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 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
24 #include "coretypes.h"
28 #include "hard-reg-set.h"
32 #include "insn-config.h"
38 #include "basic-block.h"
47 /* This file contains the reload pass of the compiler, which is
48 run after register allocation has been done. It checks that
49 each insn is valid (operands required to be in registers really
50 are in registers of the proper class) and fixes up invalid ones
51 by copying values temporarily into registers for the insns
54 The results of register allocation are described by the vector
55 reg_renumber; the insns still contain pseudo regs, but reg_renumber
56 can be used to find which hard reg, if any, a pseudo reg is in.
58 The technique we always use is to free up a few hard regs that are
59 called ``reload regs'', and for each place where a pseudo reg
60 must be in a hard reg, copy it temporarily into one of the reload regs.
62 Reload regs are allocated locally for every instruction that needs
63 reloads. When there are pseudos which are allocated to a register that
64 has been chosen as a reload reg, such pseudos must be ``spilled''.
65 This means that they go to other hard regs, or to stack slots if no other
66 available hard regs can be found. Spilling can invalidate more
67 insns, requiring additional need for reloads, so we must keep checking
68 until the process stabilizes.
70 For machines with different classes of registers, we must keep track
71 of the register class needed for each reload, and make sure that
72 we allocate enough reload registers of each class.
74 The file reload.c contains the code that checks one insn for
75 validity and reports the reloads that it needs. This file
76 is in charge of scanning the entire rtl code, accumulating the
77 reload needs, spilling, assigning reload registers to use for
78 fixing up each insn, and generating the new insns to copy values
79 into the reload registers. */
81 /* During reload_as_needed, element N contains a REG rtx for the hard reg
82 into which reg N has been reloaded (perhaps for a previous insn). */
83 static rtx *reg_last_reload_reg;
85 /* Elt N nonzero if reg_last_reload_reg[N] has been set in this insn
86 for an output reload that stores into reg N. */
87 static char *reg_has_output_reload;
89 /* Indicates which hard regs are reload-registers for an output reload
90 in the current insn. */
91 static HARD_REG_SET reg_is_output_reload;
93 /* Element N is the constant value to which pseudo reg N is equivalent,
94 or zero if pseudo reg N is not equivalent to a constant.
95 find_reloads looks at this in order to replace pseudo reg N
96 with the constant it stands for. */
97 rtx *reg_equiv_constant;
99 /* Element N is a memory location to which pseudo reg N is equivalent,
100 prior to any register elimination (such as frame pointer to stack
101 pointer). Depending on whether or not it is a valid address, this value
102 is transferred to either reg_equiv_address or reg_equiv_mem. */
103 rtx *reg_equiv_memory_loc;
105 /* Element N is the address of stack slot to which pseudo reg N is equivalent.
106 This is used when the address is not valid as a memory address
107 (because its displacement is too big for the machine.) */
108 rtx *reg_equiv_address;
110 /* Element N is the memory slot to which pseudo reg N is equivalent,
111 or zero if pseudo reg N is not equivalent to a memory slot. */
114 /* Widest width in which each pseudo reg is referred to (via subreg). */
115 static unsigned int *reg_max_ref_width;
117 /* Element N is the list of insns that initialized reg N from its equivalent
118 constant or memory slot. */
119 static rtx *reg_equiv_init;
121 /* Vector to remember old contents of reg_renumber before spilling. */
122 static short *reg_old_renumber;
124 /* During reload_as_needed, element N contains the last pseudo regno reloaded
125 into hard register N. If that pseudo reg occupied more than one register,
126 reg_reloaded_contents points to that pseudo for each spill register in
127 use; all of these must remain set for an inheritance to occur. */
128 static int reg_reloaded_contents[FIRST_PSEUDO_REGISTER];
130 /* During reload_as_needed, element N contains the insn for which
131 hard register N was last used. Its contents are significant only
132 when reg_reloaded_valid is set for this register. */
133 static rtx reg_reloaded_insn[FIRST_PSEUDO_REGISTER];
135 /* Indicate if reg_reloaded_insn / reg_reloaded_contents is valid. */
136 static HARD_REG_SET reg_reloaded_valid;
137 /* Indicate if the register was dead at the end of the reload.
138 This is only valid if reg_reloaded_contents is set and valid. */
139 static HARD_REG_SET reg_reloaded_dead;
141 /* Indicate whether the register's current value is one that is not
142 safe to retain across a call, even for registers that are normally
144 static HARD_REG_SET reg_reloaded_call_part_clobbered;
146 /* Number of spill-regs so far; number of valid elements of spill_regs. */
149 /* In parallel with spill_regs, contains REG rtx's for those regs.
150 Holds the last rtx used for any given reg, or 0 if it has never
151 been used for spilling yet. This rtx is reused, provided it has
153 static rtx spill_reg_rtx[FIRST_PSEUDO_REGISTER];
155 /* In parallel with spill_regs, contains nonzero for a spill reg
156 that was stored after the last time it was used.
157 The precise value is the insn generated to do the store. */
158 static rtx spill_reg_store[FIRST_PSEUDO_REGISTER];
160 /* This is the register that was stored with spill_reg_store. This is a
161 copy of reload_out / reload_out_reg when the value was stored; if
162 reload_out is a MEM, spill_reg_stored_to will be set to reload_out_reg. */
163 static rtx spill_reg_stored_to[FIRST_PSEUDO_REGISTER];
165 /* This table is the inverse mapping of spill_regs:
166 indexed by hard reg number,
167 it contains the position of that reg in spill_regs,
168 or -1 for something that is not in spill_regs.
170 ?!? This is no longer accurate. */
171 static short spill_reg_order[FIRST_PSEUDO_REGISTER];
173 /* This reg set indicates registers that can't be used as spill registers for
174 the currently processed insn. These are the hard registers which are live
175 during the insn, but not allocated to pseudos, as well as fixed
177 static HARD_REG_SET bad_spill_regs;
179 /* These are the hard registers that can't be used as spill register for any
180 insn. This includes registers used for user variables and registers that
181 we can't eliminate. A register that appears in this set also can't be used
182 to retry register allocation. */
183 static HARD_REG_SET bad_spill_regs_global;
185 /* Describes order of use of registers for reloading
186 of spilled pseudo-registers. `n_spills' is the number of
187 elements that are actually valid; new ones are added at the end.
189 Both spill_regs and spill_reg_order are used on two occasions:
190 once during find_reload_regs, where they keep track of the spill registers
191 for a single insn, but also during reload_as_needed where they show all
192 the registers ever used by reload. For the latter case, the information
193 is calculated during finish_spills. */
194 static short spill_regs[FIRST_PSEUDO_REGISTER];
196 /* This vector of reg sets indicates, for each pseudo, which hard registers
197 may not be used for retrying global allocation because the register was
198 formerly spilled from one of them. If we allowed reallocating a pseudo to
199 a register that it was already allocated to, reload might not
201 static HARD_REG_SET *pseudo_previous_regs;
203 /* This vector of reg sets indicates, for each pseudo, which hard
204 registers may not be used for retrying global allocation because they
205 are used as spill registers during one of the insns in which the
207 static HARD_REG_SET *pseudo_forbidden_regs;
209 /* All hard regs that have been used as spill registers for any insn are
210 marked in this set. */
211 static HARD_REG_SET used_spill_regs;
213 /* Index of last register assigned as a spill register. We allocate in
214 a round-robin fashion. */
215 static int last_spill_reg;
217 /* Nonzero if indirect addressing is supported on the machine; this means
218 that spilling (REG n) does not require reloading it into a register in
219 order to do (MEM (REG n)) or (MEM (PLUS (REG n) (CONST_INT c))). The
220 value indicates the level of indirect addressing supported, e.g., two
221 means that (MEM (MEM (REG n))) is also valid if (REG n) does not get
223 static char spill_indirect_levels;
225 /* Nonzero if indirect addressing is supported when the innermost MEM is
226 of the form (MEM (SYMBOL_REF sym)). It is assumed that the level to
227 which these are valid is the same as spill_indirect_levels, above. */
228 char indirect_symref_ok;
230 /* Nonzero if an address (plus (reg frame_pointer) (reg ...)) is valid. */
231 char double_reg_address_ok;
233 /* Record the stack slot for each spilled hard register. */
234 static rtx spill_stack_slot[FIRST_PSEUDO_REGISTER];
236 /* Width allocated so far for that stack slot. */
237 static unsigned int spill_stack_slot_width[FIRST_PSEUDO_REGISTER];
239 /* Record which pseudos needed to be spilled. */
240 static regset_head spilled_pseudos;
242 /* Used for communication between order_regs_for_reload and count_pseudo.
243 Used to avoid counting one pseudo twice. */
244 static regset_head pseudos_counted;
246 /* First uid used by insns created by reload in this function.
247 Used in find_equiv_reg. */
248 int reload_first_uid;
250 /* Flag set by local-alloc or global-alloc if anything is live in
251 a call-clobbered reg across calls. */
252 int caller_save_needed;
254 /* Set to 1 while reload_as_needed is operating.
255 Required by some machines to handle any generated moves differently. */
256 int reload_in_progress = 0;
258 /* These arrays record the insn_code of insns that may be needed to
259 perform input and output reloads of special objects. They provide a
260 place to pass a scratch register. */
261 enum insn_code reload_in_optab[NUM_MACHINE_MODES];
262 enum insn_code reload_out_optab[NUM_MACHINE_MODES];
264 /* This obstack is used for allocation of rtl during register elimination.
265 The allocated storage can be freed once find_reloads has processed the
267 struct obstack reload_obstack;
269 /* Points to the beginning of the reload_obstack. All insn_chain structures
270 are allocated first. */
271 char *reload_startobj;
273 /* The point after all insn_chain structures. Used to quickly deallocate
274 memory allocated in copy_reloads during calculate_needs_all_insns. */
275 char *reload_firstobj;
277 /* This points before all local rtl generated by register elimination.
278 Used to quickly free all memory after processing one insn. */
279 static char *reload_insn_firstobj;
281 /* List of insn_chain instructions, one for every insn that reload needs to
283 struct insn_chain *reload_insn_chain;
285 /* List of all insns needing reloads. */
286 static struct insn_chain *insns_need_reload;
288 /* This structure is used to record information about register eliminations.
289 Each array entry describes one possible way of eliminating a register
290 in favor of another. If there is more than one way of eliminating a
291 particular register, the most preferred should be specified first. */
295 int from; /* Register number to be eliminated. */
296 int to; /* Register number used as replacement. */
297 HOST_WIDE_INT initial_offset; /* Initial difference between values. */
298 int can_eliminate; /* Nonzero if this elimination can be done. */
299 int can_eliminate_previous; /* Value of CAN_ELIMINATE in previous scan over
300 insns made by reload. */
301 HOST_WIDE_INT offset; /* Current offset between the two regs. */
302 HOST_WIDE_INT previous_offset;/* Offset at end of previous insn. */
303 int ref_outside_mem; /* "to" has been referenced outside a MEM. */
304 rtx from_rtx; /* REG rtx for the register to be eliminated.
305 We cannot simply compare the number since
306 we might then spuriously replace a hard
307 register corresponding to a pseudo
308 assigned to the reg to be eliminated. */
309 rtx to_rtx; /* REG rtx for the replacement. */
312 static struct elim_table *reg_eliminate = 0;
314 /* This is an intermediate structure to initialize the table. It has
315 exactly the members provided by ELIMINABLE_REGS. */
316 static const struct elim_table_1
320 } reg_eliminate_1[] =
322 /* If a set of eliminable registers was specified, define the table from it.
323 Otherwise, default to the normal case of the frame pointer being
324 replaced by the stack pointer. */
326 #ifdef ELIMINABLE_REGS
329 {{ FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM}};
332 #define NUM_ELIMINABLE_REGS ARRAY_SIZE (reg_eliminate_1)
334 /* Record the number of pending eliminations that have an offset not equal
335 to their initial offset. If nonzero, we use a new copy of each
336 replacement result in any insns encountered. */
337 int num_not_at_initial_offset;
339 /* Count the number of registers that we may be able to eliminate. */
340 static int num_eliminable;
341 /* And the number of registers that are equivalent to a constant that
342 can be eliminated to frame_pointer / arg_pointer + constant. */
343 static int num_eliminable_invariants;
345 /* For each label, we record the offset of each elimination. If we reach
346 a label by more than one path and an offset differs, we cannot do the
347 elimination. This information is indexed by the difference of the
348 number of the label and the first label number. We can't offset the
349 pointer itself as this can cause problems on machines with segmented
350 memory. The first table is an array of flags that records whether we
351 have yet encountered a label and the second table is an array of arrays,
352 one entry in the latter array for each elimination. */
354 static int first_label_num;
355 static char *offsets_known_at;
356 static HOST_WIDE_INT (*offsets_at)[NUM_ELIMINABLE_REGS];
358 /* Number of labels in the current function. */
360 static int num_labels;
362 static void replace_pseudos_in (rtx *, enum machine_mode, rtx);
363 static void maybe_fix_stack_asms (void);
364 static void copy_reloads (struct insn_chain *);
365 static void calculate_needs_all_insns (int);
366 static int find_reg (struct insn_chain *, int);
367 static void find_reload_regs (struct insn_chain *);
368 static void select_reload_regs (void);
369 static void delete_caller_save_insns (void);
371 static void spill_failure (rtx, enum reg_class);
372 static void count_spilled_pseudo (int, int, int);
373 static void delete_dead_insn (rtx);
374 static void alter_reg (int, int);
375 static void set_label_offsets (rtx, rtx, int);
376 static void check_eliminable_occurrences (rtx);
377 static void elimination_effects (rtx, enum machine_mode);
378 static int eliminate_regs_in_insn (rtx, int);
379 static void update_eliminable_offsets (void);
380 static void mark_not_eliminable (rtx, rtx, void *);
381 static void set_initial_elim_offsets (void);
382 static void verify_initial_elim_offsets (void);
383 static void set_initial_label_offsets (void);
384 static void set_offsets_for_label (rtx);
385 static void init_elim_table (void);
386 static void update_eliminables (HARD_REG_SET *);
387 static void spill_hard_reg (unsigned int, int);
388 static int finish_spills (int);
389 static void ior_hard_reg_set (HARD_REG_SET *, HARD_REG_SET *);
390 static void scan_paradoxical_subregs (rtx);
391 static void count_pseudo (int);
392 static void order_regs_for_reload (struct insn_chain *);
393 static void reload_as_needed (int);
394 static void forget_old_reloads_1 (rtx, rtx, void *);
395 static int reload_reg_class_lower (const void *, const void *);
396 static void mark_reload_reg_in_use (unsigned int, int, enum reload_type,
398 static void clear_reload_reg_in_use (unsigned int, int, enum reload_type,
400 static int reload_reg_free_p (unsigned int, int, enum reload_type);
401 static int reload_reg_free_for_value_p (int, int, int, enum reload_type,
403 static int free_for_value_p (int, enum machine_mode, int, enum reload_type,
405 static int reload_reg_reaches_end_p (unsigned int, int, enum reload_type);
406 static int allocate_reload_reg (struct insn_chain *, int, int);
407 static int conflicts_with_override (rtx);
408 static void failed_reload (rtx, int);
409 static int set_reload_reg (int, int);
410 static void choose_reload_regs_init (struct insn_chain *, rtx *);
411 static void choose_reload_regs (struct insn_chain *);
412 static void merge_assigned_reloads (rtx);
413 static void emit_input_reload_insns (struct insn_chain *, struct reload *,
415 static void emit_output_reload_insns (struct insn_chain *, struct reload *,
417 static void do_input_reload (struct insn_chain *, struct reload *, int);
418 static void do_output_reload (struct insn_chain *, struct reload *, int);
419 static void emit_reload_insns (struct insn_chain *);
420 static void delete_output_reload (rtx, int, int);
421 static void delete_address_reloads (rtx, rtx);
422 static void delete_address_reloads_1 (rtx, rtx, rtx);
423 static rtx inc_for_reload (rtx, rtx, rtx, int);
425 static void add_auto_inc_notes (rtx, rtx);
427 static void copy_eh_notes (rtx, rtx);
429 /* Initialize the reload pass once per compilation. */
436 /* Often (MEM (REG n)) is still valid even if (REG n) is put on the stack.
437 Set spill_indirect_levels to the number of levels such addressing is
438 permitted, zero if it is not permitted at all. */
441 = gen_rtx_MEM (Pmode,
444 LAST_VIRTUAL_REGISTER + 1),
446 spill_indirect_levels = 0;
448 while (memory_address_p (QImode, tem))
450 spill_indirect_levels++;
451 tem = gen_rtx_MEM (Pmode, tem);
454 /* See if indirect addressing is valid for (MEM (SYMBOL_REF ...)). */
456 tem = gen_rtx_MEM (Pmode, gen_rtx_SYMBOL_REF (Pmode, "foo"));
457 indirect_symref_ok = memory_address_p (QImode, tem);
459 /* See if reg+reg is a valid (and offsettable) address. */
461 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
463 tem = gen_rtx_PLUS (Pmode,
464 gen_rtx_REG (Pmode, HARD_FRAME_POINTER_REGNUM),
465 gen_rtx_REG (Pmode, i));
467 /* This way, we make sure that reg+reg is an offsettable address. */
468 tem = plus_constant (tem, 4);
470 if (memory_address_p (QImode, tem))
472 double_reg_address_ok = 1;
477 /* Initialize obstack for our rtl allocation. */
478 gcc_obstack_init (&reload_obstack);
479 reload_startobj = obstack_alloc (&reload_obstack, 0);
481 INIT_REG_SET (&spilled_pseudos);
482 INIT_REG_SET (&pseudos_counted);
485 /* List of insn chains that are currently unused. */
486 static struct insn_chain *unused_insn_chains = 0;
488 /* Allocate an empty insn_chain structure. */
490 new_insn_chain (void)
492 struct insn_chain *c;
494 if (unused_insn_chains == 0)
496 c = obstack_alloc (&reload_obstack, sizeof (struct insn_chain));
497 INIT_REG_SET (&c->live_throughout);
498 INIT_REG_SET (&c->dead_or_set);
502 c = unused_insn_chains;
503 unused_insn_chains = c->next;
505 c->is_caller_save_insn = 0;
506 c->need_operand_change = 0;
512 /* Small utility function to set all regs in hard reg set TO which are
513 allocated to pseudos in regset FROM. */
516 compute_use_by_pseudos (HARD_REG_SET *to, regset from)
520 EXECUTE_IF_SET_IN_REG_SET
521 (from, FIRST_PSEUDO_REGISTER, regno,
523 int r = reg_renumber[regno];
528 /* reload_combine uses the information from
529 BASIC_BLOCK->global_live_at_start, which might still
530 contain registers that have not actually been allocated
531 since they have an equivalence. */
532 if (! reload_completed)
537 nregs = hard_regno_nregs[r][PSEUDO_REGNO_MODE (regno)];
539 SET_HARD_REG_BIT (*to, r + nregs);
544 /* Replace all pseudos found in LOC with their corresponding
548 replace_pseudos_in (rtx *loc, enum machine_mode mem_mode, rtx usage)
561 unsigned int regno = REGNO (x);
563 if (regno < FIRST_PSEUDO_REGISTER)
566 x = eliminate_regs (x, mem_mode, usage);
570 replace_pseudos_in (loc, mem_mode, usage);
574 if (reg_equiv_constant[regno])
575 *loc = reg_equiv_constant[regno];
576 else if (reg_equiv_mem[regno])
577 *loc = reg_equiv_mem[regno];
578 else if (reg_equiv_address[regno])
579 *loc = gen_rtx_MEM (GET_MODE (x), reg_equiv_address[regno]);
580 else if (GET_CODE (regno_reg_rtx[regno]) != REG
581 || REGNO (regno_reg_rtx[regno]) != regno)
582 *loc = regno_reg_rtx[regno];
588 else if (code == MEM)
590 replace_pseudos_in (& XEXP (x, 0), GET_MODE (x), usage);
594 /* Process each of our operands recursively. */
595 fmt = GET_RTX_FORMAT (code);
596 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
598 replace_pseudos_in (&XEXP (x, i), mem_mode, usage);
599 else if (*fmt == 'E')
600 for (j = 0; j < XVECLEN (x, i); j++)
601 replace_pseudos_in (& XVECEXP (x, i, j), mem_mode, usage);
605 /* Global variables used by reload and its subroutines. */
607 /* Set during calculate_needs if an insn needs register elimination. */
608 static int something_needs_elimination;
609 /* Set during calculate_needs if an insn needs an operand changed. */
610 int something_needs_operands_changed;
612 /* Nonzero means we couldn't get enough spill regs. */
615 /* Main entry point for the reload pass.
617 FIRST is the first insn of the function being compiled.
619 GLOBAL nonzero means we were called from global_alloc
620 and should attempt to reallocate any pseudoregs that we
621 displace from hard regs we will use for reloads.
622 If GLOBAL is zero, we do not have enough information to do that,
623 so any pseudo reg that is spilled must go to the stack.
625 Return value is nonzero if reload failed
626 and we must not do any more for this function. */
629 reload (rtx first, int global)
633 struct elim_table *ep;
636 /* Make sure even insns with volatile mem refs are recognizable. */
641 reload_firstobj = obstack_alloc (&reload_obstack, 0);
643 /* Make sure that the last insn in the chain
644 is not something that needs reloading. */
645 emit_note (NOTE_INSN_DELETED);
647 /* Enable find_equiv_reg to distinguish insns made by reload. */
648 reload_first_uid = get_max_uid ();
650 #ifdef SECONDARY_MEMORY_NEEDED
651 /* Initialize the secondary memory table. */
652 clear_secondary_mem ();
655 /* We don't have a stack slot for any spill reg yet. */
656 memset (spill_stack_slot, 0, sizeof spill_stack_slot);
657 memset (spill_stack_slot_width, 0, sizeof spill_stack_slot_width);
659 /* Initialize the save area information for caller-save, in case some
663 /* Compute which hard registers are now in use
664 as homes for pseudo registers.
665 This is done here rather than (eg) in global_alloc
666 because this point is reached even if not optimizing. */
667 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
670 /* A function that receives a nonlocal goto must save all call-saved
672 if (current_function_has_nonlocal_label)
673 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
674 if (! call_used_regs[i] && ! fixed_regs[i] && ! LOCAL_REGNO (i))
675 regs_ever_live[i] = 1;
677 #ifdef NON_SAVING_SETJMP
678 /* A function that calls setjmp should save and restore all the
679 call-saved registers on a system where longjmp clobbers them. */
680 if (NON_SAVING_SETJMP && current_function_calls_setjmp)
682 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
683 if (! call_used_regs[i])
684 regs_ever_live[i] = 1;
688 /* Find all the pseudo registers that didn't get hard regs
689 but do have known equivalent constants or memory slots.
690 These include parameters (known equivalent to parameter slots)
691 and cse'd or loop-moved constant memory addresses.
693 Record constant equivalents in reg_equiv_constant
694 so they will be substituted by find_reloads.
695 Record memory equivalents in reg_mem_equiv so they can
696 be substituted eventually by altering the REG-rtx's. */
698 reg_equiv_constant = xcalloc (max_regno, sizeof (rtx));
699 reg_equiv_mem = xcalloc (max_regno, sizeof (rtx));
700 reg_equiv_init = xcalloc (max_regno, sizeof (rtx));
701 reg_equiv_address = xcalloc (max_regno, sizeof (rtx));
702 reg_max_ref_width = xcalloc (max_regno, sizeof (int));
703 reg_old_renumber = xcalloc (max_regno, sizeof (short));
704 memcpy (reg_old_renumber, reg_renumber, max_regno * sizeof (short));
705 pseudo_forbidden_regs = xmalloc (max_regno * sizeof (HARD_REG_SET));
706 pseudo_previous_regs = xcalloc (max_regno, sizeof (HARD_REG_SET));
708 CLEAR_HARD_REG_SET (bad_spill_regs_global);
710 /* Look for REG_EQUIV notes; record what each pseudo is equivalent to.
711 Also find all paradoxical subregs and find largest such for each pseudo.
712 On machines with small register classes, record hard registers that
713 are used for user variables. These can never be used for spills. */
715 num_eliminable_invariants = 0;
716 for (insn = first; insn; insn = NEXT_INSN (insn))
718 rtx set = single_set (insn);
720 /* We may introduce USEs that we want to remove at the end, so
721 we'll mark them with QImode. Make sure there are no
722 previously-marked insns left by say regmove. */
723 if (INSN_P (insn) && GET_CODE (PATTERN (insn)) == USE
724 && GET_MODE (insn) != VOIDmode)
725 PUT_MODE (insn, VOIDmode);
727 if (set != 0 && GET_CODE (SET_DEST (set)) == REG)
729 rtx note = find_reg_note (insn, REG_EQUIV, NULL_RTX);
731 #ifdef LEGITIMATE_PIC_OPERAND_P
732 && (! function_invariant_p (XEXP (note, 0))
734 /* A function invariant is often CONSTANT_P but may
735 include a register. We promise to only pass
736 CONSTANT_P objects to LEGITIMATE_PIC_OPERAND_P. */
737 || (CONSTANT_P (XEXP (note, 0))
738 && LEGITIMATE_PIC_OPERAND_P (XEXP (note, 0))))
742 rtx x = XEXP (note, 0);
743 i = REGNO (SET_DEST (set));
744 if (i > LAST_VIRTUAL_REGISTER)
746 /* It can happen that a REG_EQUIV note contains a MEM
747 that is not a legitimate memory operand. As later
748 stages of reload assume that all addresses found
749 in the reg_equiv_* arrays were originally legitimate,
750 we ignore such REG_EQUIV notes. */
751 if (memory_operand (x, VOIDmode))
753 /* Always unshare the equivalence, so we can
754 substitute into this insn without touching the
756 reg_equiv_memory_loc[i] = copy_rtx (x);
758 else if (function_invariant_p (x))
760 if (GET_CODE (x) == PLUS)
762 /* This is PLUS of frame pointer and a constant,
763 and might be shared. Unshare it. */
764 reg_equiv_constant[i] = copy_rtx (x);
765 num_eliminable_invariants++;
767 else if (x == frame_pointer_rtx
768 || x == arg_pointer_rtx)
770 reg_equiv_constant[i] = x;
771 num_eliminable_invariants++;
773 else if (LEGITIMATE_CONSTANT_P (x))
774 reg_equiv_constant[i] = x;
777 reg_equiv_memory_loc[i]
778 = force_const_mem (GET_MODE (SET_DEST (set)), x);
779 if (!reg_equiv_memory_loc[i])
786 /* If this register is being made equivalent to a MEM
787 and the MEM is not SET_SRC, the equivalencing insn
788 is one with the MEM as a SET_DEST and it occurs later.
789 So don't mark this insn now. */
790 if (GET_CODE (x) != MEM
791 || rtx_equal_p (SET_SRC (set), x))
793 = gen_rtx_INSN_LIST (VOIDmode, insn, reg_equiv_init[i]);
798 /* If this insn is setting a MEM from a register equivalent to it,
799 this is the equivalencing insn. */
800 else if (set && GET_CODE (SET_DEST (set)) == MEM
801 && GET_CODE (SET_SRC (set)) == REG
802 && reg_equiv_memory_loc[REGNO (SET_SRC (set))]
803 && rtx_equal_p (SET_DEST (set),
804 reg_equiv_memory_loc[REGNO (SET_SRC (set))]))
805 reg_equiv_init[REGNO (SET_SRC (set))]
806 = gen_rtx_INSN_LIST (VOIDmode, insn,
807 reg_equiv_init[REGNO (SET_SRC (set))]);
810 scan_paradoxical_subregs (PATTERN (insn));
815 first_label_num = get_first_label_num ();
816 num_labels = max_label_num () - first_label_num;
818 /* Allocate the tables used to store offset information at labels. */
819 /* We used to use alloca here, but the size of what it would try to
820 allocate would occasionally cause it to exceed the stack limit and
821 cause a core dump. */
822 offsets_known_at = xmalloc (num_labels);
823 offsets_at = xmalloc (num_labels * NUM_ELIMINABLE_REGS * sizeof (HOST_WIDE_INT));
825 /* Alter each pseudo-reg rtx to contain its hard reg number.
826 Assign stack slots to the pseudos that lack hard regs or equivalents.
827 Do not touch virtual registers. */
829 for (i = LAST_VIRTUAL_REGISTER + 1; i < max_regno; i++)
832 /* If we have some registers we think can be eliminated, scan all insns to
833 see if there is an insn that sets one of these registers to something
834 other than itself plus a constant. If so, the register cannot be
835 eliminated. Doing this scan here eliminates an extra pass through the
836 main reload loop in the most common case where register elimination
838 for (insn = first; insn && num_eliminable; insn = NEXT_INSN (insn))
839 if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
840 || GET_CODE (insn) == CALL_INSN)
841 note_stores (PATTERN (insn), mark_not_eliminable, NULL);
843 maybe_fix_stack_asms ();
845 insns_need_reload = 0;
846 something_needs_elimination = 0;
848 /* Initialize to -1, which means take the first spill register. */
851 /* Spill any hard regs that we know we can't eliminate. */
852 CLEAR_HARD_REG_SET (used_spill_regs);
853 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
854 if (! ep->can_eliminate)
855 spill_hard_reg (ep->from, 1);
857 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
858 if (frame_pointer_needed)
859 spill_hard_reg (HARD_FRAME_POINTER_REGNUM, 1);
861 finish_spills (global);
863 /* From now on, we may need to generate moves differently. We may also
864 allow modifications of insns which cause them to not be recognized.
865 Any such modifications will be cleaned up during reload itself. */
866 reload_in_progress = 1;
868 /* This loop scans the entire function each go-round
869 and repeats until one repetition spills no additional hard regs. */
872 int something_changed;
875 HOST_WIDE_INT starting_frame_size;
877 /* Round size of stack frame to stack_alignment_needed. This must be done
878 here because the stack size may be a part of the offset computation
879 for register elimination, and there might have been new stack slots
880 created in the last iteration of this loop. */
881 if (cfun->stack_alignment_needed)
882 assign_stack_local (BLKmode, 0, cfun->stack_alignment_needed);
884 starting_frame_size = get_frame_size ();
886 set_initial_elim_offsets ();
887 set_initial_label_offsets ();
889 /* For each pseudo register that has an equivalent location defined,
890 try to eliminate any eliminable registers (such as the frame pointer)
891 assuming initial offsets for the replacement register, which
894 If the resulting location is directly addressable, substitute
895 the MEM we just got directly for the old REG.
897 If it is not addressable but is a constant or the sum of a hard reg
898 and constant, it is probably not addressable because the constant is
899 out of range, in that case record the address; we will generate
900 hairy code to compute the address in a register each time it is
901 needed. Similarly if it is a hard register, but one that is not
902 valid as an address register.
904 If the location is not addressable, but does not have one of the
905 above forms, assign a stack slot. We have to do this to avoid the
906 potential of producing lots of reloads if, e.g., a location involves
907 a pseudo that didn't get a hard register and has an equivalent memory
908 location that also involves a pseudo that didn't get a hard register.
910 Perhaps at some point we will improve reload_when_needed handling
911 so this problem goes away. But that's very hairy. */
913 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
914 if (reg_renumber[i] < 0 && reg_equiv_memory_loc[i])
916 rtx x = eliminate_regs (reg_equiv_memory_loc[i], 0, NULL_RTX);
918 if (strict_memory_address_p (GET_MODE (regno_reg_rtx[i]),
920 reg_equiv_mem[i] = x, reg_equiv_address[i] = 0;
921 else if (CONSTANT_P (XEXP (x, 0))
922 || (GET_CODE (XEXP (x, 0)) == REG
923 && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER)
924 || (GET_CODE (XEXP (x, 0)) == PLUS
925 && GET_CODE (XEXP (XEXP (x, 0), 0)) == REG
926 && (REGNO (XEXP (XEXP (x, 0), 0))
927 < FIRST_PSEUDO_REGISTER)
928 && CONSTANT_P (XEXP (XEXP (x, 0), 1))))
929 reg_equiv_address[i] = XEXP (x, 0), reg_equiv_mem[i] = 0;
932 /* Make a new stack slot. Then indicate that something
933 changed so we go back and recompute offsets for
934 eliminable registers because the allocation of memory
935 below might change some offset. reg_equiv_{mem,address}
936 will be set up for this pseudo on the next pass around
938 reg_equiv_memory_loc[i] = 0;
939 reg_equiv_init[i] = 0;
944 if (caller_save_needed)
947 /* If we allocated another stack slot, redo elimination bookkeeping. */
948 if (starting_frame_size != get_frame_size ())
951 if (caller_save_needed)
953 save_call_clobbered_regs ();
954 /* That might have allocated new insn_chain structures. */
955 reload_firstobj = obstack_alloc (&reload_obstack, 0);
958 calculate_needs_all_insns (global);
960 CLEAR_REG_SET (&spilled_pseudos);
963 something_changed = 0;
965 /* If we allocated any new memory locations, make another pass
966 since it might have changed elimination offsets. */
967 if (starting_frame_size != get_frame_size ())
968 something_changed = 1;
971 HARD_REG_SET to_spill;
972 CLEAR_HARD_REG_SET (to_spill);
973 update_eliminables (&to_spill);
974 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
975 if (TEST_HARD_REG_BIT (to_spill, i))
977 spill_hard_reg (i, 1);
980 /* Regardless of the state of spills, if we previously had
981 a register that we thought we could eliminate, but now can
982 not eliminate, we must run another pass.
984 Consider pseudos which have an entry in reg_equiv_* which
985 reference an eliminable register. We must make another pass
986 to update reg_equiv_* so that we do not substitute in the
987 old value from when we thought the elimination could be
989 something_changed = 1;
993 select_reload_regs ();
997 if (insns_need_reload != 0 || did_spill)
998 something_changed |= finish_spills (global);
1000 if (! something_changed)
1003 if (caller_save_needed)
1004 delete_caller_save_insns ();
1006 obstack_free (&reload_obstack, reload_firstobj);
1009 /* If global-alloc was run, notify it of any register eliminations we have
1012 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
1013 if (ep->can_eliminate)
1014 mark_elimination (ep->from, ep->to);
1016 /* If a pseudo has no hard reg, delete the insns that made the equivalence.
