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18ca7dab | 1 | /* Subroutines for manipulating rtx's in semantically interesting ways. |
747215f1 | 2 | Copyright (C) 1987, 91, 94-97, 1998, 1999 Free Software Foundation, Inc. |
18ca7dab RK |
3 | |
4 | This file is part of GNU CC. | |
5 | ||
6 | GNU CC is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2, or (at your option) | |
9 | any later version. | |
10 | ||
11 | GNU CC is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GNU CC; see the file COPYING. If not, write to | |
940d9d63 RK |
18 | the Free Software Foundation, 59 Temple Place - Suite 330, |
19 | Boston, MA 02111-1307, USA. */ | |
18ca7dab RK |
20 | |
21 | ||
22 | #include "config.h" | |
670ee920 | 23 | #include "system.h" |
18ca7dab RK |
24 | #include "rtl.h" |
25 | #include "tree.h" | |
26 | #include "flags.h" | |
27 | #include "expr.h" | |
28 | #include "hard-reg-set.h" | |
29 | #include "insn-config.h" | |
30 | #include "recog.h" | |
31 | #include "insn-flags.h" | |
32 | #include "insn-codes.h" | |
33 | ||
c795bca9 BS |
34 | #if !defined PREFERRED_STACK_BOUNDARY && defined STACK_BOUNDARY |
35 | #define PREFERRED_STACK_BOUNDARY STACK_BOUNDARY | |
36 | #endif | |
37 | ||
ea534b63 | 38 | static rtx break_out_memory_refs PROTO((rtx)); |
edff2491 | 39 | static void emit_stack_probe PROTO((rtx)); |
b1ec3c92 CH |
40 | /* Return an rtx for the sum of X and the integer C. |
41 | ||
8008b228 | 42 | This function should be used via the `plus_constant' macro. */ |
18ca7dab RK |
43 | |
44 | rtx | |
b1ec3c92 | 45 | plus_constant_wide (x, c) |
18ca7dab | 46 | register rtx x; |
b1ec3c92 | 47 | register HOST_WIDE_INT c; |
18ca7dab RK |
48 | { |
49 | register RTX_CODE code; | |
50 | register enum machine_mode mode; | |
51 | register rtx tem; | |
52 | int all_constant = 0; | |
53 | ||
54 | if (c == 0) | |
55 | return x; | |
56 | ||
57 | restart: | |
58 | ||
59 | code = GET_CODE (x); | |
60 | mode = GET_MODE (x); | |
61 | switch (code) | |
62 | { | |
63 | case CONST_INT: | |
b1ec3c92 | 64 | return GEN_INT (INTVAL (x) + c); |
18ca7dab RK |
65 | |
66 | case CONST_DOUBLE: | |
67 | { | |
b1ec3c92 CH |
68 | HOST_WIDE_INT l1 = CONST_DOUBLE_LOW (x); |
69 | HOST_WIDE_INT h1 = CONST_DOUBLE_HIGH (x); | |
70 | HOST_WIDE_INT l2 = c; | |
71 | HOST_WIDE_INT h2 = c < 0 ? ~0 : 0; | |
72 | HOST_WIDE_INT lv, hv; | |
18ca7dab RK |
73 | |
74 | add_double (l1, h1, l2, h2, &lv, &hv); | |
75 | ||
76 | return immed_double_const (lv, hv, VOIDmode); | |
77 | } | |
78 | ||
79 | case MEM: | |
80 | /* If this is a reference to the constant pool, try replacing it with | |
81 | a reference to a new constant. If the resulting address isn't | |
82 | valid, don't return it because we have no way to validize it. */ | |
83 | if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF | |
84 | && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0))) | |
85 | { | |
38a448ca RH |
86 | /* Any rtl we create here must go in a saveable obstack, since |
87 | we might have been called from within combine. */ | |
88 | push_obstacks_nochange (); | |
89 | rtl_in_saveable_obstack (); | |
18ca7dab RK |
90 | tem |
91 | = force_const_mem (GET_MODE (x), | |
92 | plus_constant (get_pool_constant (XEXP (x, 0)), | |
93 | c)); | |
38a448ca | 94 | pop_obstacks (); |
18ca7dab RK |
95 | if (memory_address_p (GET_MODE (tem), XEXP (tem, 0))) |
96 | return tem; | |
97 | } | |
98 | break; | |
99 | ||
100 | case CONST: | |
101 | /* If adding to something entirely constant, set a flag | |
102 | so that we can add a CONST around the result. */ | |
103 | x = XEXP (x, 0); | |
104 | all_constant = 1; | |
105 | goto restart; | |
106 | ||
107 | case SYMBOL_REF: | |
108 | case LABEL_REF: | |
109 | all_constant = 1; | |
110 | break; | |
111 | ||
112 | case PLUS: | |
113 | /* The interesting case is adding the integer to a sum. | |
114 | Look for constant term in the sum and combine | |
115 | with C. For an integer constant term, we make a combined | |
116 | integer. For a constant term that is not an explicit integer, | |
e5671f2b RK |
117 | we cannot really combine, but group them together anyway. |
118 | ||
03d937fc R |
119 | Restart or use a recursive call in case the remaining operand is |
120 | something that we handle specially, such as a SYMBOL_REF. | |
121 | ||
122 | We may not immediately return from the recursive call here, lest | |
123 | all_constant gets lost. */ | |
e5671f2b RK |
124 | |
125 | if (GET_CODE (XEXP (x, 1)) == CONST_INT) | |
03d937fc R |
126 | { |
127 | c += INTVAL (XEXP (x, 1)); | |
128 | x = XEXP (x, 0); | |
129 | goto restart; | |
130 | } | |
18ca7dab | 131 | else if (CONSTANT_P (XEXP (x, 0))) |
03d937fc R |
132 | { |
133 | x = gen_rtx_PLUS (mode, | |
134 | plus_constant (XEXP (x, 0), c), | |
135 | XEXP (x, 1)); | |
136 | c = 0; | |
137 | } | |
18ca7dab | 138 | else if (CONSTANT_P (XEXP (x, 1))) |
03d937fc R |
139 | { |
140 | x = gen_rtx_PLUS (mode, | |
141 | XEXP (x, 0), | |
142 | plus_constant (XEXP (x, 1), c)); | |
143 | c = 0; | |
144 | } | |
38a448ca RH |
145 | break; |
146 | ||
147 | default: | |
148 | break; | |
18ca7dab RK |
149 | } |
150 | ||
151 | if (c != 0) | |
38a448ca | 152 | x = gen_rtx_PLUS (mode, x, GEN_INT (c)); |
18ca7dab RK |
153 | |
154 | if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF) | |
155 | return x; | |
156 | else if (all_constant) | |
38a448ca | 157 | return gen_rtx_CONST (mode, x); |
18ca7dab RK |
158 | else |
159 | return x; | |
160 | } | |
161 | ||
b1ec3c92 CH |
162 | /* This is the same as `plus_constant', except that it handles LO_SUM. |
163 | ||
164 | This function should be used via the `plus_constant_for_output' macro. */ | |
18ca7dab RK |
165 | |
166 | rtx | |
b1ec3c92 | 167 | plus_constant_for_output_wide (x, c) |
18ca7dab | 168 | register rtx x; |
b1ec3c92 | 169 | register HOST_WIDE_INT c; |
18ca7dab | 170 | { |
18ca7dab | 171 | register enum machine_mode mode = GET_MODE (x); |
18ca7dab RK |
172 | |
173 | if (GET_CODE (x) == LO_SUM) | |
38a448ca | 174 | return gen_rtx_LO_SUM (mode, XEXP (x, 0), |
18ca7dab RK |
175 | plus_constant_for_output (XEXP (x, 1), c)); |
176 | ||
177 | else | |
178 | return plus_constant (x, c); | |
179 | } | |
180 | \f | |
181 | /* If X is a sum, return a new sum like X but lacking any constant terms. | |
182 | Add all the removed constant terms into *CONSTPTR. | |
183 | X itself is not altered. The result != X if and only if | |
184 | it is not isomorphic to X. */ | |
185 | ||
186 | rtx | |
187 | eliminate_constant_term (x, constptr) | |
188 | rtx x; | |
189 | rtx *constptr; | |
190 | { | |
191 | register rtx x0, x1; | |
192 | rtx tem; | |
193 | ||
194 | if (GET_CODE (x) != PLUS) | |
195 | return x; | |
196 | ||
197 | /* First handle constants appearing at this level explicitly. */ | |
198 | if (GET_CODE (XEXP (x, 1)) == CONST_INT | |
199 | && 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x), *constptr, | |
200 | XEXP (x, 1))) | |
201 | && GET_CODE (tem) == CONST_INT) | |
202 | { | |
203 | *constptr = tem; | |
204 | return eliminate_constant_term (XEXP (x, 0), constptr); | |
205 | } | |
206 | ||
207 | tem = const0_rtx; | |
208 | x0 = eliminate_constant_term (XEXP (x, 0), &tem); | |
209 | x1 = eliminate_constant_term (XEXP (x, 1), &tem); | |
