testsuite: Update scanning symbol sections to support AIX.
[official-gcc.git] / 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) 1987-2020 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
20 /* This file contains subroutines used only from the file reload1.c.
21 It knows how to scan one insn for operands and values
22 that need to be copied into registers to make valid code.
23 It also finds other operands and values which are valid
24 but for which equivalent values in registers exist and
25 ought to be used instead.
27 Before processing the first insn of the function, call `init_reload'.
28 init_reload actually has to be called earlier anyway.
30 To scan an insn, call `find_reloads'. This does two things:
31 1. sets up tables describing which values must be reloaded
32 for this insn, and what kind of hard regs they must be reloaded into;
33 2. optionally record the locations where those values appear in
34 the data, so they can be replaced properly later.
35 This is done only if the second arg to `find_reloads' is nonzero.
37 The third arg to `find_reloads' specifies the number of levels
38 of indirect addressing supported by the machine. If it is zero,
39 indirect addressing is not valid. If it is one, (MEM (REG n))
40 is valid even if (REG n) did not get a hard register; if it is two,
41 (MEM (MEM (REG n))) is also valid even if (REG n) did not get a
42 hard register, and similarly for higher values.
44 Then you must choose the hard regs to reload those pseudo regs into,
45 and generate appropriate load insns before this insn and perhaps
46 also store insns after this insn. Set up the array `reload_reg_rtx'
47 to contain the REG rtx's for the registers you used. In some
48 cases `find_reloads' will return a nonzero value in `reload_reg_rtx'
49 for certain reloads. Then that tells you which register to use,
50 so you do not need to allocate one. But you still do need to add extra
51 instructions to copy the value into and out of that register.
53 Finally you must call `subst_reloads' to substitute the reload reg rtx's
54 into the locations already recorded.
56 NOTE SIDE EFFECTS:
58 find_reloads can alter the operands of the instruction it is called on.
60 1. Two operands of any sort may be interchanged, if they are in a
61 commutative instruction.
62 This happens only if find_reloads thinks the instruction will compile
63 better that way.
65 2. Pseudo-registers that are equivalent to constants are replaced
66 with those constants if they are not in hard registers.
68 1 happens every time find_reloads is called.
69 2 happens only when REPLACE is 1, which is only when
70 actually doing the reloads, not when just counting them.
72 Using a reload register for several reloads in one insn:
74 When an insn has reloads, it is considered as having three parts:
75 the input reloads, the insn itself after reloading, and the output reloads.
76 Reloads of values used in memory addresses are often needed for only one part.
78 When this is so, reload_when_needed records which part needs the reload.
79 Two reloads for different parts of the insn can share the same reload
80 register.
82 When a reload is used for addresses in multiple parts, or when it is
83 an ordinary operand, it is classified as RELOAD_OTHER, and cannot share
84 a register with any other reload. */
86 #define REG_OK_STRICT
88 /* We do not enable this with CHECKING_P, since it is awfully slow. */
89 #undef DEBUG_RELOAD
91 #include "config.h"
92 #include "system.h"
93 #include "coretypes.h"
94 #include "backend.h"
95 #include "target.h"
96 #include "rtl.h"
97 #include "tree.h"
98 #include "df.h"
99 #include "memmodel.h"
100 #include "tm_p.h"
101 #include "optabs.h"
102 #include "regs.h"
103 #include "ira.h"
104 #include "recog.h"
105 #include "rtl-error.h"
106 #include "reload.h"
107 #include "addresses.h"
108 #include "function-abi.h"
110 /* True if X is a constant that can be forced into the constant pool.
111 MODE is the mode of the operand, or VOIDmode if not known. */
112 #define CONST_POOL_OK_P(MODE, X) \
113 ((MODE) != VOIDmode \
114 && CONSTANT_P (X) \
115 && GET_CODE (X) != HIGH \
116 && !targetm.cannot_force_const_mem (MODE, X))
118 /* True if C is a non-empty register class that has too few registers
119 to be safely used as a reload target class. */
121 static inline bool
122 small_register_class_p (reg_class_t rclass)
124 return (reg_class_size [(int) rclass] == 1
125 || (reg_class_size [(int) rclass] >= 1
126 && targetm.class_likely_spilled_p (rclass)));
130 /* All reloads of the current insn are recorded here. See reload.h for
131 comments. */
132 int n_reloads;
133 struct reload rld[MAX_RELOADS];
135 /* All the "earlyclobber" operands of the current insn
136 are recorded here. */
137 int n_earlyclobbers;
138 rtx reload_earlyclobbers[MAX_RECOG_OPERANDS];
140 int reload_n_operands;
142 /* Replacing reloads.
144 If `replace_reloads' is nonzero, then as each reload is recorded
145 an entry is made for it in the table `replacements'.
146 Then later `subst_reloads' can look through that table and
147 perform all the replacements needed. */
149 /* Nonzero means record the places to replace. */
150 static int replace_reloads;
152 /* Each replacement is recorded with a structure like this. */
153 struct replacement
155 rtx *where; /* Location to store in */
156 int what; /* which reload this is for */
157 machine_mode mode; /* mode it must have */
160 static struct replacement replacements[MAX_RECOG_OPERANDS * ((MAX_REGS_PER_ADDRESS * 2) + 1)];
162 /* Number of replacements currently recorded. */
163 static int n_replacements;
165 /* Used to track what is modified by an operand. */
166 struct decomposition
168 int reg_flag; /* Nonzero if referencing a register. */
169 int safe; /* Nonzero if this can't conflict with anything. */
170 rtx base; /* Base address for MEM. */
171 poly_int64_pod start; /* Starting offset or register number. */
172 poly_int64_pod end; /* Ending offset or register number. */
175 /* Save MEMs needed to copy from one class of registers to another. One MEM
176 is used per mode, but normally only one or two modes are ever used.
178 We keep two versions, before and after register elimination. The one
179 after register elimination is record separately for each operand. This
180 is done in case the address is not valid to be sure that we separately
181 reload each. */
183 static rtx secondary_memlocs[NUM_MACHINE_MODES];
184 static rtx secondary_memlocs_elim[NUM_MACHINE_MODES][MAX_RECOG_OPERANDS];
185 static int secondary_memlocs_elim_used = 0;
187 /* The instruction we are doing reloads for;
188 so we can test whether a register dies in it. */
189 static rtx_insn *this_insn;
191 /* Nonzero if this instruction is a user-specified asm with operands. */
192 static int this_insn_is_asm;
194 /* If hard_regs_live_known is nonzero,
195 we can tell which hard regs are currently live,
196 at least enough to succeed in choosing dummy reloads. */
197 static int hard_regs_live_known;
199 /* Indexed by hard reg number,
200 element is nonnegative if hard reg has been spilled.
201 This vector is passed to `find_reloads' as an argument
202 and is not changed here. */
203 static short *static_reload_reg_p;
205 /* Set to 1 in subst_reg_equivs if it changes anything. */
206 static int subst_reg_equivs_changed;
208 /* On return from push_reload, holds the reload-number for the OUT
209 operand, which can be different for that from the input operand. */
210 static int output_reloadnum;
212 /* Compare two RTX's. */
213 #define MATCHES(x, y) \
214 (x == y || (x != 0 && (REG_P (x) \
215 ? REG_P (y) && REGNO (x) == REGNO (y) \
216 : rtx_equal_p (x, y) && ! side_effects_p (x))))
218 /* Indicates if two reloads purposes are for similar enough things that we
219 can merge their reloads. */
220 #define MERGABLE_RELOADS(when1, when2, op1, op2) \
221 ((when1) == RELOAD_OTHER || (when2) == RELOAD_OTHER \
222 || ((when1) == (when2) && (op1) == (op2)) \
223 || ((when1) == RELOAD_FOR_INPUT && (when2) == RELOAD_FOR_INPUT) \
224 || ((when1) == RELOAD_FOR_OPERAND_ADDRESS \
225 && (when2) == RELOAD_FOR_OPERAND_ADDRESS) \
226 || ((when1) == RELOAD_FOR_OTHER_ADDRESS \
227 && (when2) == RELOAD_FOR_OTHER_ADDRESS))
229 /* Nonzero if these two reload purposes produce RELOAD_OTHER when merged. */
230 #define MERGE_TO_OTHER(when1, when2, op1, op2) \
231 ((when1) != (when2) \
232 || ! ((op1) == (op2) \
233 || (when1) == RELOAD_FOR_INPUT \
234 || (when1) == RELOAD_FOR_OPERAND_ADDRESS \
235 || (when1) == RELOAD_FOR_OTHER_ADDRESS))
237 /* If we are going to reload an address, compute the reload type to
238 use. */
239 #define ADDR_TYPE(type) \
240 ((type) == RELOAD_FOR_INPUT_ADDRESS \
241 ? RELOAD_FOR_INPADDR_ADDRESS \
242 : ((type) == RELOAD_FOR_OUTPUT_ADDRESS \
243 ? RELOAD_FOR_OUTADDR_ADDRESS \
244 : (type)))
246 static int push_secondary_reload (int, rtx, int, int, enum reg_class,
247 machine_mode, enum reload_type,
248 enum insn_code *, secondary_reload_info *);
249 static enum reg_class find_valid_class (machine_mode, machine_mode,
250 int, unsigned int);
251 static void push_replacement (rtx *, int, machine_mode);
252 static void dup_replacements (rtx *, rtx *);
253 static void combine_reloads (void);
254 static int find_reusable_reload (rtx *, rtx, enum reg_class,
255 enum reload_type, int, int);
256 static rtx find_dummy_reload (rtx, rtx, rtx *, rtx *, machine_mode,
257 machine_mode, reg_class_t, int, int);
258 static int hard_reg_set_here_p (unsigned int, unsigned int, rtx);
259 static struct decomposition decompose (rtx);
260 static int immune_p (rtx, rtx, struct decomposition);
261 static bool alternative_allows_const_pool_ref (rtx, const char *, int);
262 static rtx find_reloads_toplev (rtx, int, enum reload_type, int, int,
263 rtx_insn *, int *);
264 static rtx make_memloc (rtx, int);
265 static int maybe_memory_address_addr_space_p (machine_mode, rtx,
266 addr_space_t, rtx *);
267 static int find_reloads_address (machine_mode, rtx *, rtx, rtx *,
268 int, enum reload_type, int, rtx_insn *);
269 static rtx subst_reg_equivs (rtx, rtx_insn *);
270 static rtx subst_indexed_address (rtx);
271 static void update_auto_inc_notes (rtx_insn *, int, int);
272 static int find_reloads_address_1 (machine_mode, addr_space_t, rtx, int,
273 enum rtx_code, enum rtx_code, rtx *,
274 int, enum reload_type,int, rtx_insn *);
275 static void find_reloads_address_part (rtx, rtx *, enum reg_class,
276 machine_mode, int,
277 enum reload_type, int);
278 static rtx find_reloads_subreg_address (rtx, int, enum reload_type,
279 int, rtx_insn *, int *);
280 static void copy_replacements_1 (rtx *, rtx *, int);
281 static poly_int64 find_inc_amount (rtx, rtx);
282 static int refers_to_mem_for_reload_p (rtx);
283 static int refers_to_regno_for_reload_p (unsigned int, unsigned int,
284 rtx, rtx *);
286 /* Add NEW to reg_equiv_alt_mem_list[REGNO] if it's not present in the
287 list yet. */
289 static void
290 push_reg_equiv_alt_mem (int regno, rtx mem)
292 rtx it;
294 for (it = reg_equiv_alt_mem_list (regno); it; it = XEXP (it, 1))
295 if (rtx_equal_p (XEXP (it, 0), mem))
296 return;
298 reg_equiv_alt_mem_list (regno)
299 = alloc_EXPR_LIST (REG_EQUIV, mem,
300 reg_equiv_alt_mem_list (regno));
303 /* Determine if any secondary reloads are needed for loading (if IN_P is
304 nonzero) or storing (if IN_P is zero) X to or from a reload register of
305 register class RELOAD_CLASS in mode RELOAD_MODE. If secondary reloads
306 are needed, push them.
308 Return the reload number of the secondary reload we made, or -1 if
309 we didn't need one. *PICODE is set to the insn_code to use if we do
310 need a secondary reload. */
312 static int
313 push_secondary_reload (int in_p, rtx x, int opnum, int optional,
314 enum reg_class reload_class,
315 machine_mode reload_mode, enum reload_type type,
316 enum insn_code *picode, secondary_reload_info *prev_sri)
318 enum reg_class rclass = NO_REGS;
319 enum reg_class scratch_class;
320 machine_mode mode = reload_mode;
321 enum insn_code icode = CODE_FOR_nothing;
322 enum insn_code t_icode = CODE_FOR_nothing;
323 enum reload_type secondary_type;
324 int s_reload, t_reload = -1;
325 const char *scratch_constraint;
326 secondary_reload_info sri;
328 if (type == RELOAD_FOR_INPUT_ADDRESS
329 || type == RELOAD_FOR_OUTPUT_ADDRESS
330 || type == RELOAD_FOR_INPADDR_ADDRESS
331 || type == RELOAD_FOR_OUTADDR_ADDRESS)
332 secondary_type = type;
333 else
334 secondary_type = in_p ? RELOAD_FOR_INPUT_ADDRESS : RELOAD_FOR_OUTPUT_ADDRESS;
336 *picode = CODE_FOR_nothing;
338 /* If X is a paradoxical SUBREG, use the inner value to determine both the
339 mode and object being reloaded. */
340 if (paradoxical_subreg_p (x))
342 x = SUBREG_REG (x);
343 reload_mode = GET_MODE (x);
346 /* If X is a pseudo-register that has an equivalent MEM (actually, if it
347 is still a pseudo-register by now, it *must* have an equivalent MEM
348 but we don't want to assume that), use that equivalent when seeing if
349 a secondary reload is needed since whether or not a reload is needed
350 might be sensitive to the form of the MEM. */
352 if (REG_P (x) && REGNO (x) >= FIRST_PSEUDO_REGISTER
353 && reg_equiv_mem (REGNO (x)))
354 x = reg_equiv_mem (REGNO (x));
356 sri.icode = CODE_FOR_nothing;
357 sri.prev_sri = prev_sri;
358 rclass = (enum reg_class) targetm.secondary_reload (in_p, x, reload_class,
359 reload_mode, &sri);
360 icode = (enum insn_code) sri.icode;
362 /* If we don't need any secondary registers, done. */
363 if (rclass == NO_REGS && icode == CODE_FOR_nothing)
364 return -1;
366 if (rclass != NO_REGS)
367 t_reload = push_secondary_reload (in_p, x, opnum, optional, rclass,
368 reload_mode, type, &t_icode, &sri);
370 /* If we will be using an insn, the secondary reload is for a
371 scratch register. */
373 if (icode != CODE_FOR_nothing)
375 /* If IN_P is nonzero, the reload register will be the output in
376 operand 0. If IN_P is zero, the reload register will be the input
377 in operand 1. Outputs should have an initial "=", which we must
378 skip. */
380 /* ??? It would be useful to be able to handle only two, or more than
381 three, operands, but for now we can only handle the case of having
382 exactly three: output, input and one temp/scratch. */
383 gcc_assert (insn_data[(int) icode].n_operands == 3);
385 /* ??? We currently have no way to represent a reload that needs
386 an icode to reload from an intermediate tertiary reload register.
387 We should probably have a new field in struct reload to tag a
388 chain of scratch operand reloads onto. */
389 gcc_assert (rclass == NO_REGS);
391 scratch_constraint = insn_data[(int) icode].operand[2].constraint;
392 gcc_assert (*scratch_constraint == '=');
393 scratch_constraint++;
394 if (*scratch_constraint == '&')
395 scratch_constraint++;
396 scratch_class = (reg_class_for_constraint
397 (lookup_constraint (scratch_constraint)));
399 rclass = scratch_class;
400 mode = insn_data[(int) icode].operand[2].mode;
403 /* This case isn't valid, so fail. Reload is allowed to use the same
404 register for RELOAD_FOR_INPUT_ADDRESS and RELOAD_FOR_INPUT reloads, but
405 in the case of a secondary register, we actually need two different
406 registers for correct code. We fail here to prevent the possibility of
407 silently generating incorrect code later.
409 The convention is that secondary input reloads are valid only if the
410 secondary_class is different from class. If you have such a case, you
411 cannot use secondary reloads, you must work around the problem some
412 other way.
414 Allow this when a reload_in/out pattern is being used. I.e. assume
415 that the generated code handles this case. */
417 gcc_assert (!in_p || rclass != reload_class || icode != CODE_FOR_nothing
418 || t_icode != CODE_FOR_nothing);
420 /* See if we can reuse an existing secondary reload. */
421 for (s_reload = 0; s_reload < n_reloads; s_reload++)
422 if (rld[s_reload].secondary_p
423 && (reg_class_subset_p (rclass, rld[s_reload].rclass)
424 || reg_class_subset_p (rld[s_reload].rclass, rclass))
425 && ((in_p && rld[s_reload].inmode == mode)
426 || (! in_p && rld[s_reload].outmode == mode))
427 && ((in_p && rld[s_reload].secondary_in_reload == t_reload)
428 || (! in_p && rld[s_reload].secondary_out_reload == t_reload))
429 && ((in_p && rld[s_reload].secondary_in_icode == t_icode)
430 || (! in_p && rld[s_reload].secondary_out_icode == t_icode))
431 && (small_register_class_p (rclass)
432 || targetm.small_register_classes_for_mode_p (VOIDmode))
433 && MERGABLE_RELOADS (secondary_type, rld[s_reload].when_needed,
434 opnum, rld[s_reload].opnum))
436 if (in_p)
437 rld[s_reload].inmode = mode;
438 if (! in_p)
439 rld[s_reload].outmode = mode;
441 if (reg_class_subset_p (rclass, rld[s_reload].rclass))
442 rld[s_reload].rclass = rclass;
444 rld[s_reload].opnum = MIN (rld[s_reload].opnum, opnum);
445 rld[s_reload].optional &= optional;
446 rld[s_reload].secondary_p = 1;
447 if (MERGE_TO_OTHER (secondary_type, rld[s_reload].when_needed,
448 opnum, rld[s_reload].opnum))
449 rld[s_reload].when_needed = RELOAD_OTHER;
451 break;
454 if (s_reload == n_reloads)
456 /* If we need a memory location to copy between the two reload regs,
457 set it up now. Note that we do the input case before making
458 the reload and the output case after. This is due to the
459 way reloads are output. */
461 if (in_p && icode == CODE_FOR_nothing
462 && targetm.secondary_memory_needed (mode, rclass, reload_class))
464 get_secondary_mem (x, reload_mode, opnum, type);
466 /* We may have just added new reloads. Make sure we add
467 the new reload at the end. */
468 s_reload = n_reloads;
471 /* We need to make a new secondary reload for this register class. */
472 rld[s_reload].in = rld[s_reload].out = 0;
473 rld[s_reload].rclass = rclass;
475 rld[s_reload].inmode = in_p ? mode : VOIDmode;
476 rld[s_reload].outmode = ! in_p ? mode : VOIDmode;
477 rld[s_reload].reg_rtx = 0;
478 rld[s_reload].optional = optional;
479 rld[s_reload].inc = 0;
480 /* Maybe we could combine these, but it seems too tricky. */
481 rld[s_reload].nocombine = 1;
482 rld[s_reload].in_reg = 0;
483 rld[s_reload].out_reg = 0;
484 rld[s_reload].opnum = opnum;
485 rld[s_reload].when_needed = secondary_type;
486 rld[s_reload].secondary_in_reload = in_p ? t_reload : -1;
487 rld[s_reload].secondary_out_reload = ! in_p ? t_reload : -1;
488 rld[s_reload].secondary_in_icode = in_p ? t_icode : CODE_FOR_nothing;
489 rld[s_reload].secondary_out_icode
490 = ! in_p ? t_icode : CODE_FOR_nothing;
491 rld[s_reload].secondary_p = 1;
493 n_reloads++;
495 if (! in_p && icode == CODE_FOR_nothing
496 && targetm.secondary_memory_needed (mode, reload_class, rclass))
497 get_secondary_mem (x, mode, opnum, type);
500 *picode = icode;
501 return s_reload;
504 /* If a secondary reload is needed, return its class. If both an intermediate
505 register and a scratch register is needed, we return the class of the
506 intermediate register. */
507 reg_class_t
508 secondary_reload_class (bool in_p, reg_class_t rclass, machine_mode mode,
509 rtx x)
511 enum insn_code icode;
512 secondary_reload_info sri;
514 sri.icode = CODE_FOR_nothing;
515 sri.prev_sri = NULL;
516 rclass
517 = (enum reg_class) targetm.secondary_reload (in_p, x, rclass, mode, &sri);
518 icode = (enum insn_code) sri.icode;
520 /* If there are no secondary reloads at all, we return NO_REGS.
521 If an intermediate register is needed, we return its class. */
522 if (icode == CODE_FOR_nothing || rclass != NO_REGS)
523 return rclass;
525 /* No intermediate register is needed, but we have a special reload
526 pattern, which we assume for now needs a scratch register. */
527 return scratch_reload_class (icode);
530 /* ICODE is the insn_code of a reload pattern. Check that it has exactly
531 three operands, verify that operand 2 is an output operand, and return
532 its register class.
533 ??? We'd like to be able to handle any pattern with at least 2 operands,
534 for zero or more scratch registers, but that needs more infrastructure. */
535 enum reg_class
536 scratch_reload_class (enum insn_code icode)
538 const char *scratch_constraint;
539 enum reg_class rclass;
541 gcc_assert (insn_data[(int) icode].n_operands == 3);
542 scratch_constraint = insn_data[(int) icode].operand[2].constraint;
543 gcc_assert (*scratch_constraint == '=');
544 scratch_constraint++;
545 if (*scratch_constraint == '&')
546 scratch_constraint++;
547 rclass = reg_class_for_constraint (lookup_constraint (scratch_constraint));
548 gcc_assert (rclass != NO_REGS);
549 return rclass;
552 /* Return a memory location that will be used to copy X in mode MODE.
553 If we haven't already made a location for this mode in this insn,
554 call find_reloads_address on the location being returned. */
557 get_secondary_mem (rtx x ATTRIBUTE_UNUSED, machine_mode mode,
558 int opnum, enum reload_type type)
560 rtx loc;
561 int mem_valid;
563 /* By default, if MODE is narrower than a word, widen it to a word.
564 This is required because most machines that require these memory
565 locations do not support short load and stores from all registers
566 (e.g., FP registers). */
568 mode = targetm.secondary_memory_needed_mode (mode);
570 /* If we already have made a MEM for this operand in MODE, return it. */
571 if (secondary_memlocs_elim[(int) mode][opnum] != 0)
572 return secondary_memlocs_elim[(int) mode][opnum];
574 /* If this is the first time we've tried to get a MEM for this mode,
575 allocate a new one. `something_changed' in reload will get set
576 by noticing that the frame size has changed. */
578 if (secondary_memlocs[(int) mode] == 0)
580 #ifdef SECONDARY_MEMORY_NEEDED_RTX
581 secondary_memlocs[(int) mode] = SECONDARY_MEMORY_NEEDED_RTX (mode);
582 #else
583 secondary_memlocs[(int) mode]
584 = assign_stack_local (mode, GET_MODE_SIZE (mode), 0);
585 #endif
588 /* Get a version of the address doing any eliminations needed. If that
589 didn't give us a new MEM, make a new one if it isn't valid. */
591 loc = eliminate_regs (secondary_memlocs[(int) mode], VOIDmode, NULL_RTX);
592 mem_valid = strict_memory_address_addr_space_p (mode, XEXP (loc, 0),
593 MEM_ADDR_SPACE (loc));
595 if (! mem_valid && loc == secondary_memlocs[(int) mode])
596 loc = copy_rtx (loc);
598 /* The only time the call below will do anything is if the stack
599 offset is too large. In that case IND_LEVELS doesn't matter, so we
600 can just pass a zero. Adjust the type to be the address of the
601 corresponding object. If the address was valid, save the eliminated
602 address. If it wasn't valid, we need to make a reload each time, so
603 don't save it. */
605 if (! mem_valid)
607 type = (type == RELOAD_FOR_INPUT ? RELOAD_FOR_INPUT_ADDRESS
608 : type == RELOAD_FOR_OUTPUT ? RELOAD_FOR_OUTPUT_ADDRESS
609 : RELOAD_OTHER);
611 find_reloads_address (mode, &loc, XEXP (loc, 0), &XEXP (loc, 0),
612 opnum, type, 0, 0);
615 secondary_memlocs_elim[(int) mode][opnum] = loc;
616 if (secondary_memlocs_elim_used <= (int)mode)
617 secondary_memlocs_elim_used = (int)mode + 1;
618 return loc;
621 /* Clear any secondary memory locations we've made. */
623 void
624 clear_secondary_mem (void)
626 memset (secondary_memlocs, 0, sizeof secondary_memlocs);
630 /* Find the largest class which has at least one register valid in
631 mode INNER, and which for every such register, that register number
632 plus N is also valid in OUTER (if in range) and is cheap to move
633 into REGNO. Such a class must exist. */
635 static enum reg_class
636 find_valid_class (machine_mode outer ATTRIBUTE_UNUSED,
637 machine_mode inner ATTRIBUTE_UNUSED, int n,
638 unsigned int dest_regno ATTRIBUTE_UNUSED)
640 int best_cost = -1;
641 int rclass;
642 int regno;
643 enum reg_class best_class = NO_REGS;
644 enum reg_class dest_class ATTRIBUTE_UNUSED = REGNO_REG_CLASS (dest_regno);
645 unsigned int best_size = 0;
646 int cost;
648 for (rclass = 1; rclass < N_REG_CLASSES; rclass++)
650 int bad = 0;
651 int good = 0;
652 for (regno = 0; regno < FIRST_PSEUDO_REGISTER - n && ! bad; regno++)
653 if (TEST_HARD_REG_BIT (reg_class_contents[rclass], regno))
655 if (targetm.hard_regno_mode_ok (regno, inner))
657 good = 1;
658 if (TEST_HARD_REG_BIT (reg_class_contents[rclass], regno + n)
659 && !targetm.hard_regno_mode_ok (regno + n, outer))
660 bad = 1;
664 if (bad || !good)
665 continue;
666 cost = register_move_cost (outer, (enum reg_class) rclass, dest_class);
668 if ((reg_class_size[rclass] > best_size
669 && (best_cost < 0 || best_cost >= cost))
670 || best_cost > cost)
672 best_class = (enum reg_class) rclass;
673 best_size = reg_class_size[rclass];
674 best_cost = register_move_cost (outer, (enum reg_class) rclass,
675 dest_class);
679 gcc_assert (best_size != 0);
681 return best_class;
684 /* We are trying to reload a subreg of something that is not a register.
685 Find the largest class which contains only registers valid in
686 mode MODE. OUTER is the mode of the subreg, DEST_CLASS the class in
687 which we would eventually like to obtain the object. */
689 static enum reg_class
690 find_valid_class_1 (machine_mode outer ATTRIBUTE_UNUSED,
691 machine_mode mode ATTRIBUTE_UNUSED,
692 enum reg_class dest_class ATTRIBUTE_UNUSED)
694 int best_cost = -1;
695 int rclass;
696 int regno;
697 enum reg_class best_class = NO_REGS;
698 unsigned int best_size = 0;
699 int cost;
701 for (rclass = 1; rclass < N_REG_CLASSES; rclass++)
703 unsigned int computed_rclass_size = 0;
705 for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
707 if (in_hard_reg_set_p (reg_class_contents[rclass], mode, regno)
708 && targetm.hard_regno_mode_ok (regno, mode))
709 computed_rclass_size++;
712 cost = register_move_cost (outer, (enum reg_class) rclass, dest_class);
714 if ((computed_rclass_size > best_size
715 && (best_cost < 0 || best_cost >= cost))
716 || best_cost > cost)
718 best_class = (enum reg_class) rclass;
719 best_size = computed_rclass_size;
720 best_cost = register_move_cost (outer, (enum reg_class) rclass,
721 dest_class);
725 gcc_assert (best_size != 0);
727 #ifdef LIMIT_RELOAD_CLASS
728 best_class = LIMIT_RELOAD_CLASS (mode, best_class);
729 #endif
730 return best_class;
733 /* Return the number of a previously made reload that can be combined with
734 a new one, or n_reloads if none of the existing reloads can be used.
735 OUT, RCLASS, TYPE and OPNUM are the same arguments as passed to
736 push_reload, they determine the kind of the new reload that we try to
737 combine. P_IN points to the corresponding value of IN, which can be
738 modified by this function.
739 DONT_SHARE is nonzero if we can't share any input-only reload for IN. */
741 static int
742 find_reusable_reload (rtx *p_in, rtx out, enum reg_class rclass,
743 enum reload_type type, int opnum, int dont_share)
745 rtx in = *p_in;
746 int i;
747 /* We can't merge two reloads if the output of either one is
748 earlyclobbered. */
750 if (earlyclobber_operand_p (out))
751 return n_reloads;
753 /* We can use an existing reload if the class is right
754 and at least one of IN and OUT is a match
755 and the other is at worst neutral.
756 (A zero compared against anything is neutral.)
758 For targets with small register classes, don't use existing reloads
759 unless they are for the same thing since that can cause us to need
760 more reload registers than we otherwise would. */
762 for (i = 0; i < n_reloads; i++)
763 if ((reg_class_subset_p (rclass, rld[i].rclass)
764 || reg_class_subset_p (rld[i].rclass, rclass))
765 /* If the existing reload has a register, it must fit our class. */
766 && (rld[i].reg_rtx == 0
767 || TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
768 true_regnum (rld[i].reg_rtx)))
769 && ((in != 0 && MATCHES (rld[i].in, in) && ! dont_share
770 && (out == 0 || rld[i].out == 0 || MATCHES (rld[i].out, out)))
771 || (out != 0 && MATCHES (rld[i].out, out)
772 && (in == 0 || rld[i].in == 0 || MATCHES (rld[i].in, in))))
773 && (rld[i].out == 0 || ! earlyclobber_operand_p (rld[i].out))
774 && (small_register_class_p (rclass)
775 || targetm.small_register_classes_for_mode_p (VOIDmode))
776 && MERGABLE_RELOADS (type, rld[i].when_needed, opnum, rld[i].opnum))
777 return i;
779 /* Reloading a plain reg for input can match a reload to postincrement
780 that reg, since the postincrement's value is the right value.
781 Likewise, it can match a preincrement reload, since we regard
782 the preincrementation as happening before any ref in this insn
783 to that register. */
784 for (i = 0; i < n_reloads; i++)
785 if ((reg_class_subset_p (rclass, rld[i].rclass)
786 || reg_class_subset_p (rld[i].rclass, rclass))
787 /* If the existing reload has a register, it must fit our
788 class. */
789 && (rld[i].reg_rtx == 0
790 || TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
791 true_regnum (rld[i].reg_rtx)))
792 && out == 0 && rld[i].out == 0 && rld[i].in != 0
793 && ((REG_P (in)
794 && GET_RTX_CLASS (GET_CODE (rld[i].in)) == RTX_AUTOINC
795 && MATCHES (XEXP (rld[i].in, 0), in))
796 || (REG_P (rld[i].in)
797 && GET_RTX_CLASS (GET_CODE (in)) == RTX_AUTOINC
798 && MATCHES (XEXP (in, 0), rld[i].in)))
799 && (rld[i].out == 0 || ! earlyclobber_operand_p (rld[i].out))
800 && (small_register_class_p (rclass)
801 || targetm.small_register_classes_for_mode_p (VOIDmode))
802 && MERGABLE_RELOADS (type, rld[i].when_needed,
803 opnum, rld[i].opnum))
805 /* Make sure reload_in ultimately has the increment,
806 not the plain register. */
807 if (REG_P (in))
808 *p_in = rld[i].in;
809 return i;
811 return n_reloads;
814 /* Return true if:
816 (a) (subreg:OUTER_MODE REG ...) represents a word or subword subreg
817 of a multiword value; and
819 (b) the number of *words* in REG does not match the number of *registers*
820 in REG. */
822 static bool
823 complex_word_subreg_p (machine_mode outer_mode, rtx reg)
825 machine_mode inner_mode = GET_MODE (reg);
826 poly_uint64 reg_words = REG_NREGS (reg) * UNITS_PER_WORD;
827 return (known_le (GET_MODE_SIZE (outer_mode), UNITS_PER_WORD)
828 && maybe_gt (GET_MODE_SIZE (inner_mode), UNITS_PER_WORD)
829 && !known_equal_after_align_up (GET_MODE_SIZE (inner_mode),
830 reg_words, UNITS_PER_WORD));
833 /* Return true if X is a SUBREG that will need reloading of its SUBREG_REG
834 expression. MODE is the mode that X will be used in. OUTPUT is true if
835 the function is invoked for the output part of an enclosing reload. */
837 static bool
838 reload_inner_reg_of_subreg (rtx x, machine_mode mode, bool output)
840 rtx inner;
842 /* Only SUBREGs are problematical. */
843 if (GET_CODE (x) != SUBREG)
844 return false;
846 inner = SUBREG_REG (x);
848 /* If INNER is a constant or PLUS, then INNER will need reloading. */
849 if (CONSTANT_P (inner) || GET_CODE (inner) == PLUS)
850 return true;
852 /* If INNER is not a hard register, then INNER will not need reloading. */
853 if (!(REG_P (inner) && HARD_REGISTER_P (inner)))
854 return false;
856 /* If INNER is not ok for MODE, then INNER will need reloading. */
857 if (!targetm.hard_regno_mode_ok (subreg_regno (x), mode))
858 return true;
860 /* If this is for an output, and the outer part is a word or smaller,
861 INNER is larger than a word and the number of registers in INNER is
862 not the same as the number of words in INNER, then INNER will need
863 reloading (with an in-out reload). */
864 return output && complex_word_subreg_p (mode, inner);
867 /* Return nonzero if IN can be reloaded into REGNO with mode MODE without
868 requiring an extra reload register. The caller has already found that
869 IN contains some reference to REGNO, so check that we can produce the
870 new value in a single step. E.g. if we have
871 (set (reg r13) (plus (reg r13) (const int 1))), and there is an
872 instruction that adds one to a register, this should succeed.
873 However, if we have something like
874 (set (reg r13) (plus (reg r13) (const int 999))), and the constant 999
875 needs to be loaded into a register first, we need a separate reload
876 register.
877 Such PLUS reloads are generated by find_reload_address_part.
878 The out-of-range PLUS expressions are usually introduced in the instruction
879 patterns by register elimination and substituting pseudos without a home
880 by their function-invariant equivalences. */
881 static int
882 can_reload_into (rtx in, int regno, machine_mode mode)
884 rtx dst;
885 rtx_insn *test_insn;
886 int r = 0;
887 struct recog_data_d save_recog_data;
889 /* For matching constraints, we often get notional input reloads where
890 we want to use the original register as the reload register. I.e.
891 technically this is a non-optional input-output reload, but IN is
892 already a valid register, and has been chosen as the reload register.
