ada: output.adb: fix newline being inserted when buffer is full
[official-gcc.git] / gcc / reload.cc
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1 /* Search an insn for pseudo regs that must be in hard regs and are not.
2 Copyright (C) 1987-2023 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.cc.
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 bool 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 Also 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 Finally, reload the inner expression if it is a pseudo that will
1054 become a MEM and the MEM has a mode-dependent address, as in that
1055 case we obviously cannot change the mode of the MEM to that of the
1056 containing SUBREG as that would change the interpretation of the
1057 address. */
1059 scalar_int_mode inner_mode;
1060 if (in != 0 && GET_CODE (in) == SUBREG
1061 && targetm.can_change_mode_class (GET_MODE (SUBREG_REG (in)),
1062 inmode, rclass)
1063 && contains_allocatable_reg_of_mode[rclass][GET_MODE (SUBREG_REG (in))]
1064 && (strict_low
1065 || (subreg_lowpart_p (in)
1066 && (CONSTANT_P (SUBREG_REG (in))
1067 || GET_CODE (SUBREG_REG (in)) == PLUS
1068 || (((REG_P (SUBREG_REG (in))
1069 && REGNO (SUBREG_REG (in)) >= FIRST_PSEUDO_REGISTER)
1070 || MEM_P (SUBREG_REG (in)))
1071 && (paradoxical_subreg_p (inmode,
1072 GET_MODE (SUBREG_REG (in)))
1073 || (known_le (GET_MODE_SIZE (inmode), UNITS_PER_WORD)
1074 && is_a <scalar_int_mode> (GET_MODE (SUBREG_REG
1075 (in)),
1076 &inner_mode)
1077 && GET_MODE_SIZE (inner_mode) <= UNITS_PER_WORD
1078 && paradoxical_subreg_p (inmode, inner_mode)
1079 && LOAD_EXTEND_OP (inner_mode) != UNKNOWN)
1080 || (WORD_REGISTER_OPERATIONS
1081 && partial_subreg_p (inmode,
1082 GET_MODE (SUBREG_REG (in)))
1083 && (known_equal_after_align_down
1084 (GET_MODE_SIZE (inmode) - 1,
1085 GET_MODE_SIZE (GET_MODE (SUBREG_REG
1086 (in))) - 1,
1087 UNITS_PER_WORD)))))
1088 || (REG_P (SUBREG_REG (in))
1089 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
1090 /* The case where out is nonzero
1091 is handled differently in the following statement. */
1092 && (out == 0 || subreg_lowpart_p (in))
1093 && (complex_word_subreg_p (inmode, SUBREG_REG (in))
1094 || !targetm.hard_regno_mode_ok (subreg_regno (in),
1095 inmode)))
1096 || (secondary_reload_class (1, rclass, inmode, in) != NO_REGS
1097 && (secondary_reload_class (1, rclass,
1098 GET_MODE (SUBREG_REG (in)),
1099 SUBREG_REG (in))
1100 == NO_REGS))
1101 || (REG_P (SUBREG_REG (in))
1102 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
1103 && !REG_CAN_CHANGE_MODE_P (REGNO (SUBREG_REG (in)),
1104 GET_MODE (SUBREG_REG (in)),
1105 inmode))))
1106 || (REG_P (SUBREG_REG (in))
1107 && REGNO (SUBREG_REG (in)) >= FIRST_PSEUDO_REGISTER
1108 && reg_equiv_mem (REGNO (SUBREG_REG (in)))
1109 && (mode_dependent_address_p
1110 (XEXP (reg_equiv_mem (REGNO (SUBREG_REG (in))), 0),
1111 MEM_ADDR_SPACE (reg_equiv_mem (REGNO (SUBREG_REG (in)))))))))
1113 #ifdef LIMIT_RELOAD_CLASS
1114 in_subreg_loc = inloc;
1115 #endif
1116 inloc = &SUBREG_REG (in);
1117 in = *inloc;
1119 if (!WORD_REGISTER_OPERATIONS
1120 && LOAD_EXTEND_OP (GET_MODE (in)) == UNKNOWN
1121 && MEM_P (in))
1122 /* This is supposed to happen only for paradoxical subregs made by
1123 combine.cc. (SUBREG (MEM)) isn't supposed to occur other ways. */
1124 gcc_assert (known_le (GET_MODE_SIZE (GET_MODE (in)),
1125 GET_MODE_SIZE (inmode)));
1127 inmode = GET_MODE (in);
1130 /* Similar issue for (SUBREG:M1 (REG:M2 ...) ...) for a hard register R
1131 where M1 is not valid for R if it was not handled by the code above.
1133 Similar issue for (SUBREG constant ...) if it was not handled by the
1134 code above. This can happen if SUBREG_BYTE != 0.
1136 However, we must reload the inner reg *as well as* the subreg in
1137 that case. */
1139 if (in != 0 && reload_inner_reg_of_subreg (in, inmode, false))
1141 if (REG_P (SUBREG_REG (in)))
1142 subreg_in_class
1143 = find_valid_class (inmode, GET_MODE (SUBREG_REG (in)),
1144 subreg_regno_offset (REGNO (SUBREG_REG (in)),
1145 GET_MODE (SUBREG_REG (in)),
1146 SUBREG_BYTE (in),
1147 GET_MODE (in)),
1148 REGNO (SUBREG_REG (in)));
1149 else if (CONSTANT_P (SUBREG_REG (in))
1150 || GET_CODE (SUBREG_REG (in)) == PLUS)
1151 subreg_in_class = find_valid_class_1 (inmode,
1152 GET_MODE (SUBREG_REG (in)),
1153 rclass);
1155 /* This relies on the fact that emit_reload_insns outputs the
1156 instructions for input reloads of type RELOAD_OTHER in the same
1157 order as the reloads. Thus if the outer reload is also of type
1158 RELOAD_OTHER, we are guaranteed that this inner reload will be
1159 output before the outer reload. */
1160 push_reload (SUBREG_REG (in), NULL_RTX, &SUBREG_REG (in), (rtx *) 0,
1161 subreg_in_class, VOIDmode, VOIDmode, 0, 0, opnum, type);
1162 dont_remove_subreg = 1;
1165 /* Similarly for paradoxical and problematical SUBREGs on the output.
1166 Note that there is no reason we need worry about the previous value
1167 of SUBREG_REG (out); even if wider than out, storing in a subreg is
1168 entitled to clobber it all (except in the case of a word mode subreg
1169 or of a STRICT_LOW_PART, in that latter case the constraint should
1170 label it input-output.) */
1171 if (out != 0 && GET_CODE (out) == SUBREG
1172 && (subreg_lowpart_p (out) || strict_low)
1173 && targetm.can_change_mode_class (GET_MODE (SUBREG_REG (out)),
1174 outmode, rclass)
1175 && contains_allocatable_reg_of_mode[rclass][GET_MODE (SUBREG_REG (out))]
1176 && (CONSTANT_P (SUBREG_REG (out))
1177 || strict_low
1178 || (((REG_P (SUBREG_REG (out))
1179 && REGNO (SUBREG_REG (out)) >= FIRST_PSEUDO_REGISTER)
1180 || MEM_P (SUBREG_REG (out)))
1181 && (paradoxical_subreg_p (outmode, GET_MODE (SUBREG_REG (out)))
1182 || (WORD_REGISTER_OPERATIONS
1183 && partial_subreg_p (outmode, GET_MODE (SUBREG_REG (out)))
1184 && (known_equal_after_align_down
1185 (GET_MODE_SIZE (outmode) - 1,
1186 GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))) - 1,
1187 UNITS_PER_WORD)))))
1188 || (REG_P (SUBREG_REG (out))
1189 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1190 /* The case of a word mode subreg
1191 is handled differently in the following statement. */
1192 && ! (known_le (GET_MODE_SIZE (outmode), UNITS_PER_WORD)
1193 && maybe_gt (GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))),
1194 UNITS_PER_WORD))
1195 && !targetm.hard_regno_mode_ok (subreg_regno (out), outmode))
1196 || (secondary_reload_class (0, rclass, outmode, out) != NO_REGS
1197 && (secondary_reload_class (0, rclass, GET_MODE (SUBREG_REG (out)),
1198 SUBREG_REG (out))
1199 == NO_REGS))
1200 || (REG_P (SUBREG_REG (out))
1201 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1202 && !REG_CAN_CHANGE_MODE_P (REGNO (SUBREG_REG (out)),
1203 GET_MODE (SUBREG_REG (out)),
1204 outmode))))
1206 #ifdef LIMIT_RELOAD_CLASS
1207 out_subreg_loc = outloc;
1208 #endif
1209 outloc = &SUBREG_REG (out);
1210 out = *outloc;
1211 gcc_assert (WORD_REGISTER_OPERATIONS || !MEM_P (out)
1212 || known_le (GET_MODE_SIZE (GET_MODE (out)),
1213 GET_MODE_SIZE (outmode)));
1214 outmode = GET_MODE (out);
1217 /* Similar issue for (SUBREG:M1 (REG:M2 ...) ...) for a hard register R
1218 where either M1 is not valid for R or M2 is wider than a word but we
1219 only need one register to store an M2-sized quantity in R.
1221 However, we must reload the inner reg *as well as* the subreg in
1222 that case and the inner reg is an in-out reload. */
1224 if (out != 0 && reload_inner_reg_of_subreg (out, outmode, true))
1226 enum reg_class in_out_class
1227 = find_valid_class (outmode, GET_MODE (SUBREG_REG (out)),
1228 subreg_regno_offset (REGNO (SUBREG_REG (out)),
1229 GET_MODE (SUBREG_REG (out)),
1230 SUBREG_BYTE (out),
1231 GET_MODE (out)),
1232 REGNO (SUBREG_REG (out)));
1234 /* This relies on the fact that emit_reload_insns outputs the
1235 instructions for output reloads of type RELOAD_OTHER in reverse
1236 order of the reloads. Thus if the outer reload is also of type
1237 RELOAD_OTHER, we are guaranteed that this inner reload will be
1238 output after the outer reload. */
1239 push_reload (SUBREG_REG (out), SUBREG_REG (out), &SUBREG_REG (out),
1240 &SUBREG_REG (out), in_out_class, VOIDmode, VOIDmode,
1241 0, 0, opnum, RELOAD_OTHER);
1242 dont_remove_subreg = 1;
1245 /* If IN appears in OUT, we can't share any input-only reload for IN. */
1246 if (in != 0 && out != 0 && MEM_P (out)
1247 && (REG_P (in) || MEM_P (in) || GET_CODE (in) == PLUS)
1248 && reg_overlap_mentioned_for_reload_p (in, XEXP (out, 0)))
1249 dont_share = 1;
1251 /* If IN is a SUBREG of a hard register, make a new REG. This
1252 simplifies some of the cases below. */
1254 if (in != 0 && GET_CODE (in) == SUBREG && REG_P (SUBREG_REG (in))
1255 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
1256 && ! dont_remove_subreg)
1257 in = gen_rtx_REG (GET_MODE (in), subreg_regno (in));
1259 /* Similarly for OUT. */
1260 if (out != 0 && GET_CODE (out) == SUBREG
1261 && REG_P (SUBREG_REG (out))
1262 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1263 && ! dont_remove_subreg)
1264 out = gen_rtx_REG (GET_MODE (out), subreg_regno (out));
1266 /* Narrow down the class of register wanted if that is
1267 desirable on this machine for efficiency. */
1269 reg_class_t preferred_class = rclass;
1271 if (in != 0)
1272 preferred_class = targetm.preferred_reload_class (in, rclass);
1274 /* Output reloads may need analogous treatment, different in detail. */
1275 if (out != 0)
1276 preferred_class
1277 = targetm.preferred_output_reload_class (out, preferred_class);
1279 /* Discard what the target said if we cannot do it. */
1280 if (preferred_class != NO_REGS
1281 || (optional && type == RELOAD_FOR_OUTPUT))
1282 rclass = (enum reg_class) preferred_class;
1285 /* Make sure we use a class that can handle the actual pseudo
1286 inside any subreg. For example, on the 386, QImode regs
1287 can appear within SImode subregs. Although GENERAL_REGS
1288 can handle SImode, QImode needs a smaller class. */
1289 #ifdef LIMIT_RELOAD_CLASS
1290 if (in_subreg_loc)
1291 rclass = LIMIT_RELOAD_CLASS (inmode, rclass);
1292 else if (in != 0 && GET_CODE (in) == SUBREG)
1293 rclass = LIMIT_RELOAD_CLASS (GET_MODE (SUBREG_REG (in)), rclass);
1295 if (out_subreg_loc)
1296 rclass = LIMIT_RELOAD_CLASS (outmode, rclass);
1297 if (out != 0 && GET_CODE (out) == SUBREG)
1298 rclass = LIMIT_RELOAD_CLASS (GET_MODE (SUBREG_REG (out)), rclass);
1299 #endif
1301 /* Verify that this class is at least possible for the mode that
1302 is specified. */
1303 if (this_insn_is_asm)
1305 machine_mode mode;
1306 if (paradoxical_subreg_p (inmode, outmode))
1307 mode = inmode;
1308 else
1309 mode = outmode;
1310 if (mode == VOIDmode)
1312 error_for_asm (this_insn, "cannot reload integer constant "
1313 "operand in %<asm%>");
1314 mode = word_mode;
1315 if (in != 0)
1316 inmode = word_mode;
1317 if (out != 0)
1318 outmode = word_mode;
1320 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1321 if (targetm.hard_regno_mode_ok (i, mode)
1322 && in_hard_reg_set_p (reg_class_contents[(int) rclass], mode, i))
1323 break;
1324 if (i == FIRST_PSEUDO_REGISTER)
1326 error_for_asm (this_insn, "impossible register constraint "
1327 "in %<asm%>");
1328 /* Avoid further trouble with this insn. */
1329 PATTERN (this_insn) = gen_rtx_USE (VOIDmode, const0_rtx);
1330 /* We used to continue here setting class to ALL_REGS, but it triggers
1331 sanity check on i386 for:
1332 void foo(long double d)
1334 asm("" :: "a" (d));
1336 Returning zero here ought to be safe as we take care in
1337 find_reloads to not process the reloads when instruction was
1338 replaced by USE. */
1340 return 0;
1344 /* Optional output reloads are always OK even if we have no register class,
1345 since the function of these reloads is only to have spill_reg_store etc.
1346 set, so that the storing insn can be deleted later. */
1347 gcc_assert (rclass != NO_REGS
1348 || (optional != 0 && type == RELOAD_FOR_OUTPUT));
1350 i = find_reusable_reload (&in, out, rclass, type, opnum, dont_share);
1352 if (i == n_reloads)
1354 /* See if we need a secondary reload register to move between CLASS
1355 and IN or CLASS and OUT. Get the icode and push any required reloads
1356 needed for each of them if so. */
1358 if (in != 0)
1359 secondary_in_reload
1360 = push_secondary_reload (1, in, opnum, optional, rclass, inmode, type,
1361 &secondary_in_icode, NULL);
1362 if (out != 0 && GET_CODE (out) != SCRATCH)
1363 secondary_out_reload
1364 = push_secondary_reload (0, out, opnum, optional, rclass, outmode,
1365 type, &secondary_out_icode, NULL);
1367 /* We found no existing reload suitable for re-use.
1368 So add an additional reload. */
1370 if (subreg_in_class == NO_REGS
1371 && in != 0
1372 && (REG_P (in)
1373 || (GET_CODE (in) == SUBREG && REG_P (SUBREG_REG (in))))
1374 && reg_or_subregno (in) < FIRST_PSEUDO_REGISTER)
1375 subreg_in_class = REGNO_REG_CLASS (reg_or_subregno (in));
1376 /* If a memory location is needed for the copy, make one. */
1377 if (subreg_in_class != NO_REGS
1378 && targetm.secondary_memory_needed (inmode, subreg_in_class, rclass))
1379 get_secondary_mem (in, inmode, opnum, type);
1381 i = n_reloads;
1382 rld[i].in = in;
1383 rld[i].out = out;
1384 rld[i].rclass = rclass;
1385 rld[i].inmode = inmode;
1386 rld[i].outmode = outmode;
1387 rld[i].reg_rtx = 0;
1388 rld[i].optional = optional;
1389 rld[i].inc = 0;
1390 rld[i].nocombine = 0;
1391 rld[i].in_reg = inloc ? *inloc : 0;
1392 rld[i].out_reg = outloc ? *outloc : 0;
1393 rld[i].opnum = opnum;
1394 rld[i].when_needed = type;
1395 rld[i].secondary_in_reload = secondary_in_reload;
1396 rld[i].secondary_out_reload = secondary_out_reload;
1397 rld[i].secondary_in_icode = secondary_in_icode;
1398 rld[i].secondary_out_icode = secondary_out_icode;
1399 rld[i].secondary_p = 0;
1401 n_reloads++;
1403 if (out != 0
1404 && (REG_P (out)
1405 || (GET_CODE (out) == SUBREG && REG_P (SUBREG_REG (out))))
1406 && reg_or_subregno (out) < FIRST_PSEUDO_REGISTER
1407 && (targetm.secondary_memory_needed
1408 (outmode, rclass, REGNO_REG_CLASS (reg_or_subregno (out)))))
1409 get_secondary_mem (out, outmode, opnum, type);
1411 else
1413 /* We are reusing an existing reload,
1414 but we may have additional information for it.
1415 For example, we may now have both IN and OUT
1416 while the old one may have just one of them. */
1418 /* The modes can be different. If they are, we want to reload in
1419 the larger mode, so that the value is valid for both modes. */
1420 if (inmode != VOIDmode
1421 && partial_subreg_p (rld[i].inmode, inmode))
1422 rld[i].inmode = inmode;
1423 if (outmode != VOIDmode
1424 && partial_subreg_p (rld[i].outmode, outmode))
1425 rld[i].outmode = outmode;
1426 if (in != 0)
1428 rtx in_reg = inloc ? *inloc : 0;
1429 /* If we merge reloads for two distinct rtl expressions that
1430 are identical in content, there might be duplicate address
1431 reloads. Remove the extra set now, so that if we later find
1432 that we can inherit this reload, we can get rid of the
1433 address reloads altogether.
1435 Do not do this if both reloads are optional since the result
1436 would be an optional reload which could potentially leave
1437 unresolved address replacements.
1439 It is not sufficient to call transfer_replacements since
1440 choose_reload_regs will remove the replacements for address
1441 reloads of inherited reloads which results in the same
1442 problem. */
1443 if (rld[i].in != in && rtx_equal_p (in, rld[i].in)
1444 && ! (rld[i].optional && optional))
1446 /* We must keep the address reload with the lower operand
1447 number alive. */
1448 if (opnum > rld[i].opnum)
1450 remove_address_replacements (in);
1451 in = rld[i].in;
1452 in_reg = rld[i].in_reg;
1454 else
1455 remove_address_replacements (rld[i].in);
1457 /* When emitting reloads we don't necessarily look at the in-
1458 and outmode, but also directly at the operands (in and out).
1459 So we can't simply overwrite them with whatever we have found
1460 for this (to-be-merged) reload, we have to "merge" that too.
1461 Reusing another reload already verified that we deal with the
1462 same operands, just possibly in different modes. So we
1463 overwrite the operands only when the new mode is larger.
1464 See also PR33613. */
1465 if (!rld[i].in
1466 || partial_subreg_p (GET_MODE (rld[i].in), GET_MODE (in)))
1467 rld[i].in = in;
1468 if (!rld[i].in_reg
1469 || (in_reg
1470 && partial_subreg_p (GET_MODE (rld[i].in_reg),
1471 GET_MODE (in_reg))))
1472 rld[i].in_reg = in_reg;
1474 if (out != 0)
1476 if (!rld[i].out
1477 || (out
1478 && partial_subreg_p (GET_MODE (rld[i].out),
1479 GET_MODE (out))))
1480 rld[i].out = out;
1481 if (outloc
1482 && (!rld[i].out_reg
1483 || partial_subreg_p (GET_MODE (rld[i].out_reg),
1484 GET_MODE (*outloc))))
1485 rld[i].out_reg = *outloc;
1487 if (reg_class_subset_p (rclass, rld[i].rclass))
1488 rld[i].rclass = rclass;
1489 rld[i].optional &= optional;
1490 if (MERGE_TO_OTHER (type, rld[i].when_needed,
1491 opnum, rld[i].opnum))
1492 rld[i].when_needed = RELOAD_OTHER;
1493 rld[i].opnum = MIN (rld[i].opnum, opnum);
1496 /* If the ostensible rtx being reloaded differs from the rtx found
1497 in the location to substitute, this reload is not safe to combine
1498 because we cannot reliably tell whether it appears in the insn. */
1500 if (in != 0 && in != *inloc)
1501 rld[i].nocombine = 1;
1503 /* If we will replace IN and OUT with the reload-reg,
1504 record where they are located so that substitution need
1505 not do a tree walk. */
1507 if (replace_reloads)
1509 if (inloc != 0)
1511 struct replacement *r = &replacements[n_replacements++];
1512 r->what = i;
1513 r->where = inloc;
1514 r->mode = inmode;
1516 if (outloc != 0 && outloc != inloc)
1518 struct replacement *r = &replacements[n_replacements++];
1519 r->what = i;
1520 r->where = outloc;
1521 r->mode = outmode;
1525 /* If this reload is just being introduced and it has both
1526 an incoming quantity and an outgoing quantity that are
1527 supposed to be made to match, see if either one of the two
1528 can serve as the place to reload into.
1530 If one of them is acceptable, set rld[i].reg_rtx
1531 to that one. */
1533 if (in != 0 && out != 0 && in != out && rld[i].reg_rtx == 0)
1535 rld[i].reg_rtx = find_dummy_reload (in, out, inloc, outloc,
1536 inmode, outmode,
1537 rld[i].rclass, i,
1538 earlyclobber_operand_p (out));
1540 /* If the outgoing register already contains the same value
1541 as the incoming one, we can dispense with loading it.
1542 The easiest way to tell the caller that is to give a phony
1543 value for the incoming operand (same as outgoing one). */
1544 if (rld[i].reg_rtx == out
1545 && (REG_P (in) || CONSTANT_P (in))
1546 && find_equiv_reg (in, this_insn, NO_REGS, REGNO (out),
1547 static_reload_reg_p, i, inmode) != 0)
1548 rld[i].in = out;
1551 /* If this is an input reload and the operand contains a register that
1552 dies in this insn and is used nowhere else, see if it is the right class
1553 to be used for this reload. Use it if so. (This occurs most commonly
1554 in the case of paradoxical SUBREGs and in-out reloads). We cannot do
1555 this if it is also an output reload that mentions the register unless
1556 the output is a SUBREG that clobbers an entire register.
1558 Note that the operand might be one of the spill regs, if it is a
1559 pseudo reg and we are in a block where spilling has not taken place.
1560 But if there is no spilling in this block, that is OK.
1561 An explicitly used hard reg cannot be a spill reg. */
1563 if (rld[i].reg_rtx == 0 && in != 0 && hard_regs_live_known)
1565 rtx note;
1566 int regno;
1567 machine_mode rel_mode = inmode;
1569 if (out && partial_subreg_p (rel_mode, outmode))
1570 rel_mode = outmode;
1572 for (note = REG_NOTES (this_insn); note; note = XEXP (note, 1))
1573 if (REG_NOTE_KIND (note) == REG_DEAD
1574 && REG_P (XEXP (note, 0))
1575 && (regno = REGNO (XEXP (note, 0))) < FIRST_PSEUDO_REGISTER
1576 && reg_mentioned_p (XEXP (note, 0), in)
1577 /* Check that a former pseudo is valid; see find_dummy_reload. */
1578 && (ORIGINAL_REGNO (XEXP (note, 0)) < FIRST_PSEUDO_REGISTER
1579 || (! bitmap_bit_p (DF_LR_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun)),
1580 ORIGINAL_REGNO (XEXP (note, 0)))
1581 && REG_NREGS (XEXP (note, 0)) == 1))
1582 && ! refers_to_regno_for_reload_p (regno,
1583 end_hard_regno (rel_mode,
1584 regno),
1585 PATTERN (this_insn), inloc)
1586 && ! find_reg_fusage (this_insn, USE, XEXP (note, 0))
1587 /* If this is also an output reload, IN cannot be used as
1588 the reload register if it is set in this insn unless IN
1589 is also OUT. */
1590 && (out == 0 || in == out
1591 || ! hard_reg_set_here_p (regno,
1592 end_hard_regno (rel_mode, regno),
1593 PATTERN (this_insn)))
1594 /* ??? Why is this code so different from the previous?
1595 Is there any simple coherent way to describe the two together?
1596 What's going on here. */
1597 && (in != out
1598 || (GET_CODE (in) == SUBREG
1599 && (known_equal_after_align_up
1600 (GET_MODE_SIZE (GET_MODE (in)),
1601 GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))),
1602 UNITS_PER_WORD))))
1603 /* Make sure the operand fits in the reg that dies. */
1604 && known_le (GET_MODE_SIZE (rel_mode),
1605 GET_MODE_SIZE (GET_MODE (XEXP (note, 0))))
1606 && targetm.hard_regno_mode_ok (regno, inmode)
1607 && targetm.hard_regno_mode_ok (regno, outmode))
1609 unsigned int offs;
1610 unsigned int nregs = MAX (hard_regno_nregs (regno, inmode),
1611 hard_regno_nregs (regno, outmode));
1613 for (offs = 0; offs < nregs; offs++)
1614 if (fixed_regs[regno + offs]
1615 || ! TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
1616 regno + offs))
1617 break;
1619 if (offs == nregs
1620 && (! (refers_to_regno_for_reload_p
1621 (regno, end_hard_regno (inmode, regno), in, (rtx *) 0))
1622 || can_reload_into (in, regno, inmode)))
1624 rld[i].reg_rtx = gen_rtx_REG (rel_mode, regno);
1625 break;
1630 if (out)
1631 output_reloadnum = i;
1633 return i;
1636 /* Record an additional place we must replace a value
1637 for which we have already recorded a reload.
1638 RELOADNUM is the value returned by push_reload
1639 when the reload was recorded.
1640 This is used in insn patterns that use match_dup. */
1642 static void
1643 push_replacement (rtx *loc, int reloadnum, machine_mode mode)
1645 if (replace_reloads)
1647 struct replacement *r = &replacements[n_replacements++];
1648 r->what = reloadnum;
1649 r->where = loc;
1650 r->mode = mode;
1654 /* Duplicate any replacement we have recorded to apply at
1655 location ORIG_LOC to also be performed at DUP_LOC.
1656 This is used in insn patterns that use match_dup. */
1658 static void
1659 dup_replacements (rtx *dup_loc, rtx *orig_loc)
1661 int i, n = n_replacements;
1663 for (i = 0; i < n; i++)
1665 struct replacement *r = &replacements[i];
1666 if (r->where == orig_loc)
1667 push_replacement (dup_loc, r->what, r->mode);
1671 /* Transfer all replacements that used to be in reload FROM to be in
1672 reload TO. */
1674 void
1675 transfer_replacements (int to, int from)
1677 int i;
1679 for (i = 0; i < n_replacements; i++)
1680 if (replacements[i].what == from)
1681 replacements[i].what = to;
1684 /* IN_RTX is the value loaded by a reload that we now decided to inherit,
1685 or a subpart of it. If we have any replacements registered for IN_RTX,
1686 cancel the reloads that were supposed to load them.
1687 Return nonzero if we canceled any reloads. */
1689 remove_address_replacements (rtx in_rtx)
1691 int i, j;
1692 char reload_flags[MAX_RELOADS];
1693 int something_changed = 0;
1695 memset (reload_flags, 0, sizeof reload_flags);
1696 for (i = 0, j = 0; i < n_replacements; i++)
1698 if (loc_mentioned_in_p (replacements[i].where, in_rtx))
1699 reload_flags[replacements[i].what] |= 1;
1700 else
1702 replacements[j++] = replacements[i];
1703 reload_flags[replacements[i].what] |= 2;
1706 /* Note that the following store must be done before the recursive calls. */
1707 n_replacements = j;
1709 for (i = n_reloads - 1; i >= 0; i--)
1711 if (reload_flags[i] == 1)
1713 deallocate_reload_reg (i);
1714 remove_address_replacements (rld[i].in);
1715 rld[i].in = 0;
1716 something_changed = 1;
1719 return something_changed;
1722 /* If there is only one output reload, and it is not for an earlyclobber
1723 operand, try to combine it with a (logically unrelated) input reload
1724 to reduce the number of reload registers needed.
1726 This is safe if the input reload does not appear in
1727 the value being output-reloaded, because this implies
1728 it is not needed any more once the original insn completes.
