| blob | 700564a33dbcb49dd775e78fee514dbaba26b072 |
1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998
3 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
10 version.
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
20 02111-1307, USA. */
43 #ifndef STACK_POINTER_OFFSET
44 #define STACK_POINTER_OFFSET 0
45 #endif
47 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
48 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
50 /* Data structure and subroutines used within expand_call. */
52 struct arg_data
53 {
54 /* Tree node for this argument. */
55 tree tree_value;
56 /* Mode for value; TYPE_MODE unless promoted. */
58 /* Current RTL value for argument, or 0 if it isn't precomputed. */
59 rtx value;
60 /* Initially-compute RTL value for argument; only for const functions. */
61 rtx initial_value;
62 /* Register to pass this argument in, 0 if passed on stack, or an
63 PARALLEL if the arg is to be copied into multiple non-contiguous
64 registers. */
65 rtx reg;
66 /* Register to pass this argument in when generating tail call sequence.
67 This is not the same register as for normal calls on machines with
68 register windows. */
69 rtx tail_call_reg;
70 /* If REG was promoted from the actual mode of the argument expression,
71 indicates whether the promotion is sign- or zero-extended. */
73 /* Number of registers to use. 0 means put the whole arg in registers.
74 Also 0 if not passed in registers. */
76 /* Nonzero if argument must be passed on stack.
77 Note that some arguments may be passed on the stack
78 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
79 pass_on_stack identifies arguments that *cannot* go in registers. */
81 /* Some fields packaged up for locate_and_pad_parm. */
83 /* Location on the stack at which parameter should be stored. The store
84 has already been done if STACK == VALUE. */
85 rtx stack;
86 /* Location on the stack of the start of this argument slot. This can
87 differ from STACK if this arg pads downward. This location is known
88 to be aligned to FUNCTION_ARG_BOUNDARY. */
89 rtx stack_slot;
90 /* Place that this stack area has been saved, if needed. */
91 rtx save_area;
92 /* If an argument's alignment does not permit direct copying into registers,
93 copy in smaller-sized pieces into pseudos. These are stored in a
94 block pointed to by this field. The next field says how many
95 word-sized pseudos we made. */
98 };
100 /* A vector of one char per byte of stack space. A byte if nonzero if
101 the corresponding stack location has been used.
102 This vector is used to prevent a function call within an argument from
103 clobbering any stack already set up. */
106 /* Size of STACK_USAGE_MAP. */
109 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
110 stack location's tail call argument has been already stored into the stack.
111 This bitmap is used to prevent sibling call optimization if function tries
112 to use parent's incoming argument slots when they have been already
113 overwritten with tail call arguments. */
116 /* stack_arg_under_construction is nonzero when an argument may be
117 initialized with a constructor call (including a C function that
118 returns a BLKmode struct) and expand_call must take special action
119 to make sure the object being constructed does not overlap the
120 argument list for the constructor call. */
128 CUMULATIVE_ARGS *);
155 #ifdef REG_PARM_STACK_SPACE
158 #endif
159 \f
160 /* If WHICH is 1, return 1 if EXP contains a call to the built-in function
161 `alloca'.
163 If WHICH is 0, return 1 if EXP contains a call to any function.
164 Actually, we only need return 1 if evaluating EXP would require pushing
165 arguments on the stack, but that is too difficult to compute, so we just
166 assume any function call might require the stack. */
170 static int
172 {
179 }
181 /* Recursive function to do the work of above function. */
183 static int
185 {
191 /* If this code is language-specific, we don't know what it will do. */
196 {
202 && (TYPE_RETURNS_STACK_DEPRESSED
216 {
217 tree tem;
222 }
232 calls_function_save_exprs);
237 {
238 tree local;
239 tree subblock;
247 subblock;
251 }
262 }
264 /* Only expressions, references, and blocks can contain calls. */
274 }
275 \f
276 /* Force FUNEXP into a form suitable for the address of a CALL,
277 and return that as an rtx. Also load the static chain register
278 if FNDECL is a nested function.
280 CALL_FUSAGE points to a variable holding the prospective
281 CALL_INSN_FUNCTION_USAGE information. */
283 rtx
286 {
292 /* Get possible static chain value for nested function in C. */
295 /* Make a valid memory address and copy constants thru pseudo-regs,
296 but not for a constant address if -fno-function-cse. */
298 /* If we are using registers for parameters, force the
299 function address into a register now. */
304 {
305 #ifndef NO_FUNCTION_CSE
307 #ifdef NO_RECURSIVE_FUNCTION_CSE
309 #endif
311 #endif
312 }
315 {
320 }
323 }
325 /* Generate instructions to call function FUNEXP,
326 and optionally pop the results.
327 The CALL_INSN is the first insn generated.
329 FNDECL is the declaration node of the function. This is given to the
330 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
332 FUNTYPE is the data type of the function. This is given to the macro
333 RETURN_POPS_ARGS to determine whether this function pops its own args.
334 We used to allow an identifier for library functions, but that doesn't
335 work when the return type is an aggregate type and the calling convention
336 says that the pointer to this aggregate is to be popped by the callee.
338 STACK_SIZE is the number of bytes of arguments on the stack,
339 ROUNDED_STACK_SIZE is that number rounded up to
340 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
341 both to put into the call insn and to generate explicit popping
342 code if necessary.
344 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
345 It is zero if this call doesn't want a structure value.
347 NEXT_ARG_REG is the rtx that results from executing
348 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
349 just after all the args have had their registers assigned.
350 This could be whatever you like, but normally it is the first
351 arg-register beyond those used for args in this call,
352 or 0 if all the arg-registers are used in this call.
353 It is passed on to `gen_call' so you can put this info in the call insn.
355 VALREG is a hard register in which a value is returned,
356 or 0 if the call does not return a value.
358 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
359 the args to this call were processed.
360 We restore `inhibit_defer_pop' to that value.
362 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
363 denote registers used by the called function. */
365 static void
367 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
368 HOST_WIDE_INT rounded_stack_size,
369 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
373 {
375 rtx call_insn;
378 #if defined (HAVE_call) && defined (HAVE_call_value)
379 rtx struct_value_size_rtx;
381 #endif
383 #ifdef CALL_POPS_ARGS
385 #endif
387 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
388 and we don't want to load it into a register as an optimization,
389 because prepare_call_address already did it if it should be done. */
393 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
397 {
399 rtx pat;
401 /* If this subroutine pops its own args, record that in the call insn
402 if possible, for the sake of frame pointer elimination. */
408 n_pop);
409 else
415 }
416 else
417 #endif
419 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
420 /* If the target has "call" or "call_value" insns, then prefer them
421 if no arguments are actually popped. If the target does not have
422 "call" or "call_value" insns, then we must use the popping versions
423 even if the call has no arguments to pop. */
424 #if defined (HAVE_call) && defined (HAVE_call_value)
427 #else
429 #endif
430 {
432 rtx pat;
434 /* If this subroutine pops its own args, record that in the call insn
435 if possible, for the sake of frame pointer elimination. */
441 else
447 }
448 else
449 #endif
451 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
454 {
458 rounded_stack_size_rtx,
460 else
463 struct_value_size_rtx));
464 }
465 else
466 #endif
468 #if defined (HAVE_call) && defined (HAVE_call_value)
470 {
475 NULL_RTX));
476 else
479 struct_value_size_rtx));
480 }
481 else
482 #endif
485 /* Find the call we just emitted. */
488 /* Mark memory as used for "pure" function call. */
490 call_fusage
491 = gen_rtx_EXPR_LIST
495 call_fusage);
497 /* Put the register usage information there. */
500 /* If this is a const call, then set the insn's unchanging bit. */
504 /* If this call can't throw, attach a REG_EH_REGION reg note to that
505 effect. */
509 else
520 {
524 }
528 /* Restore this now, so that we do defer pops for this call's args
529 if the context of the call as a whole permits. */
532 /* Don't bother cleaning up after a noreturn function. */
537 {
546 }
549 {
550 /* If returning from the subroutine does not automatically pop the args,
551 we need an instruction to pop them sooner or later.
552 Perhaps do it now; perhaps just record how much space to pop later.
554 If returning from the subroutine does pop the args, indicate that the
555 stack pointer will be changed. */
558 {
560 /* Just pretend we did the pop. */
565 else
567 }
568 }
569 /* When we accumulate outgoing args, we must avoid any stack manipulations.
570 Restore the stack pointer to its original value now. Usually
571 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
572 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
573 popping variants of functions exist as well.
575 ??? We may optimize similar to defer_pop above, but it is
576 probably not worthwhile.
578 ??? It will be worthwhile to enable combine_stack_adjustments even for
579 such machines. */
582 }
584 /* Determine if the function identified by NAME and FNDECL is one with
585 special properties we wish to know about.
587 For example, if the function might return more than one time (setjmp), then
588 set RETURNS_TWICE to a nonzero value.
