| blob | 1eb4ec7549f1b45bf03ed0bd81213012af41deef |
1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989-2015 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
53 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
54 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
56 /* Data structure and subroutines used within expand_call. */
58 struct arg_data
59 {
60 /* Tree node for this argument. */
61 tree tree_value;
62 /* Mode for value; TYPE_MODE unless promoted. */
63 machine_mode mode;
64 /* Current RTL value for argument, or 0 if it isn't precomputed. */
65 rtx value;
66 /* Initially-compute RTL value for argument; only for const functions. */
67 rtx initial_value;
68 /* Register to pass this argument in, 0 if passed on stack, or an
69 PARALLEL if the arg is to be copied into multiple non-contiguous
70 registers. */
71 rtx reg;
72 /* Register to pass this argument in when generating tail call sequence.
73 This is not the same register as for normal calls on machines with
74 register windows. */
75 rtx tail_call_reg;
76 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
77 form for emit_group_move. */
78 rtx parallel_value;
79 /* If value is passed in neither reg nor stack, this field holds a number
80 of a special slot to be used. */
81 rtx special_slot;
82 /* For pointer bounds hold an index of parm bounds are bound to. -1 if
83 there is no such pointer. */
85 /* If pointer_arg refers a structure, then pointer_offset holds an offset
86 of a pointer in this structure. */
88 /* If REG was promoted from the actual mode of the argument expression,
89 indicates whether the promotion is sign- or zero-extended. */
91 /* Number of bytes to put in registers. 0 means put the whole arg
92 in registers. Also 0 if not passed in registers. */
94 /* Nonzero if argument must be passed on stack.
95 Note that some arguments may be passed on the stack
96 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
97 pass_on_stack identifies arguments that *cannot* go in registers. */
99 /* Some fields packaged up for locate_and_pad_parm. */
101 /* Location on the stack at which parameter should be stored. The store
102 has already been done if STACK == VALUE. */
103 rtx stack;
104 /* Location on the stack of the start of this argument slot. This can
105 differ from STACK if this arg pads downward. This location is known
106 to be aligned to TARGET_FUNCTION_ARG_BOUNDARY. */
107 rtx stack_slot;
108 /* Place that this stack area has been saved, if needed. */
109 rtx save_area;
110 /* If an argument's alignment does not permit direct copying into registers,
111 copy in smaller-sized pieces into pseudos. These are stored in a
112 block pointed to by this field. The next field says how many
113 word-sized pseudos we made. */
116 };
118 /* A vector of one char per byte of stack space. A byte if nonzero if
119 the corresponding stack location has been used.
120 This vector is used to prevent a function call within an argument from
121 clobbering any stack already set up. */
124 /* Size of STACK_USAGE_MAP. */
127 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
128 stack location's tail call argument has been already stored into the stack.
129 This bitmap is used to prevent sibling call optimization if function tries
130 to use parent's incoming argument slots when they have been already
131 overwritten with tail call arguments. */
134 /* stack_arg_under_construction is nonzero when an argument may be
135 initialized with a constructor call (including a C function that
136 returns a BLKmode struct) and expand_call must take special action
137 to make sure the object being constructed does not overlap the
138 argument list for the constructor call. */
143 cumulative_args_t);
172 #ifdef REG_PARM_STACK_SPACE
175 #endif
176 \f
177 /* Force FUNEXP into a form suitable for the address of a CALL,
178 and return that as an rtx. Also load the static chain register
179 if FNDECL is a nested function.
181 CALL_FUSAGE points to a variable holding the prospective
182 CALL_INSN_FUNCTION_USAGE information. */
184 rtx
187 {
188 /* Make a valid memory address and copy constants through pseudo-regs,
189 but not for a constant address if -fno-function-cse. */
191 /* If we are using registers for parameters, force the
192 function address into a register now. */
193 funexp = ((reg_parm_seen
198 {
201 }
206 {
207 rtx chain;
215 }
218 }
220 /* Generate instructions to call function FUNEXP,
221 and optionally pop the results.
222 The CALL_INSN is the first insn generated.
224 FNDECL is the declaration node of the function. This is given to the
225 hook TARGET_RETURN_POPS_ARGS to determine whether this function pops
226 its own args.
228 FUNTYPE is the data type of the function. This is given to the hook
229 TARGET_RETURN_POPS_ARGS to determine whether this function pops its
230 own args. We used to allow an identifier for library functions, but
231 that doesn't work when the return type is an aggregate type and the
232 calling convention says that the pointer to this aggregate is to be
233 popped by the callee.
235 STACK_SIZE is the number of bytes of arguments on the stack,
236 ROUNDED_STACK_SIZE is that number rounded up to
237 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
238 both to put into the call insn and to generate explicit popping
239 code if necessary.
