see an input reload that must not share its reload register
4982 with any new earlyclobber, but might otherwise share the reload
4983 register with an output or input-output reload. */
4984 int check_earlyclobber = 0;
4988 if (TEST_HARD_REG_BIT (reload_reg_unavailable, regno))
4991 if (out == const0_rtx)
4997 /* We use some pseudo 'time' value to check if the lifetimes of the
4998 new register use would overlap with the one of a previous reload
4999 that is not read-only or uses a different value.
5000 The 'time' used doesn't have to be linear in any shape or form, just
5002 Some reload types use different 'buckets' for each operand.
5003 So there are MAX_RECOG_OPERANDS different time values for each
5005 We compute TIME1 as the time when the register for the prospective
5006 new reload ceases to be live, and TIME2 for each existing
5007 reload as the time when that the reload register of that reload
5009 Where there is little to be gained by exact lifetime calculations,
5010 we just make conservative assumptions, i.e. a longer lifetime;
5011 this is done in the 'default:' cases. */
5014 case RELOAD_FOR_OTHER_ADDRESS:
5015 /* RELOAD_FOR_OTHER_ADDRESS conflicts with RELOAD_OTHER reloads. */
5016 time1 = copy ? 0 : 1;
5019 time1 = copy ? 1 : MAX_RECOG_OPERANDS * 5 + 5;
5021 /* For each input, we may have a sequence of RELOAD_FOR_INPADDR_ADDRESS,
5022 RELOAD_FOR_INPUT_ADDRESS and RELOAD_FOR_INPUT. By adding 0 / 1 / 2 ,
5023 respectively, to the time values for these, we get distinct time
5024 values. To get distinct time values for each operand, we have to
5025 multiply opnum by at least three. We round that up to four because
5026 multiply by four is often cheaper. */
5027 case RELOAD_FOR_INPADDR_ADDRESS:
5028 time1 = opnum * 4 + 2;
5030 case RELOAD_FOR_INPUT_ADDRESS:
5031 time1 = opnum * 4 + 3;
5033 case RELOAD_FOR_INPUT:
5034 /* All RELOAD_FOR_INPUT reloads remain live till the instruction
5035 executes (inclusive). */
5036 time1 = copy ? opnum * 4 + 4 : MAX_RECOG_OPERANDS * 4 + 3;
5038 case RELOAD_FOR_OPADDR_ADDR:
5040 <= (MAX_RECOG_OPERANDS - 1) * 4 + 4 == MAX_RECOG_OPERANDS * 4 */
5041 time1 = MAX_RECOG_OPERANDS * 4 + 1;
5043 case RELOAD_FOR_OPERAND_ADDRESS:
5044 /* RELOAD_FOR_OPERAND_ADDRESS reloads are live even while the insn
5046 time1 = copy ? MAX_RECOG_OPERANDS * 4 + 2 : MAX_RECOG_OPERANDS * 4 + 3;
5048 case RELOAD_FOR_OUTADDR_ADDRESS:
5049 time1 = MAX_RECOG_OPERANDS * 4 + 4 + opnum;
5051 case RELOAD_FOR_OUTPUT_ADDRESS:
5052 time1 = MAX_RECOG_OPERANDS * 4 + 5 + opnum;
5055 time1 = MAX_RECOG_OPERANDS * 5 + 5;
5058 for (i = 0; i < n_reloads; i++)
5060 rtx reg = rld[i].reg_rtx;
5061 if (reg && REG_P (reg)
5062 && ((unsigned) regno - true_regnum (reg)
5063 <= hard_regno_nregs[REGNO (reg)][GET_MODE (reg)] - (unsigned) 1)
5066 rtx other_input = rld[i].in;
5068 /* If the other reload loads the same input value, that
5069 will not cause a conflict only if it's loading it into
5070 the same register. */
5071 if (true_regnum (reg) != start_regno)
5072 other_input = NULL_RTX;
5073 if (! other_input || ! rtx_equal_p (other_input, value)
5074 || rld[i].out || out)
5077 switch (rld[i].when_needed)
5079 case RELOAD_FOR_OTHER_ADDRESS:
5082 case RELOAD_FOR_INPADDR_ADDRESS:
5083 /* find_reloads makes sure that a
5084 RELOAD_FOR_{INP,OP,OUT}ADDR_ADDRESS reload is only used
5085 by at most one - the first -
5086 RELOAD_FOR_{INPUT,OPERAND,OUTPUT}_ADDRESS . If the
5087 address reload is inherited, the address address reload
5088 goes away, so we can ignore this conflict. */
5089 if (type == RELOAD_FOR_INPUT_ADDRESS && reloadnum == i + 1
5090 && ignore_address_reloads
5091 /* Unless the RELOAD_FOR_INPUT is an auto_inc expression.
5092 Then the address address is still needed to store
5093 back the new address. */
5094 && ! rld[reloadnum].out)
5096 /* Likewise, if a RELOAD_FOR_INPUT can inherit a value, its
5097 RELOAD_FOR_INPUT_ADDRESS / RELOAD_FOR_INPADDR_ADDRESS
5099 if (type == RELOAD_FOR_INPUT && opnum == rld[i].opnum
5100 && ignore_address_reloads
5101 /* Unless we are reloading an auto_inc expression. */
5102 && ! rld[reloadnum].out)
5104 time2 = rld[i].opnum * 4 + 2;
5106 case RELOAD_FOR_INPUT_ADDRESS:
5107 if (type == RELOAD_FOR_INPUT && opnum == rld[i].opnum
5108 && ignore_address_reloads
5109 && ! rld[reloadnum].out)
5111 time2 = rld[i].opnum * 4 + 3;
5113 case RELOAD_FOR_INPUT:
5114 time2 = rld[i].opnum * 4 + 4;
5115 check_earlyclobber = 1;
5117 /* rld[i].opnum * 4 + 4 <= (MAX_RECOG_OPERAND - 1) * 4 + 4
5118 == MAX_RECOG_OPERAND * 4 */
5119 case RELOAD_FOR_OPADDR_ADDR:
5120 if (type == RELOAD_FOR_OPERAND_ADDRESS && reloadnum == i + 1
5121 && ignore_address_reloads
5122 && ! rld[reloadnum].out)
5124 time2 = MAX_RECOG_OPERANDS * 4 + 1;
5126 case RELOAD_FOR_OPERAND_ADDRESS:
5127 time2 = MAX_RECOG_OPERANDS * 4 + 2;
5128 check_earlyclobber = 1;
5130 case RELOAD_FOR_INSN:
5131 time2 = MAX_RECOG_OPERANDS * 4 + 3;
5133 case RELOAD_FOR_OUTPUT:
5134 /* All RELOAD_FOR_OUTPUT reloads become live just after the
5135 instruction is executed. */
5136 time2 = MAX_RECOG_OPERANDS * 4 + 4;
5138 /* The first RELOAD_FOR_OUTADDR_ADDRESS reload conflicts with
5139 the RELOAD_FOR_OUTPUT reloads, so assign it the same time
5141 case RELOAD_FOR_OUTADDR_ADDRESS:
5142 if (type == RELOAD_FOR_OUTPUT_ADDRESS && reloadnum == i + 1
5143 && ignore_address_reloads
5144 && ! rld[reloadnum].out)
5146 time2 = MAX_RECOG_OPERANDS * 4 + 4 + rld[i].opnum;
5148 case RELOAD_FOR_OUTPUT_ADDRESS:
5149 time2 = MAX_RECOG_OPERANDS * 4 + 5 + rld[i].opnum;
5152 /* If there is no conflict in the input part, handle this
5153 like an output reload. */
5154 if (! rld[i].in || rtx_equal_p (other_input, value))
5156 time2 = MAX_RECOG_OPERANDS * 4 + 4;
5157 /* Earlyclobbered outputs must conflict with inputs. */
5158 if (earlyclobber_operand_p (rld[i].out))
5159 time2 = MAX_RECOG_OPERANDS * 4 + 3;
5164 /* RELOAD_OTHER might be live beyond instruction execution,
5165 but this is not obvious when we set time2 = 1. So check
5166 here if there might be a problem with the new reload
5167 clobbering the register used by the RELOAD_OTHER. */
5175 && (! rld[i].in || rld[i].out
5176 || ! rtx_equal_p (other_input, value)))
5177 || (out && rld[reloadnum].out_reg
5178 && time2 >= MAX_RECOG_OPERANDS * 4 + 3))
5184 /* Earlyclobbered outputs must conflict with inputs. */
5185 if (check_earlyclobber && out && earlyclobber_operand_p (out))
5191 /* Return 1 if the value in reload reg REGNO, as used by a reload
5192 needed for the part of the insn specified by OPNUM and TYPE,
5193 may be used to load VALUE into it.
5195 MODE is the mode in which the register is used, this is needed to
5196 determine how many hard regs to test.
5198 Other read-only reloads with the same value do not conflict
5199 unless OUT is nonzero and these other reloads have to live while
5200 output reloads live.
5201 If OUT is CONST0_RTX, this is a special case: it means that the
5202 test should not be for using register REGNO as reload register, but
5203 for copying from register REGNO into the reload register.
5205 RELOADNUM is the number of the reload we want to load this value for;
5206 a reload does not conflict with itself.
5208 When IGNORE_ADDRESS_RELOADS is set, we can not have conflicts with
5209 reloads that load an address for the very reload we are considering.
5211 The caller has to make sure that there is no conflict with the return
5215 free_for_value_p (int regno, enum machine_mode mode, int opnum,
5216 enum reload_type type, rtx value, rtx out, int reloadnum,
5217 int ignore_address_reloads)
5219 int nregs = hard_regno_nregs[regno][mode];
5221 if (! reload_reg_free_for_value_p (regno, regno + nregs, opnum, type,
5222 value, out, reloadnum,
5223 ignore_address_reloads))
5228 /* Return nonzero if the rtx X is invariant over the current function. */
5229 /* ??? Actually, the places where we use this expect exactly what is
5230 tested here, and not everything that is function invariant. In
5231 particular, the frame pointer and arg pointer are special cased;
5232 pic_offset_table_rtx is not, and we must not spill these things to
5236 function_invariant_p (rtx x)
5240 if (x == frame_pointer_rtx || x == arg_pointer_rtx)
5242 if (GET_CODE (x) == PLUS
5243 && (XEXP (x, 0) == frame_pointer_rtx || XEXP (x, 0) == arg_pointer_rtx)
5244 && CONSTANT_P (XEXP (x, 1)))
5249 /* Determine whether the reload reg X overlaps any rtx'es used for
5250 overriding inheritance. Return nonzero if so. */
5253 conflicts_with_override (rtx x)
5256 for (i = 0; i < n_reloads; i++)
5257 if (reload_override_in[i]
5258 && reg_overlap_mentioned_p (x, reload_override_in[i]))
5263 /* Give an error message saying we failed to find a reload for INSN,
5264 and clear out reload R. */
5266 failed_reload (rtx insn, int r)
5268 if (asm_noperands (PATTERN (insn)) < 0)
5269 /* It's the compiler's fault. */
5270 fatal_insn ("could not find a spill register", insn);
5272 /* It's the user's fault; the operand's mode and constraint
5273 don't match. Disable this reload so we don't crash in final. */
5274 error_for_asm (insn,
5275 "%<asm%> operand constraint incompatible with operand size");
5279 rld[r].optional = 1;
5280 rld[r].secondary_p = 1;
5283 /* I is the index in SPILL_REG_RTX of the reload register we are to allocate
5284 for reload R. If it's valid, get an rtx for it. Return nonzero if
5287 set_reload_reg (int i, int r)
5290 rtx reg = spill_reg_rtx[i];
5292 if (reg == 0 || GET_MODE (reg) != rld[r].mode)
5293 spill_reg_rtx[i] = reg
5294 = gen_rtx_REG (rld[r].mode, spill_regs[i]);
5296 regno = true_regnum (reg);
5298 /* Detect when the reload reg can't hold the reload mode.
5299 This used to be one `if', but Sequent compiler can't handle that. */
5300 if (HARD_REGNO_MODE_OK (regno, rld[r].mode))
5302 enum machine_mode test_mode = VOIDmode;
5304 test_mode = GET_MODE (rld[r].in);
5305 /* If rld[r].in has VOIDmode, it means we will load it
5306 in whatever mode the reload reg has: to wit, rld[r].mode.
5307 We have already tested that for validity. */
5308 /* Aside from that, we need to test that the expressions
5309 to reload from or into have modes which are valid for this
5310 reload register. Otherwise the reload insns would be invalid. */
5311 if (! (rld[r].in != 0 && test_mode != VOIDmode
5312 && ! HARD_REGNO_MODE_OK (regno, test_mode)))
5313 if (! (rld[r].out != 0
5314 && ! HARD_REGNO_MODE_OK (regno, GET_MODE (rld[r].out))))
5316 /* The reg is OK. */
5319 /* Mark as in use for this insn the reload regs we use
5321 mark_reload_reg_in_use (spill_regs[i], rld[r].opnum,
5322 rld[r].when_needed, rld[r].mode);
5324 rld[r].reg_rtx = reg;
5325 reload_spill_index[r] = spill_regs[i];
5332 /* Find a spill register to use as a reload register for reload R.
5333 LAST_RELOAD is nonzero if this is the last reload for the insn being
5336 Set rld[R].reg_rtx to the register allocated.
5338 We return 1 if successful, or 0 if we couldn't find a spill reg and
5339 we didn't change anything. */
5342 allocate_reload_reg (struct insn_chain *chain ATTRIBUTE_UNUSED, int r,
5347 /* If we put this reload ahead, thinking it is a group,
5348 then insist on finding a group. Otherwise we can grab a
5349 reg that some other reload needs.
5350 (That can happen when we have a 68000 DATA_OR_FP_REG
5351 which is a group of data regs or one fp reg.)
5352 We need not be so restrictive if there are no more reloads
5355 ??? Really it would be nicer to have smarter handling
5356 for that kind of reg class, where a problem like this is normal.
5357 Perhaps those classes should be avoided for reloading
5358 by use of more alternatives. */
5360 int force_group = rld[r].nregs > 1 && ! last_reload;
5362 /* If we want a single register and haven't yet found one,
5363 take any reg in the right class and not in use.
5364 If we want a consecutive group, here is where we look for it.
5366 We use two passes so we can first look for reload regs to
5367 reuse, which are already in use for other reloads in this insn,
5368 and only then use additional registers.
5369 I think that maximizing reuse is needed to make sure we don't
5370 run out of reload regs. Suppose we have three reloads, and
5371 reloads A and B can share regs. These need two regs.
5372 Suppose A and B are given different regs.
5373 That leaves none for C. */
5374 for (pass = 0; pass < 2; pass++)
5376 /* I is the index in spill_regs.
