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[dragonfly.git] / contrib / gcc-4.4 / gcc / reload.c
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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, 2008, 2009
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 rclass = 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 rclass = 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 (rclass == NO_REGS && icode == CODE_FOR_nothing)
370 return -1;
372 if (rclass != NO_REGS)
373 t_reload = push_secondary_reload (in_p, x, opnum, optional, rclass,
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 (rclass == 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 rclass = 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 || rclass != 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 (rclass, rld[s_reload].rclass)
432 || reg_class_subset_p (rld[s_reload].rclass, rclass))
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 (rclass) || 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 (rclass, rld[s_reload].rclass))
449 rld[s_reload].rclass = rclass;
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;
458 break;
461 if (s_reload == n_reloads)
463 #ifdef SECONDARY_MEMORY_NEEDED
464 /* If we need a memory location to copy between the two reload regs,
465 set it up now. Note that we do the input case before making
466 the reload and the output case after. This is due to the
467 way reloads are output. */
469 if (in_p && icode == CODE_FOR_nothing
470 && SECONDARY_MEMORY_NEEDED (rclass, reload_class, mode))
472 get_secondary_mem (x, reload_mode, opnum, type);
474 /* We may have just added new reloads. Make sure we add
475 the new reload at the end. */
476 s_reload = n_reloads;
478 #endif
480 /* We need to make a new secondary reload for this register class. */
481 rld[s_reload].in = rld[s_reload].out = 0;
482 rld[s_reload].rclass = rclass;
484 rld[s_reload].inmode = in_p ? mode : VOIDmode;
485 rld[s_reload].outmode = ! in_p ? mode : VOIDmode;
486 rld[s_reload].reg_rtx = 0;
487 rld[s_reload].optional = optional;
488 rld[s_reload].inc = 0;
489 /* Maybe we could combine these, but it seems too tricky. */
490 rld[s_reload].nocombine = 1;
491 rld[s_reload].in_reg = 0;
492 rld[s_reload].out_reg = 0;
493 rld[s_reload].opnum = opnum;
494 rld[s_reload].when_needed = secondary_type;
495 rld[s_reload].secondary_in_reload = in_p ? t_reload : -1;
496 rld[s_reload].secondary_out_reload = ! in_p ? t_reload : -1;
497 rld[s_reload].secondary_in_icode = in_p ? t_icode : CODE_FOR_nothing;
498 rld[s_reload].secondary_out_icode
499 = ! in_p ? t_icode : CODE_FOR_nothing;
500 rld[s_reload].secondary_p = 1;
502 n_reloads++;
504 #ifdef SECONDARY_MEMORY_NEEDED
505 if (! in_p && icode == CODE_FOR_nothing
506 && SECONDARY_MEMORY_NEEDED (reload_class, rclass, mode))
507 get_secondary_mem (x, mode, opnum, type);
508 #endif
511 *picode = icode;
512 return s_reload;
515 /* If a secondary reload is needed, return its class. If both an intermediate
516 register and a scratch register is needed, we return the class of the
517 intermediate register. */
518 enum reg_class
519 secondary_reload_class (bool in_p, enum reg_class rclass,
520 enum machine_mode mode, rtx x)
522 enum insn_code icode;
523 secondary_reload_info sri;
525 sri.icode = CODE_FOR_nothing;
526 sri.prev_sri = NULL;
527 rclass = targetm.secondary_reload (in_p, x, rclass, mode, &sri);
528 icode = sri.icode;
530 /* If there are no secondary reloads at all, we return NO_REGS.
531 If an intermediate register is needed, we return its class. */
532 if (icode == CODE_FOR_nothing || rclass != NO_REGS)
533 return rclass;
535 /* No intermediate register is needed, but we have a special reload
536 pattern, which we assume for now needs a scratch register. */
537 return scratch_reload_class (icode);
540 /* ICODE is the insn_code of a reload pattern. Check that it has exactly
541 three operands, verify that operand 2 is an output operand, and return
542 its register class.
543 ??? We'd like to be able to handle any pattern with at least 2 operands,
544 for zero or more scratch registers, but that needs more infrastructure. */
545 enum reg_class
546 scratch_reload_class (enum insn_code icode)
548 const char *scratch_constraint;
549 char scratch_letter;
550 enum reg_class rclass;
552 gcc_assert (insn_data[(int) icode].n_operands == 3);
553 scratch_constraint = insn_data[(int) icode].operand[2].constraint;
554 gcc_assert (*scratch_constraint == '=');
555 scratch_constraint++;
556 if (*scratch_constraint == '&')
557 scratch_constraint++;
558 scratch_letter = *scratch_constraint;
559 if (scratch_letter == 'r')
560 return GENERAL_REGS;
561 rclass = REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
562 scratch_constraint);
563 gcc_assert (rclass != NO_REGS);
564 return rclass;
567 #ifdef SECONDARY_MEMORY_NEEDED
569 /* Return a memory location that will be used to copy X in mode MODE.
570 If we haven't already made a location for this mode in this insn,
571 call find_reloads_address on the location being returned. */
574 get_secondary_mem (rtx x ATTRIBUTE_UNUSED, enum machine_mode mode,
575 int opnum, enum reload_type type)
577 rtx loc;
578 int mem_valid;
580 /* By default, if MODE is narrower than a word, widen it to a word.
581 This is required because most machines that require these memory
582 locations do not support short load and stores from all registers
583 (e.g., FP registers). */
585 #ifdef SECONDARY_MEMORY_NEEDED_MODE
586 mode = SECONDARY_MEMORY_NEEDED_MODE (mode);
587 #else
588 if (GET_MODE_BITSIZE (mode) < BITS_PER_WORD && INTEGRAL_MODE_P (mode))
589 mode = mode_for_size (BITS_PER_WORD, GET_MODE_CLASS (mode), 0);
590 #endif
592 /* If we already have made a MEM for this operand in MODE, return it. */
593 if (secondary_memlocs_elim[(int) mode][opnum] != 0)
594 return secondary_memlocs_elim[(int) mode][opnum];
596 /* If this is the first time we've tried to get a MEM for this mode,
597 allocate a new one. `something_changed' in reload will get set
598 by noticing that the frame size has changed. */
600 if (secondary_memlocs[(int) mode] == 0)
602 #ifdef SECONDARY_MEMORY_NEEDED_RTX
603 secondary_memlocs[(int) mode] = SECONDARY_MEMORY_NEEDED_RTX (mode);
604 #else
605 secondary_memlocs[(int) mode]
606 = assign_stack_local (mode, GET_MODE_SIZE (mode), 0);
607 #endif
610 /* Get a version of the address doing any eliminations needed. If that
611 didn't give us a new MEM, make a new one if it isn't valid. */
613 loc = eliminate_regs (secondary_memlocs[(int) mode], VOIDmode, NULL_RTX);
614 mem_valid = strict_memory_address_p (mode, XEXP (loc, 0));
616 if (! mem_valid && loc == secondary_memlocs[(int) mode])
617 loc = copy_rtx (loc);
619 /* The only time the call below will do anything is if the stack
620 offset is too large. In that case IND_LEVELS doesn't matter, so we
621 can just pass a zero. Adjust the type to be the address of the
622 corresponding object. If the address was valid, save the eliminated
623 address. If it wasn't valid, we need to make a reload each time, so
624 don't save it. */
626 if (! mem_valid)
628 type = (type == RELOAD_FOR_INPUT ? RELOAD_FOR_INPUT_ADDRESS
629 : type == RELOAD_FOR_OUTPUT ? RELOAD_FOR_OUTPUT_ADDRESS
630 : RELOAD_OTHER);
632 find_reloads_address (mode, &loc, XEXP (loc, 0), &XEXP (loc, 0),
633 opnum, type, 0, 0);
636 secondary_memlocs_elim[(int) mode][opnum] = loc;
637 if (secondary_memlocs_elim_used <= (int)mode)
638 secondary_memlocs_elim_used = (int)mode + 1;
639 return loc;
642 /* Clear any secondary memory locations we've made. */
644 void
645 clear_secondary_mem (void)
647 memset (secondary_memlocs, 0, sizeof secondary_memlocs);
649 #endif /* SECONDARY_MEMORY_NEEDED */
652 /* Find the largest class which has at least one register valid in
653 mode INNER, and which for every such register, that register number
654 plus N is also valid in OUTER (if in range) and is cheap to move
655 into REGNO. Such a class must exist. */
657 static enum reg_class
658 find_valid_class (enum machine_mode outer ATTRIBUTE_UNUSED,
659 enum machine_mode inner ATTRIBUTE_UNUSED, int n,
660 unsigned int dest_regno ATTRIBUTE_UNUSED)
662 int best_cost = -1;
663 int rclass;
664 int regno;
665 enum reg_class best_class = NO_REGS;
666 enum reg_class dest_class ATTRIBUTE_UNUSED = REGNO_REG_CLASS (dest_regno);
667 unsigned int best_size = 0;
668 int cost;
670 for (rclass = 1; rclass < N_REG_CLASSES; rclass++)
672 int bad = 0;
673 int good = 0;
674 for (regno = 0; regno < FIRST_PSEUDO_REGISTER - n && ! bad; regno++)
675 if (TEST_HARD_REG_BIT (reg_class_contents[rclass], regno))
677 if (HARD_REGNO_MODE_OK (regno, inner))
679 good = 1;
680 if (! TEST_HARD_REG_BIT (reg_class_contents[rclass], regno + n)
681 || ! HARD_REGNO_MODE_OK (regno + n, outer))
682 bad = 1;
686 if (bad || !good)
687 continue;
688 cost = REGISTER_MOVE_COST (outer, rclass, dest_class);
690 if ((reg_class_size[rclass] > best_size
691 && (best_cost < 0 || best_cost >= cost))
692 || best_cost > cost)
694 best_class = rclass;
695 best_size = reg_class_size[rclass];
696 best_cost = REGISTER_MOVE_COST (outer, rclass, dest_class);
700 gcc_assert (best_size != 0);
702 return best_class;
705 /* Return the number of a previously made reload that can be combined with
706 a new one, or n_reloads if none of the existing reloads can be used.
707 OUT, RCLASS, TYPE and OPNUM are the same arguments as passed to
708 push_reload, they determine the kind of the new reload that we try to
709 combine. P_IN points to the corresponding value of IN, which can be
710 modified by this function.
711 DONT_SHARE is nonzero if we can't share any input-only reload for IN. */
713 static int
714 find_reusable_reload (rtx *p_in, rtx out, enum reg_class rclass,
715 enum reload_type type, int opnum, int dont_share)
717 rtx in = *p_in;
718 int i;
719 /* We can't merge two reloads if the output of either one is
720 earlyclobbered. */
722 if (earlyclobber_operand_p (out))
723 return n_reloads;
725 /* We can use an existing reload if the class is right
726 and at least one of IN and OUT is a match
727 and the other is at worst neutral.
728 (A zero compared against anything is neutral.)
730 If SMALL_REGISTER_CLASSES, don't use existing reloads unless they are
731 for the same thing since that can cause us to need more reload registers
732 than we otherwise would. */
734 for (i = 0; i < n_reloads; i++)
735 if ((reg_class_subset_p (rclass, rld[i].rclass)
736 || reg_class_subset_p (rld[i].rclass, rclass))
737 /* If the existing reload has a register, it must fit our class. */
738 && (rld[i].reg_rtx == 0
739 || TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
740 true_regnum (rld[i].reg_rtx)))
741 && ((in != 0 && MATCHES (rld[i].in, in) && ! dont_share
742 && (out == 0 || rld[i].out == 0 || MATCHES (rld[i].out, out)))
743 || (out != 0 && MATCHES (rld[i].out, out)
744 && (in == 0 || rld[i].in == 0 || MATCHES (rld[i].in, in))))
745 && (rld[i].out == 0 || ! earlyclobber_operand_p (rld[i].out))
746 && (SMALL_REGISTER_CLASS_P (rclass) || SMALL_REGISTER_CLASSES)
747 && MERGABLE_RELOADS (type, rld[i].when_needed, opnum, rld[i].opnum))
748 return i;
750 /* Reloading a plain reg for input can match a reload to postincrement
751 that reg, since the postincrement's value is the right value.
752 Likewise, it can match a preincrement reload, since we regard
753 the preincrementation as happening before any ref in this insn
754 to that register. */
755 for (i = 0; i < n_reloads; i++)
756 if ((reg_class_subset_p (rclass, rld[i].rclass)
757 || reg_class_subset_p (rld[i].rclass, rclass))
758 /* If the existing reload has a register, it must fit our
759 class. */
760 && (rld[i].reg_rtx == 0
761 || TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
762 true_regnum (rld[i].reg_rtx)))
763 && out == 0 && rld[i].out == 0 && rld[i].in != 0
764 && ((REG_P (in)
765 && GET_RTX_CLASS (GET_CODE (rld[i].in)) == RTX_AUTOINC
766 && MATCHES (XEXP (rld[i].in, 0), in))
767 || (REG_P (rld[i].in)
768 && GET_RTX_CLASS (GET_CODE (in)) == RTX_AUTOINC
769 && MATCHES (XEXP (in, 0), rld[i].in)))
770 && (rld[i].out == 0 || ! earlyclobber_operand_p (rld[i].out))
771 && (SMALL_REGISTER_CLASS_P (rclass) || SMALL_REGISTER_CLASSES)
772 && MERGABLE_RELOADS (type, rld[i].when_needed,
773 opnum, rld[i].opnum))
775 /* Make sure reload_in ultimately has the increment,
776 not the plain register. */
777 if (REG_P (in))
778 *p_in = rld[i].in;
779 return i;
781 return n_reloads;
784 /* Return nonzero if X is a SUBREG which will require reloading of its
785 SUBREG_REG expression. */
787 static int
788 reload_inner_reg_of_subreg (rtx x, enum machine_mode mode, int output)
790 rtx inner;
792 /* Only SUBREGs are problematical. */
793 if (GET_CODE (x) != SUBREG)
794 return 0;
796 inner = SUBREG_REG (x);
798 /* If INNER is a constant or PLUS, then INNER must be reloaded. */
799 if (CONSTANT_P (inner) || GET_CODE (inner) == PLUS)
800 return 1;
802 /* If INNER is not a hard register, then INNER will not need to
803 be reloaded. */
804 if (!REG_P (inner)
805 || REGNO (inner) >= FIRST_PSEUDO_REGISTER)
806 return 0;
808 /* If INNER is not ok for MODE, then INNER will need reloading. */
809 if (! HARD_REGNO_MODE_OK (subreg_regno (x), mode))
810 return 1;
812 /* If the outer part is a word or smaller, INNER larger than a
813 word and the number of regs for INNER is not the same as the
814 number of words in INNER, then INNER will need reloading. */
815 return (GET_MODE_SIZE (mode) <= UNITS_PER_WORD
816 && output
817 && GET_MODE_SIZE (GET_MODE (inner)) > UNITS_PER_WORD
818 && ((GET_MODE_SIZE (GET_MODE (inner)) / UNITS_PER_WORD)
819 != (int) hard_regno_nregs[REGNO (inner)][GET_MODE (inner)]));
822 /* Return nonzero if IN can be reloaded into REGNO with mode MODE without
823 requiring an extra reload register. The caller has already found that
824 IN contains some reference to REGNO, so check that we can produce the
825 new value in a single step. E.g. if we have
826 (set (reg r13) (plus (reg r13) (const int 1))), and there is an
827 instruction that adds one to a register, this should succeed.
828 However, if we have something like
829 (set (reg r13) (plus (reg r13) (const int 999))), and the constant 999
830 needs to be loaded into a register first, we need a separate reload
831 register.
832 Such PLUS reloads are generated by find_reload_address_part.
833 The out-of-range PLUS expressions are usually introduced in the instruction
834 patterns by register elimination and substituting pseudos without a home
835 by their function-invariant equivalences. */
836 static int
837 can_reload_into (rtx in, int regno, enum machine_mode mode)
839 rtx dst, test_insn;
840 int r = 0;
841 struct recog_data save_recog_data;
843 /* For matching constraints, we often get notional input reloads where
844 we want to use the original register as the reload register. I.e.
845 technically this is a non-optional input-output reload, but IN is
846 already a valid register, and has been chosen as the reload register.
847 Speed this up, since it trivially works. */
848 if (REG_P (in))
849 return 1;
851 /* To test MEMs properly, we'd have to take into account all the reloads
852 that are already scheduled, which can become quite complicated.
853 And since we've already handled address reloads for this MEM, it
854 should always succeed anyway. */
855 if (MEM_P (in))
856 return 1;
858 /* If we can make a simple SET insn that does the job, everything should
859 be fine. */
860 dst = gen_rtx_REG (mode, regno);
861 test_insn = make_insn_raw (gen_rtx_SET (VOIDmode, dst, in));
862 save_recog_data = recog_data;
863 if (recog_memoized (test_insn) >= 0)
865 extract_insn (test_insn);
866 r = constrain_operands (1);
868 recog_data = save_recog_data;
869 return r;
872 /* Record one reload that needs to be performed.
873 IN is an rtx saying where the data are to be found before this instruction.
874 OUT says where they must be stored after the instruction.
875 (IN is zero for data not read, and OUT is zero for data not written.)
876 INLOC and OUTLOC point to the places in the instructions where
877 IN and OUT were found.
878 If IN and OUT are both nonzero, it means the same register must be used
879 to reload both IN and OUT.
881 RCLASS is a register class required for the reloaded data.
882 INMODE is the machine mode that the instruction requires
883 for the reg that replaces IN and OUTMODE is likewise for OUT.
885 If IN is zero, then OUT's location and mode should be passed as
886 INLOC and INMODE.
888 STRICT_LOW is the 1 if there is a containing STRICT_LOW_PART rtx.
890 OPTIONAL nonzero means this reload does not need to be performed:
891 it can be discarded if that is more convenient.
893 OPNUM and TYPE say what the purpose of this reload is.
895 The return value is the reload-number for this reload.
897 If both IN and OUT are nonzero, in some rare cases we might
898 want to make two separate reloads. (Actually we never do this now.)
899 Therefore, the reload-number for OUT is stored in
900 output_reloadnum when we return; the return value applies to IN.
901 Usually (presently always), when IN and OUT are nonzero,
902 the two reload-numbers are equal, but the caller should be careful to
903 distinguish them. */
906 push_reload (rtx in, rtx out, rtx *inloc, rtx *outloc,
907 enum reg_class rclass, enum machine_mode inmode,
908 enum machine_mode outmode, int strict_low, int optional,
909 int opnum, enum reload_type type)
911 int i;
912 int dont_share = 0;
913 int dont_remove_subreg = 0;
914 rtx *in_subreg_loc = 0, *out_subreg_loc = 0;
915 int secondary_in_reload = -1, secondary_out_reload = -1;
916 enum insn_code secondary_in_icode = CODE_FOR_nothing;
917 enum insn_code secondary_out_icode = CODE_FOR_nothing;
919 /* INMODE and/or OUTMODE could be VOIDmode if no mode
920 has been specified for the operand. In that case,
921 use the operand's mode as the mode to reload. */
922 if (inmode == VOIDmode && in != 0)
923 inmode = GET_MODE (in);
924 if (outmode == VOIDmode && out != 0)
925 outmode = GET_MODE (out);
927 /* If find_reloads and friends until now missed to replace a pseudo
928 with a constant of reg_equiv_constant something went wrong
929 beforehand.
930 Note that it can't simply be done here if we missed it earlier
931 since the constant might need to be pushed into the literal pool
932 and the resulting memref would probably need further
933 reloading. */
934 if (in != 0 && REG_P (in))
936 int regno = REGNO (in);
938 gcc_assert (regno < FIRST_PSEUDO_REGISTER
939 || reg_renumber[regno] >= 0
940 || reg_equiv_constant[regno] == NULL_RTX);
943 /* reg_equiv_constant only contains constants which are obviously
944 not appropriate as destination. So if we would need to replace
945 the destination pseudo with a constant we are in real
946 trouble. */
947 if (out != 0 && REG_P (out))
949 int regno = REGNO (out);
951 gcc_assert (regno < FIRST_PSEUDO_REGISTER
952 || reg_renumber[regno] >= 0
953 || reg_equiv_constant[regno] == NULL_RTX);
956 /* If we have a read-write operand with an address side-effect,
957 change either IN or OUT so the side-effect happens only once. */
958 if (in != 0 && out != 0 && MEM_P (in) && rtx_equal_p (in, out))
959 switch (GET_CODE (XEXP (in, 0)))
961 case POST_INC: case POST_DEC: case POST_MODIFY:
962 in = replace_equiv_address_nv (in, XEXP (XEXP (in, 0), 0));
963 break;
965 case PRE_INC: case PRE_DEC: case PRE_MODIFY:
966 out = replace_equiv_address_nv (out, XEXP (XEXP (out, 0), 0));
967 break;
969 default:
970 break;
973 /* If we are reloading a (SUBREG constant ...), really reload just the
974 inside expression in its own mode. Similarly for (SUBREG (PLUS ...)).
975 If we have (SUBREG:M1 (MEM:M2 ...) ...) (or an inner REG that is still
976 a pseudo and hence will become a MEM) with M1 wider than M2 and the
977 register is a pseudo, also reload the inside expression.
978 For machines that extend byte loads, do this for any SUBREG of a pseudo
979 where both M1 and M2 are a word or smaller, M1 is wider than M2, and
980 M2 is an integral mode that gets extended when loaded.
981 Similar issue for (SUBREG:M1 (REG:M2 ...) ...) for a hard register R where
982 either M1 is not valid for R or M2 is wider than a word but we only
983 need one word to store an M2-sized quantity in R.
984 (However, if OUT is nonzero, we need to reload the reg *and*
985 the subreg, so do nothing here, and let following statement handle it.)
987 Note that the case of (SUBREG (CONST_INT...)...) is handled elsewhere;
988 we can't handle it here because CONST_INT does not indicate a mode.
990 Similarly, we must reload the inside expression if we have a
991 STRICT_LOW_PART (presumably, in == out in this case).
993 Also reload the inner expression if it does not require a secondary
994 reload but the SUBREG does.
996 Finally, reload the inner expression if it is a register that is in
997 the class whose registers cannot be referenced in a different size
998 and M1 is not the same size as M2. If subreg_lowpart_p is false, we
999 cannot reload just the inside since we might end up with the wrong
1000 register class. But if it is inside a STRICT_LOW_PART, we have
1001 no choice, so we hope we do get the right register class there. */
1003 if (in != 0 && GET_CODE (in) == SUBREG
1004 && (subreg_lowpart_p (in) || strict_low)
1005 #ifdef CANNOT_CHANGE_MODE_CLASS
1006 && !CANNOT_CHANGE_MODE_CLASS (GET_MODE (SUBREG_REG (in)), inmode, rclass)
1007 #endif
1008 && (CONSTANT_P (SUBREG_REG (in))
1009 || GET_CODE (SUBREG_REG (in)) == PLUS
1010 || strict_low
1011 || (((REG_P (SUBREG_REG (in))
1012 && REGNO (SUBREG_REG (in)) >= FIRST_PSEUDO_REGISTER)
1013 || MEM_P (SUBREG_REG (in)))
1014 && ((GET_MODE_SIZE (inmode)
1015 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))))
1016 #ifdef LOAD_EXTEND_OP
1017 || (GET_MODE_SIZE (inmode) <= UNITS_PER_WORD
1018 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
1019 <= UNITS_PER_WORD)
1020 && (GET_MODE_SIZE (inmode)
1021 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))))
1022 && INTEGRAL_MODE_P (GET_MODE (SUBREG_REG (in)))
1023 && LOAD_EXTEND_OP (GET_MODE (SUBREG_REG (in))) != UNKNOWN)
1024 #endif
1025 #ifdef WORD_REGISTER_OPERATIONS
1026 || ((GET_MODE_SIZE (inmode)
1027 < GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))))
1028 && ((GET_MODE_SIZE (inmode) - 1) / UNITS_PER_WORD ==
1029 ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))) - 1)
1030 / UNITS_PER_WORD)))
1031 #endif
1033 || (REG_P (SUBREG_REG (in))
1034 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
1035 /* The case where out is nonzero
1036 is handled differently in the following statement. */
1037 && (out == 0 || subreg_lowpart_p (in))
1038 && ((GET_MODE_SIZE (inmode) <= UNITS_PER_WORD
1039 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
1040 > UNITS_PER_WORD)
1041 && ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
1042 / UNITS_PER_WORD)
1043 != (int) hard_regno_nregs[REGNO (SUBREG_REG (in))]
1044 [GET_MODE (SUBREG_REG (in))]))
1045 || ! HARD_REGNO_MODE_OK (subreg_regno (in), inmode)))
1046 || (secondary_reload_class (1, rclass, inmode, in) != NO_REGS
1047 && (secondary_reload_class (1, rclass, GET_MODE (SUBREG_REG (in)),
1048 SUBREG_REG (in))
1049 == NO_REGS))
1050 #ifdef CANNOT_CHANGE_MODE_CLASS
1051 || (REG_P (SUBREG_REG (in))
1052 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
1053 && REG_CANNOT_CHANGE_MODE_P
1054 (REGNO (SUBREG_REG (in)), GET_MODE (SUBREG_REG (in)), inmode))
1055 #endif
1058 in_subreg_loc = inloc;
1059 inloc = &SUBREG_REG (in);
1060 in = *inloc;
1061 #if ! defined (LOAD_EXTEND_OP) && ! defined (WORD_REGISTER_OPERATIONS)
1062 if (MEM_P (in))
1063 /* This is supposed to happen only for paradoxical subregs made by
1064 combine.c. (SUBREG (MEM)) isn't supposed to occur other ways. */
1065 gcc_assert (GET_MODE_SIZE (GET_MODE (in)) <= GET_MODE_SIZE (inmode));
1066 #endif
1067 inmode = GET_MODE (in);
1070 /* Similar issue for (SUBREG:M1 (REG:M2 ...) ...) for a hard register R where
1071 either M1 is not valid for R or M2 is wider than a word but we only
1072 need one word to store an M2-sized quantity in R.
1074 However, we must reload the inner reg *as well as* the subreg in
1075 that case. */
1077 /* Similar issue for (SUBREG constant ...) if it was not handled by the
1078 code above. This can happen if SUBREG_BYTE != 0. */
1080 if (in != 0 && reload_inner_reg_of_subreg (in, inmode, 0))
1082 enum reg_class in_class = rclass;
1084 if (REG_P (SUBREG_REG (in)))
1085 in_class
1086 = find_valid_class (inmode, GET_MODE (SUBREG_REG (in)),
1087 subreg_regno_offset (REGNO (SUBREG_REG (in)),
1088 GET_MODE (SUBREG_REG (in)),
1089 SUBREG_BYTE (in),
1090 GET_MODE (in)),
1091 REGNO (SUBREG_REG (in)));
1093 /* This relies on the fact that emit_reload_insns outputs the
1094 instructions for input reloads of type RELOAD_OTHER in the same
1095 order as the reloads. Thus if the outer reload is also of type
1096 RELOAD_OTHER, we are guaranteed that this inner reload will be
1097 output before the outer reload. */
1098 push_reload (SUBREG_REG (in), NULL_RTX, &SUBREG_REG (in), (rtx *) 0,
1099 in_class, VOIDmode, VOIDmode, 0, 0, opnum, type);
1100 dont_remove_subreg = 1;
1103 /* Similarly for paradoxical and problematical SUBREGs on the output.
1104 Note that there is no reason we need worry about the previous value
1105 of SUBREG_REG (out); even if wider than out,
1106 storing in a subreg is entitled to clobber it all
1107 (except in the case of STRICT_LOW_PART,
1108 and in that case the constraint should label it input-output.) */
1109 if (out != 0 && GET_CODE (out) == SUBREG
1110 && (subreg_lowpart_p (out) || strict_low)
1111 #ifdef CANNOT_CHANGE_MODE_CLASS
1112 && !CANNOT_CHANGE_MODE_CLASS (GET_MODE (SUBREG_REG (out)), outmode, rclass)
1113 #endif
1114 && (CONSTANT_P (SUBREG_REG (out))
1115 || strict_low
1116 || (((REG_P (SUBREG_REG (out))
1117 && REGNO (SUBREG_REG (out)) >= FIRST_PSEUDO_REGISTER)
1118 || MEM_P (SUBREG_REG (out)))
1119 && ((GET_MODE_SIZE (outmode)
1120 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))))
1121 #ifdef WORD_REGISTER_OPERATIONS
1122 || ((GET_MODE_SIZE (outmode)
1123 < GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))))
1124 && ((GET_MODE_SIZE (outmode) - 1) / UNITS_PER_WORD ==
1125 ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))) - 1)
1126 / UNITS_PER_WORD)))
1127 #endif
1129 || (REG_P (SUBREG_REG (out))
1130 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1131 && ((GET_MODE_SIZE (outmode) <= UNITS_PER_WORD
1132 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (out)))
1133 > UNITS_PER_WORD)
1134 && ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (out)))
1135 / UNITS_PER_WORD)
1136 != (int) hard_regno_nregs[REGNO (SUBREG_REG (out))]
1137 [GET_MODE (SUBREG_REG (out))]))
1138 || ! HARD_REGNO_MODE_OK (subreg_regno (out), outmode)))
1139 || (secondary_reload_class (0, rclass, outmode, out) != NO_REGS
1140 && (secondary_reload_class (0, rclass, GET_MODE (SUBREG_REG (out)),
1141 SUBREG_REG (out))
1142 == NO_REGS))
1143 #ifdef CANNOT_CHANGE_MODE_CLASS
1144 || (REG_P (SUBREG_REG (out))
1145 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1146 && REG_CANNOT_CHANGE_MODE_P (REGNO (SUBREG_REG (out)),
1147 GET_MODE (SUBREG_REG (out)),
1148 outmode))
1149 #endif
1152 out_subreg_loc = outloc;
1153 outloc = &SUBREG_REG (out);
1154 out = *outloc;
1155 #if ! defined (LOAD_EXTEND_OP) && ! defined (WORD_REGISTER_OPERATIONS)
1156 gcc_assert (!MEM_P (out)
1157 || GET_MODE_SIZE (GET_MODE (out))
1158 <= GET_MODE_SIZE (outmode));
1159 #endif
1160 outmode = GET_MODE (out);
1163 /* Similar issue for (SUBREG:M1 (REG:M2 ...) ...) for a hard register R where
1164 either M1 is not valid for R or M2 is wider than a word but we only
1165 need one word to store an M2-sized quantity in R.