1017 If that insn didn't set the register (i.e., it copied the register to
1018 memory), just delete that insn instead of the equivalencing insn plus
1019 anything now dead. If we call delete_dead_insn on that insn, we may
1020 delete the insn that actually sets the register if the register dies
1021 there and that is incorrect. */
1023 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
1025 if (reg_renumber[i] < 0 && reg_equiv_init[i] != 0)
1028 for (list = reg_equiv_init[i]; list; list = XEXP (list, 1))
1030 rtx equiv_insn = XEXP (list, 0);
1032 /* If we already deleted the insn or if it may trap, we can't
1033 delete it. The latter case shouldn't happen, but can
1034 if an insn has a variable address, gets a REG_EH_REGION
1035 note added to it, and then gets converted into an load
1036 from a constant address. */
1037 if (GET_CODE (equiv_insn) == NOTE
1038 || can_throw_internal (equiv_insn))
1040 else if (reg_set_p (regno_reg_rtx[i], PATTERN (equiv_insn)))
1041 delete_dead_insn (equiv_insn);
1044 PUT_CODE (equiv_insn, NOTE);
1045 NOTE_SOURCE_FILE (equiv_insn) = 0;
1046 NOTE_LINE_NUMBER (equiv_insn) = NOTE_INSN_DELETED;
1052 /* Use the reload registers where necessary
1053 by generating move instructions to move the must-be-register
1054 values into or out of the reload registers. */
1056 if (insns_need_reload != 0 || something_needs_elimination
1057 || something_needs_operands_changed)
1059 HOST_WIDE_INT old_frame_size = get_frame_size ();
1061 reload_as_needed (global);
1063 if (old_frame_size != get_frame_size ())
1067 verify_initial_elim_offsets ();
1070 /* If we were able to eliminate the frame pointer, show that it is no
1071 longer live at the start of any basic block. If it ls live by
1072 virtue of being in a pseudo, that pseudo will be marked live
1073 and hence the frame pointer will be known to be live via that
1076 if (! frame_pointer_needed)
1078 CLEAR_REGNO_REG_SET (bb->global_live_at_start,
1079 HARD_FRAME_POINTER_REGNUM);
1081 /* Come here (with failure set nonzero) if we can't get enough spill regs
1082 and we decide not to abort about it. */
1085 CLEAR_REG_SET (&spilled_pseudos);
1086 reload_in_progress = 0;
1088 /* Now eliminate all pseudo regs by modifying them into
1089 their equivalent memory references.
1090 The REG-rtx's for the pseudos are modified in place,
1091 so all insns that used to refer to them now refer to memory.
1093 For a reg that has a reg_equiv_address, all those insns
1094 were changed by reloading so that no insns refer to it any longer;
1095 but the DECL_RTL of a variable decl may refer to it,
1096 and if so this causes the debugging info to mention the variable. */
1098 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
1102 if (reg_equiv_mem[i])
1103 addr = XEXP (reg_equiv_mem[i], 0);
1105 if (reg_equiv_address[i])
1106 addr = reg_equiv_address[i];
1110 if (reg_renumber[i] < 0)
1112 rtx reg = regno_reg_rtx[i];
1114 REG_USERVAR_P (reg) = 0;
1115 PUT_CODE (reg, MEM);
1116 XEXP (reg, 0) = addr;
1117 if (reg_equiv_memory_loc[i])
1118 MEM_COPY_ATTRIBUTES (reg, reg_equiv_memory_loc[i]);
1121 RTX_UNCHANGING_P (reg) = MEM_IN_STRUCT_P (reg)
1122 = MEM_SCALAR_P (reg) = 0;
1123 MEM_ATTRS (reg) = 0;
1126 else if (reg_equiv_mem[i])
1127 XEXP (reg_equiv_mem[i], 0) = addr;
1131 /* We must set reload_completed now since the cleanup_subreg_operands call
1132 below will re-recognize each insn and reload may have generated insns
1133 which are only valid during and after reload. */
1134 reload_completed = 1;
1136 /* Make a pass over all the insns and delete all USEs which we inserted
1137 only to tag a REG_EQUAL note on them. Remove all REG_DEAD and REG_UNUSED
1138 notes. Delete all CLOBBER insns, except those that refer to the return
1139 value and the special mem:BLK CLOBBERs added to prevent the scheduler
1140 from misarranging variable-array code, and simplify (subreg (reg))
1141 operands. Also remove all REG_RETVAL and REG_LIBCALL notes since they
1142 are no longer useful or accurate. Strip and regenerate REG_INC notes
1143 that may have been moved around. */
1145 for (insn = first; insn; insn = NEXT_INSN (insn))
1150 if (GET_CODE (insn) == CALL_INSN)
1151 replace_pseudos_in (& CALL_INSN_FUNCTION_USAGE (insn),
1152 VOIDmode, CALL_INSN_FUNCTION_USAGE (insn));
1154 if ((GET_CODE (PATTERN (insn)) == USE
1155 /* We mark with QImode USEs introduced by reload itself. */
1156 && (GET_MODE (insn) == QImode
1157 || find_reg_note (insn, REG_EQUAL, NULL_RTX)))
1158 || (GET_CODE (PATTERN (insn)) == CLOBBER
1159 && (GET_CODE (XEXP (PATTERN (insn), 0)) != MEM
1160 || GET_MODE (XEXP (PATTERN (insn), 0)) != BLKmode
1161 || (GET_CODE (XEXP (XEXP (PATTERN (insn), 0), 0)) != SCRATCH
1162 && XEXP (XEXP (PATTERN (insn), 0), 0)
1163 != stack_pointer_rtx))
1164 && (GET_CODE (XEXP (PATTERN (insn), 0)) != REG
1165 || ! REG_FUNCTION_VALUE_P (XEXP (PATTERN (insn), 0)))))
1171 /* Some CLOBBERs may survive until here and still reference unassigned
1172 pseudos with const equivalent, which may in turn cause ICE in later
1173 passes if the reference remains in place. */
1174 if (GET_CODE (PATTERN (insn)) == CLOBBER)
1175 replace_pseudos_in (& XEXP (PATTERN (insn), 0),
1176 VOIDmode, PATTERN (insn));
1178 pnote = ®_NOTES (insn);
1181 if (REG_NOTE_KIND (*pnote) == REG_DEAD
1182 || REG_NOTE_KIND (*pnote) == REG_UNUSED
1183 || REG_NOTE_KIND (*pnote) == REG_INC
1184 || REG_NOTE_KIND (*pnote) == REG_RETVAL
1185 || REG_NOTE_KIND (*pnote) == REG_LIBCALL)
1186 *pnote = XEXP (*pnote, 1);
1188 pnote = &XEXP (*pnote, 1);
1192 add_auto_inc_notes (insn, PATTERN (insn));
1195 /* And simplify (subreg (reg)) if it appears as an operand. */
1196 cleanup_subreg_operands (insn);
1199 /* If we are doing stack checking, give a warning if this function's
1200 frame size is larger than we expect. */
1201 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
1203 HOST_WIDE_INT size = get_frame_size () + STACK_CHECK_FIXED_FRAME_SIZE;
1204 static int verbose_warned = 0;
1206 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1207 if (regs_ever_live[i] && ! fixed_regs[i] && call_used_regs[i])
1208 size += UNITS_PER_WORD;
1210 if (size > STACK_CHECK_MAX_FRAME_SIZE)
1212 warning ("frame size too large for reliable stack checking");
1213 if (! verbose_warned)
1215 warning ("try reducing the number of local variables");
1221 /* Indicate that we no longer have known memory locations or constants. */
1222 if (reg_equiv_constant)
1223 free (reg_equiv_constant);
1224 reg_equiv_constant = 0;
1225 if (reg_equiv_memory_loc)
1226 free (reg_equiv_memory_loc);
1227 reg_equiv_memory_loc = 0;
1229 if (offsets_known_at)
1230 free (offsets_known_at);
1234 free (reg_equiv_mem);
1235 free (reg_equiv_init);
1236 free (reg_equiv_address);
1237 free (reg_max_ref_width);
1238 free (reg_old_renumber);
1239 free (pseudo_previous_regs);
1240 free (pseudo_forbidden_regs);
1242 CLEAR_HARD_REG_SET (used_spill_regs);
1243 for (i = 0; i < n_spills; i++)
1244 SET_HARD_REG_BIT (used_spill_regs, spill_regs[i]);
1246 /* Free all the insn_chain structures at once. */
1247 obstack_free (&reload_obstack, reload_startobj);
1248 unused_insn_chains = 0;
1249 fixup_abnormal_edges ();
1251 /* Replacing pseudos with their memory equivalents might have
1252 created shared rtx. Subsequent passes would get confused
1253 by this, so unshare everything here. */
1254 unshare_all_rtl_again (first);
1256 #ifdef STACK_BOUNDARY
1257 /* init_emit has set the alignment of the hard frame pointer
1258 to STACK_BOUNDARY. It is very likely no longer valid if
1259 the hard frame pointer was used for register allocation. */
1260 if (!frame_pointer_needed)
1261 REGNO_POINTER_ALIGN (HARD_FRAME_POINTER_REGNUM) = BITS_PER_UNIT;
1267 /* Yet another special case. Unfortunately, reg-stack forces people to
1268 write incorrect clobbers in asm statements. These clobbers must not
1269 cause the register to appear in bad_spill_regs, otherwise we'll call
1270 fatal_insn later. We clear the corresponding regnos in the live
1271 register sets to avoid this.
1272 The whole thing is rather sick, I'm afraid. */
1275 maybe_fix_stack_asms (void)
1278 const char *constraints[MAX_RECOG_OPERANDS];
1279 enum machine_mode operand_mode[MAX_RECOG_OPERANDS];
1280 struct insn_chain *chain;
1282 for (chain = reload_insn_chain; chain != 0; chain = chain->next)
1285 HARD_REG_SET clobbered, allowed;
1288 if (! INSN_P (chain->insn)
1289 || (noperands = asm_noperands (PATTERN (chain->insn))) < 0)
1291 pat = PATTERN (chain->insn);
1292 if (GET_CODE (pat) != PARALLEL)
1295 CLEAR_HARD_REG_SET (clobbered);
1296 CLEAR_HARD_REG_SET (allowed);
1298 /* First, make a mask of all stack regs that are clobbered. */
1299 for (i = 0; i < XVECLEN (pat, 0); i++)
1301 rtx t = XVECEXP (pat, 0, i);
1302 if (GET_CODE (t) == CLOBBER && STACK_REG_P (XEXP (t, 0)))
1303 SET_HARD_REG_BIT (clobbered, REGNO (XEXP (t, 0)));
1306 /* Get the operand values and constraints out of the insn. */
1307 decode_asm_operands (pat, recog_data.operand, recog_data.operand_loc,
1308 constraints, operand_mode);
1310 /* For every operand, see what registers are allowed. */
1311 for (i = 0; i < noperands; i++)
1313 const char *p = constraints[i];
1314 /* For every alternative, we compute the class of registers allowed
1315 for reloading in CLS, and merge its contents into the reg set
1317 int cls = (int) NO_REGS;
1323 if (c == '\0' || c == ',' || c == '#')
1325 /* End of one alternative - mark the regs in the current
1326 class, and reset the class. */
1327 IOR_HARD_REG_SET (allowed, reg_class_contents[cls]);
1333 } while (c != '\0' && c != ',');
1341 case '=': case '+': case '*': case '%': case '?': case '!':
1342 case '0': case '1': case '2': case '3': case '4': case 'm':
1343 case '<': case '>': case 'V': case 'o': case '&': case 'E':
1344 case 'F': case 's': case 'i': case 'n': case 'X': case 'I':
1345 case 'J': case 'K': case 'L': case 'M': case 'N': case 'O':
1350 cls = (int) reg_class_subunion[cls]
1351 [(int) MODE_BASE_REG_CLASS (VOIDmode)];
1356 cls = (int) reg_class_subunion[cls][(int) GENERAL_REGS];
1360 if (EXTRA_ADDRESS_CONSTRAINT (c, p))
1361 cls = (int) reg_class_subunion[cls]
1362 [(int) MODE_BASE_REG_CLASS (VOIDmode)];
1364 cls = (int) reg_class_subunion[cls]
1365 [(int) REG_CLASS_FROM_CONSTRAINT (c, p)];
1367 p += CONSTRAINT_LEN (c, p);
1370 /* Those of the registers which are clobbered, but allowed by the
1371 constraints, must be usable as reload registers. So clear them
1372 out of the life information. */
1373 AND_HARD_REG_SET (allowed, clobbered);
1374 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1375 if (TEST_HARD_REG_BIT (allowed, i))
1377 CLEAR_REGNO_REG_SET (&chain->live_throughout, i);
1378 CLEAR_REGNO_REG_SET (&chain->dead_or_set, i);
1385 /* Copy the global variables n_reloads and rld into the corresponding elts
1388 copy_reloads (struct insn_chain *chain)
1390 chain->n_reloads = n_reloads;
1391 chain->rld = obstack_alloc (&reload_obstack,
1392 n_reloads * sizeof (struct reload));
1393 memcpy (chain->rld, rld, n_reloads * sizeof (struct reload));
1394 reload_insn_firstobj = obstack_alloc (&reload_obstack, 0);
1397 /* Walk the chain of insns, and determine for each whether it needs reloads
1398 and/or eliminations. Build the corresponding insns_need_reload list, and
1399 set something_needs_elimination as appropriate. */
1401 calculate_needs_all_insns (int global)
1403 struct insn_chain **pprev_reload = &insns_need_reload;
1404 struct insn_chain *chain, *next = 0;
1406 something_needs_elimination = 0;
1408 reload_insn_firstobj = obstack_alloc (&reload_obstack, 0);
1409 for (chain = reload_insn_chain; chain != 0; chain = next)
1411 rtx insn = chain->insn;
1415 /* Clear out the shortcuts. */
1416 chain->n_reloads = 0;
1417 chain->need_elim = 0;
1418 chain->need_reload = 0;
1419 chain->need_operand_change = 0;
1421 /* If this is a label, a JUMP_INSN, or has REG_NOTES (which might
1422 include REG_LABEL), we need to see what effects this has on the
1423 known offsets at labels. */
1425 if (GET_CODE (insn) == CODE_LABEL || GET_CODE (insn) == JUMP_INSN
1426 || (INSN_P (insn) && REG_NOTES (insn) != 0))
1427 set_label_offsets (insn, insn, 0);
1431 rtx old_body = PATTERN (insn);
1432 int old_code = INSN_CODE (insn);
1433 rtx old_notes = REG_NOTES (insn);
1434 int did_elimination = 0;
1435 int operands_changed = 0;
1436 rtx set = single_set (insn);
1438 /* Skip insns that only set an equivalence. */
1439 if (set && GET_CODE (SET_DEST (set)) == REG
1440 && reg_renumber[REGNO (SET_DEST (set))] < 0
1441 && reg_equiv_constant[REGNO (SET_DEST (set))])
1444 /* If needed, eliminate any eliminable registers. */
1445 if (num_eliminable || num_eliminable_invariants)
1446 did_elimination = eliminate_regs_in_insn (insn, 0);
1448 /* Analyze the instruction. */
1449 operands_changed = find_reloads (insn, 0, spill_indirect_levels,
1450 global, spill_reg_order);
1452 /* If a no-op set needs more than one reload, this is likely
1453 to be something that needs input address reloads. We
1454 can't get rid of this cleanly later, and it is of no use
1455 anyway, so discard it now.
1456 We only do this when expensive_optimizations is enabled,
1457 since this complements reload inheritance / output
1458 reload deletion, and it can make debugging harder. */
1459 if (flag_expensive_optimizations && n_reloads > 1)
1461 rtx set = single_set (insn);
1463 && SET_SRC (set) == SET_DEST (set)
1464 && GET_CODE (SET_SRC (set)) == REG
1465 && REGNO (SET_SRC (set)) >= FIRST_PSEUDO_REGISTER)
1468 /* Delete it from the reload chain. */
1470 chain->prev->next = next;
1472 reload_insn_chain = next;
1474 next->prev = chain->prev;
1475 chain->next = unused_insn_chains;
1476 unused_insn_chains = chain;
1481 update_eliminable_offsets ();
1483 /* Remember for later shortcuts which insns had any reloads or
1484 register eliminations. */
1485 chain->need_elim = did_elimination;
1486 chain->need_reload = n_reloads > 0;
1487 chain->need_operand_change = operands_changed;
1489 /* Discard any register replacements done. */
1490 if (did_elimination)
1492 obstack_free (&reload_obstack, reload_insn_firstobj);
1493 PATTERN (insn) = old_body;
1494 INSN_CODE (insn) = old_code;
1495 REG_NOTES (insn) = old_notes;
1496 something_needs_elimination = 1;
1499 something_needs_operands_changed |= operands_changed;
1503 copy_reloads (chain);
1504 *pprev_reload = chain;
1505 pprev_reload = &chain->next_need_reload;
1512 /* Comparison function for qsort to decide which of two reloads
1513 should be handled first. *P1 and *P2 are the reload numbers. */
1516 reload_reg_class_lower (const void *r1p, const void *r2p)
1518 int r1 = *(const short *) r1p, r2 = *(const short *) r2p;
1521 /* Consider required reloads before optional ones. */
1522 t = rld[r1].optional - rld[r2].optional;
1526 /* Count all solitary classes before non-solitary ones. */
1527 t = ((reg_class_size[(int) rld[r2].class] == 1)
1528 - (reg_class_size[(int) rld[r1].class] == 1));
1532 /* Aside from solitaires, consider all multi-reg groups first. */
1533 t = rld[r2].nregs - rld[r1].nregs;
1537 /* Consider reloads in order of increasing reg-class number. */
1538 t = (int) rld[r1].class - (int) rld[r2].class;
1542 /* If reloads are equally urgent, sort by reload number,
1543 so that the results of qsort leave nothing to chance. */
1547 /* The cost of spilling each hard reg. */
1548 static int spill_cost[FIRST_PSEUDO_REGISTER];
1550 /* When spilling multiple hard registers, we use SPILL_COST for the first
1551 spilled hard reg and SPILL_ADD_COST for subsequent regs. SPILL_ADD_COST
1552 only the first hard reg for a multi-reg pseudo. */
1553 static int spill_add_cost[FIRST_PSEUDO_REGISTER];
1555 /* Update the spill cost arrays, considering that pseudo REG is live. */
1558 count_pseudo (int reg)
1560 int freq = REG_FREQ (reg);
1561 int r = reg_renumber[reg];
1564 if (REGNO_REG_SET_P (&pseudos_counted, reg)
1565 || REGNO_REG_SET_P (&spilled_pseudos, reg))
1568 SET_REGNO_REG_SET (&pseudos_counted, reg);
1573 spill_add_cost[r] += freq;
1575 nregs = hard_regno_nregs[r][PSEUDO_REGNO_MODE (reg)];
1577 spill_cost[r + nregs] += freq;
1580 /* Calculate the SPILL_COST and SPILL_ADD_COST arrays and determine the
1581 contents of BAD_SPILL_REGS for the insn described by CHAIN. */
1584 order_regs_for_reload (struct insn_chain *chain)
1587 HARD_REG_SET used_by_pseudos;
1588 HARD_REG_SET used_by_pseudos2;
1590 COPY_HARD_REG_SET (bad_spill_regs, fixed_reg_set);
1592 memset (spill_cost, 0, sizeof spill_cost);
1593 memset (spill_add_cost, 0, sizeof spill_add_cost);
1595 /* Count number of uses of each hard reg by pseudo regs allocated to it
1596 and then order them by decreasing use. First exclude hard registers
1597 that are live in or across this insn. */
1599 REG_SET_TO_HARD_REG_SET (used_by_pseudos, &chain->live_throughout);
1600 REG_SET_TO_HARD_REG_SET (used_by_pseudos2, &chain->dead_or_set);
1601 IOR_HARD_REG_SET (bad_spill_regs, used_by_pseudos);
1602 IOR_HARD_REG_SET (bad_spill_regs, used_by_pseudos2);
1604 /* Now find out which pseudos are allocated to it, and update
1606 CLEAR_REG_SET (&pseudos_counted);
1608 EXECUTE_IF_SET_IN_REG_SET
1609 (&chain->live_throughout, FIRST_PSEUDO_REGISTER, i,
1613 EXECUTE_IF_SET_IN_REG_SET
1614 (&chain->dead_or_set, FIRST_PSEUDO_REGISTER, i,
1618 CLEAR_REG_SET (&pseudos_counted);
1621 /* Vector of reload-numbers showing the order in which the reloads should
1623 static short reload_order[MAX_RELOADS];
1625 /* This is used to keep track of the spill regs used in one insn. */
1626 static HARD_REG_SET used_spill_regs_local;
1628 /* We decided to spill hard register SPILLED, which has a size of
1629 SPILLED_NREGS. Determine how pseudo REG, which is live during the insn,
1630 is affected. We will add it to SPILLED_PSEUDOS if necessary, and we will
1631 update SPILL_COST/SPILL_ADD_COST. */
1634 count_spilled_pseudo (int spilled, int spilled_nregs, int reg)
1636 int r = reg_renumber[reg];
1637 int nregs = hard_regno_nregs[r][PSEUDO_REGNO_MODE (reg)];
1639 if (REGNO_REG_SET_P (&spilled_pseudos, reg)
1640 || spilled + spilled_nregs <= r || r + nregs <= spilled)
1643 SET_REGNO_REG_SET (&spilled_pseudos, reg);
1645 spill_add_cost[r] -= REG_FREQ (reg);
1647 spill_cost[r + nregs] -= REG_FREQ (reg);
1650 /* Find reload register to use for reload number ORDER. */
1653 find_reg (struct insn_chain *chain, int order)
1655 int rnum = reload_order[order];
1656 struct reload *rl = rld + rnum;
1657 int best_cost = INT_MAX;
1661 HARD_REG_SET not_usable;
1662 HARD_REG_SET used_by_other_reload;
1664 COPY_HARD_REG_SET (not_usable, bad_spill_regs);
1665 IOR_HARD_REG_SET (not_usable, bad_spill_regs_global);
1666 IOR_COMPL_HARD_REG_SET (not_usable, reg_class_contents[rl->class]);
1668 CLEAR_HARD_REG_SET (used_by_other_reload);
1669 for (k = 0; k < order; k++)
1671 int other = reload_order[k];
1673 if (rld[other].regno >= 0 && reloads_conflict (other, rnum))
1674 for (j = 0; j < rld[other].nregs; j++)
1675 SET_HARD_REG_BIT (used_by_other_reload, rld[other].regno + j);
1678 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1680 unsigned int regno = i;
1682 if (! TEST_HARD_REG_BIT (not_usable, regno)
1683 && ! TEST_HARD_REG_BIT (used_by_other_reload, regno)
1684 && HARD_REGNO_MODE_OK (regno, rl->mode))
1686 int this_cost = spill_cost[regno];
1688 unsigned int this_nregs = hard_regno_nregs[regno][rl->mode];
1690 for (j = 1; j < this_nregs; j++)
1692 this_cost += spill_add_cost[regno + j];
1693 if ((TEST_HARD_REG_BIT (not_usable, regno + j))
1694 || TEST_HARD_REG_BIT (used_by_other_reload, regno + j))
1699 if (rl->in && GET_CODE (rl->in) == REG && REGNO (rl->in) == regno)
1701 if (rl->out && GET_CODE (rl->out) == REG && REGNO (rl->out) == regno)
1703 if (this_cost < best_cost
1704 /* Among registers with equal cost, prefer caller-saved ones, or
1705 use REG_ALLOC_ORDER if it is defined. */
1706 || (this_cost == best_cost
1707 #ifdef REG_ALLOC_ORDER
1708 && (inv_reg_alloc_order[regno]
1709 < inv_reg_alloc_order[best_reg])
1711 && call_used_regs[regno]
1712 && ! call_used_regs[best_reg]
1717 best_cost = this_cost;
1725 fprintf (rtl_dump_file, "Using reg %d for reload %d\n", best_reg, rnum);
1727 rl->nregs = hard_regno_nregs[best_reg][rl->mode];
1728 rl->regno = best_reg;
1730 EXECUTE_IF_SET_IN_REG_SET
1731 (&chain->live_throughout, FIRST_PSEUDO_REGISTER, j,
1733 count_spilled_pseudo (best_reg, rl->nregs, j);
1736 EXECUTE_IF_SET_IN_REG_SET
1737 (&chain->dead_or_set, FIRST_PSEUDO_REGISTER, j,
1739 count_spilled_pseudo (best_reg, rl->nregs, j);
1742 for (i = 0; i < rl->nregs; i++)
1744 if (spill_cost[best_reg + i] != 0
1745 || spill_add_cost[best_reg + i] != 0)
1747 SET_HARD_REG_BIT (used_spill_regs_local, best_reg + i);
1752 /* Find more reload regs to satisfy the remaining need of an insn, which
1754 Do it by ascending class number, since otherwise a reg
1755 might be spilled for a big class and might fail to count
1756 for a smaller class even though it belongs to that class. */
1759 find_reload_regs (struct insn_chain *chain)
1763 /* In order to be certain of getting the registers we need,
1764 we must sort the reloads into order of increasing register class.
1765 Then our grabbing of reload registers will parallel the process
1766 that provided the reload registers. */
1767 for (i = 0; i < chain->n_reloads; i++)
1769 /* Show whether this reload already has a hard reg. */
1770 if (chain->rld[i].reg_rtx)
1772 int regno = REGNO (chain->rld[i].reg_rtx);
1773 chain->rld[i].regno = regno;
1775 = hard_regno_nregs[regno][GET_MODE (chain->rld[i].reg_rtx)];
1778 chain->rld[i].regno = -1;
1779 reload_order[i] = i;
1782 n_reloads = chain->n_reloads;
1783 memcpy (rld, chain->rld, n_reloads * sizeof (struct reload));
1785 CLEAR_HARD_REG_SET (used_spill_regs_local);
1788 fprintf (rtl_dump_file, "Spilling for insn %d.\n", INSN_UID (chain->insn));
1790 qsort (reload_order, n_reloads, sizeof (short), reload_reg_class_lower);
1792 /* Compute the order of preference for hard registers to spill. */
1794 order_regs_for_reload (chain);
1796 for (i = 0; i < n_reloads; i++)
1798 int r = reload_order[i];
1800 /* Ignore reloads that got marked inoperative. */
1801 if ((rld[r].out != 0 || rld[r].in != 0 || rld[r].secondary_p)
1802 && ! rld[r].optional
1803 && rld[r].regno == -1)
1804 if (! find_reg (chain, i))
1806 spill_failure (chain->insn, rld[r].class);
1812 COPY_HARD_REG_SET (chain->used_spill_regs, used_spill_regs_local);
1813 IOR_HARD_REG_SET (used_spill_regs, used_spill_regs_local);
1815 memcpy (chain->rld, rld, n_reloads * sizeof (struct reload));
1819 select_reload_regs (void)
1821 struct insn_chain *chain;
1823 /* Try to satisfy the needs for each insn. */
1824 for (chain = insns_need_reload; chain != 0;
1825 chain = chain->next_need_reload)
1826 find_reload_regs (chain);
1829 /* Delete all insns that were inserted by emit_caller_save_insns during
1832 delete_caller_save_insns (void)
1834 struct insn_chain *c = reload_insn_chain;
1838 while (c != 0 && c->is_caller_save_insn)
1840 struct insn_chain *next = c->next;
1843 if (c == reload_insn_chain)
1844 reload_insn_chain = next;
1848 next->prev = c->prev;
1850 c->prev->next = next;
1851 c->next = unused_insn_chains;
1852 unused_insn_chains = c;
1860 /* Handle the failure to find a register to spill.
1861 INSN should be one of the insns which needed this particular spill reg. */
1864 spill_failure (rtx insn, enum reg_class class)
1866 static const char *const reg_class_names[] = REG_CLASS_NAMES;
1867 if (asm_noperands (PATTERN (insn)) >= 0)
1868 error_for_asm (insn, "can't find a register in class `%s' while reloading `asm'",
1869 reg_class_names[class]);
1872 error ("unable to find a register to spill in class `%s'",
1873 reg_class_names[class]);
1874 fatal_insn ("this is the insn:", insn);
1878 /* Delete an unneeded INSN and any previous insns who sole purpose is loading
1879 data that is dead in INSN. */
1882 delete_dead_insn (rtx insn)
1884 rtx prev = prev_real_insn (insn);
1887 /* If the previous insn sets a register that dies in our insn, delete it
1889 if (prev && GET_CODE (PATTERN (prev)) == SET
1890 && (prev_dest = SET_DEST (PATTERN (prev)), GET_CODE (prev_dest) == REG)
1891 && reg_mentioned_p (prev_dest, PATTERN (insn))
1892 && find_regno_note (insn, REG_DEAD, REGNO (prev_dest))
1893 && ! side_effects_p (SET_SRC (PATTERN (prev))))
1894 delete_dead_insn (prev);
1896 PUT_CODE (insn, NOTE);
1897 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
1898 NOTE_SOURCE_FILE (insn) = 0;
1901 /* Modify the home of pseudo-reg I.
1902 The new home is present in reg_renumber[I].
1904 FROM_REG may be the hard reg that the pseudo-reg is being spilled from;
1905 or it may be -1, meaning there is none or it is not relevant.
1906 This is used so that all pseudos spilled from a given hard reg
1907 can share one stack slot. */
1910 alter_reg (int i, int from_reg)
1912 /* When outputting an inline function, this can happen
1913 for a reg that isn't actually used. */
1914 if (regno_reg_rtx[i] == 0)
1917 /* If the reg got changed to a MEM at rtl-generation time,
1919 if (GET_CODE (regno_reg_rtx[i]) != REG)
1922 /* Modify the reg-rtx to contain the new hard reg
1923 number or else to contain its pseudo reg number. */
1924 REGNO (regno_reg_rtx[i])
1925 = reg_renumber[i] >= 0 ? reg_renumber[i] : i;
1927 /* If we have a pseudo that is needed but has no hard reg or equivalent,
1928 allocate a stack slot for it. */
1930 if (reg_renumber[i] < 0
1931 && REG_N_REFS (i) > 0
1932 && reg_equiv_constant[i] == 0
1933 && reg_equiv_memory_loc[i] == 0)
1936 unsigned int inherent_size = PSEUDO_REGNO_BYTES (i);
1937 unsigned int total_size = MAX (inherent_size, reg_max_ref_width[i]);
1940 /* Each pseudo reg has an inherent size which comes from its own mode,
1941 and a total size which provides room for paradoxical subregs
1942 which refer to the pseudo reg in wider modes.
1944 We can use a slot already allocated if it provides both
1945 enough inherent space and enough total space.
1946 Otherwise, we allocate a new slot, making sure that it has no less
1947 inherent space, and no less total space, then the previous slot. */
1950 /* No known place to spill from => no slot to reuse. */
1951 x = assign_stack_local (GET_MODE (regno_reg_rtx[i]), total_size,
1952 inherent_size == total_size ? 0 : -1);
1953 if (BYTES_BIG_ENDIAN)
1954 /* Cancel the big-endian correction done in assign_stack_local.
1955 Get the address of the beginning of the slot.
1956 This is so we can do a big-endian correction unconditionally
1958 adjust = inherent_size - total_size;
1960 RTX_UNCHANGING_P (x) = RTX_UNCHANGING_P (regno_reg_rtx[i]);
1962 /* Nothing can alias this slot except this pseudo. */
1963 set_mem_alias_set (x, new_alias_set ());
1966 /* Reuse a stack slot if possible. */
1967 else if (spill_stack_slot[from_reg] != 0
1968 && spill_stack_slot_width[from_reg] >= total_size
1969 && (GET_MODE_SIZE (GET_MODE (spill_stack_slot[from_reg]))
1971 x = spill_stack_slot[from_reg];
1973 /* Allocate a bigger slot. */
1976 /* Compute maximum size needed, both for inherent size
1977 and for total size. */
1978 enum machine_mode mode = GET_MODE (regno_reg_rtx[i]);
1981 if (spill_stack_slot[from_reg])
1983 if (GET_MODE_SIZE (GET_MODE (spill_stack_slot[from_reg]))
1985 mode = GET_MODE (spill_stack_slot[from_reg]);
1986 if (spill_stack_slot_width[from_reg] > total_size)
1987 total_size = spill_stack_slot_width[from_reg];
1990 /* Make a slot with that size. */
1991 x = assign_stack_local (mode, total_size,
1992 inherent_size == total_size ? 0 : -1);
1995 /* All pseudos mapped to this slot can alias each other. */
1996 if (spill_stack_slot[from_reg])
1997 set_mem_alias_set (x, MEM_ALIAS_SET (spill_stack_slot[from_reg]));
1999 set_mem_alias_set (x, new_alias_set ());
2001 if (BYTES_BIG_ENDIAN)
2003 /* Cancel the big-endian correction done in assign_stack_local.
2004 Get the address of the beginning of the slot.
2005 This is so we can do a big-endian correction unconditionally
2007 adjust = GET_MODE_SIZE (mode) - total_size;
2010 = adjust_address_nv (x, mode_for_size (total_size
2016 spill_stack_slot[from_reg] = stack_slot;
2017 spill_stack_slot_width[from_reg] = total_size;
2020 /* On a big endian machine, the "address" of the slot
2021 is the address of the low part that fits its inherent mode. */
2022 if (BYTES_BIG_ENDIAN && inherent_size < total_size)
2023 adjust += (total_size - inherent_size);
2025 /* If we have any adjustment to make, or if the stack slot is the
2026 wrong mode, make a new stack slot. */
2027 x = adjust_address_nv (x, GET_MODE (regno_reg_rtx[i]), adjust);
2029 /* If we have a decl for the original register, set it for the
2030 memory. If this is a shared MEM, make a copy. */
2031 if (REG_EXPR (regno_reg_rtx[i])
2032 && TREE_CODE_CLASS (TREE_CODE (REG_EXPR (regno_reg_rtx[i]))) == 'd')
2034 rtx decl = DECL_RTL_IF_SET (REG_EXPR (regno_reg_rtx[i]));
2036 /* We can do this only for the DECLs home pseudo, not for
2037 any copies of it, since otherwise when the stack slot
2038 is reused, nonoverlapping_memrefs_p might think they
2040 if (decl && GET_CODE (decl) == REG && REGNO (decl) == (unsigned) i)
2042 if (from_reg != -1 && spill_stack_slot[from_reg] == x)
2045 set_mem_attrs_from_reg (x, regno_reg_rtx[i]);
2049 /* Save the stack slot for later. */
2050 reg_equiv_memory_loc[i] = x;
2054 /* Mark the slots in regs_ever_live for the hard regs
2055 used by pseudo-reg number REGNO. */
2058 mark_home_live (int regno)
2062 i = reg_renumber[regno];
2065 lim = i + hard_regno_nregs[i][PSEUDO_REGNO_MODE (regno)];
2067 regs_ever_live[i++] = 1;
2070 /* This function handles the tracking of elimination offsets around branches.