1730 If that doesn't work, see we can use any of the registers that
1731 die in this insn as a reload register. We can if it is of the right
1732 class and does not appear in the value being output-reloaded. */
1734 static void
1735 combine_reloads (void)
1737 int i, regno;
1738 int output_reload = -1;
1739 int secondary_out = -1;
1740 rtx note;
1742 /* Find the output reload; return unless there is exactly one
1743 and that one is mandatory. */
1745 for (i = 0; i < n_reloads; i++)
1746 if (rld[i].out != 0)
1748 if (output_reload >= 0)
1749 return;
1750 output_reload = i;
1753 if (output_reload < 0 || rld[output_reload].optional)
1754 return;
1756 /* An input-output reload isn't combinable. */
1758 if (rld[output_reload].in != 0)
1759 return;
1761 /* If this reload is for an earlyclobber operand, we can't do anything. */
1762 if (earlyclobber_operand_p (rld[output_reload].out))
1763 return;
1765 /* If there is a reload for part of the address of this operand, we would
1766 need to change it to RELOAD_FOR_OTHER_ADDRESS. But that would extend
1767 its life to the point where doing this combine would not lower the
1768 number of spill registers needed. */
1769 for (i = 0; i < n_reloads; i++)
1770 if ((rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
1771 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
1772 && rld[i].opnum == rld[output_reload].opnum)
1773 return;
1775 /* Check each input reload; can we combine it? */
1777 for (i = 0; i < n_reloads; i++)
1778 if (rld[i].in && ! rld[i].optional && ! rld[i].nocombine
1779 /* Life span of this reload must not extend past main insn. */
1780 && rld[i].when_needed != RELOAD_FOR_OUTPUT_ADDRESS
1781 && rld[i].when_needed != RELOAD_FOR_OUTADDR_ADDRESS
1782 && rld[i].when_needed != RELOAD_OTHER
1783 && (ira_reg_class_max_nregs [(int)rld[i].rclass][(int) rld[i].inmode]
1784 == ira_reg_class_max_nregs [(int) rld[output_reload].rclass]
1785 [(int) rld[output_reload].outmode])
1786 && known_eq (rld[i].inc, 0)
1787 && rld[i].reg_rtx == 0
1788 /* Don't combine two reloads with different secondary
1789 memory locations. */
1790 && (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum] == 0
1791 || secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum] == 0
1792 || rtx_equal_p (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum],
1793 secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum]))
1794 && (targetm.small_register_classes_for_mode_p (VOIDmode)
1795 ? (rld[i].rclass == rld[output_reload].rclass)
1796 : (reg_class_subset_p (rld[i].rclass,
1797 rld[output_reload].rclass)
1798 || reg_class_subset_p (rld[output_reload].rclass,
1799 rld[i].rclass)))
1800 && (MATCHES (rld[i].in, rld[output_reload].out)
1801 /* Args reversed because the first arg seems to be
1802 the one that we imagine being modified
1803 while the second is the one that might be affected. */
1804 || (! reg_overlap_mentioned_for_reload_p (rld[output_reload].out,
1805 rld[i].in)
1806 /* However, if the input is a register that appears inside
1807 the output, then we also can't share.
1808 Imagine (set (mem (reg 69)) (plus (reg 69) ...)).
1809 If the same reload reg is used for both reg 69 and the
1810 result to be stored in memory, then that result
1811 will clobber the address of the memory ref. */
1812 && ! (REG_P (rld[i].in)
1813 && reg_overlap_mentioned_for_reload_p (rld[i].in,
1814 rld[output_reload].out))))
1815 && ! reload_inner_reg_of_subreg (rld[i].in, rld[i].inmode,
1816 rld[i].when_needed != RELOAD_FOR_INPUT)
1817 && (reg_class_size[(int) rld[i].rclass]
1818 || targetm.small_register_classes_for_mode_p (VOIDmode))
1819 /* We will allow making things slightly worse by combining an
1820 input and an output, but no worse than that. */
1821 && (rld[i].when_needed == RELOAD_FOR_INPUT
1822 || rld[i].when_needed == RELOAD_FOR_OUTPUT))
1824 int j;
1826 /* We have found a reload to combine with! */
1827 rld[i].out = rld[output_reload].out;
1828 rld[i].out_reg = rld[output_reload].out_reg;
1829 rld[i].outmode = rld[output_reload].outmode;
1830 /* Mark the old output reload as inoperative. */
1831 rld[output_reload].out = 0;
1832 /* The combined reload is needed for the entire insn. */
1833 rld[i].when_needed = RELOAD_OTHER;
1834 /* If the output reload had a secondary reload, copy it. */
1835 if (rld[output_reload].secondary_out_reload != -1)
1837 rld[i].secondary_out_reload
1838 = rld[output_reload].secondary_out_reload;
1839 rld[i].secondary_out_icode
1840 = rld[output_reload].secondary_out_icode;
1843 /* Copy any secondary MEM. */
1844 if (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum] != 0)
1845 secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum]
1846 = secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum];
1847 /* If required, minimize the register class. */
1848 if (reg_class_subset_p (rld[output_reload].rclass,
1849 rld[i].rclass))
1850 rld[i].rclass = rld[output_reload].rclass;
1852 /* Transfer all replacements from the old reload to the combined. */
1853 for (j = 0; j < n_replacements; j++)
1854 if (replacements[j].what == output_reload)
1855 replacements[j].what = i;
1857 return;
1860 /* If this insn has only one operand that is modified or written (assumed
1861 to be the first), it must be the one corresponding to this reload. It
1862 is safe to use anything that dies in this insn for that output provided
1863 that it does not occur in the output (we already know it isn't an
1864 earlyclobber. If this is an asm insn, give up. */
1866 if (INSN_CODE (this_insn) == -1)
1867 return;
1869 for (i = 1; i < insn_data[INSN_CODE (this_insn)].n_operands; i++)
1870 if (insn_data[INSN_CODE (this_insn)].operand[i].constraint[0] == '='
1871 || insn_data[INSN_CODE (this_insn)].operand[i].constraint[0] == '+')
1872 return;
1874 /* See if some hard register that dies in this insn and is not used in
1875 the output is the right class. Only works if the register we pick
1876 up can fully hold our output reload. */
1877 for (note = REG_NOTES (this_insn); note; note = XEXP (note, 1))
1878 if (REG_NOTE_KIND (note) == REG_DEAD
1879 && REG_P (XEXP (note, 0))
1880 && !reg_overlap_mentioned_for_reload_p (XEXP (note, 0),
1881 rld[output_reload].out)
1882 && (regno = REGNO (XEXP (note, 0))) < FIRST_PSEUDO_REGISTER
1883 && targetm.hard_regno_mode_ok (regno, rld[output_reload].outmode)
1884 && TEST_HARD_REG_BIT (reg_class_contents[(int) rld[output_reload].rclass],
1885 regno)
1886 && (hard_regno_nregs (regno, rld[output_reload].outmode)
1887 <= REG_NREGS (XEXP (note, 0)))
1888 /* Ensure that a secondary or tertiary reload for this output
1889 won't want this register. */
1890 && ((secondary_out = rld[output_reload].secondary_out_reload) == -1
1891 || (!(TEST_HARD_REG_BIT
1892 (reg_class_contents[(int) rld[secondary_out].rclass], regno))
1893 && ((secondary_out = rld[secondary_out].secondary_out_reload) == -1
1894 || !(TEST_HARD_REG_BIT
1895 (reg_class_contents[(int) rld[secondary_out].rclass],
1896 regno)))))
1897 && !fixed_regs[regno]
1898 /* Check that a former pseudo is valid; see find_dummy_reload. */
1899 && (ORIGINAL_REGNO (XEXP (note, 0)) < FIRST_PSEUDO_REGISTER
1900 || (!bitmap_bit_p (DF_LR_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun)),
1901 ORIGINAL_REGNO (XEXP (note, 0)))
1902 && REG_NREGS (XEXP (note, 0)) == 1)))
1904 rld[output_reload].reg_rtx
1905 = gen_rtx_REG (rld[output_reload].outmode, regno);
1906 return;
1910 /* Try to find a reload register for an in-out reload (expressions IN and OUT).
1911 See if one of IN and OUT is a register that may be used;
1912 this is desirable since a spill-register won't be needed.
1913 If so, return the register rtx that proves acceptable.
1915 INLOC and OUTLOC are locations where IN and OUT appear in the insn.
1916 RCLASS is the register class required for the reload.
1918 If FOR_REAL is >= 0, it is the number of the reload,
1919 and in some cases when it can be discovered that OUT doesn't need
1920 to be computed, clear out rld[FOR_REAL].out.
1922 If FOR_REAL is -1, this should not be done, because this call
1923 is just to see if a register can be found, not to find and install it.
1925 EARLYCLOBBER is nonzero if OUT is an earlyclobber operand. This
1926 puts an additional constraint on being able to use IN for OUT since
1927 IN must not appear elsewhere in the insn (it is assumed that IN itself
1928 is safe from the earlyclobber). */
1930 static rtx
1931 find_dummy_reload (rtx real_in, rtx real_out, rtx *inloc, rtx *outloc,
1932 machine_mode inmode, machine_mode outmode,
1933 reg_class_t rclass, int for_real, int earlyclobber)
1935 rtx in = real_in;
1936 rtx out = real_out;
1937 int in_offset = 0;
1938 int out_offset = 0;
1939 rtx value = 0;
1941 /* If operands exceed a word, we can't use either of them
1942 unless they have the same size. */
1943 if (maybe_ne (GET_MODE_SIZE (outmode), GET_MODE_SIZE (inmode))
1944 && (maybe_gt (GET_MODE_SIZE (outmode), UNITS_PER_WORD)
1945 || maybe_gt (GET_MODE_SIZE (inmode), UNITS_PER_WORD)))
1946 return 0;
1948 /* Note that {in,out}_offset are needed only when 'in' or 'out'
1949 respectively refers to a hard register. */
1951 /* Find the inside of any subregs. */
1952 while (GET_CODE (out) == SUBREG)
1954 if (REG_P (SUBREG_REG (out))
1955 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER)
1956 out_offset += subreg_regno_offset (REGNO (SUBREG_REG (out)),
1957 GET_MODE (SUBREG_REG (out)),
1958 SUBREG_BYTE (out),
1959 GET_MODE (out));
1960 out = SUBREG_REG (out);
1962 while (GET_CODE (in) == SUBREG)
1964 if (REG_P (SUBREG_REG (in))
1965 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER)
1966 in_offset += subreg_regno_offset (REGNO (SUBREG_REG (in)),
1967 GET_MODE (SUBREG_REG (in)),
1968 SUBREG_BYTE (in),
1969 GET_MODE (in));
1970 in = SUBREG_REG (in);
1973 /* Narrow down the reg class, the same way push_reload will;
1974 otherwise we might find a dummy now, but push_reload won't. */
1976 reg_class_t preferred_class = targetm.preferred_reload_class (in, rclass);
1977 if (preferred_class != NO_REGS)
1978 rclass = (enum reg_class) preferred_class;
1981 /* See if OUT will do. */
1982 if (REG_P (out)
1983 && REGNO (out) < FIRST_PSEUDO_REGISTER)
1985 unsigned int regno = REGNO (out) + out_offset;
1986 unsigned int nwords = hard_regno_nregs (regno, outmode);
1987 rtx saved_rtx;
1989 /* When we consider whether the insn uses OUT,
1990 ignore references within IN. They don't prevent us
1991 from copying IN into OUT, because those refs would
1992 move into the insn that reloads IN.
1994 However, we only ignore IN in its role as this reload.
1995 If the insn uses IN elsewhere and it contains OUT,
1996 that counts. We can't be sure it's the "same" operand
1997 so it might not go through this reload.
1999 We also need to avoid using OUT if it, or part of it, is a
2000 fixed register. Modifying such registers, even transiently,
2001 may have undefined effects on the machine, such as modifying
2002 the stack pointer. */
2003 saved_rtx = *inloc;
2004 *inloc = const0_rtx;
2006 if (regno < FIRST_PSEUDO_REGISTER
2007 && targetm.hard_regno_mode_ok (regno, outmode)
2008 && ! refers_to_regno_for_reload_p (regno, regno + nwords,
2009 PATTERN (this_insn), outloc))
2011 unsigned int i;
2013 for (i = 0; i < nwords; i++)
2014 if (! TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
2015 regno + i)
2016 || fixed_regs[regno + i])
2017 break;
2019 if (i == nwords)
2021 if (REG_P (real_out))
2022 value = real_out;
2023 else
2024 value = gen_rtx_REG (outmode, regno);
2028 *inloc = saved_rtx;
2031 /* Consider using IN if OUT was not acceptable
2032 or if OUT dies in this insn (like the quotient in a divmod insn).
2033 We can't use IN unless it is dies in this insn,
2034 which means we must know accurately which hard regs are live.
2035 Also, the result can't go in IN if IN is used within OUT,
2036 or if OUT is an earlyclobber and IN appears elsewhere in the insn. */
2037 if (hard_regs_live_known
2038 && REG_P (in)
2039 && REGNO (in) < FIRST_PSEUDO_REGISTER
2040 && (value == 0
2041 || find_reg_note (this_insn, REG_UNUSED, real_out))
2042 && find_reg_note (this_insn, REG_DEAD, real_in)
2043 && !fixed_regs[REGNO (in)]
2044 && targetm.hard_regno_mode_ok (REGNO (in),
2045 /* The only case where out and real_out
2046 might have different modes is where
2047 real_out is a subreg, and in that
2048 case, out has a real mode. */
2049 (GET_MODE (out) != VOIDmode
2050 ? GET_MODE (out) : outmode))
2051 && (ORIGINAL_REGNO (in) < FIRST_PSEUDO_REGISTER
2052 /* However only do this if we can be sure that this input
2053 operand doesn't correspond with an uninitialized pseudo.
2054 global can assign some hardreg to it that is the same as
2055 the one assigned to a different, also live pseudo (as it
2056 can ignore the conflict). We must never introduce writes
2057 to such hardregs, as they would clobber the other live
2058 pseudo. See PR 20973. */
2059 || (!bitmap_bit_p (DF_LR_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun)),
2060 ORIGINAL_REGNO (in))
2061 /* Similarly, only do this if we can be sure that the death
2062 note is still valid. global can assign some hardreg to
2063 the pseudo referenced in the note and simultaneously a
2064 subword of this hardreg to a different, also live pseudo,
2065 because only another subword of the hardreg is actually
2066 used in the insn. This cannot happen if the pseudo has
2067 been assigned exactly one hardreg. See PR 33732. */
2068 && REG_NREGS (in) == 1)))
2070 unsigned int regno = REGNO (in) + in_offset;
2071 unsigned int nwords = hard_regno_nregs (regno, inmode);
2073 if (! refers_to_regno_for_reload_p (regno, regno + nwords, out, (rtx*) 0)
2074 && ! hard_reg_set_here_p (regno, regno + nwords,
2075 PATTERN (this_insn))
2076 && (! earlyclobber
2077 || ! refers_to_regno_for_reload_p (regno, regno + nwords,
2078 PATTERN (this_insn), inloc)))
2080 unsigned int i;
2082 for (i = 0; i < nwords; i++)
2083 if (! TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
2084 regno + i))
2085 break;
2087 if (i == nwords)
2089 /* If we were going to use OUT as the reload reg
2090 and changed our mind, it means OUT is a dummy that
2091 dies here. So don't bother copying value to it. */
2092 if (for_real >= 0 && value == real_out)
2093 rld[for_real].out = 0;
2094 if (REG_P (real_in))
2095 value = real_in;
2096 else
2097 value = gen_rtx_REG (inmode, regno);
2102 return value;
2105 /* This page contains subroutines used mainly for determining
2106 whether the IN or an OUT of a reload can serve as the
2107 reload register. */
2109 /* Return 1 if X is an operand of an insn that is being earlyclobbered. */
2112 earlyclobber_operand_p (rtx x)
2114 int i;
2116 for (i = 0; i < n_earlyclobbers; i++)
2117 if (reload_earlyclobbers[i] == x)
2118 return 1;
2120 return 0;
2123 /* Return 1 if expression X alters a hard reg in the range
2124 from BEG_REGNO (inclusive) to END_REGNO (exclusive),
2125 either explicitly or in the guise of a pseudo-reg allocated to REGNO.
2126 X should be the body of an instruction. */
2128 static int
2129 hard_reg_set_here_p (unsigned int beg_regno, unsigned int end_regno, rtx x)
2131 if (GET_CODE (x) == SET || GET_CODE (x) == CLOBBER)
2133 rtx op0 = SET_DEST (x);
2135 while (GET_CODE (op0) == SUBREG)
2136 op0 = SUBREG_REG (op0);
2137 if (REG_P (op0))
2139 unsigned int r = REGNO (op0);
2141 /* See if this reg overlaps range under consideration. */
2142 if (r < end_regno
2143 && end_hard_regno (GET_MODE (op0), r) > beg_regno)
2144 return 1;
2147 else if (GET_CODE (x) == PARALLEL)
2149 int i = XVECLEN (x, 0) - 1;
2151 for (; i >= 0; i--)
2152 if (hard_reg_set_here_p (beg_regno, end_regno, XVECEXP (x, 0, i)))
2153 return 1;
2156 return 0;
2159 /* Return true if ADDR is a valid memory address for mode MODE
2160 in address space AS, and check that each pseudo reg has the
2161 proper kind of hard reg. */
2163 bool
2164 strict_memory_address_addr_space_p (machine_mode mode ATTRIBUTE_UNUSED,
2165 rtx addr, addr_space_t as)
2167 #ifdef GO_IF_LEGITIMATE_ADDRESS
2168 gcc_assert (ADDR_SPACE_GENERIC_P (as));
2169 GO_IF_LEGITIMATE_ADDRESS (mode, addr, win);
2170 return false;
2172 win:
2173 return true;
2174 #else
2175 return targetm.addr_space.legitimate_address_p (mode, addr, 1, as);
2176 #endif
2179 /* Like rtx_equal_p except that it allows a REG and a SUBREG to match
2180 if they are the same hard reg, and has special hacks for
2181 autoincrement and autodecrement.
2182 This is specifically intended for find_reloads to use
2183 in determining whether two operands match.
2184 X is the operand whose number is the lower of the two.
2186 The value is 2 if Y contains a pre-increment that matches
2187 a non-incrementing address in X. */
2189 /* ??? To be completely correct, we should arrange to pass
2190 for X the output operand and for Y the input operand.
2191 For now, we assume that the output operand has the lower number
2192 because that is natural in (SET output (... input ...)). */
2195 operands_match_p (rtx x, rtx y)
2197 int i;
2198 RTX_CODE code = GET_CODE (x);
2199 const char *fmt;
2200 int success_2;
2202 if (x == y)
2203 return 1;
2204 if ((code == REG || (code == SUBREG && REG_P (SUBREG_REG (x))))
2205 && (REG_P (y) || (GET_CODE (y) == SUBREG
2206 && REG_P (SUBREG_REG (y)))))
2208 int j;
2210 if (code == SUBREG)
2212 i = REGNO (SUBREG_REG (x));
2213 if (i >= FIRST_PSEUDO_REGISTER)
2214 goto slow;
2215 i += subreg_regno_offset (REGNO (SUBREG_REG (x)),
2216 GET_MODE (SUBREG_REG (x)),
2217 SUBREG_BYTE (x),
2218 GET_MODE (x));
2220 else
2221 i = REGNO (x);
2223 if (GET_CODE (y) == SUBREG)
2225 j = REGNO (SUBREG_REG (y));
2226 if (j >= FIRST_PSEUDO_REGISTER)
2227 goto slow;
2228 j += subreg_regno_offset (REGNO (SUBREG_REG (y)),
2229 GET_MODE (SUBREG_REG (y)),
2230 SUBREG_BYTE (y),
2231 GET_MODE (y));
2233 else
2234 j = REGNO (y);
2236 /* On a REG_WORDS_BIG_ENDIAN machine, point to the last register of a
2237 multiple hard register group of scalar integer registers, so that
2238 for example (reg:DI 0) and (reg:SI 1) will be considered the same
2239 register. */
2240 scalar_int_mode xmode;
2241 if (REG_WORDS_BIG_ENDIAN
2242 && is_a <scalar_int_mode> (GET_MODE (x), &xmode)
2243 && GET_MODE_SIZE (xmode) > UNITS_PER_WORD
2244 && i < FIRST_PSEUDO_REGISTER)
2245 i += hard_regno_nregs (i, xmode) - 1;
2246 scalar_int_mode ymode;
2247 if (REG_WORDS_BIG_ENDIAN
2248 && is_a <scalar_int_mode> (GET_MODE (y), &ymode)
2249 && GET_MODE_SIZE (ymode) > UNITS_PER_WORD
2250 && j < FIRST_PSEUDO_REGISTER)
2251 j += hard_regno_nregs (j, ymode) - 1;
2253 return i == j;
2255 /* If two operands must match, because they are really a single
2256 operand of an assembler insn, then two postincrements are invalid
2257 because the assembler insn would increment only once.
2258 On the other hand, a postincrement matches ordinary indexing
2259 if the postincrement is the output operand. */
2260 if (code == POST_DEC || code == POST_INC || code == POST_MODIFY)
2261 return operands_match_p (XEXP (x, 0), y);
2262 /* Two preincrements are invalid
2263 because the assembler insn would increment only once.
2264 On the other hand, a preincrement matches ordinary indexing
2265 if the preincrement is the input operand.
2266 In this case, return 2, since some callers need to do special
2267 things when this happens. */
2268 if (GET_CODE (y) == PRE_DEC || GET_CODE (y) == PRE_INC
2269 || GET_CODE (y) == PRE_MODIFY)
2270 return operands_match_p (x, XEXP (y, 0)) ? 2 : 0;
2272 slow:
2274 /* Now we have disposed of all the cases in which different rtx codes
2275 can match. */
2276 if (code != GET_CODE (y))
2277 return 0;
2279 /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. */
2280 if (GET_MODE (x) != GET_MODE (y))
2281 return 0;
2283 /* MEMs referring to different address space are not equivalent. */
2284 if (code == MEM && MEM_ADDR_SPACE (x) != MEM_ADDR_SPACE (y))
2285 return 0;
2287 switch (code)
2289 CASE_CONST_UNIQUE:
2290 return 0;
2292 case CONST_VECTOR:
2293 if (!same_vector_encodings_p (x, y))
2294 return false;
2295 break;
2297 case LABEL_REF:
2298 return label_ref_label (x) == label_ref_label (y);
2299 case SYMBOL_REF:
2300 return XSTR (x, 0) == XSTR (y, 0);
2302 default:
2303 break;
2306 /* Compare the elements. If any pair of corresponding elements
2307 fail to match, return 0 for the whole things. */
2309 success_2 = 0;
2310 fmt = GET_RTX_FORMAT (code);
2311 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2313 int val, j;
2314 switch (fmt[i])
2316 case 'w':
2317 if (XWINT (x, i) != XWINT (y, i))
2318 return 0;
2319 break;
2321 case 'i':
2322 if (XINT (x, i) != XINT (y, i))
2323 return 0;
2324 break;
2326 case 'p':
2327 if (maybe_ne (SUBREG_BYTE (x), SUBREG_BYTE (y)))
2328 return 0;
2329 break;
2331 case 'e':
2332 val = operands_match_p (XEXP (x, i), XEXP (y, i));
2333 if (val == 0)
2334 return 0;
2335 /* If any subexpression returns 2,
2336 we should return 2 if we are successful. */
2337 if (val == 2)
2338 success_2 = 1;
2339 break;
2341 case '0':
2342 break;
2344 case 'E':
2345 if (XVECLEN (x, i) != XVECLEN (y, i))
2346 return 0;
2347 for (j = XVECLEN (x, i) - 1; j >= 0; --j)
2349 val = operands_match_p (XVECEXP (x, i, j), XVECEXP (y, i, j));
2350 if (val == 0)
2351 return 0;
2352 if (val == 2)
2353 success_2 = 1;
2355 break;
2357 /* It is believed that rtx's at this level will never
2358 contain anything but integers and other rtx's,
2359 except for within LABEL_REFs and SYMBOL_REFs. */
2360 default:
2361 gcc_unreachable ();
2364 return 1 + success_2;
2367 /* Describe the range of registers or memory referenced by X.
2368 If X is a register, set REG_FLAG and put the first register
2369 number into START and the last plus one into END.
2370 If X is a memory reference, put a base address into BASE
2371 and a range of integer offsets into START and END.
2372 If X is pushing on the stack, we can assume it causes no trouble,
2373 so we set the SAFE field. */
2375 static struct decomposition
2376 decompose (rtx x)
2378 struct decomposition val;
2379 int all_const = 0, regno;
2381 memset (&val, 0, sizeof (val));
2383 switch (GET_CODE (x))
2385 case MEM:
2387 rtx base = NULL_RTX, offset = 0;
2388 rtx addr = XEXP (x, 0);
2390 if (GET_CODE (addr) == PRE_DEC || GET_CODE (addr) == PRE_INC
2391 || GET_CODE (addr) == POST_DEC || GET_CODE (addr) == POST_INC)
2393 val.base = XEXP (addr, 0);
2394 val.start = -GET_MODE_SIZE (GET_MODE (x));
2395 val.end = GET_MODE_SIZE (GET_MODE (x));
2396 val.safe = REGNO (val.base) == STACK_POINTER_REGNUM;
2397 return val;
2400 if (GET_CODE (addr) == PRE_MODIFY || GET_CODE (addr) == POST_MODIFY)
2402 if (GET_CODE (XEXP (addr, 1)) == PLUS
2403 && XEXP (addr, 0) == XEXP (XEXP (addr, 1), 0)
2404 && CONSTANT_P (XEXP (XEXP (addr, 1), 1)))
2406 val.base = XEXP (addr, 0);
2407 val.start = -INTVAL (XEXP (XEXP (addr, 1), 1));
2408 val.end = INTVAL (XEXP (XEXP (addr, 1), 1));
2409 val.safe = REGNO (val.base) == STACK_POINTER_REGNUM;
2410 return val;
2414 if (GET_CODE (addr) == CONST)
2416 addr = XEXP (addr, 0);
2417 all_const = 1;
2419 if (GET_CODE (addr) == PLUS)
2421 if (CONSTANT_P (XEXP (addr, 0)))
2423 base = XEXP (addr, 1);
2424 offset = XEXP (addr, 0);
2426 else if (CONSTANT_P (XEXP (addr, 1)))
2428 base = XEXP (addr, 0);
2429 offset = XEXP (addr, 1);
2433 if (offset == 0)
2435 base = addr;
2436 offset = const0_rtx;
2438 if (GET_CODE (offset) == CONST)
2439 offset = XEXP (offset, 0);
2440 if (GET_CODE (offset) == PLUS)
2442 if (CONST_INT_P (XEXP (offset, 0)))
2444 base = gen_rtx_PLUS (GET_MODE (base), base, XEXP (offset, 1));
2445 offset = XEXP (offset, 0);
2447 else if (CONST_INT_P (XEXP (offset, 1)))
2449 base = gen_rtx_PLUS (GET_MODE (base), base, XEXP (offset, 0));
2450 offset = XEXP (offset, 1);
2452 else
2454 base = gen_rtx_PLUS (GET_MODE (base), base, offset);
2455 offset = const0_rtx;
2458 else if (!CONST_INT_P (offset))
2460 base = gen_rtx_PLUS (GET_MODE (base), base, offset);
2461 offset = const0_rtx;
2464 if (all_const && GET_CODE (base) == PLUS)
2465 base = gen_rtx_CONST (GET_MODE (base), base);
2467 gcc_assert (CONST_INT_P (offset));
2469 val.start = INTVAL (offset);
2470 val.end = val.start + GET_MODE_SIZE (GET_MODE (x));
2471 val.base = base;
2473 break;
2475 case REG:
2476 val.reg_flag = 1;
2477 regno = true_regnum (x);
2478 if (regno < 0 || regno >= FIRST_PSEUDO_REGISTER)
2480 /* A pseudo with no hard reg. */
2481 val.start = REGNO (x);
2482 val.end = val.start + 1;
2484 else
2486 /* A hard reg. */
2487 val.start = regno;
2488 val.end = end_hard_regno (GET_MODE (x), regno);
2490 break;
2492 case SUBREG:
2493 if (!REG_P (SUBREG_REG (x)))
2494 /* This could be more precise, but it's good enough. */
2495 return decompose (SUBREG_REG (x));
2496 regno = true_regnum (x);
2497 if (regno < 0 || regno >= FIRST_PSEUDO_REGISTER)
2498 return decompose (SUBREG_REG (x));
2500 /* A hard reg. */
2501 val.reg_flag = 1;
2502 val.start = regno;
2503 val.end = regno + subreg_nregs (x);
2504 break;
2506 case SCRATCH:
2507 /* This hasn't been assigned yet, so it can't conflict yet. */
2508 val.safe = 1;
2509 break;
2511 default:
2512 gcc_assert (CONSTANT_P (x));
2513 val.safe = 1;
2514 break;
2516 return val;
2519 /* Return 1 if altering Y will not modify the value of X.
2520 Y is also described by YDATA, which should be decompose (Y). */
2522 static int
2523 immune_p (rtx x, rtx y, struct decomposition ydata)
2525 struct decomposition xdata;
2527 if (ydata.reg_flag)
2528 /* In this case the decomposition structure contains register
2529 numbers rather than byte offsets. */
2530 return !refers_to_regno_for_reload_p (ydata.start.to_constant (),
2531 ydata.end.to_constant (),
2532 x, (rtx *) 0);
2533 if (ydata.safe)
2534 return 1;
2536 gcc_assert (MEM_P (y));
2537 /* If Y is memory and X is not, Y can't affect X. */
2538 if (!MEM_P (x))
2539 return 1;
2541 xdata = decompose (x);
2543 if (! rtx_equal_p (xdata.base, ydata.base))
2545 /* If bases are distinct symbolic constants, there is no overlap. */
2546 if (CONSTANT_P (xdata.base) && CONSTANT_P (ydata.base))
2547 return 1;
2548 /* Constants and stack slots never overlap. */
2549 if (CONSTANT_P (xdata.base)
2550 && (ydata.base == frame_pointer_rtx
2551 || ydata.base == hard_frame_pointer_rtx
2552 || ydata.base == stack_pointer_rtx))
2553 return 1;
2554 if (CONSTANT_P (ydata.base)
2555 && (xdata.base == frame_pointer_rtx
2556 || xdata.base == hard_frame_pointer_rtx
2557 || xdata.base == stack_pointer_rtx))
2558 return 1;
2559 /* If either base is variable, we don't know anything. */
2560 return 0;
2563 return known_ge (xdata.start, ydata.end) || known_ge (ydata.start, xdata.end);
2566 /* Similar, but calls decompose. */
2569 safe_from_earlyclobber (rtx op, rtx clobber)
2571 struct decomposition early_data;
2573 early_data = decompose (clobber);
2574 return immune_p (op, clobber, early_data);
2577 /* Main entry point of this file: search the body of INSN
2578 for values that need reloading and record them with push_reload.
2579 REPLACE nonzero means record also where the values occur
2580 so that subst_reloads can be used.
2582 IND_LEVELS says how many levels of indirection are supported by this
2583 machine; a value of zero means that a memory reference is not a valid
2584 memory address.
2586 LIVE_KNOWN says we have valid information about which hard
2587 regs are live at each point in the program; this is true when
2588 we are called from global_alloc but false when stupid register
2589 allocation has been done.