241 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
242 It is zero if this call doesn't want a structure value.
244 NEXT_ARG_REG is the rtx that results from executing
245 targetm.calls.function_arg (&args_so_far, VOIDmode, void_type_node, true)
246 just after all the args have had their registers assigned.
247 This could be whatever you like, but normally it is the first
248 arg-register beyond those used for args in this call,
249 or 0 if all the arg-registers are used in this call.
250 It is passed on to `gen_call' so you can put this info in the call insn.
252 VALREG is a hard register in which a value is returned,
253 or 0 if the call does not return a value.
255 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
256 the args to this call were processed.
257 We restore `inhibit_defer_pop' to that value.
259 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
260 denote registers used by the called function. */
262 static void
264 tree funtype ATTRIBUTE_UNUSED,
265 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
266 HOST_WIDE_INT rounded_stack_size,
267 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
270 cumulative_args_t args_so_far ATTRIBUTE_UNUSED)
271 {
275 HOST_WIDE_INT n_popped
278 #ifdef CALL_POPS_ARGS
280 #endif
282 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
283 and we don't want to load it into a register as an optimization,
284 because prepare_call_address already did it if it should be done. */
290 {
293 /* Although a built-in FUNCTION_DECL and its non-__builtin
294 counterpart compare equal and get a shared mem_attrs, they
295 produce different dump output in compare-debug compilations,
296 if an entry gets garbage collected in one compilation, then
297 adds a different (but equivalent) entry, while the other
298 doesn't run the garbage collector at the same spot and then
299 shares the mem_attr with the equivalent entry. */
301 {
305 }
308 }
313 {
316 rounded_stack_size_rtx,
318 else
321 }
322 /* If the target has "call" or "call_value" insns, then prefer them
323 if no arguments are actually popped. If the target does not have
324 "call" or "call_value" insns, then we must use the popping versions
325 even if the call has no arguments to pop. */
327 || !(valreg
330 {
333 /* If this subroutine pops its own args, record that in the call insn
334 if possible, for the sake of frame pointer elimination. */
338 rounded_stack_size_rtx,
340 else
345 }
346 else
347 {
351 else
354 }
357 /* Find the call we just emitted. */
360 /* Some target create a fresh MEM instead of reusing the one provided
361 above. Set its MEM_EXPR. */
368 /* Mark instrumented calls. */
372 /* Put the register usage information there. */
375 /* If this is a const call, then set the insn's unchanging bit. */
379 /* If this is a pure call, then set the insn's unchanging bit. */
383 /* If this is a const call, then set the insn's unchanging bit. */
387 /* Create a nothrow REG_EH_REGION note, if needed. */
394 {
397 }
401 /* Restore this now, so that we do defer pops for this call's args
402 if the context of the call as a whole permits. */
406 {
418 /* If popup is needed, stack realign must use DRAP */
421 }
422 /* For noreturn calls when not accumulating outgoing args force
423 REG_ARGS_SIZE note to prevent crossjumping of calls with different
424 args sizes. */
429 {
430 /* If returning from the subroutine does not automatically pop the args,
431 we need an instruction to pop them sooner or later.
432 Perhaps do it now; perhaps just record how much space to pop later.
434 If returning from the subroutine does pop the args, indicate that the
435 stack pointer will be changed. */
438 {
440 /* Just pretend we did the pop. */
445 else
447 }
448 }
449 /* When we accumulate outgoing args, we must avoid any stack manipulations.
450 Restore the stack pointer to its original value now. Usually
451 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
452 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
453 popping variants of functions exist as well.
455 ??? We may optimize similar to defer_pop above, but it is
456 probably not worthwhile.
458 ??? It will be worthwhile to enable combine_stack_adjustments even for
459 such machines. */
462 }
464 /* Determine if the function identified by NAME and FNDECL is one with
465 special properties we wish to know about.
467 For example, if the function might return more than one time (setjmp), then
468 set RETURNS_TWICE to a nonzero value.
470 Similarly set NORETURN if the function is in the longjmp family.
472 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
473 space from the stack such as alloca. */
475 static int
477 {
480 /* For instrumentation clones we want to derive flags
481 from the original name. */
488 /* Exclude functions not at the file scope, or not `extern',
489 since they are not the magic functions we would otherwise
490 think they are.