590 Similarly set LONGJMP for if the function is in the longjmp family.
592 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
593 space from the stack such as alloca. */
595 static int
597 {
601 /* Exclude functions not at the file scope, or not `extern',
602 since they are not the magic functions we would otherwise
603 think they are. */
605 {
609 /* We assume that alloca will always be called by name. It
610 makes no sense to pass it as a pointer-to-function to
611 anything that does not understand its behavior. */
620 /* Disregard prefix _, __ or __x. */
622 {
627 else
629 }
632 {
645 }
658 /* Linux specific: __clone. check NAME to insist on the
659 leading underscores, to avoid polluting the ISO / POSIX
660 namespace. */
669 }
671 }
673 /* Return nonzero when tree represent call to longjmp. */
675 int
677 {
679 }
681 /* Return true when exp contains alloca call. */
682 bool
684 {
693 }
695 /* Detect flags (function attributes) from the function decl or type node. */
697 int
699 {
704 {
709 {
714 }
716 /* The function exp may have the `malloc' attribute. */
720 /* The function exp may have the `pure' attribute. */
726 }
734 /* Mark if the function returns with the stack pointer depressed. We
735 cannot consider it pure or constant in that case. */
737 {
740 }
743 }
745 /* Precompute all register parameters as described by ARGS, storing values
746 into fields within the ARGS array.
748 NUM_ACTUALS indicates the total number elements in the ARGS array.
750 Set REG_PARM_SEEN if we encounter a register parameter. */
752 static void
754 {
761 {
765 {
772 /* ANSI doesn't require a sequence point here,
773 but PCC has one, so this will avoid some problems. */
775 }
777 /* If the value is a non-legitimate constant, force it into a
778 pseudo now. TLS symbols sometimes need a call to resolve. */
783 /* If we are to promote the function arg to a wider mode,
784 do it now. */
792 /* If the value is expensive, and we are inside an appropriately
793 short loop, put the value into a pseudo and then put the pseudo
794 into the hard reg.
796 For small register classes, also do this if this call uses
797 register parameters. This is to avoid reload conflicts while
798 loading the parameters registers. */
808 }
809 }
811 #ifdef REG_PARM_STACK_SPACE
813 /* The argument list is the property of the called routine and it
814 may clobber it. If the fixed area has been used for previous
815 parameters, we must save and restore it. */
817 static rtx
818 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
819 {
823 /* Compute the boundary of the area that needs to be saved, if any. */
825 #ifdef ARGS_GROW_DOWNWARD
827 #endif
833 {
837 rtx stack_area;
838 rtx save_area;
841 ;
849 /* If we don't have the required alignment, must do this
850 in BLKmode. */
855 #ifdef ARGS_GROW_DOWNWARD
857 #else
859 #endif
863 delta)));
867 {
871 }
872 else
873 {
876 }
879 }
882 }
884 static void
886 {
889 rtx stack_area;
891 #ifdef ARGS_GROW_DOWNWARD
893 #else
895 #endif
903 else
906 BLOCK_OP_CALL_PARM);
907 }
910 /* If any elements in ARGS refer to parameters that are to be passed in
911 registers, but not in memory, and whose alignment does not permit a
912 direct copy into registers. Copy the values into a group of pseudos
913 which we will later copy into the appropriate hard registers.
915 Pseudos for each unaligned argument will be stored into the array
916 args[argnum].aligned_regs. The caller is responsible for deallocating
917 the aligned_regs array if it is nonzero. */
919 static void
921 {
929 {
940 /* Structures smaller than a word are aligned to the least
941 significant byte (to the right). On a BYTES_BIG_ENDIAN machine,
942 this means we must skip the empty high order bytes when
943 calculating the bit offset. */
949 {
956 /* There is no need to restrict this code to loading items
957 in TYPE_ALIGN sized hunks. The bitfield instructions can
958 load up entire word sized registers efficiently.
960 ??? This may not be needed anymore.
961 We use to emit a clobber here but that doesn't let later
962 passes optimize the instructions we emit. By storing 0 into
963 the register later passes know the first AND to zero out the
964 bitfield being set in the register is unnecessary. The store
965 of 0 will be deleted as will at least the first AND. */
973 BITS_PER_WORD),
974 BITS_PER_WORD);
975 }
976 }
977 }
979 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
980 ACTPARMS.
982 NUM_ACTUALS is the total number of parameters.
984 N_NAMED_ARGS is the total number of named arguments.
986 FNDECL is the tree code for the target of this call (if known)
988 ARGS_SO_FAR holds state needed by the target to know where to place
989 the next argument.
991 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
992 for arguments which are passed in registers.
994 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
995 and may be modified by this routine.
997 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
998 flags which may may be modified by this routine. */
1000 static void
1010 {
1011 /* 1 if scanning parms front to back, -1 if scanning back to front. */
1014 /* Count arg position in order args appear. */
1018 tree p;
1023 /* In this loop, we consider args in the order they are written.
1024 We fill up ARGS from the front or from the back if necessary
1025 so that in any case the first arg to be pushed ends up at the front. */
1028 {
1030 /* In this case, must reverse order of args
1031 so that we compute and push the last arg first. */
1032 }
1033 else
1034 {
1036 }
1038 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1040 {
1047 /* Replace erroneous argument with constant zero. */
1051 /* If TYPE is a transparent union, pass things the way we would
1052 pass the first field of the union. We have already verified that
1053 the modes are the same. */
1057 /* Decide where to pass this arg.
1059 args[i].reg is nonzero if all or part is passed in registers.
1061 args[i].partial is nonzero if part but not all is passed in registers,
1062 and the exact value says how many words are passed in registers.
1064 args[i].pass_on_stack is nonzero if the argument must at least be
1065 computed on the stack. It may then be loaded back into registers
1066 if args[i].reg is nonzero.
1068 These decisions are driven by the FUNCTION_... macros and must agree
1069 with those made by function.c. */
1071 /* See if this argument should be passed by invisible reference. */
1074 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
1077 #endif
1078 )
1079 {
1080 /* If we're compiling a thunk, pass through invisible
1081 references instead of making a copy. */
1083 #ifdef FUNCTION_ARG_CALLEE_COPIES
1086 /* If it's in a register, we must make a copy of it too. */
1087 /* ??? Is this a sufficient test? Is there a better one? */
1091 #endif
1092 )
1093 {
1094 /* C++ uses a TARGET_EXPR to indicate that we want to make a
1095 new object from the argument. If we are passing by
1096 invisible reference, the callee will do that for us, so we
1097 can strip off the TARGET_EXPR. This is not always safe,
1098 but it is safe in the only case where this is a useful
1099 optimization; namely, when the argument is a plain object.
1100 In that case, the frontend is just asking the backend to
1101 make a bitwise copy of the argument. */
1112 }
1114 {
1115 /* In the V3 C++ ABI, parameters are destroyed in the caller.
1116 We implement this by passing the address of the temporary
1117 rather than expanding it into another allocated slot. */
1122 }
1123 else
1124 {
1125 /* We make a copy of the object and pass the address to the
1126 function being called. */
1127 rtx copy;
1133 STACK_CHECK_MAX_VAR_SIZE))))
1134 {
1135 /* This is a variable-sized object. Make space on the stack
1136 for it. */
1140 {
1144 }
1147 allocate_dynamic_stack_space
1150 }
1151 else
1161 }
1162 }
1167 #ifdef PROMOTE_FUNCTION_ARGS
1169 #endif
1176 #ifdef FUNCTION_INCOMING_ARG
1177 /* If this is a sibling call and the machine has register windows, the
1178 register window has to be unwinded before calling the routine, so
1179 arguments have to go into the incoming registers. */
1182 #else
1184 #endif
1186 #ifdef FUNCTION_ARG_PARTIAL_NREGS
1191 #endif
1195 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1196 it means that we are to pass this arg in the register(s) designated
1197 by the PARALLEL, but also to pass it in the stack. */
1202 /* If this is an addressable type, we must preallocate the stack
1203 since we must evaluate the object into its final location.
1205 If this is to be passed in both registers and the stack, it is simpler
1206 to preallocate. */
1211 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
1212 we cannot consider this function call constant. */
1216 /* Compute the stack-size of this argument. */
1221 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1223 #else
1225 #endif
1229 /* Update ARGS_SIZE, the total stack space for args so far. */
1235 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1236 have been used, etc. */
1240 }
1241 }
1243 /* Update ARGS_SIZE to contain the total size for the argument block.
1244 Return the original constant component of the argument block's size.
1246 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1247 for arguments passed in registers. */
1249 static int
1253 {
1256 /* For accumulate outgoing args mode we don't need to align, since the frame
1257 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1258 backends from generating misaligned frame sizes. */
1262 /* Compute the actual size of the argument block required. The variable
1263 and constant sizes must be combined, the size may have to be rounded,
1264 and there may be a minimum required size. */
1267 {
1273 {
1274 /* We don't handle this case yet. To handle it correctly we have
1275 to add the delta, round and subtract the delta.
