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51bbfa0c RS |
1 | /* Convert function calls to rtl insns, for GNU C compiler. |
2 | Copyright (C) 1989, 1992 Free Software Foundation, Inc. | |
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 | |
18 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
19 | ||
20 | #include "config.h" | |
21 | #include "rtl.h" | |
22 | #include "tree.h" | |
23 | #include "flags.h" | |
24 | #include "expr.h" | |
25 | #include "insn-flags.h" | |
26 | ||
27 | /* Decide whether a function's arguments should be processed | |
28 | from first to last or from last to first. */ | |
29 | ||
30 | #ifdef STACK_GROWS_DOWNWARD | |
31 | #ifdef PUSH_ROUNDING | |
32 | #define PUSH_ARGS_REVERSED /* If it's last to first */ | |
33 | #endif | |
34 | #endif | |
35 | ||
36 | /* Like STACK_BOUNDARY but in units of bytes, not bits. */ | |
37 | #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT) | |
38 | ||
39 | /* Data structure and subroutines used within expand_call. */ | |
40 | ||
41 | struct arg_data | |
42 | { | |
43 | /* Tree node for this argument. */ | |
44 | tree tree_value; | |
45 | /* Current RTL value for argument, or 0 if it isn't precomputed. */ | |
46 | rtx value; | |
47 | /* Initially-compute RTL value for argument; only for const functions. */ | |
48 | rtx initial_value; | |
49 | /* Register to pass this argument in, 0 if passed on stack, or an | |
50 | EXPR_LIST if the arg is to be copied into multiple different | |
51 | registers. */ | |
52 | rtx reg; | |
53 | /* Number of registers to use. 0 means put the whole arg in registers. | |
54 | Also 0 if not passed in registers. */ | |
55 | int partial; | |
56 | /* Non-zero if argument must be passed on stack. */ | |
57 | int pass_on_stack; | |
58 | /* Offset of this argument from beginning of stack-args. */ | |
59 | struct args_size offset; | |
60 | /* Similar, but offset to the start of the stack slot. Different from | |
61 | OFFSET if this arg pads downward. */ | |
62 | struct args_size slot_offset; | |
63 | /* Size of this argument on the stack, rounded up for any padding it gets, | |
64 | parts of the argument passed in registers do not count. | |
65 | If REG_PARM_STACK_SPACE is defined, then register parms | |
66 | are counted here as well. */ | |
67 | struct args_size size; | |
68 | /* Location on the stack at which parameter should be stored. The store | |
69 | has already been done if STACK == VALUE. */ | |
70 | rtx stack; | |
71 | /* Location on the stack of the start of this argument slot. This can | |
72 | differ from STACK if this arg pads downward. This location is known | |
73 | to be aligned to FUNCTION_ARG_BOUNDARY. */ | |
74 | rtx stack_slot; | |
75 | #ifdef ACCUMULATE_OUTGOING_ARGS | |
76 | /* Place that this stack area has been saved, if needed. */ | |
77 | rtx save_area; | |
78 | #endif | |
79 | }; | |
80 | ||
81 | #ifdef ACCUMULATE_OUTGOING_ARGS | |
82 | /* A vector of one char per word of stack space. A byte if non-zero if | |
83 | the corresponding stack location has been used. | |
84 | This vector is used to prevent a function call within an argument from | |
85 | clobbering any stack already set up. */ | |
86 | static char *stack_usage_map; | |
87 | ||
88 | /* Size of STACK_USAGE_MAP. */ | |
89 | static int highest_outgoing_arg_in_use; | |
90 | #endif | |
91 | ||
92 | static void store_one_arg (); | |
93 | extern enum machine_mode mode_for_size (); | |
94 | \f | |
95 | /* Return 1 if EXP contains a call to the built-in function `alloca'. */ | |
96 | ||
97 | static int | |
98 | calls_alloca (exp) | |
99 | tree exp; | |
100 | { | |
101 | register int i; | |
102 | int type = TREE_CODE_CLASS (TREE_CODE (exp)); | |
103 | int length = tree_code_length[(int) TREE_CODE (exp)]; | |
104 | ||
105 | /* Only expressions and references can contain calls. */ | |
106 | ||
107 | if (type != 'e' && type != '<' && type != '1' && type != '2' && type != 'r') | |
108 | return 0; | |
109 | ||
110 | switch (TREE_CODE (exp)) | |
111 | { | |
112 | case CALL_EXPR: | |
113 | if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR | |
114 | && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0)) | |
115 | == FUNCTION_DECL) | |
116 | && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (exp, 0), 0)) | |
117 | && (DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0)) | |
118 | == BUILT_IN_ALLOCA)) | |
119 | return 1; | |
120 | ||
121 | /* Third operand is RTL. */ | |
122 | length = 2; | |
123 | break; | |
124 | ||
125 | case SAVE_EXPR: | |
126 | if (SAVE_EXPR_RTL (exp) != 0) | |
127 | return 0; | |
128 | break; | |
129 | ||
130 | case BLOCK: | |
131 | /* Must not look at BLOCK_SUPERCONTEXT since it will point back to | |
132 | us. */ | |
133 | length = 3; | |
134 | break; | |
135 | ||
136 | case METHOD_CALL_EXPR: | |
137 | length = 3; | |
138 | break; | |
139 | ||
140 | case WITH_CLEANUP_EXPR: | |
141 | length = 1; | |
142 | break; | |
143 | ||
144 | case RTL_EXPR: | |
145 | return 0; | |
146 | } | |
147 | ||
148 | for (i = 0; i < length; i++) | |
149 | if (TREE_OPERAND (exp, i) != 0 | |
150 | && calls_alloca (TREE_OPERAND (exp, i))) | |
151 | return 1; | |
152 | ||
153 | return 0; | |
154 | } | |
155 | \f | |
156 | /* Force FUNEXP into a form suitable for the address of a CALL, | |
157 | and return that as an rtx. Also load the static chain register | |
158 | if FNDECL is a nested function. | |
159 | ||
160 | USE_INSNS points to a variable holding a chain of USE insns | |
161 | to which a USE of the static chain | |
162 | register should be added, if required. */ | |
163 | ||
164 | rtx | |
165 | prepare_call_address (funexp, fndecl, use_insns) | |
166 | rtx funexp; | |
167 | tree fndecl; | |
168 | rtx *use_insns; | |
169 | { | |
170 | rtx static_chain_value = 0; | |
171 | ||
172 | funexp = protect_from_queue (funexp, 0); | |
173 | ||
174 | if (fndecl != 0) | |
175 | /* Get possible static chain value for nested function in C. */ | |
176 | static_chain_value = lookup_static_chain (fndecl); | |
177 | ||
178 | /* Make a valid memory address and copy constants thru pseudo-regs, | |
179 | but not for a constant address if -fno-function-cse. */ | |
180 | if (GET_CODE (funexp) != SYMBOL_REF) | |
181 | funexp = memory_address (FUNCTION_MODE, funexp); | |
182 | else | |
183 | { | |
184 | #ifndef NO_FUNCTION_CSE | |
185 | if (optimize && ! flag_no_function_cse) | |
186 | #ifdef NO_RECURSIVE_FUNCTION_CSE | |
187 | if (fndecl != current_function_decl) | |
188 | #endif | |
189 | funexp = force_reg (Pmode, funexp); | |
190 | #endif | |
191 | } | |
192 | ||
193 | if (static_chain_value != 0) | |
194 | { | |
195 | emit_move_insn (static_chain_rtx, static_chain_value); | |
196 | ||
197 | /* Put the USE insn in the chain we were passed. It will later be | |
198 | output immediately in front of the CALL insn. */ | |
199 | push_to_sequence (*use_insns); | |
200 | emit_insn (gen_rtx (USE, VOIDmode, static_chain_rtx)); | |
201 | *use_insns = get_insns (); | |
202 | end_sequence (); | |
203 | } | |
204 | ||
205 | return funexp; | |
206 | } | |
207 | ||
208 | /* Generate instructions to call function FUNEXP, | |
209 | and optionally pop the results. | |
210 | The CALL_INSN is the first insn generated. | |
211 | ||
212 | FUNTYPE is the data type of the function, or, for a library call, | |
213 | the identifier for the name of the call. This is given to the | |
214 | macro RETURN_POPS_ARGS to determine whether this function pops its own args. | |
215 | ||
216 | STACK_SIZE is the number of bytes of arguments on the stack, | |
217 | rounded up to STACK_BOUNDARY; zero if the size is variable. | |
218 | This is both to put into the call insn and | |
219 | to generate explicit popping code if necessary. | |
220 | ||
221 | STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value. | |
222 | It is zero if this call doesn't want a structure value. | |
223 | ||
224 | NEXT_ARG_REG is the rtx that results from executing | |
225 | FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1) | |
226 | just after all the args have had their registers assigned. | |
227 | This could be whatever you like, but normally it is the first | |
228 | arg-register beyond those used for args in this call, | |
229 | or 0 if all the arg-registers are used in this call. | |
230 | It is passed on to `gen_call' so you can put this info in the call insn. | |
231 | ||
232 | VALREG is a hard register in which a value is returned, | |
233 | or 0 if the call does not return a value. | |
234 | ||
235 | OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before | |
236 | the args to this call were processed. | |
237 | We restore `inhibit_defer_pop' to that value. | |
238 | ||
239 | USE_INSNS is a chain of USE insns to be emitted immediately before | |
240 | the actual CALL insn. | |
241 | ||
242 | IS_CONST is true if this is a `const' call. */ | |
243 | ||
244 | void | |
245 | emit_call_1 (funexp, funtype, stack_size, struct_value_size, next_arg_reg, | |
246 | valreg, old_inhibit_defer_pop, use_insns, is_const) | |
247 | rtx funexp; | |