491 FIXME: this should be handled with attributes, not with this
492 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
493 because you can declare fork() inside a function if you
494 wish. */
498 {
502 /* We assume that alloca will always be called by name. It
503 makes no sense to pass it as a pointer-to-function to
504 anything that does not understand its behavior. */
510 /* Disregard prefix _, __, __x or __builtin_. */
512 {
521 else
523 }
526 {
539 }
551 }
555 {
562 }
565 }
567 /* Similar to special_function_p; return a set of ERF_ flags for the
568 function FNDECL. */
569 static int
571 {
572 tree attr;
586 {
599 }
600 }
602 /* Return nonzero when FNDECL represents a call to setjmp. */
604 int
606 {
610 }
613 /* Return true if STMT is an alloca call. */
615 bool
617 {
618 tree fndecl;
628 }
630 /* Return true when exp contains alloca call. */
632 bool
634 {
635 tree fndecl;
641 }
643 /* Return TRUE if FNDECL is either a TM builtin or a TM cloned
644 function. Return FALSE otherwise. */
646 static bool
648 {
656 {
658 {
701 }
702 }
704 }
706 /* Detect flags (function attributes) from the function decl or type node. */
708 int
710 {
714 {
715 /* The function exp may have the `malloc' attribute. */
719 /* The function exp may have the `returns_twice' attribute. */
723 /* Process the pure and const attributes. */
740 {
747 }
750 }
752 {
760 }
761 else
765 {
769 }
772 }
774 /* Detect flags from a CALL_EXPR. */
776 int
778 {
786 else
787 {
791 else
793 }
796 }
798 /* Return true if TYPE should be passed by invisible reference. */
800 bool
803 {
805 {
806 /* If this type contains non-trivial constructors, then it is
807 forbidden for the middle-end to create any new copies. */
811 /* GCC post 3.4 passes *all* variable sized types by reference. */
815 /* If a record type should be passed the same as its first (and only)
816 member, use the type and mode of that member. */
818 {
821 }
822 }
826 }
828 /* Return true if TYPE, which is passed by reference, should be callee
829 copied instead of caller copied. */
831 bool
834 {
838 named_arg);
839 }
842 /* Precompute all register parameters as described by ARGS, storing values
843 into fields within the ARGS array.
845 NUM_ACTUALS indicates the total number elements in the ARGS array.
847 Set REG_PARM_SEEN if we encounter a register parameter. */
849 static void
852 {
859 {
863 {
868 }
870 /* If we are to promote the function arg to a wider mode,
871 do it now. */
879 /* If the value is a non-legitimate constant, force it into a
880 pseudo now. TLS symbols sometimes need a call to resolve. */
885 /* If we're going to have to load the value by parts, pull the
886 parts into pseudos. The part extraction process can involve
887 non-trivial computation. */
889 {
894 }
896 /* If the value is expensive, and we are inside an appropriately
897 short loop, put the value into a pseudo and then put the pseudo
898 into the hard reg.
900 For small register classes, also do this if this call uses
901 register parameters. This is to avoid reload conflicts while
902 loading the parameters registers. */
911 && ((*reg_parm_seen
915 }
916 }
918 #ifdef REG_PARM_STACK_SPACE
920 /* The argument list is the property of the called routine and it
921 may clobber it. If the fixed area has been used for previous
922 parameters, we must save and restore it. */
924 static rtx
925 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
926 {
930 /* Compute the boundary of the area that needs to be saved, if any. */
940 {
942 machine_mode save_mode;
944 rtx addr;
945 rtx stack_area;
946 rtx save_area;
949 ;
957 /* If we don't have the required alignment, must do this
958 in BLKmode. */
965 else
973 {
977 }
978 else
979 {
982 }
985 }
988 }
990 static void
992 {
999 else
1008 else
1011 BLOCK_OP_CALL_PARM);
1012 }
1015 /* If any elements in ARGS refer to parameters that are to be passed in
1016 registers, but not in memory, and whose alignment does not permit a
1017 direct copy into registers. Copy the values into a group of pseudos
1018 which we will later copy into the appropriate hard registers.
1020 Pseudos for each unaligned argument will be stored into the array
1021 args[argnum].aligned_regs. The caller is responsible for deallocating
1022 the aligned_regs array if it is nonzero. */
1024 static void
1026 {
1036 {
1041 {
1044 }
1045 else
1046 {
1049 }
1053 /* Structures smaller than a word are normally aligned to the
1054 least significant byte. On a BYTES_BIG_ENDIAN machine,
1055 this means we must skip the empty high order bytes when
1056 calculating the bit offset. */
1058 #ifdef BLOCK_REG_PADDING
1062 #else
1063 && BYTES_BIG_ENDIAN
1064 #endif
1065 )
1069 {
1078 /* There is no need to restrict this code to loading items
1079 in TYPE_ALIGN sized hunks. The bitfield instructions can
1080 load up entire word sized registers efficiently.
1082 ??? This may not be needed anymore.
1083 We use to emit a clobber here but that doesn't let later
1084 passes optimize the instructions we emit. By storing 0 into
1085 the register later passes know the first AND to zero out the
1086 bitfield being set in the register is unnecessary. The store
1087 of 0 will be deleted as will at least the first AND. */
1094 }
1095 }
1096 }
1098 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1099 CALL_EXPR EXP.
