Merge with gcc-4_3-branch up to revision 175516.
[official-gcc.git] / gcc / reload.c
blobcfe6be8c5643e9f34c6ca6023f9b7947c5471eb3
1 /* Search an insn for pseudo regs that must be in hard regs and are not.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* This file contains subroutines used only from the file reload1.c.
23 It knows how to scan one insn for operands and values
24 that need to be copied into registers to make valid code.
25 It also finds other operands and values which are valid
26 but for which equivalent values in registers exist and
27 ought to be used instead.
29 Before processing the first insn of the function, call `init_reload'.
30 init_reload actually has to be called earlier anyway.
32 To scan an insn, call `find_reloads'. This does two things:
33 1. sets up tables describing which values must be reloaded
34 for this insn, and what kind of hard regs they must be reloaded into;
35 2. optionally record the locations where those values appear in
36 the data, so they can be replaced properly later.
37 This is done only if the second arg to `find_reloads' is nonzero.
39 The third arg to `find_reloads' specifies the number of levels
40 of indirect addressing supported by the machine. If it is zero,
41 indirect addressing is not valid. If it is one, (MEM (REG n))
42 is valid even if (REG n) did not get a hard register; if it is two,
43 (MEM (MEM (REG n))) is also valid even if (REG n) did not get a
44 hard register, and similarly for higher values.
46 Then you must choose the hard regs to reload those pseudo regs into,
47 and generate appropriate load insns before this insn and perhaps
48 also store insns after this insn. Set up the array `reload_reg_rtx'
49 to contain the REG rtx's for the registers you used. In some
50 cases `find_reloads' will return a nonzero value in `reload_reg_rtx'
51 for certain reloads. Then that tells you which register to use,
52 so you do not need to allocate one. But you still do need to add extra
53 instructions to copy the value into and out of that register.
55 Finally you must call `subst_reloads' to substitute the reload reg rtx's
56 into the locations already recorded.
58 NOTE SIDE EFFECTS:
60 find_reloads can alter the operands of the instruction it is called on.
62 1. Two operands of any sort may be interchanged, if they are in a
63 commutative instruction.
64 This happens only if find_reloads thinks the instruction will compile
65 better that way.
67 2. Pseudo-registers that are equivalent to constants are replaced
68 with those constants if they are not in hard registers.
70 1 happens every time find_reloads is called.
71 2 happens only when REPLACE is 1, which is only when
72 actually doing the reloads, not when just counting them.
74 Using a reload register for several reloads in one insn:
76 When an insn has reloads, it is considered as having three parts:
77 the input reloads, the insn itself after reloading, and the output reloads.
78 Reloads of values used in memory addresses are often needed for only one part.
80 When this is so, reload_when_needed records which part needs the reload.
81 Two reloads for different parts of the insn can share the same reload
82 register.
84 When a reload is used for addresses in multiple parts, or when it is
85 an ordinary operand, it is classified as RELOAD_OTHER, and cannot share
86 a register with any other reload. */
88 #define REG_OK_STRICT
90 /* We do not enable this with ENABLE_CHECKING, since it is awfully slow. */
91 #undef DEBUG_RELOAD
93 #include "config.h"
94 #include "system.h"
95 #include "coretypes.h"
96 #include "tm.h"
97 #include "rtl.h"
98 #include "tm_p.h"
99 #include "insn-config.h"
100 #include "expr.h"
101 #include "optabs.h"
102 #include "recog.h"
103 #include "reload.h"
104 #include "regs.h"
105 #include "addresses.h"
106 #include "hard-reg-set.h"
107 #include "flags.h"
108 #include "real.h"
109 #include "output.h"
110 #include "function.h"
111 #include "toplev.h"
112 #include "params.h"
113 #include "target.h"
114 #include "df.h"
116 /* True if X is a constant that can be forced into the constant pool. */
117 #define CONST_POOL_OK_P(X) \
118 (CONSTANT_P (X) \
119 && GET_CODE (X) != HIGH \
120 && !targetm.cannot_force_const_mem (X))
122 /* True if C is a non-empty register class that has too few registers
123 to be safely used as a reload target class. */
124 #define SMALL_REGISTER_CLASS_P(C) \
125 (reg_class_size [(C)] == 1 \
126 || (reg_class_size [(C)] >= 1 && CLASS_LIKELY_SPILLED_P (C)))
129 /* All reloads of the current insn are recorded here. See reload.h for
130 comments. */
131 int n_reloads;
132 struct reload rld[MAX_RELOADS];
134 /* All the "earlyclobber" operands of the current insn
135 are recorded here. */
136 int n_earlyclobbers;
137 rtx reload_earlyclobbers[MAX_RECOG_OPERANDS];
139 int reload_n_operands;
141 /* Replacing reloads.
143 If `replace_reloads' is nonzero, then as each reload is recorded
144 an entry is made for it in the table `replacements'.
145 Then later `subst_reloads' can look through that table and
146 perform all the replacements needed. */
148 /* Nonzero means record the places to replace. */
149 static int replace_reloads;
151 /* Each replacement is recorded with a structure like this. */
152 struct replacement
154 rtx *where; /* Location to store in */
155 rtx *subreg_loc; /* Location of SUBREG if WHERE is inside
156 a SUBREG; 0 otherwise. */
157 int what; /* which reload this is for */
158 enum machine_mode mode; /* mode it must have */
161 static struct replacement replacements[MAX_RECOG_OPERANDS * ((MAX_REGS_PER_ADDRESS * 2) + 1)];
163 /* Number of replacements currently recorded. */
164 static int n_replacements;
166 /* Used to track what is modified by an operand. */
167 struct decomposition
169 int reg_flag; /* Nonzero if referencing a register. */
170 int safe; /* Nonzero if this can't conflict with anything. */
171 rtx base; /* Base address for MEM. */
172 HOST_WIDE_INT start; /* Starting offset or register number. */
173 HOST_WIDE_INT end; /* Ending offset or register number. */
176 #ifdef SECONDARY_MEMORY_NEEDED
178 /* Save MEMs needed to copy from one class of registers to another. One MEM
179 is used per mode, but normally only one or two modes are ever used.
181 We keep two versions, before and after register elimination. The one
182 after register elimination is record separately for each operand. This
183 is done in case the address is not valid to be sure that we separately
184 reload each. */
186 static rtx secondary_memlocs[NUM_MACHINE_MODES];
187 static rtx secondary_memlocs_elim[NUM_MACHINE_MODES][MAX_RECOG_OPERANDS];
188 static int secondary_memlocs_elim_used = 0;
189 #endif
191 /* The instruction we are doing reloads for;
192 so we can test whether a register dies in it. */
193 static rtx this_insn;
195 /* Nonzero if this instruction is a user-specified asm with operands. */
196 static int this_insn_is_asm;
198 /* If hard_regs_live_known is nonzero,
199 we can tell which hard regs are currently live,
200 at least enough to succeed in choosing dummy reloads. */
201 static int hard_regs_live_known;
203 /* Indexed by hard reg number,
204 element is nonnegative if hard reg has been spilled.
205 This vector is passed to `find_reloads' as an argument
206 and is not changed here. */
207 static short *static_reload_reg_p;
209 /* Set to 1 in subst_reg_equivs if it changes anything. */
210 static int subst_reg_equivs_changed;
212 /* On return from push_reload, holds the reload-number for the OUT
213 operand, which can be different for that from the input operand. */
214 static int output_reloadnum;
216 /* Compare two RTX's. */
217 #define MATCHES(x, y) \
218 (x == y || (x != 0 && (REG_P (x) \
219 ? REG_P (y) && REGNO (x) == REGNO (y) \
220 : rtx_equal_p (x, y) && ! side_effects_p (x))))
222 /* Indicates if two reloads purposes are for similar enough things that we
223 can merge their reloads. */
224 #define MERGABLE_RELOADS(when1, when2, op1, op2) \
225 ((when1) == RELOAD_OTHER || (when2) == RELOAD_OTHER \
226 || ((when1) == (when2) && (op1) == (op2)) \
227 || ((when1) == RELOAD_FOR_INPUT && (when2) == RELOAD_FOR_INPUT) \
228 || ((when1) == RELOAD_FOR_OPERAND_ADDRESS \
229 && (when2) == RELOAD_FOR_OPERAND_ADDRESS) \
230 || ((when1) == RELOAD_FOR_OTHER_ADDRESS \
231 && (when2) == RELOAD_FOR_OTHER_ADDRESS))
233 /* Nonzero if these two reload purposes produce RELOAD_OTHER when merged. */
234 #define MERGE_TO_OTHER(when1, when2, op1, op2) \
235 ((when1) != (when2) \
236 || ! ((op1) == (op2) \
237 || (when1) == RELOAD_FOR_INPUT \
238 || (when1) == RELOAD_FOR_OPERAND_ADDRESS \
239 || (when1) == RELOAD_FOR_OTHER_ADDRESS))
241 /* If we are going to reload an address, compute the reload type to
242 use. */
243 #define ADDR_TYPE(type) \
244 ((type) == RELOAD_FOR_INPUT_ADDRESS \
245 ? RELOAD_FOR_INPADDR_ADDRESS \
246 : ((type) == RELOAD_FOR_OUTPUT_ADDRESS \
247 ? RELOAD_FOR_OUTADDR_ADDRESS \
248 : (type)))
250 static int push_secondary_reload (int, rtx, int, int, enum reg_class,
251 enum machine_mode, enum reload_type,
252 enum insn_code *, secondary_reload_info *);
253 static enum reg_class find_valid_class (enum machine_mode, enum machine_mode,
254 int, unsigned int);
255 static int reload_inner_reg_of_subreg (rtx, enum machine_mode, int);
256 static void push_replacement (rtx *, int, enum machine_mode);
257 static void dup_replacements (rtx *, rtx *);
258 static void combine_reloads (void);
259 static int find_reusable_reload (rtx *, rtx, enum reg_class,
260 enum reload_type, int, int);
261 static rtx find_dummy_reload (rtx, rtx, rtx *, rtx *, enum machine_mode,
262 enum machine_mode, enum reg_class, int, int);
263 static int hard_reg_set_here_p (unsigned int, unsigned int, rtx);
264 static struct decomposition decompose (rtx);
265 static int immune_p (rtx, rtx, struct decomposition);
266 static bool alternative_allows_const_pool_ref (rtx, const char *, int);
267 static rtx find_reloads_toplev (rtx, int, enum reload_type, int, int, rtx,
268 int *);
269 static rtx make_memloc (rtx, int);
270 static int maybe_memory_address_p (enum machine_mode, rtx, rtx *);
271 static int find_reloads_address (enum machine_mode, rtx *, rtx, rtx *,
272 int, enum reload_type, int, rtx);
273 static rtx subst_reg_equivs (rtx, rtx);
274 static rtx subst_indexed_address (rtx);
275 static void update_auto_inc_notes (rtx, int, int);
276 static int find_reloads_address_1 (enum machine_mode, rtx, int,
277 enum rtx_code, enum rtx_code, rtx *,
278 int, enum reload_type,int, rtx);
279 static void find_reloads_address_part (rtx, rtx *, enum reg_class,
280 enum machine_mode, int,
281 enum reload_type, int);
282 static rtx find_reloads_subreg_address (rtx, int, int, enum reload_type,
283 int, rtx);
284 static void copy_replacements_1 (rtx *, rtx *, int);
285 static int find_inc_amount (rtx, rtx);
286 static int refers_to_mem_for_reload_p (rtx);
287 static int refers_to_regno_for_reload_p (unsigned int, unsigned int,
288 rtx, rtx *);
290 /* Add NEW to reg_equiv_alt_mem_list[REGNO] if it's not present in the
291 list yet. */
293 static void
294 push_reg_equiv_alt_mem (int regno, rtx mem)
296 rtx it;
298 for (it = reg_equiv_alt_mem_list [regno]; it; it = XEXP (it, 1))
299 if (rtx_equal_p (XEXP (it, 0), mem))
300 return;
302 reg_equiv_alt_mem_list [regno]
303 = alloc_EXPR_LIST (REG_EQUIV, mem,
304 reg_equiv_alt_mem_list [regno]);
307 /* Determine if any secondary reloads are needed for loading (if IN_P is
308 nonzero) or storing (if IN_P is zero) X to or from a reload register of
309 register class RELOAD_CLASS in mode RELOAD_MODE. If secondary reloads
310 are needed, push them.
312 Return the reload number of the secondary reload we made, or -1 if
313 we didn't need one. *PICODE is set to the insn_code to use if we do
314 need a secondary reload. */
316 static int
317 push_secondary_reload (int in_p, rtx x, int opnum, int optional,
318 enum reg_class reload_class,
319 enum machine_mode reload_mode, enum reload_type type,
320 enum insn_code *picode, secondary_reload_info *prev_sri)
322 enum reg_class class = NO_REGS;
323 enum reg_class scratch_class;
324 enum machine_mode mode = reload_mode;
325 enum insn_code icode = CODE_FOR_nothing;
326 enum insn_code t_icode = CODE_FOR_nothing;
327 enum reload_type secondary_type;
328 int s_reload, t_reload = -1;
329 const char *scratch_constraint;
330 char letter;
331 secondary_reload_info sri;
333 if (type == RELOAD_FOR_INPUT_ADDRESS
334 || type == RELOAD_FOR_OUTPUT_ADDRESS
335 || type == RELOAD_FOR_INPADDR_ADDRESS
336 || type == RELOAD_FOR_OUTADDR_ADDRESS)
337 secondary_type = type;
338 else
339 secondary_type = in_p ? RELOAD_FOR_INPUT_ADDRESS : RELOAD_FOR_OUTPUT_ADDRESS;
341 *picode = CODE_FOR_nothing;
343 /* If X is a paradoxical SUBREG, use the inner value to determine both the
344 mode and object being reloaded. */
345 if (GET_CODE (x) == SUBREG
346 && (GET_MODE_SIZE (GET_MODE (x))
347 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))))
349 x = SUBREG_REG (x);
350 reload_mode = GET_MODE (x);
353 /* If X is a pseudo-register that has an equivalent MEM (actually, if it
354 is still a pseudo-register by now, it *must* have an equivalent MEM
355 but we don't want to assume that), use that equivalent when seeing if
356 a secondary reload is needed since whether or not a reload is needed
357 might be sensitive to the form of the MEM. */
359 if (REG_P (x) && REGNO (x) >= FIRST_PSEUDO_REGISTER
360 && reg_equiv_mem[REGNO (x)] != 0)
361 x = reg_equiv_mem[REGNO (x)];
363 sri.icode = CODE_FOR_nothing;
364 sri.prev_sri = prev_sri;
365 class = targetm.secondary_reload (in_p, x, reload_class, reload_mode, &sri);
366 icode = sri.icode;
368 /* If we don't need any secondary registers, done. */
369 if (class == NO_REGS && icode == CODE_FOR_nothing)
370 return -1;
372 if (class != NO_REGS)
373 t_reload = push_secondary_reload (in_p, x, opnum, optional, class,
374 reload_mode, type, &t_icode, &sri);
376 /* If we will be using an insn, the secondary reload is for a
377 scratch register. */
379 if (icode != CODE_FOR_nothing)
381 /* If IN_P is nonzero, the reload register will be the output in
382 operand 0. If IN_P is zero, the reload register will be the input
383 in operand 1. Outputs should have an initial "=", which we must
384 skip. */
386 /* ??? It would be useful to be able to handle only two, or more than
387 three, operands, but for now we can only handle the case of having
388 exactly three: output, input and one temp/scratch. */
389 gcc_assert (insn_data[(int) icode].n_operands == 3);
391 /* ??? We currently have no way to represent a reload that needs
392 an icode to reload from an intermediate tertiary reload register.
393 We should probably have a new field in struct reload to tag a
394 chain of scratch operand reloads onto. */
395 gcc_assert (class == NO_REGS);
397 scratch_constraint = insn_data[(int) icode].operand[2].constraint;
398 gcc_assert (*scratch_constraint == '=');
399 scratch_constraint++;
400 if (*scratch_constraint == '&')
401 scratch_constraint++;
402 letter = *scratch_constraint;
403 scratch_class = (letter == 'r' ? GENERAL_REGS
404 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) letter,
405 scratch_constraint));
407 class = scratch_class;
408 mode = insn_data[(int) icode].operand[2].mode;
411 /* This case isn't valid, so fail. Reload is allowed to use the same
412 register for RELOAD_FOR_INPUT_ADDRESS and RELOAD_FOR_INPUT reloads, but
413 in the case of a secondary register, we actually need two different
414 registers for correct code. We fail here to prevent the possibility of
415 silently generating incorrect code later.
417 The convention is that secondary input reloads are valid only if the
418 secondary_class is different from class. If you have such a case, you
419 can not use secondary reloads, you must work around the problem some
420 other way.
422 Allow this when a reload_in/out pattern is being used. I.e. assume
423 that the generated code handles this case. */
425 gcc_assert (!in_p || class != reload_class || icode != CODE_FOR_nothing
426 || t_icode != CODE_FOR_nothing);
428 /* See if we can reuse an existing secondary reload. */
429 for (s_reload = 0; s_reload < n_reloads; s_reload++)
430 if (rld[s_reload].secondary_p
431 && (reg_class_subset_p (class, rld[s_reload].class)
432 || reg_class_subset_p (rld[s_reload].class, class))
433 && ((in_p && rld[s_reload].inmode == mode)
434 || (! in_p && rld[s_reload].outmode == mode))
435 && ((in_p && rld[s_reload].secondary_in_reload == t_reload)
436 || (! in_p && rld[s_reload].secondary_out_reload == t_reload))
437 && ((in_p && rld[s_reload].secondary_in_icode == t_icode)
438 || (! in_p && rld[s_reload].secondary_out_icode == t_icode))
439 && (SMALL_REGISTER_CLASS_P (class) || SMALL_REGISTER_CLASSES)
440 && MERGABLE_RELOADS (secondary_type, rld[s_reload].when_needed,
441 opnum, rld[s_reload].opnum))
443 if (in_p)
444 rld[s_reload].inmode = mode;
445 if (! in_p)
446 rld[s_reload].outmode = mode;
448 if (reg_class_subset_p (class, rld[s_reload].class))
449 rld[s_reload].class = class;
451 rld[s_reload].opnum = MIN (rld[s_reload].opnum, opnum);
452 rld[s_reload].optional &= optional;
453 rld[s_reload].secondary_p = 1;
454 if (MERGE_TO_OTHER (secondary_type, rld[s_reload].when_needed,
455 opnum, rld[s_reload].opnum))
456 rld[s_reload].when_needed = RELOAD_OTHER;
459 if (s_reload == n_reloads)
461 #ifdef SECONDARY_MEMORY_NEEDED
462 /* If we need a memory location to copy between the two reload regs,
463 set it up now. Note that we do the input case before making
464 the reload and the output case after. This is due to the
465 way reloads are output. */
467 if (in_p && icode == CODE_FOR_nothing
468 && SECONDARY_MEMORY_NEEDED (class, reload_class, mode))
470 get_secondary_mem (x, reload_mode, opnum, type);
472 /* We may have just added new reloads. Make sure we add
473 the new reload at the end. */
474 s_reload = n_reloads;
476 #endif
478 /* We need to make a new secondary reload for this register class. */
479 rld[s_reload].in = rld[s_reload].out = 0;
480 rld[s_reload].class = class;
482 rld[s_reload].inmode = in_p ? mode : VOIDmode;
483 rld[s_reload].outmode = ! in_p ? mode : VOIDmode;
484 rld[s_reload].reg_rtx = 0;
485 rld[s_reload].optional = optional;
486 rld[s_reload].inc = 0;
487 /* Maybe we could combine these, but it seems too tricky. */
488 rld[s_reload].nocombine = 1;
489 rld[s_reload].in_reg = 0;
490 rld[s_reload].out_reg = 0;
491 rld[s_reload].opnum = opnum;
492 rld[s_reload].when_needed = secondary_type;
493 rld[s_reload].secondary_in_reload = in_p ? t_reload : -1;
494 rld[s_reload].secondary_out_reload = ! in_p ? t_reload : -1;
495 rld[s_reload].secondary_in_icode = in_p ? t_icode : CODE_FOR_nothing;
496 rld[s_reload].secondary_out_icode
497 = ! in_p ? t_icode : CODE_FOR_nothing;
498 rld[s_reload].secondary_p = 1;
500 n_reloads++;
502 #ifdef SECONDARY_MEMORY_NEEDED
503 if (! in_p && icode == CODE_FOR_nothing
504 && SECONDARY_MEMORY_NEEDED (reload_class, class, mode))
505 get_secondary_mem (x, mode, opnum, type);
506 #endif
509 *picode = icode;
510 return s_reload;
513 /* If a secondary reload is needed, return its class. If both an intermediate
514 register and a scratch register is needed, we return the class of the
515 intermediate register. */
516 enum reg_class
517 secondary_reload_class (bool in_p, enum reg_class class,
518 enum machine_mode mode, rtx x)
520 enum insn_code icode;
521 secondary_reload_info sri;
523 sri.icode = CODE_FOR_nothing;
524 sri.prev_sri = NULL;
525 class = targetm.secondary_reload (in_p, x, class, mode, &sri);
526 icode = sri.icode;
528 /* If there are no secondary reloads at all, we return NO_REGS.
529 If an intermediate register is needed, we return its class. */
530 if (icode == CODE_FOR_nothing || class != NO_REGS)
531 return class;
533 /* No intermediate register is needed, but we have a special reload
534 pattern, which we assume for now needs a scratch register. */
535 return scratch_reload_class (icode);
538 /* ICODE is the insn_code of a reload pattern. Check that it has exactly
539 three operands, verify that operand 2 is an output operand, and return
540 its register class.
541 ??? We'd like to be able to handle any pattern with at least 2 operands,
542 for zero or more scratch registers, but that needs more infrastructure. */
543 enum reg_class
544 scratch_reload_class (enum insn_code icode)
546 const char *scratch_constraint;
547 char scratch_letter;
548 enum reg_class class;
550 gcc_assert (insn_data[(int) icode].n_operands == 3);
551 scratch_constraint = insn_data[(int) icode].operand[2].constraint;
552 gcc_assert (*scratch_constraint == '=');
553 scratch_constraint++;
554 if (*scratch_constraint == '&')
555 scratch_constraint++;
556 scratch_letter = *scratch_constraint;
557 if (scratch_letter == 'r')
558 return GENERAL_REGS;
559 class = REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
560 scratch_constraint);
561 gcc_assert (class != NO_REGS);
562 return class;
565 #ifdef SECONDARY_MEMORY_NEEDED
567 /* Return a memory location that will be used to copy X in mode MODE.
568 If we haven't already made a location for this mode in this insn,
569 call find_reloads_address on the location being returned. */
572 get_secondary_mem (rtx x ATTRIBUTE_UNUSED, enum machine_mode mode,
573 int opnum, enum reload_type type)
575 rtx loc;
576 int mem_valid;
578 /* By default, if MODE is narrower than a word, widen it to a word.
579 This is required because most machines that require these memory
580 locations do not support short load and stores from all registers
581 (e.g., FP registers). */
583 #ifdef SECONDARY_MEMORY_NEEDED_MODE
584 mode = SECONDARY_MEMORY_NEEDED_MODE (mode);
585 #else
586 if (GET_MODE_BITSIZE (mode) < BITS_PER_WORD && INTEGRAL_MODE_P (mode))
587 mode = mode_for_size (BITS_PER_WORD, GET_MODE_CLASS (mode), 0);
588 #endif
590 /* If we already have made a MEM for this operand in MODE, return it. */
591 if (secondary_memlocs_elim[(int) mode][opnum] != 0)
592 return secondary_memlocs_elim[(int) mode][opnum];
594 /* If this is the first time we've tried to get a MEM for this mode,
595 allocate a new one. `something_changed' in reload will get set
596 by noticing that the frame size has changed. */
598 if (secondary_memlocs[(int) mode] == 0)
600 #ifdef SECONDARY_MEMORY_NEEDED_RTX
601 secondary_memlocs[(int) mode] = SECONDARY_MEMORY_NEEDED_RTX (mode);
602 #else
603 secondary_memlocs[(int) mode]
604 = assign_stack_local (mode, GET_MODE_SIZE (mode), 0);
605 #endif
608 /* Get a version of the address doing any eliminations needed. If that
609 didn't give us a new MEM, make a new one if it isn't valid. */
611 loc = eliminate_regs (secondary_memlocs[(int) mode], VOIDmode, NULL_RTX);
612 mem_valid = strict_memory_address_p (mode, XEXP (loc, 0));
614 if (! mem_valid && loc == secondary_memlocs[(int) mode])
615 loc = copy_rtx (loc);
617 /* The only time the call below will do anything is if the stack
618 offset is too large. In that case IND_LEVELS doesn't matter, so we
619 can just pass a zero. Adjust the type to be the address of the
620 corresponding object. If the address was valid, save the eliminated
621 address. If it wasn't valid, we need to make a reload each time, so
622 don't save it. */
624 if (! mem_valid)
626 type = (type == RELOAD_FOR_INPUT ? RELOAD_FOR_INPUT_ADDRESS
627 : type == RELOAD_FOR_OUTPUT ? RELOAD_FOR_OUTPUT_ADDRESS
628 : RELOAD_OTHER);
630 find_reloads_address (mode, &loc, XEXP (loc, 0), &XEXP (loc, 0),
631 opnum, type, 0, 0);
634 secondary_memlocs_elim[(int) mode][opnum] = loc;
635 if (secondary_memlocs_elim_used <= (int)mode)
636 secondary_memlocs_elim_used = (int)mode + 1;
637 return loc;
640 /* Clear any secondary memory locations we've made. */
642 void
643 clear_secondary_mem (void)
645 memset (secondary_memlocs, 0, sizeof secondary_memlocs);
647 #endif /* SECONDARY_MEMORY_NEEDED */
650 /* Find the largest class which has at least one register valid in
651 mode INNER, and which for every such register, that register number
652 plus N is also valid in OUTER (if in range) and is cheap to move
653 into REGNO. Such a class must exist. */
655 static enum reg_class
656 find_valid_class (enum machine_mode outer ATTRIBUTE_UNUSED,
657 enum machine_mode inner ATTRIBUTE_UNUSED, int n,
658 unsigned int dest_regno ATTRIBUTE_UNUSED)
660 int best_cost = -1;
661 int class;
662 int regno;
663 enum reg_class best_class = NO_REGS;
664 enum reg_class dest_class ATTRIBUTE_UNUSED = REGNO_REG_CLASS (dest_regno);
665 unsigned int best_size = 0;
666 int cost;
668 for (class = 1; class < N_REG_CLASSES; class++)
670 int bad = 0;
671 int good = 0;
672 for (regno = 0; regno < FIRST_PSEUDO_REGISTER - n && ! bad; regno++)
673 if (TEST_HARD_REG_BIT (reg_class_contents[class], regno))
675 if (HARD_REGNO_MODE_OK (regno, inner))
677 good = 1;
678 if (! TEST_HARD_REG_BIT (reg_class_contents[class], regno + n)
679 || ! HARD_REGNO_MODE_OK (regno + n, outer))
680 bad = 1;
684 if (bad || !good)
685 continue;
686 cost = REGISTER_MOVE_COST (outer, class, dest_class);
688 if ((reg_class_size[class] > best_size
689 && (best_cost < 0 || best_cost >= cost))
690 || best_cost > cost)
692 best_class = class;
693 best_size = reg_class_size[class];
694 best_cost = REGISTER_MOVE_COST (outer, class, dest_class);
698 gcc_assert (best_size != 0);
700 return best_class;
703 /* Return the number of a previously made reload that can be combined with
704 a new one, or n_reloads if none of the existing reloads can be used.
705 OUT, CLASS, TYPE and OPNUM are the same arguments as passed to
706 push_reload, they determine the kind of the new reload that we try to
707 combine. P_IN points to the corresponding value of IN, which can be
708 modified by this function.
709 DONT_SHARE is nonzero if we can't share any input-only reload for IN. */
711 static int
712 find_reusable_reload (rtx *p_in, rtx out, enum reg_class class,
713 enum reload_type type, int opnum, int dont_share)
715 rtx in = *p_in;
716 int i;
717 /* We can't merge two reloads if the output of either one is
718 earlyclobbered. */
720 if (earlyclobber_operand_p (out))
721 return n_reloads;
723 /* We can use an existing reload if the class is right
724 and at least one of IN and OUT is a match
725 and the other is at worst neutral.
726 (A zero compared against anything is neutral.)
728 If SMALL_REGISTER_CLASSES, don't use existing reloads unless they are
729 for the same thing since that can cause us to need more reload registers
730 than we otherwise would. */
732 for (i = 0; i < n_reloads; i++)
733 if ((reg_class_subset_p (class, rld[i].class)
734 || reg_class_subset_p (rld[i].class, class))
735 /* If the existing reload has a register, it must fit our class. */
736 && (rld[i].reg_rtx == 0
737 || TEST_HARD_REG_BIT (reg_class_contents[(int) class],
738 true_regnum (rld[i].reg_rtx)))
739 && ((in != 0 && MATCHES (rld[i].in, in) && ! dont_share
740 && (out == 0 || rld[i].out == 0 || MATCHES (rld[i].out, out)))
741 || (out != 0 && MATCHES (rld[i].out, out)
742 && (in == 0 || rld[i].in == 0 || MATCHES (rld[i].in, in))))
743 && (rld[i].out == 0 || ! earlyclobber_operand_p (rld[i].out))
744 && (SMALL_REGISTER_CLASS_P (class) || SMALL_REGISTER_CLASSES)
745 && MERGABLE_RELOADS (type, rld[i].when_needed, opnum, rld[i].opnum))
746 return i;
748 /* Reloading a plain reg for input can match a reload to postincrement
749 that reg, since the postincrement's value is the right value.
750 Likewise, it can match a preincrement reload, since we regard
751 the preincrementation as happening before any ref in this insn
752 to that register. */
753 for (i = 0; i < n_reloads; i++)
754 if ((reg_class_subset_p (class, rld[i].class)
755 || reg_class_subset_p (rld[i].class, class))
756 /* If the existing reload has a register, it must fit our
757 class. */
758 && (rld[i].reg_rtx == 0
759 || TEST_HARD_REG_BIT (reg_class_contents[(int) class],
760 true_regnum (rld[i].reg_rtx)))
761 && out == 0 && rld[i].out == 0 && rld[i].in != 0
762 && ((REG_P (in)
763 && GET_RTX_CLASS (GET_CODE (rld[i].in)) == RTX_AUTOINC
764 && MATCHES (XEXP (rld[i].in, 0), in))
765 || (REG_P (rld[i].in)
766 && GET_RTX_CLASS (GET_CODE (in)) == RTX_AUTOINC
767 && MATCHES (XEXP (in, 0), rld[i].in)))
768 && (rld[i].out == 0 || ! earlyclobber_operand_p (rld[i].out))
769 && (SMALL_REGISTER_CLASS_P (class) || SMALL_REGISTER_CLASSES)
770 && MERGABLE_RELOADS (type, rld[i].when_needed,
771 opnum, rld[i].opnum))
773 /* Make sure reload_in ultimately has the increment,
774 not the plain register. */
775 if (REG_P (in))
776 *p_in = rld[i].in;
777 return i;
779 return n_reloads;
782 /* Return nonzero if X is a SUBREG which will require reloading of its
783 SUBREG_REG expression. */
785 static int
786 reload_inner_reg_of_subreg (rtx x, enum machine_mode mode, int output)
788 rtx inner;
790 /* Only SUBREGs are problematical. */
791 if (GET_CODE (x) != SUBREG)
792 return 0;
794 inner = SUBREG_REG (x);
796 /* If INNER is a constant or PLUS, then INNER must be reloaded. */
797 if (CONSTANT_P (inner) || GET_CODE (inner) == PLUS)
798 return 1;
800 /* If INNER is not a hard register, then INNER will not need to
801 be reloaded. */
802 if (!REG_P (inner)
803 || REGNO (inner) >= FIRST_PSEUDO_REGISTER)
804 return 0;
806 /* If INNER is not ok for MODE, then INNER will need reloading. */
807 if (! HARD_REGNO_MODE_OK (subreg_regno (x), mode))
808 return 1;
810 /* If the outer part is a word or smaller, INNER larger than a
811 word and the number of regs for INNER is not the same as the
812 number of words in INNER, then INNER will need reloading. */
813 return (GET_MODE_SIZE (mode) <= UNITS_PER_WORD
814 && output
815 && GET_MODE_SIZE (GET_MODE (inner)) > UNITS_PER_WORD
816 && ((GET_MODE_SIZE (GET_MODE (inner)) / UNITS_PER_WORD)
817 != (int) hard_regno_nregs[REGNO (inner)][GET_MODE (inner)]));
820 /* Return nonzero if IN can be reloaded into REGNO with mode MODE without
821 requiring an extra reload register. The caller has already found that
822 IN contains some reference to REGNO, so check that we can produce the
823 new value in a single step. E.g. if we have
824 (set (reg r13) (plus (reg r13) (const int 1))), and there is an
825 instruction that adds one to a register, this should succeed.
826 However, if we have something like
827 (set (reg r13) (plus (reg r13) (const int 999))), and the constant 999
828 needs to be loaded into a register first, we need a separate reload
829 register.
830 Such PLUS reloads are generated by find_reload_address_part.
831 The out-of-range PLUS expressions are usually introduced in the instruction
832 patterns by register elimination and substituting pseudos without a home
833 by their function-invariant equivalences. */
834 static int
835 can_reload_into (rtx in, int regno, enum machine_mode mode)
837 rtx dst, test_insn;
838 int r = 0;
839 struct recog_data save_recog_data;
841 /* For matching constraints, we often get notional input reloads where
842 we want to use the original register as the reload register. I.e.
843 technically this is a non-optional input-output reload, but IN is
844 already a valid register, and has been chosen as the reload register.
845 Speed this up, since it trivially works. */
846 if (REG_P (in))
847 return 1;
849 /* To test MEMs properly, we'd have to take into account all the reloads
850 that are already scheduled, which can become quite complicated.
851 And since we've already handled address reloads for this MEM, it
852 should always succeed anyway. */
853 if (MEM_P (in))
854 return 1;
856 /* If we can make a simple SET insn that does the job, everything should
857 be fine. */
858 dst = gen_rtx_REG (mode, regno);
859 test_insn = make_insn_raw (gen_rtx_SET (VOIDmode, dst, in));
860 save_recog_data = recog_data;
861 if (recog_memoized (test_insn) >= 0)
863 extract_insn (test_insn);
864 r = constrain_operands (1);
866 recog_data = save_recog_data;
867 return r;
870 /* Record one reload that needs to be performed.
871 IN is an rtx saying where the data are to be found before this instruction.
872 OUT says where they must be stored after the instruction.
873 (IN is zero for data not read, and OUT is zero for data not written.)
874 INLOC and OUTLOC point to the places in the instructions where
875 IN and OUT were found.
876 If IN and OUT are both nonzero, it means the same register must be used
877 to reload both IN and OUT.
879 CLASS is a register class required for the reloaded data.
880 INMODE is the machine mode that the instruction requires
881 for the reg that replaces IN and OUTMODE is likewise for OUT.