2591 RELOAD_REG_P if nonzero is a vector indexed by hard reg number
2592 which is nonnegative if the reg has been commandeered for reloading into.
2593 It is copied into STATIC_RELOAD_REG_P and referenced from there
2594 by various subroutines.
2596 Return TRUE if some operands need to be changed, because of swapping
2597 commutative operands, reg_equiv_address substitution, or whatever. */
2600 find_reloads (rtx_insn *insn, int replace, int ind_levels, int live_known,
2601 short *reload_reg_p)
2603 int insn_code_number;
2604 int i, j;
2605 int noperands;
2606 /* These start out as the constraints for the insn
2607 and they are chewed up as we consider alternatives. */
2608 const char *constraints[MAX_RECOG_OPERANDS];
2609 /* These are the preferred classes for an operand, or NO_REGS if it isn't
2610 a register. */
2611 enum reg_class preferred_class[MAX_RECOG_OPERANDS];
2612 char pref_or_nothing[MAX_RECOG_OPERANDS];
2613 /* Nonzero for a MEM operand whose entire address needs a reload.
2614 May be -1 to indicate the entire address may or may not need a reload. */
2615 int address_reloaded[MAX_RECOG_OPERANDS];
2616 /* Nonzero for an address operand that needs to be completely reloaded.
2617 May be -1 to indicate the entire operand may or may not need a reload. */
2618 int address_operand_reloaded[MAX_RECOG_OPERANDS];
2619 /* Value of enum reload_type to use for operand. */
2620 enum reload_type operand_type[MAX_RECOG_OPERANDS];
2621 /* Value of enum reload_type to use within address of operand. */
2622 enum reload_type address_type[MAX_RECOG_OPERANDS];
2623 /* Save the usage of each operand. */
2624 enum reload_usage { RELOAD_READ, RELOAD_READ_WRITE, RELOAD_WRITE } modified[MAX_RECOG_OPERANDS];
2625 int no_input_reloads = 0, no_output_reloads = 0;
2626 int n_alternatives;
2627 reg_class_t this_alternative[MAX_RECOG_OPERANDS];
2628 char this_alternative_match_win[MAX_RECOG_OPERANDS];
2629 char this_alternative_win[MAX_RECOG_OPERANDS];
2630 char this_alternative_offmemok[MAX_RECOG_OPERANDS];
2631 char this_alternative_earlyclobber[MAX_RECOG_OPERANDS];
2632 int this_alternative_matches[MAX_RECOG_OPERANDS];
2633 reg_class_t goal_alternative[MAX_RECOG_OPERANDS];
2634 int this_alternative_number;
2635 int goal_alternative_number = 0;
2636 int operand_reloadnum[MAX_RECOG_OPERANDS];
2637 int goal_alternative_matches[MAX_RECOG_OPERANDS];
2638 int goal_alternative_matched[MAX_RECOG_OPERANDS];
2639 char goal_alternative_match_win[MAX_RECOG_OPERANDS];
2640 char goal_alternative_win[MAX_RECOG_OPERANDS];
2641 char goal_alternative_offmemok[MAX_RECOG_OPERANDS];
2642 char goal_alternative_earlyclobber[MAX_RECOG_OPERANDS];
2643 int goal_alternative_swapped;
2644 int best;
2645 int commutative;
2646 char operands_match[MAX_RECOG_OPERANDS][MAX_RECOG_OPERANDS];
2647 rtx substed_operand[MAX_RECOG_OPERANDS];
2648 rtx body = PATTERN (insn);
2649 rtx set = single_set (insn);
2650 int goal_earlyclobber = 0, this_earlyclobber;
2651 machine_mode operand_mode[MAX_RECOG_OPERANDS];
2652 int retval = 0;
2654 this_insn = insn;
2655 n_reloads = 0;
2656 n_replacements = 0;
2657 n_earlyclobbers = 0;
2658 replace_reloads = replace;
2659 hard_regs_live_known = live_known;
2660 static_reload_reg_p = reload_reg_p;
2662 if (JUMP_P (insn) && INSN_CODE (insn) < 0)
2664 extract_insn (insn);
2665 for (i = 0; i < recog_data.n_operands; i++)
2666 if (recog_data.operand_type[i] != OP_IN)
2667 break;
2668 if (i < recog_data.n_operands)
2670 error_for_asm (insn,
2671 "the target does not support %<asm goto%> "
2672 "with outputs in %<asm%>");
2673 ira_nullify_asm_goto (insn);
2674 return 0;
2678 /* JUMP_INSNs and CALL_INSNs are not allowed to have any output reloads. */
2679 if (JUMP_P (insn) || CALL_P (insn))
2680 no_output_reloads = 1;
2682 /* The eliminated forms of any secondary memory locations are per-insn, so
2683 clear them out here. */
2685 if (secondary_memlocs_elim_used)
2687 memset (secondary_memlocs_elim, 0,
2688 sizeof (secondary_memlocs_elim[0]) * secondary_memlocs_elim_used);
2689 secondary_memlocs_elim_used = 0;
2692 /* Dispose quickly of (set (reg..) (reg..)) if both have hard regs and it
2693 is cheap to move between them. If it is not, there may not be an insn
2694 to do the copy, so we may need a reload. */
2695 if (GET_CODE (body) == SET
2696 && REG_P (SET_DEST (body))
2697 && REGNO (SET_DEST (body)) < FIRST_PSEUDO_REGISTER
2698 && REG_P (SET_SRC (body))
2699 && REGNO (SET_SRC (body)) < FIRST_PSEUDO_REGISTER
2700 && register_move_cost (GET_MODE (SET_SRC (body)),
2701 REGNO_REG_CLASS (REGNO (SET_SRC (body))),
2702 REGNO_REG_CLASS (REGNO (SET_DEST (body)))) == 2)
2703 return 0;
2705 extract_insn (insn);
2707 noperands = reload_n_operands = recog_data.n_operands;
2708 n_alternatives = recog_data.n_alternatives;
2710 /* Just return "no reloads" if insn has no operands with constraints. */
2711 if (noperands == 0 || n_alternatives == 0)
2712 return 0;
2714 insn_code_number = INSN_CODE (insn);
2715 this_insn_is_asm = insn_code_number < 0;
2717 memcpy (operand_mode, recog_data.operand_mode,
2718 noperands * sizeof (machine_mode));
2719 memcpy (constraints, recog_data.constraints,
2720 noperands * sizeof (const char *));
2722 commutative = -1;
2724 /* If we will need to know, later, whether some pair of operands
2725 are the same, we must compare them now and save the result.
2726 Reloading the base and index registers will clobber them
2727 and afterward they will fail to match. */
2729 for (i = 0; i < noperands; i++)
2731 const char *p;
2732 int c;
2733 char *end;
2735 substed_operand[i] = recog_data.operand[i];
2736 p = constraints[i];
2738 modified[i] = RELOAD_READ;
2740 /* Scan this operand's constraint to see if it is an output operand,
2741 an in-out operand, is commutative, or should match another. */
2743 while ((c = *p))
2745 p += CONSTRAINT_LEN (c, p);
2746 switch (c)
2748 case '=':
2749 modified[i] = RELOAD_WRITE;
2750 break;
2751 case '+':
2752 modified[i] = RELOAD_READ_WRITE;
2753 break;
2754 case '%':
2756 /* The last operand should not be marked commutative. */
2757 gcc_assert (i != noperands - 1);
2759 /* We currently only support one commutative pair of
2760 operands. Some existing asm code currently uses more
2761 than one pair. Previously, that would usually work,
2762 but sometimes it would crash the compiler. We
2763 continue supporting that case as well as we can by
2764 silently ignoring all but the first pair. In the
2765 future we may handle it correctly. */
2766 if (commutative < 0)
2767 commutative = i;
2768 else
2769 gcc_assert (this_insn_is_asm);
2771 break;
2772 /* Use of ISDIGIT is tempting here, but it may get expensive because
2773 of locale support we don't want. */
2774 case '0': case '1': case '2': case '3': case '4':
2775 case '5': case '6': case '7': case '8': case '9':
2777 c = strtoul (p - 1, &end, 10);
2778 p = end;
2780 operands_match[c][i]
2781 = operands_match_p (recog_data.operand[c],
2782 recog_data.operand[i]);
2784 /* An operand may not match itself. */
2785 gcc_assert (c != i);
2787 /* If C can be commuted with C+1, and C might need to match I,
2788 then C+1 might also need to match I. */
2789 if (commutative >= 0)
2791 if (c == commutative || c == commutative + 1)
2793 int other = c + (c == commutative ? 1 : -1);
2794 operands_match[other][i]
2795 = operands_match_p (recog_data.operand[other],
2796 recog_data.operand[i]);
2798 if (i == commutative || i == commutative + 1)
2800 int other = i + (i == commutative ? 1 : -1);
2801 operands_match[c][other]
2802 = operands_match_p (recog_data.operand[c],
2803 recog_data.operand[other]);
2805 /* Note that C is supposed to be less than I.
2806 No need to consider altering both C and I because in
2807 that case we would alter one into the other. */
2814 /* Examine each operand that is a memory reference or memory address
2815 and reload parts of the addresses into index registers.
2816 Also here any references to pseudo regs that didn't get hard regs
2817 but are equivalent to constants get replaced in the insn itself
2818 with those constants. Nobody will ever see them again.
2820 Finally, set up the preferred classes of each operand. */
2822 for (i = 0; i < noperands; i++)
2824 RTX_CODE code = GET_CODE (recog_data.operand[i]);
2826 address_reloaded[i] = 0;
2827 address_operand_reloaded[i] = 0;
2828 operand_type[i] = (modified[i] == RELOAD_READ ? RELOAD_FOR_INPUT
2829 : modified[i] == RELOAD_WRITE ? RELOAD_FOR_OUTPUT
2830 : RELOAD_OTHER);
2831 address_type[i]
2832 = (modified[i] == RELOAD_READ ? RELOAD_FOR_INPUT_ADDRESS
2833 : modified[i] == RELOAD_WRITE ? RELOAD_FOR_OUTPUT_ADDRESS
2834 : RELOAD_OTHER);
2836 if (*constraints[i] == 0)
2837 /* Ignore things like match_operator operands. */
2839 else if (insn_extra_address_constraint
2840 (lookup_constraint (constraints[i])))
2842 address_operand_reloaded[i]
2843 = find_reloads_address (recog_data.operand_mode[i], (rtx*) 0,
2844 recog_data.operand[i],
2845 recog_data.operand_loc[i],
2846 i, operand_type[i], ind_levels, insn);
2848 /* If we now have a simple operand where we used to have a
2849 PLUS or MULT or ASHIFT, re-recognize and try again. */
2850 if ((OBJECT_P (*recog_data.operand_loc[i])
2851 || GET_CODE (*recog_data.operand_loc[i]) == SUBREG)
2852 && (GET_CODE (recog_data.operand[i]) == MULT
2853 || GET_CODE (recog_data.operand[i]) == ASHIFT
2854 || GET_CODE (recog_data.operand[i]) == PLUS))
2856 INSN_CODE (insn) = -1;
2857 retval = find_reloads (insn, replace, ind_levels, live_known,
2858 reload_reg_p);
2859 return retval;
2862 recog_data.operand[i] = *recog_data.operand_loc[i];
2863 substed_operand[i] = recog_data.operand[i];
2865 /* Address operands are reloaded in their existing mode,
2866 no matter what is specified in the machine description. */
2867 operand_mode[i] = GET_MODE (recog_data.operand[i]);
2869 /* If the address is a single CONST_INT pick address mode
2870 instead otherwise we will later not know in which mode
2871 the reload should be performed. */
2872 if (operand_mode[i] == VOIDmode)
2873 operand_mode[i] = Pmode;
2876 else if (code == MEM)
2878 address_reloaded[i]
2879 = find_reloads_address (GET_MODE (recog_data.operand[i]),
2880 recog_data.operand_loc[i],
2881 XEXP (recog_data.operand[i], 0),
2882 &XEXP (recog_data.operand[i], 0),
2883 i, address_type[i], ind_levels, insn);
2884 recog_data.operand[i] = *recog_data.operand_loc[i];
2885 substed_operand[i] = recog_data.operand[i];
2887 else if (code == SUBREG)
2889 rtx reg = SUBREG_REG (recog_data.operand[i]);
2890 rtx op
2891 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2892 ind_levels,
2893 set != 0
2894 && &SET_DEST (set) == recog_data.operand_loc[i],
2895 insn,
2896 &address_reloaded[i]);
2898 /* If we made a MEM to load (a part of) the stackslot of a pseudo
2899 that didn't get a hard register, emit a USE with a REG_EQUAL
2900 note in front so that we might inherit a previous, possibly
2901 wider reload. */
2903 if (replace
2904 && MEM_P (op)
2905 && REG_P (reg)
2906 && known_ge (GET_MODE_SIZE (GET_MODE (reg)),
2907 GET_MODE_SIZE (GET_MODE (op)))
2908 && reg_equiv_constant (REGNO (reg)) == 0)
2909 set_unique_reg_note (emit_insn_before (gen_rtx_USE (VOIDmode, reg),
2910 insn),
2911 REG_EQUAL, reg_equiv_memory_loc (REGNO (reg)));
2913 substed_operand[i] = recog_data.operand[i] = op;
2915 else if (code == PLUS || GET_RTX_CLASS (code) == RTX_UNARY)
2916 /* We can get a PLUS as an "operand" as a result of register
2917 elimination. See eliminate_regs and gen_reload. We handle
2918 a unary operator by reloading the operand. */
2919 substed_operand[i] = recog_data.operand[i]
2920 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2921 ind_levels, 0, insn,
2922 &address_reloaded[i]);
2923 else if (code == REG)
2925 /* This is equivalent to calling find_reloads_toplev.
2926 The code is duplicated for speed.
2927 When we find a pseudo always equivalent to a constant,
2928 we replace it by the constant. We must be sure, however,
2929 that we don't try to replace it in the insn in which it
2930 is being set. */
2931 int regno = REGNO (recog_data.operand[i]);
2932 if (reg_equiv_constant (regno) != 0
2933 && (set == 0 || &SET_DEST (set) != recog_data.operand_loc[i]))
2935 /* Record the existing mode so that the check if constants are
2936 allowed will work when operand_mode isn't specified. */
2938 if (operand_mode[i] == VOIDmode)
2939 operand_mode[i] = GET_MODE (recog_data.operand[i]);
2941 substed_operand[i] = recog_data.operand[i]
2942 = reg_equiv_constant (regno);
2944 if (reg_equiv_memory_loc (regno) != 0
2945 && (reg_equiv_address (regno) != 0 || num_not_at_initial_offset))
2946 /* We need not give a valid is_set_dest argument since the case
2947 of a constant equivalence was checked above. */
2948 substed_operand[i] = recog_data.operand[i]
2949 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2950 ind_levels, 0, insn,
2951 &address_reloaded[i]);
2953 /* If the operand is still a register (we didn't replace it with an
2954 equivalent), get the preferred class to reload it into. */
2955 code = GET_CODE (recog_data.operand[i]);
2956 preferred_class[i]
2957 = ((code == REG && REGNO (recog_data.operand[i])
2958 >= FIRST_PSEUDO_REGISTER)
2959 ? reg_preferred_class (REGNO (recog_data.operand[i]))
2960 : NO_REGS);
2961 pref_or_nothing[i]
2962 = (code == REG
2963 && REGNO (recog_data.operand[i]) >= FIRST_PSEUDO_REGISTER
2964 && reg_alternate_class (REGNO (recog_data.operand[i])) == NO_REGS);
2967 /* If this is simply a copy from operand 1 to operand 0, merge the
2968 preferred classes for the operands. */
2969 if (set != 0 && noperands >= 2 && recog_data.operand[0] == SET_DEST (set)
2970 && recog_data.operand[1] == SET_SRC (set))
2972 preferred_class[0] = preferred_class[1]
2973 = reg_class_subunion[(int) preferred_class[0]][(int) preferred_class[1]];
2974 pref_or_nothing[0] |= pref_or_nothing[1];
2975 pref_or_nothing[1] |= pref_or_nothing[0];
2978 /* Now see what we need for pseudo-regs that didn't get hard regs
2979 or got the wrong kind of hard reg. For this, we must consider
2980 all the operands together against the register constraints. */
2982 best = MAX_RECOG_OPERANDS * 2 + 600;
2984 goal_alternative_swapped = 0;
2986 /* The constraints are made of several alternatives.
2987 Each operand's constraint looks like foo,bar,... with commas
2988 separating the alternatives. The first alternatives for all
2989 operands go together, the second alternatives go together, etc.
2991 First loop over alternatives. */
2993 alternative_mask enabled = get_enabled_alternatives (insn);
2994 for (this_alternative_number = 0;
2995 this_alternative_number < n_alternatives;
2996 this_alternative_number++)
2998 int swapped;
3000 if (!TEST_BIT (enabled, this_alternative_number))
3002 int i;
3004 for (i = 0; i < recog_data.n_operands; i++)
3005 constraints[i] = skip_alternative (constraints[i]);
3007 continue;
3010 /* If insn is commutative (it's safe to exchange a certain pair
3011 of operands) then we need to try each alternative twice, the
3012 second time matching those two operands as if we had
3013 exchanged them. To do this, really exchange them in
3014 operands. */
3015 for (swapped = 0; swapped < (commutative >= 0 ? 2 : 1); swapped++)
3017 /* Loop over operands for one constraint alternative. */
3018 /* LOSERS counts those that don't fit this alternative
3019 and would require loading. */
3020 int losers = 0;
3021 /* BAD is set to 1 if it some operand can't fit this alternative
3022 even after reloading. */
3023 int bad = 0;
3024 /* REJECT is a count of how undesirable this alternative says it is
3025 if any reloading is required. If the alternative matches exactly
3026 then REJECT is ignored, but otherwise it gets this much
3027 counted against it in addition to the reloading needed. Each
3028 ? counts three times here since we want the disparaging caused by
3029 a bad register class to only count 1/3 as much. */
3030 int reject = 0;
3032 if (swapped)
3034 recog_data.operand[commutative] = substed_operand[commutative + 1];
3035 recog_data.operand[commutative + 1] = substed_operand[commutative];
3036 /* Swap the duplicates too. */
3037 for (i = 0; i < recog_data.n_dups; i++)
3038 if (recog_data.dup_num[i] == commutative
3039 || recog_data.dup_num[i] == commutative + 1)
3040 *recog_data.dup_loc[i]
3041 = recog_data.operand[(int) recog_data.dup_num[i]];
3043 std::swap (preferred_class[commutative],
3044 preferred_class[commutative + 1]);
3045 std::swap (pref_or_nothing[commutative],
3046 pref_or_nothing[commutative + 1]);
3047 std::swap (address_reloaded[commutative],
3048 address_reloaded[commutative + 1]);
3051 this_earlyclobber = 0;
3053 for (i = 0; i < noperands; i++)
3055 const char *p = constraints[i];
3056 char *end;
3057 int len;
3058 int win = 0;
3059 int did_match = 0;
3060 /* 0 => this operand can be reloaded somehow for this alternative. */
3061 int badop = 1;
3062 /* 0 => this operand can be reloaded if the alternative allows regs. */
3063 int winreg = 0;
3064 int c;
3065 int m;
3066 rtx operand = recog_data.operand[i];
3067 int offset = 0;
3068 /* Nonzero means this is a MEM that must be reloaded into a reg
3069 regardless of what the constraint says. */
3070 int force_reload = 0;
3071 int offmemok = 0;
3072 /* Nonzero if a constant forced into memory would be OK for this
3073 operand. */
3074 int constmemok = 0;
3075 int earlyclobber = 0;
3076 enum constraint_num cn;
3077 enum reg_class cl;
3079 /* If the predicate accepts a unary operator, it means that
3080 we need to reload the operand, but do not do this for
3081 match_operator and friends. */
3082 if (UNARY_P (operand) && *p != 0)
3083 operand = XEXP (operand, 0);
3085 /* If the operand is a SUBREG, extract
3086 the REG or MEM (or maybe even a constant) within.
3087 (Constants can occur as a result of reg_equiv_constant.) */
3089 while (GET_CODE (operand) == SUBREG)
3091 /* Offset only matters when operand is a REG and
3092 it is a hard reg. This is because it is passed
3093 to reg_fits_class_p if it is a REG and all pseudos
3094 return 0 from that function. */
3095 if (REG_P (SUBREG_REG (operand))
3096 && REGNO (SUBREG_REG (operand)) < FIRST_PSEUDO_REGISTER)
3098 if (simplify_subreg_regno (REGNO (SUBREG_REG (operand)),
3099 GET_MODE (SUBREG_REG (operand)),
3100 SUBREG_BYTE (operand),
3101 GET_MODE (operand)) < 0)
3102 force_reload = 1;
3103 offset += subreg_regno_offset (REGNO (SUBREG_REG (operand)),
3104 GET_MODE (SUBREG_REG (operand)),
3105 SUBREG_BYTE (operand),
3106 GET_MODE (operand));
3108 operand = SUBREG_REG (operand);
3109 /* Force reload if this is a constant or PLUS or if there may
3110 be a problem accessing OPERAND in the outer mode. */
3111 scalar_int_mode inner_mode;
3112 if (CONSTANT_P (operand)
3113 || GET_CODE (operand) == PLUS
3114 /* We must force a reload of paradoxical SUBREGs
3115 of a MEM because the alignment of the inner value
3116 may not be enough to do the outer reference. On
3117 big-endian machines, it may also reference outside
3118 the object.
3120 On machines that extend byte operations and we have a
3121 SUBREG where both the inner and outer modes are no wider
3122 than a word and the inner mode is narrower, is integral,
3123 and gets extended when loaded from memory, combine.cc has
3124 made assumptions about the behavior of the machine in such
3125 register access. If the data is, in fact, in memory we
3126 must always load using the size assumed to be in the
3127 register and let the insn do the different-sized
3128 accesses.
3130 This is doubly true if WORD_REGISTER_OPERATIONS. In
3131 this case eliminate_regs has left non-paradoxical
3132 subregs for push_reload to see. Make sure it does
3133 by forcing the reload.
3135 ??? When is it right at this stage to have a subreg
3136 of a mem that is _not_ to be handled specially? IMO
3137 those should have been reduced to just a mem. */
3138 || ((MEM_P (operand)
3139 || (REG_P (operand)
3140 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
3141 && (WORD_REGISTER_OPERATIONS
3142 || (((maybe_lt
3143 (GET_MODE_BITSIZE (GET_MODE (operand)),
3144 BIGGEST_ALIGNMENT))
3145 && (paradoxical_subreg_p
3146 (operand_mode[i], GET_MODE (operand)))))
3147 || BYTES_BIG_ENDIAN
3148 || (known_le (GET_MODE_SIZE (operand_mode[i]),
3149 UNITS_PER_WORD)
3150 && (is_a <scalar_int_mode>
3151 (GET_MODE (operand), &inner_mode))
3152 && (GET_MODE_SIZE (inner_mode)
3153 <= UNITS_PER_WORD)
3154 && paradoxical_subreg_p (operand_mode[i],
3155 inner_mode)
3156 && LOAD_EXTEND_OP (inner_mode) != UNKNOWN)))
3157 /* We must force a reload of a SUBREG's inner expression
3158 if it is a pseudo that will become a MEM and the MEM
3159 has a mode-dependent address, as in that case we
3160 obviously cannot change the mode of the MEM to that
3161 of the containing SUBREG as that would change the
3162 interpretation of the address. */
3163 || (REG_P (operand)
3164 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3165 && reg_equiv_mem (REGNO (operand))
3166 && (mode_dependent_address_p
3167 (XEXP (reg_equiv_mem (REGNO (operand)), 0),
3168 (MEM_ADDR_SPACE
3169 (reg_equiv_mem (REGNO (operand)))))))
3171 force_reload = 1;
3174 this_alternative[i] = NO_REGS;
3175 this_alternative_win[i] = 0;
3176 this_alternative_match_win[i] = 0;
3177 this_alternative_offmemok[i] = 0;
3178 this_alternative_earlyclobber[i] = 0;
3179 this_alternative_matches[i] = -1;
3181 /* An empty constraint or empty alternative
3182 allows anything which matched the pattern. */
3183 if (*p == 0 || *p == ',')
3184 win = 1, badop = 0;
3186 /* Scan this alternative's specs for this operand;
3187 set WIN if the operand fits any letter in this alternative.
3188 Otherwise, clear BADOP if this operand could
3189 fit some letter after reloads,
3190 or set WINREG if this operand could fit after reloads
3191 provided the constraint allows some registers. */
3194 switch ((c = *p, len = CONSTRAINT_LEN (c, p)), c)
3196 case '\0':
3197 len = 0;
3198 break;
3199 case ',':
3200 c = '\0';
3201 break;
3203 case '?':
3204 reject += 6;
3205 break;
3207 case '!':
3208 reject = 600;
3209 break;
3211 case '#':
3212 /* Ignore rest of this alternative as far as
3213 reloading is concerned. */
3215 p++;
3216 while (*p && *p != ',');
3217 len = 0;
3218 break;
3220 case '0': case '1': case '2': case '3': case '4':
3221 case '5': case '6': case '7': case '8': case '9':
3222 m = strtoul (p, &end, 10);
3223 p = end;
3224 len = 0;
3226 this_alternative_matches[i] = m;
3227 /* We are supposed to match a previous operand.
3228 If we do, we win if that one did.
3229 If we do not, count both of the operands as losers.
3230 (This is too conservative, since most of the time
3231 only a single reload insn will be needed to make
3232 the two operands win. As a result, this alternative
3233 may be rejected when it is actually desirable.) */
3234 if ((swapped && (m != commutative || i != commutative + 1))
3235 /* If we are matching as if two operands were swapped,
3236 also pretend that operands_match had been computed
3237 with swapped.
3238 But if I is the second of those and C is the first,
3239 don't exchange them, because operands_match is valid
3240 only on one side of its diagonal. */
3241 ? (operands_match
3242 [(m == commutative || m == commutative + 1)
3243 ? 2 * commutative + 1 - m : m]
3244 [(i == commutative || i == commutative + 1)
3245 ? 2 * commutative + 1 - i : i])
3246 : operands_match[m][i])
3248 /* If we are matching a non-offsettable address where an
3249 offsettable address was expected, then we must reject
3250 this combination, because we can't reload it. */
3251 if (this_alternative_offmemok[m]
3252 && MEM_P (recog_data.operand[m])
3253 && this_alternative[m] == NO_REGS
3254 && ! this_alternative_win[m])
3255 bad = 1;
3257 did_match = this_alternative_win[m];
3259 else
3261 /* Operands don't match. */
3262 rtx value;
3263 int loc1, loc2;
3264 /* Retroactively mark the operand we had to match
3265 as a loser, if it wasn't already. */
3266 if (this_alternative_win[m])
3267 losers++;
3268 this_alternative_win[m] = 0;
3269 if (this_alternative[m] == NO_REGS)
3270 bad = 1;
3271 /* But count the pair only once in the total badness of
3272 this alternative, if the pair can be a dummy reload.