5377 We advance it round-robin between insns to use all spill regs
5378 equally, so that inherited reloads have a chance
5379 of leapfrogging each other. */
5383 for (count = 0; count < n_spills; count++)
5385 int class = (int) rld[r].class;
5391 regnum = spill_regs[i];
5393 if ((reload_reg_free_p (regnum, rld[r].opnum,
5396 /* We check reload_reg_used to make sure we
5397 don't clobber the return register. */
5398 && ! TEST_HARD_REG_BIT (reload_reg_used, regnum)
5399 && free_for_value_p (regnum, rld[r].mode, rld[r].opnum,
5400 rld[r].when_needed, rld[r].in,
5402 && TEST_HARD_REG_BIT (reg_class_contents[class], regnum)
5403 && HARD_REGNO_MODE_OK (regnum, rld[r].mode)
5404 /* Look first for regs to share, then for unshared. But
5405 don't share regs used for inherited reloads; they are
5406 the ones we want to preserve. */
5408 || (TEST_HARD_REG_BIT (reload_reg_used_at_all,
5410 && ! TEST_HARD_REG_BIT (reload_reg_used_for_inherit,
5413 int nr = hard_regno_nregs[regnum][rld[r].mode];
5414 /* Avoid the problem where spilling a GENERAL_OR_FP_REG
5415 (on 68000) got us two FP regs. If NR is 1,
5416 we would reject both of them. */
5419 /* If we need only one reg, we have already won. */
5422 /* But reject a single reg if we demand a group. */
5427 /* Otherwise check that as many consecutive regs as we need
5428 are available here. */
5431 int regno = regnum + nr - 1;
5432 if (!(TEST_HARD_REG_BIT (reg_class_contents[class], regno)
5433 && spill_reg_order[regno] >= 0
5434 && reload_reg_free_p (regno, rld[r].opnum,
5435 rld[r].when_needed)))
5444 /* If we found something on pass 1, omit pass 2. */
5445 if (count < n_spills)
5449 /* We should have found a spill register by now. */
5450 if (count >= n_spills)
5453 /* I is the index in SPILL_REG_RTX of the reload register we are to
5454 allocate. Get an rtx for it and find its register number. */
5456 return set_reload_reg (i, r);
5459 /* Initialize all the tables needed to allocate reload registers.
5460 CHAIN is the insn currently being processed; SAVE_RELOAD_REG_RTX
5461 is the array we use to restore the reg_rtx field for every reload. */
5464 choose_reload_regs_init (struct insn_chain *chain, rtx *save_reload_reg_rtx)
5468 for (i = 0; i < n_reloads; i++)
5469 rld[i].reg_rtx = save_reload_reg_rtx[i];
5471 memset (reload_inherited, 0, MAX_RELOADS);
5472 memset (reload_inheritance_insn, 0, MAX_RELOADS * sizeof (rtx));
5473 memset (reload_override_in, 0, MAX_RELOADS * sizeof (rtx));
5475 CLEAR_HARD_REG_SET (reload_reg_used);
5476 CLEAR_HARD_REG_SET (reload_reg_used_at_all);
5477 CLEAR_HARD_REG_SET (reload_reg_used_in_op_addr);
5478 CLEAR_HARD_REG_SET (reload_reg_used_in_op_addr_reload);
5479 CLEAR_HARD_REG_SET (reload_reg_used_in_insn);
5480 CLEAR_HARD_REG_SET (reload_reg_used_in_other_addr);
5482 CLEAR_HARD_REG_SET (reg_used_in_insn);
5485 REG_SET_TO_HARD_REG_SET (tmp, &chain->live_throughout);
5486 IOR_HARD_REG_SET (reg_used_in_insn, tmp);
5487 REG_SET_TO_HARD_REG_SET (tmp, &chain->dead_or_set);
5488 IOR_HARD_REG_SET (reg_used_in_insn, tmp);
5489 compute_use_by_pseudos (®_used_in_insn, &chain->live_throughout);
5490 compute_use_by_pseudos (®_used_in_insn, &chain->dead_or_set);
5493 for (i = 0; i < reload_n_operands; i++)
5495 CLEAR_HARD_REG_SET (reload_reg_used_in_output[i]);
5496 CLEAR_HARD_REG_SET (reload_reg_used_in_input[i]);
5497 CLEAR_HARD_REG_SET (reload_reg_used_in_input_addr[i]);
5498 CLEAR_HARD_REG_SET (reload_reg_used_in_inpaddr_addr[i]);
5499 CLEAR_HARD_REG_SET (reload_reg_used_in_output_addr[i]);
5500 CLEAR_HARD_REG_SET (reload_reg_used_in_outaddr_addr[i]);
5503 COMPL_HARD_REG_SET (reload_reg_unavailable, chain->used_spill_regs);
5505 CLEAR_HARD_REG_SET (reload_reg_used_for_inherit);
5507 for (i = 0; i < n_reloads; i++)
5508 /* If we have already decided to use a certain register,
5509 don't use it in another way. */
5511 mark_reload_reg_in_use (REGNO (rld[i].reg_rtx), rld[i].opnum,
5512 rld[i].when_needed, rld[i].mode);
5515 /* Assign hard reg targets for the pseudo-registers we must reload
5516 into hard regs for this insn.
5517 Also output the instructions to copy them in and out of the hard regs.
5519 For machines with register classes, we are responsible for
5520 finding a reload reg in the proper class. */
5523 choose_reload_regs (struct insn_chain *chain)
5525 rtx insn = chain->insn;
5527 unsigned int max_group_size = 1;
5528 enum reg_class group_class = NO_REGS;
5529 int pass, win, inheritance;
5531 rtx save_reload_reg_rtx[MAX_RELOADS];
5533 /* In order to be certain of getting the registers we need,
5534 we must sort the reloads into order of increasing register class.
5535 Then our grabbing of reload registers will parallel the process
5536 that provided the reload registers.
5538 Also note whether any of the reloads wants a consecutive group of regs.
5539 If so, record the maximum size of the group desired and what
5540 register class contains all the groups needed by this insn. */
5542 for (j = 0; j < n_reloads; j++)
5544 reload_order[j] = j;
5545 reload_spill_index[j] = -1;
5547 if (rld[j].nregs > 1)
5549 max_group_size = MAX (rld[j].nregs, max_group_size);
5551 = reg_class_superunion[(int) rld[j].class][(int) group_class];
5554 save_reload_reg_rtx[j] = rld[j].reg_rtx;
5558 qsort (reload_order, n_reloads, sizeof (short), reload_reg_class_lower);
5560 /* If -O, try first with inheritance, then turning it off.
5561 If not -O, don't do inheritance.
5562 Using inheritance when not optimizing leads to paradoxes
5563 with fp on the 68k: fp numbers (not NaNs) fail to be equal to themselves
5564 because one side of the comparison might be inherited. */
5566 for (inheritance = optimize > 0; inheritance >= 0; inheritance--)
5568 choose_reload_regs_init (chain, save_reload_reg_rtx);
5570 /* Process the reloads in order of preference just found.
5571 Beyond this point, subregs can be found in reload_reg_rtx.
5573 This used to look for an existing reloaded home for all of the
5574 reloads, and only then perform any new reloads. But that could lose
5575 if the reloads were done out of reg-class order because a later
5576 reload with a looser constraint might have an old home in a register
5577 needed by an earlier reload with a tighter constraint.
5579 To solve this, we make two passes over the reloads, in the order
5580 described above. In the first pass we try to inherit a reload
5581 from a previous insn. If there is a later reload that needs a
5582 class that is a proper subset of the class being processed, we must
5583 also allocate a spill register during the first pass.
5585 Then make a second pass over the reloads to allocate any reloads
5586 that haven't been given registers yet. */
5588 for (j = 0; j < n_reloads; j++)
5590 int r = reload_order[j];
5591 rtx search_equiv = NULL_RTX;
5593 /* Ignore reloads that got marked inoperative. */
5594 if (rld[r].out == 0 && rld[r].in == 0
5595 && ! rld[r].secondary_p)
5598 /* If find_reloads chose to use reload_in or reload_out as a reload
5599 register, we don't need to chose one. Otherwise, try even if it
5600 found one since we might save an insn if we find the value lying
5602 Try also when reload_in is a pseudo without a hard reg. */
5603 if (rld[r].in != 0 && rld[r].reg_rtx != 0
5604 && (rtx_equal_p (rld[r].in, rld[r].reg_rtx)
5605 || (rtx_equal_p (rld[r].out, rld[r].reg_rtx)
5606 && !MEM_P (rld[r].in)
5607 && true_regnum (rld[r].in) < FIRST_PSEUDO_REGISTER)))
5610 #if 0 /* No longer needed for correct operation.
5611 It might give better code, or might not; worth an experiment? */
5612 /* If this is an optional reload, we can't inherit from earlier insns
5613 until we are sure that any non-optional reloads have been allocated.
5614 The following code takes advantage of the fact that optional reloads
5615 are at the end of reload_order. */
5616 if (rld[r].optional != 0)
5617 for (i = 0; i < j; i++)
5618 if ((rld[reload_order[i]].out != 0
5619 || rld[reload_order[i]].in != 0
5620 || rld[reload_order[i]].secondary_p)
5621 && ! rld[reload_order[i]].optional
5622 && rld[reload_order[i]].reg_rtx == 0)
5623 allocate_reload_reg (chain, reload_order[i], 0);
5626 /* First see if this pseudo is already available as reloaded
5627 for a previous insn. We cannot try to inherit for reloads
5628 that are smaller than the maximum number of registers needed
5629 for groups unless the register we would allocate cannot be used
5632 We could check here to see if this is a secondary reload for
5633 an object that is already in a register of the desired class.
5634 This would avoid the need for the secondary reload register.
5635 But this is complex because we can't easily determine what
5636 objects might want to be loaded via this reload. So let a
5637 register be allocated here. In `emit_reload_insns' we suppress
5638 one of the loads in the case described above. */
5644 enum machine_mode mode = VOIDmode;
5648 else if (REG_P (rld[r].in))
5650 regno = REGNO (rld[r].in);
5651 mode = GET_MODE (rld[r].in);
5653 else if (REG_P (rld[r].in_reg))
5655 regno = REGNO (rld[r].in_reg);
5656 mode = GET_MODE (rld[r].in_reg);
5658 else if (GET_CODE (rld[r].in_reg) == SUBREG
5659 && REG_P (SUBREG_REG (rld[r].in_reg)))
5661 regno = REGNO (SUBREG_REG (rld[r].in_reg));
5662 if (regno < FIRST_PSEUDO_REGISTER)
5663 regno = subreg_regno (rld[r].in_reg);
5665 byte = SUBREG_BYTE (rld[r].in_reg);
5666 mode = GET_MODE (rld[r].in_reg);
5669 else if (GET_RTX_CLASS (GET_CODE (rld[r].in_reg)) == RTX_AUTOINC
5670 && REG_P (XEXP (rld[r].in_reg, 0)))
5672 regno = REGNO (XEXP (rld[r].in_reg, 0));
5673 mode = GET_MODE (XEXP (rld[r].in_reg, 0));
5674 rld[r].out = rld[r].in;
5678 /* This won't work, since REGNO can be a pseudo reg number.
5679 Also, it takes much more hair to keep track of all the things
5680 that can invalidate an inherited reload of part of a pseudoreg. */
5681 else if (GET_CODE (rld[r].in) == SUBREG
5682 && REG_P (SUBREG_REG (rld[r].in)))
5683 regno = subreg_regno (rld[r].in);
5687 && reg_last_reload_reg[regno] != 0
5688 #ifdef CANNOT_CHANGE_MODE_CLASS
5689 /* Verify that the register it's in can be used in
5691 && !REG_CANNOT_CHANGE_MODE_P (REGNO (reg_last_reload_reg[regno]),
5692 GET_MODE (reg_last_reload_reg[regno]),
5697 enum reg_class class = rld[r].class, last_class;
5698 rtx last_reg = reg_last_reload_reg[regno];
5699 enum machine_mode need_mode;
5701 i = REGNO (last_reg);
5702 i += subreg_regno_offset (i, GET_MODE (last_reg), byte, mode);
5703 last_class = REGNO_REG_CLASS (i);
5709 = smallest_mode_for_size (GET_MODE_BITSIZE (mode)
5710 + byte * BITS_PER_UNIT,
5711 GET_MODE_CLASS (mode));
5713 if ((GET_MODE_SIZE (GET_MODE (last_reg))
5714 >= GET_MODE_SIZE (need_mode))
5715 && reg_reloaded_contents[i] == regno
5716 && TEST_HARD_REG_BIT (reg_reloaded_valid, i)
5717 && HARD_REGNO_MODE_OK (i, rld[r].mode)
5718 && (TEST_HARD_REG_BIT (reg_class_contents[(int) class], i)
5719 /* Even if we can't use this register as a reload
5720 register, we might use it for reload_override_in,
5721 if copying it to the desired class is cheap
5723 || ((REGISTER_MOVE_COST (mode, last_class, class)
5724 < MEMORY_MOVE_COST (mode, class, 1))
5725 && (secondary_reload_class (1, class, mode,
5728 #ifdef SECONDARY_MEMORY_NEEDED
5729 && ! SECONDARY_MEMORY_NEEDED (last_class, class,
5734 && (rld[r].nregs == max_group_size
5735 || ! TEST_HARD_REG_BIT (reg_class_contents[(int) group_class],
5737 && free_for_value_p (i, rld[r].mode, rld[r].opnum,
5738 rld[r].when_needed, rld[r].in,
5741 /* If a group is needed, verify that all the subsequent
5742 registers still have their values intact. */
5743 int nr = hard_regno_nregs[i][rld[r].mode];
5746 for (k = 1; k < nr; k++)
5747 if (reg_reloaded_contents[i + k] != regno
5748 || ! TEST_HARD_REG_BIT (reg_reloaded_valid, i + k))
5756 last_reg = (GET_MODE (last_reg) == mode
5757 ? last_reg : gen_rtx_REG (mode, i));
5760 for (k = 0; k < nr; k++)
5761 bad_for_class |= ! TEST_HARD_REG_BIT (reg_class_contents[(int) rld[r].class],
5764 /* We found a register that contains the
5765 value we need. If this register is the
5766 same as an `earlyclobber' operand of the
5767 current insn, just mark it as a place to
5768 reload from since we can't use it as the
5769 reload register itself. */
5771 for (i1 = 0; i1 < n_earlyclobbers; i1++)
5772 if (reg_overlap_mentioned_for_reload_p
5773 (reg_last_reload_reg[regno],
5774 reload_earlyclobbers[i1]))
5777 if (i1 != n_earlyclobbers
5778 || ! (free_for_value_p (i, rld[r].mode,
5780 rld[r].when_needed, rld[r].in,
5782 /* Don't use it if we'd clobber a pseudo reg. */
5783 || (TEST_HARD_REG_BIT (reg_used_in_insn, i)
5785 && ! TEST_HARD_REG_BIT (reg_reloaded_dead, i))
5786 /* Don't clobber the frame pointer. */
5787 || (i == HARD_FRAME_POINTER_REGNUM
5788 && frame_pointer_needed
5790 /* Don't really use the inherited spill reg
5791 if we need it wider than we've got it. */
5792 || (GET_MODE_SIZE (rld[r].mode)
5793 > GET_MODE_SIZE (mode))
5796 /* If find_reloads chose reload_out as reload
5797 register, stay with it - that leaves the
5798 inherited register for subsequent reloads. */
5799 || (rld[r].out && rld[r].reg_rtx
5800 && rtx_equal_p (rld[r].out, rld[r].reg_rtx)))
5802 if (! rld[r].optional)
5804 reload_override_in[r] = last_reg;
5805 reload_inheritance_insn[r]
5806 = reg_reloaded_insn[i];
5812 /* We can use this as a reload reg. */
5813 /* Mark the register as in use for this part of
5815 mark_reload_reg_in_use (i,
5819 rld[r].reg_rtx = last_reg;
5820 reload_inherited[r] = 1;
5821 reload_inheritance_insn[r]
5822 = reg_reloaded_insn[i];
5823 reload_spill_index[r] = i;
5824 for (k = 0; k < nr; k++)
5825 SET_HARD_REG_BIT (reload_reg_used_for_inherit,
5833 /* Here's another way to see if the value is already lying around. */
5836 && ! reload_inherited[r]
5838 && (CONSTANT_P (rld[r].in)
5839 || GET_CODE (rld[r].in) == PLUS
5840 || REG_P (rld[r].in)
5841 || MEM_P (rld[r].in))
5842 && (rld[r].nregs == max_group_size
5843 || ! reg_classes_intersect_p (rld[r].class, group_class)))
5844 search_equiv = rld[r].in;
5845 /* If this is an output reload from a simple move insn, look
5846 if an equivalence for the input is available. */
5847 else if (inheritance && rld[r].in == 0 && rld[r].out != 0)
5849 rtx set = single_set (insn);
5852 && rtx_equal_p (rld[r].out, SET_DEST (set))
5853 && CONSTANT_P (SET_SRC (set)))
5854 search_equiv = SET_SRC (set);
5860 = find_equiv_reg (search_equiv, insn, rld[r].class,
5861 -1, NULL, 0, rld[r].mode);
5867 regno = REGNO (equiv);
5870 /* This must be a SUBREG of a hard register.