210 | if ((x1 != XEXP (x, 1) || x0 != XEXP (x, 0)) | |
211 | && 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x), | |
212 | *constptr, tem)) | |
213 | && GET_CODE (tem) == CONST_INT) | |
214 | { | |
215 | *constptr = tem; | |
38a448ca | 216 | return gen_rtx_PLUS (GET_MODE (x), x0, x1); |
18ca7dab RK |
217 | } |
218 | ||
219 | return x; | |
220 | } | |
221 | ||
222 | /* Returns the insn that next references REG after INSN, or 0 | |
223 | if REG is clobbered before next referenced or we cannot find | |
224 | an insn that references REG in a straight-line piece of code. */ | |
225 | ||
226 | rtx | |
227 | find_next_ref (reg, insn) | |
228 | rtx reg; | |
229 | rtx insn; | |
230 | { | |
231 | rtx next; | |
232 | ||
233 | for (insn = NEXT_INSN (insn); insn; insn = next) | |
234 | { | |
235 | next = NEXT_INSN (insn); | |
236 | if (GET_CODE (insn) == NOTE) | |
237 | continue; | |
238 | if (GET_CODE (insn) == CODE_LABEL | |
239 | || GET_CODE (insn) == BARRIER) | |
240 | return 0; | |
241 | if (GET_CODE (insn) == INSN | |
242 | || GET_CODE (insn) == JUMP_INSN | |
243 | || GET_CODE (insn) == CALL_INSN) | |
244 | { | |
245 | if (reg_set_p (reg, insn)) | |
246 | return 0; | |
247 | if (reg_mentioned_p (reg, PATTERN (insn))) | |
248 | return insn; | |
249 | if (GET_CODE (insn) == JUMP_INSN) | |
250 | { | |
251 | if (simplejump_p (insn)) | |
252 | next = JUMP_LABEL (insn); | |
253 | else | |
254 | return 0; | |
255 | } | |
256 | if (GET_CODE (insn) == CALL_INSN | |
257 | && REGNO (reg) < FIRST_PSEUDO_REGISTER | |
258 | && call_used_regs[REGNO (reg)]) | |
259 | return 0; | |
260 | } | |
261 | else | |
262 | abort (); | |
263 | } | |
264 | return 0; | |
265 | } | |
266 | ||
267 | /* Return an rtx for the size in bytes of the value of EXP. */ | |
268 | ||
269 | rtx | |
270 | expr_size (exp) | |
271 | tree exp; | |
272 | { | |
99098c66 RK |
273 | tree size = size_in_bytes (TREE_TYPE (exp)); |
274 | ||
275 | if (TREE_CODE (size) != INTEGER_CST | |
276 | && contains_placeholder_p (size)) | |
277 | size = build (WITH_RECORD_EXPR, sizetype, size, exp); | |
278 | ||
8fbea4dc RK |
279 | return expand_expr (size, NULL_RTX, TYPE_MODE (sizetype), |
280 | EXPAND_MEMORY_USE_BAD); | |
18ca7dab RK |
281 | } |
282 | \f | |
283 | /* Return a copy of X in which all memory references | |
284 | and all constants that involve symbol refs | |
285 | have been replaced with new temporary registers. | |
286 | Also emit code to load the memory locations and constants | |
287 | into those registers. | |
288 | ||
289 | If X contains no such constants or memory references, | |
290 | X itself (not a copy) is returned. | |
291 | ||
292 | If a constant is found in the address that is not a legitimate constant | |
293 | in an insn, it is left alone in the hope that it might be valid in the | |
294 | address. | |
295 | ||
296 | X may contain no arithmetic except addition, subtraction and multiplication. | |
297 | Values returned by expand_expr with 1 for sum_ok fit this constraint. */ | |
298 | ||
299 | static rtx | |
300 | break_out_memory_refs (x) | |
301 | register rtx x; | |
302 | { | |
303 | if (GET_CODE (x) == MEM | |
cabeca29 | 304 | || (CONSTANT_P (x) && CONSTANT_ADDRESS_P (x) |
18ca7dab | 305 | && GET_MODE (x) != VOIDmode)) |
2cca6e3f | 306 | x = force_reg (GET_MODE (x), x); |
18ca7dab RK |
307 | else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS |
308 | || GET_CODE (x) == MULT) | |
309 | { | |
310 | register rtx op0 = break_out_memory_refs (XEXP (x, 0)); | |
311 | register rtx op1 = break_out_memory_refs (XEXP (x, 1)); | |
2cca6e3f | 312 | |
18ca7dab | 313 | if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1)) |
38a448ca | 314 | x = gen_rtx_fmt_ee (GET_CODE (x), Pmode, op0, op1); |
18ca7dab | 315 | } |
2cca6e3f | 316 | |
18ca7dab RK |
317 | return x; |
318 | } | |
319 | ||
ea534b63 RK |
320 | #ifdef POINTERS_EXTEND_UNSIGNED |
321 | ||
322 | /* Given X, a memory address in ptr_mode, convert it to an address | |
498b529f RK |
323 | in Pmode, or vice versa (TO_MODE says which way). We take advantage of |
324 | the fact that pointers are not allowed to overflow by commuting arithmetic | |
325 | operations over conversions so that address arithmetic insns can be | |
326 | used. */ | |
ea534b63 | 327 | |
498b529f RK |
328 | rtx |
329 | convert_memory_address (to_mode, x) | |
330 | enum machine_mode to_mode; | |
ea534b63 RK |
331 | rtx x; |
332 | { | |
0b04ec8c | 333 | enum machine_mode from_mode = to_mode == ptr_mode ? Pmode : ptr_mode; |
498b529f RK |
334 | rtx temp; |
335 | ||
0b04ec8c RK |
336 | /* Here we handle some special cases. If none of them apply, fall through |
337 | to the default case. */ | |
ea534b63 RK |
338 | switch (GET_CODE (x)) |
339 | { | |
340 | case CONST_INT: | |
341 | case CONST_DOUBLE: | |
498b529f RK |
342 | return x; |
343 | ||
ea534b63 | 344 | case LABEL_REF: |
38a448ca RH |
345 | temp = gen_rtx_LABEL_REF (to_mode, XEXP (x, 0)); |
346 | LABEL_REF_NONLOCAL_P (temp) = LABEL_REF_NONLOCAL_P (x); | |
347 | return temp; | |
498b529f | 348 | |
ea534b63 | 349 | case SYMBOL_REF: |
38a448ca | 350 | temp = gen_rtx_SYMBOL_REF (to_mode, XSTR (x, 0)); |
498b529f | 351 | SYMBOL_REF_FLAG (temp) = SYMBOL_REF_FLAG (x); |
d7dc4377 | 352 | CONSTANT_POOL_ADDRESS_P (temp) = CONSTANT_POOL_ADDRESS_P (x); |
498b529f | 353 | return temp; |
ea534b63 | 354 | |
498b529f | 355 | case CONST: |
38a448ca RH |
356 | return gen_rtx_CONST (to_mode, |
357 | convert_memory_address (to_mode, XEXP (x, 0))); | |
ea534b63 | 358 | |
0b04ec8c RK |
359 | case PLUS: |
360 | case MULT: | |
361 | /* For addition the second operand is a small constant, we can safely | |
38a448ca | 362 | permute the conversion and addition operation. We can always safely |
60725c78 RK |
363 | permute them if we are making the address narrower. In addition, |
364 | always permute the operations if this is a constant. */ | |
0b04ec8c RK |
365 | if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode) |
366 | || (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 1)) == CONST_INT | |
60725c78 RK |
367 | && (INTVAL (XEXP (x, 1)) + 20000 < 40000 |
368 | || CONSTANT_P (XEXP (x, 0))))) | |
38a448ca RH |
369 | return gen_rtx_fmt_ee (GET_CODE (x), to_mode, |
370 | convert_memory_address (to_mode, XEXP (x, 0)), | |
371 | convert_memory_address (to_mode, XEXP (x, 1))); | |
372 | break; | |
373 | ||
374 | default: | |
375 | break; | |
ea534b63 | 376 | } |
0b04ec8c RK |
377 | |
378 | return convert_modes (to_mode, from_mode, | |
379 | x, POINTERS_EXTEND_UNSIGNED); | |
ea534b63 RK |
380 | } |
381 | #endif | |
382 | ||
18ca7dab RK |
383 | /* Given a memory address or facsimile X, construct a new address, |
384 | currently equivalent, that is stable: future stores won't change it. | |
385 | ||
386 | X must be composed of constants, register and memory references | |
387 | combined with addition, subtraction and multiplication: | |
388 | in other words, just what you can get from expand_expr if sum_ok is 1. | |
389 | ||
390 | Works by making copies of all regs and memory locations used | |
391 | by X and combining them the same way X does. | |
392 | You could also stabilize the reference to this address | |
393 | by copying the address to a register with copy_to_reg; | |