1276 Currently no machine description requires this support. */
1280 }
1283 {
1284 args_size->var
1288 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1289 /* The area corresponding to register parameters is not to count in
1290 the size of the block we need. So make the adjustment. */
1291 args_size->var
1294 #endif
1295 }
1296 }
1297 else
1298 {
1303 + stack_pointer_delta
1305 / preferred_stack_boundary
1310 reg_parm_stack_space);
1312 #ifdef MAYBE_REG_PARM_STACK_SPACE
1315 #endif
1317 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1319 #endif
1320 }
1322 }
1324 /* Precompute parameters as needed for a function call.
1326 FLAGS is mask of ECF_* constants.
1328 NUM_ACTUALS is the number of arguments.
1330 ARGS is an array containing information for each argument; this
1331 routine fills in the INITIAL_VALUE and VALUE fields for each
1332 precomputed argument. */
1334 static void
1336 {
1339 /* If this function call is cse'able, precompute all the parameters.
1340 Note that if the parameter is constructed into a temporary, this will
1341 cause an additional copy because the parameter will be constructed
1342 into a temporary location and then copied into the outgoing arguments.
1343 If a parameter contains a call to alloca and this function uses the
1344 stack, precompute the parameter. */
1346 /* If we preallocated the stack space, and some arguments must be passed
1347 on the stack, then we must precompute any parameter which contains a
1348 function call which will store arguments on the stack.
1349 Otherwise, evaluating the parameter may clobber previous parameters
1350 which have already been stored into the stack. (we have code to avoid
1351 such case by saving the outgoing stack arguments, but it results in
1352 worse code) */
1357 {
1360 /* If this is an addressable type, we cannot pre-evaluate it. */
1367 /* ANSI doesn't require a sequence point here,
1368 but PCC has one, so this will avoid some problems. */
1376 {
1380 #ifdef PROMOTE_FOR_CALL_ONLY
1381 /* CSE will replace this only if it contains args[i].value
1382 pseudo, so convert it down to the declared mode using
1383 a SUBREG. */
1386 {
1392 }
1393 #endif
1394 }
1395 }
1396 }
1398 /* Given the current state of MUST_PREALLOCATE and information about
1399 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1400 compute and return the final value for MUST_PREALLOCATE. */
1402 static int
1403 finalize_must_preallocate (int must_preallocate, int num_actuals, struct arg_data *args, struct args_size *args_size)
1404 {
1405 /* See if we have or want to preallocate stack space.
1407 If we would have to push a partially-in-regs parm
1408 before other stack parms, preallocate stack space instead.
1410 If the size of some parm is not a multiple of the required stack
1411 alignment, we must preallocate.
1413 If the total size of arguments that would otherwise create a copy in
1414 a temporary (such as a CALL) is more than half the total argument list
1415 size, preallocation is faster.
1417 Another reason to preallocate is if we have a machine (like the m88k)
1418 where stack alignment is required to be maintained between every
1419 pair of insns, not just when the call is made. However, we assume here
1420 that such machines either do not have push insns (and hence preallocation
1421 would occur anyway) or the problem is taken care of with
1422 PUSH_ROUNDING. */
1425 {
1431 {
1442 copy_to_evaluate_size
1444 }
1449 }
1451 }
1453 /* If we preallocated stack space, compute the address of each argument
1454 and store it into the ARGS array.
1456 We need not ensure it is a valid memory address here; it will be
1457 validized when it is used.
1459 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1461 static void
1463 {
1465 {
1473 {
1476 rtx addr;
1478 /* Skip this parm if it will not be passed on the stack. */
1484 else
1495 else
1504 /* Function incoming arguments may overlap with sibling call
1505 outgoing arguments and we cannot allow reordering of reads
1506 from function arguments with stores to outgoing arguments
1507 of sibling calls. */
1510 }
1511 }
1512 }
1514 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1515 in a call instruction.
1517 FNDECL is the tree node for the target function. For an indirect call
1518 FNDECL will be NULL_TREE.
1520 ADDR is the operand 0 of CALL_EXPR for this call. */
1522 static rtx
1524 {
1525 rtx funexp;
1527 /* Get the function to call, in the form of RTL. */
1529 {
1530 /* If this is the first use of the function, see if we need to
1531 make an external definition for it. */
1533 {
1536 }
1538 /* Get a SYMBOL_REF rtx for the function address. */
1540 }
1541 else
1542 /* Generate an rtx (probably a pseudo-register) for the address. */
1543 {
1548 }
1550 }
1552 /* Do the register loads required for any wholly-register parms or any
1553 parms which are passed both on the stack and in a register. Their
1554 expressions were already evaluated.
1556 Mark all register-parms as living through the call, putting these USE
1557 insns in the CALL_INSN_FUNCTION_USAGE field.
1559 When IS_SIBCALL, perform the check_sibcall_overlap_argument_overlap
1560 checking, setting *SIBCALL_FAILURE if appropriate. */
1562 static void
1566 {
1569 #ifdef LOAD_ARGS_REVERSED
1571 #else
1573 #endif
1574 {
1581 {
1583 /* Set to non-negative if must move a word at a time, even if just
1584 one word (e.g, partial == 1 && mode == DFmode). Set to -1 if
1585 we just use a normal move insn. This value can be zero if the
1586 argument is a zero size structure with no fields. */
1593 /* Handle calls that pass values in multiple non-contiguous
1594 locations. The Irix 6 ABI has examples of this. */
1600 /* If simple case, just do move. If normal partial, store_one_arg
1601 has already loaded the register for us. In all other cases,
1602 load the register(s) from memory. */
1607 /* If we have pre-computed the values to put in the registers in
1608 the case of non-aligned structures, copy them in now. */
1620 /* When a parameter is a block, and perhaps in other cases, it is
1621 possible that it did a load from an argument slot that was
1622 already clobbered. */
1627 /* Handle calls that pass values in multiple non-contiguous
1628 locations. The Irix 6 ABI has examples of this. */
1633 else
1635 }
1636 }
1637 }
1639 /* Try to integrate function. See expand_inline_function for documentation
1640 about the parameters. */
1642 static rtx
1645 {
1646 rtx temp;
1647 rtx before_call;
1652 #ifdef REG_PARM_STACK_SPACE
1653 #ifdef MAYBE_REG_PARM_STACK_SPACE
1655 #else
1657 #endif
1658 #endif
1666 structure_value_addr);
1670 /* If inlining succeeded, return. */
1672 {
1674 {
1675 /* If the outgoing argument list must be preserved, push
1676 the stack before executing the inlined function if it
1677 makes any calls. */
1683 ;
1686 {
1687 rtx first_insn
1691 /* Look for a call in the inline function code.
1692 If DECL_SAVED_INSNS (fndecl)->outgoing_args_size is
1693 nonzero then there is a call and it is not necessary
1694 to scan the insns. */
1702 {
1703 /* Reserve enough stack space so that the largest
1704 argument list of any function call in the inline
1705 function does not overlap the argument list being
1706 evaluated. This is usually an overestimate because
1707 allocate_dynamic_stack_space reserves space for an
1708 outgoing argument list in addition to the requested
1709 space, but there is no way to ask for stack space such
1710 that an argument list of a certain length can be
1711 safely constructed.
1713 Add the stack space reserved for register arguments, if
1714 any, in the inline function. What is really needed is the
1715 largest value of reg_parm_stack_space in the inline
1716 function, but that is not available. Using the current
1717 value of reg_parm_stack_space is wrong, but gives
1718 correct results on all supported machines. */
1731 }
1732 }
1733 }
1735 /* If the result is equivalent to TARGET, return TARGET to simplify
1736 checks in store_expr. They can be equivalent but not equal in the
1737 case of a function that returns BLKmode. */
1741 }
1743 /* If inlining failed, mark FNDECL as needing to be compiled
1744 separately after all. If function was declared inline,
1745 give a warning. */
1748 {
1751 }
1754 }
1756 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1757 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1758 bytes, then we would need to push some additional bytes to pad the
1759 arguments. So, we compute an adjust to the stack pointer for an
1760 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1761 bytes. Then, when the arguments are pushed the stack will be perfectly
1762 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1763 be popped after the call. Returns the adjustment. */
1765 static int
1769 {
1770 /* The number of bytes to pop so that the stack will be
1771 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1772 HOST_WIDE_INT adjustment;
1773 /* The alignment of the stack after the arguments are pushed, if we
1774 just pushed the arguments without adjust the stack here. */
1775 HOST_WIDE_INT unadjusted_alignment;
1777 unadjusted_alignment
1781 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1782 as possible -- leaving just enough left to cancel out the
1783 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1784 PENDING_STACK_ADJUST is non-negative, and congruent to
1785 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1787 /* Begin by trying to pop all the bytes. */
1788 unadjusted_alignment
1789 = (unadjusted_alignment
1792 /* Push enough additional bytes that the stack will be aligned
1793 after the arguments are pushed. */
1795 {
1798 else
1800 }
1802 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1803 bytes after the call. The right number is the entire
1804 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1805 by the arguments in the first place. */
1806 args_size->constant
1810 }
1812 /* Scan X expression if it does not dereference any argument slots
1813 we already clobbered by tail call arguments (as noted in stored_args_map
1814 bitmap).