248 | tree funtype; | |
249 | int stack_size; | |
250 | int struct_value_size; | |
251 | rtx next_arg_reg; | |
252 | rtx valreg; | |
253 | int old_inhibit_defer_pop; | |
254 | rtx use_insns; | |
255 | int is_const; | |
256 | { | |
257 | rtx stack_size_rtx = gen_rtx (CONST_INT, VOIDmode, stack_size); | |
258 | rtx struct_value_size_rtx = gen_rtx (CONST_INT, VOIDmode, struct_value_size); | |
259 | rtx call_insn; | |
260 | int already_popped = 0; | |
261 | ||
262 | /* Ensure address is valid. SYMBOL_REF is already valid, so no need, | |
263 | and we don't want to load it into a register as an optimization, | |
264 | because prepare_call_address already did it if it should be done. */ | |
265 | if (GET_CODE (funexp) != SYMBOL_REF) | |
266 | funexp = memory_address (FUNCTION_MODE, funexp); | |
267 | ||
268 | #ifndef ACCUMULATE_OUTGOING_ARGS | |
269 | #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop) | |
270 | if (HAVE_call_pop && HAVE_call_value_pop | |
271 | && (RETURN_POPS_ARGS (funtype, stack_size) > 0 || stack_size == 0)) | |
272 | { | |
273 | rtx n_pop = gen_rtx (CONST_INT, VOIDmode, | |
274 | RETURN_POPS_ARGS (funtype, stack_size)); | |
275 | rtx pat; | |
276 | ||
277 | /* If this subroutine pops its own args, record that in the call insn | |
278 | if possible, for the sake of frame pointer elimination. */ | |
279 | if (valreg) | |
280 | pat = gen_call_value_pop (valreg, | |
281 | gen_rtx (MEM, FUNCTION_MODE, funexp), | |
282 | stack_size_rtx, next_arg_reg, n_pop); | |
283 | else | |
284 | pat = gen_call_pop (gen_rtx (MEM, FUNCTION_MODE, funexp), | |
285 | stack_size_rtx, next_arg_reg, n_pop); | |
286 | ||
287 | emit_call_insn (pat); | |
288 | already_popped = 1; | |
289 | } | |
290 | else | |
291 | #endif | |
292 | #endif | |
293 | ||
294 | #if defined (HAVE_call) && defined (HAVE_call_value) | |
295 | if (HAVE_call && HAVE_call_value) | |
296 | { | |
297 | if (valreg) | |
298 | emit_call_insn (gen_call_value (valreg, | |
299 | gen_rtx (MEM, FUNCTION_MODE, funexp), | |
300 | stack_size_rtx, next_arg_reg)); | |
301 | else | |
302 | emit_call_insn (gen_call (gen_rtx (MEM, FUNCTION_MODE, funexp), | |
303 | stack_size_rtx, next_arg_reg, | |
304 | struct_value_size_rtx)); | |
305 | } | |
306 | else | |
307 | #endif | |
308 | abort (); | |
309 | ||
310 | /* Find the CALL insn we just emitted and write the USE insns before it. */ | |
311 | for (call_insn = get_last_insn (); | |
312 | call_insn && GET_CODE (call_insn) != CALL_INSN; | |
313 | call_insn = PREV_INSN (call_insn)) | |
314 | ; | |
315 | ||
316 | if (! call_insn) | |
317 | abort (); | |
318 | ||
319 | /* Put the USE insns before the CALL. */ | |
320 | emit_insns_before (use_insns, call_insn); | |
321 | ||
322 | /* If this is a const call, then set the insn's unchanging bit. */ | |
323 | if (is_const) | |
324 | CONST_CALL_P (call_insn) = 1; | |
325 | ||
326 | inhibit_defer_pop = old_inhibit_defer_pop; | |
327 | ||
328 | #ifndef ACCUMULATE_OUTGOING_ARGS | |
329 | /* If returning from the subroutine does not automatically pop the args, | |
330 | we need an instruction to pop them sooner or later. | |
331 | Perhaps do it now; perhaps just record how much space to pop later. | |
332 | ||
333 | If returning from the subroutine does pop the args, indicate that the | |
334 | stack pointer will be changed. */ | |
335 | ||
336 | if (stack_size != 0 && RETURN_POPS_ARGS (funtype, stack_size) > 0) | |
337 | { | |
338 | if (!already_popped) | |
339 | emit_insn (gen_rtx (CLOBBER, VOIDmode, stack_pointer_rtx)); | |
340 | stack_size -= RETURN_POPS_ARGS (funtype, stack_size); | |
341 | stack_size_rtx = gen_rtx (CONST_INT, VOIDmode, stack_size); | |
342 | } | |
343 | ||
344 | if (stack_size != 0) | |
345 | { | |
346 | if (flag_defer_pop && inhibit_defer_pop == 0) | |
347 | pending_stack_adjust += stack_size; | |
348 | else | |
349 | adjust_stack (stack_size_rtx); | |
350 | } | |
351 | #endif | |
352 | } | |
353 | ||
354 | /* Generate all the code for a function call | |
355 | and return an rtx for its value. | |
356 | Store the value in TARGET (specified as an rtx) if convenient. | |
357 | If the value is stored in TARGET then TARGET is returned. | |
358 | If IGNORE is nonzero, then we ignore the value of the function call. */ | |
359 | ||
360 | rtx | |
361 | expand_call (exp, target, ignore, modifier) | |
362 | tree exp; | |
363 | rtx target; | |
364 | int ignore; | |
365 | enum expand_modifier modifier; | |
366 | { | |
367 | /* List of actual parameters. */ | |
368 | tree actparms = TREE_OPERAND (exp, 1); | |
369 | /* RTX for the function to be called. */ | |
370 | rtx funexp; | |
371 | /* Tree node for the function to be called (not the address!). */ | |
372 | tree funtree; | |
373 | /* Data type of the function. */ | |
374 | tree funtype; | |
375 | /* Declaration of the function being called, | |
376 | or 0 if the function is computed (not known by name). */ | |
377 | tree fndecl = 0; | |
378 | char *name = 0; | |
379 | ||
380 | /* Register in which non-BLKmode value will be returned, | |
381 | or 0 if no value or if value is BLKmode. */ | |
382 | rtx valreg; | |
383 | /* Address where we should return a BLKmode value; | |
384 | 0 if value not BLKmode. */ | |
385 | rtx structure_value_addr = 0; | |
386 | /* Nonzero if that address is being passed by treating it as | |
387 | an extra, implicit first parameter. Otherwise, | |
388 | it is passed by being copied directly into struct_value_rtx. */ | |
389 | int structure_value_addr_parm = 0; | |
390 | /* Size of aggregate value wanted, or zero if none wanted | |
391 | or if we are using the non-reentrant PCC calling convention | |
392 | or expecting the value in registers. */ | |
393 | int struct_value_size = 0; | |
394 | /* Nonzero if called function returns an aggregate in memory PCC style, | |
395 | by returning the address of where to find it. */ | |
396 | int pcc_struct_value = 0; | |
397 | ||
398 | /* Number of actual parameters in this call, including struct value addr. */ | |
399 | int num_actuals; | |
400 | /* Number of named args. Args after this are anonymous ones | |
401 | and they must all go on the stack. */ | |
402 | int n_named_args; | |
403 | /* Count arg position in order args appear. */ | |
404 | int argpos; | |
405 | ||
406 | /* Vector of information about each argument. | |
407 | Arguments are numbered in the order they will be pushed, | |
408 | not the order they are written. */ | |
409 | struct arg_data *args; | |
410 | ||
411 | /* Total size in bytes of all the stack-parms scanned so far. */ | |
412 | struct args_size args_size; | |
413 | /* Size of arguments before any adjustments (such as rounding). */ | |
414 | struct args_size original_args_size; | |
415 | /* Data on reg parms scanned so far. */ | |
416 | CUMULATIVE_ARGS args_so_far; | |
417 | /* Nonzero if a reg parm has been scanned. */ | |
418 | int reg_parm_seen; | |
419 | ||
420 | /* Nonzero if we must avoid push-insns in the args for this call. | |
421 | If stack space is allocated for register parameters, but not by the | |
422 | caller, then it is preallocated in the fixed part of the stack frame. | |
423 | So the entire argument block must then be preallocated (i.e., we | |
424 | ignore PUSH_ROUNDING in that case). */ | |
425 | ||
426 | #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE) | |
427 | int must_preallocate = 1; | |
428 | #else | |
429 | #ifdef PUSH_ROUNDING | |
430 | int must_preallocate = 0; | |
431 | #else | |
432 | int must_preallocate = 1; | |
433 | #endif | |
434 | #endif | |
435 | ||
436 | /* 1 if scanning parms front to back, -1 if scanning back to front. */ | |
437 | int inc; | |
438 | /* Address of space preallocated for stack parms | |
439 | (on machines that lack push insns), or 0 if space not preallocated. */ | |
440 | rtx argblock = 0; | |
441 | ||
442 | /* Nonzero if it is plausible that this is a call to alloca. */ | |
443 | int may_be_alloca; | |
444 | /* Nonzero if this is a call to setjmp or a related function. */ | |
445 | int returns_twice; | |
446 | /* Nonzero if this is a call to `longjmp'. */ | |
447 | int is_longjmp; | |
448 | /* Nonzero if this is a call to an inline function. */ | |
449 | int is_integrable = 0; | |
450 | /* Nonzero if this is a call to __builtin_new. */ | |
451 | int is_builtin_new; | |
452 | /* Nonzero if this is a call to a `const' function. | |
453 | Note that only explicitly named functions are handled as `const' here. */ | |
454 | int is_const = 0; | |
455 | /* Nonzero if this is a call to a `volatile' function. */ | |
456 | int is_volatile = 0; | |
457 | #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE) | |
458 | /* Define the boundary of the register parm stack space that needs to be | |
459 | save, if any. */ | |
460 | int low_to_save = -1, high_to_save; | |
461 | rtx save_area = 0; /* Place that it is saved */ | |
462 | #endif | |
463 | ||
464 | #ifdef ACCUMULATE_OUTGOING_ARGS | |
465 | int initial_highest_arg_in_use = highest_outgoing_arg_in_use; | |
466 | char *initial_stack_usage_map = stack_usage_map; | |
467 | #endif | |