1101 NUM_ACTUALS is the total number of parameters.
1103 N_NAMED_ARGS is the total number of named arguments.
1105 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
1106 value, or null.
1108 FNDECL is the tree code for the target of this call (if known)
1110 ARGS_SO_FAR holds state needed by the target to know where to place
1111 the next argument.
1113 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1114 for arguments which are passed in registers.
1116 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1117 and may be modified by this routine.
1119 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1120 flags which may be modified by this routine.
1122 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
1123 that requires allocation of stack space.
1125 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
1126 the thunked-to function. */
1128 static void
1135 cumulative_args_t args_so_far,
1140 {
1144 /* Count arg position in order args appear. */
1154 /* In this loop, we consider args in the order they are written.
1155 We fill up ARGS from the back. */
1158 {
1160 call_expr_arg_iterator iter;
1161 tree arg;
1165 {
1167 j--;
1169 /* If we pass structure address then we need to
1170 create bounds for it. Since created bounds is
1171 a call statement, we expand it right here to avoid
1172 fixing all other places where it may be expanded. */
1174 {
1181 j--;
1182 }
1183 }
1185 {
1188 /* Remember last param with pointer and associate it
1189 with following pointer bounds. */
1192 {
1197 {
1200 }
1201 }
1203 {
1204 /* We expect bounds in instrumented calls only.
1205 Otherwise it is a sign we lost flag due to some optimization
1206 and may emit call args incorrectly. */
1209 /* For structures look for the next available pointer. */
1211 {
1218 /* Check we have no more pointers in the structure. */
1221 }
1224 /* Check we covered all pointers in the previous
1225 non bounds arg. */
1228 }
1229 else
1233 && argtype
1236 {
1239 j--;
1241 }
1242 else
1244 j--;
1245 }
1249 }
1253 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1255 {
1258 machine_mode mode;
1260 /* Replace erroneous argument with constant zero. */
1264 /* If TYPE is a transparent union or record, pass things the way
1265 we would pass the first field of the union or record. We have
1266 already verified that the modes are the same. */
1271 /* Decide where to pass this arg.
1273 args[i].reg is nonzero if all or part is passed in registers.
1275 args[i].partial is nonzero if part but not all is passed in registers,
1276 and the exact value says how many bytes are passed in registers.
1278 args[i].pass_on_stack is nonzero if the argument must at least be
1279 computed on the stack. It may then be loaded back into registers
1280 if args[i].reg is nonzero.
1282 These decisions are driven by the FUNCTION_... macros and must agree
1283 with those made by function.c. */
1285 /* See if this argument should be passed by invisible reference. */
1288 {
1292 callee_copies
1296 /* If we're compiling a thunk, pass through invisible references
1297 instead of making a copy. */
1299 || (callee_copies
1304 {
1305 /* We may have turned the parameter value into an SSA name.
1306 Go back to the original parameter so we can take the
1307 address. */
1309 {
1313 }
1314 /* Argument setup code may have copied the value to register. We
1315 revert that optimization now because the tail call code must
1316 use the original location. */
1326 /* We can't use sibcalls if a callee-copied argument is
1327 stored in the current function's frame. */
1337 }
1338 else
1339 {
1340 /* We make a copy of the object and pass the address to the
1341 function being called. */
1342 rtx copy;
1349 {
1350 /* This is a variable-sized object. Make space on the stack
1351 for it. */
1355 {
1359 }
1361 /* We can pass TRUE as the 4th argument because we just
1362 saved the stack pointer and will restore it right after
1363 the call. */
1370 }
1371 else
1376 /* Just change the const function to pure and then let
1377 the next test clear the pure based on
1378 callee_copies. */
1380 {
1383 }
1392 }
1393 }
1406 {
1409 }
1411 /* If this is a sibling call and the machine has register windows, the
1412 register window has to be unwinded before calling the routine, so
1413 arguments have to go into the incoming registers. */
1418 else
1428 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1429 it means that we are to pass this arg in the register(s) designated
1430 by the PARALLEL, but also to pass it in the stack. */
1435 /* If this is an addressable type, we must preallocate the stack
1436 since we must evaluate the object into its final location.
1438 If this is to be passed in both registers and the stack, it is simpler
1439 to preallocate. */
1444 /* No stack allocation and padding for bounds. */
1446 ;
1447 /* Compute the stack-size of this argument. */
1452 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1454 #else
1456 #endif
1457 reg_parm_stack_space,
1460 #ifdef BLOCK_REG_PADDING
1461 else
1462 /* The argument is passed entirely in registers. See at which
1463 end it should be padded. */
1467 #endif
1469 /* Update ARGS_SIZE, the total stack space for args so far. */
1475 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1476 have been used, etc. */
1480 }
1481 }
1483 /* Update ARGS_SIZE to contain the total size for the argument block.