394 | but then you wouldn't get indexed addressing in the reference. */ | |
395 | ||
396 | rtx | |
397 | copy_all_regs (x) | |
398 | register rtx x; | |
399 | { | |
400 | if (GET_CODE (x) == REG) | |
401 | { | |
11c50c5e DE |
402 | if (REGNO (x) != FRAME_POINTER_REGNUM |
403 | #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM | |
404 | && REGNO (x) != HARD_FRAME_POINTER_REGNUM | |
405 | #endif | |
406 | ) | |
18ca7dab RK |
407 | x = copy_to_reg (x); |
408 | } | |
409 | else if (GET_CODE (x) == MEM) | |
410 | x = copy_to_reg (x); | |
411 | else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS | |
412 | || GET_CODE (x) == MULT) | |
413 | { | |
414 | register rtx op0 = copy_all_regs (XEXP (x, 0)); | |
415 | register rtx op1 = copy_all_regs (XEXP (x, 1)); | |
416 | if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1)) | |
38a448ca | 417 | x = gen_rtx_fmt_ee (GET_CODE (x), Pmode, op0, op1); |
18ca7dab RK |
418 | } |
419 | return x; | |
420 | } | |
421 | \f | |
422 | /* Return something equivalent to X but valid as a memory address | |
423 | for something of mode MODE. When X is not itself valid, this | |
424 | works by copying X or subexpressions of it into registers. */ | |
425 | ||
426 | rtx | |
427 | memory_address (mode, x) | |
428 | enum machine_mode mode; | |
429 | register rtx x; | |
430 | { | |
18b9ca6f | 431 | register rtx oldx = x; |
18ca7dab | 432 | |
38a448ca RH |
433 | if (GET_CODE (x) == ADDRESSOF) |
434 | return x; | |
435 | ||
ea534b63 RK |
436 | #ifdef POINTERS_EXTEND_UNSIGNED |
437 | if (GET_MODE (x) == ptr_mode) | |
498b529f | 438 | x = convert_memory_address (Pmode, x); |
ea534b63 RK |
439 | #endif |
440 | ||
18ca7dab RK |
441 | /* By passing constant addresses thru registers |
442 | we get a chance to cse them. */ | |
cabeca29 | 443 | if (! cse_not_expected && CONSTANT_P (x) && CONSTANT_ADDRESS_P (x)) |
18b9ca6f | 444 | x = force_reg (Pmode, x); |
18ca7dab RK |
445 | |
446 | /* Accept a QUEUED that refers to a REG | |
447 | even though that isn't a valid address. | |
448 | On attempting to put this in an insn we will call protect_from_queue | |
449 | which will turn it into a REG, which is valid. */ | |
18b9ca6f | 450 | else if (GET_CODE (x) == QUEUED |
18ca7dab | 451 | && GET_CODE (QUEUED_VAR (x)) == REG) |
18b9ca6f | 452 | ; |
18ca7dab RK |
453 | |
454 | /* We get better cse by rejecting indirect addressing at this stage. | |
455 | Let the combiner create indirect addresses where appropriate. | |
456 | For now, generate the code so that the subexpressions useful to share | |
457 | are visible. But not if cse won't be done! */ | |
18b9ca6f | 458 | else |
18ca7dab | 459 | { |
18b9ca6f RK |
460 | if (! cse_not_expected && GET_CODE (x) != REG) |
461 | x = break_out_memory_refs (x); | |
462 | ||
463 | /* At this point, any valid address is accepted. */ | |
464 | GO_IF_LEGITIMATE_ADDRESS (mode, x, win); | |
465 | ||
466 | /* If it was valid before but breaking out memory refs invalidated it, | |
467 | use it the old way. */ | |
468 | if (memory_address_p (mode, oldx)) | |
469 | goto win2; | |
470 | ||
471 | /* Perform machine-dependent transformations on X | |
472 | in certain cases. This is not necessary since the code | |
473 | below can handle all possible cases, but machine-dependent | |
474 | transformations can make better code. */ | |
475 | LEGITIMIZE_ADDRESS (x, oldx, mode, win); | |
476 | ||
477 | /* PLUS and MULT can appear in special ways | |
478 | as the result of attempts to make an address usable for indexing. | |
479 | Usually they are dealt with by calling force_operand, below. | |
480 | But a sum containing constant terms is special | |
481 | if removing them makes the sum a valid address: | |
482 | then we generate that address in a register | |
483 | and index off of it. We do this because it often makes | |
484 | shorter code, and because the addresses thus generated | |
485 | in registers often become common subexpressions. */ | |
486 | if (GET_CODE (x) == PLUS) | |
487 | { | |
488 | rtx constant_term = const0_rtx; | |
489 | rtx y = eliminate_constant_term (x, &constant_term); | |
490 | if (constant_term == const0_rtx | |
491 | || ! memory_address_p (mode, y)) | |
492 | x = force_operand (x, NULL_RTX); | |
493 | else | |
494 | { | |
38a448ca | 495 | y = gen_rtx_PLUS (GET_MODE (x), copy_to_reg (y), constant_term); |
18b9ca6f RK |
496 | if (! memory_address_p (mode, y)) |
497 | x = force_operand (x, NULL_RTX); | |
498 | else | |
499 | x = y; | |
500 | } | |
501 | } | |
18ca7dab | 502 | |
e475ed2a | 503 | else if (GET_CODE (x) == MULT || GET_CODE (x) == MINUS) |
18b9ca6f | 504 | x = force_operand (x, NULL_RTX); |
18ca7dab | 505 | |
18b9ca6f RK |
506 | /* If we have a register that's an invalid address, |
507 | it must be a hard reg of the wrong class. Copy it to a pseudo. */ | |
508 | else if (GET_CODE (x) == REG) | |
509 | x = copy_to_reg (x); | |
510 | ||
511 | /* Last resort: copy the value to a register, since | |
512 | the register is a valid address. */ | |
513 | else | |
514 | x = force_reg (Pmode, x); | |
515 | ||
516 | goto done; | |
18ca7dab | 517 | |
c02a7fbb RK |
518 | win2: |
519 | x = oldx; | |
520 | win: | |
521 | if (flag_force_addr && ! cse_not_expected && GET_CODE (x) != REG | |
522 | /* Don't copy an addr via a reg if it is one of our stack slots. */ | |
523 | && ! (GET_CODE (x) == PLUS | |
524 | && (XEXP (x, 0) == virtual_stack_vars_rtx | |
525 | || XEXP (x, 0) == virtual_incoming_args_rtx))) | |
526 | { | |
527 | if (general_operand (x, Pmode)) | |
528 | x = force_reg (Pmode, x); | |
529 | else | |
530 | x = force_operand (x, NULL_RTX); | |
531 | } | |
18ca7dab | 532 | } |
18b9ca6f RK |
533 | |
534 | done: | |
535 | ||
2cca6e3f RK |
536 | /* If we didn't change the address, we are done. Otherwise, mark |
537 | a reg as a pointer if we have REG or REG + CONST_INT. */ | |
538 | if (oldx == x) | |
539 | return x; | |
540 | else if (GET_CODE (x) == REG) | |
305f22b5 | 541 | mark_reg_pointer (x, 1); |
2cca6e3f RK |
542 | else if (GET_CODE (x) == PLUS |
543 | && GET_CODE (XEXP (x, 0)) == REG | |
544 | && GET_CODE (XEXP (x, 1)) == CONST_INT) | |
305f22b5 | 545 | mark_reg_pointer (XEXP (x, 0), 1); |
2cca6e3f | 546 | |
18b9ca6f RK |
547 | /* OLDX may have been the address on a temporary. Update the address |
548 | to indicate that X is now used. */ | |
549 | update_temp_slot_address (oldx, x); | |
550 | ||
18ca7dab RK |
551 | return x; |
552 | } | |
553 | ||
554 | /* Like `memory_address' but pretend `flag_force_addr' is 0. */ | |
555 | ||
556 | rtx | |
557 | memory_address_noforce (mode, x) | |
558 | enum machine_mode mode; | |
559 | rtx x; | |
560 | { | |
561 | int ambient_force_addr = flag_force_addr; | |
562 | rtx val; | |
563 | ||
564 | flag_force_addr = 0; | |
565 | val = memory_address (mode, x); | |
566 | flag_force_addr = ambient_force_addr; | |
567 | return val; | |
568 | } | |
569 | ||
570 | /* Convert a mem ref into one with a valid memory address. | |
571 | Pass through anything else unchanged. */ | |
572 | ||
573 | rtx | |
574 | validize_mem (ref) | |
575 | rtx ref; | |
576 | { | |
577 | if (GET_CODE (ref) != MEM) | |
578 | return ref; | |
579 | if (memory_address_p (GET_MODE (ref), XEXP (ref, 0))) | |
580 | return ref; | |