1167 However, we must reload the inner reg *as well as* the subreg in
1168 that case. In this case, the inner reg is an in-out reload. */
1170 if (out != 0 && reload_inner_reg_of_subreg (out, outmode, 1))
1172 /* This relies on the fact that emit_reload_insns outputs the
1173 instructions for output reloads of type RELOAD_OTHER in reverse
1174 order of the reloads. Thus if the outer reload is also of type
1175 RELOAD_OTHER, we are guaranteed that this inner reload will be
1176 output after the outer reload. */
1177 dont_remove_subreg = 1;
1178 push_reload (SUBREG_REG (out), SUBREG_REG (out), &SUBREG_REG (out),
1179 &SUBREG_REG (out),
1180 find_valid_class (outmode, GET_MODE (SUBREG_REG (out)),
1181 subreg_regno_offset (REGNO (SUBREG_REG (out)),
1182 GET_MODE (SUBREG_REG (out)),
1183 SUBREG_BYTE (out),
1184 GET_MODE (out)),
1185 REGNO (SUBREG_REG (out))),
1186 VOIDmode, VOIDmode, 0, 0,
1187 opnum, RELOAD_OTHER);
1190 /* If IN appears in OUT, we can't share any input-only reload for IN. */
1191 if (in != 0 && out != 0 && MEM_P (out)
1192 && (REG_P (in) || MEM_P (in) || GET_CODE (in) == PLUS)
1193 && reg_overlap_mentioned_for_reload_p (in, XEXP (out, 0)))
1194 dont_share = 1;
1196 /* If IN is a SUBREG of a hard register, make a new REG. This
1197 simplifies some of the cases below. */
1199 if (in != 0 && GET_CODE (in) == SUBREG && REG_P (SUBREG_REG (in))
1200 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
1201 && ! dont_remove_subreg)
1202 in = gen_rtx_REG (GET_MODE (in), subreg_regno (in));
1204 /* Similarly for OUT. */
1205 if (out != 0 && GET_CODE (out) == SUBREG
1206 && REG_P (SUBREG_REG (out))
1207 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1208 && ! dont_remove_subreg)
1209 out = gen_rtx_REG (GET_MODE (out), subreg_regno (out));
1211 /* Narrow down the class of register wanted if that is
1212 desirable on this machine for efficiency. */
1214 enum reg_class preferred_class = rclass;
1216 if (in != 0)
1217 preferred_class = PREFERRED_RELOAD_CLASS (in, rclass);
1219 /* Output reloads may need analogous treatment, different in detail. */
1220 #ifdef PREFERRED_OUTPUT_RELOAD_CLASS
1221 if (out != 0)
1222 preferred_class = PREFERRED_OUTPUT_RELOAD_CLASS (out, preferred_class);
1223 #endif
1225 /* Discard what the target said if we cannot do it. */
1226 if (preferred_class != NO_REGS
1227 || (optional && type == RELOAD_FOR_OUTPUT))
1228 rclass = preferred_class;
1231 /* Make sure we use a class that can handle the actual pseudo
1232 inside any subreg. For example, on the 386, QImode regs
1233 can appear within SImode subregs. Although GENERAL_REGS
1234 can handle SImode, QImode needs a smaller class. */
1235 #ifdef LIMIT_RELOAD_CLASS
1236 if (in_subreg_loc)
1237 rclass = LIMIT_RELOAD_CLASS (inmode, rclass);
1238 else if (in != 0 && GET_CODE (in) == SUBREG)
1239 rclass = LIMIT_RELOAD_CLASS (GET_MODE (SUBREG_REG (in)), rclass);
1241 if (out_subreg_loc)
1242 rclass = LIMIT_RELOAD_CLASS (outmode, rclass);
1243 if (out != 0 && GET_CODE (out) == SUBREG)
1244 rclass = LIMIT_RELOAD_CLASS (GET_MODE (SUBREG_REG (out)), rclass);
1245 #endif
1247 /* Verify that this class is at least possible for the mode that
1248 is specified. */
1249 if (this_insn_is_asm)
1251 enum machine_mode mode;
1252 if (GET_MODE_SIZE (inmode) > GET_MODE_SIZE (outmode))
1253 mode = inmode;
1254 else
1255 mode = outmode;
1256 if (mode == VOIDmode)
1258 error_for_asm (this_insn, "cannot reload integer constant "
1259 "operand in %<asm%>");
1260 mode = word_mode;
1261 if (in != 0)
1262 inmode = word_mode;
1263 if (out != 0)
1264 outmode = word_mode;
1266 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1267 if (HARD_REGNO_MODE_OK (i, mode)
1268 && in_hard_reg_set_p (reg_class_contents[(int) rclass], mode, i))
1269 break;
1270 if (i == FIRST_PSEUDO_REGISTER)
1272 error_for_asm (this_insn, "impossible register constraint "
1273 "in %<asm%>");
1274 /* Avoid further trouble with this insn. */
1275 PATTERN (this_insn) = gen_rtx_USE (VOIDmode, const0_rtx);
1276 /* We used to continue here setting class to ALL_REGS, but it triggers
1277 sanity check on i386 for:
1278 void foo(long double d)
1280 asm("" :: "a" (d));
1282 Returning zero here ought to be safe as we take care in
1283 find_reloads to not process the reloads when instruction was
1284 replaced by USE. */
1286 return 0;
1290 /* Optional output reloads are always OK even if we have no register class,
1291 since the function of these reloads is only to have spill_reg_store etc.
1292 set, so that the storing insn can be deleted later. */
1293 gcc_assert (rclass != NO_REGS
1294 || (optional != 0 && type == RELOAD_FOR_OUTPUT));
1296 i = find_reusable_reload (&in, out, rclass, type, opnum, dont_share);
1298 if (i == n_reloads)
1300 /* See if we need a secondary reload register to move between CLASS
1301 and IN or CLASS and OUT. Get the icode and push any required reloads
1302 needed for each of them if so. */
1304 if (in != 0)
1305 secondary_in_reload
1306 = push_secondary_reload (1, in, opnum, optional, rclass, inmode, type,
1307 &secondary_in_icode, NULL);
1308 if (out != 0 && GET_CODE (out) != SCRATCH)
1309 secondary_out_reload
1310 = push_secondary_reload (0, out, opnum, optional, rclass, outmode,
1311 type, &secondary_out_icode, NULL);
1313 /* We found no existing reload suitable for re-use.
1314 So add an additional reload. */
1316 #ifdef SECONDARY_MEMORY_NEEDED
1317 /* If a memory location is needed for the copy, make one. */
1318 if (in != 0
1319 && (REG_P (in)
1320 || (GET_CODE (in) == SUBREG && REG_P (SUBREG_REG (in))))
1321 && reg_or_subregno (in) < FIRST_PSEUDO_REGISTER
1322 && SECONDARY_MEMORY_NEEDED (REGNO_REG_CLASS (reg_or_subregno (in)),
1323 rclass, inmode))
1324 get_secondary_mem (in, inmode, opnum, type);
1325 #endif
1327 i = n_reloads;
1328 rld[i].in = in;
1329 rld[i].out = out;
1330 rld[i].rclass = rclass;
1331 rld[i].inmode = inmode;
1332 rld[i].outmode = outmode;
1333 rld[i].reg_rtx = 0;
1334 rld[i].optional = optional;
1335 rld[i].inc = 0;
1336 rld[i].nocombine = 0;
1337 rld[i].in_reg = inloc ? *inloc : 0;
1338 rld[i].out_reg = outloc ? *outloc : 0;
1339 rld[i].opnum = opnum;
1340 rld[i].when_needed = type;
1341 rld[i].secondary_in_reload = secondary_in_reload;
1342 rld[i].secondary_out_reload = secondary_out_reload;
1343 rld[i].secondary_in_icode = secondary_in_icode;
1344 rld[i].secondary_out_icode = secondary_out_icode;
1345 rld[i].secondary_p = 0;
1347 n_reloads++;
1349 #ifdef SECONDARY_MEMORY_NEEDED
1350 if (out != 0
1351 && (REG_P (out)
1352 || (GET_CODE (out) == SUBREG && REG_P (SUBREG_REG (out))))
1353 && reg_or_subregno (out) < FIRST_PSEUDO_REGISTER
1354 && SECONDARY_MEMORY_NEEDED (rclass,
1355 REGNO_REG_CLASS (reg_or_subregno (out)),
1356 outmode))
1357 get_secondary_mem (out, outmode, opnum, type);
1358 #endif
1360 else
1362 /* We are reusing an existing reload,
1363 but we may have additional information for it.
1364 For example, we may now have both IN and OUT
1365 while the old one may have just one of them. */
1367 /* The modes can be different. If they are, we want to reload in
1368 the larger mode, so that the value is valid for both modes. */
1369 if (inmode != VOIDmode
1370 && GET_MODE_SIZE (inmode) > GET_MODE_SIZE (rld[i].inmode))
1371 rld[i].inmode = inmode;
1372 if (outmode != VOIDmode
1373 && GET_MODE_SIZE (outmode) > GET_MODE_SIZE (rld[i].outmode))
1374 rld[i].outmode = outmode;
1375 if (in != 0)
1377 rtx in_reg = inloc ? *inloc : 0;
1378 /* If we merge reloads for two distinct rtl expressions that
1379 are identical in content, there might be duplicate address
1380 reloads. Remove the extra set now, so that if we later find
1381 that we can inherit this reload, we can get rid of the
1382 address reloads altogether.
1384 Do not do this if both reloads are optional since the result
1385 would be an optional reload which could potentially leave
1386 unresolved address replacements.
1388 It is not sufficient to call transfer_replacements since
1389 choose_reload_regs will remove the replacements for address
1390 reloads of inherited reloads which results in the same
1391 problem. */
1392 if (rld[i].in != in && rtx_equal_p (in, rld[i].in)
1393 && ! (rld[i].optional && optional))
1395 /* We must keep the address reload with the lower operand
1396 number alive. */
1397 if (opnum > rld[i].opnum)
1399 remove_address_replacements (in);
1400 in = rld[i].in;
1401 in_reg = rld[i].in_reg;
1403 else
1404 remove_address_replacements (rld[i].in);
1406 /* When emitting reloads we don't necessarily look at the in-
1407 and outmode, but also directly at the operands (in and out).
1408 So we can't simply overwrite them with whatever we have found
1409 for this (to-be-merged) reload, we have to "merge" that too.
1410 Reusing another reload already verified that we deal with the
1411 same operands, just possibly in different modes. So we
1412 overwrite the operands only when the new mode is larger.
1413 See also PR33613. */
1414 if (!rld[i].in
1415 || GET_MODE_SIZE (GET_MODE (in))
1416 > GET_MODE_SIZE (GET_MODE (rld[i].in)))
1417 rld[i].in = in;
1418 if (!rld[i].in_reg
1419 || (in_reg
1420 && GET_MODE_SIZE (GET_MODE (in_reg))
1421 > GET_MODE_SIZE (GET_MODE (rld[i].in_reg))))
1422 rld[i].in_reg = in_reg;
1424 if (out != 0)
1426 if (!rld[i].out
1427 || (out
1428 && GET_MODE_SIZE (GET_MODE (out))
1429 > GET_MODE_SIZE (GET_MODE (rld[i].out))))
1430 rld[i].out = out;
1431 if (outloc
1432 && (!rld[i].out_reg
1433 || GET_MODE_SIZE (GET_MODE (*outloc))
1434 > GET_MODE_SIZE (GET_MODE (rld[i].out_reg))))
1435 rld[i].out_reg = *outloc;
1437 if (reg_class_subset_p (rclass, rld[i].rclass))
1438 rld[i].rclass = rclass;
1439 rld[i].optional &= optional;
1440 if (MERGE_TO_OTHER (type, rld[i].when_needed,
1441 opnum, rld[i].opnum))
1442 rld[i].when_needed = RELOAD_OTHER;
1443 rld[i].opnum = MIN (rld[i].opnum, opnum);
1446 /* If the ostensible rtx being reloaded differs from the rtx found
1447 in the location to substitute, this reload is not safe to combine
1448 because we cannot reliably tell whether it appears in the insn. */
1450 if (in != 0 && in != *inloc)
1451 rld[i].nocombine = 1;
1453 #if 0
1454 /* This was replaced by changes in find_reloads_address_1 and the new
1455 function inc_for_reload, which go with a new meaning of reload_inc. */
1457 /* If this is an IN/OUT reload in an insn that sets the CC,
1458 it must be for an autoincrement. It doesn't work to store
1459 the incremented value after the insn because that would clobber the CC.
1460 So we must do the increment of the value reloaded from,
1461 increment it, store it back, then decrement again. */
1462 if (out != 0 && sets_cc0_p (PATTERN (this_insn)))
1464 out = 0;
1465 rld[i].out = 0;
1466 rld[i].inc = find_inc_amount (PATTERN (this_insn), in);
1467 /* If we did not find a nonzero amount-to-increment-by,
1468 that contradicts the belief that IN is being incremented
1469 in an address in this insn. */
1470 gcc_assert (rld[i].inc != 0);
1472 #endif
1474 /* If we will replace IN and OUT with the reload-reg,
1475 record where they are located so that substitution need
1476 not do a tree walk. */
1478 if (replace_reloads)
1480 if (inloc != 0)
1482 struct replacement *r = &replacements[n_replacements++];
1483 r->what = i;
1484 r->subreg_loc = in_subreg_loc;
1485 r->where = inloc;
1486 r->mode = inmode;
1488 if (outloc != 0 && outloc != inloc)
1490 struct replacement *r = &replacements[n_replacements++];
1491 r->what = i;
1492 r->where = outloc;
1493 r->subreg_loc = out_subreg_loc;
1494 r->mode = outmode;
1498 /* If this reload is just being introduced and it has both
1499 an incoming quantity and an outgoing quantity that are
1500 supposed to be made to match, see if either one of the two
1501 can serve as the place to reload into.
1503 If one of them is acceptable, set rld[i].reg_rtx
1504 to that one. */
1506 if (in != 0 && out != 0 && in != out && rld[i].reg_rtx == 0)
1508 rld[i].reg_rtx = find_dummy_reload (in, out, inloc, outloc,
1509 inmode, outmode,
1510 rld[i].rclass, i,
1511 earlyclobber_operand_p (out));
1513 /* If the outgoing register already contains the same value
1514 as the incoming one, we can dispense with loading it.
1515 The easiest way to tell the caller that is to give a phony
1516 value for the incoming operand (same as outgoing one). */
1517 if (rld[i].reg_rtx == out
1518 && (REG_P (in) || CONSTANT_P (in))
1519 && 0 != find_equiv_reg (in, this_insn, 0, REGNO (out),
1520 static_reload_reg_p, i, inmode))
1521 rld[i].in = out;
1524 /* If this is an input reload and the operand contains a register that
1525 dies in this insn and is used nowhere else, see if it is the right class
1526 to be used for this reload. Use it if so. (This occurs most commonly
1527 in the case of paradoxical SUBREGs and in-out reloads). We cannot do
1528 this if it is also an output reload that mentions the register unless
1529 the output is a SUBREG that clobbers an entire register.
1531 Note that the operand might be one of the spill regs, if it is a
1532 pseudo reg and we are in a block where spilling has not taken place.
1533 But if there is no spilling in this block, that is OK.
1534 An explicitly used hard reg cannot be a spill reg. */
1536 if (rld[i].reg_rtx == 0 && in != 0 && hard_regs_live_known)
1538 rtx note;
1539 int regno;
1540 enum machine_mode rel_mode = inmode;
1542 if (out && GET_MODE_SIZE (outmode) > GET_MODE_SIZE (inmode))
1543 rel_mode = outmode;
1545 for (note = REG_NOTES (this_insn); note; note = XEXP (note, 1))
1546 if (REG_NOTE_KIND (note) == REG_DEAD
1547 && REG_P (XEXP (note, 0))
1548 && (regno = REGNO (XEXP (note, 0))) < FIRST_PSEUDO_REGISTER
1549 && reg_mentioned_p (XEXP (note, 0), in)
1550 /* Check that a former pseudo is valid; see find_dummy_reload. */
1551 && (ORIGINAL_REGNO (XEXP (note, 0)) < FIRST_PSEUDO_REGISTER
1552 || (! bitmap_bit_p (DF_LR_OUT (ENTRY_BLOCK_PTR),
1553 ORIGINAL_REGNO (XEXP (note, 0)))
1554 && hard_regno_nregs[regno][GET_MODE (XEXP (note, 0))] == 1))
1555 && ! refers_to_regno_for_reload_p (regno,
1556 end_hard_regno (rel_mode,
1557 regno),
1558 PATTERN (this_insn), inloc)
1559 /* If this is also an output reload, IN cannot be used as
1560 the reload register if it is set in this insn unless IN
1561 is also OUT. */
1562 && (out == 0 || in == out
1563 || ! hard_reg_set_here_p (regno,
1564 end_hard_regno (rel_mode, regno),
1565 PATTERN (this_insn)))
1566 /* ??? Why is this code so different from the previous?
1567 Is there any simple coherent way to describe the two together?
1568 What's going on here. */
1569 && (in != out
1570 || (GET_CODE (in) == SUBREG
1571 && (((GET_MODE_SIZE (GET_MODE (in)) + (UNITS_PER_WORD - 1))
1572 / UNITS_PER_WORD)
1573 == ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
1574 + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD))))
1575 /* Make sure the operand fits in the reg that dies. */
1576 && (GET_MODE_SIZE (rel_mode)
1577 <= GET_MODE_SIZE (GET_MODE (XEXP (note, 0))))
1578 && HARD_REGNO_MODE_OK (regno, inmode)
1579 && HARD_REGNO_MODE_OK (regno, outmode))
1581 unsigned int offs;
1582 unsigned int nregs = MAX (hard_regno_nregs[regno][inmode],
1583 hard_regno_nregs[regno][outmode]);
1585 for (offs = 0; offs < nregs; offs++)
1586 if (fixed_regs[regno + offs]
1587 || ! TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
1588 regno + offs))
1589 break;
1591 if (offs == nregs
1592 && (! (refers_to_regno_for_reload_p
1593 (regno, end_hard_regno (inmode, regno), in, (rtx *) 0))
1594 || can_reload_into (in, regno, inmode)))
1596 rld[i].reg_rtx = gen_rtx_REG (rel_mode, regno);
1597 break;
1602 if (out)
1603 output_reloadnum = i;
1605 return i;
1608 /* Record an additional place we must replace a value
1609 for which we have already recorded a reload.
1610 RELOADNUM is the value returned by push_reload
1611 when the reload was recorded.
1612 This is used in insn patterns that use match_dup. */
1614 static void
1615 push_replacement (rtx *loc, int reloadnum, enum machine_mode mode)
1617 if (replace_reloads)
1619 struct replacement *r = &replacements[n_replacements++];
1620 r->what = reloadnum;
1621 r->where = loc;
1622 r->subreg_loc = 0;
1623 r->mode = mode;
1627 /* Duplicate any replacement we have recorded to apply at
1628 location ORIG_LOC to also be performed at DUP_LOC.
1629 This is used in insn patterns that use match_dup. */
1631 static void
1632 dup_replacements (rtx *dup_loc, rtx *orig_loc)
1634 int i, n = n_replacements;
1636 for (i = 0; i < n; i++)
1638 struct replacement *r = &replacements[i];
1639 if (r->where == orig_loc)
1640 push_replacement (dup_loc, r->what, r->mode);
1644 /* Transfer all replacements that used to be in reload FROM to be in
1645 reload TO. */
1647 void
1648 transfer_replacements (int to, int from)
1650 int i;
1652 for (i = 0; i < n_replacements; i++)
1653 if (replacements[i].what == from)
1654 replacements[i].what = to;
1657 /* IN_RTX is the value loaded by a reload that we now decided to inherit,
1658 or a subpart of it. If we have any replacements registered for IN_RTX,
1659 cancel the reloads that were supposed to load them.
1660 Return nonzero if we canceled any reloads. */
1662 remove_address_replacements (rtx in_rtx)
1664 int i, j;
1665 char reload_flags[MAX_RELOADS];
1666 int something_changed = 0;
1668 memset (reload_flags, 0, sizeof reload_flags);
1669 for (i = 0, j = 0; i < n_replacements; i++)
1671 if (loc_mentioned_in_p (replacements[i].where, in_rtx))
1672 reload_flags[replacements[i].what] |= 1;
1673 else
1675 replacements[j++] = replacements[i];
1676 reload_flags[replacements[i].what] |= 2;
1679 /* Note that the following store must be done before the recursive calls. */
1680 n_replacements = j;
1682 for (i = n_reloads - 1; i >= 0; i--)
1684 if (reload_flags[i] == 1)
1686 deallocate_reload_reg (i);
1687 remove_address_replacements (rld[i].in);
1688 rld[i].in = 0;
1689 something_changed = 1;
1692 return something_changed;
1695 /* If there is only one output reload, and it is not for an earlyclobber
1696 operand, try to combine it with a (logically unrelated) input reload
1697 to reduce the number of reload registers needed.
1699 This is safe if the input reload does not appear in
1700 the value being output-reloaded, because this implies
1701 it is not needed any more once the original insn completes.
1703 If that doesn't work, see we can use any of the registers that
1704 die in this insn as a reload register. We can if it is of the right
1705 class and does not appear in the value being output-reloaded. */
1707 static void
1708 combine_reloads (void)
1710 int i, regno;
1711 int output_reload = -1;
1712 int secondary_out = -1;
1713 rtx note;
1715 /* Find the output reload; return unless there is exactly one
1716 and that one is mandatory. */
1718 for (i = 0; i < n_reloads; i++)
1719 if (rld[i].out != 0)
1721 if (output_reload >= 0)
1722 return;
1723 output_reload = i;
1726 if (output_reload < 0 || rld[output_reload].optional)
1727 return;
1729 /* An input-output reload isn't combinable. */
1731 if (rld[output_reload].in != 0)
1732 return;
1734 /* If this reload is for an earlyclobber operand, we can't do anything. */
1735 if (earlyclobber_operand_p (rld[output_reload].out))
1736 return;
1738 /* If there is a reload for part of the address of this operand, we would
1739 need to change it to RELOAD_FOR_OTHER_ADDRESS. But that would extend
1740 its life to the point where doing this combine would not lower the
1741 number of spill registers needed. */
1742 for (i = 0; i < n_reloads; i++)
1743 if ((rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
1744 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
1745 && rld[i].opnum == rld[output_reload].opnum)
1746 return;
1748 /* Check each input reload; can we combine it? */
1750 for (i = 0; i < n_reloads; i++)
1751 if (rld[i].in && ! rld[i].optional && ! rld[i].nocombine
1752 /* Life span of this reload must not extend past main insn. */
1753 && rld[i].when_needed != RELOAD_FOR_OUTPUT_ADDRESS
1754 && rld[i].when_needed != RELOAD_FOR_OUTADDR_ADDRESS
1755 && rld[i].when_needed != RELOAD_OTHER
1756 && (CLASS_MAX_NREGS (rld[i].rclass, rld[i].inmode)
1757 == CLASS_MAX_NREGS (rld[output_reload].rclass,
1758 rld[output_reload].outmode))
1759 && rld[i].inc == 0
1760 && rld[i].reg_rtx == 0
1761 #ifdef SECONDARY_MEMORY_NEEDED
1762 /* Don't combine two reloads with different secondary
1763 memory locations. */
1764 && (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum] == 0
1765 || secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum] == 0
1766 || rtx_equal_p (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum],
1767 secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum]))
1768 #endif
1769 && (SMALL_REGISTER_CLASSES
1770 ? (rld[i].rclass == rld[output_reload].rclass)
1771 : (reg_class_subset_p (rld[i].rclass,
1772 rld[output_reload].rclass)
1773 || reg_class_subset_p (rld[output_reload].rclass,
1774 rld[i].rclass)))
1775 && (MATCHES (rld[i].in, rld[output_reload].out)
1776 /* Args reversed because the first arg seems to be
1777 the one that we imagine being modified
1778 while the second is the one that might be affected. */
1779 || (! reg_overlap_mentioned_for_reload_p (rld[output_reload].out,
1780 rld[i].in)
1781 /* However, if the input is a register that appears inside
1782 the output, then we also can't share.
1783 Imagine (set (mem (reg 69)) (plus (reg 69) ...)).
1784 If the same reload reg is used for both reg 69 and the
1785 result to be stored in memory, then that result
1786 will clobber the address of the memory ref. */
1787 && ! (REG_P (rld[i].in)
1788 && reg_overlap_mentioned_for_reload_p (rld[i].in,
1789 rld[output_reload].out))))
1790 && ! reload_inner_reg_of_subreg (rld[i].in, rld[i].inmode,
1791 rld[i].when_needed != RELOAD_FOR_INPUT)
1792 && (reg_class_size[(int) rld[i].rclass]
1793 || SMALL_REGISTER_CLASSES)
1794 /* We will allow making things slightly worse by combining an
1795 input and an output, but no worse than that. */
1796 && (rld[i].when_needed == RELOAD_FOR_INPUT
1797 || rld[i].when_needed == RELOAD_FOR_OUTPUT))
1799 int j;
1801 /* We have found a reload to combine with! */
1802 rld[i].out = rld[output_reload].out;
1803 rld[i].out_reg = rld[output_reload].out_reg;
1804 rld[i].outmode = rld[output_reload].outmode;
1805 /* Mark the old output reload as inoperative. */
1806 rld[output_reload].out = 0;
1807 /* The combined reload is needed for the entire insn. */
1808 rld[i].when_needed = RELOAD_OTHER;
1809 /* If the output reload had a secondary reload, copy it. */
1810 if (rld[output_reload].secondary_out_reload != -1)
1812 rld[i].secondary_out_reload
1813 = rld[output_reload].secondary_out_reload;
1814 rld[i].secondary_out_icode
1815 = rld[output_reload].secondary_out_icode;
1818 #ifdef SECONDARY_MEMORY_NEEDED
1819 /* Copy any secondary MEM. */
1820 if (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum] != 0)
1821 secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum]
1822 = secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum];
1823 #endif
1824 /* If required, minimize the register class. */
1825 if (reg_class_subset_p (rld[output_reload].rclass,
1826 rld[i].rclass))
1827 rld[i].rclass = rld[output_reload].rclass;
1829 /* Transfer all replacements from the old reload to the combined. */
1830 for (j = 0; j < n_replacements; j++)
1831 if (replacements[j].what == output_reload)
1832 replacements[j].what = i;
1834 return;
1837 /* If this insn has only one operand that is modified or written (assumed
1838 to be the first), it must be the one corresponding to this reload. It
1839 is safe to use anything that dies in this insn for that output provided
1840 that it does not occur in the output (we already know it isn't an
1841 earlyclobber. If this is an asm insn, give up. */
1843 if (INSN_CODE (this_insn) == -1)
1844 return;
1846 for (i = 1; i < insn_data[INSN_CODE (this_insn)].n_operands; i++)
1847 if (insn_data[INSN_CODE (this_insn)].operand[i].constraint[0] == '='
1848 || insn_data[INSN_CODE (this_insn)].operand[i].constraint[0] == '+')
1849 return;
1851 /* See if some hard register that dies in this insn and is not used in
1852 the output is the right class. Only works if the register we pick
1853 up can fully hold our output reload. */
1854 for (note = REG_NOTES (this_insn); note; note = XEXP (note, 1))
1855 if (REG_NOTE_KIND (note) == REG_DEAD
1856 && REG_P (XEXP (note, 0))
1857 && !reg_overlap_mentioned_for_reload_p (XEXP (note, 0),
1858 rld[output_reload].out)
1859 && (regno = REGNO (XEXP (note, 0))) < FIRST_PSEUDO_REGISTER
1860 && HARD_REGNO_MODE_OK (regno, rld[output_reload].outmode)
1861 && TEST_HARD_REG_BIT (reg_class_contents[(int) rld[output_reload].rclass],
1862 regno)
1863 && (hard_regno_nregs[regno][rld[output_reload].outmode]
1864 <= hard_regno_nregs[regno][GET_MODE (XEXP (note, 0))])
1865 /* Ensure that a secondary or tertiary reload for this output
1866 won't want this register. */
1867 && ((secondary_out = rld[output_reload].secondary_out_reload) == -1
1868 || (!(TEST_HARD_REG_BIT
1869 (reg_class_contents[(int) rld[secondary_out].rclass], regno))
1870 && ((secondary_out = rld[secondary_out].secondary_out_reload) == -1
1871 || !(TEST_HARD_REG_BIT
1872 (reg_class_contents[(int) rld[secondary_out].rclass],
1873 regno)))))
1874 && !fixed_regs[regno]
1875 /* Check that a former pseudo is valid; see find_dummy_reload. */
1876 && (ORIGINAL_REGNO (XEXP (note, 0)) < FIRST_PSEUDO_REGISTER
1877 || (!bitmap_bit_p (DF_LR_OUT (ENTRY_BLOCK_PTR),
1878 ORIGINAL_REGNO (XEXP (note, 0)))
1879 && hard_regno_nregs[regno][GET_MODE (XEXP (note, 0))] == 1)))
1881 rld[output_reload].reg_rtx
1882 = gen_rtx_REG (rld[output_reload].outmode, regno);
1883 return;
1887 /* Try to find a reload register for an in-out reload (expressions IN and OUT).
1888 See if one of IN and OUT is a register that may be used;
1889 this is desirable since a spill-register won't be needed.
1890 If so, return the register rtx that proves acceptable.
1892 INLOC and OUTLOC are locations where IN and OUT appear in the insn.
1893 RCLASS is the register class required for the reload.
1895 If FOR_REAL is >= 0, it is the number of the reload,
1896 and in some cases when it can be discovered that OUT doesn't need
1897 to be computed, clear out rld[FOR_REAL].out.
1899 If FOR_REAL is -1, this should not be done, because this call
1900 is just to see if a register can be found, not to find and install it.
1902 EARLYCLOBBER is nonzero if OUT is an earlyclobber operand. This
1903 puts an additional constraint on being able to use IN for OUT since
1904 IN must not appear elsewhere in the insn (it is assumed that IN itself
1905 is safe from the earlyclobber). */
1907 static rtx
1908 find_dummy_reload (rtx real_in, rtx real_out, rtx *inloc, rtx *outloc,
1909 enum machine_mode inmode, enum machine_mode outmode,
1910 enum reg_class rclass, int for_real, int earlyclobber)
1912 rtx in = real_in;
1913 rtx out = real_out;
1914 int in_offset = 0;
1915 int out_offset = 0;
1916 rtx value = 0;
1918 /* If operands exceed a word, we can't use either of them
1919 unless they have the same size. */
1920 if (GET_MODE_SIZE (outmode) != GET_MODE_SIZE (inmode)
1921 && (GET_MODE_SIZE (outmode) > UNITS_PER_WORD
1922 || GET_MODE_SIZE (inmode) > UNITS_PER_WORD))
1923 return 0;
1925 /* Note that {in,out}_offset are needed only when 'in' or 'out'
1926 respectively refers to a hard register. */
1928 /* Find the inside of any subregs. */
1929 while (GET_CODE (out) == SUBREG)
1931 if (REG_P (SUBREG_REG (out))
1932 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER)
1933 out_offset += subreg_regno_offset (REGNO (SUBREG_REG (out)),
1934 GET_MODE (SUBREG_REG (out)),
1935 SUBREG_BYTE (out),
1936 GET_MODE (out));
1937 out = SUBREG_REG (out);
1939 while (GET_CODE (in) == SUBREG)
1941 if (REG_P (SUBREG_REG (in))
1942 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER)
1943 in_offset += subreg_regno_offset (REGNO (SUBREG_REG (in)),
1944 GET_MODE (SUBREG_REG (in)),
1945 SUBREG_BYTE (in),
1946 GET_MODE (in));
1947 in = SUBREG_REG (in);
1950 /* Narrow down the reg class, the same way push_reload will;
1951 otherwise we might find a dummy now, but push_reload won't. */
1953 enum reg_class preferred_class = PREFERRED_RELOAD_CLASS (in, rclass);
1954 if (preferred_class != NO_REGS)
1955 rclass = preferred_class;
1958 /* See if OUT will do. */
1959 if (REG_P (out)
1960 && REGNO (out) < FIRST_PSEUDO_REGISTER)
1962 unsigned int regno = REGNO (out) + out_offset;
1963 unsigned int nwords = hard_regno_nregs[regno][outmode];
1964 rtx saved_rtx;
1966 /* When we consider whether the insn uses OUT,
1967 ignore references within IN. They don't prevent us
1968 from copying IN into OUT, because those refs would
1969 move into the insn that reloads IN.
1971 However, we only ignore IN in its role as this reload.
1972 If the insn uses IN elsewhere and it contains OUT,
1973 that counts. We can't be sure it's the "same" operand
1974 so it might not go through this reload. */
1975 saved_rtx = *inloc;
1976 *inloc = const0_rtx;
1978 if (regno < FIRST_PSEUDO_REGISTER
1979 && HARD_REGNO_MODE_OK (regno, outmode)
1980 && ! refers_to_regno_for_reload_p (regno, regno + nwords,
1981 PATTERN (this_insn), outloc))
1983 unsigned int i;
1985 for (i = 0; i < nwords; i++)
1986 if (! TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
1987 regno + i))
1988 break;
1990 if (i == nwords)
1992 if (REG_P (real_out))
1993 value = real_out;
1994 else
1995 value = gen_rtx_REG (outmode, regno);
1999 *inloc = saved_rtx;
2002 /* Consider using IN if OUT was not acceptable
2003 or if OUT dies in this insn (like the quotient in a divmod insn).
2004 We can't use IN unless it is dies in this insn,
2005 which means we must know accurately which hard regs are live.
2006 Also, the result can't go in IN if IN is used within OUT,
2007 or if OUT is an earlyclobber and IN appears elsewhere in the insn. */
2008 if (hard_regs_live_known
2009 && REG_P (in)
2010 && REGNO (in) < FIRST_PSEUDO_REGISTER
2011 && (value == 0
2012 || find_reg_note (this_insn, REG_UNUSED, real_out))
2013 && find_reg_note (this_insn, REG_DEAD, real_in)
2014 && !fixed_regs[REGNO (in)]
2015 && HARD_REGNO_MODE_OK (REGNO (in),
2016 /* The only case where out and real_out might
2017 have different modes is where real_out
2018 is a subreg, and in that case, out
2019 has a real mode. */
2020 (GET_MODE (out) != VOIDmode
2021 ? GET_MODE (out) : outmode))
2022 && (ORIGINAL_REGNO (in) < FIRST_PSEUDO_REGISTER
2023 /* However only do this if we can be sure that this input
2024 operand doesn't correspond with an uninitialized pseudo.