2072 X is a piece of RTL being scanned.
2074 INSN is the insn that it came from, if any.
2076 INITIAL_P is nonzero if we are to set the offset to be the initial
2077 offset and zero if we are setting the offset of the label to be the
2081 set_label_offsets (rtx x, rtx insn, int initial_p)
2083 enum rtx_code code = GET_CODE (x);
2086 struct elim_table *p;
2091 if (LABEL_REF_NONLOCAL_P (x))
2096 /* ... fall through ... */
2099 /* If we know nothing about this label, set the desired offsets. Note
2100 that this sets the offset at a label to be the offset before a label
2101 if we don't know anything about the label. This is not correct for
2102 the label after a BARRIER, but is the best guess we can make. If
2103 we guessed wrong, we will suppress an elimination that might have
2104 been possible had we been able to guess correctly. */
2106 if (! offsets_known_at[CODE_LABEL_NUMBER (x) - first_label_num])
2108 for (i = 0; i < NUM_ELIMINABLE_REGS; i++)
2109 offsets_at[CODE_LABEL_NUMBER (x) - first_label_num][i]
2110 = (initial_p ? reg_eliminate[i].initial_offset
2111 : reg_eliminate[i].offset);
2112 offsets_known_at[CODE_LABEL_NUMBER (x) - first_label_num] = 1;
2115 /* Otherwise, if this is the definition of a label and it is
2116 preceded by a BARRIER, set our offsets to the known offset of
2120 && (tem = prev_nonnote_insn (insn)) != 0
2121 && GET_CODE (tem) == BARRIER)
2122 set_offsets_for_label (insn);
2124 /* If neither of the above cases is true, compare each offset
2125 with those previously recorded and suppress any eliminations
2126 where the offsets disagree. */
2128 for (i = 0; i < NUM_ELIMINABLE_REGS; i++)
2129 if (offsets_at[CODE_LABEL_NUMBER (x) - first_label_num][i]
2130 != (initial_p ? reg_eliminate[i].initial_offset
2131 : reg_eliminate[i].offset))
2132 reg_eliminate[i].can_eliminate = 0;
2137 set_label_offsets (PATTERN (insn), insn, initial_p);
2139 /* ... fall through ... */
2143 /* Any labels mentioned in REG_LABEL notes can be branched to indirectly
2144 and hence must have all eliminations at their initial offsets. */
2145 for (tem = REG_NOTES (x); tem; tem = XEXP (tem, 1))
2146 if (REG_NOTE_KIND (tem) == REG_LABEL)
2147 set_label_offsets (XEXP (tem, 0), insn, 1);
2153 /* Each of the labels in the parallel or address vector must be
2154 at their initial offsets. We want the first field for PARALLEL
2155 and ADDR_VEC and the second field for ADDR_DIFF_VEC. */
2157 for (i = 0; i < (unsigned) XVECLEN (x, code == ADDR_DIFF_VEC); i++)
2158 set_label_offsets (XVECEXP (x, code == ADDR_DIFF_VEC, i),
2163 /* We only care about setting PC. If the source is not RETURN,
2164 IF_THEN_ELSE, or a label, disable any eliminations not at
2165 their initial offsets. Similarly if any arm of the IF_THEN_ELSE
2166 isn't one of those possibilities. For branches to a label,
2167 call ourselves recursively.
2169 Note that this can disable elimination unnecessarily when we have
2170 a non-local goto since it will look like a non-constant jump to
2171 someplace in the current function. This isn't a significant
2172 problem since such jumps will normally be when all elimination
2173 pairs are back to their initial offsets. */
2175 if (SET_DEST (x) != pc_rtx)
2178 switch (GET_CODE (SET_SRC (x)))
2185 set_label_offsets (XEXP (SET_SRC (x), 0), insn, initial_p);
2189 tem = XEXP (SET_SRC (x), 1);
2190 if (GET_CODE (tem) == LABEL_REF)
2191 set_label_offsets (XEXP (tem, 0), insn, initial_p);
2192 else if (GET_CODE (tem) != PC && GET_CODE (tem) != RETURN)
2195 tem = XEXP (SET_SRC (x), 2);
2196 if (GET_CODE (tem) == LABEL_REF)
2197 set_label_offsets (XEXP (tem, 0), insn, initial_p);
2198 else if (GET_CODE (tem) != PC && GET_CODE (tem) != RETURN)
2206 /* If we reach here, all eliminations must be at their initial
2207 offset because we are doing a jump to a variable address. */
2208 for (p = reg_eliminate; p < ®_eliminate[NUM_ELIMINABLE_REGS]; p++)
2209 if (p->offset != p->initial_offset)
2210 p->can_eliminate = 0;
2218 /* Scan X and replace any eliminable registers (such as fp) with a
2219 replacement (such as sp), plus an offset.
2221 MEM_MODE is the mode of an enclosing MEM. We need this to know how
2222 much to adjust a register for, e.g., PRE_DEC. Also, if we are inside a
2223 MEM, we are allowed to replace a sum of a register and the constant zero
2224 with the register, which we cannot do outside a MEM. In addition, we need
2225 to record the fact that a register is referenced outside a MEM.
2227 If INSN is an insn, it is the insn containing X. If we replace a REG
2228 in a SET_DEST with an equivalent MEM and INSN is nonzero, write a
2229 CLOBBER of the pseudo after INSN so find_equiv_regs will know that
2230 the REG is being modified.
2232 Alternatively, INSN may be a note (an EXPR_LIST or INSN_LIST).
2233 That's used when we eliminate in expressions stored in notes.
2234 This means, do not set ref_outside_mem even if the reference
2237 REG_EQUIV_MEM and REG_EQUIV_ADDRESS contain address that have had
2238 replacements done assuming all offsets are at their initial values. If
2239 they are not, or if REG_EQUIV_ADDRESS is nonzero for a pseudo we
2240 encounter, return the actual location so that find_reloads will do
2241 the proper thing. */
2244 eliminate_regs (rtx x, enum machine_mode mem_mode, rtx insn)
2246 enum rtx_code code = GET_CODE (x);
2247 struct elim_table *ep;
2254 if (! current_function_decl)
2274 /* This is only for the benefit of the debugging backends, which call
2275 eliminate_regs on DECL_RTL; any ADDRESSOFs in the actual insns are
2276 removed after CSE. */
2277 new = eliminate_regs (XEXP (x, 0), 0, insn);
2278 if (GET_CODE (new) == MEM)
2279 return XEXP (new, 0);
2285 /* First handle the case where we encounter a bare register that
2286 is eliminable. Replace it with a PLUS. */
2287 if (regno < FIRST_PSEUDO_REGISTER)
2289 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
2291 if (ep->from_rtx == x && ep->can_eliminate)
2292 return plus_constant (ep->to_rtx, ep->previous_offset);
2295 else if (reg_renumber && reg_renumber[regno] < 0
2296 && reg_equiv_constant && reg_equiv_constant[regno]
2297 && ! CONSTANT_P (reg_equiv_constant[regno]))
2298 return eliminate_regs (copy_rtx (reg_equiv_constant[regno]),
2302 /* You might think handling MINUS in a manner similar to PLUS is a
2303 good idea. It is not. It has been tried multiple times and every
2304 time the change has had to have been reverted.
2306 Other parts of reload know a PLUS is special (gen_reload for example)
2307 and require special code to handle code a reloaded PLUS operand.
2309 Also consider backends where the flags register is clobbered by a
2310 MINUS, but we can emit a PLUS that does not clobber flags (IA-32,
2311 lea instruction comes to mind). If we try to reload a MINUS, we
2312 may kill the flags register that was holding a useful value.
2314 So, please before trying to handle MINUS, consider reload as a
2315 whole instead of this little section as well as the backend issues. */
2317 /* If this is the sum of an eliminable register and a constant, rework
2319 if (GET_CODE (XEXP (x, 0)) == REG
2320 && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER
2321 && CONSTANT_P (XEXP (x, 1)))
2323 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
2325 if (ep->from_rtx == XEXP (x, 0) && ep->can_eliminate)
2327 /* The only time we want to replace a PLUS with a REG (this
2328 occurs when the constant operand of the PLUS is the negative
2329 of the offset) is when we are inside a MEM. We won't want
2330 to do so at other times because that would change the
2331 structure of the insn in a way that reload can't handle.
2332 We special-case the commonest situation in
2333 eliminate_regs_in_insn, so just replace a PLUS with a
2334 PLUS here, unless inside a MEM. */
2335 if (mem_mode != 0 && GET_CODE (XEXP (x, 1)) == CONST_INT
2336 && INTVAL (XEXP (x, 1)) == - ep->previous_offset)
2339 return gen_rtx_PLUS (Pmode, ep->to_rtx,
2340 plus_constant (XEXP (x, 1),
2341 ep->previous_offset));
2344 /* If the register is not eliminable, we are done since the other
2345 operand is a constant. */
2349 /* If this is part of an address, we want to bring any constant to the
2350 outermost PLUS. We will do this by doing register replacement in
2351 our operands and seeing if a constant shows up in one of them.
2353 Note that there is no risk of modifying the structure of the insn,
2354 since we only get called for its operands, thus we are either
2355 modifying the address inside a MEM, or something like an address
2356 operand of a load-address insn. */
2359 rtx new0 = eliminate_regs (XEXP (x, 0), mem_mode, insn);
2360 rtx new1 = eliminate_regs (XEXP (x, 1), mem_mode, insn);
2362 if (reg_renumber && (new0 != XEXP (x, 0) || new1 != XEXP (x, 1)))
2364 /* If one side is a PLUS and the other side is a pseudo that
2365 didn't get a hard register but has a reg_equiv_constant,
2366 we must replace the constant here since it may no longer
2367 be in the position of any operand. */
2368 if (GET_CODE (new0) == PLUS && GET_CODE (new1) == REG
2369 && REGNO (new1) >= FIRST_PSEUDO_REGISTER
2370 && reg_renumber[REGNO (new1)] < 0
2371 && reg_equiv_constant != 0
2372 && reg_equiv_constant[REGNO (new1)] != 0)
2373 new1 = reg_equiv_constant[REGNO (new1)];
2374 else if (GET_CODE (new1) == PLUS && GET_CODE (new0) == REG
2375 && REGNO (new0) >= FIRST_PSEUDO_REGISTER
2376 && reg_renumber[REGNO (new0)] < 0
2377 && reg_equiv_constant[REGNO (new0)] != 0)
2378 new0 = reg_equiv_constant[REGNO (new0)];
2380 new = form_sum (new0, new1);
2382 /* As above, if we are not inside a MEM we do not want to
2383 turn a PLUS into something else. We might try to do so here
2384 for an addition of 0 if we aren't optimizing. */
2385 if (! mem_mode && GET_CODE (new) != PLUS)
2386 return gen_rtx_PLUS (GET_MODE (x), new, const0_rtx);
2394 /* If this is the product of an eliminable register and a
2395 constant, apply the distribute law and move the constant out
2396 so that we have (plus (mult ..) ..). This is needed in order
2397 to keep load-address insns valid. This case is pathological.
2398 We ignore the possibility of overflow here. */
2399 if (GET_CODE (XEXP (x, 0)) == REG
2400 && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER
2401 && GET_CODE (XEXP (x, 1)) == CONST_INT)
2402 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
2404 if (ep->from_rtx == XEXP (x, 0) && ep->can_eliminate)
2407 /* Refs inside notes don't count for this purpose. */
2408 && ! (insn != 0 && (GET_CODE (insn) == EXPR_LIST
2409 || GET_CODE (insn) == INSN_LIST)))
2410 ep->ref_outside_mem = 1;
2413 plus_constant (gen_rtx_MULT (Pmode, ep->to_rtx, XEXP (x, 1)),
2414 ep->previous_offset * INTVAL (XEXP (x, 1)));
2417 /* ... fall through ... */
2421 /* See comments before PLUS about handling MINUS. */
2423 case DIV: case UDIV:
2424 case MOD: case UMOD:
2425 case AND: case IOR: case XOR:
2426 case ROTATERT: case ROTATE:
2427 case ASHIFTRT: case LSHIFTRT: case ASHIFT:
2429 case GE: case GT: case GEU: case GTU:
2430 case LE: case LT: case LEU: case LTU:
2432 rtx new0 = eliminate_regs (XEXP (x, 0), mem_mode, insn);
2434 = XEXP (x, 1) ? eliminate_regs (XEXP (x, 1), mem_mode, insn) : 0;
2436 if (new0 != XEXP (x, 0) || new1 != XEXP (x, 1))
2437 return gen_rtx_fmt_ee (code, GET_MODE (x), new0, new1);
2442 /* If we have something in XEXP (x, 0), the usual case, eliminate it. */
2445 new = eliminate_regs (XEXP (x, 0), mem_mode, insn);
2446 if (new != XEXP (x, 0))
2448 /* If this is a REG_DEAD note, it is not valid anymore.
2449 Using the eliminated version could result in creating a
2450 REG_DEAD note for the stack or frame pointer. */
2451 if (GET_MODE (x) == REG_DEAD)
2453 ? eliminate_regs (XEXP (x, 1), mem_mode, insn)
2456 x = gen_rtx_EXPR_LIST (REG_NOTE_KIND (x), new, XEXP (x, 1));
2460 /* ... fall through ... */
2463 /* Now do eliminations in the rest of the chain. If this was
2464 an EXPR_LIST, this might result in allocating more memory than is
2465 strictly needed, but it simplifies the code. */
2468 new = eliminate_regs (XEXP (x, 1), mem_mode, insn);
2469 if (new != XEXP (x, 1))
2471 gen_rtx_fmt_ee (GET_CODE (x), GET_MODE (x), XEXP (x, 0), new);
2479 case STRICT_LOW_PART:
2481 case SIGN_EXTEND: case ZERO_EXTEND:
2482 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
2483 case FLOAT: case FIX:
2484 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
2492 new = eliminate_regs (XEXP (x, 0), mem_mode, insn);
2493 if (new != XEXP (x, 0))
2494 return gen_rtx_fmt_e (code, GET_MODE (x), new);
2498 /* Similar to above processing, but preserve SUBREG_BYTE.
2499 Convert (subreg (mem)) to (mem) if not paradoxical.
2500 Also, if we have a non-paradoxical (subreg (pseudo)) and the
2501 pseudo didn't get a hard reg, we must replace this with the
2502 eliminated version of the memory location because push_reload
2503 may do the replacement in certain circumstances. */
2504 if (GET_CODE (SUBREG_REG (x)) == REG
2505 && (GET_MODE_SIZE (GET_MODE (x))
2506 <= GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
2507 && reg_equiv_memory_loc != 0
2508 && reg_equiv_memory_loc[REGNO (SUBREG_REG (x))] != 0)
2510 new = SUBREG_REG (x);
2513 new = eliminate_regs (SUBREG_REG (x), mem_mode, insn);
2515 if (new != SUBREG_REG (x))
2517 int x_size = GET_MODE_SIZE (GET_MODE (x));
2518 int new_size = GET_MODE_SIZE (GET_MODE (new));
2520 if (GET_CODE (new) == MEM
2521 && ((x_size < new_size
2522 #ifdef WORD_REGISTER_OPERATIONS
2523 /* On these machines, combine can create rtl of the form
2524 (set (subreg:m1 (reg:m2 R) 0) ...)
2525 where m1 < m2, and expects something interesting to
2526 happen to the entire word. Moreover, it will use the
2527 (reg:m2 R) later, expecting all bits to be preserved.
2528 So if the number of words is the same, preserve the
2529 subreg so that push_reload can see it. */
2530 && ! ((x_size - 1) / UNITS_PER_WORD
2531 == (new_size -1 ) / UNITS_PER_WORD)
2534 || x_size == new_size)
2536 return adjust_address_nv (new, GET_MODE (x), SUBREG_BYTE (x));
2538 return gen_rtx_SUBREG (GET_MODE (x), new, SUBREG_BYTE (x));
2544 /* This is only for the benefit of the debugging backends, which call
2545 eliminate_regs on DECL_RTL; any ADDRESSOFs in the actual insns are
2546 removed after CSE. */
2547 if (GET_CODE (XEXP (x, 0)) == ADDRESSOF)
2548 return eliminate_regs (XEXP (XEXP (x, 0), 0), 0, insn);
2550 /* Our only special processing is to pass the mode of the MEM to our
2551 recursive call and copy the flags. While we are here, handle this
2552 case more efficiently. */
2554 replace_equiv_address_nv (x,
2555 eliminate_regs (XEXP (x, 0),
2556 GET_MODE (x), insn));
2559 /* Handle insn_list USE that a call to a pure function may generate. */
2560 new = eliminate_regs (XEXP (x, 0), 0, insn);
2561 if (new != XEXP (x, 0))
2562 return gen_rtx_USE (GET_MODE (x), new);
2574 /* Process each of our operands recursively. If any have changed, make a
2576 fmt = GET_RTX_FORMAT (code);
2577 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2581 new = eliminate_regs (XEXP (x, i), mem_mode, insn);
2582 if (new != XEXP (x, i) && ! copied)
2584 rtx new_x = rtx_alloc (code);
2585 memcpy (new_x, x, RTX_SIZE (code));
2591 else if (*fmt == 'E')
2594 for (j = 0; j < XVECLEN (x, i); j++)
2596 new = eliminate_regs (XVECEXP (x, i, j), mem_mode, insn);
2597 if (new != XVECEXP (x, i, j) && ! copied_vec)
2599 rtvec new_v = gen_rtvec_v (XVECLEN (x, i),
2603 rtx new_x = rtx_alloc (code);
2604 memcpy (new_x, x, RTX_SIZE (code));
2608 XVEC (x, i) = new_v;
2611 XVECEXP (x, i, j) = new;
2619 /* Scan rtx X for modifications of elimination target registers. Update
2620 the table of eliminables to reflect the changed state. MEM_MODE is
2621 the mode of an enclosing MEM rtx, or VOIDmode if not within a MEM. */
2624 elimination_effects (rtx x, enum machine_mode mem_mode)
2626 enum rtx_code code = GET_CODE (x);
2627 struct elim_table *ep;
2654 /* First handle the case where we encounter a bare register that
2655 is eliminable. Replace it with a PLUS. */
2656 if (regno < FIRST_PSEUDO_REGISTER)
2658 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
2660 if (ep->from_rtx == x && ep->can_eliminate)
2663 ep->ref_outside_mem = 1;
2668 else if (reg_renumber[regno] < 0 && reg_equiv_constant
2669 && reg_equiv_constant[regno]
2670 && ! function_invariant_p (reg_equiv_constant[regno]))
2671 elimination_effects (reg_equiv_constant[regno], mem_mode);
2680 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2681 if (ep->to_rtx == XEXP (x, 0))
2683 int size = GET_MODE_SIZE (mem_mode);
2685 /* If more bytes than MEM_MODE are pushed, account for them. */
2686 #ifdef PUSH_ROUNDING
2687 if (ep->to_rtx == stack_pointer_rtx)
2688 size = PUSH_ROUNDING (size);
2690 if (code == PRE_DEC || code == POST_DEC)
2692 else if (code == PRE_INC || code == POST_INC)
2694 else if ((code == PRE_MODIFY || code == POST_MODIFY)
2695 && GET_CODE (XEXP (x, 1)) == PLUS
2696 && XEXP (x, 0) == XEXP (XEXP (x, 1), 0)
2697 && CONSTANT_P (XEXP (XEXP (x, 1), 1)))
2698 ep->offset -= INTVAL (XEXP (XEXP (x, 1), 1));
2701 /* These two aren't unary operators. */
2702 if (code == POST_MODIFY || code == PRE_MODIFY)
2705 /* Fall through to generic unary operation case. */
2706 case STRICT_LOW_PART:
2708 case SIGN_EXTEND: case ZERO_EXTEND:
2709 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
2710 case FLOAT: case FIX:
2711 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
2719 elimination_effects (XEXP (x, 0), mem_mode);
2723 if (GET_CODE (SUBREG_REG (x)) == REG
2724 && (GET_MODE_SIZE (GET_MODE (x))
2725 <= GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
2726 && reg_equiv_memory_loc != 0
2727 && reg_equiv_memory_loc[REGNO (SUBREG_REG (x))] != 0)
2730 elimination_effects (SUBREG_REG (x), mem_mode);
2734 /* If using a register that is the source of an eliminate we still
2735 think can be performed, note it cannot be performed since we don't
2736 know how this register is used. */
2737 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2738 if (ep->from_rtx == XEXP (x, 0))
2739 ep->can_eliminate = 0;
2741 elimination_effects (XEXP (x, 0), mem_mode);
2745 /* If clobbering a register that is the replacement register for an
2746 elimination we still think can be performed, note that it cannot
2747 be performed. Otherwise, we need not be concerned about it. */
2748 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2749 if (ep->to_rtx == XEXP (x, 0))
2750 ep->can_eliminate = 0;
2752 elimination_effects (XEXP (x, 0), mem_mode);
2756 /* Check for setting a register that we know about. */
2757 if (GET_CODE (SET_DEST (x)) == REG)
2759 /* See if this is setting the replacement register for an
2762 If DEST is the hard frame pointer, we do nothing because we
2763 assume that all assignments to the frame pointer are for
2764 non-local gotos and are being done at a time when they are valid
2765 and do not disturb anything else. Some machines want to
2766 eliminate a fake argument pointer (or even a fake frame pointer)
2767 with either the real frame or the stack pointer. Assignments to
2768 the hard frame pointer must not prevent this elimination. */
2770 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
2772 if (ep->to_rtx == SET_DEST (x)
2773 && SET_DEST (x) != hard_frame_pointer_rtx)
2775 /* If it is being incremented, adjust the offset. Otherwise,
2776 this elimination can't be done. */
2777 rtx src = SET_SRC (x);
2779 if (GET_CODE (src) == PLUS
2780 && XEXP (src, 0) == SET_DEST (x)
2781 && GET_CODE (XEXP (src, 1)) == CONST_INT)
2782 ep->offset -= INTVAL (XEXP (src, 1));
2784 ep->can_eliminate = 0;
2788 elimination_effects (SET_DEST (x), 0);
2789 elimination_effects (SET_SRC (x), 0);
2793 if (GET_CODE (XEXP (x, 0)) == ADDRESSOF)
2796 /* Our only special processing is to pass the mode of the MEM to our
2798 elimination_effects (XEXP (x, 0), GET_MODE (x));
2805 fmt = GET_RTX_FORMAT (code);
2806 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2809 elimination_effects (XEXP (x, i), mem_mode);
2810 else if (*fmt == 'E')
2811 for (j = 0; j < XVECLEN (x, i); j++)
2812 elimination_effects (XVECEXP (x, i, j), mem_mode);
2816 /* Descend through rtx X and verify that no references to eliminable registers
2817 remain. If any do remain, mark the involved register as not
2821 check_eliminable_occurrences (rtx x)
2830 code = GET_CODE (x);
2832 if (code == REG && REGNO (x) < FIRST_PSEUDO_REGISTER)
2834 struct elim_table *ep;
2836 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2837 if (ep->from_rtx == x)
2838 ep->can_eliminate = 0;
2842 fmt = GET_RTX_FORMAT (code);
2843 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2846 check_eliminable_occurrences (XEXP (x, i));
2847 else if (*fmt == 'E')
2850 for (j = 0; j < XVECLEN (x, i); j++)
2851 check_eliminable_occurrences (XVECEXP (x, i, j));
2856 /* Scan INSN and eliminate all eliminable registers in it.
2858 If REPLACE is nonzero, do the replacement destructively. Also
2859 delete the insn as dead it if it is setting an eliminable register.
2861 If REPLACE is zero, do all our allocations in reload_obstack.
2863 If no eliminations were done and this insn doesn't require any elimination
2864 processing (these are not identical conditions: it might be updating sp,
2865 but not referencing fp; this needs to be seen during reload_as_needed so
2866 that the offset between fp and sp can be taken into consideration), zero
2867 is returned. Otherwise, 1 is returned. */
2870 eliminate_regs_in_insn (rtx insn, int replace)
2872 int icode = recog_memoized (insn);
2873 rtx old_body = PATTERN (insn);
2874 int insn_is_asm = asm_noperands (old_body) >= 0;
2875 rtx old_set = single_set (insn);
2879 rtx substed_operand[MAX_RECOG_OPERANDS];
2880 rtx orig_operand[MAX_RECOG_OPERANDS];
2881 struct elim_table *ep;
2884 if (! insn_is_asm && icode < 0)
2886 if (GET_CODE (PATTERN (insn)) == USE
2887 || GET_CODE (PATTERN (insn)) == CLOBBER
2888 || GET_CODE (PATTERN (insn)) == ADDR_VEC
2889 || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
2890 || GET_CODE (PATTERN (insn)) == ASM_INPUT)
2895 if (old_set != 0 && GET_CODE (SET_DEST (old_set)) == REG
2896 && REGNO (SET_DEST (old_set)) < FIRST_PSEUDO_REGISTER)
2898 /* Check for setting an eliminable register. */
2899 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2900 if (ep->from_rtx == SET_DEST (old_set) && ep->can_eliminate)
2902 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
2903 /* If this is setting the frame pointer register to the
2904 hardware frame pointer register and this is an elimination
2905 that will be done (tested above), this insn is really
2906 adjusting the frame pointer downward to compensate for
2907 the adjustment done before a nonlocal goto. */
2908 if (ep->from == FRAME_POINTER_REGNUM
2909 && ep->to == HARD_FRAME_POINTER_REGNUM)
2911 rtx base = SET_SRC (old_set);
2912 rtx base_insn = insn;
2913 HOST_WIDE_INT offset = 0;
2915 while (base != ep->to_rtx)
2917 rtx prev_insn, prev_set;
2919 if (GET_CODE (base) == PLUS
2920 && GET_CODE (XEXP (base, 1)) == CONST_INT)
2922 offset += INTVAL (XEXP (base, 1));
2923 base = XEXP (base, 0);
2925 else if ((prev_insn = prev_nonnote_insn (base_insn)) != 0
2926 && (prev_set = single_set (prev_insn)) != 0
2927 && rtx_equal_p (SET_DEST (prev_set), base))
2929 base = SET_SRC (prev_set);
2930 base_insn = prev_insn;
2936 if (base == ep->to_rtx)
2939 = plus_constant (ep->to_rtx, offset - ep->offset);
2941 new_body = old_body;
2944 new_body = copy_insn (old_body);
2945 if (REG_NOTES (insn))
2946 REG_NOTES (insn) = copy_insn_1 (REG_NOTES (insn));
2948 PATTERN (insn) = new_body;
2949 old_set = single_set (insn);
2951 /* First see if this insn remains valid when we
2952 make the change. If not, keep the INSN_CODE
2953 the same and let reload fit it up. */
2954 validate_change (insn, &SET_SRC (old_set), src, 1);
2955 validate_change (insn, &SET_DEST (old_set),
2957 if (! apply_change_group ())
2959 SET_SRC (old_set) = src;
2960 SET_DEST (old_set) = ep->to_rtx;
2969 /* In this case this insn isn't serving a useful purpose. We
2970 will delete it in reload_as_needed once we know that this
2971 elimination is, in fact, being done.
2973 If REPLACE isn't set, we can't delete this insn, but needn't
2974 process it since it won't be used unless something changes. */
2977 delete_dead_insn (insn);
2985 /* We allow one special case which happens to work on all machines we
2986 currently support: a single set with the source or a REG_EQUAL
2987 note being a PLUS of an eliminable register and a constant. */
2989 if (old_set && GET_CODE (SET_DEST (old_set)) == REG)
2991 /* First see if the source is of the form (plus (reg) CST). */
2992 if (GET_CODE (SET_SRC (old_set)) == PLUS
2993 && GET_CODE (XEXP (SET_SRC (old_set), 0)) == REG
2994 && GET_CODE (XEXP (SET_SRC (old_set), 1)) == CONST_INT
2995 && REGNO (XEXP (SET_SRC (old_set), 0)) < FIRST_PSEUDO_REGISTER)
2996 plus_src = SET_SRC (old_set);
2997 else if (GET_CODE (SET_SRC (old_set)) == REG)
2999 /* Otherwise, see if we have a REG_EQUAL note of the form
3000 (plus (reg) CST). */
3002 for (links = REG_NOTES (insn); links; links = XEXP (links, 1))
3004 if (REG_NOTE_KIND (links) == REG_EQUAL
3005 && GET_CODE (XEXP (links, 0)) == PLUS
3006 && GET_CODE (XEXP (XEXP (links, 0), 0)) == REG
3007 && GET_CODE (XEXP (XEXP (links, 0), 1)) == CONST_INT
3008 && REGNO (XEXP (XEXP (links, 0), 0)) < FIRST_PSEUDO_REGISTER)
3010 plus_src = XEXP (links, 0);
3018 rtx reg = XEXP (plus_src, 0);
3019 HOST_WIDE_INT offset = INTVAL (XEXP (plus_src, 1));
3021 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3022 if (ep->from_rtx == reg && ep->can_eliminate)
3024 offset += ep->offset;
3029 /* We assume here that if we need a PARALLEL with
3030 CLOBBERs for this assignment, we can do with the
3031 MATCH_SCRATCHes that add_clobbers allocates.
3032 There's not much we can do if that doesn't work. */
3033 PATTERN (insn) = gen_rtx_SET (VOIDmode,
3037 INSN_CODE (insn) = recog (PATTERN (insn), insn, &num_clobbers);
3040 rtvec vec = rtvec_alloc (num_clobbers + 1);
3042 vec->elem[0] = PATTERN (insn);
3043 PATTERN (insn) = gen_rtx_PARALLEL (VOIDmode, vec);
3044 add_clobbers (PATTERN (insn), INSN_CODE (insn));
3046 if (INSN_CODE (insn) < 0)
3049 /* If we have a nonzero offset, and the source is already
3050 a simple REG, the following transformation would
3051 increase the cost of the insn by replacing a simple REG
3052 with (plus (reg sp) CST). So try only when plus_src
3053 comes from old_set proper, not REG_NOTES. */
3054 else if (SET_SRC (old_set) == plus_src)
3056 new_body = old_body;
3059 new_body = copy_insn (old_body);
3060 if (REG_NOTES (insn))
3061 REG_NOTES (insn) = copy_insn_1 (REG_NOTES (insn));
3063 PATTERN (insn) = new_body;
3064 old_set = single_set (insn);
3066 XEXP (SET_SRC (old_set), 0) = ep->to_rtx;
3067 XEXP (SET_SRC (old_set), 1) = GEN_INT (offset);
3073 /* This can't have an effect on elimination offsets, so skip right
3079 /* Determine the effects of this insn on elimination offsets. */
3080 elimination_effects (old_body, 0);
3082 /* Eliminate all eliminable registers occurring in operands that
3083 can be handled by reload. */
3084 extract_insn (insn);
3085 for (i = 0; i < recog_data.n_operands; i++)
3087 orig_operand[i] = recog_data.operand[i];
3088 substed_operand[i] = recog_data.operand[i];
3090 /* For an asm statement, every operand is eliminable. */
3091 if (insn_is_asm || insn_data[icode].operand[i].eliminable)
3093 /* Check for setting a register that we know about. */
3094 if (recog_data.operand_type[i] != OP_IN
3095 && GET_CODE (orig_operand[i]) == REG)
3097 /* If we are assigning to a register that can be eliminated, it
3098 must be as part of a PARALLEL, since the code above handles
3099 single SETs. We must indicate that we can no longer
3100 eliminate this reg. */
3101 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
3103 if (ep->from_rtx == orig_operand[i])
3104 ep->can_eliminate = 0;
3107 substed_operand[i] = eliminate_regs (recog_data.operand[i], 0,
3108 replace ? insn : NULL_RTX);
3109 if (substed_operand[i] != orig_operand[i])
3111 /* Terminate the search in check_eliminable_occurrences at
3113 *recog_data.operand_loc[i] = 0;
3115 /* If an output operand changed from a REG to a MEM and INSN is an
3116 insn, write a CLOBBER insn. */
3117 if (recog_data.operand_type[i] != OP_IN
3118 && GET_CODE (orig_operand[i]) == REG
3119 && GET_CODE (substed_operand[i]) == MEM
3121 emit_insn_after (gen_rtx_CLOBBER (VOIDmode, orig_operand[i]),
3126 for (i = 0; i < recog_data.n_dups; i++)
3127 *recog_data.dup_loc[i]
3128 = *recog_data.operand_loc[(int) recog_data.dup_num[i]];
3130 /* If any eliminable remain, they aren't eliminable anymore. */
3131 check_eliminable_occurrences (old_body);
3133 /* Substitute the operands; the new values are in the substed_operand
3135 for (i = 0; i < recog_data.n_operands; i++)
3136 *recog_data.operand_loc[i] = substed_operand[i];
3137 for (i = 0; i < recog_data.n_dups; i++)
3138 *recog_data.dup_loc[i] = substed_operand[(int) recog_data.dup_num[i]];
3140 /* If we are replacing a body that was a (set X (plus Y Z)), try to
3141 re-recognize the insn. We do this in case we had a simple addition
3142 but now can do this as a load-address. This saves an insn in this
3144 If re-recognition fails, the old insn code number will still be used,
3145 and some register operands may have changed into PLUS expressions.