1815 Return nonzero if X expression dereferences such argument slots,
1816 zero otherwise. */
1818 static int
1820 {
1821 RTX_CODE code;
1832 {
1837 current_function_internal_arg_pointer
1840 else
1843 #ifdef ARGS_GROW_DOWNWARD
1845 #endif
1853 }
1855 /* Scan all subexpressions. */
1858 {
1860 {
1863 }
1865 {
1869 }
1870 }
1872 }
1874 /* Scan sequence after INSN if it does not dereference any argument slots
1875 we already clobbered by tail call arguments (as noted in stored_args_map
1876 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1877 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1878 should be 0). Return nonzero if sequence after INSN dereferences such argument
1879 slots, zero otherwise. */
1881 static int
1883 {
1888 else
1897 {
1898 #ifdef ARGS_GROW_DOWNWARD
1900 #else
1902 #endif
1906 }
1908 }
1910 static tree
1912 {
1914 {
1923 {
1929 }
1934 }
1936 }
1938 /* Generate all the code for a function call
1939 and return an rtx for its value.
1940 Store the value in TARGET (specified as an rtx) if convenient.
1941 If the value is stored in TARGET then TARGET is returned.
1942 If IGNORE is nonzero, then we ignore the value of the function call. */
1944 rtx
1946 {
1947 /* Nonzero if we are currently expanding a call. */
1950 /* List of actual parameters. */
1952 /* RTX for the function to be called. */
1953 rtx funexp;
1954 /* Sequence of insns to perform a tail recursive "call". */
1956 /* Sequence of insns to perform a normal "call". */
1958 /* Sequence of insns to perform a tail recursive "call". */
1960 /* Data type of the function. */
1961 tree funtype;
1962 tree type_arg_types;
1963 /* Declaration of the function being called,
1964 or 0 if the function is computed (not known by name). */
1966 rtx insn;
1971 /* Register in which non-BLKmode value will be returned,
1972 or 0 if no value or if value is BLKmode. */
1973 rtx valreg;
1974 /* Address where we should return a BLKmode value;
1975 0 if value not BLKmode. */
1977 /* Nonzero if that address is being passed by treating it as
1978 an extra, implicit first parameter. Otherwise,
1979 it is passed by being copied directly into struct_value_rtx. */
1981 /* Size of aggregate value wanted, or zero if none wanted
1982 or if we are using the non-reentrant PCC calling convention
1983 or expecting the value in registers. */
1985 /* Nonzero if called function returns an aggregate in memory PCC style,
1986 by returning the address of where to find it. */
1989 /* Number of actual parameters in this call, including struct value addr. */
1991 /* Number of named args. Args after this are anonymous ones
1992 and they must all go on the stack. */
1995 /* Vector of information about each argument.
1996 Arguments are numbered in the order they will be pushed,
1997 not the order they are written. */
2000 /* Total size in bytes of all the stack-parms scanned so far. */
2003 /* Size of arguments before any adjustments (such as rounding). */
2005 /* Data on reg parms scanned so far. */
2006 CUMULATIVE_ARGS args_so_far;
2007 /* Nonzero if a reg parm has been scanned. */
2009 /* Nonzero if this is an indirect function call. */
2011 /* Nonzero if we must avoid push-insns in the args for this call.
2012 If stack space is allocated for register parameters, but not by the
2013 caller, then it is preallocated in the fixed part of the stack frame.
2014 So the entire argument block must then be preallocated (i.e., we
2015 ignore PUSH_ROUNDING in that case). */
2019 /* Size of the stack reserved for parameter registers. */
2022 /* Address of space preallocated for stack parms
2023 (on machines that lack push insns), or 0 if space not preallocated. */
2026 /* Mask of ECF_ flags. */
2028 /* Nonzero if this is a call to an inline function. */
2030 #ifdef REG_PARM_STACK_SPACE
2031 /* Define the boundary of the register parm stack space that needs to be
2032 saved, if any. */
2035 #endif
2042 /* State variables to track stack modifications. */
2048 /* Some stack pointer alterations we make are performed via
2049 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2050 which we then also need to save/restore along the way. */
2053 rtx call_fusage;
2057 /* The alignment of the stack, in bits. */
2058 HOST_WIDE_INT preferred_stack_boundary;
2059 /* The alignment of the stack, in bytes. */
2060 HOST_WIDE_INT preferred_unit_stack_boundary;
2062 /* See if this is "nothrow" function call. */
2066 /* See if we can find a DECL-node for the actual function.
2067 As a result, decide whether this is a call to an integrable function. */
2071 {
2079 {
2080 /* In case this function later becomes inlinable,
2081 record that there was already a non-inline call to it.
2083 Use abstraction instead of setting TREE_ADDRESSABLE
2084 directly. */
2087 {
2090 }
2092 }
2095 }
2097 /* If we don't have specific function to call, see if we have a
2098 attributes set in the type. */
2099 else
2102 /* Warn if this value is an aggregate type,
2103 regardless of which calling convention we are using for it. */
2107 /* If the result of a pure or const function call is ignored (or void),
2108 and none of its arguments are volatile, we can avoid expanding the
2109 call and just evaluate the arguments for side-effects. */
2113 {
2115 tree arg;
2119 {
2122 }
2125 {
2130 }
2131 }
2133 #ifdef REG_PARM_STACK_SPACE
2134 #ifdef MAYBE_REG_PARM_STACK_SPACE
2136 #else
2138 #endif
2139 #endif
2141 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2144 #endif
2146 /* Set up a place to return a structure. */
2148 /* Cater to broken compilers. */
2150 {
2151 /* This call returns a big structure. */
2154 #ifdef PCC_STATIC_STRUCT_RETURN
2155 {
2157 /* Easier than making that case work right. */
2159 {
2160 /* In case this is a static function, note that it has been
2161 used. */
2165 }
2166 }
2168 {
2172 {
2173 /* The structure value address arg is already in actparms.
2174 Pull it out. It might be nice to just leave it there, but
2175 we need to set structure_value_addr. */
2180 }
2183 else
2184 {
2185 /* For variable-sized objects, we must be called with a target
2186 specified. If we were to allocate space on the stack here,
2187 we would have no way of knowing when to free it. */
2193 }
2194 }
2196 }
2198 /* If called function is inline, try to integrate it. */
2201 {
2204 structure_value_addr);
2207 }
2209 /* Figure out the amount to which the stack should be aligned. */
2212 {
2216 }
2218 /* Operand 0 is a pointer-to-function; get the type of the function. */
2224 /* Munge the tree to split complex arguments into their imaginary
2225 and real parts. */
2227 {
2230 }
2231 else
2234 /* See if this is a call to a function that can return more than once
2235 or a call to longjmp or malloc. */
2241 /* If struct_value_rtx is 0, it means pass the address
2242 as if it were an extra parameter. */
2244 {
2245 /* If structure_value_addr is a REG other than
2246 virtual_outgoing_args_rtx, we can use always use it. If it
2247 is not a REG, we must always copy it into a register.
2248 If it is virtual_outgoing_args_rtx, we must copy it to another
2249 register in some cases. */
2251 || (ACCUMULATE_OUTGOING_ARGS
2252 && stack_arg_under_construction
2257 actparms
2260 temp),
2261 actparms);
2263 }
2265 /* Count the arguments and set NUM_ACTUALS. */
2267 num_actuals++;
2269 /* Compute number of named args.
2270 Normally, don't include the last named arg if anonymous args follow.
2271 We do include the last named arg if STRICT_ARGUMENT_NAMING is nonzero.
2272 (If no anonymous args follow, the result of list_length is actually
2273 one too large. This is harmless.)
2275 If PRETEND_OUTGOING_VARARGS_NAMED is set and STRICT_ARGUMENT_NAMING is
2276 zero, this machine will be able to place unnamed args that were
2277 passed in registers into the stack. So treat all args as named.
2278 This allows the insns emitting for a specific argument list to be
2279 independent of the function declaration.
2281 If PRETEND_OUTGOING_VARARGS_NAMED is not set, we do not have any
2282 reliable way to pass unnamed args in registers, so we must force
2283 them into memory. */
2288 n_named_args
2290 /* Don't include the last named arg. */
2292 /* Count the struct value address, if it is passed as a parm. */
2294 else
2295 /* If we know nothing, treat all args as named. */
2298 /* Start updating where the next arg would go.