883 If IN is zero, then OUT's location and mode should be passed as
884 INLOC and INMODE.
886 STRICT_LOW is the 1 if there is a containing STRICT_LOW_PART rtx.
888 OPTIONAL nonzero means this reload does not need to be performed:
889 it can be discarded if that is more convenient.
891 OPNUM and TYPE say what the purpose of this reload is.
893 The return value is the reload-number for this reload.
895 If both IN and OUT are nonzero, in some rare cases we might
896 want to make two separate reloads. (Actually we never do this now.)
897 Therefore, the reload-number for OUT is stored in
898 output_reloadnum when we return; the return value applies to IN.
899 Usually (presently always), when IN and OUT are nonzero,
900 the two reload-numbers are equal, but the caller should be careful to
901 distinguish them. */
904 push_reload (rtx in, rtx out, rtx *inloc, rtx *outloc,
905 enum reg_class class, enum machine_mode inmode,
906 enum machine_mode outmode, int strict_low, int optional,
907 int opnum, enum reload_type type)
909 int i;
910 int dont_share = 0;
911 int dont_remove_subreg = 0;
912 rtx *in_subreg_loc = 0, *out_subreg_loc = 0;
913 int secondary_in_reload = -1, secondary_out_reload = -1;
914 enum insn_code secondary_in_icode = CODE_FOR_nothing;
915 enum insn_code secondary_out_icode = CODE_FOR_nothing;
917 /* INMODE and/or OUTMODE could be VOIDmode if no mode
918 has been specified for the operand. In that case,
919 use the operand's mode as the mode to reload. */
920 if (inmode == VOIDmode && in != 0)
921 inmode = GET_MODE (in);
922 if (outmode == VOIDmode && out != 0)
923 outmode = GET_MODE (out);
925 /* If find_reloads and friends until now missed to replace a pseudo
926 with a constant of reg_equiv_constant something went wrong
927 beforehand.
928 Note that it can't simply be done here if we missed it earlier
929 since the constant might need to be pushed into the literal pool
930 and the resulting memref would probably need further
931 reloading. */
932 if (in != 0 && REG_P (in))
934 int regno = REGNO (in);
936 gcc_assert (regno < FIRST_PSEUDO_REGISTER
937 || reg_renumber[regno] >= 0
938 || reg_equiv_constant[regno] == NULL_RTX);
941 /* reg_equiv_constant only contains constants which are obviously
942 not appropriate as destination. So if we would need to replace
943 the destination pseudo with a constant we are in real
944 trouble. */
945 if (out != 0 && REG_P (out))
947 int regno = REGNO (out);
949 gcc_assert (regno < FIRST_PSEUDO_REGISTER
950 || reg_renumber[regno] >= 0
951 || reg_equiv_constant[regno] == NULL_RTX);
954 /* If we have a read-write operand with an address side-effect,
955 change either IN or OUT so the side-effect happens only once. */
956 if (in != 0 && out != 0 && MEM_P (in) && rtx_equal_p (in, out))
957 switch (GET_CODE (XEXP (in, 0)))
959 case POST_INC: case POST_DEC: case POST_MODIFY:
960 in = replace_equiv_address_nv (in, XEXP (XEXP (in, 0), 0));
961 break;
963 case PRE_INC: case PRE_DEC: case PRE_MODIFY:
964 out = replace_equiv_address_nv (out, XEXP (XEXP (out, 0), 0));
965 break;
967 default:
968 break;
971 /* If we are reloading a (SUBREG constant ...), really reload just the
972 inside expression in its own mode. Similarly for (SUBREG (PLUS ...)).
973 If we have (SUBREG:M1 (MEM:M2 ...) ...) (or an inner REG that is still
974 a pseudo and hence will become a MEM) with M1 wider than M2 and the
975 register is a pseudo, also reload the inside expression.
976 For machines that extend byte loads, do this for any SUBREG of a pseudo
977 where both M1 and M2 are a word or smaller, M1 is wider than M2, and
978 M2 is an integral mode that gets extended when loaded.
979 Similar issue for (SUBREG:M1 (REG:M2 ...) ...) for a hard register R where
980 either M1 is not valid for R or M2 is wider than a word but we only
981 need one word to store an M2-sized quantity in R.
982 (However, if OUT is nonzero, we need to reload the reg *and*
983 the subreg, so do nothing here, and let following statement handle it.)
985 Note that the case of (SUBREG (CONST_INT...)...) is handled elsewhere;
986 we can't handle it here because CONST_INT does not indicate a mode.
988 Similarly, we must reload the inside expression if we have a
989 STRICT_LOW_PART (presumably, in == out in the cas).
991 Also reload the inner expression if it does not require a secondary
992 reload but the SUBREG does.
994 Finally, reload the inner expression if it is a register that is in
995 the class whose registers cannot be referenced in a different size
996 and M1 is not the same size as M2. If subreg_lowpart_p is false, we
997 cannot reload just the inside since we might end up with the wrong
998 register class. But if it is inside a STRICT_LOW_PART, we have
999 no choice, so we hope we do get the right register class there. */
1001 if (in != 0 && GET_CODE (in) == SUBREG
1002 && (subreg_lowpart_p (in) || strict_low)
1003 #ifdef CANNOT_CHANGE_MODE_CLASS
1004 && !CANNOT_CHANGE_MODE_CLASS (GET_MODE (SUBREG_REG (in)), inmode, class)
1005 #endif
1006 && (CONSTANT_P (SUBREG_REG (in))
1007 || GET_CODE (SUBREG_REG (in)) == PLUS
1008 || strict_low
1009 || (((REG_P (SUBREG_REG (in))
1010 && REGNO (SUBREG_REG (in)) >= FIRST_PSEUDO_REGISTER)
1011 || MEM_P (SUBREG_REG (in)))
1012 && ((GET_MODE_SIZE (inmode)
1013 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))))
1014 #ifdef LOAD_EXTEND_OP
1015 || (GET_MODE_SIZE (inmode) <= UNITS_PER_WORD
1016 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
1017 <= UNITS_PER_WORD)
1018 && (GET_MODE_SIZE (inmode)
1019 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))))
1020 && INTEGRAL_MODE_P (GET_MODE (SUBREG_REG (in)))
1021 && LOAD_EXTEND_OP (GET_MODE (SUBREG_REG (in))) != UNKNOWN)
1022 #endif
1023 #ifdef WORD_REGISTER_OPERATIONS
1024 || ((GET_MODE_SIZE (inmode)
1025 < GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))))
1026 && ((GET_MODE_SIZE (inmode) - 1) / UNITS_PER_WORD ==
1027 ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))) - 1)
1028 / UNITS_PER_WORD)))
1029 #endif
1031 || (REG_P (SUBREG_REG (in))
1032 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
1033 /* The case where out is nonzero
1034 is handled differently in the following statement. */
1035 && (out == 0 || subreg_lowpart_p (in))
1036 && ((GET_MODE_SIZE (inmode) <= UNITS_PER_WORD
1037 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
1038 > UNITS_PER_WORD)
1039 && ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
1040 / UNITS_PER_WORD)
1041 != (int) hard_regno_nregs[REGNO (SUBREG_REG (in))]
1042 [GET_MODE (SUBREG_REG (in))]))
1043 || ! HARD_REGNO_MODE_OK (subreg_regno (in), inmode)))
1044 || (secondary_reload_class (1, class, inmode, in) != NO_REGS
1045 && (secondary_reload_class (1, class, GET_MODE (SUBREG_REG (in)),
1046 SUBREG_REG (in))
1047 == NO_REGS))
1048 #ifdef CANNOT_CHANGE_MODE_CLASS
1049 || (REG_P (SUBREG_REG (in))
1050 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
1051 && REG_CANNOT_CHANGE_MODE_P
1052 (REGNO (SUBREG_REG (in)), GET_MODE (SUBREG_REG (in)), inmode))
1053 #endif
1056 in_subreg_loc = inloc;
1057 inloc = &SUBREG_REG (in);
1058 in = *inloc;
1059 #if ! defined (LOAD_EXTEND_OP) && ! defined (WORD_REGISTER_OPERATIONS)
1060 if (MEM_P (in))
1061 /* This is supposed to happen only for paradoxical subregs made by
1062 combine.c. (SUBREG (MEM)) isn't supposed to occur other ways. */
1063 gcc_assert (GET_MODE_SIZE (GET_MODE (in)) <= GET_MODE_SIZE (inmode));
1064 #endif
1065 inmode = GET_MODE (in);
1068 /* Similar issue for (SUBREG:M1 (REG:M2 ...) ...) for a hard register R where
1069 either M1 is not valid for R or M2 is wider than a word but we only
1070 need one word to store an M2-sized quantity in R.
1072 However, we must reload the inner reg *as well as* the subreg in
1073 that case. */
1075 /* Similar issue for (SUBREG constant ...) if it was not handled by the
1076 code above. This can happen if SUBREG_BYTE != 0. */
1078 if (in != 0 && reload_inner_reg_of_subreg (in, inmode, 0))
1080 enum reg_class in_class = class;
1082 if (REG_P (SUBREG_REG (in)))
1083 in_class
1084 = find_valid_class (inmode, GET_MODE (SUBREG_REG (in)),
1085 subreg_regno_offset (REGNO (SUBREG_REG (in)),
1086 GET_MODE (SUBREG_REG (in)),
1087 SUBREG_BYTE (in),
1088 GET_MODE (in)),
1089 REGNO (SUBREG_REG (in)));
1091 /* This relies on the fact that emit_reload_insns outputs the
1092 instructions for input reloads of type RELOAD_OTHER in the same
1093 order as the reloads. Thus if the outer reload is also of type
1094 RELOAD_OTHER, we are guaranteed that this inner reload will be
1095 output before the outer reload. */
1096 push_reload (SUBREG_REG (in), NULL_RTX, &SUBREG_REG (in), (rtx *) 0,
1097 in_class, VOIDmode, VOIDmode, 0, 0, opnum, type);
1098 dont_remove_subreg = 1;
1101 /* Similarly for paradoxical and problematical SUBREGs on the output.
1102 Note that there is no reason we need worry about the previous value
1103 of SUBREG_REG (out); even if wider than out,
1104 storing in a subreg is entitled to clobber it all
1105 (except in the case of STRICT_LOW_PART,
1106 and in that case the constraint should label it input-output.) */
1107 if (out != 0 && GET_CODE (out) == SUBREG
1108 && (subreg_lowpart_p (out) || strict_low)
1109 #ifdef CANNOT_CHANGE_MODE_CLASS
1110 && !CANNOT_CHANGE_MODE_CLASS (GET_MODE (SUBREG_REG (out)), outmode, class)
1111 #endif
1112 && (CONSTANT_P (SUBREG_REG (out))
1113 || strict_low
1114 || (((REG_P (SUBREG_REG (out))
1115 && REGNO (SUBREG_REG (out)) >= FIRST_PSEUDO_REGISTER)
1116 || MEM_P (SUBREG_REG (out)))
1117 && ((GET_MODE_SIZE (outmode)
1118 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))))
1119 #ifdef WORD_REGISTER_OPERATIONS
1120 || ((GET_MODE_SIZE (outmode)
1121 < GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))))
1122 && ((GET_MODE_SIZE (outmode) - 1) / UNITS_PER_WORD ==
1123 ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))) - 1)
1124 / UNITS_PER_WORD)))
1125 #endif
1127 || (REG_P (SUBREG_REG (out))
1128 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1129 && ((GET_MODE_SIZE (outmode) <= UNITS_PER_WORD
1130 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (out)))
1131 > UNITS_PER_WORD)
1132 && ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (out)))
1133 / UNITS_PER_WORD)
1134 != (int) hard_regno_nregs[REGNO (SUBREG_REG (out))]
1135 [GET_MODE (SUBREG_REG (out))]))
1136 || ! HARD_REGNO_MODE_OK (subreg_regno (out), outmode)))
1137 || (secondary_reload_class (0, class, outmode, out) != NO_REGS
1138 && (secondary_reload_class (0, class, GET_MODE (SUBREG_REG (out)),
1139 SUBREG_REG (out))
1140 == NO_REGS))
1141 #ifdef CANNOT_CHANGE_MODE_CLASS
1142 || (REG_P (SUBREG_REG (out))
1143 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1144 && REG_CANNOT_CHANGE_MODE_P (REGNO (SUBREG_REG (out)),
1145 GET_MODE (SUBREG_REG (out)),
1146 outmode))
1147 #endif
1150 out_subreg_loc = outloc;
1151 outloc = &SUBREG_REG (out);
1152 out = *outloc;
1153 #if ! defined (LOAD_EXTEND_OP) && ! defined (WORD_REGISTER_OPERATIONS)
1154 gcc_assert (!MEM_P (out)
1155 || GET_MODE_SIZE (GET_MODE (out))
1156 <= GET_MODE_SIZE (outmode));
1157 #endif
1158 outmode = GET_MODE (out);
1161 /* Similar issue for (SUBREG:M1 (REG:M2 ...) ...) for a hard register R where
1162 either M1 is not valid for R or M2 is wider than a word but we only
1163 need one word to store an M2-sized quantity in R.
1165 However, we must reload the inner reg *as well as* the subreg in
1166 that case. In this case, the inner reg is an in-out reload. */
1168 if (out != 0 && reload_inner_reg_of_subreg (out, outmode, 1))
1170 /* This relies on the fact that emit_reload_insns outputs the
1171 instructions for output reloads of type RELOAD_OTHER in reverse
1172 order of the reloads. Thus if the outer reload is also of type
1173 RELOAD_OTHER, we are guaranteed that this inner reload will be
1174 output after the outer reload. */
1175 dont_remove_subreg = 1;
1176 push_reload (SUBREG_REG (out), SUBREG_REG (out), &SUBREG_REG (out),
1177 &SUBREG_REG (out),
1178 find_valid_class (outmode, GET_MODE (SUBREG_REG (out)),
1179 subreg_regno_offset (REGNO (SUBREG_REG (out)),
1180 GET_MODE (SUBREG_REG (out)),
1181 SUBREG_BYTE (out),
1182 GET_MODE (out)),
1183 REGNO (SUBREG_REG (out))),
1184 VOIDmode, VOIDmode, 0, 0,
1185 opnum, RELOAD_OTHER);
1188 /* If IN appears in OUT, we can't share any input-only reload for IN. */
1189 if (in != 0 && out != 0 && MEM_P (out)
1190 && (REG_P (in) || MEM_P (in) || GET_CODE (in) == PLUS)
1191 && reg_overlap_mentioned_for_reload_p (in, XEXP (out, 0)))
1192 dont_share = 1;
1194 /* If IN is a SUBREG of a hard register, make a new REG. This
1195 simplifies some of the cases below. */
1197 if (in != 0 && GET_CODE (in) == SUBREG && REG_P (SUBREG_REG (in))
1198 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
1199 && ! dont_remove_subreg)
1200 in = gen_rtx_REG (GET_MODE (in), subreg_regno (in));
1202 /* Similarly for OUT. */
1203 if (out != 0 && GET_CODE (out) == SUBREG
1204 && REG_P (SUBREG_REG (out))
1205 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1206 && ! dont_remove_subreg)
1207 out = gen_rtx_REG (GET_MODE (out), subreg_regno (out));
1209 /* Narrow down the class of register wanted if that is
1210 desirable on this machine for efficiency. */
1212 enum reg_class preferred_class = class;
1214 if (in != 0)
1215 preferred_class = PREFERRED_RELOAD_CLASS (in, class);
1217 /* Output reloads may need analogous treatment, different in detail. */
1218 #ifdef PREFERRED_OUTPUT_RELOAD_CLASS
1219 if (out != 0)
1220 preferred_class = PREFERRED_OUTPUT_RELOAD_CLASS (out, preferred_class);
1221 #endif
1223 /* Discard what the target said if we cannot do it. */
1224 if (preferred_class != NO_REGS
1225 || (optional && type == RELOAD_FOR_OUTPUT))
1226 class = preferred_class;
1229 /* Make sure we use a class that can handle the actual pseudo
1230 inside any subreg. For example, on the 386, QImode regs
1231 can appear within SImode subregs. Although GENERAL_REGS
1232 can handle SImode, QImode needs a smaller class. */
1233 #ifdef LIMIT_RELOAD_CLASS
1234 if (in_subreg_loc)
1235 class = LIMIT_RELOAD_CLASS (inmode, class);
1236 else if (in != 0 && GET_CODE (in) == SUBREG)
1237 class = LIMIT_RELOAD_CLASS (GET_MODE (SUBREG_REG (in)), class);
1239 if (out_subreg_loc)
1240 class = LIMIT_RELOAD_CLASS (outmode, class);
1241 if (out != 0 && GET_CODE (out) == SUBREG)
1242 class = LIMIT_RELOAD_CLASS (GET_MODE (SUBREG_REG (out)), class);
1243 #endif
1245 /* Verify that this class is at least possible for the mode that
1246 is specified. */
1247 if (this_insn_is_asm)
1249 enum machine_mode mode;
1250 if (GET_MODE_SIZE (inmode) > GET_MODE_SIZE (outmode))
1251 mode = inmode;
1252 else
1253 mode = outmode;
1254 if (mode == VOIDmode)
1256 error_for_asm (this_insn, "cannot reload integer constant "
1257 "operand in %<asm%>");
1258 mode = word_mode;
1259 if (in != 0)
1260 inmode = word_mode;
1261 if (out != 0)
1262 outmode = word_mode;
1264 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1265 if (HARD_REGNO_MODE_OK (i, mode)
1266 && in_hard_reg_set_p (reg_class_contents[(int) class], mode, i))
1267 break;
1268 if (i == FIRST_PSEUDO_REGISTER)
1270 error_for_asm (this_insn, "impossible register constraint "
1271 "in %<asm%>");
1272 /* Avoid further trouble with this insn. */
1273 PATTERN (this_insn) = gen_rtx_USE (VOIDmode, const0_rtx);
1274 /* We used to continue here setting class to ALL_REGS, but it triggers
1275 sanity check on i386 for:
1276 void foo(long double d)
1278 asm("" :: "a" (d));
1280 Returning zero here ought to be safe as we take care in
1281 find_reloads to not process the reloads when instruction was
1282 replaced by USE. */
1284 return 0;
1288 /* Optional output reloads are always OK even if we have no register class,
1289 since the function of these reloads is only to have spill_reg_store etc.
1290 set, so that the storing insn can be deleted later. */
1291 gcc_assert (class != NO_REGS
1292 || (optional != 0 && type == RELOAD_FOR_OUTPUT));
1294 i = find_reusable_reload (&in, out, class, type, opnum, dont_share);
1296 if (i == n_reloads)
1298 /* See if we need a secondary reload register to move between CLASS
1299 and IN or CLASS and OUT. Get the icode and push any required reloads
1300 needed for each of them if so. */
1302 if (in != 0)
1303 secondary_in_reload
1304 = push_secondary_reload (1, in, opnum, optional, class, inmode, type,
1305 &secondary_in_icode, NULL);
1306 if (out != 0 && GET_CODE (out) != SCRATCH)
1307 secondary_out_reload
1308 = push_secondary_reload (0, out, opnum, optional, class, outmode,
1309 type, &secondary_out_icode, NULL);
1311 /* We found no existing reload suitable for re-use.
1312 So add an additional reload. */
1314 #ifdef SECONDARY_MEMORY_NEEDED
1315 /* If a memory location is needed for the copy, make one. */
1316 if (in != 0
1317 && (REG_P (in)
1318 || (GET_CODE (in) == SUBREG && REG_P (SUBREG_REG (in))))
1319 && reg_or_subregno (in) < FIRST_PSEUDO_REGISTER
1320 && SECONDARY_MEMORY_NEEDED (REGNO_REG_CLASS (reg_or_subregno (in)),
1321 class, inmode))
1322 get_secondary_mem (in, inmode, opnum, type);
1323 #endif
1325 i = n_reloads;
1326 rld[i].in = in;
1327 rld[i].out = out;
1328 rld[i].class = class;
1329 rld[i].inmode = inmode;
1330 rld[i].outmode = outmode;
1331 rld[i].reg_rtx = 0;
1332 rld[i].optional = optional;
1333 rld[i].inc = 0;
1334 rld[i].nocombine = 0;
1335 rld[i].in_reg = inloc ? *inloc : 0;
1336 rld[i].out_reg = outloc ? *outloc : 0;
1337 rld[i].opnum = opnum;
1338 rld[i].when_needed = type;
1339 rld[i].secondary_in_reload = secondary_in_reload;
1340 rld[i].secondary_out_reload = secondary_out_reload;
1341 rld[i].secondary_in_icode = secondary_in_icode;
1342 rld[i].secondary_out_icode = secondary_out_icode;
1343 rld[i].secondary_p = 0;
1345 n_reloads++;
1347 #ifdef SECONDARY_MEMORY_NEEDED
1348 if (out != 0
1349 && (REG_P (out)
1350 || (GET_CODE (out) == SUBREG && REG_P (SUBREG_REG (out))))
1351 && reg_or_subregno (out) < FIRST_PSEUDO_REGISTER
1352 && SECONDARY_MEMORY_NEEDED (class,
1353 REGNO_REG_CLASS (reg_or_subregno (out)),
1354 outmode))
1355 get_secondary_mem (out, outmode, opnum, type);
1356 #endif
1358 else
1360 /* We are reusing an existing reload,
1361 but we may have additional information for it.
1362 For example, we may now have both IN and OUT
1363 while the old one may have just one of them. */
1365 /* The modes can be different. If they are, we want to reload in
1366 the larger mode, so that the value is valid for both modes. */
1367 if (inmode != VOIDmode
1368 && GET_MODE_SIZE (inmode) > GET_MODE_SIZE (rld[i].inmode))
1369 rld[i].inmode = inmode;
1370 if (outmode != VOIDmode
1371 && GET_MODE_SIZE (outmode) > GET_MODE_SIZE (rld[i].outmode))
1372 rld[i].outmode = outmode;
1373 if (in != 0)
1375 rtx in_reg = inloc ? *inloc : 0;
1376 /* If we merge reloads for two distinct rtl expressions that
1377 are identical in content, there might be duplicate address
1378 reloads. Remove the extra set now, so that if we later find
1379 that we can inherit this reload, we can get rid of the
1380 address reloads altogether.
1382 Do not do this if both reloads are optional since the result
1383 would be an optional reload which could potentially leave
1384 unresolved address replacements.
1386 It is not sufficient to call transfer_replacements since
1387 choose_reload_regs will remove the replacements for address
1388 reloads of inherited reloads which results in the same
1389 problem. */
1390 if (rld[i].in != in && rtx_equal_p (in, rld[i].in)
1391 && ! (rld[i].optional && optional))
1393 /* We must keep the address reload with the lower operand
1394 number alive. */
1395 if (opnum > rld[i].opnum)
1397 remove_address_replacements (in);
1398 in = rld[i].in;
1399 in_reg = rld[i].in_reg;
1401 else
1402 remove_address_replacements (rld[i].in);
1404 /* When emitting reloads we don't necessarily look at the in-
1405 and outmode, but also directly at the operands (in and out).
1406 So we can't simply overwrite them with whatever we have found
1407 for this (to-be-merged) reload, we have to "merge" that too.
1408 Reusing another reload already verified that we deal with the
1409 same operands, just possibly in different modes. So we
1410 overwrite the operands only when the new mode is larger.
1411 See also PR33613. */
1412 if (!rld[i].in
1413 || GET_MODE_SIZE (GET_MODE (in))
1414 > GET_MODE_SIZE (GET_MODE (rld[i].in)))
1415 rld[i].in = in;
1416 if (!rld[i].in_reg
1417 || (in_reg
1418 && GET_MODE_SIZE (GET_MODE (in_reg))
1419 > GET_MODE_SIZE (GET_MODE (rld[i].in_reg))))
1420 rld[i].in_reg = in_reg;
1422 if (out != 0)
1424 if (!rld[i].out
1425 || (out
1426 && GET_MODE_SIZE (GET_MODE (out))
1427 > GET_MODE_SIZE (GET_MODE (rld[i].out))))
1428 rld[i].out = out;
1429 if (outloc
1430 && (!rld[i].out_reg
1431 || GET_MODE_SIZE (GET_MODE (*outloc))
1432 > GET_MODE_SIZE (GET_MODE (rld[i].out_reg))))
1433 rld[i].out_reg = *outloc;
1435 if (reg_class_subset_p (class, rld[i].class))
1436 rld[i].class = class;
1437 rld[i].optional &= optional;
1438 if (MERGE_TO_OTHER (type, rld[i].when_needed,
1439 opnum, rld[i].opnum))
1440 rld[i].when_needed = RELOAD_OTHER;
1441 rld[i].opnum = MIN (rld[i].opnum, opnum);
1444 /* If the ostensible rtx being reloaded differs from the rtx found
1445 in the location to substitute, this reload is not safe to combine
1446 because we cannot reliably tell whether it appears in the insn. */
1448 if (in != 0 && in != *inloc)
1449 rld[i].nocombine = 1;
1451 #if 0
1452 /* This was replaced by changes in find_reloads_address_1 and the new
1453 function inc_for_reload, which go with a new meaning of reload_inc. */
1455 /* If this is an IN/OUT reload in an insn that sets the CC,
1456 it must be for an autoincrement. It doesn't work to store
1457 the incremented value after the insn because that would clobber the CC.
1458 So we must do the increment of the value reloaded from,
1459 increment it, store it back, then decrement again. */
1460 if (out != 0 && sets_cc0_p (PATTERN (this_insn)))
1462 out = 0;
1463 rld[i].out = 0;
1464 rld[i].inc = find_inc_amount (PATTERN (this_insn), in);
1465 /* If we did not find a nonzero amount-to-increment-by,
1466 that contradicts the belief that IN is being incremented
1467 in an address in this insn. */
1468 gcc_assert (rld[i].inc != 0);
1470 #endif
1472 /* If we will replace IN and OUT with the reload-reg,
1473 record where they are located so that substitution need
1474 not do a tree walk. */
1476 if (replace_reloads)
1478 if (inloc != 0)
1480 struct replacement *r = &replacements[n_replacements++];
1481 r->what = i;
1482 r->subreg_loc = in_subreg_loc;
1483 r->where = inloc;
1484 r->mode = inmode;
1486 if (outloc != 0 && outloc != inloc)
1488 struct replacement *r = &replacements[n_replacements++];
1489 r->what = i;
1490 r->where = outloc;
1491 r->subreg_loc = out_subreg_loc;
1492 r->mode = outmode;
1496 /* If this reload is just being introduced and it has both
1497 an incoming quantity and an outgoing quantity that are
1498 supposed to be made to match, see if either one of the two
1499 can serve as the place to reload into.
1501 If one of them is acceptable, set rld[i].reg_rtx
1502 to that one. */
1504 if (in != 0 && out != 0 && in != out && rld[i].reg_rtx == 0)
1506 rld[i].reg_rtx = find_dummy_reload (in, out, inloc, outloc,
1507 inmode, outmode,
1508 rld[i].class, i,
1509 earlyclobber_operand_p (out));
1511 /* If the outgoing register already contains the same value
1512 as the incoming one, we can dispense with loading it.
1513 The easiest way to tell the caller that is to give a phony
1514 value for the incoming operand (same as outgoing one). */
1515 if (rld[i].reg_rtx == out
1516 && (REG_P (in) || CONSTANT_P (in))
1517 && 0 != find_equiv_reg (in, this_insn, 0, REGNO (out),
1518 static_reload_reg_p, i, inmode))
1519 rld[i].in = out;
1522 /* If this is an input reload and the operand contains a register that
1523 dies in this insn and is used nowhere else, see if it is the right class
1524 to be used for this reload. Use it if so. (This occurs most commonly
1525 in the case of paradoxical SUBREGs and in-out reloads). We cannot do
1526 this if it is also an output reload that mentions the register unless
1527 the output is a SUBREG that clobbers an entire register.
1529 Note that the operand might be one of the spill regs, if it is a
1530 pseudo reg and we are in a block where spilling has not taken place.
1531 But if there is no spilling in this block, that is OK.
1532 An explicitly used hard reg cannot be a spill reg. */
1534 if (rld[i].reg_rtx == 0 && in != 0 && hard_regs_live_known)
1536 rtx note;
1537 int regno;
1538 enum machine_mode rel_mode = inmode;
1540 if (out && GET_MODE_SIZE (outmode) > GET_MODE_SIZE (inmode))
1541 rel_mode = outmode;
1543 for (note = REG_NOTES (this_insn); note; note = XEXP (note, 1))
1544 if (REG_NOTE_KIND (note) == REG_DEAD
1545 && REG_P (XEXP (note, 0))
1546 && (regno = REGNO (XEXP (note, 0))) < FIRST_PSEUDO_REGISTER
1547 && reg_mentioned_p (XEXP (note, 0), in)
1548 /* Check that a former pseudo is valid; see find_dummy_reload. */
1549 && (ORIGINAL_REGNO (XEXP (note, 0)) < FIRST_PSEUDO_REGISTER
1550 || (!bitmap_bit_p (DF_LIVE_OUT (ENTRY_BLOCK_PTR),
1551 ORIGINAL_REGNO (XEXP (note, 0)))
1552 && hard_regno_nregs[regno][GET_MODE (XEXP (note, 0))] == 1))
1553 && ! refers_to_regno_for_reload_p (regno,
1554 end_hard_regno (rel_mode,
1555 regno),
1556 PATTERN (this_insn), inloc)
1557 /* If this is also an output reload, IN cannot be used as
1558 the reload register if it is set in this insn unless IN
1559 is also OUT. */
1560 && (out == 0 || in == out
1561 || ! hard_reg_set_here_p (regno,
1562 end_hard_regno (rel_mode, regno),
1563 PATTERN (this_insn)))
1564 /* ??? Why is this code so different from the previous?
1565 Is there any simple coherent way to describe the two together?
1566 What's going on here. */
1567 && (in != out
1568 || (GET_CODE (in) == SUBREG
1569 && (((GET_MODE_SIZE (GET_MODE (in)) + (UNITS_PER_WORD - 1))
1570 / UNITS_PER_WORD)
1571 == ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
1572 + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD))))
1573 /* Make sure the operand fits in the reg that dies. */
1574 && (GET_MODE_SIZE (rel_mode)
1575 <= GET_MODE_SIZE (GET_MODE (XEXP (note, 0))))
1576 && HARD_REGNO_MODE_OK (regno, inmode)
1577 && HARD_REGNO_MODE_OK (regno, outmode))
1579 unsigned int offs;
1580 unsigned int nregs = MAX (hard_regno_nregs[regno][inmode],
1581 hard_regno_nregs[regno][outmode]);
1583 for (offs = 0; offs < nregs; offs++)
1584 if (fixed_regs[regno + offs]
1585 || ! TEST_HARD_REG_BIT (reg_class_contents[(int) class],
1586 regno + offs))
1587 break;
1589 if (offs == nregs
1590 && (! (refers_to_regno_for_reload_p
1591 (regno, end_hard_regno (inmode, regno), in, (rtx *) 0))
1592 || can_reload_into (in, regno, inmode)))
1594 rld[i].reg_rtx = gen_rtx_REG (rel_mode, regno);
1595 break;
1600 if (out)
1601 output_reloadnum = i;
1603 return i;
1606 /* Record an additional place we must replace a value
1607 for which we have already recorded a reload.
1608 RELOADNUM is the value returned by push_reload
1609 when the reload was recorded.
1610 This is used in insn patterns that use match_dup. */
1612 static void
1613 push_replacement (rtx *loc, int reloadnum, enum machine_mode mode)
1615 if (replace_reloads)
1617 struct replacement *r = &replacements[n_replacements++];
1618 r->what = reloadnum;
1619 r->where = loc;
1620 r->subreg_loc = 0;
1621 r->mode = mode;
1625 /* Duplicate any replacement we have recorded to apply at
1626 location ORIG_LOC to also be performed at DUP_LOC.
1627 This is used in insn patterns that use match_dup. */
1629 static void
1630 dup_replacements (rtx *dup_loc, rtx *orig_loc)
1632 int i, n = n_replacements;
1634 for (i = 0; i < n; i++)
1636 struct replacement *r = &replacements[i];
1637 if (r->where == orig_loc)
1638 push_replacement (dup_loc, r->what, r->mode);
1642 /* Transfer all replacements that used to be in reload FROM to be in
1643 reload TO. */
1645 void
1646 transfer_replacements (int to, int from)
1648 int i;
1650 for (i = 0; i < n_replacements; i++)
1651 if (replacements[i].what == from)
1652 replacements[i].what = to;
1655 /* IN_RTX is the value loaded by a reload that we now decided to inherit,
1656 or a subpart of it. If we have any replacements registered for IN_RTX,
1657 cancel the reloads that were supposed to load them.
1658 Return nonzero if we canceled any reloads. */
1660 remove_address_replacements (rtx in_rtx)
1662 int i, j;
1663 char reload_flags[MAX_RELOADS];
1664 int something_changed = 0;
1666 memset (reload_flags, 0, sizeof reload_flags);
1667 for (i = 0, j = 0; i < n_replacements; i++)
1669 if (loc_mentioned_in_p (replacements[i].where, in_rtx))
1670 reload_flags[replacements[i].what] |= 1;
1671 else
1673 replacements[j++] = replacements[i];
1674 reload_flags[replacements[i].what] |= 2;
1677 /* Note that the following store must be done before the recursive calls. */
1678 n_replacements = j;
1680 for (i = n_reloads - 1; i >= 0; i--)
1682 if (reload_flags[i] == 1)
1684 deallocate_reload_reg (i);
1685 remove_address_replacements (rld[i].in);
1686 rld[i].in = 0;
1687 something_changed = 1;
1690 return something_changed;
1693 /* If there is only one output reload, and it is not for an earlyclobber
1694 operand, try to combine it with a (logically unrelated) input reload
1695 to reduce the number of reload registers needed.
1697 This is safe if the input reload does not appear in
1698 the value being output-reloaded, because this implies
1699 it is not needed any more once the original insn completes.