5871 Make a new REG since this might be used in an
5872 address and not all machines support SUBREGs
5874 gcc_assert (GET_CODE (equiv) == SUBREG);
5875 regno = subreg_regno (equiv);
5876 equiv = gen_rtx_REG (rld[r].mode, regno);
5877 /* If we choose EQUIV as the reload register, but the
5878 loop below decides to cancel the inheritance, we'll
5879 end up reloading EQUIV in rld[r].mode, not the mode
5880 it had originally. That isn't safe when EQUIV isn't
5881 available as a spill register since its value might
5882 still be live at this point. */
5883 for (i = regno; i < regno + (int) rld[r].nregs; i++)
5884 if (TEST_HARD_REG_BIT (reload_reg_unavailable, i))
5889 /* If we found a spill reg, reject it unless it is free
5890 and of the desired class. */
5894 int bad_for_class = 0;
5895 int max_regno = regno + rld[r].nregs;
5897 for (i = regno; i < max_regno; i++)
5899 regs_used |= TEST_HARD_REG_BIT (reload_reg_used_at_all,
5901 bad_for_class |= ! TEST_HARD_REG_BIT (reg_class_contents[(int) rld[r].class],
5906 && ! free_for_value_p (regno, rld[r].mode,
5907 rld[r].opnum, rld[r].when_needed,
5908 rld[r].in, rld[r].out, r, 1))
5913 if (equiv != 0 && ! HARD_REGNO_MODE_OK (regno, rld[r].mode))
5916 /* We found a register that contains the value we need.
5917 If this register is the same as an `earlyclobber' operand
5918 of the current insn, just mark it as a place to reload from
5919 since we can't use it as the reload register itself. */
5922 for (i = 0; i < n_earlyclobbers; i++)
5923 if (reg_overlap_mentioned_for_reload_p (equiv,
5924 reload_earlyclobbers[i]))
5926 if (! rld[r].optional)
5927 reload_override_in[r] = equiv;
5932 /* If the equiv register we have found is explicitly clobbered
5933 in the current insn, it depends on the reload type if we
5934 can use it, use it for reload_override_in, or not at all.
5935 In particular, we then can't use EQUIV for a
5936 RELOAD_FOR_OUTPUT_ADDRESS reload. */
5940 if (regno_clobbered_p (regno, insn, rld[r].mode, 2))
5941 switch (rld[r].when_needed)
5943 case RELOAD_FOR_OTHER_ADDRESS:
5944 case RELOAD_FOR_INPADDR_ADDRESS:
5945 case RELOAD_FOR_INPUT_ADDRESS:
5946 case RELOAD_FOR_OPADDR_ADDR:
5949 case RELOAD_FOR_INPUT:
5950 case RELOAD_FOR_OPERAND_ADDRESS:
5951 if (! rld[r].optional)
5952 reload_override_in[r] = equiv;
5958 else if (regno_clobbered_p (regno, insn, rld[r].mode, 1))
5959 switch (rld[r].when_needed)
5961 case RELOAD_FOR_OTHER_ADDRESS:
5962 case RELOAD_FOR_INPADDR_ADDRESS:
5963 case RELOAD_FOR_INPUT_ADDRESS:
5964 case RELOAD_FOR_OPADDR_ADDR:
5965 case RELOAD_FOR_OPERAND_ADDRESS:
5966 case RELOAD_FOR_INPUT:
5969 if (! rld[r].optional)
5970 reload_override_in[r] = equiv;
5978 /* If we found an equivalent reg, say no code need be generated
5979 to load it, and use it as our reload reg. */
5981 && (regno != HARD_FRAME_POINTER_REGNUM
5982 || !frame_pointer_needed))
5984 int nr = hard_regno_nregs[regno][rld[r].mode];
5986 rld[r].reg_rtx = equiv;
5987 reload_inherited[r] = 1;
5989 /* If reg_reloaded_valid is not set for this register,
5990 there might be a stale spill_reg_store lying around.
5991 We must clear it, since otherwise emit_reload_insns
5992 might delete the store. */
5993 if (! TEST_HARD_REG_BIT (reg_reloaded_valid, regno))
5994 spill_reg_store[regno] = NULL_RTX;
5995 /* If any of the hard registers in EQUIV are spill
5996 registers, mark them as in use for this insn. */
5997 for (k = 0; k < nr; k++)
5999 i = spill_reg_order[regno + k];
6002 mark_reload_reg_in_use (regno, rld[r].opnum,
6005 SET_HARD_REG_BIT (reload_reg_used_for_inherit,
6012 /* If we found a register to use already, or if this is an optional
6013 reload, we are done. */
6014 if (rld[r].reg_rtx != 0 || rld[r].optional != 0)
6018 /* No longer needed for correct operation. Might or might
6019 not give better code on the average. Want to experiment? */
6021 /* See if there is a later reload that has a class different from our
6022 class that intersects our class or that requires less register
6023 than our reload. If so, we must allocate a register to this
6024 reload now, since that reload might inherit a previous reload
6025 and take the only available register in our class. Don't do this
6026 for optional reloads since they will force all previous reloads
6027 to be allocated. Also don't do this for reloads that have been
6030 for (i = j + 1; i < n_reloads; i++)
6032 int s = reload_order[i];
6034 if ((rld[s].in == 0 && rld[s].out == 0
6035 && ! rld[s].secondary_p)
6039 if ((rld[s].class != rld[r].class
6040 && reg_classes_intersect_p (rld[r].class,
6042 || rld[s].nregs < rld[r].nregs)
6049 allocate_reload_reg (chain, r, j == n_reloads - 1);
6053 /* Now allocate reload registers for anything non-optional that
6054 didn't get one yet. */
6055 for (j = 0; j < n_reloads; j++)
6057 int r = reload_order[j];
6059 /* Ignore reloads that got marked inoperative. */
6060 if (rld[r].out == 0 && rld[r].in == 0 && ! rld[r].secondary_p)
6063 /* Skip reloads that already have a register allocated or are
6065 if (rld[r].reg_rtx != 0 || rld[r].optional)
6068 if (! allocate_reload_reg (chain, r, j == n_reloads - 1))
6072 /* If that loop got all the way, we have won. */
6079 /* Loop around and try without any inheritance. */
6084 /* First undo everything done by the failed attempt
6085 to allocate with inheritance. */
6086 choose_reload_regs_init (chain, save_reload_reg_rtx);
6088 /* Some sanity tests to verify that the reloads found in the first
6089 pass are identical to the ones we have now. */
6090 gcc_assert (chain->n_reloads == n_reloads);
6092 for (i = 0; i < n_reloads; i++)
6094 if (chain->rld[i].regno < 0 || chain->rld[i].reg_rtx != 0)
6096 gcc_assert (chain->rld[i].when_needed == rld[i].when_needed);
6097 for (j = 0; j < n_spills; j++)
6098 if (spill_regs[j] == chain->rld[i].regno)
6099 if (! set_reload_reg (j, i))
6100 failed_reload (chain->insn, i);
6104 /* If we thought we could inherit a reload, because it seemed that
6105 nothing else wanted the same reload register earlier in the insn,
6106 verify that assumption, now that all reloads have been assigned.
6107 Likewise for reloads where reload_override_in has been set. */
6109 /* If doing expensive optimizations, do one preliminary pass that doesn't
6110 cancel any inheritance, but removes reloads that have been needed only
6111 for reloads that we know can be inherited. */
6112 for (pass = flag_expensive_optimizations; pass >= 0; pass--)
6114 for (j = 0; j < n_reloads; j++)
6116 int r = reload_order[j];
6118 if (reload_inherited[r] && rld[r].reg_rtx)
6119 check_reg = rld[r].reg_rtx;
6120 else if (reload_override_in[r]
6121 && (REG_P (reload_override_in[r])
6122 || GET_CODE (reload_override_in[r]) == SUBREG))
6123 check_reg = reload_override_in[r];
6126 if (! free_for_value_p (true_regnum (check_reg), rld[r].mode,
6127 rld[r].opnum, rld[r].when_needed, rld[r].in,
6128 (reload_inherited[r]
6129 ? rld[r].out : const0_rtx),
6134 reload_inherited[r] = 0;
6135 reload_override_in[r] = 0;
6137 /* If we can inherit a RELOAD_FOR_INPUT, or can use a
6138 reload_override_in, then we do not need its related
6139 RELOAD_FOR_INPUT_ADDRESS / RELOAD_FOR_INPADDR_ADDRESS reloads;
6140 likewise for other reload types.
6141 We handle this by removing a reload when its only replacement
6142 is mentioned in reload_in of the reload we are going to inherit.
6143 A special case are auto_inc expressions; even if the input is
6144 inherited, we still need the address for the output. We can
6145 recognize them because they have RELOAD_OUT set to RELOAD_IN.
6146 If we succeeded removing some reload and we are doing a preliminary
6147 pass just to remove such reloads, make another pass, since the
6148 removal of one reload might allow us to inherit another one. */
6150 && rld[r].out != rld[r].in
6151 && remove_address_replacements (rld[r].in) && pass)
6156 /* Now that reload_override_in is known valid,
6157 actually override reload_in. */
6158 for (j = 0; j < n_reloads; j++)
6159 if (reload_override_in[j])
6160 rld[j].in = reload_override_in[j];
6162 /* If this reload won't be done because it has been canceled or is
6163 optional and not inherited, clear reload_reg_rtx so other
6164 routines (such as subst_reloads) don't get confused. */
6165 for (j = 0; j < n_reloads; j++)
6166 if (rld[j].reg_rtx != 0
6167 && ((rld[j].optional && ! reload_inherited[j])
6168 || (rld[j].in == 0 && rld[j].out == 0
6169 && ! rld[j].secondary_p)))
6171 int regno = true_regnum (rld[j].reg_rtx);
6173 if (spill_reg_order[regno] >= 0)
6174 clear_reload_reg_in_use (regno, rld[j].opnum,
6175 rld[j].when_needed, rld[j].mode);
6177 reload_spill_index[j] = -1;
6180 /* Record which pseudos and which spill regs have output reloads. */
6181 for (j = 0; j < n_reloads; j++)
6183 int r = reload_order[j];
6185 i = reload_spill_index[r];
6187 /* I is nonneg if this reload uses a register.
6188 If rld[r].reg_rtx is 0, this is an optional reload
6189 that we opted to ignore. */
6190 if (rld[r].out_reg != 0 && REG_P (rld[r].out_reg)
6191 && rld[r].reg_rtx != 0)
6193 int nregno = REGNO (rld[r].out_reg);
6196 if (nregno < FIRST_PSEUDO_REGISTER)
6197 nr = hard_regno_nregs[nregno][rld[r].mode];
6200 SET_REGNO_REG_SET (®_has_output_reload,
6205 nr = hard_regno_nregs[i][rld[r].mode];
6207 SET_HARD_REG_BIT (reg_is_output_reload, i + nr);
6210 gcc_assert (rld[r].when_needed == RELOAD_OTHER
6211 || rld[r].when_needed == RELOAD_FOR_OUTPUT
6212 || rld[r].when_needed == RELOAD_FOR_INSN);
6217 /* Deallocate the reload register for reload R. This is called from
6218 remove_address_replacements. */
6221 deallocate_reload_reg (int r)
6225 if (! rld[r].reg_rtx)
6227 regno = true_regnum (rld[r].reg_rtx);
6229 if (spill_reg_order[regno] >= 0)
6230 clear_reload_reg_in_use (regno, rld[r].opnum, rld[r].when_needed,
6232 reload_spill_index[r] = -1;
6235 /* If SMALL_REGISTER_CLASSES is nonzero, we may not have merged two
6236 reloads of the same item for fear that we might not have enough reload
6237 registers. However, normally they will get the same reload register
6238 and hence actually need not be loaded twice.
6240 Here we check for the most common case of this phenomenon: when we have
6241 a number of reloads for the same object, each of which were allocated
6242 the same reload_reg_rtx, that reload_reg_rtx is not used for any other
6243 reload, and is not modified in the insn itself. If we find such,
6244 merge all the reloads and set the resulting reload to RELOAD_OTHER.
6245 This will not increase the number of spill registers needed and will
6246 prevent redundant code. */
6249 merge_assigned_reloads (rtx insn)
6253 /* Scan all the reloads looking for ones that only load values and
6254 are not already RELOAD_OTHER and ones whose reload_reg_rtx are
6255 assigned and not modified by INSN. */
6257 for (i = 0; i < n_reloads; i++)
6259 int conflicting_input = 0;
6260 int max_input_address_opnum = -1;
6261 int min_conflicting_input_opnum = MAX_RECOG_OPERANDS;
6263 if (rld[i].in == 0 || rld[i].when_needed == RELOAD_OTHER
6264 || rld[i].out != 0 || rld[i].reg_rtx == 0
6265 || reg_set_p (rld[i].reg_rtx, insn))
6268 /* Look at all other reloads. Ensure that the only use of this
6269 reload_reg_rtx is in a reload that just loads the same value
6270 as we do. Note that any secondary reloads must be of the identical
6271 class since the values, modes, and result registers are the
6272 same, so we need not do anything with any secondary reloads. */
6274 for (j = 0; j < n_reloads; j++)
6276 if (i == j || rld[j].reg_rtx == 0
6277 || ! reg_overlap_mentioned_p (rld[j].reg_rtx,
6281 if (rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
6282 && rld[j].opnum > max_input_address_opnum)
6283 max_input_address_opnum = rld[j].opnum;
6285 /* If the reload regs aren't exactly the same (e.g, different modes)
6286 or if the values are different, we can't merge this reload.
6287 But if it is an input reload, we might still merge
6288 RELOAD_FOR_INPUT_ADDRESS and RELOAD_FOR_OTHER_ADDRESS reloads. */
6290 if (! rtx_equal_p (rld[i].reg_rtx, rld[j].reg_rtx)
6291 || rld[j].out != 0 || rld[j].in == 0
6292 || ! rtx_equal_p (rld[i].in, rld[j].in))
6294 if (rld[j].when_needed != RELOAD_FOR_INPUT
6295 || ((rld[i].when_needed != RELOAD_FOR_INPUT_ADDRESS
6296 || rld[i].opnum > rld[j].opnum)
6297 && rld[i].when_needed != RELOAD_FOR_OTHER_ADDRESS))
6299 conflicting_input = 1;
6300 if (min_conflicting_input_opnum > rld[j].opnum)
6301 min_conflicting_input_opnum = rld[j].opnum;
6305 /* If all is OK, merge the reloads. Only set this to RELOAD_OTHER if
6306 we, in fact, found any matching reloads. */
6309 && max_input_address_opnum <= min_conflicting_input_opnum)
6311 gcc_assert (rld[i].when_needed != RELOAD_FOR_OUTPUT);
6313 for (j = 0; j < n_reloads; j++)
6314 if (i != j && rld[j].reg_rtx != 0
6315 && rtx_equal_p (rld[i].reg_rtx, rld[j].reg_rtx)
6316 && (! conflicting_input
6317 || rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
6318 || rld[j].when_needed == RELOAD_FOR_OTHER_ADDRESS))
6320 rld[i].when_needed = RELOAD_OTHER;
6322 reload_spill_index[j] = -1;
6323 transfer_replacements (i, j);
6326 /* If this is now RELOAD_OTHER, look for any reloads that
6327 load parts of this operand and set them to
6328 RELOAD_FOR_OTHER_ADDRESS if they were for inputs,
6329 RELOAD_OTHER for outputs. Note that this test is
6330 equivalent to looking for reloads for this operand
6333 We must take special care with RELOAD_FOR_OUTPUT_ADDRESS;
6334 it may share registers with a RELOAD_FOR_INPUT, so we can
6335 not change it to RELOAD_FOR_OTHER_ADDRESS. We should
6336 never need to, since we do not modify RELOAD_FOR_OUTPUT.
