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1.1 root 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:
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:
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: && TYPE_MODE (TREE_TYPE (exp)) != VOIDmode)
513: is_const = 1;
514: }
515: }
516:
517: is_volatile = TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (p)));
518:
519: /* Warn if this value is an aggregate type,
520: regardless of which calling convention we are using for it. */
521: if (warn_aggregate_return
522: && (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
523: || TREE_CODE (TREE_TYPE (exp)) == UNION_TYPE
524: || TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE))
525: warning ("function call has aggregate value");
526:
527: /* Set up a place to return a structure. */
528:
529: /* Cater to broken compilers. */
530: if (aggregate_value_p (exp))
531: {
532: /* This call returns a big structure. */
533: is_const = 0;
534:
535: #ifdef PCC_STATIC_STRUCT_RETURN
536: if (flag_pcc_struct_return)
537: {
538: pcc_struct_value = 1;
539: is_integrable = 0; /* Easier than making that case work right. */
540: }
541: else
542: #endif
543: {
544: struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
545:
546: if (struct_value_size < 0)
547: abort ();
548:
549: if (target && GET_CODE (target) == MEM)
550: structure_value_addr = XEXP (target, 0);
551: else
552: {
553: /* Assign a temporary on the stack to hold the value. */
554:
555: /* For variable-sized objects, we must be called with a target
556: specified. If we were to allocate space on the stack here,
557: we would have no way of knowing when to free it. */
558:
559: structure_value_addr
560: = XEXP (assign_stack_temp (BLKmode, struct_value_size, 1), 0);
561: target = 0;
562: }
563: }
564: }
565:
566: /* If called function is inline, try to integrate it. */
567:
568: if (is_integrable)
569: {
570: rtx temp;
571:
572: temp = expand_inline_function (fndecl, actparms, target,
573: ignore, TREE_TYPE (exp),
574: structure_value_addr);
575:
576: /* If inlining succeeded, return. */
577: if ((int) temp != -1)
578: {
579: /* Perform all cleanups needed for the arguments of this call
580: (i.e. destructors in C++). It is ok if these destructors
581: clobber RETURN_VALUE_REG, because the only time we care about
582: this is when TARGET is that register. But in C++, we take
583: care to never return that register directly. */
584: expand_cleanups_to (old_cleanups);
585:
586: /* If the result is equivalent to TARGET, return TARGET to simplify
587: checks in store_expr. They can be equivalent but not equal in the
588: case of a function that returns BLKmode. */
589: if (temp != target && rtx_equal_p (temp, target))
590: return target;
591: return temp;
592: }
593:
594: /* If inlining failed, mark FNDECL as needing to be compiled
595: separately after all. */
596: mark_addressable (fndecl);
597: }
598:
599: /* When calling a const function, we must pop the stack args right away,
600: so that the pop is deleted or moved with the call. */
601: if (is_const)
602: NO_DEFER_POP;
603:
604: function_call_count++;
605:
606: if (fndecl && DECL_NAME (fndecl))
607: name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
608:
609: #if 0
610: /* Unless it's a call to a specific function that isn't alloca,
611: if it has one argument, we must assume it might be alloca. */
612:
613: may_be_alloca =
614: (!(fndecl != 0 && strcmp (name, "alloca"))
615: && actparms != 0
616: && TREE_CHAIN (actparms) == 0);
617: #else
618: /* We assume that alloca will always be called by name. It
619: makes no sense to pass it as a pointer-to-function to
620: anything that does not understand its behavior. */
621: may_be_alloca =
622: (name && ((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
623: && name[0] == 'a'
624: && ! strcmp (name, "alloca"))
625: || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
626: && name[0] == '_'
627: && ! strcmp (name, "__builtin_alloca"))));
628: #endif
629:
630: /* See if this is a call to a function that can return more than once
631: or a call to longjmp. */
632:
633: returns_twice = 0;
634: is_longjmp = 0;
635:
636: if (name != 0 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 15)
637: {
638: char *tname = name;
639:
640: if (name[0] == '_')
641: tname += ((name[1] == '_' && name[2] == 'x') ? 3 : 1);
642:
643: if (tname[0] == 's')
644: {
645: returns_twice
646: = ((tname[1] == 'e'
647: && (! strcmp (tname, "setjmp")
648: || ! strcmp (tname, "setjmp_syscall")))
649: || (tname[1] == 'i'
650: && ! strcmp (tname, "sigsetjmp"))
651: || (tname[1] == 'a'
652: && ! strcmp (tname, "savectx")));
653: if (tname[1] == 'i'
654: && ! strcmp (tname, "siglongjmp"))
655: is_longjmp = 1;
656: }
657: else if ((tname[0] == 'q' && tname[1] == 's'
658: && ! strcmp (tname, "qsetjmp"))
659: || (tname[0] == 'v' && tname[1] == 'f'
660: && ! strcmp (tname, "vfork")))
661: returns_twice = 1;
662:
663: else if (tname[0] == 'l' && tname[1] == 'o'
664: && ! strcmp (tname, "longjmp"))
665: is_longjmp = 1;
666: }
667:
668: is_builtin_new
669: = (name != 0
670: && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 13
671: && (!strcmp (name, "__builtin_new")));
672:
673: if (may_be_alloca)
674: current_function_calls_alloca = 1;
675:
676: /* Don't let pending stack adjusts add up to too much.
677: Also, do all pending adjustments now
678: if there is any chance this might be a call to alloca. */
679:
680: if (pending_stack_adjust >= 32
681: || (pending_stack_adjust > 0 && may_be_alloca))
682: do_pending_stack_adjust ();
683:
684: /* Operand 0 is a pointer-to-function; get the type of the function. */
685: funtype = TREE_TYPE (TREE_OPERAND (exp, 0));
686: if (TREE_CODE (funtype) != POINTER_TYPE)
687: abort ();
688: funtype = TREE_TYPE (funtype);
689:
690: /* Push the temporary stack slot level so that we can free temporaries used
691: by each of the arguments separately. */
692: push_temp_slots ();
693:
694: /* Start updating where the next arg would go. */
695: INIT_CUMULATIVE_ARGS (args_so_far, funtype, 0);
696:
697: /* If struct_value_rtx is 0, it means pass the address
698: as if it were an extra parameter. */
699: if (structure_value_addr && struct_value_rtx == 0)
700: {
701: actparms
702: = tree_cons (error_mark_node,
703: make_tree (build_pointer_type (TREE_TYPE (funtype)),
704: force_reg (Pmode, structure_value_addr)),
705: actparms);
706: structure_value_addr_parm = 1;
707: }
708:
709: /* Count the arguments and set NUM_ACTUALS. */
710: for (p = actparms, i = 0; p; p = TREE_CHAIN (p)) i++;
711: num_actuals = i;
712:
713: /* Compute number of named args.