3273 The pointers in operand_loc are not swapped; swap
3274 them by hand if necessary. */
3275 if (swapped && i == commutative)
3276 loc1 = commutative + 1;
3277 else if (swapped && i == commutative + 1)
3278 loc1 = commutative;
3279 else
3280 loc1 = i;
3281 if (swapped && m == commutative)
3282 loc2 = commutative + 1;
3283 else if (swapped && m == commutative + 1)
3284 loc2 = commutative;
3285 else
3286 loc2 = m;
3287 value
3288 = find_dummy_reload (recog_data.operand[i],
3289 recog_data.operand[m],
3290 recog_data.operand_loc[loc1],
3291 recog_data.operand_loc[loc2],
3292 operand_mode[i], operand_mode[m],
3293 this_alternative[m], -1,
3294 this_alternative_earlyclobber[m]);
3296 if (value != 0)
3297 losers--;
3299 /* This can be fixed with reloads if the operand
3300 we are supposed to match can be fixed with reloads. */
3301 badop = 0;
3302 this_alternative[i] = this_alternative[m];
3304 /* If we have to reload this operand and some previous
3305 operand also had to match the same thing as this
3306 operand, we don't know how to do that. So reject this
3307 alternative. */
3308 if (! did_match || force_reload)
3309 for (j = 0; j < i; j++)
3310 if (this_alternative_matches[j]
3311 == this_alternative_matches[i])
3313 badop = 1;
3314 break;
3316 break;
3318 case 'p':
3319 /* All necessary reloads for an address_operand
3320 were handled in find_reloads_address. */
3321 this_alternative[i]
3322 = base_reg_class (VOIDmode, ADDR_SPACE_GENERIC,
3323 ADDRESS, SCRATCH);
3324 win = 1;
3325 badop = 0;
3326 break;
3328 case TARGET_MEM_CONSTRAINT:
3329 if (force_reload)
3330 break;
3331 if (MEM_P (operand)
3332 || (REG_P (operand)
3333 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3334 && reg_renumber[REGNO (operand)] < 0))
3335 win = 1;
3336 if (CONST_POOL_OK_P (operand_mode[i], operand))
3337 badop = 0;
3338 constmemok = 1;
3339 break;
3341 case '<':
3342 if (MEM_P (operand)
3343 && ! address_reloaded[i]
3344 && (GET_CODE (XEXP (operand, 0)) == PRE_DEC
3345 || GET_CODE (XEXP (operand, 0)) == POST_DEC))
3346 win = 1;
3347 break;
3349 case '>':
3350 if (MEM_P (operand)
3351 && ! address_reloaded[i]
3352 && (GET_CODE (XEXP (operand, 0)) == PRE_INC
3353 || GET_CODE (XEXP (operand, 0)) == POST_INC))
3354 win = 1;
3355 break;
3357 /* Memory operand whose address is not offsettable. */
3358 case 'V':
3359 if (force_reload)
3360 break;
3361 if (MEM_P (operand)
3362 && ! (ind_levels ? offsettable_memref_p (operand)
3363 : offsettable_nonstrict_memref_p (operand))
3364 /* Certain mem addresses will become offsettable
3365 after they themselves are reloaded. This is important;
3366 we don't want our own handling of unoffsettables
3367 to override the handling of reg_equiv_address. */
3368 && !(REG_P (XEXP (operand, 0))
3369 && (ind_levels == 0
3370 || reg_equiv_address (REGNO (XEXP (operand, 0))) != 0)))
3371 win = 1;
3372 break;
3374 /* Memory operand whose address is offsettable. */
3375 case 'o':
3376 if (force_reload)
3377 break;
3378 if ((MEM_P (operand)
3379 /* If IND_LEVELS, find_reloads_address won't reload a
3380 pseudo that didn't get a hard reg, so we have to
3381 reject that case. */
3382 && ((ind_levels ? offsettable_memref_p (operand)
3383 : offsettable_nonstrict_memref_p (operand))
3384 /* A reloaded address is offsettable because it is now
3385 just a simple register indirect. */
3386 || address_reloaded[i] == 1))
3387 || (REG_P (operand)
3388 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3389 && reg_renumber[REGNO (operand)] < 0
3390 /* If reg_equiv_address is nonzero, we will be
3391 loading it into a register; hence it will be
3392 offsettable, but we cannot say that reg_equiv_mem
3393 is offsettable without checking. */
3394 && ((reg_equiv_mem (REGNO (operand)) != 0
3395 && offsettable_memref_p (reg_equiv_mem (REGNO (operand))))
3396 || (reg_equiv_address (REGNO (operand)) != 0))))
3397 win = 1;
3398 if (CONST_POOL_OK_P (operand_mode[i], operand)
3399 || MEM_P (operand))
3400 badop = 0;
3401 constmemok = 1;
3402 offmemok = 1;
3403 break;
3405 case '&':
3406 /* Output operand that is stored before the need for the
3407 input operands (and their index registers) is over. */
3408 earlyclobber = 1, this_earlyclobber = 1;
3409 break;
3411 case 'X':
3412 force_reload = 0;
3413 win = 1;
3414 break;
3416 case 'g':
3417 if (! force_reload
3418 /* A PLUS is never a valid operand, but reload can make
3419 it from a register when eliminating registers. */
3420 && GET_CODE (operand) != PLUS
3421 /* A SCRATCH is not a valid operand. */
3422 && GET_CODE (operand) != SCRATCH
3423 && (! CONSTANT_P (operand)
3424 || ! flag_pic
3425 || LEGITIMATE_PIC_OPERAND_P (operand))
3426 && (GENERAL_REGS == ALL_REGS
3427 || !REG_P (operand)
3428 || (REGNO (operand) >= FIRST_PSEUDO_REGISTER
3429 && reg_renumber[REGNO (operand)] < 0)))
3430 win = 1;
3431 cl = GENERAL_REGS;
3432 goto reg;
3434 default:
3435 cn = lookup_constraint (p);
3436 switch (get_constraint_type (cn))
3438 case CT_REGISTER:
3439 cl = reg_class_for_constraint (cn);
3440 if (cl != NO_REGS)
3441 goto reg;
3442 break;
3444 case CT_CONST_INT:
3445 if (CONST_INT_P (operand)
3446 && (insn_const_int_ok_for_constraint
3447 (INTVAL (operand), cn)))
3448 win = true;
3449 break;
3451 case CT_MEMORY:
3452 case CT_RELAXED_MEMORY:
3453 if (force_reload)
3454 break;
3455 if (constraint_satisfied_p (operand, cn))
3456 win = 1;
3457 /* If the address was already reloaded,
3458 we win as well. */
3459 else if (MEM_P (operand) && address_reloaded[i] == 1)
3460 win = 1;
3461 /* Likewise if the address will be reloaded because
3462 reg_equiv_address is nonzero. For reg_equiv_mem
3463 we have to check. */
3464 else if (REG_P (operand)
3465 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3466 && reg_renumber[REGNO (operand)] < 0
3467 && ((reg_equiv_mem (REGNO (operand)) != 0
3468 && (constraint_satisfied_p
3469 (reg_equiv_mem (REGNO (operand)),
3470 cn)))
3471 || (reg_equiv_address (REGNO (operand))
3472 != 0)))
3473 win = 1;
3475 /* If we didn't already win, we can reload
3476 constants via force_const_mem, and other
3477 MEMs by reloading the address like for 'o'. */
3478 if (CONST_POOL_OK_P (operand_mode[i], operand)
3479 || MEM_P (operand))
3480 badop = 0;
3481 constmemok = 1;
3482 offmemok = 1;
3483 break;
3485 case CT_SPECIAL_MEMORY:
3486 if (force_reload)
3487 break;
3488 if (constraint_satisfied_p (operand, cn))
3489 win = 1;
3490 /* Likewise if the address will be reloaded because
3491 reg_equiv_address is nonzero. For reg_equiv_mem
3492 we have to check. */
3493 else if (REG_P (operand)
3494 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3495 && reg_renumber[REGNO (operand)] < 0
3496 && reg_equiv_mem (REGNO (operand)) != 0
3497 && (constraint_satisfied_p
3498 (reg_equiv_mem (REGNO (operand)), cn)))
3499 win = 1;
3500 break;
3502 case CT_ADDRESS:
3503 if (constraint_satisfied_p (operand, cn))
3504 win = 1;
3506 /* If we didn't already win, we can reload
3507 the address into a base register. */
3508 this_alternative[i]
3509 = base_reg_class (VOIDmode, ADDR_SPACE_GENERIC,
3510 ADDRESS, SCRATCH);
3511 badop = 0;
3512 break;
3514 case CT_FIXED_FORM:
3515 if (constraint_satisfied_p (operand, cn))
3516 win = 1;
3517 break;
3519 break;
3521 reg:
3522 this_alternative[i]
3523 = reg_class_subunion[this_alternative[i]][cl];
3524 if (GET_MODE (operand) == BLKmode)
3525 break;
3526 winreg = 1;
3527 if (REG_P (operand)
3528 && reg_fits_class_p (operand, this_alternative[i],
3529 offset, GET_MODE (recog_data.operand[i])))
3530 win = 1;
3531 break;
3533 while ((p += len), c);
3535 if (swapped == (commutative >= 0 ? 1 : 0))
3536 constraints[i] = p;
3538 /* If this operand could be handled with a reg,
3539 and some reg is allowed, then this operand can be handled. */
3540 if (winreg && this_alternative[i] != NO_REGS
3541 && (win || !class_only_fixed_regs[this_alternative[i]]))
3542 badop = 0;
3544 /* Record which operands fit this alternative. */
3545 this_alternative_earlyclobber[i] = earlyclobber;
3546 if (win && ! force_reload)
3547 this_alternative_win[i] = 1;
3548 else if (did_match && ! force_reload)
3549 this_alternative_match_win[i] = 1;
3550 else
3552 int const_to_mem = 0;
3554 this_alternative_offmemok[i] = offmemok;
3555 losers++;
3556 if (badop)
3557 bad = 1;
3558 /* Alternative loses if it has no regs for a reg operand. */
3559 if (REG_P (operand)
3560 && this_alternative[i] == NO_REGS
3561 && this_alternative_matches[i] < 0)
3562 bad = 1;
3564 /* If this is a constant that is reloaded into the desired
3565 class by copying it to memory first, count that as another
3566 reload. This is consistent with other code and is
3567 required to avoid choosing another alternative when
3568 the constant is moved into memory by this function on
3569 an early reload pass. Note that the test here is
3570 precisely the same as in the code below that calls
3571 force_const_mem. */
3572 if (CONST_POOL_OK_P (operand_mode[i], operand)
3573 && ((targetm.preferred_reload_class (operand,
3574 this_alternative[i])
3575 == NO_REGS)
3576 || no_input_reloads))
3578 const_to_mem = 1;
3579 if (this_alternative[i] != NO_REGS)
3580 losers++;
3583 /* Alternative loses if it requires a type of reload not
3584 permitted for this insn. We can always reload SCRATCH
3585 and objects with a REG_UNUSED note. */
3586 if (GET_CODE (operand) != SCRATCH
3587 && modified[i] != RELOAD_READ && no_output_reloads
3588 && ! find_reg_note (insn, REG_UNUSED, operand))
3589 bad = 1;
3590 else if (modified[i] != RELOAD_WRITE && no_input_reloads
3591 && ! const_to_mem)
3592 bad = 1;
3594 /* If we can't reload this value at all, reject this
3595 alternative. Note that we could also lose due to
3596 LIMIT_RELOAD_CLASS, but we don't check that
3597 here. */
3599 if (! CONSTANT_P (operand) && this_alternative[i] != NO_REGS)
3601 if (targetm.preferred_reload_class (operand,
3602 this_alternative[i])
3603 == NO_REGS)
3604 reject = 600;
3606 if (operand_type[i] == RELOAD_FOR_OUTPUT
3607 && (targetm.preferred_output_reload_class (operand,
3608 this_alternative[i])
3609 == NO_REGS))
3610 reject = 600;
3613 /* We prefer to reload pseudos over reloading other things,
3614 since such reloads may be able to be eliminated later.
3615 If we are reloading a SCRATCH, we won't be generating any
3616 insns, just using a register, so it is also preferred.
3617 So bump REJECT in other cases. Don't do this in the
3618 case where we are forcing a constant into memory and
3619 it will then win since we don't want to have a different
3620 alternative match then. */
3621 if (! (REG_P (operand)
3622 && REGNO (operand) >= FIRST_PSEUDO_REGISTER)
3623 && GET_CODE (operand) != SCRATCH
3624 && ! (const_to_mem && constmemok))
3625 reject += 2;
3627 /* Input reloads can be inherited more often than output
3628 reloads can be removed, so penalize output reloads. */
3629 if (operand_type[i] != RELOAD_FOR_INPUT
3630 && GET_CODE (operand) != SCRATCH)
3631 reject++;
3634 /* If this operand is a pseudo register that didn't get
3635 a hard reg and this alternative accepts some
3636 register, see if the class that we want is a subset
3637 of the preferred class for this register. If not,
3638 but it intersects that class, we'd like to use the
3639 intersection, but the best we can do is to use the
3640 preferred class, if it is instead a subset of the
3641 class we want in this alternative. If we can't use
3642 it, show that usage of this alternative should be
3643 discouraged; it will be discouraged more still if the
3644 register is `preferred or nothing'. We do this
3645 because it increases the chance of reusing our spill
3646 register in a later insn and avoiding a pair of
3647 memory stores and loads.
3649 Don't bother with this if this alternative will
3650 accept this operand.
3652 Don't do this for a multiword operand, since it is
3653 only a small win and has the risk of requiring more
3654 spill registers, which could cause a large loss.
3656 Don't do this if the preferred class has only one
3657 register because we might otherwise exhaust the
3658 class. */
3660 if (! win && ! did_match
3661 && this_alternative[i] != NO_REGS
3662 && known_le (GET_MODE_SIZE (operand_mode[i]), UNITS_PER_WORD)
3663 && reg_class_size [(int) preferred_class[i]] > 0
3664 && ! small_register_class_p (preferred_class[i]))
3666 if (! reg_class_subset_p (this_alternative[i],
3667 preferred_class[i]))
3669 /* Since we don't have a way of forming a register
3670 class for the intersection, we just do
3671 something special if the preferred class is a
3672 subset of the class we have; that's the most
3673 common case anyway. */
3674 if (reg_class_subset_p (preferred_class[i],
3675 this_alternative[i]))
3676 this_alternative[i] = preferred_class[i];
3677 else
3678 reject += (2 + 2 * pref_or_nothing[i]);
3683 /* Now see if any output operands that are marked "earlyclobber"
3684 in this alternative conflict with any input operands
3685 or any memory addresses. */
3687 for (i = 0; i < noperands; i++)
3688 if (this_alternative_earlyclobber[i]
3689 && (this_alternative_win[i] || this_alternative_match_win[i]))
3691 struct decomposition early_data;
3693 early_data = decompose (recog_data.operand[i]);
3695 gcc_assert (modified[i] != RELOAD_READ);
3697 if (this_alternative[i] == NO_REGS)
3699 this_alternative_earlyclobber[i] = 0;
3700 gcc_assert (this_insn_is_asm);
3701 error_for_asm (this_insn,
3702 "%<&%> constraint used with no register class");
3705 for (j = 0; j < noperands; j++)
3706 /* Is this an input operand or a memory ref? */
3707 if ((MEM_P (recog_data.operand[j])
3708 || modified[j] != RELOAD_WRITE)
3709 && j != i
3710 /* Ignore things like match_operator operands. */
3711 && !recog_data.is_operator[j]
3712 /* Don't count an input operand that is constrained to match
3713 the early clobber operand. */
3714 && ! (this_alternative_matches[j] == i
3715 && rtx_equal_p (recog_data.operand[i],
3716 recog_data.operand[j]))
3717 /* Is it altered by storing the earlyclobber operand? */
3718 && !immune_p (recog_data.operand[j], recog_data.operand[i],
3719 early_data))
3721 /* If the output is in a non-empty few-regs class,
3722 it's costly to reload it, so reload the input instead. */
3723 if (small_register_class_p (this_alternative[i])
3724 && (REG_P (recog_data.operand[j])
3725 || GET_CODE (recog_data.operand[j]) == SUBREG))
3727 losers++;
3728 this_alternative_win[j] = 0;
3729 this_alternative_match_win[j] = 0;
3731 else
3732 break;
3734 /* If an earlyclobber operand conflicts with something,
3735 it must be reloaded, so request this and count the cost. */
3736 if (j != noperands)
3738 losers++;
3739 this_alternative_win[i] = 0;
3740 this_alternative_match_win[j] = 0;
3741 for (j = 0; j < noperands; j++)
3742 if (this_alternative_matches[j] == i
3743 && this_alternative_match_win[j])
3745 this_alternative_win[j] = 0;
3746 this_alternative_match_win[j] = 0;
3747 losers++;
3752 /* If one alternative accepts all the operands, no reload required,
3753 choose that alternative; don't consider the remaining ones. */
3754 if (losers == 0)
3756 /* Unswap these so that they are never swapped at `finish'. */
3757 if (swapped)
3759 recog_data.operand[commutative] = substed_operand[commutative];
3760 recog_data.operand[commutative + 1]
3761 = substed_operand[commutative + 1];
3763 for (i = 0; i < noperands; i++)
3765 goal_alternative_win[i] = this_alternative_win[i];
3766 goal_alternative_match_win[i] = this_alternative_match_win[i];
3767 goal_alternative[i] = this_alternative[i];
3768 goal_alternative_offmemok[i] = this_alternative_offmemok[i];
3769 goal_alternative_matches[i] = this_alternative_matches[i];
3770 goal_alternative_earlyclobber[i]
3771 = this_alternative_earlyclobber[i];
3773 goal_alternative_number = this_alternative_number;
3774 goal_alternative_swapped = swapped;
3775 goal_earlyclobber = this_earlyclobber;
3776 goto finish;
3779 /* REJECT, set by the ! and ? constraint characters and when a register
3780 would be reloaded into a non-preferred class, discourages the use of
3781 this alternative for a reload goal. REJECT is incremented by six
3782 for each ? and two for each non-preferred class. */
3783 losers = losers * 6 + reject;
3785 /* If this alternative can be made to work by reloading,
3786 and it needs less reloading than the others checked so far,
3787 record it as the chosen goal for reloading. */
3788 if (! bad)
3790 if (best > losers)
3792 for (i = 0; i < noperands; i++)
3794 goal_alternative[i] = this_alternative[i];
3795 goal_alternative_win[i] = this_alternative_win[i];
3796 goal_alternative_match_win[i]
3797 = this_alternative_match_win[i];
3798 goal_alternative_offmemok[i]
3799 = this_alternative_offmemok[i];
3800 goal_alternative_matches[i] = this_alternative_matches[i];
3801 goal_alternative_earlyclobber[i]
3802 = this_alternative_earlyclobber[i];
3804 goal_alternative_swapped = swapped;
3805 best = losers;
3806 goal_alternative_number = this_alternative_number;
3807 goal_earlyclobber = this_earlyclobber;
3811 if (swapped)
3813 /* If the commutative operands have been swapped, swap
3814 them back in order to check the next alternative. */
3815 recog_data.operand[commutative] = substed_operand[commutative];
3816 recog_data.operand[commutative + 1] = substed_operand[commutative + 1];
3817 /* Unswap the duplicates too. */
3818 for (i = 0; i < recog_data.n_dups; i++)
3819 if (recog_data.dup_num[i] == commutative
3820 || recog_data.dup_num[i] == commutative + 1)
3821 *recog_data.dup_loc[i]
3822 = recog_data.operand[(int) recog_data.dup_num[i]];
3824 /* Unswap the operand related information as well. */
3825 std::swap (preferred_class[commutative],
3826 preferred_class[commutative + 1]);
3827 std::swap (pref_or_nothing[commutative],
3828 pref_or_nothing[commutative + 1]);
3829 std::swap (address_reloaded[commutative],
3830 address_reloaded[commutative + 1]);
3835 /* The operands don't meet the constraints.
3836 goal_alternative describes the alternative
3837 that we could reach by reloading the fewest operands.
3838 Reload so as to fit it. */
3840 if (best == MAX_RECOG_OPERANDS * 2 + 600)
3842 /* No alternative works with reloads?? */
3843 if (insn_code_number >= 0)
3844 fatal_insn ("unable to generate reloads for:", insn);
3845 error_for_asm (insn, "inconsistent operand constraints in an %<asm%>");
3846 /* Avoid further trouble with this insn. */
3847 PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
3848 n_reloads = 0;
3849 return 0;
3852 /* Jump to `finish' from above if all operands are valid already.
3853 In that case, goal_alternative_win is all 1. */
3854 finish:
3856 /* Right now, for any pair of operands I and J that are required to match,
3857 with I < J,
3858 goal_alternative_matches[J] is I.
3859 Set up goal_alternative_matched as the inverse function:
3860 goal_alternative_matched[I] = J. */
3862 for (i = 0; i < noperands; i++)
3863 goal_alternative_matched[i] = -1;
3865 for (i = 0; i < noperands; i++)
3866 if (! goal_alternative_win[i]
3867 && goal_alternative_matches[i] >= 0)
3868 goal_alternative_matched[goal_alternative_matches[i]] = i;
3870 for (i = 0; i < noperands; i++)
3871 goal_alternative_win[i] |= goal_alternative_match_win[i];
3873 /* If the best alternative is with operands 1 and 2 swapped,
3874 consider them swapped before reporting the reloads. Update the
3875 operand numbers of any reloads already pushed. */
3877 if (goal_alternative_swapped)
3879 std::swap (substed_operand[commutative],
3880 substed_operand[commutative + 1]);
3881 std::swap (recog_data.operand[commutative],
3882 recog_data.operand[commutative + 1]);
3883 std::swap (*recog_data.operand_loc[commutative],
3884 *recog_data.operand_loc[commutative + 1]);
3886 for (i = 0; i < recog_data.n_dups; i++)
3887 if (recog_data.dup_num[i] == commutative
3888 || recog_data.dup_num[i] == commutative + 1)
3889 *recog_data.dup_loc[i]
3890 = recog_data.operand[(int) recog_data.dup_num[i]];
3892 for (i = 0; i < n_reloads; i++)
3894 if (rld[i].opnum == commutative)
3895 rld[i].opnum = commutative + 1;
3896 else if (rld[i].opnum == commutative + 1)
3897 rld[i].opnum = commutative;
3901 for (i = 0; i < noperands; i++)
3903 operand_reloadnum[i] = -1;
3905 /* If this is an earlyclobber operand, we need to widen the scope.
3906 The reload must remain valid from the start of the insn being
3907 reloaded until after the operand is stored into its destination.
3908 We approximate this with RELOAD_OTHER even though we know that we
3909 do not conflict with RELOAD_FOR_INPUT_ADDRESS reloads.
3911 One special case that is worth checking is when we have an
3912 output that is earlyclobber but isn't used past the insn (typically
3913 a SCRATCH). In this case, we only need have the reload live
3914 through the insn itself, but not for any of our input or output
3915 reloads.
3916 But we must not accidentally narrow the scope of an existing
3917 RELOAD_OTHER reload - leave these alone.
3919 In any case, anything needed to address this operand can remain
3920 however they were previously categorized. */
3922 if (goal_alternative_earlyclobber[i] && operand_type[i] != RELOAD_OTHER)
3923 operand_type[i]
3924 = (find_reg_note (insn, REG_UNUSED, recog_data.operand[i])
3925 ? RELOAD_FOR_INSN : RELOAD_OTHER);
3928 /* Any constants that aren't allowed and can't be reloaded
3929 into registers are here changed into memory references. */
3930 for (i = 0; i < noperands; i++)
3931 if (! goal_alternative_win[i])
3933 rtx op = recog_data.operand[i];
3934 rtx subreg = NULL_RTX;
3935 rtx plus = NULL_RTX;
3936 machine_mode mode = operand_mode[i];
3938 /* Reloads of SUBREGs of CONSTANT RTXs are handled later in
3939 push_reload so we have to let them pass here. */
3940 if (GET_CODE (op) == SUBREG)
3942 subreg = op;
3943 op = SUBREG_REG (op);
3944 mode = GET_MODE (op);
3947 if (GET_CODE (op) == PLUS)
3949 plus = op;
3950 op = XEXP (op, 1);
3953 if (CONST_POOL_OK_P (mode, op)
3954 && ((targetm.preferred_reload_class (op, goal_alternative[i])
3955 == NO_REGS)
3956 || no_input_reloads))
3958 int this_address_reloaded;
3959 rtx tem = force_const_mem (mode, op);
3961 /* If we stripped a SUBREG or a PLUS above add it back. */
3962 if (plus != NULL_RTX)
3963 tem = gen_rtx_PLUS (mode, XEXP (plus, 0), tem);
3965 if (subreg != NULL_RTX)
3966 tem = gen_rtx_SUBREG (operand_mode[i], tem, SUBREG_BYTE (subreg));
3968 this_address_reloaded = 0;
3969 substed_operand[i] = recog_data.operand[i]
3970 = find_reloads_toplev (tem, i, address_type[i], ind_levels,
3971 0, insn, &this_address_reloaded);
3973 /* If the alternative accepts constant pool refs directly
3974 there will be no reload needed at all. */
3975 if (plus == NULL_RTX
3976 && subreg == NULL_RTX
3977 && alternative_allows_const_pool_ref (this_address_reloaded != 1
3978 ? substed_operand[i]
3979 : NULL,
3980 recog_data.constraints[i],
3981 goal_alternative_number))
3982 goal_alternative_win[i] = 1;
3986 /* Record the values of the earlyclobber operands for the caller. */
3987 if (goal_earlyclobber)
3988 for (i = 0; i < noperands; i++)
3989 if (goal_alternative_earlyclobber[i])
3990 reload_earlyclobbers[n_earlyclobbers++] = recog_data.operand[i];
3992 /* Now record reloads for all the operands that need them. */
3993 for (i = 0; i < noperands; i++)
3994 if (! goal_alternative_win[i])
3996 /* Operands that match previous ones have already been handled. */
3997 if (goal_alternative_matches[i] >= 0)
3999 /* Handle an operand with a nonoffsettable address
4000 appearing where an offsettable address will do
4001 by reloading the address into a base register.
4003 ??? We can also do this when the operand is a register and
4004 reg_equiv_mem is not offsettable, but this is a bit tricky,
4005 so we don't bother with it. It may not be worth doing. */
4006 else if (goal_alternative_matched[i] == -1
4007 && goal_alternative_offmemok[i]
4008 && MEM_P (recog_data.operand[i]))
4010 /* If the address to be reloaded is a VOIDmode constant,
4011 use the default address mode as mode of the reload register,
4012 as would have been done by find_reloads_address. */
4013 addr_space_t as = MEM_ADDR_SPACE (recog_data.operand[i]);
4014 machine_mode address_mode;
4016 address_mode = get_address_mode (recog_data.operand[i]);
4017 operand_reloadnum[i]
4018 = push_reload (XEXP (recog_data.operand[i], 0), NULL_RTX,
4019 &XEXP (recog_data.operand[i], 0), (rtx*) 0,
4020 base_reg_class (VOIDmode, as, MEM, SCRATCH),
4021 address_mode,
4022 VOIDmode, 0, 0, i, RELOAD_OTHER);
4023 rld[operand_reloadnum[i]].inc
4024 = GET_MODE_SIZE (GET_MODE (recog_data.operand[i]));
4026 /* If this operand is an output, we will have made any
4027 reloads for its address as RELOAD_FOR_OUTPUT_ADDRESS, but
4028 now we are treating part of the operand as an input, so
4029 we must change these to RELOAD_FOR_OTHER_ADDRESS. */
4031 if (modified[i] == RELOAD_WRITE)
4033 for (j = 0; j < n_reloads; j++)
4035 if (rld[j].opnum == i)
4037 if (rld[j].when_needed == RELOAD_FOR_OUTPUT_ADDRESS)
4038 rld[j].when_needed = RELOAD_FOR_OTHER_ADDRESS;
4039 else if (rld[j].when_needed
4040 == RELOAD_FOR_OUTADDR_ADDRESS)
4041 rld[j].when_needed = RELOAD_FOR_OTHER_ADDRESS;
4046 else if (goal_alternative_matched[i] == -1)
4048 operand_reloadnum[i]
4049 = push_reload ((modified[i] != RELOAD_WRITE
4050 ? recog_data.operand[i] : 0),
4051 (modified[i] != RELOAD_READ
4052 ? recog_data.operand[i] : 0),
4053 (modified[i] != RELOAD_WRITE
4054 ? recog_data.operand_loc[i] : 0),
4055 (modified[i] != RELOAD_READ
4056 ? recog_data.operand_loc[i] : 0),
4057 (enum reg_class) goal_alternative[i],
4058 (modified[i] == RELOAD_WRITE
4059 ? VOIDmode : operand_mode[i]),
4060 (modified[i] == RELOAD_READ
4061 ? VOIDmode : operand_mode[i]),
4062 (insn_code_number < 0 ? 0
4063 : insn_data[insn_code_number].operand[i].strict_low),
4064 0, i, operand_type[i]);
4066 /* In a matching pair of operands, one must be input only
4067 and the other must be output only.
4068 Pass the input operand as IN and the other as OUT. */
4069 else if (modified[i] == RELOAD_READ
4070 && modified[goal_alternative_matched[i]] == RELOAD_WRITE)
4072 operand_reloadnum[i]
4073 = push_reload (recog_data.operand[i],
4074 recog_data.operand[goal_alternative_matched[i]],
4075 recog_data.operand_loc[i],
4076 recog_data.operand_loc[goal_alternative_matched[i]],
4077 (enum reg_class) goal_alternative[i],
4078 operand_mode[i],
4079 operand_mode[goal_alternative_matched[i]],
4080 0, 0, i, RELOAD_OTHER);
4081 operand_reloadnum[goal_alternative_matched[i]] = output_reloadnum;
4083 else if (modified[i] == RELOAD_WRITE
4084 && modified[goal_alternative_matched[i]] == RELOAD_READ)
4086 operand_reloadnum[goal_alternative_matched[i]]
4087 = push_reload (recog_data.operand[goal_alternative_matched[i]],
4088 recog_data.operand[i],
4089 recog_data.operand_loc[goal_alternative_matched[i]],
4090 recog_data.operand_loc[i],
4091 (enum reg_class) goal_alternative[i],
4092 operand_mode[goal_alternative_matched[i]],
4093 operand_mode[i],
4094 0, 0, i, RELOAD_OTHER);
4095 operand_reloadnum[i] = output_reloadnum;
4097 else
4099 gcc_assert (insn_code_number < 0);
4100 error_for_asm (insn, "inconsistent operand constraints "
4101 "in an %<asm%>");
4102 /* Avoid further trouble with this insn. */
4103 PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
4104 n_reloads = 0;
4105 return 0;
4108 else if (goal_alternative_matched[i] < 0
4109 && goal_alternative_matches[i] < 0
4110 && address_operand_reloaded[i] != 1
4111 && optimize)
4113 /* For each non-matching operand that's a MEM or a pseudo-register
4114 that didn't get a hard register, make an optional reload.
4115 This may get done even if the insn needs no reloads otherwise. */
4117 rtx operand = recog_data.operand[i];
4119 while (GET_CODE (operand) == SUBREG)
4120 operand = SUBREG_REG (operand);
4121 if ((MEM_P (operand)
4122 || (REG_P (operand)
4123 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
4124 /* If this is only for an output, the optional reload would not
4125 actually cause us to use a register now, just note that
4126 something is stored here. */
4127 && (goal_alternative[i] != NO_REGS
4128 || modified[i] == RELOAD_WRITE)
4129 && ! no_input_reloads
4130 /* An optional output reload might allow to delete INSN later.
4131 We mustn't make in-out reloads on insns that are not permitted
4132 output reloads.