3146 These will be handled by find_reloads by loading them into a register
3151 /* If we aren't replacing things permanently and we changed something,
3152 make another copy to ensure that all the RTL is new. Otherwise
3153 things can go wrong if find_reload swaps commutative operands
3154 and one is inside RTL that has been copied while the other is not. */
3155 new_body = old_body;
3158 new_body = copy_insn (old_body);
3159 if (REG_NOTES (insn))
3160 REG_NOTES (insn) = copy_insn_1 (REG_NOTES (insn));
3162 PATTERN (insn) = new_body;
3164 /* If we had a move insn but now we don't, rerecognize it. This will
3165 cause spurious re-recognition if the old move had a PARALLEL since
3166 the new one still will, but we can't call single_set without
3167 having put NEW_BODY into the insn and the re-recognition won't
3168 hurt in this rare case. */
3169 /* ??? Why this huge if statement - why don't we just rerecognize the
3173 && ((GET_CODE (SET_SRC (old_set)) == REG
3174 && (GET_CODE (new_body) != SET
3175 || GET_CODE (SET_SRC (new_body)) != REG))
3176 /* If this was a load from or store to memory, compare
3177 the MEM in recog_data.operand to the one in the insn.
3178 If they are not equal, then rerecognize the insn. */
3180 && ((GET_CODE (SET_SRC (old_set)) == MEM
3181 && SET_SRC (old_set) != recog_data.operand[1])
3182 || (GET_CODE (SET_DEST (old_set)) == MEM
3183 && SET_DEST (old_set) != recog_data.operand[0])))
3184 /* If this was an add insn before, rerecognize. */
3185 || GET_CODE (SET_SRC (old_set)) == PLUS))
3187 int new_icode = recog (PATTERN (insn), insn, 0);
3189 INSN_CODE (insn) = icode;
3193 /* Restore the old body. If there were any changes to it, we made a copy
3194 of it while the changes were still in place, so we'll correctly return
3195 a modified insn below. */
3198 /* Restore the old body. */
3199 for (i = 0; i < recog_data.n_operands; i++)
3200 *recog_data.operand_loc[i] = orig_operand[i];
3201 for (i = 0; i < recog_data.n_dups; i++)
3202 *recog_data.dup_loc[i] = orig_operand[(int) recog_data.dup_num[i]];
3205 /* Update all elimination pairs to reflect the status after the current
3206 insn. The changes we make were determined by the earlier call to
3207 elimination_effects.
3209 We also detect cases where register elimination cannot be done,
3210 namely, if a register would be both changed and referenced outside a MEM
3211 in the resulting insn since such an insn is often undefined and, even if
3212 not, we cannot know what meaning will be given to it. Note that it is
3213 valid to have a register used in an address in an insn that changes it
3214 (presumably with a pre- or post-increment or decrement).
3216 If anything changes, return nonzero. */
3218 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3220 if (ep->previous_offset != ep->offset && ep->ref_outside_mem)
3221 ep->can_eliminate = 0;
3223 ep->ref_outside_mem = 0;
3225 if (ep->previous_offset != ep->offset)
3230 /* If we changed something, perform elimination in REG_NOTES. This is
3231 needed even when REPLACE is zero because a REG_DEAD note might refer
3232 to a register that we eliminate and could cause a different number
3233 of spill registers to be needed in the final reload pass than in
3235 if (val && REG_NOTES (insn) != 0)
3236 REG_NOTES (insn) = eliminate_regs (REG_NOTES (insn), 0, REG_NOTES (insn));
3241 /* Loop through all elimination pairs.
3242 Recalculate the number not at initial offset.
3244 Compute the maximum offset (minimum offset if the stack does not
3245 grow downward) for each elimination pair. */
3248 update_eliminable_offsets (void)
3250 struct elim_table *ep;
3252 num_not_at_initial_offset = 0;
3253 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3255 ep->previous_offset = ep->offset;
3256 if (ep->can_eliminate && ep->offset != ep->initial_offset)
3257 num_not_at_initial_offset++;
3261 /* Given X, a SET or CLOBBER of DEST, if DEST is the target of a register
3262 replacement we currently believe is valid, mark it as not eliminable if X
3263 modifies DEST in any way other than by adding a constant integer to it.
3265 If DEST is the frame pointer, we do nothing because we assume that
3266 all assignments to the hard frame pointer are nonlocal gotos and are being
3267 done at a time when they are valid and do not disturb anything else.
3268 Some machines want to eliminate a fake argument pointer with either the
3269 frame or stack pointer. Assignments to the hard frame pointer must not
3270 prevent this elimination.
3272 Called via note_stores from reload before starting its passes to scan
3273 the insns of the function. */
3276 mark_not_eliminable (rtx dest, rtx x, void *data ATTRIBUTE_UNUSED)
3280 /* A SUBREG of a hard register here is just changing its mode. We should
3281 not see a SUBREG of an eliminable hard register, but check just in
3283 if (GET_CODE (dest) == SUBREG)
3284 dest = SUBREG_REG (dest);
3286 if (dest == hard_frame_pointer_rtx)
3289 for (i = 0; i < NUM_ELIMINABLE_REGS; i++)
3290 if (reg_eliminate[i].can_eliminate && dest == reg_eliminate[i].to_rtx
3291 && (GET_CODE (x) != SET
3292 || GET_CODE (SET_SRC (x)) != PLUS
3293 || XEXP (SET_SRC (x), 0) != dest
3294 || GET_CODE (XEXP (SET_SRC (x), 1)) != CONST_INT))
3296 reg_eliminate[i].can_eliminate_previous
3297 = reg_eliminate[i].can_eliminate = 0;
3302 /* Verify that the initial elimination offsets did not change since the
3303 last call to set_initial_elim_offsets. This is used to catch cases
3304 where something illegal happened during reload_as_needed that could
3305 cause incorrect code to be generated if we did not check for it. */
3308 verify_initial_elim_offsets (void)
3312 #ifdef ELIMINABLE_REGS
3313 struct elim_table *ep;
3315 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3317 INITIAL_ELIMINATION_OFFSET (ep->from, ep->to, t);
3318 if (t != ep->initial_offset)
3322 INITIAL_FRAME_POINTER_OFFSET (t);
3323 if (t != reg_eliminate[0].initial_offset)
3328 /* Reset all offsets on eliminable registers to their initial values. */
3331 set_initial_elim_offsets (void)
3333 struct elim_table *ep = reg_eliminate;
3335 #ifdef ELIMINABLE_REGS
3336 for (; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3338 INITIAL_ELIMINATION_OFFSET (ep->from, ep->to, ep->initial_offset);
3339 ep->previous_offset = ep->offset = ep->initial_offset;
3342 INITIAL_FRAME_POINTER_OFFSET (ep->initial_offset);
3343 ep->previous_offset = ep->offset = ep->initial_offset;
3346 num_not_at_initial_offset = 0;
3349 /* Initialize the known label offsets.
3350 Set a known offset for each forced label to be at the initial offset
3351 of each elimination. We do this because we assume that all
3352 computed jumps occur from a location where each elimination is
3353 at its initial offset.
3354 For all other labels, show that we don't know the offsets. */
3357 set_initial_label_offsets (void)
3360 memset (offsets_known_at, 0, num_labels);
3362 for (x = forced_labels; x; x = XEXP (x, 1))
3364 set_label_offsets (XEXP (x, 0), NULL_RTX, 1);
3367 /* Set all elimination offsets to the known values for the code label given
3371 set_offsets_for_label (rtx insn)
3374 int label_nr = CODE_LABEL_NUMBER (insn);
3375 struct elim_table *ep;
3377 num_not_at_initial_offset = 0;
3378 for (i = 0, ep = reg_eliminate; i < NUM_ELIMINABLE_REGS; ep++, i++)
3380 ep->offset = ep->previous_offset
3381 = offsets_at[label_nr - first_label_num][i];
3382 if (ep->can_eliminate && ep->offset != ep->initial_offset)
3383 num_not_at_initial_offset++;
3387 /* See if anything that happened changes which eliminations are valid.
3388 For example, on the SPARC, whether or not the frame pointer can
3389 be eliminated can depend on what registers have been used. We need
3390 not check some conditions again (such as flag_omit_frame_pointer)
3391 since they can't have changed. */
3394 update_eliminables (HARD_REG_SET *pset)
3396 int previous_frame_pointer_needed = frame_pointer_needed;
3397 struct elim_table *ep;
3399 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3400 if ((ep->from == HARD_FRAME_POINTER_REGNUM && FRAME_POINTER_REQUIRED)
3401 #ifdef ELIMINABLE_REGS
3402 || ! CAN_ELIMINATE (ep->from, ep->to)
3405 ep->can_eliminate = 0;
3407 /* Look for the case where we have discovered that we can't replace
3408 register A with register B and that means that we will now be
3409 trying to replace register A with register C. This means we can
3410 no longer replace register C with register B and we need to disable
3411 such an elimination, if it exists. This occurs often with A == ap,
3412 B == sp, and C == fp. */
3414 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3416 struct elim_table *op;
3419 if (! ep->can_eliminate && ep->can_eliminate_previous)
3421 /* Find the current elimination for ep->from, if there is a
3423 for (op = reg_eliminate;
3424 op < ®_eliminate[NUM_ELIMINABLE_REGS]; op++)
3425 if (op->from == ep->from && op->can_eliminate)
3431 /* See if there is an elimination of NEW_TO -> EP->TO. If so,
3433 for (op = reg_eliminate;
3434 op < ®_eliminate[NUM_ELIMINABLE_REGS]; op++)
3435 if (op->from == new_to && op->to == ep->to)
3436 op->can_eliminate = 0;
3440 /* See if any registers that we thought we could eliminate the previous
3441 time are no longer eliminable. If so, something has changed and we
3442 must spill the register. Also, recompute the number of eliminable
3443 registers and see if the frame pointer is needed; it is if there is
3444 no elimination of the frame pointer that we can perform. */
3446 frame_pointer_needed = 1;
3447 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3449 if (ep->can_eliminate && ep->from == FRAME_POINTER_REGNUM
3450 && ep->to != HARD_FRAME_POINTER_REGNUM)
3451 frame_pointer_needed = 0;
3453 if (! ep->can_eliminate && ep->can_eliminate_previous)
3455 ep->can_eliminate_previous = 0;
3456 SET_HARD_REG_BIT (*pset, ep->from);
3461 /* If we didn't need a frame pointer last time, but we do now, spill
3462 the hard frame pointer. */
3463 if (frame_pointer_needed && ! previous_frame_pointer_needed)
3464 SET_HARD_REG_BIT (*pset, HARD_FRAME_POINTER_REGNUM);
3467 /* Initialize the table of registers to eliminate. */
3470 init_elim_table (void)
3472 struct elim_table *ep;
3473 #ifdef ELIMINABLE_REGS
3474 const struct elim_table_1 *ep1;
3478 reg_eliminate = xcalloc (sizeof (struct elim_table), NUM_ELIMINABLE_REGS);
3480 /* Does this function require a frame pointer? */
3482 frame_pointer_needed = (! flag_omit_frame_pointer
3483 /* ?? If EXIT_IGNORE_STACK is set, we will not save
3484 and restore sp for alloca. So we can't eliminate
3485 the frame pointer in that case. At some point,
3486 we should improve this by emitting the
3487 sp-adjusting insns for this case. */
3488 || (current_function_calls_alloca
3489 && EXIT_IGNORE_STACK)
3490 || FRAME_POINTER_REQUIRED);
3494 #ifdef ELIMINABLE_REGS
3495 for (ep = reg_eliminate, ep1 = reg_eliminate_1;
3496 ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++, ep1++)
3498 ep->from = ep1->from;
3500 ep->can_eliminate = ep->can_eliminate_previous
3501 = (CAN_ELIMINATE (ep->from, ep->to)
3502 && ! (ep->to == STACK_POINTER_REGNUM && frame_pointer_needed));
3505 reg_eliminate[0].from = reg_eliminate_1[0].from;
3506 reg_eliminate[0].to = reg_eliminate_1[0].to;
3507 reg_eliminate[0].can_eliminate = reg_eliminate[0].can_eliminate_previous
3508 = ! frame_pointer_needed;
3511 /* Count the number of eliminable registers and build the FROM and TO
3512 REG rtx's. Note that code in gen_rtx_REG will cause, e.g.,
3513 gen_rtx_REG (Pmode, STACK_POINTER_REGNUM) to equal stack_pointer_rtx.
3514 We depend on this. */
3515 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3517 num_eliminable += ep->can_eliminate;
3518 ep->from_rtx = gen_rtx_REG (Pmode, ep->from);
3519 ep->to_rtx = gen_rtx_REG (Pmode, ep->to);
3523 /* Kick all pseudos out of hard register REGNO.
3525 If CANT_ELIMINATE is nonzero, it means that we are doing this spill
3526 because we found we can't eliminate some register. In the case, no pseudos
3527 are allowed to be in the register, even if they are only in a block that
3528 doesn't require spill registers, unlike the case when we are spilling this
3529 hard reg to produce another spill register.
3531 Return nonzero if any pseudos needed to be kicked out. */
3534 spill_hard_reg (unsigned int regno, int cant_eliminate)
3540 SET_HARD_REG_BIT (bad_spill_regs_global, regno);
3541 regs_ever_live[regno] = 1;
3544 /* Spill every pseudo reg that was allocated to this reg
3545 or to something that overlaps this reg. */
3547 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
3548 if (reg_renumber[i] >= 0
3549 && (unsigned int) reg_renumber[i] <= regno
3550 && ((unsigned int) reg_renumber[i]
3551 + hard_regno_nregs[(unsigned int) reg_renumber[i]]
3552 [PSEUDO_REGNO_MODE (i)]
3554 SET_REGNO_REG_SET (&spilled_pseudos, i);
3557 /* I'm getting weird preprocessor errors if I use IOR_HARD_REG_SET
3558 from within EXECUTE_IF_SET_IN_REG_SET. Hence this awkwardness. */
3561 ior_hard_reg_set (HARD_REG_SET *set1, HARD_REG_SET *set2)
3563 IOR_HARD_REG_SET (*set1, *set2);
3566 /* After find_reload_regs has been run for all insn that need reloads,
3567 and/or spill_hard_regs was called, this function is used to actually
3568 spill pseudo registers and try to reallocate them. It also sets up the
3569 spill_regs array for use by choose_reload_regs. */
3572 finish_spills (int global)
3574 struct insn_chain *chain;
3575 int something_changed = 0;
3578 /* Build the spill_regs array for the function. */
3579 /* If there are some registers still to eliminate and one of the spill regs
3580 wasn't ever used before, additional stack space may have to be
3581 allocated to store this register. Thus, we may have changed the offset
3582 between the stack and frame pointers, so mark that something has changed.
3584 One might think that we need only set VAL to 1 if this is a call-used
3585 register. However, the set of registers that must be saved by the
3586 prologue is not identical to the call-used set. For example, the
3587 register used by the call insn for the return PC is a call-used register,
3588 but must be saved by the prologue. */
3591 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3592 if (TEST_HARD_REG_BIT (used_spill_regs, i))
3594 spill_reg_order[i] = n_spills;
3595 spill_regs[n_spills++] = i;
3596 if (num_eliminable && ! regs_ever_live[i])
3597 something_changed = 1;
3598 regs_ever_live[i] = 1;
3601 spill_reg_order[i] = -1;
3603 EXECUTE_IF_SET_IN_REG_SET
3604 (&spilled_pseudos, FIRST_PSEUDO_REGISTER, i,
3606 /* Record the current hard register the pseudo is allocated to in
3607 pseudo_previous_regs so we avoid reallocating it to the same
3608 hard reg in a later pass. */
3609 if (reg_renumber[i] < 0)
3612 SET_HARD_REG_BIT (pseudo_previous_regs[i], reg_renumber[i]);
3613 /* Mark it as no longer having a hard register home. */
3614 reg_renumber[i] = -1;
3615 /* We will need to scan everything again. */
3616 something_changed = 1;
3619 /* Retry global register allocation if possible. */
3622 memset (pseudo_forbidden_regs, 0, max_regno * sizeof (HARD_REG_SET));
3623 /* For every insn that needs reloads, set the registers used as spill
3624 regs in pseudo_forbidden_regs for every pseudo live across the
3626 for (chain = insns_need_reload; chain; chain = chain->next_need_reload)
3628 EXECUTE_IF_SET_IN_REG_SET
3629 (&chain->live_throughout, FIRST_PSEUDO_REGISTER, i,
3631 ior_hard_reg_set (pseudo_forbidden_regs + i,
3632 &chain->used_spill_regs);
3634 EXECUTE_IF_SET_IN_REG_SET
3635 (&chain->dead_or_set, FIRST_PSEUDO_REGISTER, i,
3637 ior_hard_reg_set (pseudo_forbidden_regs + i,
3638 &chain->used_spill_regs);
3642 /* Retry allocating the spilled pseudos. For each reg, merge the
3643 various reg sets that indicate which hard regs can't be used,
3644 and call retry_global_alloc.
3645 We change spill_pseudos here to only contain pseudos that did not
3646 get a new hard register. */
3647 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
3648 if (reg_old_renumber[i] != reg_renumber[i])
3650 HARD_REG_SET forbidden;
3651 COPY_HARD_REG_SET (forbidden, bad_spill_regs_global);
3652 IOR_HARD_REG_SET (forbidden, pseudo_forbidden_regs[i]);
3653 IOR_HARD_REG_SET (forbidden, pseudo_previous_regs[i]);
3654 retry_global_alloc (i, forbidden);
3655 if (reg_renumber[i] >= 0)
3656 CLEAR_REGNO_REG_SET (&spilled_pseudos, i);
3660 /* Fix up the register information in the insn chain.
3661 This involves deleting those of the spilled pseudos which did not get
3662 a new hard register home from the live_{before,after} sets. */
3663 for (chain = reload_insn_chain; chain; chain = chain->next)
3665 HARD_REG_SET used_by_pseudos;
3666 HARD_REG_SET used_by_pseudos2;
3668 AND_COMPL_REG_SET (&chain->live_throughout, &spilled_pseudos);
3669 AND_COMPL_REG_SET (&chain->dead_or_set, &spilled_pseudos);
3671 /* Mark any unallocated hard regs as available for spills. That
3672 makes inheritance work somewhat better. */
3673 if (chain->need_reload)
3675 REG_SET_TO_HARD_REG_SET (used_by_pseudos, &chain->live_throughout);
3676 REG_SET_TO_HARD_REG_SET (used_by_pseudos2, &chain->dead_or_set);
3677 IOR_HARD_REG_SET (used_by_pseudos, used_by_pseudos2);
3679 /* Save the old value for the sanity test below. */
3680 COPY_HARD_REG_SET (used_by_pseudos2, chain->used_spill_regs);
3682 compute_use_by_pseudos (&used_by_pseudos, &chain->live_throughout);
3683 compute_use_by_pseudos (&used_by_pseudos, &chain->dead_or_set);
3684 COMPL_HARD_REG_SET (chain->used_spill_regs, used_by_pseudos);
3685 AND_HARD_REG_SET (chain->used_spill_regs, used_spill_regs);
3687 /* Make sure we only enlarge the set. */
3688 GO_IF_HARD_REG_SUBSET (used_by_pseudos2, chain->used_spill_regs, ok);
3694 /* Let alter_reg modify the reg rtx's for the modified pseudos. */
3695 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
3697 int regno = reg_renumber[i];
3698 if (reg_old_renumber[i] == regno)
3701 alter_reg (i, reg_old_renumber[i]);
3702 reg_old_renumber[i] = regno;
3706 fprintf (rtl_dump_file, " Register %d now on stack.\n\n", i);
3708 fprintf (rtl_dump_file, " Register %d now in %d.\n\n",
3709 i, reg_renumber[i]);
3713 return something_changed;
3716 /* Find all paradoxical subregs within X and update reg_max_ref_width.
3717 Also mark any hard registers used to store user variables as
3718 forbidden from being used for spill registers. */
3721 scan_paradoxical_subregs (rtx x)
3725 enum rtx_code code = GET_CODE (x);
3731 if (SMALL_REGISTER_CLASSES && REGNO (x) < FIRST_PSEUDO_REGISTER
3732 && REG_USERVAR_P (x))
3733 SET_HARD_REG_BIT (bad_spill_regs_global, REGNO (x));
3742 case CONST_VECTOR: /* shouldn't happen, but just in case. */
3750 if (GET_CODE (SUBREG_REG (x)) == REG
3751 && GET_MODE_SIZE (GET_MODE (x)) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
3752 reg_max_ref_width[REGNO (SUBREG_REG (x))]
3753 = GET_MODE_SIZE (GET_MODE (x));
3760 fmt = GET_RTX_FORMAT (code);
3761 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
3764 scan_paradoxical_subregs (XEXP (x, i));
3765 else if (fmt[i] == 'E')
3768 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
3769 scan_paradoxical_subregs (XVECEXP (x, i, j));
3774 /* Reload pseudo-registers into hard regs around each insn as needed.
3775 Additional register load insns are output before the insn that needs it
3776 and perhaps store insns after insns that modify the reloaded pseudo reg.
3778 reg_last_reload_reg and reg_reloaded_contents keep track of
3779 which registers are already available in reload registers.
3780 We update these for the reloads that we perform,
3781 as the insns are scanned. */
3784 reload_as_needed (int live_known)
3786 struct insn_chain *chain;
3787 #if defined (AUTO_INC_DEC)
3792 memset (spill_reg_rtx, 0, sizeof spill_reg_rtx);
3793 memset (spill_reg_store, 0, sizeof spill_reg_store);
3794 reg_last_reload_reg = xcalloc (max_regno, sizeof (rtx));
3795 reg_has_output_reload = xmalloc (max_regno);
3796 CLEAR_HARD_REG_SET (reg_reloaded_valid);
3797 CLEAR_HARD_REG_SET (reg_reloaded_call_part_clobbered);
3799 set_initial_elim_offsets ();
3801 for (chain = reload_insn_chain; chain; chain = chain->next)
3804 rtx insn = chain->insn;
3805 rtx old_next = NEXT_INSN (insn);
3807 /* If we pass a label, copy the offsets from the label information
3808 into the current offsets of each elimination. */
3809 if (GET_CODE (insn) == CODE_LABEL)
3810 set_offsets_for_label (insn);
3812 else if (INSN_P (insn))
3814 rtx oldpat = copy_rtx (PATTERN (insn));
3816 /* If this is a USE and CLOBBER of a MEM, ensure that any
3817 references to eliminable registers have been removed. */
3819 if ((GET_CODE (PATTERN (insn)) == USE
3820 || GET_CODE (PATTERN (insn)) == CLOBBER)
3821 && GET_CODE (XEXP (PATTERN (insn), 0)) == MEM)
3822 XEXP (XEXP (PATTERN (insn), 0), 0)
3823 = eliminate_regs (XEXP (XEXP (PATTERN (insn), 0), 0),
3824 GET_MODE (XEXP (PATTERN (insn), 0)),
3827 /* If we need to do register elimination processing, do so.
3828 This might delete the insn, in which case we are done. */
3829 if ((num_eliminable || num_eliminable_invariants) && chain->need_elim)
3831 eliminate_regs_in_insn (insn, 1);
3832 if (GET_CODE (insn) == NOTE)
3834 update_eliminable_offsets ();
3839 /* If need_elim is nonzero but need_reload is zero, one might think
3840 that we could simply set n_reloads to 0. However, find_reloads
3841 could have done some manipulation of the insn (such as swapping
3842 commutative operands), and these manipulations are lost during
3843 the first pass for every insn that needs register elimination.
3844 So the actions of find_reloads must be redone here. */
3846 if (! chain->need_elim && ! chain->need_reload
3847 && ! chain->need_operand_change)
3849 /* First find the pseudo regs that must be reloaded for this insn.
3850 This info is returned in the tables reload_... (see reload.h).
3851 Also modify the body of INSN by substituting RELOAD
3852 rtx's for those pseudo regs. */
3855 memset (reg_has_output_reload, 0, max_regno);
3856 CLEAR_HARD_REG_SET (reg_is_output_reload);
3858 find_reloads (insn, 1, spill_indirect_levels, live_known,
3864 rtx next = NEXT_INSN (insn);
3867 prev = PREV_INSN (insn);
3869 /* Now compute which reload regs to reload them into. Perhaps
3870 reusing reload regs from previous insns, or else output
3871 load insns to reload them. Maybe output store insns too.
3872 Record the choices of reload reg in reload_reg_rtx. */
3873 choose_reload_regs (chain);
3875 /* Merge any reloads that we didn't combine for fear of
3876 increasing the number of spill registers needed but now
3877 discover can be safely merged. */
3878 if (SMALL_REGISTER_CLASSES)
3879 merge_assigned_reloads (insn);
3881 /* Generate the insns to reload operands into or out of
3882 their reload regs. */
3883 emit_reload_insns (chain);
3885 /* Substitute the chosen reload regs from reload_reg_rtx
3886 into the insn's body (or perhaps into the bodies of other
3887 load and store insn that we just made for reloading
3888 and that we moved the structure into). */
3889 subst_reloads (insn);
3891 /* If this was an ASM, make sure that all the reload insns
3892 we have generated are valid. If not, give an error
3895 if (asm_noperands (PATTERN (insn)) >= 0)
3896 for (p = NEXT_INSN (prev); p != next; p = NEXT_INSN (p))
3897 if (p != insn && INSN_P (p)
3898 && GET_CODE (PATTERN (p)) != USE
3899 && (recog_memoized (p) < 0
3900 || (extract_insn (p), ! constrain_operands (1))))
3902 error_for_asm (insn,
3903 "`asm' operand requires impossible reload");
3908 if (num_eliminable && chain->need_elim)
3909 update_eliminable_offsets ();
3911 /* Any previously reloaded spilled pseudo reg, stored in this insn,
3912 is no longer validly lying around to save a future reload.
3913 Note that this does not detect pseudos that were reloaded
3914 for this insn in order to be stored in
3915 (obeying register constraints). That is correct; such reload
3916 registers ARE still valid. */
3917 note_stores (oldpat, forget_old_reloads_1, NULL);
3919 /* There may have been CLOBBER insns placed after INSN. So scan
3920 between INSN and NEXT and use them to forget old reloads. */
3921 for (x = NEXT_INSN (insn); x != old_next; x = NEXT_INSN (x))
3922 if (GET_CODE (x) == INSN && GET_CODE (PATTERN (x)) == CLOBBER)
3923 note_stores (PATTERN (x), forget_old_reloads_1, NULL);
3926 /* Likewise for regs altered by auto-increment in this insn.
3927 REG_INC notes have been changed by reloading:
3928 find_reloads_address_1 records substitutions for them,
3929 which have been performed by subst_reloads above. */
3930 for (i = n_reloads - 1; i >= 0; i--)
3932 rtx in_reg = rld[i].in_reg;
3935 enum rtx_code code = GET_CODE (in_reg);
3936 /* PRE_INC / PRE_DEC will have the reload register ending up
3937 with the same value as the stack slot, but that doesn't
3938 hold true for POST_INC / POST_DEC. Either we have to
3939 convert the memory access to a true POST_INC / POST_DEC,
3940 or we can't use the reload register for inheritance. */
3941 if ((code == POST_INC || code == POST_DEC)
3942 && TEST_HARD_REG_BIT (reg_reloaded_valid,
3943 REGNO (rld[i].reg_rtx))
3944 /* Make sure it is the inc/dec pseudo, and not
3945 some other (e.g. output operand) pseudo. */
3946 && ((unsigned) reg_reloaded_contents[REGNO (rld[i].reg_rtx)]
3947 == REGNO (XEXP (in_reg, 0))))
3950 rtx reload_reg = rld[i].reg_rtx;
3951 enum machine_mode mode = GET_MODE (reload_reg);
3955 for (p = PREV_INSN (old_next); p != prev; p = PREV_INSN (p))
3957 /* We really want to ignore REG_INC notes here, so
3958 use PATTERN (p) as argument to reg_set_p . */
3959 if (reg_set_p (reload_reg, PATTERN (p)))
3961 n = count_occurrences (PATTERN (p), reload_reg, 0);
3966 n = validate_replace_rtx (reload_reg,
3967 gen_rtx_fmt_e (code,
3972 /* We must also verify that the constraints
3973 are met after the replacement. */
3976 n = constrain_operands (1);
3980 /* If the constraints were not met, then
3981 undo the replacement. */
3984 validate_replace_rtx (gen_rtx_fmt_e (code,
3997 = gen_rtx_EXPR_LIST (REG_INC, reload_reg,
3999 /* Mark this as having an output reload so that the
4000 REG_INC processing code below won't invalidate
4001 the reload for inheritance. */
4002 SET_HARD_REG_BIT (reg_is_output_reload,
4003 REGNO (reload_reg));
4004 reg_has_output_reload[REGNO (XEXP (in_reg, 0))] = 1;
4007 forget_old_reloads_1 (XEXP (in_reg, 0), NULL_RTX,
4010 else if ((code == PRE_INC || code == PRE_DEC)
4011 && TEST_HARD_REG_BIT (reg_reloaded_valid,
4012 REGNO (rld[i].reg_rtx))
4013 /* Make sure it is the inc/dec pseudo, and not
4014 some other (e.g. output operand) pseudo. */
4015 && ((unsigned) reg_reloaded_contents[REGNO (rld[i].reg_rtx)]
4016 == REGNO (XEXP (in_reg, 0))))
4018 SET_HARD_REG_BIT (reg_is_output_reload,
4019 REGNO (rld[i].reg_rtx));
4020 reg_has_output_reload[REGNO (XEXP (in_reg, 0))] = 1;
4024 /* If a pseudo that got a hard register is auto-incremented,
4025 we must purge records of copying it into pseudos without
4027 for (x = REG_NOTES (insn); x; x = XEXP (x, 1))
4028 if (REG_NOTE_KIND (x) == REG_INC)
4030 /* See if this pseudo reg was reloaded in this insn.
4031 If so, its last-reload info is still valid
4032 because it is based on this insn's reload. */
4033 for (i = 0; i < n_reloads; i++)
4034 if (rld[i].out == XEXP (x, 0))
4038 forget_old_reloads_1 (XEXP (x, 0), NULL_RTX, NULL);
4042 /* A reload reg's contents are unknown after a label. */
4043 if (GET_CODE (insn) == CODE_LABEL)
4044 CLEAR_HARD_REG_SET (reg_reloaded_valid);
4046 /* Don't assume a reload reg is still good after a call insn
4047 if it is a call-used reg, or if it contains a value that will
4048 be partially clobbered by the call. */
4049 else if (GET_CODE (insn) == CALL_INSN)
4051 AND_COMPL_HARD_REG_SET (reg_reloaded_valid, call_used_reg_set);
4052 AND_COMPL_HARD_REG_SET (reg_reloaded_valid, reg_reloaded_call_part_clobbered);
4057 free (reg_last_reload_reg);
4058 free (reg_has_output_reload);
4061 /* Discard all record of any value reloaded from X,
4062 or reloaded in X from someplace else;
4063 unless X is an output reload reg of the current insn.
4065 X may be a hard reg (the reload reg)
4066 or it may be a pseudo reg that was reloaded from. */
4069 forget_old_reloads_1 (rtx x, rtx ignored ATTRIBUTE_UNUSED,
4070 void *data ATTRIBUTE_UNUSED)
4075 /* note_stores does give us subregs of hard regs,
4076 subreg_regno_offset will abort if it is not a hard reg. */
4077 while (GET_CODE (x) == SUBREG)
4079 /* We ignore the subreg offset when calculating the regno,
4080 because we are using the entire underlying hard register
4085 if (GET_CODE (x) != REG)
4090 if (regno >= FIRST_PSEUDO_REGISTER)
4096 nr = hard_regno_nregs[regno][GET_MODE (x)];
4097 /* Storing into a spilled-reg invalidates its contents.
4098 This can happen if a block-local pseudo is allocated to that reg
4099 and it wasn't spilled because this block's total need is 0.