714: Normally, don't include the last named arg if anonymous args follow.
715: (If no anonymous args follow, the result of list_length
716: is actually one too large.)
717:
718: If SETUP_INCOMING_VARARGS is defined, this machine will be able to
719: place unnamed args that were passed in registers into the stack. So
720: treat all args as named. This allows the insns emitting for a specific
1.1.1.2 ! root 721: argument list to be independent of the function declaration.
1.1 root 722:
723: If SETUP_INCOMING_VARARGS is not defined, we do not have any reliable
724: way to pass unnamed args in registers, so we must force them into
725: memory. */
726: #ifndef SETUP_INCOMING_VARARGS
727: if (TYPE_ARG_TYPES (funtype) != 0)
728: n_named_args
729: = list_length (TYPE_ARG_TYPES (funtype)) - 1
730: /* Count the struct value address, if it is passed as a parm. */
731: + structure_value_addr_parm;
732: else
733: #endif
734: /* If we know nothing, treat all args as named. */
735: n_named_args = num_actuals;
736:
737: /* Make a vector to hold all the information about each arg. */
738: args = (struct arg_data *) alloca (num_actuals * sizeof (struct arg_data));
739: bzero (args, num_actuals * sizeof (struct arg_data));
740:
741: args_size.constant = 0;
742: args_size.var = 0;
743:
744: /* In this loop, we consider args in the order they are written.
745: We fill up ARGS from the front of from the back if necessary
746: so that in any case the first arg to be pushed ends up at the front. */
747:
748: #ifdef PUSH_ARGS_REVERSED
749: i = num_actuals - 1, inc = -1;
750: /* In this case, must reverse order of args
751: so that we compute and push the last arg first. */
752: #else
753: i = 0, inc = 1;
754: #endif
755:
756: /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
757: for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
758: {
759: tree type = TREE_TYPE (TREE_VALUE (p));
760:
761: args[i].tree_value = TREE_VALUE (p);
762:
763: /* Replace erroneous argument with constant zero. */
764: if (type == error_mark_node || TYPE_SIZE (type) == 0)
765: args[i].tree_value = integer_zero_node, type = integer_type_node;
766:
767: /* Decide where to pass this arg.
768:
769: args[i].reg is nonzero if all or part is passed in registers.
770:
771: args[i].partial is nonzero if part but not all is passed in registers,
772: and the exact value says how many words are passed in registers.
773:
774: args[i].pass_on_stack is nonzero if the argument must at least be
775: computed on the stack. It may then be loaded back into registers
776: if args[i].reg is nonzero.
777:
778: These decisions are driven by the FUNCTION_... macros and must agree
779: with those made by function.c. */
780:
781: #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
782: /* See if this argument should be passed by invisible reference. */
783: if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, TYPE_MODE (type), type,
784: argpos < n_named_args))
785: {
786: /* We make a copy of the object and pass the address to the function
787: being called. */
788: int size = int_size_in_bytes (type);
789: rtx copy;
790:
791: if (size < 0)
792: {
793: /* This is a variable-sized object. Make space on the stack
794: for it. */
795: rtx size_rtx = expand_expr (size_in_bytes (type), 0,
796: VOIDmode, 0);
797:
798: if (old_stack_level == 0)
799: {
800: old_stack_level = copy_to_mode_reg (Pmode, stack_pointer_rtx);
801: old_pending_adj = pending_stack_adjust;
802: pending_stack_adjust = 0;
803: }
804:
805: copy = gen_rtx (MEM, BLKmode,
806: allocate_dynamic_stack_space (size_rtx, 0));
807: }
808: else
809: copy = assign_stack_temp (TYPE_MODE (type), size, 1);
810:
811: store_expr (args[i].tree_value, copy, 0);
812:
813: args[i].tree_value = build1 (ADDR_EXPR, build_pointer_type (type),
814: make_tree (type, copy));
815: type = build_pointer_type (type);
816: }
817: #endif
818:
819: args[i].reg = FUNCTION_ARG (args_so_far, TYPE_MODE (type), type,
820: argpos < n_named_args);
821: #ifdef FUNCTION_ARG_PARTIAL_NREGS
822: if (args[i].reg)
823: args[i].partial
824: = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, TYPE_MODE (type), type,
825: argpos < n_named_args);
826: #endif
827:
828: args[i].pass_on_stack = MUST_PASS_IN_STACK (TYPE_MODE (type), type);
829:
830: /* If FUNCTION_ARG returned an (expr_list (nil) FOO), it means that
831: we are to pass this arg in the register(s) designated by FOO, but
832: also to pass it in the stack. */
833: if (args[i].reg && GET_CODE (args[i].reg) == EXPR_LIST
834: && XEXP (args[i].reg, 0) == 0)
835: args[i].pass_on_stack = 1, args[i].reg = XEXP (args[i].reg, 1);
836:
837: /* If this is an addressable type, we must preallocate the stack
838: since we must evaluate the object into its final location.