1701 If that doesn't work, see we can use any of the registers that
1702 die in this insn as a reload register. We can if it is of the right
1703 class and does not appear in the value being output-reloaded. */
1705 static void
1706 combine_reloads (void)
1708 int i, regno;
1709 int output_reload = -1;
1710 int secondary_out = -1;
1711 rtx note;
1713 /* Find the output reload; return unless there is exactly one
1714 and that one is mandatory. */
1716 for (i = 0; i < n_reloads; i++)
1717 if (rld[i].out != 0)
1719 if (output_reload >= 0)
1720 return;
1721 output_reload = i;
1724 if (output_reload < 0 || rld[output_reload].optional)
1725 return;
1727 /* An input-output reload isn't combinable. */
1729 if (rld[output_reload].in != 0)
1730 return;
1732 /* If this reload is for an earlyclobber operand, we can't do anything. */
1733 if (earlyclobber_operand_p (rld[output_reload].out))
1734 return;
1736 /* If there is a reload for part of the address of this operand, we would
1737 need to change it to RELOAD_FOR_OTHER_ADDRESS. But that would extend
1738 its life to the point where doing this combine would not lower the
1739 number of spill registers needed. */
1740 for (i = 0; i < n_reloads; i++)
1741 if ((rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
1742 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
1743 && rld[i].opnum == rld[output_reload].opnum)
1744 return;
1746 /* Check each input reload; can we combine it? */
1748 for (i = 0; i < n_reloads; i++)
1749 if (rld[i].in && ! rld[i].optional && ! rld[i].nocombine
1750 /* Life span of this reload must not extend past main insn. */
1751 && rld[i].when_needed != RELOAD_FOR_OUTPUT_ADDRESS
1752 && rld[i].when_needed != RELOAD_FOR_OUTADDR_ADDRESS
1753 && rld[i].when_needed != RELOAD_OTHER
1754 && (CLASS_MAX_NREGS (rld[i].class, rld[i].inmode)
1755 == CLASS_MAX_NREGS (rld[output_reload].class,
1756 rld[output_reload].outmode))
1757 && rld[i].inc == 0
1758 && rld[i].reg_rtx == 0
1759 #ifdef SECONDARY_MEMORY_NEEDED
1760 /* Don't combine two reloads with different secondary
1761 memory locations. */
1762 && (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum] == 0
1763 || secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum] == 0
1764 || rtx_equal_p (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum],
1765 secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum]))
1766 #endif
1767 && (SMALL_REGISTER_CLASSES
1768 ? (rld[i].class == rld[output_reload].class)
1769 : (reg_class_subset_p (rld[i].class,
1770 rld[output_reload].class)
1771 || reg_class_subset_p (rld[output_reload].class,
1772 rld[i].class)))
1773 && (MATCHES (rld[i].in, rld[output_reload].out)
1774 /* Args reversed because the first arg seems to be
1775 the one that we imagine being modified
1776 while the second is the one that might be affected. */
1777 || (! reg_overlap_mentioned_for_reload_p (rld[output_reload].out,
1778 rld[i].in)
1779 /* However, if the input is a register that appears inside
1780 the output, then we also can't share.
1781 Imagine (set (mem (reg 69)) (plus (reg 69) ...)).
1782 If the same reload reg is used for both reg 69 and the
1783 result to be stored in memory, then that result
1784 will clobber the address of the memory ref. */
1785 && ! (REG_P (rld[i].in)
1786 && reg_overlap_mentioned_for_reload_p (rld[i].in,
1787 rld[output_reload].out))))
1788 && ! reload_inner_reg_of_subreg (rld[i].in, rld[i].inmode,
1789 rld[i].when_needed != RELOAD_FOR_INPUT)
1790 && (reg_class_size[(int) rld[i].class]
1791 || SMALL_REGISTER_CLASSES)
1792 /* We will allow making things slightly worse by combining an
1793 input and an output, but no worse than that. */
1794 && (rld[i].when_needed == RELOAD_FOR_INPUT
1795 || rld[i].when_needed == RELOAD_FOR_OUTPUT))
1797 int j;
1799 /* We have found a reload to combine with! */
1800 rld[i].out = rld[output_reload].out;
1801 rld[i].out_reg = rld[output_reload].out_reg;
1802 rld[i].outmode = rld[output_reload].outmode;
1803 /* Mark the old output reload as inoperative. */
1804 rld[output_reload].out = 0;
1805 /* The combined reload is needed for the entire insn. */
1806 rld[i].when_needed = RELOAD_OTHER;
1807 /* If the output reload had a secondary reload, copy it. */
1808 if (rld[output_reload].secondary_out_reload != -1)
1810 rld[i].secondary_out_reload
1811 = rld[output_reload].secondary_out_reload;
1812 rld[i].secondary_out_icode
1813 = rld[output_reload].secondary_out_icode;
1816 #ifdef SECONDARY_MEMORY_NEEDED
1817 /* Copy any secondary MEM. */
1818 if (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum] != 0)
1819 secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum]
1820 = secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum];
1821 #endif
1822 /* If required, minimize the register class. */
1823 if (reg_class_subset_p (rld[output_reload].class,
1824 rld[i].class))
1825 rld[i].class = rld[output_reload].class;
1827 /* Transfer all replacements from the old reload to the combined. */
1828 for (j = 0; j < n_replacements; j++)
1829 if (replacements[j].what == output_reload)
1830 replacements[j].what = i;
1832 return;
1835 /* If this insn has only one operand that is modified or written (assumed
1836 to be the first), it must be the one corresponding to this reload. It
1837 is safe to use anything that dies in this insn for that output provided
1838 that it does not occur in the output (we already know it isn't an
1839 earlyclobber. If this is an asm insn, give up. */
1841 if (INSN_CODE (this_insn) == -1)
1842 return;
1844 for (i = 1; i < insn_data[INSN_CODE (this_insn)].n_operands; i++)
1845 if (insn_data[INSN_CODE (this_insn)].operand[i].constraint[0] == '='
1846 || insn_data[INSN_CODE (this_insn)].operand[i].constraint[0] == '+')
1847 return;
1849 /* See if some hard register that dies in this insn and is not used in
1850 the output is the right class. Only works if the register we pick
1851 up can fully hold our output reload. */
1852 for (note = REG_NOTES (this_insn); note; note = XEXP (note, 1))
1853 if (REG_NOTE_KIND (note) == REG_DEAD
1854 && REG_P (XEXP (note, 0))
1855 && !reg_overlap_mentioned_for_reload_p (XEXP (note, 0),
1856 rld[output_reload].out)
1857 && (regno = REGNO (XEXP (note, 0))) < FIRST_PSEUDO_REGISTER
1858 && HARD_REGNO_MODE_OK (regno, rld[output_reload].outmode)
1859 && TEST_HARD_REG_BIT (reg_class_contents[(int) rld[output_reload].class],
1860 regno)
1861 && (hard_regno_nregs[regno][rld[output_reload].outmode]
1862 <= hard_regno_nregs[regno][GET_MODE (XEXP (note, 0))])
1863 /* Ensure that a secondary or tertiary reload for this output
1864 won't want this register. */
1865 && ((secondary_out = rld[output_reload].secondary_out_reload) == -1
1866 || (!(TEST_HARD_REG_BIT
1867 (reg_class_contents[(int) rld[secondary_out].class], regno))
1868 && ((secondary_out = rld[secondary_out].secondary_out_reload) == -1
1869 || !(TEST_HARD_REG_BIT
1870 (reg_class_contents[(int) rld[secondary_out].class],
1871 regno)))))
1872 && !fixed_regs[regno]
1873 /* Check that a former pseudo is valid; see find_dummy_reload. */
1874 && (ORIGINAL_REGNO (XEXP (note, 0)) < FIRST_PSEUDO_REGISTER
1875 || (!bitmap_bit_p (DF_LR_OUT (ENTRY_BLOCK_PTR),
1876 ORIGINAL_REGNO (XEXP (note, 0)))
1877 && hard_regno_nregs[regno][GET_MODE (XEXP (note, 0))] == 1)))
1879 rld[output_reload].reg_rtx
1880 = gen_rtx_REG (rld[output_reload].outmode, regno);
1881 return;
1885 /* Try to find a reload register for an in-out reload (expressions IN and OUT).
1886 See if one of IN and OUT is a register that may be used;
1887 this is desirable since a spill-register won't be needed.
1888 If so, return the register rtx that proves acceptable.
1890 INLOC and OUTLOC are locations where IN and OUT appear in the insn.
1891 CLASS is the register class required for the reload.
1893 If FOR_REAL is >= 0, it is the number of the reload,
1894 and in some cases when it can be discovered that OUT doesn't need
1895 to be computed, clear out rld[FOR_REAL].out.
1897 If FOR_REAL is -1, this should not be done, because this call
1898 is just to see if a register can be found, not to find and install it.
1900 EARLYCLOBBER is nonzero if OUT is an earlyclobber operand. This
1901 puts an additional constraint on being able to use IN for OUT since
1902 IN must not appear elsewhere in the insn (it is assumed that IN itself
1903 is safe from the earlyclobber). */
1905 static rtx
1906 find_dummy_reload (rtx real_in, rtx real_out, rtx *inloc, rtx *outloc,
1907 enum machine_mode inmode, enum machine_mode outmode,
1908 enum reg_class class, int for_real, int earlyclobber)
1910 rtx in = real_in;
1911 rtx out = real_out;
1912 int in_offset = 0;
1913 int out_offset = 0;
1914 rtx value = 0;
1916 /* If operands exceed a word, we can't use either of them
1917 unless they have the same size. */
1918 if (GET_MODE_SIZE (outmode) != GET_MODE_SIZE (inmode)
1919 && (GET_MODE_SIZE (outmode) > UNITS_PER_WORD
1920 || GET_MODE_SIZE (inmode) > UNITS_PER_WORD))
1921 return 0;
1923 /* Note that {in,out}_offset are needed only when 'in' or 'out'
1924 respectively refers to a hard register. */
1926 /* Find the inside of any subregs. */
1927 while (GET_CODE (out) == SUBREG)
1929 if (REG_P (SUBREG_REG (out))
1930 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER)
1931 out_offset += subreg_regno_offset (REGNO (SUBREG_REG (out)),
1932 GET_MODE (SUBREG_REG (out)),
1933 SUBREG_BYTE (out),
1934 GET_MODE (out));
1935 out = SUBREG_REG (out);
1937 while (GET_CODE (in) == SUBREG)
1939 if (REG_P (SUBREG_REG (in))
1940 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER)
1941 in_offset += subreg_regno_offset (REGNO (SUBREG_REG (in)),
1942 GET_MODE (SUBREG_REG (in)),
1943 SUBREG_BYTE (in),
1944 GET_MODE (in));
1945 in = SUBREG_REG (in);
1948 /* Narrow down the reg class, the same way push_reload will;
1949 otherwise we might find a dummy now, but push_reload won't. */
1951 enum reg_class preferred_class = PREFERRED_RELOAD_CLASS (in, class);
1952 if (preferred_class != NO_REGS)
1953 class = preferred_class;
1956 /* See if OUT will do. */
1957 if (REG_P (out)
1958 && REGNO (out) < FIRST_PSEUDO_REGISTER)
1960 unsigned int regno = REGNO (out) + out_offset;
1961 unsigned int nwords = hard_regno_nregs[regno][outmode];
1962 rtx saved_rtx;
1964 /* When we consider whether the insn uses OUT,
1965 ignore references within IN. They don't prevent us
1966 from copying IN into OUT, because those refs would
1967 move into the insn that reloads IN.
1969 However, we only ignore IN in its role as this reload.
1970 If the insn uses IN elsewhere and it contains OUT,
1971 that counts. We can't be sure it's the "same" operand
1972 so it might not go through this reload. */
1973 saved_rtx = *inloc;
1974 *inloc = const0_rtx;
1976 if (regno < FIRST_PSEUDO_REGISTER
1977 && HARD_REGNO_MODE_OK (regno, outmode)
1978 && ! refers_to_regno_for_reload_p (regno, regno + nwords,
1979 PATTERN (this_insn), outloc))
1981 unsigned int i;
1983 for (i = 0; i < nwords; i++)
1984 if (! TEST_HARD_REG_BIT (reg_class_contents[(int) class],
1985 regno + i))
1986 break;
1988 if (i == nwords)
1990 if (REG_P (real_out))
1991 value = real_out;
1992 else
1993 value = gen_rtx_REG (outmode, regno);
1997 *inloc = saved_rtx;
2000 /* Consider using IN if OUT was not acceptable
2001 or if OUT dies in this insn (like the quotient in a divmod insn).
2002 We can't use IN unless it is dies in this insn,
2003 which means we must know accurately which hard regs are live.
2004 Also, the result can't go in IN if IN is used within OUT,
2005 or if OUT is an earlyclobber and IN appears elsewhere in the insn. */
2006 if (hard_regs_live_known
2007 && REG_P (in)
2008 && REGNO (in) < FIRST_PSEUDO_REGISTER
2009 && (value == 0
2010 || find_reg_note (this_insn, REG_UNUSED, real_out))
2011 && find_reg_note (this_insn, REG_DEAD, real_in)
2012 && !fixed_regs[REGNO (in)]
2013 && HARD_REGNO_MODE_OK (REGNO (in),
2014 /* The only case where out and real_out might
2015 have different modes is where real_out
2016 is a subreg, and in that case, out
2017 has a real mode. */
2018 (GET_MODE (out) != VOIDmode
2019 ? GET_MODE (out) : outmode))
2020 && (ORIGINAL_REGNO (in) < FIRST_PSEUDO_REGISTER
2021 /* However only do this if we can be sure that this input
2022 operand doesn't correspond with an uninitialized pseudo.
2023 global can assign some hardreg to it that is the same as
2024 the one assigned to a different, also live pseudo (as it
2025 can ignore the conflict). We must never introduce writes
2026 to such hardregs, as they would clobber the other live
2027 pseudo. See PR 20973. */
2028 || (!bitmap_bit_p (DF_LIVE_OUT (ENTRY_BLOCK_PTR),
2029 ORIGINAL_REGNO (in))
2030 /* Similarly, only do this if we can be sure that the death
2031 note is still valid. global can assign some hardreg to
2032 the pseudo referenced in the note and simultaneously a
2033 subword of this hardreg to a different, also live pseudo,
2034 because only another subword of the hardreg is actually
2035 used in the insn. This cannot happen if the pseudo has
2036 been assigned exactly one hardreg. See PR 33732. */
2037 && hard_regno_nregs[REGNO (in)][GET_MODE (in)] == 1)))
2039 unsigned int regno = REGNO (in) + in_offset;
2040 unsigned int nwords = hard_regno_nregs[regno][inmode];
2042 if (! refers_to_regno_for_reload_p (regno, regno + nwords, out, (rtx*) 0)
2043 && ! hard_reg_set_here_p (regno, regno + nwords,
2044 PATTERN (this_insn))
2045 && (! earlyclobber
2046 || ! refers_to_regno_for_reload_p (regno, regno + nwords,
2047 PATTERN (this_insn), inloc)))
2049 unsigned int i;
2051 for (i = 0; i < nwords; i++)
2052 if (! TEST_HARD_REG_BIT (reg_class_contents[(int) class],
2053 regno + i))
2054 break;
2056 if (i == nwords)
2058 /* If we were going to use OUT as the reload reg
2059 and changed our mind, it means OUT is a dummy that
2060 dies here. So don't bother copying value to it. */
2061 if (for_real >= 0 && value == real_out)
2062 rld[for_real].out = 0;
2063 if (REG_P (real_in))
2064 value = real_in;
2065 else
2066 value = gen_rtx_REG (inmode, regno);
2071 return value;
2074 /* This page contains subroutines used mainly for determining
2075 whether the IN or an OUT of a reload can serve as the
2076 reload register. */
2078 /* Return 1 if X is an operand of an insn that is being earlyclobbered. */
2081 earlyclobber_operand_p (rtx x)
2083 int i;
2085 for (i = 0; i < n_earlyclobbers; i++)
2086 if (reload_earlyclobbers[i] == x)
2087 return 1;
2089 return 0;
2092 /* Return 1 if expression X alters a hard reg in the range
2093 from BEG_REGNO (inclusive) to END_REGNO (exclusive),
2094 either explicitly or in the guise of a pseudo-reg allocated to REGNO.
2095 X should be the body of an instruction. */
2097 static int
2098 hard_reg_set_here_p (unsigned int beg_regno, unsigned int end_regno, rtx x)
2100 if (GET_CODE (x) == SET || GET_CODE (x) == CLOBBER)
2102 rtx op0 = SET_DEST (x);
2104 while (GET_CODE (op0) == SUBREG)
2105 op0 = SUBREG_REG (op0);
2106 if (REG_P (op0))
2108 unsigned int r = REGNO (op0);
2110 /* See if this reg overlaps range under consideration. */
2111 if (r < end_regno
2112 && end_hard_regno (GET_MODE (op0), r) > beg_regno)
2113 return 1;
2116 else if (GET_CODE (x) == PARALLEL)
2118 int i = XVECLEN (x, 0) - 1;
2120 for (; i >= 0; i--)
2121 if (hard_reg_set_here_p (beg_regno, end_regno, XVECEXP (x, 0, i)))
2122 return 1;
2125 return 0;
2128 /* Return 1 if ADDR is a valid memory address for mode MODE,
2129 and check that each pseudo reg has the proper kind of
2130 hard reg. */
2133 strict_memory_address_p (enum machine_mode mode ATTRIBUTE_UNUSED, rtx addr)
2135 GO_IF_LEGITIMATE_ADDRESS (mode, addr, win);
2136 return 0;
2138 win:
2139 return 1;
2142 /* Like rtx_equal_p except that it allows a REG and a SUBREG to match
2143 if they are the same hard reg, and has special hacks for
2144 autoincrement and autodecrement.
2145 This is specifically intended for find_reloads to use
2146 in determining whether two operands match.
2147 X is the operand whose number is the lower of the two.
2149 The value is 2 if Y contains a pre-increment that matches
2150 a non-incrementing address in X. */
2152 /* ??? To be completely correct, we should arrange to pass
2153 for X the output operand and for Y the input operand.
2154 For now, we assume that the output operand has the lower number
2155 because that is natural in (SET output (... input ...)). */
2158 operands_match_p (rtx x, rtx y)
2160 int i;
2161 RTX_CODE code = GET_CODE (x);
2162 const char *fmt;
2163 int success_2;
2165 if (x == y)
2166 return 1;
2167 if ((code == REG || (code == SUBREG && REG_P (SUBREG_REG (x))))
2168 && (REG_P (y) || (GET_CODE (y) == SUBREG
2169 && REG_P (SUBREG_REG (y)))))
2171 int j;
2173 if (code == SUBREG)
2175 i = REGNO (SUBREG_REG (x));
2176 if (i >= FIRST_PSEUDO_REGISTER)
2177 goto slow;
2178 i += subreg_regno_offset (REGNO (SUBREG_REG (x)),
2179 GET_MODE (SUBREG_REG (x)),
2180 SUBREG_BYTE (x),
2181 GET_MODE (x));
2183 else
2184 i = REGNO (x);
2186 if (GET_CODE (y) == SUBREG)
2188 j = REGNO (SUBREG_REG (y));
2189 if (j >= FIRST_PSEUDO_REGISTER)
2190 goto slow;
2191 j += subreg_regno_offset (REGNO (SUBREG_REG (y)),
2192 GET_MODE (SUBREG_REG (y)),
2193 SUBREG_BYTE (y),
2194 GET_MODE (y));
2196 else
2197 j = REGNO (y);
2199 /* On a WORDS_BIG_ENDIAN machine, point to the last register of a
2200 multiple hard register group of scalar integer registers, so that
2201 for example (reg:DI 0) and (reg:SI 1) will be considered the same
2202 register. */
2203 if (WORDS_BIG_ENDIAN && GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD
2204 && SCALAR_INT_MODE_P (GET_MODE (x))
2205 && i < FIRST_PSEUDO_REGISTER)
2206 i += hard_regno_nregs[i][GET_MODE (x)] - 1;
2207 if (WORDS_BIG_ENDIAN && GET_MODE_SIZE (GET_MODE (y)) > UNITS_PER_WORD
2208 && SCALAR_INT_MODE_P (GET_MODE (y))
2209 && j < FIRST_PSEUDO_REGISTER)
2210 j += hard_regno_nregs[j][GET_MODE (y)] - 1;
2212 return i == j;
2214 /* If two operands must match, because they are really a single
2215 operand of an assembler insn, then two postincrements are invalid
2216 because the assembler insn would increment only once.
2217 On the other hand, a postincrement matches ordinary indexing
2218 if the postincrement is the output operand. */
2219 if (code == POST_DEC || code == POST_INC || code == POST_MODIFY)
2220 return operands_match_p (XEXP (x, 0), y);
2221 /* Two preincrements are invalid
2222 because the assembler insn would increment only once.
2223 On the other hand, a preincrement matches ordinary indexing
2224 if the preincrement is the input operand.
2225 In this case, return 2, since some callers need to do special
2226 things when this happens. */
2227 if (GET_CODE (y) == PRE_DEC || GET_CODE (y) == PRE_INC
2228 || GET_CODE (y) == PRE_MODIFY)
2229 return operands_match_p (x, XEXP (y, 0)) ? 2 : 0;
2231 slow:
2233 /* Now we have disposed of all the cases in which different rtx codes
2234 can match. */
2235 if (code != GET_CODE (y))
2236 return 0;
2238 /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. */
2239 if (GET_MODE (x) != GET_MODE (y))
2240 return 0;
2242 switch (code)
2244 case CONST_INT:
2245 case CONST_DOUBLE:
2246 case CONST_FIXED:
2247 return 0;
2249 case LABEL_REF:
2250 return XEXP (x, 0) == XEXP (y, 0);
2251 case SYMBOL_REF:
2252 return XSTR (x, 0) == XSTR (y, 0);
2254 default:
2255 break;
2258 /* Compare the elements. If any pair of corresponding elements
2259 fail to match, return 0 for the whole things. */
2261 success_2 = 0;
2262 fmt = GET_RTX_FORMAT (code);
2263 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2265 int val, j;
2266 switch (fmt[i])
2268 case 'w':
2269 if (XWINT (x, i) != XWINT (y, i))
2270 return 0;
2271 break;
2273 case 'i':
2274 if (XINT (x, i) != XINT (y, i))
2275 return 0;
2276 break;
2278 case 'e':
2279 val = operands_match_p (XEXP (x, i), XEXP (y, i));
2280 if (val == 0)
2281 return 0;
2282 /* If any subexpression returns 2,
2283 we should return 2 if we are successful. */
2284 if (val == 2)
2285 success_2 = 1;
2286 break;
2288 case '0':
2289 break;
2291 case 'E':
2292 if (XVECLEN (x, i) != XVECLEN (y, i))
2293 return 0;
2294 for (j = XVECLEN (x, i) - 1; j >= 0; --j)
2296 val = operands_match_p (XVECEXP (x, i, j), XVECEXP (y, i, j));
2297 if (val == 0)
2298 return 0;
2299 if (val == 2)
2300 success_2 = 1;
2302 break;
2304 /* It is believed that rtx's at this level will never
2305 contain anything but integers and other rtx's,
2306 except for within LABEL_REFs and SYMBOL_REFs. */
2307 default:
2308 gcc_unreachable ();
2311 return 1 + success_2;
2314 /* Describe the range of registers or memory referenced by X.
2315 If X is a register, set REG_FLAG and put the first register
2316 number into START and the last plus one into END.
2317 If X is a memory reference, put a base address into BASE
2318 and a range of integer offsets into START and END.
2319 If X is pushing on the stack, we can assume it causes no trouble,
2320 so we set the SAFE field. */
2322 static struct decomposition
2323 decompose (rtx x)
2325 struct decomposition val;
2326 int all_const = 0;
2328 memset (&val, 0, sizeof (val));
2330 switch (GET_CODE (x))
2332 case MEM:
2334 rtx base = NULL_RTX, offset = 0;
2335 rtx addr = XEXP (x, 0);
2337 if (GET_CODE (addr) == PRE_DEC || GET_CODE (addr) == PRE_INC
2338 || GET_CODE (addr) == POST_DEC || GET_CODE (addr) == POST_INC)
2340 val.base = XEXP (addr, 0);
2341 val.start = -GET_MODE_SIZE (GET_MODE (x));
2342 val.end = GET_MODE_SIZE (GET_MODE (x));
2343 val.safe = REGNO (val.base) == STACK_POINTER_REGNUM;
2344 return val;
2347 if (GET_CODE (addr) == PRE_MODIFY || GET_CODE (addr) == POST_MODIFY)
2349 if (GET_CODE (XEXP (addr, 1)) == PLUS
2350 && XEXP (addr, 0) == XEXP (XEXP (addr, 1), 0)
2351 && CONSTANT_P (XEXP (XEXP (addr, 1), 1)))
2353 val.base = XEXP (addr, 0);
2354 val.start = -INTVAL (XEXP (XEXP (addr, 1), 1));
2355 val.end = INTVAL (XEXP (XEXP (addr, 1), 1));
2356 val.safe = REGNO (val.base) == STACK_POINTER_REGNUM;
2357 return val;
2361 if (GET_CODE (addr) == CONST)
2363 addr = XEXP (addr, 0);
2364 all_const = 1;
2366 if (GET_CODE (addr) == PLUS)
2368 if (CONSTANT_P (XEXP (addr, 0)))
2370 base = XEXP (addr, 1);
2371 offset = XEXP (addr, 0);
2373 else if (CONSTANT_P (XEXP (addr, 1)))
2375 base = XEXP (addr, 0);
2376 offset = XEXP (addr, 1);
2380 if (offset == 0)
2382 base = addr;
2383 offset = const0_rtx;
2385 if (GET_CODE (offset) == CONST)
2386 offset = XEXP (offset, 0);
2387 if (GET_CODE (offset) == PLUS)
2389 if (GET_CODE (XEXP (offset, 0)) == CONST_INT)
2391 base = gen_rtx_PLUS (GET_MODE (base), base, XEXP (offset, 1));
2392 offset = XEXP (offset, 0);
2394 else if (GET_CODE (XEXP (offset, 1)) == CONST_INT)
2396 base = gen_rtx_PLUS (GET_MODE (base), base, XEXP (offset, 0));
2397 offset = XEXP (offset, 1);
2399 else
2401 base = gen_rtx_PLUS (GET_MODE (base), base, offset);
2402 offset = const0_rtx;
2405 else if (GET_CODE (offset) != CONST_INT)
2407 base = gen_rtx_PLUS (GET_MODE (base), base, offset);
2408 offset = const0_rtx;
2411 if (all_const && GET_CODE (base) == PLUS)
2412 base = gen_rtx_CONST (GET_MODE (base), base);
2414 gcc_assert (GET_CODE (offset) == CONST_INT);
2416 val.start = INTVAL (offset);
2417 val.end = val.start + GET_MODE_SIZE (GET_MODE (x));
2418 val.base = base;
2420 break;
2422 case REG:
2423 val.reg_flag = 1;
2424 val.start = true_regnum (x);
2425 if (val.start < 0 || val.start >= FIRST_PSEUDO_REGISTER)
2427 /* A pseudo with no hard reg. */
2428 val.start = REGNO (x);
2429 val.end = val.start + 1;
2431 else
2432 /* A hard reg. */
2433 val.end = end_hard_regno (GET_MODE (x), val.start);
2434 break;
2436 case SUBREG:
2437 if (!REG_P (SUBREG_REG (x)))
2438 /* This could be more precise, but it's good enough. */
2439 return decompose (SUBREG_REG (x));
2440 val.reg_flag = 1;
2441 val.start = true_regnum (x);
2442 if (val.start < 0 || val.start >= FIRST_PSEUDO_REGISTER)
2443 return decompose (SUBREG_REG (x));
2444 else
2445 /* A hard reg. */
2446 val.end = val.start + subreg_nregs (x);
2447 break;
2449 case SCRATCH:
2450 /* This hasn't been assigned yet, so it can't conflict yet. */
2451 val.safe = 1;
2452 break;
2454 default:
2455 gcc_assert (CONSTANT_P (x));
2456 val.safe = 1;
2457 break;
2459 return val;
2462 /* Return 1 if altering Y will not modify the value of X.
2463 Y is also described by YDATA, which should be decompose (Y). */
2465 static int
2466 immune_p (rtx x, rtx y, struct decomposition ydata)
2468 struct decomposition xdata;
2470 if (ydata.reg_flag)
2471 return !refers_to_regno_for_reload_p (ydata.start, ydata.end, x, (rtx*) 0);
2472 if (ydata.safe)
2473 return 1;
2475 gcc_assert (MEM_P (y));
2476 /* If Y is memory and X is not, Y can't affect X. */
2477 if (!MEM_P (x))
2478 return 1;
2480 xdata = decompose (x);
2482 if (! rtx_equal_p (xdata.base, ydata.base))
2484 /* If bases are distinct symbolic constants, there is no overlap. */
2485 if (CONSTANT_P (xdata.base) && CONSTANT_P (ydata.base))
2486 return 1;
2487 /* Constants and stack slots never overlap. */
2488 if (CONSTANT_P (xdata.base)
2489 && (ydata.base == frame_pointer_rtx
2490 || ydata.base == hard_frame_pointer_rtx
2491 || ydata.base == stack_pointer_rtx))
2492 return 1;
2493 if (CONSTANT_P (ydata.base)
2494 && (xdata.base == frame_pointer_rtx
2495 || xdata.base == hard_frame_pointer_rtx
2496 || xdata.base == stack_pointer_rtx))
2497 return 1;
2498 /* If either base is variable, we don't know anything. */
2499 return 0;
2502 return (xdata.start >= ydata.end || ydata.start >= xdata.end);
2505 /* Similar, but calls decompose. */
2508 safe_from_earlyclobber (rtx op, rtx clobber)
2510 struct decomposition early_data;
2512 early_data = decompose (clobber);
2513 return immune_p (op, clobber, early_data);
2516 /* Main entry point of this file: search the body of INSN
2517 for values that need reloading and record them with push_reload.
2518 REPLACE nonzero means record also where the values occur
2519 so that subst_reloads can be used.
2521 IND_LEVELS says how many levels of indirection are supported by this
2522 machine; a value of zero means that a memory reference is not a valid
2523 memory address.
2525 LIVE_KNOWN says we have valid information about which hard
2526 regs are live at each point in the program; this is true when
2527 we are called from global_alloc but false when stupid register
2528 allocation has been done.
2530 RELOAD_REG_P if nonzero is a vector indexed by hard reg number
2531 which is nonnegative if the reg has been commandeered for reloading into.
2532 It is copied into STATIC_RELOAD_REG_P and referenced from there
2533 by various subroutines.
2535 Return TRUE if some operands need to be changed, because of swapping
2536 commutative operands, reg_equiv_address substitution, or whatever. */
2539 find_reloads (rtx insn, int replace, int ind_levels, int live_known,
2540 short *reload_reg_p)
2542 int insn_code_number;
2543 int i, j;
2544 int noperands;
2545 /* These start out as the constraints for the insn
2546 and they are chewed up as we consider alternatives. */
2547 char *constraints[MAX_RECOG_OPERANDS];
2548 /* These are the preferred classes for an operand, or NO_REGS if it isn't
2549 a register. */
2550 enum reg_class preferred_class[MAX_RECOG_OPERANDS];
2551 char pref_or_nothing[MAX_RECOG_OPERANDS];
2552 /* Nonzero for a MEM operand whose entire address needs a reload.
2553 May be -1 to indicate the entire address may or may not need a reload. */
2554 int address_reloaded[MAX_RECOG_OPERANDS];
2555 /* Nonzero for an address operand that needs to be completely reloaded.
2556 May be -1 to indicate the entire operand may or may not need a reload. */
2557 int address_operand_reloaded[MAX_RECOG_OPERANDS];
2558 /* Value of enum reload_type to use for operand. */
2559 enum reload_type operand_type[MAX_RECOG_OPERANDS];
2560 /* Value of enum reload_type to use within address of operand. */
2561 enum reload_type address_type[MAX_RECOG_OPERANDS];
2562 /* Save the usage of each operand. */
2563 enum reload_usage { RELOAD_READ, RELOAD_READ_WRITE, RELOAD_WRITE } modified[MAX_RECOG_OPERANDS];
2564 int no_input_reloads = 0, no_output_reloads = 0;
2565 int n_alternatives;
2566 int this_alternative[MAX_RECOG_OPERANDS];
2567 char this_alternative_match_win[MAX_RECOG_OPERANDS];
2568 char this_alternative_win[MAX_RECOG_OPERANDS];
2569 char this_alternative_offmemok[MAX_RECOG_OPERANDS];
2570 char this_alternative_earlyclobber[MAX_RECOG_OPERANDS];
2571 int this_alternative_matches[MAX_RECOG_OPERANDS];
2572 int swapped;
2573 int goal_alternative[MAX_RECOG_OPERANDS];
2574 int this_alternative_number;
2575 int goal_alternative_number = 0;
2576 int operand_reloadnum[MAX_RECOG_OPERANDS];
2577 int goal_alternative_matches[MAX_RECOG_OPERANDS];
2578 int goal_alternative_matched[MAX_RECOG_OPERANDS];
2579 char goal_alternative_match_win[MAX_RECOG_OPERANDS];
2580 char goal_alternative_win[MAX_RECOG_OPERANDS];
2581 char goal_alternative_offmemok[MAX_RECOG_OPERANDS];
2582 char goal_alternative_earlyclobber[MAX_RECOG_OPERANDS];
2583 int goal_alternative_swapped;
2584 int best;
2585 int commutative;
2586 char operands_match[MAX_RECOG_OPERANDS][MAX_RECOG_OPERANDS];
2587 rtx substed_operand[MAX_RECOG_OPERANDS];
2588 rtx body = PATTERN (insn);
2589 rtx set = single_set (insn);
2590 int goal_earlyclobber = 0, this_earlyclobber;
2591 enum machine_mode operand_mode[MAX_RECOG_OPERANDS];
2592 int retval = 0;
2594 this_insn = insn;
2595 n_reloads = 0;
2596 n_replacements = 0;
2597 n_earlyclobbers = 0;
2598 replace_reloads = replace;
2599 hard_regs_live_known = live_known;
2600 static_reload_reg_p = reload_reg_p;
2602 /* JUMP_INSNs and CALL_INSNs are not allowed to have any output reloads;
2603 neither are insns that SET cc0. Insns that use CC0 are not allowed
2604 to have any input reloads. */
2605 if (JUMP_P (insn) || CALL_P (insn))
2606 no_output_reloads = 1;
2608 #ifdef HAVE_cc0
2609 if (reg_referenced_p (cc0_rtx, PATTERN (insn)))
2610 no_input_reloads = 1;
2611 if (reg_set_p (cc0_rtx, PATTERN (insn)))
2612 no_output_reloads = 1;
2613 #endif
2615 #ifdef SECONDARY_MEMORY_NEEDED
2616 /* The eliminated forms of any secondary memory locations are per-insn, so
2617 clear them out here. */
2619 if (secondary_memlocs_elim_used)
2621 memset (secondary_memlocs_elim, 0,
2622 sizeof (secondary_memlocs_elim[0]) * secondary_memlocs_elim_used);
2623 secondary_memlocs_elim_used = 0;
2625 #endif
2627 /* Dispose quickly of (set (reg..) (reg..)) if both have hard regs and it
2628 is cheap to move between them. If it is not, there may not be an insn
2629 to do the copy, so we may need a reload. */
2630 if (GET_CODE (body) == SET
2631 && REG_P (SET_DEST (body))
2632 && REGNO (SET_DEST (body)) < FIRST_PSEUDO_REGISTER
2633 && REG_P (SET_SRC (body))
2634 && REGNO (SET_SRC (body)) < FIRST_PSEUDO_REGISTER
2635 && REGISTER_MOVE_COST (GET_MODE (SET_SRC (body)),
2636 REGNO_REG_CLASS (REGNO (SET_SRC (body))),
2637 REGNO_REG_CLASS (REGNO (SET_DEST (body)))) == 2)
2638 return 0;
2640 extract_insn (insn);
2642 noperands = reload_n_operands = recog_data.n_operands;
2643 n_alternatives = recog_data.n_alternatives;
2645 /* Just return "no reloads" if insn has no operands with constraints. */
2646 if (noperands == 0 || n_alternatives == 0)
2647 return 0;
2649 insn_code_number = INSN_CODE (insn);
2650 this_insn_is_asm = insn_code_number < 0;
2652 memcpy (operand_mode, recog_data.operand_mode,
2653 noperands * sizeof (enum machine_mode));
2654 memcpy (constraints, recog_data.constraints, noperands * sizeof (char *));
2656 commutative = -1;
2658 /* If we will need to know, later, whether some pair of operands
2659 are the same, we must compare them now and save the result.