581 | /* Don't alter REF itself, since that is probably a stack slot. */ | |
582 | return change_address (ref, GET_MODE (ref), XEXP (ref, 0)); | |
583 | } | |
584 | \f | |
585 | /* Return a modified copy of X with its memory address copied | |
586 | into a temporary register to protect it from side effects. | |
587 | If X is not a MEM, it is returned unchanged (and not copied). | |
588 | Perhaps even if it is a MEM, if there is no need to change it. */ | |
589 | ||
590 | rtx | |
591 | stabilize (x) | |
592 | rtx x; | |
593 | { | |
594 | register rtx addr; | |
595 | if (GET_CODE (x) != MEM) | |
596 | return x; | |
597 | addr = XEXP (x, 0); | |
598 | if (rtx_unstable_p (addr)) | |
599 | { | |
600 | rtx temp = copy_all_regs (addr); | |
601 | rtx mem; | |
602 | if (GET_CODE (temp) != REG) | |
603 | temp = copy_to_reg (temp); | |
38a448ca | 604 | mem = gen_rtx_MEM (GET_MODE (x), temp); |
18ca7dab RK |
605 | |
606 | /* Mark returned memref with in_struct if it's in an array or | |
607 | structure. Copy const and volatile from original memref. */ | |
608 | ||
18ca7dab | 609 | RTX_UNCHANGING_P (mem) = RTX_UNCHANGING_P (x); |
c6df88cb MM |
610 | MEM_COPY_ATTRIBUTES (mem, x); |
611 | if (GET_CODE (addr) == PLUS) | |
612 | MEM_SET_IN_STRUCT_P (mem, 1); | |
41472af8 MM |
613 | |
614 | /* Since the new MEM is just like the old X, it can alias only | |
615 | the things that X could. */ | |
616 | MEM_ALIAS_SET (mem) = MEM_ALIAS_SET (x); | |
617 | ||
18ca7dab RK |
618 | return mem; |
619 | } | |
620 | return x; | |
621 | } | |
622 | \f | |
623 | /* Copy the value or contents of X to a new temp reg and return that reg. */ | |
624 | ||
625 | rtx | |
626 | copy_to_reg (x) | |
627 | rtx x; | |
628 | { | |
629 | register rtx temp = gen_reg_rtx (GET_MODE (x)); | |
630 | ||
631 | /* If not an operand, must be an address with PLUS and MULT so | |
632 | do the computation. */ | |
633 | if (! general_operand (x, VOIDmode)) | |
634 | x = force_operand (x, temp); | |
635 | ||
636 | if (x != temp) | |
637 | emit_move_insn (temp, x); | |
638 | ||
639 | return temp; | |
640 | } | |
641 | ||
642 | /* Like copy_to_reg but always give the new register mode Pmode | |
643 | in case X is a constant. */ | |
644 | ||
645 | rtx | |
646 | copy_addr_to_reg (x) | |
647 | rtx x; | |
648 | { | |
649 | return copy_to_mode_reg (Pmode, x); | |
650 | } | |
651 | ||
652 | /* Like copy_to_reg but always give the new register mode MODE | |
653 | in case X is a constant. */ | |
654 | ||
655 | rtx | |
656 | copy_to_mode_reg (mode, x) | |
657 | enum machine_mode mode; | |
658 | rtx x; | |
659 | { | |
660 | register rtx temp = gen_reg_rtx (mode); | |
661 | ||
662 | /* If not an operand, must be an address with PLUS and MULT so | |
663 | do the computation. */ | |
664 | if (! general_operand (x, VOIDmode)) | |
665 | x = force_operand (x, temp); | |
666 | ||
667 | if (GET_MODE (x) != mode && GET_MODE (x) != VOIDmode) | |
668 | abort (); | |
669 | if (x != temp) | |
670 | emit_move_insn (temp, x); | |
671 | return temp; | |
672 | } | |
673 | ||
674 | /* Load X into a register if it is not already one. | |
675 | Use mode MODE for the register. | |
676 | X should be valid for mode MODE, but it may be a constant which | |
677 | is valid for all integer modes; that's why caller must specify MODE. | |
678 | ||
679 | The caller must not alter the value in the register we return, | |
680 | since we mark it as a "constant" register. */ | |
681 | ||
682 | rtx | |
683 | force_reg (mode, x) | |
684 | enum machine_mode mode; | |
685 | rtx x; | |
686 | { | |
62874575 | 687 | register rtx temp, insn, set; |
18ca7dab RK |
688 | |
689 | if (GET_CODE (x) == REG) | |
690 | return x; | |
691 | temp = gen_reg_rtx (mode); | |
692 | insn = emit_move_insn (temp, x); | |
62874575 | 693 | |
18ca7dab | 694 | /* Let optimizers know that TEMP's value never changes |
62874575 RK |
695 | and that X can be substituted for it. Don't get confused |
696 | if INSN set something else (such as a SUBREG of TEMP). */ | |
697 | if (CONSTANT_P (x) | |
698 | && (set = single_set (insn)) != 0 | |
699 | && SET_DEST (set) == temp) | |
18ca7dab | 700 | { |
b1ec3c92 | 701 | rtx note = find_reg_note (insn, REG_EQUAL, NULL_RTX); |
18ca7dab RK |
702 | |
703 | if (note) | |
704 | XEXP (note, 0) = x; | |
705 | else | |
38a448ca | 706 | REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_EQUAL, x, REG_NOTES (insn)); |
18ca7dab RK |
707 | } |
708 | return temp; | |
709 | } | |
710 | ||
711 | /* If X is a memory ref, copy its contents to a new temp reg and return | |
712 | that reg. Otherwise, return X. */ | |
713 | ||
714 | rtx | |
715 | force_not_mem (x) | |
716 | rtx x; | |
717 | { | |
718 | register rtx temp; | |
719 | if (GET_CODE (x) != MEM || GET_MODE (x) == BLKmode) | |
720 | return x; | |
721 | temp = gen_reg_rtx (GET_MODE (x)); | |
722 | emit_move_insn (temp, x); | |
723 | return temp; | |
724 | } | |
725 | ||
726 | /* Copy X to TARGET (if it's nonzero and a reg) | |
727 | or to a new temp reg and return that reg. | |
728 | MODE is the mode to use for X in case it is a constant. */ | |
729 | ||
730 | rtx | |
731 | copy_to_suggested_reg (x, target, mode) | |
732 | rtx x, target; | |
733 | enum machine_mode mode; | |
734 | { | |
735 | register rtx temp; | |
736 | ||
737 | if (target && GET_CODE (target) == REG) | |
738 | temp = target; | |
739 | else | |
740 | temp = gen_reg_rtx (mode); | |
741 | ||
742 | emit_move_insn (temp, x); | |
743 | return temp; | |
744 | } | |
745 | \f | |
9ff65789 RK |
746 | /* Return the mode to use to store a scalar of TYPE and MODE. |
747 | PUNSIGNEDP points to the signedness of the type and may be adjusted | |
748 | to show what signedness to use on extension operations. | |
749 | ||
750 | FOR_CALL is non-zero if this call is promoting args for a call. */ | |
751 | ||
752 | enum machine_mode | |
753 | promote_mode (type, mode, punsignedp, for_call) | |
754 | tree type; | |
755 | enum machine_mode mode; | |
756 | int *punsignedp; | |
c84e2712 | 757 | int for_call ATTRIBUTE_UNUSED; |
9ff65789 RK |
758 | { |
759 | enum tree_code code = TREE_CODE (type); | |
760 | int unsignedp = *punsignedp; | |
761 | ||
762 | #ifdef PROMOTE_FOR_CALL_ONLY | |
763 | if (! for_call) | |
764 | return mode; | |
765 | #endif | |
766 | ||
767 | switch (code) | |
768 | { | |
769 | #ifdef PROMOTE_MODE | |
770 | case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE: | |
771 | case CHAR_TYPE: case REAL_TYPE: case OFFSET_TYPE: | |
772 | PROMOTE_MODE (mode, unsignedp, type); | |
773 | break; | |
774 | #endif | |
775 | ||
ea534b63 | 776 | #ifdef POINTERS_EXTEND_UNSIGNED |
56a4c9e2 | 777 | case REFERENCE_TYPE: |
9ff65789 | 778 | case POINTER_TYPE: |
ea534b63 RK |
779 | mode = Pmode; |
780 | unsignedp = POINTERS_EXTEND_UNSIGNED; | |
9ff65789 | 781 | break; |
ea534b63 | 782 | #endif |
38a448ca RH |
783 | |
784 | default: | |
785 | break; | |
9ff65789 RK |
786 | } |
787 | ||
788 | *punsignedp = unsignedp; | |
789 | return mode; | |
790 | } | |
791 | \f | |
18ca7dab RK |
792 | /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes). |
793 | This pops when ADJUST is positive. ADJUST need not be constant. */ | |
794 | ||
795 | void | |
796 | adjust_stack (adjust) | |
797 | rtx adjust; | |
798 | { | |
799 | rtx temp; | |