2300 On some machines (such as the PA) indirect calls have a different
2301 calling convention than normal calls. The last argument in
2302 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2303 or not. */
2306 /* Make a vector to hold all the information about each arg. */
2310 /* Build up entries in the ARGS array, compute the size of the
2311 arguments into ARGS_SIZE, etc. */
2319 {
2320 /* If this function requires a variable-sized argument list, don't
2321 try to make a cse'able block for this call. We may be able to
2322 do this eventually, but it is too complicated to keep track of
2323 what insns go in the cse'able block and which don't. */
2327 }
2329 /* Now make final decision about preallocating stack space. */
2334 /* If the structure value address will reference the stack pointer, we
2335 must stabilize it. We don't need to do this if we know that we are
2336 not going to adjust the stack pointer in processing this call. */
2341 structure_value_addr))
2346 /* Tail calls can make things harder to debug, and we're traditionally
2347 pushed these optimizations into -O2. Don't try if we're already
2348 expanding a call, as that means we're an argument. Don't try if
2349 there's cleanups, as we know there's code to follow the call.
2351 If rtx_equal_function_value_matters is false, that means we've
2352 finished with regular parsing. Which means that some of the
2353 machinery we use to generate tail-calls is no longer in place.
2354 This is most often true of sjlj-exceptions, which we couldn't
2355 tail-call to anyway. */
2358 || !flag_optimize_sibling_calls
2359 || !rtx_equal_function_value_matters
2364 /* Tail recursion fails, when we are not dealing with recursive calls. */
2370 /* Rest of purposes for tail call optimizations to fail. */
2372 #ifdef HAVE_sibcall_epilogue
2373 !HAVE_sibcall_epilogue
2374 #else
2375 1
2376 #endif
2377 || !try_tail_call
2378 /* Doing sibling call optimization needs some work, since
2379 structure_value_addr can be allocated on the stack.
2380 It does not seem worth the effort since few optimizable
2381 sibling calls will return a structure. */
2383 /* Check whether the target is able to optimize the call
2384 into a sibcall. */
2386 /* Functions that do not return exactly once may not be sibcall
2387 optimized. */
2390 /* If the called function is nested in the current one, it might access
2391 some of the caller's arguments, but could clobber them beforehand if
2392 the argument areas are shared. */
2394 /* If this function requires more stack slots than the current
2395 function, we cannot change it into a sibling call. */
2397 /* If the callee pops its own arguments, then it must pop exactly
2398 the same number of arguments as the current function. */
2402 current_function_args_size))
2407 {
2410 /* Ok, we're going to give the tail call the old college try.
2411 This means we're going to evaluate the function arguments
2412 up to three times. There are two degrees of badness we can
2413 encounter, those that can be unsaved and those that can't.
2414 (See unsafe_for_reeval commentary for details.)
2416 Generate a new argument list. Pass safe arguments through
2417 unchanged. For the easy badness wrap them in UNSAVE_EXPRs.
2418 For hard badness, evaluate them now and put their resulting
2419 rtx in a temporary VAR_DECL.
2421 initialize_argument_information has ordered the array for the
2422 order to be pushed, and we must remember this when reconstructing
2423 the original argument order. */
2426 {
2430 }
2431 else
2432 {
2436 }
2439 {
2441 /* We need to build actparms for optimize_tail_recursion. We can
2442 safely trash away TREE_PURPOSE, since it is unused by this
2443 function. */
2446 }
2447 /* Do the same for the function address if it is an expression. */
2450 /* Expanding one of those dangerous arguments could have added
2451 cleanups, but otherwise give it a whirl. */
2454 }
2456 /* Generate a tail recursion sequence when calling ourselves. */
2459 {
2460 /* We want to emit any pending stack adjustments before the tail
2461 recursion "call". That way we know any adjustment after the tail
2462 recursion call can be ignored if we indeed use the tail recursion
2463 call expansion. */
2467 /* Emit any queued insns now; otherwise they would end up in
2468 only one of the alternates. */
2471 /* Use a new sequence to hold any RTL we generate. We do not even
2472 know if we will use this RTL yet. The final decision can not be
2473 made until after RTL generation for the entire function is
2474 complete. */
2476 /* If expanding any of the arguments creates cleanups, we can't
2477 do a tailcall. So, we'll need to pop the pending cleanups
2478 list. If, however, all goes well, and there are no cleanups
2479 then the call to expand_start_target_temps will have no
2480 effect. */
2483 {
2486 else
2488 }
2492 /* Restore the original pending stack adjustment for the sibling and
2493 normal call cases below. */
2496 }
2499 {
2500 /* A fork duplicates the profile information, and an exec discards
2501 it. We can't rely on fork/exec to be paired. So write out the
2502 profile information we have gathered so far, and clear it. */
2503 /* ??? When Linux's __clone is called with CLONE_VM set, profiling
2504 is subject to race conditions, just as with multithreaded
2505 programs. */
2508 }
2510 /* Ensure current function's preferred stack boundary is at least
2511 what we need. We don't have to increase alignment for recursive
2512 functions. */
2521 function_call_count++;
2523 /* We want to make two insn chains; one for a sibling call, the other
2524 for a normal call. We will select one of the two chains after
2525 initial RTL generation is complete. */
2527 {
2529 /* We want to emit any pending stack adjustments before the tail
2530 recursion "call". That way we know any adjustment after the tail
2531 recursion call can be ignored if we indeed use the tail recursion
2532 call expansion. */
2535 rtx insns;
2539 {
2540 /* Emit any queued insns now; otherwise they would end up in
2541 only one of the alternates. */
2544 /* State variables we need to save and restore between
2545 iterations. */
2548 }
2551 else
2554 /* Other state variables that we must reinitialize each time
2555 through the loop (that are not initialized by the loop itself). */
2559 /* Start a new sequence for the normal call case.
2561 From this point on, if the sibling call fails, we want to set
2562 sibcall_failure instead of continuing the loop. */
2566 {
2567 /* We know at this point that there are not currently any
2568 pending cleanups. If, however, in the process of evaluating
2569 the arguments we were to create some, we'll need to be
2570 able to get rid of them. */
2572 }
2574 /* Don't let pending stack adjusts add up to too much.
2575 Also, do all pending adjustments now if there is any chance
2576 this might be a call to alloca or if we are expanding a sibling
2577 call sequence or if we are calling a function that is to return
2578 with stack pointer depressed. */
2585 /* When calling a const function, we must pop the stack args right away,
2586 so that the pop is deleted or moved with the call. */
2588 NO_DEFER_POP;
2590 #ifdef FINAL_REG_PARM_STACK_SPACE
2593 #endif
2594 /* Precompute any arguments as needed. */
2598 /* Now we are about to start emitting insns that can be deleted
2599 if a libcall is deleted. */
2604 /* Compute the actual size of the argument block required. The variable
2605 and constant sizes must be combined, the size may have to be rounded,
2606 and there may be a minimum required size. When generating a sibcall
2607 pattern, do not round up, since we'll be re-using whatever space our
2608 caller provided. */
2609 unadjusted_args_size
2617 /* The argument block when performing a sibling call is the
2618 incoming argument block. */
2620 {
2622 argblock
2623 #ifdef STACK_GROWS_DOWNWARD
2625 #else
2627 #endif
2630 }
2632 /* If we have no actual push instructions, or shouldn't use them,
2633 make space for all args right now. */
2635 {
2637 {
2642 /* stack_arg_under_construction says whether a stack arg is
2643 being constructed at the old stack level. Pushing the stack
2644 gets a clean outgoing argument block. */
2647 }
2649 }
2650 else
2651 {
2652 /* Note that we must go through the motions of allocating an argument
2653 block even if the size is zero because we may be storing args
2654 in the area reserved for register arguments, which may be part of
2655 the stack frame. */
2659 /* Store the maximum argument space used. It will be pushed by
2660 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2661 checking). */
2667 {
2669 {
2670 /* Since the stack pointer will never be pushed, it is
2671 possible for the evaluation of a parm to clobber
2672 something we have already written to the stack.
2673 Since most function calls on RISC machines do not use
2674 the stack, this is uncommon, but must work correctly.
2676 Therefore, we save any area of the stack that was already
2677 written and that we are using. Here we set up to do this
2678 by making a new stack usage map from the old one. The
2679 actual save will be done by store_one_arg.
2681 Another approach might be to try to reorder the argument
2682 evaluations to avoid this conflicting stack usage. */
2684 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2685 /* Since we will be writing into the entire argument area,
2686 the map must be allocated for its entire size, not just
2687 the part that is the responsibility of the caller. */
2689 #endif
2691 #ifdef ARGS_GROW_DOWNWARD
2694 #else
2696 needed);
2697 #endif
2698 stack_usage_map
2703 initial_highest_arg_in_use);
2707 (highest_outgoing_arg_in_use
2711 /* The address of the outgoing argument list must not be
2712 copied to a register here, because argblock would be left
2713 pointing to the wrong place after the call to
2714 allocate_dynamic_stack_space below. */
2717 }
2718 else
2719 {
2721 {
2722 /* Try to reuse some or all of the pending_stack_adjust
2723 to get this space. */
2724 needed
2725 = (combine_pending_stack_adjustment_and_call
2728 preferred_unit_stack_boundary));
2730 /* combine_pending_stack_adjustment_and_call computes
2731 an adjustment before the arguments are allocated.