4100 Then some insn might have an optional reload and use this reg. */
4101 for (i = 0; i < nr; i++)
4102 /* But don't do this if the reg actually serves as an output
4103 reload reg in the current instruction. */
4105 || ! TEST_HARD_REG_BIT (reg_is_output_reload, regno + i))
4107 CLEAR_HARD_REG_BIT (reg_reloaded_valid, regno + i);
4108 CLEAR_HARD_REG_BIT (reg_reloaded_call_part_clobbered, regno + i);
4109 spill_reg_store[regno + i] = 0;
4113 /* Since value of X has changed,
4114 forget any value previously copied from it. */
4117 /* But don't forget a copy if this is the output reload
4118 that establishes the copy's validity. */
4119 if (n_reloads == 0 || reg_has_output_reload[regno + nr] == 0)
4120 reg_last_reload_reg[regno + nr] = 0;
4123 /* The following HARD_REG_SETs indicate when each hard register is
4124 used for a reload of various parts of the current insn. */
4126 /* If reg is unavailable for all reloads. */
4127 static HARD_REG_SET reload_reg_unavailable;
4128 /* If reg is in use as a reload reg for a RELOAD_OTHER reload. */
4129 static HARD_REG_SET reload_reg_used;
4130 /* If reg is in use for a RELOAD_FOR_INPUT_ADDRESS reload for operand I. */
4131 static HARD_REG_SET reload_reg_used_in_input_addr[MAX_RECOG_OPERANDS];
4132 /* If reg is in use for a RELOAD_FOR_INPADDR_ADDRESS reload for operand I. */
4133 static HARD_REG_SET reload_reg_used_in_inpaddr_addr[MAX_RECOG_OPERANDS];
4134 /* If reg is in use for a RELOAD_FOR_OUTPUT_ADDRESS reload for operand I. */
4135 static HARD_REG_SET reload_reg_used_in_output_addr[MAX_RECOG_OPERANDS];
4136 /* If reg is in use for a RELOAD_FOR_OUTADDR_ADDRESS reload for operand I. */
4137 static HARD_REG_SET reload_reg_used_in_outaddr_addr[MAX_RECOG_OPERANDS];
4138 /* If reg is in use for a RELOAD_FOR_INPUT reload for operand I. */
4139 static HARD_REG_SET reload_reg_used_in_input[MAX_RECOG_OPERANDS];
4140 /* If reg is in use for a RELOAD_FOR_OUTPUT reload for operand I. */
4141 static HARD_REG_SET reload_reg_used_in_output[MAX_RECOG_OPERANDS];
4142 /* If reg is in use for a RELOAD_FOR_OPERAND_ADDRESS reload. */
4143 static HARD_REG_SET reload_reg_used_in_op_addr;
4144 /* If reg is in use for a RELOAD_FOR_OPADDR_ADDR reload. */
4145 static HARD_REG_SET reload_reg_used_in_op_addr_reload;
4146 /* If reg is in use for a RELOAD_FOR_INSN reload. */
4147 static HARD_REG_SET reload_reg_used_in_insn;
4148 /* If reg is in use for a RELOAD_FOR_OTHER_ADDRESS reload. */
4149 static HARD_REG_SET reload_reg_used_in_other_addr;
4151 /* If reg is in use as a reload reg for any sort of reload. */
4152 static HARD_REG_SET reload_reg_used_at_all;
4154 /* If reg is use as an inherited reload. We just mark the first register
4156 static HARD_REG_SET reload_reg_used_for_inherit;
4158 /* Records which hard regs are used in any way, either as explicit use or
4159 by being allocated to a pseudo during any point of the current insn. */
4160 static HARD_REG_SET reg_used_in_insn;
4162 /* Mark reg REGNO as in use for a reload of the sort spec'd by OPNUM and
4163 TYPE. MODE is used to indicate how many consecutive regs are
4167 mark_reload_reg_in_use (unsigned int regno, int opnum, enum reload_type type,
4168 enum machine_mode mode)
4170 unsigned int nregs = hard_regno_nregs[regno][mode];
4173 for (i = regno; i < nregs + regno; i++)
4178 SET_HARD_REG_BIT (reload_reg_used, i);
4181 case RELOAD_FOR_INPUT_ADDRESS:
4182 SET_HARD_REG_BIT (reload_reg_used_in_input_addr[opnum], i);
4185 case RELOAD_FOR_INPADDR_ADDRESS:
4186 SET_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[opnum], i);
4189 case RELOAD_FOR_OUTPUT_ADDRESS:
4190 SET_HARD_REG_BIT (reload_reg_used_in_output_addr[opnum], i);
4193 case RELOAD_FOR_OUTADDR_ADDRESS:
4194 SET_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[opnum], i);
4197 case RELOAD_FOR_OPERAND_ADDRESS:
4198 SET_HARD_REG_BIT (reload_reg_used_in_op_addr, i);
4201 case RELOAD_FOR_OPADDR_ADDR:
4202 SET_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, i);
4205 case RELOAD_FOR_OTHER_ADDRESS:
4206 SET_HARD_REG_BIT (reload_reg_used_in_other_addr, i);
4209 case RELOAD_FOR_INPUT:
4210 SET_HARD_REG_BIT (reload_reg_used_in_input[opnum], i);
4213 case RELOAD_FOR_OUTPUT:
4214 SET_HARD_REG_BIT (reload_reg_used_in_output[opnum], i);
4217 case RELOAD_FOR_INSN:
4218 SET_HARD_REG_BIT (reload_reg_used_in_insn, i);
4222 SET_HARD_REG_BIT (reload_reg_used_at_all, i);
4226 /* Similarly, but show REGNO is no longer in use for a reload. */
4229 clear_reload_reg_in_use (unsigned int regno, int opnum,
4230 enum reload_type type, enum machine_mode mode)
4232 unsigned int nregs = hard_regno_nregs[regno][mode];
4233 unsigned int start_regno, end_regno, r;
4235 /* A complication is that for some reload types, inheritance might
4236 allow multiple reloads of the same types to share a reload register.
4237 We set check_opnum if we have to check only reloads with the same
4238 operand number, and check_any if we have to check all reloads. */
4239 int check_opnum = 0;
4241 HARD_REG_SET *used_in_set;
4246 used_in_set = &reload_reg_used;
4249 case RELOAD_FOR_INPUT_ADDRESS:
4250 used_in_set = &reload_reg_used_in_input_addr[opnum];
4253 case RELOAD_FOR_INPADDR_ADDRESS:
4255 used_in_set = &reload_reg_used_in_inpaddr_addr[opnum];
4258 case RELOAD_FOR_OUTPUT_ADDRESS:
4259 used_in_set = &reload_reg_used_in_output_addr[opnum];
4262 case RELOAD_FOR_OUTADDR_ADDRESS:
4264 used_in_set = &reload_reg_used_in_outaddr_addr[opnum];
4267 case RELOAD_FOR_OPERAND_ADDRESS:
4268 used_in_set = &reload_reg_used_in_op_addr;
4271 case RELOAD_FOR_OPADDR_ADDR:
4273 used_in_set = &reload_reg_used_in_op_addr_reload;
4276 case RELOAD_FOR_OTHER_ADDRESS:
4277 used_in_set = &reload_reg_used_in_other_addr;
4281 case RELOAD_FOR_INPUT:
4282 used_in_set = &reload_reg_used_in_input[opnum];
4285 case RELOAD_FOR_OUTPUT:
4286 used_in_set = &reload_reg_used_in_output[opnum];
4289 case RELOAD_FOR_INSN:
4290 used_in_set = &reload_reg_used_in_insn;
4295 /* We resolve conflicts with remaining reloads of the same type by
4296 excluding the intervals of reload registers by them from the
4297 interval of freed reload registers. Since we only keep track of
4298 one set of interval bounds, we might have to exclude somewhat
4299 more than what would be necessary if we used a HARD_REG_SET here.
4300 But this should only happen very infrequently, so there should
4301 be no reason to worry about it. */
4303 start_regno = regno;
4304 end_regno = regno + nregs;
4305 if (check_opnum || check_any)
4307 for (i = n_reloads - 1; i >= 0; i--)
4309 if (rld[i].when_needed == type
4310 && (check_any || rld[i].opnum == opnum)
4313 unsigned int conflict_start = true_regnum (rld[i].reg_rtx);
4314 unsigned int conflict_end
4316 + hard_regno_nregs[conflict_start][rld[i].mode]);
4318 /* If there is an overlap with the first to-be-freed register,
4319 adjust the interval start. */
4320 if (conflict_start <= start_regno && conflict_end > start_regno)
4321 start_regno = conflict_end;
4322 /* Otherwise, if there is a conflict with one of the other
4323 to-be-freed registers, adjust the interval end. */
4324 if (conflict_start > start_regno && conflict_start < end_regno)
4325 end_regno = conflict_start;
4330 for (r = start_regno; r < end_regno; r++)
4331 CLEAR_HARD_REG_BIT (*used_in_set, r);
4334 /* 1 if reg REGNO is free as a reload reg for a reload of the sort
4335 specified by OPNUM and TYPE. */
4338 reload_reg_free_p (unsigned int regno, int opnum, enum reload_type type)
4342 /* In use for a RELOAD_OTHER means it's not available for anything. */
4343 if (TEST_HARD_REG_BIT (reload_reg_used, regno)
4344 || TEST_HARD_REG_BIT (reload_reg_unavailable, regno))
4350 /* In use for anything means we can't use it for RELOAD_OTHER. */
4351 if (TEST_HARD_REG_BIT (reload_reg_used_in_other_addr, regno)
4352 || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)
4353 || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno)
4354 || TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno))
4357 for (i = 0; i < reload_n_operands; i++)
4358 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4359 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno)
4360 || TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4361 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
4362 || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)
4363 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4368 case RELOAD_FOR_INPUT:
4369 if (TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4370 || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno))
4373 if (TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno))
4376 /* If it is used for some other input, can't use it. */
4377 for (i = 0; i < reload_n_operands; i++)
4378 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4381 /* If it is used in a later operand's address, can't use it. */
4382 for (i = opnum + 1; i < reload_n_operands; i++)
4383 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4384 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno))
4389 case RELOAD_FOR_INPUT_ADDRESS:
4390 /* Can't use a register if it is used for an input address for this
4391 operand or used as an input in an earlier one. */
4392 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[opnum], regno)
4393 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[opnum], regno))
4396 for (i = 0; i < opnum; i++)
4397 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4402 case RELOAD_FOR_INPADDR_ADDRESS:
4403 /* Can't use a register if it is used for an input address
4404 for this operand or used as an input in an earlier
4406 if (TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[opnum], regno))
4409 for (i = 0; i < opnum; i++)
4410 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4415 case RELOAD_FOR_OUTPUT_ADDRESS:
4416 /* Can't use a register if it is used for an output address for this
4417 operand or used as an output in this or a later operand. Note
4418 that multiple output operands are emitted in reverse order, so
4419 the conflicting ones are those with lower indices. */
4420 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[opnum], regno))
4423 for (i = 0; i <= opnum; i++)
4424 if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4429 case RELOAD_FOR_OUTADDR_ADDRESS:
4430 /* Can't use a register if it is used for an output address
4431 for this operand or used as an output in this or a
4432 later operand. Note that multiple output operands are
4433 emitted in reverse order, so the conflicting ones are
4434 those with lower indices. */
4435 if (TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[opnum], regno))
4438 for (i = 0; i <= opnum; i++)
4439 if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4444 case RELOAD_FOR_OPERAND_ADDRESS:
4445 for (i = 0; i < reload_n_operands; i++)
4446 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4449 return (! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4450 && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno));
4452 case RELOAD_FOR_OPADDR_ADDR:
4453 for (i = 0; i < reload_n_operands; i++)
4454 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4457 return (!TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno));
4459 case RELOAD_FOR_OUTPUT:
4460 /* This cannot share a register with RELOAD_FOR_INSN reloads, other
4461 outputs, or an operand address for this or an earlier output.
4462 Note that multiple output operands are emitted in reverse order,
4463 so the conflicting ones are those with higher indices. */
4464 if (TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno))
4467 for (i = 0; i < reload_n_operands; i++)
4468 if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4471 for (i = opnum; i < reload_n_operands; i++)
4472 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4473 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno))
4478 case RELOAD_FOR_INSN:
4479 for (i = 0; i < reload_n_operands; i++)
4480 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)
4481 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4484 return (! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4485 && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno));
4487 case RELOAD_FOR_OTHER_ADDRESS:
4488 return ! TEST_HARD_REG_BIT (reload_reg_used_in_other_addr, regno);
4493 /* Return 1 if the value in reload reg REGNO, as used by a reload
4494 needed for the part of the insn specified by OPNUM and TYPE,
4495 is still available in REGNO at the end of the insn.
4497 We can assume that the reload reg was already tested for availability
4498 at the time it is needed, and we should not check this again,
4499 in case the reg has already been marked in use. */
4502 reload_reg_reaches_end_p (unsigned int regno, int opnum, enum reload_type type)
4509 /* Since a RELOAD_OTHER reload claims the reg for the entire insn,
4510 its value must reach the end. */
4513 /* If this use is for part of the insn,
4514 its value reaches if no subsequent part uses the same register.
4515 Just like the above function, don't try to do this with lots
4518 case RELOAD_FOR_OTHER_ADDRESS:
4519 /* Here we check for everything else, since these don't conflict
4520 with anything else and everything comes later. */
4522 for (i = 0; i < reload_n_operands; i++)
4523 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4524 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
4525 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)
4526 || TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4527 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno)
4528 || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4531 return (! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)
4532 && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno)
4533 && ! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4534 && ! TEST_HARD_REG_BIT (reload_reg_used, regno));
4536 case RELOAD_FOR_INPUT_ADDRESS:
4537 case RELOAD_FOR_INPADDR_ADDRESS:
4538 /* Similar, except that we check only for this and subsequent inputs
4539 and the address of only subsequent inputs and we do not need
4540 to check for RELOAD_OTHER objects since they are known not to
4543 for (i = opnum; i < reload_n_operands; i++)
4544 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4547 for (i = opnum + 1; i < reload_n_operands; i++)
4548 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4549 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno))
4552 for (i = 0; i < reload_n_operands; i++)
4553 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4554 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
4555 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4558 if (TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno))
4561 return (!TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)
4562 && !TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4563 && !TEST_HARD_REG_BIT (reload_reg_used, regno));
4565 case RELOAD_FOR_INPUT:
4566 /* Similar to input address, except we start at the next operand for
4567 both input and input address and we do not check for
4568 RELOAD_FOR_OPERAND_ADDRESS and RELOAD_FOR_INSN since these
4571 for (i = opnum + 1; i < reload_n_operands; i++)
4572 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4573 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno)
4574 || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4577 /* ... fall through ... */
4579 case RELOAD_FOR_OPERAND_ADDRESS:
4580 /* Check outputs and their addresses. */
4582 for (i = 0; i < reload_n_operands; i++)
4583 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4584 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
4585 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4588 return (!TEST_HARD_REG_BIT (reload_reg_used, regno));
4590 case RELOAD_FOR_OPADDR_ADDR:
4591 for (i = 0; i < reload_n_operands; i++)
4592 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4593 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
4594 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4597 return (!TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)
4598 && !TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4599 && !TEST_HARD_REG_BIT (reload_reg_used, regno));
4601 case RELOAD_FOR_INSN:
4602 /* These conflict with other outputs with RELOAD_OTHER. So
4603 we need only check for output addresses. */
4605 opnum = reload_n_operands;
4607 /* ... fall through ... */
4609 case RELOAD_FOR_OUTPUT:
4610 case RELOAD_FOR_OUTPUT_ADDRESS:
4611 case RELOAD_FOR_OUTADDR_ADDRESS:
4612 /* We already know these can't conflict with a later output. So the
4613 only thing to check are later output addresses.
4614 Note that multiple output operands are emitted in reverse order,
4615 so the conflicting ones are those with lower indices. */
4616 for (i = 0; i < opnum; i++)
4617 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4618 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno))
4627 /* Return 1 if the reloads denoted by R1 and R2 cannot share a register.
4630 This function uses the same algorithm as reload_reg_free_p above. */
4633 reloads_conflict (int r1, int r2)
4635 enum reload_type r1_type = rld[r1].when_needed;
4636 enum reload_type r2_type = rld[r2].when_needed;
4637 int r1_opnum = rld[r1].opnum;
4638 int r2_opnum = rld[r2].opnum;
4640 /* RELOAD_OTHER conflicts with everything. */
4641 if (r2_type == RELOAD_OTHER)
4644 /* Otherwise, check conflicts differently for each type. */
4648 case RELOAD_FOR_INPUT:
4649 return (r2_type == RELOAD_FOR_INSN
4650 || r2_type == RELOAD_FOR_OPERAND_ADDRESS
4651 || r2_type == RELOAD_FOR_OPADDR_ADDR
4652 || r2_type == RELOAD_FOR_INPUT
4653 || ((r2_type == RELOAD_FOR_INPUT_ADDRESS
4654 || r2_type == RELOAD_FOR_INPADDR_ADDRESS)
4655 && r2_opnum > r1_opnum));
4657 case RELOAD_FOR_INPUT_ADDRESS:
4658 return ((r2_type == RELOAD_FOR_INPUT_ADDRESS && r1_opnum == r2_opnum)
4659 || (r2_type == RELOAD_FOR_INPUT && r2_opnum < r1_opnum));
4661 case RELOAD_FOR_INPADDR_ADDRESS:
4662 return ((r2_type == RELOAD_FOR_INPADDR_ADDRESS && r1_opnum == r2_opnum)
4663 || (r2_type == RELOAD_FOR_INPUT && r2_opnum < r1_opnum));
4665 case RELOAD_FOR_OUTPUT_ADDRESS:
4666 return ((r2_type == RELOAD_FOR_OUTPUT_ADDRESS && r2_opnum == r1_opnum)
4667 || (r2_type == RELOAD_FOR_OUTPUT && r2_opnum <= r1_opnum));
4669 case RELOAD_FOR_OUTADDR_ADDRESS:
4670 return ((r2_type == RELOAD_FOR_OUTADDR_ADDRESS && r2_opnum == r1_opnum)
4671 || (r2_type == RELOAD_FOR_OUTPUT && r2_opnum <= r1_opnum));
4673 case RELOAD_FOR_OPERAND_ADDRESS:
4674 return (r2_type == RELOAD_FOR_INPUT || r2_type == RELOAD_FOR_INSN
4675 || r2_type == RELOAD_FOR_OPERAND_ADDRESS);
4677 case RELOAD_FOR_OPADDR_ADDR:
4678 return (r2_type == RELOAD_FOR_INPUT
4679 || r2_type == RELOAD_FOR_OPADDR_ADDR);
4681 case RELOAD_FOR_OUTPUT:
4682 return (r2_type == RELOAD_FOR_INSN || r2_type == RELOAD_FOR_OUTPUT
4683 || ((r2_type == RELOAD_FOR_OUTPUT_ADDRESS
4684 || r2_type == RELOAD_FOR_OUTADDR_ADDRESS)
4685 && r2_opnum >= r1_opnum));
4687 case RELOAD_FOR_INSN:
4688 return (r2_type == RELOAD_FOR_INPUT || r2_type == RELOAD_FOR_OUTPUT
4689 || r2_type == RELOAD_FOR_INSN
4690 || r2_type == RELOAD_FOR_OPERAND_ADDRESS);
4692 case RELOAD_FOR_OTHER_ADDRESS:
4693 return r2_type == RELOAD_FOR_OTHER_ADDRESS;
4703 /* Indexed by reload number, 1 if incoming value
4704 inherited from previous insns. */
4705 char reload_inherited[MAX_RELOADS];
4707 /* For an inherited reload, this is the insn the reload was inherited from,
4708 if we know it. Otherwise, this is 0. */
4709 rtx reload_inheritance_insn[MAX_RELOADS];
4711 /* If nonzero, this is a place to get the value of the reload,
4712 rather than using reload_in. */
4713 rtx reload_override_in[MAX_RELOADS];
4715 /* For each reload, the hard register number of the register used,
4716 or -1 if we did not need a register for this reload. */
4717 int reload_spill_index[MAX_RELOADS];
4719 /* Subroutine of free_for_value_p, used to check a single register.
4720 START_REGNO is the starting regno of the full reload register
4721 (possibly comprising multiple hard registers) that we are considering. */
4724 reload_reg_free_for_value_p (int start_regno, int regno, int opnum,
4725 enum reload_type type, rtx value, rtx out,
4726 int reloadnum, int ignore_address_reloads)
4729 /* Set if we see an input reload that must not share its reload register
4730 with any new earlyclobber, but might otherwise share the reload
4731 register with an output or input-output reload. */
4732 int check_earlyclobber = 0;
4736 if (TEST_HARD_REG_BIT (reload_reg_unavailable, regno))
4739 if (out == const0_rtx)
4745 /* We use some pseudo 'time' value to check if the lifetimes of the
4746 new register use would overlap with the one of a previous reload
4747 that is not read-only or uses a different value.
4748 The 'time' used doesn't have to be linear in any shape or form, just
4750 Some reload types use different 'buckets' for each operand.
4751 So there are MAX_RECOG_OPERANDS different time values for each
4753 We compute TIME1 as the time when the register for the prospective
4754 new reload ceases to be live, and TIME2 for each existing
4755 reload as the time when that the reload register of that reload
4757 Where there is little to be gained by exact lifetime calculations,
4758 we just make conservative assumptions, i.e. a longer lifetime;
4759 this is done in the 'default:' cases. */
4762 case RELOAD_FOR_OTHER_ADDRESS:
4763 /* RELOAD_FOR_OTHER_ADDRESS conflicts with RELOAD_OTHER reloads. */
4764 time1 = copy ? 0 : 1;
4767 time1 = copy ? 1 : MAX_RECOG_OPERANDS * 5 + 5;
4769 /* For each input, we may have a sequence of RELOAD_FOR_INPADDR_ADDRESS,
4770 RELOAD_FOR_INPUT_ADDRESS and RELOAD_FOR_INPUT. By adding 0 / 1 / 2 ,
4771 respectively, to the time values for these, we get distinct time
4772 values. To get distinct time values for each operand, we have to
4773 multiply opnum by at least three. We round that up to four because
4774 multiply by four is often cheaper. */
4775 case RELOAD_FOR_INPADDR_ADDRESS:
4776 time1 = opnum * 4 + 2;
4778 case RELOAD_FOR_INPUT_ADDRESS:
4779 time1 = opnum * 4 + 3;
4781 case RELOAD_FOR_INPUT:
4782 /* All RELOAD_FOR_INPUT reloads remain live till the instruction
4783 executes (inclusive). */
4784 time1 = copy ? opnum * 4 + 4 : MAX_RECOG_OPERANDS * 4 + 3;
4786 case RELOAD_FOR_OPADDR_ADDR:
4788 <= (MAX_RECOG_OPERANDS - 1) * 4 + 4 == MAX_RECOG_OPERANDS * 4 */
4789 time1 = MAX_RECOG_OPERANDS * 4 + 1;
4791 case RELOAD_FOR_OPERAND_ADDRESS:
4792 /* RELOAD_FOR_OPERAND_ADDRESS reloads are live even while the insn
4794 time1 = copy ? MAX_RECOG_OPERANDS * 4 + 2 : MAX_RECOG_OPERANDS * 4 + 3;
4796 case RELOAD_FOR_OUTADDR_ADDRESS:
4797 time1 = MAX_RECOG_OPERANDS * 4 + 4 + opnum;
4799 case RELOAD_FOR_OUTPUT_ADDRESS:
4800 time1 = MAX_RECOG_OPERANDS * 4 + 5 + opnum;
4803 time1 = MAX_RECOG_OPERANDS * 5 + 5;
4806 for (i = 0; i < n_reloads; i++)
4808 rtx reg = rld[i].reg_rtx;
4809 if (reg && GET_CODE (reg) == REG
4810 && ((unsigned) regno - true_regnum (reg)
4811 <= hard_regno_nregs[REGNO (reg)][GET_MODE (reg)] - (unsigned) 1)
4814 rtx other_input = rld[i].in;
4816 /* If the other reload loads the same input value, that
4817 will not cause a conflict only if it's loading it into
4818 the same register. */
4819 if (true_regnum (reg) != start_regno)
4820 other_input = NULL_RTX;
4821 if (! other_input || ! rtx_equal_p (other_input, value)
4822 || rld[i].out || out)
4825 switch (rld[i].when_needed)
4827 case RELOAD_FOR_OTHER_ADDRESS:
4830 case RELOAD_FOR_INPADDR_ADDRESS:
4831 /* find_reloads makes sure that a
4832 RELOAD_FOR_{INP,OP,OUT}ADDR_ADDRESS reload is only used
4833 by at most one - the first -
4834 RELOAD_FOR_{INPUT,OPERAND,OUTPUT}_ADDRESS . If the
4835 address reload is inherited, the address address reload
4836 goes away, so we can ignore this conflict. */
4837 if (type == RELOAD_FOR_INPUT_ADDRESS && reloadnum == i + 1
4838 && ignore_address_reloads
4839 /* Unless the RELOAD_FOR_INPUT is an auto_inc expression.
4840 Then the address address is still needed to store
4841 back the new address. */
4842 && ! rld[reloadnum].out)
4844 /* Likewise, if a RELOAD_FOR_INPUT can inherit a value, its
4845 RELOAD_FOR_INPUT_ADDRESS / RELOAD_FOR_INPADDR_ADDRESS
4847 if (type == RELOAD_FOR_INPUT && opnum == rld[i].opnum
4848 && ignore_address_reloads
4849 /* Unless we are reloading an auto_inc expression. */
4850 && ! rld[reloadnum].out)
4852 time2 = rld[i].opnum * 4 + 2;
4854 case RELOAD_FOR_INPUT_ADDRESS:
4855 if (type == RELOAD_FOR_INPUT && opnum == rld[i].opnum
4856 && ignore_address_reloads
4857 && ! rld[reloadnum].out)
4859 time2 = rld[i].opnum * 4 + 3;
4861 case RELOAD_FOR_INPUT:
4862 time2 = rld[i].opnum * 4 + 4;
4863 check_earlyclobber = 1;
4865 /* rld[i].opnum * 4 + 4 <= (MAX_RECOG_OPERAND - 1) * 4 + 4
4866 == MAX_RECOG_OPERAND * 4 */
4867 case RELOAD_FOR_OPADDR_ADDR:
4868 if (type == RELOAD_FOR_OPERAND_ADDRESS && reloadnum == i + 1
4869 && ignore_address_reloads
4870 && ! rld[reloadnum].out)
4872 time2 = MAX_RECOG_OPERANDS * 4 + 1;
4874 case RELOAD_FOR_OPERAND_ADDRESS:
4875 time2 = MAX_RECOG_OPERANDS * 4 + 2;
4876 check_earlyclobber = 1;
4878 case RELOAD_FOR_INSN:
4879 time2 = MAX_RECOG_OPERANDS * 4 + 3;
4881 case RELOAD_FOR_OUTPUT:
4882 /* All RELOAD_FOR_OUTPUT reloads become live just after the
4883 instruction is executed. */
4884 time2 = MAX_RECOG_OPERANDS * 4 + 4;
4886 /* The first RELOAD_FOR_OUTADDR_ADDRESS reload conflicts with
4887 the RELOAD_FOR_OUTPUT reloads, so assign it the same time
4889 case RELOAD_FOR_OUTADDR_ADDRESS:
4890 if (type == RELOAD_FOR_OUTPUT_ADDRESS && reloadnum == i + 1
4891 && ignore_address_reloads
4892 && ! rld[reloadnum].out)
4894 time2 = MAX_RECOG_OPERANDS * 4 + 4 + rld[i].opnum;
4896 case RELOAD_FOR_OUTPUT_ADDRESS:
4897 time2 = MAX_RECOG_OPERANDS * 4 + 5 + rld[i].opnum;
4900 /* If there is no conflict in the input part, handle this
4901 like an output reload. */
4902 if (! rld[i].in || rtx_equal_p (other_input, value))
4904 time2 = MAX_RECOG_OPERANDS * 4 + 4;
4905 /* Earlyclobbered outputs must conflict with inputs. */
4906 if (earlyclobber_operand_p (rld[i].out))
4907 time2 = MAX_RECOG_OPERANDS * 4 + 3;
4912 /* RELOAD_OTHER might be live beyond instruction execution,
4913 but this is not obvious when we set time2 = 1. So check
4914 here if there might be a problem with the new reload
4915 clobbering the register used by the RELOAD_OTHER. */
4923 && (! rld[i].in || rld[i].out
4924 || ! rtx_equal_p (other_input, value)))
4925 || (out && rld[reloadnum].out_reg
4926 && time2 >= MAX_RECOG_OPERANDS * 4 + 3))
4932 /* Earlyclobbered outputs must conflict with inputs. */
4933 if (check_earlyclobber && out && earlyclobber_operand_p (out))
4939 /* Return 1 if the value in reload reg REGNO, as used by a reload
4940 needed for the part of the insn specified by OPNUM and TYPE,
4941 may be used to load VALUE into it.
4943 MODE is the mode in which the register is used, this is needed to
4944 determine how many hard regs to test.
4946 Other read-only reloads with the same value do not conflict
4947 unless OUT is nonzero and these other reloads have to live while
4948 output reloads live.
4949 If OUT is CONST0_RTX, this is a special case: it means that the
4950 test should not be for using register REGNO as reload register, but
4951 for copying from register REGNO into the reload register.
4953 RELOADNUM is the number of the reload we want to load this value for;
4954 a reload does not conflict with itself.
4956 When IGNORE_ADDRESS_RELOADS is set, we can not have conflicts with
4957 reloads that load an address for the very reload we are considering.
4959 The caller has to make sure that there is no conflict with the return
4963 free_for_value_p (int regno, enum machine_mode mode, int opnum,
4964 enum reload_type type, rtx value, rtx out, int reloadnum,
4965 int ignore_address_reloads)
4967 int nregs = hard_regno_nregs[regno][mode];
4969 if (! reload_reg_free_for_value_p (regno, regno + nregs, opnum, type,
4970 value, out, reloadnum,
4971 ignore_address_reloads))
4976 /* Determine whether the reload reg X overlaps any rtx'es used for
4977 overriding inheritance. Return nonzero if so. */
4980 conflicts_with_override (rtx x)
4983 for (i = 0; i < n_reloads; i++)
4984 if (reload_override_in[i]
4985 && reg_overlap_mentioned_p (x, reload_override_in[i]))
4990 /* Give an error message saying we failed to find a reload for INSN,
4991 and clear out reload R. */
4993 failed_reload (rtx insn, int r)
4995 if (asm_noperands (PATTERN (insn)) < 0)
4996 /* It's the compiler's fault. */
4997 fatal_insn ("could not find a spill register", insn);
4999 /* It's the user's fault; the operand's mode and constraint
5000 don't match. Disable this reload so we don't crash in final. */
5001 error_for_asm (insn,
5002 "`asm' operand constraint incompatible with operand size");
5006 rld[r].optional = 1;
5007 rld[r].secondary_p = 1;
5010 /* I is the index in SPILL_REG_RTX of the reload register we are to allocate
5011 for reload R. If it's valid, get an rtx for it. Return nonzero if
5014 set_reload_reg (int i, int r)
5017 rtx reg = spill_reg_rtx[i];
5019 if (reg == 0 || GET_MODE (reg) != rld[r].mode)
5020 spill_reg_rtx[i] = reg
5021 = gen_rtx_REG (rld[r].mode, spill_regs[i]);
5023 regno = true_regnum (reg);
5025 /* Detect when the reload reg can't hold the reload mode.
5026 This used to be one `if', but Sequent compiler can't handle that. */
5027 if (HARD_REGNO_MODE_OK (regno, rld[r].mode))
5029 enum machine_mode test_mode = VOIDmode;
5031 test_mode = GET_MODE (rld[r].in);
5032 /* If rld[r].in has VOIDmode, it means we will load it
5033 in whatever mode the reload reg has: to wit, rld[r].mode.
5034 We have already tested that for validity. */
5035 /* Aside from that, we need to test that the expressions
5036 to reload from or into have modes which are valid for this
5037 reload register. Otherwise the reload insns would be invalid. */
5038 if (! (rld[r].in != 0 && test_mode != VOIDmode
5039 && ! HARD_REGNO_MODE_OK (regno, test_mode)))
5040 if (! (rld[r].out != 0
5041 && ! HARD_REGNO_MODE_OK (regno, GET_MODE (rld[r].out))))
5043 /* The reg is OK. */
5046 /* Mark as in use for this insn the reload regs we use
5048 mark_reload_reg_in_use (spill_regs[i], rld[r].opnum,
5049 rld[r].when_needed, rld[r].mode);
5051 rld[r].reg_rtx = reg;
5052 reload_spill_index[r] = spill_regs[i];
5059 /* Find a spill register to use as a reload register for reload R.
5060 LAST_RELOAD is nonzero if this is the last reload for the insn being
5063 Set rld[R].reg_rtx to the register allocated.
5065 We return 1 if successful, or 0 if we couldn't find a spill reg and
5066 we didn't change anything. */
5069 allocate_reload_reg (struct insn_chain *chain ATTRIBUTE_UNUSED, int r,
5074 /* If we put this reload ahead, thinking it is a group,
5075 then insist on finding a group. Otherwise we can grab a
5076 reg that some other reload needs.
5077 (That can happen when we have a 68000 DATA_OR_FP_REG
5078 which is a group of data regs or one fp reg.)
5079 We need not be so restrictive if there are no more reloads
5082 ??? Really it would be nicer to have smarter handling
5083 for that kind of reg class, where a problem like this is normal.
5084 Perhaps those classes should be avoided for reloading
5085 by use of more alternatives. */
5087 int force_group = rld[r].nregs > 1 && ! last_reload;
5089 /* If we want a single register and haven't yet found one,
5090 take any reg in the right class and not in use.
5091 If we want a consecutive group, here is where we look for it.
5093 We use two passes so we can first look for reload regs to
5094 reuse, which are already in use for other reloads in this insn,
5095 and only then use additional registers.
5096 I think that maximizing reuse is needed to make sure we don't
5097 run out of reload regs. Suppose we have three reloads, and
5098 reloads A and B can share regs. These need two regs.
5099 Suppose A and B are given different regs.
5100 That leaves none for C. */
5101 for (pass = 0; pass < 2; pass++)
5103 /* I is the index in spill_regs.
5104 We advance it round-robin between insns to use all spill regs
5105 equally, so that inherited reloads have a chance
5106 of leapfrogging each other. */
5110 for (count = 0; count < n_spills; count++)
5112 int class = (int) rld[r].class;
5118 regnum = spill_regs[i];
5120 if ((reload_reg_free_p (regnum, rld[r].opnum,
5123 /* We check reload_reg_used to make sure we
5124 don't clobber the return register. */
5125 && ! TEST_HARD_REG_BIT (reload_reg_used, regnum)
5126 && free_for_value_p (regnum, rld[r].mode, rld[r].opnum,
5127 rld[r].when_needed, rld[r].in,
5129 && TEST_HARD_REG_BIT (reg_class_contents[class], regnum)
5130 && HARD_REGNO_MODE_OK (regnum, rld[r].mode)
5131 /* Look first for regs to share, then for unshared. But
5132 don't share regs used for inherited reloads; they are
5133 the ones we want to preserve. */
5135 || (TEST_HARD_REG_BIT (reload_reg_used_at_all,
5137 && ! TEST_HARD_REG_BIT (reload_reg_used_for_inherit,
5140 int nr = hard_regno_nregs[regnum][rld[r].mode];
5141 /* Avoid the problem where spilling a GENERAL_OR_FP_REG
5142 (on 68000) got us two FP regs. If NR is 1,
5143 we would reject both of them. */
5146 /* If we need only one reg, we have already won. */
5149 /* But reject a single reg if we demand a group. */
5154 /* Otherwise check that as many consecutive regs as we need
5155 are available here. */
5158 int regno = regnum + nr - 1;
5159 if (!(TEST_HARD_REG_BIT (reg_class_contents[class], regno)
5160 && spill_reg_order[regno] >= 0
5161 && reload_reg_free_p (regno, rld[r].opnum,
5162 rld[r].when_needed)))
5171 /* If we found something on pass 1, omit pass 2. */
5172 if (count < n_spills)
5176 /* We should have found a spill register by now. */
5177 if (count >= n_spills)
5180 /* I is the index in SPILL_REG_RTX of the reload register we are to
5181 allocate. Get an rtx for it and find its register number. */
5183 return set_reload_reg (i, r);
5186 /* Initialize all the tables needed to allocate reload registers.