839:
840: If this is to be passed in both registers and the stack, it is simpler
841: to preallocate. */
842: if (TREE_ADDRESSABLE (type)
843: || (args[i].pass_on_stack && args[i].reg != 0))
844: must_preallocate = 1;
845:
846: /* If this is an addressable type, we cannot pre-evaluate it. Thus,
847: we cannot consider this function call constant. */
848: if (TREE_ADDRESSABLE (type))
849: is_const = 0;
850:
851: /* Compute the stack-size of this argument. */
852: if (args[i].reg == 0 || args[i].partial != 0
853: #ifdef REG_PARM_STACK_SPACE
854: || REG_PARM_STACK_SPACE (fndecl) > 0
855: #endif
856: || args[i].pass_on_stack)
857: locate_and_pad_parm (TYPE_MODE (type), type,
858: #ifdef STACK_PARMS_IN_REG_PARM_AREA
859: 1,
860: #else
861: args[i].reg != 0,
862: #endif
863: fndecl, &args_size, &args[i].offset,
864: &args[i].size);
865:
866: #ifndef ARGS_GROW_DOWNWARD
867: args[i].slot_offset = args_size;
868: #endif
869:
870: #ifndef REG_PARM_STACK_SPACE
871: /* If a part of the arg was put into registers,
872: don't include that part in the amount pushed. */
873: if (! args[i].pass_on_stack)
874: args[i].size.constant -= ((args[i].partial * UNITS_PER_WORD)
875: / (PARM_BOUNDARY / BITS_PER_UNIT)
876: * (PARM_BOUNDARY / BITS_PER_UNIT));
877: #endif
878:
879: /* Update ARGS_SIZE, the total stack space for args so far. */
880:
881: args_size.constant += args[i].size.constant;
882: if (args[i].size.var)
883: {
884: ADD_PARM_SIZE (args_size, args[i].size.var);
885: }
886:
887: /* Since the slot offset points to the bottom of the slot,
888: we must record it after incrementing if the args grow down. */
889: #ifdef ARGS_GROW_DOWNWARD
890: args[i].slot_offset = args_size;
891:
892: args[i].slot_offset.constant = -args_size.constant;
893: if (args_size.var)
894: {
895: SUB_PARM_SIZE (args[i].slot_offset, args_size.var);
896: }
897: #endif
898:
899: /* Increment ARGS_SO_FAR, which has info about which arg-registers
900: have been used, etc. */
901:
902: FUNCTION_ARG_ADVANCE (args_so_far, TYPE_MODE (type), type,
903: argpos < n_named_args);
904: }
905:
906: /* Compute the actual size of the argument block required. The variable
907: and constant sizes must be combined, the size may have to be rounded,
908: and there may be a minimum required size. */
909:
910: original_args_size = args_size;
911: if (args_size.var)
912: {
913: /* If this function requires a variable-sized argument list, don't try to
914: make a cse'able block for this call. We may be able to do this
915: eventually, but it is too complicated to keep track of what insns go
916: in the cse'able block and which don't. */
917:
918: is_const = 0;
919: must_preallocate = 1;
920:
921: args_size.var = ARGS_SIZE_TREE (args_size);
922: args_size.constant = 0;
923:
924: #ifdef STACK_BOUNDARY
925: if (STACK_BOUNDARY != BITS_PER_UNIT)
926: args_size.var = round_up (args_size.var, STACK_BYTES);
927: #endif
928:
929: #ifdef REG_PARM_STACK_SPACE
930: if (REG_PARM_STACK_SPACE (fndecl) > 0)
931: {
932: args_size.var
933: = size_binop (MAX_EXPR, args_size.var,
934: size_int (REG_PARM_STACK_SPACE (fndecl)));
935:
936: #ifndef OUTGOING_REG_PARM_STACK_SPACE
937: /* The area corresponding to register parameters is not to count in
938: the size of the block we need. So make the adjustment. */
939: args_size.var
940: = size_binop (MINUS_EXPR, args_size.var,
941: size_int (REG_PARM_STACK_SPACE (fndecl)));
942: #endif
943: }
944: #endif
945: }
946: else
947: {
948: #ifdef STACK_BOUNDARY
949: args_size.constant = (((args_size.constant + (STACK_BYTES - 1))
950: / STACK_BYTES) * STACK_BYTES);
951: #endif
952:
953: #ifdef REG_PARM_STACK_SPACE
954: args_size.constant = MAX (args_size.constant,
955: REG_PARM_STACK_SPACE (fndecl));
956: #ifndef OUTGOING_REG_PARM_STACK_SPACE
957: args_size.constant -= REG_PARM_STACK_SPACE (fndecl);
958: #endif
959: #endif
960: }
961:
962: /* See if we have or want to preallocate stack space.
963:
964: If we would have to push a partially-in-regs parm
965: before other stack parms, preallocate stack space instead.
966:
967: If the size of some parm is not a multiple of the required stack
968: alignment, we must preallocate.
969:
970: If the total size of arguments that would otherwise create a copy in
971: a temporary (such as a CALL) is more than half the total argument list
972: size, preallocation is faster.
973:
974: Another reason to preallocate is if we have a machine (like the m88k)
975: where stack alignment is required to be maintained between every
976: pair of insns, not just when the call is made. However, we assume here
977: that such machines either do not have push insns (and hence preallocation
978: would occur anyway) or the problem is taken care of with
979: PUSH_ROUNDING. */
980:
981: if (! must_preallocate)
982: {
983: int partial_seen = 0;
984: int copy_to_evaluate_size = 0;
985:
986: for (i = 0; i < num_actuals && ! must_preallocate; i++)
987: {
988: if (args[i].partial > 0 && ! args[i].pass_on_stack)
989: partial_seen = 1;
990: else if (partial_seen && args[i].reg == 0)
991: must_preallocate = 1;
992:
993: if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
994: && (TREE_CODE (args[i].tree_value) == CALL_EXPR
995: || TREE_CODE (args[i].tree_value) == TARGET_EXPR
996: || TREE_CODE (args[i].tree_value) == COND_EXPR
997: || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
998: copy_to_evaluate_size
999: += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1000: }
1001:
1002: if (copy_to_evaluate_size >= args_size.constant / 2)
1003: must_preallocate = 1;
1004: }
1005:
1006: /* If the structure value address will reference the stack pointer, we must
1007: stabilize it. We don't need to do this if we know that we are not going
1008: to adjust the stack pointer in processing this call. */
1009:
1010: if (structure_value_addr
1011: && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
1012: || reg_mentioned_p (virtual_outgoing_args_rtx, structure_value_addr))
1013: && (args_size.var
1014: #ifndef ACCUMULATE_OUTGOING_ARGS
1015: || args_size.constant
1016: #endif
1017: ))
1018: structure_value_addr = copy_to_reg (structure_value_addr);
1019:
1020: /* If this function call is cse'able, precompute all the parameters.
1021: Note that if the parameter is constructed into a temporary, this will
1022: cause an additional copy because the parameter will be constructed
1023: into a temporary location and then copied into the outgoing arguments.