1484 Return the original constant component of the argument block's size.
1486 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1487 for arguments passed in registers. */
1489 static int
1492 tree fndecl ATTRIBUTE_UNUSED,
1493 tree fntype ATTRIBUTE_UNUSED,
1495 {
1498 /* For accumulate outgoing args mode we don't need to align, since the frame
1499 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1500 backends from generating misaligned frame sizes. */
1504 /* Compute the actual size of the argument block required. The variable
1505 and constant sizes must be combined, the size may have to be rounded,
1506 and there may be a minimum required size. */
1509 {
1515 {
1516 /* We don't handle this case yet. To handle it correctly we have
1517 to add the delta, round and subtract the delta.
1518 Currently no machine description requires this support. */
1521 }
1524 {
1525 args_size->var
1529 /* The area corresponding to register parameters is not to count in
1530 the size of the block we need. So make the adjustment. */
1532 args_size->var
1535 }
1536 }
1537 else
1538 {
1543 + stack_pointer_delta
1545 / preferred_stack_boundary
1550 reg_parm_stack_space);
1554 }
1556 }
1558 /* Precompute parameters as needed for a function call.
1560 FLAGS is mask of ECF_* constants.
1562 NUM_ACTUALS is the number of arguments.
1564 ARGS is an array containing information for each argument; this
1565 routine fills in the INITIAL_VALUE and VALUE fields for each
1566 precomputed argument. */
1568 static void
1570 {
1573 /* If this is a libcall, then precompute all arguments so that we do not
1574 get extraneous instructions emitted as part of the libcall sequence. */
1576 /* If we preallocated the stack space, and some arguments must be passed
1577 on the stack, then we must precompute any parameter which contains a
1578 function call which will store arguments on the stack.
1579 Otherwise, evaluating the parameter may clobber previous parameters
1580 which have already been stored into the stack. (we have code to avoid
1581 such case by saving the outgoing stack arguments, but it results in
1582 worse code) */
1587 {
1588 tree type;
1589 machine_mode mode;
1594 /* If this is an addressable type, we cannot pre-evaluate it. */
1603 {
1609 /* CSE will replace this only if it contains args[i].value
1610 pseudo, so convert it down to the declared mode using
1611 a SUBREG. */
1615 {
1620 }
1621 }
1622 }
1623 }
1625 /* Given the current state of MUST_PREALLOCATE and information about
1626 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1627 compute and return the final value for MUST_PREALLOCATE. */
1629 static int
1632 {
1633 /* See if we have or want to preallocate stack space.
1635 If we would have to push a partially-in-regs parm
1636 before other stack parms, preallocate stack space instead.
1638 If the size of some parm is not a multiple of the required stack
1639 alignment, we must preallocate.
1641 If the total size of arguments that would otherwise create a copy in
1642 a temporary (such as a CALL) is more than half the total argument list
1643 size, preallocation is faster.
1645 Another reason to preallocate is if we have a machine (like the m88k)
1646 where stack alignment is required to be maintained between every
1647 pair of insns, not just when the call is made. However, we assume here
1648 that such machines either do not have push insns (and hence preallocation
1649 would occur anyway) or the problem is taken care of with
1650 PUSH_ROUNDING. */
1653 {
1659 {
1664 /* We preallocate in case there are bounds passed
1665 in the bounds table to have precomputed address
1666 for bounds association. */
1676 copy_to_evaluate_size
1678 }
1683 }
1685 }
1687 /* If we preallocated stack space, compute the address of each argument
1688 and store it into the ARGS array.
1690 We need not ensure it is a valid memory address here; it will be
1691 validized when it is used.
1693 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1695 static void
1697 {
1699 {
1707 {
1710 rtx addr;
1715 /* Skip this parm if it will not be passed on the stack. */
1721 /* Pointer Bounds are never passed on the stack. */
1727 else
1733 {
1734 /* Only part of the parameter is being passed on the stack.
1735 Generate a simple memory reference of the correct size. */
1741 }
1742 else
1743 {
1747 }
1753 {
1756 }
1761 else
1767 {
1768 /* Only part of the parameter is being passed on the stack.
1769 Generate a simple memory reference of the correct size.
1770 */
1773 }
1774 else
1775 {
1779 }
1782 /* Function incoming arguments may overlap with sibling call
1783 outgoing arguments and we cannot allow reordering of reads
1784 from function arguments with stores to outgoing arguments
1785 of sibling calls. */
1788 }
1789 }
1790 }
1792 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1793 in a call instruction.