2732 Account for them and see whether or not the stack
2733 needs to go up or down. */
2737 {
2738 /* We're releasing stack space. */
2739 /* ??? We can avoid any adjustment at all if we're
2740 already aligned. FIXME. */
2744 }
2745 else
2746 /* We need to allocate space. We'll do that in
2747 push_block below. */
2749 }
2751 /* Special case this because overhead of `push_block' in
2752 this case is non-trivial. */
2755 else
2756 {
2758 #ifdef ARGS_GROW_DOWNWARD
2760 #endif
2761 }
2763 /* We only really need to call `copy_to_reg' in the case
2764 where push insns are going to be used to pass ARGBLOCK
2765 to a function call in ARGS. In that case, the stack
2766 pointer changes value from the allocation point to the
2767 call point, and hence the value of
2768 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2769 as well always do it. */
2771 }
2772 }
2773 }
2776 {
2777 /* The save/restore code in store_one_arg handles all
2778 cases except one: a constructor call (including a C
2779 function returning a BLKmode struct) to initialize
2780 an argument. */
2782 {
2783 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2786 #else
2788 #endif
2790 {
2792 NULL_RTX);
2796 /* stack_arg_under_construction says whether a stack
2797 arg is being constructed at the old stack level.
2798 Pushing the stack gets a clean outgoing argument
2799 block. */
2800 old_stack_arg_under_construction
2803 /* Make a new map for the new argument list. */
2808 }
2810 BITS_PER_UNIT);
2811 }
2813 /* If argument evaluation might modify the stack pointer,
2814 copy the address of the argument list to a register. */
2817 {
2820 }
2821 }
2825 /* If we push args individually in reverse order, perform stack alignment
2826 before the first push (the last arg). */
2829 {
2830 /* When the stack adjustment is pending, we get better code
2831 by combining the adjustments. */
2835 {
2836 pending_stack_adjust
2837 = (combine_pending_stack_adjustment_and_call
2840 preferred_unit_stack_boundary));
2842 }
2846 }
2847 /* Now that the stack is properly aligned, pops can't safely
2848 be deferred during the evaluation of the arguments. */
2849 NO_DEFER_POP;
2853 /* Figure out the register where the value, if any, will come back. */
2857 {
2861 else
2863 }
2865 /* Precompute all register parameters. It isn't safe to compute anything
2866 once we have started filling any specific hard regs. */
2869 #ifdef REG_PARM_STACK_SPACE
2870 /* Save the fixed argument area if it's part of the caller's frame and
2871 is clobbered by argument setup for this call. */
2875 #endif
2877 /* Now store (and compute if necessary) all non-register parms.
2878 These come before register parms, since they can require block-moves,
2879 which could clobber the registers used for register parms.
2880 Parms which have partial registers are not stored here,
2881 but we do preallocate space here if they want that. */
2885 {
2890 reg_parm_stack_space)
2895 }
2897 /* If we have a parm that is passed in registers but not in memory
2898 and whose alignment does not permit a direct copy into registers,
2899 make a group of pseudos that correspond to each register that we
2900 will later fill. */
2904 /* Now store any partially-in-registers parm.
2905 This is the last place a block-move can happen. */
2909 {
2914 reg_parm_stack_space)
2919 }
2921 /* If we pushed args in forward order, perform stack alignment
2922 after pushing the last arg. */
2927 /* If register arguments require space on the stack and stack space
2928 was not preallocated, allocate stack space here for arguments
2929 passed in registers. */
2930 #ifdef OUTGOING_REG_PARM_STACK_SPACE
2934 #endif
2936 /* Pass the function the address in which to return a
2937 structure value. */
2939 {
2940 #ifdef POINTERS_EXTEND_UNSIGNED
2942 structure_value_addr = convert_memory_address
2944 #endif
2948 NULL_RTX)));
2952 }
2960 /* Perform postincrements before actually calling the function. */
2963 /* Save a pointer to the last insn before the call, so that we can
2964 later safely search backwards to find the CALL_INSN. */
2967 /* Set up next argument register. For sibling calls on machines
2968 with register windows this should be the incoming register. */
2969 #ifdef FUNCTION_INCOMING_ARG
2973 else
2974 #endif
2978 /* All arguments and registers used for the call must be set up by
2979 now! */
2981 /* Stack must be properly aligned now. */
2985 /* Generate the actual call instruction. */
2991 /* If call is cse'able, make appropriate pair of reg-notes around it.
2992 Test valreg so we don't crash; may safely ignore `const'
2993 if return type is void. Disable for PARALLEL return values, because
2994 we have no way to move such values into a pseudo register. */
2996 {
2997 rtx insns;
3000 {
3004 }
3005 else
3006 {
3010 /* Mark the return value as a pointer if needed. */
3015 /* Construct an "equal form" for the value which mentions all the
3016 arguments in order as well as the function name. */
3030 note);
3035 }
3036 }
3038 {
3042 /* The return value from a malloc-like function is a pointer. */
3048 /* The return value from a malloc-like function can not alias
3049 anything else. */
3054 /* Write out the sequence. */
3059 }
3061 /* For calls to `setjmp', etc., inform flow.c it should complain
3062 if nonvolatile values are live. For functions that cannot return,
3063 inform flow that control does not fall through. */
3066 {
3067 /* The barrier must be emitted
3068 immediately after the CALL_INSN. Some ports emit more
3069 than just a CALL_INSN above, so we must search for it here. */
3073 {
3075 /* There was no CALL_INSN? */
3078 }
3082 /* Stack adjustments after a noreturn call are dead code. */
3085 }
3090 /* If value type not void, return an rtx for the value. */
3092 /* If there are cleanups to be called, don't use a hard reg as target.
3093 We need to double check this and see if it matters anymore. */
3095 {
3100 }
3106 {
3108 {
3109 target
3112 structure_value_addr));
3114 }
3115 }
3117 {
3118 /* This is the special C++ case where we need to
3119 know what the true target was. We take care to
3120 never use this value more than once in one expression. */
3124 }
3125 /* Handle calls that return values in multiple non-contiguous locations.
3126 The Irix 6 ABI has examples of this. */
3128 {
3130 {
3131 /* This will only be assigned once, so it can be readonly. */
3138 }
3144 /* We can not support sibling calls for this case. */
3146 }
3150 {
3151 /* TARGET and VALREG cannot be equal at this point because the
3152 latter would not have REG_FUNCTION_VALUE_P true, while the
3153 former would if it were referring to the same register.
3155 If they refer to the same register, this move will be a no-op,
3156 except when function inlining is being done. */
3159 /* If we are setting a MEM, this code must be executed. Since it is
3160 emitted after the call insn, sibcall optimization cannot be
3161 performed in that case. */
3164 }
3166 {
3169 /* We can not support sibling calls for this case. */
3171 }
3172 else
3175 #ifdef PROMOTE_FUNCTION_RETURN
3176 /* If we promoted this return value, make the proper SUBREG. TARGET
3177 might be const0_rtx here, so be careful. */
3181 {
3186 /* If we don't promote as expected, something is wrong. */
3194 {
3201 }
3205 }
3206 #endif
3208 /* If size of args is variable or this was a constructor call for a stack
3209 argument, restore saved stack-pointer value. */
3212 {
3220 }
3222 {
3223 #ifdef REG_PARM_STACK_SPACE
3227 #endif
3229 /* If we saved any argument areas, restore them. */
3232 {
3234 rtx stack_area
3241 else
3244 BLOCK_OP_CALL_PARM);
3245 }
3249 }
3251 /* If this was alloca, record the new stack level for nonlocal gotos.
3252 Check for the handler slots since we might not have a save area
3253 for non-local gotos. */
3258 /* Free up storage we no longer need. */
3264 {
3265 /* Undo the fake expand_start_target_temps we did earlier. If
3266 there had been any cleanups created, we've already set
3267 sibcall_failure. */
3269 }
3271 /* If this function is returning into a memory location marked as
3272 readonly, it means it is initializing that location. We normally treat
3273 functions as not clobbering such locations, so we need to specify that
3274 this one does. We do this by adding the appropriate CLOBBER to the
3275 CALL_INSN function usage list. This cannot be done by emitting a
3276 standalone CLOBBER after the call because the latter would be ignored
3277 by at least the delay slot scheduling pass. We do this now instead of
3278 adding to call_fusage before the call to emit_call_1 because TARGET
3279 may be modified in the meantime. */
3282 add_function_usage_to
3285 NULL_RTX));
3291 {
3294 /* Restore the pending stack adjustment now that we have
3295 finished generating the sibling call sequence. */
3300 /* Prepare arg structure for next iteration. */
3302 {
3306 }
3309 }
3310 else
3311 {
3314 /* Verify that we've deallocated all the stack we used. */
3319 }
3321 /* If something prevents making this a sibling call,
3322 zero out the sequence. */
3325 }
3327 /* The function optimize_sibling_and_tail_recursive_calls doesn't
3328 handle CALL_PLACEHOLDERs inside other CALL_PLACEHOLDERs. This
3329 can happen if the arguments to this function call an inline
3330 function who's expansion contains another CALL_PLACEHOLDER.