4133 If this is an asm, we can't delete it; we must not even call
4134 push_reload for an optional output reload in this case,
4135 because we can't be sure that the constraint allows a register,
4136 and push_reload verifies the constraints for asms. */
4137 && (modified[i] == RELOAD_READ
4138 || (! no_output_reloads && ! this_insn_is_asm)))
4139 operand_reloadnum[i]
4140 = push_reload ((modified[i] != RELOAD_WRITE
4141 ? recog_data.operand[i] : 0),
4142 (modified[i] != RELOAD_READ
4143 ? recog_data.operand[i] : 0),
4144 (modified[i] != RELOAD_WRITE
4145 ? recog_data.operand_loc[i] : 0),
4146 (modified[i] != RELOAD_READ
4147 ? recog_data.operand_loc[i] : 0),
4148 (enum reg_class) goal_alternative[i],
4149 (modified[i] == RELOAD_WRITE
4150 ? VOIDmode : operand_mode[i]),
4151 (modified[i] == RELOAD_READ
4152 ? VOIDmode : operand_mode[i]),
4153 (insn_code_number < 0 ? 0
4154 : insn_data[insn_code_number].operand[i].strict_low),
4155 1, i, operand_type[i]);
4156 /* If a memory reference remains (either as a MEM or a pseudo that
4157 did not get a hard register), yet we can't make an optional
4158 reload, check if this is actually a pseudo register reference;
4159 we then need to emit a USE and/or a CLOBBER so that reload
4160 inheritance will do the right thing. */
4161 else if (replace
4162 && (MEM_P (operand)
4163 || (REG_P (operand)
4164 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
4165 && reg_renumber [REGNO (operand)] < 0)))
4167 operand = *recog_data.operand_loc[i];
4169 while (GET_CODE (operand) == SUBREG)
4170 operand = SUBREG_REG (operand);
4171 if (REG_P (operand))
4173 if (modified[i] != RELOAD_WRITE)
4174 /* We mark the USE with QImode so that we recognize
4175 it as one that can be safely deleted at the end
4176 of reload. */
4177 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, operand),
4178 insn), QImode);
4179 if (modified[i] != RELOAD_READ)
4180 emit_insn_after (gen_clobber (operand), insn);
4184 else if (goal_alternative_matches[i] >= 0
4185 && goal_alternative_win[goal_alternative_matches[i]]
4186 && modified[i] == RELOAD_READ
4187 && modified[goal_alternative_matches[i]] == RELOAD_WRITE
4188 && ! no_input_reloads && ! no_output_reloads
4189 && optimize)
4191 /* Similarly, make an optional reload for a pair of matching
4192 objects that are in MEM or a pseudo that didn't get a hard reg. */
4194 rtx operand = recog_data.operand[i];
4196 while (GET_CODE (operand) == SUBREG)
4197 operand = SUBREG_REG (operand);
4198 if ((MEM_P (operand)
4199 || (REG_P (operand)
4200 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
4201 && (goal_alternative[goal_alternative_matches[i]] != NO_REGS))
4202 operand_reloadnum[i] = operand_reloadnum[goal_alternative_matches[i]]
4203 = push_reload (recog_data.operand[goal_alternative_matches[i]],
4204 recog_data.operand[i],
4205 recog_data.operand_loc[goal_alternative_matches[i]],
4206 recog_data.operand_loc[i],
4207 (enum reg_class) goal_alternative[goal_alternative_matches[i]],
4208 operand_mode[goal_alternative_matches[i]],
4209 operand_mode[i],
4210 0, 1, goal_alternative_matches[i], RELOAD_OTHER);
4213 /* Perform whatever substitutions on the operands we are supposed
4214 to make due to commutativity or replacement of registers
4215 with equivalent constants or memory slots. */
4217 for (i = 0; i < noperands; i++)
4219 /* We only do this on the last pass through reload, because it is
4220 possible for some data (like reg_equiv_address) to be changed during
4221 later passes. Moreover, we lose the opportunity to get a useful
4222 reload_{in,out}_reg when we do these replacements. */
4224 if (replace)
4226 rtx substitution = substed_operand[i];
4228 *recog_data.operand_loc[i] = substitution;
4230 /* If we're replacing an operand with a LABEL_REF, we need to
4231 make sure that there's a REG_LABEL_OPERAND note attached to
4232 this instruction. */
4233 if (GET_CODE (substitution) == LABEL_REF
4234 && !find_reg_note (insn, REG_LABEL_OPERAND,
4235 label_ref_label (substitution))
4236 /* For a JUMP_P, if it was a branch target it must have
4237 already been recorded as such. */
4238 && (!JUMP_P (insn)
4239 || !label_is_jump_target_p (label_ref_label (substitution),
4240 insn)))
4242 add_reg_note (insn, REG_LABEL_OPERAND,
4243 label_ref_label (substitution));
4244 if (LABEL_P (label_ref_label (substitution)))
4245 ++LABEL_NUSES (label_ref_label (substitution));
4249 else
4250 retval |= (substed_operand[i] != *recog_data.operand_loc[i]);
4253 /* If this insn pattern contains any MATCH_DUP's, make sure that
4254 they will be substituted if the operands they match are substituted.
4255 Also do now any substitutions we already did on the operands.
4257 Don't do this if we aren't making replacements because we might be
4258 propagating things allocated by frame pointer elimination into places
4259 it doesn't expect. */
4261 if (insn_code_number >= 0 && replace)
4262 for (i = insn_data[insn_code_number].n_dups - 1; i >= 0; i--)
4264 int opno = recog_data.dup_num[i];
4265 *recog_data.dup_loc[i] = *recog_data.operand_loc[opno];
4266 dup_replacements (recog_data.dup_loc[i], recog_data.operand_loc[opno]);
4269 #if 0
4270 /* This loses because reloading of prior insns can invalidate the equivalence
4271 (or at least find_equiv_reg isn't smart enough to find it any more),
4272 causing this insn to need more reload regs than it needed before.
4273 It may be too late to make the reload regs available.
4274 Now this optimization is done safely in choose_reload_regs. */
4276 /* For each reload of a reg into some other class of reg,
4277 search for an existing equivalent reg (same value now) in the right class.
4278 We can use it as long as we don't need to change its contents. */
4279 for (i = 0; i < n_reloads; i++)
4280 if (rld[i].reg_rtx == 0
4281 && rld[i].in != 0
4282 && REG_P (rld[i].in)
4283 && rld[i].out == 0)
4285 rld[i].reg_rtx
4286 = find_equiv_reg (rld[i].in, insn, rld[i].rclass, -1,
4287 static_reload_reg_p, 0, rld[i].inmode);
4288 /* Prevent generation of insn to load the value
4289 because the one we found already has the value. */
4290 if (rld[i].reg_rtx)
4291 rld[i].in = rld[i].reg_rtx;
4293 #endif
4295 /* If we detected error and replaced asm instruction by USE, forget about the
4296 reloads. */
4297 if (GET_CODE (PATTERN (insn)) == USE
4298 && CONST_INT_P (XEXP (PATTERN (insn), 0)))
4299 n_reloads = 0;
4301 /* Perhaps an output reload can be combined with another
4302 to reduce needs by one. */
4303 if (!goal_earlyclobber)
4304 combine_reloads ();
4306 /* If we have a pair of reloads for parts of an address, they are reloading
4307 the same object, the operands themselves were not reloaded, and they
4308 are for two operands that are supposed to match, merge the reloads and
4309 change the type of the surviving reload to RELOAD_FOR_OPERAND_ADDRESS. */
4311 for (i = 0; i < n_reloads; i++)
4313 int k;
4315 for (j = i + 1; j < n_reloads; j++)
4316 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4317 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4318 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4319 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4320 && (rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
4321 || rld[j].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4322 || rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4323 || rld[j].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4324 && rtx_equal_p (rld[i].in, rld[j].in)
4325 && (operand_reloadnum[rld[i].opnum] < 0
4326 || rld[operand_reloadnum[rld[i].opnum]].optional)
4327 && (operand_reloadnum[rld[j].opnum] < 0
4328 || rld[operand_reloadnum[rld[j].opnum]].optional)
4329 && (goal_alternative_matches[rld[i].opnum] == rld[j].opnum
4330 || (goal_alternative_matches[rld[j].opnum]
4331 == rld[i].opnum)))
4333 for (k = 0; k < n_replacements; k++)
4334 if (replacements[k].what == j)
4335 replacements[k].what = i;
4337 if (rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4338 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4339 rld[i].when_needed = RELOAD_FOR_OPADDR_ADDR;
4340 else
4341 rld[i].when_needed = RELOAD_FOR_OPERAND_ADDRESS;
4342 rld[j].in = 0;
4346 /* Scan all the reloads and update their type.
4347 If a reload is for the address of an operand and we didn't reload
4348 that operand, change the type. Similarly, change the operand number
4349 of a reload when two operands match. If a reload is optional, treat it
4350 as though the operand isn't reloaded.
4352 ??? This latter case is somewhat odd because if we do the optional
4353 reload, it means the object is hanging around. Thus we need only
4354 do the address reload if the optional reload was NOT done.
4356 Change secondary reloads to be the address type of their operand, not
4357 the normal type.
4359 If an operand's reload is now RELOAD_OTHER, change any
4360 RELOAD_FOR_INPUT_ADDRESS reloads of that operand to
4361 RELOAD_FOR_OTHER_ADDRESS. */
4363 for (i = 0; i < n_reloads; i++)
4365 if (rld[i].secondary_p
4366 && rld[i].when_needed == operand_type[rld[i].opnum])
4367 rld[i].when_needed = address_type[rld[i].opnum];
4369 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4370 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4371 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4372 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4373 && (operand_reloadnum[rld[i].opnum] < 0
4374 || rld[operand_reloadnum[rld[i].opnum]].optional))
4376 /* If we have a secondary reload to go along with this reload,
4377 change its type to RELOAD_FOR_OPADDR_ADDR. */
4379 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4380 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
4381 && rld[i].secondary_in_reload != -1)
4383 int secondary_in_reload = rld[i].secondary_in_reload;
4385 rld[secondary_in_reload].when_needed = RELOAD_FOR_OPADDR_ADDR;
4387 /* If there's a tertiary reload we have to change it also. */
4388 if (secondary_in_reload > 0
4389 && rld[secondary_in_reload].secondary_in_reload != -1)
4390 rld[rld[secondary_in_reload].secondary_in_reload].when_needed
4391 = RELOAD_FOR_OPADDR_ADDR;
4394 if ((rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4395 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4396 && rld[i].secondary_out_reload != -1)
4398 int secondary_out_reload = rld[i].secondary_out_reload;
4400 rld[secondary_out_reload].when_needed = RELOAD_FOR_OPADDR_ADDR;
4402 /* If there's a tertiary reload we have to change it also. */
4403 if (secondary_out_reload
4404 && rld[secondary_out_reload].secondary_out_reload != -1)
4405 rld[rld[secondary_out_reload].secondary_out_reload].when_needed
4406 = RELOAD_FOR_OPADDR_ADDR;
4409 if (rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4410 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4411 rld[i].when_needed = RELOAD_FOR_OPADDR_ADDR;
4412 else
4413 rld[i].when_needed = RELOAD_FOR_OPERAND_ADDRESS;
4416 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4417 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
4418 && operand_reloadnum[rld[i].opnum] >= 0
4419 && (rld[operand_reloadnum[rld[i].opnum]].when_needed
4420 == RELOAD_OTHER))
4421 rld[i].when_needed = RELOAD_FOR_OTHER_ADDRESS;
4423 if (goal_alternative_matches[rld[i].opnum] >= 0)
4424 rld[i].opnum = goal_alternative_matches[rld[i].opnum];
4427 /* Scan all the reloads, and check for RELOAD_FOR_OPERAND_ADDRESS reloads.
4428 If we have more than one, then convert all RELOAD_FOR_OPADDR_ADDR
4429 reloads to RELOAD_FOR_OPERAND_ADDRESS reloads.
4431 choose_reload_regs assumes that RELOAD_FOR_OPADDR_ADDR reloads never
4432 conflict with RELOAD_FOR_OPERAND_ADDRESS reloads. This is true for a
4433 single pair of RELOAD_FOR_OPADDR_ADDR/RELOAD_FOR_OPERAND_ADDRESS reloads.
4434 However, if there is more than one RELOAD_FOR_OPERAND_ADDRESS reload,
4435 then a RELOAD_FOR_OPADDR_ADDR reload conflicts with all
4436 RELOAD_FOR_OPERAND_ADDRESS reloads other than the one that uses it.
4437 This is complicated by the fact that a single operand can have more
4438 than one RELOAD_FOR_OPERAND_ADDRESS reload. It is very difficult to fix
4439 choose_reload_regs without affecting code quality, and cases that
4440 actually fail are extremely rare, so it turns out to be better to fix
4441 the problem here by not generating cases that choose_reload_regs will
4442 fail for. */
4443 /* There is a similar problem with RELOAD_FOR_INPUT_ADDRESS /
4444 RELOAD_FOR_OUTPUT_ADDRESS when there is more than one of a kind for
4445 a single operand.
4446 We can reduce the register pressure by exploiting that a
4447 RELOAD_FOR_X_ADDR_ADDR that precedes all RELOAD_FOR_X_ADDRESS reloads
4448 does not conflict with any of them, if it is only used for the first of
4449 the RELOAD_FOR_X_ADDRESS reloads. */
4451 int first_op_addr_num = -2;
4452 int first_inpaddr_num[MAX_RECOG_OPERANDS];
4453 int first_outpaddr_num[MAX_RECOG_OPERANDS];
4454 int need_change = 0;
4455 /* We use last_op_addr_reload and the contents of the above arrays
4456 first as flags - -2 means no instance encountered, -1 means exactly
4457 one instance encountered.
4458 If more than one instance has been encountered, we store the reload
4459 number of the first reload of the kind in question; reload numbers
4460 are known to be non-negative. */
4461 for (i = 0; i < noperands; i++)
4462 first_inpaddr_num[i] = first_outpaddr_num[i] = -2;
4463 for (i = n_reloads - 1; i >= 0; i--)
4465 switch (rld[i].when_needed)
4467 case RELOAD_FOR_OPERAND_ADDRESS:
4468 if (++first_op_addr_num >= 0)
4470 first_op_addr_num = i;
4471 need_change = 1;
4473 break;
4474 case RELOAD_FOR_INPUT_ADDRESS:
4475 if (++first_inpaddr_num[rld[i].opnum] >= 0)
4477 first_inpaddr_num[rld[i].opnum] = i;
4478 need_change = 1;
4480 break;
4481 case RELOAD_FOR_OUTPUT_ADDRESS:
4482 if (++first_outpaddr_num[rld[i].opnum] >= 0)
4484 first_outpaddr_num[rld[i].opnum] = i;
4485 need_change = 1;
4487 break;
4488 default:
4489 break;
4493 if (need_change)
4495 for (i = 0; i < n_reloads; i++)
4497 int first_num;
4498 enum reload_type type;
4500 switch (rld[i].when_needed)
4502 case RELOAD_FOR_OPADDR_ADDR:
4503 first_num = first_op_addr_num;
4504 type = RELOAD_FOR_OPERAND_ADDRESS;
4505 break;
4506 case RELOAD_FOR_INPADDR_ADDRESS:
4507 first_num = first_inpaddr_num[rld[i].opnum];
4508 type = RELOAD_FOR_INPUT_ADDRESS;
4509 break;
4510 case RELOAD_FOR_OUTADDR_ADDRESS:
4511 first_num = first_outpaddr_num[rld[i].opnum];
4512 type = RELOAD_FOR_OUTPUT_ADDRESS;
4513 break;
4514 default:
4515 continue;
4517 if (first_num < 0)
4518 continue;
4519 else if (i > first_num)
4520 rld[i].when_needed = type;
4521 else
4523 /* Check if the only TYPE reload that uses reload I is
4524 reload FIRST_NUM. */
4525 for (j = n_reloads - 1; j > first_num; j--)
4527 if (rld[j].when_needed == type
4528 && (rld[i].secondary_p
4529 ? rld[j].secondary_in_reload == i
4530 : reg_mentioned_p (rld[i].in, rld[j].in)))
4532 rld[i].when_needed = type;
4533 break;
4541 /* See if we have any reloads that are now allowed to be merged
4542 because we've changed when the reload is needed to
4543 RELOAD_FOR_OPERAND_ADDRESS or RELOAD_FOR_OTHER_ADDRESS. Only
4544 check for the most common cases. */
4546 for (i = 0; i < n_reloads; i++)
4547 if (rld[i].in != 0 && rld[i].out == 0
4548 && (rld[i].when_needed == RELOAD_FOR_OPERAND_ADDRESS
4549 || rld[i].when_needed == RELOAD_FOR_OPADDR_ADDR
4550 || rld[i].when_needed == RELOAD_FOR_OTHER_ADDRESS))
4551 for (j = 0; j < n_reloads; j++)
4552 if (i != j && rld[j].in != 0 && rld[j].out == 0
4553 && rld[j].when_needed == rld[i].when_needed
4554 && MATCHES (rld[i].in, rld[j].in)
4555 && rld[i].rclass == rld[j].rclass
4556 && !rld[i].nocombine && !rld[j].nocombine
4557 && rld[i].reg_rtx == rld[j].reg_rtx)
4559 rld[i].opnum = MIN (rld[i].opnum, rld[j].opnum);
4560 transfer_replacements (i, j);
4561 rld[j].in = 0;
4564 /* Compute reload_mode and reload_nregs. */
4565 for (i = 0; i < n_reloads; i++)
4567 rld[i].mode = rld[i].inmode;
4568 if (rld[i].mode == VOIDmode
4569 || partial_subreg_p (rld[i].mode, rld[i].outmode))
4570 rld[i].mode = rld[i].outmode;
4572 rld[i].nregs = ira_reg_class_max_nregs [rld[i].rclass][rld[i].mode];
4575 /* Special case a simple move with an input reload and a
4576 destination of a hard reg, if the hard reg is ok, use it. */
4577 for (i = 0; i < n_reloads; i++)
4578 if (rld[i].when_needed == RELOAD_FOR_INPUT
4579 && GET_CODE (PATTERN (insn)) == SET
4580 && REG_P (SET_DEST (PATTERN (insn)))
4581 && (SET_SRC (PATTERN (insn)) == rld[i].in
4582 || SET_SRC (PATTERN (insn)) == rld[i].in_reg)
4583 && !elimination_target_reg_p (SET_DEST (PATTERN (insn))))
4585 rtx dest = SET_DEST (PATTERN (insn));
4586 unsigned int regno = REGNO (dest);
4588 if (regno < FIRST_PSEUDO_REGISTER
4589 && TEST_HARD_REG_BIT (reg_class_contents[rld[i].rclass], regno)
4590 && targetm.hard_regno_mode_ok (regno, rld[i].mode))
4592 int nr = hard_regno_nregs (regno, rld[i].mode);
4593 int ok = 1, nri;
4595 for (nri = 1; nri < nr; nri ++)
4596 if (! TEST_HARD_REG_BIT (reg_class_contents[rld[i].rclass], regno + nri))
4598 ok = 0;
4599 break;
4602 if (ok)
4603 rld[i].reg_rtx = dest;
4607 return retval;
4610 /* Return true if alternative number ALTNUM in constraint-string
4611 CONSTRAINT is guaranteed to accept a reloaded constant-pool reference.
4612 MEM gives the reference if its address hasn't been fully reloaded,
4613 otherwise it is NULL. */
4615 static bool
4616 alternative_allows_const_pool_ref (rtx mem ATTRIBUTE_UNUSED,
4617 const char *constraint, int altnum)
4619 int c;
4621 /* Skip alternatives before the one requested. */
4622 while (altnum > 0)
4624 while (*constraint++ != ',')
4626 altnum--;
4628 /* Scan the requested alternative for TARGET_MEM_CONSTRAINT or 'o'.
4629 If one of them is present, this alternative accepts the result of
4630 passing a constant-pool reference through find_reloads_toplev.
4632 The same is true of extra memory constraints if the address
4633 was reloaded into a register. However, the target may elect
4634 to disallow the original constant address, forcing it to be
4635 reloaded into a register instead. */
4636 for (; (c = *constraint) && c != ',' && c != '#';
4637 constraint += CONSTRAINT_LEN (c, constraint))
4639 enum constraint_num cn = lookup_constraint (constraint);
4640 if (insn_extra_memory_constraint (cn)
4641 && (mem == NULL || constraint_satisfied_p (mem, cn)))
4642 return true;
4644 return false;
4647 /* Scan X for memory references and scan the addresses for reloading.
4648 Also checks for references to "constant" regs that we want to eliminate
4649 and replaces them with the values they stand for.
4650 We may alter X destructively if it contains a reference to such.
4651 If X is just a constant reg, we return the equivalent value
4652 instead of X.
4654 IND_LEVELS says how many levels of indirect addressing this machine
4655 supports.
4657 OPNUM and TYPE identify the purpose of the reload.
4659 IS_SET_DEST is true if X is the destination of a SET, which is not
4660 appropriate to be replaced by a constant.
4662 INSN, if nonzero, is the insn in which we do the reload. It is used
4663 to determine if we may generate output reloads, and where to put USEs
4664 for pseudos that we have to replace with stack slots.
4666 ADDRESS_RELOADED. If nonzero, is a pointer to where we put the
4667 result of find_reloads_address. */
4669 static rtx
4670 find_reloads_toplev (rtx x, int opnum, enum reload_type type,
4671 int ind_levels, int is_set_dest, rtx_insn *insn,
4672 int *address_reloaded)
4674 RTX_CODE code = GET_CODE (x);
4676 const char *fmt = GET_RTX_FORMAT (code);
4677 int i;
4678 int copied;
4680 if (code == REG)
4682 /* This code is duplicated for speed in find_reloads. */
4683 int regno = REGNO (x);
4684 if (reg_equiv_constant (regno) != 0 && !is_set_dest)
4685 x = reg_equiv_constant (regno);
4686 #if 0
4687 /* This creates (subreg (mem...)) which would cause an unnecessary
4688 reload of the mem. */
4689 else if (reg_equiv_mem (regno) != 0)
4690 x = reg_equiv_mem (regno);
4691 #endif
4692 else if (reg_equiv_memory_loc (regno)
4693 && (reg_equiv_address (regno) != 0 || num_not_at_initial_offset))
4695 rtx mem = make_memloc (x, regno);
4696 if (reg_equiv_address (regno)
4697 || ! rtx_equal_p (mem, reg_equiv_mem (regno)))
4699 /* If this is not a toplevel operand, find_reloads doesn't see
4700 this substitution. We have to emit a USE of the pseudo so
4701 that delete_output_reload can see it. */
4702 if (replace_reloads && recog_data.operand[opnum] != x)
4703 /* We mark the USE with QImode so that we recognize it
4704 as one that can be safely deleted at the end of
4705 reload. */
4706 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, x), insn),
4707 QImode);
4708 x = mem;
4709 i = find_reloads_address (GET_MODE (x), &x, XEXP (x, 0), &XEXP (x, 0),
4710 opnum, type, ind_levels, insn);
4711 if (!rtx_equal_p (x, mem))
4712 push_reg_equiv_alt_mem (regno, x);
4713 if (address_reloaded)
4714 *address_reloaded = i;
4717 return x;
4719 if (code == MEM)
4721 rtx tem = x;
4723 i = find_reloads_address (GET_MODE (x), &tem, XEXP (x, 0), &XEXP (x, 0),
4724 opnum, type, ind_levels, insn);
4725 if (address_reloaded)
4726 *address_reloaded = i;
4728 return tem;
4731 if (code == SUBREG && REG_P (SUBREG_REG (x)))
4733 /* Check for SUBREG containing a REG that's equivalent to a
4734 constant. If the constant has a known value, truncate it
4735 right now. Similarly if we are extracting a single-word of a
4736 multi-word constant. If the constant is symbolic, allow it
4737 to be substituted normally. push_reload will strip the
4738 subreg later. The constant must not be VOIDmode, because we
4739 will lose the mode of the register (this should never happen
4740 because one of the cases above should handle it). */
4742 int regno = REGNO (SUBREG_REG (x));
4743 rtx tem;
4745 if (regno >= FIRST_PSEUDO_REGISTER
4746 && reg_renumber[regno] < 0
4747 && reg_equiv_constant (regno) != 0)
4749 tem =
4750 simplify_gen_subreg (GET_MODE (x), reg_equiv_constant (regno),
4751 GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x));
4752 gcc_assert (tem);
4753 if (CONSTANT_P (tem)
4754 && !targetm.legitimate_constant_p (GET_MODE (x), tem))
4756 tem = force_const_mem (GET_MODE (x), tem);
4757 i = find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
4758 &XEXP (tem, 0), opnum, type,
4759 ind_levels, insn);
4760 if (address_reloaded)
4761 *address_reloaded = i;
4763 return tem;
4766 /* If the subreg contains a reg that will be converted to a mem,
4767 attempt to convert the whole subreg to a (narrower or wider)
4768 memory reference instead. If this succeeds, we're done --
4769 otherwise fall through to check whether the inner reg still
4770 needs address reloads anyway. */
4772 if (regno >= FIRST_PSEUDO_REGISTER
4773 && reg_equiv_memory_loc (regno) != 0)
4775 tem = find_reloads_subreg_address (x, opnum, type, ind_levels,
4776 insn, address_reloaded);
4777 if (tem)
4778 return tem;
4782 for (copied = 0, i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
4784 if (fmt[i] == 'e')
4786 rtx new_part = find_reloads_toplev (XEXP (x, i), opnum, type,
4787 ind_levels, is_set_dest, insn,
4788 address_reloaded);
4789 /* If we have replaced a reg with it's equivalent memory loc -
4790 that can still be handled here e.g. if it's in a paradoxical
4791 subreg - we must make the change in a copy, rather than using
4792 a destructive change. This way, find_reloads can still elect
4793 not to do the change. */
4794 if (new_part != XEXP (x, i) && ! CONSTANT_P (new_part) && ! copied)
4796 x = shallow_copy_rtx (x);
4797 copied = 1;
4799 XEXP (x, i) = new_part;
4802 return x;
4805 /* Return a mem ref for the memory equivalent of reg REGNO.
4806 This mem ref is not shared with anything. */
4808 static rtx
4809 make_memloc (rtx ad, int regno)
4811 /* We must rerun eliminate_regs, in case the elimination
4812 offsets have changed. */
4813 rtx tem
4814 = XEXP (eliminate_regs (reg_equiv_memory_loc (regno), VOIDmode, NULL_RTX),
4817 /* If TEM might contain a pseudo, we must copy it to avoid
4818 modifying it when we do the substitution for the reload. */
4819 if (rtx_varies_p (tem, 0))
4820 tem = copy_rtx (tem);
4822 tem = replace_equiv_address_nv (reg_equiv_memory_loc (regno), tem);
4823 tem = adjust_address_nv (tem, GET_MODE (ad), 0);
4825 /* Copy the result if it's still the same as the equivalence, to avoid
4826 modifying it when we do the substitution for the reload. */
4827 if (tem == reg_equiv_memory_loc (regno))
4828 tem = copy_rtx (tem);
4829 return tem;
4832 /* Returns true if AD could be turned into a valid memory reference
4833 to mode MODE in address space AS by reloading the part pointed to
4834 by PART into a register. */
4836 static bool
4837 maybe_memory_address_addr_space_p (machine_mode mode, rtx ad,
4838 addr_space_t as, rtx *part)
4840 bool retv;
4841 rtx tem = *part;
4842 rtx reg = gen_rtx_REG (GET_MODE (tem), max_reg_num ());
4844 *part = reg;
4845 retv = memory_address_addr_space_p (mode, ad, as);
4846 *part = tem;
4848 return retv;
4851 /* Record all reloads needed for handling memory address AD
4852 which appears in *LOC in a memory reference to mode MODE
4853 which itself is found in location *MEMREFLOC.
4854 Note that we take shortcuts assuming that no multi-reg machine mode
4855 occurs as part of an address.
4857 OPNUM and TYPE specify the purpose of this reload.
4859 IND_LEVELS says how many levels of indirect addressing this machine
4860 supports.
4862 INSN, if nonzero, is the insn in which we do the reload. It is used
4863 to determine if we may generate output reloads, and where to put USEs
4864 for pseudos that we have to replace with stack slots.
4866 Value is one if this address is reloaded or replaced as a whole; it is
4867 zero if the top level of this address was not reloaded or replaced, and
4868 it is -1 if it may or may not have been reloaded or replaced.
4870 Note that there is no verification that the address will be valid after
4871 this routine does its work. Instead, we rely on the fact that the address
4872 was valid when reload started. So we need only undo things that reload
4873 could have broken. These are wrong register types, pseudos not allocated
4874 to a hard register, and frame pointer elimination. */
4876 static int
4877 find_reloads_address (machine_mode mode, rtx *memrefloc, rtx ad,
4878 rtx *loc, int opnum, enum reload_type type,
4879 int ind_levels, rtx_insn *insn)
4881 addr_space_t as = memrefloc? MEM_ADDR_SPACE (*memrefloc)
4882 : ADDR_SPACE_GENERIC;
4883 int regno;
4884 int removed_and = 0;
4885 int op_index;
4886 rtx tem;
4888 /* If the address is a register, see if it is a legitimate address and
4889 reload if not. We first handle the cases where we need not reload
4890 or where we must reload in a non-standard way. */
4892 if (REG_P (ad))
4894 regno = REGNO (ad);
4896 if (reg_equiv_constant (regno) != 0)
4898 find_reloads_address_part (reg_equiv_constant (regno), loc,
4899 base_reg_class (mode, as, MEM, SCRATCH),
4900 GET_MODE (ad), opnum, type, ind_levels);
4901 return 1;
4904 tem = reg_equiv_memory_loc (regno);
4905 if (tem != 0)
4907 if (reg_equiv_address (regno) != 0 || num_not_at_initial_offset)
4909 tem = make_memloc (ad, regno);
4910 if (! strict_memory_address_addr_space_p (GET_MODE (tem),
4911 XEXP (tem, 0),
4912 MEM_ADDR_SPACE (tem)))
4914 rtx orig = tem;
4916 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
4917 &XEXP (tem, 0), opnum,
4918 ADDR_TYPE (type), ind_levels, insn);
4919 if (!rtx_equal_p (tem, orig))
4920 push_reg_equiv_alt_mem (regno, tem);
4922 /* We can avoid a reload if the register's equivalent memory
4923 expression is valid as an indirect memory address.