2025 global can assign some hardreg to it that is the same as
2026 the one assigned to a different, also live pseudo (as it
2027 can ignore the conflict). We must never introduce writes
2028 to such hardregs, as they would clobber the other live
2029 pseudo. See PR 20973. */
2030 || (!bitmap_bit_p (DF_LR_OUT (ENTRY_BLOCK_PTR),
2031 ORIGINAL_REGNO (in))
2032 /* Similarly, only do this if we can be sure that the death
2033 note is still valid. global can assign some hardreg to
2034 the pseudo referenced in the note and simultaneously a
2035 subword of this hardreg to a different, also live pseudo,
2036 because only another subword of the hardreg is actually
2037 used in the insn. This cannot happen if the pseudo has
2038 been assigned exactly one hardreg. See PR 33732. */
2039 && hard_regno_nregs[REGNO (in)][GET_MODE (in)] == 1)))
2041 unsigned int regno = REGNO (in) + in_offset;
2042 unsigned int nwords = hard_regno_nregs[regno][inmode];
2044 if (! refers_to_regno_for_reload_p (regno, regno + nwords, out, (rtx*) 0)
2045 && ! hard_reg_set_here_p (regno, regno + nwords,
2046 PATTERN (this_insn))
2047 && (! earlyclobber
2048 || ! refers_to_regno_for_reload_p (regno, regno + nwords,
2049 PATTERN (this_insn), inloc)))
2051 unsigned int i;
2053 for (i = 0; i < nwords; i++)
2054 if (! TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
2055 regno + i))
2056 break;
2058 if (i == nwords)
2060 /* If we were going to use OUT as the reload reg
2061 and changed our mind, it means OUT is a dummy that
2062 dies here. So don't bother copying value to it. */
2063 if (for_real >= 0 && value == real_out)
2064 rld[for_real].out = 0;
2065 if (REG_P (real_in))
2066 value = real_in;
2067 else
2068 value = gen_rtx_REG (inmode, regno);
2073 return value;
2076 /* This page contains subroutines used mainly for determining
2077 whether the IN or an OUT of a reload can serve as the
2078 reload register. */
2080 /* Return 1 if X is an operand of an insn that is being earlyclobbered. */
2083 earlyclobber_operand_p (rtx x)
2085 int i;
2087 for (i = 0; i < n_earlyclobbers; i++)
2088 if (reload_earlyclobbers[i] == x)
2089 return 1;
2091 return 0;
2094 /* Return 1 if expression X alters a hard reg in the range
2095 from BEG_REGNO (inclusive) to END_REGNO (exclusive),
2096 either explicitly or in the guise of a pseudo-reg allocated to REGNO.
2097 X should be the body of an instruction. */
2099 static int
2100 hard_reg_set_here_p (unsigned int beg_regno, unsigned int end_regno, rtx x)
2102 if (GET_CODE (x) == SET || GET_CODE (x) == CLOBBER)
2104 rtx op0 = SET_DEST (x);
2106 while (GET_CODE (op0) == SUBREG)
2107 op0 = SUBREG_REG (op0);
2108 if (REG_P (op0))
2110 unsigned int r = REGNO (op0);
2112 /* See if this reg overlaps range under consideration. */
2113 if (r < end_regno
2114 && end_hard_regno (GET_MODE (op0), r) > beg_regno)
2115 return 1;
2118 else if (GET_CODE (x) == PARALLEL)
2120 int i = XVECLEN (x, 0) - 1;
2122 for (; i >= 0; i--)
2123 if (hard_reg_set_here_p (beg_regno, end_regno, XVECEXP (x, 0, i)))
2124 return 1;
2127 return 0;
2130 /* Return 1 if ADDR is a valid memory address for mode MODE,
2131 and check that each pseudo reg has the proper kind of
2132 hard reg. */
2135 strict_memory_address_p (enum machine_mode mode ATTRIBUTE_UNUSED, rtx addr)
2137 GO_IF_LEGITIMATE_ADDRESS (mode, addr, win);
2138 return 0;
2140 win:
2141 return 1;
2144 /* Like rtx_equal_p except that it allows a REG and a SUBREG to match
2145 if they are the same hard reg, and has special hacks for
2146 autoincrement and autodecrement.
2147 This is specifically intended for find_reloads to use
2148 in determining whether two operands match.
2149 X is the operand whose number is the lower of the two.
2151 The value is 2 if Y contains a pre-increment that matches
2152 a non-incrementing address in X. */
2154 /* ??? To be completely correct, we should arrange to pass
2155 for X the output operand and for Y the input operand.
2156 For now, we assume that the output operand has the lower number
2157 because that is natural in (SET output (... input ...)). */
2160 operands_match_p (rtx x, rtx y)
2162 int i;
2163 RTX_CODE code = GET_CODE (x);
2164 const char *fmt;
2165 int success_2;
2167 if (x == y)
2168 return 1;
2169 if ((code == REG || (code == SUBREG && REG_P (SUBREG_REG (x))))
2170 && (REG_P (y) || (GET_CODE (y) == SUBREG
2171 && REG_P (SUBREG_REG (y)))))
2173 int j;
2175 if (code == SUBREG)
2177 i = REGNO (SUBREG_REG (x));
2178 if (i >= FIRST_PSEUDO_REGISTER)
2179 goto slow;
2180 i += subreg_regno_offset (REGNO (SUBREG_REG (x)),
2181 GET_MODE (SUBREG_REG (x)),
2182 SUBREG_BYTE (x),
2183 GET_MODE (x));
2185 else
2186 i = REGNO (x);
2188 if (GET_CODE (y) == SUBREG)
2190 j = REGNO (SUBREG_REG (y));
2191 if (j >= FIRST_PSEUDO_REGISTER)
2192 goto slow;
2193 j += subreg_regno_offset (REGNO (SUBREG_REG (y)),
2194 GET_MODE (SUBREG_REG (y)),
2195 SUBREG_BYTE (y),
2196 GET_MODE (y));
2198 else
2199 j = REGNO (y);
2201 /* On a WORDS_BIG_ENDIAN machine, point to the last register of a
2202 multiple hard register group of scalar integer registers, so that
2203 for example (reg:DI 0) and (reg:SI 1) will be considered the same
2204 register. */
2205 if (WORDS_BIG_ENDIAN && GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD
2206 && SCALAR_INT_MODE_P (GET_MODE (x))
2207 && i < FIRST_PSEUDO_REGISTER)
2208 i += hard_regno_nregs[i][GET_MODE (x)] - 1;
2209 if (WORDS_BIG_ENDIAN && GET_MODE_SIZE (GET_MODE (y)) > UNITS_PER_WORD
2210 && SCALAR_INT_MODE_P (GET_MODE (y))
2211 && j < FIRST_PSEUDO_REGISTER)
2212 j += hard_regno_nregs[j][GET_MODE (y)] - 1;
2214 return i == j;
2216 /* If two operands must match, because they are really a single
2217 operand of an assembler insn, then two postincrements are invalid
2218 because the assembler insn would increment only once.
2219 On the other hand, a postincrement matches ordinary indexing
2220 if the postincrement is the output operand. */
2221 if (code == POST_DEC || code == POST_INC || code == POST_MODIFY)
2222 return operands_match_p (XEXP (x, 0), y);
2223 /* Two preincrements are invalid
2224 because the assembler insn would increment only once.
2225 On the other hand, a preincrement matches ordinary indexing
2226 if the preincrement is the input operand.
2227 In this case, return 2, since some callers need to do special
2228 things when this happens. */
2229 if (GET_CODE (y) == PRE_DEC || GET_CODE (y) == PRE_INC
2230 || GET_CODE (y) == PRE_MODIFY)
2231 return operands_match_p (x, XEXP (y, 0)) ? 2 : 0;
2233 slow:
2235 /* Now we have disposed of all the cases in which different rtx codes
2236 can match. */
2237 if (code != GET_CODE (y))
2238 return 0;
2240 /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. */
2241 if (GET_MODE (x) != GET_MODE (y))
2242 return 0;
2244 switch (code)
2246 case CONST_INT:
2247 case CONST_DOUBLE:
2248 case CONST_FIXED:
2249 return 0;
2251 case LABEL_REF:
2252 return XEXP (x, 0) == XEXP (y, 0);
2253 case SYMBOL_REF:
2254 return XSTR (x, 0) == XSTR (y, 0);
2256 default:
2257 break;
2260 /* Compare the elements. If any pair of corresponding elements
2261 fail to match, return 0 for the whole things. */
2263 success_2 = 0;
2264 fmt = GET_RTX_FORMAT (code);
2265 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2267 int val, j;
2268 switch (fmt[i])
2270 case 'w':
2271 if (XWINT (x, i) != XWINT (y, i))
2272 return 0;
2273 break;
2275 case 'i':
2276 if (XINT (x, i) != XINT (y, i))
2277 return 0;
2278 break;
2280 case 'e':
2281 val = operands_match_p (XEXP (x, i), XEXP (y, i));
2282 if (val == 0)
2283 return 0;
2284 /* If any subexpression returns 2,
2285 we should return 2 if we are successful. */
2286 if (val == 2)
2287 success_2 = 1;
2288 break;
2290 case '0':
2291 break;
2293 case 'E':
2294 if (XVECLEN (x, i) != XVECLEN (y, i))
2295 return 0;
2296 for (j = XVECLEN (x, i) - 1; j >= 0; --j)
2298 val = operands_match_p (XVECEXP (x, i, j), XVECEXP (y, i, j));
2299 if (val == 0)
2300 return 0;
2301 if (val == 2)
2302 success_2 = 1;
2304 break;
2306 /* It is believed that rtx's at this level will never
2307 contain anything but integers and other rtx's,
2308 except for within LABEL_REFs and SYMBOL_REFs. */
2309 default:
2310 gcc_unreachable ();
2313 return 1 + success_2;
2316 /* Describe the range of registers or memory referenced by X.
2317 If X is a register, set REG_FLAG and put the first register
2318 number into START and the last plus one into END.
2319 If X is a memory reference, put a base address into BASE
2320 and a range of integer offsets into START and END.
2321 If X is pushing on the stack, we can assume it causes no trouble,
2322 so we set the SAFE field. */
2324 static struct decomposition
2325 decompose (rtx x)
2327 struct decomposition val;
2328 int all_const = 0;
2330 memset (&val, 0, sizeof (val));
2332 switch (GET_CODE (x))
2334 case MEM:
2336 rtx base = NULL_RTX, offset = 0;
2337 rtx addr = XEXP (x, 0);
2339 if (GET_CODE (addr) == PRE_DEC || GET_CODE (addr) == PRE_INC
2340 || GET_CODE (addr) == POST_DEC || GET_CODE (addr) == POST_INC)
2342 val.base = XEXP (addr, 0);
2343 val.start = -GET_MODE_SIZE (GET_MODE (x));
2344 val.end = GET_MODE_SIZE (GET_MODE (x));
2345 val.safe = REGNO (val.base) == STACK_POINTER_REGNUM;
2346 return val;
2349 if (GET_CODE (addr) == PRE_MODIFY || GET_CODE (addr) == POST_MODIFY)
2351 if (GET_CODE (XEXP (addr, 1)) == PLUS
2352 && XEXP (addr, 0) == XEXP (XEXP (addr, 1), 0)
2353 && CONSTANT_P (XEXP (XEXP (addr, 1), 1)))
2355 val.base = XEXP (addr, 0);
2356 val.start = -INTVAL (XEXP (XEXP (addr, 1), 1));
2357 val.end = INTVAL (XEXP (XEXP (addr, 1), 1));
2358 val.safe = REGNO (val.base) == STACK_POINTER_REGNUM;
2359 return val;
2363 if (GET_CODE (addr) == CONST)
2365 addr = XEXP (addr, 0);
2366 all_const = 1;
2368 if (GET_CODE (addr) == PLUS)
2370 if (CONSTANT_P (XEXP (addr, 0)))
2372 base = XEXP (addr, 1);
2373 offset = XEXP (addr, 0);
2375 else if (CONSTANT_P (XEXP (addr, 1)))
2377 base = XEXP (addr, 0);
2378 offset = XEXP (addr, 1);
2382 if (offset == 0)
2384 base = addr;
2385 offset = const0_rtx;
2387 if (GET_CODE (offset) == CONST)
2388 offset = XEXP (offset, 0);
2389 if (GET_CODE (offset) == PLUS)
2391 if (GET_CODE (XEXP (offset, 0)) == CONST_INT)
2393 base = gen_rtx_PLUS (GET_MODE (base), base, XEXP (offset, 1));
2394 offset = XEXP (offset, 0);
2396 else if (GET_CODE (XEXP (offset, 1)) == CONST_INT)
2398 base = gen_rtx_PLUS (GET_MODE (base), base, XEXP (offset, 0));
2399 offset = XEXP (offset, 1);
2401 else
2403 base = gen_rtx_PLUS (GET_MODE (base), base, offset);
2404 offset = const0_rtx;
2407 else if (GET_CODE (offset) != CONST_INT)
2409 base = gen_rtx_PLUS (GET_MODE (base), base, offset);
2410 offset = const0_rtx;
2413 if (all_const && GET_CODE (base) == PLUS)
2414 base = gen_rtx_CONST (GET_MODE (base), base);
2416 gcc_assert (GET_CODE (offset) == CONST_INT);
2418 val.start = INTVAL (offset);
2419 val.end = val.start + GET_MODE_SIZE (GET_MODE (x));
2420 val.base = base;
2422 break;
2424 case REG:
2425 val.reg_flag = 1;
2426 val.start = true_regnum (x);
2427 if (val.start < 0 || val.start >= FIRST_PSEUDO_REGISTER)
2429 /* A pseudo with no hard reg. */
2430 val.start = REGNO (x);
2431 val.end = val.start + 1;
2433 else
2434 /* A hard reg. */
2435 val.end = end_hard_regno (GET_MODE (x), val.start);
2436 break;
2438 case SUBREG:
2439 if (!REG_P (SUBREG_REG (x)))
2440 /* This could be more precise, but it's good enough. */
2441 return decompose (SUBREG_REG (x));
2442 val.reg_flag = 1;
2443 val.start = true_regnum (x);
2444 if (val.start < 0 || val.start >= FIRST_PSEUDO_REGISTER)
2445 return decompose (SUBREG_REG (x));
2446 else
2447 /* A hard reg. */
2448 val.end = val.start + subreg_nregs (x);
2449 break;
2451 case SCRATCH:
2452 /* This hasn't been assigned yet, so it can't conflict yet. */
2453 val.safe = 1;
2454 break;
2456 default:
2457 gcc_assert (CONSTANT_P (x));
2458 val.safe = 1;
2459 break;
2461 return val;
2464 /* Return 1 if altering Y will not modify the value of X.
2465 Y is also described by YDATA, which should be decompose (Y). */
2467 static int
2468 immune_p (rtx x, rtx y, struct decomposition ydata)
2470 struct decomposition xdata;
2472 if (ydata.reg_flag)
2473 return !refers_to_regno_for_reload_p (ydata.start, ydata.end, x, (rtx*) 0);
2474 if (ydata.safe)
2475 return 1;
2477 gcc_assert (MEM_P (y));
2478 /* If Y is memory and X is not, Y can't affect X. */
2479 if (!MEM_P (x))
2480 return 1;
2482 xdata = decompose (x);
2484 if (! rtx_equal_p (xdata.base, ydata.base))
2486 /* If bases are distinct symbolic constants, there is no overlap. */
2487 if (CONSTANT_P (xdata.base) && CONSTANT_P (ydata.base))
2488 return 1;
2489 /* Constants and stack slots never overlap. */
2490 if (CONSTANT_P (xdata.base)
2491 && (ydata.base == frame_pointer_rtx
2492 || ydata.base == hard_frame_pointer_rtx
2493 || ydata.base == stack_pointer_rtx))
2494 return 1;
2495 if (CONSTANT_P (ydata.base)
2496 && (xdata.base == frame_pointer_rtx
2497 || xdata.base == hard_frame_pointer_rtx
2498 || xdata.base == stack_pointer_rtx))
2499 return 1;
2500 /* If either base is variable, we don't know anything. */
2501 return 0;
2504 return (xdata.start >= ydata.end || ydata.start >= xdata.end);
2507 /* Similar, but calls decompose. */
2510 safe_from_earlyclobber (rtx op, rtx clobber)
2512 struct decomposition early_data;
2514 early_data = decompose (clobber);
2515 return immune_p (op, clobber, early_data);
2518 /* Main entry point of this file: search the body of INSN
2519 for values that need reloading and record them with push_reload.
2520 REPLACE nonzero means record also where the values occur
2521 so that subst_reloads can be used.
2523 IND_LEVELS says how many levels of indirection are supported by this
2524 machine; a value of zero means that a memory reference is not a valid
2525 memory address.
2527 LIVE_KNOWN says we have valid information about which hard
2528 regs are live at each point in the program; this is true when
2529 we are called from global_alloc but false when stupid register
2530 allocation has been done.
2532 RELOAD_REG_P if nonzero is a vector indexed by hard reg number
2533 which is nonnegative if the reg has been commandeered for reloading into.
2534 It is copied into STATIC_RELOAD_REG_P and referenced from there
2535 by various subroutines.
2537 Return TRUE if some operands need to be changed, because of swapping
2538 commutative operands, reg_equiv_address substitution, or whatever. */
2541 find_reloads (rtx insn, int replace, int ind_levels, int live_known,
2542 short *reload_reg_p)
2544 int insn_code_number;
2545 int i, j;
2546 int noperands;
2547 /* These start out as the constraints for the insn
2548 and they are chewed up as we consider alternatives. */
2549 const char *constraints[MAX_RECOG_OPERANDS];
2550 /* These are the preferred classes for an operand, or NO_REGS if it isn't
2551 a register. */
2552 enum reg_class preferred_class[MAX_RECOG_OPERANDS];
2553 char pref_or_nothing[MAX_RECOG_OPERANDS];
2554 /* Nonzero for a MEM operand whose entire address needs a reload.
2555 May be -1 to indicate the entire address may or may not need a reload. */
2556 int address_reloaded[MAX_RECOG_OPERANDS];
2557 /* Nonzero for an address operand that needs to be completely reloaded.
2558 May be -1 to indicate the entire operand may or may not need a reload. */
2559 int address_operand_reloaded[MAX_RECOG_OPERANDS];
2560 /* Value of enum reload_type to use for operand. */
2561 enum reload_type operand_type[MAX_RECOG_OPERANDS];
2562 /* Value of enum reload_type to use within address of operand. */
2563 enum reload_type address_type[MAX_RECOG_OPERANDS];
2564 /* Save the usage of each operand. */
2565 enum reload_usage { RELOAD_READ, RELOAD_READ_WRITE, RELOAD_WRITE } modified[MAX_RECOG_OPERANDS];
2566 int no_input_reloads = 0, no_output_reloads = 0;
2567 int n_alternatives;
2568 int this_alternative[MAX_RECOG_OPERANDS];
2569 char this_alternative_match_win[MAX_RECOG_OPERANDS];
2570 char this_alternative_win[MAX_RECOG_OPERANDS];
2571 char this_alternative_offmemok[MAX_RECOG_OPERANDS];
2572 char this_alternative_earlyclobber[MAX_RECOG_OPERANDS];
2573 int this_alternative_matches[MAX_RECOG_OPERANDS];
2574 int swapped;
2575 int goal_alternative[MAX_RECOG_OPERANDS];
2576 int this_alternative_number;
2577 int goal_alternative_number = 0;
2578 int operand_reloadnum[MAX_RECOG_OPERANDS];
2579 int goal_alternative_matches[MAX_RECOG_OPERANDS];
2580 int goal_alternative_matched[MAX_RECOG_OPERANDS];
2581 char goal_alternative_match_win[MAX_RECOG_OPERANDS];
2582 char goal_alternative_win[MAX_RECOG_OPERANDS];
2583 char goal_alternative_offmemok[MAX_RECOG_OPERANDS];
2584 char goal_alternative_earlyclobber[MAX_RECOG_OPERANDS];
2585 int goal_alternative_swapped;
2586 int best;
2587 int commutative;
2588 char operands_match[MAX_RECOG_OPERANDS][MAX_RECOG_OPERANDS];
2589 rtx substed_operand[MAX_RECOG_OPERANDS];
2590 rtx body = PATTERN (insn);
2591 rtx set = single_set (insn);
2592 int goal_earlyclobber = 0, this_earlyclobber;
2593 enum machine_mode operand_mode[MAX_RECOG_OPERANDS];
2594 int retval = 0;
2596 this_insn = insn;
2597 n_reloads = 0;
2598 n_replacements = 0;
2599 n_earlyclobbers = 0;
2600 replace_reloads = replace;
2601 hard_regs_live_known = live_known;
2602 static_reload_reg_p = reload_reg_p;
2604 /* JUMP_INSNs and CALL_INSNs are not allowed to have any output reloads;
2605 neither are insns that SET cc0. Insns that use CC0 are not allowed
2606 to have any input reloads. */
2607 if (JUMP_P (insn) || CALL_P (insn))
2608 no_output_reloads = 1;
2610 #ifdef HAVE_cc0
2611 if (reg_referenced_p (cc0_rtx, PATTERN (insn)))
2612 no_input_reloads = 1;
2613 if (reg_set_p (cc0_rtx, PATTERN (insn)))
2614 no_output_reloads = 1;
2615 #endif
2617 #ifdef SECONDARY_MEMORY_NEEDED
2618 /* The eliminated forms of any secondary memory locations are per-insn, so
2619 clear them out here. */
2621 if (secondary_memlocs_elim_used)
2623 memset (secondary_memlocs_elim, 0,
2624 sizeof (secondary_memlocs_elim[0]) * secondary_memlocs_elim_used);
2625 secondary_memlocs_elim_used = 0;
2627 #endif
2629 /* Dispose quickly of (set (reg..) (reg..)) if both have hard regs and it
2630 is cheap to move between them. If it is not, there may not be an insn
2631 to do the copy, so we may need a reload. */
2632 if (GET_CODE (body) == SET
2633 && REG_P (SET_DEST (body))
2634 && REGNO (SET_DEST (body)) < FIRST_PSEUDO_REGISTER
2635 && REG_P (SET_SRC (body))
2636 && REGNO (SET_SRC (body)) < FIRST_PSEUDO_REGISTER
2637 && REGISTER_MOVE_COST (GET_MODE (SET_SRC (body)),
2638 REGNO_REG_CLASS (REGNO (SET_SRC (body))),
2639 REGNO_REG_CLASS (REGNO (SET_DEST (body)))) == 2)
2640 return 0;
2642 extract_insn (insn);
2644 noperands = reload_n_operands = recog_data.n_operands;
2645 n_alternatives = recog_data.n_alternatives;
2647 /* Just return "no reloads" if insn has no operands with constraints. */
2648 if (noperands == 0 || n_alternatives == 0)
2649 return 0;
2651 insn_code_number = INSN_CODE (insn);
2652 this_insn_is_asm = insn_code_number < 0;
2654 memcpy (operand_mode, recog_data.operand_mode,
2655 noperands * sizeof (enum machine_mode));
2656 memcpy (constraints, recog_data.constraints,
2657 noperands * sizeof (const char *));
2659 commutative = -1;
2661 /* If we will need to know, later, whether some pair of operands
2662 are the same, we must compare them now and save the result.
2663 Reloading the base and index registers will clobber them
2664 and afterward they will fail to match. */
2666 for (i = 0; i < noperands; i++)
2668 const char *p;
2669 int c;
2670 char *end;
2672 substed_operand[i] = recog_data.operand[i];
2673 p = constraints[i];
2675 modified[i] = RELOAD_READ;
2677 /* Scan this operand's constraint to see if it is an output operand,
2678 an in-out operand, is commutative, or should match another. */
2680 while ((c = *p))
2682 p += CONSTRAINT_LEN (c, p);
2683 switch (c)
2685 case '=':
2686 modified[i] = RELOAD_WRITE;
2687 break;
2688 case '+':
2689 modified[i] = RELOAD_READ_WRITE;
2690 break;
2691 case '%':
2693 /* The last operand should not be marked commutative. */
2694 gcc_assert (i != noperands - 1);
2696 /* We currently only support one commutative pair of
2697 operands. Some existing asm code currently uses more
2698 than one pair. Previously, that would usually work,
2699 but sometimes it would crash the compiler. We
2700 continue supporting that case as well as we can by
2701 silently ignoring all but the first pair. In the
2702 future we may handle it correctly. */
2703 if (commutative < 0)
2704 commutative = i;
2705 else
2706 gcc_assert (this_insn_is_asm);
2708 break;
2709 /* Use of ISDIGIT is tempting here, but it may get expensive because
2710 of locale support we don't want. */
2711 case '0': case '1': case '2': case '3': case '4':
2712 case '5': case '6': case '7': case '8': case '9':
2714 c = strtoul (p - 1, &end, 10);
2715 p = end;
2717 operands_match[c][i]
2718 = operands_match_p (recog_data.operand[c],
2719 recog_data.operand[i]);
2721 /* An operand may not match itself. */
2722 gcc_assert (c != i);
2724 /* If C can be commuted with C+1, and C might need to match I,
2725 then C+1 might also need to match I. */
2726 if (commutative >= 0)
2728 if (c == commutative || c == commutative + 1)
2730 int other = c + (c == commutative ? 1 : -1);
2731 operands_match[other][i]
2732 = operands_match_p (recog_data.operand[other],
2733 recog_data.operand[i]);
2735 if (i == commutative || i == commutative + 1)
2737 int other = i + (i == commutative ? 1 : -1);
2738 operands_match[c][other]
2739 = operands_match_p (recog_data.operand[c],
2740 recog_data.operand[other]);
2742 /* Note that C is supposed to be less than I.
2743 No need to consider altering both C and I because in
2744 that case we would alter one into the other. */
2751 /* Examine each operand that is a memory reference or memory address
2752 and reload parts of the addresses into index registers.
2753 Also here any references to pseudo regs that didn't get hard regs
2754 but are equivalent to constants get replaced in the insn itself
2755 with those constants. Nobody will ever see them again.
2757 Finally, set up the preferred classes of each operand. */
2759 for (i = 0; i < noperands; i++)
2761 RTX_CODE code = GET_CODE (recog_data.operand[i]);
2763 address_reloaded[i] = 0;
2764 address_operand_reloaded[i] = 0;
2765 operand_type[i] = (modified[i] == RELOAD_READ ? RELOAD_FOR_INPUT
2766 : modified[i] == RELOAD_WRITE ? RELOAD_FOR_OUTPUT
2767 : RELOAD_OTHER);
2768 address_type[i]
2769 = (modified[i] == RELOAD_READ ? RELOAD_FOR_INPUT_ADDRESS
2770 : modified[i] == RELOAD_WRITE ? RELOAD_FOR_OUTPUT_ADDRESS
2771 : RELOAD_OTHER);
2773 if (*constraints[i] == 0)
2774 /* Ignore things like match_operator operands. */
2776 else if (constraints[i][0] == 'p'
2777 || EXTRA_ADDRESS_CONSTRAINT (constraints[i][0], constraints[i]))
2779 address_operand_reloaded[i]
2780 = find_reloads_address (recog_data.operand_mode[i], (rtx*) 0,
2781 recog_data.operand[i],
2782 recog_data.operand_loc[i],
2783 i, operand_type[i], ind_levels, insn);
2785 /* If we now have a simple operand where we used to have a
2786 PLUS or MULT, re-recognize and try again. */
2787 if ((OBJECT_P (*recog_data.operand_loc[i])
2788 || GET_CODE (*recog_data.operand_loc[i]) == SUBREG)
2789 && (GET_CODE (recog_data.operand[i]) == MULT
2790 || GET_CODE (recog_data.operand[i]) == PLUS))
2792 INSN_CODE (insn) = -1;
2793 retval = find_reloads (insn, replace, ind_levels, live_known,
2794 reload_reg_p);
2795 return retval;
2798 recog_data.operand[i] = *recog_data.operand_loc[i];
2799 substed_operand[i] = recog_data.operand[i];
2801 /* Address operands are reloaded in their existing mode,
2802 no matter what is specified in the machine description. */
2803 operand_mode[i] = GET_MODE (recog_data.operand[i]);
2805 else if (code == MEM)
2807 address_reloaded[i]
2808 = find_reloads_address (GET_MODE (recog_data.operand[i]),
2809 recog_data.operand_loc[i],
2810 XEXP (recog_data.operand[i], 0),
2811 &XEXP (recog_data.operand[i], 0),
2812 i, address_type[i], ind_levels, insn);
2813 recog_data.operand[i] = *recog_data.operand_loc[i];
2814 substed_operand[i] = recog_data.operand[i];
2816 else if (code == SUBREG)
2818 rtx reg = SUBREG_REG (recog_data.operand[i]);
2819 rtx op
2820 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2821 ind_levels,
2822 set != 0
2823 && &SET_DEST (set) == recog_data.operand_loc[i],
2824 insn,
2825 &address_reloaded[i]);
2827 /* If we made a MEM to load (a part of) the stackslot of a pseudo
2828 that didn't get a hard register, emit a USE with a REG_EQUAL
2829 note in front so that we might inherit a previous, possibly
2830 wider reload. */
2832 if (replace
2833 && MEM_P (op)
2834 && REG_P (reg)
2835 && (GET_MODE_SIZE (GET_MODE (reg))
2836 >= GET_MODE_SIZE (GET_MODE (op)))
2837 && reg_equiv_constant[REGNO (reg)] == 0)
2838 set_unique_reg_note (emit_insn_before (gen_rtx_USE (VOIDmode, reg),
2839 insn),
2840 REG_EQUAL, reg_equiv_memory_loc[REGNO (reg)]);
2842 substed_operand[i] = recog_data.operand[i] = op;
2844 else if (code == PLUS || GET_RTX_CLASS (code) == RTX_UNARY)
2845 /* We can get a PLUS as an "operand" as a result of register
2846 elimination. See eliminate_regs and gen_reload. We handle
2847 a unary operator by reloading the operand. */
2848 substed_operand[i] = recog_data.operand[i]
2849 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2850 ind_levels, 0, insn,
2851 &address_reloaded[i]);
2852 else if (code == REG)
2854 /* This is equivalent to calling find_reloads_toplev.
2855 The code is duplicated for speed.
2856 When we find a pseudo always equivalent to a constant,
2857 we replace it by the constant. We must be sure, however,
2858 that we don't try to replace it in the insn in which it
2859 is being set. */
2860 int regno = REGNO (recog_data.operand[i]);
2861 if (reg_equiv_constant[regno] != 0
2862 && (set == 0 || &SET_DEST (set) != recog_data.operand_loc[i]))
2864 /* Record the existing mode so that the check if constants are
2865 allowed will work when operand_mode isn't specified. */
2867 if (operand_mode[i] == VOIDmode)
2868 operand_mode[i] = GET_MODE (recog_data.operand[i]);
2870 substed_operand[i] = recog_data.operand[i]
2871 = reg_equiv_constant[regno];
2873 if (reg_equiv_memory_loc[regno] != 0
2874 && (reg_equiv_address[regno] != 0 || num_not_at_initial_offset))
2875 /* We need not give a valid is_set_dest argument since the case
2876 of a constant equivalence was checked above. */
2877 substed_operand[i] = recog_data.operand[i]
2878 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2879 ind_levels, 0, insn,
2880 &address_reloaded[i]);
2882 /* If the operand is still a register (we didn't replace it with an
2883 equivalent), get the preferred class to reload it into. */
2884 code = GET_CODE (recog_data.operand[i]);
2885 preferred_class[i]
2886 = ((code == REG && REGNO (recog_data.operand[i])
2887 >= FIRST_PSEUDO_REGISTER)
2888 ? reg_preferred_class (REGNO (recog_data.operand[i]))
2889 : NO_REGS);
2890 pref_or_nothing[i]
2891 = (code == REG
2892 && REGNO (recog_data.operand[i]) >= FIRST_PSEUDO_REGISTER
2893 && reg_alternate_class (REGNO (recog_data.operand[i])) == NO_REGS);
2896 /* If this is simply a copy from operand 1 to operand 0, merge the
2897 preferred classes for the operands. */
2898 if (set != 0 && noperands >= 2 && recog_data.operand[0] == SET_DEST (set)
2899 && recog_data.operand[1] == SET_SRC (set))
2901 preferred_class[0] = preferred_class[1]
2902 = reg_class_subunion[(int) preferred_class[0]][(int) preferred_class[1]];
2903 pref_or_nothing[0] |= pref_or_nothing[1];
2904 pref_or_nothing[1] |= pref_or_nothing[0];
2907 /* Now see what we need for pseudo-regs that didn't get hard regs
2908 or got the wrong kind of hard reg. For this, we must consider
2909 all the operands together against the register constraints. */
2911 best = MAX_RECOG_OPERANDS * 2 + 600;
2913 swapped = 0;
2914 goal_alternative_swapped = 0;
2915 try_swapped:
2917 /* The constraints are made of several alternatives.
2918 Each operand's constraint looks like foo,bar,... with commas
2919 separating the alternatives. The first alternatives for all
2920 operands go together, the second alternatives go together, etc.