893 Speed this up, since it trivially works. */
894 if (REG_P (in))
895 return 1;
897 /* To test MEMs properly, we'd have to take into account all the reloads
898 that are already scheduled, which can become quite complicated.
899 And since we've already handled address reloads for this MEM, it
900 should always succeed anyway. */
901 if (MEM_P (in))
902 return 1;
904 /* If we can make a simple SET insn that does the job, everything should
905 be fine. */
906 dst = gen_rtx_REG (mode, regno);
907 test_insn = make_insn_raw (gen_rtx_SET (dst, in));
908 save_recog_data = recog_data;
909 if (recog_memoized (test_insn) >= 0)
911 extract_insn (test_insn);
912 r = constrain_operands (1, get_enabled_alternatives (test_insn));
914 recog_data = save_recog_data;
915 return r;
918 /* Record one reload that needs to be performed.
919 IN is an rtx saying where the data are to be found before this instruction.
920 OUT says where they must be stored after the instruction.
921 (IN is zero for data not read, and OUT is zero for data not written.)
922 INLOC and OUTLOC point to the places in the instructions where
923 IN and OUT were found.
924 If IN and OUT are both nonzero, it means the same register must be used
925 to reload both IN and OUT.
927 RCLASS is a register class required for the reloaded data.
928 INMODE is the machine mode that the instruction requires
929 for the reg that replaces IN and OUTMODE is likewise for OUT.
931 If IN is zero, then OUT's location and mode should be passed as
932 INLOC and INMODE.
934 STRICT_LOW is the 1 if there is a containing STRICT_LOW_PART rtx.
936 OPTIONAL nonzero means this reload does not need to be performed:
937 it can be discarded if that is more convenient.
939 OPNUM and TYPE say what the purpose of this reload is.
941 The return value is the reload-number for this reload.
943 If both IN and OUT are nonzero, in some rare cases we might
944 want to make two separate reloads. (Actually we never do this now.)
945 Therefore, the reload-number for OUT is stored in
946 output_reloadnum when we return; the return value applies to IN.
947 Usually (presently always), when IN and OUT are nonzero,
948 the two reload-numbers are equal, but the caller should be careful to
949 distinguish them. */
952 push_reload (rtx in, rtx out, rtx *inloc, rtx *outloc,
953 enum reg_class rclass, machine_mode inmode,
954 machine_mode outmode, int strict_low, int optional,
955 int opnum, enum reload_type type)
957 int i;
958 int dont_share = 0;
959 int dont_remove_subreg = 0;
960 #ifdef LIMIT_RELOAD_CLASS
961 rtx *in_subreg_loc = 0, *out_subreg_loc = 0;
962 #endif
963 int secondary_in_reload = -1, secondary_out_reload = -1;
964 enum insn_code secondary_in_icode = CODE_FOR_nothing;
965 enum insn_code secondary_out_icode = CODE_FOR_nothing;
966 enum reg_class subreg_in_class ATTRIBUTE_UNUSED;
967 subreg_in_class = NO_REGS;
969 /* INMODE and/or OUTMODE could be VOIDmode if no mode
970 has been specified for the operand. In that case,
971 use the operand's mode as the mode to reload. */
972 if (inmode == VOIDmode && in != 0)
973 inmode = GET_MODE (in);
974 if (outmode == VOIDmode && out != 0)
975 outmode = GET_MODE (out);
977 /* If find_reloads and friends until now missed to replace a pseudo
978 with a constant of reg_equiv_constant something went wrong
979 beforehand.
980 Note that it can't simply be done here if we missed it earlier
981 since the constant might need to be pushed into the literal pool
982 and the resulting memref would probably need further
983 reloading. */
984 if (in != 0 && REG_P (in))
986 int regno = REGNO (in);
988 gcc_assert (regno < FIRST_PSEUDO_REGISTER
989 || reg_renumber[regno] >= 0
990 || reg_equiv_constant (regno) == NULL_RTX);
993 /* reg_equiv_constant only contains constants which are obviously
994 not appropriate as destination. So if we would need to replace
995 the destination pseudo with a constant we are in real
996 trouble. */
997 if (out != 0 && REG_P (out))
999 int regno = REGNO (out);
1001 gcc_assert (regno < FIRST_PSEUDO_REGISTER
1002 || reg_renumber[regno] >= 0
1003 || reg_equiv_constant (regno) == NULL_RTX);
1006 /* If we have a read-write operand with an address side-effect,
1007 change either IN or OUT so the side-effect happens only once. */
1008 if (in != 0 && out != 0 && MEM_P (in) && rtx_equal_p (in, out))
1009 switch (GET_CODE (XEXP (in, 0)))
1011 case POST_INC: case POST_DEC: case POST_MODIFY:
1012 in = replace_equiv_address_nv (in, XEXP (XEXP (in, 0), 0));
1013 break;
1015 case PRE_INC: case PRE_DEC: case PRE_MODIFY:
1016 out = replace_equiv_address_nv (out, XEXP (XEXP (out, 0), 0));
1017 break;
1019 default:
1020 break;
1023 /* If we are reloading a (SUBREG constant ...), really reload just the
1024 inside expression in its own mode. Similarly for (SUBREG (PLUS ...)).
1025 If we have (SUBREG:M1 (MEM:M2 ...) ...) (or an inner REG that is still
1026 a pseudo and hence will become a MEM) with M1 wider than M2 and the
1027 register is a pseudo, also reload the inside expression.
1028 For machines that extend byte loads, do this for any SUBREG of a pseudo
1029 where both M1 and M2 are a word or smaller, M1 is wider than M2, and
1030 M2 is an integral mode that gets extended when loaded.
1031 Similar issue for (SUBREG:M1 (REG:M2 ...) ...) for a hard register R
1032 where either M1 is not valid for R or M2 is wider than a word but we
1033 only need one register to store an M2-sized quantity in R.
1034 (However, if OUT is nonzero, we need to reload the reg *and*
1035 the subreg, so do nothing here, and let following statement handle it.)
1037 Note that the case of (SUBREG (CONST_INT...)...) is handled elsewhere;
1038 we can't handle it here because CONST_INT does not indicate a mode.
1040 Similarly, we must reload the inside expression if we have a
1041 STRICT_LOW_PART (presumably, in == out in this case).
1043 Also reload the inner expression if it does not require a secondary
1044 reload but the SUBREG does.
1046 Finally, reload the inner expression if it is a register that is in
1047 the class whose registers cannot be referenced in a different size
1048 and M1 is not the same size as M2. If subreg_lowpart_p is false, we
1049 cannot reload just the inside since we might end up with the wrong
1050 register class. But if it is inside a STRICT_LOW_PART, we have
1051 no choice, so we hope we do get the right register class there. */
1053 scalar_int_mode inner_mode;
1054 if (in != 0 && GET_CODE (in) == SUBREG
1055 && (subreg_lowpart_p (in) || strict_low)
1056 && targetm.can_change_mode_class (GET_MODE (SUBREG_REG (in)),
1057 inmode, rclass)
1058 && contains_allocatable_reg_of_mode[rclass][GET_MODE (SUBREG_REG (in))]
1059 && (CONSTANT_P (SUBREG_REG (in))
1060 || GET_CODE (SUBREG_REG (in)) == PLUS
1061 || strict_low
1062 || (((REG_P (SUBREG_REG (in))
1063 && REGNO (SUBREG_REG (in)) >= FIRST_PSEUDO_REGISTER)
1064 || MEM_P (SUBREG_REG (in)))
1065 && (paradoxical_subreg_p (inmode, GET_MODE (SUBREG_REG (in)))
1066 || (known_le (GET_MODE_SIZE (inmode), UNITS_PER_WORD)
1067 && is_a <scalar_int_mode> (GET_MODE (SUBREG_REG (in)),
1068 &inner_mode)
1069 && GET_MODE_SIZE (inner_mode) <= UNITS_PER_WORD
1070 && paradoxical_subreg_p (inmode, inner_mode)
1071 && LOAD_EXTEND_OP (inner_mode) != UNKNOWN)
1072 || (WORD_REGISTER_OPERATIONS
1073 && partial_subreg_p (inmode, GET_MODE (SUBREG_REG (in)))
1074 && (known_equal_after_align_down
1075 (GET_MODE_SIZE (inmode) - 1,
1076 GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))) - 1,
1077 UNITS_PER_WORD)))))
1078 || (REG_P (SUBREG_REG (in))
1079 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
1080 /* The case where out is nonzero
1081 is handled differently in the following statement. */
1082 && (out == 0 || subreg_lowpart_p (in))
1083 && (complex_word_subreg_p (inmode, SUBREG_REG (in))
1084 || !targetm.hard_regno_mode_ok (subreg_regno (in), inmode)))
1085 || (secondary_reload_class (1, rclass, inmode, in) != NO_REGS
1086 && (secondary_reload_class (1, rclass, GET_MODE (SUBREG_REG (in)),
1087 SUBREG_REG (in))
1088 == NO_REGS))
1089 || (REG_P (SUBREG_REG (in))
1090 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
1091 && !REG_CAN_CHANGE_MODE_P (REGNO (SUBREG_REG (in)),
1092 GET_MODE (SUBREG_REG (in)), inmode))))
1094 #ifdef LIMIT_RELOAD_CLASS
1095 in_subreg_loc = inloc;
1096 #endif
1097 inloc = &SUBREG_REG (in);
1098 in = *inloc;
1100 if (!WORD_REGISTER_OPERATIONS
1101 && LOAD_EXTEND_OP (GET_MODE (in)) == UNKNOWN
1102 && MEM_P (in))
1103 /* This is supposed to happen only for paradoxical subregs made by
1104 combine.c. (SUBREG (MEM)) isn't supposed to occur other ways. */
1105 gcc_assert (known_le (GET_MODE_SIZE (GET_MODE (in)),
1106 GET_MODE_SIZE (inmode)));
1108 inmode = GET_MODE (in);
1111 /* Similar issue for (SUBREG:M1 (REG:M2 ...) ...) for a hard register R
1112 where M1 is not valid for R if it was not handled by the code above.
1114 Similar issue for (SUBREG constant ...) if it was not handled by the
1115 code above. This can happen if SUBREG_BYTE != 0.
1117 However, we must reload the inner reg *as well as* the subreg in
1118 that case. */
1120 if (in != 0 && reload_inner_reg_of_subreg (in, inmode, false))
1122 if (REG_P (SUBREG_REG (in)))
1123 subreg_in_class
1124 = find_valid_class (inmode, GET_MODE (SUBREG_REG (in)),
1125 subreg_regno_offset (REGNO (SUBREG_REG (in)),
1126 GET_MODE (SUBREG_REG (in)),
1127 SUBREG_BYTE (in),
1128 GET_MODE (in)),
1129 REGNO (SUBREG_REG (in)));
1130 else if (CONSTANT_P (SUBREG_REG (in))
1131 || GET_CODE (SUBREG_REG (in)) == PLUS)
1132 subreg_in_class = find_valid_class_1 (inmode,
1133 GET_MODE (SUBREG_REG (in)),
1134 rclass);
1136 /* This relies on the fact that emit_reload_insns outputs the
1137 instructions for input reloads of type RELOAD_OTHER in the same
1138 order as the reloads. Thus if the outer reload is also of type
1139 RELOAD_OTHER, we are guaranteed that this inner reload will be
1140 output before the outer reload. */
1141 push_reload (SUBREG_REG (in), NULL_RTX, &SUBREG_REG (in), (rtx *) 0,
1142 subreg_in_class, VOIDmode, VOIDmode, 0, 0, opnum, type);
1143 dont_remove_subreg = 1;
1146 /* Similarly for paradoxical and problematical SUBREGs on the output.
1147 Note that there is no reason we need worry about the previous value
1148 of SUBREG_REG (out); even if wider than out, storing in a subreg is
1149 entitled to clobber it all (except in the case of a word mode subreg
1150 or of a STRICT_LOW_PART, in that latter case the constraint should
1151 label it input-output.) */
1152 if (out != 0 && GET_CODE (out) == SUBREG
1153 && (subreg_lowpart_p (out) || strict_low)
1154 && targetm.can_change_mode_class (GET_MODE (SUBREG_REG (out)),
1155 outmode, rclass)
1156 && contains_allocatable_reg_of_mode[rclass][GET_MODE (SUBREG_REG (out))]
1157 && (CONSTANT_P (SUBREG_REG (out))
1158 || strict_low
1159 || (((REG_P (SUBREG_REG (out))
1160 && REGNO (SUBREG_REG (out)) >= FIRST_PSEUDO_REGISTER)
1161 || MEM_P (SUBREG_REG (out)))
1162 && (paradoxical_subreg_p (outmode, GET_MODE (SUBREG_REG (out)))
1163 || (WORD_REGISTER_OPERATIONS
1164 && partial_subreg_p (outmode, GET_MODE (SUBREG_REG (out)))
1165 && (known_equal_after_align_down
1166 (GET_MODE_SIZE (outmode) - 1,
1167 GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))) - 1,
1168 UNITS_PER_WORD)))))
1169 || (REG_P (SUBREG_REG (out))
1170 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1171 /* The case of a word mode subreg
1172 is handled differently in the following statement. */
1173 && ! (known_le (GET_MODE_SIZE (outmode), UNITS_PER_WORD)
1174 && maybe_gt (GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))),
1175 UNITS_PER_WORD))
1176 && !targetm.hard_regno_mode_ok (subreg_regno (out), outmode))
1177 || (secondary_reload_class (0, rclass, outmode, out) != NO_REGS
1178 && (secondary_reload_class (0, rclass, GET_MODE (SUBREG_REG (out)),
1179 SUBREG_REG (out))
1180 == NO_REGS))
1181 || (REG_P (SUBREG_REG (out))
1182 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1183 && !REG_CAN_CHANGE_MODE_P (REGNO (SUBREG_REG (out)),
1184 GET_MODE (SUBREG_REG (out)),
1185 outmode))))
1187 #ifdef LIMIT_RELOAD_CLASS
1188 out_subreg_loc = outloc;
1189 #endif
1190 outloc = &SUBREG_REG (out);
1191 out = *outloc;
1192 gcc_assert (WORD_REGISTER_OPERATIONS || !MEM_P (out)
1193 || known_le (GET_MODE_SIZE (GET_MODE (out)),
1194 GET_MODE_SIZE (outmode)));
1195 outmode = GET_MODE (out);
1198 /* Similar issue for (SUBREG:M1 (REG:M2 ...) ...) for a hard register R
1199 where either M1 is not valid for R or M2 is wider than a word but we
1200 only need one register to store an M2-sized quantity in R.
1202 However, we must reload the inner reg *as well as* the subreg in
1203 that case and the inner reg is an in-out reload. */
1205 if (out != 0 && reload_inner_reg_of_subreg (out, outmode, true))
1207 enum reg_class in_out_class
1208 = find_valid_class (outmode, GET_MODE (SUBREG_REG (out)),
1209 subreg_regno_offset (REGNO (SUBREG_REG (out)),
1210 GET_MODE (SUBREG_REG (out)),
1211 SUBREG_BYTE (out),
1212 GET_MODE (out)),
1213 REGNO (SUBREG_REG (out)));
1215 /* This relies on the fact that emit_reload_insns outputs the
1216 instructions for output reloads of type RELOAD_OTHER in reverse
1217 order of the reloads. Thus if the outer reload is also of type
1218 RELOAD_OTHER, we are guaranteed that this inner reload will be
1219 output after the outer reload. */
1220 push_reload (SUBREG_REG (out), SUBREG_REG (out), &SUBREG_REG (out),
1221 &SUBREG_REG (out), in_out_class, VOIDmode, VOIDmode,
1222 0, 0, opnum, RELOAD_OTHER);
1223 dont_remove_subreg = 1;
1226 /* If IN appears in OUT, we can't share any input-only reload for IN. */
1227 if (in != 0 && out != 0 && MEM_P (out)
1228 && (REG_P (in) || MEM_P (in) || GET_CODE (in) == PLUS)
1229 && reg_overlap_mentioned_for_reload_p (in, XEXP (out, 0)))
1230 dont_share = 1;
1232 /* If IN is a SUBREG of a hard register, make a new REG. This
1233 simplifies some of the cases below. */
1235 if (in != 0 && GET_CODE (in) == SUBREG && REG_P (SUBREG_REG (in))
1236 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
1237 && ! dont_remove_subreg)
1238 in = gen_rtx_REG (GET_MODE (in), subreg_regno (in));
1240 /* Similarly for OUT. */
1241 if (out != 0 && GET_CODE (out) == SUBREG
1242 && REG_P (SUBREG_REG (out))
1243 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1244 && ! dont_remove_subreg)
1245 out = gen_rtx_REG (GET_MODE (out), subreg_regno (out));
1247 /* Narrow down the class of register wanted if that is
1248 desirable on this machine for efficiency. */
1250 reg_class_t preferred_class = rclass;
1252 if (in != 0)
1253 preferred_class = targetm.preferred_reload_class (in, rclass);
1255 /* Output reloads may need analogous treatment, different in detail. */
1256 if (out != 0)
1257 preferred_class
1258 = targetm.preferred_output_reload_class (out, preferred_class);
1260 /* Discard what the target said if we cannot do it. */
1261 if (preferred_class != NO_REGS
1262 || (optional && type == RELOAD_FOR_OUTPUT))
1263 rclass = (enum reg_class) preferred_class;
1266 /* Make sure we use a class that can handle the actual pseudo
1267 inside any subreg. For example, on the 386, QImode regs
1268 can appear within SImode subregs. Although GENERAL_REGS
1269 can handle SImode, QImode needs a smaller class. */
1270 #ifdef LIMIT_RELOAD_CLASS
1271 if (in_subreg_loc)
1272 rclass = LIMIT_RELOAD_CLASS (inmode, rclass);
1273 else if (in != 0 && GET_CODE (in) == SUBREG)
1274 rclass = LIMIT_RELOAD_CLASS (GET_MODE (SUBREG_REG (in)), rclass);
1276 if (out_subreg_loc)
1277 rclass = LIMIT_RELOAD_CLASS (outmode, rclass);
1278 if (out != 0 && GET_CODE (out) == SUBREG)
1279 rclass = LIMIT_RELOAD_CLASS (GET_MODE (SUBREG_REG (out)), rclass);
1280 #endif
1282 /* Verify that this class is at least possible for the mode that
1283 is specified. */
1284 if (this_insn_is_asm)
1286 machine_mode mode;
1287 if (paradoxical_subreg_p (inmode, outmode))
1288 mode = inmode;
1289 else
1290 mode = outmode;
1291 if (mode == VOIDmode)
1293 error_for_asm (this_insn, "cannot reload integer constant "
1294 "operand in %<asm%>");
1295 mode = word_mode;
1296 if (in != 0)
1297 inmode = word_mode;
1298 if (out != 0)
1299 outmode = word_mode;
1301 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1302 if (targetm.hard_regno_mode_ok (i, mode)
1303 && in_hard_reg_set_p (reg_class_contents[(int) rclass], mode, i))
1304 break;
1305 if (i == FIRST_PSEUDO_REGISTER)
1307 error_for_asm (this_insn, "impossible register constraint "
1308 "in %<asm%>");
1309 /* Avoid further trouble with this insn. */
1310 PATTERN (this_insn) = gen_rtx_USE (VOIDmode, const0_rtx);
1311 /* We used to continue here setting class to ALL_REGS, but it triggers
1312 sanity check on i386 for:
1313 void foo(long double d)
1315 asm("" :: "a" (d));
1317 Returning zero here ought to be safe as we take care in
1318 find_reloads to not process the reloads when instruction was
1319 replaced by USE. */
1321 return 0;
1325 /* Optional output reloads are always OK even if we have no register class,
1326 since the function of these reloads is only to have spill_reg_store etc.
1327 set, so that the storing insn can be deleted later. */
1328 gcc_assert (rclass != NO_REGS
1329 || (optional != 0 && type == RELOAD_FOR_OUTPUT));
1331 i = find_reusable_reload (&in, out, rclass, type, opnum, dont_share);
1333 if (i == n_reloads)
1335 /* See if we need a secondary reload register to move between CLASS
1336 and IN or CLASS and OUT. Get the icode and push any required reloads
1337 needed for each of them if so. */
1339 if (in != 0)
1340 secondary_in_reload
1341 = push_secondary_reload (1, in, opnum, optional, rclass, inmode, type,
1342 &secondary_in_icode, NULL);
1343 if (out != 0 && GET_CODE (out) != SCRATCH)
1344 secondary_out_reload
1345 = push_secondary_reload (0, out, opnum, optional, rclass, outmode,
1346 type, &secondary_out_icode, NULL);
1348 /* We found no existing reload suitable for re-use.
1349 So add an additional reload. */
1351 if (subreg_in_class == NO_REGS
1352 && in != 0
1353 && (REG_P (in)
1354 || (GET_CODE (in) == SUBREG && REG_P (SUBREG_REG (in))))
1355 && reg_or_subregno (in) < FIRST_PSEUDO_REGISTER)
1356 subreg_in_class = REGNO_REG_CLASS (reg_or_subregno (in));
1357 /* If a memory location is needed for the copy, make one. */
1358 if (subreg_in_class != NO_REGS
1359 && targetm.secondary_memory_needed (inmode, subreg_in_class, rclass))
1360 get_secondary_mem (in, inmode, opnum, type);
1362 i = n_reloads;
1363 rld[i].in = in;
1364 rld[i].out = out;
1365 rld[i].rclass = rclass;
1366 rld[i].inmode = inmode;
1367 rld[i].outmode = outmode;
1368 rld[i].reg_rtx = 0;
1369 rld[i].optional = optional;
1370 rld[i].inc = 0;
1371 rld[i].nocombine = 0;
1372 rld[i].in_reg = inloc ? *inloc : 0;
1373 rld[i].out_reg = outloc ? *outloc : 0;
1374 rld[i].opnum = opnum;
1375 rld[i].when_needed = type;
1376 rld[i].secondary_in_reload = secondary_in_reload;
1377 rld[i].secondary_out_reload = secondary_out_reload;
1378 rld[i].secondary_in_icode = secondary_in_icode;
1379 rld[i].secondary_out_icode = secondary_out_icode;
1380 rld[i].secondary_p = 0;
1382 n_reloads++;
1384 if (out != 0
1385 && (REG_P (out)
1386 || (GET_CODE (out) == SUBREG && REG_P (SUBREG_REG (out))))
1387 && reg_or_subregno (out) < FIRST_PSEUDO_REGISTER
1388 && (targetm.secondary_memory_needed
1389 (outmode, rclass, REGNO_REG_CLASS (reg_or_subregno (out)))))
1390 get_secondary_mem (out, outmode, opnum, type);
1392 else
1394 /* We are reusing an existing reload,
1395 but we may have additional information for it.
1396 For example, we may now have both IN and OUT
1397 while the old one may have just one of them. */
1399 /* The modes can be different. If they are, we want to reload in
1400 the larger mode, so that the value is valid for both modes. */
1401 if (inmode != VOIDmode
1402 && partial_subreg_p (rld[i].inmode, inmode))
1403 rld[i].inmode = inmode;
1404 if (outmode != VOIDmode
1405 && partial_subreg_p (rld[i].outmode, outmode))
1406 rld[i].outmode = outmode;
1407 if (in != 0)
1409 rtx in_reg = inloc ? *inloc : 0;
1410 /* If we merge reloads for two distinct rtl expressions that
1411 are identical in content, there might be duplicate address
1412 reloads. Remove the extra set now, so that if we later find
1413 that we can inherit this reload, we can get rid of the
1414 address reloads altogether.
1416 Do not do this if both reloads are optional since the result
1417 would be an optional reload which could potentially leave
1418 unresolved address replacements.
1420 It is not sufficient to call transfer_replacements since
1421 choose_reload_regs will remove the replacements for address
1422 reloads of inherited reloads which results in the same
1423 problem. */
1424 if (rld[i].in != in && rtx_equal_p (in, rld[i].in)
1425 && ! (rld[i].optional && optional))
1427 /* We must keep the address reload with the lower operand
1428 number alive. */
1429 if (opnum > rld[i].opnum)
1431 remove_address_replacements (in);
1432 in = rld[i].in;
1433 in_reg = rld[i].in_reg;
1435 else
1436 remove_address_replacements (rld[i].in);
1438 /* When emitting reloads we don't necessarily look at the in-
1439 and outmode, but also directly at the operands (in and out).
1440 So we can't simply overwrite them with whatever we have found
1441 for this (to-be-merged) reload, we have to "merge" that too.
1442 Reusing another reload already verified that we deal with the
1443 same operands, just possibly in different modes. So we
1444 overwrite the operands only when the new mode is larger.
1445 See also PR33613. */
1446 if (!rld[i].in
1447 || partial_subreg_p (GET_MODE (rld[i].in), GET_MODE (in)))
1448 rld[i].in = in;
1449 if (!rld[i].in_reg
1450 || (in_reg
1451 && partial_subreg_p (GET_MODE (rld[i].in_reg),
1452 GET_MODE (in_reg))))
1453 rld[i].in_reg = in_reg;
1455 if (out != 0)
1457 if (!rld[i].out
1458 || (out
1459 && partial_subreg_p (GET_MODE (rld[i].out),
1460 GET_MODE (out))))
1461 rld[i].out = out;
1462 if (outloc
1463 && (!rld[i].out_reg
1464 || partial_subreg_p (GET_MODE (rld[i].out_reg),
1465 GET_MODE (*outloc))))
1466 rld[i].out_reg = *outloc;
1468 if (reg_class_subset_p (rclass, rld[i].rclass))
1469 rld[i].rclass = rclass;
1470 rld[i].optional &= optional;
1471 if (MERGE_TO_OTHER (type, rld[i].when_needed,
1472 opnum, rld[i].opnum))
1473 rld[i].when_needed = RELOAD_OTHER;
1474 rld[i].opnum = MIN (rld[i].opnum, opnum);
1477 /* If the ostensible rtx being reloaded differs from the rtx found
1478 in the location to substitute, this reload is not safe to combine
1479 because we cannot reliably tell whether it appears in the insn. */
1481 if (in != 0 && in != *inloc)
1482 rld[i].nocombine = 1;
1484 #if 0
1485 /* This was replaced by changes in find_reloads_address_1 and the new
1486 function inc_for_reload, which go with a new meaning of reload_inc. */
1488 /* If this is an IN/OUT reload in an insn that sets the CC,
1489 it must be for an autoincrement. It doesn't work to store
1490 the incremented value after the insn because that would clobber the CC.
1491 So we must do the increment of the value reloaded from,
1492 increment it, store it back, then decrement again. */
1493 if (out != 0 && sets_cc0_p (PATTERN (this_insn)))
1495 out = 0;
1496 rld[i].out = 0;
1497 rld[i].inc = find_inc_amount (PATTERN (this_insn), in);
1498 /* If we did not find a nonzero amount-to-increment-by,
1499 that contradicts the belief that IN is being incremented
1500 in an address in this insn. */
1501 gcc_assert (rld[i].inc != 0);
1503 #endif
1505 /* If we will replace IN and OUT with the reload-reg,
1506 record where they are located so that substitution need
1507 not do a tree walk. */
1509 if (replace_reloads)
1511 if (inloc != 0)
1513 struct replacement *r = &replacements[n_replacements++];
1514 r->what = i;
1515 r->where = inloc;
1516 r->mode = inmode;
1518 if (outloc != 0 && outloc != inloc)
1520 struct replacement *r = &replacements[n_replacements++];
1521 r->what = i;
1522 r->where = outloc;
1523 r->mode = outmode;
1527 /* If this reload is just being introduced and it has both
1528 an incoming quantity and an outgoing quantity that are
1529 supposed to be made to match, see if either one of the two
1530 can serve as the place to reload into.
1532 If one of them is acceptable, set rld[i].reg_rtx
1533 to that one. */
1535 if (in != 0 && out != 0 && in != out && rld[i].reg_rtx == 0)
1537 rld[i].reg_rtx = find_dummy_reload (in, out, inloc, outloc,
1538 inmode, outmode,
1539 rld[i].rclass, i,
1540 earlyclobber_operand_p (out));
1542 /* If the outgoing register already contains the same value
1543 as the incoming one, we can dispense with loading it.
1544 The easiest way to tell the caller that is to give a phony
1545 value for the incoming operand (same as outgoing one). */
1546 if (rld[i].reg_rtx == out
1547 && (REG_P (in) || CONSTANT_P (in))
1548 && find_equiv_reg (in, this_insn, NO_REGS, REGNO (out),
1549 static_reload_reg_p, i, inmode) != 0)
1550 rld[i].in = out;
1553 /* If this is an input reload and the operand contains a register that
1554 dies in this insn and is used nowhere else, see if it is the right class
1555 to be used for this reload. Use it if so. (This occurs most commonly
1556 in the case of paradoxical SUBREGs and in-out reloads). We cannot do
1557 this if it is also an output reload that mentions the register unless
1558 the output is a SUBREG that clobbers an entire register.
1560 Note that the operand might be one of the spill regs, if it is a
1561 pseudo reg and we are in a block where spilling has not taken place.
1562 But if there is no spilling in this block, that is OK.
1563 An explicitly used hard reg cannot be a spill reg. */
1565 if (rld[i].reg_rtx == 0 && in != 0 && hard_regs_live_known)
1567 rtx note;
1568 int regno;
1569 machine_mode rel_mode = inmode;
1571 if (out && partial_subreg_p (rel_mode, outmode))
1572 rel_mode = outmode;
1574 for (note = REG_NOTES (this_insn); note; note = XEXP (note, 1))
1575 if (REG_NOTE_KIND (note) == REG_DEAD
1576 && REG_P (XEXP (note, 0))
1577 && (regno = REGNO (XEXP (note, 0))) < FIRST_PSEUDO_REGISTER
1578 && reg_mentioned_p (XEXP (note, 0), in)
1579 /* Check that a former pseudo is valid; see find_dummy_reload. */
1580 && (ORIGINAL_REGNO (XEXP (note, 0)) < FIRST_PSEUDO_REGISTER
1581 || (! bitmap_bit_p (DF_LR_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun)),
1582 ORIGINAL_REGNO (XEXP (note, 0)))
1583 && REG_NREGS (XEXP (note, 0)) == 1))
1584 && ! refers_to_regno_for_reload_p (regno,
1585 end_hard_regno (rel_mode,
1586 regno),
1587 PATTERN (this_insn), inloc)
1588 && ! find_reg_fusage (this_insn, USE, XEXP (note, 0))
1589 /* If this is also an output reload, IN cannot be used as
1590 the reload register if it is set in this insn unless IN
1591 is also OUT. */
1592 && (out == 0 || in == out
1593 || ! hard_reg_set_here_p (regno,
1594 end_hard_regno (rel_mode, regno),
1595 PATTERN (this_insn)))
1596 /* ??? Why is this code so different from the previous?
1597 Is there any simple coherent way to describe the two together?
1598 What's going on here. */
1599 && (in != out
1600 || (GET_CODE (in) == SUBREG
1601 && (known_equal_after_align_up
1602 (GET_MODE_SIZE (GET_MODE (in)),
1603 GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))),
1604 UNITS_PER_WORD))))
1605 /* Make sure the operand fits in the reg that dies. */
1606 && known_le (GET_MODE_SIZE (rel_mode),
1607 GET_MODE_SIZE (GET_MODE (XEXP (note, 0))))
1608 && targetm.hard_regno_mode_ok (regno, inmode)
1609 && targetm.hard_regno_mode_ok (regno, outmode))
1611 unsigned int offs;
1612 unsigned int nregs = MAX (hard_regno_nregs (regno, inmode),
1613 hard_regno_nregs (regno, outmode));
1615 for (offs = 0; offs < nregs; offs++)
1616 if (fixed_regs[regno + offs]
1617 || ! TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
1618 regno + offs))
1619 break;
1621 if (offs == nregs
1622 && (! (refers_to_regno_for_reload_p
1623 (regno, end_hard_regno (inmode, regno), in, (rtx *) 0))
1624 || can_reload_into (in, regno, inmode)))
1626 rld[i].reg_rtx = gen_rtx_REG (rel_mode, regno);
1627 break;
1632 if (out)
1633 output_reloadnum = i;
1635 return i;
1638 /* Record an additional place we must replace a value
1639 for which we have already recorded a reload.
1640 RELOADNUM is the value returned by push_reload
1641 when the reload was recorded.
1642 This is used in insn patterns that use match_dup. */
1644 static void
1645 push_replacement (rtx *loc, int reloadnum, machine_mode mode)
1647 if (replace_reloads)
1649 struct replacement *r = &replacements[n_replacements++];
1650 r->what = reloadnum;
1651 r->where = loc;
1652 r->mode = mode;
1656 /* Duplicate any replacement we have recorded to apply at
1657 location ORIG_LOC to also be performed at DUP_LOC.
1658 This is used in insn patterns that use match_dup. */
1660 static void
1661 dup_replacements (rtx *dup_loc, rtx *orig_loc)
1663 int i, n = n_replacements;
1665 for (i = 0; i < n; i++)
1667 struct replacement *r = &replacements[i];
1668 if (r->where == orig_loc)
1669 push_replacement (dup_loc, r->what, r->mode);
1673 /* Transfer all replacements that used to be in reload FROM to be in
1674 reload TO. */
1676 void
1677 transfer_replacements (int to, int from)
1679 int i;
1681 for (i = 0; i < n_replacements; i++)
1682 if (replacements[i].what == from)
1683 replacements[i].what = to;
1686 /* IN_RTX is the value loaded by a reload that we now decided to inherit,
1687 or a subpart of it. If we have any replacements registered for IN_RTX,
1688 cancel the reloads that were supposed to load them.
1689 Return nonzero if we canceled any reloads. */
1691 remove_address_replacements (rtx in_rtx)
1693 int i, j;
1694 char reload_flags[MAX_RELOADS];
1695 int something_changed = 0;
1697 memset (reload_flags, 0, sizeof reload_flags);
1698 for (i = 0, j = 0; i < n_replacements; i++)
1700 if (loc_mentioned_in_p (replacements[i].where, in_rtx))
1701 reload_flags[replacements[i].what] |= 1;
1702 else
1704 replacements[j++] = replacements[i];
1705 reload_flags[replacements[i].what] |= 2;
1708 /* Note that the following store must be done before the recursive calls. */
1709 n_replacements = j;
1711 for (i = n_reloads - 1; i >= 0; i--)
1713 if (reload_flags[i] == 1)
1715 deallocate_reload_reg (i);
1716 remove_address_replacements (rld[i].in);
1717 rld[i].in = 0;
1718 something_changed = 1;
1721 return something_changed;
1724 /* If there is only one output reload, and it is not for an earlyclobber
1725 operand, try to combine it with a (logically unrelated) input reload
1726 to reduce the number of reload registers needed.
1728 This is safe if the input reload does not appear in
1729 the value being output-reloaded, because this implies
1730 it is not needed any more once the original insn completes.