800 | adjust = protect_from_queue (adjust, 0); | |
801 | ||
802 | if (adjust == const0_rtx) | |
803 | return; | |
804 | ||
805 | temp = expand_binop (Pmode, | |
806 | #ifdef STACK_GROWS_DOWNWARD | |
807 | add_optab, | |
808 | #else | |
809 | sub_optab, | |
810 | #endif | |
811 | stack_pointer_rtx, adjust, stack_pointer_rtx, 0, | |
812 | OPTAB_LIB_WIDEN); | |
813 | ||
814 | if (temp != stack_pointer_rtx) | |
815 | emit_move_insn (stack_pointer_rtx, temp); | |
816 | } | |
817 | ||
818 | /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes). | |
819 | This pushes when ADJUST is positive. ADJUST need not be constant. */ | |
820 | ||
821 | void | |
822 | anti_adjust_stack (adjust) | |
823 | rtx adjust; | |
824 | { | |
825 | rtx temp; | |
826 | adjust = protect_from_queue (adjust, 0); | |
827 | ||
828 | if (adjust == const0_rtx) | |
829 | return; | |
830 | ||
831 | temp = expand_binop (Pmode, | |
832 | #ifdef STACK_GROWS_DOWNWARD | |
833 | sub_optab, | |
834 | #else | |
835 | add_optab, | |
836 | #endif | |
837 | stack_pointer_rtx, adjust, stack_pointer_rtx, 0, | |
838 | OPTAB_LIB_WIDEN); | |
839 | ||
840 | if (temp != stack_pointer_rtx) | |
841 | emit_move_insn (stack_pointer_rtx, temp); | |
842 | } | |
843 | ||
844 | /* Round the size of a block to be pushed up to the boundary required | |
845 | by this machine. SIZE is the desired size, which need not be constant. */ | |
846 | ||
847 | rtx | |
848 | round_push (size) | |
849 | rtx size; | |
850 | { | |
c795bca9 BS |
851 | #ifdef PREFERRED_STACK_BOUNDARY |
852 | int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT; | |
18ca7dab RK |
853 | if (align == 1) |
854 | return size; | |
855 | if (GET_CODE (size) == CONST_INT) | |
856 | { | |
857 | int new = (INTVAL (size) + align - 1) / align * align; | |
858 | if (INTVAL (size) != new) | |
b1ec3c92 | 859 | size = GEN_INT (new); |
18ca7dab RK |
860 | } |
861 | else | |
862 | { | |
5244db05 | 863 | /* CEIL_DIV_EXPR needs to worry about the addition overflowing, |
0f41302f MS |
864 | but we know it can't. So add ourselves and then do |
865 | TRUNC_DIV_EXPR. */ | |
5244db05 RK |
866 | size = expand_binop (Pmode, add_optab, size, GEN_INT (align - 1), |
867 | NULL_RTX, 1, OPTAB_LIB_WIDEN); | |
868 | size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size, GEN_INT (align), | |
b1ec3c92 CH |
869 | NULL_RTX, 1); |
870 | size = expand_mult (Pmode, size, GEN_INT (align), NULL_RTX, 1); | |
18ca7dab | 871 | } |
c795bca9 | 872 | #endif /* PREFERRED_STACK_BOUNDARY */ |
18ca7dab RK |
873 | return size; |
874 | } | |
875 | \f | |
59257ff7 RK |
876 | /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer |
877 | to a previously-created save area. If no save area has been allocated, | |
878 | this function will allocate one. If a save area is specified, it | |
879 | must be of the proper mode. | |
880 | ||
881 | The insns are emitted after insn AFTER, if nonzero, otherwise the insns | |
882 | are emitted at the current position. */ | |
883 | ||
884 | void | |
885 | emit_stack_save (save_level, psave, after) | |
886 | enum save_level save_level; | |
887 | rtx *psave; | |
888 | rtx after; | |
889 | { | |
890 | rtx sa = *psave; | |
891 | /* The default is that we use a move insn and save in a Pmode object. */ | |
0ddc9a94 | 892 | rtx (*fcn) PROTO ((rtx, rtx)) = gen_move_insn; |
a260abc9 | 893 | enum machine_mode mode = STACK_SAVEAREA_MODE (save_level); |
59257ff7 RK |
894 | |
895 | /* See if this machine has anything special to do for this kind of save. */ | |
896 | switch (save_level) | |
897 | { | |
898 | #ifdef HAVE_save_stack_block | |
899 | case SAVE_BLOCK: | |
900 | if (HAVE_save_stack_block) | |
a260abc9 | 901 | fcn = gen_save_stack_block; |
59257ff7 RK |
902 | break; |
903 | #endif | |
904 | #ifdef HAVE_save_stack_function | |
905 | case SAVE_FUNCTION: | |
906 | if (HAVE_save_stack_function) | |
a260abc9 | 907 | fcn = gen_save_stack_function; |
59257ff7 RK |
908 | break; |
909 | #endif | |
910 | #ifdef HAVE_save_stack_nonlocal | |
911 | case SAVE_NONLOCAL: | |
912 | if (HAVE_save_stack_nonlocal) | |
a260abc9 | 913 | fcn = gen_save_stack_nonlocal; |
59257ff7 RK |
914 | break; |
915 | #endif | |
38a448ca RH |
916 | default: |
917 | break; | |
59257ff7 RK |
918 | } |
919 | ||
920 | /* If there is no save area and we have to allocate one, do so. Otherwise | |
921 | verify the save area is the proper mode. */ | |
922 | ||
923 | if (sa == 0) | |
924 | { | |
925 | if (mode != VOIDmode) | |
926 | { | |
927 | if (save_level == SAVE_NONLOCAL) | |
928 | *psave = sa = assign_stack_local (mode, GET_MODE_SIZE (mode), 0); | |
929 | else | |
930 | *psave = sa = gen_reg_rtx (mode); | |
931 | } | |
932 | } | |
933 | else | |
934 | { | |
935 | if (mode == VOIDmode || GET_MODE (sa) != mode) | |
936 | abort (); | |
937 | } | |
938 | ||
939 | if (after) | |
700f6f98 RK |
940 | { |
941 | rtx seq; | |
942 | ||
943 | start_sequence (); | |
5460015d JW |
944 | /* We must validize inside the sequence, to ensure that any instructions |
945 | created by the validize call also get moved to the right place. */ | |
946 | if (sa != 0) | |
947 | sa = validize_mem (sa); | |
d072107f | 948 | emit_insn (fcn (sa, stack_pointer_rtx)); |
700f6f98 RK |
949 | seq = gen_sequence (); |
950 | end_sequence (); | |
951 | emit_insn_after (seq, after); | |
952 | } | |
59257ff7 | 953 | else |
5460015d JW |
954 | { |
955 | if (sa != 0) | |
956 | sa = validize_mem (sa); | |
957 | emit_insn (fcn (sa, stack_pointer_rtx)); | |
958 | } | |
59257ff7 RK |
959 | } |
960 | ||
961 | /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save | |
962 | area made by emit_stack_save. If it is zero, we have nothing to do. | |
963 | ||
964 | Put any emitted insns after insn AFTER, if nonzero, otherwise at | |
965 | current position. */ | |
966 | ||
967 | void | |
968 | emit_stack_restore (save_level, sa, after) | |
969 | enum save_level save_level; | |
970 | rtx after; | |
971 | rtx sa; | |
972 | { | |
973 | /* The default is that we use a move insn. */ | |
0ddc9a94 | 974 | rtx (*fcn) PROTO ((rtx, rtx)) = gen_move_insn; |
59257ff7 RK |
975 | |
976 | /* See if this machine has anything special to do for this kind of save. */ | |
977 | switch (save_level) | |
978 | { | |
979 | #ifdef HAVE_restore_stack_block | |
980 | case SAVE_BLOCK: | |
981 | if (HAVE_restore_stack_block) | |
982 | fcn = gen_restore_stack_block; | |
983 | break; | |
984 | #endif | |
985 | #ifdef HAVE_restore_stack_function | |
986 | case SAVE_FUNCTION: | |
987 | if (HAVE_restore_stack_function) | |
988 | fcn = gen_restore_stack_function; | |
989 | break; | |
990 | #endif | |
991 | #ifdef HAVE_restore_stack_nonlocal | |
59257ff7 RK |
992 | case SAVE_NONLOCAL: |
993 | if (HAVE_restore_stack_nonlocal) | |
994 | fcn = gen_restore_stack_nonlocal; | |
995 | break; | |
996 | #endif | |
38a448ca RH |
997 | default: |
998 | break; | |
59257ff7 RK |
999 | } |
1000 | ||
d072107f RK |
1001 | if (sa != 0) |
1002 | sa = validize_mem (sa); | |
1003 | ||
59257ff7 | 1004 | if (after) |
700f6f98 RK |
1005 | { |
1006 | rtx seq; | |
1007 | ||
1008 | start_sequence (); | |
d072107f | 1009 | emit_insn (fcn (stack_pointer_rtx, sa)); |
700f6f98 RK |
1010 | seq = gen_sequence (); |
1011 | end_sequence (); | |