2922 First loop over alternatives. */
2924 for (this_alternative_number = 0;
2925 this_alternative_number < n_alternatives;
2926 this_alternative_number++)
2928 /* Loop over operands for one constraint alternative. */
2929 /* LOSERS counts those that don't fit this alternative
2930 and would require loading. */
2931 int losers = 0;
2932 /* BAD is set to 1 if it some operand can't fit this alternative
2933 even after reloading. */
2934 int bad = 0;
2935 /* REJECT is a count of how undesirable this alternative says it is
2936 if any reloading is required. If the alternative matches exactly
2937 then REJECT is ignored, but otherwise it gets this much
2938 counted against it in addition to the reloading needed. Each
2939 ? counts three times here since we want the disparaging caused by
2940 a bad register class to only count 1/3 as much. */
2941 int reject = 0;
2943 if (!recog_data.alternative_enabled_p[this_alternative_number])
2945 int i;
2947 for (i = 0; i < recog_data.n_operands; i++)
2948 constraints[i] = skip_alternative (constraints[i]);
2950 continue;
2953 this_earlyclobber = 0;
2955 for (i = 0; i < noperands; i++)
2957 const char *p = constraints[i];
2958 char *end;
2959 int len;
2960 int win = 0;
2961 int did_match = 0;
2962 /* 0 => this operand can be reloaded somehow for this alternative. */
2963 int badop = 1;
2964 /* 0 => this operand can be reloaded if the alternative allows regs. */
2965 int winreg = 0;
2966 int c;
2967 int m;
2968 rtx operand = recog_data.operand[i];
2969 int offset = 0;
2970 /* Nonzero means this is a MEM that must be reloaded into a reg
2971 regardless of what the constraint says. */
2972 int force_reload = 0;
2973 int offmemok = 0;
2974 /* Nonzero if a constant forced into memory would be OK for this
2975 operand. */
2976 int constmemok = 0;
2977 int earlyclobber = 0;
2979 /* If the predicate accepts a unary operator, it means that
2980 we need to reload the operand, but do not do this for
2981 match_operator and friends. */
2982 if (UNARY_P (operand) && *p != 0)
2983 operand = XEXP (operand, 0);
2985 /* If the operand is a SUBREG, extract
2986 the REG or MEM (or maybe even a constant) within.
2987 (Constants can occur as a result of reg_equiv_constant.) */
2989 while (GET_CODE (operand) == SUBREG)
2991 /* Offset only matters when operand is a REG and
2992 it is a hard reg. This is because it is passed
2993 to reg_fits_class_p if it is a REG and all pseudos
2994 return 0 from that function. */
2995 if (REG_P (SUBREG_REG (operand))
2996 && REGNO (SUBREG_REG (operand)) < FIRST_PSEUDO_REGISTER)
2998 if (simplify_subreg_regno (REGNO (SUBREG_REG (operand)),
2999 GET_MODE (SUBREG_REG (operand)),
3000 SUBREG_BYTE (operand),
3001 GET_MODE (operand)) < 0)
3002 force_reload = 1;
3003 offset += subreg_regno_offset (REGNO (SUBREG_REG (operand)),
3004 GET_MODE (SUBREG_REG (operand)),
3005 SUBREG_BYTE (operand),
3006 GET_MODE (operand));
3008 operand = SUBREG_REG (operand);
3009 /* Force reload if this is a constant or PLUS or if there may
3010 be a problem accessing OPERAND in the outer mode. */
3011 if (CONSTANT_P (operand)
3012 || GET_CODE (operand) == PLUS
3013 /* We must force a reload of paradoxical SUBREGs
3014 of a MEM because the alignment of the inner value
3015 may not be enough to do the outer reference. On
3016 big-endian machines, it may also reference outside
3017 the object.
3019 On machines that extend byte operations and we have a
3020 SUBREG where both the inner and outer modes are no wider
3021 than a word and the inner mode is narrower, is integral,
3022 and gets extended when loaded from memory, combine.c has
3023 made assumptions about the behavior of the machine in such
3024 register access. If the data is, in fact, in memory we
3025 must always load using the size assumed to be in the
3026 register and let the insn do the different-sized
3027 accesses.
3029 This is doubly true if WORD_REGISTER_OPERATIONS. In
3030 this case eliminate_regs has left non-paradoxical
3031 subregs for push_reload to see. Make sure it does
3032 by forcing the reload.
3034 ??? When is it right at this stage to have a subreg
3035 of a mem that is _not_ to be handled specially? IMO
3036 those should have been reduced to just a mem. */
3037 || ((MEM_P (operand)
3038 || (REG_P (operand)
3039 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
3040 #ifndef WORD_REGISTER_OPERATIONS
3041 && (((GET_MODE_BITSIZE (GET_MODE (operand))
3042 < BIGGEST_ALIGNMENT)
3043 && (GET_MODE_SIZE (operand_mode[i])
3044 > GET_MODE_SIZE (GET_MODE (operand))))
3045 || BYTES_BIG_ENDIAN
3046 #ifdef LOAD_EXTEND_OP
3047 || (GET_MODE_SIZE (operand_mode[i]) <= UNITS_PER_WORD
3048 && (GET_MODE_SIZE (GET_MODE (operand))
3049 <= UNITS_PER_WORD)
3050 && (GET_MODE_SIZE (operand_mode[i])
3051 > GET_MODE_SIZE (GET_MODE (operand)))
3052 && INTEGRAL_MODE_P (GET_MODE (operand))
3053 && LOAD_EXTEND_OP (GET_MODE (operand)) != UNKNOWN)
3054 #endif
3056 #endif
3059 force_reload = 1;
3062 this_alternative[i] = (int) NO_REGS;
3063 this_alternative_win[i] = 0;
3064 this_alternative_match_win[i] = 0;
3065 this_alternative_offmemok[i] = 0;
3066 this_alternative_earlyclobber[i] = 0;
3067 this_alternative_matches[i] = -1;
3069 /* An empty constraint or empty alternative
3070 allows anything which matched the pattern. */
3071 if (*p == 0 || *p == ',')
3072 win = 1, badop = 0;
3074 /* Scan this alternative's specs for this operand;
3075 set WIN if the operand fits any letter in this alternative.
3076 Otherwise, clear BADOP if this operand could
3077 fit some letter after reloads,
3078 or set WINREG if this operand could fit after reloads
3079 provided the constraint allows some registers. */
3082 switch ((c = *p, len = CONSTRAINT_LEN (c, p)), c)
3084 case '\0':
3085 len = 0;
3086 break;
3087 case ',':
3088 c = '\0';
3089 break;
3091 case '=': case '+': case '*':
3092 break;
3094 case '%':
3095 /* We only support one commutative marker, the first
3096 one. We already set commutative above. */
3097 break;
3099 case '?':
3100 reject += 6;
3101 break;
3103 case '!':
3104 reject = 600;
3105 break;
3107 case '#':
3108 /* Ignore rest of this alternative as far as
3109 reloading is concerned. */
3111 p++;
3112 while (*p && *p != ',');
3113 len = 0;
3114 break;
3116 case '0': case '1': case '2': case '3': case '4':
3117 case '5': case '6': case '7': case '8': case '9':
3118 m = strtoul (p, &end, 10);
3119 p = end;
3120 len = 0;
3122 this_alternative_matches[i] = m;
3123 /* We are supposed to match a previous operand.
3124 If we do, we win if that one did.
3125 If we do not, count both of the operands as losers.
3126 (This is too conservative, since most of the time
3127 only a single reload insn will be needed to make
3128 the two operands win. As a result, this alternative
3129 may be rejected when it is actually desirable.) */
3130 if ((swapped && (m != commutative || i != commutative + 1))
3131 /* If we are matching as if two operands were swapped,
3132 also pretend that operands_match had been computed
3133 with swapped.
3134 But if I is the second of those and C is the first,
3135 don't exchange them, because operands_match is valid
3136 only on one side of its diagonal. */
3137 ? (operands_match
3138 [(m == commutative || m == commutative + 1)
3139 ? 2 * commutative + 1 - m : m]
3140 [(i == commutative || i == commutative + 1)
3141 ? 2 * commutative + 1 - i : i])
3142 : operands_match[m][i])
3144 /* If we are matching a non-offsettable address where an
3145 offsettable address was expected, then we must reject
3146 this combination, because we can't reload it. */
3147 if (this_alternative_offmemok[m]
3148 && MEM_P (recog_data.operand[m])
3149 && this_alternative[m] == (int) NO_REGS
3150 && ! this_alternative_win[m])
3151 bad = 1;
3153 did_match = this_alternative_win[m];
3155 else
3157 /* Operands don't match. */
3158 rtx value;
3159 int loc1, loc2;
3160 /* Retroactively mark the operand we had to match
3161 as a loser, if it wasn't already. */
3162 if (this_alternative_win[m])
3163 losers++;
3164 this_alternative_win[m] = 0;
3165 if (this_alternative[m] == (int) NO_REGS)
3166 bad = 1;
3167 /* But count the pair only once in the total badness of
3168 this alternative, if the pair can be a dummy reload.
3169 The pointers in operand_loc are not swapped; swap
3170 them by hand if necessary. */
3171 if (swapped && i == commutative)
3172 loc1 = commutative + 1;
3173 else if (swapped && i == commutative + 1)
3174 loc1 = commutative;
3175 else
3176 loc1 = i;
3177 if (swapped && m == commutative)
3178 loc2 = commutative + 1;
3179 else if (swapped && m == commutative + 1)
3180 loc2 = commutative;
3181 else
3182 loc2 = m;
3183 value
3184 = find_dummy_reload (recog_data.operand[i],
3185 recog_data.operand[m],
3186 recog_data.operand_loc[loc1],
3187 recog_data.operand_loc[loc2],
3188 operand_mode[i], operand_mode[m],
3189 this_alternative[m], -1,
3190 this_alternative_earlyclobber[m]);
3192 if (value != 0)
3193 losers--;
3195 /* This can be fixed with reloads if the operand
3196 we are supposed to match can be fixed with reloads. */
3197 badop = 0;
3198 this_alternative[i] = this_alternative[m];
3200 /* If we have to reload this operand and some previous
3201 operand also had to match the same thing as this
3202 operand, we don't know how to do that. So reject this
3203 alternative. */
3204 if (! did_match || force_reload)
3205 for (j = 0; j < i; j++)
3206 if (this_alternative_matches[j]
3207 == this_alternative_matches[i])
3208 badop = 1;
3209 break;
3211 case 'p':
3212 /* All necessary reloads for an address_operand
3213 were handled in find_reloads_address. */
3214 this_alternative[i]
3215 = (int) base_reg_class (VOIDmode, ADDRESS, SCRATCH);
3216 win = 1;
3217 badop = 0;
3218 break;
3220 case TARGET_MEM_CONSTRAINT:
3221 if (force_reload)
3222 break;
3223 if (MEM_P (operand)
3224 || (REG_P (operand)
3225 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3226 && reg_renumber[REGNO (operand)] < 0))
3227 win = 1;
3228 if (CONST_POOL_OK_P (operand))
3229 badop = 0;
3230 constmemok = 1;
3231 break;
3233 case '<':
3234 if (MEM_P (operand)
3235 && ! address_reloaded[i]
3236 && (GET_CODE (XEXP (operand, 0)) == PRE_DEC
3237 || GET_CODE (XEXP (operand, 0)) == POST_DEC))
3238 win = 1;
3239 break;
3241 case '>':
3242 if (MEM_P (operand)
3243 && ! address_reloaded[i]
3244 && (GET_CODE (XEXP (operand, 0)) == PRE_INC
3245 || GET_CODE (XEXP (operand, 0)) == POST_INC))
3246 win = 1;
3247 break;
3249 /* Memory operand whose address is not offsettable. */
3250 case 'V':
3251 if (force_reload)
3252 break;
3253 if (MEM_P (operand)
3254 && ! (ind_levels ? offsettable_memref_p (operand)
3255 : offsettable_nonstrict_memref_p (operand))
3256 /* Certain mem addresses will become offsettable
3257 after they themselves are reloaded. This is important;
3258 we don't want our own handling of unoffsettables
3259 to override the handling of reg_equiv_address. */
3260 && !(REG_P (XEXP (operand, 0))
3261 && (ind_levels == 0
3262 || reg_equiv_address[REGNO (XEXP (operand, 0))] != 0)))
3263 win = 1;
3264 break;
3266 /* Memory operand whose address is offsettable. */
3267 case 'o':
3268 if (force_reload)
3269 break;
3270 if ((MEM_P (operand)
3271 /* If IND_LEVELS, find_reloads_address won't reload a
3272 pseudo that didn't get a hard reg, so we have to
3273 reject that case. */
3274 && ((ind_levels ? offsettable_memref_p (operand)
3275 : offsettable_nonstrict_memref_p (operand))
3276 /* A reloaded address is offsettable because it is now
3277 just a simple register indirect. */
3278 || address_reloaded[i] == 1))
3279 || (REG_P (operand)
3280 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3281 && reg_renumber[REGNO (operand)] < 0
3282 /* If reg_equiv_address is nonzero, we will be
3283 loading it into a register; hence it will be
3284 offsettable, but we cannot say that reg_equiv_mem
3285 is offsettable without checking. */
3286 && ((reg_equiv_mem[REGNO (operand)] != 0
3287 && offsettable_memref_p (reg_equiv_mem[REGNO (operand)]))
3288 || (reg_equiv_address[REGNO (operand)] != 0))))
3289 win = 1;
3290 if (CONST_POOL_OK_P (operand)
3291 || MEM_P (operand))
3292 badop = 0;
3293 constmemok = 1;
3294 offmemok = 1;
3295 break;
3297 case '&':
3298 /* Output operand that is stored before the need for the
3299 input operands (and their index registers) is over. */
3300 earlyclobber = 1, this_earlyclobber = 1;
3301 break;
3303 case 'E':
3304 case 'F':
3305 if (GET_CODE (operand) == CONST_DOUBLE
3306 || (GET_CODE (operand) == CONST_VECTOR
3307 && (GET_MODE_CLASS (GET_MODE (operand))
3308 == MODE_VECTOR_FLOAT)))
3309 win = 1;
3310 break;
3312 case 'G':
3313 case 'H':
3314 if (GET_CODE (operand) == CONST_DOUBLE
3315 && CONST_DOUBLE_OK_FOR_CONSTRAINT_P (operand, c, p))
3316 win = 1;
3317 break;
3319 case 's':
3320 if (GET_CODE (operand) == CONST_INT
3321 || (GET_CODE (operand) == CONST_DOUBLE
3322 && GET_MODE (operand) == VOIDmode))
3323 break;
3324 case 'i':
3325 if (CONSTANT_P (operand)
3326 && (! flag_pic || LEGITIMATE_PIC_OPERAND_P (operand)))
3327 win = 1;
3328 break;
3330 case 'n':
3331 if (GET_CODE (operand) == CONST_INT
3332 || (GET_CODE (operand) == CONST_DOUBLE
3333 && GET_MODE (operand) == VOIDmode))
3334 win = 1;
3335 break;
3337 case 'I':
3338 case 'J':
3339 case 'K':
3340 case 'L':
3341 case 'M':
3342 case 'N':
3343 case 'O':
3344 case 'P':
3345 if (GET_CODE (operand) == CONST_INT
3346 && CONST_OK_FOR_CONSTRAINT_P (INTVAL (operand), c, p))
3347 win = 1;
3348 break;
3350 case 'X':
3351 force_reload = 0;
3352 win = 1;
3353 break;
3355 case 'g':
3356 if (! force_reload
3357 /* A PLUS is never a valid operand, but reload can make
3358 it from a register when eliminating registers. */
3359 && GET_CODE (operand) != PLUS
3360 /* A SCRATCH is not a valid operand. */
3361 && GET_CODE (operand) != SCRATCH
3362 && (! CONSTANT_P (operand)
3363 || ! flag_pic
3364 || LEGITIMATE_PIC_OPERAND_P (operand))
3365 && (GENERAL_REGS == ALL_REGS
3366 || !REG_P (operand)
3367 || (REGNO (operand) >= FIRST_PSEUDO_REGISTER
3368 && reg_renumber[REGNO (operand)] < 0)))
3369 win = 1;
3370 /* Drop through into 'r' case. */
3372 case 'r':
3373 this_alternative[i]
3374 = (int) reg_class_subunion[this_alternative[i]][(int) GENERAL_REGS];
3375 goto reg;
3377 default:
3378 if (REG_CLASS_FROM_CONSTRAINT (c, p) == NO_REGS)
3380 #ifdef EXTRA_CONSTRAINT_STR
3381 if (EXTRA_MEMORY_CONSTRAINT (c, p))
3383 if (force_reload)
3384 break;
3385 if (EXTRA_CONSTRAINT_STR (operand, c, p))
3386 win = 1;
3387 /* If the address was already reloaded,
3388 we win as well. */
3389 else if (MEM_P (operand)
3390 && address_reloaded[i] == 1)
3391 win = 1;
3392 /* Likewise if the address will be reloaded because
3393 reg_equiv_address is nonzero. For reg_equiv_mem
3394 we have to check. */
3395 else if (REG_P (operand)
3396 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3397 && reg_renumber[REGNO (operand)] < 0
3398 && ((reg_equiv_mem[REGNO (operand)] != 0
3399 && EXTRA_CONSTRAINT_STR (reg_equiv_mem[REGNO (operand)], c, p))
3400 || (reg_equiv_address[REGNO (operand)] != 0)))
3401 win = 1;
3403 /* If we didn't already win, we can reload
3404 constants via force_const_mem, and other
3405 MEMs by reloading the address like for 'o'. */
3406 if (CONST_POOL_OK_P (operand)
3407 || MEM_P (operand))
3408 badop = 0;
3409 constmemok = 1;
3410 offmemok = 1;
3411 break;
3413 if (EXTRA_ADDRESS_CONSTRAINT (c, p))
3415 if (EXTRA_CONSTRAINT_STR (operand, c, p))
3416 win = 1;
3418 /* If we didn't already win, we can reload
3419 the address into a base register. */
3420 this_alternative[i]
3421 = (int) base_reg_class (VOIDmode, ADDRESS, SCRATCH);
3422 badop = 0;
3423 break;
3426 if (EXTRA_CONSTRAINT_STR (operand, c, p))
3427 win = 1;
3428 #endif
3429 break;
3432 this_alternative[i]
3433 = (int) (reg_class_subunion
3434 [this_alternative[i]]
3435 [(int) REG_CLASS_FROM_CONSTRAINT (c, p)]);
3436 reg:
3437 if (GET_MODE (operand) == BLKmode)
3438 break;
3439 winreg = 1;
3440 if (REG_P (operand)
3441 && reg_fits_class_p (operand, this_alternative[i],
3442 offset, GET_MODE (recog_data.operand[i])))
3443 win = 1;
3444 break;
3446 while ((p += len), c);
3448 constraints[i] = p;
3450 /* If this operand could be handled with a reg,
3451 and some reg is allowed, then this operand can be handled. */
3452 if (winreg && this_alternative[i] != (int) NO_REGS)
3453 badop = 0;
3455 /* Record which operands fit this alternative. */
3456 this_alternative_earlyclobber[i] = earlyclobber;
3457 if (win && ! force_reload)
3458 this_alternative_win[i] = 1;
3459 else if (did_match && ! force_reload)
3460 this_alternative_match_win[i] = 1;
3461 else
3463 int const_to_mem = 0;
3465 this_alternative_offmemok[i] = offmemok;
3466 losers++;
3467 if (badop)
3468 bad = 1;
3469 /* Alternative loses if it has no regs for a reg operand. */
3470 if (REG_P (operand)
3471 && this_alternative[i] == (int) NO_REGS
3472 && this_alternative_matches[i] < 0)
3473 bad = 1;
3475 /* If this is a constant that is reloaded into the desired
3476 class by copying it to memory first, count that as another
3477 reload. This is consistent with other code and is
3478 required to avoid choosing another alternative when
3479 the constant is moved into memory by this function on
3480 an early reload pass. Note that the test here is
3481 precisely the same as in the code below that calls
3482 force_const_mem. */
3483 if (CONST_POOL_OK_P (operand)
3484 && ((PREFERRED_RELOAD_CLASS (operand,
3485 (enum reg_class) this_alternative[i])
3486 == NO_REGS)
3487 || no_input_reloads)
3488 && operand_mode[i] != VOIDmode)
3490 const_to_mem = 1;
3491 if (this_alternative[i] != (int) NO_REGS)
3492 losers++;
3495 /* Alternative loses if it requires a type of reload not
3496 permitted for this insn. We can always reload SCRATCH
3497 and objects with a REG_UNUSED note. */
3498 if (GET_CODE (operand) != SCRATCH
3499 && modified[i] != RELOAD_READ && no_output_reloads
3500 && ! find_reg_note (insn, REG_UNUSED, operand))
3501 bad = 1;
3502 else if (modified[i] != RELOAD_WRITE && no_input_reloads
3503 && ! const_to_mem)
3504 bad = 1;
3506 /* If we can't reload this value at all, reject this
3507 alternative. Note that we could also lose due to
3508 LIMIT_RELOAD_CLASS, but we don't check that
3509 here. */
3511 if (! CONSTANT_P (operand)
3512 && (enum reg_class) this_alternative[i] != NO_REGS)
3514 if (PREFERRED_RELOAD_CLASS
3515 (operand, (enum reg_class) this_alternative[i])
3516 == NO_REGS)
3517 reject = 600;
3519 #ifdef PREFERRED_OUTPUT_RELOAD_CLASS
3520 if (operand_type[i] == RELOAD_FOR_OUTPUT
3521 && PREFERRED_OUTPUT_RELOAD_CLASS
3522 (operand, (enum reg_class) this_alternative[i])
3523 == NO_REGS)
3524 reject = 600;
3525 #endif
3528 /* We prefer to reload pseudos over reloading other things,
3529 since such reloads may be able to be eliminated later.
3530 If we are reloading a SCRATCH, we won't be generating any
3531 insns, just using a register, so it is also preferred.
3532 So bump REJECT in other cases. Don't do this in the
3533 case where we are forcing a constant into memory and
3534 it will then win since we don't want to have a different
3535 alternative match then. */
3536 if (! (REG_P (operand)
3537 && REGNO (operand) >= FIRST_PSEUDO_REGISTER)
3538 && GET_CODE (operand) != SCRATCH
3539 && ! (const_to_mem && constmemok))
3540 reject += 2;
3542 /* Input reloads can be inherited more often than output
3543 reloads can be removed, so penalize output reloads. */
3544 if (operand_type[i] != RELOAD_FOR_INPUT
3545 && GET_CODE (operand) != SCRATCH)
3546 reject++;
3549 /* If this operand is a pseudo register that didn't get a hard
3550 reg and this alternative accepts some register, see if the
3551 class that we want is a subset of the preferred class for this
3552 register. If not, but it intersects that class, use the
3553 preferred class instead. If it does not intersect the preferred
3554 class, show that usage of this alternative should be discouraged;
3555 it will be discouraged more still if the register is `preferred
3556 or nothing'. We do this because it increases the chance of
3557 reusing our spill register in a later insn and avoiding a pair
3558 of memory stores and loads.
3560 Don't bother with this if this alternative will accept this
3561 operand.
3563 Don't do this for a multiword operand, since it is only a
3564 small win and has the risk of requiring more spill registers,
3565 which could cause a large loss.
3567 Don't do this if the preferred class has only one register
3568 because we might otherwise exhaust the class. */
3570 if (! win && ! did_match
3571 && this_alternative[i] != (int) NO_REGS
3572 && GET_MODE_SIZE (operand_mode[i]) <= UNITS_PER_WORD
3573 && reg_class_size [(int) preferred_class[i]] > 0
3574 && ! SMALL_REGISTER_CLASS_P (preferred_class[i]))
3576 if (! reg_class_subset_p (this_alternative[i],
3577 preferred_class[i]))
3579 /* Since we don't have a way of forming the intersection,
3580 we just do something special if the preferred class
3581 is a subset of the class we have; that's the most
3582 common case anyway. */
3583 if (reg_class_subset_p (preferred_class[i],
3584 this_alternative[i]))
3585 this_alternative[i] = (int) preferred_class[i];
3586 else
3587 reject += (2 + 2 * pref_or_nothing[i]);
3592 /* Now see if any output operands that are marked "earlyclobber"
3593 in this alternative conflict with any input operands
3594 or any memory addresses. */
3596 for (i = 0; i < noperands; i++)
3597 if (this_alternative_earlyclobber[i]
3598 && (this_alternative_win[i] || this_alternative_match_win[i]))
3600 struct decomposition early_data;
3602 early_data = decompose (recog_data.operand[i]);
3604 gcc_assert (modified[i] != RELOAD_READ);
3606 if (this_alternative[i] == NO_REGS)
3608 this_alternative_earlyclobber[i] = 0;
3609 gcc_assert (this_insn_is_asm);
3610 error_for_asm (this_insn,
3611 "%<&%> constraint used with no register class");
3614 for (j = 0; j < noperands; j++)
3615 /* Is this an input operand or a memory ref? */
3616 if ((MEM_P (recog_data.operand[j])
3617 || modified[j] != RELOAD_WRITE)
3618 && j != i
3619 /* Ignore things like match_operator operands. */
3620 && *recog_data.constraints[j] != 0
3621 /* Don't count an input operand that is constrained to match
3622 the early clobber operand. */
3623 && ! (this_alternative_matches[j] == i
3624 && rtx_equal_p (recog_data.operand[i],
3625 recog_data.operand[j]))
3626 /* Is it altered by storing the earlyclobber operand? */
3627 && !immune_p (recog_data.operand[j], recog_data.operand[i],
3628 early_data))
3630 /* If the output is in a non-empty few-regs class,
3631 it's costly to reload it, so reload the input instead. */
3632 if (SMALL_REGISTER_CLASS_P (this_alternative[i])
3633 && (REG_P (recog_data.operand[j])
3634 || GET_CODE (recog_data.operand[j]) == SUBREG))
3636 losers++;
3637 this_alternative_win[j] = 0;
3638 this_alternative_match_win[j] = 0;
3640 else
3641 break;
3643 /* If an earlyclobber operand conflicts with something,
3644 it must be reloaded, so request this and count the cost. */
3645 if (j != noperands)
3647 losers++;
3648 this_alternative_win[i] = 0;
3649 this_alternative_match_win[j] = 0;
3650 for (j = 0; j < noperands; j++)
3651 if (this_alternative_matches[j] == i
3652 && this_alternative_match_win[j])
3654 this_alternative_win[j] = 0;
3655 this_alternative_match_win[j] = 0;
3656 losers++;
3661 /* If one alternative accepts all the operands, no reload required,
3662 choose that alternative; don't consider the remaining ones. */
3663 if (losers == 0)
3665 /* Unswap these so that they are never swapped at `finish'. */
3666 if (commutative >= 0)
3668 recog_data.operand[commutative] = substed_operand[commutative];
3669 recog_data.operand[commutative + 1]
3670 = substed_operand[commutative + 1];
3672 for (i = 0; i < noperands; i++)
3674 goal_alternative_win[i] = this_alternative_win[i];
3675 goal_alternative_match_win[i] = this_alternative_match_win[i];
3676 goal_alternative[i] = this_alternative[i];
3677 goal_alternative_offmemok[i] = this_alternative_offmemok[i];
3678 goal_alternative_matches[i] = this_alternative_matches[i];
3679 goal_alternative_earlyclobber[i]
3680 = this_alternative_earlyclobber[i];
3682 goal_alternative_number = this_alternative_number;
3683 goal_alternative_swapped = swapped;
3684 goal_earlyclobber = this_earlyclobber;
3685 goto finish;
3688 /* REJECT, set by the ! and ? constraint characters and when a register
3689 would be reloaded into a non-preferred class, discourages the use of
3690 this alternative for a reload goal. REJECT is incremented by six
3691 for each ? and two for each non-preferred class. */
3692 losers = losers * 6 + reject;
3694 /* If this alternative can be made to work by reloading,
3695 and it needs less reloading than the others checked so far,
3696 record it as the chosen goal for reloading. */
3697 if (! bad && best > losers)
3699 for (i = 0; i < noperands; i++)
3701 goal_alternative[i] = this_alternative[i];
3702 goal_alternative_win[i] = this_alternative_win[i];
3703 goal_alternative_match_win[i] = this_alternative_match_win[i];
3704 goal_alternative_offmemok[i] = this_alternative_offmemok[i];
3705 goal_alternative_matches[i] = this_alternative_matches[i];
3706 goal_alternative_earlyclobber[i]
3707 = this_alternative_earlyclobber[i];
3709 goal_alternative_swapped = swapped;
3710 best = losers;
3711 goal_alternative_number = this_alternative_number;
3712 goal_earlyclobber = this_earlyclobber;
3716 /* If insn is commutative (it's safe to exchange a certain pair of operands)
3717 then we need to try each alternative twice,
3718 the second time matching those two operands
3719 as if we had exchanged them.
3720 To do this, really exchange them in operands.
3722 If we have just tried the alternatives the second time,
3723 return operands to normal and drop through. */
3725 if (commutative >= 0)
3727 swapped = !swapped;
3728 if (swapped)
3730 enum reg_class tclass;
3731 int t;
3733 recog_data.operand[commutative] = substed_operand[commutative + 1];
3734 recog_data.operand[commutative + 1] = substed_operand[commutative];
3735 /* Swap the duplicates too. */
3736 for (i = 0; i < recog_data.n_dups; i++)
3737 if (recog_data.dup_num[i] == commutative
3738 || recog_data.dup_num[i] == commutative + 1)
3739 *recog_data.dup_loc[i]
3740 = recog_data.operand[(int) recog_data.dup_num[i]];
3742 tclass = preferred_class[commutative];
3743 preferred_class[commutative] = preferred_class[commutative + 1];
3744 preferred_class[commutative + 1] = tclass;
3746 t = pref_or_nothing[commutative];
3747 pref_or_nothing[commutative] = pref_or_nothing[commutative + 1];
3748 pref_or_nothing[commutative + 1] = t;
3750 t = address_reloaded[commutative];
3751 address_reloaded[commutative] = address_reloaded[commutative + 1];
3752 address_reloaded[commutative + 1] = t;
3754 memcpy (constraints, recog_data.constraints,
3755 noperands * sizeof (const char *));
3756 goto try_swapped;
3758 else
3760 recog_data.operand[commutative] = substed_operand[commutative];
3761 recog_data.operand[commutative + 1]
3762 = substed_operand[commutative + 1];
3763 /* Unswap the duplicates too. */
3764 for (i = 0; i < recog_data.n_dups; i++)
3765 if (recog_data.dup_num[i] == commutative
3766 || recog_data.dup_num[i] == commutative + 1)
3767 *recog_data.dup_loc[i]
3768 = recog_data.operand[(int) recog_data.dup_num[i]];
3772 /* The operands don't meet the constraints.
3773 goal_alternative describes the alternative
3774 that we could reach by reloading the fewest operands.
3775 Reload so as to fit it. */
3777 if (best == MAX_RECOG_OPERANDS * 2 + 600)
3779 /* No alternative works with reloads?? */
3780 if (insn_code_number >= 0)
3781 fatal_insn ("unable to generate reloads for:", insn);
3782 error_for_asm (insn, "inconsistent operand constraints in an %<asm%>");
3783 /* Avoid further trouble with this insn. */
3784 PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
3785 n_reloads = 0;
3786 return 0;
3789 /* Jump to `finish' from above if all operands are valid already.
3790 In that case, goal_alternative_win is all 1. */
3791 finish:
3793 /* Right now, for any pair of operands I and J that are required to match,
3794 with I < J,
3795 goal_alternative_matches[J] is I.
3796 Set up goal_alternative_matched as the inverse function:
3797 goal_alternative_matched[I] = J. */
3799 for (i = 0; i < noperands; i++)
3800 goal_alternative_matched[i] = -1;
3802 for (i = 0; i < noperands; i++)
3803 if (! goal_alternative_win[i]
3804 && goal_alternative_matches[i] >= 0)
3805 goal_alternative_matched[goal_alternative_matches[i]] = i;
3807 for (i = 0; i < noperands; i++)
3808 goal_alternative_win[i] |= goal_alternative_match_win[i];
3810 /* If the best alternative is with operands 1 and 2 swapped,
3811 consider them swapped before reporting the reloads. Update the
3812 operand numbers of any reloads already pushed. */
3814 if (goal_alternative_swapped)
3816 rtx tem;
3818 tem = substed_operand[commutative];
3819 substed_operand[commutative] = substed_operand[commutative + 1];
3820 substed_operand[commutative + 1] = tem;
3821 tem = recog_data.operand[commutative];
3822 recog_data.operand[commutative] = recog_data.operand[commutative + 1];
3823 recog_data.operand[commutative + 1] = tem;
3824 tem = *recog_data.operand_loc[commutative];
3825 *recog_data.operand_loc[commutative]
3826 = *recog_data.operand_loc[commutative + 1];
3827 *recog_data.operand_loc[commutative + 1] = tem;
3829 for (i = 0; i < n_reloads; i++)
3831 if (rld[i].opnum == commutative)
3832 rld[i].opnum = commutative + 1;
3833 else if (rld[i].opnum == commutative + 1)
3834 rld[i].opnum = commutative;
3838 for (i = 0; i < noperands; i++)
3840 operand_reloadnum[i] = -1;
3842 /* If this is an earlyclobber operand, we need to widen the scope.
3843 The reload must remain valid from the start of the insn being
3844 reloaded until after the operand is stored into its destination.
3845 We approximate this with RELOAD_OTHER even though we know that we
3846 do not conflict with RELOAD_FOR_INPUT_ADDRESS reloads.
3848 One special case that is worth checking is when we have an
3849 output that is earlyclobber but isn't used past the insn (typically
3850 a SCRATCH). In this case, we only need have the reload live
3851 through the insn itself, but not for any of our input or output
3852 reloads.