1024: If a parameter contains a call to alloca and this function uses the
1025: stack, precompute the parameter. */
1026:
1027: for (i = 0; i < num_actuals; i++)
1028: if (is_const
1029: || ((args_size.var != 0 || args_size.constant != 0)
1030: && calls_alloca (args[i].tree_value)))
1031: {
1032: args[i].initial_value = args[i].value
1033: = expand_expr (args[i].tree_value, 0, VOIDmode, 0);
1034: preserve_temp_slots (args[i].value);
1035: free_temp_slots ();
1036:
1037: /* ANSI doesn't require a sequence point here,
1038: but PCC has one, so this will avoid some problems. */
1039: emit_queue ();
1040: }
1041:
1042: /* Now we are about to start emitting insns that can be deleted
1043: if a libcall is deleted. */
1044: if (is_const)
1045: start_sequence ();
1046:
1047: /* If we have no actual push instructions, or shouldn't use them,
1048: make space for all args right now. */
1049:
1050: if (args_size.var != 0)
1051: {
1052: if (old_stack_level == 0)
1053: {
1054: old_stack_level = copy_to_mode_reg (Pmode, stack_pointer_rtx);
1055: old_pending_adj = pending_stack_adjust;
1056: pending_stack_adjust = 0;
1057: }
1058: argblock = push_block (ARGS_SIZE_RTX (args_size), 0, 0);
1059: }
1060: else if (must_preallocate)
1061: {
1062: /* Note that we must go through the motions of allocating an argument
1063: block even if the size is zero because we may be storing args
1064: in the area reserved for register arguments, which may be part of
1065: the stack frame. */
1066: int needed = args_size.constant;
1067:
1068: #ifdef ACCUMULATE_OUTGOING_ARGS
1069: /* Store the maximum argument space used. It will be pushed by the
1070: prologue.
1071:
1072: Since the stack pointer will never be pushed, it is possible for
1073: the evaluation of a parm to clobber something we have already
1074: written to the stack. Since most function calls on RISC machines
1075: do not use the stack, this is uncommon, but must work correctly.
1076:
1077: Therefore, we save any area of the stack that was already written
1078: and that we are using. Here we set up to do this by making a new
1079: stack usage map from the old one. The actual save will be done
1080: by store_one_arg.
1081:
1082: Another approach might be to try to reorder the argument
1083: evaluations to avoid this conflicting stack usage. */
1084:
1085: if (needed > current_function_outgoing_args_size)
1086: current_function_outgoing_args_size = needed;
1087:
1088: #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
1089: /* Since we will be writing into the entire argument area, the
1090: map must be allocated for its entire size, not just the part that
1091: is the responsibility of the caller. */
1092: needed += REG_PARM_STACK_SPACE (fndecl);
1093: #endif
1094:
1095: #ifdef ARGS_GROW_DOWNWARD
1096: highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
1097: needed + 1);
1098: #else
1099: highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, needed);
1100: #endif
1101: stack_usage_map = (char *) alloca (highest_outgoing_arg_in_use);
1102:
1103: if (initial_highest_arg_in_use)
1104: bcopy (initial_stack_usage_map, stack_usage_map,
1105: initial_highest_arg_in_use);
1106:
1107: if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
1108: bzero (&stack_usage_map[initial_highest_arg_in_use],
1109: highest_outgoing_arg_in_use - initial_highest_arg_in_use);
1110: needed = 0;
1111: /* No need to copy this virtual register; the space we're
1112: using gets preallocated at the start of the function
1113: so the stack pointer won't change here. */
1114: argblock = virtual_outgoing_args_rtx;
1115: #else /* not ACCUMULATE_OUTGOING_ARGS */
1116: if (inhibit_defer_pop == 0)
1117: {
1118: /* Try to reuse some or all of the pending_stack_adjust
1119: to get this space. Maybe we can avoid any pushing. */
1120: if (needed > pending_stack_adjust)
1121: {
1122: needed -= pending_stack_adjust;
1123: pending_stack_adjust = 0;
1124: }
1125: else
1126: {
1127: pending_stack_adjust -= needed;
1128: needed = 0;
1129: }
1130: }
1131: /* Special case this because overhead of `push_block' in this
1132: case is non-trivial. */
1133: if (needed == 0)
1134: argblock = virtual_outgoing_args_rtx;
1135: else
1136: argblock = push_block (gen_rtx (CONST_INT, VOIDmode, needed), 0, 0);
1137:
1138: /* We only really need to call `copy_to_reg' in the case where push
1139: insns are going to be used to pass ARGBLOCK to a function
1140: call in ARGS. In that case, the stack pointer changes value
1141: from the allocation point to the call point, and hence
1142: the value of VIRTUAL_OUTGOING_ARGS_RTX changes as well.
1143: But might as well always do it. */
1144: argblock = copy_to_reg (argblock);
1145: #endif /* not ACCUMULATE_OUTGOING_ARGS */
1146: }
1147:
1148: /* If we preallocated stack space, compute the address of each argument.