6338 It is possible that the RELOAD_FOR_OPERAND_ADDRESS
6339 instruction is assigned the same register as the earlier
6340 RELOAD_FOR_OTHER_ADDRESS instruction. Merging these two
6341 instructions will cause the RELOAD_FOR_OTHER_ADDRESS
6342 instruction to be deleted later on. */
6344 if (rld[i].when_needed == RELOAD_OTHER)
6345 for (j = 0; j < n_reloads; j++)
6347 && rld[j].when_needed != RELOAD_OTHER
6348 && rld[j].when_needed != RELOAD_FOR_OTHER_ADDRESS
6349 && rld[j].when_needed != RELOAD_FOR_OUTPUT_ADDRESS
6350 && rld[j].when_needed != RELOAD_FOR_OPERAND_ADDRESS
6351 && (! conflicting_input
6352 || rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
6353 || rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
6354 && reg_overlap_mentioned_for_reload_p (rld[j].in,
6360 = ((rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
6361 || rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
6362 ? RELOAD_FOR_OTHER_ADDRESS : RELOAD_OTHER);
6364 /* Check to see if we accidentally converted two
6365 reloads that use the same reload register with
6366 different inputs to the same type. If so, the
6367 resulting code won't work. */
6369 for (k = 0; k < j; k++)
6370 gcc_assert (rld[k].in == 0 || rld[k].reg_rtx == 0
6371 || rld[k].when_needed != rld[j].when_needed
6372 || !rtx_equal_p (rld[k].reg_rtx,
6374 || rtx_equal_p (rld[k].in,
6381 /* These arrays are filled by emit_reload_insns and its subroutines. */
6382 static rtx input_reload_insns[MAX_RECOG_OPERANDS];
6383 static rtx other_input_address_reload_insns = 0;
6384 static rtx other_input_reload_insns = 0;
6385 static rtx input_address_reload_insns[MAX_RECOG_OPERANDS];
6386 static rtx inpaddr_address_reload_insns[MAX_RECOG_OPERANDS];
6387 static rtx output_reload_insns[MAX_RECOG_OPERANDS];
6388 static rtx output_address_reload_insns[MAX_RECOG_OPERANDS];
6389 static rtx outaddr_address_reload_insns[MAX_RECOG_OPERANDS];
6390 static rtx operand_reload_insns = 0;
6391 static rtx other_operand_reload_insns = 0;
6392 static rtx other_output_reload_insns[MAX_RECOG_OPERANDS];
6394 /* Values to be put in spill_reg_store are put here first. */
6395 static rtx new_spill_reg_store[FIRST_PSEUDO_REGISTER];
6396 static HARD_REG_SET reg_reloaded_died;
6398 /* Check if *RELOAD_REG is suitable as an intermediate or scratch register
6399 of class NEW_CLASS with mode NEW_MODE. Or alternatively, if alt_reload_reg
6400 is nonzero, if that is suitable. On success, change *RELOAD_REG to the
6401 adjusted register, and return true. Otherwise, return false. */
6403 reload_adjust_reg_for_temp (rtx *reload_reg, rtx alt_reload_reg,
6404 enum reg_class new_class,
6405 enum machine_mode new_mode)
6410 for (reg = *reload_reg; reg; reg = alt_reload_reg, alt_reload_reg = 0)
6412 unsigned regno = REGNO (reg);
6414 if (!TEST_HARD_REG_BIT (reg_class_contents[(int) new_class], regno))
6416 if (GET_MODE (reg) != new_mode)
6418 if (!HARD_REGNO_MODE_OK (regno, new_mode))
6420 if (hard_regno_nregs[regno][new_mode]
6421 > hard_regno_nregs[regno][GET_MODE (reg)])
6423 reg = reload_adjust_reg_for_mode (reg, new_mode);
6431 /* Check if *RELOAD_REG is suitable as a scratch register for the reload
6432 pattern with insn_code ICODE, or alternatively, if alt_reload_reg is
6433 nonzero, if that is suitable. On success, change *RELOAD_REG to the
6434 adjusted register, and return true. Otherwise, return false. */
6436 reload_adjust_reg_for_icode (rtx *reload_reg, rtx alt_reload_reg,
6437 enum insn_code icode)
6440 enum reg_class new_class = scratch_reload_class (icode);
6441 enum machine_mode new_mode = insn_data[(int) icode].operand[2].mode;
6443 return reload_adjust_reg_for_temp (reload_reg, alt_reload_reg,
6444 new_class, new_mode);
6447 /* Generate insns to perform reload RL, which is for the insn in CHAIN and
6448 has the number J. OLD contains the value to be used as input. */
6451 emit_input_reload_insns (struct insn_chain *chain, struct reload *rl,
6454 rtx insn = chain->insn;
6455 rtx reloadreg = rl->reg_rtx;
6456 rtx oldequiv_reg = 0;
6459 enum machine_mode mode;
6462 /* Determine the mode to reload in.
6463 This is very tricky because we have three to choose from.
6464 There is the mode the insn operand wants (rl->inmode).
6465 There is the mode of the reload register RELOADREG.
6466 There is the intrinsic mode of the operand, which we could find
6467 by stripping some SUBREGs.
6468 It turns out that RELOADREG's mode is irrelevant:
6469 we can change that arbitrarily.
6471 Consider (SUBREG:SI foo:QI) as an operand that must be SImode;
6472 then the reload reg may not support QImode moves, so use SImode.
6473 If foo is in memory due to spilling a pseudo reg, this is safe,
6474 because the QImode value is in the least significant part of a
6475 slot big enough for a SImode. If foo is some other sort of
6476 memory reference, then it is impossible to reload this case,
6477 so previous passes had better make sure this never happens.
6479 Then consider a one-word union which has SImode and one of its
6480 members is a float, being fetched as (SUBREG:SF union:SI).
6481 We must fetch that as SFmode because we could be loading into
6482 a float-only register. In this case OLD's mode is correct.
6484 Consider an immediate integer: it has VOIDmode. Here we need
6485 to get a mode from something else.
6487 In some cases, there is a fourth mode, the operand's
6488 containing mode. If the insn specifies a containing mode for
6489 this operand, it overrides all others.
6491 I am not sure whether the algorithm here is always right,
6492 but it does the right things in those cases. */
6494 mode = GET_MODE (old);
6495 if (mode == VOIDmode)
6498 /* delete_output_reload is only invoked properly if old contains
6499 the original pseudo register. Since this is replaced with a
6500 hard reg when RELOAD_OVERRIDE_IN is set, see if we can
6501 find the pseudo in RELOAD_IN_REG. */
6502 if (reload_override_in[j]
6503 && REG_P (rl->in_reg))
6510 else if (REG_P (oldequiv))
6511 oldequiv_reg = oldequiv;
6512 else if (GET_CODE (oldequiv) == SUBREG)
6513 oldequiv_reg = SUBREG_REG (oldequiv);
6515 /* If we are reloading from a register that was recently stored in
6516 with an output-reload, see if we can prove there was
6517 actually no need to store the old value in it. */
6519 if (optimize && REG_P (oldequiv)
6520 && REGNO (oldequiv) < FIRST_PSEUDO_REGISTER
6521 && spill_reg_store[REGNO (oldequiv)]
6523 && (dead_or_set_p (insn, spill_reg_stored_to[REGNO (oldequiv)])
6524 || rtx_equal_p (spill_reg_stored_to[REGNO (oldequiv)],
6526 delete_output_reload (insn, j, REGNO (oldequiv));
6528 /* Encapsulate both RELOADREG and OLDEQUIV into that mode,
6529 then load RELOADREG from OLDEQUIV. Note that we cannot use
6530 gen_lowpart_common since it can do the wrong thing when
6531 RELOADREG has a multi-word mode. Note that RELOADREG
6532 must always be a REG here. */
6534 if (GET_MODE (reloadreg) != mode)
6535 reloadreg = reload_adjust_reg_for_mode (reloadreg, mode);
6536 while (GET_CODE (oldequiv) == SUBREG && GET_MODE (oldequiv) != mode)
6537 oldequiv = SUBREG_REG (oldequiv);
6538 if (GET_MODE (oldequiv) != VOIDmode
6539 && mode != GET_MODE (oldequiv))
6540 oldequiv = gen_lowpart_SUBREG (mode, oldequiv);
6542 /* Switch to the right place to emit the reload insns. */
6543 switch (rl->when_needed)
6546 where = &other_input_reload_insns;
6548 case RELOAD_FOR_INPUT:
6549 where = &input_reload_insns[rl->opnum];
6551 case RELOAD_FOR_INPUT_ADDRESS:
6552 where = &input_address_reload_insns[rl->opnum];
6554 case RELOAD_FOR_INPADDR_ADDRESS:
6555 where = &inpaddr_address_reload_insns[rl->opnum];
6557 case RELOAD_FOR_OUTPUT_ADDRESS:
6558 where = &output_address_reload_insns[rl->opnum];
6560 case RELOAD_FOR_OUTADDR_ADDRESS:
6561 where = &outaddr_address_reload_insns[rl->opnum];
6563 case RELOAD_FOR_OPERAND_ADDRESS:
6564 where = &operand_reload_insns;
6566 case RELOAD_FOR_OPADDR_ADDR:
6567 where = &other_operand_reload_insns;
6569 case RELOAD_FOR_OTHER_ADDRESS:
6570 where = &other_input_address_reload_insns;
6576 push_to_sequence (*where);
6578 /* Auto-increment addresses must be reloaded in a special way. */
6579 if (rl->out && ! rl->out_reg)
6581 /* We are not going to bother supporting the case where a
6582 incremented register can't be copied directly from
6583 OLDEQUIV since this seems highly unlikely. */
6584 gcc_assert (rl->secondary_in_reload < 0);
6586 if (reload_inherited[j])
6587 oldequiv = reloadreg;
6589 old = XEXP (rl->in_reg, 0);
6591 if (optimize && REG_P (oldequiv)
6592 && REGNO (oldequiv) < FIRST_PSEUDO_REGISTER
6593 && spill_reg_store[REGNO (oldequiv)]
6595 && (dead_or_set_p (insn,
6596 spill_reg_stored_to[REGNO (oldequiv)])
6597 || rtx_equal_p (spill_reg_stored_to[REGNO (oldequiv)],
6599 delete_output_reload (insn, j, REGNO (oldequiv));
6601 /* Prevent normal processing of this reload. */
6603 /* Output a special code sequence for this case. */
6604 new_spill_reg_store[REGNO (reloadreg)]
6605 = inc_for_reload (reloadreg, oldequiv, rl->out,
6609 /* If we are reloading a pseudo-register that was set by the previous
6610 insn, see if we can get rid of that pseudo-register entirely
6611 by redirecting the previous insn into our reload register. */
6613 else if (optimize && REG_P (old)
6614 && REGNO (old) >= FIRST_PSEUDO_REGISTER
6615 && dead_or_set_p (insn, old)
6616 /* This is unsafe if some other reload
6617 uses the same reg first. */
6618 && ! conflicts_with_override (reloadreg)
6619 && free_for_value_p (REGNO (reloadreg), rl->mode, rl->opnum,
6620 rl->when_needed, old, rl->out, j, 0))
6622 rtx temp = PREV_INSN (insn);
6623 while (temp && NOTE_P (temp))
6624 temp = PREV_INSN (temp);
6626 && NONJUMP_INSN_P (temp)
6627 && GET_CODE (PATTERN (temp)) == SET
6628 && SET_DEST (PATTERN (temp)) == old
6629 /* Make sure we can access insn_operand_constraint. */
6630 && asm_noperands (PATTERN (temp)) < 0
6631 /* This is unsafe if operand occurs more than once in current
6632 insn. Perhaps some occurrences aren't reloaded. */
6633 && count_occurrences (PATTERN (insn), old, 0) == 1)
6635 rtx old = SET_DEST (PATTERN (temp));
6636 /* Store into the reload register instead of the pseudo. */
6637 SET_DEST (PATTERN (temp)) = reloadreg;
6639 /* Verify that resulting insn is valid. */
6640 extract_insn (temp);
6641 if (constrain_operands (1))
6643 /* If the previous insn is an output reload, the source is
6644 a reload register, and its spill_reg_store entry will
6645 contain the previous destination. This is now
6647 if (REG_P (SET_SRC (PATTERN (temp)))
6648 && REGNO (SET_SRC (PATTERN (temp))) < FIRST_PSEUDO_REGISTER)
6650 spill_reg_store[REGNO (SET_SRC (PATTERN (temp)))] = 0;
6651 spill_reg_stored_to[REGNO (SET_SRC (PATTERN (temp)))] = 0;
6654 /* If these are the only uses of the pseudo reg,
6655 pretend for GDB it lives in the reload reg we used. */
6656 if (REG_N_DEATHS (REGNO (old)) == 1
6657 && REG_N_SETS (REGNO (old)) == 1)
6659 reg_renumber[REGNO (old)] = REGNO (rl->reg_rtx);
6660 alter_reg (REGNO (old), -1);
6666 SET_DEST (PATTERN (temp)) = old;
6671 /* We can't do that, so output an insn to load RELOADREG. */
6673 /* If we have a secondary reload, pick up the secondary register
6674 and icode, if any. If OLDEQUIV and OLD are different or
6675 if this is an in-out reload, recompute whether or not we
6676 still need a secondary register and what the icode should
6677 be. If we still need a secondary register and the class or
6678 icode is different, go back to reloading from OLD if using
6679 OLDEQUIV means that we got the wrong type of register. We
6680 cannot have different class or icode due to an in-out reload
6681 because we don't make such reloads when both the input and
6682 output need secondary reload registers. */
6684 if (! special && rl->secondary_in_reload >= 0)
6686 rtx second_reload_reg = 0;
6687 rtx third_reload_reg = 0;
6688 int secondary_reload = rl->secondary_in_reload;
6689 rtx real_oldequiv = oldequiv;
6692 enum insn_code icode;
6693 enum insn_code tertiary_icode = CODE_FOR_nothing;
6695 /* If OLDEQUIV is a pseudo with a MEM, get the real MEM
6696 and similarly for OLD.
6697 See comments in get_secondary_reload in reload.c. */
6698 /* If it is a pseudo that cannot be replaced with its
6699 equivalent MEM, we must fall back to reload_in, which
6700 will have all the necessary substitutions registered.
6701 Likewise for a pseudo that can't be replaced with its
6702 equivalent constant.