3853 But we must not accidentally narrow the scope of an existing
3854 RELOAD_OTHER reload - leave these alone.
3856 In any case, anything needed to address this operand can remain
3857 however they were previously categorized. */
3859 if (goal_alternative_earlyclobber[i] && operand_type[i] != RELOAD_OTHER)
3860 operand_type[i]
3861 = (find_reg_note (insn, REG_UNUSED, recog_data.operand[i])
3862 ? RELOAD_FOR_INSN : RELOAD_OTHER);
3865 /* Any constants that aren't allowed and can't be reloaded
3866 into registers are here changed into memory references. */
3867 for (i = 0; i < noperands; i++)
3868 if (! goal_alternative_win[i])
3870 rtx op = recog_data.operand[i];
3871 rtx subreg = NULL_RTX;
3872 rtx plus = NULL_RTX;
3873 enum machine_mode mode = operand_mode[i];
3875 /* Reloads of SUBREGs of CONSTANT RTXs are handled later in
3876 push_reload so we have to let them pass here. */
3877 if (GET_CODE (op) == SUBREG)
3879 subreg = op;
3880 op = SUBREG_REG (op);
3881 mode = GET_MODE (op);
3884 if (GET_CODE (op) == PLUS)
3886 plus = op;
3887 op = XEXP (op, 1);
3890 if (CONST_POOL_OK_P (op)
3891 && ((PREFERRED_RELOAD_CLASS (op,
3892 (enum reg_class) goal_alternative[i])
3893 == NO_REGS)
3894 || no_input_reloads)
3895 && mode != VOIDmode)
3897 int this_address_reloaded;
3898 rtx tem = force_const_mem (mode, op);
3900 /* If we stripped a SUBREG or a PLUS above add it back. */
3901 if (plus != NULL_RTX)
3902 tem = gen_rtx_PLUS (mode, XEXP (plus, 0), tem);
3904 if (subreg != NULL_RTX)
3905 tem = gen_rtx_SUBREG (operand_mode[i], tem, SUBREG_BYTE (subreg));
3907 this_address_reloaded = 0;
3908 substed_operand[i] = recog_data.operand[i]
3909 = find_reloads_toplev (tem, i, address_type[i], ind_levels,
3910 0, insn, &this_address_reloaded);
3912 /* If the alternative accepts constant pool refs directly
3913 there will be no reload needed at all. */
3914 if (plus == NULL_RTX
3915 && subreg == NULL_RTX
3916 && alternative_allows_const_pool_ref (this_address_reloaded == 0
3917 ? substed_operand[i]
3918 : NULL,
3919 recog_data.constraints[i],
3920 goal_alternative_number))
3921 goal_alternative_win[i] = 1;
3925 /* Record the values of the earlyclobber operands for the caller. */
3926 if (goal_earlyclobber)
3927 for (i = 0; i < noperands; i++)
3928 if (goal_alternative_earlyclobber[i])
3929 reload_earlyclobbers[n_earlyclobbers++] = recog_data.operand[i];
3931 /* Now record reloads for all the operands that need them. */
3932 for (i = 0; i < noperands; i++)
3933 if (! goal_alternative_win[i])
3935 /* Operands that match previous ones have already been handled. */
3936 if (goal_alternative_matches[i] >= 0)
3938 /* Handle an operand with a nonoffsettable address
3939 appearing where an offsettable address will do
3940 by reloading the address into a base register.
3942 ??? We can also do this when the operand is a register and
3943 reg_equiv_mem is not offsettable, but this is a bit tricky,
3944 so we don't bother with it. It may not be worth doing. */
3945 else if (goal_alternative_matched[i] == -1
3946 && goal_alternative_offmemok[i]
3947 && MEM_P (recog_data.operand[i]))
3949 /* If the address to be reloaded is a VOIDmode constant,
3950 use Pmode as mode of the reload register, as would have
3951 been done by find_reloads_address. */
3952 enum machine_mode address_mode;
3953 address_mode = GET_MODE (XEXP (recog_data.operand[i], 0));
3954 if (address_mode == VOIDmode)
3955 address_mode = Pmode;
3957 operand_reloadnum[i]
3958 = push_reload (XEXP (recog_data.operand[i], 0), NULL_RTX,
3959 &XEXP (recog_data.operand[i], 0), (rtx*) 0,
3960 base_reg_class (VOIDmode, MEM, SCRATCH),
3961 address_mode,
3962 VOIDmode, 0, 0, i, RELOAD_FOR_INPUT);
3963 rld[operand_reloadnum[i]].inc
3964 = GET_MODE_SIZE (GET_MODE (recog_data.operand[i]));
3966 /* If this operand is an output, we will have made any
3967 reloads for its address as RELOAD_FOR_OUTPUT_ADDRESS, but
3968 now we are treating part of the operand as an input, so
3969 we must change these to RELOAD_FOR_INPUT_ADDRESS. */
3971 if (modified[i] == RELOAD_WRITE)
3973 for (j = 0; j < n_reloads; j++)
3975 if (rld[j].opnum == i)
3977 if (rld[j].when_needed == RELOAD_FOR_OUTPUT_ADDRESS)
3978 rld[j].when_needed = RELOAD_FOR_INPUT_ADDRESS;
3979 else if (rld[j].when_needed
3980 == RELOAD_FOR_OUTADDR_ADDRESS)
3981 rld[j].when_needed = RELOAD_FOR_INPADDR_ADDRESS;
3986 else if (goal_alternative_matched[i] == -1)
3988 operand_reloadnum[i]
3989 = push_reload ((modified[i] != RELOAD_WRITE
3990 ? recog_data.operand[i] : 0),
3991 (modified[i] != RELOAD_READ
3992 ? recog_data.operand[i] : 0),
3993 (modified[i] != RELOAD_WRITE
3994 ? recog_data.operand_loc[i] : 0),
3995 (modified[i] != RELOAD_READ
3996 ? recog_data.operand_loc[i] : 0),
3997 (enum reg_class) goal_alternative[i],
3998 (modified[i] == RELOAD_WRITE
3999 ? VOIDmode : operand_mode[i]),
4000 (modified[i] == RELOAD_READ
4001 ? VOIDmode : operand_mode[i]),
4002 (insn_code_number < 0 ? 0
4003 : insn_data[insn_code_number].operand[i].strict_low),
4004 0, i, operand_type[i]);
4006 /* In a matching pair of operands, one must be input only
4007 and the other must be output only.
4008 Pass the input operand as IN and the other as OUT. */
4009 else if (modified[i] == RELOAD_READ
4010 && modified[goal_alternative_matched[i]] == RELOAD_WRITE)
4012 operand_reloadnum[i]
4013 = push_reload (recog_data.operand[i],
4014 recog_data.operand[goal_alternative_matched[i]],
4015 recog_data.operand_loc[i],
4016 recog_data.operand_loc[goal_alternative_matched[i]],
4017 (enum reg_class) goal_alternative[i],
4018 operand_mode[i],
4019 operand_mode[goal_alternative_matched[i]],
4020 0, 0, i, RELOAD_OTHER);
4021 operand_reloadnum[goal_alternative_matched[i]] = output_reloadnum;
4023 else if (modified[i] == RELOAD_WRITE
4024 && modified[goal_alternative_matched[i]] == RELOAD_READ)
4026 operand_reloadnum[goal_alternative_matched[i]]
4027 = push_reload (recog_data.operand[goal_alternative_matched[i]],
4028 recog_data.operand[i],
4029 recog_data.operand_loc[goal_alternative_matched[i]],
4030 recog_data.operand_loc[i],
4031 (enum reg_class) goal_alternative[i],
4032 operand_mode[goal_alternative_matched[i]],
4033 operand_mode[i],
4034 0, 0, i, RELOAD_OTHER);
4035 operand_reloadnum[i] = output_reloadnum;
4037 else
4039 gcc_assert (insn_code_number < 0);
4040 error_for_asm (insn, "inconsistent operand constraints "
4041 "in an %<asm%>");
4042 /* Avoid further trouble with this insn. */
4043 PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
4044 n_reloads = 0;
4045 return 0;
4048 else if (goal_alternative_matched[i] < 0
4049 && goal_alternative_matches[i] < 0
4050 && address_operand_reloaded[i] != 1
4051 && optimize)
4053 /* For each non-matching operand that's a MEM or a pseudo-register
4054 that didn't get a hard register, make an optional reload.
4055 This may get done even if the insn needs no reloads otherwise. */
4057 rtx operand = recog_data.operand[i];
4059 while (GET_CODE (operand) == SUBREG)
4060 operand = SUBREG_REG (operand);
4061 if ((MEM_P (operand)
4062 || (REG_P (operand)
4063 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
4064 /* If this is only for an output, the optional reload would not
4065 actually cause us to use a register now, just note that
4066 something is stored here. */
4067 && ((enum reg_class) goal_alternative[i] != NO_REGS
4068 || modified[i] == RELOAD_WRITE)
4069 && ! no_input_reloads
4070 /* An optional output reload might allow to delete INSN later.
4071 We mustn't make in-out reloads on insns that are not permitted
4072 output reloads.
4073 If this is an asm, we can't delete it; we must not even call
4074 push_reload for an optional output reload in this case,
4075 because we can't be sure that the constraint allows a register,
4076 and push_reload verifies the constraints for asms. */
4077 && (modified[i] == RELOAD_READ
4078 || (! no_output_reloads && ! this_insn_is_asm)))
4079 operand_reloadnum[i]
4080 = push_reload ((modified[i] != RELOAD_WRITE
4081 ? recog_data.operand[i] : 0),
4082 (modified[i] != RELOAD_READ
4083 ? recog_data.operand[i] : 0),
4084 (modified[i] != RELOAD_WRITE
4085 ? recog_data.operand_loc[i] : 0),
4086 (modified[i] != RELOAD_READ
4087 ? recog_data.operand_loc[i] : 0),
4088 (enum reg_class) goal_alternative[i],
4089 (modified[i] == RELOAD_WRITE
4090 ? VOIDmode : operand_mode[i]),
4091 (modified[i] == RELOAD_READ
4092 ? VOIDmode : operand_mode[i]),
4093 (insn_code_number < 0 ? 0
4094 : insn_data[insn_code_number].operand[i].strict_low),
4095 1, i, operand_type[i]);
4096 /* If a memory reference remains (either as a MEM or a pseudo that
4097 did not get a hard register), yet we can't make an optional
4098 reload, check if this is actually a pseudo register reference;
4099 we then need to emit a USE and/or a CLOBBER so that reload
4100 inheritance will do the right thing. */
4101 else if (replace
4102 && (MEM_P (operand)
4103 || (REG_P (operand)
4104 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
4105 && reg_renumber [REGNO (operand)] < 0)))
4107 operand = *recog_data.operand_loc[i];
4109 while (GET_CODE (operand) == SUBREG)
4110 operand = SUBREG_REG (operand);
4111 if (REG_P (operand))
4113 if (modified[i] != RELOAD_WRITE)
4114 /* We mark the USE with QImode so that we recognize
4115 it as one that can be safely deleted at the end
4116 of reload. */
4117 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, operand),
4118 insn), QImode);
4119 if (modified[i] != RELOAD_READ)
4120 emit_insn_after (gen_clobber (operand), insn);
4124 else if (goal_alternative_matches[i] >= 0
4125 && goal_alternative_win[goal_alternative_matches[i]]
4126 && modified[i] == RELOAD_READ
4127 && modified[goal_alternative_matches[i]] == RELOAD_WRITE
4128 && ! no_input_reloads && ! no_output_reloads
4129 && optimize)
4131 /* Similarly, make an optional reload for a pair of matching
4132 objects that are in MEM or a pseudo that didn't get a hard reg. */
4134 rtx operand = recog_data.operand[i];
4136 while (GET_CODE (operand) == SUBREG)
4137 operand = SUBREG_REG (operand);
4138 if ((MEM_P (operand)
4139 || (REG_P (operand)
4140 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
4141 && ((enum reg_class) goal_alternative[goal_alternative_matches[i]]
4142 != NO_REGS))
4143 operand_reloadnum[i] = operand_reloadnum[goal_alternative_matches[i]]
4144 = push_reload (recog_data.operand[goal_alternative_matches[i]],
4145 recog_data.operand[i],
4146 recog_data.operand_loc[goal_alternative_matches[i]],
4147 recog_data.operand_loc[i],
4148 (enum reg_class) goal_alternative[goal_alternative_matches[i]],
4149 operand_mode[goal_alternative_matches[i]],
4150 operand_mode[i],
4151 0, 1, goal_alternative_matches[i], RELOAD_OTHER);
4154 /* Perform whatever substitutions on the operands we are supposed
4155 to make due to commutativity or replacement of registers
4156 with equivalent constants or memory slots. */
4158 for (i = 0; i < noperands; i++)
4160 /* We only do this on the last pass through reload, because it is
4161 possible for some data (like reg_equiv_address) to be changed during
4162 later passes. Moreover, we lose the opportunity to get a useful
4163 reload_{in,out}_reg when we do these replacements. */
4165 if (replace)
4167 rtx substitution = substed_operand[i];
4169 *recog_data.operand_loc[i] = substitution;
4171 /* If we're replacing an operand with a LABEL_REF, we need to
4172 make sure that there's a REG_LABEL_OPERAND note attached to
4173 this instruction. */
4174 if (GET_CODE (substitution) == LABEL_REF
4175 && !find_reg_note (insn, REG_LABEL_OPERAND,
4176 XEXP (substitution, 0))
4177 /* For a JUMP_P, if it was a branch target it must have
4178 already been recorded as such. */
4179 && (!JUMP_P (insn)
4180 || !label_is_jump_target_p (XEXP (substitution, 0),
4181 insn)))
4182 add_reg_note (insn, REG_LABEL_OPERAND, XEXP (substitution, 0));
4184 else
4185 retval |= (substed_operand[i] != *recog_data.operand_loc[i]);
4188 /* If this insn pattern contains any MATCH_DUP's, make sure that
4189 they will be substituted if the operands they match are substituted.
4190 Also do now any substitutions we already did on the operands.
4192 Don't do this if we aren't making replacements because we might be
4193 propagating things allocated by frame pointer elimination into places
4194 it doesn't expect. */
4196 if (insn_code_number >= 0 && replace)
4197 for (i = insn_data[insn_code_number].n_dups - 1; i >= 0; i--)
4199 int opno = recog_data.dup_num[i];
4200 *recog_data.dup_loc[i] = *recog_data.operand_loc[opno];
4201 dup_replacements (recog_data.dup_loc[i], recog_data.operand_loc[opno]);
4204 #if 0
4205 /* This loses because reloading of prior insns can invalidate the equivalence
4206 (or at least find_equiv_reg isn't smart enough to find it any more),
4207 causing this insn to need more reload regs than it needed before.
4208 It may be too late to make the reload regs available.
4209 Now this optimization is done safely in choose_reload_regs. */
4211 /* For each reload of a reg into some other class of reg,
4212 search for an existing equivalent reg (same value now) in the right class.
4213 We can use it as long as we don't need to change its contents. */
4214 for (i = 0; i < n_reloads; i++)
4215 if (rld[i].reg_rtx == 0
4216 && rld[i].in != 0
4217 && REG_P (rld[i].in)
4218 && rld[i].out == 0)
4220 rld[i].reg_rtx
4221 = find_equiv_reg (rld[i].in, insn, rld[i].rclass, -1,
4222 static_reload_reg_p, 0, rld[i].inmode);
4223 /* Prevent generation of insn to load the value
4224 because the one we found already has the value. */
4225 if (rld[i].reg_rtx)
4226 rld[i].in = rld[i].reg_rtx;
4228 #endif
4230 /* If we detected error and replaced asm instruction by USE, forget about the
4231 reloads. */
4232 if (GET_CODE (PATTERN (insn)) == USE
4233 && GET_CODE (XEXP (PATTERN (insn), 0)) == CONST_INT)
4234 n_reloads = 0;
4236 /* Perhaps an output reload can be combined with another
4237 to reduce needs by one. */
4238 if (!goal_earlyclobber)
4239 combine_reloads ();
4241 /* If we have a pair of reloads for parts of an address, they are reloading
4242 the same object, the operands themselves were not reloaded, and they
4243 are for two operands that are supposed to match, merge the reloads and
4244 change the type of the surviving reload to RELOAD_FOR_OPERAND_ADDRESS. */
4246 for (i = 0; i < n_reloads; i++)
4248 int k;
4250 for (j = i + 1; j < n_reloads; j++)
4251 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4252 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4253 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4254 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4255 && (rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
4256 || rld[j].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4257 || rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4258 || rld[j].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4259 && rtx_equal_p (rld[i].in, rld[j].in)
4260 && (operand_reloadnum[rld[i].opnum] < 0
4261 || rld[operand_reloadnum[rld[i].opnum]].optional)
4262 && (operand_reloadnum[rld[j].opnum] < 0
4263 || rld[operand_reloadnum[rld[j].opnum]].optional)
4264 && (goal_alternative_matches[rld[i].opnum] == rld[j].opnum
4265 || (goal_alternative_matches[rld[j].opnum]
4266 == rld[i].opnum)))
4268 for (k = 0; k < n_replacements; k++)
4269 if (replacements[k].what == j)
4270 replacements[k].what = i;
4272 if (rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4273 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4274 rld[i].when_needed = RELOAD_FOR_OPADDR_ADDR;
4275 else
4276 rld[i].when_needed = RELOAD_FOR_OPERAND_ADDRESS;
4277 rld[j].in = 0;
4281 /* Scan all the reloads and update their type.
4282 If a reload is for the address of an operand and we didn't reload
4283 that operand, change the type. Similarly, change the operand number
4284 of a reload when two operands match. If a reload is optional, treat it
4285 as though the operand isn't reloaded.
4287 ??? This latter case is somewhat odd because if we do the optional
4288 reload, it means the object is hanging around. Thus we need only
4289 do the address reload if the optional reload was NOT done.
4291 Change secondary reloads to be the address type of their operand, not
4292 the normal type.
4294 If an operand's reload is now RELOAD_OTHER, change any
4295 RELOAD_FOR_INPUT_ADDRESS reloads of that operand to
4296 RELOAD_FOR_OTHER_ADDRESS. */
4298 for (i = 0; i < n_reloads; i++)
4300 if (rld[i].secondary_p
4301 && rld[i].when_needed == operand_type[rld[i].opnum])
4302 rld[i].when_needed = address_type[rld[i].opnum];
4304 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4305 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4306 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4307 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4308 && (operand_reloadnum[rld[i].opnum] < 0
4309 || rld[operand_reloadnum[rld[i].opnum]].optional))
4311 /* If we have a secondary reload to go along with this reload,
4312 change its type to RELOAD_FOR_OPADDR_ADDR. */
4314 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4315 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
4316 && rld[i].secondary_in_reload != -1)
4318 int secondary_in_reload = rld[i].secondary_in_reload;
4320 rld[secondary_in_reload].when_needed = RELOAD_FOR_OPADDR_ADDR;
4322 /* If there's a tertiary reload we have to change it also. */
4323 if (secondary_in_reload > 0
4324 && rld[secondary_in_reload].secondary_in_reload != -1)
4325 rld[rld[secondary_in_reload].secondary_in_reload].when_needed
4326 = RELOAD_FOR_OPADDR_ADDR;
4329 if ((rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4330 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4331 && rld[i].secondary_out_reload != -1)
4333 int secondary_out_reload = rld[i].secondary_out_reload;
4335 rld[secondary_out_reload].when_needed = RELOAD_FOR_OPADDR_ADDR;
4337 /* If there's a tertiary reload we have to change it also. */
4338 if (secondary_out_reload
4339 && rld[secondary_out_reload].secondary_out_reload != -1)
4340 rld[rld[secondary_out_reload].secondary_out_reload].when_needed
4341 = RELOAD_FOR_OPADDR_ADDR;
4344 if (rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4345 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4346 rld[i].when_needed = RELOAD_FOR_OPADDR_ADDR;
4347 else
4348 rld[i].when_needed = RELOAD_FOR_OPERAND_ADDRESS;
4351 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4352 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
4353 && operand_reloadnum[rld[i].opnum] >= 0
4354 && (rld[operand_reloadnum[rld[i].opnum]].when_needed
4355 == RELOAD_OTHER))
4356 rld[i].when_needed = RELOAD_FOR_OTHER_ADDRESS;
4358 if (goal_alternative_matches[rld[i].opnum] >= 0)
4359 rld[i].opnum = goal_alternative_matches[rld[i].opnum];
4362 /* Scan all the reloads, and check for RELOAD_FOR_OPERAND_ADDRESS reloads.
4363 If we have more than one, then convert all RELOAD_FOR_OPADDR_ADDR
4364 reloads to RELOAD_FOR_OPERAND_ADDRESS reloads.
4366 choose_reload_regs assumes that RELOAD_FOR_OPADDR_ADDR reloads never
4367 conflict with RELOAD_FOR_OPERAND_ADDRESS reloads. This is true for a
4368 single pair of RELOAD_FOR_OPADDR_ADDR/RELOAD_FOR_OPERAND_ADDRESS reloads.
4369 However, if there is more than one RELOAD_FOR_OPERAND_ADDRESS reload,
4370 then a RELOAD_FOR_OPADDR_ADDR reload conflicts with all
4371 RELOAD_FOR_OPERAND_ADDRESS reloads other than the one that uses it.
4372 This is complicated by the fact that a single operand can have more
4373 than one RELOAD_FOR_OPERAND_ADDRESS reload. It is very difficult to fix
4374 choose_reload_regs without affecting code quality, and cases that
4375 actually fail are extremely rare, so it turns out to be better to fix
4376 the problem here by not generating cases that choose_reload_regs will
4377 fail for. */
4378 /* There is a similar problem with RELOAD_FOR_INPUT_ADDRESS /
4379 RELOAD_FOR_OUTPUT_ADDRESS when there is more than one of a kind for
4380 a single operand.
4381 We can reduce the register pressure by exploiting that a
4382 RELOAD_FOR_X_ADDR_ADDR that precedes all RELOAD_FOR_X_ADDRESS reloads
4383 does not conflict with any of them, if it is only used for the first of
4384 the RELOAD_FOR_X_ADDRESS reloads. */
4386 int first_op_addr_num = -2;
4387 int first_inpaddr_num[MAX_RECOG_OPERANDS];
4388 int first_outpaddr_num[MAX_RECOG_OPERANDS];
4389 int need_change = 0;
4390 /* We use last_op_addr_reload and the contents of the above arrays
4391 first as flags - -2 means no instance encountered, -1 means exactly
4392 one instance encountered.
4393 If more than one instance has been encountered, we store the reload
4394 number of the first reload of the kind in question; reload numbers
4395 are known to be non-negative. */
4396 for (i = 0; i < noperands; i++)
4397 first_inpaddr_num[i] = first_outpaddr_num[i] = -2;
4398 for (i = n_reloads - 1; i >= 0; i--)
4400 switch (rld[i].when_needed)
4402 case RELOAD_FOR_OPERAND_ADDRESS:
4403 if (++first_op_addr_num >= 0)
4405 first_op_addr_num = i;
4406 need_change = 1;
4408 break;
4409 case RELOAD_FOR_INPUT_ADDRESS:
4410 if (++first_inpaddr_num[rld[i].opnum] >= 0)
4412 first_inpaddr_num[rld[i].opnum] = i;
4413 need_change = 1;
4415 break;
4416 case RELOAD_FOR_OUTPUT_ADDRESS:
4417 if (++first_outpaddr_num[rld[i].opnum] >= 0)
4419 first_outpaddr_num[rld[i].opnum] = i;
4420 need_change = 1;
4422 break;
4423 default:
4424 break;
4428 if (need_change)
4430 for (i = 0; i < n_reloads; i++)
4432 int first_num;
4433 enum reload_type type;
4435 switch (rld[i].when_needed)
4437 case RELOAD_FOR_OPADDR_ADDR:
4438 first_num = first_op_addr_num;
4439 type = RELOAD_FOR_OPERAND_ADDRESS;
4440 break;
4441 case RELOAD_FOR_INPADDR_ADDRESS:
4442 first_num = first_inpaddr_num[rld[i].opnum];
4443 type = RELOAD_FOR_INPUT_ADDRESS;
4444 break;
4445 case RELOAD_FOR_OUTADDR_ADDRESS:
4446 first_num = first_outpaddr_num[rld[i].opnum];
4447 type = RELOAD_FOR_OUTPUT_ADDRESS;
4448 break;
4449 default:
4450 continue;
4452 if (first_num < 0)
4453 continue;
4454 else if (i > first_num)
4455 rld[i].when_needed = type;
4456 else
4458 /* Check if the only TYPE reload that uses reload I is
4459 reload FIRST_NUM. */
4460 for (j = n_reloads - 1; j > first_num; j--)
4462 if (rld[j].when_needed == type
4463 && (rld[i].secondary_p
4464 ? rld[j].secondary_in_reload == i
4465 : reg_mentioned_p (rld[i].in, rld[j].in)))
4467 rld[i].when_needed = type;
4468 break;
4476 /* See if we have any reloads that are now allowed to be merged
4477 because we've changed when the reload is needed to
4478 RELOAD_FOR_OPERAND_ADDRESS or RELOAD_FOR_OTHER_ADDRESS. Only
4479 check for the most common cases. */
4481 for (i = 0; i < n_reloads; i++)
4482 if (rld[i].in != 0 && rld[i].out == 0
4483 && (rld[i].when_needed == RELOAD_FOR_OPERAND_ADDRESS
4484 || rld[i].when_needed == RELOAD_FOR_OPADDR_ADDR
4485 || rld[i].when_needed == RELOAD_FOR_OTHER_ADDRESS))
4486 for (j = 0; j < n_reloads; j++)
4487 if (i != j && rld[j].in != 0 && rld[j].out == 0
4488 && rld[j].when_needed == rld[i].when_needed
4489 && MATCHES (rld[i].in, rld[j].in)
4490 && rld[i].rclass == rld[j].rclass
4491 && !rld[i].nocombine && !rld[j].nocombine
4492 && rld[i].reg_rtx == rld[j].reg_rtx)
4494 rld[i].opnum = MIN (rld[i].opnum, rld[j].opnum);
4495 transfer_replacements (i, j);
4496 rld[j].in = 0;
4499 #ifdef HAVE_cc0
4500 /* If we made any reloads for addresses, see if they violate a
4501 "no input reloads" requirement for this insn. But loads that we
4502 do after the insn (such as for output addresses) are fine. */
4503 if (no_input_reloads)
4504 for (i = 0; i < n_reloads; i++)
4505 gcc_assert (rld[i].in == 0
4506 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS
4507 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS);
4508 #endif
4510 /* Compute reload_mode and reload_nregs. */
4511 for (i = 0; i < n_reloads; i++)
4513 rld[i].mode
4514 = (rld[i].inmode == VOIDmode
4515 || (GET_MODE_SIZE (rld[i].outmode)
4516 > GET_MODE_SIZE (rld[i].inmode)))
4517 ? rld[i].outmode : rld[i].inmode;
4519 rld[i].nregs = CLASS_MAX_NREGS (rld[i].rclass, rld[i].mode);
4522 /* Special case a simple move with an input reload and a
4523 destination of a hard reg, if the hard reg is ok, use it. */
4524 for (i = 0; i < n_reloads; i++)
4525 if (rld[i].when_needed == RELOAD_FOR_INPUT
4526 && GET_CODE (PATTERN (insn)) == SET
4527 && REG_P (SET_DEST (PATTERN (insn)))
4528 && (SET_SRC (PATTERN (insn)) == rld[i].in
4529 || SET_SRC (PATTERN (insn)) == rld[i].in_reg)
4530 && !elimination_target_reg_p (SET_DEST (PATTERN (insn))))
4532 rtx dest = SET_DEST (PATTERN (insn));
4533 unsigned int regno = REGNO (dest);
4535 if (regno < FIRST_PSEUDO_REGISTER
4536 && TEST_HARD_REG_BIT (reg_class_contents[rld[i].rclass], regno)
4537 && HARD_REGNO_MODE_OK (regno, rld[i].mode))
4539 int nr = hard_regno_nregs[regno][rld[i].mode];
4540 int ok = 1, nri;
4542 for (nri = 1; nri < nr; nri ++)
4543 if (! TEST_HARD_REG_BIT (reg_class_contents[rld[i].rclass], regno + nri))
4544 ok = 0;
4546 if (ok)
4547 rld[i].reg_rtx = dest;
4551 return retval;
4554 /* Return true if alternative number ALTNUM in constraint-string
4555 CONSTRAINT is guaranteed to accept a reloaded constant-pool reference.
4556 MEM gives the reference if it didn't need any reloads, otherwise it
4557 is null. */
4559 static bool
4560 alternative_allows_const_pool_ref (rtx mem, const char *constraint, int altnum)
4562 int c;
4564 /* Skip alternatives before the one requested. */
4565 while (altnum > 0)
4567 while (*constraint++ != ',');
4568 altnum--;
4570 /* Scan the requested alternative for TARGET_MEM_CONSTRAINT or 'o'.
4571 If one of them is present, this alternative accepts the result of
4572 passing a constant-pool reference through find_reloads_toplev.
4574 The same is true of extra memory constraints if the address
4575 was reloaded into a register. However, the target may elect
4576 to disallow the original constant address, forcing it to be
4577 reloaded into a register instead. */
4578 for (; (c = *constraint) && c != ',' && c != '#';
4579 constraint += CONSTRAINT_LEN (c, constraint))
4581 if (c == TARGET_MEM_CONSTRAINT || c == 'o')
4582 return true;
4583 #ifdef EXTRA_CONSTRAINT_STR
4584 if (EXTRA_MEMORY_CONSTRAINT (c, constraint)
4585 && (mem == NULL || EXTRA_CONSTRAINT_STR (mem, c, constraint)))
4586 return true;
4587 #endif
4589 return false;
4592 /* Scan X for memory references and scan the addresses for reloading.
4593 Also checks for references to "constant" regs that we want to eliminate
4594 and replaces them with the values they stand for.
4595 We may alter X destructively if it contains a reference to such.
4596 If X is just a constant reg, we return the equivalent value
4597 instead of X.
4599 IND_LEVELS says how many levels of indirect addressing this machine
4600 supports.
4602 OPNUM and TYPE identify the purpose of the reload.
4604 IS_SET_DEST is true if X is the destination of a SET, which is not
4605 appropriate to be replaced by a constant.
4607 INSN, if nonzero, is the insn in which we do the reload. It is used
4608 to determine if we may generate output reloads, and where to put USEs
4609 for pseudos that we have to replace with stack slots.
4611 ADDRESS_RELOADED. If nonzero, is a pointer to where we put the
4612 result of find_reloads_address. */
4614 static rtx
4615 find_reloads_toplev (rtx x, int opnum, enum reload_type type,
4616 int ind_levels, int is_set_dest, rtx insn,
4617 int *address_reloaded)
4619 RTX_CODE code = GET_CODE (x);
4621 const char *fmt = GET_RTX_FORMAT (code);
4622 int i;
4623 int copied;
4625 if (code == REG)
4627 /* This code is duplicated for speed in find_reloads. */
4628 int regno = REGNO (x);
4629 if (reg_equiv_constant[regno] != 0 && !is_set_dest)
4630 x = reg_equiv_constant[regno];
4631 #if 0
4632 /* This creates (subreg (mem...)) which would cause an unnecessary
4633 reload of the mem. */
4634 else if (reg_equiv_mem[regno] != 0)
4635 x = reg_equiv_mem[regno];
4636 #endif
4637 else if (reg_equiv_memory_loc[regno]
4638 && (reg_equiv_address[regno] != 0 || num_not_at_initial_offset))
4640 rtx mem = make_memloc (x, regno);
4641 if (reg_equiv_address[regno]
4642 || ! rtx_equal_p (mem, reg_equiv_mem[regno]))
4644 /* If this is not a toplevel operand, find_reloads doesn't see
4645 this substitution. We have to emit a USE of the pseudo so
4646 that delete_output_reload can see it. */
4647 if (replace_reloads && recog_data.operand[opnum] != x)
4648 /* We mark the USE with QImode so that we recognize it
4649 as one that can be safely deleted at the end of
4650 reload. */
4651 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, x), insn),
4652 QImode);
4653 x = mem;
4654 i = find_reloads_address (GET_MODE (x), &x, XEXP (x, 0), &XEXP (x, 0),
4655 opnum, type, ind_levels, insn);
4656 if (!rtx_equal_p (x, mem))
4657 push_reg_equiv_alt_mem (regno, x);
4658 if (address_reloaded)
4659 *address_reloaded = i;
4662 return x;
4664 if (code == MEM)
4666 rtx tem = x;
4668 i = find_reloads_address (GET_MODE (x), &tem, XEXP (x, 0), &XEXP (x, 0),
4669 opnum, type, ind_levels, insn);
4670 if (address_reloaded)
4671 *address_reloaded = i;
4673 return tem;
4676 if (code == SUBREG && REG_P (SUBREG_REG (x)))
4678 /* Check for SUBREG containing a REG that's equivalent to a
4679 constant. If the constant has a known value, truncate it
4680 right now. Similarly if we are extracting a single-word of a
4681 multi-word constant. If the constant is symbolic, allow it
4682 to be substituted normally. push_reload will strip the
4683 subreg later. The constant must not be VOIDmode, because we
4684 will lose the mode of the register (this should never happen
4685 because one of the cases above should handle it). */
4687 int regno = REGNO (SUBREG_REG (x));
4688 rtx tem;
4690 if (regno >= FIRST_PSEUDO_REGISTER
4691 && reg_renumber[regno] < 0
4692 && reg_equiv_constant[regno] != 0)
4694 tem =
4695 simplify_gen_subreg (GET_MODE (x), reg_equiv_constant[regno],
4696 GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x));
4697 gcc_assert (tem);
4698 if (CONSTANT_P (tem) && !LEGITIMATE_CONSTANT_P (tem))
4700 tem = force_const_mem (GET_MODE (x), tem);
4701 i = find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
4702 &XEXP (tem, 0), opnum, type,
4703 ind_levels, insn);
4704 if (address_reloaded)
4705 *address_reloaded = i;
4707 return tem;
4710 /* If the subreg contains a reg that will be converted to a mem,
4711 convert the subreg to a narrower memref now.