1795 FNDECL is the tree node for the target function. For an indirect call
1796 FNDECL will be NULL_TREE.
1798 ADDR is the operand 0 of CALL_EXPR for this call. */
1800 static rtx
1802 {
1803 rtx funexp;
1805 /* Get the function to call, in the form of RTL. */
1807 {
1811 /* Get a SYMBOL_REF rtx for the function address. */
1813 }
1814 else
1815 /* Generate an rtx (probably a pseudo-register) for the address. */
1816 {
1820 }
1822 }
1824 /* Internal state for internal_arg_pointer_based_exp and its helpers. */
1825 static struct
1826 {
1827 /* Last insn that has been scanned by internal_arg_pointer_based_exp_scan,
1828 or NULL_RTX if none has been scanned yet. */
1830 /* Vector indexed by REGNO - FIRST_PSEUDO_REGISTER, recording if a pseudo is
1831 based on crtl->args.internal_arg_pointer. The element is NULL_RTX if the
1832 pseudo isn't based on it, a CONST_INT offset if the pseudo is based on it
1833 with fixed offset, or PC if this is with variable or unknown offset. */
1839 /* Helper function for internal_arg_pointer_based_exp. Scan insns in
1840 the tail call sequence, starting with first insn that hasn't been
1841 scanned yet, and note for each pseudo on the LHS whether it is based
1842 on crtl->args.internal_arg_pointer or not, and what offset from that
1843 that pointer it has. */
1845 static void
1847 {
1852 else
1856 {
1859 {
1862 /* Punt on pseudos set multiple times. */
1867 else
1870 {
1872 internal_arg_pointer_exp_state.cache
1875 }
1876 }
1880 }
1883 }
1885 /* Compute whether RTL is based on crtl->args.internal_arg_pointer. Return
1886 NULL_RTX if RTL isn't based on it, a CONST_INT offset if RTL is based on
1887 it with fixed offset, or PC if this is with variable or unknown offset.
1888 TOPLEVEL is true if the function is invoked at the topmost level. */
1890 static rtx
1892 {
1903 {
1908 }
1910 /* When called at the topmost level, scan pseudo assignments in between the
1911 last scanned instruction in the tail call sequence and the latest insn
1912 in that sequence. */
1917 {
1923 }
1927 {
1933 }
1936 }
1938 /* Return true if and only if SIZE storage units (usually bytes)
1939 starting from address ADDR overlap with already clobbered argument
1940 area. This function is used to determine if we should give up a
1941 sibcall. */
1943 static bool
1945 {
1946 HOST_WIDE_INT i;
1947 rtx val;
1956 else
1961 else
1969 {
1976 }
1979 }
1981 /* Do the register loads required for any wholly-register parms or any
1982 parms which are passed both on the stack and in a register. Their
1983 expressions were already evaluated.
1985 Mark all register-parms as living through the call, putting these USE
1986 insns in the CALL_INSN_FUNCTION_USAGE field.
1988 When IS_SIBCALL, perform the check_sibcall_argument_overlap
1989 checking, setting *SIBCALL_FAILURE if appropriate. */
1991 static void
1995 {
1999 {
2003 {
2008 /* Set non-negative if we must move a word at a time, even if
2009 just one word (e.g, partial == 4 && mode == DFmode). Set
2010 to -1 if we just use a normal move insn. This value can be
2011 zero if the argument is a zero size structure. */
2014 ;
2016 {
2019 }
2021 {
2024 }
2025 else
2028 /* Handle calls that pass values in multiple non-contiguous
2029 locations. The Irix 6 ABI has examples of this. */
2034 /* If simple case, just do move. If normal partial, store_one_arg
2035 has already loaded the register for us. In all other cases,
2036 load the register(s) from memory. */
2039 {
2041 #ifdef BLOCK_REG_PADDING
2042 /* Handle case where we have a value that needs shifting
2043 up to the msb. eg. a QImode value and we're padding
2044 upward on a BYTES_BIG_ENDIAN machine. */
2048 {
2049 rtx x;
2052 /* Assigning REG here rather than a temp makes CALL_FUSAGE
2053 report the whole reg as used. Strictly speaking, the
2054 call only uses SIZE bytes at the msb end, but it doesn't
2055 seem worth generating rtl to say that. */
2060 }
2061 #endif
2062 }
2064 /* If we have pre-computed the values to put in the registers in
2065 the case of non-aligned structures, copy them in now. */
2073 {
2076 /* Check for overlap with already clobbered argument area,
2077 providing that this has non-zero size. */
2080 || mem_overlaps_already_clobbered_arg_p
2087 else
2088 {
2102 }
2104 /* Handle a BLKmode that needs shifting. */
2106 #ifdef BLOCK_REG_PADDING
2108 #else
2109 && BYTES_BIG_ENDIAN
2110 #endif
2111 )
2112 {
2117 rtx x;
2122 }
2123 }
2125 /* When a parameter is a block, and perhaps in other cases, it is
2126 possible that it did a load from an argument slot that was
2127 already clobbered. */
2132 /* Handle calls that pass values in multiple non-contiguous
2133 locations. The Irix 6 ABI has examples of this. */
2141 }
2142 }
2143 }
2145 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
2146 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
2147 bytes, then we would need to push some additional bytes to pad the
2148 arguments. So, we compute an adjust to the stack pointer for an
2149 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