2660 Reloading the base and index registers will clobber them
2661 and afterward they will fail to match. */
2663 for (i = 0; i < noperands; i++)
2665 char *p;
2666 int c;
2668 substed_operand[i] = recog_data.operand[i];
2669 p = constraints[i];
2671 modified[i] = RELOAD_READ;
2673 /* Scan this operand's constraint to see if it is an output operand,
2674 an in-out operand, is commutative, or should match another. */
2676 while ((c = *p))
2678 p += CONSTRAINT_LEN (c, p);
2679 switch (c)
2681 case '=':
2682 modified[i] = RELOAD_WRITE;
2683 break;
2684 case '+':
2685 modified[i] = RELOAD_READ_WRITE;
2686 break;
2687 case '%':
2689 /* The last operand should not be marked commutative. */
2690 gcc_assert (i != noperands - 1);
2692 /* We currently only support one commutative pair of
2693 operands. Some existing asm code currently uses more
2694 than one pair. Previously, that would usually work,
2695 but sometimes it would crash the compiler. We
2696 continue supporting that case as well as we can by
2697 silently ignoring all but the first pair. In the
2698 future we may handle it correctly. */
2699 if (commutative < 0)
2700 commutative = i;
2701 else
2702 gcc_assert (this_insn_is_asm);
2704 break;
2705 /* Use of ISDIGIT is tempting here, but it may get expensive because
2706 of locale support we don't want. */
2707 case '0': case '1': case '2': case '3': case '4':
2708 case '5': case '6': case '7': case '8': case '9':
2710 c = strtoul (p - 1, &p, 10);
2712 operands_match[c][i]
2713 = operands_match_p (recog_data.operand[c],
2714 recog_data.operand[i]);
2716 /* An operand may not match itself. */
2717 gcc_assert (c != i);
2719 /* If C can be commuted with C+1, and C might need to match I,
2720 then C+1 might also need to match I. */
2721 if (commutative >= 0)
2723 if (c == commutative || c == commutative + 1)
2725 int other = c + (c == commutative ? 1 : -1);
2726 operands_match[other][i]
2727 = operands_match_p (recog_data.operand[other],
2728 recog_data.operand[i]);
2730 if (i == commutative || i == commutative + 1)
2732 int other = i + (i == commutative ? 1 : -1);
2733 operands_match[c][other]
2734 = operands_match_p (recog_data.operand[c],
2735 recog_data.operand[other]);
2737 /* Note that C is supposed to be less than I.
2738 No need to consider altering both C and I because in
2739 that case we would alter one into the other. */
2746 /* Examine each operand that is a memory reference or memory address
2747 and reload parts of the addresses into index registers.
2748 Also here any references to pseudo regs that didn't get hard regs
2749 but are equivalent to constants get replaced in the insn itself
2750 with those constants. Nobody will ever see them again.
2752 Finally, set up the preferred classes of each operand. */
2754 for (i = 0; i < noperands; i++)
2756 RTX_CODE code = GET_CODE (recog_data.operand[i]);
2758 address_reloaded[i] = 0;
2759 address_operand_reloaded[i] = 0;
2760 operand_type[i] = (modified[i] == RELOAD_READ ? RELOAD_FOR_INPUT
2761 : modified[i] == RELOAD_WRITE ? RELOAD_FOR_OUTPUT
2762 : RELOAD_OTHER);
2763 address_type[i]
2764 = (modified[i] == RELOAD_READ ? RELOAD_FOR_INPUT_ADDRESS
2765 : modified[i] == RELOAD_WRITE ? RELOAD_FOR_OUTPUT_ADDRESS
2766 : RELOAD_OTHER);
2768 if (*constraints[i] == 0)
2769 /* Ignore things like match_operator operands. */
2771 else if (constraints[i][0] == 'p'
2772 || EXTRA_ADDRESS_CONSTRAINT (constraints[i][0], constraints[i]))
2774 address_operand_reloaded[i]
2775 = find_reloads_address (recog_data.operand_mode[i], (rtx*) 0,
2776 recog_data.operand[i],
2777 recog_data.operand_loc[i],
2778 i, operand_type[i], ind_levels, insn);
2780 /* If we now have a simple operand where we used to have a
2781 PLUS or MULT, re-recognize and try again. */
2782 if ((OBJECT_P (*recog_data.operand_loc[i])
2783 || GET_CODE (*recog_data.operand_loc[i]) == SUBREG)
2784 && (GET_CODE (recog_data.operand[i]) == MULT
2785 || GET_CODE (recog_data.operand[i]) == PLUS))
2787 INSN_CODE (insn) = -1;
2788 retval = find_reloads (insn, replace, ind_levels, live_known,
2789 reload_reg_p);
2790 return retval;
2793 recog_data.operand[i] = *recog_data.operand_loc[i];
2794 substed_operand[i] = recog_data.operand[i];
2796 /* Address operands are reloaded in their existing mode,
2797 no matter what is specified in the machine description. */
2798 operand_mode[i] = GET_MODE (recog_data.operand[i]);
2800 else if (code == MEM)
2802 address_reloaded[i]
2803 = find_reloads_address (GET_MODE (recog_data.operand[i]),
2804 recog_data.operand_loc[i],
2805 XEXP (recog_data.operand[i], 0),
2806 &XEXP (recog_data.operand[i], 0),
2807 i, address_type[i], ind_levels, insn);
2808 recog_data.operand[i] = *recog_data.operand_loc[i];
2809 substed_operand[i] = recog_data.operand[i];
2811 else if (code == SUBREG)
2813 rtx reg = SUBREG_REG (recog_data.operand[i]);
2814 rtx op
2815 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2816 ind_levels,
2817 set != 0
2818 && &SET_DEST (set) == recog_data.operand_loc[i],
2819 insn,
2820 &address_reloaded[i]);
2822 /* If we made a MEM to load (a part of) the stackslot of a pseudo
2823 that didn't get a hard register, emit a USE with a REG_EQUAL
2824 note in front so that we might inherit a previous, possibly
2825 wider reload. */
2827 if (replace
2828 && MEM_P (op)
2829 && REG_P (reg)
2830 && (GET_MODE_SIZE (GET_MODE (reg))
2831 >= GET_MODE_SIZE (GET_MODE (op)))
2832 && reg_equiv_constant[REGNO (reg)] == 0)
2833 set_unique_reg_note (emit_insn_before (gen_rtx_USE (VOIDmode, reg),
2834 insn),
2835 REG_EQUAL, reg_equiv_memory_loc[REGNO (reg)]);
2837 substed_operand[i] = recog_data.operand[i] = op;
2839 else if (code == PLUS || GET_RTX_CLASS (code) == RTX_UNARY)
2840 /* We can get a PLUS as an "operand" as a result of register
2841 elimination. See eliminate_regs and gen_reload. We handle
2842 a unary operator by reloading the operand. */
2843 substed_operand[i] = recog_data.operand[i]
2844 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2845 ind_levels, 0, insn,
2846 &address_reloaded[i]);
2847 else if (code == REG)
2849 /* This is equivalent to calling find_reloads_toplev.
2850 The code is duplicated for speed.
2851 When we find a pseudo always equivalent to a constant,
2852 we replace it by the constant. We must be sure, however,
2853 that we don't try to replace it in the insn in which it
2854 is being set. */
2855 int regno = REGNO (recog_data.operand[i]);
2856 if (reg_equiv_constant[regno] != 0
2857 && (set == 0 || &SET_DEST (set) != recog_data.operand_loc[i]))
2859 /* Record the existing mode so that the check if constants are
2860 allowed will work when operand_mode isn't specified. */
2862 if (operand_mode[i] == VOIDmode)
2863 operand_mode[i] = GET_MODE (recog_data.operand[i]);
2865 substed_operand[i] = recog_data.operand[i]
2866 = reg_equiv_constant[regno];
2868 if (reg_equiv_memory_loc[regno] != 0
2869 && (reg_equiv_address[regno] != 0 || num_not_at_initial_offset))
2870 /* We need not give a valid is_set_dest argument since the case
2871 of a constant equivalence was checked above. */
2872 substed_operand[i] = recog_data.operand[i]
2873 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2874 ind_levels, 0, insn,
2875 &address_reloaded[i]);
2877 /* If the operand is still a register (we didn't replace it with an
2878 equivalent), get the preferred class to reload it into. */
2879 code = GET_CODE (recog_data.operand[i]);
2880 preferred_class[i]
2881 = ((code == REG && REGNO (recog_data.operand[i])
2882 >= FIRST_PSEUDO_REGISTER)
2883 ? reg_preferred_class (REGNO (recog_data.operand[i]))
2884 : NO_REGS);
2885 pref_or_nothing[i]
2886 = (code == REG
2887 && REGNO (recog_data.operand[i]) >= FIRST_PSEUDO_REGISTER
2888 && reg_alternate_class (REGNO (recog_data.operand[i])) == NO_REGS);
2891 /* If this is simply a copy from operand 1 to operand 0, merge the
2892 preferred classes for the operands. */
2893 if (set != 0 && noperands >= 2 && recog_data.operand[0] == SET_DEST (set)
2894 && recog_data.operand[1] == SET_SRC (set))
2896 preferred_class[0] = preferred_class[1]
2897 = reg_class_subunion[(int) preferred_class[0]][(int) preferred_class[1]];
2898 pref_or_nothing[0] |= pref_or_nothing[1];
2899 pref_or_nothing[1] |= pref_or_nothing[0];
2902 /* Now see what we need for pseudo-regs that didn't get hard regs
2903 or got the wrong kind of hard reg. For this, we must consider
2904 all the operands together against the register constraints. */
2906 best = MAX_RECOG_OPERANDS * 2 + 600;
2908 swapped = 0;
2909 goal_alternative_swapped = 0;
2910 try_swapped:
2912 /* The constraints are made of several alternatives.
2913 Each operand's constraint looks like foo,bar,... with commas
2914 separating the alternatives. The first alternatives for all
2915 operands go together, the second alternatives go together, etc.
2917 First loop over alternatives. */
2919 for (this_alternative_number = 0;
2920 this_alternative_number < n_alternatives;
2921 this_alternative_number++)
2923 /* Loop over operands for one constraint alternative. */
2924 /* LOSERS counts those that don't fit this alternative
2925 and would require loading. */
2926 int losers = 0;
2927 /* BAD is set to 1 if it some operand can't fit this alternative
2928 even after reloading. */
2929 int bad = 0;
2930 /* REJECT is a count of how undesirable this alternative says it is
2931 if any reloading is required. If the alternative matches exactly
2932 then REJECT is ignored, but otherwise it gets this much
2933 counted against it in addition to the reloading needed. Each
2934 ? counts three times here since we want the disparaging caused by
2935 a bad register class to only count 1/3 as much. */
2936 int reject = 0;
2938 this_earlyclobber = 0;
2940 for (i = 0; i < noperands; i++)
2942 char *p = constraints[i];
2943 char *end;
2944 int len;
2945 int win = 0;
2946 int did_match = 0;
2947 /* 0 => this operand can be reloaded somehow for this alternative. */
2948 int badop = 1;
2949 /* 0 => this operand can be reloaded if the alternative allows regs. */
2950 int winreg = 0;
2951 int c;
2952 int m;
2953 rtx operand = recog_data.operand[i];
2954 int offset = 0;
2955 /* Nonzero means this is a MEM that must be reloaded into a reg
2956 regardless of what the constraint says. */
2957 int force_reload = 0;
2958 int offmemok = 0;
2959 /* Nonzero if a constant forced into memory would be OK for this
2960 operand. */
2961 int constmemok = 0;
2962 int earlyclobber = 0;
2964 /* If the predicate accepts a unary operator, it means that
2965 we need to reload the operand, but do not do this for
2966 match_operator and friends. */
2967 if (UNARY_P (operand) && *p != 0)
2968 operand = XEXP (operand, 0);
2970 /* If the operand is a SUBREG, extract
2971 the REG or MEM (or maybe even a constant) within.
2972 (Constants can occur as a result of reg_equiv_constant.) */
2974 while (GET_CODE (operand) == SUBREG)
2976 /* Offset only matters when operand is a REG and
2977 it is a hard reg. This is because it is passed
2978 to reg_fits_class_p if it is a REG and all pseudos
2979 return 0 from that function. */
2980 if (REG_P (SUBREG_REG (operand))
2981 && REGNO (SUBREG_REG (operand)) < FIRST_PSEUDO_REGISTER)
2983 if (!subreg_offset_representable_p
2984 (REGNO (SUBREG_REG (operand)),
2985 GET_MODE (SUBREG_REG (operand)),
2986 SUBREG_BYTE (operand),
2987 GET_MODE (operand)))
2988 force_reload = 1;
2989 offset += subreg_regno_offset (REGNO (SUBREG_REG (operand)),
2990 GET_MODE (SUBREG_REG (operand)),
2991 SUBREG_BYTE (operand),
2992 GET_MODE (operand));
2994 operand = SUBREG_REG (operand);
2995 /* Force reload if this is a constant or PLUS or if there may
2996 be a problem accessing OPERAND in the outer mode. */
2997 if (CONSTANT_P (operand)
2998 || GET_CODE (operand) == PLUS
2999 /* We must force a reload of paradoxical SUBREGs
3000 of a MEM because the alignment of the inner value
3001 may not be enough to do the outer reference. On
3002 big-endian machines, it may also reference outside
3003 the object.
3005 On machines that extend byte operations and we have a
3006 SUBREG where both the inner and outer modes are no wider
3007 than a word and the inner mode is narrower, is integral,
3008 and gets extended when loaded from memory, combine.c has
3009 made assumptions about the behavior of the machine in such
3010 register access. If the data is, in fact, in memory we
3011 must always load using the size assumed to be in the
3012 register and let the insn do the different-sized
3013 accesses.
3015 This is doubly true if WORD_REGISTER_OPERATIONS. In
3016 this case eliminate_regs has left non-paradoxical
3017 subregs for push_reload to see. Make sure it does
3018 by forcing the reload.
3020 ??? When is it right at this stage to have a subreg
3021 of a mem that is _not_ to be handled specially? IMO
3022 those should have been reduced to just a mem. */
3023 || ((MEM_P (operand)
3024 || (REG_P (operand)
3025 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
3026 #ifndef WORD_REGISTER_OPERATIONS
3027 && (((GET_MODE_BITSIZE (GET_MODE (operand))
3028 < BIGGEST_ALIGNMENT)
3029 && (GET_MODE_SIZE (operand_mode[i])
3030 > GET_MODE_SIZE (GET_MODE (operand))))
3031 || BYTES_BIG_ENDIAN
3032 #ifdef LOAD_EXTEND_OP
3033 || (GET_MODE_SIZE (operand_mode[i]) <= UNITS_PER_WORD
3034 && (GET_MODE_SIZE (GET_MODE (operand))
3035 <= UNITS_PER_WORD)
3036 && (GET_MODE_SIZE (operand_mode[i])
3037 > GET_MODE_SIZE (GET_MODE (operand)))
3038 && INTEGRAL_MODE_P (GET_MODE (operand))
3039 && LOAD_EXTEND_OP (GET_MODE (operand)) != UNKNOWN)
3040 #endif
3042 #endif
3045 force_reload = 1;
3048 this_alternative[i] = (int) NO_REGS;
3049 this_alternative_win[i] = 0;
3050 this_alternative_match_win[i] = 0;
3051 this_alternative_offmemok[i] = 0;
3052 this_alternative_earlyclobber[i] = 0;
3053 this_alternative_matches[i] = -1;
3055 /* An empty constraint or empty alternative
3056 allows anything which matched the pattern. */
3057 if (*p == 0 || *p == ',')
3058 win = 1, badop = 0;
3060 /* Scan this alternative's specs for this operand;
3061 set WIN if the operand fits any letter in this alternative.
3062 Otherwise, clear BADOP if this operand could
3063 fit some letter after reloads,
3064 or set WINREG if this operand could fit after reloads
3065 provided the constraint allows some registers. */
3068 switch ((c = *p, len = CONSTRAINT_LEN (c, p)), c)
3070 case '\0':
3071 len = 0;
3072 break;
3073 case ',':
3074 c = '\0';
3075 break;
3077 case '=': case '+': case '*':
3078 break;
3080 case '%':
3081 /* We only support one commutative marker, the first
3082 one. We already set commutative above. */
3083 break;
3085 case '?':
3086 reject += 6;
3087 break;
3089 case '!':
3090 reject = 600;
3091 break;
3093 case '#':
3094 /* Ignore rest of this alternative as far as
3095 reloading is concerned. */
3097 p++;
3098 while (*p && *p != ',');
3099 len = 0;
3100 break;
3102 case '0': case '1': case '2': case '3': case '4':
3103 case '5': case '6': case '7': case '8': case '9':
3104 m = strtoul (p, &end, 10);
3105 p = end;
3106 len = 0;
3108 this_alternative_matches[i] = m;
3109 /* We are supposed to match a previous operand.
3110 If we do, we win if that one did.
3111 If we do not, count both of the operands as losers.
3112 (This is too conservative, since most of the time
3113 only a single reload insn will be needed to make
3114 the two operands win. As a result, this alternative
3115 may be rejected when it is actually desirable.) */
3116 if ((swapped && (m != commutative || i != commutative + 1))
3117 /* If we are matching as if two operands were swapped,
3118 also pretend that operands_match had been computed
3119 with swapped.
3120 But if I is the second of those and C is the first,
3121 don't exchange them, because operands_match is valid
3122 only on one side of its diagonal. */
3123 ? (operands_match
3124 [(m == commutative || m == commutative + 1)
3125 ? 2 * commutative + 1 - m : m]
3126 [(i == commutative || i == commutative + 1)
3127 ? 2 * commutative + 1 - i : i])
3128 : operands_match[m][i])
3130 /* If we are matching a non-offsettable address where an
3131 offsettable address was expected, then we must reject
3132 this combination, because we can't reload it. */
3133 if (this_alternative_offmemok[m]
3134 && MEM_P (recog_data.operand[m])
3135 && this_alternative[m] == (int) NO_REGS
3136 && ! this_alternative_win[m])
3137 bad = 1;
3139 did_match = this_alternative_win[m];
3141 else
3143 /* Operands don't match. */
3144 rtx value;
3145 int loc1, loc2;
3146 /* Retroactively mark the operand we had to match
3147 as a loser, if it wasn't already. */
3148 if (this_alternative_win[m])
3149 losers++;
3150 this_alternative_win[m] = 0;
3151 if (this_alternative[m] == (int) NO_REGS)
3152 bad = 1;
3153 /* But count the pair only once in the total badness of
3154 this alternative, if the pair can be a dummy reload.
3155 The pointers in operand_loc are not swapped; swap
3156 them by hand if necessary. */
3157 if (swapped && i == commutative)
3158 loc1 = commutative + 1;
3159 else if (swapped && i == commutative + 1)
3160 loc1 = commutative;
3161 else
3162 loc1 = i;
3163 if (swapped && m == commutative)
3164 loc2 = commutative + 1;
3165 else if (swapped && m == commutative + 1)
3166 loc2 = commutative;
3167 else
3168 loc2 = m;
3169 value
3170 = find_dummy_reload (recog_data.operand[i],
3171 recog_data.operand[m],
3172 recog_data.operand_loc[loc1],
3173 recog_data.operand_loc[loc2],
3174 operand_mode[i], operand_mode[m],
3175 this_alternative[m], -1,
3176 this_alternative_earlyclobber[m]);
3178 if (value != 0)
3179 losers--;
3181 /* This can be fixed with reloads if the operand
3182 we are supposed to match can be fixed with reloads. */
3183 badop = 0;
3184 this_alternative[i] = this_alternative[m];
3186 /* If we have to reload this operand and some previous
3187 operand also had to match the same thing as this
3188 operand, we don't know how to do that. So reject this
3189 alternative. */
3190 if (! did_match || force_reload)
3191 for (j = 0; j < i; j++)
3192 if (this_alternative_matches[j]
3193 == this_alternative_matches[i])
3194 badop = 1;
3195 break;
3197 case 'p':
3198 /* All necessary reloads for an address_operand
3199 were handled in find_reloads_address. */
3200 this_alternative[i]
3201 = (int) base_reg_class (VOIDmode, ADDRESS, SCRATCH);
3202 win = 1;
3203 badop = 0;
3204 break;
3206 case 'm':
3207 if (force_reload)
3208 break;
3209 if (MEM_P (operand)
3210 || (REG_P (operand)
3211 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3212 && reg_renumber[REGNO (operand)] < 0))
3213 win = 1;
3214 if (CONST_POOL_OK_P (operand))
3215 badop = 0;
3216 constmemok = 1;
3217 break;
3219 case '<':
3220 if (MEM_P (operand)
3221 && ! address_reloaded[i]
3222 && (GET_CODE (XEXP (operand, 0)) == PRE_DEC
3223 || GET_CODE (XEXP (operand, 0)) == POST_DEC))
3224 win = 1;
3225 break;
3227 case '>':
3228 if (MEM_P (operand)
3229 && ! address_reloaded[i]
3230 && (GET_CODE (XEXP (operand, 0)) == PRE_INC
3231 || GET_CODE (XEXP (operand, 0)) == POST_INC))
3232 win = 1;
3233 break;
3235 /* Memory operand whose address is not offsettable. */
3236 case 'V':
3237 if (force_reload)
3238 break;
3239 if (MEM_P (operand)
3240 && ! (ind_levels ? offsettable_memref_p (operand)
3241 : offsettable_nonstrict_memref_p (operand))
3242 /* Certain mem addresses will become offsettable
3243 after they themselves are reloaded. This is important;
3244 we don't want our own handling of unoffsettables
3245 to override the handling of reg_equiv_address. */
3246 && !(REG_P (XEXP (operand, 0))
3247 && (ind_levels == 0
3248 || reg_equiv_address[REGNO (XEXP (operand, 0))] != 0)))
3249 win = 1;
3250 break;
3252 /* Memory operand whose address is offsettable. */
3253 case 'o':
3254 if (force_reload)
3255 break;
3256 if ((MEM_P (operand)
3257 /* If IND_LEVELS, find_reloads_address won't reload a
3258 pseudo that didn't get a hard reg, so we have to
3259 reject that case. */
3260 && ((ind_levels ? offsettable_memref_p (operand)
3261 : offsettable_nonstrict_memref_p (operand))
3262 /* A reloaded address is offsettable because it is now
3263 just a simple register indirect. */
3264 || address_reloaded[i] == 1))
3265 || (REG_P (operand)
3266 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3267 && reg_renumber[REGNO (operand)] < 0
3268 /* If reg_equiv_address is nonzero, we will be
3269 loading it into a register; hence it will be
3270 offsettable, but we cannot say that reg_equiv_mem
3271 is offsettable without checking. */
3272 && ((reg_equiv_mem[REGNO (operand)] != 0
3273 && offsettable_memref_p (reg_equiv_mem[REGNO (operand)]))
3274 || (reg_equiv_address[REGNO (operand)] != 0))))
3275 win = 1;
3276 if (CONST_POOL_OK_P (operand)
3277 || MEM_P (operand))
3278 badop = 0;
3279 constmemok = 1;
3280 offmemok = 1;
3281 break;
3283 case '&':
3284 /* Output operand that is stored before the need for the
3285 input operands (and their index registers) is over. */
3286 earlyclobber = 1, this_earlyclobber = 1;
3287 break;
3289 case 'E':
3290 case 'F':
3291 if (GET_CODE (operand) == CONST_DOUBLE
3292 || (GET_CODE (operand) == CONST_VECTOR
3293 && (GET_MODE_CLASS (GET_MODE (operand))
3294 == MODE_VECTOR_FLOAT)))
3295 win = 1;
3296 break;
3298 case 'G':
3299 case 'H':
3300 if (GET_CODE (operand) == CONST_DOUBLE
3301 && CONST_DOUBLE_OK_FOR_CONSTRAINT_P (operand, c, p))
3302 win = 1;
3303 break;
3305 case 's':
3306 if (GET_CODE (operand) == CONST_INT
3307 || (GET_CODE (operand) == CONST_DOUBLE
3308 && GET_MODE (operand) == VOIDmode))
3309 break;
3310 case 'i':
3311 if (CONSTANT_P (operand)
3312 && (! flag_pic || LEGITIMATE_PIC_OPERAND_P (operand)))
3313 win = 1;
3314 break;
3316 case 'n':
3317 if (GET_CODE (operand) == CONST_INT
3318 || (GET_CODE (operand) == CONST_DOUBLE
3319 && GET_MODE (operand) == VOIDmode))
3320 win = 1;
3321 break;
3323 case 'I':
3324 case 'J':
3325 case 'K':
3326 case 'L':
3327 case 'M':
3328 case 'N':
3329 case 'O':
3330 case 'P':
3331 if (GET_CODE (operand) == CONST_INT
3332 && CONST_OK_FOR_CONSTRAINT_P (INTVAL (operand), c, p))
3333 win = 1;
3334 break;
3336 case 'X':
3337 force_reload = 0;
3338 win = 1;
3339 break;
3341 case 'g':
3342 if (! force_reload
3343 /* A PLUS is never a valid operand, but reload can make
3344 it from a register when eliminating registers. */
3345 && GET_CODE (operand) != PLUS
3346 /* A SCRATCH is not a valid operand. */
3347 && GET_CODE (operand) != SCRATCH
3348 && (! CONSTANT_P (operand)
3349 || ! flag_pic
3350 || LEGITIMATE_PIC_OPERAND_P (operand))
3351 && (GENERAL_REGS == ALL_REGS
3352 || !REG_P (operand)
3353 || (REGNO (operand) >= FIRST_PSEUDO_REGISTER
3354 && reg_renumber[REGNO (operand)] < 0)))
3355 win = 1;
3356 /* Drop through into 'r' case. */
3358 case 'r':
3359 this_alternative[i]
3360 = (int) reg_class_subunion[this_alternative[i]][(int) GENERAL_REGS];
3361 goto reg;
3363 default:
3364 if (REG_CLASS_FROM_CONSTRAINT (c, p) == NO_REGS)
3366 #ifdef EXTRA_CONSTRAINT_STR
3367 if (EXTRA_MEMORY_CONSTRAINT (c, p))
3369 if (force_reload)
3370 break;
3371 if (EXTRA_CONSTRAINT_STR (operand, c, p))
3372 win = 1;
3373 /* If the address was already reloaded,
3374 we win as well. */
3375 else if (MEM_P (operand)
3376 && address_reloaded[i] == 1)
3377 win = 1;
3378 /* Likewise if the address will be reloaded because
3379 reg_equiv_address is nonzero. For reg_equiv_mem
3380 we have to check. */
3381 else if (REG_P (operand)
3382 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3383 && reg_renumber[REGNO (operand)] < 0
3384 && ((reg_equiv_mem[REGNO (operand)] != 0
3385 && EXTRA_CONSTRAINT_STR (reg_equiv_mem[REGNO (operand)], c, p))
3386 || (reg_equiv_address[REGNO (operand)] != 0)))
3387 win = 1;
3389 /* If we didn't already win, we can reload
3390 constants via force_const_mem, and other
3391 MEMs by reloading the address like for 'o'. */
3392 if (CONST_POOL_OK_P (operand)
3393 || MEM_P (operand))
3394 badop = 0;
3395 constmemok = 1;
3396 offmemok = 1;
3397 break;
3399 if (EXTRA_ADDRESS_CONSTRAINT (c, p))
3401 if (EXTRA_CONSTRAINT_STR (operand, c, p))
3402 win = 1;
3404 /* If we didn't already win, we can reload
3405 the address into a base register. */
3406 this_alternative[i]
3407 = (int) base_reg_class (VOIDmode, ADDRESS, SCRATCH);
3408 badop = 0;
3409 break;
3412 if (EXTRA_CONSTRAINT_STR (operand, c, p))
3413 win = 1;
3414 #endif
3415 break;
3418 this_alternative[i]
3419 = (int) (reg_class_subunion
3420 [this_alternative[i]]
3421 [(int) REG_CLASS_FROM_CONSTRAINT (c, p)]);
3422 reg:
3423 if (GET_MODE (operand) == BLKmode)
3424 break;
3425 winreg = 1;
3426 if (REG_P (operand)
3427 && reg_fits_class_p (operand, this_alternative[i],
3428 offset, GET_MODE (recog_data.operand[i])))
3429 win = 1;
3430 break;
3432 while ((p += len), c);
3434 constraints[i] = p;
3436 /* If this operand could be handled with a reg,
3437 and some reg is allowed, then this operand can be handled. */
3438 if (winreg && this_alternative[i] != (int) NO_REGS)
3439 badop = 0;
3441 /* Record which operands fit this alternative. */
3442 this_alternative_earlyclobber[i] = earlyclobber;
3443 if (win && ! force_reload)
3444 this_alternative_win[i] = 1;
3445 else if (did_match && ! force_reload)
3446 this_alternative_match_win[i] = 1;
3447 else
3449 int const_to_mem = 0;
3451 this_alternative_offmemok[i] = offmemok;
3452 losers++;
3453 if (badop)
3454 bad = 1;
3455 /* Alternative loses if it has no regs for a reg operand. */
3456 if (REG_P (operand)
3457 && this_alternative[i] == (int) NO_REGS
3458 && this_alternative_matches[i] < 0)
3459 bad = 1;
3461 /* If this is a constant that is reloaded into the desired
3462 class by copying it to memory first, count that as another
3463 reload. This is consistent with other code and is
3464 required to avoid choosing another alternative when
3465 the constant is moved into memory by this function on
3466 an early reload pass. Note that the test here is
3467 precisely the same as in the code below that calls
3468 force_const_mem. */
3469 if (CONST_POOL_OK_P (operand)
3470 && ((PREFERRED_RELOAD_CLASS (operand,
3471 (enum reg_class) this_alternative[i])
3472 == NO_REGS)
3473 || no_input_reloads)
3474 && operand_mode[i] != VOIDmode)
3476 const_to_mem = 1;
3477 if (this_alternative[i] != (int) NO_REGS)
3478 losers++;
3481 /* Alternative loses if it requires a type of reload not
3482 permitted for this insn. We can always reload SCRATCH
3483 and objects with a REG_UNUSED note. */
3484 if (GET_CODE (operand) != SCRATCH
3485 && modified[i] != RELOAD_READ && no_output_reloads
3486 && ! find_reg_note (insn, REG_UNUSED, operand))
3487 bad = 1;
3488 else if (modified[i] != RELOAD_WRITE && no_input_reloads
3489 && ! const_to_mem)
3490 bad = 1;
3492 /* If we can't reload this value at all, reject this
3493 alternative. Note that we could also lose due to
3494 LIMIT_RELOAD_CLASS, but we don't check that
3495 here. */
3497 if (! CONSTANT_P (operand)
3498 && (enum reg_class) this_alternative[i] != NO_REGS)
3500 if (PREFERRED_RELOAD_CLASS
3501 (operand, (enum reg_class) this_alternative[i])
3502 == NO_REGS)
3503 reject = 600;
3505 #ifdef PREFERRED_OUTPUT_RELOAD_CLASS
3506 if (operand_type[i] == RELOAD_FOR_OUTPUT
3507 && PREFERRED_OUTPUT_RELOAD_CLASS
3508 (operand, (enum reg_class) this_alternative[i])
3509 == NO_REGS)
3510 reject = 600;
3511 #endif
3514 /* We prefer to reload pseudos over reloading other things,
3515 since such reloads may be able to be eliminated later.
3516 If we are reloading a SCRATCH, we won't be generating any
3517 insns, just using a register, so it is also preferred.
3518 So bump REJECT in other cases. Don't do this in the
3519 case where we are forcing a constant into memory and
3520 it will then win since we don't want to have a different
3521 alternative match then. */
3522 if (! (REG_P (operand)
3523 && REGNO (operand) >= FIRST_PSEUDO_REGISTER)
3524 && GET_CODE (operand) != SCRATCH
3525 && ! (const_to_mem && constmemok))
3526 reject += 2;
3528 /* Input reloads can be inherited more often than output
3529 reloads can be removed, so penalize output reloads. */
3530 if (operand_type[i] != RELOAD_FOR_INPUT
3531 && GET_CODE (operand) != SCRATCH)
3532 reject++;
3535 /* If this operand is a pseudo register that didn't get a hard
3536 reg and this alternative accepts some register, see if the
3537 class that we want is a subset of the preferred class for this
3538 register. If not, but it intersects that class, use the
3539 preferred class instead. If it does not intersect the preferred
3540 class, show that usage of this alternative should be discouraged;
3541 it will be discouraged more still if the register is `preferred
3542 or nothing'. We do this because it increases the chance of
3543 reusing our spill register in a later insn and avoiding a pair
3544 of memory stores and loads.
3546 Don't bother with this if this alternative will accept this
3547 operand.
3549 Don't do this for a multiword operand, since it is only a
3550 small win and has the risk of requiring more spill registers,
3551 which could cause a large loss.