1012 | emit_insn_after (seq, after); | |
1013 | } | |
59257ff7 | 1014 | else |
d072107f | 1015 | emit_insn (fcn (stack_pointer_rtx, sa)); |
59257ff7 RK |
1016 | } |
1017 | \f | |
c9ec4f99 DM |
1018 | #ifdef SETJMP_VIA_SAVE_AREA |
1019 | /* Optimize RTL generated by allocate_dynamic_stack_space for targets | |
1020 | where SETJMP_VIA_SAVE_AREA is true. The problem is that on these | |
1021 | platforms, the dynamic stack space used can corrupt the original | |
1022 | frame, thus causing a crash if a longjmp unwinds to it. */ | |
1023 | ||
1024 | void | |
1025 | optimize_save_area_alloca (insns) | |
1026 | rtx insns; | |
1027 | { | |
1028 | rtx insn; | |
1029 | ||
1030 | for (insn = insns; insn; insn = NEXT_INSN(insn)) | |
1031 | { | |
1032 | rtx note; | |
1033 | ||
1034 | if (GET_CODE (insn) != INSN) | |
1035 | continue; | |
1036 | ||
1037 | for (note = REG_NOTES (insn); note; note = XEXP (note, 1)) | |
1038 | { | |
1039 | if (REG_NOTE_KIND (note) != REG_SAVE_AREA) | |
1040 | continue; | |
1041 | ||
1042 | if (!current_function_calls_setjmp) | |
1043 | { | |
1044 | rtx pat = PATTERN (insn); | |
1045 | ||
1046 | /* If we do not see the note in a pattern matching | |
1047 | these precise characteristics, we did something | |
1048 | entirely wrong in allocate_dynamic_stack_space. | |
1049 | ||
38e01259 | 1050 | Note, one way this could happen is if SETJMP_VIA_SAVE_AREA |
c9ec4f99 DM |
1051 | was defined on a machine where stacks grow towards higher |
1052 | addresses. | |
1053 | ||
1054 | Right now only supported port with stack that grow upward | |
1055 | is the HPPA and it does not define SETJMP_VIA_SAVE_AREA. */ | |
1056 | if (GET_CODE (pat) != SET | |
1057 | || SET_DEST (pat) != stack_pointer_rtx | |
1058 | || GET_CODE (SET_SRC (pat)) != MINUS | |
1059 | || XEXP (SET_SRC (pat), 0) != stack_pointer_rtx) | |
1060 | abort (); | |
1061 | ||
1062 | /* This will now be transformed into a (set REG REG) | |
1063 | so we can just blow away all the other notes. */ | |
1064 | XEXP (SET_SRC (pat), 1) = XEXP (note, 0); | |
1065 | REG_NOTES (insn) = NULL_RTX; | |
1066 | } | |
1067 | else | |
1068 | { | |
1069 | /* setjmp was called, we must remove the REG_SAVE_AREA | |
1070 | note so that later passes do not get confused by its | |
1071 | presence. */ | |
1072 | if (note == REG_NOTES (insn)) | |
1073 | { | |
1074 | REG_NOTES (insn) = XEXP (note, 1); | |
1075 | } | |
1076 | else | |
1077 | { | |
1078 | rtx srch; | |
1079 | ||
1080 | for (srch = REG_NOTES (insn); srch; srch = XEXP (srch, 1)) | |
1081 | if (XEXP (srch, 1) == note) | |
1082 | break; | |
1083 | ||
1084 | if (srch == NULL_RTX) | |
1085 | abort(); | |
1086 | ||
1087 | XEXP (srch, 1) = XEXP (note, 1); | |
1088 | } | |
1089 | } | |
1090 | /* Once we've seen the note of interest, we need not look at | |
1091 | the rest of them. */ | |
1092 | break; | |
1093 | } | |
1094 | } | |
1095 | } | |
1096 | #endif /* SETJMP_VIA_SAVE_AREA */ | |
1097 | ||
18ca7dab RK |
1098 | /* Return an rtx representing the address of an area of memory dynamically |
1099 | pushed on the stack. This region of memory is always aligned to | |
1100 | a multiple of BIGGEST_ALIGNMENT. | |
1101 | ||
1102 | Any required stack pointer alignment is preserved. | |
1103 | ||
1104 | SIZE is an rtx representing the size of the area. | |
091ad0b9 RK |
1105 | TARGET is a place in which the address can be placed. |
1106 | ||
1107 | KNOWN_ALIGN is the alignment (in bits) that we know SIZE has. */ | |
18ca7dab RK |
1108 | |
1109 | rtx | |
091ad0b9 | 1110 | allocate_dynamic_stack_space (size, target, known_align) |
18ca7dab RK |
1111 | rtx size; |
1112 | rtx target; | |
091ad0b9 | 1113 | int known_align; |
18ca7dab | 1114 | { |
c9ec4f99 DM |
1115 | #ifdef SETJMP_VIA_SAVE_AREA |
1116 | rtx setjmpless_size = NULL_RTX; | |
1117 | #endif | |
1118 | ||
15fc0026 | 1119 | /* If we're asking for zero bytes, it doesn't matter what we point |
9faa82d8 | 1120 | to since we can't dereference it. But return a reasonable |
15fc0026 RK |
1121 | address anyway. */ |
1122 | if (size == const0_rtx) | |
1123 | return virtual_stack_dynamic_rtx; | |
1124 | ||
1125 | /* Otherwise, show we're calling alloca or equivalent. */ | |
1126 | current_function_calls_alloca = 1; | |
1127 | ||
18ca7dab RK |
1128 | /* Ensure the size is in the proper mode. */ |
1129 | if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode) | |
1130 | size = convert_to_mode (Pmode, size, 1); | |
1131 | ||
1132 | /* We will need to ensure that the address we return is aligned to | |
1133 | BIGGEST_ALIGNMENT. If STACK_DYNAMIC_OFFSET is defined, we don't | |
1134 | always know its final value at this point in the compilation (it | |
1135 | might depend on the size of the outgoing parameter lists, for | |
1136 | example), so we must align the value to be returned in that case. | |
1137 | (Note that STACK_DYNAMIC_OFFSET will have a default non-zero value if | |
1138 | STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined). | |
1139 | We must also do an alignment operation on the returned value if | |
1140 | the stack pointer alignment is less strict that BIGGEST_ALIGNMENT. | |
1141 | ||
1142 | If we have to align, we must leave space in SIZE for the hole | |
1143 | that might result from the alignment operation. */ | |
1144 | ||
c795bca9 | 1145 | #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET) || ! defined (PREFERRED_STACK_BOUNDARY) |
515a7242 JW |
1146 | #define MUST_ALIGN 1 |
1147 | #else | |
c795bca9 | 1148 | #define MUST_ALIGN (PREFERRED_STACK_BOUNDARY < BIGGEST_ALIGNMENT) |
18ca7dab RK |
1149 | #endif |
1150 | ||
515a7242 | 1151 | if (MUST_ALIGN) |
3b998c11 RK |
1152 | { |
1153 | if (GET_CODE (size) == CONST_INT) | |
b1ec3c92 CH |
1154 | size = GEN_INT (INTVAL (size) |
1155 | + (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1)); | |
3b998c11 RK |
1156 | else |
1157 | size = expand_binop (Pmode, add_optab, size, | |
b1ec3c92 CH |
1158 | GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1), |
1159 | NULL_RTX, 1, OPTAB_LIB_WIDEN); | |
3b998c11 | 1160 | } |
1d9d04f8 | 1161 | |
18ca7dab RK |
1162 | #ifdef SETJMP_VIA_SAVE_AREA |
1163 | /* If setjmp restores regs from a save area in the stack frame, | |
1164 | avoid clobbering the reg save area. Note that the offset of | |
1165 | virtual_incoming_args_rtx includes the preallocated stack args space. | |
1166 | It would be no problem to clobber that, but it's on the wrong side | |
1167 | of the old save area. */ | |
1168 | { | |
1169 | rtx dynamic_offset | |
1170 | = expand_binop (Pmode, sub_optab, virtual_stack_dynamic_rtx, | |
b1ec3c92 | 1171 | stack_pointer_rtx, NULL_RTX, 1, OPTAB_LIB_WIDEN); |
c9ec4f99 DM |
1172 | |
1173 | if (!current_function_calls_setjmp) | |
1174 | { | |
c795bca9 | 1175 | int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT; |
c9ec4f99 DM |
1176 | |
1177 | /* See optimize_save_area_alloca to understand what is being | |
1178 | set up here. */ | |
1179 | ||
c795bca9 | 1180 | #if !defined(PREFERRED_STACK_BOUNDARY) || !defined(MUST_ALIGN) || (PREFERRED_STACK_BOUNDARY != BIGGEST_ALIGNMENT) |
c9ec4f99 DM |
1181 | /* If anyone creates a target with these characteristics, let them |
1182 | know that our optimization cannot work correctly in such a case. */ | |
1183 | abort(); | |