6704 Take extra care for subregs of such pseudos. Note that
6705 we cannot use reg_equiv_mem in this case because it is
6706 not in the right mode. */
6709 if (GET_CODE (tmp) == SUBREG)
6710 tmp = SUBREG_REG (tmp);
6712 && REGNO (tmp) >= FIRST_PSEUDO_REGISTER
6713 && (reg_equiv_memory_loc[REGNO (tmp)] != 0
6714 || reg_equiv_constant[REGNO (tmp)] != 0))
6716 if (! reg_equiv_mem[REGNO (tmp)]
6717 || num_not_at_initial_offset
6718 || GET_CODE (oldequiv) == SUBREG)
6719 real_oldequiv = rl->in;
6721 real_oldequiv = reg_equiv_mem[REGNO (tmp)];
6725 if (GET_CODE (tmp) == SUBREG)
6726 tmp = SUBREG_REG (tmp);
6728 && REGNO (tmp) >= FIRST_PSEUDO_REGISTER
6729 && (reg_equiv_memory_loc[REGNO (tmp)] != 0
6730 || reg_equiv_constant[REGNO (tmp)] != 0))
6732 if (! reg_equiv_mem[REGNO (tmp)]
6733 || num_not_at_initial_offset
6734 || GET_CODE (old) == SUBREG)
6737 real_old = reg_equiv_mem[REGNO (tmp)];
6740 second_reload_reg = rld[secondary_reload].reg_rtx;
6741 if (rld[secondary_reload].secondary_in_reload >= 0)
6743 int tertiary_reload = rld[secondary_reload].secondary_in_reload;
6745 third_reload_reg = rld[tertiary_reload].reg_rtx;
6746 tertiary_icode = rld[secondary_reload].secondary_in_icode;
6747 /* We'd have to add more code for quartary reloads. */
6748 gcc_assert (rld[tertiary_reload].secondary_in_reload < 0);
6750 icode = rl->secondary_in_icode;
6752 if ((old != oldequiv && ! rtx_equal_p (old, oldequiv))
6753 || (rl->in != 0 && rl->out != 0))
6755 secondary_reload_info sri, sri2;
6756 enum reg_class new_class, new_t_class;
6758 sri.icode = CODE_FOR_nothing;
6759 sri.prev_sri = NULL;
6760 new_class = targetm.secondary_reload (1, real_oldequiv, rl->class,
6763 if (new_class == NO_REGS && sri.icode == CODE_FOR_nothing)
6764 second_reload_reg = 0;
6765 else if (new_class == NO_REGS)
6767 if (reload_adjust_reg_for_icode (&second_reload_reg,
6768 third_reload_reg, sri.icode))
6769 icode = sri.icode, third_reload_reg = 0;
6771 oldequiv = old, real_oldequiv = real_old;
6773 else if (sri.icode != CODE_FOR_nothing)
6774 /* We currently lack a way to express this in reloads. */
6778 sri2.icode = CODE_FOR_nothing;
6779 sri2.prev_sri = &sri;
6780 new_t_class = targetm.secondary_reload (1, real_oldequiv,
6781 new_class, mode, &sri);
6782 if (new_t_class == NO_REGS && sri2.icode == CODE_FOR_nothing)
6784 if (reload_adjust_reg_for_temp (&second_reload_reg,
6787 third_reload_reg = 0, tertiary_icode = sri2.icode;
6789 oldequiv = old, real_oldequiv = real_old;
6791 else if (new_t_class == NO_REGS && sri2.icode != CODE_FOR_nothing)
6793 rtx intermediate = second_reload_reg;
6795 if (reload_adjust_reg_for_temp (&intermediate, NULL,
6797 && reload_adjust_reg_for_icode (&third_reload_reg, NULL,
6800 second_reload_reg = intermediate;
6801 tertiary_icode = sri2.icode;
6804 oldequiv = old, real_oldequiv = real_old;
6806 else if (new_t_class != NO_REGS && sri2.icode == CODE_FOR_nothing)
6808 rtx intermediate = second_reload_reg;
6810 if (reload_adjust_reg_for_temp (&intermediate, NULL,
6812 && reload_adjust_reg_for_temp (&third_reload_reg, NULL,
6815 second_reload_reg = intermediate;
6816 tertiary_icode = sri2.icode;
6819 oldequiv = old, real_oldequiv = real_old;
6822 /* This could be handled more intelligently too. */
6823 oldequiv = old, real_oldequiv = real_old;
6827 /* If we still need a secondary reload register, check
6828 to see if it is being used as a scratch or intermediate
6829 register and generate code appropriately. If we need
6830 a scratch register, use REAL_OLDEQUIV since the form of
6831 the insn may depend on the actual address if it is
6834 if (second_reload_reg)
6836 if (icode != CODE_FOR_nothing)
6838 /* We'd have to add extra code to handle this case. */
6839 gcc_assert (!third_reload_reg);
6841 emit_insn (GEN_FCN (icode) (reloadreg, real_oldequiv,
6842 second_reload_reg));
6847 /* See if we need a scratch register to load the
6848 intermediate register (a tertiary reload). */
6849 if (tertiary_icode != CODE_FOR_nothing)
6851 emit_insn ((GEN_FCN (tertiary_icode)
6852 (second_reload_reg, real_oldequiv,
6853 third_reload_reg)));
6855 else if (third_reload_reg)
6857 gen_reload (third_reload_reg, real_oldequiv,
6860 gen_reload (second_reload_reg, third_reload_reg,
6865 gen_reload (second_reload_reg, real_oldequiv,
6869 oldequiv = second_reload_reg;
6874 if (! special && ! rtx_equal_p (reloadreg, oldequiv))
6876 rtx real_oldequiv = oldequiv;
6878 if ((REG_P (oldequiv)
6879 && REGNO (oldequiv) >= FIRST_PSEUDO_REGISTER
6880 && (reg_equiv_memory_loc[REGNO (oldequiv)] != 0
6881 || reg_equiv_constant[REGNO (oldequiv)] != 0))
6882 || (GET_CODE (oldequiv) == SUBREG
6883 && REG_P (SUBREG_REG (oldequiv))
6884 && (REGNO (SUBREG_REG (oldequiv))
6885 >= FIRST_PSEUDO_REGISTER)
6886 && ((reg_equiv_memory_loc
6887 [REGNO (SUBREG_REG (oldequiv))] != 0)
6888 || (reg_equiv_constant
6889 [REGNO (SUBREG_REG (oldequiv))] != 0)))
6890 || (CONSTANT_P (oldequiv)
6891 && (PREFERRED_RELOAD_CLASS (oldequiv,
6892 REGNO_REG_CLASS (REGNO (reloadreg)))
6894 real_oldequiv = rl->in;
6895 gen_reload (reloadreg, real_oldequiv, rl->opnum,
6899 if (flag_non_call_exceptions)
6900 copy_eh_notes (insn, get_insns ());
6902 /* End this sequence. */
6903 *where = get_insns ();
6906 /* Update reload_override_in so that delete_address_reloads_1
6907 can see the actual register usage. */
6909 reload_override_in[j] = oldequiv;
6912 /* Generate insns to for the output reload RL, which is for the insn described
6913 by CHAIN and has the number J. */
6915 emit_output_reload_insns (struct insn_chain *chain, struct reload *rl,
6918 rtx reloadreg = rl->reg_rtx;
6919 rtx insn = chain->insn;
6922 enum machine_mode mode = GET_MODE (old);
6925 if (rl->when_needed == RELOAD_OTHER)
6928 push_to_sequence (output_reload_insns[rl->opnum]);
6930 /* Determine the mode to reload in.
6931 See comments above (for input reloading). */
6933 if (mode == VOIDmode)
6935 /* VOIDmode should never happen for an output. */
6936 if (asm_noperands (PATTERN (insn)) < 0)
6937 /* It's the compiler's fault. */
6938 fatal_insn ("VOIDmode on an output", insn);
6939 error_for_asm (insn, "output operand is constant in %<asm%>");
6940 /* Prevent crash--use something we know is valid. */
6942 old = gen_rtx_REG (mode, REGNO (reloadreg));
6945 if (GET_MODE (reloadreg) != mode)
6946 reloadreg = reload_adjust_reg_for_mode (reloadreg, mode);
6948 /* If we need two reload regs, set RELOADREG to the intermediate
6949 one, since it will be stored into OLD. We might need a secondary
6950 register only for an input reload, so check again here. */
6952 if (rl->secondary_out_reload >= 0)
6955 int secondary_reload = rl->secondary_out_reload;
6956 int tertiary_reload = rld[secondary_reload].secondary_out_reload;
6958 if (REG_P (old) && REGNO (old) >= FIRST_PSEUDO_REGISTER
6959 && reg_equiv_mem[REGNO (old)] != 0)
6960 real_old = reg_equiv_mem[REGNO (old)];
6962 if (secondary_reload_class (0, rl->class, mode, real_old) != NO_REGS)
6964 rtx second_reloadreg = reloadreg;
6965 reloadreg = rld[secondary_reload].reg_rtx;
6967 /* See if RELOADREG is to be used as a scratch register
6968 or as an intermediate register. */
6969 if (rl->secondary_out_icode != CODE_FOR_nothing)
6971 /* We'd have to add extra code to handle this case. */
6972 gcc_assert (tertiary_reload < 0);
6974 emit_insn ((GEN_FCN (rl->secondary_out_icode)
6975 (real_old, second_reloadreg, reloadreg)));
6980 /* See if we need both a scratch and intermediate reload
6983 enum insn_code tertiary_icode
6984 = rld[secondary_reload].secondary_out_icode;
6986 /* We'd have to add more code for quartary reloads. */
6987 gcc_assert (tertiary_reload < 0
6988 || rld[tertiary_reload].secondary_out_reload < 0);
6990 if (GET_MODE (reloadreg) != mode)
6991 reloadreg = reload_adjust_reg_for_mode (reloadreg, mode);
6993 if (tertiary_icode != CODE_FOR_nothing)
6995 rtx third_reloadreg = rld[tertiary_reload].reg_rtx;
6998 /* Copy primary reload reg to secondary reload reg.
6999 (Note that these have been swapped above, then
7000 secondary reload reg to OLD using our insn.) */
7002 /* If REAL_OLD is a paradoxical SUBREG, remove it
7003 and try to put the opposite SUBREG on
7005 if (GET_CODE (real_old) == SUBREG
7006 && (GET_MODE_SIZE (GET_MODE (real_old))
7007 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (real_old))))
7008 && 0 != (tem = gen_lowpart_common
7009 (GET_MODE (SUBREG_REG (real_old)),
7011 real_old = SUBREG_REG (real_old), reloadreg = tem;
7013 gen_reload (reloadreg, second_reloadreg,
7014 rl->opnum, rl->when_needed);
7015 emit_insn ((GEN_FCN (tertiary_icode)
7016 (real_old, reloadreg, third_reloadreg)));
7022 /* Copy between the reload regs here and then to
7025 gen_reload (reloadreg, second_reloadreg,
7026 rl->opnum, rl->when_needed);
7027 if (tertiary_reload >= 0)
7029 rtx third_reloadreg = rld[tertiary_reload].reg_rtx;
7031 gen_reload (third_reloadreg, reloadreg,
7032 rl->opnum, rl->when_needed);
7033 reloadreg = third_reloadreg;
7040 /* Output the last reload insn. */
7045 /* Don't output the last reload if OLD is not the dest of
7046 INSN and is in the src and is clobbered by INSN. */
7047 if (! flag_expensive_optimizations
7049 || !(set = single_set (insn))
7050 || rtx_equal_p (old, SET_DEST (set))
7051 || !reg_mentioned_p (old, SET_SRC (set))
7052 || !((REGNO (old) < FIRST_PSEUDO_REGISTER)
7053 && regno_clobbered_p (REGNO (old), insn, rl->mode, 0)))
7054 gen_reload (old, reloadreg, rl->opnum,
7058 /* Look at all insns we emitted, just to be safe. */
7059 for (p = get_insns (); p; p = NEXT_INSN (p))
7062 rtx pat = PATTERN (p);
7064 /* If this output reload doesn't come from a spill reg,
7065 clear any memory of reloaded copies of the pseudo reg.
7066 If this output reload comes from a spill reg,
7067 reg_has_output_reload will make this do nothing. */
7068 note_stores (pat, forget_old_reloads_1, NULL);
7070 if (reg_mentioned_p (rl->reg_rtx, pat))
7072 rtx set = single_set (insn);
7073 if (reload_spill_index[j] < 0
7075 && SET_SRC (set) == rl->reg_rtx)
7077 int src = REGNO (SET_SRC (set));
7079 reload_spill_index[j] = src;
7080 SET_HARD_REG_BIT (reg_is_output_reload, src);
7081 if (find_regno_note (insn, REG_DEAD, src))
7082 SET_HARD_REG_BIT (reg_reloaded_died, src);
7084 if (REGNO (rl->reg_rtx) < FIRST_PSEUDO_REGISTER)
7086 int s = rl->secondary_out_reload;
7087 set = single_set (p);
7088 /* If this reload copies only to the secondary reload
7089 register, the secondary reload does the actual
7091 if (s >= 0 && set == NULL_RTX)
7092 /* We can't tell what function the secondary reload
7093 has and where the actual store to the pseudo is
7094 made; leave new_spill_reg_store alone. */
7097 && SET_SRC (set) == rl->reg_rtx
7098 && SET_DEST (set) == rld[s].reg_rtx)
7100 /* Usually the next instruction will be the
7101 secondary reload insn; if we can confirm
7102 that it is, setting new_spill_reg_store to
7103 that insn will allow an extra optimization. */
7104 rtx s_reg = rld[s].reg_rtx;
7105 rtx next = NEXT_INSN (p);
7106 rld[s].out = rl->out;
7107 rld[s].out_reg = rl->out_reg;
7108 set = single_set (next);
7109 if (set && SET_SRC (set) == s_reg
7110 && ! new_spill_reg_store[REGNO (s_reg)])
7112 SET_HARD_REG_BIT (reg_is_output_reload,
7114 new_spill_reg_store[REGNO (s_reg)] = next;
7118 new_spill_reg_store[REGNO (rl->reg_rtx)] = p;
7123 if (rl->when_needed == RELOAD_OTHER)
7125 emit_insn (other_output_reload_insns[rl->opnum]);
7126 other_output_reload_insns[rl->opnum] = get_insns ();
7129 output_reload_insns[rl->opnum] = get_insns ();
7131 if (flag_non_call_exceptions)
7132 copy_eh_notes (insn, get_insns ());
7137 /* Do input reloading for reload RL, which is for the insn described by CHAIN
7138 and has the number J. */
7140 do_input_reload (struct insn_chain *chain, struct reload *rl, int j)
7142 rtx insn = chain->insn;
7143 rtx old = (rl->in && MEM_P (rl->in)
7144 ? rl->in_reg : rl->in);
7147 /* AUTO_INC reloads need to be handled even if inherited. We got an
7148 AUTO_INC reload if reload_out is set but reload_out_reg isn't. */
7149 && (! reload_inherited[j] || (rl->out && ! rl->out_reg))
7150 && ! rtx_equal_p (rl->reg_rtx, old)
7151 && rl->reg_rtx != 0)
7152 emit_input_reload_insns (chain, rld + j, old, j);
7154 /* When inheriting a wider reload, we have a MEM in rl->in,
7155 e.g. inheriting a SImode output reload for
7156 (mem:HI (plus:SI (reg:SI 14 fp) (const_int 10))) */
7157 if (optimize && reload_inherited[j] && rl->in
7159 && MEM_P (rl->in_reg)
7160 && reload_spill_index[j] >= 0
7161 && TEST_HARD_REG_BIT (reg_reloaded_valid, reload_spill_index[j]))
7162 rl->in = regno_reg_rtx[reg_reloaded_contents[reload_spill_index[j]]];
7164 /* If we are reloading a register that was recently stored in with an
7165 output-reload, see if we can prove there was
7166 actually no need to store the old value in it. */
7169 && (reload_inherited[j] || reload_override_in[j])
7171 && REG_P (rl->reg_rtx)
7172 && spill_reg_store[REGNO (rl->reg_rtx)] != 0
7174 /* There doesn't seem to be any reason to restrict this to pseudos
7175 and doing so loses in the case where we are copying from a
7176 register of the wrong class. */
7177 && (REGNO (spill_reg_stored_to[REGNO (rl->reg_rtx)])
7178 >= FIRST_PSEUDO_REGISTER)
7180 /* The insn might have already some references to stackslots
7181 replaced by MEMs, while reload_out_reg still names the
7183 && (dead_or_set_p (insn,
7184 spill_reg_stored_to[REGNO (rl->reg_rtx)])
7185 || rtx_equal_p (spill_reg_stored_to[REGNO (rl->reg_rtx)],
7187 delete_output_reload (insn, j, REGNO (rl->reg_rtx));