3553 Don't do this if the preferred class has only one register
3554 because we might otherwise exhaust the class. */
3556 if (! win && ! did_match
3557 && this_alternative[i] != (int) NO_REGS
3558 && GET_MODE_SIZE (operand_mode[i]) <= UNITS_PER_WORD
3559 && reg_class_size [(int) preferred_class[i]] > 0
3560 && ! SMALL_REGISTER_CLASS_P (preferred_class[i]))
3562 if (! reg_class_subset_p (this_alternative[i],
3563 preferred_class[i]))
3565 /* Since we don't have a way of forming the intersection,
3566 we just do something special if the preferred class
3567 is a subset of the class we have; that's the most
3568 common case anyway. */
3569 if (reg_class_subset_p (preferred_class[i],
3570 this_alternative[i]))
3571 this_alternative[i] = (int) preferred_class[i];
3572 else
3573 reject += (2 + 2 * pref_or_nothing[i]);
3578 /* Now see if any output operands that are marked "earlyclobber"
3579 in this alternative conflict with any input operands
3580 or any memory addresses. */
3582 for (i = 0; i < noperands; i++)
3583 if (this_alternative_earlyclobber[i]
3584 && (this_alternative_win[i] || this_alternative_match_win[i]))
3586 struct decomposition early_data;
3588 early_data = decompose (recog_data.operand[i]);
3590 gcc_assert (modified[i] != RELOAD_READ);
3592 if (this_alternative[i] == NO_REGS)
3594 this_alternative_earlyclobber[i] = 0;
3595 gcc_assert (this_insn_is_asm);
3596 error_for_asm (this_insn,
3597 "%<&%> constraint used with no register class");
3600 for (j = 0; j < noperands; j++)
3601 /* Is this an input operand or a memory ref? */
3602 if ((MEM_P (recog_data.operand[j])
3603 || modified[j] != RELOAD_WRITE)
3604 && j != i
3605 /* Ignore things like match_operator operands. */
3606 && *recog_data.constraints[j] != 0
3607 /* Don't count an input operand that is constrained to match
3608 the early clobber operand. */
3609 && ! (this_alternative_matches[j] == i
3610 && rtx_equal_p (recog_data.operand[i],
3611 recog_data.operand[j]))
3612 /* Is it altered by storing the earlyclobber operand? */
3613 && !immune_p (recog_data.operand[j], recog_data.operand[i],
3614 early_data))
3616 /* If the output is in a non-empty few-regs class,
3617 it's costly to reload it, so reload the input instead. */
3618 if (SMALL_REGISTER_CLASS_P (this_alternative[i])
3619 && (REG_P (recog_data.operand[j])
3620 || GET_CODE (recog_data.operand[j]) == SUBREG))
3622 losers++;
3623 this_alternative_win[j] = 0;
3624 this_alternative_match_win[j] = 0;
3626 else
3627 break;
3629 /* If an earlyclobber operand conflicts with something,
3630 it must be reloaded, so request this and count the cost. */
3631 if (j != noperands)
3633 losers++;
3634 this_alternative_win[i] = 0;
3635 this_alternative_match_win[j] = 0;
3636 for (j = 0; j < noperands; j++)
3637 if (this_alternative_matches[j] == i
3638 && this_alternative_match_win[j])
3640 this_alternative_win[j] = 0;
3641 this_alternative_match_win[j] = 0;
3642 losers++;
3647 /* If one alternative accepts all the operands, no reload required,
3648 choose that alternative; don't consider the remaining ones. */
3649 if (losers == 0)
3651 /* Unswap these so that they are never swapped at `finish'. */
3652 if (commutative >= 0)
3654 recog_data.operand[commutative] = substed_operand[commutative];
3655 recog_data.operand[commutative + 1]
3656 = substed_operand[commutative + 1];
3658 for (i = 0; i < noperands; i++)
3660 goal_alternative_win[i] = this_alternative_win[i];
3661 goal_alternative_match_win[i] = this_alternative_match_win[i];
3662 goal_alternative[i] = this_alternative[i];
3663 goal_alternative_offmemok[i] = this_alternative_offmemok[i];
3664 goal_alternative_matches[i] = this_alternative_matches[i];
3665 goal_alternative_earlyclobber[i]
3666 = this_alternative_earlyclobber[i];
3668 goal_alternative_number = this_alternative_number;
3669 goal_alternative_swapped = swapped;
3670 goal_earlyclobber = this_earlyclobber;
3671 goto finish;
3674 /* REJECT, set by the ! and ? constraint characters and when a register
3675 would be reloaded into a non-preferred class, discourages the use of
3676 this alternative for a reload goal. REJECT is incremented by six
3677 for each ? and two for each non-preferred class. */
3678 losers = losers * 6 + reject;
3680 /* If this alternative can be made to work by reloading,
3681 and it needs less reloading than the others checked so far,
3682 record it as the chosen goal for reloading. */
3683 if (! bad && best > losers)
3685 for (i = 0; i < noperands; i++)
3687 goal_alternative[i] = this_alternative[i];
3688 goal_alternative_win[i] = this_alternative_win[i];
3689 goal_alternative_match_win[i] = this_alternative_match_win[i];
3690 goal_alternative_offmemok[i] = this_alternative_offmemok[i];
3691 goal_alternative_matches[i] = this_alternative_matches[i];
3692 goal_alternative_earlyclobber[i]
3693 = this_alternative_earlyclobber[i];
3695 goal_alternative_swapped = swapped;
3696 best = losers;
3697 goal_alternative_number = this_alternative_number;
3698 goal_earlyclobber = this_earlyclobber;
3702 /* If insn is commutative (it's safe to exchange a certain pair of operands)
3703 then we need to try each alternative twice,
3704 the second time matching those two operands
3705 as if we had exchanged them.
3706 To do this, really exchange them in operands.
3708 If we have just tried the alternatives the second time,
3709 return operands to normal and drop through. */
3711 if (commutative >= 0)
3713 swapped = !swapped;
3714 if (swapped)
3716 enum reg_class tclass;
3717 int t;
3719 recog_data.operand[commutative] = substed_operand[commutative + 1];
3720 recog_data.operand[commutative + 1] = substed_operand[commutative];
3721 /* Swap the duplicates too. */
3722 for (i = 0; i < recog_data.n_dups; i++)
3723 if (recog_data.dup_num[i] == commutative
3724 || recog_data.dup_num[i] == commutative + 1)
3725 *recog_data.dup_loc[i]
3726 = recog_data.operand[(int) recog_data.dup_num[i]];
3728 tclass = preferred_class[commutative];
3729 preferred_class[commutative] = preferred_class[commutative + 1];
3730 preferred_class[commutative + 1] = tclass;
3732 t = pref_or_nothing[commutative];
3733 pref_or_nothing[commutative] = pref_or_nothing[commutative + 1];
3734 pref_or_nothing[commutative + 1] = t;
3736 t = address_reloaded[commutative];
3737 address_reloaded[commutative] = address_reloaded[commutative + 1];
3738 address_reloaded[commutative + 1] = t;
3740 memcpy (constraints, recog_data.constraints,
3741 noperands * sizeof (char *));
3742 goto try_swapped;
3744 else
3746 recog_data.operand[commutative] = substed_operand[commutative];
3747 recog_data.operand[commutative + 1]
3748 = substed_operand[commutative + 1];
3749 /* Unswap the duplicates too. */
3750 for (i = 0; i < recog_data.n_dups; i++)
3751 if (recog_data.dup_num[i] == commutative
3752 || recog_data.dup_num[i] == commutative + 1)
3753 *recog_data.dup_loc[i]
3754 = recog_data.operand[(int) recog_data.dup_num[i]];
3758 /* The operands don't meet the constraints.
3759 goal_alternative describes the alternative
3760 that we could reach by reloading the fewest operands.
3761 Reload so as to fit it. */
3763 if (best == MAX_RECOG_OPERANDS * 2 + 600)
3765 /* No alternative works with reloads?? */
3766 if (insn_code_number >= 0)
3767 fatal_insn ("unable to generate reloads for:", insn);
3768 error_for_asm (insn, "inconsistent operand constraints in an %<asm%>");
3769 /* Avoid further trouble with this insn. */
3770 PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
3771 n_reloads = 0;
3772 return 0;
3775 /* Jump to `finish' from above if all operands are valid already.
3776 In that case, goal_alternative_win is all 1. */
3777 finish:
3779 /* Right now, for any pair of operands I and J that are required to match,
3780 with I < J,
3781 goal_alternative_matches[J] is I.
3782 Set up goal_alternative_matched as the inverse function:
3783 goal_alternative_matched[I] = J. */
3785 for (i = 0; i < noperands; i++)
3786 goal_alternative_matched[i] = -1;
3788 for (i = 0; i < noperands; i++)
3789 if (! goal_alternative_win[i]
3790 && goal_alternative_matches[i] >= 0)
3791 goal_alternative_matched[goal_alternative_matches[i]] = i;
3793 for (i = 0; i < noperands; i++)
3794 goal_alternative_win[i] |= goal_alternative_match_win[i];
3796 /* If the best alternative is with operands 1 and 2 swapped,
3797 consider them swapped before reporting the reloads. Update the
3798 operand numbers of any reloads already pushed. */
3800 if (goal_alternative_swapped)
3802 rtx tem;
3804 tem = substed_operand[commutative];
3805 substed_operand[commutative] = substed_operand[commutative + 1];
3806 substed_operand[commutative + 1] = tem;
3807 tem = recog_data.operand[commutative];
3808 recog_data.operand[commutative] = recog_data.operand[commutative + 1];
3809 recog_data.operand[commutative + 1] = tem;
3810 tem = *recog_data.operand_loc[commutative];
3811 *recog_data.operand_loc[commutative]
3812 = *recog_data.operand_loc[commutative + 1];
3813 *recog_data.operand_loc[commutative + 1] = tem;
3815 for (i = 0; i < n_reloads; i++)
3817 if (rld[i].opnum == commutative)
3818 rld[i].opnum = commutative + 1;
3819 else if (rld[i].opnum == commutative + 1)
3820 rld[i].opnum = commutative;
3824 for (i = 0; i < noperands; i++)
3826 operand_reloadnum[i] = -1;
3828 /* If this is an earlyclobber operand, we need to widen the scope.
3829 The reload must remain valid from the start of the insn being
3830 reloaded until after the operand is stored into its destination.
3831 We approximate this with RELOAD_OTHER even though we know that we
3832 do not conflict with RELOAD_FOR_INPUT_ADDRESS reloads.
3834 One special case that is worth checking is when we have an
3835 output that is earlyclobber but isn't used past the insn (typically
3836 a SCRATCH). In this case, we only need have the reload live
3837 through the insn itself, but not for any of our input or output
3838 reloads.
3839 But we must not accidentally narrow the scope of an existing
3840 RELOAD_OTHER reload - leave these alone.
3842 In any case, anything needed to address this operand can remain
3843 however they were previously categorized. */
3845 if (goal_alternative_earlyclobber[i] && operand_type[i] != RELOAD_OTHER)
3846 operand_type[i]
3847 = (find_reg_note (insn, REG_UNUSED, recog_data.operand[i])
3848 ? RELOAD_FOR_INSN : RELOAD_OTHER);
3851 /* Any constants that aren't allowed and can't be reloaded
3852 into registers are here changed into memory references. */
3853 for (i = 0; i < noperands; i++)
3854 if (! goal_alternative_win[i])
3856 rtx op = recog_data.operand[i];
3857 rtx subreg = NULL_RTX;
3858 rtx plus = NULL_RTX;
3859 enum machine_mode mode = operand_mode[i];
3861 /* Reloads of SUBREGs of CONSTANT RTXs are handled later in
3862 push_reload so we have to let them pass here. */
3863 if (GET_CODE (op) == SUBREG)
3865 subreg = op;
3866 op = SUBREG_REG (op);
3867 mode = GET_MODE (op);
3870 if (GET_CODE (op) == PLUS)
3872 plus = op;
3873 op = XEXP (op, 1);
3876 if (CONST_POOL_OK_P (op)
3877 && ((PREFERRED_RELOAD_CLASS (op,
3878 (enum reg_class) goal_alternative[i])
3879 == NO_REGS)
3880 || no_input_reloads)
3881 && mode != VOIDmode)
3883 int this_address_reloaded;
3884 rtx tem = force_const_mem (mode, op);
3886 /* If we stripped a SUBREG or a PLUS above add it back. */
3887 if (plus != NULL_RTX)
3888 tem = gen_rtx_PLUS (mode, XEXP (plus, 0), tem);
3890 if (subreg != NULL_RTX)
3891 tem = gen_rtx_SUBREG (operand_mode[i], tem, SUBREG_BYTE (subreg));
3893 this_address_reloaded = 0;
3894 substed_operand[i] = recog_data.operand[i]
3895 = find_reloads_toplev (tem, i, address_type[i], ind_levels,
3896 0, insn, &this_address_reloaded);
3898 /* If the alternative accepts constant pool refs directly
3899 there will be no reload needed at all. */
3900 if (plus == NULL_RTX
3901 && subreg == NULL_RTX
3902 && alternative_allows_const_pool_ref (this_address_reloaded == 0
3903 ? substed_operand[i]
3904 : NULL,
3905 recog_data.constraints[i],
3906 goal_alternative_number))
3907 goal_alternative_win[i] = 1;
3911 /* Record the values of the earlyclobber operands for the caller. */
3912 if (goal_earlyclobber)
3913 for (i = 0; i < noperands; i++)
3914 if (goal_alternative_earlyclobber[i])
3915 reload_earlyclobbers[n_earlyclobbers++] = recog_data.operand[i];
3917 /* Now record reloads for all the operands that need them. */
3918 for (i = 0; i < noperands; i++)
3919 if (! goal_alternative_win[i])
3921 /* Operands that match previous ones have already been handled. */
3922 if (goal_alternative_matches[i] >= 0)
3924 /* Handle an operand with a nonoffsettable address
3925 appearing where an offsettable address will do
3926 by reloading the address into a base register.
3928 ??? We can also do this when the operand is a register and
3929 reg_equiv_mem is not offsettable, but this is a bit tricky,
3930 so we don't bother with it. It may not be worth doing. */
3931 else if (goal_alternative_matched[i] == -1
3932 && goal_alternative_offmemok[i]
3933 && MEM_P (recog_data.operand[i]))
3935 /* If the address to be reloaded is a VOIDmode constant,
3936 use Pmode as mode of the reload register, as would have
3937 been done by find_reloads_address. */
3938 enum machine_mode address_mode;
3939 address_mode = GET_MODE (XEXP (recog_data.operand[i], 0));
3940 if (address_mode == VOIDmode)
3941 address_mode = Pmode;
3943 operand_reloadnum[i]
3944 = push_reload (XEXP (recog_data.operand[i], 0), NULL_RTX,
3945 &XEXP (recog_data.operand[i], 0), (rtx*) 0,
3946 base_reg_class (VOIDmode, MEM, SCRATCH),
3947 address_mode,
3948 VOIDmode, 0, 0, i, RELOAD_FOR_INPUT);
3949 rld[operand_reloadnum[i]].inc
3950 = GET_MODE_SIZE (GET_MODE (recog_data.operand[i]));
3952 /* If this operand is an output, we will have made any
3953 reloads for its address as RELOAD_FOR_OUTPUT_ADDRESS, but
3954 now we are treating part of the operand as an input, so
3955 we must change these to RELOAD_FOR_INPUT_ADDRESS. */
3957 if (modified[i] == RELOAD_WRITE)
3959 for (j = 0; j < n_reloads; j++)
3961 if (rld[j].opnum == i)
3963 if (rld[j].when_needed == RELOAD_FOR_OUTPUT_ADDRESS)
3964 rld[j].when_needed = RELOAD_FOR_INPUT_ADDRESS;
3965 else if (rld[j].when_needed
3966 == RELOAD_FOR_OUTADDR_ADDRESS)
3967 rld[j].when_needed = RELOAD_FOR_INPADDR_ADDRESS;
3972 else if (goal_alternative_matched[i] == -1)
3974 operand_reloadnum[i]
3975 = push_reload ((modified[i] != RELOAD_WRITE
3976 ? recog_data.operand[i] : 0),
3977 (modified[i] != RELOAD_READ
3978 ? recog_data.operand[i] : 0),
3979 (modified[i] != RELOAD_WRITE
3980 ? recog_data.operand_loc[i] : 0),
3981 (modified[i] != RELOAD_READ
3982 ? recog_data.operand_loc[i] : 0),
3983 (enum reg_class) goal_alternative[i],
3984 (modified[i] == RELOAD_WRITE
3985 ? VOIDmode : operand_mode[i]),
3986 (modified[i] == RELOAD_READ
3987 ? VOIDmode : operand_mode[i]),
3988 (insn_code_number < 0 ? 0
3989 : insn_data[insn_code_number].operand[i].strict_low),
3990 0, i, operand_type[i]);
3992 /* In a matching pair of operands, one must be input only
3993 and the other must be output only.
3994 Pass the input operand as IN and the other as OUT. */
3995 else if (modified[i] == RELOAD_READ
3996 && modified[goal_alternative_matched[i]] == RELOAD_WRITE)
3998 operand_reloadnum[i]
3999 = push_reload (recog_data.operand[i],
4000 recog_data.operand[goal_alternative_matched[i]],
4001 recog_data.operand_loc[i],
4002 recog_data.operand_loc[goal_alternative_matched[i]],
4003 (enum reg_class) goal_alternative[i],
4004 operand_mode[i],
4005 operand_mode[goal_alternative_matched[i]],
4006 0, 0, i, RELOAD_OTHER);
4007 operand_reloadnum[goal_alternative_matched[i]] = output_reloadnum;
4009 else if (modified[i] == RELOAD_WRITE
4010 && modified[goal_alternative_matched[i]] == RELOAD_READ)
4012 operand_reloadnum[goal_alternative_matched[i]]
4013 = push_reload (recog_data.operand[goal_alternative_matched[i]],
4014 recog_data.operand[i],
4015 recog_data.operand_loc[goal_alternative_matched[i]],
4016 recog_data.operand_loc[i],
4017 (enum reg_class) goal_alternative[i],
4018 operand_mode[goal_alternative_matched[i]],
4019 operand_mode[i],
4020 0, 0, i, RELOAD_OTHER);
4021 operand_reloadnum[i] = output_reloadnum;
4023 else
4025 gcc_assert (insn_code_number < 0);
4026 error_for_asm (insn, "inconsistent operand constraints "
4027 "in an %<asm%>");
4028 /* Avoid further trouble with this insn. */
4029 PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
4030 n_reloads = 0;
4031 return 0;
4034 else if (goal_alternative_matched[i] < 0
4035 && goal_alternative_matches[i] < 0
4036 && address_operand_reloaded[i] != 1
4037 && optimize)
4039 /* For each non-matching operand that's a MEM or a pseudo-register
4040 that didn't get a hard register, make an optional reload.
4041 This may get done even if the insn needs no reloads otherwise. */
4043 rtx operand = recog_data.operand[i];
4045 while (GET_CODE (operand) == SUBREG)
4046 operand = SUBREG_REG (operand);
4047 if ((MEM_P (operand)
4048 || (REG_P (operand)
4049 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
4050 /* If this is only for an output, the optional reload would not
4051 actually cause us to use a register now, just note that
4052 something is stored here. */
4053 && ((enum reg_class) goal_alternative[i] != NO_REGS
4054 || modified[i] == RELOAD_WRITE)
4055 && ! no_input_reloads
4056 /* An optional output reload might allow to delete INSN later.
4057 We mustn't make in-out reloads on insns that are not permitted
4058 output reloads.
4059 If this is an asm, we can't delete it; we must not even call
4060 push_reload for an optional output reload in this case,
4061 because we can't be sure that the constraint allows a register,
4062 and push_reload verifies the constraints for asms. */
4063 && (modified[i] == RELOAD_READ
4064 || (! no_output_reloads && ! this_insn_is_asm)))
4065 operand_reloadnum[i]
4066 = push_reload ((modified[i] != RELOAD_WRITE
4067 ? recog_data.operand[i] : 0),
4068 (modified[i] != RELOAD_READ
4069 ? recog_data.operand[i] : 0),
4070 (modified[i] != RELOAD_WRITE
4071 ? recog_data.operand_loc[i] : 0),
4072 (modified[i] != RELOAD_READ
4073 ? recog_data.operand_loc[i] : 0),
4074 (enum reg_class) goal_alternative[i],
4075 (modified[i] == RELOAD_WRITE
4076 ? VOIDmode : operand_mode[i]),
4077 (modified[i] == RELOAD_READ
4078 ? VOIDmode : operand_mode[i]),
4079 (insn_code_number < 0 ? 0
4080 : insn_data[insn_code_number].operand[i].strict_low),
4081 1, i, operand_type[i]);
4082 /* If a memory reference remains (either as a MEM or a pseudo that
4083 did not get a hard register), yet we can't make an optional
4084 reload, check if this is actually a pseudo register reference;
4085 we then need to emit a USE and/or a CLOBBER so that reload
4086 inheritance will do the right thing. */
4087 else if (replace
4088 && (MEM_P (operand)
4089 || (REG_P (operand)
4090 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
4091 && reg_renumber [REGNO (operand)] < 0)))
4093 operand = *recog_data.operand_loc[i];
4095 while (GET_CODE (operand) == SUBREG)
4096 operand = SUBREG_REG (operand);
4097 if (REG_P (operand))
4099 if (modified[i] != RELOAD_WRITE)
4100 /* We mark the USE with QImode so that we recognize
4101 it as one that can be safely deleted at the end
4102 of reload. */
4103 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, operand),
4104 insn), QImode);
4105 if (modified[i] != RELOAD_READ)
4106 emit_insn_after (gen_rtx_CLOBBER (VOIDmode, operand), insn);
4110 else if (goal_alternative_matches[i] >= 0
4111 && goal_alternative_win[goal_alternative_matches[i]]
4112 && modified[i] == RELOAD_READ
4113 && modified[goal_alternative_matches[i]] == RELOAD_WRITE
4114 && ! no_input_reloads && ! no_output_reloads
4115 && optimize)
4117 /* Similarly, make an optional reload for a pair of matching
4118 objects that are in MEM or a pseudo that didn't get a hard reg. */
4120 rtx operand = recog_data.operand[i];
4122 while (GET_CODE (operand) == SUBREG)
4123 operand = SUBREG_REG (operand);
4124 if ((MEM_P (operand)
4125 || (REG_P (operand)
4126 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
4127 && ((enum reg_class) goal_alternative[goal_alternative_matches[i]]
4128 != NO_REGS))
4129 operand_reloadnum[i] = operand_reloadnum[goal_alternative_matches[i]]
4130 = push_reload (recog_data.operand[goal_alternative_matches[i]],
4131 recog_data.operand[i],
4132 recog_data.operand_loc[goal_alternative_matches[i]],
4133 recog_data.operand_loc[i],
4134 (enum reg_class) goal_alternative[goal_alternative_matches[i]],
4135 operand_mode[goal_alternative_matches[i]],
4136 operand_mode[i],
4137 0, 1, goal_alternative_matches[i], RELOAD_OTHER);
4140 /* Perform whatever substitutions on the operands we are supposed
4141 to make due to commutativity or replacement of registers
4142 with equivalent constants or memory slots. */
4144 for (i = 0; i < noperands; i++)
4146 /* We only do this on the last pass through reload, because it is
4147 possible for some data (like reg_equiv_address) to be changed during
4148 later passes. Moreover, we lose the opportunity to get a useful
4149 reload_{in,out}_reg when we do these replacements. */
4151 if (replace)
4153 rtx substitution = substed_operand[i];
4155 *recog_data.operand_loc[i] = substitution;
4157 /* If we're replacing an operand with a LABEL_REF, we need to
4158 make sure that there's a REG_LABEL_OPERAND note attached to
4159 this instruction. */
4160 if (GET_CODE (substitution) == LABEL_REF
4161 && !find_reg_note (insn, REG_LABEL_OPERAND,
4162 XEXP (substitution, 0))
4163 /* For a JUMP_P, if it was a branch target it must have
4164 already been recorded as such. */
4165 && (!JUMP_P (insn)
4166 || !label_is_jump_target_p (XEXP (substitution, 0),
4167 insn)))
4168 REG_NOTES (insn) = gen_rtx_INSN_LIST (REG_LABEL_OPERAND,
4169 XEXP (substitution, 0),
4170 REG_NOTES (insn));
4172 else
4173 retval |= (substed_operand[i] != *recog_data.operand_loc[i]);
4176 /* If this insn pattern contains any MATCH_DUP's, make sure that
4177 they will be substituted if the operands they match are substituted.
4178 Also do now any substitutions we already did on the operands.
4180 Don't do this if we aren't making replacements because we might be
4181 propagating things allocated by frame pointer elimination into places
4182 it doesn't expect. */
4184 if (insn_code_number >= 0 && replace)
4185 for (i = insn_data[insn_code_number].n_dups - 1; i >= 0; i--)
4187 int opno = recog_data.dup_num[i];
4188 *recog_data.dup_loc[i] = *recog_data.operand_loc[opno];
4189 dup_replacements (recog_data.dup_loc[i], recog_data.operand_loc[opno]);
4192 #if 0
4193 /* This loses because reloading of prior insns can invalidate the equivalence
4194 (or at least find_equiv_reg isn't smart enough to find it any more),
4195 causing this insn to need more reload regs than it needed before.
4196 It may be too late to make the reload regs available.
4197 Now this optimization is done safely in choose_reload_regs. */
4199 /* For each reload of a reg into some other class of reg,
4200 search for an existing equivalent reg (same value now) in the right class.
4201 We can use it as long as we don't need to change its contents. */
4202 for (i = 0; i < n_reloads; i++)
4203 if (rld[i].reg_rtx == 0
4204 && rld[i].in != 0
4205 && REG_P (rld[i].in)
4206 && rld[i].out == 0)
4208 rld[i].reg_rtx
4209 = find_equiv_reg (rld[i].in, insn, rld[i].class, -1,
4210 static_reload_reg_p, 0, rld[i].inmode);
4211 /* Prevent generation of insn to load the value
4212 because the one we found already has the value. */
4213 if (rld[i].reg_rtx)
4214 rld[i].in = rld[i].reg_rtx;
4216 #endif
4218 /* If we detected error and replaced asm instruction by USE, forget about the
4219 reloads. */
4220 if (GET_CODE (PATTERN (insn)) == USE
4221 && GET_CODE (XEXP (PATTERN (insn), 0)) == CONST_INT)
4222 n_reloads = 0;
4224 /* Perhaps an output reload can be combined with another
4225 to reduce needs by one. */
4226 if (!goal_earlyclobber)
4227 combine_reloads ();
4229 /* If we have a pair of reloads for parts of an address, they are reloading
4230 the same object, the operands themselves were not reloaded, and they
4231 are for two operands that are supposed to match, merge the reloads and
4232 change the type of the surviving reload to RELOAD_FOR_OPERAND_ADDRESS. */
4234 for (i = 0; i < n_reloads; i++)
4236 int k;
4238 for (j = i + 1; j < n_reloads; j++)
4239 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4240 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4241 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4242 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4243 && (rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
4244 || rld[j].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4245 || rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4246 || rld[j].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4247 && rtx_equal_p (rld[i].in, rld[j].in)
4248 && (operand_reloadnum[rld[i].opnum] < 0
4249 || rld[operand_reloadnum[rld[i].opnum]].optional)
4250 && (operand_reloadnum[rld[j].opnum] < 0
4251 || rld[operand_reloadnum[rld[j].opnum]].optional)
4252 && (goal_alternative_matches[rld[i].opnum] == rld[j].opnum
4253 || (goal_alternative_matches[rld[j].opnum]
4254 == rld[i].opnum)))
4256 for (k = 0; k < n_replacements; k++)
4257 if (replacements[k].what == j)
4258 replacements[k].what = i;
4260 if (rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4261 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4262 rld[i].when_needed = RELOAD_FOR_OPADDR_ADDR;
4263 else
4264 rld[i].when_needed = RELOAD_FOR_OPERAND_ADDRESS;
4265 rld[j].in = 0;
4269 /* Scan all the reloads and update their type.
4270 If a reload is for the address of an operand and we didn't reload
4271 that operand, change the type. Similarly, change the operand number
4272 of a reload when two operands match. If a reload is optional, treat it
4273 as though the operand isn't reloaded.
4275 ??? This latter case is somewhat odd because if we do the optional
4276 reload, it means the object is hanging around. Thus we need only
4277 do the address reload if the optional reload was NOT done.
4279 Change secondary reloads to be the address type of their operand, not
4280 the normal type.
4282 If an operand's reload is now RELOAD_OTHER, change any
4283 RELOAD_FOR_INPUT_ADDRESS reloads of that operand to
4284 RELOAD_FOR_OTHER_ADDRESS. */
4286 for (i = 0; i < n_reloads; i++)
4288 if (rld[i].secondary_p
4289 && rld[i].when_needed == operand_type[rld[i].opnum])
4290 rld[i].when_needed = address_type[rld[i].opnum];
4292 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4293 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4294 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4295 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4296 && (operand_reloadnum[rld[i].opnum] < 0
4297 || rld[operand_reloadnum[rld[i].opnum]].optional))
4299 /* If we have a secondary reload to go along with this reload,
4300 change its type to RELOAD_FOR_OPADDR_ADDR. */
4302 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4303 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
4304 && rld[i].secondary_in_reload != -1)
4306 int secondary_in_reload = rld[i].secondary_in_reload;
4308 rld[secondary_in_reload].when_needed = RELOAD_FOR_OPADDR_ADDR;
4310 /* If there's a tertiary reload we have to change it also. */
4311 if (secondary_in_reload > 0
4312 && rld[secondary_in_reload].secondary_in_reload != -1)
4313 rld[rld[secondary_in_reload].secondary_in_reload].when_needed
4314 = RELOAD_FOR_OPADDR_ADDR;
4317 if ((rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4318 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4319 && rld[i].secondary_out_reload != -1)
4321 int secondary_out_reload = rld[i].secondary_out_reload;
4323 rld[secondary_out_reload].when_needed = RELOAD_FOR_OPADDR_ADDR;
4325 /* If there's a tertiary reload we have to change it also. */
4326 if (secondary_out_reload
4327 && rld[secondary_out_reload].secondary_out_reload != -1)
4328 rld[rld[secondary_out_reload].secondary_out_reload].when_needed
4329 = RELOAD_FOR_OPADDR_ADDR;
4332 if (rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4333 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4334 rld[i].when_needed = RELOAD_FOR_OPADDR_ADDR;
4335 else
4336 rld[i].when_needed = RELOAD_FOR_OPERAND_ADDRESS;
4339 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4340 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
4341 && operand_reloadnum[rld[i].opnum] >= 0
4342 && (rld[operand_reloadnum[rld[i].opnum]].when_needed
4343 == RELOAD_OTHER))
4344 rld[i].when_needed = RELOAD_FOR_OTHER_ADDRESS;
4346 if (goal_alternative_matches[rld[i].opnum] >= 0)
4347 rld[i].opnum = goal_alternative_matches[rld[i].opnum];
4350 /* Scan all the reloads, and check for RELOAD_FOR_OPERAND_ADDRESS reloads.
4351 If we have more than one, then convert all RELOAD_FOR_OPADDR_ADDR
4352 reloads to RELOAD_FOR_OPERAND_ADDRESS reloads.
4354 choose_reload_regs assumes that RELOAD_FOR_OPADDR_ADDR reloads never
4355 conflict with RELOAD_FOR_OPERAND_ADDRESS reloads. This is true for a
4356 single pair of RELOAD_FOR_OPADDR_ADDR/RELOAD_FOR_OPERAND_ADDRESS reloads.
4357 However, if there is more than one RELOAD_FOR_OPERAND_ADDRESS reload,
4358 then a RELOAD_FOR_OPADDR_ADDR reload conflicts with all
4359 RELOAD_FOR_OPERAND_ADDRESS reloads other than the one that uses it.
4360 This is complicated by the fact that a single operand can have more
4361 than one RELOAD_FOR_OPERAND_ADDRESS reload. It is very difficult to fix
4362 choose_reload_regs without affecting code quality, and cases that
4363 actually fail are extremely rare, so it turns out to be better to fix
4364 the problem here by not generating cases that choose_reload_regs will
4365 fail for. */
4366 /* There is a similar problem with RELOAD_FOR_INPUT_ADDRESS /
4367 RELOAD_FOR_OUTPUT_ADDRESS when there is more than one of a kind for
4368 a single operand.
4369 We can reduce the register pressure by exploiting that a
4370 RELOAD_FOR_X_ADDR_ADDR that precedes all RELOAD_FOR_X_ADDRESS reloads
4371 does not conflict with any of them, if it is only used for the first of
4372 the RELOAD_FOR_X_ADDRESS reloads. */
4374 int first_op_addr_num = -2;
4375 int first_inpaddr_num[MAX_RECOG_OPERANDS];
4376 int first_outpaddr_num[MAX_RECOG_OPERANDS];
4377 int need_change = 0;
4378 /* We use last_op_addr_reload and the contents of the above arrays
4379 first as flags - -2 means no instance encountered, -1 means exactly
4380 one instance encountered.
4381 If more than one instance has been encountered, we store the reload
4382 number of the first reload of the kind in question; reload numbers
4383 are known to be non-negative. */
4384 for (i = 0; i < noperands; i++)
4385 first_inpaddr_num[i] = first_outpaddr_num[i] = -2;
4386 for (i = n_reloads - 1; i >= 0; i--)
4388 switch (rld[i].when_needed)
4390 case RELOAD_FOR_OPERAND_ADDRESS:
4391 if (++first_op_addr_num >= 0)
4393 first_op_addr_num = i;
4394 need_change = 1;
4396 break;
4397 case RELOAD_FOR_INPUT_ADDRESS:
4398 if (++first_inpaddr_num[rld[i].opnum] >= 0)
4400 first_inpaddr_num[rld[i].opnum] = i;
4401 need_change = 1;
4403 break;
4404 case RELOAD_FOR_OUTPUT_ADDRESS:
4405 if (++first_outpaddr_num[rld[i].opnum] >= 0)
4407 first_outpaddr_num[rld[i].opnum] = i;
4408 need_change = 1;
4410 break;
4411 default:
4412 break;
4416 if (need_change)
4418 for (i = 0; i < n_reloads; i++)
4420 int first_num;
4421 enum reload_type type;
4423 switch (rld[i].when_needed)
4425 case RELOAD_FOR_OPADDR_ADDR:
4426 first_num = first_op_addr_num;
4427 type = RELOAD_FOR_OPERAND_ADDRESS;
4428 break;
4429 case RELOAD_FOR_INPADDR_ADDRESS:
4430 first_num = first_inpaddr_num[rld[i].opnum];
4431 type = RELOAD_FOR_INPUT_ADDRESS;
4432 break;
4433 case RELOAD_FOR_OUTADDR_ADDRESS:
4434 first_num = first_outpaddr_num[rld[i].opnum];
4435 type = RELOAD_FOR_OUTPUT_ADDRESS;
4436 break;
4437 default:
4438 continue;
4440 if (first_num < 0)
4441 continue;
4442 else if (i > first_num)
4443 rld[i].when_needed = type;
4444 else
4446 /* Check if the only TYPE reload that uses reload I is
4447 reload FIRST_NUM. */
4448 for (j = n_reloads - 1; j > first_num; j--)
4450 if (rld[j].when_needed == type
4451 && (rld[i].secondary_p
4452 ? rld[j].secondary_in_reload == i
4453 : reg_mentioned_p (rld[i].in, rld[j].in)))
4455 rld[i].when_needed = type;
4456 break;
4464 /* See if we have any reloads that are now allowed to be merged
4465 because we've changed when the reload is needed to
4466 RELOAD_FOR_OPERAND_ADDRESS or RELOAD_FOR_OTHER_ADDRESS. Only
4467 check for the most common cases. */
4469 for (i = 0; i < n_reloads; i++)
4470 if (rld[i].in != 0 && rld[i].out == 0
4471 && (rld[i].when_needed == RELOAD_FOR_OPERAND_ADDRESS
4472 || rld[i].when_needed == RELOAD_FOR_OPADDR_ADDR
4473 || rld[i].when_needed == RELOAD_FOR_OTHER_ADDRESS))
4474 for (j = 0; j < n_reloads; j++)
4475 if (i != j && rld[j].in != 0 && rld[j].out == 0
4476 && rld[j].when_needed == rld[i].when_needed
4477 && MATCHES (rld[i].in, rld[j].in)
4478 && rld[i].class == rld[j].class
4479 && !rld[i].nocombine && !rld[j].nocombine
4480 && rld[i].reg_rtx == rld[j].reg_rtx)
4482 rld[i].opnum = MIN (rld[i].opnum, rld[j].opnum);
4483 transfer_replacements (i, j);
4484 rld[j].in = 0;
4487 #ifdef HAVE_cc0
4488 /* If we made any reloads for addresses, see if they violate a
4489 "no input reloads" requirement for this insn. But loads that we
4490 do after the insn (such as for output addresses) are fine. */
4491 if (no_input_reloads)
4492 for (i = 0; i < n_reloads; i++)
4493 gcc_assert (rld[i].in == 0
4494 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS
4495 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS);
4496 #endif
4498 /* Compute reload_mode and reload_nregs. */
4499 for (i = 0; i < n_reloads; i++)
4501 rld[i].mode
4502 = (rld[i].inmode == VOIDmode
4503 || (GET_MODE_SIZE (rld[i].outmode)
4504 > GET_MODE_SIZE (rld[i].inmode)))
4505 ? rld[i].outmode : rld[i].inmode;
4507 rld[i].nregs = CLASS_MAX_NREGS (rld[i].class, rld[i].mode);
4510 /* Special case a simple move with an input reload and a
4511 destination of a hard reg, if the hard reg is ok, use it. */
4512 for (i = 0; i < n_reloads; i++)
4513 if (rld[i].when_needed == RELOAD_FOR_INPUT
4514 && GET_CODE (PATTERN (insn)) == SET
4515 && REG_P (SET_DEST (PATTERN (insn)))
4516 && (SET_SRC (PATTERN (insn)) == rld[i].in
4517 || SET_SRC (PATTERN (insn)) == rld[i].in_reg)
4518 && !elimination_target_reg_p (SET_DEST (PATTERN (insn))))
4520 rtx dest = SET_DEST (PATTERN (insn));
4521 unsigned int regno = REGNO (dest);
4523 if (regno < FIRST_PSEUDO_REGISTER
4524 && TEST_HARD_REG_BIT (reg_class_contents[rld[i].class], regno)
4525 && HARD_REGNO_MODE_OK (regno, rld[i].mode))
4527 int nr = hard_regno_nregs[regno][rld[i].mode];
4528 int ok = 1, nri;
4530 for (nri = 1; nri < nr; nri ++)
4531 if (! TEST_HARD_REG_BIT (reg_class_contents[rld[i].class], regno + nri))
4532 ok = 0;
4534 if (ok)
4535 rld[i].reg_rtx = dest;
4539 return retval;
4542 /* Return true if alternative number ALTNUM in constraint-string
4543 CONSTRAINT is guaranteed to accept a reloaded constant-pool reference.
4544 MEM gives the reference if it didn't need any reloads, otherwise it
4545 is null. */
4547 static bool
4548 alternative_allows_const_pool_ref (rtx mem, const char *constraint, int altnum)
4550 int c;
4552 /* Skip alternatives before the one requested. */
4553 while (altnum > 0)
4555 while (*constraint++ != ',');
4556 altnum--;
4558 /* Scan the requested alternative for 'm' or 'o'.