1732 If that doesn't work, see we can use any of the registers that
1733 die in this insn as a reload register. We can if it is of the right
1734 class and does not appear in the value being output-reloaded. */
1736 static void
1737 combine_reloads (void)
1739 int i, regno;
1740 int output_reload = -1;
1741 int secondary_out = -1;
1742 rtx note;
1744 /* Find the output reload; return unless there is exactly one
1745 and that one is mandatory. */
1747 for (i = 0; i < n_reloads; i++)
1748 if (rld[i].out != 0)
1750 if (output_reload >= 0)
1751 return;
1752 output_reload = i;
1755 if (output_reload < 0 || rld[output_reload].optional)
1756 return;
1758 /* An input-output reload isn't combinable. */
1760 if (rld[output_reload].in != 0)
1761 return;
1763 /* If this reload is for an earlyclobber operand, we can't do anything. */
1764 if (earlyclobber_operand_p (rld[output_reload].out))
1765 return;
1767 /* If there is a reload for part of the address of this operand, we would
1768 need to change it to RELOAD_FOR_OTHER_ADDRESS. But that would extend
1769 its life to the point where doing this combine would not lower the
1770 number of spill registers needed. */
1771 for (i = 0; i < n_reloads; i++)
1772 if ((rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
1773 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
1774 && rld[i].opnum == rld[output_reload].opnum)
1775 return;
1777 /* Check each input reload; can we combine it? */
1779 for (i = 0; i < n_reloads; i++)
1780 if (rld[i].in && ! rld[i].optional && ! rld[i].nocombine
1781 /* Life span of this reload must not extend past main insn. */
1782 && rld[i].when_needed != RELOAD_FOR_OUTPUT_ADDRESS
1783 && rld[i].when_needed != RELOAD_FOR_OUTADDR_ADDRESS
1784 && rld[i].when_needed != RELOAD_OTHER
1785 && (ira_reg_class_max_nregs [(int)rld[i].rclass][(int) rld[i].inmode]
1786 == ira_reg_class_max_nregs [(int) rld[output_reload].rclass]
1787 [(int) rld[output_reload].outmode])
1788 && known_eq (rld[i].inc, 0)
1789 && rld[i].reg_rtx == 0
1790 /* Don't combine two reloads with different secondary
1791 memory locations. */
1792 && (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum] == 0
1793 || secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum] == 0
1794 || rtx_equal_p (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum],
1795 secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum]))
1796 && (targetm.small_register_classes_for_mode_p (VOIDmode)
1797 ? (rld[i].rclass == rld[output_reload].rclass)
1798 : (reg_class_subset_p (rld[i].rclass,
1799 rld[output_reload].rclass)
1800 || reg_class_subset_p (rld[output_reload].rclass,
1801 rld[i].rclass)))
1802 && (MATCHES (rld[i].in, rld[output_reload].out)
1803 /* Args reversed because the first arg seems to be
1804 the one that we imagine being modified
1805 while the second is the one that might be affected. */
1806 || (! reg_overlap_mentioned_for_reload_p (rld[output_reload].out,
1807 rld[i].in)
1808 /* However, if the input is a register that appears inside
1809 the output, then we also can't share.
1810 Imagine (set (mem (reg 69)) (plus (reg 69) ...)).
1811 If the same reload reg is used for both reg 69 and the
1812 result to be stored in memory, then that result
1813 will clobber the address of the memory ref. */
1814 && ! (REG_P (rld[i].in)
1815 && reg_overlap_mentioned_for_reload_p (rld[i].in,
1816 rld[output_reload].out))))
1817 && ! reload_inner_reg_of_subreg (rld[i].in, rld[i].inmode,
1818 rld[i].when_needed != RELOAD_FOR_INPUT)
1819 && (reg_class_size[(int) rld[i].rclass]
1820 || targetm.small_register_classes_for_mode_p (VOIDmode))
1821 /* We will allow making things slightly worse by combining an
1822 input and an output, but no worse than that. */
1823 && (rld[i].when_needed == RELOAD_FOR_INPUT
1824 || rld[i].when_needed == RELOAD_FOR_OUTPUT))
1826 int j;
1828 /* We have found a reload to combine with! */
1829 rld[i].out = rld[output_reload].out;
1830 rld[i].out_reg = rld[output_reload].out_reg;
1831 rld[i].outmode = rld[output_reload].outmode;
1832 /* Mark the old output reload as inoperative. */
1833 rld[output_reload].out = 0;
1834 /* The combined reload is needed for the entire insn. */
1835 rld[i].when_needed = RELOAD_OTHER;
1836 /* If the output reload had a secondary reload, copy it. */
1837 if (rld[output_reload].secondary_out_reload != -1)
1839 rld[i].secondary_out_reload
1840 = rld[output_reload].secondary_out_reload;
1841 rld[i].secondary_out_icode
1842 = rld[output_reload].secondary_out_icode;
1845 /* Copy any secondary MEM. */
1846 if (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum] != 0)
1847 secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum]
1848 = secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum];
1849 /* If required, minimize the register class. */
1850 if (reg_class_subset_p (rld[output_reload].rclass,
1851 rld[i].rclass))
1852 rld[i].rclass = rld[output_reload].rclass;
1854 /* Transfer all replacements from the old reload to the combined. */
1855 for (j = 0; j < n_replacements; j++)
1856 if (replacements[j].what == output_reload)
1857 replacements[j].what = i;
1859 return;
1862 /* If this insn has only one operand that is modified or written (assumed
1863 to be the first), it must be the one corresponding to this reload. It
1864 is safe to use anything that dies in this insn for that output provided
1865 that it does not occur in the output (we already know it isn't an
1866 earlyclobber. If this is an asm insn, give up. */
1868 if (INSN_CODE (this_insn) == -1)
1869 return;
1871 for (i = 1; i < insn_data[INSN_CODE (this_insn)].n_operands; i++)
1872 if (insn_data[INSN_CODE (this_insn)].operand[i].constraint[0] == '='
1873 || insn_data[INSN_CODE (this_insn)].operand[i].constraint[0] == '+')
1874 return;
1876 /* See if some hard register that dies in this insn and is not used in
1877 the output is the right class. Only works if the register we pick
1878 up can fully hold our output reload. */
1879 for (note = REG_NOTES (this_insn); note; note = XEXP (note, 1))
1880 if (REG_NOTE_KIND (note) == REG_DEAD
1881 && REG_P (XEXP (note, 0))
1882 && !reg_overlap_mentioned_for_reload_p (XEXP (note, 0),
1883 rld[output_reload].out)
1884 && (regno = REGNO (XEXP (note, 0))) < FIRST_PSEUDO_REGISTER
1885 && targetm.hard_regno_mode_ok (regno, rld[output_reload].outmode)
1886 && TEST_HARD_REG_BIT (reg_class_contents[(int) rld[output_reload].rclass],
1887 regno)
1888 && (hard_regno_nregs (regno, rld[output_reload].outmode)
1889 <= REG_NREGS (XEXP (note, 0)))
1890 /* Ensure that a secondary or tertiary reload for this output
1891 won't want this register. */
1892 && ((secondary_out = rld[output_reload].secondary_out_reload) == -1
1893 || (!(TEST_HARD_REG_BIT
1894 (reg_class_contents[(int) rld[secondary_out].rclass], regno))
1895 && ((secondary_out = rld[secondary_out].secondary_out_reload) == -1
1896 || !(TEST_HARD_REG_BIT
1897 (reg_class_contents[(int) rld[secondary_out].rclass],
1898 regno)))))
1899 && !fixed_regs[regno]
1900 /* Check that a former pseudo is valid; see find_dummy_reload. */
1901 && (ORIGINAL_REGNO (XEXP (note, 0)) < FIRST_PSEUDO_REGISTER
1902 || (!bitmap_bit_p (DF_LR_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun)),
1903 ORIGINAL_REGNO (XEXP (note, 0)))
1904 && REG_NREGS (XEXP (note, 0)) == 1)))
1906 rld[output_reload].reg_rtx
1907 = gen_rtx_REG (rld[output_reload].outmode, regno);
1908 return;
1912 /* Try to find a reload register for an in-out reload (expressions IN and OUT).
1913 See if one of IN and OUT is a register that may be used;
1914 this is desirable since a spill-register won't be needed.
1915 If so, return the register rtx that proves acceptable.
1917 INLOC and OUTLOC are locations where IN and OUT appear in the insn.
1918 RCLASS is the register class required for the reload.
1920 If FOR_REAL is >= 0, it is the number of the reload,
1921 and in some cases when it can be discovered that OUT doesn't need
1922 to be computed, clear out rld[FOR_REAL].out.
1924 If FOR_REAL is -1, this should not be done, because this call
1925 is just to see if a register can be found, not to find and install it.
1927 EARLYCLOBBER is nonzero if OUT is an earlyclobber operand. This
1928 puts an additional constraint on being able to use IN for OUT since
1929 IN must not appear elsewhere in the insn (it is assumed that IN itself
1930 is safe from the earlyclobber). */
1932 static rtx
1933 find_dummy_reload (rtx real_in, rtx real_out, rtx *inloc, rtx *outloc,
1934 machine_mode inmode, machine_mode outmode,
1935 reg_class_t rclass, int for_real, int earlyclobber)
1937 rtx in = real_in;
1938 rtx out = real_out;
1939 int in_offset = 0;
1940 int out_offset = 0;
1941 rtx value = 0;
1943 /* If operands exceed a word, we can't use either of them
1944 unless they have the same size. */
1945 if (maybe_ne (GET_MODE_SIZE (outmode), GET_MODE_SIZE (inmode))
1946 && (maybe_gt (GET_MODE_SIZE (outmode), UNITS_PER_WORD)
1947 || maybe_gt (GET_MODE_SIZE (inmode), UNITS_PER_WORD)))
1948 return 0;
1950 /* Note that {in,out}_offset are needed only when 'in' or 'out'
1951 respectively refers to a hard register. */
1953 /* Find the inside of any subregs. */
1954 while (GET_CODE (out) == SUBREG)
1956 if (REG_P (SUBREG_REG (out))
1957 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER)
1958 out_offset += subreg_regno_offset (REGNO (SUBREG_REG (out)),
1959 GET_MODE (SUBREG_REG (out)),
1960 SUBREG_BYTE (out),
1961 GET_MODE (out));
1962 out = SUBREG_REG (out);
1964 while (GET_CODE (in) == SUBREG)
1966 if (REG_P (SUBREG_REG (in))
1967 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER)
1968 in_offset += subreg_regno_offset (REGNO (SUBREG_REG (in)),
1969 GET_MODE (SUBREG_REG (in)),
1970 SUBREG_BYTE (in),
1971 GET_MODE (in));
1972 in = SUBREG_REG (in);
1975 /* Narrow down the reg class, the same way push_reload will;
1976 otherwise we might find a dummy now, but push_reload won't. */
1978 reg_class_t preferred_class = targetm.preferred_reload_class (in, rclass);
1979 if (preferred_class != NO_REGS)
1980 rclass = (enum reg_class) preferred_class;
1983 /* See if OUT will do. */
1984 if (REG_P (out)
1985 && REGNO (out) < FIRST_PSEUDO_REGISTER)
1987 unsigned int regno = REGNO (out) + out_offset;
1988 unsigned int nwords = hard_regno_nregs (regno, outmode);
1989 rtx saved_rtx;
1991 /* When we consider whether the insn uses OUT,
1992 ignore references within IN. They don't prevent us
1993 from copying IN into OUT, because those refs would
1994 move into the insn that reloads IN.
1996 However, we only ignore IN in its role as this reload.
1997 If the insn uses IN elsewhere and it contains OUT,
1998 that counts. We can't be sure it's the "same" operand
1999 so it might not go through this reload.
2001 We also need to avoid using OUT if it, or part of it, is a
2002 fixed register. Modifying such registers, even transiently,
2003 may have undefined effects on the machine, such as modifying
2004 the stack pointer. */
2005 saved_rtx = *inloc;
2006 *inloc = const0_rtx;
2008 if (regno < FIRST_PSEUDO_REGISTER
2009 && targetm.hard_regno_mode_ok (regno, outmode)
2010 && ! refers_to_regno_for_reload_p (regno, regno + nwords,
2011 PATTERN (this_insn), outloc))
2013 unsigned int i;
2015 for (i = 0; i < nwords; i++)
2016 if (! TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
2017 regno + i)
2018 || fixed_regs[regno + i])
2019 break;
2021 if (i == nwords)
2023 if (REG_P (real_out))
2024 value = real_out;
2025 else
2026 value = gen_rtx_REG (outmode, regno);
2030 *inloc = saved_rtx;
2033 /* Consider using IN if OUT was not acceptable
2034 or if OUT dies in this insn (like the quotient in a divmod insn).
2035 We can't use IN unless it is dies in this insn,
2036 which means we must know accurately which hard regs are live.
2037 Also, the result can't go in IN if IN is used within OUT,
2038 or if OUT is an earlyclobber and IN appears elsewhere in the insn. */
2039 if (hard_regs_live_known
2040 && REG_P (in)
2041 && REGNO (in) < FIRST_PSEUDO_REGISTER
2042 && (value == 0
2043 || find_reg_note (this_insn, REG_UNUSED, real_out))
2044 && find_reg_note (this_insn, REG_DEAD, real_in)
2045 && !fixed_regs[REGNO (in)]
2046 && targetm.hard_regno_mode_ok (REGNO (in),
2047 /* The only case where out and real_out
2048 might have different modes is where
2049 real_out is a subreg, and in that
2050 case, out has a real mode. */
2051 (GET_MODE (out) != VOIDmode
2052 ? GET_MODE (out) : outmode))
2053 && (ORIGINAL_REGNO (in) < FIRST_PSEUDO_REGISTER
2054 /* However only do this if we can be sure that this input
2055 operand doesn't correspond with an uninitialized pseudo.
2056 global can assign some hardreg to it that is the same as
2057 the one assigned to a different, also live pseudo (as it
2058 can ignore the conflict). We must never introduce writes
2059 to such hardregs, as they would clobber the other live
2060 pseudo. See PR 20973. */
2061 || (!bitmap_bit_p (DF_LR_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun)),
2062 ORIGINAL_REGNO (in))
2063 /* Similarly, only do this if we can be sure that the death
2064 note is still valid. global can assign some hardreg to
2065 the pseudo referenced in the note and simultaneously a
2066 subword of this hardreg to a different, also live pseudo,
2067 because only another subword of the hardreg is actually
2068 used in the insn. This cannot happen if the pseudo has
2069 been assigned exactly one hardreg. See PR 33732. */
2070 && REG_NREGS (in) == 1)))
2072 unsigned int regno = REGNO (in) + in_offset;
2073 unsigned int nwords = hard_regno_nregs (regno, inmode);
2075 if (! refers_to_regno_for_reload_p (regno, regno + nwords, out, (rtx*) 0)
2076 && ! hard_reg_set_here_p (regno, regno + nwords,
2077 PATTERN (this_insn))
2078 && (! earlyclobber
2079 || ! refers_to_regno_for_reload_p (regno, regno + nwords,
2080 PATTERN (this_insn), inloc)))
2082 unsigned int i;
2084 for (i = 0; i < nwords; i++)
2085 if (! TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
2086 regno + i))
2087 break;
2089 if (i == nwords)
2091 /* If we were going to use OUT as the reload reg
2092 and changed our mind, it means OUT is a dummy that
2093 dies here. So don't bother copying value to it. */
2094 if (for_real >= 0 && value == real_out)
2095 rld[for_real].out = 0;
2096 if (REG_P (real_in))
2097 value = real_in;
2098 else
2099 value = gen_rtx_REG (inmode, regno);
2104 return value;
2107 /* This page contains subroutines used mainly for determining
2108 whether the IN or an OUT of a reload can serve as the
2109 reload register. */
2111 /* Return 1 if X is an operand of an insn that is being earlyclobbered. */
2114 earlyclobber_operand_p (rtx x)
2116 int i;
2118 for (i = 0; i < n_earlyclobbers; i++)
2119 if (reload_earlyclobbers[i] == x)
2120 return 1;
2122 return 0;
2125 /* Return 1 if expression X alters a hard reg in the range
2126 from BEG_REGNO (inclusive) to END_REGNO (exclusive),
2127 either explicitly or in the guise of a pseudo-reg allocated to REGNO.
2128 X should be the body of an instruction. */
2130 static int
2131 hard_reg_set_here_p (unsigned int beg_regno, unsigned int end_regno, rtx x)
2133 if (GET_CODE (x) == SET || GET_CODE (x) == CLOBBER)
2135 rtx op0 = SET_DEST (x);
2137 while (GET_CODE (op0) == SUBREG)
2138 op0 = SUBREG_REG (op0);
2139 if (REG_P (op0))
2141 unsigned int r = REGNO (op0);
2143 /* See if this reg overlaps range under consideration. */
2144 if (r < end_regno
2145 && end_hard_regno (GET_MODE (op0), r) > beg_regno)
2146 return 1;
2149 else if (GET_CODE (x) == PARALLEL)
2151 int i = XVECLEN (x, 0) - 1;
2153 for (; i >= 0; i--)
2154 if (hard_reg_set_here_p (beg_regno, end_regno, XVECEXP (x, 0, i)))
2155 return 1;
2158 return 0;
2161 /* Return 1 if ADDR is a valid memory address for mode MODE
2162 in address space AS, and check that each pseudo reg has the
2163 proper kind of hard reg. */
2166 strict_memory_address_addr_space_p (machine_mode mode ATTRIBUTE_UNUSED,
2167 rtx addr, addr_space_t as)
2169 #ifdef GO_IF_LEGITIMATE_ADDRESS
2170 gcc_assert (ADDR_SPACE_GENERIC_P (as));
2171 GO_IF_LEGITIMATE_ADDRESS (mode, addr, win);
2172 return 0;
2174 win:
2175 return 1;
2176 #else
2177 return targetm.addr_space.legitimate_address_p (mode, addr, 1, as);
2178 #endif
2181 /* Like rtx_equal_p except that it allows a REG and a SUBREG to match
2182 if they are the same hard reg, and has special hacks for
2183 autoincrement and autodecrement.
2184 This is specifically intended for find_reloads to use
2185 in determining whether two operands match.
2186 X is the operand whose number is the lower of the two.
2188 The value is 2 if Y contains a pre-increment that matches
2189 a non-incrementing address in X. */
2191 /* ??? To be completely correct, we should arrange to pass
2192 for X the output operand and for Y the input operand.
2193 For now, we assume that the output operand has the lower number
2194 because that is natural in (SET output (... input ...)). */
2197 operands_match_p (rtx x, rtx y)
2199 int i;
2200 RTX_CODE code = GET_CODE (x);
2201 const char *fmt;
2202 int success_2;
2204 if (x == y)
2205 return 1;
2206 if ((code == REG || (code == SUBREG && REG_P (SUBREG_REG (x))))
2207 && (REG_P (y) || (GET_CODE (y) == SUBREG
2208 && REG_P (SUBREG_REG (y)))))
2210 int j;
2212 if (code == SUBREG)
2214 i = REGNO (SUBREG_REG (x));
2215 if (i >= FIRST_PSEUDO_REGISTER)
2216 goto slow;
2217 i += subreg_regno_offset (REGNO (SUBREG_REG (x)),
2218 GET_MODE (SUBREG_REG (x)),
2219 SUBREG_BYTE (x),
2220 GET_MODE (x));
2222 else
2223 i = REGNO (x);
2225 if (GET_CODE (y) == SUBREG)
2227 j = REGNO (SUBREG_REG (y));
2228 if (j >= FIRST_PSEUDO_REGISTER)
2229 goto slow;
2230 j += subreg_regno_offset (REGNO (SUBREG_REG (y)),
2231 GET_MODE (SUBREG_REG (y)),
2232 SUBREG_BYTE (y),
2233 GET_MODE (y));
2235 else
2236 j = REGNO (y);
2238 /* On a REG_WORDS_BIG_ENDIAN machine, point to the last register of a
2239 multiple hard register group of scalar integer registers, so that
2240 for example (reg:DI 0) and (reg:SI 1) will be considered the same
2241 register. */
2242 scalar_int_mode xmode;
2243 if (REG_WORDS_BIG_ENDIAN
2244 && is_a <scalar_int_mode> (GET_MODE (x), &xmode)
2245 && GET_MODE_SIZE (xmode) > UNITS_PER_WORD
2246 && i < FIRST_PSEUDO_REGISTER)
2247 i += hard_regno_nregs (i, xmode) - 1;
2248 scalar_int_mode ymode;
2249 if (REG_WORDS_BIG_ENDIAN
2250 && is_a <scalar_int_mode> (GET_MODE (y), &ymode)
2251 && GET_MODE_SIZE (ymode) > UNITS_PER_WORD
2252 && j < FIRST_PSEUDO_REGISTER)
2253 j += hard_regno_nregs (j, ymode) - 1;
2255 return i == j;
2257 /* If two operands must match, because they are really a single
2258 operand of an assembler insn, then two postincrements are invalid
2259 because the assembler insn would increment only once.
2260 On the other hand, a postincrement matches ordinary indexing
2261 if the postincrement is the output operand. */
2262 if (code == POST_DEC || code == POST_INC || code == POST_MODIFY)
2263 return operands_match_p (XEXP (x, 0), y);
2264 /* Two preincrements are invalid
2265 because the assembler insn would increment only once.
2266 On the other hand, a preincrement matches ordinary indexing
2267 if the preincrement is the input operand.
2268 In this case, return 2, since some callers need to do special
2269 things when this happens. */
2270 if (GET_CODE (y) == PRE_DEC || GET_CODE (y) == PRE_INC
2271 || GET_CODE (y) == PRE_MODIFY)
2272 return operands_match_p (x, XEXP (y, 0)) ? 2 : 0;
2274 slow:
2276 /* Now we have disposed of all the cases in which different rtx codes
2277 can match. */
2278 if (code != GET_CODE (y))
2279 return 0;
2281 /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. */
2282 if (GET_MODE (x) != GET_MODE (y))
2283 return 0;
2285 /* MEMs referring to different address space are not equivalent. */
2286 if (code == MEM && MEM_ADDR_SPACE (x) != MEM_ADDR_SPACE (y))
2287 return 0;
2289 switch (code)
2291 CASE_CONST_UNIQUE:
2292 return 0;
2294 case LABEL_REF:
2295 return label_ref_label (x) == label_ref_label (y);
2296 case SYMBOL_REF:
2297 return XSTR (x, 0) == XSTR (y, 0);
2299 default:
2300 break;
2303 /* Compare the elements. If any pair of corresponding elements
2304 fail to match, return 0 for the whole things. */
2306 success_2 = 0;
2307 fmt = GET_RTX_FORMAT (code);
2308 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2310 int val, j;
2311 switch (fmt[i])
2313 case 'w':
2314 if (XWINT (x, i) != XWINT (y, i))
2315 return 0;
2316 break;
2318 case 'i':
2319 if (XINT (x, i) != XINT (y, i))
2320 return 0;
2321 break;
2323 case 'p':
2324 if (maybe_ne (SUBREG_BYTE (x), SUBREG_BYTE (y)))
2325 return 0;
2326 break;
2328 case 'e':
2329 val = operands_match_p (XEXP (x, i), XEXP (y, i));
2330 if (val == 0)
2331 return 0;
2332 /* If any subexpression returns 2,
2333 we should return 2 if we are successful. */
2334 if (val == 2)
2335 success_2 = 1;
2336 break;
2338 case '0':
2339 break;
2341 case 'E':
2342 if (XVECLEN (x, i) != XVECLEN (y, i))
2343 return 0;
2344 for (j = XVECLEN (x, i) - 1; j >= 0; --j)
2346 val = operands_match_p (XVECEXP (x, i, j), XVECEXP (y, i, j));
2347 if (val == 0)
2348 return 0;
2349 if (val == 2)
2350 success_2 = 1;
2352 break;
2354 /* It is believed that rtx's at this level will never
2355 contain anything but integers and other rtx's,
2356 except for within LABEL_REFs and SYMBOL_REFs. */
2357 default:
2358 gcc_unreachable ();
2361 return 1 + success_2;
2364 /* Describe the range of registers or memory referenced by X.
2365 If X is a register, set REG_FLAG and put the first register
2366 number into START and the last plus one into END.
2367 If X is a memory reference, put a base address into BASE
2368 and a range of integer offsets into START and END.
2369 If X is pushing on the stack, we can assume it causes no trouble,
2370 so we set the SAFE field. */
2372 static struct decomposition
2373 decompose (rtx x)
2375 struct decomposition val;
2376 int all_const = 0, regno;
2378 memset (&val, 0, sizeof (val));
2380 switch (GET_CODE (x))
2382 case MEM:
2384 rtx base = NULL_RTX, offset = 0;
2385 rtx addr = XEXP (x, 0);
2387 if (GET_CODE (addr) == PRE_DEC || GET_CODE (addr) == PRE_INC
2388 || GET_CODE (addr) == POST_DEC || GET_CODE (addr) == POST_INC)
2390 val.base = XEXP (addr, 0);
2391 val.start = -GET_MODE_SIZE (GET_MODE (x));
2392 val.end = GET_MODE_SIZE (GET_MODE (x));
2393 val.safe = REGNO (val.base) == STACK_POINTER_REGNUM;
2394 return val;
2397 if (GET_CODE (addr) == PRE_MODIFY || GET_CODE (addr) == POST_MODIFY)
2399 if (GET_CODE (XEXP (addr, 1)) == PLUS
2400 && XEXP (addr, 0) == XEXP (XEXP (addr, 1), 0)
2401 && CONSTANT_P (XEXP (XEXP (addr, 1), 1)))
2403 val.base = XEXP (addr, 0);
2404 val.start = -INTVAL (XEXP (XEXP (addr, 1), 1));
2405 val.end = INTVAL (XEXP (XEXP (addr, 1), 1));
2406 val.safe = REGNO (val.base) == STACK_POINTER_REGNUM;
2407 return val;
2411 if (GET_CODE (addr) == CONST)
2413 addr = XEXP (addr, 0);
2414 all_const = 1;
2416 if (GET_CODE (addr) == PLUS)
2418 if (CONSTANT_P (XEXP (addr, 0)))
2420 base = XEXP (addr, 1);
2421 offset = XEXP (addr, 0);
2423 else if (CONSTANT_P (XEXP (addr, 1)))
2425 base = XEXP (addr, 0);
2426 offset = XEXP (addr, 1);
2430 if (offset == 0)
2432 base = addr;
2433 offset = const0_rtx;
2435 if (GET_CODE (offset) == CONST)
2436 offset = XEXP (offset, 0);
2437 if (GET_CODE (offset) == PLUS)
2439 if (CONST_INT_P (XEXP (offset, 0)))
2441 base = gen_rtx_PLUS (GET_MODE (base), base, XEXP (offset, 1));
2442 offset = XEXP (offset, 0);
2444 else if (CONST_INT_P (XEXP (offset, 1)))
2446 base = gen_rtx_PLUS (GET_MODE (base), base, XEXP (offset, 0));
2447 offset = XEXP (offset, 1);
2449 else
2451 base = gen_rtx_PLUS (GET_MODE (base), base, offset);
2452 offset = const0_rtx;
2455 else if (!CONST_INT_P (offset))
2457 base = gen_rtx_PLUS (GET_MODE (base), base, offset);
2458 offset = const0_rtx;
2461 if (all_const && GET_CODE (base) == PLUS)
2462 base = gen_rtx_CONST (GET_MODE (base), base);
2464 gcc_assert (CONST_INT_P (offset));
2466 val.start = INTVAL (offset);
2467 val.end = val.start + GET_MODE_SIZE (GET_MODE (x));
2468 val.base = base;
2470 break;
2472 case REG:
2473 val.reg_flag = 1;
2474 regno = true_regnum (x);
2475 if (regno < 0 || regno >= FIRST_PSEUDO_REGISTER)
2477 /* A pseudo with no hard reg. */
2478 val.start = REGNO (x);
2479 val.end = val.start + 1;
2481 else
2483 /* A hard reg. */
2484 val.start = regno;
2485 val.end = end_hard_regno (GET_MODE (x), regno);
2487 break;
2489 case SUBREG:
2490 if (!REG_P (SUBREG_REG (x)))
2491 /* This could be more precise, but it's good enough. */
2492 return decompose (SUBREG_REG (x));
2493 regno = true_regnum (x);
2494 if (regno < 0 || regno >= FIRST_PSEUDO_REGISTER)
2495 return decompose (SUBREG_REG (x));
2497 /* A hard reg. */
2498 val.reg_flag = 1;
2499 val.start = regno;
2500 val.end = regno + subreg_nregs (x);
2501 break;
2503 case SCRATCH:
2504 /* This hasn't been assigned yet, so it can't conflict yet. */
2505 val.safe = 1;
2506 break;
2508 default:
2509 gcc_assert (CONSTANT_P (x));
2510 val.safe = 1;
2511 break;
2513 return val;
2516 /* Return 1 if altering Y will not modify the value of X.
2517 Y is also described by YDATA, which should be decompose (Y). */
2519 static int
2520 immune_p (rtx x, rtx y, struct decomposition ydata)
2522 struct decomposition xdata;
2524 if (ydata.reg_flag)
2525 /* In this case the decomposition structure contains register
2526 numbers rather than byte offsets. */
2527 return !refers_to_regno_for_reload_p (ydata.start.to_constant (),
2528 ydata.end.to_constant (),
2529 x, (rtx *) 0);
2530 if (ydata.safe)
2531 return 1;
2533 gcc_assert (MEM_P (y));
2534 /* If Y is memory and X is not, Y can't affect X. */
2535 if (!MEM_P (x))
2536 return 1;
2538 xdata = decompose (x);
2540 if (! rtx_equal_p (xdata.base, ydata.base))
2542 /* If bases are distinct symbolic constants, there is no overlap. */
2543 if (CONSTANT_P (xdata.base) && CONSTANT_P (ydata.base))
2544 return 1;
2545 /* Constants and stack slots never overlap. */
2546 if (CONSTANT_P (xdata.base)
2547 && (ydata.base == frame_pointer_rtx
2548 || ydata.base == hard_frame_pointer_rtx
2549 || ydata.base == stack_pointer_rtx))
2550 return 1;
2551 if (CONSTANT_P (ydata.base)
2552 && (xdata.base == frame_pointer_rtx
2553 || xdata.base == hard_frame_pointer_rtx
2554 || xdata.base == stack_pointer_rtx))
2555 return 1;
2556 /* If either base is variable, we don't know anything. */
2557 return 0;
2560 return known_ge (xdata.start, ydata.end) || known_ge (ydata.start, xdata.end);
2563 /* Similar, but calls decompose. */
2566 safe_from_earlyclobber (rtx op, rtx clobber)
2568 struct decomposition early_data;
2570 early_data = decompose (clobber);
2571 return immune_p (op, clobber, early_data);
2574 /* Main entry point of this file: search the body of INSN
2575 for values that need reloading and record them with push_reload.
2576 REPLACE nonzero means record also where the values occur
2577 so that subst_reloads can be used.
2579 IND_LEVELS says how many levels of indirection are supported by this
2580 machine; a value of zero means that a memory reference is not a valid
2581 memory address.
2583 LIVE_KNOWN says we have valid information about which hard
2584 regs are live at each point in the program; this is true when
2585 we are called from global_alloc but false when stupid register
2586 allocation has been done.
2588 RELOAD_REG_P if nonzero is a vector indexed by hard reg number
2589 which is nonnegative if the reg has been commandeered for reloading into.
2590 It is copied into STATIC_RELOAD_REG_P and referenced from there
2591 by various subroutines.
2593 Return TRUE if some operands need to be changed, because of swapping
2594 commutative operands, reg_equiv_address substitution, or whatever. */
2597 find_reloads (rtx_insn *insn, int replace, int ind_levels, int live_known,
2598 short *reload_reg_p)
2600 int insn_code_number;
2601 int i, j;
2602 int noperands;
2603 /* These start out as the constraints for the insn
2604 and they are chewed up as we consider alternatives. */
2605 const char *constraints[MAX_RECOG_OPERANDS];
2606 /* These are the preferred classes for an operand, or NO_REGS if it isn't
2607 a register. */
2608 enum reg_class preferred_class[MAX_RECOG_OPERANDS];
2609 char pref_or_nothing[MAX_RECOG_OPERANDS];
2610 /* Nonzero for a MEM operand whose entire address needs a reload.
2611 May be -1 to indicate the entire address may or may not need a reload. */
2612 int address_reloaded[MAX_RECOG_OPERANDS];
2613 /* Nonzero for an address operand that needs to be completely reloaded.