4712 Otherwise, we would get (subreg (mem ...) ...),
4713 which would force reload of the mem.
4715 We also need to do this if there is an equivalent MEM that is
4716 not offsettable. In that case, alter_subreg would produce an
4717 invalid address on big-endian machines.
4719 For machines that extend byte loads, we must not reload using
4720 a wider mode if we have a paradoxical SUBREG. find_reloads will
4721 force a reload in that case. So we should not do anything here. */
4723 if (regno >= FIRST_PSEUDO_REGISTER
4724 #ifdef LOAD_EXTEND_OP
4725 && (GET_MODE_SIZE (GET_MODE (x))
4726 <= GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
4727 #endif
4728 && (reg_equiv_address[regno] != 0
4729 || (reg_equiv_mem[regno] != 0
4730 && (! strict_memory_address_p (GET_MODE (x),
4731 XEXP (reg_equiv_mem[regno], 0))
4732 || ! offsettable_memref_p (reg_equiv_mem[regno])
4733 || num_not_at_initial_offset))))
4734 x = find_reloads_subreg_address (x, 1, opnum, type, ind_levels,
4735 insn);
4738 for (copied = 0, i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
4740 if (fmt[i] == 'e')
4742 rtx new_part = find_reloads_toplev (XEXP (x, i), opnum, type,
4743 ind_levels, is_set_dest, insn,
4744 address_reloaded);
4745 /* If we have replaced a reg with it's equivalent memory loc -
4746 that can still be handled here e.g. if it's in a paradoxical
4747 subreg - we must make the change in a copy, rather than using
4748 a destructive change. This way, find_reloads can still elect
4749 not to do the change. */
4750 if (new_part != XEXP (x, i) && ! CONSTANT_P (new_part) && ! copied)
4752 x = shallow_copy_rtx (x);
4753 copied = 1;
4755 XEXP (x, i) = new_part;
4758 return x;
4761 /* Return a mem ref for the memory equivalent of reg REGNO.
4762 This mem ref is not shared with anything. */
4764 static rtx
4765 make_memloc (rtx ad, int regno)
4767 /* We must rerun eliminate_regs, in case the elimination
4768 offsets have changed. */
4769 rtx tem
4770 = XEXP (eliminate_regs (reg_equiv_memory_loc[regno], 0, NULL_RTX), 0);
4772 /* If TEM might contain a pseudo, we must copy it to avoid
4773 modifying it when we do the substitution for the reload. */
4774 if (rtx_varies_p (tem, 0))
4775 tem = copy_rtx (tem);
4777 tem = replace_equiv_address_nv (reg_equiv_memory_loc[regno], tem);
4778 tem = adjust_address_nv (tem, GET_MODE (ad), 0);
4780 /* Copy the result if it's still the same as the equivalence, to avoid
4781 modifying it when we do the substitution for the reload. */
4782 if (tem == reg_equiv_memory_loc[regno])
4783 tem = copy_rtx (tem);
4784 return tem;
4787 /* Returns true if AD could be turned into a valid memory reference
4788 to mode MODE by reloading the part pointed to by PART into a
4789 register. */
4791 static int
4792 maybe_memory_address_p (enum machine_mode mode, rtx ad, rtx *part)
4794 int retv;
4795 rtx tem = *part;
4796 rtx reg = gen_rtx_REG (GET_MODE (tem), max_reg_num ());
4798 *part = reg;
4799 retv = memory_address_p (mode, ad);
4800 *part = tem;
4802 return retv;
4805 /* Record all reloads needed for handling memory address AD
4806 which appears in *LOC in a memory reference to mode MODE
4807 which itself is found in location *MEMREFLOC.
4808 Note that we take shortcuts assuming that no multi-reg machine mode
4809 occurs as part of an address.
4811 OPNUM and TYPE specify the purpose of this reload.
4813 IND_LEVELS says how many levels of indirect addressing this machine
4814 supports.
4816 INSN, if nonzero, is the insn in which we do the reload. It is used
4817 to determine if we may generate output reloads, and where to put USEs
4818 for pseudos that we have to replace with stack slots.
4820 Value is one if this address is reloaded or replaced as a whole; it is
4821 zero if the top level of this address was not reloaded or replaced, and
4822 it is -1 if it may or may not have been reloaded or replaced.
4824 Note that there is no verification that the address will be valid after
4825 this routine does its work. Instead, we rely on the fact that the address
4826 was valid when reload started. So we need only undo things that reload
4827 could have broken. These are wrong register types, pseudos not allocated
4828 to a hard register, and frame pointer elimination. */
4830 static int
4831 find_reloads_address (enum machine_mode mode, rtx *memrefloc, rtx ad,
4832 rtx *loc, int opnum, enum reload_type type,
4833 int ind_levels, rtx insn)
4835 int regno;
4836 int removed_and = 0;
4837 int op_index;
4838 rtx tem;
4840 /* If the address is a register, see if it is a legitimate address and
4841 reload if not. We first handle the cases where we need not reload
4842 or where we must reload in a non-standard way. */
4844 if (REG_P (ad))
4846 regno = REGNO (ad);
4848 if (reg_equiv_constant[regno] != 0)
4850 find_reloads_address_part (reg_equiv_constant[regno], loc,
4851 base_reg_class (mode, MEM, SCRATCH),
4852 GET_MODE (ad), opnum, type, ind_levels);
4853 return 1;
4856 tem = reg_equiv_memory_loc[regno];
4857 if (tem != 0)
4859 if (reg_equiv_address[regno] != 0 || num_not_at_initial_offset)
4861 tem = make_memloc (ad, regno);
4862 if (! strict_memory_address_p (GET_MODE (tem), XEXP (tem, 0)))
4864 rtx orig = tem;
4866 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
4867 &XEXP (tem, 0), opnum,
4868 ADDR_TYPE (type), ind_levels, insn);
4869 if (!rtx_equal_p (tem, orig))
4870 push_reg_equiv_alt_mem (regno, tem);
4872 /* We can avoid a reload if the register's equivalent memory
4873 expression is valid as an indirect memory address.
4874 But not all addresses are valid in a mem used as an indirect
4875 address: only reg or reg+constant. */
4877 if (ind_levels > 0
4878 && strict_memory_address_p (mode, tem)
4879 && (REG_P (XEXP (tem, 0))
4880 || (GET_CODE (XEXP (tem, 0)) == PLUS
4881 && REG_P (XEXP (XEXP (tem, 0), 0))
4882 && CONSTANT_P (XEXP (XEXP (tem, 0), 1)))))
4884 /* TEM is not the same as what we'll be replacing the
4885 pseudo with after reload, put a USE in front of INSN
4886 in the final reload pass. */
4887 if (replace_reloads
4888 && num_not_at_initial_offset
4889 && ! rtx_equal_p (tem, reg_equiv_mem[regno]))
4891 *loc = tem;
4892 /* We mark the USE with QImode so that we
4893 recognize it as one that can be safely
4894 deleted at the end of reload. */
4895 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, ad),
4896 insn), QImode);
4898 /* This doesn't really count as replacing the address
4899 as a whole, since it is still a memory access. */
4901 return 0;
4903 ad = tem;
4907 /* The only remaining case where we can avoid a reload is if this is a
4908 hard register that is valid as a base register and which is not the
4909 subject of a CLOBBER in this insn. */
4911 else if (regno < FIRST_PSEUDO_REGISTER
4912 && regno_ok_for_base_p (regno, mode, MEM, SCRATCH)
4913 && ! regno_clobbered_p (regno, this_insn, mode, 0))
4914 return 0;
4916 /* If we do not have one of the cases above, we must do the reload. */
4917 push_reload (ad, NULL_RTX, loc, (rtx*) 0, base_reg_class (mode, MEM, SCRATCH),
4918 GET_MODE (ad), VOIDmode, 0, 0, opnum, type);
4919 return 1;
4922 if (strict_memory_address_p (mode, ad))
4924 /* The address appears valid, so reloads are not needed.
4925 But the address may contain an eliminable register.
4926 This can happen because a machine with indirect addressing
4927 may consider a pseudo register by itself a valid address even when
4928 it has failed to get a hard reg.
4929 So do a tree-walk to find and eliminate all such regs. */
4931 /* But first quickly dispose of a common case. */
4932 if (GET_CODE (ad) == PLUS
4933 && GET_CODE (XEXP (ad, 1)) == CONST_INT
4934 && REG_P (XEXP (ad, 0))
4935 && reg_equiv_constant[REGNO (XEXP (ad, 0))] == 0)
4936 return 0;
4938 subst_reg_equivs_changed = 0;
4939 *loc = subst_reg_equivs (ad, insn);
4941 if (! subst_reg_equivs_changed)
4942 return 0;
4944 /* Check result for validity after substitution. */
4945 if (strict_memory_address_p (mode, ad))
4946 return 0;
4949 #ifdef LEGITIMIZE_RELOAD_ADDRESS
4952 if (memrefloc)
4954 LEGITIMIZE_RELOAD_ADDRESS (ad, GET_MODE (*memrefloc), opnum, type,
4955 ind_levels, win);
4957 break;
4958 win:
4959 *memrefloc = copy_rtx (*memrefloc);
4960 XEXP (*memrefloc, 0) = ad;
4961 move_replacements (&ad, &XEXP (*memrefloc, 0));
4962 return -1;
4964 while (0);
4965 #endif
4967 /* The address is not valid. We have to figure out why. First see if
4968 we have an outer AND and remove it if so. Then analyze what's inside. */
4970 if (GET_CODE (ad) == AND)
4972 removed_and = 1;
4973 loc = &XEXP (ad, 0);
4974 ad = *loc;
4977 /* One possibility for why the address is invalid is that it is itself
4978 a MEM. This can happen when the frame pointer is being eliminated, a
4979 pseudo is not allocated to a hard register, and the offset between the
4980 frame and stack pointers is not its initial value. In that case the
4981 pseudo will have been replaced by a MEM referring to the
4982 stack pointer. */
4983 if (MEM_P (ad))
4985 /* First ensure that the address in this MEM is valid. Then, unless
4986 indirect addresses are valid, reload the MEM into a register. */
4987 tem = ad;
4988 find_reloads_address (GET_MODE (ad), &tem, XEXP (ad, 0), &XEXP (ad, 0),
4989 opnum, ADDR_TYPE (type),
4990 ind_levels == 0 ? 0 : ind_levels - 1, insn);
4992 /* If tem was changed, then we must create a new memory reference to
4993 hold it and store it back into memrefloc. */
4994 if (tem != ad && memrefloc)
4996 *memrefloc = copy_rtx (*memrefloc);
4997 copy_replacements (tem, XEXP (*memrefloc, 0));
4998 loc = &XEXP (*memrefloc, 0);
4999 if (removed_and)
5000 loc = &XEXP (*loc, 0);
5003 /* Check similar cases as for indirect addresses as above except
5004 that we can allow pseudos and a MEM since they should have been
5005 taken care of above. */
5007 if (ind_levels == 0
5008 || (GET_CODE (XEXP (tem, 0)) == SYMBOL_REF && ! indirect_symref_ok)
5009 || MEM_P (XEXP (tem, 0))
5010 || ! (REG_P (XEXP (tem, 0))
5011 || (GET_CODE (XEXP (tem, 0)) == PLUS
5012 && REG_P (XEXP (XEXP (tem, 0), 0))
5013 && GET_CODE (XEXP (XEXP (tem, 0), 1)) == CONST_INT)))
5015 /* Must use TEM here, not AD, since it is the one that will
5016 have any subexpressions reloaded, if needed. */
5017 push_reload (tem, NULL_RTX, loc, (rtx*) 0,
5018 base_reg_class (mode, MEM, SCRATCH), GET_MODE (tem),
5019 VOIDmode, 0,
5020 0, opnum, type);
5021 return ! removed_and;
5023 else
5024 return 0;
5027 /* If we have address of a stack slot but it's not valid because the
5028 displacement is too large, compute the sum in a register.
5029 Handle all base registers here, not just fp/ap/sp, because on some
5030 targets (namely SH) we can also get too large displacements from
5031 big-endian corrections. */
5032 else if (GET_CODE (ad) == PLUS
5033 && REG_P (XEXP (ad, 0))
5034 && REGNO (XEXP (ad, 0)) < FIRST_PSEUDO_REGISTER
5035 && GET_CODE (XEXP (ad, 1)) == CONST_INT
5036 && regno_ok_for_base_p (REGNO (XEXP (ad, 0)), mode, PLUS,
5037 CONST_INT))
5040 /* Unshare the MEM rtx so we can safely alter it. */
5041 if (memrefloc)
5043 *memrefloc = copy_rtx (*memrefloc);
5044 loc = &XEXP (*memrefloc, 0);
5045 if (removed_and)
5046 loc = &XEXP (*loc, 0);
5049 if (double_reg_address_ok)
5051 /* Unshare the sum as well. */
5052 *loc = ad = copy_rtx (ad);
5054 /* Reload the displacement into an index reg.
5055 We assume the frame pointer or arg pointer is a base reg. */
5056 find_reloads_address_part (XEXP (ad, 1), &XEXP (ad, 1),
5057 INDEX_REG_CLASS, GET_MODE (ad), opnum,
5058 type, ind_levels);
5059 return 0;
5061 else
5063 /* If the sum of two regs is not necessarily valid,
5064 reload the sum into a base reg.
5065 That will at least work. */
5066 find_reloads_address_part (ad, loc,
5067 base_reg_class (mode, MEM, SCRATCH),
5068 Pmode, opnum, type, ind_levels);
5070 return ! removed_and;
5073 /* If we have an indexed stack slot, there are three possible reasons why
5074 it might be invalid: The index might need to be reloaded, the address
5075 might have been made by frame pointer elimination and hence have a
5076 constant out of range, or both reasons might apply.
5078 We can easily check for an index needing reload, but even if that is the
5079 case, we might also have an invalid constant. To avoid making the
5080 conservative assumption and requiring two reloads, we see if this address
5081 is valid when not interpreted strictly. If it is, the only problem is
5082 that the index needs a reload and find_reloads_address_1 will take care
5083 of it.
5085 Handle all base registers here, not just fp/ap/sp, because on some
5086 targets (namely SPARC) we can also get invalid addresses from preventive
5087 subreg big-endian corrections made by find_reloads_toplev. We
5088 can also get expressions involving LO_SUM (rather than PLUS) from
5089 find_reloads_subreg_address.
5091 If we decide to do something, it must be that `double_reg_address_ok'
5092 is true. We generate a reload of the base register + constant and
5093 rework the sum so that the reload register will be added to the index.
5094 This is safe because we know the address isn't shared.
5096 We check for the base register as both the first and second operand of
5097 the innermost PLUS and/or LO_SUM. */
5099 for (op_index = 0; op_index < 2; ++op_index)
5101 rtx operand, addend;
5102 enum rtx_code inner_code;
5104 if (GET_CODE (ad) != PLUS)
5105 continue;
5107 inner_code = GET_CODE (XEXP (ad, 0));
5108 if (!(GET_CODE (ad) == PLUS
5109 && GET_CODE (XEXP (ad, 1)) == CONST_INT
5110 && (inner_code == PLUS || inner_code == LO_SUM)))
5111 continue;
5113 operand = XEXP (XEXP (ad, 0), op_index);
5114 if (!REG_P (operand) || REGNO (operand) >= FIRST_PSEUDO_REGISTER)
5115 continue;
5117 addend = XEXP (XEXP (ad, 0), 1 - op_index);
5119 if ((regno_ok_for_base_p (REGNO (operand), mode, inner_code,
5120 GET_CODE (addend))
5121 || operand == frame_pointer_rtx
5122 #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
5123 || operand == hard_frame_pointer_rtx
5124 #endif
5125 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
5126 || operand == arg_pointer_rtx
5127 #endif
5128 || operand == stack_pointer_rtx)
5129 && ! maybe_memory_address_p (mode, ad,
5130 &XEXP (XEXP (ad, 0), 1 - op_index)))
5132 rtx offset_reg;
5133 enum reg_class cls;
5135 offset_reg = plus_constant (operand, INTVAL (XEXP (ad, 1)));
5137 /* Form the adjusted address. */
5138 if (GET_CODE (XEXP (ad, 0)) == PLUS)
5139 ad = gen_rtx_PLUS (GET_MODE (ad),
5140 op_index == 0 ? offset_reg : addend,
5141 op_index == 0 ? addend : offset_reg);
5142 else
5143 ad = gen_rtx_LO_SUM (GET_MODE (ad),
5144 op_index == 0 ? offset_reg : addend,
5145 op_index == 0 ? addend : offset_reg);
5146 *loc = ad;
5148 cls = base_reg_class (mode, MEM, GET_CODE (addend));
5149 find_reloads_address_part (XEXP (ad, op_index),
5150 &XEXP (ad, op_index), cls,
5151 GET_MODE (ad), opnum, type, ind_levels);
5152 find_reloads_address_1 (mode,
5153 XEXP (ad, 1 - op_index), 1, GET_CODE (ad),
5154 GET_CODE (XEXP (ad, op_index)),
5155 &XEXP (ad, 1 - op_index), opnum,
5156 type, 0, insn);
5158 return 0;
5162 /* See if address becomes valid when an eliminable register
5163 in a sum is replaced. */
5165 tem = ad;
5166 if (GET_CODE (ad) == PLUS)
5167 tem = subst_indexed_address (ad);
5168 if (tem != ad && strict_memory_address_p (mode, tem))
5170 /* Ok, we win that way. Replace any additional eliminable
5171 registers. */
5173 subst_reg_equivs_changed = 0;
5174 tem = subst_reg_equivs (tem, insn);
5176 /* Make sure that didn't make the address invalid again. */
5178 if (! subst_reg_equivs_changed || strict_memory_address_p (mode, tem))
5180 *loc = tem;
5181 return 0;
5185 /* If constants aren't valid addresses, reload the constant address
5186 into a register. */
5187 if (CONSTANT_P (ad) && ! strict_memory_address_p (mode, ad))
5189 /* If AD is an address in the constant pool, the MEM rtx may be shared.
5190 Unshare it so we can safely alter it. */
5191 if (memrefloc && GET_CODE (ad) == SYMBOL_REF
5192 && CONSTANT_POOL_ADDRESS_P (ad))
5194 *memrefloc = copy_rtx (*memrefloc);
5195 loc = &XEXP (*memrefloc, 0);
5196 if (removed_and)
5197 loc = &XEXP (*loc, 0);
5200 find_reloads_address_part (ad, loc, base_reg_class (mode, MEM, SCRATCH),
5201 Pmode, opnum, type, ind_levels);
5202 return ! removed_and;
5205 return find_reloads_address_1 (mode, ad, 0, MEM, SCRATCH, loc, opnum, type,
5206 ind_levels, insn);
5209 /* Find all pseudo regs appearing in AD
5210 that are eliminable in favor of equivalent values
5211 and do not have hard regs; replace them by their equivalents.
5212 INSN, if nonzero, is the insn in which we do the reload. We put USEs in
5213 front of it for pseudos that we have to replace with stack slots. */
5215 static rtx
5216 subst_reg_equivs (rtx ad, rtx insn)
5218 RTX_CODE code = GET_CODE (ad);
5219 int i;
5220 const char *fmt;
5222 switch (code)
5224 case HIGH:
5225 case CONST_INT:
5226 case CONST:
5227 case CONST_DOUBLE:
5228 case CONST_FIXED:
5229 case CONST_VECTOR:
5230 case SYMBOL_REF:
5231 case LABEL_REF:
5232 case PC:
5233 case CC0:
5234 return ad;
5236 case REG:
5238 int regno = REGNO (ad);
5240 if (reg_equiv_constant[regno] != 0)
5242 subst_reg_equivs_changed = 1;
5243 return reg_equiv_constant[regno];
5245 if (reg_equiv_memory_loc[regno] && num_not_at_initial_offset)
5247 rtx mem = make_memloc (ad, regno);
5248 if (! rtx_equal_p (mem, reg_equiv_mem[regno]))
5250 subst_reg_equivs_changed = 1;
5251 /* We mark the USE with QImode so that we recognize it
5252 as one that can be safely deleted at the end of
5253 reload. */
5254 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, ad), insn),
5255 QImode);
5256 return mem;
5260 return ad;
5262 case PLUS:
5263 /* Quickly dispose of a common case. */
5264 if (XEXP (ad, 0) == frame_pointer_rtx
5265 && GET_CODE (XEXP (ad, 1)) == CONST_INT)
5266 return ad;
5267 break;
5269 default:
5270 break;
5273 fmt = GET_RTX_FORMAT (code);
5274 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
5275 if (fmt[i] == 'e')
5276 XEXP (ad, i) = subst_reg_equivs (XEXP (ad, i), insn);
5277 return ad;
5280 /* Compute the sum of X and Y, making canonicalizations assumed in an
5281 address, namely: sum constant integers, surround the sum of two
5282 constants with a CONST, put the constant as the second operand, and
5283 group the constant on the outermost sum.
5285 This routine assumes both inputs are already in canonical form. */
5288 form_sum (rtx x, rtx y)
5290 rtx tem;
5291 enum machine_mode mode = GET_MODE (x);
5293 if (mode == VOIDmode)
5294 mode = GET_MODE (y);
5296 if (mode == VOIDmode)
5297 mode = Pmode;
5299 if (GET_CODE (x) == CONST_INT)
5300 return plus_constant (y, INTVAL (x));
5301 else if (GET_CODE (y) == CONST_INT)
5302 return plus_constant (x, INTVAL (y));
5303 else if (CONSTANT_P (x))
5304 tem = x, x = y, y = tem;
5306 if (GET_CODE (x) == PLUS && CONSTANT_P (XEXP (x, 1)))
5307 return form_sum (XEXP (x, 0), form_sum (XEXP (x, 1), y));
5309 /* Note that if the operands of Y are specified in the opposite
5310 order in the recursive calls below, infinite recursion will occur. */
5311 if (GET_CODE (y) == PLUS && CONSTANT_P (XEXP (y, 1)))
5312 return form_sum (form_sum (x, XEXP (y, 0)), XEXP (y, 1));
5314 /* If both constant, encapsulate sum. Otherwise, just form sum. A
5315 constant will have been placed second. */
5316 if (CONSTANT_P (x) && CONSTANT_P (y))
5318 if (GET_CODE (x) == CONST)
5319 x = XEXP (x, 0);
5320 if (GET_CODE (y) == CONST)
5321 y = XEXP (y, 0);
5323 return gen_rtx_CONST (VOIDmode, gen_rtx_PLUS (mode, x, y));
5326 return gen_rtx_PLUS (mode, x, y);
5329 /* If ADDR is a sum containing a pseudo register that should be
5330 replaced with a constant (from reg_equiv_constant),
5331 return the result of doing so, and also apply the associative
5332 law so that the result is more likely to be a valid address.
5333 (But it is not guaranteed to be one.)
5335 Note that at most one register is replaced, even if more are
5336 replaceable. Also, we try to put the result into a canonical form
5337 so it is more likely to be a valid address.
5339 In all other cases, return ADDR. */
5341 static rtx
5342 subst_indexed_address (rtx addr)
5344 rtx op0 = 0, op1 = 0, op2 = 0;
5345 rtx tem;
5346 int regno;
5348 if (GET_CODE (addr) == PLUS)
5350 /* Try to find a register to replace. */
5351 op0 = XEXP (addr, 0), op1 = XEXP (addr, 1), op2 = 0;
5352 if (REG_P (op0)
5353 && (regno = REGNO (op0)) >= FIRST_PSEUDO_REGISTER
5354 && reg_renumber[regno] < 0
5355 && reg_equiv_constant[regno] != 0)
5356 op0 = reg_equiv_constant[regno];
5357 else if (REG_P (op1)
5358 && (regno = REGNO (op1)) >= FIRST_PSEUDO_REGISTER
5359 && reg_renumber[regno] < 0
5360 && reg_equiv_constant[regno] != 0)
5361 op1 = reg_equiv_constant[regno];
5362 else if (GET_CODE (op0) == PLUS
5363 && (tem = subst_indexed_address (op0)) != op0)
5364 op0 = tem;
5365 else if (GET_CODE (op1) == PLUS
5366 && (tem = subst_indexed_address (op1)) != op1)
5367 op1 = tem;
5368 else
5369 return addr;
5371 /* Pick out up to three things to add. */
5372 if (GET_CODE (op1) == PLUS)
5373 op2 = XEXP (op1, 1), op1 = XEXP (op1, 0);
5374 else if (GET_CODE (op0) == PLUS)
5375 op2 = op1, op1 = XEXP (op0, 1), op0 = XEXP (op0, 0);
5377 /* Compute the sum. */
5378 if (op2 != 0)
5379 op1 = form_sum (op1, op2);
5380 if (op1 != 0)
5381 op0 = form_sum (op0, op1);
5383 return op0;
5385 return addr;
5388 /* Update the REG_INC notes for an insn. It updates all REG_INC
5389 notes for the instruction which refer to REGNO the to refer
5390 to the reload number.
5392 INSN is the insn for which any REG_INC notes need updating.
5394 REGNO is the register number which has been reloaded.
5396 RELOADNUM is the reload number. */
5398 static void
5399 update_auto_inc_notes (rtx insn ATTRIBUTE_UNUSED, int regno ATTRIBUTE_UNUSED,
5400 int reloadnum ATTRIBUTE_UNUSED)
5402 #ifdef AUTO_INC_DEC
5403 rtx link;
5405 for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
5406 if (REG_NOTE_KIND (link) == REG_INC
5407 && (int) REGNO (XEXP (link, 0)) == regno)
5408 push_replacement (&XEXP (link, 0), reloadnum, VOIDmode);
5409 #endif
5412 /* Record the pseudo registers we must reload into hard registers in a
5413 subexpression of a would-be memory address, X referring to a value
5414 in mode MODE. (This function is not called if the address we find
5415 is strictly valid.)
5417 CONTEXT = 1 means we are considering regs as index regs,
5418 = 0 means we are considering them as base regs.
5419 OUTER_CODE is the code of the enclosing RTX, typically a MEM, a PLUS,
5420 or an autoinc code.
5421 If CONTEXT == 0 and OUTER_CODE is a PLUS or LO_SUM, then INDEX_CODE
5422 is the code of the index part of the address. Otherwise, pass SCRATCH
5423 for this argument.
5424 OPNUM and TYPE specify the purpose of any reloads made.
5426 IND_LEVELS says how many levels of indirect addressing are
5427 supported at this point in the address.
5429 INSN, if nonzero, is the insn in which we do the reload. It is used
5430 to determine if we may generate output reloads.
5432 We return nonzero if X, as a whole, is reloaded or replaced. */
5434 /* Note that we take shortcuts assuming that no multi-reg machine mode
5435 occurs as part of an address.
5436 Also, this is not fully machine-customizable; it works for machines
5437 such as VAXen and 68000's and 32000's, but other possible machines
5438 could have addressing modes that this does not handle right.
5439 If you add push_reload calls here, you need to make sure gen_reload
5440 handles those cases gracefully. */
5442 static int
5443 find_reloads_address_1 (enum machine_mode mode, rtx x, int context,
5444 enum rtx_code outer_code, enum rtx_code index_code,
5445 rtx *loc, int opnum, enum reload_type type,
5446 int ind_levels, rtx insn)
5448 #define REG_OK_FOR_CONTEXT(CONTEXT, REGNO, MODE, OUTER, INDEX) \
5449 ((CONTEXT) == 0 \
5450 ? regno_ok_for_base_p (REGNO, MODE, OUTER, INDEX) \
5451 : REGNO_OK_FOR_INDEX_P (REGNO))
5453 enum reg_class context_reg_class;
5454 RTX_CODE code = GET_CODE (x);
5456 if (context == 1)
5457 context_reg_class = INDEX_REG_CLASS;
5458 else
5459 context_reg_class = base_reg_class (mode, outer_code, index_code);
5461 switch (code)
5463 case PLUS:
5465 rtx orig_op0 = XEXP (x, 0);
5466 rtx orig_op1 = XEXP (x, 1);
5467 RTX_CODE code0 = GET_CODE (orig_op0);
5468 RTX_CODE code1 = GET_CODE (orig_op1);
5469 rtx op0 = orig_op0;
5470 rtx op1 = orig_op1;
5472 if (GET_CODE (op0) == SUBREG)
5474 op0 = SUBREG_REG (op0);
5475 code0 = GET_CODE (op0);
5476 if (code0 == REG && REGNO (op0) < FIRST_PSEUDO_REGISTER)
5477 op0 = gen_rtx_REG (word_mode,
5478 (REGNO (op0) +
5479 subreg_regno_offset (REGNO (SUBREG_REG (orig_op0)),
5480 GET_MODE (SUBREG_REG (orig_op0)),
5481 SUBREG_BYTE (orig_op0),
5482 GET_MODE (orig_op0))));
5485 if (GET_CODE (op1) == SUBREG)
5487 op1 = SUBREG_REG (op1);
5488 code1 = GET_CODE (op1);
5489 if (code1 == REG && REGNO (op1) < FIRST_PSEUDO_REGISTER)
5490 /* ??? Why is this given op1's mode and above for
5491 ??? op0 SUBREGs we use word_mode? */
5492 op1 = gen_rtx_REG (GET_MODE (op1),
5493 (REGNO (op1) +
5494 subreg_regno_offset (REGNO (SUBREG_REG (orig_op1)),
5495 GET_MODE (SUBREG_REG (orig_op1)),
5496 SUBREG_BYTE (orig_op1),
5497 GET_MODE (orig_op1))));
5499 /* Plus in the index register may be created only as a result of
5500 register rematerialization for expression like &localvar*4. Reload it.