4924 But not all addresses are valid in a mem used as an indirect
4925 address: only reg or reg+constant. */
4927 if (ind_levels > 0
4928 && strict_memory_address_addr_space_p (mode, tem, as)
4929 && (REG_P (XEXP (tem, 0))
4930 || (GET_CODE (XEXP (tem, 0)) == PLUS
4931 && REG_P (XEXP (XEXP (tem, 0), 0))
4932 && CONSTANT_P (XEXP (XEXP (tem, 0), 1)))))
4934 /* TEM is not the same as what we'll be replacing the
4935 pseudo with after reload, put a USE in front of INSN
4936 in the final reload pass. */
4937 if (replace_reloads
4938 && num_not_at_initial_offset
4939 && ! rtx_equal_p (tem, reg_equiv_mem (regno)))
4941 *loc = tem;
4942 /* We mark the USE with QImode so that we
4943 recognize it as one that can be safely
4944 deleted at the end of reload. */
4945 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, ad),
4946 insn), QImode);
4948 /* This doesn't really count as replacing the address
4949 as a whole, since it is still a memory access. */
4951 return 0;
4953 ad = tem;
4957 /* The only remaining case where we can avoid a reload is if this is a
4958 hard register that is valid as a base register and which is not the
4959 subject of a CLOBBER in this insn. */
4961 else if (regno < FIRST_PSEUDO_REGISTER
4962 && regno_ok_for_base_p (regno, mode, as, MEM, SCRATCH)
4963 && ! regno_clobbered_p (regno, this_insn, mode, 0))
4964 return 0;
4966 /* If we do not have one of the cases above, we must do the reload. */
4967 push_reload (ad, NULL_RTX, loc, (rtx*) 0,
4968 base_reg_class (mode, as, MEM, SCRATCH),
4969 GET_MODE (ad), VOIDmode, 0, 0, opnum, type);
4970 return 1;
4973 if (strict_memory_address_addr_space_p (mode, ad, as))
4975 /* The address appears valid, so reloads are not needed.
4976 But the address may contain an eliminable register.
4977 This can happen because a machine with indirect addressing
4978 may consider a pseudo register by itself a valid address even when
4979 it has failed to get a hard reg.
4980 So do a tree-walk to find and eliminate all such regs. */
4982 /* But first quickly dispose of a common case. */
4983 if (GET_CODE (ad) == PLUS
4984 && CONST_INT_P (XEXP (ad, 1))
4985 && REG_P (XEXP (ad, 0))
4986 && reg_equiv_constant (REGNO (XEXP (ad, 0))) == 0)
4987 return 0;
4989 subst_reg_equivs_changed = 0;
4990 *loc = subst_reg_equivs (ad, insn);
4992 if (! subst_reg_equivs_changed)
4993 return 0;
4995 /* Check result for validity after substitution. */
4996 if (strict_memory_address_addr_space_p (mode, ad, as))
4997 return 0;
5000 #ifdef LEGITIMIZE_RELOAD_ADDRESS
5003 if (memrefloc && ADDR_SPACE_GENERIC_P (as))
5005 LEGITIMIZE_RELOAD_ADDRESS (ad, GET_MODE (*memrefloc), opnum, type,
5006 ind_levels, win);
5008 break;
5009 win:
5010 *memrefloc = copy_rtx (*memrefloc);
5011 XEXP (*memrefloc, 0) = ad;
5012 move_replacements (&ad, &XEXP (*memrefloc, 0));
5013 return -1;
5015 while (0);
5016 #endif
5018 /* The address is not valid. We have to figure out why. First see if
5019 we have an outer AND and remove it if so. Then analyze what's inside. */
5021 if (GET_CODE (ad) == AND)
5023 removed_and = 1;
5024 loc = &XEXP (ad, 0);
5025 ad = *loc;
5028 /* One possibility for why the address is invalid is that it is itself
5029 a MEM. This can happen when the frame pointer is being eliminated, a
5030 pseudo is not allocated to a hard register, and the offset between the
5031 frame and stack pointers is not its initial value. In that case the
5032 pseudo will have been replaced by a MEM referring to the
5033 stack pointer. */
5034 if (MEM_P (ad))
5036 /* First ensure that the address in this MEM is valid. Then, unless
5037 indirect addresses are valid, reload the MEM into a register. */
5038 tem = ad;
5039 find_reloads_address (GET_MODE (ad), &tem, XEXP (ad, 0), &XEXP (ad, 0),
5040 opnum, ADDR_TYPE (type),
5041 ind_levels == 0 ? 0 : ind_levels - 1, insn);
5043 /* If tem was changed, then we must create a new memory reference to
5044 hold it and store it back into memrefloc. */
5045 if (tem != ad && memrefloc)
5047 *memrefloc = copy_rtx (*memrefloc);
5048 copy_replacements (tem, XEXP (*memrefloc, 0));
5049 loc = &XEXP (*memrefloc, 0);
5050 if (removed_and)
5051 loc = &XEXP (*loc, 0);
5054 /* Check similar cases as for indirect addresses as above except
5055 that we can allow pseudos and a MEM since they should have been
5056 taken care of above. */
5058 if (ind_levels == 0
5059 || (GET_CODE (XEXP (tem, 0)) == SYMBOL_REF && ! indirect_symref_ok)
5060 || MEM_P (XEXP (tem, 0))
5061 || ! (REG_P (XEXP (tem, 0))
5062 || (GET_CODE (XEXP (tem, 0)) == PLUS
5063 && REG_P (XEXP (XEXP (tem, 0), 0))
5064 && CONST_INT_P (XEXP (XEXP (tem, 0), 1)))))
5066 /* Must use TEM here, not AD, since it is the one that will
5067 have any subexpressions reloaded, if needed. */
5068 push_reload (tem, NULL_RTX, loc, (rtx*) 0,
5069 base_reg_class (mode, as, MEM, SCRATCH), GET_MODE (tem),
5070 VOIDmode, 0,
5071 0, opnum, type);
5072 return ! removed_and;
5074 else
5075 return 0;
5078 /* If we have address of a stack slot but it's not valid because the
5079 displacement is too large, compute the sum in a register.
5080 Handle all base registers here, not just fp/ap/sp, because on some
5081 targets (namely SH) we can also get too large displacements from
5082 big-endian corrections. */
5083 else if (GET_CODE (ad) == PLUS
5084 && REG_P (XEXP (ad, 0))
5085 && REGNO (XEXP (ad, 0)) < FIRST_PSEUDO_REGISTER
5086 && CONST_INT_P (XEXP (ad, 1))
5087 && (regno_ok_for_base_p (REGNO (XEXP (ad, 0)), mode, as, PLUS,
5088 CONST_INT)
5089 /* Similarly, if we were to reload the base register and the
5090 mem+offset address is still invalid, then we want to reload
5091 the whole address, not just the base register. */
5092 || ! maybe_memory_address_addr_space_p
5093 (mode, ad, as, &(XEXP (ad, 0)))))
5096 /* Unshare the MEM rtx so we can safely alter it. */
5097 if (memrefloc)
5099 *memrefloc = copy_rtx (*memrefloc);
5100 loc = &XEXP (*memrefloc, 0);
5101 if (removed_and)
5102 loc = &XEXP (*loc, 0);
5105 if (double_reg_address_ok[mode]
5106 && regno_ok_for_base_p (REGNO (XEXP (ad, 0)), mode, as,
5107 PLUS, CONST_INT))
5109 /* Unshare the sum as well. */
5110 *loc = ad = copy_rtx (ad);
5112 /* Reload the displacement into an index reg.
5113 We assume the frame pointer or arg pointer is a base reg. */
5114 find_reloads_address_part (XEXP (ad, 1), &XEXP (ad, 1),
5115 INDEX_REG_CLASS, GET_MODE (ad), opnum,
5116 type, ind_levels);
5117 return 0;
5119 else
5121 /* If the sum of two regs is not necessarily valid,
5122 reload the sum into a base reg.
5123 That will at least work. */
5124 find_reloads_address_part (ad, loc,
5125 base_reg_class (mode, as, MEM, SCRATCH),
5126 GET_MODE (ad), opnum, type, ind_levels);
5128 return ! removed_and;
5131 /* If we have an indexed stack slot, there are three possible reasons why
5132 it might be invalid: The index might need to be reloaded, the address
5133 might have been made by frame pointer elimination and hence have a
5134 constant out of range, or both reasons might apply.
5136 We can easily check for an index needing reload, but even if that is the
5137 case, we might also have an invalid constant. To avoid making the
5138 conservative assumption and requiring two reloads, we see if this address
5139 is valid when not interpreted strictly. If it is, the only problem is
5140 that the index needs a reload and find_reloads_address_1 will take care
5141 of it.
5143 Handle all base registers here, not just fp/ap/sp, because on some
5144 targets (namely SPARC) we can also get invalid addresses from preventive
5145 subreg big-endian corrections made by find_reloads_toplev. We
5146 can also get expressions involving LO_SUM (rather than PLUS) from
5147 find_reloads_subreg_address.
5149 If we decide to do something, it must be that `double_reg_address_ok'
5150 is true. We generate a reload of the base register + constant and
5151 rework the sum so that the reload register will be added to the index.
5152 This is safe because we know the address isn't shared.
5154 We check for the base register as both the first and second operand of
5155 the innermost PLUS and/or LO_SUM. */
5157 for (op_index = 0; op_index < 2; ++op_index)
5159 rtx operand, addend;
5160 enum rtx_code inner_code;
5162 if (GET_CODE (ad) != PLUS)
5163 continue;
5165 inner_code = GET_CODE (XEXP (ad, 0));
5166 if (!(GET_CODE (ad) == PLUS
5167 && CONST_INT_P (XEXP (ad, 1))
5168 && (inner_code == PLUS || inner_code == LO_SUM)))
5169 continue;
5171 operand = XEXP (XEXP (ad, 0), op_index);
5172 if (!REG_P (operand) || REGNO (operand) >= FIRST_PSEUDO_REGISTER)
5173 continue;
5175 addend = XEXP (XEXP (ad, 0), 1 - op_index);
5177 if ((regno_ok_for_base_p (REGNO (operand), mode, as, inner_code,
5178 GET_CODE (addend))
5179 || operand == frame_pointer_rtx
5180 || (!HARD_FRAME_POINTER_IS_FRAME_POINTER
5181 && operand == hard_frame_pointer_rtx)
5182 || (FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
5183 && operand == arg_pointer_rtx)
5184 || operand == stack_pointer_rtx)
5185 && ! maybe_memory_address_addr_space_p
5186 (mode, ad, as, &XEXP (XEXP (ad, 0), 1 - op_index)))
5188 rtx offset_reg;
5189 enum reg_class cls;
5191 offset_reg = plus_constant (GET_MODE (ad), operand,
5192 INTVAL (XEXP (ad, 1)));
5194 /* Form the adjusted address. */
5195 if (GET_CODE (XEXP (ad, 0)) == PLUS)
5196 ad = gen_rtx_PLUS (GET_MODE (ad),
5197 op_index == 0 ? offset_reg : addend,
5198 op_index == 0 ? addend : offset_reg);
5199 else
5200 ad = gen_rtx_LO_SUM (GET_MODE (ad),
5201 op_index == 0 ? offset_reg : addend,
5202 op_index == 0 ? addend : offset_reg);
5203 *loc = ad;
5205 cls = base_reg_class (mode, as, MEM, GET_CODE (addend));
5206 find_reloads_address_part (XEXP (ad, op_index),
5207 &XEXP (ad, op_index), cls,
5208 GET_MODE (ad), opnum, type, ind_levels);
5209 find_reloads_address_1 (mode, as,
5210 XEXP (ad, 1 - op_index), 1, GET_CODE (ad),
5211 GET_CODE (XEXP (ad, op_index)),
5212 &XEXP (ad, 1 - op_index), opnum,
5213 type, 0, insn);
5215 return 0;
5219 /* See if address becomes valid when an eliminable register
5220 in a sum is replaced. */
5222 tem = ad;
5223 if (GET_CODE (ad) == PLUS)
5224 tem = subst_indexed_address (ad);
5225 if (tem != ad && strict_memory_address_addr_space_p (mode, tem, as))
5227 /* Ok, we win that way. Replace any additional eliminable
5228 registers. */
5230 subst_reg_equivs_changed = 0;
5231 tem = subst_reg_equivs (tem, insn);
5233 /* Make sure that didn't make the address invalid again. */
5235 if (! subst_reg_equivs_changed
5236 || strict_memory_address_addr_space_p (mode, tem, as))
5238 *loc = tem;
5239 return 0;
5243 /* If constants aren't valid addresses, reload the constant address
5244 into a register. */
5245 if (CONSTANT_P (ad) && ! strict_memory_address_addr_space_p (mode, ad, as))
5247 machine_mode address_mode = GET_MODE (ad);
5248 if (address_mode == VOIDmode)
5249 address_mode = targetm.addr_space.address_mode (as);
5251 /* If AD is an address in the constant pool, the MEM rtx may be shared.
5252 Unshare it so we can safely alter it. */
5253 if (memrefloc && GET_CODE (ad) == SYMBOL_REF
5254 && CONSTANT_POOL_ADDRESS_P (ad))
5256 *memrefloc = copy_rtx (*memrefloc);
5257 loc = &XEXP (*memrefloc, 0);
5258 if (removed_and)
5259 loc = &XEXP (*loc, 0);
5262 find_reloads_address_part (ad, loc,
5263 base_reg_class (mode, as, MEM, SCRATCH),
5264 address_mode, opnum, type, ind_levels);
5265 return ! removed_and;
5268 return find_reloads_address_1 (mode, as, ad, 0, MEM, SCRATCH, loc,
5269 opnum, type, ind_levels, insn);
5272 /* Find all pseudo regs appearing in AD
5273 that are eliminable in favor of equivalent values
5274 and do not have hard regs; replace them by their equivalents.
5275 INSN, if nonzero, is the insn in which we do the reload. We put USEs in
5276 front of it for pseudos that we have to replace with stack slots. */
5278 static rtx
5279 subst_reg_equivs (rtx ad, rtx_insn *insn)
5281 RTX_CODE code = GET_CODE (ad);
5282 int i;
5283 const char *fmt;
5285 switch (code)
5287 case HIGH:
5288 case CONST:
5289 CASE_CONST_ANY:
5290 case SYMBOL_REF:
5291 case LABEL_REF:
5292 case PC:
5293 return ad;
5295 case REG:
5297 int regno = REGNO (ad);
5299 if (reg_equiv_constant (regno) != 0)
5301 subst_reg_equivs_changed = 1;
5302 return reg_equiv_constant (regno);
5304 if (reg_equiv_memory_loc (regno) && num_not_at_initial_offset)
5306 rtx mem = make_memloc (ad, regno);
5307 if (! rtx_equal_p (mem, reg_equiv_mem (regno)))
5309 subst_reg_equivs_changed = 1;
5310 /* We mark the USE with QImode so that we recognize it
5311 as one that can be safely deleted at the end of
5312 reload. */
5313 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, ad), insn),
5314 QImode);
5315 return mem;
5319 return ad;
5321 case PLUS:
5322 /* Quickly dispose of a common case. */
5323 if (XEXP (ad, 0) == frame_pointer_rtx
5324 && CONST_INT_P (XEXP (ad, 1)))
5325 return ad;
5326 break;
5328 default:
5329 break;
5332 fmt = GET_RTX_FORMAT (code);
5333 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
5334 if (fmt[i] == 'e')
5335 XEXP (ad, i) = subst_reg_equivs (XEXP (ad, i), insn);
5336 return ad;
5339 /* Compute the sum of X and Y, making canonicalizations assumed in an
5340 address, namely: sum constant integers, surround the sum of two
5341 constants with a CONST, put the constant as the second operand, and
5342 group the constant on the outermost sum.
5344 This routine assumes both inputs are already in canonical form. */
5347 form_sum (machine_mode mode, rtx x, rtx y)
5349 rtx tem;
5351 gcc_assert (GET_MODE (x) == mode || GET_MODE (x) == VOIDmode);
5352 gcc_assert (GET_MODE (y) == mode || GET_MODE (y) == VOIDmode);
5354 if (CONST_INT_P (x))
5355 return plus_constant (mode, y, INTVAL (x));
5356 else if (CONST_INT_P (y))
5357 return plus_constant (mode, x, INTVAL (y));
5358 else if (CONSTANT_P (x))
5359 tem = x, x = y, y = tem;
5361 if (GET_CODE (x) == PLUS && CONSTANT_P (XEXP (x, 1)))
5362 return form_sum (mode, XEXP (x, 0), form_sum (mode, XEXP (x, 1), y));
5364 /* Note that if the operands of Y are specified in the opposite
5365 order in the recursive calls below, infinite recursion will occur. */
5366 if (GET_CODE (y) == PLUS && CONSTANT_P (XEXP (y, 1)))
5367 return form_sum (mode, form_sum (mode, x, XEXP (y, 0)), XEXP (y, 1));
5369 /* If both constant, encapsulate sum. Otherwise, just form sum. A
5370 constant will have been placed second. */
5371 if (CONSTANT_P (x) && CONSTANT_P (y))
5373 if (GET_CODE (x) == CONST)
5374 x = XEXP (x, 0);
5375 if (GET_CODE (y) == CONST)
5376 y = XEXP (y, 0);
5378 return gen_rtx_CONST (VOIDmode, gen_rtx_PLUS (mode, x, y));
5381 return gen_rtx_PLUS (mode, x, y);
5384 /* If ADDR is a sum containing a pseudo register that should be
5385 replaced with a constant (from reg_equiv_constant),
5386 return the result of doing so, and also apply the associative
5387 law so that the result is more likely to be a valid address.
5388 (But it is not guaranteed to be one.)
5390 Note that at most one register is replaced, even if more are
5391 replaceable. Also, we try to put the result into a canonical form
5392 so it is more likely to be a valid address.
5394 In all other cases, return ADDR. */
5396 static rtx
5397 subst_indexed_address (rtx addr)
5399 rtx op0 = 0, op1 = 0, op2 = 0;
5400 rtx tem;
5401 int regno;
5403 if (GET_CODE (addr) == PLUS)
5405 /* Try to find a register to replace. */
5406 op0 = XEXP (addr, 0), op1 = XEXP (addr, 1), op2 = 0;
5407 if (REG_P (op0)
5408 && (regno = REGNO (op0)) >= FIRST_PSEUDO_REGISTER
5409 && reg_renumber[regno] < 0
5410 && reg_equiv_constant (regno) != 0)
5411 op0 = reg_equiv_constant (regno);
5412 else if (REG_P (op1)
5413 && (regno = REGNO (op1)) >= FIRST_PSEUDO_REGISTER
5414 && reg_renumber[regno] < 0
5415 && reg_equiv_constant (regno) != 0)
5416 op1 = reg_equiv_constant (regno);
5417 else if (GET_CODE (op0) == PLUS
5418 && (tem = subst_indexed_address (op0)) != op0)
5419 op0 = tem;
5420 else if (GET_CODE (op1) == PLUS
5421 && (tem = subst_indexed_address (op1)) != op1)
5422 op1 = tem;
5423 else
5424 return addr;
5426 /* Pick out up to three things to add. */
5427 if (GET_CODE (op1) == PLUS)
5428 op2 = XEXP (op1, 1), op1 = XEXP (op1, 0);
5429 else if (GET_CODE (op0) == PLUS)
5430 op2 = op1, op1 = XEXP (op0, 1), op0 = XEXP (op0, 0);
5432 /* Compute the sum. */
5433 if (op2 != 0)
5434 op1 = form_sum (GET_MODE (addr), op1, op2);
5435 if (op1 != 0)
5436 op0 = form_sum (GET_MODE (addr), op0, op1);
5438 return op0;
5440 return addr;
5443 /* Update the REG_INC notes for an insn. It updates all REG_INC
5444 notes for the instruction which refer to REGNO the to refer
5445 to the reload number.
5447 INSN is the insn for which any REG_INC notes need updating.
5449 REGNO is the register number which has been reloaded.
5451 RELOADNUM is the reload number. */
5453 static void
5454 update_auto_inc_notes (rtx_insn *insn ATTRIBUTE_UNUSED, int regno ATTRIBUTE_UNUSED,
5455 int reloadnum ATTRIBUTE_UNUSED)
5457 if (!AUTO_INC_DEC)
5458 return;
5460 for (rtx link = REG_NOTES (insn); link; link = XEXP (link, 1))
5461 if (REG_NOTE_KIND (link) == REG_INC
5462 && (int) REGNO (XEXP (link, 0)) == regno)
5463 push_replacement (&XEXP (link, 0), reloadnum, VOIDmode);
5466 /* Record the pseudo registers we must reload into hard registers in a
5467 subexpression of a would-be memory address, X referring to a value
5468 in mode MODE. (This function is not called if the address we find
5469 is strictly valid.)
5471 CONTEXT = 1 means we are considering regs as index regs,
5472 = 0 means we are considering them as base regs.
5473 OUTER_CODE is the code of the enclosing RTX, typically a MEM, a PLUS,
5474 or an autoinc code.
5475 If CONTEXT == 0 and OUTER_CODE is a PLUS or LO_SUM, then INDEX_CODE
5476 is the code of the index part of the address. Otherwise, pass SCRATCH
5477 for this argument.
5478 OPNUM and TYPE specify the purpose of any reloads made.
5480 IND_LEVELS says how many levels of indirect addressing are
5481 supported at this point in the address.
5483 INSN, if nonzero, is the insn in which we do the reload. It is used
5484 to determine if we may generate output reloads.
5486 We return nonzero if X, as a whole, is reloaded or replaced. */
5488 /* Note that we take shortcuts assuming that no multi-reg machine mode
5489 occurs as part of an address.
5490 Also, this is not fully machine-customizable; it works for machines
5491 such as VAXen and 68000's and 32000's, but other possible machines
5492 could have addressing modes that this does not handle right.
5493 If you add push_reload calls here, you need to make sure gen_reload
5494 handles those cases gracefully. */
5496 static int
5497 find_reloads_address_1 (machine_mode mode, addr_space_t as,
5498 rtx x, int context,
5499 enum rtx_code outer_code, enum rtx_code index_code,
5500 rtx *loc, int opnum, enum reload_type type,
5501 int ind_levels, rtx_insn *insn)
5503 #define REG_OK_FOR_CONTEXT(CONTEXT, REGNO, MODE, AS, OUTER, INDEX) \
5504 ((CONTEXT) == 0 \
5505 ? regno_ok_for_base_p (REGNO, MODE, AS, OUTER, INDEX) \
5506 : REGNO_OK_FOR_INDEX_P (REGNO))
5508 enum reg_class context_reg_class;
5509 RTX_CODE code = GET_CODE (x);
5510 bool reloaded_inner_of_autoinc = false;
5512 if (context == 1)
5513 context_reg_class = INDEX_REG_CLASS;
5514 else
5515 context_reg_class = base_reg_class (mode, as, outer_code, index_code);
5517 switch (code)
5519 case PLUS:
5521 rtx orig_op0 = XEXP (x, 0);
5522 rtx orig_op1 = XEXP (x, 1);
5523 RTX_CODE code0 = GET_CODE (orig_op0);
5524 RTX_CODE code1 = GET_CODE (orig_op1);
5525 rtx op0 = orig_op0;
5526 rtx op1 = orig_op1;
5528 if (GET_CODE (op0) == SUBREG)
5530 op0 = SUBREG_REG (op0);
5531 code0 = GET_CODE (op0);
5532 if (code0 == REG && REGNO (op0) < FIRST_PSEUDO_REGISTER)
5533 op0 = gen_rtx_REG (word_mode,
5534 (REGNO (op0) +
5535 subreg_regno_offset (REGNO (SUBREG_REG (orig_op0)),
5536 GET_MODE (SUBREG_REG (orig_op0)),
5537 SUBREG_BYTE (orig_op0),
5538 GET_MODE (orig_op0))));
5541 if (GET_CODE (op1) == SUBREG)
5543 op1 = SUBREG_REG (op1);
5544 code1 = GET_CODE (op1);
5545 if (code1 == REG && REGNO (op1) < FIRST_PSEUDO_REGISTER)
5546 /* ??? Why is this given op1's mode and above for
5547 ??? op0 SUBREGs we use word_mode? */
5548 op1 = gen_rtx_REG (GET_MODE (op1),
5549 (REGNO (op1) +
5550 subreg_regno_offset (REGNO (SUBREG_REG (orig_op1)),
5551 GET_MODE (SUBREG_REG (orig_op1)),
5552 SUBREG_BYTE (orig_op1),
5553 GET_MODE (orig_op1))));
5555 /* Plus in the index register may be created only as a result of
5556 register rematerialization for expression like &localvar*4. Reload it.
5557 It may be possible to combine the displacement on the outer level,
5558 but it is probably not worthwhile to do so. */
5559 if (context == 1)
5561 find_reloads_address (GET_MODE (x), loc, XEXP (x, 0), &XEXP (x, 0),
5562 opnum, ADDR_TYPE (type), ind_levels, insn);
5563 push_reload (*loc, NULL_RTX, loc, (rtx*) 0,
5564 context_reg_class,
5565 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5566 return 1;
5569 if (code0 == MULT || code0 == ASHIFT
5570 || code0 == SIGN_EXTEND || code0 == TRUNCATE
5571 || code0 == ZERO_EXTEND || code1 == MEM)
5573 find_reloads_address_1 (mode, as, orig_op0, 1, PLUS, SCRATCH,
5574 &XEXP (x, 0), opnum, type, ind_levels,
5575 insn);
5576 find_reloads_address_1 (mode, as, orig_op1, 0, PLUS, code0,
5577 &XEXP (x, 1), opnum, type, ind_levels,
5578 insn);
5581 else if (code1 == MULT || code1 == ASHIFT
5582 || code1 == SIGN_EXTEND || code1 == TRUNCATE
5583 || code1 == ZERO_EXTEND || code0 == MEM)
5585 find_reloads_address_1 (mode, as, orig_op0, 0, PLUS, code1,
5586 &XEXP (x, 0), opnum, type, ind_levels,
5587 insn);
5588 find_reloads_address_1 (mode, as, orig_op1, 1, PLUS, SCRATCH,
5589 &XEXP (x, 1), opnum, type, ind_levels,
5590 insn);
5593 else if (code0 == CONST_INT || code0 == CONST
5594 || code0 == SYMBOL_REF || code0 == LABEL_REF)
5595 find_reloads_address_1 (mode, as, orig_op1, 0, PLUS, code0,
5596 &XEXP (x, 1), opnum, type, ind_levels,
5597 insn);
5599 else if (code1 == CONST_INT || code1 == CONST
5600 || code1 == SYMBOL_REF || code1 == LABEL_REF)
5601 find_reloads_address_1 (mode, as, orig_op0, 0, PLUS, code1,
5602 &XEXP (x, 0), opnum, type, ind_levels,
5603 insn);
5605 else if (code0 == REG && code1 == REG)
5607 if (REGNO_OK_FOR_INDEX_P (REGNO (op1))
5608 && regno_ok_for_base_p (REGNO (op0), mode, as, PLUS, REG))
5609 return 0;
5610 else if (REGNO_OK_FOR_INDEX_P (REGNO (op0))
5611 && regno_ok_for_base_p (REGNO (op1), mode, as, PLUS, REG))
5612 return 0;
5613 else if (regno_ok_for_base_p (REGNO (op0), mode, as, PLUS, REG))
5614 find_reloads_address_1 (mode, as, orig_op1, 1, PLUS, SCRATCH,
5615 &XEXP (x, 1), opnum, type, ind_levels,
5616 insn);
5617 else if (REGNO_OK_FOR_INDEX_P (REGNO (op1)))
5618 find_reloads_address_1 (mode, as, orig_op0, 0, PLUS, REG,
5619 &XEXP (x, 0), opnum, type, ind_levels,
5620 insn);
5621 else if (regno_ok_for_base_p (REGNO (op1), mode, as, PLUS, REG))
5622 find_reloads_address_1 (mode, as, orig_op0, 1, PLUS, SCRATCH,
5623 &XEXP (x, 0), opnum, type, ind_levels,
5624 insn);
5625 else if (REGNO_OK_FOR_INDEX_P (REGNO (op0)))
5626 find_reloads_address_1 (mode, as, orig_op1, 0, PLUS, REG,
5627 &XEXP (x, 1), opnum, type, ind_levels,
5628 insn);
5629 else
5631 find_reloads_address_1 (mode, as, orig_op0, 0, PLUS, REG,
5632 &XEXP (x, 0), opnum, type, ind_levels,
5633 insn);
5634 find_reloads_address_1 (mode, as, orig_op1, 1, PLUS, SCRATCH,
5635 &XEXP (x, 1), opnum, type, ind_levels,
5636 insn);
5640 else if (code0 == REG)
5642 find_reloads_address_1 (mode, as, orig_op0, 1, PLUS, SCRATCH,
5643 &XEXP (x, 0), opnum, type, ind_levels,
5644 insn);
5645 find_reloads_address_1 (mode, as, orig_op1, 0, PLUS, REG,
5646 &XEXP (x, 1), opnum, type, ind_levels,
5647 insn);
5650 else if (code1 == REG)
5652 find_reloads_address_1 (mode, as, orig_op1, 1, PLUS, SCRATCH,
5653 &XEXP (x, 1), opnum, type, ind_levels,
5654 insn);
5655 find_reloads_address_1 (mode, as, orig_op0, 0, PLUS, REG,
5656 &XEXP (x, 0), opnum, type, ind_levels,
5657 insn);
5661 return 0;
5663 case POST_MODIFY:
5664 case PRE_MODIFY:
5666 rtx op0 = XEXP (x, 0);
5667 rtx op1 = XEXP (x, 1);
5668 enum rtx_code index_code;
5669 int regno;
5670 int reloadnum;
5672 if (GET_CODE (op1) != PLUS && GET_CODE (op1) != MINUS)
5673 return 0;
5675 /* Currently, we only support {PRE,POST}_MODIFY constructs
5676 where a base register is {inc,dec}remented by the contents
5677 of another register or by a constant value. Thus, these
5678 operands must match. */
5679 gcc_assert (op0 == XEXP (op1, 0));
5681 /* Require index register (or constant). Let's just handle the
5682 register case in the meantime... If the target allows
5683 auto-modify by a constant then we could try replacing a pseudo
5684 register with its equivalent constant where applicable.
5686 We also handle the case where the register was eliminated
5687 resulting in a PLUS subexpression.