5187 CHAIN is the insn currently being processed; SAVE_RELOAD_REG_RTX
5188 is the array we use to restore the reg_rtx field for every reload. */
5191 choose_reload_regs_init (struct insn_chain *chain, rtx *save_reload_reg_rtx)
5195 for (i = 0; i < n_reloads; i++)
5196 rld[i].reg_rtx = save_reload_reg_rtx[i];
5198 memset (reload_inherited, 0, MAX_RELOADS);
5199 memset (reload_inheritance_insn, 0, MAX_RELOADS * sizeof (rtx));
5200 memset (reload_override_in, 0, MAX_RELOADS * sizeof (rtx));
5202 CLEAR_HARD_REG_SET (reload_reg_used);
5203 CLEAR_HARD_REG_SET (reload_reg_used_at_all);
5204 CLEAR_HARD_REG_SET (reload_reg_used_in_op_addr);
5205 CLEAR_HARD_REG_SET (reload_reg_used_in_op_addr_reload);
5206 CLEAR_HARD_REG_SET (reload_reg_used_in_insn);
5207 CLEAR_HARD_REG_SET (reload_reg_used_in_other_addr);
5209 CLEAR_HARD_REG_SET (reg_used_in_insn);
5212 REG_SET_TO_HARD_REG_SET (tmp, &chain->live_throughout);
5213 IOR_HARD_REG_SET (reg_used_in_insn, tmp);
5214 REG_SET_TO_HARD_REG_SET (tmp, &chain->dead_or_set);
5215 IOR_HARD_REG_SET (reg_used_in_insn, tmp);
5216 compute_use_by_pseudos (®_used_in_insn, &chain->live_throughout);
5217 compute_use_by_pseudos (®_used_in_insn, &chain->dead_or_set);
5220 for (i = 0; i < reload_n_operands; i++)
5222 CLEAR_HARD_REG_SET (reload_reg_used_in_output[i]);
5223 CLEAR_HARD_REG_SET (reload_reg_used_in_input[i]);
5224 CLEAR_HARD_REG_SET (reload_reg_used_in_input_addr[i]);
5225 CLEAR_HARD_REG_SET (reload_reg_used_in_inpaddr_addr[i]);
5226 CLEAR_HARD_REG_SET (reload_reg_used_in_output_addr[i]);
5227 CLEAR_HARD_REG_SET (reload_reg_used_in_outaddr_addr[i]);
5230 COMPL_HARD_REG_SET (reload_reg_unavailable, chain->used_spill_regs);
5232 CLEAR_HARD_REG_SET (reload_reg_used_for_inherit);
5234 for (i = 0; i < n_reloads; i++)
5235 /* If we have already decided to use a certain register,
5236 don't use it in another way. */
5238 mark_reload_reg_in_use (REGNO (rld[i].reg_rtx), rld[i].opnum,
5239 rld[i].when_needed, rld[i].mode);
5242 /* Assign hard reg targets for the pseudo-registers we must reload
5243 into hard regs for this insn.
5244 Also output the instructions to copy them in and out of the hard regs.
5246 For machines with register classes, we are responsible for
5247 finding a reload reg in the proper class. */
5250 choose_reload_regs (struct insn_chain *chain)
5252 rtx insn = chain->insn;
5254 unsigned int max_group_size = 1;
5255 enum reg_class group_class = NO_REGS;
5256 int pass, win, inheritance;
5258 rtx save_reload_reg_rtx[MAX_RELOADS];
5260 /* In order to be certain of getting the registers we need,
5261 we must sort the reloads into order of increasing register class.
5262 Then our grabbing of reload registers will parallel the process
5263 that provided the reload registers.
5265 Also note whether any of the reloads wants a consecutive group of regs.
5266 If so, record the maximum size of the group desired and what
5267 register class contains all the groups needed by this insn. */
5269 for (j = 0; j < n_reloads; j++)
5271 reload_order[j] = j;
5272 reload_spill_index[j] = -1;
5274 if (rld[j].nregs > 1)
5276 max_group_size = MAX (rld[j].nregs, max_group_size);
5278 = reg_class_superunion[(int) rld[j].class][(int) group_class];
5281 save_reload_reg_rtx[j] = rld[j].reg_rtx;
5285 qsort (reload_order, n_reloads, sizeof (short), reload_reg_class_lower);
5287 /* If -O, try first with inheritance, then turning it off.
5288 If not -O, don't do inheritance.
5289 Using inheritance when not optimizing leads to paradoxes
5290 with fp on the 68k: fp numbers (not NaNs) fail to be equal to themselves
5291 because one side of the comparison might be inherited. */
5293 for (inheritance = optimize > 0; inheritance >= 0; inheritance--)
5295 choose_reload_regs_init (chain, save_reload_reg_rtx);
5297 /* Process the reloads in order of preference just found.
5298 Beyond this point, subregs can be found in reload_reg_rtx.
5300 This used to look for an existing reloaded home for all of the
5301 reloads, and only then perform any new reloads. But that could lose
5302 if the reloads were done out of reg-class order because a later
5303 reload with a looser constraint might have an old home in a register
5304 needed by an earlier reload with a tighter constraint.
5306 To solve this, we make two passes over the reloads, in the order
5307 described above. In the first pass we try to inherit a reload
5308 from a previous insn. If there is a later reload that needs a
5309 class that is a proper subset of the class being processed, we must
5310 also allocate a spill register during the first pass.
5312 Then make a second pass over the reloads to allocate any reloads
5313 that haven't been given registers yet. */
5315 for (j = 0; j < n_reloads; j++)
5317 int r = reload_order[j];
5318 rtx search_equiv = NULL_RTX;
5320 /* Ignore reloads that got marked inoperative. */
5321 if (rld[r].out == 0 && rld[r].in == 0
5322 && ! rld[r].secondary_p)
5325 /* If find_reloads chose to use reload_in or reload_out as a reload
5326 register, we don't need to chose one. Otherwise, try even if it
5327 found one since we might save an insn if we find the value lying
5329 Try also when reload_in is a pseudo without a hard reg. */
5330 if (rld[r].in != 0 && rld[r].reg_rtx != 0
5331 && (rtx_equal_p (rld[r].in, rld[r].reg_rtx)
5332 || (rtx_equal_p (rld[r].out, rld[r].reg_rtx)
5333 && GET_CODE (rld[r].in) != MEM
5334 && true_regnum (rld[r].in) < FIRST_PSEUDO_REGISTER)))
5337 #if 0 /* No longer needed for correct operation.
5338 It might give better code, or might not; worth an experiment? */
5339 /* If this is an optional reload, we can't inherit from earlier insns
5340 until we are sure that any non-optional reloads have been allocated.
5341 The following code takes advantage of the fact that optional reloads
5342 are at the end of reload_order. */
5343 if (rld[r].optional != 0)
5344 for (i = 0; i < j; i++)
5345 if ((rld[reload_order[i]].out != 0
5346 || rld[reload_order[i]].in != 0
5347 || rld[reload_order[i]].secondary_p)
5348 && ! rld[reload_order[i]].optional
5349 && rld[reload_order[i]].reg_rtx == 0)
5350 allocate_reload_reg (chain, reload_order[i], 0);
5353 /* First see if this pseudo is already available as reloaded
5354 for a previous insn. We cannot try to inherit for reloads
5355 that are smaller than the maximum number of registers needed
5356 for groups unless the register we would allocate cannot be used
5359 We could check here to see if this is a secondary reload for
5360 an object that is already in a register of the desired class.
5361 This would avoid the need for the secondary reload register.
5362 But this is complex because we can't easily determine what
5363 objects might want to be loaded via this reload. So let a
5364 register be allocated here. In `emit_reload_insns' we suppress
5365 one of the loads in the case described above. */
5371 enum machine_mode mode = VOIDmode;
5375 else if (GET_CODE (rld[r].in) == REG)
5377 regno = REGNO (rld[r].in);
5378 mode = GET_MODE (rld[r].in);
5380 else if (GET_CODE (rld[r].in_reg) == REG)
5382 regno = REGNO (rld[r].in_reg);
5383 mode = GET_MODE (rld[r].in_reg);
5385 else if (GET_CODE (rld[r].in_reg) == SUBREG
5386 && GET_CODE (SUBREG_REG (rld[r].in_reg)) == REG)
5388 byte = SUBREG_BYTE (rld[r].in_reg);
5389 regno = REGNO (SUBREG_REG (rld[r].in_reg));
5390 if (regno < FIRST_PSEUDO_REGISTER)
5391 regno = subreg_regno (rld[r].in_reg);
5392 mode = GET_MODE (rld[r].in_reg);
5395 else if ((GET_CODE (rld[r].in_reg) == PRE_INC
5396 || GET_CODE (rld[r].in_reg) == PRE_DEC
5397 || GET_CODE (rld[r].in_reg) == POST_INC
5398 || GET_CODE (rld[r].in_reg) == POST_DEC)
5399 && GET_CODE (XEXP (rld[r].in_reg, 0)) == REG)
5401 regno = REGNO (XEXP (rld[r].in_reg, 0));
5402 mode = GET_MODE (XEXP (rld[r].in_reg, 0));
5403 rld[r].out = rld[r].in;
5407 /* This won't work, since REGNO can be a pseudo reg number.
5408 Also, it takes much more hair to keep track of all the things
5409 that can invalidate an inherited reload of part of a pseudoreg. */
5410 else if (GET_CODE (rld[r].in) == SUBREG
5411 && GET_CODE (SUBREG_REG (rld[r].in)) == REG)
5412 regno = subreg_regno (rld[r].in);
5415 if (regno >= 0 && reg_last_reload_reg[regno] != 0)
5417 enum reg_class class = rld[r].class, last_class;
5418 rtx last_reg = reg_last_reload_reg[regno];
5419 enum machine_mode need_mode;
5421 i = REGNO (last_reg);
5422 i += subreg_regno_offset (i, GET_MODE (last_reg), byte, mode);
5423 last_class = REGNO_REG_CLASS (i);
5429 = smallest_mode_for_size (GET_MODE_SIZE (mode) + byte,
5430 GET_MODE_CLASS (mode));
5433 #ifdef CANNOT_CHANGE_MODE_CLASS
5434 (!REG_CANNOT_CHANGE_MODE_P (i, GET_MODE (last_reg),
5438 (GET_MODE_SIZE (GET_MODE (last_reg))
5439 >= GET_MODE_SIZE (need_mode))
5440 #ifdef CANNOT_CHANGE_MODE_CLASS
5443 && reg_reloaded_contents[i] == regno
5444 && TEST_HARD_REG_BIT (reg_reloaded_valid, i)
5445 && HARD_REGNO_MODE_OK (i, rld[r].mode)
5446 && (TEST_HARD_REG_BIT (reg_class_contents[(int) class], i)
5447 /* Even if we can't use this register as a reload
5448 register, we might use it for reload_override_in,
5449 if copying it to the desired class is cheap
5451 || ((REGISTER_MOVE_COST (mode, last_class, class)
5452 < MEMORY_MOVE_COST (mode, class, 1))
5453 #ifdef SECONDARY_INPUT_RELOAD_CLASS
5454 && (SECONDARY_INPUT_RELOAD_CLASS (class, mode,
5458 #ifdef SECONDARY_MEMORY_NEEDED
5459 && ! SECONDARY_MEMORY_NEEDED (last_class, class,
5464 && (rld[r].nregs == max_group_size
5465 || ! TEST_HARD_REG_BIT (reg_class_contents[(int) group_class],
5467 && free_for_value_p (i, rld[r].mode, rld[r].opnum,
5468 rld[r].when_needed, rld[r].in,
5471 /* If a group is needed, verify that all the subsequent
5472 registers still have their values intact. */
5473 int nr = hard_regno_nregs[i][rld[r].mode];
5476 for (k = 1; k < nr; k++)
5477 if (reg_reloaded_contents[i + k] != regno
5478 || ! TEST_HARD_REG_BIT (reg_reloaded_valid, i + k))
5486 last_reg = (GET_MODE (last_reg) == mode
5487 ? last_reg : gen_rtx_REG (mode, i));
5490 for (k = 0; k < nr; k++)
5491 bad_for_class |= ! TEST_HARD_REG_BIT (reg_class_contents[(int) rld[r].class],
5494 /* We found a register that contains the
5495 value we need. If this register is the
5496 same as an `earlyclobber' operand of the
5497 current insn, just mark it as a place to
5498 reload from since we can't use it as the
5499 reload register itself. */
5501 for (i1 = 0; i1 < n_earlyclobbers; i1++)
5502 if (reg_overlap_mentioned_for_reload_p
5503 (reg_last_reload_reg[regno],
5504 reload_earlyclobbers[i1]))
5507 if (i1 != n_earlyclobbers
5508 || ! (free_for_value_p (i, rld[r].mode,
5510 rld[r].when_needed, rld[r].in,
5512 /* Don't use it if we'd clobber a pseudo reg. */
5513 || (TEST_HARD_REG_BIT (reg_used_in_insn, i)
5515 && ! TEST_HARD_REG_BIT (reg_reloaded_dead, i))
5516 /* Don't clobber the frame pointer. */
5517 || (i == HARD_FRAME_POINTER_REGNUM
5518 && frame_pointer_needed
5520 /* Don't really use the inherited spill reg
5521 if we need it wider than we've got it. */
5522 || (GET_MODE_SIZE (rld[r].mode)
5523 > GET_MODE_SIZE (mode))
5526 /* If find_reloads chose reload_out as reload
5527 register, stay with it - that leaves the
5528 inherited register for subsequent reloads. */
5529 || (rld[r].out && rld[r].reg_rtx
5530 && rtx_equal_p (rld[r].out, rld[r].reg_rtx)))
5532 if (! rld[r].optional)
5534 reload_override_in[r] = last_reg;
5535 reload_inheritance_insn[r]
5536 = reg_reloaded_insn[i];
5542 /* We can use this as a reload reg. */
5543 /* Mark the register as in use for this part of
5545 mark_reload_reg_in_use (i,
5549 rld[r].reg_rtx = last_reg;
5550 reload_inherited[r] = 1;
5551 reload_inheritance_insn[r]
5552 = reg_reloaded_insn[i];
5553 reload_spill_index[r] = i;
5554 for (k = 0; k < nr; k++)
5555 SET_HARD_REG_BIT (reload_reg_used_for_inherit,
5563 /* Here's another way to see if the value is already lying around. */
5566 && ! reload_inherited[r]
5568 && (CONSTANT_P (rld[r].in)
5569 || GET_CODE (rld[r].in) == PLUS
5570 || GET_CODE (rld[r].in) == REG
5571 || GET_CODE (rld[r].in) == MEM)
5572 && (rld[r].nregs == max_group_size
5573 || ! reg_classes_intersect_p (rld[r].class, group_class)))
5574 search_equiv = rld[r].in;
5575 /* If this is an output reload from a simple move insn, look
5576 if an equivalence for the input is available. */
5577 else if (inheritance && rld[r].in == 0 && rld[r].out != 0)
5579 rtx set = single_set (insn);
5582 && rtx_equal_p (rld[r].out, SET_DEST (set))
5583 && CONSTANT_P (SET_SRC (set)))
5584 search_equiv = SET_SRC (set);
5590 = find_equiv_reg (search_equiv, insn, rld[r].class,
5591 -1, NULL, 0, rld[r].mode);
5596 if (GET_CODE (equiv) == REG)
5597 regno = REGNO (equiv);
5598 else if (GET_CODE (equiv) == SUBREG)
5600 /* This must be a SUBREG of a hard register.
5601 Make a new REG since this might be used in an
5602 address and not all machines support SUBREGs
5604 regno = subreg_regno (equiv);
5605 equiv = gen_rtx_REG (rld[r].mode, regno);
5611 /* If we found a spill reg, reject it unless it is free
5612 and of the desired class. */
5616 int bad_for_class = 0;
5617 int max_regno = regno + rld[r].nregs;
5619 for (i = regno; i < max_regno; i++)
5621 regs_used |= TEST_HARD_REG_BIT (reload_reg_used_at_all,
5623 bad_for_class |= ! TEST_HARD_REG_BIT (reg_class_contents[(int) rld[r].class],
5628 && ! free_for_value_p (regno, rld[r].mode,
5629 rld[r].opnum, rld[r].when_needed,
5630 rld[r].in, rld[r].out, r, 1))
5635 if (equiv != 0 && ! HARD_REGNO_MODE_OK (regno, rld[r].mode))
5638 /* We found a register that contains the value we need.
5639 If this register is the same as an `earlyclobber' operand
5640 of the current insn, just mark it as a place to reload from
5641 since we can't use it as the reload register itself. */
5644 for (i = 0; i < n_earlyclobbers; i++)
5645 if (reg_overlap_mentioned_for_reload_p (equiv,
5646 reload_earlyclobbers[i]))
5648 if (! rld[r].optional)
5649 reload_override_in[r] = equiv;
5654 /* If the equiv register we have found is explicitly clobbered
5655 in the current insn, it depends on the reload type if we
5656 can use it, use it for reload_override_in, or not at all.
5657 In particular, we then can't use EQUIV for a
5658 RELOAD_FOR_OUTPUT_ADDRESS reload. */
5662 if (regno_clobbered_p (regno, insn, rld[r].mode, 0))
5663 switch (rld[r].when_needed)
5665 case RELOAD_FOR_OTHER_ADDRESS:
5666 case RELOAD_FOR_INPADDR_ADDRESS:
5667 case RELOAD_FOR_INPUT_ADDRESS:
5668 case RELOAD_FOR_OPADDR_ADDR:
5671 case RELOAD_FOR_INPUT:
5672 case RELOAD_FOR_OPERAND_ADDRESS:
5673 if (! rld[r].optional)
5674 reload_override_in[r] = equiv;
5680 else if (regno_clobbered_p (regno, insn, rld[r].mode, 1))
5681 switch (rld[r].when_needed)
5683 case RELOAD_FOR_OTHER_ADDRESS:
5684 case RELOAD_FOR_INPADDR_ADDRESS:
5685 case RELOAD_FOR_INPUT_ADDRESS:
5686 case RELOAD_FOR_OPADDR_ADDR:
5687 case RELOAD_FOR_OPERAND_ADDRESS:
5688 case RELOAD_FOR_INPUT:
5691 if (! rld[r].optional)
5692 reload_override_in[r] = equiv;
5700 /* If we found an equivalent reg, say no code need be generated
5701 to load it, and use it as our reload reg. */
5703 && (regno != HARD_FRAME_POINTER_REGNUM
5704 || !frame_pointer_needed))
5706 int nr = hard_regno_nregs[regno][rld[r].mode];
5708 rld[r].reg_rtx = equiv;
5709 reload_inherited[r] = 1;
5711 /* If reg_reloaded_valid is not set for this register,
5712 there might be a stale spill_reg_store lying around.
5713 We must clear it, since otherwise emit_reload_insns
5714 might delete the store. */
5715 if (! TEST_HARD_REG_BIT (reg_reloaded_valid, regno))
5716 spill_reg_store[regno] = NULL_RTX;
5717 /* If any of the hard registers in EQUIV are spill
5718 registers, mark them as in use for this insn. */
5719 for (k = 0; k < nr; k++)
5721 i = spill_reg_order[regno + k];
5724 mark_reload_reg_in_use (regno, rld[r].opnum,
5727 SET_HARD_REG_BIT (reload_reg_used_for_inherit,
5734 /* If we found a register to use already, or if this is an optional
5735 reload, we are done. */
5736 if (rld[r].reg_rtx != 0 || rld[r].optional != 0)
5740 /* No longer needed for correct operation. Might or might
5741 not give better code on the average. Want to experiment? */
5743 /* See if there is a later reload that has a class different from our
5744 class that intersects our class or that requires less register
5745 than our reload. If so, we must allocate a register to this
5746 reload now, since that reload might inherit a previous reload
5747 and take the only available register in our class. Don't do this
5748 for optional reloads since they will force all previous reloads
5749 to be allocated. Also don't do this for reloads that have been
5752 for (i = j + 1; i < n_reloads; i++)
5754 int s = reload_order[i];
5756 if ((rld[s].in == 0 && rld[s].out == 0
5757 && ! rld[s].secondary_p)
5761 if ((rld[s].class != rld[r].class
5762 && reg_classes_intersect_p (rld[r].class,
5764 || rld[s].nregs < rld[r].nregs)
5771 allocate_reload_reg (chain, r, j == n_reloads - 1);
5775 /* Now allocate reload registers for anything non-optional that
5776 didn't get one yet. */
5777 for (j = 0; j < n_reloads; j++)
5779 int r = reload_order[j];
5781 /* Ignore reloads that got marked inoperative. */
5782 if (rld[r].out == 0 && rld[r].in == 0 && ! rld[r].secondary_p)
5785 /* Skip reloads that already have a register allocated or are
5787 if (rld[r].reg_rtx != 0 || rld[r].optional)
5790 if (! allocate_reload_reg (chain, r, j == n_reloads - 1))
5794 /* If that loop got all the way, we have won. */
5801 /* Loop around and try without any inheritance. */
5806 /* First undo everything done by the failed attempt
5807 to allocate with inheritance. */
5808 choose_reload_regs_init (chain, save_reload_reg_rtx);
5810 /* Some sanity tests to verify that the reloads found in the first
5811 pass are identical to the ones we have now. */
5812 if (chain->n_reloads != n_reloads)
5815 for (i = 0; i < n_reloads; i++)
5817 if (chain->rld[i].regno < 0 || chain->rld[i].reg_rtx != 0)
5819 if (chain->rld[i].when_needed != rld[i].when_needed)
5821 for (j = 0; j < n_spills; j++)
5822 if (spill_regs[j] == chain->rld[i].regno)
5823 if (! set_reload_reg (j, i))
5824 failed_reload (chain->insn, i);
5828 /* If we thought we could inherit a reload, because it seemed that
5829 nothing else wanted the same reload register earlier in the insn,
5830 verify that assumption, now that all reloads have been assigned.
5831 Likewise for reloads where reload_override_in has been set. */
5833 /* If doing expensive optimizations, do one preliminary pass that doesn't
5834 cancel any inheritance, but removes reloads that have been needed only
5835 for reloads that we know can be inherited. */
5836 for (pass = flag_expensive_optimizations; pass >= 0; pass--)
5838 for (j = 0; j < n_reloads; j++)
5840 int r = reload_order[j];
5842 if (reload_inherited[r] && rld[r].reg_rtx)
5843 check_reg = rld[r].reg_rtx;
5844 else if (reload_override_in[r]
5845 && (GET_CODE (reload_override_in[r]) == REG
5846 || GET_CODE (reload_override_in[r]) == SUBREG))
5847 check_reg = reload_override_in[r];
5850 if (! free_for_value_p (true_regnum (check_reg), rld[r].mode,
5851 rld[r].opnum, rld[r].when_needed, rld[r].in,
5852 (reload_inherited[r]
5853 ? rld[r].out : const0_rtx),
5858 reload_inherited[r] = 0;
5859 reload_override_in[r] = 0;
5861 /* If we can inherit a RELOAD_FOR_INPUT, or can use a
5862 reload_override_in, then we do not need its related
5863 RELOAD_FOR_INPUT_ADDRESS / RELOAD_FOR_INPADDR_ADDRESS reloads;
5864 likewise for other reload types.
5865 We handle this by removing a reload when its only replacement
5866 is mentioned in reload_in of the reload we are going to inherit.
5867 A special case are auto_inc expressions; even if the input is
5868 inherited, we still need the address for the output. We can
5869 recognize them because they have RELOAD_OUT set to RELOAD_IN.
5870 If we succeeded removing some reload and we are doing a preliminary
5871 pass just to remove such reloads, make another pass, since the
5872 removal of one reload might allow us to inherit another one. */
5874 && rld[r].out != rld[r].in
5875 && remove_address_replacements (rld[r].in) && pass)
5880 /* Now that reload_override_in is known valid,
5881 actually override reload_in. */
5882 for (j = 0; j < n_reloads; j++)
5883 if (reload_override_in[j])
5884 rld[j].in = reload_override_in[j];
5886 /* If this reload won't be done because it has been canceled or is
5887 optional and not inherited, clear reload_reg_rtx so other
5888 routines (such as subst_reloads) don't get confused. */
5889 for (j = 0; j < n_reloads; j++)
5890 if (rld[j].reg_rtx != 0
5891 && ((rld[j].optional && ! reload_inherited[j])
5892 || (rld[j].in == 0 && rld[j].out == 0
5893 && ! rld[j].secondary_p)))
5895 int regno = true_regnum (rld[j].reg_rtx);
5897 if (spill_reg_order[regno] >= 0)
5898 clear_reload_reg_in_use (regno, rld[j].opnum,
5899 rld[j].when_needed, rld[j].mode);
5901 reload_spill_index[j] = -1;
5904 /* Record which pseudos and which spill regs have output reloads. */
5905 for (j = 0; j < n_reloads; j++)
5907 int r = reload_order[j];
5909 i = reload_spill_index[r];
5911 /* I is nonneg if this reload uses a register.
5912 If rld[r].reg_rtx is 0, this is an optional reload
5913 that we opted to ignore. */
5914 if (rld[r].out_reg != 0 && GET_CODE (rld[r].out_reg) == REG
5915 && rld[r].reg_rtx != 0)
5917 int nregno = REGNO (rld[r].out_reg);
5920 if (nregno < FIRST_PSEUDO_REGISTER)
5921 nr = hard_regno_nregs[nregno][rld[r].mode];
5924 reg_has_output_reload[nregno + nr] = 1;
5928 nr = hard_regno_nregs[i][rld[r].mode];
5930 SET_HARD_REG_BIT (reg_is_output_reload, i + nr);
5933 if (rld[r].when_needed != RELOAD_OTHER
5934 && rld[r].when_needed != RELOAD_FOR_OUTPUT
5935 && rld[r].when_needed != RELOAD_FOR_INSN)
5941 /* Deallocate the reload register for reload R. This is called from
5942 remove_address_replacements. */
5945 deallocate_reload_reg (int r)
5949 if (! rld[r].reg_rtx)
5951 regno = true_regnum (rld[r].reg_rtx);
5953 if (spill_reg_order[regno] >= 0)
5954 clear_reload_reg_in_use (regno, rld[r].opnum, rld[r].when_needed,
5956 reload_spill_index[r] = -1;
5959 /* If SMALL_REGISTER_CLASSES is nonzero, we may not have merged two
5960 reloads of the same item for fear that we might not have enough reload
5961 registers. However, normally they will get the same reload register
5962 and hence actually need not be loaded twice.
5964 Here we check for the most common case of this phenomenon: when we have
5965 a number of reloads for the same object, each of which were allocated
5966 the same reload_reg_rtx, that reload_reg_rtx is not used for any other
5967 reload, and is not modified in the insn itself. If we find such,
5968 merge all the reloads and set the resulting reload to RELOAD_OTHER.
5969 This will not increase the number of spill registers needed and will
5970 prevent redundant code. */
5973 merge_assigned_reloads (rtx insn)
5977 /* Scan all the reloads looking for ones that only load values and
5978 are not already RELOAD_OTHER and ones whose reload_reg_rtx are
5979 assigned and not modified by INSN. */
5981 for (i = 0; i < n_reloads; i++)
5983 int conflicting_input = 0;
5984 int max_input_address_opnum = -1;
5985 int min_conflicting_input_opnum = MAX_RECOG_OPERANDS;
5987 if (rld[i].in == 0 || rld[i].when_needed == RELOAD_OTHER
5988 || rld[i].out != 0 || rld[i].reg_rtx == 0
5989 || reg_set_p (rld[i].reg_rtx, insn))
5992 /* Look at all other reloads. Ensure that the only use of this
5993 reload_reg_rtx is in a reload that just loads the same value
5994 as we do. Note that any secondary reloads must be of the identical
5995 class since the values, modes, and result registers are the
5996 same, so we need not do anything with any secondary reloads. */
5998 for (j = 0; j < n_reloads; j++)
6000 if (i == j || rld[j].reg_rtx == 0
6001 || ! reg_overlap_mentioned_p (rld[j].reg_rtx,
6005 if (rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
6006 && rld[j].opnum > max_input_address_opnum)
6007 max_input_address_opnum = rld[j].opnum;
6009 /* If the reload regs aren't exactly the same (e.g, different modes)
6010 or if the values are different, we can't merge this reload.
6011 But if it is an input reload, we might still merge
6012 RELOAD_FOR_INPUT_ADDRESS and RELOAD_FOR_OTHER_ADDRESS reloads. */
6014 if (! rtx_equal_p (rld[i].reg_rtx, rld[j].reg_rtx)
6015 || rld[j].out != 0 || rld[j].in == 0
6016 || ! rtx_equal_p (rld[i].in, rld[j].in))
6018 if (rld[j].when_needed != RELOAD_FOR_INPUT
6019 || ((rld[i].when_needed != RELOAD_FOR_INPUT_ADDRESS
6020 || rld[i].opnum > rld[j].opnum)
6021 && rld[i].when_needed != RELOAD_FOR_OTHER_ADDRESS))
6023 conflicting_input = 1;
6024 if (min_conflicting_input_opnum > rld[j].opnum)
6025 min_conflicting_input_opnum = rld[j].opnum;
6029 /* If all is OK, merge the reloads. Only set this to RELOAD_OTHER if
6030 we, in fact, found any matching reloads. */
6033 && max_input_address_opnum <= min_conflicting_input_opnum)
6035 for (j = 0; j < n_reloads; j++)
6036 if (i != j && rld[j].reg_rtx != 0
6037 && rtx_equal_p (rld[i].reg_rtx, rld[j].reg_rtx)
6038 && (! conflicting_input
6039 || rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
6040 || rld[j].when_needed == RELOAD_FOR_OTHER_ADDRESS))
6042 rld[i].when_needed = RELOAD_OTHER;
6044 reload_spill_index[j] = -1;
6045 transfer_replacements (i, j);
6048 /* If this is now RELOAD_OTHER, look for any reloads that load
6049 parts of this operand and set them to RELOAD_FOR_OTHER_ADDRESS
6050 if they were for inputs, RELOAD_OTHER for outputs. Note that
6051 this test is equivalent to looking for reloads for this operand
6053 /* We must take special care when there are two or more reloads to
6054 be merged and a RELOAD_FOR_OUTPUT_ADDRESS reload that loads the
6055 same value or a part of it; we must not change its type if there
6056 is a conflicting input. */
6058 if (rld[i].when_needed == RELOAD_OTHER)
6059 for (j = 0; j < n_reloads; j++)
6061 && rld[j].when_needed != RELOAD_OTHER
6062 && rld[j].when_needed != RELOAD_FOR_OTHER_ADDRESS
6063 && (! conflicting_input
6064 || rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
6065 || rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
6066 && reg_overlap_mentioned_for_reload_p (rld[j].in,
6072 = ((rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
6073 || rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
6074 ? RELOAD_FOR_OTHER_ADDRESS : RELOAD_OTHER);
6076 /* Check to see if we accidentally converted two reloads
6077 that use the same reload register with different inputs
6078 to the same type. If so, the resulting code won't work,
6081 for (k = 0; k < j; k++)
6082 if (rld[k].in != 0 && rld[k].reg_rtx != 0
6083 && rld[k].when_needed == rld[j].when_needed
6084 && rtx_equal_p (rld[k].reg_rtx, rld[j].reg_rtx)
6085 && ! rtx_equal_p (rld[k].in, rld[j].in))
6092 /* These arrays are filled by emit_reload_insns and its subroutines. */
6093 static rtx input_reload_insns[MAX_RECOG_OPERANDS];
6094 static rtx other_input_address_reload_insns = 0;
6095 static rtx other_input_reload_insns = 0;
6096 static rtx input_address_reload_insns[MAX_RECOG_OPERANDS];
6097 static rtx inpaddr_address_reload_insns[MAX_RECOG_OPERANDS];
6098 static rtx output_reload_insns[MAX_RECOG_OPERANDS];
6099 static rtx output_address_reload_insns[MAX_RECOG_OPERANDS];
6100 static rtx outaddr_address_reload_insns[MAX_RECOG_OPERANDS];
6101 static rtx operand_reload_insns = 0;
6102 static rtx other_operand_reload_insns = 0;
6103 static rtx other_output_reload_insns[MAX_RECOG_OPERANDS];
6105 /* Values to be put in spill_reg_store are put here first. */
6106 static rtx new_spill_reg_store[FIRST_PSEUDO_REGISTER];
6107 static HARD_REG_SET reg_reloaded_died;
6109 /* Generate insns to perform reload RL, which is for the insn in CHAIN and
6110 has the number J. OLD contains the value to be used as input. */
6113 emit_input_reload_insns (struct insn_chain *chain, struct reload *rl,
6116 rtx insn = chain->insn;
6117 rtx reloadreg = rl->reg_rtx;
6118 rtx oldequiv_reg = 0;
6121 enum machine_mode mode;
6124 /* Determine the mode to reload in.
6125 This is very tricky because we have three to choose from.
6126 There is the mode the insn operand wants (rl->inmode).
6127 There is the mode of the reload register RELOADREG.
6128 There is the intrinsic mode of the operand, which we could find
6129 by stripping some SUBREGs.
6130 It turns out that RELOADREG's mode is irrelevant:
6131 we can change that arbitrarily.
6133 Consider (SUBREG:SI foo:QI) as an operand that must be SImode;
6134 then the reload reg may not support QImode moves, so use SImode.
6135 If foo is in memory due to spilling a pseudo reg, this is safe,
6136 because the QImode value is in the least significant part of a
6137 slot big enough for a SImode. If foo is some other sort of
6138 memory reference, then it is impossible to reload this case,
6139 so previous passes had better make sure this never happens.
6141 Then consider a one-word union which has SImode and one of its
6142 members is a float, being fetched as (SUBREG:SF union:SI).
6143 We must fetch that as SFmode because we could be loading into
6144 a float-only register. In this case OLD's mode is correct.
6146 Consider an immediate integer: it has VOIDmode. Here we need
6147 to get a mode from something else.
6149 In some cases, there is a fourth mode, the operand's
6150 containing mode. If the insn specifies a containing mode for
6151 this operand, it overrides all others.