7190 /* Do output reloading for reload RL, which is for the insn described by
7191 CHAIN and has the number J.
7192 ??? At some point we need to support handling output reloads of
7193 JUMP_INSNs or insns that set cc0. */
7195 do_output_reload (struct insn_chain *chain, struct reload *rl, int j)
7198 rtx insn = chain->insn;
7199 /* If this is an output reload that stores something that is
7200 not loaded in this same reload, see if we can eliminate a previous
7202 rtx pseudo = rl->out_reg;
7207 && ! rtx_equal_p (rl->in_reg, pseudo)
7208 && REGNO (pseudo) >= FIRST_PSEUDO_REGISTER
7209 && reg_last_reload_reg[REGNO (pseudo)])
7211 int pseudo_no = REGNO (pseudo);
7212 int last_regno = REGNO (reg_last_reload_reg[pseudo_no]);
7214 /* We don't need to test full validity of last_regno for
7215 inherit here; we only want to know if the store actually
7216 matches the pseudo. */
7217 if (TEST_HARD_REG_BIT (reg_reloaded_valid, last_regno)
7218 && reg_reloaded_contents[last_regno] == pseudo_no
7219 && spill_reg_store[last_regno]
7220 && rtx_equal_p (pseudo, spill_reg_stored_to[last_regno]))
7221 delete_output_reload (insn, j, last_regno);
7226 || rl->reg_rtx == old
7227 || rl->reg_rtx == 0)
7230 /* An output operand that dies right away does need a reload,
7231 but need not be copied from it. Show the new location in the
7233 if ((REG_P (old) || GET_CODE (old) == SCRATCH)
7234 && (note = find_reg_note (insn, REG_UNUSED, old)) != 0)
7236 XEXP (note, 0) = rl->reg_rtx;
7239 /* Likewise for a SUBREG of an operand that dies. */
7240 else if (GET_CODE (old) == SUBREG
7241 && REG_P (SUBREG_REG (old))
7242 && 0 != (note = find_reg_note (insn, REG_UNUSED,
7245 XEXP (note, 0) = gen_lowpart_common (GET_MODE (old),
7249 else if (GET_CODE (old) == SCRATCH)
7250 /* If we aren't optimizing, there won't be a REG_UNUSED note,
7251 but we don't want to make an output reload. */
7254 /* If is a JUMP_INSN, we can't support output reloads yet. */
7255 gcc_assert (NONJUMP_INSN_P (insn));
7257 emit_output_reload_insns (chain, rld + j, j);
7260 /* Reload number R reloads from or to a group of hard registers starting at
7261 register REGNO. Return true if it can be treated for inheritance purposes
7262 like a group of reloads, each one reloading a single hard register.
7263 The caller has already checked that the spill register and REGNO use
7264 the same number of registers to store the reload value. */
7267 inherit_piecemeal_p (int r ATTRIBUTE_UNUSED, int regno ATTRIBUTE_UNUSED)
7269 #ifdef CANNOT_CHANGE_MODE_CLASS
7270 return (!REG_CANNOT_CHANGE_MODE_P (reload_spill_index[r],
7271 GET_MODE (rld[r].reg_rtx),
7272 reg_raw_mode[reload_spill_index[r]])
7273 && !REG_CANNOT_CHANGE_MODE_P (regno,
7274 GET_MODE (rld[r].reg_rtx),
7275 reg_raw_mode[regno]));
7281 /* Output insns to reload values in and out of the chosen reload regs. */
7284 emit_reload_insns (struct insn_chain *chain)
7286 rtx insn = chain->insn;
7290 CLEAR_HARD_REG_SET (reg_reloaded_died);
7292 for (j = 0; j < reload_n_operands; j++)
7293 input_reload_insns[j] = input_address_reload_insns[j]
7294 = inpaddr_address_reload_insns[j]
7295 = output_reload_insns[j] = output_address_reload_insns[j]
7296 = outaddr_address_reload_insns[j]
7297 = other_output_reload_insns[j] = 0;
7298 other_input_address_reload_insns = 0;
7299 other_input_reload_insns = 0;
7300 operand_reload_insns = 0;
7301 other_operand_reload_insns = 0;
7303 /* Dump reloads into the dump file. */
7306 fprintf (dump_file, "\nReloads for insn # %d\n", INSN_UID (insn));
7307 debug_reload_to_stream (dump_file);
7310 /* Now output the instructions to copy the data into and out of the
7311 reload registers. Do these in the order that the reloads were reported,
7312 since reloads of base and index registers precede reloads of operands
7313 and the operands may need the base and index registers reloaded. */
7315 for (j = 0; j < n_reloads; j++)
7318 && REGNO (rld[j].reg_rtx) < FIRST_PSEUDO_REGISTER)
7319 new_spill_reg_store[REGNO (rld[j].reg_rtx)] = 0;
7321 do_input_reload (chain, rld + j, j);
7322 do_output_reload (chain, rld + j, j);
7325 /* Now write all the insns we made for reloads in the order expected by
7326 the allocation functions. Prior to the insn being reloaded, we write
7327 the following reloads:
7329 RELOAD_FOR_OTHER_ADDRESS reloads for input addresses.
7331 RELOAD_OTHER reloads.
7333 For each operand, any RELOAD_FOR_INPADDR_ADDRESS reloads followed
7334 by any RELOAD_FOR_INPUT_ADDRESS reloads followed by the
7335 RELOAD_FOR_INPUT reload for the operand.
7337 RELOAD_FOR_OPADDR_ADDRS reloads.
7339 RELOAD_FOR_OPERAND_ADDRESS reloads.
7341 After the insn being reloaded, we write the following:
7343 For each operand, any RELOAD_FOR_OUTADDR_ADDRESS reloads followed
7344 by any RELOAD_FOR_OUTPUT_ADDRESS reload followed by the
7345 RELOAD_FOR_OUTPUT reload, followed by any RELOAD_OTHER output
7346 reloads for the operand. The RELOAD_OTHER output reloads are
7347 output in descending order by reload number. */
7349 emit_insn_before (other_input_address_reload_insns, insn);
7350 emit_insn_before (other_input_reload_insns, insn);
7352 for (j = 0; j < reload_n_operands; j++)
7354 emit_insn_before (inpaddr_address_reload_insns[j], insn);
7355 emit_insn_before (input_address_reload_insns[j], insn);
7356 emit_insn_before (input_reload_insns[j], insn);
7359 emit_insn_before (other_operand_reload_insns, insn);
7360 emit_insn_before (operand_reload_insns, insn);
7362 for (j = 0; j < reload_n_operands; j++)
7364 rtx x = emit_insn_after (outaddr_address_reload_insns[j], insn);
7365 x = emit_insn_after (output_address_reload_insns[j], x);
7366 x = emit_insn_after (output_reload_insns[j], x);
7367 emit_insn_after (other_output_reload_insns[j], x);
7370 /* For all the spill regs newly reloaded in this instruction,
7371 record what they were reloaded from, so subsequent instructions
7372 can inherit the reloads.
7374 Update spill_reg_store for the reloads of this insn.
7375 Copy the elements that were updated in the loop above. */
7377 for (j = 0; j < n_reloads; j++)
7379 int r = reload_order[j];
7380 int i = reload_spill_index[r];
7382 /* If this is a non-inherited input reload from a pseudo, we must
7383 clear any memory of a previous store to the same pseudo. Only do
7384 something if there will not be an output reload for the pseudo
7386 if (rld[r].in_reg != 0
7387 && ! (reload_inherited[r] || reload_override_in[r]))
7389 rtx reg = rld[r].in_reg;
7391 if (GET_CODE (reg) == SUBREG)
7392 reg = SUBREG_REG (reg);
7395 && REGNO (reg) >= FIRST_PSEUDO_REGISTER
7396 && !REGNO_REG_SET_P (®_has_output_reload, REGNO (reg)))
7398 int nregno = REGNO (reg);
7400 if (reg_last_reload_reg[nregno])
7402 int last_regno = REGNO (reg_last_reload_reg[nregno]);
7404 if (reg_reloaded_contents[last_regno] == nregno)
7405 spill_reg_store[last_regno] = 0;
7410 /* I is nonneg if this reload used a register.
7411 If rld[r].reg_rtx is 0, this is an optional reload
7412 that we opted to ignore. */
7414 if (i >= 0 && rld[r].reg_rtx != 0)
7416 int nr = hard_regno_nregs[i][GET_MODE (rld[r].reg_rtx)];
7418 int part_reaches_end = 0;
7419 int all_reaches_end = 1;
7421 /* For a multi register reload, we need to check if all or part
7422 of the value lives to the end. */
7423 for (k = 0; k < nr; k++)
7425 if (reload_reg_reaches_end_p (i + k, rld[r].opnum,
7426 rld[r].when_needed))
7427 part_reaches_end = 1;
7429 all_reaches_end = 0;
7432 /* Ignore reloads that don't reach the end of the insn in
7434 if (all_reaches_end)
7436 /* First, clear out memory of what used to be in this spill reg.
7437 If consecutive registers are used, clear them all. */
7439 for (k = 0; k < nr; k++)
7441 CLEAR_HARD_REG_BIT (reg_reloaded_valid, i + k);
7442 CLEAR_HARD_REG_BIT (reg_reloaded_call_part_clobbered, i + k);
7445 /* Maybe the spill reg contains a copy of reload_out. */
7447 && (REG_P (rld[r].out)
7451 || REG_P (rld[r].out_reg)))
7453 rtx out = (REG_P (rld[r].out)
7457 /* AUTO_INC */ : XEXP (rld[r].in_reg, 0));
7458 int nregno = REGNO (out);
7459 int nnr = (nregno >= FIRST_PSEUDO_REGISTER ? 1
7460 : hard_regno_nregs[nregno]
7461 [GET_MODE (rld[r].reg_rtx)]);
7464 spill_reg_store[i] = new_spill_reg_store[i];
7465 spill_reg_stored_to[i] = out;
7466 reg_last_reload_reg[nregno] = rld[r].reg_rtx;
7468 piecemeal = (nregno < FIRST_PSEUDO_REGISTER
7470 && inherit_piecemeal_p (r, nregno));
7472 /* If NREGNO is a hard register, it may occupy more than
7473 one register. If it does, say what is in the
7474 rest of the registers assuming that both registers
7475 agree on how many words the object takes. If not,
7476 invalidate the subsequent registers. */
7478 if (nregno < FIRST_PSEUDO_REGISTER)
7479 for (k = 1; k < nnr; k++)
7480 reg_last_reload_reg[nregno + k]
7482 ? regno_reg_rtx[REGNO (rld[r].reg_rtx) + k]
7485 /* Now do the inverse operation. */
7486 for (k = 0; k < nr; k++)
7488 CLEAR_HARD_REG_BIT (reg_reloaded_dead, i + k);
7489 reg_reloaded_contents[i + k]
7490 = (nregno >= FIRST_PSEUDO_REGISTER || !piecemeal
7493 reg_reloaded_insn[i + k] = insn;
7494 SET_HARD_REG_BIT (reg_reloaded_valid, i + k);
7495 if (HARD_REGNO_CALL_PART_CLOBBERED (i + k, GET_MODE (out)))
7496 SET_HARD_REG_BIT (reg_reloaded_call_part_clobbered, i + k);
7500 /* Maybe the spill reg contains a copy of reload_in. Only do
7501 something if there will not be an output reload for
7502 the register being reloaded. */
7503 else if (rld[r].out_reg == 0
7505 && ((REG_P (rld[r].in)
7506 && REGNO (rld[r].in) >= FIRST_PSEUDO_REGISTER
7507 && !REGNO_REG_SET_P (®_has_output_reload,
7509 || (REG_P (rld[r].in_reg)
7510 && !REGNO_REG_SET_P (®_has_output_reload,
7511 REGNO (rld[r].in_reg))))
7512 && ! reg_set_p (rld[r].reg_rtx, PATTERN (insn)))
7519 if (REG_P (rld[r].in)
7520 && REGNO (rld[r].in) >= FIRST_PSEUDO_REGISTER)
7522 else if (REG_P (rld[r].in_reg))
7525 in = XEXP (rld[r].in_reg, 0);
7526 nregno = REGNO (in);
7528 nnr = (nregno >= FIRST_PSEUDO_REGISTER ? 1
7529 : hard_regno_nregs[nregno]
7530 [GET_MODE (rld[r].reg_rtx)]);
7532 reg_last_reload_reg[nregno] = rld[r].reg_rtx;
7534 piecemeal = (nregno < FIRST_PSEUDO_REGISTER
7536 && inherit_piecemeal_p (r, nregno));
7538 if (nregno < FIRST_PSEUDO_REGISTER)
7539 for (k = 1; k < nnr; k++)
7540 reg_last_reload_reg[nregno + k]
7542 ? regno_reg_rtx[REGNO (rld[r].reg_rtx) + k]
7545 /* Unless we inherited this reload, show we haven't
7546 recently done a store.
7547 Previous stores of inherited auto_inc expressions
7548 also have to be discarded. */
7549 if (! reload_inherited[r]
7550 || (rld[r].out && ! rld[r].out_reg))
7551 spill_reg_store[i] = 0;
7553 for (k = 0; k < nr; k++)
7555 CLEAR_HARD_REG_BIT (reg_reloaded_dead, i + k);
7556 reg_reloaded_contents[i + k]
7557 = (nregno >= FIRST_PSEUDO_REGISTER || !piecemeal
7560 reg_reloaded_insn[i + k] = insn;
7561 SET_HARD_REG_BIT (reg_reloaded_valid, i + k);
7562 if (HARD_REGNO_CALL_PART_CLOBBERED (i + k, GET_MODE (in)))
7563 SET_HARD_REG_BIT (reg_reloaded_call_part_clobbered, i + k);
7568 /* However, if part of the reload reaches the end, then we must
7569 invalidate the old info for the part that survives to the end. */
7570 else if (part_reaches_end)
7572 for (k = 0; k < nr; k++)
7573 if (reload_reg_reaches_end_p (i + k,
7575 rld[r].when_needed))
7576 CLEAR_HARD_REG_BIT (reg_reloaded_valid, i + k);
7580 /* The following if-statement was #if 0'd in 1.34 (or before...).
7581 It's reenabled in 1.35 because supposedly nothing else
7582 deals with this problem. */
7584 /* If a register gets output-reloaded from a non-spill register,
7585 that invalidates any previous reloaded copy of it.
7586 But forget_old_reloads_1 won't get to see it, because
7587 it thinks only about the original insn. So invalidate it here.
7588 Also do the same thing for RELOAD_OTHER constraints where the
7589 output is discarded. */
7591 && ((rld[r].out != 0
7592 && (REG_P (rld[r].out)
7593 || (MEM_P (rld[r].out)
7594 && REG_P (rld[r].out_reg))))
7595 || (rld[r].out == 0 && rld[r].out_reg
7596 && REG_P (rld[r].out_reg))))
7598 rtx out = ((rld[r].out && REG_P (rld[r].out))
7599 ? rld[r].out : rld[r].out_reg);
7600 int nregno = REGNO (out);
7602 /* REG_RTX is now set or clobbered by the main instruction.
7603 As the comment above explains, forget_old_reloads_1 only
7604 sees the original instruction, and there is no guarantee
7605 that the original instruction also clobbered REG_RTX.
7606 For example, if find_reloads sees that the input side of
7607 a matched operand pair dies in this instruction, it may
7608 use the input register as the reload register.