5689 If we later decide to reload the whole PRE_MODIFY or
5690 POST_MODIFY, inc_for_reload might clobber the reload register
5691 before reading the index. The index register might therefore
5692 need to live longer than a TYPE reload normally would, so be
5693 conservative and class it as RELOAD_OTHER. */
5694 if ((REG_P (XEXP (op1, 1))
5695 && !REGNO_OK_FOR_INDEX_P (REGNO (XEXP (op1, 1))))
5696 || GET_CODE (XEXP (op1, 1)) == PLUS)
5697 find_reloads_address_1 (mode, as, XEXP (op1, 1), 1, code, SCRATCH,
5698 &XEXP (op1, 1), opnum, RELOAD_OTHER,
5699 ind_levels, insn);
5701 gcc_assert (REG_P (XEXP (op1, 0)));
5703 regno = REGNO (XEXP (op1, 0));
5704 index_code = GET_CODE (XEXP (op1, 1));
5706 /* A register that is incremented cannot be constant! */
5707 gcc_assert (regno < FIRST_PSEUDO_REGISTER
5708 || reg_equiv_constant (regno) == 0);
5710 /* Handle a register that is equivalent to a memory location
5711 which cannot be addressed directly. */
5712 if (reg_equiv_memory_loc (regno) != 0
5713 && (reg_equiv_address (regno) != 0
5714 || num_not_at_initial_offset))
5716 rtx tem = make_memloc (XEXP (x, 0), regno);
5718 if (reg_equiv_address (regno)
5719 || ! rtx_equal_p (tem, reg_equiv_mem (regno)))
5721 rtx orig = tem;
5723 /* First reload the memory location's address.
5724 We can't use ADDR_TYPE (type) here, because we need to
5725 write back the value after reading it, hence we actually
5726 need two registers. */
5727 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
5728 &XEXP (tem, 0), opnum,
5729 RELOAD_OTHER,
5730 ind_levels, insn);
5732 if (!rtx_equal_p (tem, orig))
5733 push_reg_equiv_alt_mem (regno, tem);
5735 /* Then reload the memory location into a base
5736 register. */
5737 reloadnum = push_reload (tem, tem, &XEXP (x, 0),
5738 &XEXP (op1, 0),
5739 base_reg_class (mode, as,
5740 code, index_code),
5741 GET_MODE (x), GET_MODE (x), 0,
5742 0, opnum, RELOAD_OTHER);
5744 update_auto_inc_notes (this_insn, regno, reloadnum);
5745 return 0;
5749 if (reg_renumber[regno] >= 0)
5750 regno = reg_renumber[regno];
5752 /* We require a base register here... */
5753 if (!regno_ok_for_base_p (regno, GET_MODE (x), as, code, index_code))
5755 reloadnum = push_reload (XEXP (op1, 0), XEXP (x, 0),
5756 &XEXP (op1, 0), &XEXP (x, 0),
5757 base_reg_class (mode, as,
5758 code, index_code),
5759 GET_MODE (x), GET_MODE (x), 0, 0,
5760 opnum, RELOAD_OTHER);
5762 update_auto_inc_notes (this_insn, regno, reloadnum);
5763 return 0;
5766 return 0;
5768 case POST_INC:
5769 case POST_DEC:
5770 case PRE_INC:
5771 case PRE_DEC:
5772 if (REG_P (XEXP (x, 0)))
5774 int regno = REGNO (XEXP (x, 0));
5775 int value = 0;
5776 rtx x_orig = x;
5778 /* A register that is incremented cannot be constant! */
5779 gcc_assert (regno < FIRST_PSEUDO_REGISTER
5780 || reg_equiv_constant (regno) == 0);
5782 /* Handle a register that is equivalent to a memory location
5783 which cannot be addressed directly. */
5784 if (reg_equiv_memory_loc (regno) != 0
5785 && (reg_equiv_address (regno) != 0 || num_not_at_initial_offset))
5787 rtx tem = make_memloc (XEXP (x, 0), regno);
5788 if (reg_equiv_address (regno)
5789 || ! rtx_equal_p (tem, reg_equiv_mem (regno)))
5791 rtx orig = tem;
5793 /* First reload the memory location's address.
5794 We can't use ADDR_TYPE (type) here, because we need to
5795 write back the value after reading it, hence we actually
5796 need two registers. */
5797 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
5798 &XEXP (tem, 0), opnum, type,
5799 ind_levels, insn);
5800 reloaded_inner_of_autoinc = true;
5801 if (!rtx_equal_p (tem, orig))
5802 push_reg_equiv_alt_mem (regno, tem);
5803 /* Put this inside a new increment-expression. */
5804 x = gen_rtx_fmt_e (GET_CODE (x), GET_MODE (x), tem);
5805 /* Proceed to reload that, as if it contained a register. */
5809 /* If we have a hard register that is ok in this incdec context,
5810 don't make a reload. If the register isn't nice enough for
5811 autoincdec, we can reload it. But, if an autoincrement of a
5812 register that we here verified as playing nice, still outside
5813 isn't "valid", it must be that no autoincrement is "valid".
5814 If that is true and something made an autoincrement anyway,
5815 this must be a special context where one is allowed.
5816 (For example, a "push" instruction.)
5817 We can't improve this address, so leave it alone. */
5819 /* Otherwise, reload the autoincrement into a suitable hard reg
5820 and record how much to increment by. */
5822 if (reg_renumber[regno] >= 0)
5823 regno = reg_renumber[regno];
5824 if (regno >= FIRST_PSEUDO_REGISTER
5825 || !REG_OK_FOR_CONTEXT (context, regno, mode, as, code,
5826 index_code))
5828 int reloadnum;
5830 /* If we can output the register afterwards, do so, this
5831 saves the extra update.
5832 We can do so if we have an INSN - i.e. no JUMP_INSN nor
5833 CALL_INSN.
5834 But don't do this if we cannot directly address the
5835 memory location, since this will make it harder to
5836 reuse address reloads, and increases register pressure.
5837 Also don't do this if we can probably update x directly. */
5838 rtx equiv = (MEM_P (XEXP (x, 0))
5839 ? XEXP (x, 0)
5840 : reg_equiv_mem (regno));
5841 enum insn_code icode = optab_handler (add_optab, GET_MODE (x));
5842 if (insn && NONJUMP_INSN_P (insn)
5843 && (regno < FIRST_PSEUDO_REGISTER
5844 || (equiv
5845 && memory_operand (equiv, GET_MODE (equiv))
5846 && ! (icode != CODE_FOR_nothing
5847 && insn_operand_matches (icode, 0, equiv)
5848 && insn_operand_matches (icode, 1, equiv))))
5849 /* Using RELOAD_OTHER means we emit this and the reload we
5850 made earlier in the wrong order. */
5851 && !reloaded_inner_of_autoinc)
5853 /* We use the original pseudo for loc, so that
5854 emit_reload_insns() knows which pseudo this
5855 reload refers to and updates the pseudo rtx, not
5856 its equivalent memory location, as well as the
5857 corresponding entry in reg_last_reload_reg. */
5858 loc = &XEXP (x_orig, 0);
5859 x = XEXP (x, 0);
5860 reloadnum
5861 = push_reload (x, x, loc, loc,
5862 context_reg_class,
5863 GET_MODE (x), GET_MODE (x), 0, 0,
5864 opnum, RELOAD_OTHER);
5866 else
5868 reloadnum
5869 = push_reload (x, x, loc, (rtx*) 0,
5870 context_reg_class,
5871 GET_MODE (x), GET_MODE (x), 0, 0,
5872 opnum, type);
5873 rld[reloadnum].inc
5874 = find_inc_amount (PATTERN (this_insn), XEXP (x_orig, 0));
5876 value = 1;
5879 update_auto_inc_notes (this_insn, REGNO (XEXP (x_orig, 0)),
5880 reloadnum);
5882 return value;
5884 return 0;
5886 case TRUNCATE:
5887 case SIGN_EXTEND:
5888 case ZERO_EXTEND:
5889 /* Look for parts to reload in the inner expression and reload them
5890 too, in addition to this operation. Reloading all inner parts in
5891 addition to this one shouldn't be necessary, but at this point,
5892 we don't know if we can possibly omit any part that *can* be
5893 reloaded. Targets that are better off reloading just either part
5894 (or perhaps even a different part of an outer expression), should
5895 define LEGITIMIZE_RELOAD_ADDRESS. */
5896 find_reloads_address_1 (GET_MODE (XEXP (x, 0)), as, XEXP (x, 0),
5897 context, code, SCRATCH, &XEXP (x, 0), opnum,
5898 type, ind_levels, insn);
5899 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5900 context_reg_class,
5901 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5902 return 1;
5904 case MEM:
5905 /* This is probably the result of a substitution, by eliminate_regs, of
5906 an equivalent address for a pseudo that was not allocated to a hard
5907 register. Verify that the specified address is valid and reload it
5908 into a register.
5910 Since we know we are going to reload this item, don't decrement for
5911 the indirection level.
5913 Note that this is actually conservative: it would be slightly more
5914 efficient to use the value of SPILL_INDIRECT_LEVELS from
5915 reload1.cc here. */
5917 find_reloads_address (GET_MODE (x), loc, XEXP (x, 0), &XEXP (x, 0),
5918 opnum, ADDR_TYPE (type), ind_levels, insn);
5919 push_reload (*loc, NULL_RTX, loc, (rtx*) 0,
5920 context_reg_class,
5921 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5922 return 1;
5924 case REG:
5926 int regno = REGNO (x);
5928 if (reg_equiv_constant (regno) != 0)
5930 find_reloads_address_part (reg_equiv_constant (regno), loc,
5931 context_reg_class,
5932 GET_MODE (x), opnum, type, ind_levels);
5933 return 1;
5936 #if 0 /* This might screw code in reload1.cc to delete prior output-reload
5937 that feeds this insn. */
5938 if (reg_equiv_mem (regno) != 0)
5940 push_reload (reg_equiv_mem (regno), NULL_RTX, loc, (rtx*) 0,
5941 context_reg_class,
5942 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5943 return 1;
5945 #endif
5947 if (reg_equiv_memory_loc (regno)
5948 && (reg_equiv_address (regno) != 0 || num_not_at_initial_offset))
5950 rtx tem = make_memloc (x, regno);
5951 if (reg_equiv_address (regno) != 0
5952 || ! rtx_equal_p (tem, reg_equiv_mem (regno)))
5954 x = tem;
5955 find_reloads_address (GET_MODE (x), &x, XEXP (x, 0),
5956 &XEXP (x, 0), opnum, ADDR_TYPE (type),
5957 ind_levels, insn);
5958 if (!rtx_equal_p (x, tem))
5959 push_reg_equiv_alt_mem (regno, x);
5963 if (reg_renumber[regno] >= 0)
5964 regno = reg_renumber[regno];
5966 if (regno >= FIRST_PSEUDO_REGISTER
5967 || !REG_OK_FOR_CONTEXT (context, regno, mode, as, outer_code,
5968 index_code))
5970 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5971 context_reg_class,
5972 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5973 return 1;
5976 /* If a register appearing in an address is the subject of a CLOBBER
5977 in this insn, reload it into some other register to be safe.
5978 The CLOBBER is supposed to make the register unavailable
5979 from before this insn to after it. */
5980 if (regno_clobbered_p (regno, this_insn, GET_MODE (x), 0))
5982 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5983 context_reg_class,
5984 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5985 return 1;
5988 return 0;
5990 case SUBREG:
5991 if (REG_P (SUBREG_REG (x)))
5993 /* If this is a SUBREG of a hard register and the resulting register
5994 is of the wrong class, reload the whole SUBREG. This avoids
5995 needless copies if SUBREG_REG is multi-word. */
5996 if (REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER)
5998 int regno ATTRIBUTE_UNUSED = subreg_regno (x);
6000 if (!REG_OK_FOR_CONTEXT (context, regno, mode, as, outer_code,
6001 index_code))
6003 push_reload (x, NULL_RTX, loc, (rtx*) 0,
6004 context_reg_class,
6005 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
6006 return 1;
6009 /* If this is a SUBREG of a pseudo-register, and the pseudo-register
6010 is larger than the class size, then reload the whole SUBREG. */
6011 else
6013 enum reg_class rclass = context_reg_class;
6014 if (ira_reg_class_max_nregs [rclass][GET_MODE (SUBREG_REG (x))]
6015 > reg_class_size[(int) rclass])
6017 /* If the inner register will be replaced by a memory
6018 reference, we can do this only if we can replace the
6019 whole subreg by a (narrower) memory reference. If
6020 this is not possible, fall through and reload just
6021 the inner register (including address reloads). */
6022 if (reg_equiv_memory_loc (REGNO (SUBREG_REG (x))) != 0)
6024 rtx tem = find_reloads_subreg_address (x, opnum,
6025 ADDR_TYPE (type),
6026 ind_levels, insn,
6027 NULL);
6028 if (tem)
6030 push_reload (tem, NULL_RTX, loc, (rtx*) 0, rclass,
6031 GET_MODE (tem), VOIDmode, 0, 0,
6032 opnum, type);
6033 return 1;
6036 else
6038 push_reload (x, NULL_RTX, loc, (rtx*) 0, rclass,
6039 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
6040 return 1;
6045 break;
6047 default:
6048 break;
6052 const char *fmt = GET_RTX_FORMAT (code);
6053 int i;
6055 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
6057 if (fmt[i] == 'e')
6058 /* Pass SCRATCH for INDEX_CODE, since CODE can never be a PLUS once
6059 we get here. */
6060 find_reloads_address_1 (mode, as, XEXP (x, i), context,
6061 code, SCRATCH, &XEXP (x, i),
6062 opnum, type, ind_levels, insn);
6066 #undef REG_OK_FOR_CONTEXT
6067 return 0;
6070 /* X, which is found at *LOC, is a part of an address that needs to be
6071 reloaded into a register of class RCLASS. If X is a constant, or if
6072 X is a PLUS that contains a constant, check that the constant is a
6073 legitimate operand and that we are supposed to be able to load
6074 it into the register.
6076 If not, force the constant into memory and reload the MEM instead.
6078 MODE is the mode to use, in case X is an integer constant.
6080 OPNUM and TYPE describe the purpose of any reloads made.
6082 IND_LEVELS says how many levels of indirect addressing this machine
6083 supports. */
6085 static void
6086 find_reloads_address_part (rtx x, rtx *loc, enum reg_class rclass,
6087 machine_mode mode, int opnum,
6088 enum reload_type type, int ind_levels)
6090 if (CONSTANT_P (x)
6091 && (!targetm.legitimate_constant_p (mode, x)
6092 || targetm.preferred_reload_class (x, rclass) == NO_REGS))
6094 x = force_const_mem (mode, x);
6095 find_reloads_address (mode, &x, XEXP (x, 0), &XEXP (x, 0),
6096 opnum, type, ind_levels, 0);
6099 else if (GET_CODE (x) == PLUS
6100 && CONSTANT_P (XEXP (x, 1))
6101 && (!targetm.legitimate_constant_p (GET_MODE (x), XEXP (x, 1))
6102 || targetm.preferred_reload_class (XEXP (x, 1), rclass)
6103 == NO_REGS))
6105 rtx tem;
6107 tem = force_const_mem (GET_MODE (x), XEXP (x, 1));
6108 x = gen_rtx_PLUS (GET_MODE (x), XEXP (x, 0), tem);
6109 find_reloads_address (mode, &XEXP (x, 1), XEXP (tem, 0), &XEXP (tem, 0),
6110 opnum, type, ind_levels, 0);
6113 push_reload (x, NULL_RTX, loc, (rtx*) 0, rclass,
6114 mode, VOIDmode, 0, 0, opnum, type);
6117 /* X, a subreg of a pseudo, is a part of an address that needs to be
6118 reloaded, and the pseusdo is equivalent to a memory location.
6120 Attempt to replace the whole subreg by a (possibly narrower or wider)
6121 memory reference. If this is possible, return this new memory
6122 reference, and push all required address reloads. Otherwise,
6123 return NULL.
6125 OPNUM and TYPE identify the purpose of the reload.
6127 IND_LEVELS says how many levels of indirect addressing are
6128 supported at this point in the address.
6130 INSN, if nonzero, is the insn in which we do the reload. It is used
6131 to determine where to put USEs for pseudos that we have to replace with
6132 stack slots. */
6134 static rtx
6135 find_reloads_subreg_address (rtx x, int opnum, enum reload_type type,
6136 int ind_levels, rtx_insn *insn,
6137 int *address_reloaded)
6139 machine_mode outer_mode = GET_MODE (x);
6140 machine_mode inner_mode = GET_MODE (SUBREG_REG (x));
6141 int regno = REGNO (SUBREG_REG (x));
6142 int reloaded = 0;
6143 rtx tem, orig;
6144 poly_int64 offset;
6146 gcc_assert (reg_equiv_memory_loc (regno) != 0);
6148 /* We cannot replace the subreg with a modified memory reference if:
6150 - we have a paradoxical subreg that implicitly acts as a zero or
6151 sign extension operation due to LOAD_EXTEND_OP;
6153 - we have a subreg that is implicitly supposed to act on the full
6154 register due to WORD_REGISTER_OPERATIONS (see also eliminate_regs);
6156 - the address of the equivalent memory location is mode-dependent; or
6158 - we have a paradoxical subreg and the resulting memory is not
6159 sufficiently aligned to allow access in the wider mode.
6161 In addition, we choose not to perform the replacement for *any*
6162 paradoxical subreg, even if it were possible in principle. This
6163 is to avoid generating wider memory references than necessary.
6165 This corresponds to how previous versions of reload used to handle
6166 paradoxical subregs where no address reload was required. */
6168 if (paradoxical_subreg_p (x))
6169 return NULL;
6171 if (WORD_REGISTER_OPERATIONS
6172 && partial_subreg_p (outer_mode, inner_mode)
6173 && known_equal_after_align_down (GET_MODE_SIZE (outer_mode) - 1,
6174 GET_MODE_SIZE (inner_mode) - 1,
6175 UNITS_PER_WORD))
6176 return NULL;
6178 /* Since we don't attempt to handle paradoxical subregs, we can just
6179 call into simplify_subreg, which will handle all remaining checks
6180 for us. */
6181 orig = make_memloc (SUBREG_REG (x), regno);
6182 offset = SUBREG_BYTE (x);
6183 tem = simplify_subreg (outer_mode, orig, inner_mode, offset);
6184 if (!tem || !MEM_P (tem))
6185 return NULL;
6187 /* Now push all required address reloads, if any. */
6188 reloaded = find_reloads_address (GET_MODE (tem), &tem,
6189 XEXP (tem, 0), &XEXP (tem, 0),
6190 opnum, type, ind_levels, insn);
6191 /* ??? Do we need to handle nonzero offsets somehow? */
6192 if (known_eq (offset, 0) && !rtx_equal_p (tem, orig))
6193 push_reg_equiv_alt_mem (regno, tem);
6195 /* For some processors an address may be valid in the original mode but
6196 not in a smaller mode. For example, ARM accepts a scaled index register
6197 in SImode but not in HImode. Note that this is only a problem if the
6198 address in reg_equiv_mem is already invalid in the new mode; other
6199 cases would be fixed by find_reloads_address as usual.
6201 ??? We attempt to handle such cases here by doing an additional reload
6202 of the full address after the usual processing by find_reloads_address.
6203 Note that this may not work in the general case, but it seems to cover
6204 the cases where this situation currently occurs. A more general fix
6205 might be to reload the *value* instead of the address, but this would
6206 not be expected by the callers of this routine as-is.
6208 If find_reloads_address already completed replaced the address, there
6209 is nothing further to do. */
6210 if (reloaded == 0
6211 && reg_equiv_mem (regno) != 0
6212 && !strict_memory_address_addr_space_p
6213 (GET_MODE (x), XEXP (reg_equiv_mem (regno), 0),
6214 MEM_ADDR_SPACE (reg_equiv_mem (regno))))
6216 push_reload (XEXP (tem, 0), NULL_RTX, &XEXP (tem, 0), (rtx*) 0,
6217 base_reg_class (GET_MODE (tem), MEM_ADDR_SPACE (tem),
6218 MEM, SCRATCH),
6219 GET_MODE (XEXP (tem, 0)), VOIDmode, 0, 0, opnum, type);
6220 reloaded = 1;
6223 /* If this is not a toplevel operand, find_reloads doesn't see this
6224 substitution. We have to emit a USE of the pseudo so that
6225 delete_output_reload can see it. */
6226 if (replace_reloads && recog_data.operand[opnum] != x)
6227 /* We mark the USE with QImode so that we recognize it as one that
6228 can be safely deleted at the end of reload. */
6229 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, SUBREG_REG (x)), insn),
6230 QImode);
6232 if (address_reloaded)
6233 *address_reloaded = reloaded;
6235 return tem;
6238 /* Substitute into the current INSN the registers into which we have reloaded
6239 the things that need reloading. The array `replacements'
6240 contains the locations of all pointers that must be changed
6241 and says what to replace them with.
6243 Return the rtx that X translates into; usually X, but modified. */
6245 void
6246 subst_reloads (rtx_insn *insn)
6248 int i;
6250 for (i = 0; i < n_replacements; i++)
6252 struct replacement *r = &replacements[i];
6253 rtx reloadreg = rld[r->what].reg_rtx;
6254 if (reloadreg)
6256 #ifdef DEBUG_RELOAD
6257 /* This checking takes a very long time on some platforms
6258 causing the gcc.c-torture/compile/limits-fnargs.c test
6259 to time out during testing. See PR 31850.
6261 Internal consistency test. Check that we don't modify
6262 anything in the equivalence arrays. Whenever something from
6263 those arrays needs to be reloaded, it must be unshared before
6264 being substituted into; the equivalence must not be modified.
6265 Otherwise, if the equivalence is used after that, it will
6266 have been modified, and the thing substituted (probably a
6267 register) is likely overwritten and not a usable equivalence. */
6268 int check_regno;
6270 for (check_regno = 0; check_regno < max_regno; check_regno++)
6272 #define CHECK_MODF(ARRAY) \
6273 gcc_assert (!(*reg_equivs)[check_regno].ARRAY \
6274 || !loc_mentioned_in_p (r->where, \
6275 (*reg_equivs)[check_regno].ARRAY))
6277 CHECK_MODF (constant);
6278 CHECK_MODF (memory_loc);
6279 CHECK_MODF (address);
6280 CHECK_MODF (mem);
6281 #undef CHECK_MODF
6283 #endif /* DEBUG_RELOAD */
6285 /* If we're replacing a LABEL_REF with a register, there must
6286 already be an indication (to e.g. flow) which label this
6287 register refers to. */
6288 gcc_assert (GET_CODE (*r->where) != LABEL_REF
6289 || !JUMP_P (insn)
6290 || find_reg_note (insn,
6291 REG_LABEL_OPERAND,
6292 XEXP (*r->where, 0))
6293 || label_is_jump_target_p (XEXP (*r->where, 0), insn));
6295 /* Encapsulate RELOADREG so its machine mode matches what
6296 used to be there. Note that gen_lowpart_common will
6297 do the wrong thing if RELOADREG is multi-word. RELOADREG
6298 will always be a REG here. */
6299 if (GET_MODE (reloadreg) != r->mode && r->mode != VOIDmode)
6300 reloadreg = reload_adjust_reg_for_mode (reloadreg, r->mode);
6302 *r->where = reloadreg;
6304 /* If reload got no reg and isn't optional, something's wrong. */
6305 else
6306 gcc_assert (rld[r->what].optional);
6310 /* Make a copy of any replacements being done into X and move those
6311 copies to locations in Y, a copy of X. */
6313 void
6314 copy_replacements (rtx x, rtx y)
6316 copy_replacements_1 (&x, &y, n_replacements);
6319 static void
6320 copy_replacements_1 (rtx *px, rtx *py, int orig_replacements)
6322 int i, j;
6323 rtx x, y;
6324 struct replacement *r;
6325 enum rtx_code code;
6326 const char *fmt;
6328 for (j = 0; j < orig_replacements; j++)
6329 if (replacements[j].where == px)
6331 r = &replacements[n_replacements++];
6332 r->where = py;
6333 r->what = replacements[j].what;
6334 r->mode = replacements[j].mode;
6337 x = *px;
6338 y = *py;
6339 code = GET_CODE (x);
6340 fmt = GET_RTX_FORMAT (code);
6342 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
6344 if (fmt[i] == 'e')
6345 copy_replacements_1 (&XEXP (x, i), &XEXP (y, i), orig_replacements);
6346 else if (fmt[i] == 'E')
6347 for (j = XVECLEN (x, i); --j >= 0; )
6348 copy_replacements_1 (&XVECEXP (x, i, j), &XVECEXP (y, i, j),
6349 orig_replacements);
6353 /* Change any replacements being done to *X to be done to *Y. */
6355 void
6356 move_replacements (rtx *x, rtx *y)
6358 int i;
6360 for (i = 0; i < n_replacements; i++)
6361 if (replacements[i].where == x)
6362 replacements[i].where = y;
6365 /* If LOC was scheduled to be replaced by something, return the replacement.
6366 Otherwise, return *LOC. */
6369 find_replacement (rtx *loc)
6371 struct replacement *r;
6373 for (r = &replacements[0]; r < &replacements[n_replacements]; r++)
6375 rtx reloadreg = rld[r->what].reg_rtx;
6377 if (reloadreg && r->where == loc)
6379 if (r->mode != VOIDmode && GET_MODE (reloadreg) != r->mode)
6380 reloadreg = reload_adjust_reg_for_mode (reloadreg, r->mode);
6382 return reloadreg;
6384 else if (reloadreg && GET_CODE (*loc) == SUBREG
6385 && r->where == &SUBREG_REG (*loc))
6387 if (r->mode != VOIDmode && GET_MODE (reloadreg) != r->mode)
6388 reloadreg = reload_adjust_reg_for_mode (reloadreg, r->mode);
6390 return simplify_gen_subreg (GET_MODE (*loc), reloadreg,
6391 GET_MODE (SUBREG_REG (*loc)),
6392 SUBREG_BYTE (*loc));
6396 /* If *LOC is a PLUS, MINUS, or MULT, see if a replacement is scheduled for
6397 what's inside and make a new rtl if so. */
6398 if (GET_CODE (*loc) == PLUS || GET_CODE (*loc) == MINUS
6399 || GET_CODE (*loc) == MULT)
6401 rtx x = find_replacement (&XEXP (*loc, 0));
6402 rtx y = find_replacement (&XEXP (*loc, 1));
6404 if (x != XEXP (*loc, 0) || y != XEXP (*loc, 1))
6405 return gen_rtx_fmt_ee (GET_CODE (*loc), GET_MODE (*loc), x, y);
6408 return *loc;
6411 /* Return nonzero if register in range [REGNO, ENDREGNO)
6412 appears either explicitly or implicitly in X
6413 other than being stored into (except for earlyclobber operands).
6415 References contained within the substructure at LOC do not count.
6416 LOC may be zero, meaning don't ignore anything.
6418 This is similar to refers_to_regno_p in rtlanal.cc except that we
6419 look at equivalences for pseudos that didn't get hard registers. */
6421 static int
6422 refers_to_regno_for_reload_p (unsigned int regno, unsigned int endregno,
6423 rtx x, rtx *loc)
6425 int i;
6426 unsigned int r;
6427 RTX_CODE code;
6428 const char *fmt;
6430 if (x == 0)
6431 return 0;
6433 repeat:
6434 code = GET_CODE (x);
6436 switch (code)
6438 case REG:
6439 r = REGNO (x);
6441 /* If this is a pseudo, a hard register must not have been allocated.
6442 X must therefore either be a constant or be in memory. */
6443 if (r >= FIRST_PSEUDO_REGISTER)
6445 if (reg_equiv_memory_loc (r))
6446 return refers_to_regno_for_reload_p (regno, endregno,
6447 reg_equiv_memory_loc (r),
6448 (rtx*) 0);
6450 gcc_assert (reg_equiv_constant (r) || reg_equiv_invariant (r));
6451 return 0;
6454 return endregno > r && regno < END_REGNO (x);
6456 case SUBREG:
6457 /* If this is a SUBREG of a hard reg, we can see exactly which
6458 registers are being modified. Otherwise, handle normally. */
6459 if (REG_P (SUBREG_REG (x))
6460 && REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER)
6462 unsigned int inner_regno = subreg_regno (x);
6463 unsigned int inner_endregno
6464 = inner_regno + (inner_regno < FIRST_PSEUDO_REGISTER
6465 ? subreg_nregs (x) : 1);
6467 return endregno > inner_regno && regno < inner_endregno;
6469 break;
6471 case CLOBBER:
6472 case SET:
6473 if (&SET_DEST (x) != loc
6474 /* Note setting a SUBREG counts as referring to the REG it is in for
6475 a pseudo but not for hard registers since we can
6476 treat each word individually. */
6477 && ((GET_CODE (SET_DEST (x)) == SUBREG
6478 && loc != &SUBREG_REG (SET_DEST (x))
6479 && REG_P (SUBREG_REG (SET_DEST (x)))
6480 && REGNO (SUBREG_REG (SET_DEST (x))) >= FIRST_PSEUDO_REGISTER
6481 && refers_to_regno_for_reload_p (regno, endregno,
6482 SUBREG_REG (SET_DEST (x)),
6483 loc))
6484 /* If the output is an earlyclobber operand, this is
6485 a conflict. */
6486 || ((!REG_P (SET_DEST (x))
6487 || earlyclobber_operand_p (SET_DEST (x)))
6488 && refers_to_regno_for_reload_p (regno, endregno,
6489 SET_DEST (x), loc))))
6490 return 1;
6492 if (code == CLOBBER || loc == &SET_SRC (x))
6493 return 0;
6494 x = SET_SRC (x);
6495 goto repeat;
6497 default:
6498 break;
6501 /* X does not match, so try its subexpressions. */
6503 fmt = GET_RTX_FORMAT (code);
6504 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
6506 if (fmt[i] == 'e' && loc != &XEXP (x, i))
6508 if (i == 0)
6510 x = XEXP (x, 0);
6511 goto repeat;
6513 else
6514 if (refers_to_regno_for_reload_p (regno, endregno,
6515 XEXP (x, i), loc))
6516 return 1;
6518 else if (fmt[i] == 'E')
6520 int j;
6521 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
6522 if (loc != &XVECEXP (x, i, j)
6523 && refers_to_regno_for_reload_p (regno, endregno,
6524 XVECEXP (x, i, j), loc))
6525 return 1;
6528 return 0;
6531 /* Nonzero if modifying X will affect IN. If X is a register or a SUBREG,
6532 we check if any register number in X conflicts with the relevant register
6533 numbers. If X is a constant, return 0. If X is a MEM, return 1 iff IN
6534 contains a MEM (we don't bother checking for memory addresses that can't
6535 conflict because we expect this to be a rare case.