2150 bytes. Then, when the arguments are pushed the stack will be perfectly
2151 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
2152 be popped after the call. Returns the adjustment. */
2154 static int
2158 {
2159 /* The number of bytes to pop so that the stack will be
2160 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
2161 HOST_WIDE_INT adjustment;
2162 /* The alignment of the stack after the arguments are pushed, if we
2163 just pushed the arguments without adjust the stack here. */
2166 unadjusted_alignment
2170 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
2171 as possible -- leaving just enough left to cancel out the
2172 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
2173 PENDING_STACK_ADJUST is non-negative, and congruent to
2174 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
2176 /* Begin by trying to pop all the bytes. */
2177 unadjusted_alignment
2178 = (unadjusted_alignment
2181 /* Push enough additional bytes that the stack will be aligned
2182 after the arguments are pushed. */
2184 {
2187 else
2189 }
2191 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
2192 bytes after the call. The right number is the entire
2193 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
2194 by the arguments in the first place. */
2195 args_size->constant
2199 }
2201 /* Scan X expression if it does not dereference any argument slots
2202 we already clobbered by tail call arguments (as noted in stored_args_map
2203 bitmap).
2204 Return nonzero if X expression dereferences such argument slots,
2205 zero otherwise. */
2207 static int
2209 {
2210 RTX_CODE code;
2219 /* We need not check the operands of the CALL expression itself. */
2227 /* Scan all subexpressions. */
2230 {
2232 {
2235 }
2237 {
2241 }
2242 }
2244 }
2246 /* Scan sequence after INSN if it does not dereference any argument slots
2247 we already clobbered by tail call arguments (as noted in stored_args_map
2248 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
2249 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
2250 should be 0). Return nonzero if sequence after INSN dereferences such argument
2251 slots, zero otherwise. */
2253 static int
2256 {
2261 else
2270 {
2273 else
2278 }
2280 }
2282 /* Given that a function returns a value of mode MODE at the most
2283 significant end of hard register VALUE, shift VALUE left or right
2284 as specified by LEFT_P. Return true if some action was needed. */
2286 bool
2288 {
2289 HOST_WIDE_INT shift;
2296 /* Use ashr rather than lshr for right shifts. This is for the benefit
2297 of the MIPS port, which requires SImode values to be sign-extended
2298 when stored in 64-bit registers. */
2303 }
2305 /* If X is a likely-spilled register value, copy it to a pseudo
2306 register and return that register. Return X otherwise. */
2308 static rtx
2310 {
2311 rtx new_rtx;
2316 {
2317 /* Make sure that we generate a REG rather than a CONCAT.
2318 Moves into CONCATs can need nontrivial instructions,
2319 and the whole point of this function is to avoid
2320 using the hard register directly in such a situation. */
2326 }
2328 }
2330 /* Generate all the code for a CALL_EXPR exp
2331 and return an rtx for its value.
2332 Store the value in TARGET (specified as an rtx) if convenient.
2333 If the value is stored in TARGET then TARGET is returned.
2334 If IGNORE is nonzero, then we ignore the value of the function call. */
2336 rtx
2338 {
2339 /* Nonzero if we are currently expanding a call. */
2342 /* RTX for the function to be called. */
2343 rtx funexp;
2344 /* Sequence of insns to perform a normal "call". */
2346 /* Sequence of insns to perform a tail "call". */
2348 /* Data type of the function. */
2349 tree funtype;
2350 tree type_arg_types;
2351 tree rettype;
2352 /* Declaration of the function being called,
2353 or 0 if the function is computed (not known by name). */
2355 /* The type of the function being called. */
2356 tree fntype;
2360 /* Register in which non-BLKmode value will be returned,
2361 or 0 if no value or if value is BLKmode. */
2362 rtx valreg;
2363 /* Register(s) in which bounds are returned. */
2365 /* Address where we should return a BLKmode value;
2366 0 if value not BLKmode. */
2368 /* Nonzero if that address is being passed by treating it as
2369 an extra, implicit first parameter. Otherwise,
2370 it is passed by being copied directly into struct_value_rtx. */
2372 /* Holds the value of implicit argument for the struct value. */
2374 /* Size of aggregate value wanted, or zero if none wanted
2375 or if we are using the non-reentrant PCC calling convention
2376 or expecting the value in registers. */
2378 /* Nonzero if called function returns an aggregate in memory PCC style,
2379 by returning the address of where to find it. */
2383 /* Number of actual parameters in this call, including struct value addr. */
2385 /* Number of named args. Args after this are anonymous ones
2386 and they must all go on the stack. */
2388 /* Number of complex actual arguments that need to be split. */
2391 /* Vector of information about each argument.