468 | ||
469 | rtx old_stack_level = 0; | |
470 | int old_pending_adj; | |
471 | int old_inhibit_defer_pop = inhibit_defer_pop; | |
472 | tree old_cleanups = cleanups_this_call; | |
473 | ||
474 | rtx use_insns = 0; | |
475 | ||
476 | register tree p; | |
477 | register int i; | |
478 | ||
479 | /* See if we can find a DECL-node for the actual function. | |
480 | As a result, decide whether this is a call to an integrable function. */ | |
481 | ||
482 | p = TREE_OPERAND (exp, 0); | |
483 | if (TREE_CODE (p) == ADDR_EXPR) | |
484 | { | |
485 | fndecl = TREE_OPERAND (p, 0); | |
486 | if (TREE_CODE (fndecl) != FUNCTION_DECL) | |
487 | { | |
488 | /* May still be a `const' function if it is | |
489 | a call through a pointer-to-const. | |
490 | But we don't handle that. */ | |
491 | fndecl = 0; | |
492 | } | |
493 | else | |
494 | { | |
495 | if (!flag_no_inline | |
496 | && fndecl != current_function_decl | |
497 | && DECL_SAVED_INSNS (fndecl)) | |
498 | is_integrable = 1; | |
499 | else if (! TREE_ADDRESSABLE (fndecl)) | |
500 | { | |
501 | /* In case this function later becomes inlineable, | |
502 | record that there was already a non-inline call to it. | |
503 | ||
504 | Use abstraction instead of setting TREE_ADDRESSABLE | |
505 | directly. */ | |
506 | if (TREE_INLINE (fndecl) && extra_warnings && !flag_no_inline) | |
507 | warning_with_decl (fndecl, "can't inline call to `%s' which was declared inline"); | |
508 | mark_addressable (fndecl); | |
509 | } | |
510 | ||
511 | if (TREE_READONLY (fndecl) && ! TREE_THIS_VOLATILE (fndecl)) | |
512 | is_const = 1; | |
513 | } | |
514 | } | |
515 | ||
516 | is_volatile = TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (p))); | |
517 | ||
518 | /* Warn if this value is an aggregate type, | |
519 | regardless of which calling convention we are using for it. */ | |
520 | if (warn_aggregate_return | |
521 | && (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE | |
522 | || TREE_CODE (TREE_TYPE (exp)) == UNION_TYPE | |
523 | || TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE)) | |
524 | warning ("function call has aggregate value"); | |
525 | ||
526 | /* Set up a place to return a structure. */ | |
527 | ||
528 | /* Cater to broken compilers. */ | |
529 | if (aggregate_value_p (exp)) | |
530 | { | |
531 | /* This call returns a big structure. */ | |
532 | is_const = 0; | |
533 | ||
534 | #ifdef PCC_STATIC_STRUCT_RETURN | |
535 | if (flag_pcc_struct_return) | |
536 | { | |
537 | pcc_struct_value = 1; | |
538 | is_integrable = 0; /* Easier than making that case work right. */ | |
539 | } | |
540 | else | |
541 | #endif | |
542 | { | |
543 | struct_value_size = int_size_in_bytes (TREE_TYPE (exp)); | |
544 | ||
545 | if (struct_value_size < 0) | |
546 | abort (); | |
547 | ||
548 | if (target && GET_CODE (target) == MEM) | |
549 | structure_value_addr = XEXP (target, 0); | |
550 | else | |
551 | { | |
552 | /* Assign a temporary on the stack to hold the value. */ | |
553 | ||
554 | /* For variable-sized objects, we must be called with a target | |
555 | specified. If we were to allocate space on the stack here, | |
556 | we would have no way of knowing when to free it. */ | |
557 | ||
558 | structure_value_addr | |
559 | = XEXP (assign_stack_temp (BLKmode, struct_value_size, 1), 0); | |
560 | target = 0; | |
561 | } | |
562 | } | |
563 | } | |
564 | ||
565 | /* If called function is inline, try to integrate it. */ | |
566 | ||
567 | if (is_integrable) | |
568 | { | |
569 | rtx temp; | |
570 | ||
571 | temp = expand_inline_function (fndecl, actparms, target, | |
572 | ignore, TREE_TYPE (exp), | |
573 | structure_value_addr); | |
574 | ||
575 | /* If inlining succeeded, return. */ | |
576 | if ((int) temp != -1) | |
577 | { | |
578 | /* Perform all cleanups needed for the arguments of this call | |
579 | (i.e. destructors in C++). It is ok if these destructors | |
580 | clobber RETURN_VALUE_REG, because the only time we care about | |
581 | this is when TARGET is that register. But in C++, we take | |
582 | care to never return that register directly. */ | |
583 | expand_cleanups_to (old_cleanups); | |
584 | ||
585 | /* If the result is equivalent to TARGET, return TARGET to simplify | |
586 | checks in store_expr. They can be equivalent but not equal in the | |
587 | case of a function that returns BLKmode. */ | |
588 | if (temp != target && rtx_equal_p (temp, target)) | |
589 | return target; | |
590 | return temp; | |
591 | } | |
592 | ||
593 | /* If inlining failed, mark FNDECL as needing to be compiled | |
594 | separately after all. */ | |
595 | mark_addressable (fndecl); | |
596 | } | |
597 | ||
598 | /* When calling a const function, we must pop the stack args right away, | |
599 | so that the pop is deleted or moved with the call. */ | |
600 | if (is_const) | |
601 | NO_DEFER_POP; | |
602 | ||
603 | function_call_count++; | |
604 | ||
605 | if (fndecl && DECL_NAME (fndecl)) | |
606 | name = IDENTIFIER_POINTER (DECL_NAME (fndecl)); | |
607 | ||
608 | #if 0 | |
609 | /* Unless it's a call to a specific function that isn't alloca, | |
610 | if it has one argument, we must assume it might be alloca. */ | |
611 | ||
612 | may_be_alloca = | |
613 | (!(fndecl != 0 && strcmp (name, "alloca")) | |
614 | && actparms != 0 | |
615 | && TREE_CHAIN (actparms) == 0); | |
616 | #else | |
617 | /* We assume that alloca will always be called by name. It | |
618 | makes no sense to pass it as a pointer-to-function to | |
619 | anything that does not understand its behavior. */ | |
620 | may_be_alloca = | |
621 | (name && ((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6 | |
622 | && name[0] == 'a' | |
623 | && ! strcmp (name, "alloca")) | |
624 | || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16 | |
625 | && name[0] == '_' | |
626 | && ! strcmp (name, "__builtin_alloca")))); | |
627 | #endif | |
628 | ||
629 | /* See if this is a call to a function that can return more than once | |
630 | or a call to longjmp. */ | |
631 | ||
632 | returns_twice = 0; | |
633 | is_longjmp = 0; | |
634 | ||
635 | if (name != 0 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 15) | |
636 | { | |
637 | char *tname = name; | |
638 | ||
639 | if (name[0] == '_') | |
640 | tname += ((name[1] == '_' && name[2] == 'x') ? 3 : 1); | |
641 | ||
642 | if (tname[0] == 's') | |
643 | { | |
644 | returns_twice | |
645 | = ((tname[1] == 'e' | |
646 | && (! strcmp (tname, "setjmp") | |
647 | || ! strcmp (tname, "setjmp_syscall"))) | |
648 | || (tname[1] == 'i' | |
649 | && ! strcmp (tname, "sigsetjmp")) | |
650 | || (tname[1] == 'a' | |
651 | && ! strcmp (tname, "savectx"))); | |
652 | if (tname[1] == 'i' | |
653 | && ! strcmp (tname, "siglongjmp")) | |
654 | is_longjmp = 1; | |
655 | } | |
656 | else if ((tname[0] == 'q' && tname[1] == 's' | |
657 | && ! strcmp (tname, "qsetjmp")) | |
658 | || (tname[0] == 'v' && tname[1] == 'f' | |
659 | && ! strcmp (tname, "vfork"))) | |
660 | returns_twice = 1; | |
661 | ||
662 | else if (tname[0] == 'l' && tname[1] == 'o' | |
663 | && ! strcmp (tname, "longjmp")) | |
664 | is_longjmp = 1; | |
665 | } | |
666 | ||
667 | is_builtin_new | |
668 | = (name != 0 | |
669 | && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 13 | |
670 | && (!strcmp (name, "__builtin_new"))); | |
671 | ||
672 | if (may_be_alloca) | |
673 | current_function_calls_alloca = 1; | |
674 | ||
675 | /* Don't let pending stack adjusts add up to too much. | |
676 | Also, do all pending adjustments now | |
677 | if there is any chance this might be a call to alloca. */ | |
678 | ||
679 | if (pending_stack_adjust >= 32 | |
680 | || (pending_stack_adjust > 0 && may_be_alloca)) | |
681 | do_pending_stack_adjust (); | |
682 | ||
683 | /* Operand 0 is a pointer-to-function; get the type of the function. */ | |
684 | funtype = TREE_TYPE (TREE_OPERAND (exp, 0)); | |
685 | if (TREE_CODE (funtype) != POINTER_TYPE) | |
686 | abort (); | |
687 | funtype = TREE_TYPE (funtype); | |
688 | ||
689 | /* Push the temporary stack slot level so that we can free temporaries used | |
690 | by each of the arguments separately. */ | |
691 | push_temp_slots (); | |
692 | ||
693 | /* Start updating where the next arg would go. */ | |
694 | INIT_CUMULATIVE_ARGS (args_so_far, funtype, 0); | |
695 | ||
696 | /* If struct_value_rtx is 0, it means pass the address | |
697 | as if it were an extra parameter. */ | |
698 | if (structure_value_addr && struct_value_rtx == 0) | |
699 | { | |
700 | actparms | |
701 | = tree_cons (error_mark_node, | |
702 | make_tree (build_pointer_type (TREE_TYPE (funtype)), | |
703 | force_reg (Pmode, structure_value_addr)), | |
704 | actparms); | |
705 | structure_value_addr_parm = 1; | |
706 | } | |
707 | ||
708 | /* Count the arguments and set NUM_ACTUALS. */ | |
709 | for (p = actparms, i = 0; p; p = TREE_CHAIN (p)) i++; | |
710 | num_actuals = i; | |
711 | ||
712 | /* Compute number of named args. | |
713 | Normally, don't include the last named arg if anonymous args follow. | |
714 | (If no anonymous args follow, the result of list_length | |