4559 If one of them is present, this alternative accepts the result of
4560 passing a constant-pool reference through find_reloads_toplev.
4562 The same is true of extra memory constraints if the address
4563 was reloaded into a register. However, the target may elect
4564 to disallow the original constant address, forcing it to be
4565 reloaded into a register instead. */
4566 for (; (c = *constraint) && c != ',' && c != '#';
4567 constraint += CONSTRAINT_LEN (c, constraint))
4569 if (c == 'm' || c == 'o')
4570 return true;
4571 #ifdef EXTRA_CONSTRAINT_STR
4572 if (EXTRA_MEMORY_CONSTRAINT (c, constraint)
4573 && (mem == NULL || EXTRA_CONSTRAINT_STR (mem, c, constraint)))
4574 return true;
4575 #endif
4577 return false;
4580 /* Scan X for memory references and scan the addresses for reloading.
4581 Also checks for references to "constant" regs that we want to eliminate
4582 and replaces them with the values they stand for.
4583 We may alter X destructively if it contains a reference to such.
4584 If X is just a constant reg, we return the equivalent value
4585 instead of X.
4587 IND_LEVELS says how many levels of indirect addressing this machine
4588 supports.
4590 OPNUM and TYPE identify the purpose of the reload.
4592 IS_SET_DEST is true if X is the destination of a SET, which is not
4593 appropriate to be replaced by a constant.
4595 INSN, if nonzero, is the insn in which we do the reload. It is used
4596 to determine if we may generate output reloads, and where to put USEs
4597 for pseudos that we have to replace with stack slots.
4599 ADDRESS_RELOADED. If nonzero, is a pointer to where we put the
4600 result of find_reloads_address. */
4602 static rtx
4603 find_reloads_toplev (rtx x, int opnum, enum reload_type type,
4604 int ind_levels, int is_set_dest, rtx insn,
4605 int *address_reloaded)
4607 RTX_CODE code = GET_CODE (x);
4609 const char *fmt = GET_RTX_FORMAT (code);
4610 int i;
4611 int copied;
4613 if (code == REG)
4615 /* This code is duplicated for speed in find_reloads. */
4616 int regno = REGNO (x);
4617 if (reg_equiv_constant[regno] != 0 && !is_set_dest)
4618 x = reg_equiv_constant[regno];
4619 #if 0
4620 /* This creates (subreg (mem...)) which would cause an unnecessary
4621 reload of the mem. */
4622 else if (reg_equiv_mem[regno] != 0)
4623 x = reg_equiv_mem[regno];
4624 #endif
4625 else if (reg_equiv_memory_loc[regno]
4626 && (reg_equiv_address[regno] != 0 || num_not_at_initial_offset))
4628 rtx mem = make_memloc (x, regno);
4629 if (reg_equiv_address[regno]
4630 || ! rtx_equal_p (mem, reg_equiv_mem[regno]))
4632 /* If this is not a toplevel operand, find_reloads doesn't see
4633 this substitution. We have to emit a USE of the pseudo so
4634 that delete_output_reload can see it. */
4635 if (replace_reloads && recog_data.operand[opnum] != x)
4636 /* We mark the USE with QImode so that we recognize it
4637 as one that can be safely deleted at the end of
4638 reload. */
4639 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, x), insn),
4640 QImode);
4641 x = mem;
4642 i = find_reloads_address (GET_MODE (x), &x, XEXP (x, 0), &XEXP (x, 0),
4643 opnum, type, ind_levels, insn);
4644 if (!rtx_equal_p (x, mem))
4645 push_reg_equiv_alt_mem (regno, x);
4646 if (address_reloaded)
4647 *address_reloaded = i;
4650 return x;
4652 if (code == MEM)
4654 rtx tem = x;
4656 i = find_reloads_address (GET_MODE (x), &tem, XEXP (x, 0), &XEXP (x, 0),
4657 opnum, type, ind_levels, insn);
4658 if (address_reloaded)
4659 *address_reloaded = i;
4661 return tem;
4664 if (code == SUBREG && REG_P (SUBREG_REG (x)))
4666 /* Check for SUBREG containing a REG that's equivalent to a
4667 constant. If the constant has a known value, truncate it
4668 right now. Similarly if we are extracting a single-word of a
4669 multi-word constant. If the constant is symbolic, allow it
4670 to be substituted normally. push_reload will strip the
4671 subreg later. The constant must not be VOIDmode, because we
4672 will lose the mode of the register (this should never happen
4673 because one of the cases above should handle it). */
4675 int regno = REGNO (SUBREG_REG (x));
4676 rtx tem;
4678 if (regno >= FIRST_PSEUDO_REGISTER
4679 && reg_renumber[regno] < 0
4680 && reg_equiv_constant[regno] != 0)
4682 tem =
4683 simplify_gen_subreg (GET_MODE (x), reg_equiv_constant[regno],
4684 GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x));
4685 gcc_assert (tem);
4686 if (CONSTANT_P (tem) && !LEGITIMATE_CONSTANT_P (tem))
4688 tem = force_const_mem (GET_MODE (x), tem);
4689 i = find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
4690 &XEXP (tem, 0), opnum, type,
4691 ind_levels, insn);
4692 if (address_reloaded)
4693 *address_reloaded = i;
4695 return tem;
4698 /* If the subreg contains a reg that will be converted to a mem,
4699 convert the subreg to a narrower memref now.
4700 Otherwise, we would get (subreg (mem ...) ...),
4701 which would force reload of the mem.
4703 We also need to do this if there is an equivalent MEM that is
4704 not offsettable. In that case, alter_subreg would produce an
4705 invalid address on big-endian machines.
4707 For machines that extend byte loads, we must not reload using
4708 a wider mode if we have a paradoxical SUBREG. find_reloads will
4709 force a reload in that case. So we should not do anything here. */
4711 if (regno >= FIRST_PSEUDO_REGISTER
4712 #ifdef LOAD_EXTEND_OP
4713 && (GET_MODE_SIZE (GET_MODE (x))
4714 <= GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
4715 #endif
4716 && (reg_equiv_address[regno] != 0
4717 || (reg_equiv_mem[regno] != 0
4718 && (! strict_memory_address_p (GET_MODE (x),
4719 XEXP (reg_equiv_mem[regno], 0))
4720 || ! offsettable_memref_p (reg_equiv_mem[regno])
4721 || num_not_at_initial_offset))))
4722 x = find_reloads_subreg_address (x, 1, opnum, type, ind_levels,
4723 insn);
4726 for (copied = 0, i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
4728 if (fmt[i] == 'e')
4730 rtx new_part = find_reloads_toplev (XEXP (x, i), opnum, type,
4731 ind_levels, is_set_dest, insn,
4732 address_reloaded);
4733 /* If we have replaced a reg with it's equivalent memory loc -
4734 that can still be handled here e.g. if it's in a paradoxical
4735 subreg - we must make the change in a copy, rather than using
4736 a destructive change. This way, find_reloads can still elect
4737 not to do the change. */
4738 if (new_part != XEXP (x, i) && ! CONSTANT_P (new_part) && ! copied)
4740 x = shallow_copy_rtx (x);
4741 copied = 1;
4743 XEXP (x, i) = new_part;
4746 return x;
4749 /* Return a mem ref for the memory equivalent of reg REGNO.
4750 This mem ref is not shared with anything. */
4752 static rtx
4753 make_memloc (rtx ad, int regno)
4755 /* We must rerun eliminate_regs, in case the elimination
4756 offsets have changed. */
4757 rtx tem
4758 = XEXP (eliminate_regs (reg_equiv_memory_loc[regno], 0, NULL_RTX), 0);
4760 /* If TEM might contain a pseudo, we must copy it to avoid
4761 modifying it when we do the substitution for the reload. */
4762 if (rtx_varies_p (tem, 0))
4763 tem = copy_rtx (tem);
4765 tem = replace_equiv_address_nv (reg_equiv_memory_loc[regno], tem);
4766 tem = adjust_address_nv (tem, GET_MODE (ad), 0);
4768 /* Copy the result if it's still the same as the equivalence, to avoid
4769 modifying it when we do the substitution for the reload. */
4770 if (tem == reg_equiv_memory_loc[regno])
4771 tem = copy_rtx (tem);
4772 return tem;
4775 /* Returns true if AD could be turned into a valid memory reference
4776 to mode MODE by reloading the part pointed to by PART into a
4777 register. */
4779 static int
4780 maybe_memory_address_p (enum machine_mode mode, rtx ad, rtx *part)
4782 int retv;
4783 rtx tem = *part;
4784 rtx reg = gen_rtx_REG (GET_MODE (tem), max_reg_num ());
4786 *part = reg;
4787 retv = memory_address_p (mode, ad);
4788 *part = tem;
4790 return retv;
4793 /* Record all reloads needed for handling memory address AD
4794 which appears in *LOC in a memory reference to mode MODE
4795 which itself is found in location *MEMREFLOC.
4796 Note that we take shortcuts assuming that no multi-reg machine mode
4797 occurs as part of an address.
4799 OPNUM and TYPE specify the purpose of this reload.
4801 IND_LEVELS says how many levels of indirect addressing this machine
4802 supports.
4804 INSN, if nonzero, is the insn in which we do the reload. It is used
4805 to determine if we may generate output reloads, and where to put USEs
4806 for pseudos that we have to replace with stack slots.
4808 Value is one if this address is reloaded or replaced as a whole; it is
4809 zero if the top level of this address was not reloaded or replaced, and
4810 it is -1 if it may or may not have been reloaded or replaced.
4812 Note that there is no verification that the address will be valid after
4813 this routine does its work. Instead, we rely on the fact that the address
4814 was valid when reload started. So we need only undo things that reload
4815 could have broken. These are wrong register types, pseudos not allocated
4816 to a hard register, and frame pointer elimination. */
4818 static int
4819 find_reloads_address (enum machine_mode mode, rtx *memrefloc, rtx ad,
4820 rtx *loc, int opnum, enum reload_type type,
4821 int ind_levels, rtx insn)
4823 int regno;
4824 int removed_and = 0;
4825 int op_index;
4826 rtx tem;
4828 /* If the address is a register, see if it is a legitimate address and
4829 reload if not. We first handle the cases where we need not reload
4830 or where we must reload in a non-standard way. */
4832 if (REG_P (ad))
4834 regno = REGNO (ad);
4836 if (reg_equiv_constant[regno] != 0)
4838 find_reloads_address_part (reg_equiv_constant[regno], loc,
4839 base_reg_class (mode, MEM, SCRATCH),
4840 GET_MODE (ad), opnum, type, ind_levels);
4841 return 1;
4844 tem = reg_equiv_memory_loc[regno];
4845 if (tem != 0)
4847 if (reg_equiv_address[regno] != 0 || num_not_at_initial_offset)
4849 tem = make_memloc (ad, regno);
4850 if (! strict_memory_address_p (GET_MODE (tem), XEXP (tem, 0)))
4852 rtx orig = tem;
4854 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
4855 &XEXP (tem, 0), opnum,
4856 ADDR_TYPE (type), ind_levels, insn);
4857 if (!rtx_equal_p (tem, orig))
4858 push_reg_equiv_alt_mem (regno, tem);
4860 /* We can avoid a reload if the register's equivalent memory
4861 expression is valid as an indirect memory address.
4862 But not all addresses are valid in a mem used as an indirect
4863 address: only reg or reg+constant. */
4865 if (ind_levels > 0
4866 && strict_memory_address_p (mode, tem)
4867 && (REG_P (XEXP (tem, 0))
4868 || (GET_CODE (XEXP (tem, 0)) == PLUS
4869 && REG_P (XEXP (XEXP (tem, 0), 0))
4870 && CONSTANT_P (XEXP (XEXP (tem, 0), 1)))))
4872 /* TEM is not the same as what we'll be replacing the
4873 pseudo with after reload, put a USE in front of INSN
4874 in the final reload pass. */
4875 if (replace_reloads
4876 && num_not_at_initial_offset
4877 && ! rtx_equal_p (tem, reg_equiv_mem[regno]))
4879 *loc = tem;
4880 /* We mark the USE with QImode so that we
4881 recognize it as one that can be safely
4882 deleted at the end of reload. */
4883 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, ad),
4884 insn), QImode);
4886 /* This doesn't really count as replacing the address
4887 as a whole, since it is still a memory access. */
4889 return 0;
4891 ad = tem;
4895 /* The only remaining case where we can avoid a reload is if this is a
4896 hard register that is valid as a base register and which is not the
4897 subject of a CLOBBER in this insn. */
4899 else if (regno < FIRST_PSEUDO_REGISTER
4900 && regno_ok_for_base_p (regno, mode, MEM, SCRATCH)
4901 && ! regno_clobbered_p (regno, this_insn, mode, 0))
4902 return 0;
4904 /* If we do not have one of the cases above, we must do the reload. */
4905 push_reload (ad, NULL_RTX, loc, (rtx*) 0, base_reg_class (mode, MEM, SCRATCH),
4906 GET_MODE (ad), VOIDmode, 0, 0, opnum, type);
4907 return 1;
4910 if (strict_memory_address_p (mode, ad))
4912 /* The address appears valid, so reloads are not needed.
4913 But the address may contain an eliminable register.
4914 This can happen because a machine with indirect addressing
4915 may consider a pseudo register by itself a valid address even when
4916 it has failed to get a hard reg.
4917 So do a tree-walk to find and eliminate all such regs. */
4919 /* But first quickly dispose of a common case. */
4920 if (GET_CODE (ad) == PLUS
4921 && GET_CODE (XEXP (ad, 1)) == CONST_INT
4922 && REG_P (XEXP (ad, 0))
4923 && reg_equiv_constant[REGNO (XEXP (ad, 0))] == 0)
4924 return 0;
4926 subst_reg_equivs_changed = 0;
4927 *loc = subst_reg_equivs (ad, insn);
4929 if (! subst_reg_equivs_changed)
4930 return 0;
4932 /* Check result for validity after substitution. */
4933 if (strict_memory_address_p (mode, ad))
4934 return 0;
4937 #ifdef LEGITIMIZE_RELOAD_ADDRESS
4940 if (memrefloc)
4942 LEGITIMIZE_RELOAD_ADDRESS (ad, GET_MODE (*memrefloc), opnum, type,
4943 ind_levels, win);
4945 break;
4946 win:
4947 *memrefloc = copy_rtx (*memrefloc);
4948 XEXP (*memrefloc, 0) = ad;
4949 move_replacements (&ad, &XEXP (*memrefloc, 0));
4950 return -1;
4952 while (0);
4953 #endif
4955 /* The address is not valid. We have to figure out why. First see if
4956 we have an outer AND and remove it if so. Then analyze what's inside. */
4958 if (GET_CODE (ad) == AND)
4960 removed_and = 1;
4961 loc = &XEXP (ad, 0);
4962 ad = *loc;
4965 /* One possibility for why the address is invalid is that it is itself
4966 a MEM. This can happen when the frame pointer is being eliminated, a
4967 pseudo is not allocated to a hard register, and the offset between the
4968 frame and stack pointers is not its initial value. In that case the
4969 pseudo will have been replaced by a MEM referring to the
4970 stack pointer. */
4971 if (MEM_P (ad))
4973 /* First ensure that the address in this MEM is valid. Then, unless
4974 indirect addresses are valid, reload the MEM into a register. */
4975 tem = ad;
4976 find_reloads_address (GET_MODE (ad), &tem, XEXP (ad, 0), &XEXP (ad, 0),
4977 opnum, ADDR_TYPE (type),
4978 ind_levels == 0 ? 0 : ind_levels - 1, insn);
4980 /* If tem was changed, then we must create a new memory reference to
4981 hold it and store it back into memrefloc. */
4982 if (tem != ad && memrefloc)
4984 *memrefloc = copy_rtx (*memrefloc);
4985 copy_replacements (tem, XEXP (*memrefloc, 0));
4986 loc = &XEXP (*memrefloc, 0);
4987 if (removed_and)
4988 loc = &XEXP (*loc, 0);
4991 /* Check similar cases as for indirect addresses as above except
4992 that we can allow pseudos and a MEM since they should have been
4993 taken care of above. */
4995 if (ind_levels == 0
4996 || (GET_CODE (XEXP (tem, 0)) == SYMBOL_REF && ! indirect_symref_ok)
4997 || MEM_P (XEXP (tem, 0))
4998 || ! (REG_P (XEXP (tem, 0))
4999 || (GET_CODE (XEXP (tem, 0)) == PLUS
5000 && REG_P (XEXP (XEXP (tem, 0), 0))
5001 && GET_CODE (XEXP (XEXP (tem, 0), 1)) == CONST_INT)))
5003 /* Must use TEM here, not AD, since it is the one that will
5004 have any subexpressions reloaded, if needed. */
5005 push_reload (tem, NULL_RTX, loc, (rtx*) 0,
5006 base_reg_class (mode, MEM, SCRATCH), GET_MODE (tem),
5007 VOIDmode, 0,
5008 0, opnum, type);
5009 return ! removed_and;
5011 else
5012 return 0;
5015 /* If we have address of a stack slot but it's not valid because the
5016 displacement is too large, compute the sum in a register.
5017 Handle all base registers here, not just fp/ap/sp, because on some
5018 targets (namely SH) we can also get too large displacements from
5019 big-endian corrections. */
5020 else if (GET_CODE (ad) == PLUS
5021 && REG_P (XEXP (ad, 0))
5022 && REGNO (XEXP (ad, 0)) < FIRST_PSEUDO_REGISTER
5023 && GET_CODE (XEXP (ad, 1)) == CONST_INT
5024 && regno_ok_for_base_p (REGNO (XEXP (ad, 0)), mode, PLUS,
5025 CONST_INT))
5028 /* Unshare the MEM rtx so we can safely alter it. */
5029 if (memrefloc)
5031 *memrefloc = copy_rtx (*memrefloc);
5032 loc = &XEXP (*memrefloc, 0);
5033 if (removed_and)
5034 loc = &XEXP (*loc, 0);
5037 if (double_reg_address_ok)
5039 /* Unshare the sum as well. */
5040 *loc = ad = copy_rtx (ad);
5042 /* Reload the displacement into an index reg.
5043 We assume the frame pointer or arg pointer is a base reg. */
5044 find_reloads_address_part (XEXP (ad, 1), &XEXP (ad, 1),
5045 INDEX_REG_CLASS, GET_MODE (ad), opnum,
5046 type, ind_levels);
5047 return 0;
5049 else
5051 /* If the sum of two regs is not necessarily valid,
5052 reload the sum into a base reg.
5053 That will at least work. */
5054 find_reloads_address_part (ad, loc,
5055 base_reg_class (mode, MEM, SCRATCH),
5056 Pmode, opnum, type, ind_levels);
5058 return ! removed_and;
5061 /* If we have an indexed stack slot, there are three possible reasons why
5062 it might be invalid: The index might need to be reloaded, the address
5063 might have been made by frame pointer elimination and hence have a
5064 constant out of range, or both reasons might apply.
5066 We can easily check for an index needing reload, but even if that is the
5067 case, we might also have an invalid constant. To avoid making the
5068 conservative assumption and requiring two reloads, we see if this address
5069 is valid when not interpreted strictly. If it is, the only problem is
5070 that the index needs a reload and find_reloads_address_1 will take care
5071 of it.
5073 Handle all base registers here, not just fp/ap/sp, because on some
5074 targets (namely SPARC) we can also get invalid addresses from preventive
5075 subreg big-endian corrections made by find_reloads_toplev. We
5076 can also get expressions involving LO_SUM (rather than PLUS) from
5077 find_reloads_subreg_address.
5079 If we decide to do something, it must be that `double_reg_address_ok'
5080 is true. We generate a reload of the base register + constant and
5081 rework the sum so that the reload register will be added to the index.
5082 This is safe because we know the address isn't shared.
5084 We check for the base register as both the first and second operand of
5085 the innermost PLUS and/or LO_SUM. */
5087 for (op_index = 0; op_index < 2; ++op_index)
5089 rtx operand, addend;
5090 enum rtx_code inner_code;
5092 if (GET_CODE (ad) != PLUS)
5093 continue;
5095 inner_code = GET_CODE (XEXP (ad, 0));
5096 if (!(GET_CODE (ad) == PLUS
5097 && GET_CODE (XEXP (ad, 1)) == CONST_INT
5098 && (inner_code == PLUS || inner_code == LO_SUM)))
5099 continue;
5101 operand = XEXP (XEXP (ad, 0), op_index);
5102 if (!REG_P (operand) || REGNO (operand) >= FIRST_PSEUDO_REGISTER)
5103 continue;
5105 addend = XEXP (XEXP (ad, 0), 1 - op_index);
5107 if ((regno_ok_for_base_p (REGNO (operand), mode, inner_code,
5108 GET_CODE (addend))
5109 || operand == frame_pointer_rtx
5110 #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
5111 || operand == hard_frame_pointer_rtx
5112 #endif
5113 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
5114 || operand == arg_pointer_rtx
5115 #endif
5116 || operand == stack_pointer_rtx)
5117 && ! maybe_memory_address_p (mode, ad,
5118 &XEXP (XEXP (ad, 0), 1 - op_index)))
5120 rtx offset_reg;
5121 enum reg_class cls;
5123 offset_reg = plus_constant (operand, INTVAL (XEXP (ad, 1)));
5125 /* Form the adjusted address. */
5126 if (GET_CODE (XEXP (ad, 0)) == PLUS)
5127 ad = gen_rtx_PLUS (GET_MODE (ad),
5128 op_index == 0 ? offset_reg : addend,
5129 op_index == 0 ? addend : offset_reg);
5130 else
5131 ad = gen_rtx_LO_SUM (GET_MODE (ad),
5132 op_index == 0 ? offset_reg : addend,
5133 op_index == 0 ? addend : offset_reg);
5134 *loc = ad;
5136 cls = base_reg_class (mode, MEM, GET_CODE (addend));
5137 find_reloads_address_part (XEXP (ad, op_index),
5138 &XEXP (ad, op_index), cls,
5139 GET_MODE (ad), opnum, type, ind_levels);
5140 find_reloads_address_1 (mode,
5141 XEXP (ad, 1 - op_index), 1, GET_CODE (ad),
5142 GET_CODE (XEXP (ad, op_index)),
5143 &XEXP (ad, 1 - op_index), opnum,
5144 type, 0, insn);
5146 return 0;
5150 /* See if address becomes valid when an eliminable register
5151 in a sum is replaced. */
5153 tem = ad;
5154 if (GET_CODE (ad) == PLUS)
5155 tem = subst_indexed_address (ad);
5156 if (tem != ad && strict_memory_address_p (mode, tem))
5158 /* Ok, we win that way. Replace any additional eliminable
5159 registers. */
5161 subst_reg_equivs_changed = 0;
5162 tem = subst_reg_equivs (tem, insn);
5164 /* Make sure that didn't make the address invalid again. */
5166 if (! subst_reg_equivs_changed || strict_memory_address_p (mode, tem))
5168 *loc = tem;
5169 return 0;
5173 /* If constants aren't valid addresses, reload the constant address
5174 into a register. */
5175 if (CONSTANT_P (ad) && ! strict_memory_address_p (mode, ad))
5177 /* If AD is an address in the constant pool, the MEM rtx may be shared.
5178 Unshare it so we can safely alter it. */
5179 if (memrefloc && GET_CODE (ad) == SYMBOL_REF
5180 && CONSTANT_POOL_ADDRESS_P (ad))
5182 *memrefloc = copy_rtx (*memrefloc);
5183 loc = &XEXP (*memrefloc, 0);
5184 if (removed_and)
5185 loc = &XEXP (*loc, 0);
5188 find_reloads_address_part (ad, loc, base_reg_class (mode, MEM, SCRATCH),
5189 Pmode, opnum, type, ind_levels);
5190 return ! removed_and;
5193 return find_reloads_address_1 (mode, ad, 0, MEM, SCRATCH, loc, opnum, type,
5194 ind_levels, insn);
5197 /* Find all pseudo regs appearing in AD
5198 that are eliminable in favor of equivalent values
5199 and do not have hard regs; replace them by their equivalents.
5200 INSN, if nonzero, is the insn in which we do the reload. We put USEs in
5201 front of it for pseudos that we have to replace with stack slots. */
5203 static rtx
5204 subst_reg_equivs (rtx ad, rtx insn)
5206 RTX_CODE code = GET_CODE (ad);
5207 int i;
5208 const char *fmt;
5210 switch (code)
5212 case HIGH:
5213 case CONST_INT:
5214 case CONST:
5215 case CONST_DOUBLE:
5216 case CONST_FIXED:
5217 case CONST_VECTOR:
5218 case SYMBOL_REF:
5219 case LABEL_REF:
5220 case PC:
5221 case CC0:
5222 return ad;
5224 case REG:
5226 int regno = REGNO (ad);
5228 if (reg_equiv_constant[regno] != 0)
5230 subst_reg_equivs_changed = 1;
5231 return reg_equiv_constant[regno];
5233 if (reg_equiv_memory_loc[regno] && num_not_at_initial_offset)
5235 rtx mem = make_memloc (ad, regno);
5236 if (! rtx_equal_p (mem, reg_equiv_mem[regno]))
5238 subst_reg_equivs_changed = 1;
5239 /* We mark the USE with QImode so that we recognize it
5240 as one that can be safely deleted at the end of
5241 reload. */
5242 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, ad), insn),
5243 QImode);
5244 return mem;
5248 return ad;
5250 case PLUS:
5251 /* Quickly dispose of a common case. */
5252 if (XEXP (ad, 0) == frame_pointer_rtx
5253 && GET_CODE (XEXP (ad, 1)) == CONST_INT)
5254 return ad;
5255 break;
5257 default:
5258 break;
5261 fmt = GET_RTX_FORMAT (code);
5262 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
5263 if (fmt[i] == 'e')
5264 XEXP (ad, i) = subst_reg_equivs (XEXP (ad, i), insn);
5265 return ad;
5268 /* Compute the sum of X and Y, making canonicalizations assumed in an
5269 address, namely: sum constant integers, surround the sum of two
5270 constants with a CONST, put the constant as the second operand, and
5271 group the constant on the outermost sum.
5273 This routine assumes both inputs are already in canonical form. */
5276 form_sum (rtx x, rtx y)
5278 rtx tem;
5279 enum machine_mode mode = GET_MODE (x);
5281 if (mode == VOIDmode)
5282 mode = GET_MODE (y);
5284 if (mode == VOIDmode)
5285 mode = Pmode;
5287 if (GET_CODE (x) == CONST_INT)
5288 return plus_constant (y, INTVAL (x));
5289 else if (GET_CODE (y) == CONST_INT)
5290 return plus_constant (x, INTVAL (y));
5291 else if (CONSTANT_P (x))
5292 tem = x, x = y, y = tem;
5294 if (GET_CODE (x) == PLUS && CONSTANT_P (XEXP (x, 1)))
5295 return form_sum (XEXP (x, 0), form_sum (XEXP (x, 1), y));
5297 /* Note that if the operands of Y are specified in the opposite
5298 order in the recursive calls below, infinite recursion will occur. */
5299 if (GET_CODE (y) == PLUS && CONSTANT_P (XEXP (y, 1)))
5300 return form_sum (form_sum (x, XEXP (y, 0)), XEXP (y, 1));
5302 /* If both constant, encapsulate sum. Otherwise, just form sum. A
5303 constant will have been placed second. */
5304 if (CONSTANT_P (x) && CONSTANT_P (y))
5306 if (GET_CODE (x) == CONST)
5307 x = XEXP (x, 0);
5308 if (GET_CODE (y) == CONST)
5309 y = XEXP (y, 0);
5311 return gen_rtx_CONST (VOIDmode, gen_rtx_PLUS (mode, x, y));
5314 return gen_rtx_PLUS (mode, x, y);
5317 /* If ADDR is a sum containing a pseudo register that should be
5318 replaced with a constant (from reg_equiv_constant),
5319 return the result of doing so, and also apply the associative
5320 law so that the result is more likely to be a valid address.
5321 (But it is not guaranteed to be one.)
5323 Note that at most one register is replaced, even if more are
5324 replaceable. Also, we try to put the result into a canonical form
5325 so it is more likely to be a valid address.
5327 In all other cases, return ADDR. */
5329 static rtx
5330 subst_indexed_address (rtx addr)
5332 rtx op0 = 0, op1 = 0, op2 = 0;
5333 rtx tem;
5334 int regno;
5336 if (GET_CODE (addr) == PLUS)
5338 /* Try to find a register to replace. */
5339 op0 = XEXP (addr, 0), op1 = XEXP (addr, 1), op2 = 0;
5340 if (REG_P (op0)
5341 && (regno = REGNO (op0)) >= FIRST_PSEUDO_REGISTER
5342 && reg_renumber[regno] < 0
5343 && reg_equiv_constant[regno] != 0)
5344 op0 = reg_equiv_constant[regno];
5345 else if (REG_P (op1)
5346 && (regno = REGNO (op1)) >= FIRST_PSEUDO_REGISTER
5347 && reg_renumber[regno] < 0
5348 && reg_equiv_constant[regno] != 0)
5349 op1 = reg_equiv_constant[regno];
5350 else if (GET_CODE (op0) == PLUS
5351 && (tem = subst_indexed_address (op0)) != op0)
5352 op0 = tem;
5353 else if (GET_CODE (op1) == PLUS
5354 && (tem = subst_indexed_address (op1)) != op1)
5355 op1 = tem;
5356 else
5357 return addr;
5359 /* Pick out up to three things to add. */
5360 if (GET_CODE (op1) == PLUS)
5361 op2 = XEXP (op1, 1), op1 = XEXP (op1, 0);
5362 else if (GET_CODE (op0) == PLUS)
5363 op2 = op1, op1 = XEXP (op0, 1), op0 = XEXP (op0, 0);
5365 /* Compute the sum. */
5366 if (op2 != 0)
5367 op1 = form_sum (op1, op2);
5368 if (op1 != 0)
5369 op0 = form_sum (op0, op1);
5371 return op0;
5373 return addr;
5376 /* Update the REG_INC notes for an insn. It updates all REG_INC
5377 notes for the instruction which refer to REGNO the to refer
5378 to the reload number.
5380 INSN is the insn for which any REG_INC notes need updating.
5382 REGNO is the register number which has been reloaded.
5384 RELOADNUM is the reload number. */
5386 static void
5387 update_auto_inc_notes (rtx insn ATTRIBUTE_UNUSED, int regno ATTRIBUTE_UNUSED,
5388 int reloadnum ATTRIBUTE_UNUSED)
5390 #ifdef AUTO_INC_DEC
5391 rtx link;
5393 for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
5394 if (REG_NOTE_KIND (link) == REG_INC
5395 && (int) REGNO (XEXP (link, 0)) == regno)
5396 push_replacement (&XEXP (link, 0), reloadnum, VOIDmode);
5397 #endif
5400 /* Record the pseudo registers we must reload into hard registers in a
5401 subexpression of a would-be memory address, X referring to a value
5402 in mode MODE. (This function is not called if the address we find
5403 is strictly valid.)
5405 CONTEXT = 1 means we are considering regs as index regs,
5406 = 0 means we are considering them as base regs.
5407 OUTER_CODE is the code of the enclosing RTX, typically a MEM, a PLUS,
5408 or an autoinc code.
5409 If CONTEXT == 0 and OUTER_CODE is a PLUS or LO_SUM, then INDEX_CODE
5410 is the code of the index part of the address. Otherwise, pass SCRATCH
5411 for this argument.
5412 OPNUM and TYPE specify the purpose of any reloads made.
5414 IND_LEVELS says how many levels of indirect addressing are
5415 supported at this point in the address.
5417 INSN, if nonzero, is the insn in which we do the reload. It is used
5418 to determine if we may generate output reloads.
5420 We return nonzero if X, as a whole, is reloaded or replaced. */
5422 /* Note that we take shortcuts assuming that no multi-reg machine mode
5423 occurs as part of an address.
5424 Also, this is not fully machine-customizable; it works for machines
5425 such as VAXen and 68000's and 32000's, but other possible machines
5426 could have addressing modes that this does not handle right.