2614 May be -1 to indicate the entire operand may or may not need a reload. */
2615 int address_operand_reloaded[MAX_RECOG_OPERANDS];
2616 /* Value of enum reload_type to use for operand. */
2617 enum reload_type operand_type[MAX_RECOG_OPERANDS];
2618 /* Value of enum reload_type to use within address of operand. */
2619 enum reload_type address_type[MAX_RECOG_OPERANDS];
2620 /* Save the usage of each operand. */
2621 enum reload_usage { RELOAD_READ, RELOAD_READ_WRITE, RELOAD_WRITE } modified[MAX_RECOG_OPERANDS];
2622 int no_input_reloads = 0, no_output_reloads = 0;
2623 int n_alternatives;
2624 reg_class_t this_alternative[MAX_RECOG_OPERANDS];
2625 char this_alternative_match_win[MAX_RECOG_OPERANDS];
2626 char this_alternative_win[MAX_RECOG_OPERANDS];
2627 char this_alternative_offmemok[MAX_RECOG_OPERANDS];
2628 char this_alternative_earlyclobber[MAX_RECOG_OPERANDS];
2629 int this_alternative_matches[MAX_RECOG_OPERANDS];
2630 reg_class_t goal_alternative[MAX_RECOG_OPERANDS];
2631 int this_alternative_number;
2632 int goal_alternative_number = 0;
2633 int operand_reloadnum[MAX_RECOG_OPERANDS];
2634 int goal_alternative_matches[MAX_RECOG_OPERANDS];
2635 int goal_alternative_matched[MAX_RECOG_OPERANDS];
2636 char goal_alternative_match_win[MAX_RECOG_OPERANDS];
2637 char goal_alternative_win[MAX_RECOG_OPERANDS];
2638 char goal_alternative_offmemok[MAX_RECOG_OPERANDS];
2639 char goal_alternative_earlyclobber[MAX_RECOG_OPERANDS];
2640 int goal_alternative_swapped;
2641 int best;
2642 int commutative;
2643 char operands_match[MAX_RECOG_OPERANDS][MAX_RECOG_OPERANDS];
2644 rtx substed_operand[MAX_RECOG_OPERANDS];
2645 rtx body = PATTERN (insn);
2646 rtx set = single_set (insn);
2647 int goal_earlyclobber = 0, this_earlyclobber;
2648 machine_mode operand_mode[MAX_RECOG_OPERANDS];
2649 int retval = 0;
2651 this_insn = insn;
2652 n_reloads = 0;
2653 n_replacements = 0;
2654 n_earlyclobbers = 0;
2655 replace_reloads = replace;
2656 hard_regs_live_known = live_known;
2657 static_reload_reg_p = reload_reg_p;
2659 if (JUMP_P (insn) && INSN_CODE (insn) < 0)
2661 extract_insn (insn);
2662 for (i = 0; i < recog_data.n_operands; i++)
2663 if (recog_data.operand_type[i] != OP_IN)
2664 break;
2665 if (i < recog_data.n_operands)
2667 error_for_asm (insn,
2668 "the target does not support asm goto "
2669 "with outputs in %<asm%>");
2670 ira_nullify_asm_goto (insn);
2671 return 0;
2675 /* JUMP_INSNs and CALL_INSNs are not allowed to have any output reloads;
2676 neither are insns that SET cc0. Insns that use CC0 are not allowed
2677 to have any input reloads. */
2678 if (JUMP_P (insn) || CALL_P (insn))
2679 no_output_reloads = 1;
2681 if (HAVE_cc0 && reg_referenced_p (cc0_rtx, PATTERN (insn)))
2682 no_input_reloads = 1;
2683 if (HAVE_cc0 && reg_set_p (cc0_rtx, PATTERN (insn)))
2684 no_output_reloads = 1;
2686 /* The eliminated forms of any secondary memory locations are per-insn, so
2687 clear them out here. */
2689 if (secondary_memlocs_elim_used)
2691 memset (secondary_memlocs_elim, 0,
2692 sizeof (secondary_memlocs_elim[0]) * secondary_memlocs_elim_used);
2693 secondary_memlocs_elim_used = 0;
2696 /* Dispose quickly of (set (reg..) (reg..)) if both have hard regs and it
2697 is cheap to move between them. If it is not, there may not be an insn
2698 to do the copy, so we may need a reload. */
2699 if (GET_CODE (body) == SET
2700 && REG_P (SET_DEST (body))
2701 && REGNO (SET_DEST (body)) < FIRST_PSEUDO_REGISTER
2702 && REG_P (SET_SRC (body))
2703 && REGNO (SET_SRC (body)) < FIRST_PSEUDO_REGISTER
2704 && register_move_cost (GET_MODE (SET_SRC (body)),
2705 REGNO_REG_CLASS (REGNO (SET_SRC (body))),
2706 REGNO_REG_CLASS (REGNO (SET_DEST (body)))) == 2)
2707 return 0;
2709 extract_insn (insn);
2711 noperands = reload_n_operands = recog_data.n_operands;
2712 n_alternatives = recog_data.n_alternatives;
2714 /* Just return "no reloads" if insn has no operands with constraints. */
2715 if (noperands == 0 || n_alternatives == 0)
2716 return 0;
2718 insn_code_number = INSN_CODE (insn);
2719 this_insn_is_asm = insn_code_number < 0;
2721 memcpy (operand_mode, recog_data.operand_mode,
2722 noperands * sizeof (machine_mode));
2723 memcpy (constraints, recog_data.constraints,
2724 noperands * sizeof (const char *));
2726 commutative = -1;
2728 /* If we will need to know, later, whether some pair of operands
2729 are the same, we must compare them now and save the result.
2730 Reloading the base and index registers will clobber them
2731 and afterward they will fail to match. */
2733 for (i = 0; i < noperands; i++)
2735 const char *p;
2736 int c;
2737 char *end;
2739 substed_operand[i] = recog_data.operand[i];
2740 p = constraints[i];
2742 modified[i] = RELOAD_READ;
2744 /* Scan this operand's constraint to see if it is an output operand,
2745 an in-out operand, is commutative, or should match another. */
2747 while ((c = *p))
2749 p += CONSTRAINT_LEN (c, p);
2750 switch (c)
2752 case '=':
2753 modified[i] = RELOAD_WRITE;
2754 break;
2755 case '+':
2756 modified[i] = RELOAD_READ_WRITE;
2757 break;
2758 case '%':
2760 /* The last operand should not be marked commutative. */
2761 gcc_assert (i != noperands - 1);
2763 /* We currently only support one commutative pair of
2764 operands. Some existing asm code currently uses more
2765 than one pair. Previously, that would usually work,
2766 but sometimes it would crash the compiler. We
2767 continue supporting that case as well as we can by
2768 silently ignoring all but the first pair. In the
2769 future we may handle it correctly. */
2770 if (commutative < 0)
2771 commutative = i;
2772 else
2773 gcc_assert (this_insn_is_asm);
2775 break;
2776 /* Use of ISDIGIT is tempting here, but it may get expensive because
2777 of locale support we don't want. */
2778 case '0': case '1': case '2': case '3': case '4':
2779 case '5': case '6': case '7': case '8': case '9':
2781 c = strtoul (p - 1, &end, 10);
2782 p = end;
2784 operands_match[c][i]
2785 = operands_match_p (recog_data.operand[c],
2786 recog_data.operand[i]);
2788 /* An operand may not match itself. */
2789 gcc_assert (c != i);
2791 /* If C can be commuted with C+1, and C might need to match I,
2792 then C+1 might also need to match I. */
2793 if (commutative >= 0)
2795 if (c == commutative || c == commutative + 1)
2797 int other = c + (c == commutative ? 1 : -1);
2798 operands_match[other][i]
2799 = operands_match_p (recog_data.operand[other],
2800 recog_data.operand[i]);
2802 if (i == commutative || i == commutative + 1)
2804 int other = i + (i == commutative ? 1 : -1);
2805 operands_match[c][other]
2806 = operands_match_p (recog_data.operand[c],
2807 recog_data.operand[other]);
2809 /* Note that C is supposed to be less than I.
2810 No need to consider altering both C and I because in
2811 that case we would alter one into the other. */
2818 /* Examine each operand that is a memory reference or memory address
2819 and reload parts of the addresses into index registers.
2820 Also here any references to pseudo regs that didn't get hard regs
2821 but are equivalent to constants get replaced in the insn itself
2822 with those constants. Nobody will ever see them again.
2824 Finally, set up the preferred classes of each operand. */
2826 for (i = 0; i < noperands; i++)
2828 RTX_CODE code = GET_CODE (recog_data.operand[i]);
2830 address_reloaded[i] = 0;
2831 address_operand_reloaded[i] = 0;
2832 operand_type[i] = (modified[i] == RELOAD_READ ? RELOAD_FOR_INPUT
2833 : modified[i] == RELOAD_WRITE ? RELOAD_FOR_OUTPUT
2834 : RELOAD_OTHER);
2835 address_type[i]
2836 = (modified[i] == RELOAD_READ ? RELOAD_FOR_INPUT_ADDRESS
2837 : modified[i] == RELOAD_WRITE ? RELOAD_FOR_OUTPUT_ADDRESS
2838 : RELOAD_OTHER);
2840 if (*constraints[i] == 0)
2841 /* Ignore things like match_operator operands. */
2843 else if (insn_extra_address_constraint
2844 (lookup_constraint (constraints[i])))
2846 address_operand_reloaded[i]
2847 = find_reloads_address (recog_data.operand_mode[i], (rtx*) 0,
2848 recog_data.operand[i],
2849 recog_data.operand_loc[i],
2850 i, operand_type[i], ind_levels, insn);
2852 /* If we now have a simple operand where we used to have a
2853 PLUS or MULT, re-recognize and try again. */
2854 if ((OBJECT_P (*recog_data.operand_loc[i])
2855 || GET_CODE (*recog_data.operand_loc[i]) == SUBREG)
2856 && (GET_CODE (recog_data.operand[i]) == MULT
2857 || GET_CODE (recog_data.operand[i]) == PLUS))
2859 INSN_CODE (insn) = -1;
2860 retval = find_reloads (insn, replace, ind_levels, live_known,
2861 reload_reg_p);
2862 return retval;
2865 recog_data.operand[i] = *recog_data.operand_loc[i];
2866 substed_operand[i] = recog_data.operand[i];
2868 /* Address operands are reloaded in their existing mode,
2869 no matter what is specified in the machine description. */
2870 operand_mode[i] = GET_MODE (recog_data.operand[i]);
2872 /* If the address is a single CONST_INT pick address mode
2873 instead otherwise we will later not know in which mode
2874 the reload should be performed. */
2875 if (operand_mode[i] == VOIDmode)
2876 operand_mode[i] = Pmode;
2879 else if (code == MEM)
2881 address_reloaded[i]
2882 = find_reloads_address (GET_MODE (recog_data.operand[i]),
2883 recog_data.operand_loc[i],
2884 XEXP (recog_data.operand[i], 0),
2885 &XEXP (recog_data.operand[i], 0),
2886 i, address_type[i], ind_levels, insn);
2887 recog_data.operand[i] = *recog_data.operand_loc[i];
2888 substed_operand[i] = recog_data.operand[i];
2890 else if (code == SUBREG)
2892 rtx reg = SUBREG_REG (recog_data.operand[i]);
2893 rtx op
2894 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2895 ind_levels,
2896 set != 0
2897 && &SET_DEST (set) == recog_data.operand_loc[i],
2898 insn,
2899 &address_reloaded[i]);
2901 /* If we made a MEM to load (a part of) the stackslot of a pseudo
2902 that didn't get a hard register, emit a USE with a REG_EQUAL
2903 note in front so that we might inherit a previous, possibly
2904 wider reload. */
2906 if (replace
2907 && MEM_P (op)
2908 && REG_P (reg)
2909 && known_ge (GET_MODE_SIZE (GET_MODE (reg)),
2910 GET_MODE_SIZE (GET_MODE (op)))
2911 && reg_equiv_constant (REGNO (reg)) == 0)
2912 set_unique_reg_note (emit_insn_before (gen_rtx_USE (VOIDmode, reg),
2913 insn),
2914 REG_EQUAL, reg_equiv_memory_loc (REGNO (reg)));
2916 substed_operand[i] = recog_data.operand[i] = op;
2918 else if (code == PLUS || GET_RTX_CLASS (code) == RTX_UNARY)
2919 /* We can get a PLUS as an "operand" as a result of register
2920 elimination. See eliminate_regs and gen_reload. We handle
2921 a unary operator by reloading the operand. */
2922 substed_operand[i] = recog_data.operand[i]
2923 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2924 ind_levels, 0, insn,
2925 &address_reloaded[i]);
2926 else if (code == REG)
2928 /* This is equivalent to calling find_reloads_toplev.
2929 The code is duplicated for speed.
2930 When we find a pseudo always equivalent to a constant,
2931 we replace it by the constant. We must be sure, however,
2932 that we don't try to replace it in the insn in which it
2933 is being set. */
2934 int regno = REGNO (recog_data.operand[i]);
2935 if (reg_equiv_constant (regno) != 0
2936 && (set == 0 || &SET_DEST (set) != recog_data.operand_loc[i]))
2938 /* Record the existing mode so that the check if constants are
2939 allowed will work when operand_mode isn't specified. */
2941 if (operand_mode[i] == VOIDmode)
2942 operand_mode[i] = GET_MODE (recog_data.operand[i]);
2944 substed_operand[i] = recog_data.operand[i]
2945 = reg_equiv_constant (regno);
2947 if (reg_equiv_memory_loc (regno) != 0
2948 && (reg_equiv_address (regno) != 0 || num_not_at_initial_offset))
2949 /* We need not give a valid is_set_dest argument since the case
2950 of a constant equivalence was checked above. */
2951 substed_operand[i] = recog_data.operand[i]
2952 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2953 ind_levels, 0, insn,
2954 &address_reloaded[i]);
2956 /* If the operand is still a register (we didn't replace it with an
2957 equivalent), get the preferred class to reload it into. */
2958 code = GET_CODE (recog_data.operand[i]);
2959 preferred_class[i]
2960 = ((code == REG && REGNO (recog_data.operand[i])
2961 >= FIRST_PSEUDO_REGISTER)
2962 ? reg_preferred_class (REGNO (recog_data.operand[i]))
2963 : NO_REGS);
2964 pref_or_nothing[i]
2965 = (code == REG
2966 && REGNO (recog_data.operand[i]) >= FIRST_PSEUDO_REGISTER
2967 && reg_alternate_class (REGNO (recog_data.operand[i])) == NO_REGS);
2970 /* If this is simply a copy from operand 1 to operand 0, merge the
2971 preferred classes for the operands. */
2972 if (set != 0 && noperands >= 2 && recog_data.operand[0] == SET_DEST (set)
2973 && recog_data.operand[1] == SET_SRC (set))
2975 preferred_class[0] = preferred_class[1]
2976 = reg_class_subunion[(int) preferred_class[0]][(int) preferred_class[1]];
2977 pref_or_nothing[0] |= pref_or_nothing[1];
2978 pref_or_nothing[1] |= pref_or_nothing[0];
2981 /* Now see what we need for pseudo-regs that didn't get hard regs
2982 or got the wrong kind of hard reg. For this, we must consider
2983 all the operands together against the register constraints. */
2985 best = MAX_RECOG_OPERANDS * 2 + 600;
2987 goal_alternative_swapped = 0;
2989 /* The constraints are made of several alternatives.
2990 Each operand's constraint looks like foo,bar,... with commas
2991 separating the alternatives. The first alternatives for all
2992 operands go together, the second alternatives go together, etc.
2994 First loop over alternatives. */
2996 alternative_mask enabled = get_enabled_alternatives (insn);
2997 for (this_alternative_number = 0;
2998 this_alternative_number < n_alternatives;
2999 this_alternative_number++)
3001 int swapped;
3003 if (!TEST_BIT (enabled, this_alternative_number))
3005 int i;
3007 for (i = 0; i < recog_data.n_operands; i++)
3008 constraints[i] = skip_alternative (constraints[i]);
3010 continue;
3013 /* If insn is commutative (it's safe to exchange a certain pair
3014 of operands) then we need to try each alternative twice, the
3015 second time matching those two operands as if we had
3016 exchanged them. To do this, really exchange them in
3017 operands. */
3018 for (swapped = 0; swapped < (commutative >= 0 ? 2 : 1); swapped++)
3020 /* Loop over operands for one constraint alternative. */
3021 /* LOSERS counts those that don't fit this alternative
3022 and would require loading. */
3023 int losers = 0;
3024 /* BAD is set to 1 if it some operand can't fit this alternative
3025 even after reloading. */
3026 int bad = 0;
3027 /* REJECT is a count of how undesirable this alternative says it is
3028 if any reloading is required. If the alternative matches exactly
3029 then REJECT is ignored, but otherwise it gets this much
3030 counted against it in addition to the reloading needed. Each
3031 ? counts three times here since we want the disparaging caused by
3032 a bad register class to only count 1/3 as much. */
3033 int reject = 0;
3035 if (swapped)
3037 recog_data.operand[commutative] = substed_operand[commutative + 1];
3038 recog_data.operand[commutative + 1] = substed_operand[commutative];
3039 /* Swap the duplicates too. */
3040 for (i = 0; i < recog_data.n_dups; i++)
3041 if (recog_data.dup_num[i] == commutative
3042 || recog_data.dup_num[i] == commutative + 1)
3043 *recog_data.dup_loc[i]
3044 = recog_data.operand[(int) recog_data.dup_num[i]];
3046 std::swap (preferred_class[commutative],
3047 preferred_class[commutative + 1]);
3048 std::swap (pref_or_nothing[commutative],
3049 pref_or_nothing[commutative + 1]);
3050 std::swap (address_reloaded[commutative],
3051 address_reloaded[commutative + 1]);
3054 this_earlyclobber = 0;
3056 for (i = 0; i < noperands; i++)
3058 const char *p = constraints[i];
3059 char *end;
3060 int len;
3061 int win = 0;
3062 int did_match = 0;
3063 /* 0 => this operand can be reloaded somehow for this alternative. */
3064 int badop = 1;
3065 /* 0 => this operand can be reloaded if the alternative allows regs. */
3066 int winreg = 0;
3067 int c;
3068 int m;
3069 rtx operand = recog_data.operand[i];
3070 int offset = 0;
3071 /* Nonzero means this is a MEM that must be reloaded into a reg
3072 regardless of what the constraint says. */
3073 int force_reload = 0;
3074 int offmemok = 0;
3075 /* Nonzero if a constant forced into memory would be OK for this
3076 operand. */
3077 int constmemok = 0;
3078 int earlyclobber = 0;
3079 enum constraint_num cn;
3080 enum reg_class cl;
3082 /* If the predicate accepts a unary operator, it means that
3083 we need to reload the operand, but do not do this for
3084 match_operator and friends. */
3085 if (UNARY_P (operand) && *p != 0)
3086 operand = XEXP (operand, 0);
3088 /* If the operand is a SUBREG, extract
3089 the REG or MEM (or maybe even a constant) within.
3090 (Constants can occur as a result of reg_equiv_constant.) */
3092 while (GET_CODE (operand) == SUBREG)
3094 /* Offset only matters when operand is a REG and
3095 it is a hard reg. This is because it is passed
3096 to reg_fits_class_p if it is a REG and all pseudos
3097 return 0 from that function. */
3098 if (REG_P (SUBREG_REG (operand))
3099 && REGNO (SUBREG_REG (operand)) < FIRST_PSEUDO_REGISTER)
3101 if (simplify_subreg_regno (REGNO (SUBREG_REG (operand)),
3102 GET_MODE (SUBREG_REG (operand)),
3103 SUBREG_BYTE (operand),
3104 GET_MODE (operand)) < 0)
3105 force_reload = 1;
3106 offset += subreg_regno_offset (REGNO (SUBREG_REG (operand)),
3107 GET_MODE (SUBREG_REG (operand)),
3108 SUBREG_BYTE (operand),
3109 GET_MODE (operand));
3111 operand = SUBREG_REG (operand);
3112 /* Force reload if this is a constant or PLUS or if there may
3113 be a problem accessing OPERAND in the outer mode. */
3114 scalar_int_mode inner_mode;
3115 if (CONSTANT_P (operand)
3116 || GET_CODE (operand) == PLUS
3117 /* We must force a reload of paradoxical SUBREGs
3118 of a MEM because the alignment of the inner value
3119 may not be enough to do the outer reference. On
3120 big-endian machines, it may also reference outside
3121 the object.
3123 On machines that extend byte operations and we have a
3124 SUBREG where both the inner and outer modes are no wider
3125 than a word and the inner mode is narrower, is integral,
3126 and gets extended when loaded from memory, combine.c has
3127 made assumptions about the behavior of the machine in such
3128 register access. If the data is, in fact, in memory we
3129 must always load using the size assumed to be in the
3130 register and let the insn do the different-sized
3131 accesses.
3133 This is doubly true if WORD_REGISTER_OPERATIONS. In
3134 this case eliminate_regs has left non-paradoxical
3135 subregs for push_reload to see. Make sure it does
3136 by forcing the reload.
3138 ??? When is it right at this stage to have a subreg
3139 of a mem that is _not_ to be handled specially? IMO
3140 those should have been reduced to just a mem. */
3141 || ((MEM_P (operand)
3142 || (REG_P (operand)
3143 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
3144 && (WORD_REGISTER_OPERATIONS
3145 || (((maybe_lt
3146 (GET_MODE_BITSIZE (GET_MODE (operand)),
3147 BIGGEST_ALIGNMENT))
3148 && (paradoxical_subreg_p
3149 (operand_mode[i], GET_MODE (operand)))))
3150 || BYTES_BIG_ENDIAN
3151 || (known_le (GET_MODE_SIZE (operand_mode[i]),
3152 UNITS_PER_WORD)
3153 && (is_a <scalar_int_mode>
3154 (GET_MODE (operand), &inner_mode))
3155 && (GET_MODE_SIZE (inner_mode)
3156 <= UNITS_PER_WORD)
3157 && paradoxical_subreg_p (operand_mode[i],
3158 inner_mode)
3159 && LOAD_EXTEND_OP (inner_mode) != UNKNOWN)))
3161 force_reload = 1;
3164 this_alternative[i] = NO_REGS;
3165 this_alternative_win[i] = 0;
3166 this_alternative_match_win[i] = 0;
3167 this_alternative_offmemok[i] = 0;
3168 this_alternative_earlyclobber[i] = 0;
3169 this_alternative_matches[i] = -1;
3171 /* An empty constraint or empty alternative
3172 allows anything which matched the pattern. */
3173 if (*p == 0 || *p == ',')
3174 win = 1, badop = 0;
3176 /* Scan this alternative's specs for this operand;
3177 set WIN if the operand fits any letter in this alternative.
3178 Otherwise, clear BADOP if this operand could
3179 fit some letter after reloads,
3180 or set WINREG if this operand could fit after reloads
3181 provided the constraint allows some registers. */
3184 switch ((c = *p, len = CONSTRAINT_LEN (c, p)), c)
3186 case '\0':
3187 len = 0;
3188 break;
3189 case ',':
3190 c = '\0';
3191 break;
3193 case '?':
3194 reject += 6;
3195 break;
3197 case '!':
3198 reject = 600;
3199 break;
3201 case '#':
3202 /* Ignore rest of this alternative as far as
3203 reloading is concerned. */
3205 p++;
3206 while (*p && *p != ',');
3207 len = 0;
3208 break;
3210 case '0': case '1': case '2': case '3': case '4':
3211 case '5': case '6': case '7': case '8': case '9':
3212 m = strtoul (p, &end, 10);
3213 p = end;
3214 len = 0;
3216 this_alternative_matches[i] = m;
3217 /* We are supposed to match a previous operand.
3218 If we do, we win if that one did.
3219 If we do not, count both of the operands as losers.
3220 (This is too conservative, since most of the time
3221 only a single reload insn will be needed to make
3222 the two operands win. As a result, this alternative
3223 may be rejected when it is actually desirable.) */
3224 if ((swapped && (m != commutative || i != commutative + 1))
3225 /* If we are matching as if two operands were swapped,
3226 also pretend that operands_match had been computed
3227 with swapped.
3228 But if I is the second of those and C is the first,
3229 don't exchange them, because operands_match is valid
3230 only on one side of its diagonal. */
3231 ? (operands_match
3232 [(m == commutative || m == commutative + 1)
3233 ? 2 * commutative + 1 - m : m]
3234 [(i == commutative || i == commutative + 1)
3235 ? 2 * commutative + 1 - i : i])
3236 : operands_match[m][i])
3238 /* If we are matching a non-offsettable address where an
3239 offsettable address was expected, then we must reject
3240 this combination, because we can't reload it. */
3241 if (this_alternative_offmemok[m]
3242 && MEM_P (recog_data.operand[m])
3243 && this_alternative[m] == NO_REGS
3244 && ! this_alternative_win[m])
3245 bad = 1;
3247 did_match = this_alternative_win[m];
3249 else
3251 /* Operands don't match. */
3252 rtx value;
3253 int loc1, loc2;
3254 /* Retroactively mark the operand we had to match
3255 as a loser, if it wasn't already. */
3256 if (this_alternative_win[m])
3257 losers++;
3258 this_alternative_win[m] = 0;
3259 if (this_alternative[m] == NO_REGS)
3260 bad = 1;
3261 /* But count the pair only once in the total badness of
3262 this alternative, if the pair can be a dummy reload.
3263 The pointers in operand_loc are not swapped; swap
3264 them by hand if necessary. */
3265 if (swapped && i == commutative)
3266 loc1 = commutative + 1;
3267 else if (swapped && i == commutative + 1)
3268 loc1 = commutative;
3269 else
3270 loc1 = i;
3271 if (swapped && m == commutative)
3272 loc2 = commutative + 1;
3273 else if (swapped && m == commutative + 1)
3274 loc2 = commutative;
3275 else
3276 loc2 = m;
3277 value
3278 = find_dummy_reload (recog_data.operand[i],
3279 recog_data.operand[m],
3280 recog_data.operand_loc[loc1],
3281 recog_data.operand_loc[loc2],
3282 operand_mode[i], operand_mode[m],
3283 this_alternative[m], -1,
3284 this_alternative_earlyclobber[m]);
3286 if (value != 0)
3287 losers--;
3289 /* This can be fixed with reloads if the operand
3290 we are supposed to match can be fixed with reloads. */
3291 badop = 0;
3292 this_alternative[i] = this_alternative[m];
3294 /* If we have to reload this operand and some previous
3295 operand also had to match the same thing as this
3296 operand, we don't know how to do that. So reject this
3297 alternative. */
3298 if (! did_match || force_reload)
3299 for (j = 0; j < i; j++)
3300 if (this_alternative_matches[j]
3301 == this_alternative_matches[i])
3303 badop = 1;
3304 break;
3306 break;
3308 case 'p':
3309 /* All necessary reloads for an address_operand
3310 were handled in find_reloads_address. */
3311 this_alternative[i]
3312 = base_reg_class (VOIDmode, ADDR_SPACE_GENERIC,
3313 ADDRESS, SCRATCH);
3314 win = 1;
3315 badop = 0;
3316 break;
3318 case TARGET_MEM_CONSTRAINT:
3319 if (force_reload)
3320 break;
3321 if (MEM_P (operand)
3322 || (REG_P (operand)
3323 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3324 && reg_renumber[REGNO (operand)] < 0))
3325 win = 1;
3326 if (CONST_POOL_OK_P (operand_mode[i], operand))
3327 badop = 0;
3328 constmemok = 1;
3329 break;
3331 case '<':
3332 if (MEM_P (operand)
3333 && ! address_reloaded[i]
3334 && (GET_CODE (XEXP (operand, 0)) == PRE_DEC
3335 || GET_CODE (XEXP (operand, 0)) == POST_DEC))
3336 win = 1;
3337 break;
3339 case '>':
3340 if (MEM_P (operand)
3341 && ! address_reloaded[i]
3342 && (GET_CODE (XEXP (operand, 0)) == PRE_INC
3343 || GET_CODE (XEXP (operand, 0)) == POST_INC))
3344 win = 1;
3345 break;
3347 /* Memory operand whose address is not offsettable. */
3348 case 'V':
3349 if (force_reload)
3350 break;
3351 if (MEM_P (operand)
3352 && ! (ind_levels ? offsettable_memref_p (operand)
3353 : offsettable_nonstrict_memref_p (operand))
3354 /* Certain mem addresses will become offsettable
3355 after they themselves are reloaded. This is important;
3356 we don't want our own handling of unoffsettables
3357 to override the handling of reg_equiv_address. */
3358 && !(REG_P (XEXP (operand, 0))
3359 && (ind_levels == 0
3360 || reg_equiv_address (REGNO (XEXP (operand, 0))) != 0)))
3361 win = 1;
3362 break;
3364 /* Memory operand whose address is offsettable. */
3365 case 'o':
3366 if (force_reload)
3367 break;
3368 if ((MEM_P (operand)
3369 /* If IND_LEVELS, find_reloads_address won't reload a
3370 pseudo that didn't get a hard reg, so we have to
3371 reject that case. */
3372 && ((ind_levels ? offsettable_memref_p (operand)
3373 : offsettable_nonstrict_memref_p (operand))
3374 /* A reloaded address is offsettable because it is now
3375 just a simple register indirect. */
3376 || address_reloaded[i] == 1))
3377 || (REG_P (operand)
3378 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3379 && reg_renumber[REGNO (operand)] < 0
3380 /* If reg_equiv_address is nonzero, we will be
3381 loading it into a register; hence it will be
3382 offsettable, but we cannot say that reg_equiv_mem
3383 is offsettable without checking. */
3384 && ((reg_equiv_mem (REGNO (operand)) != 0
3385 && offsettable_memref_p (reg_equiv_mem (REGNO (operand))))
3386 || (reg_equiv_address (REGNO (operand)) != 0))))
3387 win = 1;
3388 if (CONST_POOL_OK_P (operand_mode[i], operand)
3389 || MEM_P (operand))
3390 badop = 0;
3391 constmemok = 1;
3392 offmemok = 1;
3393 break;
3395 case '&':
3396 /* Output operand that is stored before the need for the
3397 input operands (and their index registers) is over. */
3398 earlyclobber = 1, this_earlyclobber = 1;
3399 break;
3401 case 'X':
3402 force_reload = 0;
3403 win = 1;
3404 break;
3406 case 'g':
3407 if (! force_reload
3408 /* A PLUS is never a valid operand, but reload can make
3409 it from a register when eliminating registers. */
3410 && GET_CODE (operand) != PLUS
3411 /* A SCRATCH is not a valid operand. */
3412 && GET_CODE (operand) != SCRATCH
3413 && (! CONSTANT_P (operand)
3414 || ! flag_pic
3415 || LEGITIMATE_PIC_OPERAND_P (operand))
3416 && (GENERAL_REGS == ALL_REGS
3417 || !REG_P (operand)
3418 || (REGNO (operand) >= FIRST_PSEUDO_REGISTER
3419 && reg_renumber[REGNO (operand)] < 0)))
3420 win = 1;
3421 cl = GENERAL_REGS;
3422 goto reg;
3424 default:
3425 cn = lookup_constraint (p);
3426 switch (get_constraint_type (cn))
3428 case CT_REGISTER:
3429 cl = reg_class_for_constraint (cn);
3430 if (cl != NO_REGS)
3431 goto reg;
3432 break;
3434 case CT_CONST_INT:
3435 if (CONST_INT_P (operand)
3436 && (insn_const_int_ok_for_constraint
3437 (INTVAL (operand), cn)))
3438 win = true;
3439 break;
3441 case CT_MEMORY:
3442 if (force_reload)
3443 break;
3444 if (constraint_satisfied_p (operand, cn))
3445 win = 1;
3446 /* If the address was already reloaded,
3447 we win as well. */
3448 else if (MEM_P (operand) && address_reloaded[i] == 1)
3449 win = 1;
3450 /* Likewise if the address will be reloaded because
3451 reg_equiv_address is nonzero. For reg_equiv_mem
3452 we have to check. */
3453 else if (REG_P (operand)
3454 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3455 && reg_renumber[REGNO (operand)] < 0
3456 && ((reg_equiv_mem (REGNO (operand)) != 0
3457 && (constraint_satisfied_p
3458 (reg_equiv_mem (REGNO (operand)),
3459 cn)))
3460 || (reg_equiv_address (REGNO (operand))
3461 != 0)))
3462 win = 1;
3464 /* If we didn't already win, we can reload
3465 constants via force_const_mem, and other
3466 MEMs by reloading the address like for 'o'. */
3467 if (CONST_POOL_OK_P (operand_mode[i], operand)
3468 || MEM_P (operand))
3469 badop = 0;
3470 constmemok = 1;
3471 offmemok = 1;
3472 break;
3474 case CT_SPECIAL_MEMORY:
3475 if (force_reload)
3476 break;
3477 if (constraint_satisfied_p (operand, cn))
3478 win = 1;
3479 /* Likewise if the address will be reloaded because
3480 reg_equiv_address is nonzero. For reg_equiv_mem
3481 we have to check. */
3482 else if (REG_P (operand)
3483 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3484 && reg_renumber[REGNO (operand)] < 0
3485 && reg_equiv_mem (REGNO (operand)) != 0
3486 && (constraint_satisfied_p
3487 (reg_equiv_mem (REGNO (operand)), cn)))
3488 win = 1;
3489 break;
3491 case CT_ADDRESS:
3492 if (constraint_satisfied_p (operand, cn))
3493 win = 1;
3495 /* If we didn't already win, we can reload
3496 the address into a base register. */
3497 this_alternative[i]
3498 = base_reg_class (VOIDmode, ADDR_SPACE_GENERIC,
3499 ADDRESS, SCRATCH);
3500 badop = 0;
3501 break;
3503 case CT_FIXED_FORM:
3504 if (constraint_satisfied_p (operand, cn))
3505 win = 1;
3506 break;
3508 break;
3510 reg:
3511 this_alternative[i]
3512 = reg_class_subunion[this_alternative[i]][cl];
3513 if (GET_MODE (operand) == BLKmode)
3514 break;
3515 winreg = 1;
3516 if (REG_P (operand)
3517 && reg_fits_class_p (operand, this_alternative[i],
3518 offset, GET_MODE (recog_data.operand[i])))
3519 win = 1;
3520 break;
3522 while ((p += len), c);
3524 if (swapped == (commutative >= 0 ? 1 : 0))
3525 constraints[i] = p;
3527 /* If this operand could be handled with a reg,
3528 and some reg is allowed, then this operand can be handled. */
3529 if (winreg && this_alternative[i] != NO_REGS
3530 && (win || !class_only_fixed_regs[this_alternative[i]]))
3531 badop = 0;
3533 /* Record which operands fit this alternative. */
3534 this_alternative_earlyclobber[i] = earlyclobber;
3535 if (win && ! force_reload)
3536 this_alternative_win[i] = 1;
3537 else if (did_match && ! force_reload)
3538 this_alternative_match_win[i] = 1;
3539 else
3541 int const_to_mem = 0;
3543 this_alternative_offmemok[i] = offmemok;
3544 losers++;
3545 if (badop)
3546 bad = 1;
3547 /* Alternative loses if it has no regs for a reg operand. */
3548 if (REG_P (operand)
3549 && this_alternative[i] == NO_REGS
3550 && this_alternative_matches[i] < 0)
3551 bad = 1;
3553 /* If this is a constant that is reloaded into the desired
3554 class by copying it to memory first, count that as another
3555 reload. This is consistent with other code and is
3556 required to avoid choosing another alternative when
3557 the constant is moved into memory by this function on
3558 an early reload pass. Note that the test here is
3559 precisely the same as in the code below that calls
3560 force_const_mem. */
3561 if (CONST_POOL_OK_P (operand_mode[i], operand)
3562 && ((targetm.preferred_reload_class (operand,
3563 this_alternative[i])
3564 == NO_REGS)
3565 || no_input_reloads))
3567 const_to_mem = 1;
3568 if (this_alternative[i] != NO_REGS)
3569 losers++;
3572 /* Alternative loses if it requires a type of reload not
3573 permitted for this insn. We can always reload SCRATCH
3574 and objects with a REG_UNUSED note. */
3575 if (GET_CODE (operand) != SCRATCH
3576 && modified[i] != RELOAD_READ && no_output_reloads
3577 && ! find_reg_note (insn, REG_UNUSED, operand))
3578 bad = 1;
3579 else if (modified[i] != RELOAD_WRITE && no_input_reloads
3580 && ! const_to_mem)
3581 bad = 1;
3583 /* If we can't reload this value at all, reject this
3584 alternative. Note that we could also lose due to
3585 LIMIT_RELOAD_CLASS, but we don't check that
3586 here. */
3588 if (! CONSTANT_P (operand) && this_alternative[i] != NO_REGS)
3590 if (targetm.preferred_reload_class (operand,
3591 this_alternative[i])
3592 == NO_REGS)
3593 reject = 600;
3595 if (operand_type[i] == RELOAD_FOR_OUTPUT
3596 && (targetm.preferred_output_reload_class (operand,
3597 this_alternative[i])
3598 == NO_REGS))
3599 reject = 600;
3602 /* We prefer to reload pseudos over reloading other things,
3603 since such reloads may be able to be eliminated later.
3604 If we are reloading a SCRATCH, we won't be generating any
3605 insns, just using a register, so it is also preferred.