1184 | #endif | |
1185 | ||
1186 | if (GET_CODE (size) == CONST_INT) | |
1187 | { | |
1188 | int new = INTVAL (size) / align * align; | |
1189 | ||
1190 | if (INTVAL (size) != new) | |
1191 | setjmpless_size = GEN_INT (new); | |
1192 | else | |
1193 | setjmpless_size = size; | |
1194 | } | |
1195 | else | |
1196 | { | |
1197 | /* Since we know overflow is not possible, we avoid using | |
1198 | CEIL_DIV_EXPR and use TRUNC_DIV_EXPR instead. */ | |
1199 | setjmpless_size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size, | |
1200 | GEN_INT (align), NULL_RTX, 1); | |
1201 | setjmpless_size = expand_mult (Pmode, setjmpless_size, | |
1202 | GEN_INT (align), NULL_RTX, 1); | |
1203 | } | |
1204 | /* Our optimization works based upon being able to perform a simple | |
1205 | transformation of this RTL into a (set REG REG) so make sure things | |
1206 | did in fact end up in a REG. */ | |
1207 | if (!arith_operand (setjmpless_size, Pmode)) | |
1208 | setjmpless_size = force_reg (Pmode, setjmpless_size); | |
1209 | } | |
1210 | ||
18ca7dab | 1211 | size = expand_binop (Pmode, add_optab, size, dynamic_offset, |
b1ec3c92 | 1212 | NULL_RTX, 1, OPTAB_LIB_WIDEN); |
18ca7dab RK |
1213 | } |
1214 | #endif /* SETJMP_VIA_SAVE_AREA */ | |
1215 | ||
1216 | /* Round the size to a multiple of the required stack alignment. | |
1217 | Since the stack if presumed to be rounded before this allocation, | |
1218 | this will maintain the required alignment. | |
1219 | ||
1220 | If the stack grows downward, we could save an insn by subtracting | |
1221 | SIZE from the stack pointer and then aligning the stack pointer. | |
1222 | The problem with this is that the stack pointer may be unaligned | |
1223 | between the execution of the subtraction and alignment insns and | |
1224 | some machines do not allow this. Even on those that do, some | |
1225 | signal handlers malfunction if a signal should occur between those | |
1226 | insns. Since this is an extremely rare event, we have no reliable | |
1227 | way of knowing which systems have this problem. So we avoid even | |
1228 | momentarily mis-aligning the stack. */ | |
1229 | ||
c795bca9 | 1230 | #ifdef PREFERRED_STACK_BOUNDARY |
86b25e81 RS |
1231 | /* If we added a variable amount to SIZE, |
1232 | we can no longer assume it is aligned. */ | |
515a7242 | 1233 | #if !defined (SETJMP_VIA_SAVE_AREA) |
c795bca9 | 1234 | if (MUST_ALIGN || known_align % PREFERRED_STACK_BOUNDARY != 0) |
34c9156a | 1235 | #endif |
091ad0b9 | 1236 | size = round_push (size); |
89d825c9 | 1237 | #endif |
18ca7dab RK |
1238 | |
1239 | do_pending_stack_adjust (); | |
1240 | ||
edff2491 RK |
1241 | /* If needed, check that we have the required amount of stack. Take into |
1242 | account what has already been checked. */ | |
1243 | if (flag_stack_check && ! STACK_CHECK_BUILTIN) | |
1244 | probe_stack_range (STACK_CHECK_MAX_FRAME_SIZE + STACK_CHECK_PROTECT, size); | |
1245 | ||
091ad0b9 RK |
1246 | /* Don't use a TARGET that isn't a pseudo. */ |
1247 | if (target == 0 || GET_CODE (target) != REG | |
1248 | || REGNO (target) < FIRST_PSEUDO_REGISTER) | |
18ca7dab RK |
1249 | target = gen_reg_rtx (Pmode); |
1250 | ||
305f22b5 | 1251 | mark_reg_pointer (target, known_align / BITS_PER_UNIT); |
3ad69266 | 1252 | |
18ca7dab RK |
1253 | /* Perform the required allocation from the stack. Some systems do |
1254 | this differently than simply incrementing/decrementing from the | |
38a448ca | 1255 | stack pointer, such as acquiring the space by calling malloc(). */ |
18ca7dab RK |
1256 | #ifdef HAVE_allocate_stack |
1257 | if (HAVE_allocate_stack) | |
1258 | { | |
39403d82 DE |
1259 | enum machine_mode mode = STACK_SIZE_MODE; |
1260 | ||
18ca7dab RK |
1261 | if (insn_operand_predicate[(int) CODE_FOR_allocate_stack][0] |
1262 | && ! ((*insn_operand_predicate[(int) CODE_FOR_allocate_stack][0]) | |
38a448ca RH |
1263 | (target, Pmode))) |
1264 | target = copy_to_mode_reg (Pmode, target); | |
39403d82 | 1265 | size = convert_modes (mode, ptr_mode, size, 1); |
38a448ca RH |
1266 | if (insn_operand_predicate[(int) CODE_FOR_allocate_stack][1] |
1267 | && ! ((*insn_operand_predicate[(int) CODE_FOR_allocate_stack][1]) | |
39403d82 DE |
1268 | (size, mode))) |
1269 | size = copy_to_mode_reg (mode, size); | |
18ca7dab | 1270 | |
38a448ca | 1271 | emit_insn (gen_allocate_stack (target, size)); |
18ca7dab RK |
1272 | } |
1273 | else | |
1274 | #endif | |
ea534b63 | 1275 | { |
38a448ca RH |
1276 | #ifndef STACK_GROWS_DOWNWARD |
1277 | emit_move_insn (target, virtual_stack_dynamic_rtx); | |
1278 | #endif | |
ea534b63 RK |
1279 | size = convert_modes (Pmode, ptr_mode, size, 1); |
1280 | anti_adjust_stack (size); | |
c9ec4f99 DM |
1281 | #ifdef SETJMP_VIA_SAVE_AREA |
1282 | if (setjmpless_size != NULL_RTX) | |
1283 | { | |
1284 | rtx note_target = get_last_insn (); | |
1285 | ||
9e6a5703 JC |
1286 | REG_NOTES (note_target) |
1287 | = gen_rtx_EXPR_LIST (REG_SAVE_AREA, setjmpless_size, | |
1288 | REG_NOTES (note_target)); | |
c9ec4f99 DM |
1289 | } |
1290 | #endif /* SETJMP_VIA_SAVE_AREA */ | |
18ca7dab RK |
1291 | #ifdef STACK_GROWS_DOWNWARD |
1292 | emit_move_insn (target, virtual_stack_dynamic_rtx); | |
1293 | #endif | |
38a448ca | 1294 | } |
18ca7dab | 1295 | |
515a7242 | 1296 | if (MUST_ALIGN) |
091ad0b9 | 1297 | { |
5244db05 | 1298 | /* CEIL_DIV_EXPR needs to worry about the addition overflowing, |
0f41302f MS |
1299 | but we know it can't. So add ourselves and then do |
1300 | TRUNC_DIV_EXPR. */ | |
0f56a403 | 1301 | target = expand_binop (Pmode, add_optab, target, |
5244db05 RK |
1302 | GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1), |
1303 | NULL_RTX, 1, OPTAB_LIB_WIDEN); | |
1304 | target = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, target, | |
b1ec3c92 CH |
1305 | GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT), |
1306 | NULL_RTX, 1); | |
091ad0b9 | 1307 | target = expand_mult (Pmode, target, |
b1ec3c92 CH |
1308 | GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT), |
1309 | NULL_RTX, 1); | |
091ad0b9 | 1310 | } |
18ca7dab RK |
1311 | |
1312 | /* Some systems require a particular insn to refer to the stack | |
1313 | to make the pages exist. */ | |
1314 | #ifdef HAVE_probe | |
1315 | if (HAVE_probe) | |
1316 | emit_insn (gen_probe ()); | |
1317 | #endif | |
1318 | ||
15fc0026 | 1319 | /* Record the new stack level for nonlocal gotos. */ |
ba716ac9 | 1320 | if (nonlocal_goto_handler_slots != 0) |
15fc0026 RK |
1321 | emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX); |
1322 | ||
18ca7dab RK |
1323 | return target; |
1324 | } | |
1325 | \f | |
edff2491 RK |
1326 | /* Emit one stack probe at ADDRESS, an address within the stack. */ |
1327 | ||
1328 | static void | |
1329 | emit_stack_probe (address) | |
1330 | rtx address; | |
1331 | { | |
38a448ca | 1332 | rtx memref = gen_rtx_MEM (word_mode, address); |
edff2491 RK |
1333 | |
1334 | MEM_VOLATILE_P (memref) = 1; | |
1335 | ||
1336 | if (STACK_CHECK_PROBE_LOAD) | |
1337 | emit_move_insn (gen_reg_rtx (word_mode), memref); | |
1338 | else | |
1339 | emit_move_insn (memref, const0_rtx); | |
1340 | } | |
1341 | ||
1342 | /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive. | |
1343 | FIRST is a constant and size is a Pmode RTX. These are offsets from the | |