5427 If you add push_reload calls here, you need to make sure gen_reload
5428 handles those cases gracefully. */
5430 static int
5431 find_reloads_address_1 (enum machine_mode mode, rtx x, int context,
5432 enum rtx_code outer_code, enum rtx_code index_code,
5433 rtx *loc, int opnum, enum reload_type type,
5434 int ind_levels, rtx insn)
5436 #define REG_OK_FOR_CONTEXT(CONTEXT, REGNO, MODE, OUTER, INDEX) \
5437 ((CONTEXT) == 0 \
5438 ? regno_ok_for_base_p (REGNO, MODE, OUTER, INDEX) \
5439 : REGNO_OK_FOR_INDEX_P (REGNO))
5441 enum reg_class context_reg_class;
5442 RTX_CODE code = GET_CODE (x);
5444 if (context == 1)
5445 context_reg_class = INDEX_REG_CLASS;
5446 else
5447 context_reg_class = base_reg_class (mode, outer_code, index_code);
5449 switch (code)
5451 case PLUS:
5453 rtx orig_op0 = XEXP (x, 0);
5454 rtx orig_op1 = XEXP (x, 1);
5455 RTX_CODE code0 = GET_CODE (orig_op0);
5456 RTX_CODE code1 = GET_CODE (orig_op1);
5457 rtx op0 = orig_op0;
5458 rtx op1 = orig_op1;
5460 if (GET_CODE (op0) == SUBREG)
5462 op0 = SUBREG_REG (op0);
5463 code0 = GET_CODE (op0);
5464 if (code0 == REG && REGNO (op0) < FIRST_PSEUDO_REGISTER)
5465 op0 = gen_rtx_REG (word_mode,
5466 (REGNO (op0) +
5467 subreg_regno_offset (REGNO (SUBREG_REG (orig_op0)),
5468 GET_MODE (SUBREG_REG (orig_op0)),
5469 SUBREG_BYTE (orig_op0),
5470 GET_MODE (orig_op0))));
5473 if (GET_CODE (op1) == SUBREG)
5475 op1 = SUBREG_REG (op1);
5476 code1 = GET_CODE (op1);
5477 if (code1 == REG && REGNO (op1) < FIRST_PSEUDO_REGISTER)
5478 /* ??? Why is this given op1's mode and above for
5479 ??? op0 SUBREGs we use word_mode? */
5480 op1 = gen_rtx_REG (GET_MODE (op1),
5481 (REGNO (op1) +
5482 subreg_regno_offset (REGNO (SUBREG_REG (orig_op1)),
5483 GET_MODE (SUBREG_REG (orig_op1)),
5484 SUBREG_BYTE (orig_op1),
5485 GET_MODE (orig_op1))));
5487 /* Plus in the index register may be created only as a result of
5488 register rematerialization for expression like &localvar*4. Reload it.
5489 It may be possible to combine the displacement on the outer level,
5490 but it is probably not worthwhile to do so. */
5491 if (context == 1)
5493 find_reloads_address (GET_MODE (x), loc, XEXP (x, 0), &XEXP (x, 0),
5494 opnum, ADDR_TYPE (type), ind_levels, insn);
5495 push_reload (*loc, NULL_RTX, loc, (rtx*) 0,
5496 context_reg_class,
5497 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5498 return 1;
5501 if (code0 == MULT || code0 == SIGN_EXTEND || code0 == TRUNCATE
5502 || code0 == ZERO_EXTEND || code1 == MEM)
5504 find_reloads_address_1 (mode, orig_op0, 1, PLUS, SCRATCH,
5505 &XEXP (x, 0), opnum, type, ind_levels,
5506 insn);
5507 find_reloads_address_1 (mode, orig_op1, 0, PLUS, code0,
5508 &XEXP (x, 1), opnum, type, ind_levels,
5509 insn);
5512 else if (code1 == MULT || code1 == SIGN_EXTEND || code1 == TRUNCATE
5513 || code1 == ZERO_EXTEND || code0 == MEM)
5515 find_reloads_address_1 (mode, orig_op0, 0, PLUS, code1,
5516 &XEXP (x, 0), opnum, type, ind_levels,
5517 insn);
5518 find_reloads_address_1 (mode, orig_op1, 1, PLUS, SCRATCH,
5519 &XEXP (x, 1), opnum, type, ind_levels,
5520 insn);
5523 else if (code0 == CONST_INT || code0 == CONST
5524 || code0 == SYMBOL_REF || code0 == LABEL_REF)
5525 find_reloads_address_1 (mode, orig_op1, 0, PLUS, code0,
5526 &XEXP (x, 1), opnum, type, ind_levels,
5527 insn);
5529 else if (code1 == CONST_INT || code1 == CONST
5530 || code1 == SYMBOL_REF || code1 == LABEL_REF)
5531 find_reloads_address_1 (mode, orig_op0, 0, PLUS, code1,
5532 &XEXP (x, 0), opnum, type, ind_levels,
5533 insn);
5535 else if (code0 == REG && code1 == REG)
5537 if (REGNO_OK_FOR_INDEX_P (REGNO (op1))
5538 && regno_ok_for_base_p (REGNO (op0), mode, PLUS, REG))
5539 return 0;
5540 else if (REGNO_OK_FOR_INDEX_P (REGNO (op0))
5541 && regno_ok_for_base_p (REGNO (op1), mode, PLUS, REG))
5542 return 0;
5543 else if (regno_ok_for_base_p (REGNO (op0), mode, PLUS, REG))
5544 find_reloads_address_1 (mode, orig_op1, 1, PLUS, SCRATCH,
5545 &XEXP (x, 1), opnum, type, ind_levels,
5546 insn);
5547 else if (REGNO_OK_FOR_INDEX_P (REGNO (op1)))
5548 find_reloads_address_1 (mode, orig_op0, 0, PLUS, REG,
5549 &XEXP (x, 0), opnum, type, ind_levels,
5550 insn);
5551 else if (regno_ok_for_base_p (REGNO (op1), mode, PLUS, REG))
5552 find_reloads_address_1 (mode, orig_op0, 1, PLUS, SCRATCH,
5553 &XEXP (x, 0), opnum, type, ind_levels,
5554 insn);
5555 else if (REGNO_OK_FOR_INDEX_P (REGNO (op0)))
5556 find_reloads_address_1 (mode, orig_op1, 0, PLUS, REG,
5557 &XEXP (x, 1), opnum, type, ind_levels,
5558 insn);
5559 else
5561 find_reloads_address_1 (mode, orig_op0, 0, PLUS, REG,
5562 &XEXP (x, 0), opnum, type, ind_levels,
5563 insn);
5564 find_reloads_address_1 (mode, orig_op1, 1, PLUS, SCRATCH,
5565 &XEXP (x, 1), opnum, type, ind_levels,
5566 insn);
5570 else if (code0 == REG)
5572 find_reloads_address_1 (mode, orig_op0, 1, PLUS, SCRATCH,
5573 &XEXP (x, 0), opnum, type, ind_levels,
5574 insn);
5575 find_reloads_address_1 (mode, orig_op1, 0, PLUS, REG,
5576 &XEXP (x, 1), opnum, type, ind_levels,
5577 insn);
5580 else if (code1 == REG)
5582 find_reloads_address_1 (mode, orig_op1, 1, PLUS, SCRATCH,
5583 &XEXP (x, 1), opnum, type, ind_levels,
5584 insn);
5585 find_reloads_address_1 (mode, orig_op0, 0, PLUS, REG,
5586 &XEXP (x, 0), opnum, type, ind_levels,
5587 insn);
5591 return 0;
5593 case POST_MODIFY:
5594 case PRE_MODIFY:
5596 rtx op0 = XEXP (x, 0);
5597 rtx op1 = XEXP (x, 1);
5598 enum rtx_code index_code;
5599 int regno;
5600 int reloadnum;
5602 if (GET_CODE (op1) != PLUS && GET_CODE (op1) != MINUS)
5603 return 0;
5605 /* Currently, we only support {PRE,POST}_MODIFY constructs
5606 where a base register is {inc,dec}remented by the contents
5607 of another register or by a constant value. Thus, these
5608 operands must match. */
5609 gcc_assert (op0 == XEXP (op1, 0));
5611 /* Require index register (or constant). Let's just handle the
5612 register case in the meantime... If the target allows
5613 auto-modify by a constant then we could try replacing a pseudo
5614 register with its equivalent constant where applicable.
5616 We also handle the case where the register was eliminated
5617 resulting in a PLUS subexpression.
5619 If we later decide to reload the whole PRE_MODIFY or
5620 POST_MODIFY, inc_for_reload might clobber the reload register
5621 before reading the index. The index register might therefore
5622 need to live longer than a TYPE reload normally would, so be
5623 conservative and class it as RELOAD_OTHER. */
5624 if ((REG_P (XEXP (op1, 1))
5625 && !REGNO_OK_FOR_INDEX_P (REGNO (XEXP (op1, 1))))
5626 || GET_CODE (XEXP (op1, 1)) == PLUS)
5627 find_reloads_address_1 (mode, XEXP (op1, 1), 1, code, SCRATCH,
5628 &XEXP (op1, 1), opnum, RELOAD_OTHER,
5629 ind_levels, insn);
5631 gcc_assert (REG_P (XEXP (op1, 0)));
5633 regno = REGNO (XEXP (op1, 0));
5634 index_code = GET_CODE (XEXP (op1, 1));
5636 /* A register that is incremented cannot be constant! */
5637 gcc_assert (regno < FIRST_PSEUDO_REGISTER
5638 || reg_equiv_constant[regno] == 0);
5640 /* Handle a register that is equivalent to a memory location
5641 which cannot be addressed directly. */
5642 if (reg_equiv_memory_loc[regno] != 0
5643 && (reg_equiv_address[regno] != 0
5644 || num_not_at_initial_offset))
5646 rtx tem = make_memloc (XEXP (x, 0), regno);
5648 if (reg_equiv_address[regno]
5649 || ! rtx_equal_p (tem, reg_equiv_mem[regno]))
5651 rtx orig = tem;
5653 /* First reload the memory location's address.
5654 We can't use ADDR_TYPE (type) here, because we need to
5655 write back the value after reading it, hence we actually
5656 need two registers. */
5657 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
5658 &XEXP (tem, 0), opnum,
5659 RELOAD_OTHER,
5660 ind_levels, insn);
5662 if (!rtx_equal_p (tem, orig))
5663 push_reg_equiv_alt_mem (regno, tem);
5665 /* Then reload the memory location into a base
5666 register. */
5667 reloadnum = push_reload (tem, tem, &XEXP (x, 0),
5668 &XEXP (op1, 0),
5669 base_reg_class (mode, code,
5670 index_code),
5671 GET_MODE (x), GET_MODE (x), 0,
5672 0, opnum, RELOAD_OTHER);
5674 update_auto_inc_notes (this_insn, regno, reloadnum);
5675 return 0;
5679 if (reg_renumber[regno] >= 0)
5680 regno = reg_renumber[regno];
5682 /* We require a base register here... */
5683 if (!regno_ok_for_base_p (regno, GET_MODE (x), code, index_code))
5685 reloadnum = push_reload (XEXP (op1, 0), XEXP (x, 0),
5686 &XEXP (op1, 0), &XEXP (x, 0),
5687 base_reg_class (mode, code, index_code),
5688 GET_MODE (x), GET_MODE (x), 0, 0,
5689 opnum, RELOAD_OTHER);
5691 update_auto_inc_notes (this_insn, regno, reloadnum);
5692 return 0;
5695 return 0;
5697 case POST_INC:
5698 case POST_DEC:
5699 case PRE_INC:
5700 case PRE_DEC:
5701 if (REG_P (XEXP (x, 0)))
5703 int regno = REGNO (XEXP (x, 0));
5704 int value = 0;
5705 rtx x_orig = x;
5707 /* A register that is incremented cannot be constant! */
5708 gcc_assert (regno < FIRST_PSEUDO_REGISTER
5709 || reg_equiv_constant[regno] == 0);
5711 /* Handle a register that is equivalent to a memory location
5712 which cannot be addressed directly. */
5713 if (reg_equiv_memory_loc[regno] != 0
5714 && (reg_equiv_address[regno] != 0 || num_not_at_initial_offset))
5716 rtx tem = make_memloc (XEXP (x, 0), regno);
5717 if (reg_equiv_address[regno]
5718 || ! rtx_equal_p (tem, reg_equiv_mem[regno]))
5720 rtx orig = tem;
5722 /* First reload the memory location's address.
5723 We can't use ADDR_TYPE (type) here, because we need to
5724 write back the value after reading it, hence we actually
5725 need two registers. */
5726 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
5727 &XEXP (tem, 0), opnum, type,
5728 ind_levels, insn);
5729 if (!rtx_equal_p (tem, orig))
5730 push_reg_equiv_alt_mem (regno, tem);
5731 /* Put this inside a new increment-expression. */
5732 x = gen_rtx_fmt_e (GET_CODE (x), GET_MODE (x), tem);
5733 /* Proceed to reload that, as if it contained a register. */
5737 /* If we have a hard register that is ok in this incdec context,
5738 don't make a reload. If the register isn't nice enough for
5739 autoincdec, we can reload it. But, if an autoincrement of a
5740 register that we here verified as playing nice, still outside
5741 isn't "valid", it must be that no autoincrement is "valid".
5742 If that is true and something made an autoincrement anyway,
5743 this must be a special context where one is allowed.
5744 (For example, a "push" instruction.)
5745 We can't improve this address, so leave it alone. */
5747 /* Otherwise, reload the autoincrement into a suitable hard reg
5748 and record how much to increment by. */
5750 if (reg_renumber[regno] >= 0)
5751 regno = reg_renumber[regno];
5752 if (regno >= FIRST_PSEUDO_REGISTER
5753 || !REG_OK_FOR_CONTEXT (context, regno, mode, code,
5754 index_code))
5756 int reloadnum;
5758 /* If we can output the register afterwards, do so, this
5759 saves the extra update.
5760 We can do so if we have an INSN - i.e. no JUMP_INSN nor
5761 CALL_INSN - and it does not set CC0.
5762 But don't do this if we cannot directly address the
5763 memory location, since this will make it harder to
5764 reuse address reloads, and increases register pressure.
5765 Also don't do this if we can probably update x directly. */
5766 rtx equiv = (MEM_P (XEXP (x, 0))
5767 ? XEXP (x, 0)
5768 : reg_equiv_mem[regno]);
5769 int icode = (int) optab_handler (add_optab, Pmode)->insn_code;
5770 if (insn && NONJUMP_INSN_P (insn) && equiv
5771 && memory_operand (equiv, GET_MODE (equiv))
5772 #ifdef HAVE_cc0
5773 && ! sets_cc0_p (PATTERN (insn))
5774 #endif
5775 && ! (icode != CODE_FOR_nothing
5776 && ((*insn_data[icode].operand[0].predicate)
5777 (equiv, Pmode))
5778 && ((*insn_data[icode].operand[1].predicate)
5779 (equiv, Pmode))))
5781 /* We use the original pseudo for loc, so that
5782 emit_reload_insns() knows which pseudo this
5783 reload refers to and updates the pseudo rtx, not
5784 its equivalent memory location, as well as the
5785 corresponding entry in reg_last_reload_reg. */
5786 loc = &XEXP (x_orig, 0);
5787 x = XEXP (x, 0);
5788 reloadnum
5789 = push_reload (x, x, loc, loc,
5790 context_reg_class,
5791 GET_MODE (x), GET_MODE (x), 0, 0,
5792 opnum, RELOAD_OTHER);
5794 else
5796 reloadnum
5797 = push_reload (x, x, loc, (rtx*) 0,
5798 context_reg_class,
5799 GET_MODE (x), GET_MODE (x), 0, 0,
5800 opnum, type);
5801 rld[reloadnum].inc
5802 = find_inc_amount (PATTERN (this_insn), XEXP (x_orig, 0));
5804 value = 1;
5807 update_auto_inc_notes (this_insn, REGNO (XEXP (x_orig, 0)),
5808 reloadnum);
5810 return value;
5812 return 0;
5814 case TRUNCATE:
5815 case SIGN_EXTEND:
5816 case ZERO_EXTEND:
5817 /* Look for parts to reload in the inner expression and reload them
5818 too, in addition to this operation. Reloading all inner parts in
5819 addition to this one shouldn't be necessary, but at this point,
5820 we don't know if we can possibly omit any part that *can* be
5821 reloaded. Targets that are better off reloading just either part
5822 (or perhaps even a different part of an outer expression), should
5823 define LEGITIMIZE_RELOAD_ADDRESS. */
5824 find_reloads_address_1 (GET_MODE (XEXP (x, 0)), XEXP (x, 0),
5825 context, code, SCRATCH, &XEXP (x, 0), opnum,
5826 type, ind_levels, insn);
5827 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5828 context_reg_class,
5829 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5830 return 1;
5832 case MEM:
5833 /* This is probably the result of a substitution, by eliminate_regs, of
5834 an equivalent address for a pseudo that was not allocated to a hard
5835 register. Verify that the specified address is valid and reload it
5836 into a register.
5838 Since we know we are going to reload this item, don't decrement for
5839 the indirection level.
5841 Note that this is actually conservative: it would be slightly more
5842 efficient to use the value of SPILL_INDIRECT_LEVELS from
5843 reload1.c here. */
5845 find_reloads_address (GET_MODE (x), loc, XEXP (x, 0), &XEXP (x, 0),
5846 opnum, ADDR_TYPE (type), ind_levels, insn);
5847 push_reload (*loc, NULL_RTX, loc, (rtx*) 0,
5848 context_reg_class,
5849 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5850 return 1;
5852 case REG:
5854 int regno = REGNO (x);
5856 if (reg_equiv_constant[regno] != 0)
5858 find_reloads_address_part (reg_equiv_constant[regno], loc,
5859 context_reg_class,
5860 GET_MODE (x), opnum, type, ind_levels);
5861 return 1;
5864 #if 0 /* This might screw code in reload1.c to delete prior output-reload
5865 that feeds this insn. */
5866 if (reg_equiv_mem[regno] != 0)
5868 push_reload (reg_equiv_mem[regno], NULL_RTX, loc, (rtx*) 0,
5869 context_reg_class,
5870 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5871 return 1;
5873 #endif
5875 if (reg_equiv_memory_loc[regno]
5876 && (reg_equiv_address[regno] != 0 || num_not_at_initial_offset))
5878 rtx tem = make_memloc (x, regno);
5879 if (reg_equiv_address[regno] != 0
5880 || ! rtx_equal_p (tem, reg_equiv_mem[regno]))
5882 x = tem;
5883 find_reloads_address (GET_MODE (x), &x, XEXP (x, 0),
5884 &XEXP (x, 0), opnum, ADDR_TYPE (type),
5885 ind_levels, insn);
5886 if (!rtx_equal_p (x, tem))
5887 push_reg_equiv_alt_mem (regno, x);
5891 if (reg_renumber[regno] >= 0)
5892 regno = reg_renumber[regno];
5894 if (regno >= FIRST_PSEUDO_REGISTER
5895 || !REG_OK_FOR_CONTEXT (context, regno, mode, outer_code,
5896 index_code))
5898 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5899 context_reg_class,
5900 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5901 return 1;
5904 /* If a register appearing in an address is the subject of a CLOBBER
5905 in this insn, reload it into some other register to be safe.
5906 The CLOBBER is supposed to make the register unavailable
5907 from before this insn to after it. */
5908 if (regno_clobbered_p (regno, this_insn, GET_MODE (x), 0))
5910 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5911 context_reg_class,
5912 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5913 return 1;
5916 return 0;
5918 case SUBREG:
5919 if (REG_P (SUBREG_REG (x)))
5921 /* If this is a SUBREG of a hard register and the resulting register
5922 is of the wrong class, reload the whole SUBREG. This avoids
5923 needless copies if SUBREG_REG is multi-word. */
5924 if (REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER)
5926 int regno ATTRIBUTE_UNUSED = subreg_regno (x);
5928 if (!REG_OK_FOR_CONTEXT (context, regno, mode, outer_code,
5929 index_code))
5931 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5932 context_reg_class,
5933 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5934 return 1;
5937 /* If this is a SUBREG of a pseudo-register, and the pseudo-register
5938 is larger than the class size, then reload the whole SUBREG. */
5939 else
5941 enum reg_class class = context_reg_class;
5942 if ((unsigned) CLASS_MAX_NREGS (class, GET_MODE (SUBREG_REG (x)))
5943 > reg_class_size[class])
5945 x = find_reloads_subreg_address (x, 0, opnum,
5946 ADDR_TYPE (type),
5947 ind_levels, insn);
5948 push_reload (x, NULL_RTX, loc, (rtx*) 0, class,
5949 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5950 return 1;
5954 break;
5956 default:
5957 break;
5961 const char *fmt = GET_RTX_FORMAT (code);
5962 int i;
5964 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
5966 if (fmt[i] == 'e')
5967 /* Pass SCRATCH for INDEX_CODE, since CODE can never be a PLUS once
5968 we get here. */
5969 find_reloads_address_1 (mode, XEXP (x, i), context, code, SCRATCH,
5970 &XEXP (x, i), opnum, type, ind_levels, insn);
5974 #undef REG_OK_FOR_CONTEXT
5975 return 0;
5978 /* X, which is found at *LOC, is a part of an address that needs to be
5979 reloaded into a register of class CLASS. If X is a constant, or if
5980 X is a PLUS that contains a constant, check that the constant is a
5981 legitimate operand and that we are supposed to be able to load
5982 it into the register.
5984 If not, force the constant into memory and reload the MEM instead.
5986 MODE is the mode to use, in case X is an integer constant.
5988 OPNUM and TYPE describe the purpose of any reloads made.
5990 IND_LEVELS says how many levels of indirect addressing this machine
5991 supports. */
5993 static void
5994 find_reloads_address_part (rtx x, rtx *loc, enum reg_class class,
5995 enum machine_mode mode, int opnum,
5996 enum reload_type type, int ind_levels)
5998 if (CONSTANT_P (x)
5999 && (! LEGITIMATE_CONSTANT_P (x)
6000 || PREFERRED_RELOAD_CLASS (x, class) == NO_REGS))
6002 x = force_const_mem (mode, x);
6003 find_reloads_address (mode, &x, XEXP (x, 0), &XEXP (x, 0),
6004 opnum, type, ind_levels, 0);
6007 else if (GET_CODE (x) == PLUS
6008 && CONSTANT_P (XEXP (x, 1))
6009 && (! LEGITIMATE_CONSTANT_P (XEXP (x, 1))
6010 || PREFERRED_RELOAD_CLASS (XEXP (x, 1), class) == NO_REGS))
6012 rtx tem;
6014 tem = force_const_mem (GET_MODE (x), XEXP (x, 1));
6015 x = gen_rtx_PLUS (GET_MODE (x), XEXP (x, 0), tem);
6016 find_reloads_address (mode, &XEXP (x, 1), XEXP (tem, 0), &XEXP (tem, 0),
6017 opnum, type, ind_levels, 0);
6020 push_reload (x, NULL_RTX, loc, (rtx*) 0, class,
6021 mode, VOIDmode, 0, 0, opnum, type);
6024 /* X, a subreg of a pseudo, is a part of an address that needs to be
6025 reloaded.
6027 If the pseudo is equivalent to a memory location that cannot be directly
6028 addressed, make the necessary address reloads.
6030 If address reloads have been necessary, or if the address is changed
6031 by register elimination, return the rtx of the memory location;
6032 otherwise, return X.
6034 If FORCE_REPLACE is nonzero, unconditionally replace the subreg with the
6035 memory location.
6037 OPNUM and TYPE identify the purpose of the reload.
6039 IND_LEVELS says how many levels of indirect addressing are
6040 supported at this point in the address.
6042 INSN, if nonzero, is the insn in which we do the reload. It is used
6043 to determine where to put USEs for pseudos that we have to replace with
6044 stack slots. */
6046 static rtx
6047 find_reloads_subreg_address (rtx x, int force_replace, int opnum,
6048 enum reload_type type, int ind_levels, rtx insn)
6050 int regno = REGNO (SUBREG_REG (x));
6052 if (reg_equiv_memory_loc[regno])
6054 /* If the address is not directly addressable, or if the address is not
6055 offsettable, then it must be replaced. */
6056 if (! force_replace
6057 && (reg_equiv_address[regno]
6058 || ! offsettable_memref_p (reg_equiv_mem[regno])))
6059 force_replace = 1;
6061 if (force_replace || num_not_at_initial_offset)
6063 rtx tem = make_memloc (SUBREG_REG (x), regno);
6065 /* If the address changes because of register elimination, then
6066 it must be replaced. */
6067 if (force_replace
6068 || ! rtx_equal_p (tem, reg_equiv_mem[regno]))
6070 unsigned outer_size = GET_MODE_SIZE (GET_MODE (x));
6071 unsigned inner_size = GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)));
6072 int offset;
6073 rtx orig = tem;
6074 int reloaded;
6076 /* For big-endian paradoxical subregs, SUBREG_BYTE does not
6077 hold the correct (negative) byte offset. */
6078 if (BYTES_BIG_ENDIAN && outer_size > inner_size)
6079 offset = inner_size - outer_size;
6080 else
6081 offset = SUBREG_BYTE (x);
6083 XEXP (tem, 0) = plus_constant (XEXP (tem, 0), offset);
6084 PUT_MODE (tem, GET_MODE (x));
6085 if (MEM_OFFSET (tem))
6086 set_mem_offset (tem, plus_constant (MEM_OFFSET (tem), offset));
6088 /* If this was a paradoxical subreg that we replaced, the
6089 resulting memory must be sufficiently aligned to allow
6090 us to widen the mode of the memory. */
6091 if (outer_size > inner_size)
6093 rtx base;
6095 base = XEXP (tem, 0);
6096 if (GET_CODE (base) == PLUS)
6098 if (GET_CODE (XEXP (base, 1)) == CONST_INT
6099 && INTVAL (XEXP (base, 1)) % outer_size != 0)
6100 return x;
6101 base = XEXP (base, 0);
6103 if (!REG_P (base)
6104 || (REGNO_POINTER_ALIGN (REGNO (base))
6105 < outer_size * BITS_PER_UNIT))
6106 return x;
6109 reloaded = find_reloads_address (GET_MODE (tem), &tem,
6110 XEXP (tem, 0), &XEXP (tem, 0),
6111 opnum, type, ind_levels, insn);
6112 /* ??? Do we need to handle nonzero offsets somehow? */
6113 if (!offset && !rtx_equal_p (tem, orig))
6114 push_reg_equiv_alt_mem (regno, tem);
6116 /* For some processors an address may be valid in the
6117 original mode but not in a smaller mode. For
6118 example, ARM accepts a scaled index register in
6119 SImode but not in HImode. Similarly, the address may
6120 have been valid before the subreg offset was added,
6121 but not afterwards. find_reloads_address
6122 assumes that we pass it a valid address, and doesn't
6123 force a reload. This will probably be fine if
6124 find_reloads_address finds some reloads. But if it
6125 doesn't find any, then we may have just converted a
6126 valid address into an invalid one. Check for that
6127 here. */
6128 if (reloaded == 0
6129 && !strict_memory_address_p (GET_MODE (tem),
6130 XEXP (tem, 0)))
6131 push_reload (XEXP (tem, 0), NULL_RTX, &XEXP (tem, 0), (rtx*) 0,
6132 base_reg_class (GET_MODE (tem), MEM, SCRATCH),
6133 GET_MODE (XEXP (tem, 0)), VOIDmode, 0, 0,
6134 opnum, type);
6136 /* If this is not a toplevel operand, find_reloads doesn't see
6137 this substitution. We have to emit a USE of the pseudo so
6138 that delete_output_reload can see it. */
6139 if (replace_reloads && recog_data.operand[opnum] != x)
6140 /* We mark the USE with QImode so that we recognize it
6141 as one that can be safely deleted at the end of
6142 reload. */
6143 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode,
6144 SUBREG_REG (x)),
6145 insn), QImode);
6146 x = tem;
6150 return x;
6153 /* Substitute into the current INSN the registers into which we have reloaded
6154 the things that need reloading. The array `replacements'
6155 contains the locations of all pointers that must be changed
6156 and says what to replace them with.
6158 Return the rtx that X translates into; usually X, but modified. */
6160 void
6161 subst_reloads (rtx insn)
6163 int i;
6165 for (i = 0; i < n_replacements; i++)
6167 struct replacement *r = &replacements[i];
6168 rtx reloadreg = rld[r->what].reg_rtx;
6169 if (reloadreg)
6171 #ifdef DEBUG_RELOAD
6172 /* This checking takes a very long time on some platforms
6173 causing the gcc.c-torture/compile/limits-fnargs.c test
6174 to time out during testing. See PR 31850.
6176 Internal consistency test. Check that we don't modify
6177 anything in the equivalence arrays. Whenever something from
6178 those arrays needs to be reloaded, it must be unshared before
6179 being substituted into; the equivalence must not be modified.
6180 Otherwise, if the equivalence is used after that, it will
6181 have been modified, and the thing substituted (probably a
6182 register) is likely overwritten and not a usable equivalence. */
6183 int check_regno;
6185 for (check_regno = 0; check_regno < max_regno; check_regno++)
6187 #define CHECK_MODF(ARRAY) \
6188 gcc_assert (!ARRAY[check_regno] \
6189 || !loc_mentioned_in_p (r->where, \
6190 ARRAY[check_regno]))
6192 CHECK_MODF (reg_equiv_constant);
6193 CHECK_MODF (reg_equiv_memory_loc);
6194 CHECK_MODF (reg_equiv_address);
6195 CHECK_MODF (reg_equiv_mem);
6196 #undef CHECK_MODF
6198 #endif /* DEBUG_RELOAD */
6200 /* If we're replacing a LABEL_REF with a register, there must
6201 already be an indication (to e.g. flow) which label this
6202 register refers to. */
6203 gcc_assert (GET_CODE (*r->where) != LABEL_REF
6204 || !JUMP_P (insn)
6205 || find_reg_note (insn,
6206 REG_LABEL_OPERAND,
6207 XEXP (*r->where, 0))
6208 || label_is_jump_target_p (XEXP (*r->where, 0), insn));
6210 /* Encapsulate RELOADREG so its machine mode matches what
6211 used to be there. Note that gen_lowpart_common will
6212 do the wrong thing if RELOADREG is multi-word. RELOADREG
6213 will always be a REG here. */
6214 if (GET_MODE (reloadreg) != r->mode && r->mode != VOIDmode)
6215 reloadreg = reload_adjust_reg_for_mode (reloadreg, r->mode);
6217 /* If we are putting this into a SUBREG and RELOADREG is a
6218 SUBREG, we would be making nested SUBREGs, so we have to fix
6219 this up. Note that r->where == &SUBREG_REG (*r->subreg_loc). */
6221 if (r->subreg_loc != 0 && GET_CODE (reloadreg) == SUBREG)
6223 if (GET_MODE (*r->subreg_loc)
6224 == GET_MODE (SUBREG_REG (reloadreg)))
6225 *r->subreg_loc = SUBREG_REG (reloadreg);
6226 else
6228 int final_offset =
6229 SUBREG_BYTE (*r->subreg_loc) + SUBREG_BYTE (reloadreg);
6231 /* When working with SUBREGs the rule is that the byte
6232 offset must be a multiple of the SUBREG's mode. */
6233 final_offset = (final_offset /
6234 GET_MODE_SIZE (GET_MODE (*r->subreg_loc)));
6235 final_offset = (final_offset *
6236 GET_MODE_SIZE (GET_MODE (*r->subreg_loc)));
6238 *r->where = SUBREG_REG (reloadreg);
6239 SUBREG_BYTE (*r->subreg_loc) = final_offset;
6242 else
6243 *r->where = reloadreg;
6245 /* If reload got no reg and isn't optional, something's wrong. */
6246 else
6247 gcc_assert (rld[r->what].optional);
6251 /* Make a copy of any replacements being done into X and move those
6252 copies to locations in Y, a copy of X. */
6254 void
6255 copy_replacements (rtx x, rtx y)
6257 /* We can't support X being a SUBREG because we might then need to know its
6258 location if something inside it was replaced. */
6259 gcc_assert (GET_CODE (x) != SUBREG);
6261 copy_replacements_1 (&x, &y, n_replacements);
6264 static void
6265 copy_replacements_1 (rtx *px, rtx *py, int orig_replacements)
6267 int i, j;
6268 rtx x, y;
6269 struct replacement *r;
6270 enum rtx_code code;
6271 const char *fmt;
6273 for (j = 0; j < orig_replacements; j++)
6275 if (replacements[j].subreg_loc == px)
6277 r = &replacements[n_replacements++];
6278 r->where = replacements[j].where;
6279 r->subreg_loc = py;
6280 r->what = replacements[j].what;
6281 r->mode = replacements[j].mode;
6283 else if (replacements[j].where == px)
6285 r = &replacements[n_replacements++];
6286 r->where = py;
6287 r->subreg_loc = 0;
6288 r->what = replacements[j].what;
6289 r->mode = replacements[j].mode;
6293 x = *px;
6294 y = *py;
6295 code = GET_CODE (x);
6296 fmt = GET_RTX_FORMAT (code);
6298 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
6300 if (fmt[i] == 'e')
6301 copy_replacements_1 (&XEXP (x, i), &XEXP (y, i), orig_replacements);
6302 else if (fmt[i] == 'E')
6303 for (j = XVECLEN (x, i); --j >= 0; )
6304 copy_replacements_1 (&XVECEXP (x, i, j), &XVECEXP (y, i, j),
6305 orig_replacements);
6309 /* Change any replacements being done to *X to be done to *Y. */
6311 void
6312 move_replacements (rtx *x, rtx *y)
6314 int i;
6316 for (i = 0; i < n_replacements; i++)
6317 if (replacements[i].subreg_loc == x)
6318 replacements[i].subreg_loc = y;
6319 else if (replacements[i].where == x)
6321 replacements[i].where = y;
6322 replacements[i].subreg_loc = 0;
6326 /* If LOC was scheduled to be replaced by something, return the replacement.
6327 Otherwise, return *LOC. */
6330 find_replacement (rtx *loc)
6332 struct replacement *r;
6334 for (r = &replacements[0]; r < &replacements[n_replacements]; r++)
6336 rtx reloadreg = rld[r->what].reg_rtx;
6338 if (reloadreg && r->where == loc)
6340 if (r->mode != VOIDmode && GET_MODE (reloadreg) != r->mode)
6341 reloadreg = gen_rtx_REG (r->mode, REGNO (reloadreg));
6343 return reloadreg;
6345 else if (reloadreg && r->subreg_loc == loc)
6347 /* RELOADREG must be either a REG or a SUBREG.
6349 ??? Is it actually still ever a SUBREG? If so, why? */
6351 if (REG_P (reloadreg))
6352 return gen_rtx_REG (GET_MODE (*loc),
6353 (REGNO (reloadreg) +
6354 subreg_regno_offset (REGNO (SUBREG_REG (*loc)),
6355 GET_MODE (SUBREG_REG (*loc)),
6356 SUBREG_BYTE (*loc),
6357 GET_MODE (*loc))));
6358 else if (GET_MODE (reloadreg) == GET_MODE (*loc))
6359 return reloadreg;
6360 else
6362 int final_offset = SUBREG_BYTE (reloadreg) + SUBREG_BYTE (*loc);
6364 /* When working with SUBREGs the rule is that the byte
6365 offset must be a multiple of the SUBREG's mode. */
6366 final_offset = (final_offset / GET_MODE_SIZE (GET_MODE (*loc)));
6367 final_offset = (final_offset * GET_MODE_SIZE (GET_MODE (*loc)));
6368 return gen_rtx_SUBREG (GET_MODE (*loc), SUBREG_REG (reloadreg),
6369 final_offset);
6374 /* If *LOC is a PLUS, MINUS, or MULT, see if a replacement is scheduled for
6375 what's inside and make a new rtl if so. */
6376 if (GET_CODE (*loc) == PLUS || GET_CODE (*loc) == MINUS
6377 || GET_CODE (*loc) == MULT)
6379 rtx x = find_replacement (&XEXP (*loc, 0));
6380 rtx y = find_replacement (&XEXP (*loc, 1));
6382 if (x != XEXP (*loc, 0) || y != XEXP (*loc, 1))
6383 return gen_rtx_fmt_ee (GET_CODE (*loc), GET_MODE (*loc), x, y);
6386 return *loc;
6389 /* Return nonzero if register in range [REGNO, ENDREGNO)
6390 appears either explicitly or implicitly in X
6391 other than being stored into (except for earlyclobber operands).