3606 So bump REJECT in other cases. Don't do this in the
3607 case where we are forcing a constant into memory and
3608 it will then win since we don't want to have a different
3609 alternative match then. */
3610 if (! (REG_P (operand)
3611 && REGNO (operand) >= FIRST_PSEUDO_REGISTER)
3612 && GET_CODE (operand) != SCRATCH
3613 && ! (const_to_mem && constmemok))
3614 reject += 2;
3616 /* Input reloads can be inherited more often than output
3617 reloads can be removed, so penalize output reloads. */
3618 if (operand_type[i] != RELOAD_FOR_INPUT
3619 && GET_CODE (operand) != SCRATCH)
3620 reject++;
3623 /* If this operand is a pseudo register that didn't get
3624 a hard reg and this alternative accepts some
3625 register, see if the class that we want is a subset
3626 of the preferred class for this register. If not,
3627 but it intersects that class, use the preferred class
3628 instead. If it does not intersect the preferred
3629 class, show that usage of this alternative should be
3630 discouraged; it will be discouraged more still if the
3631 register is `preferred or nothing'. We do this
3632 because it increases the chance of reusing our spill
3633 register in a later insn and avoiding a pair of
3634 memory stores and loads.
3636 Don't bother with this if this alternative will
3637 accept this operand.
3639 Don't do this for a multiword operand, since it is
3640 only a small win and has the risk of requiring more
3641 spill registers, which could cause a large loss.
3643 Don't do this if the preferred class has only one
3644 register because we might otherwise exhaust the
3645 class. */
3647 if (! win && ! did_match
3648 && this_alternative[i] != NO_REGS
3649 && known_le (GET_MODE_SIZE (operand_mode[i]), UNITS_PER_WORD)
3650 && reg_class_size [(int) preferred_class[i]] > 0
3651 && ! small_register_class_p (preferred_class[i]))
3653 if (! reg_class_subset_p (this_alternative[i],
3654 preferred_class[i]))
3656 /* Since we don't have a way of forming the intersection,
3657 we just do something special if the preferred class
3658 is a subset of the class we have; that's the most
3659 common case anyway. */
3660 if (reg_class_subset_p (preferred_class[i],
3661 this_alternative[i]))
3662 this_alternative[i] = preferred_class[i];
3663 else
3664 reject += (2 + 2 * pref_or_nothing[i]);
3669 /* Now see if any output operands that are marked "earlyclobber"
3670 in this alternative conflict with any input operands
3671 or any memory addresses. */
3673 for (i = 0; i < noperands; i++)
3674 if (this_alternative_earlyclobber[i]
3675 && (this_alternative_win[i] || this_alternative_match_win[i]))
3677 struct decomposition early_data;
3679 early_data = decompose (recog_data.operand[i]);
3681 gcc_assert (modified[i] != RELOAD_READ);
3683 if (this_alternative[i] == NO_REGS)
3685 this_alternative_earlyclobber[i] = 0;
3686 gcc_assert (this_insn_is_asm);
3687 error_for_asm (this_insn,
3688 "%<&%> constraint used with no register class");
3691 for (j = 0; j < noperands; j++)
3692 /* Is this an input operand or a memory ref? */
3693 if ((MEM_P (recog_data.operand[j])
3694 || modified[j] != RELOAD_WRITE)
3695 && j != i
3696 /* Ignore things like match_operator operands. */
3697 && !recog_data.is_operator[j]
3698 /* Don't count an input operand that is constrained to match
3699 the early clobber operand. */
3700 && ! (this_alternative_matches[j] == i
3701 && rtx_equal_p (recog_data.operand[i],
3702 recog_data.operand[j]))
3703 /* Is it altered by storing the earlyclobber operand? */
3704 && !immune_p (recog_data.operand[j], recog_data.operand[i],
3705 early_data))
3707 /* If the output is in a non-empty few-regs class,
3708 it's costly to reload it, so reload the input instead. */
3709 if (small_register_class_p (this_alternative[i])
3710 && (REG_P (recog_data.operand[j])
3711 || GET_CODE (recog_data.operand[j]) == SUBREG))
3713 losers++;
3714 this_alternative_win[j] = 0;
3715 this_alternative_match_win[j] = 0;
3717 else
3718 break;
3720 /* If an earlyclobber operand conflicts with something,
3721 it must be reloaded, so request this and count the cost. */
3722 if (j != noperands)
3724 losers++;
3725 this_alternative_win[i] = 0;
3726 this_alternative_match_win[j] = 0;
3727 for (j = 0; j < noperands; j++)
3728 if (this_alternative_matches[j] == i
3729 && this_alternative_match_win[j])
3731 this_alternative_win[j] = 0;
3732 this_alternative_match_win[j] = 0;
3733 losers++;
3738 /* If one alternative accepts all the operands, no reload required,
3739 choose that alternative; don't consider the remaining ones. */
3740 if (losers == 0)
3742 /* Unswap these so that they are never swapped at `finish'. */
3743 if (swapped)
3745 recog_data.operand[commutative] = substed_operand[commutative];
3746 recog_data.operand[commutative + 1]
3747 = substed_operand[commutative + 1];
3749 for (i = 0; i < noperands; i++)
3751 goal_alternative_win[i] = this_alternative_win[i];
3752 goal_alternative_match_win[i] = this_alternative_match_win[i];
3753 goal_alternative[i] = this_alternative[i];
3754 goal_alternative_offmemok[i] = this_alternative_offmemok[i];
3755 goal_alternative_matches[i] = this_alternative_matches[i];
3756 goal_alternative_earlyclobber[i]
3757 = this_alternative_earlyclobber[i];
3759 goal_alternative_number = this_alternative_number;
3760 goal_alternative_swapped = swapped;
3761 goal_earlyclobber = this_earlyclobber;
3762 goto finish;
3765 /* REJECT, set by the ! and ? constraint characters and when a register
3766 would be reloaded into a non-preferred class, discourages the use of
3767 this alternative for a reload goal. REJECT is incremented by six
3768 for each ? and two for each non-preferred class. */
3769 losers = losers * 6 + reject;
3771 /* If this alternative can be made to work by reloading,
3772 and it needs less reloading than the others checked so far,
3773 record it as the chosen goal for reloading. */
3774 if (! bad)
3776 if (best > losers)
3778 for (i = 0; i < noperands; i++)
3780 goal_alternative[i] = this_alternative[i];
3781 goal_alternative_win[i] = this_alternative_win[i];
3782 goal_alternative_match_win[i]
3783 = this_alternative_match_win[i];
3784 goal_alternative_offmemok[i]
3785 = this_alternative_offmemok[i];
3786 goal_alternative_matches[i] = this_alternative_matches[i];
3787 goal_alternative_earlyclobber[i]
3788 = this_alternative_earlyclobber[i];
3790 goal_alternative_swapped = swapped;
3791 best = losers;
3792 goal_alternative_number = this_alternative_number;
3793 goal_earlyclobber = this_earlyclobber;
3797 if (swapped)
3799 /* If the commutative operands have been swapped, swap
3800 them back in order to check the next alternative. */
3801 recog_data.operand[commutative] = substed_operand[commutative];
3802 recog_data.operand[commutative + 1] = substed_operand[commutative + 1];
3803 /* Unswap the duplicates too. */
3804 for (i = 0; i < recog_data.n_dups; i++)
3805 if (recog_data.dup_num[i] == commutative
3806 || recog_data.dup_num[i] == commutative + 1)
3807 *recog_data.dup_loc[i]
3808 = recog_data.operand[(int) recog_data.dup_num[i]];
3810 /* Unswap the operand related information as well. */
3811 std::swap (preferred_class[commutative],
3812 preferred_class[commutative + 1]);
3813 std::swap (pref_or_nothing[commutative],
3814 pref_or_nothing[commutative + 1]);
3815 std::swap (address_reloaded[commutative],
3816 address_reloaded[commutative + 1]);
3821 /* The operands don't meet the constraints.
3822 goal_alternative describes the alternative
3823 that we could reach by reloading the fewest operands.
3824 Reload so as to fit it. */
3826 if (best == MAX_RECOG_OPERANDS * 2 + 600)
3828 /* No alternative works with reloads?? */
3829 if (insn_code_number >= 0)
3830 fatal_insn ("unable to generate reloads for:", insn);
3831 error_for_asm (insn, "inconsistent operand constraints in an %<asm%>");
3832 /* Avoid further trouble with this insn. */
3833 PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
3834 n_reloads = 0;
3835 return 0;
3838 /* Jump to `finish' from above if all operands are valid already.
3839 In that case, goal_alternative_win is all 1. */
3840 finish:
3842 /* Right now, for any pair of operands I and J that are required to match,
3843 with I < J,
3844 goal_alternative_matches[J] is I.
3845 Set up goal_alternative_matched as the inverse function:
3846 goal_alternative_matched[I] = J. */
3848 for (i = 0; i < noperands; i++)
3849 goal_alternative_matched[i] = -1;
3851 for (i = 0; i < noperands; i++)
3852 if (! goal_alternative_win[i]
3853 && goal_alternative_matches[i] >= 0)
3854 goal_alternative_matched[goal_alternative_matches[i]] = i;
3856 for (i = 0; i < noperands; i++)
3857 goal_alternative_win[i] |= goal_alternative_match_win[i];
3859 /* If the best alternative is with operands 1 and 2 swapped,
3860 consider them swapped before reporting the reloads. Update the
3861 operand numbers of any reloads already pushed. */
3863 if (goal_alternative_swapped)
3865 std::swap (substed_operand[commutative],
3866 substed_operand[commutative + 1]);
3867 std::swap (recog_data.operand[commutative],
3868 recog_data.operand[commutative + 1]);
3869 std::swap (*recog_data.operand_loc[commutative],
3870 *recog_data.operand_loc[commutative + 1]);
3872 for (i = 0; i < recog_data.n_dups; i++)
3873 if (recog_data.dup_num[i] == commutative
3874 || recog_data.dup_num[i] == commutative + 1)
3875 *recog_data.dup_loc[i]
3876 = recog_data.operand[(int) recog_data.dup_num[i]];
3878 for (i = 0; i < n_reloads; i++)
3880 if (rld[i].opnum == commutative)
3881 rld[i].opnum = commutative + 1;
3882 else if (rld[i].opnum == commutative + 1)
3883 rld[i].opnum = commutative;
3887 for (i = 0; i < noperands; i++)
3889 operand_reloadnum[i] = -1;
3891 /* If this is an earlyclobber operand, we need to widen the scope.
3892 The reload must remain valid from the start of the insn being
3893 reloaded until after the operand is stored into its destination.
3894 We approximate this with RELOAD_OTHER even though we know that we
3895 do not conflict with RELOAD_FOR_INPUT_ADDRESS reloads.
3897 One special case that is worth checking is when we have an
3898 output that is earlyclobber but isn't used past the insn (typically
3899 a SCRATCH). In this case, we only need have the reload live
3900 through the insn itself, but not for any of our input or output
3901 reloads.
3902 But we must not accidentally narrow the scope of an existing
3903 RELOAD_OTHER reload - leave these alone.
3905 In any case, anything needed to address this operand can remain
3906 however they were previously categorized. */
3908 if (goal_alternative_earlyclobber[i] && operand_type[i] != RELOAD_OTHER)
3909 operand_type[i]
3910 = (find_reg_note (insn, REG_UNUSED, recog_data.operand[i])
3911 ? RELOAD_FOR_INSN : RELOAD_OTHER);
3914 /* Any constants that aren't allowed and can't be reloaded
3915 into registers are here changed into memory references. */
3916 for (i = 0; i < noperands; i++)
3917 if (! goal_alternative_win[i])
3919 rtx op = recog_data.operand[i];
3920 rtx subreg = NULL_RTX;
3921 rtx plus = NULL_RTX;
3922 machine_mode mode = operand_mode[i];
3924 /* Reloads of SUBREGs of CONSTANT RTXs are handled later in
3925 push_reload so we have to let them pass here. */
3926 if (GET_CODE (op) == SUBREG)
3928 subreg = op;
3929 op = SUBREG_REG (op);
3930 mode = GET_MODE (op);
3933 if (GET_CODE (op) == PLUS)
3935 plus = op;
3936 op = XEXP (op, 1);
3939 if (CONST_POOL_OK_P (mode, op)
3940 && ((targetm.preferred_reload_class (op, goal_alternative[i])
3941 == NO_REGS)
3942 || no_input_reloads))
3944 int this_address_reloaded;
3945 rtx tem = force_const_mem (mode, op);
3947 /* If we stripped a SUBREG or a PLUS above add it back. */
3948 if (plus != NULL_RTX)
3949 tem = gen_rtx_PLUS (mode, XEXP (plus, 0), tem);
3951 if (subreg != NULL_RTX)
3952 tem = gen_rtx_SUBREG (operand_mode[i], tem, SUBREG_BYTE (subreg));
3954 this_address_reloaded = 0;
3955 substed_operand[i] = recog_data.operand[i]
3956 = find_reloads_toplev (tem, i, address_type[i], ind_levels,
3957 0, insn, &this_address_reloaded);
3959 /* If the alternative accepts constant pool refs directly
3960 there will be no reload needed at all. */
3961 if (plus == NULL_RTX
3962 && subreg == NULL_RTX
3963 && alternative_allows_const_pool_ref (this_address_reloaded != 1
3964 ? substed_operand[i]
3965 : NULL,
3966 recog_data.constraints[i],
3967 goal_alternative_number))
3968 goal_alternative_win[i] = 1;
3972 /* Record the values of the earlyclobber operands for the caller. */
3973 if (goal_earlyclobber)
3974 for (i = 0; i < noperands; i++)
3975 if (goal_alternative_earlyclobber[i])
3976 reload_earlyclobbers[n_earlyclobbers++] = recog_data.operand[i];
3978 /* Now record reloads for all the operands that need them. */
3979 for (i = 0; i < noperands; i++)
3980 if (! goal_alternative_win[i])
3982 /* Operands that match previous ones have already been handled. */
3983 if (goal_alternative_matches[i] >= 0)
3985 /* Handle an operand with a nonoffsettable address
3986 appearing where an offsettable address will do
3987 by reloading the address into a base register.
3989 ??? We can also do this when the operand is a register and
3990 reg_equiv_mem is not offsettable, but this is a bit tricky,
3991 so we don't bother with it. It may not be worth doing. */
3992 else if (goal_alternative_matched[i] == -1
3993 && goal_alternative_offmemok[i]
3994 && MEM_P (recog_data.operand[i]))
3996 /* If the address to be reloaded is a VOIDmode constant,
3997 use the default address mode as mode of the reload register,
3998 as would have been done by find_reloads_address. */
3999 addr_space_t as = MEM_ADDR_SPACE (recog_data.operand[i]);
4000 machine_mode address_mode;
4002 address_mode = get_address_mode (recog_data.operand[i]);
4003 operand_reloadnum[i]
4004 = push_reload (XEXP (recog_data.operand[i], 0), NULL_RTX,
4005 &XEXP (recog_data.operand[i], 0), (rtx*) 0,
4006 base_reg_class (VOIDmode, as, MEM, SCRATCH),
4007 address_mode,
4008 VOIDmode, 0, 0, i, RELOAD_OTHER);
4009 rld[operand_reloadnum[i]].inc
4010 = GET_MODE_SIZE (GET_MODE (recog_data.operand[i]));
4012 /* If this operand is an output, we will have made any
4013 reloads for its address as RELOAD_FOR_OUTPUT_ADDRESS, but
4014 now we are treating part of the operand as an input, so
4015 we must change these to RELOAD_FOR_OTHER_ADDRESS. */
4017 if (modified[i] == RELOAD_WRITE)
4019 for (j = 0; j < n_reloads; j++)
4021 if (rld[j].opnum == i)
4023 if (rld[j].when_needed == RELOAD_FOR_OUTPUT_ADDRESS)
4024 rld[j].when_needed = RELOAD_FOR_OTHER_ADDRESS;
4025 else if (rld[j].when_needed
4026 == RELOAD_FOR_OUTADDR_ADDRESS)
4027 rld[j].when_needed = RELOAD_FOR_OTHER_ADDRESS;
4032 else if (goal_alternative_matched[i] == -1)
4034 operand_reloadnum[i]
4035 = push_reload ((modified[i] != RELOAD_WRITE
4036 ? recog_data.operand[i] : 0),
4037 (modified[i] != RELOAD_READ
4038 ? recog_data.operand[i] : 0),
4039 (modified[i] != RELOAD_WRITE
4040 ? recog_data.operand_loc[i] : 0),
4041 (modified[i] != RELOAD_READ
4042 ? recog_data.operand_loc[i] : 0),
4043 (enum reg_class) goal_alternative[i],
4044 (modified[i] == RELOAD_WRITE
4045 ? VOIDmode : operand_mode[i]),
4046 (modified[i] == RELOAD_READ
4047 ? VOIDmode : operand_mode[i]),
4048 (insn_code_number < 0 ? 0
4049 : insn_data[insn_code_number].operand[i].strict_low),
4050 0, i, operand_type[i]);
4052 /* In a matching pair of operands, one must be input only
4053 and the other must be output only.
4054 Pass the input operand as IN and the other as OUT. */
4055 else if (modified[i] == RELOAD_READ
4056 && modified[goal_alternative_matched[i]] == RELOAD_WRITE)
4058 operand_reloadnum[i]
4059 = push_reload (recog_data.operand[i],
4060 recog_data.operand[goal_alternative_matched[i]],
4061 recog_data.operand_loc[i],
4062 recog_data.operand_loc[goal_alternative_matched[i]],
4063 (enum reg_class) goal_alternative[i],
4064 operand_mode[i],
4065 operand_mode[goal_alternative_matched[i]],
4066 0, 0, i, RELOAD_OTHER);
4067 operand_reloadnum[goal_alternative_matched[i]] = output_reloadnum;
4069 else if (modified[i] == RELOAD_WRITE
4070 && modified[goal_alternative_matched[i]] == RELOAD_READ)
4072 operand_reloadnum[goal_alternative_matched[i]]
4073 = push_reload (recog_data.operand[goal_alternative_matched[i]],
4074 recog_data.operand[i],
4075 recog_data.operand_loc[goal_alternative_matched[i]],
4076 recog_data.operand_loc[i],
4077 (enum reg_class) goal_alternative[i],
4078 operand_mode[goal_alternative_matched[i]],
4079 operand_mode[i],
4080 0, 0, i, RELOAD_OTHER);
4081 operand_reloadnum[i] = output_reloadnum;
4083 else
4085 gcc_assert (insn_code_number < 0);
4086 error_for_asm (insn, "inconsistent operand constraints "
4087 "in an %<asm%>");
4088 /* Avoid further trouble with this insn. */
4089 PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
4090 n_reloads = 0;
4091 return 0;
4094 else if (goal_alternative_matched[i] < 0
4095 && goal_alternative_matches[i] < 0
4096 && address_operand_reloaded[i] != 1
4097 && optimize)
4099 /* For each non-matching operand that's a MEM or a pseudo-register
4100 that didn't get a hard register, make an optional reload.
4101 This may get done even if the insn needs no reloads otherwise. */
4103 rtx operand = recog_data.operand[i];
4105 while (GET_CODE (operand) == SUBREG)
4106 operand = SUBREG_REG (operand);
4107 if ((MEM_P (operand)
4108 || (REG_P (operand)
4109 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
4110 /* If this is only for an output, the optional reload would not
4111 actually cause us to use a register now, just note that
4112 something is stored here. */
4113 && (goal_alternative[i] != NO_REGS
4114 || modified[i] == RELOAD_WRITE)
4115 && ! no_input_reloads
4116 /* An optional output reload might allow to delete INSN later.
4117 We mustn't make in-out reloads on insns that are not permitted
4118 output reloads.
4119 If this is an asm, we can't delete it; we must not even call
4120 push_reload for an optional output reload in this case,
4121 because we can't be sure that the constraint allows a register,
4122 and push_reload verifies the constraints for asms. */
4123 && (modified[i] == RELOAD_READ
4124 || (! no_output_reloads && ! this_insn_is_asm)))
4125 operand_reloadnum[i]
4126 = push_reload ((modified[i] != RELOAD_WRITE
4127 ? recog_data.operand[i] : 0),
4128 (modified[i] != RELOAD_READ
4129 ? recog_data.operand[i] : 0),
4130 (modified[i] != RELOAD_WRITE
4131 ? recog_data.operand_loc[i] : 0),
4132 (modified[i] != RELOAD_READ
4133 ? recog_data.operand_loc[i] : 0),
4134 (enum reg_class) goal_alternative[i],
4135 (modified[i] == RELOAD_WRITE
4136 ? VOIDmode : operand_mode[i]),
4137 (modified[i] == RELOAD_READ
4138 ? VOIDmode : operand_mode[i]),
4139 (insn_code_number < 0 ? 0
4140 : insn_data[insn_code_number].operand[i].strict_low),
4141 1, i, operand_type[i]);
4142 /* If a memory reference remains (either as a MEM or a pseudo that
4143 did not get a hard register), yet we can't make an optional
4144 reload, check if this is actually a pseudo register reference;
4145 we then need to emit a USE and/or a CLOBBER so that reload
4146 inheritance will do the right thing. */
4147 else if (replace
4148 && (MEM_P (operand)
4149 || (REG_P (operand)
4150 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
4151 && reg_renumber [REGNO (operand)] < 0)))
4153 operand = *recog_data.operand_loc[i];
4155 while (GET_CODE (operand) == SUBREG)
4156 operand = SUBREG_REG (operand);
4157 if (REG_P (operand))
4159 if (modified[i] != RELOAD_WRITE)
4160 /* We mark the USE with QImode so that we recognize
4161 it as one that can be safely deleted at the end
4162 of reload. */
4163 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, operand),
4164 insn), QImode);
4165 if (modified[i] != RELOAD_READ)
4166 emit_insn_after (gen_clobber (operand), insn);
4170 else if (goal_alternative_matches[i] >= 0
4171 && goal_alternative_win[goal_alternative_matches[i]]
4172 && modified[i] == RELOAD_READ
4173 && modified[goal_alternative_matches[i]] == RELOAD_WRITE
4174 && ! no_input_reloads && ! no_output_reloads
4175 && optimize)
4177 /* Similarly, make an optional reload for a pair of matching
4178 objects that are in MEM or a pseudo that didn't get a hard reg. */
4180 rtx operand = recog_data.operand[i];
4182 while (GET_CODE (operand) == SUBREG)
4183 operand = SUBREG_REG (operand);
4184 if ((MEM_P (operand)
4185 || (REG_P (operand)
4186 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
4187 && (goal_alternative[goal_alternative_matches[i]] != NO_REGS))
4188 operand_reloadnum[i] = operand_reloadnum[goal_alternative_matches[i]]
4189 = push_reload (recog_data.operand[goal_alternative_matches[i]],
4190 recog_data.operand[i],
4191 recog_data.operand_loc[goal_alternative_matches[i]],
4192 recog_data.operand_loc[i],
4193 (enum reg_class) goal_alternative[goal_alternative_matches[i]],
4194 operand_mode[goal_alternative_matches[i]],
4195 operand_mode[i],
4196 0, 1, goal_alternative_matches[i], RELOAD_OTHER);
4199 /* Perform whatever substitutions on the operands we are supposed
4200 to make due to commutativity or replacement of registers
4201 with equivalent constants or memory slots. */
4203 for (i = 0; i < noperands; i++)
4205 /* We only do this on the last pass through reload, because it is
4206 possible for some data (like reg_equiv_address) to be changed during
4207 later passes. Moreover, we lose the opportunity to get a useful
4208 reload_{in,out}_reg when we do these replacements. */
4210 if (replace)
4212 rtx substitution = substed_operand[i];
4214 *recog_data.operand_loc[i] = substitution;
4216 /* If we're replacing an operand with a LABEL_REF, we need to
4217 make sure that there's a REG_LABEL_OPERAND note attached to
4218 this instruction. */
4219 if (GET_CODE (substitution) == LABEL_REF
4220 && !find_reg_note (insn, REG_LABEL_OPERAND,
4221 label_ref_label (substitution))
4222 /* For a JUMP_P, if it was a branch target it must have
4223 already been recorded as such. */
4224 && (!JUMP_P (insn)
4225 || !label_is_jump_target_p (label_ref_label (substitution),
4226 insn)))
4228 add_reg_note (insn, REG_LABEL_OPERAND,
4229 label_ref_label (substitution));
4230 if (LABEL_P (label_ref_label (substitution)))
4231 ++LABEL_NUSES (label_ref_label (substitution));
4235 else
4236 retval |= (substed_operand[i] != *recog_data.operand_loc[i]);
4239 /* If this insn pattern contains any MATCH_DUP's, make sure that
4240 they will be substituted if the operands they match are substituted.
4241 Also do now any substitutions we already did on the operands.
4243 Don't do this if we aren't making replacements because we might be
4244 propagating things allocated by frame pointer elimination into places
4245 it doesn't expect. */
4247 if (insn_code_number >= 0 && replace)
4248 for (i = insn_data[insn_code_number].n_dups - 1; i >= 0; i--)
4250 int opno = recog_data.dup_num[i];
4251 *recog_data.dup_loc[i] = *recog_data.operand_loc[opno];
4252 dup_replacements (recog_data.dup_loc[i], recog_data.operand_loc[opno]);
4255 #if 0
4256 /* This loses because reloading of prior insns can invalidate the equivalence
4257 (or at least find_equiv_reg isn't smart enough to find it any more),
4258 causing this insn to need more reload regs than it needed before.
4259 It may be too late to make the reload regs available.
4260 Now this optimization is done safely in choose_reload_regs. */
4262 /* For each reload of a reg into some other class of reg,
4263 search for an existing equivalent reg (same value now) in the right class.
4264 We can use it as long as we don't need to change its contents. */
4265 for (i = 0; i < n_reloads; i++)
4266 if (rld[i].reg_rtx == 0
4267 && rld[i].in != 0
4268 && REG_P (rld[i].in)
4269 && rld[i].out == 0)
4271 rld[i].reg_rtx
4272 = find_equiv_reg (rld[i].in, insn, rld[i].rclass, -1,
4273 static_reload_reg_p, 0, rld[i].inmode);
4274 /* Prevent generation of insn to load the value
4275 because the one we found already has the value. */
4276 if (rld[i].reg_rtx)
4277 rld[i].in = rld[i].reg_rtx;
4279 #endif
4281 /* If we detected error and replaced asm instruction by USE, forget about the
4282 reloads. */
4283 if (GET_CODE (PATTERN (insn)) == USE
4284 && CONST_INT_P (XEXP (PATTERN (insn), 0)))
4285 n_reloads = 0;
4287 /* Perhaps an output reload can be combined with another
4288 to reduce needs by one. */
4289 if (!goal_earlyclobber)
4290 combine_reloads ();
4292 /* If we have a pair of reloads for parts of an address, they are reloading
4293 the same object, the operands themselves were not reloaded, and they
4294 are for two operands that are supposed to match, merge the reloads and
4295 change the type of the surviving reload to RELOAD_FOR_OPERAND_ADDRESS. */
4297 for (i = 0; i < n_reloads; i++)
4299 int k;
4301 for (j = i + 1; j < n_reloads; j++)
4302 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4303 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4304 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4305 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4306 && (rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
4307 || rld[j].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4308 || rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4309 || rld[j].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4310 && rtx_equal_p (rld[i].in, rld[j].in)
4311 && (operand_reloadnum[rld[i].opnum] < 0
4312 || rld[operand_reloadnum[rld[i].opnum]].optional)
4313 && (operand_reloadnum[rld[j].opnum] < 0
4314 || rld[operand_reloadnum[rld[j].opnum]].optional)
4315 && (goal_alternative_matches[rld[i].opnum] == rld[j].opnum
4316 || (goal_alternative_matches[rld[j].opnum]
4317 == rld[i].opnum)))
4319 for (k = 0; k < n_replacements; k++)
4320 if (replacements[k].what == j)
4321 replacements[k].what = i;
4323 if (rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4324 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4325 rld[i].when_needed = RELOAD_FOR_OPADDR_ADDR;
4326 else
4327 rld[i].when_needed = RELOAD_FOR_OPERAND_ADDRESS;
4328 rld[j].in = 0;
4332 /* Scan all the reloads and update their type.
4333 If a reload is for the address of an operand and we didn't reload
4334 that operand, change the type. Similarly, change the operand number
4335 of a reload when two operands match. If a reload is optional, treat it
4336 as though the operand isn't reloaded.
4338 ??? This latter case is somewhat odd because if we do the optional
4339 reload, it means the object is hanging around. Thus we need only
4340 do the address reload if the optional reload was NOT done.
4342 Change secondary reloads to be the address type of their operand, not
4343 the normal type.
4345 If an operand's reload is now RELOAD_OTHER, change any
4346 RELOAD_FOR_INPUT_ADDRESS reloads of that operand to
4347 RELOAD_FOR_OTHER_ADDRESS. */
4349 for (i = 0; i < n_reloads; i++)
4351 if (rld[i].secondary_p
4352 && rld[i].when_needed == operand_type[rld[i].opnum])
4353 rld[i].when_needed = address_type[rld[i].opnum];
4355 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4356 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4357 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4358 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4359 && (operand_reloadnum[rld[i].opnum] < 0
4360 || rld[operand_reloadnum[rld[i].opnum]].optional))
4362 /* If we have a secondary reload to go along with this reload,
4363 change its type to RELOAD_FOR_OPADDR_ADDR. */
4365 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4366 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
4367 && rld[i].secondary_in_reload != -1)
4369 int secondary_in_reload = rld[i].secondary_in_reload;
4371 rld[secondary_in_reload].when_needed = RELOAD_FOR_OPADDR_ADDR;
4373 /* If there's a tertiary reload we have to change it also. */
4374 if (secondary_in_reload > 0
4375 && rld[secondary_in_reload].secondary_in_reload != -1)
4376 rld[rld[secondary_in_reload].secondary_in_reload].when_needed
4377 = RELOAD_FOR_OPADDR_ADDR;
4380 if ((rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4381 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4382 && rld[i].secondary_out_reload != -1)
4384 int secondary_out_reload = rld[i].secondary_out_reload;
4386 rld[secondary_out_reload].when_needed = RELOAD_FOR_OPADDR_ADDR;
4388 /* If there's a tertiary reload we have to change it also. */
4389 if (secondary_out_reload
4390 && rld[secondary_out_reload].secondary_out_reload != -1)
4391 rld[rld[secondary_out_reload].secondary_out_reload].when_needed
4392 = RELOAD_FOR_OPADDR_ADDR;
4395 if (rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4396 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4397 rld[i].when_needed = RELOAD_FOR_OPADDR_ADDR;
4398 else
4399 rld[i].when_needed = RELOAD_FOR_OPERAND_ADDRESS;
4402 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4403 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
4404 && operand_reloadnum[rld[i].opnum] >= 0
4405 && (rld[operand_reloadnum[rld[i].opnum]].when_needed
4406 == RELOAD_OTHER))
4407 rld[i].when_needed = RELOAD_FOR_OTHER_ADDRESS;
4409 if (goal_alternative_matches[rld[i].opnum] >= 0)
4410 rld[i].opnum = goal_alternative_matches[rld[i].opnum];
4413 /* Scan all the reloads, and check for RELOAD_FOR_OPERAND_ADDRESS reloads.
4414 If we have more than one, then convert all RELOAD_FOR_OPADDR_ADDR
4415 reloads to RELOAD_FOR_OPERAND_ADDRESS reloads.
4417 choose_reload_regs assumes that RELOAD_FOR_OPADDR_ADDR reloads never
4418 conflict with RELOAD_FOR_OPERAND_ADDRESS reloads. This is true for a
4419 single pair of RELOAD_FOR_OPADDR_ADDR/RELOAD_FOR_OPERAND_ADDRESS reloads.
4420 However, if there is more than one RELOAD_FOR_OPERAND_ADDRESS reload,
4421 then a RELOAD_FOR_OPADDR_ADDR reload conflicts with all
4422 RELOAD_FOR_OPERAND_ADDRESS reloads other than the one that uses it.
4423 This is complicated by the fact that a single operand can have more
4424 than one RELOAD_FOR_OPERAND_ADDRESS reload. It is very difficult to fix
4425 choose_reload_regs without affecting code quality, and cases that
4426 actually fail are extremely rare, so it turns out to be better to fix
4427 the problem here by not generating cases that choose_reload_regs will
4428 fail for. */
4429 /* There is a similar problem with RELOAD_FOR_INPUT_ADDRESS /
4430 RELOAD_FOR_OUTPUT_ADDRESS when there is more than one of a kind for
4431 a single operand.
4432 We can reduce the register pressure by exploiting that a
4433 RELOAD_FOR_X_ADDR_ADDR that precedes all RELOAD_FOR_X_ADDRESS reloads
4434 does not conflict with any of them, if it is only used for the first of
4435 the RELOAD_FOR_X_ADDRESS reloads. */
4437 int first_op_addr_num = -2;
4438 int first_inpaddr_num[MAX_RECOG_OPERANDS];
4439 int first_outpaddr_num[MAX_RECOG_OPERANDS];
4440 int need_change = 0;
4441 /* We use last_op_addr_reload and the contents of the above arrays
4442 first as flags - -2 means no instance encountered, -1 means exactly
4443 one instance encountered.