7610 Calling forget_old_reloads_1 is a waste of effort if
7611 REG_RTX is also the output register.
7613 If we know that REG_RTX holds the value of a pseudo
7614 register, the code after the call will record that fact. */
7615 if (rld[r].reg_rtx && rld[r].reg_rtx != out)
7616 forget_old_reloads_1 (rld[r].reg_rtx, NULL_RTX, NULL);
7618 if (nregno >= FIRST_PSEUDO_REGISTER)
7620 rtx src_reg, store_insn = NULL_RTX;
7622 reg_last_reload_reg[nregno] = 0;
7624 /* If we can find a hard register that is stored, record
7625 the storing insn so that we may delete this insn with
7626 delete_output_reload. */
7627 src_reg = rld[r].reg_rtx;
7629 /* If this is an optional reload, try to find the source reg
7630 from an input reload. */
7633 rtx set = single_set (insn);
7634 if (set && SET_DEST (set) == rld[r].out)
7638 src_reg = SET_SRC (set);
7640 for (k = 0; k < n_reloads; k++)
7642 if (rld[k].in == src_reg)
7644 src_reg = rld[k].reg_rtx;
7651 store_insn = new_spill_reg_store[REGNO (src_reg)];
7652 if (src_reg && REG_P (src_reg)
7653 && REGNO (src_reg) < FIRST_PSEUDO_REGISTER)
7655 int src_regno = REGNO (src_reg);
7656 int nr = hard_regno_nregs[src_regno][rld[r].mode];
7657 /* The place where to find a death note varies with
7658 PRESERVE_DEATH_INFO_REGNO_P . The condition is not
7659 necessarily checked exactly in the code that moves
7660 notes, so just check both locations. */
7661 rtx note = find_regno_note (insn, REG_DEAD, src_regno);
7662 if (! note && store_insn)
7663 note = find_regno_note (store_insn, REG_DEAD, src_regno);
7666 spill_reg_store[src_regno + nr] = store_insn;
7667 spill_reg_stored_to[src_regno + nr] = out;
7668 reg_reloaded_contents[src_regno + nr] = nregno;
7669 reg_reloaded_insn[src_regno + nr] = store_insn;
7670 CLEAR_HARD_REG_BIT (reg_reloaded_dead, src_regno + nr);
7671 SET_HARD_REG_BIT (reg_reloaded_valid, src_regno + nr);
7672 if (HARD_REGNO_CALL_PART_CLOBBERED (src_regno + nr,
7673 GET_MODE (src_reg)))
7674 SET_HARD_REG_BIT (reg_reloaded_call_part_clobbered,
7676 SET_HARD_REG_BIT (reg_is_output_reload, src_regno + nr);
7678 SET_HARD_REG_BIT (reg_reloaded_died, src_regno);
7680 CLEAR_HARD_REG_BIT (reg_reloaded_died, src_regno);
7682 reg_last_reload_reg[nregno] = src_reg;
7683 /* We have to set reg_has_output_reload here, or else
7684 forget_old_reloads_1 will clear reg_last_reload_reg
7686 SET_REGNO_REG_SET (®_has_output_reload,
7692 int num_regs = hard_regno_nregs[nregno][GET_MODE (out)];
7694 while (num_regs-- > 0)
7695 reg_last_reload_reg[nregno + num_regs] = 0;
7699 IOR_HARD_REG_SET (reg_reloaded_dead, reg_reloaded_died);
7702 /* Go through the motions to emit INSN and test if it is strictly valid.
7703 Return the emitted insn if valid, else return NULL. */
7706 emit_insn_if_valid_for_reload (rtx insn)
7708 rtx last = get_last_insn ();
7711 insn = emit_insn (insn);
7712 code = recog_memoized (insn);
7716 extract_insn (insn);
7717 /* We want constrain operands to treat this insn strictly in its
7718 validity determination, i.e., the way it would after reload has
7720 if (constrain_operands (1))
7724 delete_insns_since (last);
7728 /* Emit code to perform a reload from IN (which may be a reload register) to
7729 OUT (which may also be a reload register). IN or OUT is from operand
7730 OPNUM with reload type TYPE.
7732 Returns first insn emitted. */
7735 gen_reload (rtx out, rtx in, int opnum, enum reload_type type)
7737 rtx last = get_last_insn ();
7740 /* If IN is a paradoxical SUBREG, remove it and try to put the
7741 opposite SUBREG on OUT. Likewise for a paradoxical SUBREG on OUT. */
7742 if (GET_CODE (in) == SUBREG
7743 && (GET_MODE_SIZE (GET_MODE (in))
7744 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))))
7745 && (tem = gen_lowpart_common (GET_MODE (SUBREG_REG (in)), out)) != 0)
7746 in = SUBREG_REG (in), out = tem;
7747 else if (GET_CODE (out) == SUBREG
7748 && (GET_MODE_SIZE (GET_MODE (out))
7749 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))))
7750 && (tem = gen_lowpart_common (GET_MODE (SUBREG_REG (out)), in)) != 0)
7751 out = SUBREG_REG (out), in = tem;
7753 /* How to do this reload can get quite tricky. Normally, we are being
7754 asked to reload a simple operand, such as a MEM, a constant, or a pseudo
7755 register that didn't get a hard register. In that case we can just
7756 call emit_move_insn.
7758 We can also be asked to reload a PLUS that adds a register or a MEM to
7759 another register, constant or MEM. This can occur during frame pointer
7760 elimination and while reloading addresses. This case is handled by
7761 trying to emit a single insn to perform the add. If it is not valid,
7762 we use a two insn sequence.
7764 Or we can be asked to reload an unary operand that was a fragment of
7765 an addressing mode, into a register. If it isn't recognized as-is,
7766 we try making the unop operand and the reload-register the same:
7767 (set reg:X (unop:X expr:Y))
7768 -> (set reg:Y expr:Y) (set reg:X (unop:X reg:Y)).
7770 Finally, we could be called to handle an 'o' constraint by putting
7771 an address into a register. In that case, we first try to do this
7772 with a named pattern of "reload_load_address". If no such pattern
7773 exists, we just emit a SET insn and hope for the best (it will normally
7774 be valid on machines that use 'o').
7776 This entire process is made complex because reload will never
7777 process the insns we generate here and so we must ensure that
7778 they will fit their constraints and also by the fact that parts of
7779 IN might be being reloaded separately and replaced with spill registers.
7780 Because of this, we are, in some sense, just guessing the right approach
7781 here. The one listed above seems to work.
7783 ??? At some point, this whole thing needs to be rethought. */
7785 if (GET_CODE (in) == PLUS
7786 && (REG_P (XEXP (in, 0))
7787 || GET_CODE (XEXP (in, 0)) == SUBREG
7788 || MEM_P (XEXP (in, 0)))
7789 && (REG_P (XEXP (in, 1))
7790 || GET_CODE (XEXP (in, 1)) == SUBREG
7791 || CONSTANT_P (XEXP (in, 1))
7792 || MEM_P (XEXP (in, 1))))
7794 /* We need to compute the sum of a register or a MEM and another
7795 register, constant, or MEM, and put it into the reload
7796 register. The best possible way of doing this is if the machine
7797 has a three-operand ADD insn that accepts the required operands.
7799 The simplest approach is to try to generate such an insn and see if it
7800 is recognized and matches its constraints. If so, it can be used.
7802 It might be better not to actually emit the insn unless it is valid,
7803 but we need to pass the insn as an operand to `recog' and
7804 `extract_insn' and it is simpler to emit and then delete the insn if
7805 not valid than to dummy things up. */
7807 rtx op0, op1, tem, insn;
7810 op0 = find_replacement (&XEXP (in, 0));
7811 op1 = find_replacement (&XEXP (in, 1));
7813 /* Since constraint checking is strict, commutativity won't be
7814 checked, so we need to do that here to avoid spurious failure
7815 if the add instruction is two-address and the second operand
7816 of the add is the same as the reload reg, which is frequently
7817 the case. If the insn would be A = B + A, rearrange it so
7818 it will be A = A + B as constrain_operands expects. */
7820 if (REG_P (XEXP (in, 1))
7821 && REGNO (out) == REGNO (XEXP (in, 1)))
7822 tem = op0, op0 = op1, op1 = tem;
7824 if (op0 != XEXP (in, 0) || op1 != XEXP (in, 1))
7825 in = gen_rtx_PLUS (GET_MODE (in), op0, op1);
7827 insn = emit_insn_if_valid_for_reload (gen_rtx_SET (VOIDmode, out, in));
7831 /* If that failed, we must use a conservative two-insn sequence.
7833 Use a move to copy one operand into the reload register. Prefer
7834 to reload a constant, MEM or pseudo since the move patterns can
7835 handle an arbitrary operand. If OP1 is not a constant, MEM or
7836 pseudo and OP1 is not a valid operand for an add instruction, then
7839 After reloading one of the operands into the reload register, add
7840 the reload register to the output register.
7842 If there is another way to do this for a specific machine, a
7843 DEFINE_PEEPHOLE should be specified that recognizes the sequence
7846 code = (int) add_optab->handlers[(int) GET_MODE (out)].insn_code;
7848 if (CONSTANT_P (op1) || MEM_P (op1) || GET_CODE (op1) == SUBREG
7850 && REGNO (op1) >= FIRST_PSEUDO_REGISTER)
7851 || (code != CODE_FOR_nothing
7852 && ! ((*insn_data[code].operand[2].predicate)
7853 (op1, insn_data[code].operand[2].mode))))
7854 tem = op0, op0 = op1, op1 = tem;
7856 gen_reload (out, op0, opnum, type);
7858 /* If OP0 and OP1 are the same, we can use OUT for OP1.
7859 This fixes a problem on the 32K where the stack pointer cannot
7860 be used as an operand of an add insn. */
7862 if (rtx_equal_p (op0, op1))
7865 insn = emit_insn_if_valid_for_reload (gen_add2_insn (out, op1));
7868 /* Add a REG_EQUIV note so that find_equiv_reg can find it. */
7869 set_unique_reg_note (insn, REG_EQUIV, in);
7873 /* If that failed, copy the address register to the reload register.
7874 Then add the constant to the reload register. */
7876 gen_reload (out, op1, opnum, type);
7877 insn = emit_insn (gen_add2_insn (out, op0));
7878 set_unique_reg_note (insn, REG_EQUIV, in);
7881 #ifdef SECONDARY_MEMORY_NEEDED
7882 /* If we need a memory location to do the move, do it that way. */
7883 else if ((REG_P (in) || GET_CODE (in) == SUBREG)
7884 && reg_or_subregno (in) < FIRST_PSEUDO_REGISTER
7885 && (REG_P (out) || GET_CODE (out) == SUBREG)
7886 && reg_or_subregno (out) < FIRST_PSEUDO_REGISTER
7887 && SECONDARY_MEMORY_NEEDED (REGNO_REG_CLASS (reg_or_subregno (in)),
7888 REGNO_REG_CLASS (reg_or_subregno (out)),
7891 /* Get the memory to use and rewrite both registers to its mode. */
7892 rtx loc = get_secondary_mem (in, GET_MODE (out), opnum, type);
7894 if (GET_MODE (loc) != GET_MODE (out))
7895 out = gen_rtx_REG (GET_MODE (loc), REGNO (out));
7897 if (GET_MODE (loc) != GET_MODE (in))
7898 in = gen_rtx_REG (GET_MODE (loc), REGNO (in));
7900 gen_reload (loc, in, opnum, type);
7901 gen_reload (out, loc, opnum, type);
7904 else if (REG_P (out) && UNARY_P (in))
7911 op1 = find_replacement (&XEXP (in, 0));
7912 if (op1 != XEXP (in, 0))
7913 in = gen_rtx_fmt_e (GET_CODE (in), GET_MODE (in), op1);
7915 /* First, try a plain SET. */
7916 set = emit_insn_if_valid_for_reload (gen_rtx_SET (VOIDmode, out, in));
7920 /* If that failed, move the inner operand to the reload
7921 register, and try the same unop with the inner expression
7922 replaced with the reload register. */
7924 if (GET_MODE (op1) != GET_MODE (out))
7925 out_moded = gen_rtx_REG (GET_MODE (op1), REGNO (out));
7929 gen_reload (out_moded, op1, opnum, type);
7932 = gen_rtx_SET (VOIDmode, out,
7933 gen_rtx_fmt_e (GET_CODE (in), GET_MODE (in),
7935 insn = emit_insn_if_valid_for_reload (insn);
7938 set_unique_reg_note (insn, REG_EQUIV, in);
7942 fatal_insn ("Failure trying to reload:", set);
7944 /* If IN is a simple operand, use gen_move_insn. */
7945 else if (OBJECT_P (in) || GET_CODE (in) == SUBREG)
7947 tem = emit_insn (gen_move_insn (out, in));
7948 /* IN may contain a LABEL_REF, if so add a REG_LABEL note. */
7949 mark_jump_label (in, tem, 0);
7952 #ifdef HAVE_reload_load_address
7953 else if (HAVE_reload_load_address)
7954 emit_insn (gen_reload_load_address (out, in));
7957 /* Otherwise, just write (set OUT IN) and hope for the best. */
7959 emit_insn (gen_rtx_SET (VOIDmode, out, in));
7961 /* Return the first insn emitted.
7962 We can not just return get_last_insn, because there may have
7963 been multiple instructions emitted. Also note that gen_move_insn may
7964 emit more than one insn itself, so we can not assume that there is one
7965 insn emitted per emit_insn_before call. */
7967 return last ? NEXT_INSN (last) : get_insns ();
7970 /* Delete a previously made output-reload whose result we now believe
7971 is not needed. First we double-check.
7973 INSN is the insn now being processed.
7974 LAST_RELOAD_REG is the hard register number for which we want to delete
7975 the last output reload.
7976 J is the reload-number that originally used REG. The caller has made
7977 certain that reload J doesn't use REG any longer for input. */
7980 delete_output_reload (rtx insn, int j, int last_reload_reg)
7982 rtx output_reload_insn = spill_reg_store[last_reload_reg];
7983 rtx reg = spill_reg_stored_to[last_reload_reg];
7986 int n_inherited = 0;
7990 /* It is possible that this reload has been only used to set another reload
7991 we eliminated earlier and thus deleted this instruction too. */
7992 if (INSN_DELETED_P (output_reload_insn))
7995 /* Get the raw pseudo-register referred to. */
7997 while (GET_CODE (reg) == SUBREG)
7998 reg = SUBREG_REG (reg);
7999 substed = reg_equiv_memory_loc[REGNO (reg)];
8001 /* This is unsafe if the operand occurs more often in the current
8002 insn than it is inherited. */
8003 for (k = n_reloads - 1; k >= 0; k--)
8005 rtx reg2 = rld[k].in;
8008 if (MEM_P (reg2) || reload_override_in[k])
8009 reg2 = rld[k].in_reg;
8011 if (rld[k].out && ! rld[k].out_reg)
8012 reg2 = XEXP (rld[k].in_reg, 0);
8014 while (GET_CODE (reg2) == SUBREG)
8015 reg2 = SUBREG_REG (reg2);
8016 if (rtx_equal_p (reg2, reg))
8018 if (reload_inherited[k] || reload_override_in[k] || k == j)
8024 n_occurrences = count_occurrences (PATTERN (insn), reg, 0);
8025 if (CALL_P (insn) && CALL_INSN_FUNCTION_USAGE (insn))
8026 n_occurrences += count_occurrences (CALL_INSN_FUNCTION_USAGE (insn),
8029 n_occurrences += count_occurrences (PATTERN (insn),
8030 eliminate_regs (substed, 0,
8032 for (i1 = reg_equiv_alt_mem_list [REGNO (reg)]; i1; i1 = XEXP (i1, 1))
8034 gcc_assert (!rtx_equal_p (XEXP (i1, 0), substed));
8035 n_occurrences += count_occurrences (PATTERN (insn), XEXP (i1, 0), 0);
8037 if (n_occurrences > n_inherited)
8040 /* If the pseudo-reg we are reloading is no longer referenced
8041 anywhere between the store into it and here,
8042 and we're within the same basic block, then the value can only
8043 pass through the reload reg and end up here.