3332 If there are any C_Ps in any of these sequences, replace them
3333 with their normal call. */
3350 /* If this was a potential tail recursion site, then emit a
3351 CALL_PLACEHOLDER with the normal and the tail recursion streams.
3352 One of them will be selected later. */
3354 {
3355 /* The tail recursion label must be kept around. We could expose
3356 its use in the CALL_PLACEHOLDER, but that creates unwanted edges
3357 and makes determining true tail recursion sites difficult.
3359 So we set LABEL_PRESERVE_P here, then clear it when we select
3360 one of the call sequences after rtl generation is complete. */
3364 tail_call_insns,
3365 tail_recursion_insns,
3366 tail_recursion_label));
3367 }
3368 else
3371 currently_expanding_call--;
3373 /* If this function returns with the stack pointer depressed, ensure
3374 this block saves and restores the stack pointer, show it was
3375 changed, and adjust for any outgoing arg space. */
3377 {
3382 }
3385 }
3387 /* Traverse an argument list in VALUES and expand all complex
3388 arguments into their components. */
3389 tree
3391 {
3392 tree p;
3397 {
3399 tree complex_type;
3406 {
3407 tree subtype;
3421 /* Skip the newly created node. */
3423 }
3424 }
3427 }
3429 /* Traverse a list of TYPES and expand all complex types into their
3430 components. */
3431 tree
3433 {
3434 tree p;
3439 {
3443 {
3446 /* Rewrite complex type with component type. */
3450 /* Add another component type for the imaginary part. */
3455 /* Skip the newly created node. */
3457 }
3458 }
3461 }
3462 \f
3463 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3464 The RETVAL parameter specifies whether return value needs to be saved, other
3465 parameters are documented in the emit_library_call function below. */
3467 static rtx
3471 {
3472 /* Total size in bytes of all the stack-parms scanned so far. */
3474 /* Size of arguments before any adjustments (such as rounding). */
3477 rtx fun;
3481 CUMULATIVE_ARGS args_so_far;
3482 struct arg
3483 {
3484 rtx value;
3486 rtx reg;
3489 rtx save_area;
3490 };
3495 rtx valreg;
3501 rtx before_call;
3504 #ifdef REG_PARM_STACK_SPACE
3505 /* Define the boundary of the register parm stack space that needs to be
3506 save, if any. */
3509 #endif
3511 /* Size of the stack reserved for parameter registers. */
3515 #ifdef REG_PARM_STACK_SPACE
3516 #ifdef MAYBE_REG_PARM_STACK_SPACE
3518 #else
3520 #endif
3521 #endif
3523 /* By default, library functions can not throw. */
3527 {
3554 }
3557 /* Ensure current function's preferred stack boundary is at least
3558 what we need. */
3562 /* If this kind of value comes back in memory,
3563 decide where in memory it should come back. */
3565 {
3568 {
3569 #ifdef PCC_STATIC_STRUCT_RETURN
3570 rtx pointer_reg
3580 else
3582 #endif
3583 /* This call returns a big structure. */
3585 }
3586 }
3587 else
3590 /* ??? Unfinished: must pass the memory address as an argument. */
3592 /* Copy all the libcall-arguments out of the varargs data
3593 and into a vector ARGVEC.
3595 Compute how to pass each argument. We only support a very small subset
3596 of the full argument passing conventions to limit complexity here since
3597 library functions shouldn't have many args. */
3602 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3604 #else
3606 #endif
3613 /* Now we are about to start emitting insns that can be deleted
3614 if a libcall is deleted. */
3620 /* If there's a structure value address to be passed,
3621 either pass it in the special place, or pass it as an extra argument. */
3623 {
3625 nargs++;
3627 /* Make sure it is a reasonable operand for a move or push insn. */
3637 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3640 #endif
3643 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3645 #else
3647 #endif
3656 count++;
3657 }
3660 {
3664 /* We cannot convert the arg value to the mode the library wants here;
3665 must do it earlier where we know the signedness of the arg. */
3670 /* On some machines, there's no way to pass a float to a library fcn.
3671 Pass it as a double instead. */
3672 #ifdef LIBGCC_NEEDS_DOUBLE
3675 #endif
3677 /* There's no need to call protect_from_queue, because
3678 either emit_move_insn or emit_push_insn will do that. */
3680 /* Make sure it is a reasonable operand for a move or push insn. */
3685 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
3687 {
3688 rtx slot;
3690 #ifdef FUNCTION_ARG_CALLEE_COPIES
3693 #endif
3694 ;
3696 /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure
3697 functions, so we have to pretend this isn't such a function. */
3699 {
3703 }
3706 /* If this was a CONST function, it is now PURE since
3707 it now reads memory. */
3709 {
3712 }
3717 {
3721 }
3722 else
3723 {
3726 slot
3732 }
3736 call_fusage);
3740 slot),
3741 call_fusage);
3745 }
3746 #endif
3753 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3756 #else
3758 #endif
3761 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3763 #else
3765 #endif
3777 }
3779 #ifdef FINAL_REG_PARM_STACK_SPACE
3782 #endif
3783 /* If this machine requires an external definition for library
3784 functions, write one out. */
3789 + stack_pointer_delta
3791 / STACK_BYTES
3796 reg_parm_stack_space);
3798 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3800 #endif
3806 {
3807 /* Since the stack pointer will never be pushed, it is possible for
3808 the evaluation of a parm to clobber something we have already
3809 written to the stack. Since most function calls on RISC machines
3810 do not use the stack, this is uncommon, but must work correctly.
3812 Therefore, we save any area of the stack that was already written
3813 and that we are using. Here we set up to do this by making a new
3814 stack usage map from the old one.
3816 Another approach might be to try to reorder the argument
3817 evaluations to avoid this conflicting stack usage. */
3821 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3822 /* Since we will be writing into the entire argument area, the
3823 map must be allocated for its entire size, not just the part that
3824 is the responsibility of the caller. */
3826 #endif
3828 #ifdef ARGS_GROW_DOWNWARD
3831 #else
3833 needed);
3834 #endif
3839 initial_highest_arg_in_use);
3846 /* We must be careful to use virtual regs before they're instantiated,
3847 and real regs afterwards. Loop optimization, for example, can create
3848 new libcalls after we've instantiated the virtual regs, and if we
3849 use virtuals anyway, they won't match the rtl patterns. */
3853 else
3855 }
3856 else
3857 {
3860 }
3862 /* If we push args individually in reverse order, perform stack alignment
3863 before the first push (the last arg). */
3869 {
3872 }
3873 else
3874 {
3877 }
3879 #ifdef REG_PARM_STACK_SPACE
3881 {
3882 /* The argument list is the property of the called routine and it
3883 may clobber it. If the fixed area has been used for previous
3884 parameters, we must save and restore it. */
3887 }
3888 #endif
3890 /* Push the args that need to be pushed. */
3892 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3893 are to be pushed. */
3895 {
3903 {
3905 {
3906 /* If this is being stored into a pre-allocated, fixed-size,
3907 stack area, save any previous data at that location. */
3909 #ifdef ARGS_GROW_DOWNWARD
3910 /* stack_slot is negative, but we want to index stack_usage_map
3911 with positive values. */
3914 #else
3917 #endif
3920 /* Don't worry about things in the fixed argument area;
3921 it has already been saved. */
3925 i++;
3928 {
3929 /* We need to make a save area. */
3930 unsigned int size
3932 enum machine_mode save_mode
3934 rtx adr
3937 rtx stack_area
3942 }
3943 }
3948 reg_parm_stack_space,
3951 /* Now mark the segment we just used. */
3956 NO_DEFER_POP;
3957 }
3958 }
3960 /* If we pushed args in forward order, perform stack alignment
3961 after pushing the last arg. */
3968 else
3973 /* Now load any reg parms into their regs. */
3975 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3976 are to be pushed. */
3978 {
3983 /* Handle calls that pass values in multiple non-contiguous
3984 locations. The PA64 has examples of this for library calls. */
3990 NO_DEFER_POP;
3991 }
3993 /* Any regs containing parms remain in use through the call. */
3995 {
4001 }
4003 /* Pass the function the address in which to return a structure value. */
4005 {
4009 NULL_RTX)));
4012 }
4014 /* Don't allow popping to be deferred, since then
4015 cse'ing of library calls could delete a call and leave the pop. */
4016 NO_DEFER_POP;
4020 /* Stack must be properly aligned now. */
4026 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
4027 will set inhibit_defer_pop to that value. */
4028 /* The return type is needed to decide how many bytes the function pops.