4444 If more than one instance has been encountered, we store the reload
4445 number of the first reload of the kind in question; reload numbers
4446 are known to be non-negative. */
4447 for (i = 0; i < noperands; i++)
4448 first_inpaddr_num[i] = first_outpaddr_num[i] = -2;
4449 for (i = n_reloads - 1; i >= 0; i--)
4451 switch (rld[i].when_needed)
4453 case RELOAD_FOR_OPERAND_ADDRESS:
4454 if (++first_op_addr_num >= 0)
4456 first_op_addr_num = i;
4457 need_change = 1;
4459 break;
4460 case RELOAD_FOR_INPUT_ADDRESS:
4461 if (++first_inpaddr_num[rld[i].opnum] >= 0)
4463 first_inpaddr_num[rld[i].opnum] = i;
4464 need_change = 1;
4466 break;
4467 case RELOAD_FOR_OUTPUT_ADDRESS:
4468 if (++first_outpaddr_num[rld[i].opnum] >= 0)
4470 first_outpaddr_num[rld[i].opnum] = i;
4471 need_change = 1;
4473 break;
4474 default:
4475 break;
4479 if (need_change)
4481 for (i = 0; i < n_reloads; i++)
4483 int first_num;
4484 enum reload_type type;
4486 switch (rld[i].when_needed)
4488 case RELOAD_FOR_OPADDR_ADDR:
4489 first_num = first_op_addr_num;
4490 type = RELOAD_FOR_OPERAND_ADDRESS;
4491 break;
4492 case RELOAD_FOR_INPADDR_ADDRESS:
4493 first_num = first_inpaddr_num[rld[i].opnum];
4494 type = RELOAD_FOR_INPUT_ADDRESS;
4495 break;
4496 case RELOAD_FOR_OUTADDR_ADDRESS:
4497 first_num = first_outpaddr_num[rld[i].opnum];
4498 type = RELOAD_FOR_OUTPUT_ADDRESS;
4499 break;
4500 default:
4501 continue;
4503 if (first_num < 0)
4504 continue;
4505 else if (i > first_num)
4506 rld[i].when_needed = type;
4507 else
4509 /* Check if the only TYPE reload that uses reload I is
4510 reload FIRST_NUM. */
4511 for (j = n_reloads - 1; j > first_num; j--)
4513 if (rld[j].when_needed == type
4514 && (rld[i].secondary_p
4515 ? rld[j].secondary_in_reload == i
4516 : reg_mentioned_p (rld[i].in, rld[j].in)))
4518 rld[i].when_needed = type;
4519 break;
4527 /* See if we have any reloads that are now allowed to be merged
4528 because we've changed when the reload is needed to
4529 RELOAD_FOR_OPERAND_ADDRESS or RELOAD_FOR_OTHER_ADDRESS. Only
4530 check for the most common cases. */
4532 for (i = 0; i < n_reloads; i++)
4533 if (rld[i].in != 0 && rld[i].out == 0
4534 && (rld[i].when_needed == RELOAD_FOR_OPERAND_ADDRESS
4535 || rld[i].when_needed == RELOAD_FOR_OPADDR_ADDR
4536 || rld[i].when_needed == RELOAD_FOR_OTHER_ADDRESS))
4537 for (j = 0; j < n_reloads; j++)
4538 if (i != j && rld[j].in != 0 && rld[j].out == 0
4539 && rld[j].when_needed == rld[i].when_needed
4540 && MATCHES (rld[i].in, rld[j].in)
4541 && rld[i].rclass == rld[j].rclass
4542 && !rld[i].nocombine && !rld[j].nocombine
4543 && rld[i].reg_rtx == rld[j].reg_rtx)
4545 rld[i].opnum = MIN (rld[i].opnum, rld[j].opnum);
4546 transfer_replacements (i, j);
4547 rld[j].in = 0;
4550 /* If we made any reloads for addresses, see if they violate a
4551 "no input reloads" requirement for this insn. But loads that we
4552 do after the insn (such as for output addresses) are fine. */
4553 if (HAVE_cc0 && no_input_reloads)
4554 for (i = 0; i < n_reloads; i++)
4555 gcc_assert (rld[i].in == 0
4556 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS
4557 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS);
4559 /* Compute reload_mode and reload_nregs. */
4560 for (i = 0; i < n_reloads; i++)
4562 rld[i].mode = rld[i].inmode;
4563 if (rld[i].mode == VOIDmode
4564 || partial_subreg_p (rld[i].mode, rld[i].outmode))
4565 rld[i].mode = rld[i].outmode;
4567 rld[i].nregs = ira_reg_class_max_nregs [rld[i].rclass][rld[i].mode];
4570 /* Special case a simple move with an input reload and a
4571 destination of a hard reg, if the hard reg is ok, use it. */
4572 for (i = 0; i < n_reloads; i++)
4573 if (rld[i].when_needed == RELOAD_FOR_INPUT
4574 && GET_CODE (PATTERN (insn)) == SET
4575 && REG_P (SET_DEST (PATTERN (insn)))
4576 && (SET_SRC (PATTERN (insn)) == rld[i].in
4577 || SET_SRC (PATTERN (insn)) == rld[i].in_reg)
4578 && !elimination_target_reg_p (SET_DEST (PATTERN (insn))))
4580 rtx dest = SET_DEST (PATTERN (insn));
4581 unsigned int regno = REGNO (dest);
4583 if (regno < FIRST_PSEUDO_REGISTER
4584 && TEST_HARD_REG_BIT (reg_class_contents[rld[i].rclass], regno)
4585 && targetm.hard_regno_mode_ok (regno, rld[i].mode))
4587 int nr = hard_regno_nregs (regno, rld[i].mode);
4588 int ok = 1, nri;
4590 for (nri = 1; nri < nr; nri ++)
4591 if (! TEST_HARD_REG_BIT (reg_class_contents[rld[i].rclass], regno + nri))
4593 ok = 0;
4594 break;
4597 if (ok)
4598 rld[i].reg_rtx = dest;
4602 return retval;
4605 /* Return true if alternative number ALTNUM in constraint-string
4606 CONSTRAINT is guaranteed to accept a reloaded constant-pool reference.
4607 MEM gives the reference if its address hasn't been fully reloaded,
4608 otherwise it is NULL. */
4610 static bool
4611 alternative_allows_const_pool_ref (rtx mem ATTRIBUTE_UNUSED,
4612 const char *constraint, int altnum)
4614 int c;
4616 /* Skip alternatives before the one requested. */
4617 while (altnum > 0)
4619 while (*constraint++ != ',')
4621 altnum--;
4623 /* Scan the requested alternative for TARGET_MEM_CONSTRAINT or 'o'.
4624 If one of them is present, this alternative accepts the result of
4625 passing a constant-pool reference through find_reloads_toplev.
4627 The same is true of extra memory constraints if the address
4628 was reloaded into a register. However, the target may elect
4629 to disallow the original constant address, forcing it to be
4630 reloaded into a register instead. */
4631 for (; (c = *constraint) && c != ',' && c != '#';
4632 constraint += CONSTRAINT_LEN (c, constraint))
4634 enum constraint_num cn = lookup_constraint (constraint);
4635 if (insn_extra_memory_constraint (cn)
4636 && (mem == NULL || constraint_satisfied_p (mem, cn)))
4637 return true;
4639 return false;
4642 /* Scan X for memory references and scan the addresses for reloading.
4643 Also checks for references to "constant" regs that we want to eliminate
4644 and replaces them with the values they stand for.
4645 We may alter X destructively if it contains a reference to such.
4646 If X is just a constant reg, we return the equivalent value
4647 instead of X.
4649 IND_LEVELS says how many levels of indirect addressing this machine
4650 supports.
4652 OPNUM and TYPE identify the purpose of the reload.
4654 IS_SET_DEST is true if X is the destination of a SET, which is not
4655 appropriate to be replaced by a constant.
4657 INSN, if nonzero, is the insn in which we do the reload. It is used
4658 to determine if we may generate output reloads, and where to put USEs
4659 for pseudos that we have to replace with stack slots.
4661 ADDRESS_RELOADED. If nonzero, is a pointer to where we put the
4662 result of find_reloads_address. */
4664 static rtx
4665 find_reloads_toplev (rtx x, int opnum, enum reload_type type,
4666 int ind_levels, int is_set_dest, rtx_insn *insn,
4667 int *address_reloaded)
4669 RTX_CODE code = GET_CODE (x);
4671 const char *fmt = GET_RTX_FORMAT (code);
4672 int i;
4673 int copied;
4675 if (code == REG)
4677 /* This code is duplicated for speed in find_reloads. */
4678 int regno = REGNO (x);
4679 if (reg_equiv_constant (regno) != 0 && !is_set_dest)
4680 x = reg_equiv_constant (regno);
4681 #if 0
4682 /* This creates (subreg (mem...)) which would cause an unnecessary
4683 reload of the mem. */
4684 else if (reg_equiv_mem (regno) != 0)
4685 x = reg_equiv_mem (regno);
4686 #endif
4687 else if (reg_equiv_memory_loc (regno)
4688 && (reg_equiv_address (regno) != 0 || num_not_at_initial_offset))
4690 rtx mem = make_memloc (x, regno);
4691 if (reg_equiv_address (regno)
4692 || ! rtx_equal_p (mem, reg_equiv_mem (regno)))
4694 /* If this is not a toplevel operand, find_reloads doesn't see
4695 this substitution. We have to emit a USE of the pseudo so
4696 that delete_output_reload can see it. */
4697 if (replace_reloads && recog_data.operand[opnum] != x)
4698 /* We mark the USE with QImode so that we recognize it
4699 as one that can be safely deleted at the end of
4700 reload. */
4701 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, x), insn),
4702 QImode);
4703 x = mem;
4704 i = find_reloads_address (GET_MODE (x), &x, XEXP (x, 0), &XEXP (x, 0),
4705 opnum, type, ind_levels, insn);
4706 if (!rtx_equal_p (x, mem))
4707 push_reg_equiv_alt_mem (regno, x);
4708 if (address_reloaded)
4709 *address_reloaded = i;
4712 return x;
4714 if (code == MEM)
4716 rtx tem = x;
4718 i = find_reloads_address (GET_MODE (x), &tem, XEXP (x, 0), &XEXP (x, 0),
4719 opnum, type, ind_levels, insn);
4720 if (address_reloaded)
4721 *address_reloaded = i;
4723 return tem;
4726 if (code == SUBREG && REG_P (SUBREG_REG (x)))
4728 /* Check for SUBREG containing a REG that's equivalent to a
4729 constant. If the constant has a known value, truncate it
4730 right now. Similarly if we are extracting a single-word of a
4731 multi-word constant. If the constant is symbolic, allow it
4732 to be substituted normally. push_reload will strip the
4733 subreg later. The constant must not be VOIDmode, because we
4734 will lose the mode of the register (this should never happen
4735 because one of the cases above should handle it). */
4737 int regno = REGNO (SUBREG_REG (x));
4738 rtx tem;
4740 if (regno >= FIRST_PSEUDO_REGISTER
4741 && reg_renumber[regno] < 0
4742 && reg_equiv_constant (regno) != 0)
4744 tem =
4745 simplify_gen_subreg (GET_MODE (x), reg_equiv_constant (regno),
4746 GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x));
4747 gcc_assert (tem);
4748 if (CONSTANT_P (tem)
4749 && !targetm.legitimate_constant_p (GET_MODE (x), tem))
4751 tem = force_const_mem (GET_MODE (x), tem);
4752 i = find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
4753 &XEXP (tem, 0), opnum, type,
4754 ind_levels, insn);
4755 if (address_reloaded)
4756 *address_reloaded = i;
4758 return tem;
4761 /* If the subreg contains a reg that will be converted to a mem,
4762 attempt to convert the whole subreg to a (narrower or wider)
4763 memory reference instead. If this succeeds, we're done --
4764 otherwise fall through to check whether the inner reg still
4765 needs address reloads anyway. */
4767 if (regno >= FIRST_PSEUDO_REGISTER
4768 && reg_equiv_memory_loc (regno) != 0)
4770 tem = find_reloads_subreg_address (x, opnum, type, ind_levels,
4771 insn, address_reloaded);
4772 if (tem)
4773 return tem;
4777 for (copied = 0, i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
4779 if (fmt[i] == 'e')
4781 rtx new_part = find_reloads_toplev (XEXP (x, i), opnum, type,
4782 ind_levels, is_set_dest, insn,
4783 address_reloaded);
4784 /* If we have replaced a reg with it's equivalent memory loc -
4785 that can still be handled here e.g. if it's in a paradoxical
4786 subreg - we must make the change in a copy, rather than using
4787 a destructive change. This way, find_reloads can still elect
4788 not to do the change. */
4789 if (new_part != XEXP (x, i) && ! CONSTANT_P (new_part) && ! copied)
4791 x = shallow_copy_rtx (x);
4792 copied = 1;
4794 XEXP (x, i) = new_part;
4797 return x;
4800 /* Return a mem ref for the memory equivalent of reg REGNO.
4801 This mem ref is not shared with anything. */
4803 static rtx
4804 make_memloc (rtx ad, int regno)
4806 /* We must rerun eliminate_regs, in case the elimination
4807 offsets have changed. */
4808 rtx tem
4809 = XEXP (eliminate_regs (reg_equiv_memory_loc (regno), VOIDmode, NULL_RTX),
4812 /* If TEM might contain a pseudo, we must copy it to avoid
4813 modifying it when we do the substitution for the reload. */
4814 if (rtx_varies_p (tem, 0))
4815 tem = copy_rtx (tem);
4817 tem = replace_equiv_address_nv (reg_equiv_memory_loc (regno), tem);
4818 tem = adjust_address_nv (tem, GET_MODE (ad), 0);
4820 /* Copy the result if it's still the same as the equivalence, to avoid
4821 modifying it when we do the substitution for the reload. */
4822 if (tem == reg_equiv_memory_loc (regno))
4823 tem = copy_rtx (tem);
4824 return tem;
4827 /* Returns true if AD could be turned into a valid memory reference
4828 to mode MODE in address space AS by reloading the part pointed to
4829 by PART into a register. */
4831 static int
4832 maybe_memory_address_addr_space_p (machine_mode mode, rtx ad,
4833 addr_space_t as, rtx *part)
4835 int retv;
4836 rtx tem = *part;
4837 rtx reg = gen_rtx_REG (GET_MODE (tem), max_reg_num ());
4839 *part = reg;
4840 retv = memory_address_addr_space_p (mode, ad, as);
4841 *part = tem;
4843 return retv;
4846 /* Record all reloads needed for handling memory address AD
4847 which appears in *LOC in a memory reference to mode MODE
4848 which itself is found in location *MEMREFLOC.
4849 Note that we take shortcuts assuming that no multi-reg machine mode
4850 occurs as part of an address.
4852 OPNUM and TYPE specify the purpose of this reload.
4854 IND_LEVELS says how many levels of indirect addressing this machine
4855 supports.
4857 INSN, if nonzero, is the insn in which we do the reload. It is used
4858 to determine if we may generate output reloads, and where to put USEs
4859 for pseudos that we have to replace with stack slots.
4861 Value is one if this address is reloaded or replaced as a whole; it is
4862 zero if the top level of this address was not reloaded or replaced, and
4863 it is -1 if it may or may not have been reloaded or replaced.
4865 Note that there is no verification that the address will be valid after
4866 this routine does its work. Instead, we rely on the fact that the address
4867 was valid when reload started. So we need only undo things that reload
4868 could have broken. These are wrong register types, pseudos not allocated
4869 to a hard register, and frame pointer elimination. */
4871 static int
4872 find_reloads_address (machine_mode mode, rtx *memrefloc, rtx ad,
4873 rtx *loc, int opnum, enum reload_type type,
4874 int ind_levels, rtx_insn *insn)
4876 addr_space_t as = memrefloc? MEM_ADDR_SPACE (*memrefloc)
4877 : ADDR_SPACE_GENERIC;
4878 int regno;
4879 int removed_and = 0;
4880 int op_index;
4881 rtx tem;
4883 /* If the address is a register, see if it is a legitimate address and
4884 reload if not. We first handle the cases where we need not reload
4885 or where we must reload in a non-standard way. */
4887 if (REG_P (ad))
4889 regno = REGNO (ad);
4891 if (reg_equiv_constant (regno) != 0)
4893 find_reloads_address_part (reg_equiv_constant (regno), loc,
4894 base_reg_class (mode, as, MEM, SCRATCH),
4895 GET_MODE (ad), opnum, type, ind_levels);
4896 return 1;
4899 tem = reg_equiv_memory_loc (regno);
4900 if (tem != 0)
4902 if (reg_equiv_address (regno) != 0 || num_not_at_initial_offset)
4904 tem = make_memloc (ad, regno);
4905 if (! strict_memory_address_addr_space_p (GET_MODE (tem),
4906 XEXP (tem, 0),
4907 MEM_ADDR_SPACE (tem)))
4909 rtx orig = tem;
4911 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
4912 &XEXP (tem, 0), opnum,
4913 ADDR_TYPE (type), ind_levels, insn);
4914 if (!rtx_equal_p (tem, orig))
4915 push_reg_equiv_alt_mem (regno, tem);
4917 /* We can avoid a reload if the register's equivalent memory
4918 expression is valid as an indirect memory address.
4919 But not all addresses are valid in a mem used as an indirect
4920 address: only reg or reg+constant. */
4922 if (ind_levels > 0
4923 && strict_memory_address_addr_space_p (mode, tem, as)
4924 && (REG_P (XEXP (tem, 0))
4925 || (GET_CODE (XEXP (tem, 0)) == PLUS
4926 && REG_P (XEXP (XEXP (tem, 0), 0))
4927 && CONSTANT_P (XEXP (XEXP (tem, 0), 1)))))
4929 /* TEM is not the same as what we'll be replacing the
4930 pseudo with after reload, put a USE in front of INSN
4931 in the final reload pass. */
4932 if (replace_reloads
4933 && num_not_at_initial_offset
4934 && ! rtx_equal_p (tem, reg_equiv_mem (regno)))
4936 *loc = tem;
4937 /* We mark the USE with QImode so that we
4938 recognize it as one that can be safely
4939 deleted at the end of reload. */
4940 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, ad),
4941 insn), QImode);
4943 /* This doesn't really count as replacing the address
4944 as a whole, since it is still a memory access. */
4946 return 0;
4948 ad = tem;
4952 /* The only remaining case where we can avoid a reload is if this is a
4953 hard register that is valid as a base register and which is not the
4954 subject of a CLOBBER in this insn. */
4956 else if (regno < FIRST_PSEUDO_REGISTER
4957 && regno_ok_for_base_p (regno, mode, as, MEM, SCRATCH)
4958 && ! regno_clobbered_p (regno, this_insn, mode, 0))
4959 return 0;
4961 /* If we do not have one of the cases above, we must do the reload. */
4962 push_reload (ad, NULL_RTX, loc, (rtx*) 0,
4963 base_reg_class (mode, as, MEM, SCRATCH),
4964 GET_MODE (ad), VOIDmode, 0, 0, opnum, type);
4965 return 1;
4968 if (strict_memory_address_addr_space_p (mode, ad, as))
4970 /* The address appears valid, so reloads are not needed.
4971 But the address may contain an eliminable register.
4972 This can happen because a machine with indirect addressing
4973 may consider a pseudo register by itself a valid address even when
4974 it has failed to get a hard reg.
4975 So do a tree-walk to find and eliminate all such regs. */
4977 /* But first quickly dispose of a common case. */
4978 if (GET_CODE (ad) == PLUS
4979 && CONST_INT_P (XEXP (ad, 1))
4980 && REG_P (XEXP (ad, 0))
4981 && reg_equiv_constant (REGNO (XEXP (ad, 0))) == 0)
4982 return 0;
4984 subst_reg_equivs_changed = 0;
4985 *loc = subst_reg_equivs (ad, insn);
4987 if (! subst_reg_equivs_changed)
4988 return 0;
4990 /* Check result for validity after substitution. */
4991 if (strict_memory_address_addr_space_p (mode, ad, as))
4992 return 0;
4995 #ifdef LEGITIMIZE_RELOAD_ADDRESS
4998 if (memrefloc && ADDR_SPACE_GENERIC_P (as))
5000 LEGITIMIZE_RELOAD_ADDRESS (ad, GET_MODE (*memrefloc), opnum, type,
5001 ind_levels, win);
5003 break;
5004 win:
5005 *memrefloc = copy_rtx (*memrefloc);
5006 XEXP (*memrefloc, 0) = ad;
5007 move_replacements (&ad, &XEXP (*memrefloc, 0));
5008 return -1;
5010 while (0);
5011 #endif
5013 /* The address is not valid. We have to figure out why. First see if
5014 we have an outer AND and remove it if so. Then analyze what's inside. */
5016 if (GET_CODE (ad) == AND)
5018 removed_and = 1;
5019 loc = &XEXP (ad, 0);
5020 ad = *loc;
5023 /* One possibility for why the address is invalid is that it is itself
5024 a MEM. This can happen when the frame pointer is being eliminated, a
5025 pseudo is not allocated to a hard register, and the offset between the
5026 frame and stack pointers is not its initial value. In that case the
5027 pseudo will have been replaced by a MEM referring to the
5028 stack pointer. */
5029 if (MEM_P (ad))
5031 /* First ensure that the address in this MEM is valid. Then, unless
5032 indirect addresses are valid, reload the MEM into a register. */
5033 tem = ad;
5034 find_reloads_address (GET_MODE (ad), &tem, XEXP (ad, 0), &XEXP (ad, 0),
5035 opnum, ADDR_TYPE (type),
5036 ind_levels == 0 ? 0 : ind_levels - 1, insn);
5038 /* If tem was changed, then we must create a new memory reference to
5039 hold it and store it back into memrefloc. */
5040 if (tem != ad && memrefloc)
5042 *memrefloc = copy_rtx (*memrefloc);
5043 copy_replacements (tem, XEXP (*memrefloc, 0));
5044 loc = &XEXP (*memrefloc, 0);
5045 if (removed_and)
5046 loc = &XEXP (*loc, 0);
5049 /* Check similar cases as for indirect addresses as above except
5050 that we can allow pseudos and a MEM since they should have been
5051 taken care of above. */
5053 if (ind_levels == 0
5054 || (GET_CODE (XEXP (tem, 0)) == SYMBOL_REF && ! indirect_symref_ok)
5055 || MEM_P (XEXP (tem, 0))
5056 || ! (REG_P (XEXP (tem, 0))
5057 || (GET_CODE (XEXP (tem, 0)) == PLUS
5058 && REG_P (XEXP (XEXP (tem, 0), 0))
5059 && CONST_INT_P (XEXP (XEXP (tem, 0), 1)))))
5061 /* Must use TEM here, not AD, since it is the one that will
5062 have any subexpressions reloaded, if needed. */
5063 push_reload (tem, NULL_RTX, loc, (rtx*) 0,
5064 base_reg_class (mode, as, MEM, SCRATCH), GET_MODE (tem),
5065 VOIDmode, 0,
5066 0, opnum, type);
5067 return ! removed_and;
5069 else
5070 return 0;
5073 /* If we have address of a stack slot but it's not valid because the
5074 displacement is too large, compute the sum in a register.
5075 Handle all base registers here, not just fp/ap/sp, because on some
5076 targets (namely SH) we can also get too large displacements from
5077 big-endian corrections. */
5078 else if (GET_CODE (ad) == PLUS
5079 && REG_P (XEXP (ad, 0))
5080 && REGNO (XEXP (ad, 0)) < FIRST_PSEUDO_REGISTER
5081 && CONST_INT_P (XEXP (ad, 1))
5082 && (regno_ok_for_base_p (REGNO (XEXP (ad, 0)), mode, as, PLUS,
5083 CONST_INT)
5084 /* Similarly, if we were to reload the base register and the
5085 mem+offset address is still invalid, then we want to reload
5086 the whole address, not just the base register. */
5087 || ! maybe_memory_address_addr_space_p
5088 (mode, ad, as, &(XEXP (ad, 0)))))
5091 /* Unshare the MEM rtx so we can safely alter it. */
5092 if (memrefloc)
5094 *memrefloc = copy_rtx (*memrefloc);
5095 loc = &XEXP (*memrefloc, 0);
5096 if (removed_and)
5097 loc = &XEXP (*loc, 0);
5100 if (double_reg_address_ok[mode]
5101 && regno_ok_for_base_p (REGNO (XEXP (ad, 0)), mode, as,
5102 PLUS, CONST_INT))
5104 /* Unshare the sum as well. */
5105 *loc = ad = copy_rtx (ad);
5107 /* Reload the displacement into an index reg.
5108 We assume the frame pointer or arg pointer is a base reg. */
5109 find_reloads_address_part (XEXP (ad, 1), &XEXP (ad, 1),
5110 INDEX_REG_CLASS, GET_MODE (ad), opnum,
5111 type, ind_levels);
5112 return 0;
5114 else
5116 /* If the sum of two regs is not necessarily valid,
5117 reload the sum into a base reg.
5118 That will at least work. */
5119 find_reloads_address_part (ad, loc,
5120 base_reg_class (mode, as, MEM, SCRATCH),
5121 GET_MODE (ad), opnum, type, ind_levels);
5123 return ! removed_and;
5126 /* If we have an indexed stack slot, there are three possible reasons why
5127 it might be invalid: The index might need to be reloaded, the address
5128 might have been made by frame pointer elimination and hence have a
5129 constant out of range, or both reasons might apply.
5131 We can easily check for an index needing reload, but even if that is the
5132 case, we might also have an invalid constant. To avoid making the
5133 conservative assumption and requiring two reloads, we see if this address
5134 is valid when not interpreted strictly. If it is, the only problem is
5135 that the index needs a reload and find_reloads_address_1 will take care
5136 of it.
5138 Handle all base registers here, not just fp/ap/sp, because on some
5139 targets (namely SPARC) we can also get invalid addresses from preventive
5140 subreg big-endian corrections made by find_reloads_toplev. We
5141 can also get expressions involving LO_SUM (rather than PLUS) from
5142 find_reloads_subreg_address.
5144 If we decide to do something, it must be that `double_reg_address_ok'
5145 is true. We generate a reload of the base register + constant and
5146 rework the sum so that the reload register will be added to the index.
5147 This is safe because we know the address isn't shared.
5149 We check for the base register as both the first and second operand of
5150 the innermost PLUS and/or LO_SUM. */
5152 for (op_index = 0; op_index < 2; ++op_index)
5154 rtx operand, addend;
5155 enum rtx_code inner_code;
5157 if (GET_CODE (ad) != PLUS)
5158 continue;
5160 inner_code = GET_CODE (XEXP (ad, 0));
5161 if (!(GET_CODE (ad) == PLUS
5162 && CONST_INT_P (XEXP (ad, 1))
5163 && (inner_code == PLUS || inner_code == LO_SUM)))
5164 continue;
5166 operand = XEXP (XEXP (ad, 0), op_index);
5167 if (!REG_P (operand) || REGNO (operand) >= FIRST_PSEUDO_REGISTER)
5168 continue;
5170 addend = XEXP (XEXP (ad, 0), 1 - op_index);
5172 if ((regno_ok_for_base_p (REGNO (operand), mode, as, inner_code,
5173 GET_CODE (addend))
5174 || operand == frame_pointer_rtx
5175 || (!HARD_FRAME_POINTER_IS_FRAME_POINTER
5176 && operand == hard_frame_pointer_rtx)
5177 || (FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
5178 && operand == arg_pointer_rtx)
5179 || operand == stack_pointer_rtx)
5180 && ! maybe_memory_address_addr_space_p
5181 (mode, ad, as, &XEXP (XEXP (ad, 0), 1 - op_index)))
5183 rtx offset_reg;
5184 enum reg_class cls;
5186 offset_reg = plus_constant (GET_MODE (ad), operand,
5187 INTVAL (XEXP (ad, 1)));
5189 /* Form the adjusted address. */
5190 if (GET_CODE (XEXP (ad, 0)) == PLUS)
5191 ad = gen_rtx_PLUS (GET_MODE (ad),
5192 op_index == 0 ? offset_reg : addend,
5193 op_index == 0 ? addend : offset_reg);
5194 else
5195 ad = gen_rtx_LO_SUM (GET_MODE (ad),
5196 op_index == 0 ? offset_reg : addend,
5197 op_index == 0 ? addend : offset_reg);
5198 *loc = ad;
5200 cls = base_reg_class (mode, as, MEM, GET_CODE (addend));
5201 find_reloads_address_part (XEXP (ad, op_index),
5202 &XEXP (ad, op_index), cls,
5203 GET_MODE (ad), opnum, type, ind_levels);
5204 find_reloads_address_1 (mode, as,
5205 XEXP (ad, 1 - op_index), 1, GET_CODE (ad),
5206 GET_CODE (XEXP (ad, op_index)),
5207 &XEXP (ad, 1 - op_index), opnum,
5208 type, 0, insn);
5210 return 0;
5214 /* See if address becomes valid when an eliminable register
5215 in a sum is replaced. */
5217 tem = ad;
5218 if (GET_CODE (ad) == PLUS)
5219 tem = subst_indexed_address (ad);
5220 if (tem != ad && strict_memory_address_addr_space_p (mode, tem, as))
5222 /* Ok, we win that way. Replace any additional eliminable
5223 registers. */
5225 subst_reg_equivs_changed = 0;
5226 tem = subst_reg_equivs (tem, insn);
5228 /* Make sure that didn't make the address invalid again. */
5230 if (! subst_reg_equivs_changed
5231 || strict_memory_address_addr_space_p (mode, tem, as))
5233 *loc = tem;
5234 return 0;
5238 /* If constants aren't valid addresses, reload the constant address
5239 into a register. */
5240 if (CONSTANT_P (ad) && ! strict_memory_address_addr_space_p (mode, ad, as))
5242 machine_mode address_mode = GET_MODE (ad);
5243 if (address_mode == VOIDmode)
5244 address_mode = targetm.addr_space.address_mode (as);
5246 /* If AD is an address in the constant pool, the MEM rtx may be shared.
5247 Unshare it so we can safely alter it. */
5248 if (memrefloc && GET_CODE (ad) == SYMBOL_REF
5249 && CONSTANT_POOL_ADDRESS_P (ad))
5251 *memrefloc = copy_rtx (*memrefloc);
5252 loc = &XEXP (*memrefloc, 0);
5253 if (removed_and)
5254 loc = &XEXP (*loc, 0);
5257 find_reloads_address_part (ad, loc,
5258 base_reg_class (mode, as, MEM, SCRATCH),
5259 address_mode, opnum, type, ind_levels);
5260 return ! removed_and;
5263 return find_reloads_address_1 (mode, as, ad, 0, MEM, SCRATCH, loc,
5264 opnum, type, ind_levels, insn);
5267 /* Find all pseudo regs appearing in AD
5268 that are eliminable in favor of equivalent values
5269 and do not have hard regs; replace them by their equivalents.
5270 INSN, if nonzero, is the insn in which we do the reload. We put USEs in
5271 front of it for pseudos that we have to replace with stack slots. */
5273 static rtx
5274 subst_reg_equivs (rtx ad, rtx_insn *insn)
5276 RTX_CODE code = GET_CODE (ad);
5277 int i;
5278 const char *fmt;
5280 switch (code)
5282 case HIGH:
5283 case CONST:
5284 CASE_CONST_ANY:
5285 case SYMBOL_REF:
5286 case LABEL_REF:
5287 case PC:
5288 case CC0:
5289 return ad;
5291 case REG:
5293 int regno = REGNO (ad);
5295 if (reg_equiv_constant (regno) != 0)
5297 subst_reg_equivs_changed = 1;
5298 return reg_equiv_constant (regno);
5300 if (reg_equiv_memory_loc (regno) && num_not_at_initial_offset)
5302 rtx mem = make_memloc (ad, regno);
5303 if (! rtx_equal_p (mem, reg_equiv_mem (regno)))
5305 subst_reg_equivs_changed = 1;
5306 /* We mark the USE with QImode so that we recognize it
5307 as one that can be safely deleted at the end of
5308 reload. */
5309 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, ad), insn),
5310 QImode);
5311 return mem;
5315 return ad;
5317 case PLUS:
5318 /* Quickly dispose of a common case. */
5319 if (XEXP (ad, 0) == frame_pointer_rtx
5320 && CONST_INT_P (XEXP (ad, 1)))
5321 return ad;
5322 break;
5324 default:
5325 break;
5328 fmt = GET_RTX_FORMAT (code);
5329 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
5330 if (fmt[i] == 'e')
5331 XEXP (ad, i) = subst_reg_equivs (XEXP (ad, i), insn);
5332 return ad;
5335 /* Compute the sum of X and Y, making canonicalizations assumed in an
5336 address, namely: sum constant integers, surround the sum of two
5337 constants with a CONST, put the constant as the second operand, and
5338 group the constant on the outermost sum.
5340 This routine assumes both inputs are already in canonical form. */
5343 form_sum (machine_mode mode, rtx x, rtx y)
5345 rtx tem;
5347 gcc_assert (GET_MODE (x) == mode || GET_MODE (x) == VOIDmode);
5348 gcc_assert (GET_MODE (y) == mode || GET_MODE (y) == VOIDmode);
5350 if (CONST_INT_P (x))
5351 return plus_constant (mode, y, INTVAL (x));
5352 else if (CONST_INT_P (y))
5353 return plus_constant (mode, x, INTVAL (y));
5354 else if (CONSTANT_P (x))
5355 tem = x, x = y, y = tem;
5357 if (GET_CODE (x) == PLUS && CONSTANT_P (XEXP (x, 1)))
5358 return form_sum (mode, XEXP (x, 0), form_sum (mode, XEXP (x, 1), y));
5360 /* Note that if the operands of Y are specified in the opposite
5361 order in the recursive calls below, infinite recursion will occur. */
5362 if (GET_CODE (y) == PLUS && CONSTANT_P (XEXP (y, 1)))
5363 return form_sum (mode, form_sum (mode, x, XEXP (y, 0)), XEXP (y, 1));
5365 /* If both constant, encapsulate sum. Otherwise, just form sum. A
5366 constant will have been placed second. */
5367 if (CONSTANT_P (x) && CONSTANT_P (y))
5369 if (GET_CODE (x) == CONST)
5370 x = XEXP (x, 0);
5371 if (GET_CODE (y) == CONST)
5372 y = XEXP (y, 0);
5374 return gen_rtx_CONST (VOIDmode, gen_rtx_PLUS (mode, x, y));
5377 return gen_rtx_PLUS (mode, x, y);
5380 /* If ADDR is a sum containing a pseudo register that should be
5381 replaced with a constant (from reg_equiv_constant),
5382 return the result of doing so, and also apply the associative
5383 law so that the result is more likely to be a valid address.
5384 (But it is not guaranteed to be one.)
5386 Note that at most one register is replaced, even if more are
5387 replaceable. Also, we try to put the result into a canonical form
5388 so it is more likely to be a valid address.
5390 In all other cases, return ADDR. */
5392 static rtx
5393 subst_indexed_address (rtx addr)
5395 rtx op0 = 0, op1 = 0, op2 = 0;
5396 rtx tem;
5397 int regno;
5399 if (GET_CODE (addr) == PLUS)
5401 /* Try to find a register to replace. */
5402 op0 = XEXP (addr, 0), op1 = XEXP (addr, 1), op2 = 0;
5403 if (REG_P (op0)
5404 && (regno = REGNO (op0)) >= FIRST_PSEUDO_REGISTER
5405 && reg_renumber[regno] < 0
5406 && reg_equiv_constant (regno) != 0)
5407 op0 = reg_equiv_constant (regno);
5408 else if (REG_P (op1)
5409 && (regno = REGNO (op1)) >= FIRST_PSEUDO_REGISTER
5410 && reg_renumber[regno] < 0
5411 && reg_equiv_constant (regno) != 0)
5412 op1 = reg_equiv_constant (regno);
5413 else if (GET_CODE (op0) == PLUS
5414 && (tem = subst_indexed_address (op0)) != op0)
5415 op0 = tem;
5416 else if (GET_CODE (op1) == PLUS
5417 && (tem = subst_indexed_address (op1)) != op1)
5418 op1 = tem;
5419 else
5420 return addr;
5422 /* Pick out up to three things to add. */
5423 if (GET_CODE (op1) == PLUS)
5424 op2 = XEXP (op1, 1), op1 = XEXP (op1, 0);
5425 else if (GET_CODE (op0) == PLUS)
5426 op2 = op1, op1 = XEXP (op0, 1), op0 = XEXP (op0, 0);
5428 /* Compute the sum. */
5429 if (op2 != 0)
5430 op1 = form_sum (GET_MODE (addr), op1, op2);
5431 if (op1 != 0)
5432 op0 = form_sum (GET_MODE (addr), op0, op1);
5434 return op0;
5436 return addr;
5439 /* Update the REG_INC notes for an insn. It updates all REG_INC
5440 notes for the instruction which refer to REGNO the to refer
5441 to the reload number.