5501 It may be possible to combine the displacement on the outer level,
5502 but it is probably not worthwhile to do so. */
5503 if (context == 1)
5505 find_reloads_address (GET_MODE (x), loc, XEXP (x, 0), &XEXP (x, 0),
5506 opnum, ADDR_TYPE (type), ind_levels, insn);
5507 push_reload (*loc, NULL_RTX, loc, (rtx*) 0,
5508 context_reg_class,
5509 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5510 return 1;
5513 if (code0 == MULT || code0 == SIGN_EXTEND || code0 == TRUNCATE
5514 || code0 == ZERO_EXTEND || code1 == MEM)
5516 find_reloads_address_1 (mode, orig_op0, 1, PLUS, SCRATCH,
5517 &XEXP (x, 0), opnum, type, ind_levels,
5518 insn);
5519 find_reloads_address_1 (mode, orig_op1, 0, PLUS, code0,
5520 &XEXP (x, 1), opnum, type, ind_levels,
5521 insn);
5524 else if (code1 == MULT || code1 == SIGN_EXTEND || code1 == TRUNCATE
5525 || code1 == ZERO_EXTEND || code0 == MEM)
5527 find_reloads_address_1 (mode, orig_op0, 0, PLUS, code1,
5528 &XEXP (x, 0), opnum, type, ind_levels,
5529 insn);
5530 find_reloads_address_1 (mode, orig_op1, 1, PLUS, SCRATCH,
5531 &XEXP (x, 1), opnum, type, ind_levels,
5532 insn);
5535 else if (code0 == CONST_INT || code0 == CONST
5536 || code0 == SYMBOL_REF || code0 == LABEL_REF)
5537 find_reloads_address_1 (mode, orig_op1, 0, PLUS, code0,
5538 &XEXP (x, 1), opnum, type, ind_levels,
5539 insn);
5541 else if (code1 == CONST_INT || code1 == CONST
5542 || code1 == SYMBOL_REF || code1 == LABEL_REF)
5543 find_reloads_address_1 (mode, orig_op0, 0, PLUS, code1,
5544 &XEXP (x, 0), opnum, type, ind_levels,
5545 insn);
5547 else if (code0 == REG && code1 == REG)
5549 if (REGNO_OK_FOR_INDEX_P (REGNO (op1))
5550 && regno_ok_for_base_p (REGNO (op0), mode, PLUS, REG))
5551 return 0;
5552 else if (REGNO_OK_FOR_INDEX_P (REGNO (op0))
5553 && regno_ok_for_base_p (REGNO (op1), mode, PLUS, REG))
5554 return 0;
5555 else if (regno_ok_for_base_p (REGNO (op0), mode, PLUS, REG))
5556 find_reloads_address_1 (mode, orig_op1, 1, PLUS, SCRATCH,
5557 &XEXP (x, 1), opnum, type, ind_levels,
5558 insn);
5559 else if (REGNO_OK_FOR_INDEX_P (REGNO (op1)))
5560 find_reloads_address_1 (mode, orig_op0, 0, PLUS, REG,
5561 &XEXP (x, 0), opnum, type, ind_levels,
5562 insn);
5563 else if (regno_ok_for_base_p (REGNO (op1), mode, PLUS, REG))
5564 find_reloads_address_1 (mode, orig_op0, 1, PLUS, SCRATCH,
5565 &XEXP (x, 0), opnum, type, ind_levels,
5566 insn);
5567 else if (REGNO_OK_FOR_INDEX_P (REGNO (op0)))
5568 find_reloads_address_1 (mode, orig_op1, 0, PLUS, REG,
5569 &XEXP (x, 1), opnum, type, ind_levels,
5570 insn);
5571 else
5573 find_reloads_address_1 (mode, orig_op0, 0, PLUS, REG,
5574 &XEXP (x, 0), opnum, type, ind_levels,
5575 insn);
5576 find_reloads_address_1 (mode, orig_op1, 1, PLUS, SCRATCH,
5577 &XEXP (x, 1), opnum, type, ind_levels,
5578 insn);
5582 else if (code0 == REG)
5584 find_reloads_address_1 (mode, orig_op0, 1, PLUS, SCRATCH,
5585 &XEXP (x, 0), opnum, type, ind_levels,
5586 insn);
5587 find_reloads_address_1 (mode, orig_op1, 0, PLUS, REG,
5588 &XEXP (x, 1), opnum, type, ind_levels,
5589 insn);
5592 else if (code1 == REG)
5594 find_reloads_address_1 (mode, orig_op1, 1, PLUS, SCRATCH,
5595 &XEXP (x, 1), opnum, type, ind_levels,
5596 insn);
5597 find_reloads_address_1 (mode, orig_op0, 0, PLUS, REG,
5598 &XEXP (x, 0), opnum, type, ind_levels,
5599 insn);
5603 return 0;
5605 case POST_MODIFY:
5606 case PRE_MODIFY:
5608 rtx op0 = XEXP (x, 0);
5609 rtx op1 = XEXP (x, 1);
5610 enum rtx_code index_code;
5611 int regno;
5612 int reloadnum;
5614 if (GET_CODE (op1) != PLUS && GET_CODE (op1) != MINUS)
5615 return 0;
5617 /* Currently, we only support {PRE,POST}_MODIFY constructs
5618 where a base register is {inc,dec}remented by the contents
5619 of another register or by a constant value. Thus, these
5620 operands must match. */
5621 gcc_assert (op0 == XEXP (op1, 0));
5623 /* Require index register (or constant). Let's just handle the
5624 register case in the meantime... If the target allows
5625 auto-modify by a constant then we could try replacing a pseudo
5626 register with its equivalent constant where applicable.
5628 We also handle the case where the register was eliminated
5629 resulting in a PLUS subexpression.
5631 If we later decide to reload the whole PRE_MODIFY or
5632 POST_MODIFY, inc_for_reload might clobber the reload register
5633 before reading the index. The index register might therefore
5634 need to live longer than a TYPE reload normally would, so be
5635 conservative and class it as RELOAD_OTHER. */
5636 if ((REG_P (XEXP (op1, 1))
5637 && !REGNO_OK_FOR_INDEX_P (REGNO (XEXP (op1, 1))))
5638 || GET_CODE (XEXP (op1, 1)) == PLUS)
5639 find_reloads_address_1 (mode, XEXP (op1, 1), 1, code, SCRATCH,
5640 &XEXP (op1, 1), opnum, RELOAD_OTHER,
5641 ind_levels, insn);
5643 gcc_assert (REG_P (XEXP (op1, 0)));
5645 regno = REGNO (XEXP (op1, 0));
5646 index_code = GET_CODE (XEXP (op1, 1));
5648 /* A register that is incremented cannot be constant! */
5649 gcc_assert (regno < FIRST_PSEUDO_REGISTER
5650 || reg_equiv_constant[regno] == 0);
5652 /* Handle a register that is equivalent to a memory location
5653 which cannot be addressed directly. */
5654 if (reg_equiv_memory_loc[regno] != 0
5655 && (reg_equiv_address[regno] != 0
5656 || num_not_at_initial_offset))
5658 rtx tem = make_memloc (XEXP (x, 0), regno);
5660 if (reg_equiv_address[regno]
5661 || ! rtx_equal_p (tem, reg_equiv_mem[regno]))
5663 rtx orig = tem;
5665 /* First reload the memory location's address.
5666 We can't use ADDR_TYPE (type) here, because we need to
5667 write back the value after reading it, hence we actually
5668 need two registers. */
5669 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
5670 &XEXP (tem, 0), opnum,
5671 RELOAD_OTHER,
5672 ind_levels, insn);
5674 if (!rtx_equal_p (tem, orig))
5675 push_reg_equiv_alt_mem (regno, tem);
5677 /* Then reload the memory location into a base
5678 register. */
5679 reloadnum = push_reload (tem, tem, &XEXP (x, 0),
5680 &XEXP (op1, 0),
5681 base_reg_class (mode, code,
5682 index_code),
5683 GET_MODE (x), GET_MODE (x), 0,
5684 0, opnum, RELOAD_OTHER);
5686 update_auto_inc_notes (this_insn, regno, reloadnum);
5687 return 0;
5691 if (reg_renumber[regno] >= 0)
5692 regno = reg_renumber[regno];
5694 /* We require a base register here... */
5695 if (!regno_ok_for_base_p (regno, GET_MODE (x), code, index_code))
5697 reloadnum = push_reload (XEXP (op1, 0), XEXP (x, 0),
5698 &XEXP (op1, 0), &XEXP (x, 0),
5699 base_reg_class (mode, code, index_code),
5700 GET_MODE (x), GET_MODE (x), 0, 0,
5701 opnum, RELOAD_OTHER);
5703 update_auto_inc_notes (this_insn, regno, reloadnum);
5704 return 0;
5707 return 0;
5709 case POST_INC:
5710 case POST_DEC:
5711 case PRE_INC:
5712 case PRE_DEC:
5713 if (REG_P (XEXP (x, 0)))
5715 int regno = REGNO (XEXP (x, 0));
5716 int value = 0;
5717 rtx x_orig = x;
5719 /* A register that is incremented cannot be constant! */
5720 gcc_assert (regno < FIRST_PSEUDO_REGISTER
5721 || reg_equiv_constant[regno] == 0);
5723 /* Handle a register that is equivalent to a memory location
5724 which cannot be addressed directly. */
5725 if (reg_equiv_memory_loc[regno] != 0
5726 && (reg_equiv_address[regno] != 0 || num_not_at_initial_offset))
5728 rtx tem = make_memloc (XEXP (x, 0), regno);
5729 if (reg_equiv_address[regno]
5730 || ! rtx_equal_p (tem, reg_equiv_mem[regno]))
5732 rtx orig = tem;
5734 /* First reload the memory location's address.
5735 We can't use ADDR_TYPE (type) here, because we need to
5736 write back the value after reading it, hence we actually
5737 need two registers. */
5738 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
5739 &XEXP (tem, 0), opnum, type,
5740 ind_levels, insn);
5741 if (!rtx_equal_p (tem, orig))
5742 push_reg_equiv_alt_mem (regno, tem);
5743 /* Put this inside a new increment-expression. */
5744 x = gen_rtx_fmt_e (GET_CODE (x), GET_MODE (x), tem);
5745 /* Proceed to reload that, as if it contained a register. */
5749 /* If we have a hard register that is ok in this incdec context,
5750 don't make a reload. If the register isn't nice enough for
5751 autoincdec, we can reload it. But, if an autoincrement of a
5752 register that we here verified as playing nice, still outside
5753 isn't "valid", it must be that no autoincrement is "valid".
5754 If that is true and something made an autoincrement anyway,
5755 this must be a special context where one is allowed.
5756 (For example, a "push" instruction.)
5757 We can't improve this address, so leave it alone. */
5759 /* Otherwise, reload the autoincrement into a suitable hard reg
5760 and record how much to increment by. */
5762 if (reg_renumber[regno] >= 0)
5763 regno = reg_renumber[regno];
5764 if (regno >= FIRST_PSEUDO_REGISTER
5765 || !REG_OK_FOR_CONTEXT (context, regno, mode, code,
5766 index_code))
5768 int reloadnum;
5770 /* If we can output the register afterwards, do so, this
5771 saves the extra update.
5772 We can do so if we have an INSN - i.e. no JUMP_INSN nor
5773 CALL_INSN - and it does not set CC0.
5774 But don't do this if we cannot directly address the
5775 memory location, since this will make it harder to
5776 reuse address reloads, and increases register pressure.
5777 Also don't do this if we can probably update x directly. */
5778 rtx equiv = (MEM_P (XEXP (x, 0))
5779 ? XEXP (x, 0)
5780 : reg_equiv_mem[regno]);
5781 int icode = (int) optab_handler (add_optab, Pmode)->insn_code;
5782 if (insn && NONJUMP_INSN_P (insn) && equiv
5783 && memory_operand (equiv, GET_MODE (equiv))
5784 #ifdef HAVE_cc0
5785 && ! sets_cc0_p (PATTERN (insn))
5786 #endif
5787 && ! (icode != CODE_FOR_nothing
5788 && ((*insn_data[icode].operand[0].predicate)
5789 (equiv, Pmode))
5790 && ((*insn_data[icode].operand[1].predicate)
5791 (equiv, Pmode))))
5793 /* We use the original pseudo for loc, so that
5794 emit_reload_insns() knows which pseudo this
5795 reload refers to and updates the pseudo rtx, not
5796 its equivalent memory location, as well as the
5797 corresponding entry in reg_last_reload_reg. */
5798 loc = &XEXP (x_orig, 0);
5799 x = XEXP (x, 0);
5800 reloadnum
5801 = push_reload (x, x, loc, loc,
5802 context_reg_class,
5803 GET_MODE (x), GET_MODE (x), 0, 0,
5804 opnum, RELOAD_OTHER);
5806 else
5808 reloadnum
5809 = push_reload (x, x, loc, (rtx*) 0,
5810 context_reg_class,
5811 GET_MODE (x), GET_MODE (x), 0, 0,
5812 opnum, type);
5813 rld[reloadnum].inc
5814 = find_inc_amount (PATTERN (this_insn), XEXP (x_orig, 0));
5816 value = 1;
5819 update_auto_inc_notes (this_insn, REGNO (XEXP (x_orig, 0)),
5820 reloadnum);
5822 return value;
5824 return 0;
5826 case TRUNCATE:
5827 case SIGN_EXTEND:
5828 case ZERO_EXTEND:
5829 /* Look for parts to reload in the inner expression and reload them
5830 too, in addition to this operation. Reloading all inner parts in
5831 addition to this one shouldn't be necessary, but at this point,
5832 we don't know if we can possibly omit any part that *can* be
5833 reloaded. Targets that are better off reloading just either part
5834 (or perhaps even a different part of an outer expression), should
5835 define LEGITIMIZE_RELOAD_ADDRESS. */
5836 find_reloads_address_1 (GET_MODE (XEXP (x, 0)), XEXP (x, 0),
5837 context, code, SCRATCH, &XEXP (x, 0), opnum,
5838 type, ind_levels, insn);
5839 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5840 context_reg_class,
5841 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5842 return 1;
5844 case MEM:
5845 /* This is probably the result of a substitution, by eliminate_regs, of
5846 an equivalent address for a pseudo that was not allocated to a hard
5847 register. Verify that the specified address is valid and reload it
5848 into a register.
5850 Since we know we are going to reload this item, don't decrement for
5851 the indirection level.
5853 Note that this is actually conservative: it would be slightly more
5854 efficient to use the value of SPILL_INDIRECT_LEVELS from
5855 reload1.c here. */
5857 find_reloads_address (GET_MODE (x), loc, XEXP (x, 0), &XEXP (x, 0),
5858 opnum, ADDR_TYPE (type), ind_levels, insn);
5859 push_reload (*loc, NULL_RTX, loc, (rtx*) 0,
5860 context_reg_class,
5861 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5862 return 1;
5864 case REG:
5866 int regno = REGNO (x);
5868 if (reg_equiv_constant[regno] != 0)
5870 find_reloads_address_part (reg_equiv_constant[regno], loc,
5871 context_reg_class,
5872 GET_MODE (x), opnum, type, ind_levels);
5873 return 1;
5876 #if 0 /* This might screw code in reload1.c to delete prior output-reload
5877 that feeds this insn. */
5878 if (reg_equiv_mem[regno] != 0)
5880 push_reload (reg_equiv_mem[regno], NULL_RTX, loc, (rtx*) 0,
5881 context_reg_class,
5882 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5883 return 1;
5885 #endif
5887 if (reg_equiv_memory_loc[regno]
5888 && (reg_equiv_address[regno] != 0 || num_not_at_initial_offset))
5890 rtx tem = make_memloc (x, regno);
5891 if (reg_equiv_address[regno] != 0
5892 || ! rtx_equal_p (tem, reg_equiv_mem[regno]))
5894 x = tem;
5895 find_reloads_address (GET_MODE (x), &x, XEXP (x, 0),
5896 &XEXP (x, 0), opnum, ADDR_TYPE (type),
5897 ind_levels, insn);
5898 if (!rtx_equal_p (x, tem))
5899 push_reg_equiv_alt_mem (regno, x);
5903 if (reg_renumber[regno] >= 0)
5904 regno = reg_renumber[regno];
5906 if (regno >= FIRST_PSEUDO_REGISTER
5907 || !REG_OK_FOR_CONTEXT (context, regno, mode, outer_code,
5908 index_code))
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 /* If a register appearing in an address is the subject of a CLOBBER
5917 in this insn, reload it into some other register to be safe.
5918 The CLOBBER is supposed to make the register unavailable
5919 from before this insn to after it. */
5920 if (regno_clobbered_p (regno, this_insn, GET_MODE (x), 0))
5922 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5923 context_reg_class,
5924 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5925 return 1;
5928 return 0;
5930 case SUBREG:
5931 if (REG_P (SUBREG_REG (x)))
5933 /* If this is a SUBREG of a hard register and the resulting register
5934 is of the wrong class, reload the whole SUBREG. This avoids
5935 needless copies if SUBREG_REG is multi-word. */
5936 if (REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER)
5938 int regno ATTRIBUTE_UNUSED = subreg_regno (x);
5940 if (!REG_OK_FOR_CONTEXT (context, regno, mode, outer_code,
5941 index_code))
5943 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5944 context_reg_class,
5945 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5946 return 1;
5949 /* If this is a SUBREG of a pseudo-register, and the pseudo-register
5950 is larger than the class size, then reload the whole SUBREG. */
5951 else
5953 enum reg_class rclass = context_reg_class;
5954 if ((unsigned) CLASS_MAX_NREGS (rclass, GET_MODE (SUBREG_REG (x)))
5955 > reg_class_size[rclass])
5957 x = find_reloads_subreg_address (x, 0, opnum,
5958 ADDR_TYPE (type),
5959 ind_levels, insn);
5960 push_reload (x, NULL_RTX, loc, (rtx*) 0, rclass,
5961 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5962 return 1;
5966 break;
5968 default:
5969 break;
5973 const char *fmt = GET_RTX_FORMAT (code);
5974 int i;
5976 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
5978 if (fmt[i] == 'e')
5979 /* Pass SCRATCH for INDEX_CODE, since CODE can never be a PLUS once
5980 we get here. */
5981 find_reloads_address_1 (mode, XEXP (x, i), context, code, SCRATCH,
5982 &XEXP (x, i), opnum, type, ind_levels, insn);
5986 #undef REG_OK_FOR_CONTEXT
5987 return 0;
5990 /* X, which is found at *LOC, is a part of an address that needs to be
5991 reloaded into a register of class RCLASS. If X is a constant, or if
5992 X is a PLUS that contains a constant, check that the constant is a
5993 legitimate operand and that we are supposed to be able to load
5994 it into the register.
5996 If not, force the constant into memory and reload the MEM instead.
5998 MODE is the mode to use, in case X is an integer constant.
6000 OPNUM and TYPE describe the purpose of any reloads made.
6002 IND_LEVELS says how many levels of indirect addressing this machine
6003 supports. */
6005 static void
6006 find_reloads_address_part (rtx x, rtx *loc, enum reg_class rclass,
6007 enum machine_mode mode, int opnum,
6008 enum reload_type type, int ind_levels)
6010 if (CONSTANT_P (x)
6011 && (! LEGITIMATE_CONSTANT_P (x)
6012 || PREFERRED_RELOAD_CLASS (x, rclass) == NO_REGS))
6014 x = force_const_mem (mode, x);
6015 find_reloads_address (mode, &x, XEXP (x, 0), &XEXP (x, 0),
6016 opnum, type, ind_levels, 0);
6019 else if (GET_CODE (x) == PLUS
6020 && CONSTANT_P (XEXP (x, 1))
6021 && (! LEGITIMATE_CONSTANT_P (XEXP (x, 1))
6022 || PREFERRED_RELOAD_CLASS (XEXP (x, 1), rclass) == NO_REGS))
6024 rtx tem;
6026 tem = force_const_mem (GET_MODE (x), XEXP (x, 1));
6027 x = gen_rtx_PLUS (GET_MODE (x), XEXP (x, 0), tem);
6028 find_reloads_address (mode, &XEXP (x, 1), XEXP (tem, 0), &XEXP (tem, 0),
6029 opnum, type, ind_levels, 0);
6032 push_reload (x, NULL_RTX, loc, (rtx*) 0, rclass,
6033 mode, VOIDmode, 0, 0, opnum, type);
6036 /* X, a subreg of a pseudo, is a part of an address that needs to be
6037 reloaded.
6039 If the pseudo is equivalent to a memory location that cannot be directly
6040 addressed, make the necessary address reloads.
6042 If address reloads have been necessary, or if the address is changed
6043 by register elimination, return the rtx of the memory location;
6044 otherwise, return X.
6046 If FORCE_REPLACE is nonzero, unconditionally replace the subreg with the
6047 memory location.
6049 OPNUM and TYPE identify the purpose of the reload.
6051 IND_LEVELS says how many levels of indirect addressing are
6052 supported at this point in the address.
6054 INSN, if nonzero, is the insn in which we do the reload. It is used
6055 to determine where to put USEs for pseudos that we have to replace with
6056 stack slots. */
6058 static rtx
6059 find_reloads_subreg_address (rtx x, int force_replace, int opnum,
6060 enum reload_type type, int ind_levels, rtx insn)
6062 int regno = REGNO (SUBREG_REG (x));
6064 if (reg_equiv_memory_loc[regno])
6066 /* If the address is not directly addressable, or if the address is not
6067 offsettable, then it must be replaced. */
6068 if (! force_replace
6069 && (reg_equiv_address[regno]
6070 || ! offsettable_memref_p (reg_equiv_mem[regno])))
6071 force_replace = 1;
6073 if (force_replace || num_not_at_initial_offset)
6075 rtx tem = make_memloc (SUBREG_REG (x), regno);
6077 /* If the address changes because of register elimination, then
6078 it must be replaced. */
6079 if (force_replace
6080 || ! rtx_equal_p (tem, reg_equiv_mem[regno]))
6082 unsigned outer_size = GET_MODE_SIZE (GET_MODE (x));
6083 unsigned inner_size = GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)));
6084 int offset;
6085 rtx orig = tem;
6086 int reloaded;
6088 /* For big-endian paradoxical subregs, SUBREG_BYTE does not
6089 hold the correct (negative) byte offset. */
6090 if (BYTES_BIG_ENDIAN && outer_size > inner_size)
6091 offset = inner_size - outer_size;
6092 else
6093 offset = SUBREG_BYTE (x);
6095 XEXP (tem, 0) = plus_constant (XEXP (tem, 0), offset);
6096 PUT_MODE (tem, GET_MODE (x));
6097 if (MEM_OFFSET (tem))
6098 set_mem_offset (tem, plus_constant (MEM_OFFSET (tem), offset));
6100 /* If this was a paradoxical subreg that we replaced, the
6101 resulting memory must be sufficiently aligned to allow
6102 us to widen the mode of the memory. */
6103 if (outer_size > inner_size)
6105 rtx base;
6107 base = XEXP (tem, 0);
6108 if (GET_CODE (base) == PLUS)
6110 if (GET_CODE (XEXP (base, 1)) == CONST_INT
6111 && INTVAL (XEXP (base, 1)) % outer_size != 0)
6112 return x;
6113 base = XEXP (base, 0);
6115 if (!REG_P (base)
6116 || (REGNO_POINTER_ALIGN (REGNO (base))
6117 < outer_size * BITS_PER_UNIT))
6118 return x;
6121 reloaded = find_reloads_address (GET_MODE (tem), &tem,
6122 XEXP (tem, 0), &XEXP (tem, 0),
6123 opnum, type, ind_levels, insn);
6124 /* ??? Do we need to handle nonzero offsets somehow? */
6125 if (!offset && !rtx_equal_p (tem, orig))
6126 push_reg_equiv_alt_mem (regno, tem);
6128 /* For some processors an address may be valid in the
6129 original mode but not in a smaller mode. For
6130 example, ARM accepts a scaled index register in
6131 SImode but not in HImode. Similarly, the address may
6132 have been valid before the subreg offset was added,
6133 but not afterwards. find_reloads_address
6134 assumes that we pass it a valid address, and doesn't
6135 force a reload. This will probably be fine if
6136 find_reloads_address finds some reloads. But if it
6137 doesn't find any, then we may have just converted a
6138 valid address into an invalid one. Check for that
6139 here. */
6140 if (reloaded == 0
6141 && !strict_memory_address_p (GET_MODE (tem),
6142 XEXP (tem, 0)))
6143 push_reload (XEXP (tem, 0), NULL_RTX, &XEXP (tem, 0), (rtx*) 0,
6144 base_reg_class (GET_MODE (tem), MEM, SCRATCH),
6145 GET_MODE (XEXP (tem, 0)), VOIDmode, 0, 0,
6146 opnum, type);
6148 /* If this is not a toplevel operand, find_reloads doesn't see
6149 this substitution. We have to emit a USE of the pseudo so
6150 that delete_output_reload can see it. */
6151 if (replace_reloads && recog_data.operand[opnum] != x)
6152 /* We mark the USE with QImode so that we recognize it
6153 as one that can be safely deleted at the end of
6154 reload. */
6155 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode,
6156 SUBREG_REG (x)),
6157 insn), QImode);
6158 x = tem;
6162 return x;
6165 /* Substitute into the current INSN the registers into which we have reloaded
6166 the things that need reloading. The array `replacements'
6167 contains the locations of all pointers that must be changed
6168 and says what to replace them with.
6170 Return the rtx that X translates into; usually X, but modified. */
6172 void
6173 subst_reloads (rtx insn)
6175 int i;
6177 for (i = 0; i < n_replacements; i++)
6179 struct replacement *r = &replacements[i];
6180 rtx reloadreg = rld[r->what].reg_rtx;
6181 if (reloadreg)
6183 #ifdef DEBUG_RELOAD
6184 /* This checking takes a very long time on some platforms
6185 causing the gcc.c-torture/compile/limits-fnargs.c test
6186 to time out during testing. See PR 31850.
6188 Internal consistency test. Check that we don't modify
6189 anything in the equivalence arrays. Whenever something from
6190 those arrays needs to be reloaded, it must be unshared before
6191 being substituted into; the equivalence must not be modified.
6192 Otherwise, if the equivalence is used after that, it will
6193 have been modified, and the thing substituted (probably a
6194 register) is likely overwritten and not a usable equivalence. */
6195 int check_regno;
6197 for (check_regno = 0; check_regno < max_regno; check_regno++)
6199 #define CHECK_MODF(ARRAY) \
6200 gcc_assert (!ARRAY[check_regno] \
6201 || !loc_mentioned_in_p (r->where, \
6202 ARRAY[check_regno]))
6204 CHECK_MODF (reg_equiv_constant);
6205 CHECK_MODF (reg_equiv_memory_loc);
6206 CHECK_MODF (reg_equiv_address);
6207 CHECK_MODF (reg_equiv_mem);
6208 #undef CHECK_MODF
6210 #endif /* DEBUG_RELOAD */
6212 /* If we're replacing a LABEL_REF with a register, there must
6213 already be an indication (to e.g. flow) which label this
6214 register refers to. */
6215 gcc_assert (GET_CODE (*r->where) != LABEL_REF
6216 || !JUMP_P (insn)
6217 || find_reg_note (insn,
6218 REG_LABEL_OPERAND,
6219 XEXP (*r->where, 0))
6220 || label_is_jump_target_p (XEXP (*r->where, 0), insn));
6222 /* Encapsulate RELOADREG so its machine mode matches what
6223 used to be there. Note that gen_lowpart_common will
6224 do the wrong thing if RELOADREG is multi-word. RELOADREG
6225 will always be a REG here. */
6226 if (GET_MODE (reloadreg) != r->mode && r->mode != VOIDmode)
6227 reloadreg = reload_adjust_reg_for_mode (reloadreg, r->mode);
6229 /* If we are putting this into a SUBREG and RELOADREG is a
6230 SUBREG, we would be making nested SUBREGs, so we have to fix
6231 this up. Note that r->where == &SUBREG_REG (*r->subreg_loc). */
6233 if (r->subreg_loc != 0 && GET_CODE (reloadreg) == SUBREG)
6235 if (GET_MODE (*r->subreg_loc)
6236 == GET_MODE (SUBREG_REG (reloadreg)))
6237 *r->subreg_loc = SUBREG_REG (reloadreg);
6238 else
6240 int final_offset =
6241 SUBREG_BYTE (*r->subreg_loc) + SUBREG_BYTE (reloadreg);
6243 /* When working with SUBREGs the rule is that the byte
6244 offset must be a multiple of the SUBREG's mode. */
6245 final_offset = (final_offset /
6246 GET_MODE_SIZE (GET_MODE (*r->subreg_loc)));
6247 final_offset = (final_offset *
6248 GET_MODE_SIZE (GET_MODE (*r->subreg_loc)));
6250 *r->where = SUBREG_REG (reloadreg);
6251 SUBREG_BYTE (*r->subreg_loc) = final_offset;
6254 else
6255 *r->where = reloadreg;
6257 /* If reload got no reg and isn't optional, something's wrong. */
6258 else
6259 gcc_assert (rld[r->what].optional);
6263 /* Make a copy of any replacements being done into X and move those
6264 copies to locations in Y, a copy of X. */
6266 void
6267 copy_replacements (rtx x, rtx y)
6269 /* We can't support X being a SUBREG because we might then need to know its
6270 location if something inside it was replaced. */
6271 gcc_assert (GET_CODE (x) != SUBREG);
6273 copy_replacements_1 (&x, &y, n_replacements);
6276 static void
6277 copy_replacements_1 (rtx *px, rtx *py, int orig_replacements)
6279 int i, j;
6280 rtx x, y;
6281 struct replacement *r;
6282 enum rtx_code code;
6283 const char *fmt;
6285 for (j = 0; j < orig_replacements; j++)
6287 if (replacements[j].subreg_loc == px)
6289 r = &replacements[n_replacements++];
6290 r->where = replacements[j].where;
6291 r->subreg_loc = py;
6292 r->what = replacements[j].what;
6293 r->mode = replacements[j].mode;
6295 else if (replacements[j].where == px)
6297 r = &replacements[n_replacements++];
6298 r->where = py;
6299 r->subreg_loc = 0;
6300 r->what = replacements[j].what;
6301 r->mode = replacements[j].mode;
6305 x = *px;
6306 y = *py;
6307 code = GET_CODE (x);
6308 fmt = GET_RTX_FORMAT (code);
6310 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
6312 if (fmt[i] == 'e')
6313 copy_replacements_1 (&XEXP (x, i), &XEXP (y, i), orig_replacements);
6314 else if (fmt[i] == 'E')
6315 for (j = XVECLEN (x, i); --j >= 0; )
6316 copy_replacements_1 (&XVECEXP (x, i, j), &XVECEXP (y, i, j),
6317 orig_replacements);
6321 /* Change any replacements being done to *X to be done to *Y. */
6323 void
6324 move_replacements (rtx *x, rtx *y)
6326 int i;
6328 for (i = 0; i < n_replacements; i++)
6329 if (replacements[i].subreg_loc == x)
6330 replacements[i].subreg_loc = y;
6331 else if (replacements[i].where == x)
6333 replacements[i].where = y;
6334 replacements[i].subreg_loc = 0;
6338 /* If LOC was scheduled to be replaced by something, return the replacement.
6339 Otherwise, return *LOC. */
6342 find_replacement (rtx *loc)
6344 struct replacement *r;
6346 for (r = &replacements[0]; r < &replacements[n_replacements]; r++)
6348 rtx reloadreg = rld[r->what].reg_rtx;
6350 if (reloadreg && r->where == loc)
6352 if (r->mode != VOIDmode && GET_MODE (reloadreg) != r->mode)
6353 reloadreg = gen_rtx_REG (r->mode, REGNO (reloadreg));
6355 return reloadreg;
6357 else if (reloadreg && r->subreg_loc == loc)
6359 /* RELOADREG must be either a REG or a SUBREG.
6361 ??? Is it actually still ever a SUBREG? If so, why? */
6363 if (REG_P (reloadreg))
6364 return gen_rtx_REG (GET_MODE (*loc),
6365 (REGNO (reloadreg) +
6366 subreg_regno_offset (REGNO (SUBREG_REG (*loc)),
6367 GET_MODE (SUBREG_REG (*loc)),
6368 SUBREG_BYTE (*loc),
6369 GET_MODE (*loc))));
6370 else if (GET_MODE (reloadreg) == GET_MODE (*loc))
6371 return reloadreg;
6372 else
6374 int final_offset = SUBREG_BYTE (reloadreg) + SUBREG_BYTE (*loc);
6376 /* When working with SUBREGs the rule is that the byte
6377 offset must be a multiple of the SUBREG's mode. */
6378 final_offset = (final_offset / GET_MODE_SIZE (GET_MODE (*loc)));
6379 final_offset = (final_offset * GET_MODE_SIZE (GET_MODE (*loc)));
6380 return gen_rtx_SUBREG (GET_MODE (*loc), SUBREG_REG (reloadreg),
6381 final_offset);
6386 /* If *LOC is a PLUS, MINUS, or MULT, see if a replacement is scheduled for
6387 what's inside and make a new rtl if so. */
6388 if (GET_CODE (*loc) == PLUS || GET_CODE (*loc) == MINUS
6389 || GET_CODE (*loc) == MULT)
6391 rtx x = find_replacement (&XEXP (*loc, 0));
6392 rtx y = find_replacement (&XEXP (*loc, 1));
6394 if (x != XEXP (*loc, 0) || y != XEXP (*loc, 1))
6395 return gen_rtx_fmt_ee (GET_CODE (*loc), GET_MODE (*loc), x, y);
6398 return *loc;
6401 /* Return nonzero if register in range [REGNO, ENDREGNO)
6402 appears either explicitly or implicitly in X
6403 other than being stored into (except for earlyclobber operands).
6405 References contained within the substructure at LOC do not count.
6406 LOC may be zero, meaning don't ignore anything.
6408 This is similar to refers_to_regno_p in rtlanal.c except that we
6409 look at equivalences for pseudos that didn't get hard registers. */
6411 static int
6412 refers_to_regno_for_reload_p (unsigned int regno, unsigned int endregno,
6413 rtx x, rtx *loc)
6415 int i;
6416 unsigned int r;
6417 RTX_CODE code;
6418 const char *fmt;
6420 if (x == 0)
6421 return 0;
6423 repeat:
6424 code = GET_CODE (x);
6426 switch (code)
6428 case REG:
6429 r = REGNO (x);
6431 /* If this is a pseudo, a hard register must not have been allocated.