715 | is actually one too large.) | |
716 | ||
717 | If SETUP_INCOMING_VARARGS is defined, this machine will be able to | |
718 | place unnamed args that were passed in registers into the stack. So | |
719 | treat all args as named. This allows the insns emitting for a specific | |
720 | argument list to be independant of the function declaration. | |
721 | ||
722 | If SETUP_INCOMING_VARARGS is not defined, we do not have any reliable | |
723 | way to pass unnamed args in registers, so we must force them into | |
724 | memory. */ | |
725 | #ifndef SETUP_INCOMING_VARARGS | |
726 | if (TYPE_ARG_TYPES (funtype) != 0) | |
727 | n_named_args | |
728 | = list_length (TYPE_ARG_TYPES (funtype)) - 1 | |
729 | /* Count the struct value address, if it is passed as a parm. */ | |
730 | + structure_value_addr_parm; | |
731 | else | |
732 | #endif | |
733 | /* If we know nothing, treat all args as named. */ | |
734 | n_named_args = num_actuals; | |
735 | ||
736 | /* Make a vector to hold all the information about each arg. */ | |
737 | args = (struct arg_data *) alloca (num_actuals * sizeof (struct arg_data)); | |
738 | bzero (args, num_actuals * sizeof (struct arg_data)); | |
739 | ||
740 | args_size.constant = 0; | |
741 | args_size.var = 0; | |
742 | ||
743 | /* In this loop, we consider args in the order they are written. | |
744 | We fill up ARGS from the front of from the back if necessary | |
745 | so that in any case the first arg to be pushed ends up at the front. */ | |
746 | ||
747 | #ifdef PUSH_ARGS_REVERSED | |
748 | i = num_actuals - 1, inc = -1; | |
749 | /* In this case, must reverse order of args | |
750 | so that we compute and push the last arg first. */ | |
751 | #else | |
752 | i = 0, inc = 1; | |
753 | #endif | |
754 | ||
755 | /* I counts args in order (to be) pushed; ARGPOS counts in order written. */ | |
756 | for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++) | |
757 | { | |
758 | tree type = TREE_TYPE (TREE_VALUE (p)); | |
759 | ||
760 | args[i].tree_value = TREE_VALUE (p); | |
761 | ||
762 | /* Replace erroneous argument with constant zero. */ | |
763 | if (type == error_mark_node || TYPE_SIZE (type) == 0) | |
764 | args[i].tree_value = integer_zero_node, type = integer_type_node; | |
765 | ||
766 | /* Decide where to pass this arg. | |
767 | ||
768 | args[i].reg is nonzero if all or part is passed in registers. | |
769 | ||
770 | args[i].partial is nonzero if part but not all is passed in registers, | |
771 | and the exact value says how many words are passed in registers. | |
772 | ||
773 | args[i].pass_on_stack is nonzero if the argument must at least be | |
774 | computed on the stack. It may then be loaded back into registers | |
775 | if args[i].reg is nonzero. | |
776 | ||
777 | These decisions are driven by the FUNCTION_... macros and must agree | |
778 | with those made by function.c. */ | |
779 | ||
780 | #ifdef FUNCTION_ARG_PASS_BY_REFERENCE | |
781 | /* See if this argument should be passed by invisible reference. */ | |
782 | if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, TYPE_MODE (type), type, | |
783 | argpos < n_named_args)) | |
784 | { | |
785 | /* We make a copy of the object and pass the address to the function | |
786 | being called. */ | |
787 | int size = int_size_in_bytes (type); | |
788 | rtx copy; | |
789 | ||
790 | if (size < 0) | |
791 | { | |
792 | /* This is a variable-sized object. Make space on the stack | |
793 | for it. */ | |
794 | rtx size_rtx = expand_expr (size_in_bytes (type), 0, | |
795 | VOIDmode, 0); | |
796 | ||
797 | if (old_stack_level == 0) | |
798 | { | |
799 | old_stack_level = copy_to_mode_reg (Pmode, stack_pointer_rtx); | |
800 | old_pending_adj = pending_stack_adjust; | |
801 | pending_stack_adjust = 0; | |
802 | } | |
803 | ||
804 | copy = gen_rtx (MEM, BLKmode, | |
805 | allocate_dynamic_stack_space (size_rtx, 0)); | |
806 | } | |
807 | else | |
808 | copy = assign_stack_temp (TYPE_MODE (type), size, 1); | |
809 | ||
810 | store_expr (args[i].tree_value, copy, 0); | |
811 | ||
812 | args[i].tree_value = build1 (ADDR_EXPR, build_pointer_type (type), | |
813 | make_tree (type, copy)); | |
814 | type = build_pointer_type (type); | |
815 | } | |
816 | #endif | |
817 | ||
818 | args[i].reg = FUNCTION_ARG (args_so_far, TYPE_MODE (type), type, | |
819 | argpos < n_named_args); | |
820 | #ifdef FUNCTION_ARG_PARTIAL_NREGS | |
821 | if (args[i].reg) | |
822 | args[i].partial | |
823 | = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, TYPE_MODE (type), type, | |
824 | argpos < n_named_args); | |
825 | #endif | |
826 | ||
827 | args[i].pass_on_stack = MUST_PASS_IN_STACK (TYPE_MODE (type), type); | |
828 | ||
829 | /* If FUNCTION_ARG returned an (expr_list (nil) FOO), it means that | |
830 | we are to pass this arg in the register(s) designated by FOO, but | |
831 | also to pass it in the stack. */ | |
832 | if (args[i].reg && GET_CODE (args[i].reg) == EXPR_LIST | |
833 | && XEXP (args[i].reg, 0) == 0) | |
834 | args[i].pass_on_stack = 1, args[i].reg = XEXP (args[i].reg, 1); | |
835 | ||
836 | /* If this is an addressable type, we must preallocate the stack | |
837 | since we must evaluate the object into its final location. | |
838 | ||
839 | If this is to be passed in both registers and the stack, it is simpler | |
840 | to preallocate. */ | |
841 | if (TREE_ADDRESSABLE (type) | |
842 | || (args[i].pass_on_stack && args[i].reg != 0)) | |
843 | must_preallocate = 1; | |
844 | ||
845 | /* If this is an addressable type, we cannot pre-evaluate it. Thus, | |
846 | we cannot consider this function call constant. */ | |
847 | if (TREE_ADDRESSABLE (type)) | |
848 | is_const = 0; | |
849 | ||
850 | /* Compute the stack-size of this argument. */ | |
851 | if (args[i].reg == 0 || args[i].partial != 0 | |
852 | #ifdef REG_PARM_STACK_SPACE | |
853 | || REG_PARM_STACK_SPACE (fndecl) > 0 | |
854 | #endif | |
855 | || args[i].pass_on_stack) | |
856 | locate_and_pad_parm (TYPE_MODE (type), type, | |
857 | #ifdef STACK_PARMS_IN_REG_PARM_AREA | |
858 | 1, | |
859 | #else | |
860 | args[i].reg != 0, | |
861 | #endif | |
862 | fndecl, &args_size, &args[i].offset, | |
863 | &args[i].size); | |
864 | ||
865 | #ifndef ARGS_GROW_DOWNWARD | |
866 | args[i].slot_offset = args_size; | |
867 | #endif | |
868 | ||
869 | #ifndef REG_PARM_STACK_SPACE | |
870 | /* If a part of the arg was put into registers, | |
871 | don't include that part in the amount pushed. */ | |
872 | if (! args[i].pass_on_stack) | |
873 | args[i].size.constant -= ((args[i].partial * UNITS_PER_WORD) | |
874 | / (PARM_BOUNDARY / BITS_PER_UNIT) | |
875 | * (PARM_BOUNDARY / BITS_PER_UNIT)); | |
876 | #endif | |
877 | ||
878 | /* Update ARGS_SIZE, the total stack space for args so far. */ | |
879 | ||
880 | args_size.constant += args[i].size.constant; | |
881 | if (args[i].size.var) | |
882 | { | |
883 | ADD_PARM_SIZE (args_size, args[i].size.var); | |
884 | } | |
885 | ||
886 | /* Since the slot offset points to the bottom of the slot, | |
887 | we must record it after incrementing if the args grow down. */ | |
888 | #ifdef ARGS_GROW_DOWNWARD | |
889 | args[i].slot_offset = args_size; | |
890 | ||
891 | args[i].slot_offset.constant = -args_size.constant; | |
892 | if (args_size.var) | |
893 | { | |
894 | SUB_PARM_SIZE (args[i].slot_offset, args_size.var); | |
895 | } | |
896 | #endif | |
897 | ||
898 | /* Increment ARGS_SO_FAR, which has info about which arg-registers | |
899 | have been used, etc. */ | |
900 | ||
901 | FUNCTION_ARG_ADVANCE (args_so_far, TYPE_MODE (type), type, | |
902 | argpos < n_named_args); | |
903 | } | |
904 | ||
905 | /* Compute the actual size of the argument block required. The variable | |
906 | and constant sizes must be combined, the size may have to be rounded, | |
907 | and there may be a minimum required size. */ | |
908 | ||
909 | original_args_size = args_size; | |
910 | if (args_size.var) | |
911 | { | |
912 | /* If this function requires a variable-sized argument list, don't try to | |
913 | make a cse'able block for this call. We may be able to do this | |
914 | eventually, but it is too complicated to keep track of what insns go | |
915 | in the cse'able block and which don't. */ | |
916 | ||
917 | is_const = 0; | |
918 | must_preallocate = 1; | |
919 | ||
920 | args_size.var = ARGS_SIZE_TREE (args_size); | |
921 | args_size.constant = 0; | |
922 | ||
923 | #ifdef STACK_BOUNDARY | |
924 | if (STACK_BOUNDARY != BITS_PER_UNIT) | |
925 | args_size.var = round_up (args_size.var, STACK_BYTES); | |
926 | #endif | |
927 | ||
928 | #ifdef REG_PARM_STACK_SPACE | |
929 | if (REG_PARM_STACK_SPACE (fndecl) > 0) | |
930 | { | |
931 | args_size.var | |
932 | = size_binop (MAX_EXPR, args_size.var, | |
933 | size_int (REG_PARM_STACK_SPACE (fndecl))); | |
934 | ||
935 | #ifndef OUTGOING_REG_PARM_STACK_SPACE | |
936 | /* The area corresponding to register parameters is not to count in | |
937 | the size of the block we need. So make the adjustment. */ | |
938 | args_size.var | |
939 | = size_binop (MINUS_EXPR, args_size.var, | |