1149: We need not ensure it is a valid memory address here; it will be
1150: validized when it is used. */
1151: if (argblock)
1152: {
1153: rtx arg_reg = argblock;
1154: int arg_offset = 0;
1155:
1156: if (GET_CODE (argblock) == PLUS)
1157: arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1158:
1159: for (i = 0; i < num_actuals; i++)
1160: {
1161: rtx offset = ARGS_SIZE_RTX (args[i].offset);
1162: rtx slot_offset = ARGS_SIZE_RTX (args[i].slot_offset);
1163: rtx addr;
1164:
1165: /* Skip this parm if it will not be passed on the stack. */
1166: if (! args[i].pass_on_stack && args[i].reg != 0)
1167: continue;
1168:
1169: if (GET_CODE (offset) == CONST_INT)
1170: addr = plus_constant (arg_reg, INTVAL (offset));
1171: else
1172: addr = gen_rtx (PLUS, Pmode, arg_reg, offset);
1173:
1174: addr = plus_constant (addr, arg_offset);
1175: args[i].stack
1176: = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (args[i].tree_value)), addr);
1177:
1178: if (GET_CODE (slot_offset) == CONST_INT)
1179: addr = plus_constant (arg_reg, INTVAL (slot_offset));
1180: else
1181: addr = gen_rtx (PLUS, Pmode, arg_reg, slot_offset);
1182:
1183: addr = plus_constant (addr, arg_offset);
1184: args[i].stack_slot
1185: = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (args[i].tree_value)), addr);
1186: }
1187: }
1188:
1189: #ifdef PUSH_ARGS_REVERSED
1190: #ifdef STACK_BOUNDARY
1191: /* If we push args individually in reverse order, perform stack alignment
1192: before the first push (the last arg). */
1193: if (argblock == 0)
1194: anti_adjust_stack (gen_rtx (CONST_INT, VOIDmode,
1195: (args_size.constant
1196: - original_args_size.constant)));
1197: #endif
1198: #endif
1199:
1200: /* Don't try to defer pops if preallocating, not even from the first arg,
1201: since ARGBLOCK probably refers to the SP. */
1202: if (argblock)
1203: NO_DEFER_POP;
1204:
1205: /* Get the function to call, in the form of RTL. */
1206: if (fndecl)
1207: /* Get a SYMBOL_REF rtx for the function address. */
1208: funexp = XEXP (DECL_RTL (fndecl), 0);
1209: else
1210: /* Generate an rtx (probably a pseudo-register) for the address. */
1211: {
1212: funexp = expand_expr (TREE_OPERAND (exp, 0), 0, VOIDmode, 0);
1213: free_temp_slots (); /* FUNEXP can't be BLKmode */
1214: emit_queue ();
1215: }
1216:
1217: /* Figure out the register where the value, if any, will come back. */
1218: valreg = 0;
1219: if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
1220: && ! structure_value_addr)
1221: {
1222: if (pcc_struct_value)
1223: valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
1224: fndecl);
1225: else
1226: valreg = hard_function_value (TREE_TYPE (exp), fndecl);
1227: }
1228:
1229: /* Precompute all register parameters. It isn't safe to compute anything
1230: once we have started filling any specific hard regs. */
1231: reg_parm_seen = 0;
1232: for (i = 0; i < num_actuals; i++)
1233: if (args[i].reg != 0 && ! args[i].pass_on_stack)
1234: {
1235: reg_parm_seen = 1;
1236:
1237: if (args[i].value == 0)
1238: {
1239: args[i].value = expand_expr (args[i].tree_value, 0, VOIDmode, 0);
1240: preserve_temp_slots (args[i].value);
1241: free_temp_slots ();
1242:
1243: /* ANSI doesn't require a sequence point here,
1244: but PCC has one, so this will avoid some problems. */
1245: emit_queue ();
1246: }
1247: }
1248:
1249: #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
1250: /* The argument list is the property of the called routine and it
1251: may clobber it. If the fixed area has been used for previous
1252: parameters, we must save and restore it.
1253:
1254: Here we compute the boundary of the that needs to be saved, if any. */
1255:
1256: for (i = 0; i < REG_PARM_STACK_SPACE (fndecl); i++)
1257: {
1258: if (i >= highest_outgoing_arg_in_use
1259: || stack_usage_map[i] == 0)
1260: continue;
1261:
1262: if (low_to_save == -1)
1263: low_to_save = i;
1264:
1265: high_to_save = i;
1266: }
1267:
1268: if (low_to_save >= 0)
1269: {
1270: int num_to_save = high_to_save - low_to_save + 1;
1271: enum machine_mode save_mode
1272: = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
1273: rtx stack_area;
1274:
1275: /* If we don't have the required alignment, must do this in BLKmode. */
1276: if ((low_to_save & (MIN (GET_MODE_SIZE (save_mode),
1277: BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
1278: save_mode = BLKmode;
1279:
1280: stack_area = gen_rtx (MEM, save_mode,
1281: memory_address (save_mode,
1282: plus_constant (argblock,
1283: low_to_save)));
1284: if (save_mode == BLKmode)
1285: {
1286: save_area = assign_stack_temp (BLKmode, num_to_save, 1);
1287: emit_block_move (validize_mem (save_area), stack_area,
1288: gen_rtx (CONST_INT, VOIDmode, num_to_save),
1289: PARM_BOUNDARY / BITS_PER_UNIT);
1290: }
1291: else
1292: {
1293: save_area = gen_reg_rtx (save_mode);
1294: emit_move_insn (save_area, stack_area);
1295: }
1296: }
1297: #endif
1298:
1299:
1300: /* Now store (and compute if necessary) all non-register parms.
1301: These come before register parms, since they can require block-moves,
1302: which could clobber the registers used for register parms.
1303: Parms which have partial registers are not stored here,
1304: but we do preallocate space here if they want that. */
1305:
1306: for (i = 0; i < num_actuals; i++)
1307: if (args[i].reg == 0 || args[i].pass_on_stack)
1308: store_one_arg (&args[i], argblock, may_be_alloca,
1309: args_size.var != 0, fndecl);
1310:
1311: /* Now store any partially-in-registers parm.
1312: This is the last place a block-move can happen. */
1313: if (reg_parm_seen)
1314: for (i = 0; i < num_actuals; i++)
1315: if (args[i].partial != 0 && ! args[i].pass_on_stack)
1316: store_one_arg (&args[i], argblock, may_be_alloca,
1317: args_size.var != 0, fndecl);
1318:
1319: #ifndef PUSH_ARGS_REVERSED
1320: #ifdef STACK_BOUNDARY
1321: /* If we pushed args in forward order, perform stack alignment
1322: after pushing the last arg. */
1323: if (argblock == 0)
1324: anti_adjust_stack (gen_rtx (CONST_INT, VOIDmode,
1325: (args_size.constant
1326: - original_args_size.constant)));
1327: #endif
1328: #endif
1329:
1330: /* Pass the function the address in which to return a structure value. */
1331: if (structure_value_addr && ! structure_value_addr_parm)
1332: {
1333: emit_move_insn (struct_value_rtx,
1334: force_reg (Pmode,
1335: force_operand (structure_value_addr, 0)));
1336: if (GET_CODE (struct_value_rtx) == REG)
1337: {
1338: push_to_sequence (use_insns);
1339: emit_insn (gen_rtx (USE, VOIDmode, struct_value_rtx));
1340: use_insns = get_insns ();
1341: end_sequence ();
1342: }
1343: }
1344:
1345: /* Now do the register loads required for any wholly-register parms or any
1346: parms which are passed both on the stack and in a register. Their
1347: expressions were already evaluated.