6432 X must therefore either be a constant or be in memory. */
6433 if (r >= FIRST_PSEUDO_REGISTER)
6435 if (reg_equiv_memory_loc[r])
6436 return refers_to_regno_for_reload_p (regno, endregno,
6437 reg_equiv_memory_loc[r],
6438 (rtx*) 0);
6440 gcc_assert (reg_equiv_constant[r] || reg_equiv_invariant[r]);
6441 return 0;
6444 return (endregno > r
6445 && regno < r + (r < FIRST_PSEUDO_REGISTER
6446 ? hard_regno_nregs[r][GET_MODE (x)]
6447 : 1));
6449 case SUBREG:
6450 /* If this is a SUBREG of a hard reg, we can see exactly which
6451 registers are being modified. Otherwise, handle normally. */
6452 if (REG_P (SUBREG_REG (x))
6453 && REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER)
6455 unsigned int inner_regno = subreg_regno (x);
6456 unsigned int inner_endregno
6457 = inner_regno + (inner_regno < FIRST_PSEUDO_REGISTER
6458 ? subreg_nregs (x) : 1);
6460 return endregno > inner_regno && regno < inner_endregno;
6462 break;
6464 case CLOBBER:
6465 case SET:
6466 if (&SET_DEST (x) != loc
6467 /* Note setting a SUBREG counts as referring to the REG it is in for
6468 a pseudo but not for hard registers since we can
6469 treat each word individually. */
6470 && ((GET_CODE (SET_DEST (x)) == SUBREG
6471 && loc != &SUBREG_REG (SET_DEST (x))
6472 && REG_P (SUBREG_REG (SET_DEST (x)))
6473 && REGNO (SUBREG_REG (SET_DEST (x))) >= FIRST_PSEUDO_REGISTER
6474 && refers_to_regno_for_reload_p (regno, endregno,
6475 SUBREG_REG (SET_DEST (x)),
6476 loc))
6477 /* If the output is an earlyclobber operand, this is
6478 a conflict. */
6479 || ((!REG_P (SET_DEST (x))
6480 || earlyclobber_operand_p (SET_DEST (x)))
6481 && refers_to_regno_for_reload_p (regno, endregno,
6482 SET_DEST (x), loc))))
6483 return 1;
6485 if (code == CLOBBER || loc == &SET_SRC (x))
6486 return 0;
6487 x = SET_SRC (x);
6488 goto repeat;
6490 default:
6491 break;
6494 /* X does not match, so try its subexpressions. */
6496 fmt = GET_RTX_FORMAT (code);
6497 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
6499 if (fmt[i] == 'e' && loc != &XEXP (x, i))
6501 if (i == 0)
6503 x = XEXP (x, 0);
6504 goto repeat;
6506 else
6507 if (refers_to_regno_for_reload_p (regno, endregno,
6508 XEXP (x, i), loc))
6509 return 1;
6511 else if (fmt[i] == 'E')
6513 int j;
6514 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
6515 if (loc != &XVECEXP (x, i, j)
6516 && refers_to_regno_for_reload_p (regno, endregno,
6517 XVECEXP (x, i, j), loc))
6518 return 1;
6521 return 0;
6524 /* Nonzero if modifying X will affect IN. If X is a register or a SUBREG,
6525 we check if any register number in X conflicts with the relevant register
6526 numbers. If X is a constant, return 0. If X is a MEM, return 1 iff IN
6527 contains a MEM (we don't bother checking for memory addresses that can't
6528 conflict because we expect this to be a rare case.
6530 This function is similar to reg_overlap_mentioned_p in rtlanal.c except
6531 that we look at equivalences for pseudos that didn't get hard registers. */
6534 reg_overlap_mentioned_for_reload_p (rtx x, rtx in)
6536 int regno, endregno;
6538 /* Overly conservative. */
6539 if (GET_CODE (x) == STRICT_LOW_PART
6540 || GET_RTX_CLASS (GET_CODE (x)) == RTX_AUTOINC)
6541 x = XEXP (x, 0);
6543 /* If either argument is a constant, then modifying X can not affect IN. */
6544 if (CONSTANT_P (x) || CONSTANT_P (in))
6545 return 0;
6546 else if (GET_CODE (x) == SUBREG && GET_CODE (SUBREG_REG (x)) == MEM)
6547 return refers_to_mem_for_reload_p (in);
6548 else if (GET_CODE (x) == SUBREG)
6550 regno = REGNO (SUBREG_REG (x));
6551 if (regno < FIRST_PSEUDO_REGISTER)
6552 regno += subreg_regno_offset (REGNO (SUBREG_REG (x)),
6553 GET_MODE (SUBREG_REG (x)),
6554 SUBREG_BYTE (x),
6555 GET_MODE (x));
6556 endregno = regno + (regno < FIRST_PSEUDO_REGISTER
6557 ? subreg_nregs (x) : 1);
6559 return refers_to_regno_for_reload_p (regno, endregno, in, (rtx*) 0);
6561 else if (REG_P (x))
6563 regno = REGNO (x);
6565 /* If this is a pseudo, it must not have been assigned a hard register.
6566 Therefore, it must either be in memory or be a constant. */
6568 if (regno >= FIRST_PSEUDO_REGISTER)
6570 if (reg_equiv_memory_loc[regno])
6571 return refers_to_mem_for_reload_p (in);
6572 gcc_assert (reg_equiv_constant[regno]);
6573 return 0;
6576 endregno = END_HARD_REGNO (x);
6578 return refers_to_regno_for_reload_p (regno, endregno, in, (rtx*) 0);
6580 else if (MEM_P (x))
6581 return refers_to_mem_for_reload_p (in);
6582 else if (GET_CODE (x) == SCRATCH || GET_CODE (x) == PC
6583 || GET_CODE (x) == CC0)
6584 return reg_mentioned_p (x, in);
6585 else
6587 gcc_assert (GET_CODE (x) == PLUS);
6589 /* We actually want to know if X is mentioned somewhere inside IN.
6590 We must not say that (plus (sp) (const_int 124)) is in
6591 (plus (sp) (const_int 64)), since that can lead to incorrect reload
6592 allocation when spuriously changing a RELOAD_FOR_OUTPUT_ADDRESS
6593 into a RELOAD_OTHER on behalf of another RELOAD_OTHER. */
6594 while (MEM_P (in))
6595 in = XEXP (in, 0);
6596 if (REG_P (in))
6597 return 0;
6598 else if (GET_CODE (in) == PLUS)
6599 return (rtx_equal_p (x, in)
6600 || reg_overlap_mentioned_for_reload_p (x, XEXP (in, 0))
6601 || reg_overlap_mentioned_for_reload_p (x, XEXP (in, 1)));
6602 else return (reg_overlap_mentioned_for_reload_p (XEXP (x, 0), in)
6603 || reg_overlap_mentioned_for_reload_p (XEXP (x, 1), in));
6606 gcc_unreachable ();
6609 /* Return nonzero if anything in X contains a MEM. Look also for pseudo
6610 registers. */
6612 static int
6613 refers_to_mem_for_reload_p (rtx x)
6615 const char *fmt;
6616 int i;
6618 if (MEM_P (x))
6619 return 1;
6621 if (REG_P (x))
6622 return (REGNO (x) >= FIRST_PSEUDO_REGISTER
6623 && reg_equiv_memory_loc[REGNO (x)]);
6625 fmt = GET_RTX_FORMAT (GET_CODE (x));
6626 for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--)
6627 if (fmt[i] == 'e'
6628 && (MEM_P (XEXP (x, i))
6629 || refers_to_mem_for_reload_p (XEXP (x, i))))
6630 return 1;
6632 return 0;
6635 /* Check the insns before INSN to see if there is a suitable register
6636 containing the same value as GOAL.
6637 If OTHER is -1, look for a register in class RCLASS.
6638 Otherwise, just see if register number OTHER shares GOAL's value.
6640 Return an rtx for the register found, or zero if none is found.
6642 If RELOAD_REG_P is (short *)1,
6643 we reject any hard reg that appears in reload_reg_rtx
6644 because such a hard reg is also needed coming into this insn.
6646 If RELOAD_REG_P is any other nonzero value,
6647 it is a vector indexed by hard reg number
6648 and we reject any hard reg whose element in the vector is nonnegative
6649 as well as any that appears in reload_reg_rtx.
6651 If GOAL is zero, then GOALREG is a register number; we look
6652 for an equivalent for that register.
6654 MODE is the machine mode of the value we want an equivalence for.
6655 If GOAL is nonzero and not VOIDmode, then it must have mode MODE.
6657 This function is used by jump.c as well as in the reload pass.
6659 If GOAL is the sum of the stack pointer and a constant, we treat it
6660 as if it were a constant except that sp is required to be unchanging. */
6663 find_equiv_reg (rtx goal, rtx insn, enum reg_class rclass, int other,
6664 short *reload_reg_p, int goalreg, enum machine_mode mode)
6666 rtx p = insn;
6667 rtx goaltry, valtry, value, where;
6668 rtx pat;
6669 int regno = -1;
6670 int valueno;
6671 int goal_mem = 0;
6672 int goal_const = 0;
6673 int goal_mem_addr_varies = 0;
6674 int need_stable_sp = 0;
6675 int nregs;
6676 int valuenregs;
6677 int num = 0;
6679 if (goal == 0)
6680 regno = goalreg;
6681 else if (REG_P (goal))
6682 regno = REGNO (goal);
6683 else if (MEM_P (goal))
6685 enum rtx_code code = GET_CODE (XEXP (goal, 0));
6686 if (MEM_VOLATILE_P (goal))
6687 return 0;
6688 if (flag_float_store && SCALAR_FLOAT_MODE_P (GET_MODE (goal)))
6689 return 0;
6690 /* An address with side effects must be reexecuted. */
6691 switch (code)
6693 case POST_INC:
6694 case PRE_INC:
6695 case POST_DEC:
6696 case PRE_DEC:
6697 case POST_MODIFY:
6698 case PRE_MODIFY:
6699 return 0;
6700 default:
6701 break;
6703 goal_mem = 1;
6705 else if (CONSTANT_P (goal))
6706 goal_const = 1;
6707 else if (GET_CODE (goal) == PLUS
6708 && XEXP (goal, 0) == stack_pointer_rtx
6709 && CONSTANT_P (XEXP (goal, 1)))
6710 goal_const = need_stable_sp = 1;
6711 else if (GET_CODE (goal) == PLUS
6712 && XEXP (goal, 0) == frame_pointer_rtx
6713 && CONSTANT_P (XEXP (goal, 1)))
6714 goal_const = 1;
6715 else
6716 return 0;
6718 num = 0;
6719 /* Scan insns back from INSN, looking for one that copies
6720 a value into or out of GOAL.
6721 Stop and give up if we reach a label. */
6723 while (1)
6725 p = PREV_INSN (p);
6726 num++;
6727 if (p == 0 || LABEL_P (p)
6728 || num > PARAM_VALUE (PARAM_MAX_RELOAD_SEARCH_INSNS))
6729 return 0;
6731 if (NONJUMP_INSN_P (p)
6732 /* If we don't want spill regs ... */
6733 && (! (reload_reg_p != 0
6734 && reload_reg_p != (short *) (HOST_WIDE_INT) 1)
6735 /* ... then ignore insns introduced by reload; they aren't
6736 useful and can cause results in reload_as_needed to be
6737 different from what they were when calculating the need for
6738 spills. If we notice an input-reload insn here, we will
6739 reject it below, but it might hide a usable equivalent.
6740 That makes bad code. It may even fail: perhaps no reg was
6741 spilled for this insn because it was assumed we would find
6742 that equivalent. */
6743 || INSN_UID (p) < reload_first_uid))
6745 rtx tem;
6746 pat = single_set (p);
6748 /* First check for something that sets some reg equal to GOAL. */
6749 if (pat != 0
6750 && ((regno >= 0
6751 && true_regnum (SET_SRC (pat)) == regno
6752 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0)
6754 (regno >= 0
6755 && true_regnum (SET_DEST (pat)) == regno
6756 && (valueno = true_regnum (valtry = SET_SRC (pat))) >= 0)
6758 (goal_const && rtx_equal_p (SET_SRC (pat), goal)
6759 /* When looking for stack pointer + const,
6760 make sure we don't use a stack adjust. */
6761 && !reg_overlap_mentioned_for_reload_p (SET_DEST (pat), goal)
6762 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0)
6763 || (goal_mem
6764 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0
6765 && rtx_renumbered_equal_p (goal, SET_SRC (pat)))
6766 || (goal_mem
6767 && (valueno = true_regnum (valtry = SET_SRC (pat))) >= 0
6768 && rtx_renumbered_equal_p (goal, SET_DEST (pat)))
6769 /* If we are looking for a constant,
6770 and something equivalent to that constant was copied
6771 into a reg, we can use that reg. */
6772 || (goal_const && REG_NOTES (p) != 0
6773 && (tem = find_reg_note (p, REG_EQUIV, NULL_RTX))
6774 && ((rtx_equal_p (XEXP (tem, 0), goal)
6775 && (valueno
6776 = true_regnum (valtry = SET_DEST (pat))) >= 0)
6777 || (REG_P (SET_DEST (pat))
6778 && GET_CODE (XEXP (tem, 0)) == CONST_DOUBLE
6779 && SCALAR_FLOAT_MODE_P (GET_MODE (XEXP (tem, 0)))
6780 && GET_CODE (goal) == CONST_INT
6781 && 0 != (goaltry
6782 = operand_subword (XEXP (tem, 0), 0, 0,
6783 VOIDmode))
6784 && rtx_equal_p (goal, goaltry)
6785 && (valtry
6786 = operand_subword (SET_DEST (pat), 0, 0,
6787 VOIDmode))
6788 && (valueno = true_regnum (valtry)) >= 0)))
6789 || (goal_const && (tem = find_reg_note (p, REG_EQUIV,
6790 NULL_RTX))
6791 && REG_P (SET_DEST (pat))
6792 && GET_CODE (XEXP (tem, 0)) == CONST_DOUBLE
6793 && SCALAR_FLOAT_MODE_P (GET_MODE (XEXP (tem, 0)))
6794 && GET_CODE (goal) == CONST_INT
6795 && 0 != (goaltry = operand_subword (XEXP (tem, 0), 1, 0,
6796 VOIDmode))
6797 && rtx_equal_p (goal, goaltry)
6798 && (valtry
6799 = operand_subword (SET_DEST (pat), 1, 0, VOIDmode))
6800 && (valueno = true_regnum (valtry)) >= 0)))
6802 if (other >= 0)
6804 if (valueno != other)
6805 continue;
6807 else if ((unsigned) valueno >= FIRST_PSEUDO_REGISTER)
6808 continue;
6809 else if (!in_hard_reg_set_p (reg_class_contents[(int) rclass],
6810 mode, valueno))
6811 continue;
6812 value = valtry;
6813 where = p;
6814 break;
6819 /* We found a previous insn copying GOAL into a suitable other reg VALUE
6820 (or copying VALUE into GOAL, if GOAL is also a register).
6821 Now verify that VALUE is really valid. */
6823 /* VALUENO is the register number of VALUE; a hard register. */
6825 /* Don't try to re-use something that is killed in this insn. We want
6826 to be able to trust REG_UNUSED notes. */
6827 if (REG_NOTES (where) != 0 && find_reg_note (where, REG_UNUSED, value))
6828 return 0;
6830 /* If we propose to get the value from the stack pointer or if GOAL is
6831 a MEM based on the stack pointer, we need a stable SP. */
6832 if (valueno == STACK_POINTER_REGNUM || regno == STACK_POINTER_REGNUM
6833 || (goal_mem && reg_overlap_mentioned_for_reload_p (stack_pointer_rtx,
6834 goal)))
6835 need_stable_sp = 1;
6837 /* Reject VALUE if the copy-insn moved the wrong sort of datum. */
6838 if (GET_MODE (value) != mode)
6839 return 0;
6841 /* Reject VALUE if it was loaded from GOAL
6842 and is also a register that appears in the address of GOAL. */
6844 if (goal_mem && value == SET_DEST (single_set (where))
6845 && refers_to_regno_for_reload_p (valueno, end_hard_regno (mode, valueno),
6846 goal, (rtx*) 0))
6847 return 0;
6849 /* Reject registers that overlap GOAL. */
6851 if (regno >= 0 && regno < FIRST_PSEUDO_REGISTER)
6852 nregs = hard_regno_nregs[regno][mode];
6853 else
6854 nregs = 1;
6855 valuenregs = hard_regno_nregs[valueno][mode];
6857 if (!goal_mem && !goal_const
6858 && regno + nregs > valueno && regno < valueno + valuenregs)
6859 return 0;
6861 /* Reject VALUE if it is one of the regs reserved for reloads.
6862 Reload1 knows how to reuse them anyway, and it would get
6863 confused if we allocated one without its knowledge.
6864 (Now that insns introduced by reload are ignored above,
6865 this case shouldn't happen, but I'm not positive.) */
6867 if (reload_reg_p != 0 && reload_reg_p != (short *) (HOST_WIDE_INT) 1)
6869 int i;
6870 for (i = 0; i < valuenregs; ++i)
6871 if (reload_reg_p[valueno + i] >= 0)
6872 return 0;
6875 /* Reject VALUE if it is a register being used for an input reload
6876 even if it is not one of those reserved. */
6878 if (reload_reg_p != 0)
6880 int i;
6881 for (i = 0; i < n_reloads; i++)
6882 if (rld[i].reg_rtx != 0 && rld[i].in)
6884 int regno1 = REGNO (rld[i].reg_rtx);
6885 int nregs1 = hard_regno_nregs[regno1]
6886 [GET_MODE (rld[i].reg_rtx)];
6887 if (regno1 < valueno + valuenregs
6888 && regno1 + nregs1 > valueno)
6889 return 0;
6893 if (goal_mem)
6894 /* We must treat frame pointer as varying here,
6895 since it can vary--in a nonlocal goto as generated by expand_goto. */
6896 goal_mem_addr_varies = !CONSTANT_ADDRESS_P (XEXP (goal, 0));
6898 /* Now verify that the values of GOAL and VALUE remain unaltered
6899 until INSN is reached. */
6901 p = insn;
6902 while (1)
6904 p = PREV_INSN (p);
6905 if (p == where)
6906 return value;
6908 /* Don't trust the conversion past a function call
6909 if either of the two is in a call-clobbered register, or memory. */
6910 if (CALL_P (p))
6912 int i;
6914 if (goal_mem || need_stable_sp)
6915 return 0;
6917 if (regno >= 0 && regno < FIRST_PSEUDO_REGISTER)
6918 for (i = 0; i < nregs; ++i)
6919 if (call_used_regs[regno + i]
6920 || HARD_REGNO_CALL_PART_CLOBBERED (regno + i, mode))
6921 return 0;
6923 if (valueno >= 0 && valueno < FIRST_PSEUDO_REGISTER)
6924 for (i = 0; i < valuenregs; ++i)
6925 if (call_used_regs[valueno + i]
6926 || HARD_REGNO_CALL_PART_CLOBBERED (valueno + i, mode))
6927 return 0;
6930 if (INSN_P (p))
6932 pat = PATTERN (p);
6934 /* Watch out for unspec_volatile, and volatile asms. */
6935 if (volatile_insn_p (pat))
6936 return 0;
6938 /* If this insn P stores in either GOAL or VALUE, return 0.
6939 If GOAL is a memory ref and this insn writes memory, return 0.
6940 If GOAL is a memory ref and its address is not constant,
6941 and this insn P changes a register used in GOAL, return 0. */
6943 if (GET_CODE (pat) == COND_EXEC)
6944 pat = COND_EXEC_CODE (pat);
6945 if (GET_CODE (pat) == SET || GET_CODE (pat) == CLOBBER)
6947 rtx dest = SET_DEST (pat);
6948 while (GET_CODE (dest) == SUBREG
6949 || GET_CODE (dest) == ZERO_EXTRACT
6950 || GET_CODE (dest) == STRICT_LOW_PART)
6951 dest = XEXP (dest, 0);
6952 if (REG_P (dest))
6954 int xregno = REGNO (dest);
6955 int xnregs;
6956 if (REGNO (dest) < FIRST_PSEUDO_REGISTER)
6957 xnregs = hard_regno_nregs[xregno][GET_MODE (dest)];
6958 else
6959 xnregs = 1;
6960 if (xregno < regno + nregs && xregno + xnregs > regno)
6961 return 0;
6962 if (xregno < valueno + valuenregs
6963 && xregno + xnregs > valueno)
6964 return 0;
6965 if (goal_mem_addr_varies
6966 && reg_overlap_mentioned_for_reload_p (dest, goal))
6967 return 0;
6968 if (xregno == STACK_POINTER_REGNUM && need_stable_sp)
6969 return 0;
6971 else if (goal_mem && MEM_P (dest)
6972 && ! push_operand (dest, GET_MODE (dest)))
6973 return 0;
6974 else if (MEM_P (dest) && regno >= FIRST_PSEUDO_REGISTER
6975 && reg_equiv_memory_loc[regno] != 0)
6976 return 0;
6977 else if (need_stable_sp && push_operand (dest, GET_MODE (dest)))
6978 return 0;
6980 else if (GET_CODE (pat) == PARALLEL)
6982 int i;
6983 for (i = XVECLEN (pat, 0) - 1; i >= 0; i--)
6985 rtx v1 = XVECEXP (pat, 0, i);
6986 if (GET_CODE (v1) == COND_EXEC)
6987 v1 = COND_EXEC_CODE (v1);
6988 if (GET_CODE (v1) == SET || GET_CODE (v1) == CLOBBER)
6990 rtx dest = SET_DEST (v1);
6991 while (GET_CODE (dest) == SUBREG
6992 || GET_CODE (dest) == ZERO_EXTRACT
6993 || GET_CODE (dest) == STRICT_LOW_PART)
6994 dest = XEXP (dest, 0);
6995 if (REG_P (dest))
6997 int xregno = REGNO (dest);
6998 int xnregs;
6999 if (REGNO (dest) < FIRST_PSEUDO_REGISTER)
7000 xnregs = hard_regno_nregs[xregno][GET_MODE (dest)];
7001 else
7002 xnregs = 1;
7003 if (xregno < regno + nregs
7004 && xregno + xnregs > regno)
7005 return 0;
7006 if (xregno < valueno + valuenregs
7007 && xregno + xnregs > valueno)
7008 return 0;
7009 if (goal_mem_addr_varies
7010 && reg_overlap_mentioned_for_reload_p (dest,
7011 goal))
7012 return 0;
7013 if (xregno == STACK_POINTER_REGNUM && need_stable_sp)
7014 return 0;
7016 else if (goal_mem && MEM_P (dest)
7017 && ! push_operand (dest, GET_MODE (dest)))
7018 return 0;
7019 else if (MEM_P (dest) && regno >= FIRST_PSEUDO_REGISTER
7020 && reg_equiv_memory_loc[regno] != 0)
7021 return 0;
7022 else if (need_stable_sp
7023 && push_operand (dest, GET_MODE (dest)))
7024 return 0;
7029 if (CALL_P (p) && CALL_INSN_FUNCTION_USAGE (p))
7031 rtx link;
7033 for (link = CALL_INSN_FUNCTION_USAGE (p); XEXP (link, 1) != 0;
7034 link = XEXP (link, 1))
7036 pat = XEXP (link, 0);
7037 if (GET_CODE (pat) == CLOBBER)
7039 rtx dest = SET_DEST (pat);
7041 if (REG_P (dest))
7043 int xregno = REGNO (dest);
7044 int xnregs
7045 = hard_regno_nregs[xregno][GET_MODE (dest)];
7047 if (xregno < regno + nregs
7048 && xregno + xnregs > regno)
7049 return 0;
7050 else if (xregno < valueno + valuenregs
7051 && xregno + xnregs > valueno)
7052 return 0;
7053 else if (goal_mem_addr_varies
7054 && reg_overlap_mentioned_for_reload_p (dest,
7055 goal))
7056 return 0;
7059 else if (goal_mem && MEM_P (dest)
7060 && ! push_operand (dest, GET_MODE (dest)))
7061 return 0;
7062 else if (need_stable_sp
7063 && push_operand (dest, GET_MODE (dest)))
7064 return 0;
7069 #ifdef AUTO_INC_DEC
7070 /* If this insn auto-increments or auto-decrements
7071 either regno or valueno, return 0 now.
7072 If GOAL is a memory ref and its address is not constant,
7073 and this insn P increments a register used in GOAL, return 0. */
7075 rtx link;
7077 for (link = REG_NOTES (p); link; link = XEXP (link, 1))
7078 if (REG_NOTE_KIND (link) == REG_INC
7079 && REG_P (XEXP (link, 0)))
7081 int incno = REGNO (XEXP (link, 0));
7082 if (incno < regno + nregs && incno >= regno)
7083 return 0;
7084 if (incno < valueno + valuenregs && incno >= valueno)
7085 return 0;
7086 if (goal_mem_addr_varies
7087 && reg_overlap_mentioned_for_reload_p (XEXP (link, 0),
7088 goal))
7089 return 0;
7092 #endif
7097 /* Find a place where INCED appears in an increment or decrement operator
7098 within X, and return the amount INCED is incremented or decremented by.
7099 The value is always positive. */
7101 static int
7102 find_inc_amount (rtx x, rtx inced)
7104 enum rtx_code code = GET_CODE (x);
7105 const char *fmt;
7106 int i;
7108 if (code == MEM)
7110 rtx addr = XEXP (x, 0);
7111 if ((GET_CODE (addr) == PRE_DEC
7112 || GET_CODE (addr) == POST_DEC
7113 || GET_CODE (addr) == PRE_INC
7114 || GET_CODE (addr) == POST_INC)
7115 && XEXP (addr, 0) == inced)
7116 return GET_MODE_SIZE (GET_MODE (x));
7117 else if ((GET_CODE (addr) == PRE_MODIFY
7118 || GET_CODE (addr) == POST_MODIFY)
7119 && GET_CODE (XEXP (addr, 1)) == PLUS
7120 && XEXP (addr, 0) == XEXP (XEXP (addr, 1), 0)
7121 && XEXP (addr, 0) == inced
7122 && GET_CODE (XEXP (XEXP (addr, 1), 1)) == CONST_INT)
7124 i = INTVAL (XEXP (XEXP (addr, 1), 1));
7125 return i < 0 ? -i : i;
7129 fmt = GET_RTX_FORMAT (code);
7130 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
7132 if (fmt[i] == 'e')
7134 int tem = find_inc_amount (XEXP (x, i), inced);
7135 if (tem != 0)
7136 return tem;
7138 if (fmt[i] == 'E')
7140 int j;
7141 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
7143 int tem = find_inc_amount (XVECEXP (x, i, j), inced);
7144 if (tem != 0)
7145 return tem;
7150 return 0;
7153 /* Return 1 if registers from REGNO to ENDREGNO are the subjects of a
7154 REG_INC note in insn INSN. REGNO must refer to a hard register. */
7156 #ifdef AUTO_INC_DEC
7157 static int
7158 reg_inc_found_and_valid_p (unsigned int regno, unsigned int endregno,
7159 rtx insn)
7161 rtx link;
7163 gcc_assert (insn);
7165 if (! INSN_P (insn))
7166 return 0;
7168 for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
7169 if (REG_NOTE_KIND (link) == REG_INC)
7171 unsigned int test = (int) REGNO (XEXP (link, 0));
7172 if (test >= regno && test < endregno)
7173 return 1;
7175 return 0;
7177 #else
7179 #define reg_inc_found_and_valid_p(regno,endregno,insn) 0
7181 #endif
7183 /* Return 1 if register REGNO is the subject of a clobber in insn INSN.
7184 If SETS is 1, also consider SETs. If SETS is 2, enable checking
7185 REG_INC. REGNO must refer to a hard register. */
7188 regno_clobbered_p (unsigned int regno, rtx insn, enum machine_mode mode,
7189 int sets)
7191 unsigned int nregs, endregno;
7193 /* regno must be a hard register. */
7194 gcc_assert (regno < FIRST_PSEUDO_REGISTER);
7196 nregs = hard_regno_nregs[regno][mode];
7197 endregno = regno + nregs;
7199 if ((GET_CODE (PATTERN (insn)) == CLOBBER
7200 || (sets == 1 && GET_CODE (PATTERN (insn)) == SET))
7201 && REG_P (XEXP (PATTERN (insn), 0)))
7203 unsigned int test = REGNO (XEXP (PATTERN (insn), 0));
7205 return test >= regno && test < endregno;
7208 if (sets == 2 && reg_inc_found_and_valid_p (regno, endregno, insn))
7209 return 1;
7211 if (GET_CODE (PATTERN (insn)) == PARALLEL)
7213 int i = XVECLEN (PATTERN (insn), 0) - 1;
7215 for (; i >= 0; i--)
7217 rtx elt = XVECEXP (PATTERN (insn), 0, i);
7218 if ((GET_CODE (elt) == CLOBBER
7219 || (sets == 1 && GET_CODE (PATTERN (insn)) == SET))
7220 && REG_P (XEXP (elt, 0)))
7222 unsigned int test = REGNO (XEXP (elt, 0));
7224 if (test >= regno && test < endregno)
7225 return 1;
7227 if (sets == 2
7228 && reg_inc_found_and_valid_p (regno, endregno, elt))
7229 return 1;
7233 return 0;
7236 /* Find the low part, with mode MODE, of a hard regno RELOADREG. */
7238 reload_adjust_reg_for_mode (rtx reloadreg, enum machine_mode mode)
7240 int regno;
7242 if (GET_MODE (reloadreg) == mode)
7243 return reloadreg;
7245 regno = REGNO (reloadreg);
7247 if (WORDS_BIG_ENDIAN)
7248 regno += (int) hard_regno_nregs[regno][GET_MODE (reloadreg)]
7249 - (int) hard_regno_nregs[regno][mode];
7251 return gen_rtx_REG (mode, regno);
7254 static const char *const reload_when_needed_name[] =
7256 "RELOAD_FOR_INPUT",
7257 "RELOAD_FOR_OUTPUT",
7258 "RELOAD_FOR_INSN",
7259 "RELOAD_FOR_INPUT_ADDRESS",
7260 "RELOAD_FOR_INPADDR_ADDRESS",
7261 "RELOAD_FOR_OUTPUT_ADDRESS",
7262 "RELOAD_FOR_OUTADDR_ADDRESS",
7263 "RELOAD_FOR_OPERAND_ADDRESS",
7264 "RELOAD_FOR_OPADDR_ADDR",
7265 "RELOAD_OTHER",
7266 "RELOAD_FOR_OTHER_ADDRESS"
7269 /* These functions are used to print the variables set by 'find_reloads' */
7271 void
7272 debug_reload_to_stream (FILE *f)
7274 int r;
7275 const char *prefix;
7277 if (! f)
7278 f = stderr;
7279 for (r = 0; r < n_reloads; r++)
7281 fprintf (f, "Reload %d: ", r);
7283 if (rld[r].in != 0)
7285 fprintf (f, "reload_in (%s) = ",
7286 GET_MODE_NAME (rld[r].inmode));
7287 print_inline_rtx (f, rld[r].in, 24);
7288 fprintf (f, "\n\t");
7291 if (rld[r].out != 0)
7293 fprintf (f, "reload_out (%s) = ",
7294 GET_MODE_NAME (rld[r].outmode));
7295 print_inline_rtx (f, rld[r].out, 24);
7296 fprintf (f, "\n\t");
7299 fprintf (f, "%s, ", reg_class_names[(int) rld[r].rclass]);
7301 fprintf (f, "%s (opnum = %d)",
7302 reload_when_needed_name[(int) rld[r].when_needed],
7303 rld[r].opnum);
7305 if (rld[r].optional)
7306 fprintf (f, ", optional");
7308 if (rld[r].nongroup)
7309 fprintf (f, ", nongroup");
7311 if (rld[r].inc != 0)
7312 fprintf (f, ", inc by %d", rld[r].inc);
7314 if (rld[r].nocombine)
7315 fprintf (f, ", can't combine");
7317 if (rld[r].secondary_p)
7318 fprintf (f, ", secondary_reload_p");
7320 if (rld[r].in_reg != 0)
7322 fprintf (f, "\n\treload_in_reg: ");
7323 print_inline_rtx (f, rld[r].in_reg, 24);
7326 if (rld[r].out_reg != 0)
7328 fprintf (f, "\n\treload_out_reg: ");
7329 print_inline_rtx (f, rld[r].out_reg, 24);
7332 if (rld[r].reg_rtx != 0)
7334 fprintf (f, "\n\treload_reg_rtx: ");
7335 print_inline_rtx (f, rld[r].reg_rtx, 24);
7338 prefix = "\n\t";
7339 if (rld[r].secondary_in_reload != -1)
7341 fprintf (f, "%ssecondary_in_reload = %d",
7342 prefix, rld[r].secondary_in_reload);
7343 prefix = ", ";
7346 if (rld[r].secondary_out_reload != -1)
7347 fprintf (f, "%ssecondary_out_reload = %d\n",
7348 prefix, rld[r].secondary_out_reload);
7350 prefix = "\n\t";
7351 if (rld[r].secondary_in_icode != CODE_FOR_nothing)
7353 fprintf (f, "%ssecondary_in_icode = %s", prefix,
7354 insn_data[rld[r].secondary_in_icode].name);
7355 prefix = ", ";
7358 if (rld[r].secondary_out_icode != CODE_FOR_nothing)
7359 fprintf (f, "%ssecondary_out_icode = %s", prefix,
7360 insn_data[rld[r].secondary_out_icode].name);
7362 fprintf (f, "\n");
7366 void
7367 debug_reload (void)
7369 debug_reload_to_stream (stderr);