940 | size_int (REG_PARM_STACK_SPACE (fndecl))); | |
941 | #endif | |
942 | } | |
943 | #endif | |
944 | } | |
945 | else | |
946 | { | |
947 | #ifdef STACK_BOUNDARY | |
948 | args_size.constant = (((args_size.constant + (STACK_BYTES - 1)) | |
949 | / STACK_BYTES) * STACK_BYTES); | |
950 | #endif | |
951 | ||
952 | #ifdef REG_PARM_STACK_SPACE | |
953 | args_size.constant = MAX (args_size.constant, | |
954 | REG_PARM_STACK_SPACE (fndecl)); | |
955 | #ifndef OUTGOING_REG_PARM_STACK_SPACE | |
956 | args_size.constant -= REG_PARM_STACK_SPACE (fndecl); | |
957 | #endif | |
958 | #endif | |
959 | } | |
960 | ||
961 | /* See if we have or want to preallocate stack space. | |
962 | ||
963 | If we would have to push a partially-in-regs parm | |
964 | before other stack parms, preallocate stack space instead. | |
965 | ||
966 | If the size of some parm is not a multiple of the required stack | |
967 | alignment, we must preallocate. | |
968 | ||
969 | If the total size of arguments that would otherwise create a copy in | |
970 | a temporary (such as a CALL) is more than half the total argument list | |
971 | size, preallocation is faster. | |
972 | ||
973 | Another reason to preallocate is if we have a machine (like the m88k) | |
974 | where stack alignment is required to be maintained between every | |
975 | pair of insns, not just when the call is made. However, we assume here | |
976 | that such machines either do not have push insns (and hence preallocation | |
977 | would occur anyway) or the problem is taken care of with | |
978 | PUSH_ROUNDING. */ | |
979 | ||
980 | if (! must_preallocate) | |
981 | { | |
982 | int partial_seen = 0; | |
983 | int copy_to_evaluate_size = 0; | |
984 | ||
985 | for (i = 0; i < num_actuals && ! must_preallocate; i++) | |
986 | { | |
987 | if (args[i].partial > 0 && ! args[i].pass_on_stack) | |
988 | partial_seen = 1; | |
989 | else if (partial_seen && args[i].reg == 0) | |
990 | must_preallocate = 1; | |
991 | ||
992 | if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode | |
993 | && (TREE_CODE (args[i].tree_value) == CALL_EXPR | |
994 | || TREE_CODE (args[i].tree_value) == TARGET_EXPR | |
995 | || TREE_CODE (args[i].tree_value) == COND_EXPR | |
996 | || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)))) | |
997 | copy_to_evaluate_size | |
998 | += int_size_in_bytes (TREE_TYPE (args[i].tree_value)); | |
999 | } | |
1000 | ||
1001 | if (copy_to_evaluate_size >= args_size.constant / 2) | |
1002 | must_preallocate = 1; | |
1003 | } | |
1004 | ||
1005 | /* If the structure value address will reference the stack pointer, we must | |
1006 | stabilize it. We don't need to do this if we know that we are not going | |
1007 | to adjust the stack pointer in processing this call. */ | |
1008 | ||
1009 | if (structure_value_addr | |
1010 | && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr) | |
1011 | || reg_mentioned_p (virtual_outgoing_args_rtx, structure_value_addr)) | |
1012 | && (args_size.var | |
1013 | #ifndef ACCUMULATE_OUTGOING_ARGS | |
1014 | || args_size.constant | |
1015 | #endif | |
1016 | )) | |
1017 | structure_value_addr = copy_to_reg (structure_value_addr); | |
1018 | ||
1019 | /* If this function call is cse'able, precompute all the parameters. | |
1020 | Note that if the parameter is constructed into a temporary, this will | |
1021 | cause an additional copy because the parameter will be constructed | |
1022 | into a temporary location and then copied into the outgoing arguments. | |
1023 | If a parameter contains a call to alloca and this function uses the | |
1024 | stack, precompute the parameter. */ | |
1025 | ||
1026 | for (i = 0; i < num_actuals; i++) | |
1027 | if (is_const | |
1028 | || ((args_size.var != 0 || args_size.constant != 0) | |
1029 | && calls_alloca (args[i].tree_value))) | |
1030 | { | |
1031 | args[i].initial_value = args[i].value | |
1032 | = expand_expr (args[i].tree_value, 0, VOIDmode, 0); | |
1033 | preserve_temp_slots (args[i].value); | |
1034 | free_temp_slots (); | |
1035 | ||
1036 | /* ANSI doesn't require a sequence point here, | |
1037 | but PCC has one, so this will avoid some problems. */ | |
1038 | emit_queue (); | |
1039 | } | |
1040 | ||
1041 | /* Now we are about to start emitting insns that can be deleted | |
1042 | if a libcall is deleted. */ | |
1043 | if (is_const) | |
1044 | start_sequence (); | |
1045 | ||
1046 | /* If we have no actual push instructions, or shouldn't use them, | |
1047 | make space for all args right now. */ | |
1048 | ||
1049 | if (args_size.var != 0) | |
1050 | { | |
1051 | if (old_stack_level == 0) | |
1052 | { | |
1053 | old_stack_level = copy_to_mode_reg (Pmode, stack_pointer_rtx); | |
1054 | old_pending_adj = pending_stack_adjust; | |
1055 | pending_stack_adjust = 0; | |
1056 | } | |
1057 | argblock = push_block (ARGS_SIZE_RTX (args_size), 0, 0); | |
1058 | } | |
1059 | else if (must_preallocate) | |
1060 | { | |
1061 | /* Note that we must go through the motions of allocating an argument | |
1062 | block even if the size is zero because we may be storing args | |
1063 | in the area reserved for register arguments, which may be part of | |
1064 | the stack frame. */ | |
1065 | int needed = args_size.constant; | |
1066 | ||
1067 | #ifdef ACCUMULATE_OUTGOING_ARGS | |
1068 | /* Store the maximum argument space used. It will be pushed by the | |
1069 | prologue. | |
1070 | ||
1071 | Since the stack pointer will never be pushed, it is possible for | |
1072 | the evaluation of a parm to clobber something we have already | |
1073 | written to the stack. Since most function calls on RISC machines | |
1074 | do not use the stack, this is uncommon, but must work correctly. | |
1075 | ||
1076 | Therefore, we save any area of the stack that was already written | |
1077 | and that we are using. Here we set up to do this by making a new | |
1078 | stack usage map from the old one. The actual save will be done | |
1079 | by store_one_arg. | |
1080 | ||
1081 | Another approach might be to try to reorder the argument | |
1082 | evaluations to avoid this conflicting stack usage. */ | |
1083 | ||
1084 | if (needed > current_function_outgoing_args_size) | |
1085 | current_function_outgoing_args_size = needed; | |
1086 | ||
1087 | #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE) | |
1088 | /* Since we will be writing into the entire argument area, the | |
1089 | map must be allocated for its entire size, not just the part that | |
1090 | is the responsibility of the caller. */ | |
1091 | needed += REG_PARM_STACK_SPACE (fndecl); | |
1092 | #endif | |
1093 | ||
1094 | #ifdef ARGS_GROW_DOWNWARD | |
1095 | highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, | |
1096 | needed + 1); | |
1097 | #else | |
1098 | highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, needed); | |
1099 | #endif | |
1100 | stack_usage_map = (char *) alloca (highest_outgoing_arg_in_use); | |
1101 | ||
1102 | if (initial_highest_arg_in_use) | |
1103 | bcopy (initial_stack_usage_map, stack_usage_map, | |
1104 | initial_highest_arg_in_use); | |
1105 | ||
1106 | if (initial_highest_arg_in_use != highest_outgoing_arg_in_use) | |
1107 | bzero (&stack_usage_map[initial_highest_arg_in_use], | |
1108 | highest_outgoing_arg_in_use - initial_highest_arg_in_use); | |
1109 | needed = 0; | |
1110 | /* No need to copy this virtual register; the space we're | |
1111 | using gets preallocated at the start of the function | |
1112 | so the stack pointer won't change here. */ | |
1113 | argblock = virtual_outgoing_args_rtx; | |
1114 | #else /* not ACCUMULATE_OUTGOING_ARGS */ | |
1115 | if (inhibit_defer_pop == 0) | |
1116 | { | |
1117 | /* Try to reuse some or all of the pending_stack_adjust | |
1118 | to get this space. Maybe we can avoid any pushing. */ | |
1119 | if (needed > pending_stack_adjust) | |
1120 | { | |
1121 | needed -= pending_stack_adjust; | |
1122 | pending_stack_adjust = 0; | |
1123 | } | |
1124 | else | |
1125 | { | |
1126 | pending_stack_adjust -= needed; | |
1127 | needed = 0; | |
1128 | } | |
1129 | } | |
1130 | /* Special case this because overhead of `push_block' in this | |
1131 | case is non-trivial. */ | |
1132 | if (needed == 0) | |
1133 | argblock = virtual_outgoing_args_rtx; | |
1134 | else | |
1135 | argblock = push_block (gen_rtx (CONST_INT, VOIDmode, needed), 0, 0); | |
1136 | ||
1137 | /* We only really need to call `copy_to_reg' in the case where push | |
1138 | insns are going to be used to pass ARGBLOCK to a function | |
1139 | call in ARGS. In that case, the stack pointer changes value | |
1140 | from the allocation point to the call point, and hence | |
1141 | the value of VIRTUAL_OUTGOING_ARGS_RTX changes as well. | |
1142 | But might as well always do it. */ | |
1143 | argblock = copy_to_reg (argblock); | |
1144 | #endif /* not ACCUMULATE_OUTGOING_ARGS */ | |
1145 | } | |
1146 | ||
1147 | /* If we preallocated stack space, compute the address of each argument. | |
1148 | We need not ensure it is a valid memory address here; it will be | |