1348:
1349: Mark all register-parms as living through the call, putting these USE
1350: insns in a list headed by USE_INSNS. */
1351:
1352: for (i = 0; i < num_actuals; i++)
1353: {
1354: rtx list = args[i].reg;
1355: int partial = args[i].partial;
1356:
1357: while (list)
1358: {
1359: rtx reg;
1360: int nregs;
1361:
1362: /* Process each register that needs to get this arg. */
1363: if (GET_CODE (list) == EXPR_LIST)
1364: reg = XEXP (list, 0), list = XEXP (list, 1);
1365: else
1366: reg = list, list = 0;
1367:
1368: /* Set to non-zero if must move a word at a time, even if just one
1369: word (e.g, partial == 1 && mode == DFmode). Set to zero if
1370: we just use a normal move insn. */
1371: nregs = (partial ? partial
1372: : (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1373: ? ((int_size_in_bytes (TREE_TYPE (args[i].tree_value))
1374: + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)
1375: : 0));
1376:
1377: /* If simple case, just do move. If normal partial, store_one_arg
1378: has already loaded the register for us. In all other cases,
1379: load the register(s) from memory. */
1380:
1381: if (nregs == 0)
1382: emit_move_insn (reg, args[i].value);
1383: else if (args[i].partial == 0 || args[i].pass_on_stack)
1384: move_block_to_reg (REGNO (reg),
1385: validize_mem (args[i].value), nregs,
1386: TYPE_MODE (TREE_TYPE (args[i].tree_value)));
1387:
1388: push_to_sequence (use_insns);
1389: if (nregs == 0)
1390: emit_insn (gen_rtx (USE, VOIDmode, reg));
1391: else
1392: use_regs (REGNO (reg), nregs);
1393: use_insns = get_insns ();
1394: end_sequence ();
1395:
1396: /* PARTIAL referred only to the first register, so clear it for the
1397: next time. */
1398: partial = 0;
1399: }
1400: }
1401:
1402: /* Perform postincrements before actually calling the function. */
1403: emit_queue ();
1404:
1405: /* All arguments and registers used for the call must be set up by now! */
1406:
1407: funexp = prepare_call_address (funexp, fndecl, &use_insns);
1408:
1409: /* Generate the actual call instruction. */
1410: emit_call_1 (funexp, funtype, args_size.constant, struct_value_size,
1411: FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
1412: valreg, old_inhibit_defer_pop, use_insns, is_const);
1413:
1414: /* If call is cse'able, make appropriate pair of reg-notes around it.
1415: Test valreg so we don't crash; may safely ignore `const'
1416: if return type is void. */
1417: if (is_const && valreg != 0)
1418: {
1419: rtx note = 0;
1420: rtx temp = gen_reg_rtx (GET_MODE (valreg));
1421: rtx insns;
1422:
1423: /* Construct an "equal form" for the value which mentions all the
1424: arguments in order as well as the function name. */
1425: #ifdef PUSH_ARGS_REVERSED
1426: for (i = 0; i < num_actuals; i++)
1427: note = gen_rtx (EXPR_LIST, VOIDmode, args[i].initial_value, note);
1428: #else
1429: for (i = num_actuals - 1; i >= 0; i--)
1430: note = gen_rtx (EXPR_LIST, VOIDmode, args[i].initial_value, note);
1431: #endif
1432: note = gen_rtx (EXPR_LIST, VOIDmode, funexp, note);
1433:
1434: insns = get_insns ();
1435: end_sequence ();
1436:
1437: emit_libcall_block (insns, temp, valreg, note);
1438:
1439: valreg = temp;
1440: }
1441:
1442: /* For calls to `setjmp', etc., inform flow.c it should complain
1443: if nonvolatile values are live. */
1444:
1445: if (returns_twice)
1446: {
1447: emit_note (name, NOTE_INSN_SETJMP);
1448: current_function_calls_setjmp = 1;
1449: }
1450:
1451: if (is_longjmp)
1452: current_function_calls_longjmp = 1;
1453:
1454: /* Notice functions that cannot return.
1455: If optimizing, insns emitted below will be dead.
1456: If not optimizing, they will exist, which is useful
1457: if the user uses the `return' command in the debugger. */
1458:
1459: if (is_volatile || is_longjmp)
1460: emit_barrier ();
1461:
1462: /* For calls to __builtin_new, note that it can never return 0.
1463: This is because a new handler will be called, and 0 it not
1464: among the numbers it is supposed to return. */
1465: #if 0
1466: if (is_builtin_new)
1467: emit_note (name, NOTE_INSN_BUILTIN_NEW);
1468: #endif
1469:
1470: /* If value type not void, return an rtx for the value. */
1471:
1472: /* If there are cleanups to be called, don't use a hard reg as target. */
1473: if (cleanups_this_call != old_cleanups
1474: && target && REG_P (target)
1475: && REGNO (target) < FIRST_PSEUDO_REGISTER)
1476: target = 0;
1477:
1478: if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
1479: || ignore)
1480: {
1481: target = const0_rtx;
1482: }
1483: else if (structure_value_addr)
1484: {
1485: if (target == 0 || GET_CODE (target) != MEM)
1486: target = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)),
1487: memory_address (TYPE_MODE (TREE_TYPE (exp)),
1488: structure_value_addr));
1489: }
1490: else if (pcc_struct_value)
1491: {
1492: if (target == 0)
1493: target = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)),
1494: copy_to_reg (valreg));
1495: else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1496: emit_move_insn (target, gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)),
1497: copy_to_reg (valreg)));
1498: else
1499: emit_block_move (target, gen_rtx (MEM, BLKmode, copy_to_reg (valreg)),
1500: expr_size (exp),
1501: TYPE_ALIGN (TREE_TYPE (exp)) / BITS_PER_UNIT);
1502: }
1503: else if (target && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp)))
1504: /* TARGET and VALREG cannot be equal at this point because the latter
1505: would not have REG_FUNCTION_VALUE_P true, while the former would if
1506: it were referring to the same register.