6393 References contained within the substructure at LOC do not count.
6394 LOC may be zero, meaning don't ignore anything.
6396 This is similar to refers_to_regno_p in rtlanal.c except that we
6397 look at equivalences for pseudos that didn't get hard registers. */
6399 static int
6400 refers_to_regno_for_reload_p (unsigned int regno, unsigned int endregno,
6401 rtx x, rtx *loc)
6403 int i;
6404 unsigned int r;
6405 RTX_CODE code;
6406 const char *fmt;
6408 if (x == 0)
6409 return 0;
6411 repeat:
6412 code = GET_CODE (x);
6414 switch (code)
6416 case REG:
6417 r = REGNO (x);
6419 /* If this is a pseudo, a hard register must not have been allocated.
6420 X must therefore either be a constant or be in memory. */
6421 if (r >= FIRST_PSEUDO_REGISTER)
6423 if (reg_equiv_memory_loc[r])
6424 return refers_to_regno_for_reload_p (regno, endregno,
6425 reg_equiv_memory_loc[r],
6426 (rtx*) 0);
6428 gcc_assert (reg_equiv_constant[r] || reg_equiv_invariant[r]);
6429 return 0;
6432 return (endregno > r
6433 && regno < r + (r < FIRST_PSEUDO_REGISTER
6434 ? hard_regno_nregs[r][GET_MODE (x)]
6435 : 1));
6437 case SUBREG:
6438 /* If this is a SUBREG of a hard reg, we can see exactly which
6439 registers are being modified. Otherwise, handle normally. */
6440 if (REG_P (SUBREG_REG (x))
6441 && REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER)
6443 unsigned int inner_regno = subreg_regno (x);
6444 unsigned int inner_endregno
6445 = inner_regno + (inner_regno < FIRST_PSEUDO_REGISTER
6446 ? subreg_nregs (x) : 1);
6448 return endregno > inner_regno && regno < inner_endregno;
6450 break;
6452 case CLOBBER:
6453 case SET:
6454 if (&SET_DEST (x) != loc
6455 /* Note setting a SUBREG counts as referring to the REG it is in for
6456 a pseudo but not for hard registers since we can
6457 treat each word individually. */
6458 && ((GET_CODE (SET_DEST (x)) == SUBREG
6459 && loc != &SUBREG_REG (SET_DEST (x))
6460 && REG_P (SUBREG_REG (SET_DEST (x)))
6461 && REGNO (SUBREG_REG (SET_DEST (x))) >= FIRST_PSEUDO_REGISTER
6462 && refers_to_regno_for_reload_p (regno, endregno,
6463 SUBREG_REG (SET_DEST (x)),
6464 loc))
6465 /* If the output is an earlyclobber operand, this is
6466 a conflict. */
6467 || ((!REG_P (SET_DEST (x))
6468 || earlyclobber_operand_p (SET_DEST (x)))
6469 && refers_to_regno_for_reload_p (regno, endregno,
6470 SET_DEST (x), loc))))
6471 return 1;
6473 if (code == CLOBBER || loc == &SET_SRC (x))
6474 return 0;
6475 x = SET_SRC (x);
6476 goto repeat;
6478 default:
6479 break;
6482 /* X does not match, so try its subexpressions. */
6484 fmt = GET_RTX_FORMAT (code);
6485 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
6487 if (fmt[i] == 'e' && loc != &XEXP (x, i))
6489 if (i == 0)
6491 x = XEXP (x, 0);
6492 goto repeat;
6494 else
6495 if (refers_to_regno_for_reload_p (regno, endregno,
6496 XEXP (x, i), loc))
6497 return 1;
6499 else if (fmt[i] == 'E')
6501 int j;
6502 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
6503 if (loc != &XVECEXP (x, i, j)
6504 && refers_to_regno_for_reload_p (regno, endregno,
6505 XVECEXP (x, i, j), loc))
6506 return 1;
6509 return 0;
6512 /* Nonzero if modifying X will affect IN. If X is a register or a SUBREG,
6513 we check if any register number in X conflicts with the relevant register
6514 numbers. If X is a constant, return 0. If X is a MEM, return 1 iff IN
6515 contains a MEM (we don't bother checking for memory addresses that can't
6516 conflict because we expect this to be a rare case.
6518 This function is similar to reg_overlap_mentioned_p in rtlanal.c except
6519 that we look at equivalences for pseudos that didn't get hard registers. */
6522 reg_overlap_mentioned_for_reload_p (rtx x, rtx in)
6524 int regno, endregno;
6526 /* Overly conservative. */
6527 if (GET_CODE (x) == STRICT_LOW_PART
6528 || GET_RTX_CLASS (GET_CODE (x)) == RTX_AUTOINC)
6529 x = XEXP (x, 0);
6531 /* If either argument is a constant, then modifying X can not affect IN. */
6532 if (CONSTANT_P (x) || CONSTANT_P (in))
6533 return 0;
6534 else if (GET_CODE (x) == SUBREG && GET_CODE (SUBREG_REG (x)) == MEM)
6535 return refers_to_mem_for_reload_p (in);
6536 else if (GET_CODE (x) == SUBREG)
6538 regno = REGNO (SUBREG_REG (x));
6539 if (regno < FIRST_PSEUDO_REGISTER)
6540 regno += subreg_regno_offset (REGNO (SUBREG_REG (x)),
6541 GET_MODE (SUBREG_REG (x)),
6542 SUBREG_BYTE (x),
6543 GET_MODE (x));
6544 endregno = regno + (regno < FIRST_PSEUDO_REGISTER
6545 ? subreg_nregs (x) : 1);
6547 return refers_to_regno_for_reload_p (regno, endregno, in, (rtx*) 0);
6549 else if (REG_P (x))
6551 regno = REGNO (x);
6553 /* If this is a pseudo, it must not have been assigned a hard register.
6554 Therefore, it must either be in memory or be a constant. */
6556 if (regno >= FIRST_PSEUDO_REGISTER)
6558 if (reg_equiv_memory_loc[regno])
6559 return refers_to_mem_for_reload_p (in);
6560 gcc_assert (reg_equiv_constant[regno]);
6561 return 0;
6564 endregno = END_HARD_REGNO (x);
6566 return refers_to_regno_for_reload_p (regno, endregno, in, (rtx*) 0);
6568 else if (MEM_P (x))
6569 return refers_to_mem_for_reload_p (in);
6570 else if (GET_CODE (x) == SCRATCH || GET_CODE (x) == PC
6571 || GET_CODE (x) == CC0)
6572 return reg_mentioned_p (x, in);
6573 else
6575 gcc_assert (GET_CODE (x) == PLUS);
6577 /* We actually want to know if X is mentioned somewhere inside IN.
6578 We must not say that (plus (sp) (const_int 124)) is in
6579 (plus (sp) (const_int 64)), since that can lead to incorrect reload
6580 allocation when spuriously changing a RELOAD_FOR_OUTPUT_ADDRESS
6581 into a RELOAD_OTHER on behalf of another RELOAD_OTHER. */
6582 while (MEM_P (in))
6583 in = XEXP (in, 0);
6584 if (REG_P (in))
6585 return 0;
6586 else if (GET_CODE (in) == PLUS)
6587 return (rtx_equal_p (x, in)
6588 || reg_overlap_mentioned_for_reload_p (x, XEXP (in, 0))
6589 || reg_overlap_mentioned_for_reload_p (x, XEXP (in, 1)));
6590 else return (reg_overlap_mentioned_for_reload_p (XEXP (x, 0), in)
6591 || reg_overlap_mentioned_for_reload_p (XEXP (x, 1), in));
6594 gcc_unreachable ();
6597 /* Return nonzero if anything in X contains a MEM. Look also for pseudo
6598 registers. */
6600 static int
6601 refers_to_mem_for_reload_p (rtx x)
6603 const char *fmt;
6604 int i;
6606 if (MEM_P (x))
6607 return 1;
6609 if (REG_P (x))
6610 return (REGNO (x) >= FIRST_PSEUDO_REGISTER
6611 && reg_equiv_memory_loc[REGNO (x)]);
6613 fmt = GET_RTX_FORMAT (GET_CODE (x));
6614 for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--)
6615 if (fmt[i] == 'e'
6616 && (MEM_P (XEXP (x, i))
6617 || refers_to_mem_for_reload_p (XEXP (x, i))))
6618 return 1;
6620 return 0;
6623 /* Check the insns before INSN to see if there is a suitable register
6624 containing the same value as GOAL.
6625 If OTHER is -1, look for a register in class CLASS.
6626 Otherwise, just see if register number OTHER shares GOAL's value.
6628 Return an rtx for the register found, or zero if none is found.
6630 If RELOAD_REG_P is (short *)1,
6631 we reject any hard reg that appears in reload_reg_rtx
6632 because such a hard reg is also needed coming into this insn.
6634 If RELOAD_REG_P is any other nonzero value,
6635 it is a vector indexed by hard reg number
6636 and we reject any hard reg whose element in the vector is nonnegative
6637 as well as any that appears in reload_reg_rtx.
6639 If GOAL is zero, then GOALREG is a register number; we look
6640 for an equivalent for that register.
6642 MODE is the machine mode of the value we want an equivalence for.
6643 If GOAL is nonzero and not VOIDmode, then it must have mode MODE.
6645 This function is used by jump.c as well as in the reload pass.
6647 If GOAL is the sum of the stack pointer and a constant, we treat it
6648 as if it were a constant except that sp is required to be unchanging. */
6651 find_equiv_reg (rtx goal, rtx insn, enum reg_class class, int other,
6652 short *reload_reg_p, int goalreg, enum machine_mode mode)
6654 rtx p = insn;
6655 rtx goaltry, valtry, value, where;
6656 rtx pat;
6657 int regno = -1;
6658 int valueno;
6659 int goal_mem = 0;
6660 int goal_const = 0;
6661 int goal_mem_addr_varies = 0;
6662 int need_stable_sp = 0;
6663 int nregs;
6664 int valuenregs;
6665 int num = 0;
6667 if (goal == 0)
6668 regno = goalreg;
6669 else if (REG_P (goal))
6670 regno = REGNO (goal);
6671 else if (MEM_P (goal))
6673 enum rtx_code code = GET_CODE (XEXP (goal, 0));
6674 if (MEM_VOLATILE_P (goal))
6675 return 0;
6676 if (flag_float_store && SCALAR_FLOAT_MODE_P (GET_MODE (goal)))
6677 return 0;
6678 /* An address with side effects must be reexecuted. */
6679 switch (code)
6681 case POST_INC:
6682 case PRE_INC:
6683 case POST_DEC:
6684 case PRE_DEC:
6685 case POST_MODIFY:
6686 case PRE_MODIFY:
6687 return 0;
6688 default:
6689 break;
6691 goal_mem = 1;
6693 else if (CONSTANT_P (goal))
6694 goal_const = 1;
6695 else if (GET_CODE (goal) == PLUS
6696 && XEXP (goal, 0) == stack_pointer_rtx
6697 && CONSTANT_P (XEXP (goal, 1)))
6698 goal_const = need_stable_sp = 1;
6699 else if (GET_CODE (goal) == PLUS
6700 && XEXP (goal, 0) == frame_pointer_rtx
6701 && CONSTANT_P (XEXP (goal, 1)))
6702 goal_const = 1;
6703 else
6704 return 0;
6706 num = 0;
6707 /* Scan insns back from INSN, looking for one that copies
6708 a value into or out of GOAL.
6709 Stop and give up if we reach a label. */
6711 while (1)
6713 p = PREV_INSN (p);
6714 num++;
6715 if (p == 0 || LABEL_P (p)
6716 || num > PARAM_VALUE (PARAM_MAX_RELOAD_SEARCH_INSNS))
6717 return 0;
6719 /* Don't reuse register contents from before a setjmp-type
6720 function call; on the second return (from the longjmp) it
6721 might have been clobbered by a later reuse. It doesn't
6722 seem worthwhile to actually go and see if it is actually
6723 reused even if that information would be readily available;
6724 just don't reuse it across the setjmp call. */
6725 if (CALL_P (p) && find_reg_note (p, REG_SETJMP, NULL_RTX))
6726 return 0;
6728 if (NONJUMP_INSN_P (p)
6729 /* If we don't want spill regs ... */
6730 && (! (reload_reg_p != 0
6731 && reload_reg_p != (short *) (HOST_WIDE_INT) 1)
6732 /* ... then ignore insns introduced by reload; they aren't
6733 useful and can cause results in reload_as_needed to be
6734 different from what they were when calculating the need for
6735 spills. If we notice an input-reload insn here, we will
6736 reject it below, but it might hide a usable equivalent.
6737 That makes bad code. It may even fail: perhaps no reg was
6738 spilled for this insn because it was assumed we would find
6739 that equivalent. */
6740 || INSN_UID (p) < reload_first_uid))
6742 rtx tem;
6743 pat = single_set (p);
6745 /* First check for something that sets some reg equal to GOAL. */
6746 if (pat != 0
6747 && ((regno >= 0
6748 && true_regnum (SET_SRC (pat)) == regno
6749 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0)
6751 (regno >= 0
6752 && true_regnum (SET_DEST (pat)) == regno
6753 && (valueno = true_regnum (valtry = SET_SRC (pat))) >= 0)
6755 (goal_const && rtx_equal_p (SET_SRC (pat), goal)
6756 /* When looking for stack pointer + const,
6757 make sure we don't use a stack adjust. */
6758 && !reg_overlap_mentioned_for_reload_p (SET_DEST (pat), goal)
6759 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0)
6760 || (goal_mem
6761 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0
6762 && rtx_renumbered_equal_p (goal, SET_SRC (pat)))
6763 || (goal_mem
6764 && (valueno = true_regnum (valtry = SET_SRC (pat))) >= 0
6765 && rtx_renumbered_equal_p (goal, SET_DEST (pat)))
6766 /* If we are looking for a constant,
6767 and something equivalent to that constant was copied
6768 into a reg, we can use that reg. */
6769 || (goal_const && REG_NOTES (p) != 0
6770 && (tem = find_reg_note (p, REG_EQUIV, NULL_RTX))
6771 && ((rtx_equal_p (XEXP (tem, 0), goal)
6772 && (valueno
6773 = true_regnum (valtry = SET_DEST (pat))) >= 0)
6774 || (REG_P (SET_DEST (pat))
6775 && GET_CODE (XEXP (tem, 0)) == CONST_DOUBLE
6776 && SCALAR_FLOAT_MODE_P (GET_MODE (XEXP (tem, 0)))
6777 && GET_CODE (goal) == CONST_INT
6778 && 0 != (goaltry
6779 = operand_subword (XEXP (tem, 0), 0, 0,
6780 VOIDmode))
6781 && rtx_equal_p (goal, goaltry)
6782 && (valtry
6783 = operand_subword (SET_DEST (pat), 0, 0,
6784 VOIDmode))
6785 && (valueno = true_regnum (valtry)) >= 0)))
6786 || (goal_const && (tem = find_reg_note (p, REG_EQUIV,
6787 NULL_RTX))
6788 && REG_P (SET_DEST (pat))
6789 && GET_CODE (XEXP (tem, 0)) == CONST_DOUBLE
6790 && SCALAR_FLOAT_MODE_P (GET_MODE (XEXP (tem, 0)))
6791 && GET_CODE (goal) == CONST_INT
6792 && 0 != (goaltry = operand_subword (XEXP (tem, 0), 1, 0,
6793 VOIDmode))
6794 && rtx_equal_p (goal, goaltry)
6795 && (valtry
6796 = operand_subword (SET_DEST (pat), 1, 0, VOIDmode))
6797 && (valueno = true_regnum (valtry)) >= 0)))
6799 if (other >= 0)
6801 if (valueno != other)
6802 continue;
6804 else if ((unsigned) valueno >= FIRST_PSEUDO_REGISTER)
6805 continue;
6806 else if (!in_hard_reg_set_p (reg_class_contents[(int) class],
6807 mode, valueno))
6808 continue;
6809 value = valtry;
6810 where = p;
6811 break;
6816 /* We found a previous insn copying GOAL into a suitable other reg VALUE
6817 (or copying VALUE into GOAL, if GOAL is also a register).
6818 Now verify that VALUE is really valid. */
6820 /* VALUENO is the register number of VALUE; a hard register. */
6822 /* Don't try to re-use something that is killed in this insn. We want
6823 to be able to trust REG_UNUSED notes. */
6824 if (REG_NOTES (where) != 0 && find_reg_note (where, REG_UNUSED, value))
6825 return 0;
6827 /* If we propose to get the value from the stack pointer or if GOAL is
6828 a MEM based on the stack pointer, we need a stable SP. */
6829 if (valueno == STACK_POINTER_REGNUM || regno == STACK_POINTER_REGNUM
6830 || (goal_mem && reg_overlap_mentioned_for_reload_p (stack_pointer_rtx,
6831 goal)))
6832 need_stable_sp = 1;
6834 /* Reject VALUE if the copy-insn moved the wrong sort of datum. */
6835 if (GET_MODE (value) != mode)
6836 return 0;
6838 /* Reject VALUE if it was loaded from GOAL
6839 and is also a register that appears in the address of GOAL. */
6841 if (goal_mem && value == SET_DEST (single_set (where))
6842 && refers_to_regno_for_reload_p (valueno, end_hard_regno (mode, valueno),
6843 goal, (rtx*) 0))
6844 return 0;
6846 /* Reject registers that overlap GOAL. */
6848 if (regno >= 0 && regno < FIRST_PSEUDO_REGISTER)
6849 nregs = hard_regno_nregs[regno][mode];
6850 else
6851 nregs = 1;
6852 valuenregs = hard_regno_nregs[valueno][mode];
6854 if (!goal_mem && !goal_const
6855 && regno + nregs > valueno && regno < valueno + valuenregs)
6856 return 0;
6858 /* Reject VALUE if it is one of the regs reserved for reloads.
6859 Reload1 knows how to reuse them anyway, and it would get
6860 confused if we allocated one without its knowledge.
6861 (Now that insns introduced by reload are ignored above,
6862 this case shouldn't happen, but I'm not positive.) */
6864 if (reload_reg_p != 0 && reload_reg_p != (short *) (HOST_WIDE_INT) 1)
6866 int i;
6867 for (i = 0; i < valuenregs; ++i)
6868 if (reload_reg_p[valueno + i] >= 0)
6869 return 0;
6872 /* Reject VALUE if it is a register being used for an input reload
6873 even if it is not one of those reserved. */
6875 if (reload_reg_p != 0)
6877 int i;
6878 for (i = 0; i < n_reloads; i++)
6879 if (rld[i].reg_rtx != 0 && rld[i].in)
6881 int regno1 = REGNO (rld[i].reg_rtx);
6882 int nregs1 = hard_regno_nregs[regno1]
6883 [GET_MODE (rld[i].reg_rtx)];
6884 if (regno1 < valueno + valuenregs
6885 && regno1 + nregs1 > valueno)
6886 return 0;
6890 if (goal_mem)
6891 /* We must treat frame pointer as varying here,
6892 since it can vary--in a nonlocal goto as generated by expand_goto. */
6893 goal_mem_addr_varies = !CONSTANT_ADDRESS_P (XEXP (goal, 0));
6895 /* Now verify that the values of GOAL and VALUE remain unaltered
6896 until INSN is reached. */
6898 p = insn;
6899 while (1)
6901 p = PREV_INSN (p);
6902 if (p == where)
6903 return value;
6905 /* Don't trust the conversion past a function call
6906 if either of the two is in a call-clobbered register, or memory. */
6907 if (CALL_P (p))
6909 int i;
6911 if (goal_mem || need_stable_sp)
6912 return 0;
6914 if (regno >= 0 && regno < FIRST_PSEUDO_REGISTER)
6915 for (i = 0; i < nregs; ++i)
6916 if (call_used_regs[regno + i]
6917 || HARD_REGNO_CALL_PART_CLOBBERED (regno + i, mode))
6918 return 0;
6920 if (valueno >= 0 && valueno < FIRST_PSEUDO_REGISTER)
6921 for (i = 0; i < valuenregs; ++i)
6922 if (call_used_regs[valueno + i]
6923 || HARD_REGNO_CALL_PART_CLOBBERED (valueno + i, mode))
6924 return 0;
6927 if (INSN_P (p))
6929 pat = PATTERN (p);
6931 /* Watch out for unspec_volatile, and volatile asms. */
6932 if (volatile_insn_p (pat))
6933 return 0;
6935 /* If this insn P stores in either GOAL or VALUE, return 0.
6936 If GOAL is a memory ref and this insn writes memory, return 0.
6937 If GOAL is a memory ref and its address is not constant,
6938 and this insn P changes a register used in GOAL, return 0. */
6940 if (GET_CODE (pat) == COND_EXEC)
6941 pat = COND_EXEC_CODE (pat);
6942 if (GET_CODE (pat) == SET || GET_CODE (pat) == CLOBBER)
6944 rtx dest = SET_DEST (pat);
6945 while (GET_CODE (dest) == SUBREG
6946 || GET_CODE (dest) == ZERO_EXTRACT
6947 || GET_CODE (dest) == STRICT_LOW_PART)
6948 dest = XEXP (dest, 0);
6949 if (REG_P (dest))
6951 int xregno = REGNO (dest);
6952 int xnregs;
6953 if (REGNO (dest) < FIRST_PSEUDO_REGISTER)
6954 xnregs = hard_regno_nregs[xregno][GET_MODE (dest)];
6955 else
6956 xnregs = 1;
6957 if (xregno < regno + nregs && xregno + xnregs > regno)
6958 return 0;
6959 if (xregno < valueno + valuenregs
6960 && xregno + xnregs > valueno)
6961 return 0;
6962 if (goal_mem_addr_varies
6963 && reg_overlap_mentioned_for_reload_p (dest, goal))
6964 return 0;
6965 if (xregno == STACK_POINTER_REGNUM && need_stable_sp)
6966 return 0;
6968 else if (goal_mem && MEM_P (dest)
6969 && ! push_operand (dest, GET_MODE (dest)))
6970 return 0;
6971 else if (MEM_P (dest) && regno >= FIRST_PSEUDO_REGISTER
6972 && reg_equiv_memory_loc[regno] != 0)
6973 return 0;
6974 else if (need_stable_sp && push_operand (dest, GET_MODE (dest)))
6975 return 0;
6977 else if (GET_CODE (pat) == PARALLEL)
6979 int i;
6980 for (i = XVECLEN (pat, 0) - 1; i >= 0; i--)
6982 rtx v1 = XVECEXP (pat, 0, i);
6983 if (GET_CODE (v1) == COND_EXEC)
6984 v1 = COND_EXEC_CODE (v1);
6985 if (GET_CODE (v1) == SET || GET_CODE (v1) == CLOBBER)
6987 rtx dest = SET_DEST (v1);
6988 while (GET_CODE (dest) == SUBREG
6989 || GET_CODE (dest) == ZERO_EXTRACT
6990 || GET_CODE (dest) == STRICT_LOW_PART)
6991 dest = XEXP (dest, 0);
6992 if (REG_P (dest))
6994 int xregno = REGNO (dest);
6995 int xnregs;
6996 if (REGNO (dest) < FIRST_PSEUDO_REGISTER)
6997 xnregs = hard_regno_nregs[xregno][GET_MODE (dest)];
6998 else
6999 xnregs = 1;
7000 if (xregno < regno + nregs
7001 && xregno + xnregs > regno)
7002 return 0;
7003 if (xregno < valueno + valuenregs
7004 && xregno + xnregs > valueno)
7005 return 0;
7006 if (goal_mem_addr_varies
7007 && reg_overlap_mentioned_for_reload_p (dest,
7008 goal))
7009 return 0;
7010 if (xregno == STACK_POINTER_REGNUM && need_stable_sp)
7011 return 0;
7013 else if (goal_mem && MEM_P (dest)
7014 && ! push_operand (dest, GET_MODE (dest)))
7015 return 0;
7016 else if (MEM_P (dest) && regno >= FIRST_PSEUDO_REGISTER
7017 && reg_equiv_memory_loc[regno] != 0)
7018 return 0;
7019 else if (need_stable_sp
7020 && push_operand (dest, GET_MODE (dest)))
7021 return 0;
7026 if (CALL_P (p) && CALL_INSN_FUNCTION_USAGE (p))
7028 rtx link;
7030 for (link = CALL_INSN_FUNCTION_USAGE (p); XEXP (link, 1) != 0;
7031 link = XEXP (link, 1))
7033 pat = XEXP (link, 0);
7034 if (GET_CODE (pat) == CLOBBER)
7036 rtx dest = SET_DEST (pat);
7038 if (REG_P (dest))
7040 int xregno = REGNO (dest);
7041 int xnregs
7042 = hard_regno_nregs[xregno][GET_MODE (dest)];
7044 if (xregno < regno + nregs
7045 && xregno + xnregs > regno)
7046 return 0;
7047 else if (xregno < valueno + valuenregs
7048 && xregno + xnregs > valueno)
7049 return 0;
7050 else if (goal_mem_addr_varies
7051 && reg_overlap_mentioned_for_reload_p (dest,
7052 goal))
7053 return 0;
7056 else if (goal_mem && MEM_P (dest)
7057 && ! push_operand (dest, GET_MODE (dest)))
7058 return 0;
7059 else if (need_stable_sp
7060 && push_operand (dest, GET_MODE (dest)))
7061 return 0;
7066 #ifdef AUTO_INC_DEC
7067 /* If this insn auto-increments or auto-decrements
7068 either regno or valueno, return 0 now.
7069 If GOAL is a memory ref and its address is not constant,
7070 and this insn P increments a register used in GOAL, return 0. */
7072 rtx link;
7074 for (link = REG_NOTES (p); link; link = XEXP (link, 1))
7075 if (REG_NOTE_KIND (link) == REG_INC
7076 && REG_P (XEXP (link, 0)))
7078 int incno = REGNO (XEXP (link, 0));
7079 if (incno < regno + nregs && incno >= regno)
7080 return 0;
7081 if (incno < valueno + valuenregs && incno >= valueno)
7082 return 0;
7083 if (goal_mem_addr_varies
7084 && reg_overlap_mentioned_for_reload_p (XEXP (link, 0),
7085 goal))
7086 return 0;
7089 #endif
7094 /* Find a place where INCED appears in an increment or decrement operator
7095 within X, and return the amount INCED is incremented or decremented by.
7096 The value is always positive. */
7098 static int
7099 find_inc_amount (rtx x, rtx inced)
7101 enum rtx_code code = GET_CODE (x);
7102 const char *fmt;
7103 int i;
7105 if (code == MEM)
7107 rtx addr = XEXP (x, 0);
7108 if ((GET_CODE (addr) == PRE_DEC
7109 || GET_CODE (addr) == POST_DEC
7110 || GET_CODE (addr) == PRE_INC
7111 || GET_CODE (addr) == POST_INC)
7112 && XEXP (addr, 0) == inced)
7113 return GET_MODE_SIZE (GET_MODE (x));
7114 else if ((GET_CODE (addr) == PRE_MODIFY
7115 || GET_CODE (addr) == POST_MODIFY)
7116 && GET_CODE (XEXP (addr, 1)) == PLUS
7117 && XEXP (addr, 0) == XEXP (XEXP (addr, 1), 0)
7118 && XEXP (addr, 0) == inced
7119 && GET_CODE (XEXP (XEXP (addr, 1), 1)) == CONST_INT)
7121 i = INTVAL (XEXP (XEXP (addr, 1), 1));
7122 return i < 0 ? -i : i;
7126 fmt = GET_RTX_FORMAT (code);
7127 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
7129 if (fmt[i] == 'e')
7131 int tem = find_inc_amount (XEXP (x, i), inced);
7132 if (tem != 0)
7133 return tem;
7135 if (fmt[i] == 'E')
7137 int j;
7138 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
7140 int tem = find_inc_amount (XVECEXP (x, i, j), inced);
7141 if (tem != 0)
7142 return tem;
7147 return 0;
7150 /* Return 1 if registers from REGNO to ENDREGNO are the subjects of a
7151 REG_INC note in insn INSN. REGNO must refer to a hard register. */
7153 #ifdef AUTO_INC_DEC
7154 static int
7155 reg_inc_found_and_valid_p (unsigned int regno, unsigned int endregno,
7156 rtx insn)
7158 rtx link;
7160 gcc_assert (insn);
7162 if (! INSN_P (insn))
7163 return 0;
7165 for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
7166 if (REG_NOTE_KIND (link) == REG_INC)
7168 unsigned int test = (int) REGNO (XEXP (link, 0));
7169 if (test >= regno && test < endregno)
7170 return 1;
7172 return 0;
7174 #else
7176 #define reg_inc_found_and_valid_p(regno,endregno,insn) 0
7178 #endif
7180 /* Return 1 if register REGNO is the subject of a clobber in insn INSN.
7181 If SETS is 1, also consider SETs. If SETS is 2, enable checking
7182 REG_INC. REGNO must refer to a hard register. */
7185 regno_clobbered_p (unsigned int regno, rtx insn, enum machine_mode mode,
7186 int sets)
7188 unsigned int nregs, endregno;
7190 /* regno must be a hard register. */
7191 gcc_assert (regno < FIRST_PSEUDO_REGISTER);
7193 nregs = hard_regno_nregs[regno][mode];
7194 endregno = regno + nregs;
7196 if ((GET_CODE (PATTERN (insn)) == CLOBBER
7197 || (sets == 1 && GET_CODE (PATTERN (insn)) == SET))
7198 && REG_P (XEXP (PATTERN (insn), 0)))
7200 unsigned int test = REGNO (XEXP (PATTERN (insn), 0));
7202 return test >= regno && test < endregno;
7205 if (sets == 2 && reg_inc_found_and_valid_p (regno, endregno, insn))
7206 return 1;
7208 if (GET_CODE (PATTERN (insn)) == PARALLEL)
7210 int i = XVECLEN (PATTERN (insn), 0) - 1;
7212 for (; i >= 0; i--)
7214 rtx elt = XVECEXP (PATTERN (insn), 0, i);
7215 if ((GET_CODE (elt) == CLOBBER
7216 || (sets == 1 && GET_CODE (PATTERN (insn)) == SET))
7217 && REG_P (XEXP (elt, 0)))
7219 unsigned int test = REGNO (XEXP (elt, 0));
7221 if (test >= regno && test < endregno)
7222 return 1;
7224 if (sets == 2
7225 && reg_inc_found_and_valid_p (regno, endregno, elt))
7226 return 1;
7230 return 0;
7233 /* Find the low part, with mode MODE, of a hard regno RELOADREG. */
7235 reload_adjust_reg_for_mode (rtx reloadreg, enum machine_mode mode)
7237 int regno;
7239 if (GET_MODE (reloadreg) == mode)
7240 return reloadreg;
7242 regno = REGNO (reloadreg);
7244 if (WORDS_BIG_ENDIAN)
7245 regno += (int) hard_regno_nregs[regno][GET_MODE (reloadreg)]
7246 - (int) hard_regno_nregs[regno][mode];
7248 return gen_rtx_REG (mode, regno);
7251 static const char *const reload_when_needed_name[] =
7253 "RELOAD_FOR_INPUT",
7254 "RELOAD_FOR_OUTPUT",
7255 "RELOAD_FOR_INSN",
7256 "RELOAD_FOR_INPUT_ADDRESS",
7257 "RELOAD_FOR_INPADDR_ADDRESS",
7258 "RELOAD_FOR_OUTPUT_ADDRESS",
7259 "RELOAD_FOR_OUTADDR_ADDRESS",
7260 "RELOAD_FOR_OPERAND_ADDRESS",
7261 "RELOAD_FOR_OPADDR_ADDR",
7262 "RELOAD_OTHER",
7263 "RELOAD_FOR_OTHER_ADDRESS"
7266 /* These functions are used to print the variables set by 'find_reloads' */
7268 void
7269 debug_reload_to_stream (FILE *f)
7271 int r;
7272 const char *prefix;
7274 if (! f)
7275 f = stderr;
7276 for (r = 0; r < n_reloads; r++)
7278 fprintf (f, "Reload %d: ", r);
7280 if (rld[r].in != 0)
7282 fprintf (f, "reload_in (%s) = ",
7283 GET_MODE_NAME (rld[r].inmode));
7284 print_inline_rtx (f, rld[r].in, 24);
7285 fprintf (f, "\n\t");
7288 if (rld[r].out != 0)
7290 fprintf (f, "reload_out (%s) = ",
7291 GET_MODE_NAME (rld[r].outmode));
7292 print_inline_rtx (f, rld[r].out, 24);
7293 fprintf (f, "\n\t");
7296 fprintf (f, "%s, ", reg_class_names[(int) rld[r].class]);
7298 fprintf (f, "%s (opnum = %d)",
7299 reload_when_needed_name[(int) rld[r].when_needed],
7300 rld[r].opnum);
7302 if (rld[r].optional)
7303 fprintf (f, ", optional");
7305 if (rld[r].nongroup)
7306 fprintf (f, ", nongroup");
7308 if (rld[r].inc != 0)
7309 fprintf (f, ", inc by %d", rld[r].inc);
7311 if (rld[r].nocombine)
7312 fprintf (f, ", can't combine");
7314 if (rld[r].secondary_p)
7315 fprintf (f, ", secondary_reload_p");
7317 if (rld[r].in_reg != 0)
7319 fprintf (f, "\n\treload_in_reg: ");
7320 print_inline_rtx (f, rld[r].in_reg, 24);
7323 if (rld[r].out_reg != 0)
7325 fprintf (f, "\n\treload_out_reg: ");
7326 print_inline_rtx (f, rld[r].out_reg, 24);
7329 if (rld[r].reg_rtx != 0)
7331 fprintf (f, "\n\treload_reg_rtx: ");
7332 print_inline_rtx (f, rld[r].reg_rtx, 24);
7335 prefix = "\n\t";
7336 if (rld[r].secondary_in_reload != -1)
7338 fprintf (f, "%ssecondary_in_reload = %d",
7339 prefix, rld[r].secondary_in_reload);
7340 prefix = ", ";
7343 if (rld[r].secondary_out_reload != -1)
7344 fprintf (f, "%ssecondary_out_reload = %d\n",
7345 prefix, rld[r].secondary_out_reload);
7347 prefix = "\n\t";
7348 if (rld[r].secondary_in_icode != CODE_FOR_nothing)
7350 fprintf (f, "%ssecondary_in_icode = %s", prefix,
7351 insn_data[rld[r].secondary_in_icode].name);
7352 prefix = ", ";
7355 if (rld[r].secondary_out_icode != CODE_FOR_nothing)
7356 fprintf (f, "%ssecondary_out_icode = %s", prefix,
7357 insn_data[rld[r].secondary_out_icode].name);
7359 fprintf (f, "\n");
7363 void
7364 debug_reload (void)
7366 debug_reload_to_stream (stderr);