1149 | validized when it is used. */ | |
1150 | if (argblock) | |
1151 | { | |
1152 | rtx arg_reg = argblock; | |
1153 | int arg_offset = 0; | |
1154 | ||
1155 | if (GET_CODE (argblock) == PLUS) | |
1156 | arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1)); | |
1157 | ||
1158 | for (i = 0; i < num_actuals; i++) | |
1159 | { | |
1160 | rtx offset = ARGS_SIZE_RTX (args[i].offset); | |
1161 | rtx slot_offset = ARGS_SIZE_RTX (args[i].slot_offset); | |
1162 | rtx addr; | |
1163 | ||
1164 | /* Skip this parm if it will not be passed on the stack. */ | |
1165 | if (! args[i].pass_on_stack && args[i].reg != 0) | |
1166 | continue; | |
1167 | ||
1168 | if (GET_CODE (offset) == CONST_INT) | |
1169 | addr = plus_constant (arg_reg, INTVAL (offset)); | |
1170 | else | |
1171 | addr = gen_rtx (PLUS, Pmode, arg_reg, offset); | |
1172 | ||
1173 | addr = plus_constant (addr, arg_offset); | |
1174 | args[i].stack | |
1175 | = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (args[i].tree_value)), addr); | |
1176 | ||
1177 | if (GET_CODE (slot_offset) == CONST_INT) | |
1178 | addr = plus_constant (arg_reg, INTVAL (slot_offset)); | |
1179 | else | |
1180 | addr = gen_rtx (PLUS, Pmode, arg_reg, slot_offset); | |
1181 | ||
1182 | addr = plus_constant (addr, arg_offset); | |
1183 | args[i].stack_slot | |
1184 | = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (args[i].tree_value)), addr); | |
1185 | } | |
1186 | } | |
1187 | ||
1188 | #ifdef PUSH_ARGS_REVERSED | |
1189 | #ifdef STACK_BOUNDARY | |
1190 | /* If we push args individually in reverse order, perform stack alignment | |
1191 | before the first push (the last arg). */ | |
1192 | if (argblock == 0) | |
1193 | anti_adjust_stack (gen_rtx (CONST_INT, VOIDmode, | |
1194 | (args_size.constant | |
1195 | - original_args_size.constant))); | |
1196 | #endif | |
1197 | #endif | |
1198 | ||
1199 | /* Don't try to defer pops if preallocating, not even from the first arg, | |
1200 | since ARGBLOCK probably refers to the SP. */ | |
1201 | if (argblock) | |
1202 | NO_DEFER_POP; | |
1203 | ||
1204 | /* Get the function to call, in the form of RTL. */ | |
1205 | if (fndecl) | |
1206 | /* Get a SYMBOL_REF rtx for the function address. */ | |
1207 | funexp = XEXP (DECL_RTL (fndecl), 0); | |
1208 | else | |
1209 | /* Generate an rtx (probably a pseudo-register) for the address. */ | |
1210 | { | |
1211 | funexp = expand_expr (TREE_OPERAND (exp, 0), 0, VOIDmode, 0); | |
1212 | free_temp_slots (); /* FUNEXP can't be BLKmode */ | |
1213 | emit_queue (); | |
1214 | } | |
1215 | ||
1216 | /* Figure out the register where the value, if any, will come back. */ | |
1217 | valreg = 0; | |
1218 | if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode | |
1219 | && ! structure_value_addr) | |
1220 | { | |
1221 | if (pcc_struct_value) | |
1222 | valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)), | |
1223 | fndecl); | |
1224 | else | |
1225 | valreg = hard_function_value (TREE_TYPE (exp), fndecl); | |
1226 | } | |
1227 | ||
1228 | /* Precompute all register parameters. It isn't safe to compute anything | |
1229 | once we have started filling any specific hard regs. */ | |
1230 | reg_parm_seen = 0; | |
1231 | for (i = 0; i < num_actuals; i++) | |
1232 | if (args[i].reg != 0 && ! args[i].pass_on_stack) | |
1233 | { | |
1234 | reg_parm_seen = 1; | |
1235 | ||
1236 | if (args[i].value == 0) | |
1237 | { | |
1238 | args[i].value = expand_expr (args[i].tree_value, 0, VOIDmode, 0); | |
1239 | preserve_temp_slots (args[i].value); | |
1240 | free_temp_slots (); | |
1241 | ||
1242 | /* ANSI doesn't require a sequence point here, | |
1243 | but PCC has one, so this will avoid some problems. */ | |
1244 | emit_queue (); | |
1245 | } | |
1246 | } | |
1247 | ||
1248 | #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE) | |
1249 | /* The argument list is the property of the called routine and it | |
1250 | may clobber it. If the fixed area has been used for previous | |
1251 | parameters, we must save and restore it. | |
1252 | ||
1253 | Here we compute the boundary of the that needs to be saved, if any. */ | |
1254 | ||
1255 | for (i = 0; i < REG_PARM_STACK_SPACE (fndecl); i++) | |
1256 | { | |
1257 | if (i >= highest_outgoing_arg_in_use | |
1258 | || stack_usage_map[i] == 0) | |
1259 | continue; | |
1260 | ||
1261 | if (low_to_save == -1) | |
1262 | low_to_save = i; | |
1263 | ||
1264 | high_to_save = i; | |
1265 | } | |
1266 | ||
1267 | if (low_to_save >= 0) | |
1268 | { | |
1269 | int num_to_save = high_to_save - low_to_save + 1; | |
1270 | enum machine_mode save_mode | |
1271 | = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1); | |
1272 | rtx stack_area; | |
1273 | ||
1274 | /* If we don't have the required alignment, must do this in BLKmode. */ | |
1275 | if ((low_to_save & (MIN (GET_MODE_SIZE (save_mode), | |
1276 | BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1))) | |
1277 | save_mode = BLKmode; | |
1278 | ||
1279 | stack_area = gen_rtx (MEM, save_mode, | |
1280 | memory_address (save_mode, | |
1281 | plus_constant (argblock, | |
1282 | low_to_save))); | |
1283 | if (save_mode == BLKmode) | |
1284 | { | |
1285 | save_area = assign_stack_temp (BLKmode, num_to_save, 1); | |
1286 | emit_block_move (validize_mem (save_area), stack_area, | |
1287 | gen_rtx (CONST_INT, VOIDmode, num_to_save), | |
1288 | PARM_BOUNDARY / BITS_PER_UNIT); | |
1289 | } | |
1290 | else | |
1291 | { | |
1292 | save_area = gen_reg_rtx (save_mode); | |
1293 | emit_move_insn (save_area, stack_area); | |
1294 | } | |
1295 | } | |
1296 | #endif | |
1297 | ||
1298 | ||
1299 | /* Now store (and compute if necessary) all non-register parms. | |
1300 | These come before register parms, since they can require block-moves, | |
1301 | which could clobber the registers used for register parms. | |
1302 | Parms which have partial registers are not stored here, | |
1303 | but we do preallocate space here if they want that. */ | |
1304 | ||
1305 | for (i = 0; i < num_actuals; i++) | |
1306 | if (args[i].reg == 0 || args[i].pass_on_stack) | |
1307 | store_one_arg (&args[i], argblock, may_be_alloca, | |
1308 | args_size.var != 0, fndecl); | |
1309 | ||
1310 | /* Now store any partially-in-registers parm. | |
1311 | This is the last place a block-move can happen. */ | |
1312 | if (reg_parm_seen) | |
1313 | for (i = 0; i < num_actuals; i++) | |
1314 | if (args[i].partial != 0 && ! args[i].pass_on_stack) | |
1315 | store_one_arg (&args[i], argblock, may_be_alloca, | |
1316 | args_size.var != 0, fndecl); | |
1317 | ||
1318 | #ifndef PUSH_ARGS_REVERSED | |
1319 | #ifdef STACK_BOUNDARY | |
1320 | /* If we pushed args in forward order, perform stack alignment | |
1321 | after pushing the last arg. */ | |
1322 | if (argblock == 0) | |
1323 | anti_adjust_stack (gen_rtx (CONST_INT, VOIDmode, | |
1324 | (args_size.constant | |
1325 | - original_args_size.constant))); | |
1326 | #endif | |
1327 | #endif | |
1328 | ||
1329 | /* Pass the function the address in which to return a structure value. */ | |
1330 | if (structure_value_addr && ! structure_value_addr_parm) | |
1331 | { | |
1332 | emit_move_insn (struct_value_rtx, | |
1333 | force_reg (Pmode, | |
1334 | force_operand (structure_value_addr, 0))); | |
1335 | if (GET_CODE (struct_value_rtx) == REG) | |
1336 | { | |
1337 | push_to_sequence (use_insns); | |
1338 | emit_insn (gen_rtx (USE, VOIDmode, struct_value_rtx)); | |
1339 | use_insns = get_insns (); | |
1340 | end_sequence (); | |
1341 | } | |
1342 | } | |
1343 | ||
1344 | /* Now do the register loads required for any wholly-register parms or any | |
1345 | parms which are passed both on the stack and in a register. Their | |
1346 | expressions were already evaluated. | |
1347 | ||
1348 | Mark all register-parms as living through the call, putting these USE | |
1349 | insns in a list headed by USE_INSNS. */ | |
1350 | ||
1351 | for (i = 0; i < num_actuals; i++) | |
1352 | { | |
1353 | rtx list = args[i].reg; | |
1354 | int partial = args[i].partial; | |
1355 | ||
1356 | while (list) | |
1357 | { | |
1358 | rtx reg; | |
1359 | int nregs; | |
1360 | ||
1361 | /* Process each register that needs to get this arg. */ | |
1362 | if (GET_CODE (list) == EXPR_LIST) | |
1363 | reg = XEXP (list, 0), list = XEXP (list, 1); | |
1364 | else | |
1365 | reg = list, list = 0; | |
1366 | ||
1367 | /* Set to non-zero if must move a word at a time, even if just one | |
1368 | word (e.g, partial == 1 && mode == DFmode). Set to zero if | |
1369 | we just use a normal move insn. */ | |
1370 | nregs = (partial ? partial | |
1371 | : (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode | |
1372 | ? ((int_size_in_bytes (TREE_TYPE (args[i].tree_value)) | |
1373 | + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD) | |
1374 | : 0)); | |
1375 | ||
1376 | /* If simple case, just do move. If normal partial, store_one_arg | |
1377 | has already loaded the register for us. In all other cases, | |
1378 | load the register(s) from memory. */ | |
1379 | ||
1380 | if (nregs == 0) | |
1381 | emit_move_insn (reg, args[i].value); | |