6153 I am not sure whether the algorithm here is always right,
6154 but it does the right things in those cases. */
6156 mode = GET_MODE (old);
6157 if (mode == VOIDmode)
6160 #ifdef SECONDARY_INPUT_RELOAD_CLASS
6161 /* If we need a secondary register for this operation, see if
6162 the value is already in a register in that class. Don't
6163 do this if the secondary register will be used as a scratch
6166 if (rl->secondary_in_reload >= 0
6167 && rl->secondary_in_icode == CODE_FOR_nothing
6170 = find_equiv_reg (old, insn,
6171 rld[rl->secondary_in_reload].class,
6175 /* If reloading from memory, see if there is a register
6176 that already holds the same value. If so, reload from there.
6177 We can pass 0 as the reload_reg_p argument because
6178 any other reload has either already been emitted,
6179 in which case find_equiv_reg will see the reload-insn,
6180 or has yet to be emitted, in which case it doesn't matter
6181 because we will use this equiv reg right away. */
6183 if (oldequiv == 0 && optimize
6184 && (GET_CODE (old) == MEM
6185 || (GET_CODE (old) == REG
6186 && REGNO (old) >= FIRST_PSEUDO_REGISTER
6187 && reg_renumber[REGNO (old)] < 0)))
6188 oldequiv = find_equiv_reg (old, insn, ALL_REGS, -1, NULL, 0, mode);
6192 unsigned int regno = true_regnum (oldequiv);
6194 /* Don't use OLDEQUIV if any other reload changes it at an
6195 earlier stage of this insn or at this stage. */
6196 if (! free_for_value_p (regno, rl->mode, rl->opnum, rl->when_needed,
6197 rl->in, const0_rtx, j, 0))
6200 /* If it is no cheaper to copy from OLDEQUIV into the
6201 reload register than it would be to move from memory,
6202 don't use it. Likewise, if we need a secondary register
6206 && (((enum reg_class) REGNO_REG_CLASS (regno) != rl->class
6207 && (REGISTER_MOVE_COST (mode, REGNO_REG_CLASS (regno),
6209 >= MEMORY_MOVE_COST (mode, rl->class, 1)))
6210 #ifdef SECONDARY_INPUT_RELOAD_CLASS
6211 || (SECONDARY_INPUT_RELOAD_CLASS (rl->class,
6215 #ifdef SECONDARY_MEMORY_NEEDED
6216 || SECONDARY_MEMORY_NEEDED (REGNO_REG_CLASS (regno),
6224 /* delete_output_reload is only invoked properly if old contains
6225 the original pseudo register. Since this is replaced with a
6226 hard reg when RELOAD_OVERRIDE_IN is set, see if we can
6227 find the pseudo in RELOAD_IN_REG. */
6229 && reload_override_in[j]
6230 && GET_CODE (rl->in_reg) == REG)
6237 else if (GET_CODE (oldequiv) == REG)
6238 oldequiv_reg = oldequiv;
6239 else if (GET_CODE (oldequiv) == SUBREG)
6240 oldequiv_reg = SUBREG_REG (oldequiv);
6242 /* If we are reloading from a register that was recently stored in
6243 with an output-reload, see if we can prove there was
6244 actually no need to store the old value in it. */
6246 if (optimize && GET_CODE (oldequiv) == REG
6247 && REGNO (oldequiv) < FIRST_PSEUDO_REGISTER
6248 && spill_reg_store[REGNO (oldequiv)]
6249 && GET_CODE (old) == REG
6250 && (dead_or_set_p (insn, spill_reg_stored_to[REGNO (oldequiv)])
6251 || rtx_equal_p (spill_reg_stored_to[REGNO (oldequiv)],
6253 delete_output_reload (insn, j, REGNO (oldequiv));
6255 /* Encapsulate both RELOADREG and OLDEQUIV into that mode,
6256 then load RELOADREG from OLDEQUIV. Note that we cannot use
6257 gen_lowpart_common since it can do the wrong thing when
6258 RELOADREG has a multi-word mode. Note that RELOADREG
6259 must always be a REG here. */
6261 if (GET_MODE (reloadreg) != mode)
6262 reloadreg = reload_adjust_reg_for_mode (reloadreg, mode);
6263 while (GET_CODE (oldequiv) == SUBREG && GET_MODE (oldequiv) != mode)
6264 oldequiv = SUBREG_REG (oldequiv);
6265 if (GET_MODE (oldequiv) != VOIDmode
6266 && mode != GET_MODE (oldequiv))
6267 oldequiv = gen_lowpart_SUBREG (mode, oldequiv);
6269 /* Switch to the right place to emit the reload insns. */
6270 switch (rl->when_needed)
6273 where = &other_input_reload_insns;
6275 case RELOAD_FOR_INPUT:
6276 where = &input_reload_insns[rl->opnum];
6278 case RELOAD_FOR_INPUT_ADDRESS:
6279 where = &input_address_reload_insns[rl->opnum];
6281 case RELOAD_FOR_INPADDR_ADDRESS:
6282 where = &inpaddr_address_reload_insns[rl->opnum];
6284 case RELOAD_FOR_OUTPUT_ADDRESS:
6285 where = &output_address_reload_insns[rl->opnum];
6287 case RELOAD_FOR_OUTADDR_ADDRESS:
6288 where = &outaddr_address_reload_insns[rl->opnum];
6290 case RELOAD_FOR_OPERAND_ADDRESS:
6291 where = &operand_reload_insns;
6293 case RELOAD_FOR_OPADDR_ADDR:
6294 where = &other_operand_reload_insns;
6296 case RELOAD_FOR_OTHER_ADDRESS:
6297 where = &other_input_address_reload_insns;
6303 push_to_sequence (*where);
6305 /* Auto-increment addresses must be reloaded in a special way. */
6306 if (rl->out && ! rl->out_reg)
6308 /* We are not going to bother supporting the case where a
6309 incremented register can't be copied directly from
6310 OLDEQUIV since this seems highly unlikely. */
6311 if (rl->secondary_in_reload >= 0)
6314 if (reload_inherited[j])
6315 oldequiv = reloadreg;
6317 old = XEXP (rl->in_reg, 0);
6319 if (optimize && GET_CODE (oldequiv) == REG
6320 && REGNO (oldequiv) < FIRST_PSEUDO_REGISTER
6321 && spill_reg_store[REGNO (oldequiv)]
6322 && GET_CODE (old) == REG
6323 && (dead_or_set_p (insn,
6324 spill_reg_stored_to[REGNO (oldequiv)])
6325 || rtx_equal_p (spill_reg_stored_to[REGNO (oldequiv)],
6327 delete_output_reload (insn, j, REGNO (oldequiv));
6329 /* Prevent normal processing of this reload. */
6331 /* Output a special code sequence for this case. */
6332 new_spill_reg_store[REGNO (reloadreg)]
6333 = inc_for_reload (reloadreg, oldequiv, rl->out,
6337 /* If we are reloading a pseudo-register that was set by the previous
6338 insn, see if we can get rid of that pseudo-register entirely
6339 by redirecting the previous insn into our reload register. */
6341 else if (optimize && GET_CODE (old) == REG
6342 && REGNO (old) >= FIRST_PSEUDO_REGISTER
6343 && dead_or_set_p (insn, old)
6344 /* This is unsafe if some other reload
6345 uses the same reg first. */
6346 && ! conflicts_with_override (reloadreg)
6347 && free_for_value_p (REGNO (reloadreg), rl->mode, rl->opnum,
6348 rl->when_needed, old, rl->out, j, 0))
6350 rtx temp = PREV_INSN (insn);
6351 while (temp && GET_CODE (temp) == NOTE)
6352 temp = PREV_INSN (temp);
6354 && GET_CODE (temp) == INSN
6355 && GET_CODE (PATTERN (temp)) == SET
6356 && SET_DEST (PATTERN (temp)) == old
6357 /* Make sure we can access insn_operand_constraint. */
6358 && asm_noperands (PATTERN (temp)) < 0
6359 /* This is unsafe if operand occurs more than once in current
6360 insn. Perhaps some occurrences aren't reloaded. */
6361 && count_occurrences (PATTERN (insn), old, 0) == 1)
6363 rtx old = SET_DEST (PATTERN (temp));
6364 /* Store into the reload register instead of the pseudo. */
6365 SET_DEST (PATTERN (temp)) = reloadreg;
6367 /* Verify that resulting insn is valid. */
6368 extract_insn (temp);
6369 if (constrain_operands (1))
6371 /* If the previous insn is an output reload, the source is
6372 a reload register, and its spill_reg_store entry will
6373 contain the previous destination. This is now
6375 if (GET_CODE (SET_SRC (PATTERN (temp))) == REG
6376 && REGNO (SET_SRC (PATTERN (temp))) < FIRST_PSEUDO_REGISTER)
6378 spill_reg_store[REGNO (SET_SRC (PATTERN (temp)))] = 0;
6379 spill_reg_stored_to[REGNO (SET_SRC (PATTERN (temp)))] = 0;
6382 /* If these are the only uses of the pseudo reg,
6383 pretend for GDB it lives in the reload reg we used. */
6384 if (REG_N_DEATHS (REGNO (old)) == 1
6385 && REG_N_SETS (REGNO (old)) == 1)
6387 reg_renumber[REGNO (old)] = REGNO (rl->reg_rtx);
6388 alter_reg (REGNO (old), -1);
6394 SET_DEST (PATTERN (temp)) = old;
6399 /* We can't do that, so output an insn to load RELOADREG. */
6401 #ifdef SECONDARY_INPUT_RELOAD_CLASS
6402 /* If we have a secondary reload, pick up the secondary register
6403 and icode, if any. If OLDEQUIV and OLD are different or
6404 if this is an in-out reload, recompute whether or not we
6405 still need a secondary register and what the icode should
6406 be. If we still need a secondary register and the class or
6407 icode is different, go back to reloading from OLD if using
6408 OLDEQUIV means that we got the wrong type of register. We
6409 cannot have different class or icode due to an in-out reload
6410 because we don't make such reloads when both the input and
6411 output need secondary reload registers. */
6413 if (! special && rl->secondary_in_reload >= 0)
6415 rtx second_reload_reg = 0;
6416 int secondary_reload = rl->secondary_in_reload;
6417 rtx real_oldequiv = oldequiv;
6420 enum insn_code icode;
6422 /* If OLDEQUIV is a pseudo with a MEM, get the real MEM
6423 and similarly for OLD.
6424 See comments in get_secondary_reload in reload.c. */
6425 /* If it is a pseudo that cannot be replaced with its
6426 equivalent MEM, we must fall back to reload_in, which
6427 will have all the necessary substitutions registered.
6428 Likewise for a pseudo that can't be replaced with its
6429 equivalent constant.
6431 Take extra care for subregs of such pseudos. Note that
6432 we cannot use reg_equiv_mem in this case because it is
6433 not in the right mode. */
6436 if (GET_CODE (tmp) == SUBREG)
6437 tmp = SUBREG_REG (tmp);
6438 if (GET_CODE (tmp) == REG
6439 && REGNO (tmp) >= FIRST_PSEUDO_REGISTER
6440 && (reg_equiv_memory_loc[REGNO (tmp)] != 0
6441 || reg_equiv_constant[REGNO (tmp)] != 0))
6443 if (! reg_equiv_mem[REGNO (tmp)]
6444 || num_not_at_initial_offset
6445 || GET_CODE (oldequiv) == SUBREG)
6446 real_oldequiv = rl->in;
6448 real_oldequiv = reg_equiv_mem[REGNO (tmp)];
6452 if (GET_CODE (tmp) == SUBREG)
6453 tmp = SUBREG_REG (tmp);
6454 if (GET_CODE (tmp) == REG
6455 && REGNO (tmp) >= FIRST_PSEUDO_REGISTER
6456 && (reg_equiv_memory_loc[REGNO (tmp)] != 0
6457 || reg_equiv_constant[REGNO (tmp)] != 0))
6459 if (! reg_equiv_mem[REGNO (tmp)]
6460 || num_not_at_initial_offset
6461 || GET_CODE (old) == SUBREG)
6464 real_old = reg_equiv_mem[REGNO (tmp)];
6467 second_reload_reg = rld[secondary_reload].reg_rtx;
6468 icode = rl->secondary_in_icode;
6470 if ((old != oldequiv && ! rtx_equal_p (old, oldequiv))
6471 || (rl->in != 0 && rl->out != 0))
6473 enum reg_class new_class
6474 = SECONDARY_INPUT_RELOAD_CLASS (rl->class,
6475 mode, real_oldequiv);
6477 if (new_class == NO_REGS)
6478 second_reload_reg = 0;
6481 enum insn_code new_icode;
6482 enum machine_mode new_mode;
6484 if (! TEST_HARD_REG_BIT (reg_class_contents[(int) new_class],
6485 REGNO (second_reload_reg)))
6486 oldequiv = old, real_oldequiv = real_old;
6489 new_icode = reload_in_optab[(int) mode];
6490 if (new_icode != CODE_FOR_nothing
6491 && ((insn_data[(int) new_icode].operand[0].predicate
6492 && ! ((*insn_data[(int) new_icode].operand[0].predicate)
6494 || (insn_data[(int) new_icode].operand[1].predicate
6495 && ! ((*insn_data[(int) new_icode].operand[1].predicate)
6496 (real_oldequiv, mode)))))
6497 new_icode = CODE_FOR_nothing;
6499 if (new_icode == CODE_FOR_nothing)
6502 new_mode = insn_data[(int) new_icode].operand[2].mode;
6504 if (GET_MODE (second_reload_reg) != new_mode)
6506 if (!HARD_REGNO_MODE_OK (REGNO (second_reload_reg),
6508 oldequiv = old, real_oldequiv = real_old;
6511 = reload_adjust_reg_for_mode (second_reload_reg,
6518 /* If we still need a secondary reload register, check
6519 to see if it is being used as a scratch or intermediate
6520 register and generate code appropriately. If we need
6521 a scratch register, use REAL_OLDEQUIV since the form of
6522 the insn may depend on the actual address if it is
6525 if (second_reload_reg)
6527 if (icode != CODE_FOR_nothing)
6529 emit_insn (GEN_FCN (icode) (reloadreg, real_oldequiv,
6530 second_reload_reg));
6535 /* See if we need a scratch register to load the
6536 intermediate register (a tertiary reload). */
6537 enum insn_code tertiary_icode
6538 = rld[secondary_reload].secondary_in_icode;
6540 if (tertiary_icode != CODE_FOR_nothing)
6542 rtx third_reload_reg
6543 = rld[rld[secondary_reload].secondary_in_reload].reg_rtx;
6545 emit_insn ((GEN_FCN (tertiary_icode)
6546 (second_reload_reg, real_oldequiv,
6547 third_reload_reg)));
6550 gen_reload (second_reload_reg, real_oldequiv,
6554 oldequiv = second_reload_reg;
6560 if (! special && ! rtx_equal_p (reloadreg, oldequiv))
6562 rtx real_oldequiv = oldequiv;
6564 if ((GET_CODE (oldequiv) == REG
6565 && REGNO (oldequiv) >= FIRST_PSEUDO_REGISTER
6566 && (reg_equiv_memory_loc[REGNO (oldequiv)] != 0
6567 || reg_equiv_constant[REGNO (oldequiv)] != 0))
6568 || (GET_CODE (oldequiv) == SUBREG
6569 && GET_CODE (SUBREG_REG (oldequiv)) == REG
6570 && (REGNO (SUBREG_REG (oldequiv))
6571 >= FIRST_PSEUDO_REGISTER)
6572 && ((reg_equiv_memory_loc
6573 [REGNO (SUBREG_REG (oldequiv))] != 0)
6574 || (reg_equiv_constant
6575 [REGNO (SUBREG_REG (oldequiv))] != 0)))
6576 || (CONSTANT_P (oldequiv)
6577 && (PREFERRED_RELOAD_CLASS (oldequiv,
6578 REGNO_REG_CLASS (REGNO (reloadreg)))
6580 real_oldequiv = rl->in;
6581 gen_reload (reloadreg, real_oldequiv, rl->opnum,
6585 if (flag_non_call_exceptions)
6586 copy_eh_notes (insn, get_insns ());
6588 /* End this sequence. */
6589 *where = get_insns ();
6592 /* Update reload_override_in so that delete_address_reloads_1
6593 can see the actual register usage. */
6595 reload_override_in[j] = oldequiv;
6598 /* Generate insns to for the output reload RL, which is for the insn described
6599 by CHAIN and has the number J. */
6601 emit_output_reload_insns (struct insn_chain *chain, struct reload *rl,
6604 rtx reloadreg = rl->reg_rtx;
6605 rtx insn = chain->insn;
6608 enum machine_mode mode = GET_MODE (old);
6611 if (rl->when_needed == RELOAD_OTHER)
6614 push_to_sequence (output_reload_insns[rl->opnum]);
6616 /* Determine the mode to reload in.
6617 See comments above (for input reloading). */
6619 if (mode == VOIDmode)
6621 /* VOIDmode should never happen for an output. */
6622 if (asm_noperands (PATTERN (insn)) < 0)
6623 /* It's the compiler's fault. */
6624 fatal_insn ("VOIDmode on an output", insn);
6625 error_for_asm (insn, "output operand is constant in `asm'");
6626 /* Prevent crash--use something we know is valid. */
6628 old = gen_rtx_REG (mode, REGNO (reloadreg));
6631 if (GET_MODE (reloadreg) != mode)
6632 reloadreg = reload_adjust_reg_for_mode (reloadreg, mode);
6634 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
6636 /* If we need two reload regs, set RELOADREG to the intermediate
6637 one, since it will be stored into OLD. We might need a secondary
6638 register only for an input reload, so check again here. */
6640 if (rl->secondary_out_reload >= 0)
6644 if (GET_CODE (old) == REG && REGNO (old) >= FIRST_PSEUDO_REGISTER
6645 && reg_equiv_mem[REGNO (old)] != 0)
6646 real_old = reg_equiv_mem[REGNO (old)];
6648 if ((SECONDARY_OUTPUT_RELOAD_CLASS (rl->class,
6652 rtx second_reloadreg = reloadreg;
6653 reloadreg = rld[rl->secondary_out_reload].reg_rtx;
6655 /* See if RELOADREG is to be used as a scratch register
6656 or as an intermediate register. */
6657 if (rl->secondary_out_icode != CODE_FOR_nothing)
6659 emit_insn ((GEN_FCN (rl->secondary_out_icode)
6660 (real_old, second_reloadreg, reloadreg)));
6665 /* See if we need both a scratch and intermediate reload
6668 int secondary_reload = rl->secondary_out_reload;
6669 enum insn_code tertiary_icode
6670 = rld[secondary_reload].secondary_out_icode;
6672 if (GET_MODE (reloadreg) != mode)
6673 reloadreg = reload_adjust_reg_for_mode (reloadreg, mode);
6675 if (tertiary_icode != CODE_FOR_nothing)
6678 = rld[rld[secondary_reload].secondary_out_reload].reg_rtx;
6681 /* Copy primary reload reg to secondary reload reg.
6682 (Note that these have been swapped above, then
6683 secondary reload reg to OLD using our insn.) */
6685 /* If REAL_OLD is a paradoxical SUBREG, remove it
6686 and try to put the opposite SUBREG on
6688 if (GET_CODE (real_old) == SUBREG
6689 && (GET_MODE_SIZE (GET_MODE (real_old))
6690 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (real_old))))
6691 && 0 != (tem = gen_lowpart_common
6692 (GET_MODE (SUBREG_REG (real_old)),
6694 real_old = SUBREG_REG (real_old), reloadreg = tem;
6696 gen_reload (reloadreg, second_reloadreg,
6697 rl->opnum, rl->when_needed);
6698 emit_insn ((GEN_FCN (tertiary_icode)
6699 (real_old, reloadreg, third_reloadreg)));
6704 /* Copy between the reload regs here and then to
6707 gen_reload (reloadreg, second_reloadreg,
6708 rl->opnum, rl->when_needed);
6714 /* Output the last reload insn. */
6719 /* Don't output the last reload if OLD is not the dest of
6720 INSN and is in the src and is clobbered by INSN. */
6721 if (! flag_expensive_optimizations
6722 || GET_CODE (old) != REG
6723 || !(set = single_set (insn))
6724 || rtx_equal_p (old, SET_DEST (set))
6725 || !reg_mentioned_p (old, SET_SRC (set))
6726 || !regno_clobbered_p (REGNO (old), insn, rl->mode, 0))
6727 gen_reload (old, reloadreg, rl->opnum,
6731 /* Look at all insns we emitted, just to be safe. */
6732 for (p = get_insns (); p; p = NEXT_INSN (p))
6735 rtx pat = PATTERN (p);
6737 /* If this output reload doesn't come from a spill reg,
6738 clear any memory of reloaded copies of the pseudo reg.
6739 If this output reload comes from a spill reg,
6740 reg_has_output_reload will make this do nothing. */
6741 note_stores (pat, forget_old_reloads_1, NULL);
6743 if (reg_mentioned_p (rl->reg_rtx, pat))
6745 rtx set = single_set (insn);
6746 if (reload_spill_index[j] < 0
6748 && SET_SRC (set) == rl->reg_rtx)
6750 int src = REGNO (SET_SRC (set));
6752 reload_spill_index[j] = src;
6753 SET_HARD_REG_BIT (reg_is_output_reload, src);
6754 if (find_regno_note (insn, REG_DEAD, src))
6755 SET_HARD_REG_BIT (reg_reloaded_died, src);
6757 if (REGNO (rl->reg_rtx) < FIRST_PSEUDO_REGISTER)
6759 int s = rl->secondary_out_reload;
6760 set = single_set (p);
6761 /* If this reload copies only to the secondary reload
6762 register, the secondary reload does the actual
6764 if (s >= 0 && set == NULL_RTX)
6765 /* We can't tell what function the secondary reload
6766 has and where the actual store to the pseudo is
6767 made; leave new_spill_reg_store alone. */
6770 && SET_SRC (set) == rl->reg_rtx
6771 && SET_DEST (set) == rld[s].reg_rtx)
6773 /* Usually the next instruction will be the
6774 secondary reload insn; if we can confirm
6775 that it is, setting new_spill_reg_store to
6776 that insn will allow an extra optimization. */
6777 rtx s_reg = rld[s].reg_rtx;
6778 rtx next = NEXT_INSN (p);
6779 rld[s].out = rl->out;
6780 rld[s].out_reg = rl->out_reg;
6781 set = single_set (next);
6782 if (set && SET_SRC (set) == s_reg
6783 && ! new_spill_reg_store[REGNO (s_reg)])
6785 SET_HARD_REG_BIT (reg_is_output_reload,
6787 new_spill_reg_store[REGNO (s_reg)] = next;
6791 new_spill_reg_store[REGNO (rl->reg_rtx)] = p;
6796 if (rl->when_needed == RELOAD_OTHER)
6798 emit_insn (other_output_reload_insns[rl->opnum]);
6799 other_output_reload_insns[rl->opnum] = get_insns ();
6802 output_reload_insns[rl->opnum] = get_insns ();
6804 if (flag_non_call_exceptions)
6805 copy_eh_notes (insn, get_insns ());
6810 /* Do input reloading for reload RL, which is for the insn described by CHAIN
6811 and has the number J. */
6813 do_input_reload (struct insn_chain *chain, struct reload *rl, int j)
6815 rtx insn = chain->insn;
6816 rtx old = (rl->in && GET_CODE (rl->in) == MEM
6817 ? rl->in_reg : rl->in);
6820 /* AUTO_INC reloads need to be handled even if inherited. We got an
6821 AUTO_INC reload if reload_out is set but reload_out_reg isn't. */
6822 && (! reload_inherited[j] || (rl->out && ! rl->out_reg))
6823 && ! rtx_equal_p (rl->reg_rtx, old)
6824 && rl->reg_rtx != 0)
6825 emit_input_reload_insns (chain, rld + j, old, j);
6827 /* When inheriting a wider reload, we have a MEM in rl->in,
6828 e.g. inheriting a SImode output reload for
6829 (mem:HI (plus:SI (reg:SI 14 fp) (const_int 10))) */
6830 if (optimize && reload_inherited[j] && rl->in
6831 && GET_CODE (rl->in) == MEM
6832 && GET_CODE (rl->in_reg) == MEM
6833 && reload_spill_index[j] >= 0
6834 && TEST_HARD_REG_BIT (reg_reloaded_valid, reload_spill_index[j]))
6835 rl->in = regno_reg_rtx[reg_reloaded_contents[reload_spill_index[j]]];
6837 /* If we are reloading a register that was recently stored in with an
6838 output-reload, see if we can prove there was
6839 actually no need to store the old value in it. */
6842 && (reload_inherited[j] || reload_override_in[j])
6844 && GET_CODE (rl->reg_rtx) == REG
6845 && spill_reg_store[REGNO (rl->reg_rtx)] != 0
6847 /* There doesn't seem to be any reason to restrict this to pseudos
6848 and doing so loses in the case where we are copying from a
6849 register of the wrong class. */
6850 && (REGNO (spill_reg_stored_to[REGNO (rl->reg_rtx)])
6851 >= FIRST_PSEUDO_REGISTER)
6853 /* The insn might have already some references to stackslots
6854 replaced by MEMs, while reload_out_reg still names the
6856 && (dead_or_set_p (insn,
6857 spill_reg_stored_to[REGNO (rl->reg_rtx)])
6858 || rtx_equal_p (spill_reg_stored_to[REGNO (rl->reg_rtx)],
6860 delete_output_reload (insn, j, REGNO (rl->reg_rtx));
6863 /* Do output reloading for reload RL, which is for the insn described by
6864 CHAIN and has the number J.
6865 ??? At some point we need to support handling output reloads of
6866 JUMP_INSNs or insns that set cc0. */
6868 do_output_reload (struct insn_chain *chain, struct reload *rl, int j)
6871 rtx insn = chain->insn;
6872 /* If this is an output reload that stores something that is
6873 not loaded in this same reload, see if we can eliminate a previous
6875 rtx pseudo = rl->out_reg;
6879 && GET_CODE (pseudo) == REG
6880 && ! rtx_equal_p (rl->in_reg, pseudo)
6881 && REGNO (pseudo) >= FIRST_PSEUDO_REGISTER
6882 && reg_last_reload_reg[REGNO (pseudo)])
6884 int pseudo_no = REGNO (pseudo);
6885 int last_regno = REGNO (reg_last_reload_reg[pseudo_no]);
6887 /* We don't need to test full validity of last_regno for
6888 inherit here; we only want to know if the store actually
6889 matches the pseudo. */
6890 if (TEST_HARD_REG_BIT (reg_reloaded_valid, last_regno)
6891 && reg_reloaded_contents[last_regno] == pseudo_no
6892 && spill_reg_store[last_regno]
6893 && rtx_equal_p (pseudo, spill_reg_stored_to[last_regno]))
6894 delete_output_reload (insn, j, last_regno);
6899 || rl->reg_rtx == old
6900 || rl->reg_rtx == 0)
6903 /* An output operand that dies right away does need a reload,
6904 but need not be copied from it. Show the new location in the
6906 if ((GET_CODE (old) == REG || GET_CODE (old) == SCRATCH)
6907 && (note = find_reg_note (insn, REG_UNUSED, old)) != 0)
6909 XEXP (note, 0) = rl->reg_rtx;
6912 /* Likewise for a SUBREG of an operand that dies. */
6913 else if (GET_CODE (old) == SUBREG
6914 && GET_CODE (SUBREG_REG (old)) == REG
6915 && 0 != (note = find_reg_note (insn, REG_UNUSED,
6918 XEXP (note, 0) = gen_lowpart_common (GET_MODE (old),
6922 else if (GET_CODE (old) == SCRATCH)
6923 /* If we aren't optimizing, there won't be a REG_UNUSED note,
6924 but we don't want to make an output reload. */
6927 /* If is a JUMP_INSN, we can't support output reloads yet. */
6928 if (GET_CODE (insn) == JUMP_INSN)
6931 emit_output_reload_insns (chain, rld + j, j);
6934 /* Output insns to reload values in and out of the chosen reload regs. */
6937 emit_reload_insns (struct insn_chain *chain)
6939 rtx insn = chain->insn;
6943 CLEAR_HARD_REG_SET (reg_reloaded_died);
6945 for (j = 0; j < reload_n_operands; j++)
6946 input_reload_insns[j] = input_address_reload_insns[j]
6947 = inpaddr_address_reload_insns[j]
6948 = output_reload_insns[j] = output_address_reload_insns[j]
6949 = outaddr_address_reload_insns[j]
6950 = other_output_reload_insns[j] = 0;
6951 other_input_address_reload_insns = 0;
6952 other_input_reload_insns = 0;
6953 operand_reload_insns = 0;
6954 other_operand_reload_insns = 0;
6956 /* Dump reloads into the dump file. */
6959 fprintf (rtl_dump_file, "\nReloads for insn # %d\n", INSN_UID (insn));
6960 debug_reload_to_stream (rtl_dump_file);
6963 /* Now output the instructions to copy the data into and out of the
6964 reload registers. Do these in the order that the reloads were reported,
6965 since reloads of base and index registers precede reloads of operands
6966 and the operands may need the base and index registers reloaded. */
6968 for (j = 0; j < n_reloads; j++)
6971 && REGNO (rld[j].reg_rtx) < FIRST_PSEUDO_REGISTER)
6972 new_spill_reg_store[REGNO (rld[j].reg_rtx)] = 0;
6974 do_input_reload (chain, rld + j, j);
6975 do_output_reload (chain, rld + j, j);
6978 /* Now write all the insns we made for reloads in the order expected by
6979 the allocation functions. Prior to the insn being reloaded, we write
6980 the following reloads:
6982 RELOAD_FOR_OTHER_ADDRESS reloads for input addresses.
6984 RELOAD_OTHER reloads.
6986 For each operand, any RELOAD_FOR_INPADDR_ADDRESS reloads followed
6987 by any RELOAD_FOR_INPUT_ADDRESS reloads followed by the
6988 RELOAD_FOR_INPUT reload for the operand.
6990 RELOAD_FOR_OPADDR_ADDRS reloads.
6992 RELOAD_FOR_OPERAND_ADDRESS reloads.
6994 After the insn being reloaded, we write the following:
6996 For each operand, any RELOAD_FOR_OUTADDR_ADDRESS reloads followed
6997 by any RELOAD_FOR_OUTPUT_ADDRESS reload followed by the
6998 RELOAD_FOR_OUTPUT reload, followed by any RELOAD_OTHER output
6999 reloads for the operand. The RELOAD_OTHER output reloads are
7000 output in descending order by reload number. */
7002 emit_insn_before_sameloc (other_input_address_reload_insns, insn);
7003 emit_insn_before_sameloc (other_input_reload_insns, insn);
7005 for (j = 0; j < reload_n_operands; j++)
7007 emit_insn_before_sameloc (inpaddr_address_reload_insns[j], insn);
7008 emit_insn_before_sameloc (input_address_reload_insns[j], insn);
7009 emit_insn_before_sameloc (input_reload_insns[j], insn);
7012 emit_insn_before_sameloc (other_operand_reload_insns, insn);
7013 emit_insn_before_sameloc (operand_reload_insns, insn);
7015 for (j = 0; j < reload_n_operands; j++)
7017 rtx x = emit_insn_after_sameloc (outaddr_address_reload_insns[j], insn);
7018 x = emit_insn_after_sameloc (output_address_reload_insns[j], x);
7019 x = emit_insn_after_sameloc (output_reload_insns[j], x);
7020 emit_insn_after_sameloc (other_output_reload_insns[j], x);
7023 /* For all the spill regs newly reloaded in this instruction,
7024 record what they were reloaded from, so subsequent instructions
7025 can inherit the reloads.
7027 Update spill_reg_store for the reloads of this insn.
7028 Copy the elements that were updated in the loop above. */
7030 for (j = 0; j < n_reloads; j++)
7032 int r = reload_order[j];
7033 int i = reload_spill_index[r];
7035 /* If this is a non-inherited input reload from a pseudo, we must
7036 clear any memory of a previous store to the same pseudo. Only do
7037 something if there will not be an output reload for the pseudo
7039 if (rld[r].in_reg != 0
7040 && ! (reload_inherited[r] || reload_override_in[r]))
7042 rtx reg = rld[r].in_reg;
7044 if (GET_CODE (reg) == SUBREG)
7045 reg = SUBREG_REG (reg);
7047 if (GET_CODE (reg) == REG
7048 && REGNO (reg) >= FIRST_PSEUDO_REGISTER
7049 && ! reg_has_output_reload[REGNO (reg)])
7051 int nregno = REGNO (reg);
7053 if (reg_last_reload_reg[nregno])
7055 int last_regno = REGNO (reg_last_reload_reg[nregno]);
7057 if (reg_reloaded_contents[last_regno] == nregno)
7058 spill_reg_store[last_regno] = 0;
7063 /* I is nonneg if this reload used a register.
7064 If rld[r].reg_rtx is 0, this is an optional reload
7065 that we opted to ignore. */
7067 if (i >= 0 && rld[r].reg_rtx != 0)
7069 int nr = hard_regno_nregs[i][GET_MODE (rld[r].reg_rtx)];
7071 int part_reaches_end = 0;
7072 int all_reaches_end = 1;
7074 /* For a multi register reload, we need to check if all or part
7075 of the value lives to the end. */
7076 for (k = 0; k < nr; k++)
7078 if (reload_reg_reaches_end_p (i + k, rld[r].opnum,
7079 rld[r].when_needed))
7080 part_reaches_end = 1;
7082 all_reaches_end = 0;
7085 /* Ignore reloads that don't reach the end of the insn in
7087 if (all_reaches_end)
7089 /* First, clear out memory of what used to be in this spill reg.