1344 | current stack pointer. STACK_GROWS_DOWNWARD says whether to add or | |
1345 | subtract from the stack. If SIZE is constant, this is done | |
1346 | with a fixed number of probes. Otherwise, we must make a loop. */ | |
1347 | ||
1348 | #ifdef STACK_GROWS_DOWNWARD | |
1349 | #define STACK_GROW_OP MINUS | |
1350 | #else | |
1351 | #define STACK_GROW_OP PLUS | |
1352 | #endif | |
1353 | ||
1354 | void | |
1355 | probe_stack_range (first, size) | |
1356 | HOST_WIDE_INT first; | |
1357 | rtx size; | |
1358 | { | |
1359 | /* First see if we have an insn to check the stack. Use it if so. */ | |
1360 | #ifdef HAVE_check_stack | |
1361 | if (HAVE_check_stack) | |
1362 | { | |
38a448ca RH |
1363 | rtx last_addr |
1364 | = force_operand (gen_rtx_STACK_GROW_OP (Pmode, | |
1365 | stack_pointer_rtx, | |
1366 | plus_constant (size, first)), | |
1367 | NULL_RTX); | |
edff2491 RK |
1368 | |
1369 | if (insn_operand_predicate[(int) CODE_FOR_check_stack][0] | |
1370 | && ! ((*insn_operand_predicate[(int) CODE_FOR_check_stack][0]) | |
1371 | (last_address, Pmode))) | |
1372 | last_address = copy_to_mode_reg (Pmode, last_address); | |
1373 | ||
1374 | emit_insn (gen_check_stack (last_address)); | |
1375 | return; | |
1376 | } | |
1377 | #endif | |
1378 | ||
1379 | /* If we have to generate explicit probes, see if we have a constant | |
95a086b1 | 1380 | small number of them to generate. If so, that's the easy case. */ |
e5e809f4 JL |
1381 | if (GET_CODE (size) == CONST_INT |
1382 | && INTVAL (size) < 10 * STACK_CHECK_PROBE_INTERVAL) | |
edff2491 RK |
1383 | { |
1384 | HOST_WIDE_INT offset; | |
1385 | ||
1386 | /* Start probing at FIRST + N * STACK_CHECK_PROBE_INTERVAL | |
1387 | for values of N from 1 until it exceeds LAST. If only one | |
1388 | probe is needed, this will not generate any code. Then probe | |
1389 | at LAST. */ | |
1390 | for (offset = first + STACK_CHECK_PROBE_INTERVAL; | |
1391 | offset < INTVAL (size); | |
1392 | offset = offset + STACK_CHECK_PROBE_INTERVAL) | |
38a448ca RH |
1393 | emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, |
1394 | stack_pointer_rtx, | |
1395 | GEN_INT (offset))); | |
edff2491 | 1396 | |
38a448ca RH |
1397 | emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, |
1398 | stack_pointer_rtx, | |
1399 | plus_constant (size, first))); | |
edff2491 RK |
1400 | } |
1401 | ||
1402 | /* In the variable case, do the same as above, but in a loop. We emit loop | |
1403 | notes so that loop optimization can be done. */ | |
1404 | else | |
1405 | { | |
1406 | rtx test_addr | |
38a448ca RH |
1407 | = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, |
1408 | stack_pointer_rtx, | |
1409 | GEN_INT (first + STACK_CHECK_PROBE_INTERVAL)), | |
edff2491 RK |
1410 | NULL_RTX); |
1411 | rtx last_addr | |
38a448ca RH |
1412 | = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, |
1413 | stack_pointer_rtx, | |
1414 | plus_constant (size, first)), | |
edff2491 RK |
1415 | NULL_RTX); |
1416 | rtx incr = GEN_INT (STACK_CHECK_PROBE_INTERVAL); | |
1417 | rtx loop_lab = gen_label_rtx (); | |
1418 | rtx test_lab = gen_label_rtx (); | |
1419 | rtx end_lab = gen_label_rtx (); | |
1420 | rtx temp; | |
1421 | ||
1422 | if (GET_CODE (test_addr) != REG | |
1423 | || REGNO (test_addr) < FIRST_PSEUDO_REGISTER) | |
1424 | test_addr = force_reg (Pmode, test_addr); | |
1425 | ||
1426 | emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG); | |
1427 | emit_jump (test_lab); | |
1428 | ||
1429 | emit_label (loop_lab); | |
1430 | emit_stack_probe (test_addr); | |
1431 | ||
1432 | emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT); | |
1433 | ||
1434 | #ifdef STACK_GROWS_DOWNWARD | |
1435 | #define CMP_OPCODE GTU | |
1436 | temp = expand_binop (Pmode, sub_optab, test_addr, incr, test_addr, | |
1437 | 1, OPTAB_WIDEN); | |
1438 | #else | |
1439 | #define CMP_OPCODE LTU | |
1440 | temp = expand_binop (Pmode, add_optab, test_addr, incr, test_addr, | |
1441 | 1, OPTAB_WIDEN); | |
1442 | #endif | |
1443 | ||
1444 | if (temp != test_addr) | |
1445 | abort (); | |
1446 | ||
1447 | emit_label (test_lab); | |
1448 | emit_cmp_insn (test_addr, last_addr, CMP_OPCODE, NULL_RTX, Pmode, 1, 0); | |
1449 | emit_jump_insn ((*bcc_gen_fctn[(int) CMP_OPCODE]) (loop_lab)); | |
1450 | emit_jump (end_lab); | |
1451 | emit_note (NULL_PTR, NOTE_INSN_LOOP_END); | |
1452 | emit_label (end_lab); | |
1453 | ||
38a448ca RH |
1454 | /* If will be doing stupid optimization, show test_addr is still live. */ |
1455 | if (obey_regdecls) | |
1456 | emit_insn (gen_rtx_USE (VOIDmode, test_addr)); | |
1457 | ||
edff2491 RK |
1458 | emit_stack_probe (last_addr); |
1459 | } | |
1460 | } | |
1461 | \f | |
18ca7dab RK |
1462 | /* Return an rtx representing the register or memory location |
1463 | in which a scalar value of data type VALTYPE | |
1464 | was returned by a function call to function FUNC. | |
1465 | FUNC is a FUNCTION_DECL node if the precise function is known, | |
1466 | otherwise 0. */ | |
1467 | ||
1468 | rtx | |
1469 | hard_function_value (valtype, func) | |
1470 | tree valtype; | |
1471 | tree func; | |
1472 | { | |
e1a4071f JL |
1473 | rtx val = FUNCTION_VALUE (valtype, func); |
1474 | if (GET_CODE (val) == REG | |
1475 | && GET_MODE (val) == BLKmode) | |
1476 | { | |
1477 | int bytes = int_size_in_bytes (valtype); | |
1478 | enum machine_mode tmpmode; | |
1479 | for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT); | |
1480 | tmpmode != MAX_MACHINE_MODE; | |
1481 | tmpmode = GET_MODE_WIDER_MODE (tmpmode)) | |
1482 | { | |
1483 | /* Have we found a large enough mode? */ | |
1484 | if (GET_MODE_SIZE (tmpmode) >= bytes) | |
1485 | break; | |
1486 | } | |
1487 | ||
1488 | /* No suitable mode found. */ | |
1489 | if (tmpmode == MAX_MACHINE_MODE) | |
1490 | abort (); | |
1491 | ||
1492 | PUT_MODE (val, tmpmode); | |
1493 | } | |
1494 | return val; | |
18ca7dab RK |
1495 | } |
1496 | ||
1497 | /* Return an rtx representing the register or memory location | |
1498 | in which a scalar value of mode MODE was returned by a library call. */ | |
1499 | ||
1500 | rtx | |
1501 | hard_libcall_value (mode) | |
1502 | enum machine_mode mode; | |
1503 | { | |
1504 | return LIBCALL_VALUE (mode); | |
1505 | } | |
0c5e217d RS |
1506 | |
1507 | /* Look up the tree code for a given rtx code | |
1508 | to provide the arithmetic operation for REAL_ARITHMETIC. | |
1509 | The function returns an int because the caller may not know | |
1510 | what `enum tree_code' means. */ | |
1511 | ||
1512 | int | |
1513 | rtx_to_tree_code (code) | |
1514 | enum rtx_code code; | |
1515 | { | |
1516 | enum tree_code tcode; | |
1517 | ||
1518 | switch (code) | |
1519 | { | |
1520 | case PLUS: | |
1521 | tcode = PLUS_EXPR; | |
1522 | break; | |
1523 | case MINUS: | |
1524 | tcode = MINUS_EXPR; | |
1525 | break; | |
1526 | case MULT: | |
1527 | tcode = MULT_EXPR; | |
1528 | break; | |
1529 | case DIV: | |
1530 | tcode = RDIV_EXPR; | |
1531 | break; | |
1532 | case SMIN: | |
1533 | tcode = MIN_EXPR; | |
1534 | break; | |
1535 | case SMAX: | |
1536 | tcode = MAX_EXPR; | |
1537 | break; | |
1538 | default: | |
1539 | tcode = LAST_AND_UNUSED_TREE_CODE; | |
1540 | break; | |
1541 | } | |
1542 | return ((int) tcode); | |
1543 | } |