1382 | else if (args[i].partial == 0 || args[i].pass_on_stack) | |
1383 | move_block_to_reg (REGNO (reg), | |
1384 | validize_mem (args[i].value), nregs, | |
1385 | TYPE_MODE (TREE_TYPE (args[i].tree_value))); | |
1386 | ||
1387 | push_to_sequence (use_insns); | |
1388 | if (nregs == 0) | |
1389 | emit_insn (gen_rtx (USE, VOIDmode, reg)); | |
1390 | else | |
1391 | use_regs (REGNO (reg), nregs); | |
1392 | use_insns = get_insns (); | |
1393 | end_sequence (); | |
1394 | ||
1395 | /* PARTIAL referred only to the first register, so clear it for the | |
1396 | next time. */ | |
1397 | partial = 0; | |
1398 | } | |
1399 | } | |
1400 | ||
1401 | /* Perform postincrements before actually calling the function. */ | |
1402 | emit_queue (); | |
1403 | ||
1404 | /* All arguments and registers used for the call must be set up by now! */ | |
1405 | ||
1406 | funexp = prepare_call_address (funexp, fndecl, &use_insns); | |
1407 | ||
1408 | /* Generate the actual call instruction. */ | |
1409 | emit_call_1 (funexp, funtype, args_size.constant, struct_value_size, | |
1410 | FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1), | |
1411 | valreg, old_inhibit_defer_pop, use_insns, is_const); | |
1412 | ||
1413 | /* If call is cse'able, make appropriate pair of reg-notes around it. | |
1414 | Test valreg so we don't crash; may safely ignore `const' | |
1415 | if return type is void. */ | |
1416 | if (is_const && valreg != 0) | |
1417 | { | |
1418 | rtx note = 0; | |
1419 | rtx temp = gen_reg_rtx (GET_MODE (valreg)); | |
1420 | rtx insns; | |
1421 | ||
1422 | /* Construct an "equal form" for the value which mentions all the | |
1423 | arguments in order as well as the function name. */ | |
1424 | #ifdef PUSH_ARGS_REVERSED | |
1425 | for (i = 0; i < num_actuals; i++) | |
1426 | note = gen_rtx (EXPR_LIST, VOIDmode, args[i].initial_value, note); | |
1427 | #else | |
1428 | for (i = num_actuals - 1; i >= 0; i--) | |
1429 | note = gen_rtx (EXPR_LIST, VOIDmode, args[i].initial_value, note); | |
1430 | #endif | |
1431 | note = gen_rtx (EXPR_LIST, VOIDmode, funexp, note); | |
1432 | ||
1433 | insns = get_insns (); | |
1434 | end_sequence (); | |
1435 | ||
1436 | emit_libcall_block (insns, temp, valreg, note); | |
1437 | ||
1438 | valreg = temp; | |
1439 | } | |
1440 | ||
1441 | /* For calls to `setjmp', etc., inform flow.c it should complain | |
1442 | if nonvolatile values are live. */ | |
1443 | ||
1444 | if (returns_twice) | |
1445 | { | |
1446 | emit_note (name, NOTE_INSN_SETJMP); | |
1447 | current_function_calls_setjmp = 1; | |
1448 | } | |
1449 | ||
1450 | if (is_longjmp) | |
1451 | current_function_calls_longjmp = 1; | |
1452 | ||
1453 | /* Notice functions that cannot return. | |
1454 | If optimizing, insns emitted below will be dead. | |
1455 | If not optimizing, they will exist, which is useful | |
1456 | if the user uses the `return' command in the debugger. */ | |
1457 | ||
1458 | if (is_volatile || is_longjmp) | |
1459 | emit_barrier (); | |
1460 | ||
1461 | /* For calls to __builtin_new, note that it can never return 0. | |
1462 | This is because a new handler will be called, and 0 it not | |
1463 | among the numbers it is supposed to return. */ | |
1464 | #if 0 | |
1465 | if (is_builtin_new) | |
1466 | emit_note (name, NOTE_INSN_BUILTIN_NEW); | |
1467 | #endif | |
1468 | ||
1469 | /* If value type not void, return an rtx for the value. */ | |
1470 | ||
1471 | /* If there are cleanups to be called, don't use a hard reg as target. */ | |
1472 | if (cleanups_this_call != old_cleanups | |
1473 | && target && REG_P (target) | |
1474 | && REGNO (target) < FIRST_PSEUDO_REGISTER) | |
1475 | target = 0; | |
1476 | ||
1477 | if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode | |
1478 | || ignore) | |
1479 | { | |
1480 | target = const0_rtx; | |
1481 | } | |
1482 | else if (structure_value_addr) | |
1483 | { | |
1484 | if (target == 0 || GET_CODE (target) != MEM) | |
1485 | target = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)), | |
1486 | memory_address (TYPE_MODE (TREE_TYPE (exp)), | |
1487 | structure_value_addr)); | |
1488 | } | |
1489 | else if (pcc_struct_value) | |
1490 | { | |
1491 | if (target == 0) | |
1492 | target = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)), | |
1493 | copy_to_reg (valreg)); | |
1494 | else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode) | |
1495 | emit_move_insn (target, gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)), | |
1496 | copy_to_reg (valreg))); | |
1497 | else | |
1498 | emit_block_move (target, gen_rtx (MEM, BLKmode, copy_to_reg (valreg)), | |
1499 | expr_size (exp), | |
1500 | TYPE_ALIGN (TREE_TYPE (exp)) / BITS_PER_UNIT); | |
1501 | } | |
1502 | else if (target && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))) | |
1503 | /* TARGET and VALREG cannot be equal at this point because the latter | |
1504 | would not have REG_FUNCTION_VALUE_P true, while the former would if | |
1505 | it were referring to the same register. | |
1506 | ||
1507 | If they refer to the same register, this move will be a no-op, except | |
1508 | when function inlining is being done. */ | |
1509 | emit_move_insn (target, valreg); | |
1510 | else | |
1511 | target = copy_to_reg (valreg); | |
1512 | ||
1513 | /* Perform all cleanups needed for the arguments of this call | |
1514 | (i.e. destructors in C++). */ | |
1515 | expand_cleanups_to (old_cleanups); | |
1516 | ||
1517 | /* If size of args is variable, restore saved stack-pointer value. */ | |
1518 | ||
1519 | if (old_stack_level) | |
1520 | { | |
1521 | emit_move_insn (stack_pointer_rtx, old_stack_level); | |
1522 | pending_stack_adjust = old_pending_adj; | |
1523 | } | |
1524 | ||
1525 | #ifdef ACCUMULATE_OUTGOING_ARGS | |
1526 | else | |
1527 | { | |
1528 | #ifdef REG_PARM_STACK_SPACE | |
1529 | if (save_area) | |
1530 | { | |
1531 | enum machine_mode save_mode = GET_MODE (save_area); | |
1532 | rtx stack_area | |
1533 | = gen_rtx (MEM, save_mode, | |
1534 | memory_address (save_mode, | |
1535 | plus_constant (argblock, low_to_save))); | |
1536 | ||
1537 | if (save_mode != BLKmode) | |
1538 | emit_move_insn (stack_area, save_area); | |
1539 | else | |
1540 | emit_block_move (stack_area, validize_mem (save_area), | |
1541 | gen_rtx (CONST_INT, VOIDmode, | |
1542 | high_to_save - low_to_save + 1, | |
1543 | PARM_BOUNDARY / BITS_PER_UNIT)); | |
1544 | } | |
1545 | #endif | |
1546 | ||
1547 | /* If we saved any argument areas, restore them. */ | |
1548 | for (i = 0; i < num_actuals; i++) | |
1549 | if (args[i].save_area) | |
1550 | { | |
1551 | enum machine_mode save_mode = GET_MODE (args[i].save_area); | |
1552 | rtx stack_area | |
1553 | = gen_rtx (MEM, save_mode, | |
1554 | memory_address (save_mode, | |
1555 | XEXP (args[i].stack_slot, 0))); | |
1556 | ||
1557 | if (save_mode != BLKmode) | |
1558 | emit_move_insn (stack_area, args[i].save_area); | |
1559 | else | |
1560 | emit_block_move (stack_area, validize_mem (args[i].save_area), | |
1561 | gen_rtx (CONST_INT, VOIDmode, | |
1562 | args[i].size.constant), | |
1563 | PARM_BOUNDARY / BITS_PER_UNIT); | |
1564 | } | |
1565 | ||
1566 | highest_outgoing_arg_in_use = initial_highest_arg_in_use; | |
1567 | stack_usage_map = initial_stack_usage_map; | |
1568 | } | |
1569 | #endif | |
1570 | ||
1571 | /* If this was alloca, record the new stack level for nonlocal gotos. */ | |
1572 | if (may_be_alloca && nonlocal_goto_stack_level != 0) | |
1573 | emit_move_insn (nonlocal_goto_stack_level, stack_pointer_rtx); | |
1574 | ||
1575 | pop_temp_slots (); | |
1576 | ||
1577 | return target; | |
1578 | } | |
1579 | \f | |
1580 | #if 0 | |
1581 | /* Return an rtx which represents a suitable home on the stack | |
1582 | given TYPE, the type of the argument looking for a home. | |
1583 | This is called only for BLKmode arguments. | |
1584 | ||
1585 | SIZE is the size needed for this target. | |
1586 | ARGS_ADDR is the address of the bottom of the argument block for this call. | |
1587 | OFFSET describes this parameter's offset into ARGS_ADDR. It is meaningless | |
1588 | if this machine uses push insns. */ | |
1589 | ||
1590 | static rtx | |
1591 | target_for_arg (type, size, args_addr, offset) | |
1592 | tree type; | |
1593 | rtx size; | |
1594 | rtx args_addr; | |
1595 | struct args_size offset; | |
1596 | { | |
1597 | rtx target; | |
1598 | rtx offset_rtx = ARGS_SIZE_RTX (offset); | |
1599 | ||
1600 | /* We do not call memory_address if possible, | |
1601 | because we want to address as close to the stack | |
1602 | as possible. For non-variable sized arguments, | |
1603 | this will be stack-pointer relative addressing. */ | |
1604 | if (GET_CODE (offset_rtx) == CONST_INT) | |
1605 | target = plus_constant (args_addr, INTVAL (offset_rtx)); | |
1606 | else | |
1607 | { | |
1608 | /* I have no idea how to guarantee that this | |
1609 | will work in the presence of register parameters. */ | |
1610 | target = gen_rtx (PLUS, Pmode, args_addr, offset_rtx); | |
1611 | target = memory_address (QImode, target); | |
1612 | } | |