5443 INSN is the insn for which any REG_INC notes need updating.
5445 REGNO is the register number which has been reloaded.
5447 RELOADNUM is the reload number. */
5449 static void
5450 update_auto_inc_notes (rtx_insn *insn ATTRIBUTE_UNUSED, int regno ATTRIBUTE_UNUSED,
5451 int reloadnum ATTRIBUTE_UNUSED)
5453 if (!AUTO_INC_DEC)
5454 return;
5456 for (rtx link = REG_NOTES (insn); link; link = XEXP (link, 1))
5457 if (REG_NOTE_KIND (link) == REG_INC
5458 && (int) REGNO (XEXP (link, 0)) == regno)
5459 push_replacement (&XEXP (link, 0), reloadnum, VOIDmode);
5462 /* Record the pseudo registers we must reload into hard registers in a
5463 subexpression of a would-be memory address, X referring to a value
5464 in mode MODE. (This function is not called if the address we find
5465 is strictly valid.)
5467 CONTEXT = 1 means we are considering regs as index regs,
5468 = 0 means we are considering them as base regs.
5469 OUTER_CODE is the code of the enclosing RTX, typically a MEM, a PLUS,
5470 or an autoinc code.
5471 If CONTEXT == 0 and OUTER_CODE is a PLUS or LO_SUM, then INDEX_CODE
5472 is the code of the index part of the address. Otherwise, pass SCRATCH
5473 for this argument.
5474 OPNUM and TYPE specify the purpose of any reloads made.
5476 IND_LEVELS says how many levels of indirect addressing are
5477 supported at this point in the address.
5479 INSN, if nonzero, is the insn in which we do the reload. It is used
5480 to determine if we may generate output reloads.
5482 We return nonzero if X, as a whole, is reloaded or replaced. */
5484 /* Note that we take shortcuts assuming that no multi-reg machine mode
5485 occurs as part of an address.
5486 Also, this is not fully machine-customizable; it works for machines
5487 such as VAXen and 68000's and 32000's, but other possible machines
5488 could have addressing modes that this does not handle right.
5489 If you add push_reload calls here, you need to make sure gen_reload
5490 handles those cases gracefully. */
5492 static int
5493 find_reloads_address_1 (machine_mode mode, addr_space_t as,
5494 rtx x, int context,
5495 enum rtx_code outer_code, enum rtx_code index_code,
5496 rtx *loc, int opnum, enum reload_type type,
5497 int ind_levels, rtx_insn *insn)
5499 #define REG_OK_FOR_CONTEXT(CONTEXT, REGNO, MODE, AS, OUTER, INDEX) \
5500 ((CONTEXT) == 0 \
5501 ? regno_ok_for_base_p (REGNO, MODE, AS, OUTER, INDEX) \
5502 : REGNO_OK_FOR_INDEX_P (REGNO))
5504 enum reg_class context_reg_class;
5505 RTX_CODE code = GET_CODE (x);
5506 bool reloaded_inner_of_autoinc = false;
5508 if (context == 1)
5509 context_reg_class = INDEX_REG_CLASS;
5510 else
5511 context_reg_class = base_reg_class (mode, as, outer_code, index_code);
5513 switch (code)
5515 case PLUS:
5517 rtx orig_op0 = XEXP (x, 0);
5518 rtx orig_op1 = XEXP (x, 1);
5519 RTX_CODE code0 = GET_CODE (orig_op0);
5520 RTX_CODE code1 = GET_CODE (orig_op1);
5521 rtx op0 = orig_op0;
5522 rtx op1 = orig_op1;
5524 if (GET_CODE (op0) == SUBREG)
5526 op0 = SUBREG_REG (op0);
5527 code0 = GET_CODE (op0);
5528 if (code0 == REG && REGNO (op0) < FIRST_PSEUDO_REGISTER)
5529 op0 = gen_rtx_REG (word_mode,
5530 (REGNO (op0) +
5531 subreg_regno_offset (REGNO (SUBREG_REG (orig_op0)),
5532 GET_MODE (SUBREG_REG (orig_op0)),
5533 SUBREG_BYTE (orig_op0),
5534 GET_MODE (orig_op0))));
5537 if (GET_CODE (op1) == SUBREG)
5539 op1 = SUBREG_REG (op1);
5540 code1 = GET_CODE (op1);
5541 if (code1 == REG && REGNO (op1) < FIRST_PSEUDO_REGISTER)
5542 /* ??? Why is this given op1's mode and above for
5543 ??? op0 SUBREGs we use word_mode? */
5544 op1 = gen_rtx_REG (GET_MODE (op1),
5545 (REGNO (op1) +
5546 subreg_regno_offset (REGNO (SUBREG_REG (orig_op1)),
5547 GET_MODE (SUBREG_REG (orig_op1)),
5548 SUBREG_BYTE (orig_op1),
5549 GET_MODE (orig_op1))));
5551 /* Plus in the index register may be created only as a result of
5552 register rematerialization for expression like &localvar*4. Reload it.
5553 It may be possible to combine the displacement on the outer level,
5554 but it is probably not worthwhile to do so. */
5555 if (context == 1)
5557 find_reloads_address (GET_MODE (x), loc, XEXP (x, 0), &XEXP (x, 0),
5558 opnum, ADDR_TYPE (type), ind_levels, insn);
5559 push_reload (*loc, NULL_RTX, loc, (rtx*) 0,
5560 context_reg_class,
5561 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5562 return 1;
5565 if (code0 == MULT || code0 == SIGN_EXTEND || code0 == TRUNCATE
5566 || code0 == ZERO_EXTEND || code1 == MEM)
5568 find_reloads_address_1 (mode, as, orig_op0, 1, PLUS, SCRATCH,
5569 &XEXP (x, 0), opnum, type, ind_levels,
5570 insn);
5571 find_reloads_address_1 (mode, as, orig_op1, 0, PLUS, code0,
5572 &XEXP (x, 1), opnum, type, ind_levels,
5573 insn);
5576 else if (code1 == MULT || code1 == SIGN_EXTEND || code1 == TRUNCATE
5577 || code1 == ZERO_EXTEND || code0 == MEM)
5579 find_reloads_address_1 (mode, as, orig_op0, 0, PLUS, code1,
5580 &XEXP (x, 0), opnum, type, ind_levels,
5581 insn);
5582 find_reloads_address_1 (mode, as, orig_op1, 1, PLUS, SCRATCH,
5583 &XEXP (x, 1), opnum, type, ind_levels,
5584 insn);
5587 else if (code0 == CONST_INT || code0 == CONST
5588 || code0 == SYMBOL_REF || code0 == LABEL_REF)
5589 find_reloads_address_1 (mode, as, orig_op1, 0, PLUS, code0,
5590 &XEXP (x, 1), opnum, type, ind_levels,
5591 insn);
5593 else if (code1 == CONST_INT || code1 == CONST
5594 || code1 == SYMBOL_REF || code1 == LABEL_REF)
5595 find_reloads_address_1 (mode, as, orig_op0, 0, PLUS, code1,
5596 &XEXP (x, 0), opnum, type, ind_levels,
5597 insn);
5599 else if (code0 == REG && code1 == REG)
5601 if (REGNO_OK_FOR_INDEX_P (REGNO (op1))
5602 && regno_ok_for_base_p (REGNO (op0), mode, as, PLUS, REG))
5603 return 0;
5604 else if (REGNO_OK_FOR_INDEX_P (REGNO (op0))
5605 && regno_ok_for_base_p (REGNO (op1), mode, as, PLUS, REG))
5606 return 0;
5607 else if (regno_ok_for_base_p (REGNO (op0), mode, as, PLUS, REG))
5608 find_reloads_address_1 (mode, as, orig_op1, 1, PLUS, SCRATCH,
5609 &XEXP (x, 1), opnum, type, ind_levels,
5610 insn);
5611 else if (REGNO_OK_FOR_INDEX_P (REGNO (op1)))
5612 find_reloads_address_1 (mode, as, orig_op0, 0, PLUS, REG,
5613 &XEXP (x, 0), opnum, type, ind_levels,
5614 insn);
5615 else if (regno_ok_for_base_p (REGNO (op1), mode, as, PLUS, REG))
5616 find_reloads_address_1 (mode, as, orig_op0, 1, PLUS, SCRATCH,
5617 &XEXP (x, 0), opnum, type, ind_levels,
5618 insn);
5619 else if (REGNO_OK_FOR_INDEX_P (REGNO (op0)))
5620 find_reloads_address_1 (mode, as, orig_op1, 0, PLUS, REG,
5621 &XEXP (x, 1), opnum, type, ind_levels,
5622 insn);
5623 else
5625 find_reloads_address_1 (mode, as, orig_op0, 0, PLUS, REG,
5626 &XEXP (x, 0), opnum, type, ind_levels,
5627 insn);
5628 find_reloads_address_1 (mode, as, orig_op1, 1, PLUS, SCRATCH,
5629 &XEXP (x, 1), opnum, type, ind_levels,
5630 insn);
5634 else if (code0 == REG)
5636 find_reloads_address_1 (mode, as, orig_op0, 1, PLUS, SCRATCH,
5637 &XEXP (x, 0), opnum, type, ind_levels,
5638 insn);
5639 find_reloads_address_1 (mode, as, orig_op1, 0, PLUS, REG,
5640 &XEXP (x, 1), opnum, type, ind_levels,
5641 insn);
5644 else if (code1 == REG)
5646 find_reloads_address_1 (mode, as, orig_op1, 1, PLUS, SCRATCH,
5647 &XEXP (x, 1), opnum, type, ind_levels,
5648 insn);
5649 find_reloads_address_1 (mode, as, orig_op0, 0, PLUS, REG,
5650 &XEXP (x, 0), opnum, type, ind_levels,
5651 insn);
5655 return 0;
5657 case POST_MODIFY:
5658 case PRE_MODIFY:
5660 rtx op0 = XEXP (x, 0);
5661 rtx op1 = XEXP (x, 1);
5662 enum rtx_code index_code;
5663 int regno;
5664 int reloadnum;
5666 if (GET_CODE (op1) != PLUS && GET_CODE (op1) != MINUS)
5667 return 0;
5669 /* Currently, we only support {PRE,POST}_MODIFY constructs
5670 where a base register is {inc,dec}remented by the contents
5671 of another register or by a constant value. Thus, these
5672 operands must match. */
5673 gcc_assert (op0 == XEXP (op1, 0));
5675 /* Require index register (or constant). Let's just handle the
5676 register case in the meantime... If the target allows
5677 auto-modify by a constant then we could try replacing a pseudo
5678 register with its equivalent constant where applicable.
5680 We also handle the case where the register was eliminated
5681 resulting in a PLUS subexpression.
5683 If we later decide to reload the whole PRE_MODIFY or
5684 POST_MODIFY, inc_for_reload might clobber the reload register
5685 before reading the index. The index register might therefore
5686 need to live longer than a TYPE reload normally would, so be
5687 conservative and class it as RELOAD_OTHER. */
5688 if ((REG_P (XEXP (op1, 1))
5689 && !REGNO_OK_FOR_INDEX_P (REGNO (XEXP (op1, 1))))
5690 || GET_CODE (XEXP (op1, 1)) == PLUS)
5691 find_reloads_address_1 (mode, as, XEXP (op1, 1), 1, code, SCRATCH,
5692 &XEXP (op1, 1), opnum, RELOAD_OTHER,
5693 ind_levels, insn);
5695 gcc_assert (REG_P (XEXP (op1, 0)));
5697 regno = REGNO (XEXP (op1, 0));
5698 index_code = GET_CODE (XEXP (op1, 1));
5700 /* A register that is incremented cannot be constant! */
5701 gcc_assert (regno < FIRST_PSEUDO_REGISTER
5702 || reg_equiv_constant (regno) == 0);
5704 /* Handle a register that is equivalent to a memory location
5705 which cannot be addressed directly. */
5706 if (reg_equiv_memory_loc (regno) != 0
5707 && (reg_equiv_address (regno) != 0
5708 || num_not_at_initial_offset))
5710 rtx tem = make_memloc (XEXP (x, 0), regno);
5712 if (reg_equiv_address (regno)
5713 || ! rtx_equal_p (tem, reg_equiv_mem (regno)))
5715 rtx orig = tem;
5717 /* First reload the memory location's address.
5718 We can't use ADDR_TYPE (type) here, because we need to
5719 write back the value after reading it, hence we actually
5720 need two registers. */
5721 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
5722 &XEXP (tem, 0), opnum,
5723 RELOAD_OTHER,
5724 ind_levels, insn);
5726 if (!rtx_equal_p (tem, orig))
5727 push_reg_equiv_alt_mem (regno, tem);
5729 /* Then reload the memory location into a base
5730 register. */
5731 reloadnum = push_reload (tem, tem, &XEXP (x, 0),
5732 &XEXP (op1, 0),
5733 base_reg_class (mode, as,
5734 code, index_code),
5735 GET_MODE (x), GET_MODE (x), 0,
5736 0, opnum, RELOAD_OTHER);
5738 update_auto_inc_notes (this_insn, regno, reloadnum);
5739 return 0;
5743 if (reg_renumber[regno] >= 0)
5744 regno = reg_renumber[regno];
5746 /* We require a base register here... */
5747 if (!regno_ok_for_base_p (regno, GET_MODE (x), as, code, index_code))
5749 reloadnum = push_reload (XEXP (op1, 0), XEXP (x, 0),
5750 &XEXP (op1, 0), &XEXP (x, 0),
5751 base_reg_class (mode, as,
5752 code, index_code),
5753 GET_MODE (x), GET_MODE (x), 0, 0,
5754 opnum, RELOAD_OTHER);
5756 update_auto_inc_notes (this_insn, regno, reloadnum);
5757 return 0;
5760 return 0;
5762 case POST_INC:
5763 case POST_DEC:
5764 case PRE_INC:
5765 case PRE_DEC:
5766 if (REG_P (XEXP (x, 0)))
5768 int regno = REGNO (XEXP (x, 0));
5769 int value = 0;
5770 rtx x_orig = x;
5772 /* A register that is incremented cannot be constant! */
5773 gcc_assert (regno < FIRST_PSEUDO_REGISTER
5774 || reg_equiv_constant (regno) == 0);
5776 /* Handle a register that is equivalent to a memory location
5777 which cannot be addressed directly. */
5778 if (reg_equiv_memory_loc (regno) != 0
5779 && (reg_equiv_address (regno) != 0 || num_not_at_initial_offset))
5781 rtx tem = make_memloc (XEXP (x, 0), regno);
5782 if (reg_equiv_address (regno)
5783 || ! rtx_equal_p (tem, reg_equiv_mem (regno)))
5785 rtx orig = tem;
5787 /* First reload the memory location's address.
5788 We can't use ADDR_TYPE (type) here, because we need to
5789 write back the value after reading it, hence we actually
5790 need two registers. */
5791 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
5792 &XEXP (tem, 0), opnum, type,
5793 ind_levels, insn);
5794 reloaded_inner_of_autoinc = true;
5795 if (!rtx_equal_p (tem, orig))
5796 push_reg_equiv_alt_mem (regno, tem);
5797 /* Put this inside a new increment-expression. */
5798 x = gen_rtx_fmt_e (GET_CODE (x), GET_MODE (x), tem);
5799 /* Proceed to reload that, as if it contained a register. */
5803 /* If we have a hard register that is ok in this incdec context,
5804 don't make a reload. If the register isn't nice enough for
5805 autoincdec, we can reload it. But, if an autoincrement of a
5806 register that we here verified as playing nice, still outside
5807 isn't "valid", it must be that no autoincrement is "valid".
5808 If that is true and something made an autoincrement anyway,
5809 this must be a special context where one is allowed.
5810 (For example, a "push" instruction.)
5811 We can't improve this address, so leave it alone. */
5813 /* Otherwise, reload the autoincrement into a suitable hard reg
5814 and record how much to increment by. */
5816 if (reg_renumber[regno] >= 0)
5817 regno = reg_renumber[regno];
5818 if (regno >= FIRST_PSEUDO_REGISTER
5819 || !REG_OK_FOR_CONTEXT (context, regno, mode, as, code,
5820 index_code))
5822 int reloadnum;
5824 /* If we can output the register afterwards, do so, this
5825 saves the extra update.
5826 We can do so if we have an INSN - i.e. no JUMP_INSN nor
5827 CALL_INSN - and it does not set CC0.
5828 But don't do this if we cannot directly address the
5829 memory location, since this will make it harder to
5830 reuse address reloads, and increases register pressure.
5831 Also don't do this if we can probably update x directly. */
5832 rtx equiv = (MEM_P (XEXP (x, 0))
5833 ? XEXP (x, 0)
5834 : reg_equiv_mem (regno));
5835 enum insn_code icode = optab_handler (add_optab, GET_MODE (x));
5836 if (insn && NONJUMP_INSN_P (insn)
5837 #if HAVE_cc0
5838 && ! sets_cc0_p (PATTERN (insn))
5839 #endif
5840 && (regno < FIRST_PSEUDO_REGISTER
5841 || (equiv
5842 && memory_operand (equiv, GET_MODE (equiv))
5843 && ! (icode != CODE_FOR_nothing
5844 && insn_operand_matches (icode, 0, equiv)
5845 && insn_operand_matches (icode, 1, equiv))))
5846 /* Using RELOAD_OTHER means we emit this and the reload we
5847 made earlier in the wrong order. */
5848 && !reloaded_inner_of_autoinc)
5850 /* We use the original pseudo for loc, so that
5851 emit_reload_insns() knows which pseudo this
5852 reload refers to and updates the pseudo rtx, not
5853 its equivalent memory location, as well as the
5854 corresponding entry in reg_last_reload_reg. */
5855 loc = &XEXP (x_orig, 0);
5856 x = XEXP (x, 0);
5857 reloadnum
5858 = push_reload (x, x, loc, loc,
5859 context_reg_class,
5860 GET_MODE (x), GET_MODE (x), 0, 0,
5861 opnum, RELOAD_OTHER);
5863 else
5865 reloadnum
5866 = push_reload (x, x, loc, (rtx*) 0,
5867 context_reg_class,
5868 GET_MODE (x), GET_MODE (x), 0, 0,
5869 opnum, type);
5870 rld[reloadnum].inc
5871 = find_inc_amount (PATTERN (this_insn), XEXP (x_orig, 0));
5873 value = 1;
5876 update_auto_inc_notes (this_insn, REGNO (XEXP (x_orig, 0)),
5877 reloadnum);
5879 return value;
5881 return 0;
5883 case TRUNCATE:
5884 case SIGN_EXTEND:
5885 case ZERO_EXTEND:
5886 /* Look for parts to reload in the inner expression and reload them
5887 too, in addition to this operation. Reloading all inner parts in
5888 addition to this one shouldn't be necessary, but at this point,
5889 we don't know if we can possibly omit any part that *can* be
5890 reloaded. Targets that are better off reloading just either part
5891 (or perhaps even a different part of an outer expression), should
5892 define LEGITIMIZE_RELOAD_ADDRESS. */
5893 find_reloads_address_1 (GET_MODE (XEXP (x, 0)), as, XEXP (x, 0),
5894 context, code, SCRATCH, &XEXP (x, 0), opnum,
5895 type, ind_levels, insn);
5896 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5897 context_reg_class,
5898 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5899 return 1;
5901 case MEM:
5902 /* This is probably the result of a substitution, by eliminate_regs, of
5903 an equivalent address for a pseudo that was not allocated to a hard
5904 register. Verify that the specified address is valid and reload it
5905 into a register.
5907 Since we know we are going to reload this item, don't decrement for
5908 the indirection level.
5910 Note that this is actually conservative: it would be slightly more
5911 efficient to use the value of SPILL_INDIRECT_LEVELS from
5912 reload1.c here. */
5914 find_reloads_address (GET_MODE (x), loc, XEXP (x, 0), &XEXP (x, 0),
5915 opnum, ADDR_TYPE (type), ind_levels, insn);
5916 push_reload (*loc, NULL_RTX, loc, (rtx*) 0,
5917 context_reg_class,
5918 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5919 return 1;
5921 case REG:
5923 int regno = REGNO (x);
5925 if (reg_equiv_constant (regno) != 0)
5927 find_reloads_address_part (reg_equiv_constant (regno), loc,
5928 context_reg_class,
5929 GET_MODE (x), opnum, type, ind_levels);
5930 return 1;
5933 #if 0 /* This might screw code in reload1.c to delete prior output-reload
5934 that feeds this insn. */
5935 if (reg_equiv_mem (regno) != 0)
5937 push_reload (reg_equiv_mem (regno), NULL_RTX, loc, (rtx*) 0,
5938 context_reg_class,
5939 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5940 return 1;
5942 #endif
5944 if (reg_equiv_memory_loc (regno)
5945 && (reg_equiv_address (regno) != 0 || num_not_at_initial_offset))
5947 rtx tem = make_memloc (x, regno);
5948 if (reg_equiv_address (regno) != 0
5949 || ! rtx_equal_p (tem, reg_equiv_mem (regno)))
5951 x = tem;
5952 find_reloads_address (GET_MODE (x), &x, XEXP (x, 0),
5953 &XEXP (x, 0), opnum, ADDR_TYPE (type),
5954 ind_levels, insn);
5955 if (!rtx_equal_p (x, tem))
5956 push_reg_equiv_alt_mem (regno, x);
5960 if (reg_renumber[regno] >= 0)
5961 regno = reg_renumber[regno];
5963 if (regno >= FIRST_PSEUDO_REGISTER
5964 || !REG_OK_FOR_CONTEXT (context, regno, mode, as, outer_code,
5965 index_code))
5967 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5968 context_reg_class,
5969 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5970 return 1;
5973 /* If a register appearing in an address is the subject of a CLOBBER
5974 in this insn, reload it into some other register to be safe.
5975 The CLOBBER is supposed to make the register unavailable
5976 from before this insn to after it. */
5977 if (regno_clobbered_p (regno, this_insn, GET_MODE (x), 0))
5979 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5980 context_reg_class,
5981 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5982 return 1;
5985 return 0;
5987 case SUBREG:
5988 if (REG_P (SUBREG_REG (x)))
5990 /* If this is a SUBREG of a hard register and the resulting register
5991 is of the wrong class, reload the whole SUBREG. This avoids
5992 needless copies if SUBREG_REG is multi-word. */
5993 if (REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER)
5995 int regno ATTRIBUTE_UNUSED = subreg_regno (x);
5997 if (!REG_OK_FOR_CONTEXT (context, regno, mode, as, outer_code,
5998 index_code))
6000 push_reload (x, NULL_RTX, loc, (rtx*) 0,
6001 context_reg_class,
6002 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
6003 return 1;
6006 /* If this is a SUBREG of a pseudo-register, and the pseudo-register
6007 is larger than the class size, then reload the whole SUBREG. */
6008 else
6010 enum reg_class rclass = context_reg_class;
6011 if (ira_reg_class_max_nregs [rclass][GET_MODE (SUBREG_REG (x))]
6012 > reg_class_size[(int) rclass])
6014 /* If the inner register will be replaced by a memory
6015 reference, we can do this only if we can replace the
6016 whole subreg by a (narrower) memory reference. If
6017 this is not possible, fall through and reload just
6018 the inner register (including address reloads). */
6019 if (reg_equiv_memory_loc (REGNO (SUBREG_REG (x))) != 0)
6021 rtx tem = find_reloads_subreg_address (x, opnum,
6022 ADDR_TYPE (type),
6023 ind_levels, insn,
6024 NULL);
6025 if (tem)
6027 push_reload (tem, NULL_RTX, loc, (rtx*) 0, rclass,
6028 GET_MODE (tem), VOIDmode, 0, 0,
6029 opnum, type);
6030 return 1;
6033 else
6035 push_reload (x, NULL_RTX, loc, (rtx*) 0, rclass,
6036 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
6037 return 1;
6042 break;
6044 default:
6045 break;
6049 const char *fmt = GET_RTX_FORMAT (code);
6050 int i;
6052 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
6054 if (fmt[i] == 'e')
6055 /* Pass SCRATCH for INDEX_CODE, since CODE can never be a PLUS once
6056 we get here. */
6057 find_reloads_address_1 (mode, as, XEXP (x, i), context,
6058 code, SCRATCH, &XEXP (x, i),
6059 opnum, type, ind_levels, insn);
6063 #undef REG_OK_FOR_CONTEXT
6064 return 0;
6067 /* X, which is found at *LOC, is a part of an address that needs to be
6068 reloaded into a register of class RCLASS. If X is a constant, or if
6069 X is a PLUS that contains a constant, check that the constant is a
6070 legitimate operand and that we are supposed to be able to load
6071 it into the register.
6073 If not, force the constant into memory and reload the MEM instead.
6075 MODE is the mode to use, in case X is an integer constant.
6077 OPNUM and TYPE describe the purpose of any reloads made.
6079 IND_LEVELS says how many levels of indirect addressing this machine
6080 supports. */
6082 static void
6083 find_reloads_address_part (rtx x, rtx *loc, enum reg_class rclass,
6084 machine_mode mode, int opnum,
6085 enum reload_type type, int ind_levels)
6087 if (CONSTANT_P (x)
6088 && (!targetm.legitimate_constant_p (mode, x)
6089 || targetm.preferred_reload_class (x, rclass) == NO_REGS))
6091 x = force_const_mem (mode, x);
6092 find_reloads_address (mode, &x, XEXP (x, 0), &XEXP (x, 0),
6093 opnum, type, ind_levels, 0);
6096 else if (GET_CODE (x) == PLUS
6097 && CONSTANT_P (XEXP (x, 1))
6098 && (!targetm.legitimate_constant_p (GET_MODE (x), XEXP (x, 1))
6099 || targetm.preferred_reload_class (XEXP (x, 1), rclass)
6100 == NO_REGS))
6102 rtx tem;
6104 tem = force_const_mem (GET_MODE (x), XEXP (x, 1));
6105 x = gen_rtx_PLUS (GET_MODE (x), XEXP (x, 0), tem);
6106 find_reloads_address (mode, &XEXP (x, 1), XEXP (tem, 0), &XEXP (tem, 0),
6107 opnum, type, ind_levels, 0);
6110 push_reload (x, NULL_RTX, loc, (rtx*) 0, rclass,
6111 mode, VOIDmode, 0, 0, opnum, type);
6114 /* X, a subreg of a pseudo, is a part of an address that needs to be
6115 reloaded, and the pseusdo is equivalent to a memory location.
6117 Attempt to replace the whole subreg by a (possibly narrower or wider)
6118 memory reference. If this is possible, return this new memory
6119 reference, and push all required address reloads. Otherwise,
6120 return NULL.
6122 OPNUM and TYPE identify the purpose of the reload.
6124 IND_LEVELS says how many levels of indirect addressing are
6125 supported at this point in the address.
6127 INSN, if nonzero, is the insn in which we do the reload. It is used
6128 to determine where to put USEs for pseudos that we have to replace with
6129 stack slots. */
6131 static rtx
6132 find_reloads_subreg_address (rtx x, int opnum, enum reload_type type,
6133 int ind_levels, rtx_insn *insn,
6134 int *address_reloaded)
6136 machine_mode outer_mode = GET_MODE (x);
6137 machine_mode inner_mode = GET_MODE (SUBREG_REG (x));
6138 int regno = REGNO (SUBREG_REG (x));
6139 int reloaded = 0;
6140 rtx tem, orig;
6141 poly_int64 offset;
6143 gcc_assert (reg_equiv_memory_loc (regno) != 0);
6145 /* We cannot replace the subreg with a modified memory reference if:
6147 - we have a paradoxical subreg that implicitly acts as a zero or
6148 sign extension operation due to LOAD_EXTEND_OP;
6150 - we have a subreg that is implicitly supposed to act on the full
6151 register due to WORD_REGISTER_OPERATIONS (see also eliminate_regs);
6153 - the address of the equivalent memory location is mode-dependent; or
6155 - we have a paradoxical subreg and the resulting memory is not
6156 sufficiently aligned to allow access in the wider mode.
6158 In addition, we choose not to perform the replacement for *any*
6159 paradoxical subreg, even if it were possible in principle. This
6160 is to avoid generating wider memory references than necessary.
6162 This corresponds to how previous versions of reload used to handle
6163 paradoxical subregs where no address reload was required. */
6165 if (paradoxical_subreg_p (x))
6166 return NULL;
6168 if (WORD_REGISTER_OPERATIONS
6169 && partial_subreg_p (outer_mode, inner_mode)
6170 && known_equal_after_align_down (GET_MODE_SIZE (outer_mode) - 1,
6171 GET_MODE_SIZE (inner_mode) - 1,
6172 UNITS_PER_WORD))
6173 return NULL;
6175 /* Since we don't attempt to handle paradoxical subregs, we can just
6176 call into simplify_subreg, which will handle all remaining checks
6177 for us. */
6178 orig = make_memloc (SUBREG_REG (x), regno);
6179 offset = SUBREG_BYTE (x);
6180 tem = simplify_subreg (outer_mode, orig, inner_mode, offset);
6181 if (!tem || !MEM_P (tem))
6182 return NULL;
6184 /* Now push all required address reloads, if any. */
6185 reloaded = find_reloads_address (GET_MODE (tem), &tem,
6186 XEXP (tem, 0), &XEXP (tem, 0),
6187 opnum, type, ind_levels, insn);
6188 /* ??? Do we need to handle nonzero offsets somehow? */
6189 if (known_eq (offset, 0) && !rtx_equal_p (tem, orig))
6190 push_reg_equiv_alt_mem (regno, tem);
6192 /* For some processors an address may be valid in the original mode but
6193 not in a smaller mode. For example, ARM accepts a scaled index register
6194 in SImode but not in HImode. Note that this is only a problem if the
6195 address in reg_equiv_mem is already invalid in the new mode; other
6196 cases would be fixed by find_reloads_address as usual.
6198 ??? We attempt to handle such cases here by doing an additional reload
6199 of the full address after the usual processing by find_reloads_address.
6200 Note that this may not work in the general case, but it seems to cover
6201 the cases where this situation currently occurs. A more general fix
6202 might be to reload the *value* instead of the address, but this would
6203 not be expected by the callers of this routine as-is.
6205 If find_reloads_address already completed replaced the address, there
6206 is nothing further to do. */
6207 if (reloaded == 0
6208 && reg_equiv_mem (regno) != 0
6209 && !strict_memory_address_addr_space_p
6210 (GET_MODE (x), XEXP (reg_equiv_mem (regno), 0),
6211 MEM_ADDR_SPACE (reg_equiv_mem (regno))))
6213 push_reload (XEXP (tem, 0), NULL_RTX, &XEXP (tem, 0), (rtx*) 0,
6214 base_reg_class (GET_MODE (tem), MEM_ADDR_SPACE (tem),
6215 MEM, SCRATCH),
6216 GET_MODE (XEXP (tem, 0)), VOIDmode, 0, 0, opnum, type);
6217 reloaded = 1;
6220 /* If this is not a toplevel operand, find_reloads doesn't see this
6221 substitution. We have to emit a USE of the pseudo so that
6222 delete_output_reload can see it. */
6223 if (replace_reloads && recog_data.operand[opnum] != x)
6224 /* We mark the USE with QImode so that we recognize it as one that
6225 can be safely deleted at the end of reload. */
6226 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, SUBREG_REG (x)), insn),
6227 QImode);
6229 if (address_reloaded)
6230 *address_reloaded = reloaded;
6232 return tem;
6235 /* Substitute into the current INSN the registers into which we have reloaded
6236 the things that need reloading. The array `replacements'
6237 contains the locations of all pointers that must be changed
6238 and says what to replace them with.
6240 Return the rtx that X translates into; usually X, but modified. */
6242 void
6243 subst_reloads (rtx_insn *insn)
6245 int i;
6247 for (i = 0; i < n_replacements; i++)
6249 struct replacement *r = &replacements[i];
6250 rtx reloadreg = rld[r->what].reg_rtx;
6251 if (reloadreg)
6253 #ifdef DEBUG_RELOAD
6254 /* This checking takes a very long time on some platforms
6255 causing the gcc.c-torture/compile/limits-fnargs.c test
6256 to time out during testing. See PR 31850.
6258 Internal consistency test. Check that we don't modify
6259 anything in the equivalence arrays. Whenever something from
6260 those arrays needs to be reloaded, it must be unshared before
6261 being substituted into; the equivalence must not be modified.
6262 Otherwise, if the equivalence is used after that, it will
6263 have been modified, and the thing substituted (probably a
6264 register) is likely overwritten and not a usable equivalence. */
6265 int check_regno;
6267 for (check_regno = 0; check_regno < max_regno; check_regno++)
6269 #define CHECK_MODF(ARRAY) \
6270 gcc_assert (!(*reg_equivs)[check_regno].ARRAY \
6271 || !loc_mentioned_in_p (r->where, \
6272 (*reg_equivs)[check_regno].ARRAY))
6274 CHECK_MODF (constant);
6275 CHECK_MODF (memory_loc);
6276 CHECK_MODF (address);
6277 CHECK_MODF (mem);
6278 #undef CHECK_MODF
6280 #endif /* DEBUG_RELOAD */
6282 /* If we're replacing a LABEL_REF with a register, there must
6283 already be an indication (to e.g. flow) which label this
6284 register refers to. */
6285 gcc_assert (GET_CODE (*r->where) != LABEL_REF
6286 || !JUMP_P (insn)
6287 || find_reg_note (insn,
6288 REG_LABEL_OPERAND,
6289 XEXP (*r->where, 0))
6290 || label_is_jump_target_p (XEXP (*r->where, 0), insn));
6292 /* Encapsulate RELOADREG so its machine mode matches what
6293 used to be there. Note that gen_lowpart_common will
6294 do the wrong thing if RELOADREG is multi-word. RELOADREG
6295 will always be a REG here. */
6296 if (GET_MODE (reloadreg) != r->mode && r->mode != VOIDmode)
6297 reloadreg = reload_adjust_reg_for_mode (reloadreg, r->mode);
6299 *r->where = reloadreg;
6301 /* If reload got no reg and isn't optional, something's wrong. */
6302 else
6303 gcc_assert (rld[r->what].optional);
6307 /* Make a copy of any replacements being done into X and move those
6308 copies to locations in Y, a copy of X. */
6310 void
6311 copy_replacements (rtx x, rtx y)
6313 copy_replacements_1 (&x, &y, n_replacements);
6316 static void
6317 copy_replacements_1 (rtx *px, rtx *py, int orig_replacements)
6319 int i, j;
6320 rtx x, y;
6321 struct replacement *r;
6322 enum rtx_code code;
6323 const char *fmt;
6325 for (j = 0; j < orig_replacements; j++)
6326 if (replacements[j].where == px)
6328 r = &replacements[n_replacements++];
6329 r->where = py;
6330 r->what = replacements[j].what;
6331 r->mode = replacements[j].mode;
6334 x = *px;
6335 y = *py;
6336 code = GET_CODE (x);
6337 fmt = GET_RTX_FORMAT (code);
6339 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
6341 if (fmt[i] == 'e')
6342 copy_replacements_1 (&XEXP (x, i), &XEXP (y, i), orig_replacements);
6343 else if (fmt[i] == 'E')
6344 for (j = XVECLEN (x, i); --j >= 0; )
6345 copy_replacements_1 (&XVECEXP (x, i, j), &XVECEXP (y, i, j),
6346 orig_replacements);
6350 /* Change any replacements being done to *X to be done to *Y. */
6352 void
6353 move_replacements (rtx *x, rtx *y)
6355 int i;
6357 for (i = 0; i < n_replacements; i++)
6358 if (replacements[i].where == x)
6359 replacements[i].where = y;
6362 /* If LOC was scheduled to be replaced by something, return the replacement.