8044 Otherwise, give up--return. */
8045 for (i1 = NEXT_INSN (output_reload_insn);
8046 i1 != insn; i1 = NEXT_INSN (i1))
8048 if (NOTE_INSN_BASIC_BLOCK_P (i1))
8050 if ((NONJUMP_INSN_P (i1) || CALL_P (i1))
8051 && reg_mentioned_p (reg, PATTERN (i1)))
8053 /* If this is USE in front of INSN, we only have to check that
8054 there are no more references than accounted for by inheritance. */
8055 while (NONJUMP_INSN_P (i1) && GET_CODE (PATTERN (i1)) == USE)
8057 n_occurrences += rtx_equal_p (reg, XEXP (PATTERN (i1), 0)) != 0;
8058 i1 = NEXT_INSN (i1);
8060 if (n_occurrences <= n_inherited && i1 == insn)
8066 /* We will be deleting the insn. Remove the spill reg information. */
8067 for (k = hard_regno_nregs[last_reload_reg][GET_MODE (reg)]; k-- > 0; )
8069 spill_reg_store[last_reload_reg + k] = 0;
8070 spill_reg_stored_to[last_reload_reg + k] = 0;
8073 /* The caller has already checked that REG dies or is set in INSN.
8074 It has also checked that we are optimizing, and thus some
8075 inaccuracies in the debugging information are acceptable.
8076 So we could just delete output_reload_insn. But in some cases
8077 we can improve the debugging information without sacrificing
8078 optimization - maybe even improving the code: See if the pseudo
8079 reg has been completely replaced with reload regs. If so, delete
8080 the store insn and forget we had a stack slot for the pseudo. */
8081 if (rld[j].out != rld[j].in
8082 && REG_N_DEATHS (REGNO (reg)) == 1
8083 && REG_N_SETS (REGNO (reg)) == 1
8084 && REG_BASIC_BLOCK (REGNO (reg)) >= 0
8085 && find_regno_note (insn, REG_DEAD, REGNO (reg)))
8089 /* We know that it was used only between here and the beginning of
8090 the current basic block. (We also know that the last use before
8091 INSN was the output reload we are thinking of deleting, but never
8092 mind that.) Search that range; see if any ref remains. */
8093 for (i2 = PREV_INSN (insn); i2; i2 = PREV_INSN (i2))
8095 rtx set = single_set (i2);
8097 /* Uses which just store in the pseudo don't count,
8098 since if they are the only uses, they are dead. */
8099 if (set != 0 && SET_DEST (set) == reg)
8104 if ((NONJUMP_INSN_P (i2) || CALL_P (i2))
8105 && reg_mentioned_p (reg, PATTERN (i2)))
8107 /* Some other ref remains; just delete the output reload we
8109 delete_address_reloads (output_reload_insn, insn);
8110 delete_insn (output_reload_insn);
8115 /* Delete the now-dead stores into this pseudo. Note that this
8116 loop also takes care of deleting output_reload_insn. */
8117 for (i2 = PREV_INSN (insn); i2; i2 = PREV_INSN (i2))
8119 rtx set = single_set (i2);
8121 if (set != 0 && SET_DEST (set) == reg)
8123 delete_address_reloads (i2, insn);
8131 /* For the debugging info, say the pseudo lives in this reload reg. */
8132 reg_renumber[REGNO (reg)] = REGNO (rld[j].reg_rtx);
8133 alter_reg (REGNO (reg), -1);
8137 delete_address_reloads (output_reload_insn, insn);
8138 delete_insn (output_reload_insn);
8142 /* We are going to delete DEAD_INSN. Recursively delete loads of
8143 reload registers used in DEAD_INSN that are not used till CURRENT_INSN.
8144 CURRENT_INSN is being reloaded, so we have to check its reloads too. */
8146 delete_address_reloads (rtx dead_insn, rtx current_insn)
8148 rtx set = single_set (dead_insn);
8149 rtx set2, dst, prev, next;
8152 rtx dst = SET_DEST (set);
8154 delete_address_reloads_1 (dead_insn, XEXP (dst, 0), current_insn);
8156 /* If we deleted the store from a reloaded post_{in,de}c expression,
8157 we can delete the matching adds. */
8158 prev = PREV_INSN (dead_insn);
8159 next = NEXT_INSN (dead_insn);
8160 if (! prev || ! next)
8162 set = single_set (next);
8163 set2 = single_set (prev);
8165 || GET_CODE (SET_SRC (set)) != PLUS || GET_CODE (SET_SRC (set2)) != PLUS
8166 || GET_CODE (XEXP (SET_SRC (set), 1)) != CONST_INT
8167 || GET_CODE (XEXP (SET_SRC (set2), 1)) != CONST_INT)
8169 dst = SET_DEST (set);
8170 if (! rtx_equal_p (dst, SET_DEST (set2))
8171 || ! rtx_equal_p (dst, XEXP (SET_SRC (set), 0))
8172 || ! rtx_equal_p (dst, XEXP (SET_SRC (set2), 0))
8173 || (INTVAL (XEXP (SET_SRC (set), 1))
8174 != -INTVAL (XEXP (SET_SRC (set2), 1))))
8176 delete_related_insns (prev);
8177 delete_related_insns (next);
8180 /* Subfunction of delete_address_reloads: process registers found in X. */
8182 delete_address_reloads_1 (rtx dead_insn, rtx x, rtx current_insn)
8184 rtx prev, set, dst, i2;
8186 enum rtx_code code = GET_CODE (x);
8190 const char *fmt = GET_RTX_FORMAT (code);
8191 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
8194 delete_address_reloads_1 (dead_insn, XEXP (x, i), current_insn);
8195 else if (fmt[i] == 'E')
8197 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
8198 delete_address_reloads_1 (dead_insn, XVECEXP (x, i, j),
8205 if (spill_reg_order[REGNO (x)] < 0)
8208 /* Scan backwards for the insn that sets x. This might be a way back due
8210 for (prev = PREV_INSN (dead_insn); prev; prev = PREV_INSN (prev))
8212 code = GET_CODE (prev);
8213 if (code == CODE_LABEL || code == JUMP_INSN)
8217 if (reg_set_p (x, PATTERN (prev)))
8219 if (reg_referenced_p (x, PATTERN (prev)))
8222 if (! prev || INSN_UID (prev) < reload_first_uid)
8224 /* Check that PREV only sets the reload register. */
8225 set = single_set (prev);
8228 dst = SET_DEST (set);
8230 || ! rtx_equal_p (dst, x))
8232 if (! reg_set_p (dst, PATTERN (dead_insn)))
8234 /* Check if DST was used in a later insn -
8235 it might have been inherited. */
8236 for (i2 = NEXT_INSN (dead_insn); i2; i2 = NEXT_INSN (i2))
8242 if (reg_referenced_p (dst, PATTERN (i2)))
8244 /* If there is a reference to the register in the current insn,
8245 it might be loaded in a non-inherited reload. If no other
8246 reload uses it, that means the register is set before
8248 if (i2 == current_insn)
8250 for (j = n_reloads - 1; j >= 0; j--)
8251 if ((rld[j].reg_rtx == dst && reload_inherited[j])
8252 || reload_override_in[j] == dst)
8254 for (j = n_reloads - 1; j >= 0; j--)
8255 if (rld[j].in && rld[j].reg_rtx == dst)
8264 /* If DST is still live at CURRENT_INSN, check if it is used for
8265 any reload. Note that even if CURRENT_INSN sets DST, we still
8266 have to check the reloads. */
8267 if (i2 == current_insn)
8269 for (j = n_reloads - 1; j >= 0; j--)
8270 if ((rld[j].reg_rtx == dst && reload_inherited[j])
8271 || reload_override_in[j] == dst)
8273 /* ??? We can't finish the loop here, because dst might be
8274 allocated to a pseudo in this block if no reload in this
8275 block needs any of the classes containing DST - see
8276 spill_hard_reg. There is no easy way to tell this, so we
8277 have to scan till the end of the basic block. */
8279 if (reg_set_p (dst, PATTERN (i2)))
8283 delete_address_reloads_1 (prev, SET_SRC (set), current_insn);
8284 reg_reloaded_contents[REGNO (dst)] = -1;
8288 /* Output reload-insns to reload VALUE into RELOADREG.
8289 VALUE is an autoincrement or autodecrement RTX whose operand
8290 is a register or memory location;
8291 so reloading involves incrementing that location.
8292 IN is either identical to VALUE, or some cheaper place to reload from.
8294 INC_AMOUNT is the number to increment or decrement by (always positive).
8295 This cannot be deduced from VALUE.
8297 Return the instruction that stores into RELOADREG. */
8300 inc_for_reload (rtx reloadreg, rtx in, rtx value, int inc_amount)
8302 /* REG or MEM to be copied and incremented. */
8303 rtx incloc = find_replacement (&XEXP (value, 0));
8304 /* Nonzero if increment after copying. */
8305 int post = (GET_CODE (value) == POST_DEC || GET_CODE (value) == POST_INC
8306 || GET_CODE (value) == POST_MODIFY);
8312 rtx real_in = in == value ? incloc : in;
8314 /* No hard register is equivalent to this register after
8315 inc/dec operation. If REG_LAST_RELOAD_REG were nonzero,
8316 we could inc/dec that register as well (maybe even using it for
8317 the source), but I'm not sure it's worth worrying about. */
8319 reg_last_reload_reg[REGNO (incloc)] = 0;
8321 if (GET_CODE (value) == PRE_MODIFY || GET_CODE (value) == POST_MODIFY)
8323 gcc_assert (GET_CODE (XEXP (value, 1)) == PLUS);
8324 inc = find_replacement (&XEXP (XEXP (value, 1), 1));
8328 if (GET_CODE (value) == PRE_DEC || GET_CODE (value) == POST_DEC)
8329 inc_amount = -inc_amount;
8331 inc = GEN_INT (inc_amount);
8334 /* If this is post-increment, first copy the location to the reload reg. */
8335 if (post && real_in != reloadreg)
8336 emit_insn (gen_move_insn (reloadreg, real_in));
8340 /* See if we can directly increment INCLOC. Use a method similar to
8341 that in gen_reload. */
8343 last = get_last_insn ();
8344 add_insn = emit_insn (gen_rtx_SET (VOIDmode, incloc,
8345 gen_rtx_PLUS (GET_MODE (incloc),
8348 code = recog_memoized (add_insn);
8351 extract_insn (add_insn);
8352 if (constrain_operands (1))
8354 /* If this is a pre-increment and we have incremented the value
8355 where it lives, copy the incremented value to RELOADREG to
8356 be used as an address. */
8359 emit_insn (gen_move_insn (reloadreg, incloc));
8364 delete_insns_since (last);
8367 /* If couldn't do the increment directly, must increment in RELOADREG.
8368 The way we do this depends on whether this is pre- or post-increment.
8369 For pre-increment, copy INCLOC to the reload register, increment it
8370 there, then save back. */
8374 if (in != reloadreg)
8375 emit_insn (gen_move_insn (reloadreg, real_in));
8376 emit_insn (gen_add2_insn (reloadreg, inc));
8377 store = emit_insn (gen_move_insn (incloc, reloadreg));
8382 Because this might be a jump insn or a compare, and because RELOADREG
8383 may not be available after the insn in an input reload, we must do
8384 the incrementation before the insn being reloaded for.
8386 We have already copied IN to RELOADREG. Increment the copy in
8387 RELOADREG, save that back, then decrement RELOADREG so it has
8388 the original value. */
8390 emit_insn (gen_add2_insn (reloadreg, inc));
8391 store = emit_insn (gen_move_insn (incloc, reloadreg));
8392 if (GET_CODE (inc) == CONST_INT)
8393 emit_insn (gen_add2_insn (reloadreg, GEN_INT (-INTVAL (inc))));
8395 emit_insn (gen_sub2_insn (reloadreg, inc));
8403 add_auto_inc_notes (rtx insn, rtx x)
8405 enum rtx_code code = GET_CODE (x);
8409 if (code == MEM && auto_inc_p (XEXP (x, 0)))
8412 = gen_rtx_EXPR_LIST (REG_INC, XEXP (XEXP (x, 0), 0), REG_NOTES (insn));
8416 /* Scan all the operand sub-expressions. */
8417 fmt = GET_RTX_FORMAT (code);
8418 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
8421 add_auto_inc_notes (insn, XEXP (x, i));
8422 else if (fmt[i] == 'E')
8423 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
8424 add_auto_inc_notes (insn, XVECEXP (x, i, j));
8429 /* Copy EH notes from an insn to its reloads. */
8431 copy_eh_notes (rtx insn, rtx x)
8433 rtx eh_note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
8436 for (; x != 0; x = NEXT_INSN (x))
8438 if (may_trap_p (PATTERN (x)))
8440 = gen_rtx_EXPR_LIST (REG_EH_REGION, XEXP (eh_note, 0),
8446 /* This is used by reload pass, that does emit some instructions after
8447 abnormal calls moving basic block end, but in fact it wants to emit
8448 them on the edge. Looks for abnormal call edges, find backward the
8449 proper call and fix the damage.
8451 Similar handle instructions throwing exceptions internally. */
8453 fixup_abnormal_edges (void)
8455 bool inserted = false;
8463 /* Look for cases we are interested in - calls or instructions causing
8465 FOR_EACH_EDGE (e, ei, bb->succs)
8467 if (e->flags & EDGE_ABNORMAL_CALL)
8469 if ((e->flags & (EDGE_ABNORMAL | EDGE_EH))
8470 == (EDGE_ABNORMAL | EDGE_EH))
8473 if (e && !CALL_P (BB_END (bb))
8474 && !can_throw_internal (BB_END (bb)))
8478 /* Get past the new insns generated. Allow notes, as the insns
8479 may be already deleted. */
8481 while ((NONJUMP_INSN_P (insn) || NOTE_P (insn))
8482 && !can_throw_internal (insn)
8483 && insn != BB_HEAD (bb))
8484 insn = PREV_INSN (insn);
8486 if (CALL_P (insn) || can_throw_internal (insn))
8490 stop = NEXT_INSN (BB_END (bb));
8492 insn = NEXT_INSN (insn);
8494 FOR_EACH_EDGE (e, ei, bb->succs)
8495 if (e->flags & EDGE_FALLTHRU)
8498 while (insn && insn != stop)
8500 next = NEXT_INSN (insn);
8505 /* Sometimes there's still the return value USE.
8506 If it's placed after a trapping call (i.e. that
8507 call is the last insn anyway), we have no fallthru
8508 edge. Simply delete this use and don't try to insert
8509 on the non-existent edge. */
8510 if (GET_CODE (PATTERN (insn)) != USE)
8512 /* We're not deleting it, we're moving it. */
8513 INSN_DELETED_P (insn) = 0;
8514 PREV_INSN (insn) = NULL_RTX;
8515 NEXT_INSN (insn) = NULL_RTX;
8517 insert_insn_on_edge (insn, e);
8525 /* It may be that we don't find any such trapping insn. In this
8526 case we discovered quite late that the insn that had been
8527 marked as can_throw_internal in fact couldn't trap at all.
8528 So we should in fact delete the EH edges out of the block. */
8530 purge_dead_edges (bb);
8534 /* We've possibly turned single trapping insn into multiple ones. */
8535 if (flag_non_call_exceptions)
8538 blocks = sbitmap_alloc (last_basic_block);
8539 sbitmap_ones (blocks);
8540 find_many_sub_basic_blocks (blocks);
8544 commit_edge_insertions ();
8546 #ifdef ENABLE_CHECKING
8547 /* Verify that we didn't turn one trapping insn into many, and that
8548 we found and corrected all of the problems wrt fixups on the
8550 verify_flow_info ();
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