1613 | ||
1614 | return gen_rtx (MEM, BLKmode, target); | |
1615 | } | |
1616 | #endif | |
1617 | \f | |
1618 | /* Store a single argument for a function call | |
1619 | into the register or memory area where it must be passed. | |
1620 | *ARG describes the argument value and where to pass it. | |
1621 | ||
1622 | ARGBLOCK is the address of the stack-block for all the arguments, | |
1623 | or 0 on a machine where arguemnts are pushed individually. | |
1624 | ||
1625 | MAY_BE_ALLOCA nonzero says this could be a call to `alloca' | |
1626 | so must be careful about how the stack is used. | |
1627 | ||
1628 | VARIABLE_SIZE nonzero says that this was a variable-sized outgoing | |
1629 | argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate | |
1630 | that we need not worry about saving and restoring the stack. | |
1631 | ||
1632 | FNDECL is the declaration of the function we are calling. */ | |
1633 | ||
1634 | static void | |
1635 | store_one_arg (arg, argblock, may_be_alloca, variable_size, fndecl) | |
1636 | struct arg_data *arg; | |
1637 | rtx argblock; | |
1638 | int may_be_alloca; | |
1639 | int variable_size; | |
1640 | tree fndecl; | |
1641 | { | |
1642 | register tree pval = arg->tree_value; | |
1643 | rtx reg = 0; | |
1644 | int partial = 0; | |
1645 | int used = 0; | |
1646 | int i, lower_bound, upper_bound; | |
1647 | ||
1648 | if (TREE_CODE (pval) == ERROR_MARK) | |
1649 | return; | |
1650 | ||
1651 | #ifdef ACCUMULATE_OUTGOING_ARGS | |
1652 | /* If this is being stored into a pre-allocated, fixed-size, stack area, | |
1653 | save any previous data at that location. */ | |
1654 | if (argblock && ! variable_size && arg->stack) | |
1655 | { | |
1656 | #ifdef ARGS_GROW_DOWNWARD | |
1657 | /* stack_slot is negative, but we want to index stack_usage_map */ | |
1658 | /* with positive values. */ | |
1659 | if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS) | |
1660 | upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1; | |
1661 | else | |
1662 | abort (); | |
1663 | ||
1664 | lower_bound = upper_bound - arg->size.constant; | |
1665 | #else | |
1666 | if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS) | |
1667 | lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)); | |
1668 | else | |
1669 | lower_bound = 0; | |
1670 | ||
1671 | upper_bound = lower_bound + arg->size.constant; | |
1672 | #endif | |
1673 | ||
1674 | for (i = lower_bound; i < upper_bound; i++) | |
1675 | if (stack_usage_map[i] | |
1676 | #ifdef REG_PARM_STACK_SPACE | |
1677 | /* Don't store things in the fixed argument area at this point; | |
1678 | it has already been saved. */ | |
1679 | && i > REG_PARM_STACK_SPACE (fndecl) | |
1680 | #endif | |
1681 | ) | |
1682 | break; | |
1683 | ||
1684 | if (i != upper_bound) | |
1685 | { | |
1686 | /* We need to make a save area. See what mode we can make it. */ | |
1687 | enum machine_mode save_mode | |
1688 | = mode_for_size (arg->size.constant * BITS_PER_UNIT, MODE_INT, 1); | |
1689 | rtx stack_area | |
1690 | = gen_rtx (MEM, save_mode, | |
1691 | memory_address (save_mode, XEXP (arg->stack_slot, 0))); | |
1692 | ||
1693 | if (save_mode == BLKmode) | |
1694 | { | |
1695 | arg->save_area = assign_stack_temp (BLKmode, | |
1696 | arg->size.constant, 1); | |
1697 | emit_block_move (validize_mem (arg->save_area), stack_area, | |
1698 | gen_rtx (CONST_INT, VOIDmode, | |
1699 | arg->size.constant), | |
1700 | PARM_BOUNDARY / BITS_PER_UNIT); | |
1701 | } | |
1702 | else | |
1703 | { | |
1704 | arg->save_area = gen_reg_rtx (save_mode); | |
1705 | emit_move_insn (arg->save_area, stack_area); | |
1706 | } | |
1707 | } | |
1708 | } | |
1709 | #endif | |
1710 | ||
1711 | /* If this isn't going to be placed on both the stack and in registers, | |
1712 | set up the register and number of words. */ | |
1713 | if (! arg->pass_on_stack) | |
1714 | reg = arg->reg, partial = arg->partial; | |
1715 | ||
1716 | if (reg != 0 && partial == 0) | |
1717 | /* Being passed entirely in a register. We shouldn't be called in | |
1718 | this case. */ | |
1719 | abort (); | |
1720 | ||
1721 | /* If this is being partially passed in a register, but multiple locations | |
1722 | are specified, we assume that the one partially used is the one that is | |
1723 | listed first. */ | |
1724 | if (reg && GET_CODE (reg) == EXPR_LIST) | |
1725 | reg = XEXP (reg, 0); | |
1726 | ||
1727 | /* If this is being passes partially in a register, we can't evaluate | |
1728 | it directly into its stack slot. Otherwise, we can. */ | |
1729 | if (arg->value == 0) | |
1730 | arg->value = expand_expr (pval, partial ? 0 : arg->stack, VOIDmode, 0); | |
1731 | ||
1732 | /* Don't allow anything left on stack from computation | |
1733 | of argument to alloca. */ | |
1734 | if (may_be_alloca) | |
1735 | do_pending_stack_adjust (); | |
1736 | ||
1737 | if (arg->value == arg->stack) | |
1738 | /* If the value is already in the stack slot, we are done. */ | |
1739 | ; | |
1740 | else if (TYPE_MODE (TREE_TYPE (pval)) != BLKmode) | |
1741 | { | |
1742 | register int size; | |
1743 | ||
1744 | /* Argument is a scalar, not entirely passed in registers. | |
1745 | (If part is passed in registers, arg->partial says how much | |
1746 | and emit_push_insn will take care of putting it there.) | |
1747 | ||
1748 | Push it, and if its size is less than the | |
1749 | amount of space allocated to it, | |
1750 | also bump stack pointer by the additional space. | |
1751 | Note that in C the default argument promotions | |
1752 | will prevent such mismatches. */ | |
1753 | ||
1754 | size = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (pval))); | |
1755 | /* Compute how much space the push instruction will push. | |
1756 | On many machines, pushing a byte will advance the stack | |
1757 | pointer by a halfword. */ | |
1758 | #ifdef PUSH_ROUNDING | |
1759 | size = PUSH_ROUNDING (size); | |
1760 | #endif | |
1761 | used = size; | |
1762 | ||
1763 | /* Compute how much space the argument should get: | |
1764 | round up to a multiple of the alignment for arguments. */ | |
1765 | if (none != FUNCTION_ARG_PADDING (TYPE_MODE (TREE_TYPE (pval)), | |
1766 | TREE_TYPE (pval))) | |
1767 | used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1) | |
1768 | / (PARM_BOUNDARY / BITS_PER_UNIT)) | |
1769 | * (PARM_BOUNDARY / BITS_PER_UNIT)); | |
1770 | ||
1771 | /* This isn't already where we want it on the stack, so put it there. | |
1772 | This can either be done with push or copy insns. */ | |
1773 | emit_push_insn (arg->value, TYPE_MODE (TREE_TYPE (pval)), | |
1774 | TREE_TYPE (pval), 0, 0, partial, reg, | |
1775 | used - size, argblock, ARGS_SIZE_RTX (arg->offset)); | |
1776 | } | |
1777 | else | |
1778 | { | |
1779 | /* BLKmode, at least partly to be pushed. */ | |
1780 | ||
1781 | register int excess; | |
1782 | rtx size_rtx; | |
1783 | ||
1784 | /* Pushing a nonscalar. | |
1785 | If part is passed in registers, PARTIAL says how much | |
1786 | and emit_push_insn will take care of putting it there. */ | |
1787 | ||
1788 | /* Round its size up to a multiple | |
1789 | of the allocation unit for arguments. */ | |
1790 | ||
1791 | if (arg->size.var != 0) | |
1792 | { | |
1793 | excess = 0; | |
1794 | size_rtx = ARGS_SIZE_RTX (arg->size); | |
1795 | } | |
1796 | else | |
1797 | { | |
1798 | register tree size = size_in_bytes (TREE_TYPE (pval)); | |
1799 | /* PUSH_ROUNDING has no effect on us, because | |
1800 | emit_push_insn for BLKmode is careful to avoid it. */ | |
1801 | excess = (arg->size.constant - TREE_INT_CST_LOW (size) | |
1802 | + partial * UNITS_PER_WORD); | |
1803 | size_rtx = expand_expr (size, 0, VOIDmode, 0); | |
1804 | } | |
1805 | ||
1806 | emit_push_insn (arg->value, TYPE_MODE (TREE_TYPE (pval)), | |
1807 | TREE_TYPE (pval), size_rtx, | |
1808 | TYPE_ALIGN (TREE_TYPE (pval)) / BITS_PER_UNIT, partial, | |
1809 | reg, excess, argblock, ARGS_SIZE_RTX (arg->offset)); | |
1810 | } | |
1811 | ||
1812 | ||
1813 | /* Unless this is a partially-in-register argument, the argument is now | |
1814 | in the stack. | |
1815 | ||
1816 | ??? Note that this can change arg->value from arg->stack to | |
1817 | arg->stack_slot and it matters when they are not the same. | |
1818 | It isn't totally clear that this is correct in all cases. */ | |
1819 | if (partial == 0) | |
1820 | arg->value = arg->stack_slot; | |
1821 | ||
1822 | /* Once we have pushed something, pops can't safely | |
1823 | be deferred during the rest of the arguments. */ | |
1824 | NO_DEFER_POP; | |
1825 | ||
1826 | /* ANSI doesn't require a sequence point here, | |
1827 | but PCC has one, so this will avoid some problems. */ | |
1828 | emit_queue (); | |
1829 | ||
1830 | /* Free any temporary slots made in processing this argument. */ | |
1831 | free_temp_slots (); | |
1832 | ||
1833 | #ifdef ACCUMULATE_OUTGOING_ARGS | |
1834 | /* Now mark the segment we just used. */ | |
1835 | if (argblock && ! variable_size && arg->stack) | |
1836 | for (i = lower_bound; i < upper_bound; i++) | |
1837 | stack_usage_map[i] = 1; | |
1838 | #endif | |
1839 | } |