6363 Otherwise, return *LOC. */
6366 find_replacement (rtx *loc)
6368 struct replacement *r;
6370 for (r = &replacements[0]; r < &replacements[n_replacements]; r++)
6372 rtx reloadreg = rld[r->what].reg_rtx;
6374 if (reloadreg && r->where == loc)
6376 if (r->mode != VOIDmode && GET_MODE (reloadreg) != r->mode)
6377 reloadreg = reload_adjust_reg_for_mode (reloadreg, r->mode);
6379 return reloadreg;
6381 else if (reloadreg && GET_CODE (*loc) == SUBREG
6382 && r->where == &SUBREG_REG (*loc))
6384 if (r->mode != VOIDmode && GET_MODE (reloadreg) != r->mode)
6385 reloadreg = reload_adjust_reg_for_mode (reloadreg, r->mode);
6387 return simplify_gen_subreg (GET_MODE (*loc), reloadreg,
6388 GET_MODE (SUBREG_REG (*loc)),
6389 SUBREG_BYTE (*loc));
6393 /* If *LOC is a PLUS, MINUS, or MULT, see if a replacement is scheduled for
6394 what's inside and make a new rtl if so. */
6395 if (GET_CODE (*loc) == PLUS || GET_CODE (*loc) == MINUS
6396 || GET_CODE (*loc) == MULT)
6398 rtx x = find_replacement (&XEXP (*loc, 0));
6399 rtx y = find_replacement (&XEXP (*loc, 1));
6401 if (x != XEXP (*loc, 0) || y != XEXP (*loc, 1))
6402 return gen_rtx_fmt_ee (GET_CODE (*loc), GET_MODE (*loc), x, y);
6405 return *loc;
6408 /* Return nonzero if register in range [REGNO, ENDREGNO)
6409 appears either explicitly or implicitly in X
6410 other than being stored into (except for earlyclobber operands).
6412 References contained within the substructure at LOC do not count.
6413 LOC may be zero, meaning don't ignore anything.
6415 This is similar to refers_to_regno_p in rtlanal.c except that we
6416 look at equivalences for pseudos that didn't get hard registers. */
6418 static int
6419 refers_to_regno_for_reload_p (unsigned int regno, unsigned int endregno,
6420 rtx x, rtx *loc)
6422 int i;
6423 unsigned int r;
6424 RTX_CODE code;
6425 const char *fmt;
6427 if (x == 0)
6428 return 0;
6430 repeat:
6431 code = GET_CODE (x);
6433 switch (code)
6435 case REG:
6436 r = REGNO (x);
6438 /* If this is a pseudo, a hard register must not have been allocated.
6439 X must therefore either be a constant or be in memory. */
6440 if (r >= FIRST_PSEUDO_REGISTER)
6442 if (reg_equiv_memory_loc (r))
6443 return refers_to_regno_for_reload_p (regno, endregno,
6444 reg_equiv_memory_loc (r),
6445 (rtx*) 0);
6447 gcc_assert (reg_equiv_constant (r) || reg_equiv_invariant (r));
6448 return 0;
6451 return endregno > r && regno < END_REGNO (x);
6453 case SUBREG:
6454 /* If this is a SUBREG of a hard reg, we can see exactly which
6455 registers are being modified. Otherwise, handle normally. */
6456 if (REG_P (SUBREG_REG (x))
6457 && REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER)
6459 unsigned int inner_regno = subreg_regno (x);
6460 unsigned int inner_endregno
6461 = inner_regno + (inner_regno < FIRST_PSEUDO_REGISTER
6462 ? subreg_nregs (x) : 1);
6464 return endregno > inner_regno && regno < inner_endregno;
6466 break;
6468 case CLOBBER:
6469 case SET:
6470 if (&SET_DEST (x) != loc
6471 /* Note setting a SUBREG counts as referring to the REG it is in for
6472 a pseudo but not for hard registers since we can
6473 treat each word individually. */
6474 && ((GET_CODE (SET_DEST (x)) == SUBREG
6475 && loc != &SUBREG_REG (SET_DEST (x))
6476 && REG_P (SUBREG_REG (SET_DEST (x)))
6477 && REGNO (SUBREG_REG (SET_DEST (x))) >= FIRST_PSEUDO_REGISTER
6478 && refers_to_regno_for_reload_p (regno, endregno,
6479 SUBREG_REG (SET_DEST (x)),
6480 loc))
6481 /* If the output is an earlyclobber operand, this is
6482 a conflict. */
6483 || ((!REG_P (SET_DEST (x))
6484 || earlyclobber_operand_p (SET_DEST (x)))
6485 && refers_to_regno_for_reload_p (regno, endregno,
6486 SET_DEST (x), loc))))
6487 return 1;
6489 if (code == CLOBBER || loc == &SET_SRC (x))
6490 return 0;
6491 x = SET_SRC (x);
6492 goto repeat;
6494 default:
6495 break;
6498 /* X does not match, so try its subexpressions. */
6500 fmt = GET_RTX_FORMAT (code);
6501 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
6503 if (fmt[i] == 'e' && loc != &XEXP (x, i))
6505 if (i == 0)
6507 x = XEXP (x, 0);
6508 goto repeat;
6510 else
6511 if (refers_to_regno_for_reload_p (regno, endregno,
6512 XEXP (x, i), loc))
6513 return 1;
6515 else if (fmt[i] == 'E')
6517 int j;
6518 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
6519 if (loc != &XVECEXP (x, i, j)
6520 && refers_to_regno_for_reload_p (regno, endregno,
6521 XVECEXP (x, i, j), loc))
6522 return 1;
6525 return 0;
6528 /* Nonzero if modifying X will affect IN. If X is a register or a SUBREG,
6529 we check if any register number in X conflicts with the relevant register
6530 numbers. If X is a constant, return 0. If X is a MEM, return 1 iff IN
6531 contains a MEM (we don't bother checking for memory addresses that can't
6532 conflict because we expect this to be a rare case.
6534 This function is similar to reg_overlap_mentioned_p in rtlanal.c except
6535 that we look at equivalences for pseudos that didn't get hard registers. */
6538 reg_overlap_mentioned_for_reload_p (rtx x, rtx in)
6540 int regno, endregno;
6542 /* Overly conservative. */
6543 if (GET_CODE (x) == STRICT_LOW_PART
6544 || GET_RTX_CLASS (GET_CODE (x)) == RTX_AUTOINC)
6545 x = XEXP (x, 0);
6547 /* If either argument is a constant, then modifying X cannot affect IN. */
6548 if (CONSTANT_P (x) || CONSTANT_P (in))
6549 return 0;
6550 else if (GET_CODE (x) == SUBREG && MEM_P (SUBREG_REG (x)))
6551 return refers_to_mem_for_reload_p (in);
6552 else if (GET_CODE (x) == SUBREG)
6554 regno = REGNO (SUBREG_REG (x));
6555 if (regno < FIRST_PSEUDO_REGISTER)
6556 regno += subreg_regno_offset (REGNO (SUBREG_REG (x)),
6557 GET_MODE (SUBREG_REG (x)),
6558 SUBREG_BYTE (x),
6559 GET_MODE (x));
6560 endregno = regno + (regno < FIRST_PSEUDO_REGISTER
6561 ? subreg_nregs (x) : 1);
6563 return refers_to_regno_for_reload_p (regno, endregno, in, (rtx*) 0);
6565 else if (REG_P (x))
6567 regno = REGNO (x);
6569 /* If this is a pseudo, it must not have been assigned a hard register.
6570 Therefore, it must either be in memory or be a constant. */
6572 if (regno >= FIRST_PSEUDO_REGISTER)
6574 if (reg_equiv_memory_loc (regno))
6575 return refers_to_mem_for_reload_p (in);
6576 gcc_assert (reg_equiv_constant (regno));
6577 return 0;
6580 endregno = END_REGNO (x);
6582 return refers_to_regno_for_reload_p (regno, endregno, in, (rtx*) 0);
6584 else if (MEM_P (x))
6585 return refers_to_mem_for_reload_p (in);
6586 else if (GET_CODE (x) == SCRATCH || GET_CODE (x) == PC
6587 || GET_CODE (x) == CC0)
6588 return reg_mentioned_p (x, in);
6589 else
6591 gcc_assert (GET_CODE (x) == PLUS);
6593 /* We actually want to know if X is mentioned somewhere inside IN.
6594 We must not say that (plus (sp) (const_int 124)) is in
6595 (plus (sp) (const_int 64)), since that can lead to incorrect reload
6596 allocation when spuriously changing a RELOAD_FOR_OUTPUT_ADDRESS
6597 into a RELOAD_OTHER on behalf of another RELOAD_OTHER. */
6598 while (MEM_P (in))
6599 in = XEXP (in, 0);
6600 if (REG_P (in))
6601 return 0;
6602 else if (GET_CODE (in) == PLUS)
6603 return (rtx_equal_p (x, in)
6604 || reg_overlap_mentioned_for_reload_p (x, XEXP (in, 0))
6605 || reg_overlap_mentioned_for_reload_p (x, XEXP (in, 1)));
6606 else return (reg_overlap_mentioned_for_reload_p (XEXP (x, 0), in)
6607 || reg_overlap_mentioned_for_reload_p (XEXP (x, 1), in));
6610 gcc_unreachable ();
6613 /* Return nonzero if anything in X contains a MEM. Look also for pseudo
6614 registers. */
6616 static int
6617 refers_to_mem_for_reload_p (rtx x)
6619 const char *fmt;
6620 int i;
6622 if (MEM_P (x))
6623 return 1;
6625 if (REG_P (x))
6626 return (REGNO (x) >= FIRST_PSEUDO_REGISTER
6627 && reg_equiv_memory_loc (REGNO (x)));
6629 fmt = GET_RTX_FORMAT (GET_CODE (x));
6630 for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--)
6631 if (fmt[i] == 'e'
6632 && (MEM_P (XEXP (x, i))
6633 || refers_to_mem_for_reload_p (XEXP (x, i))))
6634 return 1;
6636 return 0;
6639 /* Check the insns before INSN to see if there is a suitable register
6640 containing the same value as GOAL.
6641 If OTHER is -1, look for a register in class RCLASS.
6642 Otherwise, just see if register number OTHER shares GOAL's value.
6644 Return an rtx for the register found, or zero if none is found.
6646 If RELOAD_REG_P is (short *)1,
6647 we reject any hard reg that appears in reload_reg_rtx
6648 because such a hard reg is also needed coming into this insn.
6650 If RELOAD_REG_P is any other nonzero value,
6651 it is a vector indexed by hard reg number
6652 and we reject any hard reg whose element in the vector is nonnegative
6653 as well as any that appears in reload_reg_rtx.
6655 If GOAL is zero, then GOALREG is a register number; we look
6656 for an equivalent for that register.
6658 MODE is the machine mode of the value we want an equivalence for.
6659 If GOAL is nonzero and not VOIDmode, then it must have mode MODE.
6661 This function is used by jump.c as well as in the reload pass.
6663 If GOAL is the sum of the stack pointer and a constant, we treat it
6664 as if it were a constant except that sp is required to be unchanging. */
6667 find_equiv_reg (rtx goal, rtx_insn *insn, enum reg_class rclass, int other,
6668 short *reload_reg_p, int goalreg, machine_mode mode)
6670 rtx_insn *p = insn;
6671 rtx goaltry, valtry, value;
6672 rtx_insn *where;
6673 rtx pat;
6674 int regno = -1;
6675 int valueno;
6676 int goal_mem = 0;
6677 int goal_const = 0;
6678 int goal_mem_addr_varies = 0;
6679 int need_stable_sp = 0;
6680 int nregs;
6681 int valuenregs;
6682 int num = 0;
6684 if (goal == 0)
6685 regno = goalreg;
6686 else if (REG_P (goal))
6687 regno = REGNO (goal);
6688 else if (MEM_P (goal))
6690 enum rtx_code code = GET_CODE (XEXP (goal, 0));
6691 if (MEM_VOLATILE_P (goal))
6692 return 0;
6693 if (flag_float_store && SCALAR_FLOAT_MODE_P (GET_MODE (goal)))
6694 return 0;
6695 /* An address with side effects must be reexecuted. */
6696 switch (code)
6698 case POST_INC:
6699 case PRE_INC:
6700 case POST_DEC:
6701 case PRE_DEC:
6702 case POST_MODIFY:
6703 case PRE_MODIFY:
6704 return 0;
6705 default:
6706 break;
6708 goal_mem = 1;
6710 else if (CONSTANT_P (goal))
6711 goal_const = 1;
6712 else if (GET_CODE (goal) == PLUS
6713 && XEXP (goal, 0) == stack_pointer_rtx
6714 && CONSTANT_P (XEXP (goal, 1)))
6715 goal_const = need_stable_sp = 1;
6716 else if (GET_CODE (goal) == PLUS
6717 && XEXP (goal, 0) == frame_pointer_rtx
6718 && CONSTANT_P (XEXP (goal, 1)))
6719 goal_const = 1;
6720 else
6721 return 0;
6723 num = 0;
6724 /* Scan insns back from INSN, looking for one that copies
6725 a value into or out of GOAL.
6726 Stop and give up if we reach a label. */
6728 while (1)
6730 p = PREV_INSN (p);
6731 if (p && DEBUG_INSN_P (p))
6732 continue;
6733 num++;
6734 if (p == 0 || LABEL_P (p)
6735 || num > param_max_reload_search_insns)
6736 return 0;
6738 /* Don't reuse register contents from before a setjmp-type
6739 function call; on the second return (from the longjmp) it
6740 might have been clobbered by a later reuse. It doesn't
6741 seem worthwhile to actually go and see if it is actually
6742 reused even if that information would be readily available;
6743 just don't reuse it across the setjmp call. */
6744 if (CALL_P (p) && find_reg_note (p, REG_SETJMP, NULL_RTX))
6745 return 0;
6747 if (NONJUMP_INSN_P (p)
6748 /* If we don't want spill regs ... */
6749 && (! (reload_reg_p != 0
6750 && reload_reg_p != (short *) HOST_WIDE_INT_1)
6751 /* ... then ignore insns introduced by reload; they aren't
6752 useful and can cause results in reload_as_needed to be
6753 different from what they were when calculating the need for
6754 spills. If we notice an input-reload insn here, we will
6755 reject it below, but it might hide a usable equivalent.
6756 That makes bad code. It may even fail: perhaps no reg was
6757 spilled for this insn because it was assumed we would find
6758 that equivalent. */
6759 || INSN_UID (p) < reload_first_uid))
6761 rtx tem;
6762 pat = single_set (p);
6764 /* First check for something that sets some reg equal to GOAL. */
6765 if (pat != 0
6766 && ((regno >= 0
6767 && true_regnum (SET_SRC (pat)) == regno
6768 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0)
6770 (regno >= 0
6771 && true_regnum (SET_DEST (pat)) == regno
6772 && (valueno = true_regnum (valtry = SET_SRC (pat))) >= 0)
6774 (goal_const && rtx_equal_p (SET_SRC (pat), goal)
6775 /* When looking for stack pointer + const,
6776 make sure we don't use a stack adjust. */
6777 && !reg_overlap_mentioned_for_reload_p (SET_DEST (pat), goal)
6778 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0)
6779 || (goal_mem
6780 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0
6781 && rtx_renumbered_equal_p (goal, SET_SRC (pat)))
6782 || (goal_mem
6783 && (valueno = true_regnum (valtry = SET_SRC (pat))) >= 0
6784 && rtx_renumbered_equal_p (goal, SET_DEST (pat)))
6785 /* If we are looking for a constant,
6786 and something equivalent to that constant was copied
6787 into a reg, we can use that reg. */
6788 || (goal_const && REG_NOTES (p) != 0
6789 && (tem = find_reg_note (p, REG_EQUIV, NULL_RTX))
6790 && ((rtx_equal_p (XEXP (tem, 0), goal)
6791 && (valueno
6792 = true_regnum (valtry = SET_DEST (pat))) >= 0)
6793 || (REG_P (SET_DEST (pat))
6794 && CONST_DOUBLE_AS_FLOAT_P (XEXP (tem, 0))
6795 && SCALAR_FLOAT_MODE_P (GET_MODE (XEXP (tem, 0)))
6796 && CONST_INT_P (goal)
6797 && (goaltry = operand_subword (XEXP (tem, 0), 0,
6798 0, VOIDmode)) != 0
6799 && rtx_equal_p (goal, goaltry)
6800 && (valtry
6801 = operand_subword (SET_DEST (pat), 0, 0,
6802 VOIDmode))
6803 && (valueno = true_regnum (valtry)) >= 0)))
6804 || (goal_const && (tem = find_reg_note (p, REG_EQUIV,
6805 NULL_RTX))
6806 && REG_P (SET_DEST (pat))
6807 && CONST_DOUBLE_AS_FLOAT_P (XEXP (tem, 0))
6808 && SCALAR_FLOAT_MODE_P (GET_MODE (XEXP (tem, 0)))
6809 && CONST_INT_P (goal)
6810 && (goaltry = operand_subword (XEXP (tem, 0), 1, 0,
6811 VOIDmode)) != 0
6812 && rtx_equal_p (goal, goaltry)
6813 && (valtry
6814 = operand_subword (SET_DEST (pat), 1, 0, VOIDmode))
6815 && (valueno = true_regnum (valtry)) >= 0)))
6817 if (other >= 0)
6819 if (valueno != other)
6820 continue;
6822 else if ((unsigned) valueno >= FIRST_PSEUDO_REGISTER)
6823 continue;
6824 else if (!in_hard_reg_set_p (reg_class_contents[(int) rclass],
6825 mode, valueno))
6826 continue;
6827 value = valtry;
6828 where = p;
6829 break;
6834 /* We found a previous insn copying GOAL into a suitable other reg VALUE
6835 (or copying VALUE into GOAL, if GOAL is also a register).
6836 Now verify that VALUE is really valid. */
6838 /* VALUENO is the register number of VALUE; a hard register. */
6840 /* Don't try to re-use something that is killed in this insn. We want
6841 to be able to trust REG_UNUSED notes. */
6842 if (REG_NOTES (where) != 0 && find_reg_note (where, REG_UNUSED, value))
6843 return 0;
6845 /* If we propose to get the value from the stack pointer or if GOAL is
6846 a MEM based on the stack pointer, we need a stable SP. */
6847 if (valueno == STACK_POINTER_REGNUM || regno == STACK_POINTER_REGNUM
6848 || (goal_mem && reg_overlap_mentioned_for_reload_p (stack_pointer_rtx,
6849 goal)))
6850 need_stable_sp = 1;
6852 /* Reject VALUE if the copy-insn moved the wrong sort of datum. */
6853 if (GET_MODE (value) != mode)
6854 return 0;
6856 /* Reject VALUE if it was loaded from GOAL
6857 and is also a register that appears in the address of GOAL. */
6859 if (goal_mem && value == SET_DEST (single_set (where))
6860 && refers_to_regno_for_reload_p (valueno, end_hard_regno (mode, valueno),
6861 goal, (rtx*) 0))
6862 return 0;
6864 /* Reject registers that overlap GOAL. */
6866 if (regno >= 0 && regno < FIRST_PSEUDO_REGISTER)
6867 nregs = hard_regno_nregs (regno, mode);
6868 else
6869 nregs = 1;
6870 valuenregs = hard_regno_nregs (valueno, mode);
6872 if (!goal_mem && !goal_const
6873 && regno + nregs > valueno && regno < valueno + valuenregs)
6874 return 0;
6876 /* Reject VALUE if it is one of the regs reserved for reloads.
6877 Reload1 knows how to reuse them anyway, and it would get
6878 confused if we allocated one without its knowledge.
6879 (Now that insns introduced by reload are ignored above,
6880 this case shouldn't happen, but I'm not positive.) */
6882 if (reload_reg_p != 0 && reload_reg_p != (short *) HOST_WIDE_INT_1)
6884 int i;
6885 for (i = 0; i < valuenregs; ++i)
6886 if (reload_reg_p[valueno + i] >= 0)
6887 return 0;
6890 /* Reject VALUE if it is a register being used for an input reload
6891 even if it is not one of those reserved. */
6893 if (reload_reg_p != 0)
6895 int i;
6896 for (i = 0; i < n_reloads; i++)
6897 if (rld[i].reg_rtx != 0
6898 && rld[i].in
6899 && (int) REGNO (rld[i].reg_rtx) < valueno + valuenregs
6900 && (int) END_REGNO (rld[i].reg_rtx) > valueno)
6901 return 0;
6904 if (goal_mem)
6905 /* We must treat frame pointer as varying here,
6906 since it can vary--in a nonlocal goto as generated by expand_goto. */
6907 goal_mem_addr_varies = !CONSTANT_ADDRESS_P (XEXP (goal, 0));
6909 /* Now verify that the values of GOAL and VALUE remain unaltered
6910 until INSN is reached. */
6912 p = insn;
6913 while (1)
6915 p = PREV_INSN (p);
6916 if (p == where)
6917 return value;
6919 /* Don't trust the conversion past a function call
6920 if either of the two is in a call-clobbered register, or memory. */
6921 if (CALL_P (p))
6923 if (goal_mem || need_stable_sp)
6924 return 0;
6926 function_abi callee_abi = insn_callee_abi (p);
6927 if (regno >= 0
6928 && regno < FIRST_PSEUDO_REGISTER
6929 && callee_abi.clobbers_reg_p (mode, regno))
6930 return 0;
6932 if (valueno >= 0
6933 && valueno < FIRST_PSEUDO_REGISTER
6934 && callee_abi.clobbers_reg_p (mode, valueno))
6935 return 0;
6938 if (INSN_P (p))
6940 pat = PATTERN (p);
6942 /* Watch out for unspec_volatile, and volatile asms. */
6943 if (volatile_insn_p (pat))
6944 return 0;
6946 /* If this insn P stores in either GOAL or VALUE, return 0.
6947 If GOAL is a memory ref and this insn writes memory, return 0.
6948 If GOAL is a memory ref and its address is not constant,
6949 and this insn P changes a register used in GOAL, return 0. */
6951 if (GET_CODE (pat) == COND_EXEC)
6952 pat = COND_EXEC_CODE (pat);
6953 if (GET_CODE (pat) == SET || GET_CODE (pat) == CLOBBER)
6955 rtx dest = SET_DEST (pat);
6956 while (GET_CODE (dest) == SUBREG
6957 || GET_CODE (dest) == ZERO_EXTRACT
6958 || GET_CODE (dest) == STRICT_LOW_PART)
6959 dest = XEXP (dest, 0);
6960 if (REG_P (dest))
6962 int xregno = REGNO (dest);
6963 int end_xregno = END_REGNO (dest);
6964 if (xregno < regno + nregs && end_xregno > regno)
6965 return 0;
6966 if (xregno < valueno + valuenregs
6967 && end_xregno > valueno)
6968 return 0;
6969 if (goal_mem_addr_varies
6970 && reg_overlap_mentioned_for_reload_p (dest, goal))
6971 return 0;
6972 if (xregno == STACK_POINTER_REGNUM && need_stable_sp)
6973 return 0;
6975 else if (goal_mem && MEM_P (dest)
6976 && ! push_operand (dest, GET_MODE (dest)))
6977 return 0;
6978 else if (MEM_P (dest) && regno >= FIRST_PSEUDO_REGISTER
6979 && reg_equiv_memory_loc (regno) != 0)
6980 return 0;
6981 else if (need_stable_sp && push_operand (dest, GET_MODE (dest)))
6982 return 0;
6984 else if (GET_CODE (pat) == PARALLEL)
6986 int i;
6987 for (i = XVECLEN (pat, 0) - 1; i >= 0; i--)
6989 rtx v1 = XVECEXP (pat, 0, i);
6990 if (GET_CODE (v1) == COND_EXEC)
6991 v1 = COND_EXEC_CODE (v1);
6992 if (GET_CODE (v1) == SET || GET_CODE (v1) == CLOBBER)
6994 rtx dest = SET_DEST (v1);
6995 while (GET_CODE (dest) == SUBREG
6996 || GET_CODE (dest) == ZERO_EXTRACT
6997 || GET_CODE (dest) == STRICT_LOW_PART)
6998 dest = XEXP (dest, 0);
6999 if (REG_P (dest))
7001 int xregno = REGNO (dest);
7002 int end_xregno = END_REGNO (dest);
7003 if (xregno < regno + nregs
7004 && end_xregno > regno)
7005 return 0;
7006 if (xregno < valueno + valuenregs
7007 && end_xregno > 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 end_xregno = END_REGNO (dest);
7046 if (xregno < regno + nregs
7047 && end_xregno > regno)
7048 return 0;
7049 else if (xregno < valueno + valuenregs
7050 && end_xregno > valueno)
7051 return 0;
7052 else if (goal_mem_addr_varies
7053 && reg_overlap_mentioned_for_reload_p (dest,
7054 goal))
7055 return 0;
7058 else if (goal_mem && MEM_P (dest)
7059 && ! push_operand (dest, GET_MODE (dest)))
7060 return 0;
7061 else if (need_stable_sp
7062 && push_operand (dest, GET_MODE (dest)))
7063 return 0;
7068 #if AUTO_INC_DEC
7069 /* If this insn auto-increments or auto-decrements
7070 either regno or valueno, return 0 now.
7071 If GOAL is a memory ref and its address is not constant,
7072 and this insn P increments a register used in GOAL, return 0. */
7074 rtx link;
7076 for (link = REG_NOTES (p); link; link = XEXP (link, 1))
7077 if (REG_NOTE_KIND (link) == REG_INC
7078 && REG_P (XEXP (link, 0)))
7080 int incno = REGNO (XEXP (link, 0));
7081 if (incno < regno + nregs && incno >= regno)
7082 return 0;
7083 if (incno < valueno + valuenregs && incno >= valueno)
7084 return 0;
7085 if (goal_mem_addr_varies
7086 && reg_overlap_mentioned_for_reload_p (XEXP (link, 0),
7087 goal))
7088 return 0;
7091 #endif
7096 /* Find a place where INCED appears in an increment or decrement operator
7097 within X, and return the amount INCED is incremented or decremented by.
7098 The value is always positive. */
7100 static poly_int64
7101 find_inc_amount (rtx x, rtx inced)
7103 enum rtx_code code = GET_CODE (x);
7104 const char *fmt;
7105 int i;
7107 if (code == MEM)
7109 rtx addr = XEXP (x, 0);
7110 if ((GET_CODE (addr) == PRE_DEC
7111 || GET_CODE (addr) == POST_DEC
7112 || GET_CODE (addr) == PRE_INC
7113 || GET_CODE (addr) == POST_INC)
7114 && XEXP (addr, 0) == inced)
7115 return GET_MODE_SIZE (GET_MODE (x));
7116 else if ((GET_CODE (addr) == PRE_MODIFY
7117 || GET_CODE (addr) == POST_MODIFY)
7118 && GET_CODE (XEXP (addr, 1)) == PLUS
7119 && XEXP (addr, 0) == XEXP (XEXP (addr, 1), 0)
7120 && XEXP (addr, 0) == inced
7121 && CONST_INT_P (XEXP (XEXP (addr, 1), 1)))
7123 i = INTVAL (XEXP (XEXP (addr, 1), 1));
7124 return i < 0 ? -i : i;
7128 fmt = GET_RTX_FORMAT (code);
7129 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
7131 if (fmt[i] == 'e')
7133 poly_int64 tem = find_inc_amount (XEXP (x, i), inced);
7134 if (maybe_ne (tem, 0))
7135 return tem;
7137 if (fmt[i] == 'E')
7139 int j;
7140 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
7142 poly_int64 tem = find_inc_amount (XVECEXP (x, i, j), inced);
7143 if (maybe_ne (tem, 0))
7144 return tem;
7149 return 0;
7152 /* Return 1 if registers from REGNO to ENDREGNO are the subjects of a
7153 REG_INC note in insn INSN. REGNO must refer to a hard register. */
7155 static int
7156 reg_inc_found_and_valid_p (unsigned int regno, unsigned int endregno,
7157 rtx insn)
7159 rtx link;
7161 if (!AUTO_INC_DEC)
7162 return 0;
7164 gcc_assert (insn);
7166 if (! INSN_P (insn))
7167 return 0;
7169 for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
7170 if (REG_NOTE_KIND (link) == REG_INC)
7172 unsigned int test = (int) REGNO (XEXP (link, 0));
7173 if (test >= regno && test < endregno)
7174 return 1;
7176 return 0;
7179 /* Return 1 if register REGNO is the subject of a clobber in insn INSN.
7180 If SETS is 1, also consider SETs. If SETS is 2, enable checking
7181 REG_INC. REGNO must refer to a hard register. */
7184 regno_clobbered_p (unsigned int regno, rtx_insn *insn, machine_mode mode,
7185 int sets)
7187 /* regno must be a hard register. */
7188 gcc_assert (regno < FIRST_PSEUDO_REGISTER);
7190 unsigned int endregno = end_hard_regno (mode, regno);
7192 if ((GET_CODE (PATTERN (insn)) == CLOBBER
7193 || (sets == 1 && GET_CODE (PATTERN (insn)) == SET))
7194 && REG_P (XEXP (PATTERN (insn), 0)))
7196 unsigned int test = REGNO (XEXP (PATTERN (insn), 0));
7198 return test >= regno && test < endregno;
7201 if (sets == 2 && reg_inc_found_and_valid_p (regno, endregno, insn))
7202 return 1;
7204 if (GET_CODE (PATTERN (insn)) == PARALLEL)
7206 int i = XVECLEN (PATTERN (insn), 0) - 1;
7208 for (; i >= 0; i--)
7210 rtx elt = XVECEXP (PATTERN (insn), 0, i);
7211 if ((GET_CODE (elt) == CLOBBER
7212 || (sets == 1 && GET_CODE (elt) == SET))
7213 && REG_P (XEXP (elt, 0)))
7215 unsigned int test = REGNO (XEXP (elt, 0));
7217 if (test >= regno && test < endregno)
7218 return 1;
7220 if (sets == 2
7221 && reg_inc_found_and_valid_p (regno, endregno, elt))
7222 return 1;
7226 return 0;
7229 /* Find the low part, with mode MODE, of a hard regno RELOADREG. */
7231 reload_adjust_reg_for_mode (rtx reloadreg, machine_mode mode)
7233 int regno;
7235 if (GET_MODE (reloadreg) == mode)
7236 return reloadreg;
7238 regno = REGNO (reloadreg);
7240 if (REG_WORDS_BIG_ENDIAN)
7241 regno += ((int) REG_NREGS (reloadreg)
7242 - (int) hard_regno_nregs (regno, mode));
7244 return gen_rtx_REG (mode, regno);
7247 static const char *const reload_when_needed_name[] =
7249 "RELOAD_FOR_INPUT",
7250 "RELOAD_FOR_OUTPUT",
7251 "RELOAD_FOR_INSN",
7252 "RELOAD_FOR_INPUT_ADDRESS",
7253 "RELOAD_FOR_INPADDR_ADDRESS",
7254 "RELOAD_FOR_OUTPUT_ADDRESS",
7255 "RELOAD_FOR_OUTADDR_ADDRESS",
7256 "RELOAD_FOR_OPERAND_ADDRESS",
7257 "RELOAD_FOR_OPADDR_ADDR",
7258 "RELOAD_OTHER",
7259 "RELOAD_FOR_OTHER_ADDRESS"
7262 /* These functions are used to print the variables set by 'find_reloads' */
7264 DEBUG_FUNCTION void
7265 debug_reload_to_stream (FILE *f)
7267 int r;
7268 const char *prefix;
7270 if (! f)
7271 f = stderr;
7272 for (r = 0; r < n_reloads; r++)
7274 fprintf (f, "Reload %d: ", r);
7276 if (rld[r].in != 0)
7278 fprintf (f, "reload_in (%s) = ",
7279 GET_MODE_NAME (rld[r].inmode));
7280 print_inline_rtx (f, rld[r].in, 24);
7281 fprintf (f, "\n\t");
7284 if (rld[r].out != 0)
7286 fprintf (f, "reload_out (%s) = ",
7287 GET_MODE_NAME (rld[r].outmode));
7288 print_inline_rtx (f, rld[r].out, 24);
7289 fprintf (f, "\n\t");
7292 fprintf (f, "%s, ", reg_class_names[(int) rld[r].rclass]);
7294 fprintf (f, "%s (opnum = %d)",
7295 reload_when_needed_name[(int) rld[r].when_needed],
7296 rld[r].opnum);
7298 if (rld[r].optional)
7299 fprintf (f, ", optional");
7301 if (rld[r].nongroup)
7302 fprintf (f, ", nongroup");
7304 if (maybe_ne (rld[r].inc, 0))
7306 fprintf (f, ", inc by ");
7307 print_dec (rld[r].inc, f, SIGNED);
7310 if (rld[r].nocombine)
7311 fprintf (f, ", can't combine");
7313 if (rld[r].secondary_p)
7314 fprintf (f, ", secondary_reload_p");
7316 if (rld[r].in_reg != 0)
7318 fprintf (f, "\n\treload_in_reg: ");
7319 print_inline_rtx (f, rld[r].in_reg, 24);
7322 if (rld[r].out_reg != 0)
7324 fprintf (f, "\n\treload_out_reg: ");
7325 print_inline_rtx (f, rld[r].out_reg, 24);
7328 if (rld[r].reg_rtx != 0)
7330 fprintf (f, "\n\treload_reg_rtx: ");
7331 print_inline_rtx (f, rld[r].reg_rtx, 24);
7334 prefix = "\n\t";
7335 if (rld[r].secondary_in_reload != -1)
7337 fprintf (f, "%ssecondary_in_reload = %d",
7338 prefix, rld[r].secondary_in_reload);
7339 prefix = ", ";
7342 if (rld[r].secondary_out_reload != -1)
7343 fprintf (f, "%ssecondary_out_reload = %d\n",
7344 prefix, rld[r].secondary_out_reload);
7346 prefix = "\n\t";
7347 if (rld[r].secondary_in_icode != CODE_FOR_nothing)
7349 fprintf (f, "%ssecondary_in_icode = %s", prefix,
7350 insn_data[rld[r].secondary_in_icode].name);
7351 prefix = ", ";
7354 if (rld[r].secondary_out_icode != CODE_FOR_nothing)
7355 fprintf (f, "%ssecondary_out_icode = %s", prefix,
7356 insn_data[rld[r].secondary_out_icode].name);
7358 fprintf (f, "\n");
7362 DEBUG_FUNCTION void
7363 debug_reload (void)
7365 debug_reload_to_stream (stderr);