1507:
1508: If they refer to the same register, this move will be a no-op, except
1509: when function inlining is being done. */
1510: emit_move_insn (target, valreg);
1511: else
1512: target = copy_to_reg (valreg);
1513:
1514: /* Perform all cleanups needed for the arguments of this call
1515: (i.e. destructors in C++). */
1516: expand_cleanups_to (old_cleanups);
1517:
1518: /* If size of args is variable, restore saved stack-pointer value. */
1519:
1520: if (old_stack_level)
1521: {
1522: emit_move_insn (stack_pointer_rtx, old_stack_level);
1523: pending_stack_adjust = old_pending_adj;
1524: }
1525:
1526: #ifdef ACCUMULATE_OUTGOING_ARGS
1527: else
1528: {
1529: #ifdef REG_PARM_STACK_SPACE
1530: if (save_area)
1531: {
1532: enum machine_mode save_mode = GET_MODE (save_area);
1533: rtx stack_area
1534: = gen_rtx (MEM, save_mode,
1535: memory_address (save_mode,
1536: plus_constant (argblock, low_to_save)));
1537:
1538: if (save_mode != BLKmode)
1539: emit_move_insn (stack_area, save_area);
1540: else
1541: emit_block_move (stack_area, validize_mem (save_area),
1542: gen_rtx (CONST_INT, VOIDmode,
1543: high_to_save - low_to_save + 1,
1544: PARM_BOUNDARY / BITS_PER_UNIT));
1545: }
1546: #endif
1547:
1548: /* If we saved any argument areas, restore them. */
1549: for (i = 0; i < num_actuals; i++)
1550: if (args[i].save_area)
1551: {
1552: enum machine_mode save_mode = GET_MODE (args[i].save_area);
1553: rtx stack_area
1554: = gen_rtx (MEM, save_mode,
1555: memory_address (save_mode,
1556: XEXP (args[i].stack_slot, 0)));
1557:
1558: if (save_mode != BLKmode)
1559: emit_move_insn (stack_area, args[i].save_area);
1560: else
1561: emit_block_move (stack_area, validize_mem (args[i].save_area),
1562: gen_rtx (CONST_INT, VOIDmode,
1563: args[i].size.constant),
1564: PARM_BOUNDARY / BITS_PER_UNIT);
1565: }
1566:
1567: highest_outgoing_arg_in_use = initial_highest_arg_in_use;
1568: stack_usage_map = initial_stack_usage_map;
1569: }
1570: #endif
1571:
1572: /* If this was alloca, record the new stack level for nonlocal gotos. */
1573: if (may_be_alloca && nonlocal_goto_stack_level != 0)
1574: emit_move_insn (nonlocal_goto_stack_level, stack_pointer_rtx);
1575:
1576: pop_temp_slots ();
1577:
1578: return target;
1579: }
1580:
1581: #if 0
1582: /* Return an rtx which represents a suitable home on the stack
1583: given TYPE, the type of the argument looking for a home.
1584: This is called only for BLKmode arguments.
1585:
1586: SIZE is the size needed for this target.
1587: ARGS_ADDR is the address of the bottom of the argument block for this call.
1588: OFFSET describes this parameter's offset into ARGS_ADDR. It is meaningless
1589: if this machine uses push insns. */
1590:
1591: static rtx
1592: target_for_arg (type, size, args_addr, offset)
1593: tree type;
1594: rtx size;
1595: rtx args_addr;
1596: struct args_size offset;
1597: {
1598: rtx target;
1599: rtx offset_rtx = ARGS_SIZE_RTX (offset);
1600:
1601: /* We do not call memory_address if possible,
1602: because we want to address as close to the stack
1603: as possible. For non-variable sized arguments,
1604: this will be stack-pointer relative addressing. */
1605: if (GET_CODE (offset_rtx) == CONST_INT)
1606: target = plus_constant (args_addr, INTVAL (offset_rtx));
1607: else
1608: {
1609: /* I have no idea how to guarantee that this
1610: will work in the presence of register parameters. */
1611: target = gen_rtx (PLUS, Pmode, args_addr, offset_rtx);
1612: target = memory_address (QImode, target);
1613: }
1614:
1615: return gen_rtx (MEM, BLKmode, target);
1616: }
1617: #endif
1618:
1619: /* Store a single argument for a function call
1620: into the register or memory area where it must be passed.
1621: *ARG describes the argument value and where to pass it.
1622:
1623: ARGBLOCK is the address of the stack-block for all the arguments,
1.1.1.2 ! root 1624: or 0 on a machine where arguments are pushed individually.
1.1 root 1625:
1626: MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
1627: so must be careful about how the stack is used.
1628:
1629: VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
1630: argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
1631: that we need not worry about saving and restoring the stack.