7090 If consecutive registers are used, clear them all. */
7092 for (k = 0; k < nr; k++)
7094 CLEAR_HARD_REG_BIT (reg_reloaded_valid, i + k);
7095 CLEAR_HARD_REG_BIT (reg_reloaded_call_part_clobbered, i + k);
7098 /* Maybe the spill reg contains a copy of reload_out. */
7100 && (GET_CODE (rld[r].out) == REG
7104 || GET_CODE (rld[r].out_reg) == REG))
7106 rtx out = (GET_CODE (rld[r].out) == REG
7110 /* AUTO_INC */ : XEXP (rld[r].in_reg, 0));
7111 int nregno = REGNO (out);
7112 int nnr = (nregno >= FIRST_PSEUDO_REGISTER ? 1
7113 : hard_regno_nregs[nregno]
7114 [GET_MODE (rld[r].reg_rtx)]);
7116 spill_reg_store[i] = new_spill_reg_store[i];
7117 spill_reg_stored_to[i] = out;
7118 reg_last_reload_reg[nregno] = rld[r].reg_rtx;
7120 /* If NREGNO is a hard register, it may occupy more than
7121 one register. If it does, say what is in the
7122 rest of the registers assuming that both registers
7123 agree on how many words the object takes. If not,
7124 invalidate the subsequent registers. */
7126 if (nregno < FIRST_PSEUDO_REGISTER)
7127 for (k = 1; k < nnr; k++)
7128 reg_last_reload_reg[nregno + k]
7130 ? regno_reg_rtx[REGNO (rld[r].reg_rtx) + k]
7133 /* Now do the inverse operation. */
7134 for (k = 0; k < nr; k++)
7136 CLEAR_HARD_REG_BIT (reg_reloaded_dead, i + k);
7137 reg_reloaded_contents[i + k]
7138 = (nregno >= FIRST_PSEUDO_REGISTER || nr != nnr
7141 reg_reloaded_insn[i + k] = insn;
7142 SET_HARD_REG_BIT (reg_reloaded_valid, i + k);
7143 if (HARD_REGNO_CALL_PART_CLOBBERED (i + k, GET_MODE (out)))
7144 SET_HARD_REG_BIT (reg_reloaded_call_part_clobbered, i + k);
7148 /* Maybe the spill reg contains a copy of reload_in. Only do
7149 something if there will not be an output reload for
7150 the register being reloaded. */
7151 else if (rld[r].out_reg == 0
7153 && ((GET_CODE (rld[r].in) == REG
7154 && REGNO (rld[r].in) >= FIRST_PSEUDO_REGISTER
7155 && ! reg_has_output_reload[REGNO (rld[r].in)])
7156 || (GET_CODE (rld[r].in_reg) == REG
7157 && ! reg_has_output_reload[REGNO (rld[r].in_reg)]))
7158 && ! reg_set_p (rld[r].reg_rtx, PATTERN (insn)))
7164 if (GET_CODE (rld[r].in) == REG
7165 && REGNO (rld[r].in) >= FIRST_PSEUDO_REGISTER)
7167 else if (GET_CODE (rld[r].in_reg) == REG)
7170 in = XEXP (rld[r].in_reg, 0);
7171 nregno = REGNO (in);
7173 nnr = (nregno >= FIRST_PSEUDO_REGISTER ? 1
7174 : hard_regno_nregs[nregno]
7175 [GET_MODE (rld[r].reg_rtx)]);
7177 reg_last_reload_reg[nregno] = rld[r].reg_rtx;
7179 if (nregno < FIRST_PSEUDO_REGISTER)
7180 for (k = 1; k < nnr; k++)
7181 reg_last_reload_reg[nregno + k]
7183 ? regno_reg_rtx[REGNO (rld[r].reg_rtx) + k]
7186 /* Unless we inherited this reload, show we haven't
7187 recently done a store.
7188 Previous stores of inherited auto_inc expressions
7189 also have to be discarded. */
7190 if (! reload_inherited[r]
7191 || (rld[r].out && ! rld[r].out_reg))
7192 spill_reg_store[i] = 0;
7194 for (k = 0; k < nr; k++)
7196 CLEAR_HARD_REG_BIT (reg_reloaded_dead, i + k);
7197 reg_reloaded_contents[i + k]
7198 = (nregno >= FIRST_PSEUDO_REGISTER || nr != nnr
7201 reg_reloaded_insn[i + k] = insn;
7202 SET_HARD_REG_BIT (reg_reloaded_valid, i + k);
7203 if (HARD_REGNO_CALL_PART_CLOBBERED (i + k, GET_MODE (in)))
7204 SET_HARD_REG_BIT (reg_reloaded_call_part_clobbered, i + k);
7209 /* However, if part of the reload reaches the end, then we must
7210 invalidate the old info for the part that survives to the end. */
7211 else if (part_reaches_end)
7213 for (k = 0; k < nr; k++)
7214 if (reload_reg_reaches_end_p (i + k,
7216 rld[r].when_needed))
7217 CLEAR_HARD_REG_BIT (reg_reloaded_valid, i + k);
7221 /* The following if-statement was #if 0'd in 1.34 (or before...).
7222 It's reenabled in 1.35 because supposedly nothing else
7223 deals with this problem. */
7225 /* If a register gets output-reloaded from a non-spill register,
7226 that invalidates any previous reloaded copy of it.
7227 But forget_old_reloads_1 won't get to see it, because
7228 it thinks only about the original insn. So invalidate it here. */
7229 if (i < 0 && rld[r].out != 0
7230 && (GET_CODE (rld[r].out) == REG
7231 || (GET_CODE (rld[r].out) == MEM
7232 && GET_CODE (rld[r].out_reg) == REG)))
7234 rtx out = (GET_CODE (rld[r].out) == REG
7235 ? rld[r].out : rld[r].out_reg);
7236 int nregno = REGNO (out);
7237 if (nregno >= FIRST_PSEUDO_REGISTER)
7239 rtx src_reg, store_insn = NULL_RTX;
7241 reg_last_reload_reg[nregno] = 0;
7243 /* If we can find a hard register that is stored, record
7244 the storing insn so that we may delete this insn with
7245 delete_output_reload. */
7246 src_reg = rld[r].reg_rtx;
7248 /* If this is an optional reload, try to find the source reg
7249 from an input reload. */
7252 rtx set = single_set (insn);
7253 if (set && SET_DEST (set) == rld[r].out)
7257 src_reg = SET_SRC (set);
7259 for (k = 0; k < n_reloads; k++)
7261 if (rld[k].in == src_reg)
7263 src_reg = rld[k].reg_rtx;
7270 store_insn = new_spill_reg_store[REGNO (src_reg)];
7271 if (src_reg && GET_CODE (src_reg) == REG
7272 && REGNO (src_reg) < FIRST_PSEUDO_REGISTER)
7274 int src_regno = REGNO (src_reg);
7275 int nr = hard_regno_nregs[src_regno][rld[r].mode];
7276 /* The place where to find a death note varies with
7277 PRESERVE_DEATH_INFO_REGNO_P . The condition is not
7278 necessarily checked exactly in the code that moves
7279 notes, so just check both locations. */
7280 rtx note = find_regno_note (insn, REG_DEAD, src_regno);
7281 if (! note && store_insn)
7282 note = find_regno_note (store_insn, REG_DEAD, src_regno);
7285 spill_reg_store[src_regno + nr] = store_insn;
7286 spill_reg_stored_to[src_regno + nr] = out;
7287 reg_reloaded_contents[src_regno + nr] = nregno;
7288 reg_reloaded_insn[src_regno + nr] = store_insn;
7289 CLEAR_HARD_REG_BIT (reg_reloaded_dead, src_regno + nr);
7290 SET_HARD_REG_BIT (reg_reloaded_valid, src_regno + nr);
7291 if (HARD_REGNO_CALL_PART_CLOBBERED (src_regno + nr,
7292 GET_MODE (src_reg)))
7293 SET_HARD_REG_BIT (reg_reloaded_call_part_clobbered,
7295 SET_HARD_REG_BIT (reg_is_output_reload, src_regno + nr);
7297 SET_HARD_REG_BIT (reg_reloaded_died, src_regno);
7299 CLEAR_HARD_REG_BIT (reg_reloaded_died, src_regno);
7301 reg_last_reload_reg[nregno] = src_reg;
7306 int num_regs = hard_regno_nregs[nregno][GET_MODE (rld[r].out)];
7308 while (num_regs-- > 0)
7309 reg_last_reload_reg[nregno + num_regs] = 0;
7313 IOR_HARD_REG_SET (reg_reloaded_dead, reg_reloaded_died);
7316 /* Emit code to perform a reload from IN (which may be a reload register) to
7317 OUT (which may also be a reload register). IN or OUT is from operand
7318 OPNUM with reload type TYPE.
7320 Returns first insn emitted. */
7323 gen_reload (rtx out, rtx in, int opnum, enum reload_type type)
7325 rtx last = get_last_insn ();
7328 /* If IN is a paradoxical SUBREG, remove it and try to put the
7329 opposite SUBREG on OUT. Likewise for a paradoxical SUBREG on OUT. */
7330 if (GET_CODE (in) == SUBREG
7331 && (GET_MODE_SIZE (GET_MODE (in))
7332 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))))
7333 && (tem = gen_lowpart_common (GET_MODE (SUBREG_REG (in)), out)) != 0)
7334 in = SUBREG_REG (in), out = tem;
7335 else if (GET_CODE (out) == SUBREG
7336 && (GET_MODE_SIZE (GET_MODE (out))
7337 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))))
7338 && (tem = gen_lowpart_common (GET_MODE (SUBREG_REG (out)), in)) != 0)
7339 out = SUBREG_REG (out), in = tem;
7341 /* How to do this reload can get quite tricky. Normally, we are being
7342 asked to reload a simple operand, such as a MEM, a constant, or a pseudo
7343 register that didn't get a hard register. In that case we can just
7344 call emit_move_insn.
7346 We can also be asked to reload a PLUS that adds a register or a MEM to
7347 another register, constant or MEM. This can occur during frame pointer
7348 elimination and while reloading addresses. This case is handled by
7349 trying to emit a single insn to perform the add. If it is not valid,
7350 we use a two insn sequence.
7352 Finally, we could be called to handle an 'o' constraint by putting
7353 an address into a register. In that case, we first try to do this
7354 with a named pattern of "reload_load_address". If no such pattern
7355 exists, we just emit a SET insn and hope for the best (it will normally
7356 be valid on machines that use 'o').
7358 This entire process is made complex because reload will never
7359 process the insns we generate here and so we must ensure that
7360 they will fit their constraints and also by the fact that parts of
7361 IN might be being reloaded separately and replaced with spill registers.
7362 Because of this, we are, in some sense, just guessing the right approach
7363 here. The one listed above seems to work.
7365 ??? At some point, this whole thing needs to be rethought. */
7367 if (GET_CODE (in) == PLUS
7368 && (GET_CODE (XEXP (in, 0)) == REG
7369 || GET_CODE (XEXP (in, 0)) == SUBREG
7370 || GET_CODE (XEXP (in, 0)) == MEM)
7371 && (GET_CODE (XEXP (in, 1)) == REG
7372 || GET_CODE (XEXP (in, 1)) == SUBREG
7373 || CONSTANT_P (XEXP (in, 1))
7374 || GET_CODE (XEXP (in, 1)) == MEM))
7376 /* We need to compute the sum of a register or a MEM and another
7377 register, constant, or MEM, and put it into the reload
7378 register. The best possible way of doing this is if the machine
7379 has a three-operand ADD insn that accepts the required operands.
7381 The simplest approach is to try to generate such an insn and see if it
7382 is recognized and matches its constraints. If so, it can be used.
7384 It might be better not to actually emit the insn unless it is valid,
7385 but we need to pass the insn as an operand to `recog' and
7386 `extract_insn' and it is simpler to emit and then delete the insn if
7387 not valid than to dummy things up. */
7389 rtx op0, op1, tem, insn;
7392 op0 = find_replacement (&XEXP (in, 0));
7393 op1 = find_replacement (&XEXP (in, 1));
7395 /* Since constraint checking is strict, commutativity won't be
7396 checked, so we need to do that here to avoid spurious failure
7397 if the add instruction is two-address and the second operand
7398 of the add is the same as the reload reg, which is frequently
7399 the case. If the insn would be A = B + A, rearrange it so
7400 it will be A = A + B as constrain_operands expects. */
7402 if (GET_CODE (XEXP (in, 1)) == REG
7403 && REGNO (out) == REGNO (XEXP (in, 1)))
7404 tem = op0, op0 = op1, op1 = tem;
7406 if (op0 != XEXP (in, 0) || op1 != XEXP (in, 1))
7407 in = gen_rtx_PLUS (GET_MODE (in), op0, op1);
7409 insn = emit_insn (gen_rtx_SET (VOIDmode, out, in));
7410 code = recog_memoized (insn);
7414 extract_insn (insn);
7415 /* We want constrain operands to treat this insn strictly in
7416 its validity determination, i.e., the way it would after reload
7418 if (constrain_operands (1))
7422 delete_insns_since (last);
7424 /* If that failed, we must use a conservative two-insn sequence.
7426 Use a move to copy one operand into the reload register. Prefer
7427 to reload a constant, MEM or pseudo since the move patterns can
7428 handle an arbitrary operand. If OP1 is not a constant, MEM or
7429 pseudo and OP1 is not a valid operand for an add instruction, then
7432 After reloading one of the operands into the reload register, add
7433 the reload register to the output register.
7435 If there is another way to do this for a specific machine, a
7436 DEFINE_PEEPHOLE should be specified that recognizes the sequence
7439 code = (int) add_optab->handlers[(int) GET_MODE (out)].insn_code;
7441 if (CONSTANT_P (op1) || GET_CODE (op1) == MEM || GET_CODE (op1) == SUBREG
7442 || (GET_CODE (op1) == REG
7443 && REGNO (op1) >= FIRST_PSEUDO_REGISTER)
7444 || (code != CODE_FOR_nothing
7445 && ! ((*insn_data[code].operand[2].predicate)
7446 (op1, insn_data[code].operand[2].mode))))
7447 tem = op0, op0 = op1, op1 = tem;
7449 gen_reload (out, op0, opnum, type);
7451 /* If OP0 and OP1 are the same, we can use OUT for OP1.
7452 This fixes a problem on the 32K where the stack pointer cannot
7453 be used as an operand of an add insn. */
7455 if (rtx_equal_p (op0, op1))
7458 insn = emit_insn (gen_add2_insn (out, op1));
7460 /* If that failed, copy the address register to the reload register.
7461 Then add the constant to the reload register. */
7463 code = recog_memoized (insn);
7467 extract_insn (insn);
7468 /* We want constrain operands to treat this insn strictly in
7469 its validity determination, i.e., the way it would after reload
7471 if (constrain_operands (1))
7473 /* Add a REG_EQUIV note so that find_equiv_reg can find it. */
7475 = gen_rtx_EXPR_LIST (REG_EQUIV, in, REG_NOTES (insn));
7480 delete_insns_since (last);
7482 gen_reload (out, op1, opnum, type);
7483 insn = emit_insn (gen_add2_insn (out, op0));
7484 REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_EQUIV, in, REG_NOTES (insn));
7487 #ifdef SECONDARY_MEMORY_NEEDED
7488 /* If we need a memory location to do the move, do it that way. */
7489 else if ((GET_CODE (in) == REG || GET_CODE (in) == SUBREG)
7490 && reg_or_subregno (in) < FIRST_PSEUDO_REGISTER
7491 && (GET_CODE (out) == REG || GET_CODE (out) == SUBREG)
7492 && reg_or_subregno (out) < FIRST_PSEUDO_REGISTER
7493 && SECONDARY_MEMORY_NEEDED (REGNO_REG_CLASS (reg_or_subregno (in)),
7494 REGNO_REG_CLASS (reg_or_subregno (out)),
7497 /* Get the memory to use and rewrite both registers to its mode. */
7498 rtx loc = get_secondary_mem (in, GET_MODE (out), opnum, type);
7500 if (GET_MODE (loc) != GET_MODE (out))
7501 out = gen_rtx_REG (GET_MODE (loc), REGNO (out));
7503 if (GET_MODE (loc) != GET_MODE (in))
7504 in = gen_rtx_REG (GET_MODE (loc), REGNO (in));
7506 gen_reload (loc, in, opnum, type);
7507 gen_reload (out, loc, opnum, type);
7511 /* If IN is a simple operand, use gen_move_insn. */
7512 else if (GET_RTX_CLASS (GET_CODE (in)) == 'o' || GET_CODE (in) == SUBREG)
7513 emit_insn (gen_move_insn (out, in));
7515 #ifdef HAVE_reload_load_address
7516 else if (HAVE_reload_load_address)
7517 emit_insn (gen_reload_load_address (out, in));
7520 /* Otherwise, just write (set OUT IN) and hope for the best. */
7522 emit_insn (gen_rtx_SET (VOIDmode, out, in));
7524 /* Return the first insn emitted.
7525 We can not just return get_last_insn, because there may have
7526 been multiple instructions emitted. Also note that gen_move_insn may
7527 emit more than one insn itself, so we can not assume that there is one
7528 insn emitted per emit_insn_before call. */
7530 return last ? NEXT_INSN (last) : get_insns ();
7533 /* Delete a previously made output-reload whose result we now believe
7534 is not needed. First we double-check.
7536 INSN is the insn now being processed.
7537 LAST_RELOAD_REG is the hard register number for which we want to delete
7538 the last output reload.
7539 J is the reload-number that originally used REG. The caller has made
7540 certain that reload J doesn't use REG any longer for input. */
7543 delete_output_reload (rtx insn, int j, int last_reload_reg)
7545 rtx output_reload_insn = spill_reg_store[last_reload_reg];
7546 rtx reg = spill_reg_stored_to[last_reload_reg];
7549 int n_inherited = 0;
7553 /* It is possible that this reload has been only used to set another reload
7554 we eliminated earlier and thus deleted this instruction too. */
7555 if (INSN_DELETED_P (output_reload_insn))
7558 /* Get the raw pseudo-register referred to. */
7560 while (GET_CODE (reg) == SUBREG)
7561 reg = SUBREG_REG (reg);
7562 substed = reg_equiv_memory_loc[REGNO (reg)];
7564 /* This is unsafe if the operand occurs more often in the current
7565 insn than it is inherited. */
7566 for (k = n_reloads - 1; k >= 0; k--)
7568 rtx reg2 = rld[k].in;
7571 if (GET_CODE (reg2) == MEM || reload_override_in[k])
7572 reg2 = rld[k].in_reg;
7574 if (rld[k].out && ! rld[k].out_reg)
7575 reg2 = XEXP (rld[k].in_reg, 0);
7577 while (GET_CODE (reg2) == SUBREG)
7578 reg2 = SUBREG_REG (reg2);
7579 if (rtx_equal_p (reg2, reg))
7581 if (reload_inherited[k] || reload_override_in[k] || k == j)
7584 reg2 = rld[k].out_reg;
7587 while (GET_CODE (reg2) == SUBREG)
7588 reg2 = XEXP (reg2, 0);
7589 if (rtx_equal_p (reg2, reg))
7596 n_occurrences = count_occurrences (PATTERN (insn), reg, 0);
7598 n_occurrences += count_occurrences (PATTERN (insn),
7599 eliminate_regs (substed, 0,
7601 if (n_occurrences > n_inherited)
7604 /* If the pseudo-reg we are reloading is no longer referenced
7605 anywhere between the store into it and here,
7606 and no jumps or labels intervene, then the value can get
7607 here through the reload reg alone.
7608 Otherwise, give up--return. */
7609 for (i1 = NEXT_INSN (output_reload_insn);
7610 i1 != insn; i1 = NEXT_INSN (i1))
7612 if (GET_CODE (i1) == CODE_LABEL || GET_CODE (i1) == JUMP_INSN)
7614 if ((GET_CODE (i1) == INSN || GET_CODE (i1) == CALL_INSN)
7615 && reg_mentioned_p (reg, PATTERN (i1)))
7617 /* If this is USE in front of INSN, we only have to check that
7618 there are no more references than accounted for by inheritance. */
7619 while (GET_CODE (i1) == INSN && GET_CODE (PATTERN (i1)) == USE)
7621 n_occurrences += rtx_equal_p (reg, XEXP (PATTERN (i1), 0)) != 0;
7622 i1 = NEXT_INSN (i1);
7624 if (n_occurrences <= n_inherited && i1 == insn)
7630 /* We will be deleting the insn. Remove the spill reg information. */
7631 for (k = hard_regno_nregs[last_reload_reg][GET_MODE (reg)]; k-- > 0; )
7633 spill_reg_store[last_reload_reg + k] = 0;
7634 spill_reg_stored_to[last_reload_reg + k] = 0;
7637 /* The caller has already checked that REG dies or is set in INSN.
7638 It has also checked that we are optimizing, and thus some
7639 inaccuracies in the debugging information are acceptable.
7640 So we could just delete output_reload_insn. But in some cases
7641 we can improve the debugging information without sacrificing
7642 optimization - maybe even improving the code: See if the pseudo
7643 reg has been completely replaced with reload regs. If so, delete
7644 the store insn and forget we had a stack slot for the pseudo. */
7645 if (rld[j].out != rld[j].in
7646 && REG_N_DEATHS (REGNO (reg)) == 1
7647 && REG_N_SETS (REGNO (reg)) == 1
7648 && REG_BASIC_BLOCK (REGNO (reg)) >= 0
7649 && find_regno_note (insn, REG_DEAD, REGNO (reg)))
7653 /* We know that it was used only between here and the beginning of
7654 the current basic block. (We also know that the last use before
7655 INSN was the output reload we are thinking of deleting, but never
7656 mind that.) Search that range; see if any ref remains. */
7657 for (i2 = PREV_INSN (insn); i2; i2 = PREV_INSN (i2))
7659 rtx set = single_set (i2);
7661 /* Uses which just store in the pseudo don't count,
7662 since if they are the only uses, they are dead. */
7663 if (set != 0 && SET_DEST (set) == reg)
7665 if (GET_CODE (i2) == CODE_LABEL
7666 || GET_CODE (i2) == JUMP_INSN)
7668 if ((GET_CODE (i2) == INSN || GET_CODE (i2) == CALL_INSN)
7669 && reg_mentioned_p (reg, PATTERN (i2)))
7671 /* Some other ref remains; just delete the output reload we
7673 delete_address_reloads (output_reload_insn, insn);
7674 delete_insn (output_reload_insn);
7679 /* Delete the now-dead stores into this pseudo. Note that this
7680 loop also takes care of deleting output_reload_insn. */
7681 for (i2 = PREV_INSN (insn); i2; i2 = PREV_INSN (i2))
7683 rtx set = single_set (i2);
7685 if (set != 0 && SET_DEST (set) == reg)
7687 delete_address_reloads (i2, insn);
7690 if (GET_CODE (i2) == CODE_LABEL
7691 || GET_CODE (i2) == JUMP_INSN)
7695 /* For the debugging info, say the pseudo lives in this reload reg. */
7696 reg_renumber[REGNO (reg)] = REGNO (rld[j].reg_rtx);
7697 alter_reg (REGNO (reg), -1);
7701 delete_address_reloads (output_reload_insn, insn);
7702 delete_insn (output_reload_insn);
7706 /* We are going to delete DEAD_INSN. Recursively delete loads of
7707 reload registers used in DEAD_INSN that are not used till CURRENT_INSN.
7708 CURRENT_INSN is being reloaded, so we have to check its reloads too. */
7710 delete_address_reloads (rtx dead_insn, rtx current_insn)
7712 rtx set = single_set (dead_insn);
7713 rtx set2, dst, prev, next;
7716 rtx dst = SET_DEST (set);
7717 if (GET_CODE (dst) == MEM)
7718 delete_address_reloads_1 (dead_insn, XEXP (dst, 0), current_insn);
7720 /* If we deleted the store from a reloaded post_{in,de}c expression,
7721 we can delete the matching adds. */
7722 prev = PREV_INSN (dead_insn);
7723 next = NEXT_INSN (dead_insn);
7724 if (! prev || ! next)
7726 set = single_set (next);
7727 set2 = single_set (prev);
7729 || GET_CODE (SET_SRC (set)) != PLUS || GET_CODE (SET_SRC (set2)) != PLUS
7730 || GET_CODE (XEXP (SET_SRC (set), 1)) != CONST_INT
7731 || GET_CODE (XEXP (SET_SRC (set2), 1)) != CONST_INT)
7733 dst = SET_DEST (set);
7734 if (! rtx_equal_p (dst, SET_DEST (set2))
7735 || ! rtx_equal_p (dst, XEXP (SET_SRC (set), 0))
7736 || ! rtx_equal_p (dst, XEXP (SET_SRC (set2), 0))
7737 || (INTVAL (XEXP (SET_SRC (set), 1))
7738 != -INTVAL (XEXP (SET_SRC (set2), 1))))
7740 delete_related_insns (prev);
7741 delete_related_insns (next);
7744 /* Subfunction of delete_address_reloads: process registers found in X. */
7746 delete_address_reloads_1 (rtx dead_insn, rtx x, rtx current_insn)
7748 rtx prev, set, dst, i2;
7750 enum rtx_code code = GET_CODE (x);
7754 const char *fmt = GET_RTX_FORMAT (code);
7755 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
7758 delete_address_reloads_1 (dead_insn, XEXP (x, i), current_insn);
7759 else if (fmt[i] == 'E')
7761 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
7762 delete_address_reloads_1 (dead_insn, XVECEXP (x, i, j),
7769 if (spill_reg_order[REGNO (x)] < 0)
7772 /* Scan backwards for the insn that sets x. This might be a way back due
7774 for (prev = PREV_INSN (dead_insn); prev; prev = PREV_INSN (prev))
7776 code = GET_CODE (prev);
7777 if (code == CODE_LABEL || code == JUMP_INSN)
7779 if (GET_RTX_CLASS (code) != 'i')
7781 if (reg_set_p (x, PATTERN (prev)))
7783 if (reg_referenced_p (x, PATTERN (prev)))
7786 if (! prev || INSN_UID (prev) < reload_first_uid)
7788 /* Check that PREV only sets the reload register. */
7789 set = single_set (prev);
7792 dst = SET_DEST (set);
7793 if (GET_CODE (dst) != REG
7794 || ! rtx_equal_p (dst, x))
7796 if (! reg_set_p (dst, PATTERN (dead_insn)))
7798 /* Check if DST was used in a later insn -
7799 it might have been inherited. */
7800 for (i2 = NEXT_INSN (dead_insn); i2; i2 = NEXT_INSN (i2))
7802 if (GET_CODE (i2) == CODE_LABEL)
7806 if (reg_referenced_p (dst, PATTERN (i2)))
7808 /* If there is a reference to the register in the current insn,
7809 it might be loaded in a non-inherited reload. If no other
7810 reload uses it, that means the register is set before
7812 if (i2 == current_insn)
7814 for (j = n_reloads - 1; j >= 0; j--)
7815 if ((rld[j].reg_rtx == dst && reload_inherited[j])
7816 || reload_override_in[j] == dst)
7818 for (j = n_reloads - 1; j >= 0; j--)
7819 if (rld[j].in && rld[j].reg_rtx == dst)
7826 if (GET_CODE (i2) == JUMP_INSN)
7828 /* If DST is still live at CURRENT_INSN, check if it is used for
7829 any reload. Note that even if CURRENT_INSN sets DST, we still
7830 have to check the reloads. */
7831 if (i2 == current_insn)
7833 for (j = n_reloads - 1; j >= 0; j--)
7834 if ((rld[j].reg_rtx == dst && reload_inherited[j])
7835 || reload_override_in[j] == dst)
7837 /* ??? We can't finish the loop here, because dst might be
7838 allocated to a pseudo in this block if no reload in this
7839 block needs any of the classes containing DST - see
7840 spill_hard_reg. There is no easy way to tell this, so we
7841 have to scan till the end of the basic block. */
7843 if (reg_set_p (dst, PATTERN (i2)))
7847 delete_address_reloads_1 (prev, SET_SRC (set), current_insn);
7848 reg_reloaded_contents[REGNO (dst)] = -1;
7852 /* Output reload-insns to reload VALUE into RELOADREG.
7853 VALUE is an autoincrement or autodecrement RTX whose operand
7854 is a register or memory location;
7855 so reloading involves incrementing that location.
7856 IN is either identical to VALUE, or some cheaper place to reload from.
7858 INC_AMOUNT is the number to increment or decrement by (always positive).
7859 This cannot be deduced from VALUE.
7861 Return the instruction that stores into RELOADREG. */
7864 inc_for_reload (rtx reloadreg, rtx in, rtx value, int inc_amount)
7866 /* REG or MEM to be copied and incremented. */
7867 rtx incloc = XEXP (value, 0);
7868 /* Nonzero if increment after copying. */
7869 int post = (GET_CODE (value) == POST_DEC || GET_CODE (value) == POST_INC);
7875 rtx real_in = in == value ? XEXP (in, 0) : in;
7877 /* No hard register is equivalent to this register after
7878 inc/dec operation. If REG_LAST_RELOAD_REG were nonzero,
7879 we could inc/dec that register as well (maybe even using it for
7880 the source), but I'm not sure it's worth worrying about. */
7881 if (GET_CODE (incloc) == REG)
7882 reg_last_reload_reg[REGNO (incloc)] = 0;
7884 if (GET_CODE (value) == PRE_DEC || GET_CODE (value) == POST_DEC)
7885 inc_amount = -inc_amount;
7887 inc = GEN_INT (inc_amount);
7889 /* If this is post-increment, first copy the location to the reload reg. */
7890 if (post && real_in != reloadreg)
7891 emit_insn (gen_move_insn (reloadreg, real_in));
7895 /* See if we can directly increment INCLOC. Use a method similar to
7896 that in gen_reload. */
7898 last = get_last_insn ();
7899 add_insn = emit_insn (gen_rtx_SET (VOIDmode, incloc,
7900 gen_rtx_PLUS (GET_MODE (incloc),
7903 code = recog_memoized (add_insn);
7906 extract_insn (add_insn);
7907 if (constrain_operands (1))
7909 /* If this is a pre-increment and we have incremented the value
7910 where it lives, copy the incremented value to RELOADREG to
7911 be used as an address. */
7914 emit_insn (gen_move_insn (reloadreg, incloc));
7919 delete_insns_since (last);
7922 /* If couldn't do the increment directly, must increment in RELOADREG.
7923 The way we do this depends on whether this is pre- or post-increment.
7924 For pre-increment, copy INCLOC to the reload register, increment it
7925 there, then save back. */
7929 if (in != reloadreg)
7930 emit_insn (gen_move_insn (reloadreg, real_in));
7931 emit_insn (gen_add2_insn (reloadreg, inc));
7932 store = emit_insn (gen_move_insn (incloc, reloadreg));
7937 Because this might be a jump insn or a compare, and because RELOADREG
7938 may not be available after the insn in an input reload, we must do
7939 the incrementation before the insn being reloaded for.
7941 We have already copied IN to RELOADREG. Increment the copy in
7942 RELOADREG, save that back, then decrement RELOADREG so it has
7943 the original value. */
7945 emit_insn (gen_add2_insn (reloadreg, inc));
7946 store = emit_insn (gen_move_insn (incloc, reloadreg));
7947 emit_insn (gen_add2_insn (reloadreg, GEN_INT (-inc_amount)));
7955 add_auto_inc_notes (rtx insn, rtx x)
7957 enum rtx_code code = GET_CODE (x);
7961 if (code == MEM && auto_inc_p (XEXP (x, 0)))
7964 = gen_rtx_EXPR_LIST (REG_INC, XEXP (XEXP (x, 0), 0), REG_NOTES (insn));
7968 /* Scan all the operand sub-expressions. */
7969 fmt = GET_RTX_FORMAT (code);
7970 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
7973 add_auto_inc_notes (insn, XEXP (x, i));
7974 else if (fmt[i] == 'E')
7975 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
7976 add_auto_inc_notes (insn, XVECEXP (x, i, j));
7981 /* Copy EH notes from an insn to its reloads. */
7983 copy_eh_notes (rtx insn, rtx x)
7985 rtx eh_note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
7988 for (; x != 0; x = NEXT_INSN (x))
7990 if (may_trap_p (PATTERN (x)))
7992 = gen_rtx_EXPR_LIST (REG_EH_REGION, XEXP (eh_note, 0),
7998 /* This is used by reload pass, that does emit some instructions after
7999 abnormal calls moving basic block end, but in fact it wants to emit
8000 them on the edge. Looks for abnormal call edges, find backward the
8001 proper call and fix the damage.
8003 Similar handle instructions throwing exceptions internally. */
8005 fixup_abnormal_edges (void)
8007 bool inserted = false;
8014 /* Look for cases we are interested in - calls or instructions causing
8016 for (e = bb->succ; e; e = e->succ_next)
8018 if (e->flags & EDGE_ABNORMAL_CALL)
8020 if ((e->flags & (EDGE_ABNORMAL | EDGE_EH))
8021 == (EDGE_ABNORMAL | EDGE_EH))
8024 if (e && GET_CODE (BB_END (bb)) != CALL_INSN
8025 && !can_throw_internal (BB_END (bb)))
8027 rtx insn = BB_END (bb), stop = NEXT_INSN (BB_END (bb));
8029 for (e = bb->succ; e; e = e->succ_next)
8030 if (e->flags & EDGE_FALLTHRU)
8032 /* Get past the new insns generated. Allow notes, as the insns may
8033 be already deleted. */
8034 while ((GET_CODE (insn) == INSN || GET_CODE (insn) == NOTE)
8035 && !can_throw_internal (insn)
8036 && insn != BB_HEAD (bb))
8037 insn = PREV_INSN (insn);
8038 if (GET_CODE (insn) != CALL_INSN && !can_throw_internal (insn))
8042 insn = NEXT_INSN (insn);
8043 while (insn && insn != stop)
8045 next = NEXT_INSN (insn);
8050 /* Sometimes there's still the return value USE.
8051 If it's placed after a trapping call (i.e. that
8052 call is the last insn anyway), we have no fallthru
8053 edge. Simply delete this use and don't try to insert
8054 on the non-existent edge. */
8055 if (GET_CODE (PATTERN (insn)) != USE)
8057 /* We're not deleting it, we're moving it. */
8058 INSN_DELETED_P (insn) = 0;
8059 PREV_INSN (insn) = NULL_RTX;
8060 NEXT_INSN (insn) = NULL_RTX;
8062 insert_insn_on_edge (insn, e);
8069 /* We've possibly turned single trapping insn into multiple ones. */
8070 if (flag_non_call_exceptions)
8073 blocks = sbitmap_alloc (last_basic_block);
8074 sbitmap_ones (blocks);
8075 find_many_sub_basic_blocks (blocks);
8078 commit_edge_insertions ();
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