4029 Signedness plays no role in that, so for simplicity, we pretend it's
4030 always signed. We also assume that the list of arguments passed has
4031 no impact, so we pretend it is unknown. */
4037 struct_value_size,
4039 valreg,
4042 /* For calls to `setjmp', etc., inform flow.c it should complain
4043 if nonvolatile values are live. For functions that cannot return,
4044 inform flow that control does not fall through. */
4047 {
4048 /* The barrier note must be emitted
4049 immediately after the CALL_INSN. Some ports emit more than
4050 just a CALL_INSN above, so we must search for it here. */
4054 {
4056 /* There was no CALL_INSN? */
4059 }
4062 }
4064 /* Now restore inhibit_defer_pop to its actual original value. */
4065 OK_DEFER_POP;
4067 /* If call is cse'able, make appropriate pair of reg-notes around it.
4068 Test valreg so we don't crash; may safely ignore `const'
4069 if return type is void. Disable for PARALLEL return values, because
4070 we have no way to move such values into a pseudo register. */
4072 {
4073 rtx insns;
4076 {
4080 }
4081 else
4082 {
4084 rtx temp;
4088 {
4092 }
4096 /* Construct an "equal form" for the value which mentions all the
4097 arguments in order as well as the function name. */
4110 note);
4115 }
4116 }
4119 /* Copy the value to the right place. */
4121 {
4123 {
4128 }
4130 {
4134 }
4137 else
4139 }
4142 {
4143 #ifdef REG_PARM_STACK_SPACE
4147 #endif
4149 /* If we saved any argument areas, restore them. */
4152 {
4160 }
4164 }
4168 }
4169 \f
4170 /* Output a library call to function FUN (a SYMBOL_REF rtx)
4171 (emitting the queue unless NO_QUEUE is nonzero),
4172 for a value of mode OUTMODE,
4173 with NARGS different arguments, passed as alternating rtx values
4174 and machine_modes to convert them to.
4175 The rtx values should have been passed through protect_from_queue already.
4177 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const'
4178 calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls
4179 which should be enclosed in REG_LIBCALL/REG_RETVAL notes,
4180 LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in
4181 REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)),
4182 or other LCT_ value for other types of library calls. */
4184 void
4187 {
4193 }
4194 \f
4195 /* Like emit_library_call except that an extra argument, VALUE,
4196 comes second and says where to store the result.
4197 (If VALUE is zero, this function chooses a convenient way
4198 to return the value.
4200 This function returns an rtx for where the value is to be found.
4201 If VALUE is nonzero, VALUE is returned. */
4203 rtx
4207 {
4208 rtx result;
4217 }
4218 \f
4219 /* Store a single argument for a function call
4220 into the register or memory area where it must be passed.
4221 *ARG describes the argument value and where to pass it.
4223 ARGBLOCK is the address of the stack-block for all the arguments,
4224 or 0 on a machine where arguments are pushed individually.
4226 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4227 so must be careful about how the stack is used.
4229 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4230 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4231 that we need not worry about saving and restoring the stack.
4233 FNDECL is the declaration of the function we are calling.
4235 Return nonzero if this arg should cause sibcall failure,
4236 zero otherwise. */
4238 static int
4241 {
4252 /* Push a new temporary level for any temporaries we make for
4253 this argument. */
4257 {
4258 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4259 save any previous data at that location. */
4261 {
4262 #ifdef ARGS_GROW_DOWNWARD
4263 /* stack_slot is negative, but we want to index stack_usage_map
4264 with positive values. */
4267 else
4271 #else
4274 else
4278 #endif
4281 /* Don't worry about things in the fixed argument area;
4282 it has already been saved. */
4286 i++;
4289 {
4290 /* We need to make a save area. */
4297 {
4306 BLOCK_OP_CALL_PARM);
4307 }
4308 else
4309 {
4312 }
4313 }
4314 }
4315 }
4317 /* If this isn't going to be placed on both the stack and in registers,
4318 set up the register and number of words. */
4320 {
4323 else
4326 }
4329 /* Being passed entirely in a register. We shouldn't be called in
4330 this case. */
4333 /* If this arg needs special alignment, don't load the registers
4334 here. */
4338 /* If this is being passed partially in a register, we can't evaluate
4339 it directly into its stack slot. Otherwise, we can. */
4341 {
4342 /* stack_arg_under_construction is nonzero if a function argument is
4343 being evaluated directly into the outgoing argument list and
4344 expand_call must take special action to preserve the argument list
4345 if it is called recursively.
4347 For scalar function arguments stack_usage_map is sufficient to
4348 determine which stack slots must be saved and restored. Scalar
4349 arguments in general have pass_on_stack == 0.
4351 If this argument is initialized by a function which takes the
4352 address of the argument (a C++ constructor or a C function
4353 returning a BLKmode structure), then stack_usage_map is
4354 insufficient and expand_call must push the stack around the
4355 function call. Such arguments have pass_on_stack == 1.
4357 Note that it is always safe to set stack_arg_under_construction,
4358 but this generates suboptimal code if set when not needed. */
4361 stack_arg_under_construction++;
4364 (partial
4369 /* If we are promoting object (or for any other reason) the mode
4370 doesn't agree, convert the mode. */
4377 stack_arg_under_construction--;
4378 }
4380 /* Don't allow anything left on stack from computation
4381 of argument to alloca. */
4386 /* If the value is already in the stack slot, we are done. */
4387 ;
4389 {
4392 /* Argument is a scalar, not entirely passed in registers.
4393 (If part is passed in registers, arg->partial says how much
4394 and emit_push_insn will take care of putting it there.)
4396 Push it, and if its size is less than the
4397 amount of space allocated to it,
4398 also bump stack pointer by the additional space.
4399 Note that in C the default argument promotions
4400 will prevent such mismatches. */
4403 /* Compute how much space the push instruction will push.
4404 On many machines, pushing a byte will advance the stack
4405 pointer by a halfword. */
4406 #ifdef PUSH_ROUNDING
4408 #endif
4411 /* Compute how much space the argument should get:
4412 round up to a multiple of the alignment for arguments. */
4418 /* This isn't already where we want it on the stack, so put it there.
4419 This can either be done with push or copy insns. */
4425 /* Unless this is a partially-in-register argument, the argument is now
4426 in the stack. */
4429 }
4430 else
4431 {
4432 /* BLKmode, at least partly to be pushed. */
4436 rtx size_rtx;
4438 /* Pushing a nonscalar.
4439 If part is passed in registers, PARTIAL says how much
4440 and emit_push_insn will take care of putting it there. */
4442 /* Round its size up to a multiple
4443 of the allocation unit for arguments. */
4446 {
4449 }
4450 else
4451 {
4452 /* PUSH_ROUNDING has no effect on us, because
4453 emit_push_insn for BLKmode is careful to avoid it. */
4459 }
4461 /* Some types will require stricter alignment, which will be
4462 provided for elsewhere in argument layout. */
4465 /* When an argument is padded down, the block is aligned to
4466 PARM_BOUNDARY, but the actual argument isn't. */
4468 {
4472 {
4475 }
4476 }
4479 {
4480 /* emit_push_insn might not work properly if arg->value and
4481 argblock + arg->locate.offset areas overlap. */
4488 current_function_internal_arg_pointer
4490 {
4494 /* expand_call should ensure this */
4499 {
4502 }
4504 {
4507 }
4508 }
4509 }
4516 /* Unless this is a partially-in-register argument, the argument is now
4517 in the stack.
4519 ??? Unlike the case above, in which we want the actual
4520 address of the data, so that we can load it directly into a
4521 register, here we want the address of the stack slot, so that
4522 it's properly aligned for word-by-word copying or something
4523 like that. It's not clear that this is always correct. */
4526 }
4528 /* Mark all slots this store used. */
4534 /* Once we have pushed something, pops can't safely
4535 be deferred during the rest of the arguments. */
4536 NO_DEFER_POP;
4538 /* ANSI doesn't require a sequence point here,
4539 but PCC has one, so this will avoid some problems. */
4542 /* Free any temporary slots made in processing this argument. Show
4543 that we might have taken the address of something and pushed that
4544 as an operand. */
4550 }
4552 /* Nonzero if we do not know how to pass TYPE solely in registers.
4553 We cannot do so in the following cases:
4555 - if the type has variable size
4556 - if the type is marked as addressable (it is required to be constructed
4557 into the stack)
4558 - if the padding and mode of the type is such that a copy into a register
4559 would put it into the wrong part of the register.
4561 Which padding can't be supported depends on the byte endianness.
4563 A value in a register is implicitly padded at the most significant end.
4564 On a big-endian machine, that is the lower end in memory.
4565 So a value padded in memory at the upper end can't go in a register.
4566 For a little-endian machine, the reverse is true. */
4568 bool
4570 {
4574 /* If the type has variable size... */
4578 /* If the type is marked as addressable (it is required
4579 to be constructed into the stack)... */
4583 /* If the padding and mode of the type is such that a copy into
4584 a register would put it into the wrong part of the register. */
4592 }