1632:
1633: FNDECL is the declaration of the function we are calling. */
1634:
1635: static void
1636: store_one_arg (arg, argblock, may_be_alloca, variable_size, fndecl)
1637: struct arg_data *arg;
1638: rtx argblock;
1639: int may_be_alloca;
1640: int variable_size;
1641: tree fndecl;
1642: {
1643: register tree pval = arg->tree_value;
1644: rtx reg = 0;
1645: int partial = 0;
1646: int used = 0;
1647: int i, lower_bound, upper_bound;
1648:
1649: if (TREE_CODE (pval) == ERROR_MARK)
1650: return;
1651:
1652: #ifdef ACCUMULATE_OUTGOING_ARGS
1653: /* If this is being stored into a pre-allocated, fixed-size, stack area,
1654: save any previous data at that location. */
1655: if (argblock && ! variable_size && arg->stack)
1656: {
1657: #ifdef ARGS_GROW_DOWNWARD
1658: /* stack_slot is negative, but we want to index stack_usage_map */
1659: /* with positive values. */
1660: if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
1661: upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
1662: else
1663: abort ();
1664:
1665: lower_bound = upper_bound - arg->size.constant;
1666: #else
1667: if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
1668: lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
1669: else
1670: lower_bound = 0;
1671:
1672: upper_bound = lower_bound + arg->size.constant;
1673: #endif
1674:
1675: for (i = lower_bound; i < upper_bound; i++)
1676: if (stack_usage_map[i]
1677: #ifdef REG_PARM_STACK_SPACE
1678: /* Don't store things in the fixed argument area at this point;
1679: it has already been saved. */
1680: && i > REG_PARM_STACK_SPACE (fndecl)
1681: #endif
1682: )
1683: break;
1684:
1685: if (i != upper_bound)
1686: {
1687: /* We need to make a save area. See what mode we can make it. */
1688: enum machine_mode save_mode
1689: = mode_for_size (arg->size.constant * BITS_PER_UNIT, MODE_INT, 1);
1690: rtx stack_area
1691: = gen_rtx (MEM, save_mode,
1692: memory_address (save_mode, XEXP (arg->stack_slot, 0)));
1693:
1694: if (save_mode == BLKmode)
1695: {
1696: arg->save_area = assign_stack_temp (BLKmode,
1697: arg->size.constant, 1);
1698: emit_block_move (validize_mem (arg->save_area), stack_area,
1699: gen_rtx (CONST_INT, VOIDmode,
1700: arg->size.constant),
1701: PARM_BOUNDARY / BITS_PER_UNIT);
1702: }
1703: else
1704: {
1705: arg->save_area = gen_reg_rtx (save_mode);
1706: emit_move_insn (arg->save_area, stack_area);
1707: }
1708: }
1709: }
1710: #endif
1711:
1712: /* If this isn't going to be placed on both the stack and in registers,
1713: set up the register and number of words. */
1714: if (! arg->pass_on_stack)
1715: reg = arg->reg, partial = arg->partial;
1716:
1717: if (reg != 0 && partial == 0)
1718: /* Being passed entirely in a register. We shouldn't be called in
1719: this case. */
1720: abort ();
1721:
1722: /* If this is being partially passed in a register, but multiple locations
1723: are specified, we assume that the one partially used is the one that is
1724: listed first. */
1725: if (reg && GET_CODE (reg) == EXPR_LIST)
1726: reg = XEXP (reg, 0);
1727:
1728: /* If this is being passes partially in a register, we can't evaluate
1729: it directly into its stack slot. Otherwise, we can. */
1730: if (arg->value == 0)
1731: arg->value = expand_expr (pval, partial ? 0 : arg->stack, VOIDmode, 0);
1732:
1733: /* Don't allow anything left on stack from computation
1734: of argument to alloca. */
1735: if (may_be_alloca)
1736: do_pending_stack_adjust ();
1737:
1738: if (arg->value == arg->stack)
1739: /* If the value is already in the stack slot, we are done. */
1740: ;
1741: else if (TYPE_MODE (TREE_TYPE (pval)) != BLKmode)
1742: {
1743: register int size;
1744:
1745: /* Argument is a scalar, not entirely passed in registers.
1746: (If part is passed in registers, arg->partial says how much
1747: and emit_push_insn will take care of putting it there.)
1748:
1749: Push it, and if its size is less than the
1750: amount of space allocated to it,
1751: also bump stack pointer by the additional space.
1752: Note that in C the default argument promotions
1753: will prevent such mismatches. */
1754:
1755: size = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (pval)));
1756: /* Compute how much space the push instruction will push.
1757: On many machines, pushing a byte will advance the stack
1758: pointer by a halfword. */
1759: #ifdef PUSH_ROUNDING
1760: size = PUSH_ROUNDING (size);
1761: #endif
1762: used = size;
1763:
1764: /* Compute how much space the argument should get:
1765: round up to a multiple of the alignment for arguments. */
1766: if (none != FUNCTION_ARG_PADDING (TYPE_MODE (TREE_TYPE (pval)),
1767: TREE_TYPE (pval)))
1768: used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
1769: / (PARM_BOUNDARY / BITS_PER_UNIT))
1770: * (PARM_BOUNDARY / BITS_PER_UNIT));
1771:
1772: /* This isn't already where we want it on the stack, so put it there.
1773: This can either be done with push or copy insns. */
1774: emit_push_insn (arg->value, TYPE_MODE (TREE_TYPE (pval)),
1775: TREE_TYPE (pval), 0, 0, partial, reg,
1776: used - size, argblock, ARGS_SIZE_RTX (arg->offset));
1777: }
1778: else
1779: {
1780: /* BLKmode, at least partly to be pushed. */
1781:
1782: register int excess;
1783: rtx size_rtx;
1784:
1785: /* Pushing a nonscalar.
1786: If part is passed in registers, PARTIAL says how much
1787: and emit_push_insn will take care of putting it there. */
1788:
1789: /* Round its size up to a multiple
1790: of the allocation unit for arguments. */
1791:
1792: if (arg->size.var != 0)
1793: {
1794: excess = 0;
1795: size_rtx = ARGS_SIZE_RTX (arg->size);
1796: }
1797: else
1798: {
1799: register tree size = size_in_bytes (TREE_TYPE (pval));
1800: /* PUSH_ROUNDING has no effect on us, because
1801: emit_push_insn for BLKmode is careful to avoid it. */
1802: excess = (arg->size.constant - TREE_INT_CST_LOW (size)
1803: + partial * UNITS_PER_WORD);
1804: size_rtx = expand_expr (size, 0, VOIDmode, 0);
1805: }
1806:
1807: emit_push_insn (arg->value, TYPE_MODE (TREE_TYPE (pval)),
1808: TREE_TYPE (pval), size_rtx,
1809: TYPE_ALIGN (TREE_TYPE (pval)) / BITS_PER_UNIT, partial,
1810: reg, excess, argblock, ARGS_SIZE_RTX (arg->offset));
1811: }
1812:
1813:
1814: /* Unless this is a partially-in-register argument, the argument is now
1815: in the stack.
1816:
1817: ??? Note that this can change arg->value from arg->stack to
1818: arg->stack_slot and it matters when they are not the same.
1819: It isn't totally clear that this is correct in all cases. */
1820: if (partial == 0)
1821: arg->value = arg->stack_slot;
1822:
1823: /* Once we have pushed something, pops can't safely
1824: be deferred during the rest of the arguments. */
1825: NO_DEFER_POP;
1826:
1827: /* ANSI doesn't require a sequence point here,
1828: but PCC has one, so this will avoid some problems. */
1829: emit_queue ();
1830:
1831: /* Free any temporary slots made in processing this argument. */
1832: free_temp_slots ();
1833:
1834: #ifdef ACCUMULATE_OUTGOING_ARGS
1835: /* Now mark the segment we just used. */
1836: if (argblock && ! variable_size && arg->stack)
1837: for (i = lower_bound; i < upper_bound; i++)
1838: stack_usage_map[i] = 1;
1839: #endif
1840: }
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