6537 This function is similar to reg_overlap_mentioned_p in rtlanal.cc except
6538 that we look at equivalences for pseudos that didn't get hard registers. */
6541 reg_overlap_mentioned_for_reload_p (rtx x, rtx in)
6543 int regno, endregno;
6545 /* Overly conservative. */
6546 if (GET_CODE (x) == STRICT_LOW_PART
6547 || GET_RTX_CLASS (GET_CODE (x)) == RTX_AUTOINC)
6548 x = XEXP (x, 0);
6550 /* If either argument is a constant, then modifying X cannot affect IN. */
6551 if (CONSTANT_P (x) || CONSTANT_P (in))
6552 return 0;
6553 else if (GET_CODE (x) == SUBREG && MEM_P (SUBREG_REG (x)))
6554 return refers_to_mem_for_reload_p (in);
6555 else if (GET_CODE (x) == SUBREG)
6557 regno = REGNO (SUBREG_REG (x));
6558 if (regno < FIRST_PSEUDO_REGISTER)
6559 regno += subreg_regno_offset (REGNO (SUBREG_REG (x)),
6560 GET_MODE (SUBREG_REG (x)),
6561 SUBREG_BYTE (x),
6562 GET_MODE (x));
6563 endregno = regno + (regno < FIRST_PSEUDO_REGISTER
6564 ? subreg_nregs (x) : 1);
6566 return refers_to_regno_for_reload_p (regno, endregno, in, (rtx*) 0);
6568 else if (REG_P (x))
6570 regno = REGNO (x);
6572 /* If this is a pseudo, it must not have been assigned a hard register.
6573 Therefore, it must either be in memory or be a constant. */
6575 if (regno >= FIRST_PSEUDO_REGISTER)
6577 if (reg_equiv_memory_loc (regno))
6578 return refers_to_mem_for_reload_p (in);
6579 gcc_assert (reg_equiv_constant (regno));
6580 return 0;
6583 endregno = END_REGNO (x);
6585 return refers_to_regno_for_reload_p (regno, endregno, in, (rtx*) 0);
6587 else if (MEM_P (x))
6588 return refers_to_mem_for_reload_p (in);
6589 else if (GET_CODE (x) == SCRATCH || GET_CODE (x) == PC)
6590 return reg_mentioned_p (x, in);
6591 else
6593 gcc_assert (GET_CODE (x) == PLUS);
6595 /* We actually want to know if X is mentioned somewhere inside IN.
6596 We must not say that (plus (sp) (const_int 124)) is in
6597 (plus (sp) (const_int 64)), since that can lead to incorrect reload
6598 allocation when spuriously changing a RELOAD_FOR_OUTPUT_ADDRESS
6599 into a RELOAD_OTHER on behalf of another RELOAD_OTHER. */
6600 while (MEM_P (in))
6601 in = XEXP (in, 0);
6602 if (REG_P (in))
6603 return 0;
6604 else if (GET_CODE (in) == PLUS)
6605 return (rtx_equal_p (x, in)
6606 || reg_overlap_mentioned_for_reload_p (x, XEXP (in, 0))
6607 || reg_overlap_mentioned_for_reload_p (x, XEXP (in, 1)));
6608 else
6609 return (reg_overlap_mentioned_for_reload_p (XEXP (x, 0), in)
6610 || reg_overlap_mentioned_for_reload_p (XEXP (x, 1), in));
6614 /* Return nonzero if anything in X contains a MEM. Look also for pseudo
6615 registers. */
6617 static int
6618 refers_to_mem_for_reload_p (rtx x)
6620 const char *fmt;
6621 int i;
6623 if (MEM_P (x))
6624 return 1;
6626 if (REG_P (x))
6627 return (REGNO (x) >= FIRST_PSEUDO_REGISTER
6628 && reg_equiv_memory_loc (REGNO (x)));
6630 fmt = GET_RTX_FORMAT (GET_CODE (x));
6631 for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--)
6632 if (fmt[i] == 'e'
6633 && (MEM_P (XEXP (x, i))
6634 || refers_to_mem_for_reload_p (XEXP (x, i))))
6635 return 1;
6637 return 0;
6640 /* Check the insns before INSN to see if there is a suitable register
6641 containing the same value as GOAL.
6642 If OTHER is -1, look for a register in class RCLASS.
6643 Otherwise, just see if register number OTHER shares GOAL's value.
6645 Return an rtx for the register found, or zero if none is found.
6647 If RELOAD_REG_P is (short *)1,
6648 we reject any hard reg that appears in reload_reg_rtx
6649 because such a hard reg is also needed coming into this insn.
6651 If RELOAD_REG_P is any other nonzero value,
6652 it is a vector indexed by hard reg number
6653 and we reject any hard reg whose element in the vector is nonnegative
6654 as well as any that appears in reload_reg_rtx.
6656 If GOAL is zero, then GOALREG is a register number; we look
6657 for an equivalent for that register.
6659 MODE is the machine mode of the value we want an equivalence for.
6660 If GOAL is nonzero and not VOIDmode, then it must have mode MODE.
6662 This function is used by jump.cc as well as in the reload pass.
6664 If GOAL is the sum of the stack pointer and a constant, we treat it
6665 as if it were a constant except that sp is required to be unchanging. */
6668 find_equiv_reg (rtx goal, rtx_insn *insn, enum reg_class rclass, int other,
6669 short *reload_reg_p, int goalreg, machine_mode mode)
6671 rtx_insn *p = insn;
6672 rtx goaltry, valtry, value;
6673 rtx_insn *where;
6674 rtx pat;
6675 int regno = -1;
6676 int valueno;
6677 int goal_mem = 0;
6678 int goal_const = 0;
6679 int goal_mem_addr_varies = 0;
6680 int need_stable_sp = 0;
6681 int nregs;
6682 int valuenregs;
6683 int num = 0;
6685 if (goal == 0)
6686 regno = goalreg;
6687 else if (REG_P (goal))
6688 regno = REGNO (goal);
6689 else if (MEM_P (goal))
6691 enum rtx_code code = GET_CODE (XEXP (goal, 0));
6692 if (MEM_VOLATILE_P (goal))
6693 return 0;
6694 if (flag_float_store && SCALAR_FLOAT_MODE_P (GET_MODE (goal)))
6695 return 0;
6696 /* An address with side effects must be reexecuted. */
6697 switch (code)
6699 case POST_INC:
6700 case PRE_INC:
6701 case POST_DEC:
6702 case PRE_DEC:
6703 case POST_MODIFY:
6704 case PRE_MODIFY:
6705 return 0;
6706 default:
6707 break;
6709 goal_mem = 1;
6711 else if (CONSTANT_P (goal))
6712 goal_const = 1;
6713 else if (GET_CODE (goal) == PLUS
6714 && XEXP (goal, 0) == stack_pointer_rtx
6715 && CONSTANT_P (XEXP (goal, 1)))
6716 goal_const = need_stable_sp = 1;
6717 else if (GET_CODE (goal) == PLUS
6718 && XEXP (goal, 0) == frame_pointer_rtx
6719 && CONSTANT_P (XEXP (goal, 1)))
6720 goal_const = 1;
6721 else
6722 return 0;
6724 num = 0;
6725 /* Scan insns back from INSN, looking for one that copies
6726 a value into or out of GOAL.
6727 Stop and give up if we reach a label. */
6729 while (1)
6731 p = PREV_INSN (p);
6732 if (p && DEBUG_INSN_P (p))
6733 continue;
6734 num++;
6735 if (p == 0 || LABEL_P (p)
6736 || num > param_max_reload_search_insns)
6737 return 0;
6739 /* Don't reuse register contents from before a setjmp-type
6740 function call; on the second return (from the longjmp) it
6741 might have been clobbered by a later reuse. It doesn't
6742 seem worthwhile to actually go and see if it is actually
6743 reused even if that information would be readily available;
6744 just don't reuse it across the setjmp call. */
6745 if (CALL_P (p) && find_reg_note (p, REG_SETJMP, NULL_RTX))
6746 return 0;
6748 if (NONJUMP_INSN_P (p)
6749 /* If we don't want spill regs ... */
6750 && (! (reload_reg_p != 0
6751 && reload_reg_p != (short *) HOST_WIDE_INT_1)
6752 /* ... then ignore insns introduced by reload; they aren't
6753 useful and can cause results in reload_as_needed to be
6754 different from what they were when calculating the need for
6755 spills. If we notice an input-reload insn here, we will
6756 reject it below, but it might hide a usable equivalent.
6757 That makes bad code. It may even fail: perhaps no reg was
6758 spilled for this insn because it was assumed we would find
6759 that equivalent. */
6760 || INSN_UID (p) < reload_first_uid))
6762 rtx tem;
6763 pat = single_set (p);
6765 /* First check for something that sets some reg equal to GOAL. */
6766 if (pat != 0
6767 && ((regno >= 0
6768 && true_regnum (SET_SRC (pat)) == regno
6769 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0)
6771 (regno >= 0
6772 && true_regnum (SET_DEST (pat)) == regno
6773 && (valueno = true_regnum (valtry = SET_SRC (pat))) >= 0)
6775 (goal_const && rtx_equal_p (SET_SRC (pat), goal)
6776 /* When looking for stack pointer + const,
6777 make sure we don't use a stack adjust. */
6778 && !reg_overlap_mentioned_for_reload_p (SET_DEST (pat), goal)
6779 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0)
6780 || (goal_mem
6781 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0
6782 && rtx_renumbered_equal_p (goal, SET_SRC (pat)))
6783 || (goal_mem
6784 && (valueno = true_regnum (valtry = SET_SRC (pat))) >= 0
6785 && rtx_renumbered_equal_p (goal, SET_DEST (pat)))
6786 /* If we are looking for a constant,
6787 and something equivalent to that constant was copied
6788 into a reg, we can use that reg. */
6789 || (goal_const && REG_NOTES (p) != 0
6790 && (tem = find_reg_note (p, REG_EQUIV, NULL_RTX))
6791 && ((rtx_equal_p (XEXP (tem, 0), goal)
6792 && (valueno
6793 = true_regnum (valtry = SET_DEST (pat))) >= 0)
6794 || (REG_P (SET_DEST (pat))
6795 && CONST_DOUBLE_AS_FLOAT_P (XEXP (tem, 0))
6796 && SCALAR_FLOAT_MODE_P (GET_MODE (XEXP (tem, 0)))
6797 && CONST_INT_P (goal)
6798 && (goaltry = operand_subword (XEXP (tem, 0), 0,
6799 0, VOIDmode)) != 0
6800 && rtx_equal_p (goal, goaltry)
6801 && (valtry
6802 = operand_subword (SET_DEST (pat), 0, 0,
6803 VOIDmode))
6804 && (valueno = true_regnum (valtry)) >= 0)))
6805 || (goal_const && (tem = find_reg_note (p, REG_EQUIV,
6806 NULL_RTX))
6807 && REG_P (SET_DEST (pat))
6808 && CONST_DOUBLE_AS_FLOAT_P (XEXP (tem, 0))
6809 && SCALAR_FLOAT_MODE_P (GET_MODE (XEXP (tem, 0)))
6810 && CONST_INT_P (goal)
6811 && (goaltry = operand_subword (XEXP (tem, 0), 1, 0,
6812 VOIDmode)) != 0
6813 && rtx_equal_p (goal, goaltry)
6814 && (valtry
6815 = operand_subword (SET_DEST (pat), 1, 0, VOIDmode))
6816 && (valueno = true_regnum (valtry)) >= 0)))
6818 if (other >= 0)
6820 if (valueno != other)
6821 continue;
6823 else if ((unsigned) valueno >= FIRST_PSEUDO_REGISTER)
6824 continue;
6825 else if (!in_hard_reg_set_p (reg_class_contents[(int) rclass],
6826 mode, valueno))
6827 continue;
6828 value = valtry;
6829 where = p;
6830 break;
6835 /* We found a previous insn copying GOAL into a suitable other reg VALUE
6836 (or copying VALUE into GOAL, if GOAL is also a register).
6837 Now verify that VALUE is really valid. */
6839 /* VALUENO is the register number of VALUE; a hard register. */
6841 /* Don't try to re-use something that is killed in this insn. We want
6842 to be able to trust REG_UNUSED notes. */
6843 if (REG_NOTES (where) != 0 && find_reg_note (where, REG_UNUSED, value))
6844 return 0;
6846 /* If we propose to get the value from the stack pointer or if GOAL is
6847 a MEM based on the stack pointer, we need a stable SP. */
6848 if (valueno == STACK_POINTER_REGNUM || regno == STACK_POINTER_REGNUM
6849 || (goal_mem && reg_overlap_mentioned_for_reload_p (stack_pointer_rtx,
6850 goal)))
6851 need_stable_sp = 1;
6853 /* Reject VALUE if the copy-insn moved the wrong sort of datum. */
6854 if (GET_MODE (value) != mode)
6855 return 0;
6857 /* Reject VALUE if it was loaded from GOAL
6858 and is also a register that appears in the address of GOAL. */
6860 if (goal_mem && value == SET_DEST (single_set (where))
6861 && refers_to_regno_for_reload_p (valueno, end_hard_regno (mode, valueno),
6862 goal, (rtx*) 0))
6863 return 0;
6865 /* Reject registers that overlap GOAL. */
6867 if (regno >= 0 && regno < FIRST_PSEUDO_REGISTER)
6868 nregs = hard_regno_nregs (regno, mode);
6869 else
6870 nregs = 1;
6871 valuenregs = hard_regno_nregs (valueno, mode);
6873 if (!goal_mem && !goal_const
6874 && regno + nregs > valueno && regno < valueno + valuenregs)
6875 return 0;
6877 /* Reject VALUE if it is one of the regs reserved for reloads.
6878 Reload1 knows how to reuse them anyway, and it would get
6879 confused if we allocated one without its knowledge.
6880 (Now that insns introduced by reload are ignored above,
6881 this case shouldn't happen, but I'm not positive.) */
6883 if (reload_reg_p != 0 && reload_reg_p != (short *) HOST_WIDE_INT_1)
6885 int i;
6886 for (i = 0; i < valuenregs; ++i)
6887 if (reload_reg_p[valueno + i] >= 0)
6888 return 0;
6891 /* Reject VALUE if it is a register being used for an input reload
6892 even if it is not one of those reserved. */
6894 if (reload_reg_p != 0)
6896 int i;
6897 for (i = 0; i < n_reloads; i++)
6898 if (rld[i].reg_rtx != 0
6899 && rld[i].in
6900 && (int) REGNO (rld[i].reg_rtx) < valueno + valuenregs
6901 && (int) END_REGNO (rld[i].reg_rtx) > valueno)
6902 return 0;
6905 if (goal_mem)
6906 /* We must treat frame pointer as varying here,
6907 since it can vary--in a nonlocal goto as generated by expand_goto. */
6908 goal_mem_addr_varies = !CONSTANT_ADDRESS_P (XEXP (goal, 0));
6910 /* Now verify that the values of GOAL and VALUE remain unaltered
6911 until INSN is reached. */
6913 p = insn;
6914 while (1)
6916 p = PREV_INSN (p);
6917 if (p == where)
6918 return value;
6920 /* Don't trust the conversion past a function call
6921 if either of the two is in a call-clobbered register, or memory. */
6922 if (CALL_P (p))
6924 if (goal_mem || need_stable_sp)
6925 return 0;
6927 function_abi callee_abi = insn_callee_abi (p);
6928 if (regno >= 0
6929 && regno < FIRST_PSEUDO_REGISTER
6930 && callee_abi.clobbers_reg_p (mode, regno))
6931 return 0;
6933 if (valueno >= 0
6934 && valueno < FIRST_PSEUDO_REGISTER
6935 && callee_abi.clobbers_reg_p (mode, valueno))
6936 return 0;
6939 if (INSN_P (p))
6941 pat = PATTERN (p);
6943 /* Watch out for unspec_volatile, and volatile asms. */
6944 if (volatile_insn_p (pat))
6945 return 0;
6947 /* If this insn P stores in either GOAL or VALUE, return 0.
6948 If GOAL is a memory ref and this insn writes memory, return 0.
6949 If GOAL is a memory ref and its address is not constant,
6950 and this insn P changes a register used in GOAL, return 0. */
6952 if (GET_CODE (pat) == COND_EXEC)
6953 pat = COND_EXEC_CODE (pat);
6954 if (GET_CODE (pat) == SET || GET_CODE (pat) == CLOBBER)
6956 rtx dest = SET_DEST (pat);
6957 while (GET_CODE (dest) == SUBREG
6958 || GET_CODE (dest) == ZERO_EXTRACT
6959 || GET_CODE (dest) == STRICT_LOW_PART)
6960 dest = XEXP (dest, 0);
6961 if (REG_P (dest))
6963 int xregno = REGNO (dest);
6964 int end_xregno = END_REGNO (dest);
6965 if (xregno < regno + nregs && end_xregno > regno)
6966 return 0;
6967 if (xregno < valueno + valuenregs
6968 && end_xregno > valueno)
6969 return 0;
6970 if (goal_mem_addr_varies
6971 && reg_overlap_mentioned_for_reload_p (dest, goal))
6972 return 0;
6973 if (xregno == STACK_POINTER_REGNUM && need_stable_sp)
6974 return 0;
6976 else if (goal_mem && MEM_P (dest)
6977 && ! push_operand (dest, GET_MODE (dest)))
6978 return 0;
6979 else if (MEM_P (dest) && regno >= FIRST_PSEUDO_REGISTER
6980 && reg_equiv_memory_loc (regno) != 0)
6981 return 0;
6982 else if (need_stable_sp && push_operand (dest, GET_MODE (dest)))
6983 return 0;
6985 else if (GET_CODE (pat) == PARALLEL)
6987 int i;
6988 for (i = XVECLEN (pat, 0) - 1; i >= 0; i--)
6990 rtx v1 = XVECEXP (pat, 0, i);
6991 if (GET_CODE (v1) == COND_EXEC)
6992 v1 = COND_EXEC_CODE (v1);
6993 if (GET_CODE (v1) == SET || GET_CODE (v1) == CLOBBER)
6995 rtx dest = SET_DEST (v1);
6996 while (GET_CODE (dest) == SUBREG
6997 || GET_CODE (dest) == ZERO_EXTRACT
6998 || GET_CODE (dest) == STRICT_LOW_PART)
6999 dest = XEXP (dest, 0);
7000 if (REG_P (dest))
7002 int xregno = REGNO (dest);
7003 int end_xregno = END_REGNO (dest);
7004 if (xregno < regno + nregs
7005 && end_xregno > regno)
7006 return 0;
7007 if (xregno < valueno + valuenregs
7008 && end_xregno > valueno)
7009 return 0;
7010 if (goal_mem_addr_varies
7011 && reg_overlap_mentioned_for_reload_p (dest,
7012 goal))
7013 return 0;
7014 if (xregno == STACK_POINTER_REGNUM && need_stable_sp)
7015 return 0;
7017 else if (goal_mem && MEM_P (dest)
7018 && ! push_operand (dest, GET_MODE (dest)))
7019 return 0;
7020 else if (MEM_P (dest) && regno >= FIRST_PSEUDO_REGISTER
7021 && reg_equiv_memory_loc (regno) != 0)
7022 return 0;
7023 else if (need_stable_sp
7024 && push_operand (dest, GET_MODE (dest)))
7025 return 0;
7030 if (CALL_P (p) && CALL_INSN_FUNCTION_USAGE (p))
7032 rtx link;
7034 for (link = CALL_INSN_FUNCTION_USAGE (p); XEXP (link, 1) != 0;
7035 link = XEXP (link, 1))
7037 pat = XEXP (link, 0);
7038 if (GET_CODE (pat) == CLOBBER)
7040 rtx dest = SET_DEST (pat);
7042 if (REG_P (dest))
7044 int xregno = REGNO (dest);
7045 int end_xregno = END_REGNO (dest);
7047 if (xregno < regno + nregs
7048 && end_xregno > regno)
7049 return 0;
7050 else if (xregno < valueno + valuenregs
7051 && end_xregno > valueno)
7052 return 0;
7053 else if (goal_mem_addr_varies
7054 && reg_overlap_mentioned_for_reload_p (dest,
7055 goal))
7056 return 0;
7059 else if (goal_mem && MEM_P (dest)
7060 && ! push_operand (dest, GET_MODE (dest)))
7061 return 0;
7062 else if (need_stable_sp
7063 && push_operand (dest, GET_MODE (dest)))
7064 return 0;
7069 #if AUTO_INC_DEC
7070 /* If this insn auto-increments or auto-decrements
7071 either regno or valueno, return 0 now.
7072 If GOAL is a memory ref and its address is not constant,
7073 and this insn P increments a register used in GOAL, return 0. */
7075 rtx link;
7077 for (link = REG_NOTES (p); link; link = XEXP (link, 1))
7078 if (REG_NOTE_KIND (link) == REG_INC
7079 && REG_P (XEXP (link, 0)))
7081 int incno = REGNO (XEXP (link, 0));
7082 if (incno < regno + nregs && incno >= regno)
7083 return 0;
7084 if (incno < valueno + valuenregs && incno >= valueno)
7085 return 0;
7086 if (goal_mem_addr_varies
7087 && reg_overlap_mentioned_for_reload_p (XEXP (link, 0),
7088 goal))
7089 return 0;
7092 #endif
7097 /* Find a place where INCED appears in an increment or decrement operator
7098 within X, and return the amount INCED is incremented or decremented by.
7099 The value is always positive. */
7101 static poly_int64
7102 find_inc_amount (rtx x, rtx inced)
7104 enum rtx_code code = GET_CODE (x);
7105 const char *fmt;
7106 int i;
7108 if (code == MEM)
7110 rtx addr = XEXP (x, 0);
7111 if ((GET_CODE (addr) == PRE_DEC
7112 || GET_CODE (addr) == POST_DEC
7113 || GET_CODE (addr) == PRE_INC
7114 || GET_CODE (addr) == POST_INC)
7115 && XEXP (addr, 0) == inced)
7116 return GET_MODE_SIZE (GET_MODE (x));
7117 else if ((GET_CODE (addr) == PRE_MODIFY
7118 || GET_CODE (addr) == POST_MODIFY)
7119 && GET_CODE (XEXP (addr, 1)) == PLUS
7120 && XEXP (addr, 0) == XEXP (XEXP (addr, 1), 0)
7121 && XEXP (addr, 0) == inced
7122 && CONST_INT_P (XEXP (XEXP (addr, 1), 1)))
7124 i = INTVAL (XEXP (XEXP (addr, 1), 1));
7125 return i < 0 ? -i : i;
7129 fmt = GET_RTX_FORMAT (code);
7130 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
7132 if (fmt[i] == 'e')
7134 poly_int64 tem = find_inc_amount (XEXP (x, i), inced);
7135 if (maybe_ne (tem, 0))
7136 return tem;
7138 if (fmt[i] == 'E')
7140 int j;
7141 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
7143 poly_int64 tem = find_inc_amount (XVECEXP (x, i, j), inced);
7144 if (maybe_ne (tem, 0))
7145 return tem;
7150 return 0;
7153 /* Return 1 if registers from REGNO to ENDREGNO are the subjects of a
7154 REG_INC note in insn INSN. REGNO must refer to a hard register. */
7156 static int
7157 reg_inc_found_and_valid_p (unsigned int regno, unsigned int endregno,
7158 rtx insn)
7160 rtx link;
7162 if (!AUTO_INC_DEC)
7163 return 0;
7165 gcc_assert (insn);
7167 if (! INSN_P (insn))
7168 return 0;
7170 for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
7171 if (REG_NOTE_KIND (link) == REG_INC)
7173 unsigned int test = (int) REGNO (XEXP (link, 0));
7174 if (test >= regno && test < endregno)
7175 return 1;
7177 return 0;
7180 /* Return 1 if register REGNO is the subject of a clobber in insn INSN.
7181 If SETS is 1, also consider SETs. If SETS is 2, enable checking
7182 REG_INC. REGNO must refer to a hard register. */
7185 regno_clobbered_p (unsigned int regno, rtx_insn *insn, machine_mode mode,
7186 int sets)
7188 /* regno must be a hard register. */
7189 gcc_assert (regno < FIRST_PSEUDO_REGISTER);
7191 unsigned int endregno = end_hard_regno (mode, regno);
7193 if ((GET_CODE (PATTERN (insn)) == CLOBBER
7194 || (sets == 1 && GET_CODE (PATTERN (insn)) == SET))
7195 && REG_P (XEXP (PATTERN (insn), 0)))
7197 unsigned int test = REGNO (XEXP (PATTERN (insn), 0));
7199 return test >= regno && test < endregno;
7202 if (sets == 2 && reg_inc_found_and_valid_p (regno, endregno, insn))
7203 return 1;
7205 if (GET_CODE (PATTERN (insn)) == PARALLEL)
7207 int i = XVECLEN (PATTERN (insn), 0) - 1;
7209 for (; i >= 0; i--)
7211 rtx elt = XVECEXP (PATTERN (insn), 0, i);
7212 if ((GET_CODE (elt) == CLOBBER
7213 || (sets == 1 && GET_CODE (elt) == SET))
7214 && REG_P (XEXP (elt, 0)))
7216 unsigned int test = REGNO (XEXP (elt, 0));
7218 if (test >= regno && test < endregno)
7219 return 1;
7221 if (sets == 2
7222 && reg_inc_found_and_valid_p (regno, endregno, elt))
7223 return 1;
7227 return 0;
7230 /* Find the low part, with mode MODE, of a hard regno RELOADREG. */
7232 reload_adjust_reg_for_mode (rtx reloadreg, machine_mode mode)
7234 int regno;
7236 if (GET_MODE (reloadreg) == mode)
7237 return reloadreg;
7239 regno = REGNO (reloadreg);
7241 if (REG_WORDS_BIG_ENDIAN)
7242 regno += ((int) REG_NREGS (reloadreg)
7243 - (int) hard_regno_nregs (regno, mode));
7245 return gen_rtx_REG (mode, regno);
7248 static const char *const reload_when_needed_name[] =
7250 "RELOAD_FOR_INPUT",
7251 "RELOAD_FOR_OUTPUT",
7252 "RELOAD_FOR_INSN",
7253 "RELOAD_FOR_INPUT_ADDRESS",
7254 "RELOAD_FOR_INPADDR_ADDRESS",
7255 "RELOAD_FOR_OUTPUT_ADDRESS",
7256 "RELOAD_FOR_OUTADDR_ADDRESS",
7257 "RELOAD_FOR_OPERAND_ADDRESS",
7258 "RELOAD_FOR_OPADDR_ADDR",
7259 "RELOAD_OTHER",
7260 "RELOAD_FOR_OTHER_ADDRESS"
7263 /* These functions are used to print the variables set by 'find_reloads' */
7265 DEBUG_FUNCTION void
7266 debug_reload_to_stream (FILE *f)
7268 int r;
7269 const char *prefix;
7271 if (! f)
7272 f = stderr;
7273 for (r = 0; r < n_reloads; r++)
7275 fprintf (f, "Reload %d: ", r);
7277 if (rld[r].in != 0)
7279 fprintf (f, "reload_in (%s) = ",
7280 GET_MODE_NAME (rld[r].inmode));
7281 print_inline_rtx (f, rld[r].in, 24);
7282 fprintf (f, "\n\t");
7285 if (rld[r].out != 0)
7287 fprintf (f, "reload_out (%s) = ",
7288 GET_MODE_NAME (rld[r].outmode));
7289 print_inline_rtx (f, rld[r].out, 24);
7290 fprintf (f, "\n\t");
7293 fprintf (f, "%s, ", reg_class_names[(int) rld[r].rclass]);
7295 fprintf (f, "%s (opnum = %d)",
7296 reload_when_needed_name[(int) rld[r].when_needed],
7297 rld[r].opnum);
7299 if (rld[r].optional)
7300 fprintf (f, ", optional");
7302 if (rld[r].nongroup)
7303 fprintf (f, ", nongroup");
7305 if (maybe_ne (rld[r].inc, 0))
7307 fprintf (f, ", inc by ");
7308 print_dec (rld[r].inc, f, SIGNED);
7311 if (rld[r].nocombine)
7312 fprintf (f, ", can't combine");
7314 if (rld[r].secondary_p)
7315 fprintf (f, ", secondary_reload_p");
7317 if (rld[r].in_reg != 0)
7319 fprintf (f, "\n\treload_in_reg: ");
7320 print_inline_rtx (f, rld[r].in_reg, 24);
7323 if (rld[r].out_reg != 0)
7325 fprintf (f, "\n\treload_out_reg: ");
7326 print_inline_rtx (f, rld[r].out_reg, 24);
7329 if (rld[r].reg_rtx != 0)
7331 fprintf (f, "\n\treload_reg_rtx: ");
7332 print_inline_rtx (f, rld[r].reg_rtx, 24);
7335 prefix = "\n\t";
7336 if (rld[r].secondary_in_reload != -1)
7338 fprintf (f, "%ssecondary_in_reload = %d",
7339 prefix, rld[r].secondary_in_reload);
7340 prefix = ", ";
7343 if (rld[r].secondary_out_reload != -1)
7344 fprintf (f, "%ssecondary_out_reload = %d\n",
7345 prefix, rld[r].secondary_out_reload);
7347 prefix = "\n\t";
7348 if (rld[r].secondary_in_icode != CODE_FOR_nothing)
7350 fprintf (f, "%ssecondary_in_icode = %s", prefix,
7351 insn_data[rld[r].secondary_in_icode].name);
7352 prefix = ", ";
7355 if (rld[r].secondary_out_icode != CODE_FOR_nothing)
7356 fprintf (f, "%ssecondary_out_icode = %s", prefix,
7357 insn_data[rld[r].secondary_out_icode].name);
7359 fprintf (f, "\n");
7363 DEBUG_FUNCTION void
7364 debug_reload (void)
7366 debug_reload_to_stream (stderr);