2392 Arguments are numbered in the order they will be pushed,
2393 not the order they are written. */
2396 /* Total size in bytes of all the stack-parms scanned so far. */
2399 /* Size of arguments before any adjustments (such as rounding). */
2401 /* Data on reg parms scanned so far. */
2402 CUMULATIVE_ARGS args_so_far_v;
2403 cumulative_args_t args_so_far;
2404 /* Nonzero if a reg parm has been scanned. */
2406 /* Nonzero if this is an indirect function call. */
2408 /* Nonzero if we must avoid push-insns in the args for this call.
2409 If stack space is allocated for register parameters, but not by the
2410 caller, then it is preallocated in the fixed part of the stack frame.
2411 So the entire argument block must then be preallocated (i.e., we
2412 ignore PUSH_ROUNDING in that case). */
2416 /* Size of the stack reserved for parameter registers. */
2419 /* Address of space preallocated for stack parms
2420 (on machines that lack push insns), or 0 if space not preallocated. */
2423 /* Mask of ECF_ and ERF_ flags. */
2426 #ifdef REG_PARM_STACK_SPACE
2427 /* Define the boundary of the register parm stack space that needs to be
2428 saved, if any. */
2431 #endif
2439 /* State variables to track stack modifications. */
2445 /* Some stack pointer alterations we make are performed via
2446 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2447 which we then also need to save/restore along the way. */
2450 rtx call_fusage;
2453 /* The alignment of the stack, in bits. */
2455 /* The alignment of the stack, in bytes. */
2457 /* The static chain value to use for this call. */
2458 rtx static_chain_value;
2459 /* See if this is "nothrow" function call. */
2463 /* See if we can find a DECL-node for the actual function, and get the
2464 function attributes (flags) from the function decl or type node. */
2467 {
2471 }
2472 else
2473 {
2476 }
2481 /* Warn if this value is an aggregate type,
2482 regardless of which calling convention we are using for it. */
2486 /* If the result of a non looping pure or const function call is
2487 ignored (or void), and none of its arguments are volatile, we can
2488 avoid expanding the call and just evaluate the arguments for
2489 side-effects. */
2494 {
2496 tree arg;
2497 call_expr_arg_iterator iter;
2501 {
2504 }
2507 {
2511 }
2512 }
2514 #ifdef REG_PARM_STACK_SPACE
2516 #endif
2522 /* Set up a place to return a structure. */
2524 /* Cater to broken compilers. */
2526 {
2527 /* This call returns a big structure. */
2530 #ifdef PCC_STATIC_STRUCT_RETURN
2531 {
2533 }
2535 {
2538 /* Even if it is semantically safe to use the target as the return
2539 slot, it may be not sufficiently aligned for the return type. */
2541 && target
2547 else
2548 {
2549 /* For variable-sized objects, we must be called with a target
2550 specified. If we were to allocate space on the stack here,
2551 we would have no way of knowing when to free it. */
2555 }
2556 }
2558 }
2560 /* Figure out the amount to which the stack should be aligned. */
2563 {
2565 /* Without automatic stack alignment, we can't increase preferred
2566 stack boundary. With automatic stack alignment, it is
2567 unnecessary since unless we can guarantee that all callers will
2568 align the outgoing stack properly, callee has to align its
2569 stack anyway. */
2574 }
2576 /* Operand 0 is a pointer-to-function; get the type of the function. */
2581 /* Count whether there are actual complex arguments that need to be split
2582 into their real and imaginary parts. Munge the type_arg_types
2583 appropriately here as well. */
2585 {
2586 call_expr_arg_iterator iter;
2587 tree arg;
2589 {
2593 num_complex_actuals++;
2594 }
2596 }
2597 else
2603 /* If struct_value_rtx is 0, it means pass the address
2604 as if it were an extra parameter. Put the argument expression
2605 in structure_value_addr_value. */
2607 {
2608 /* If structure_value_addr is a REG other than
2609 virtual_outgoing_args_rtx, we can use always use it. If it
2610 is not a REG, we must always copy it into a register.
2611 If it is virtual_outgoing_args_rtx, we must copy it to another
2612 register in some cases. */
2614 || (ACCUMULATE_OUTGOING_ARGS
2615 && stack_arg_under_construction
2621 structure_value_addr_value =
2624 }
2626 /* Count the arguments and set NUM_ACTUALS. */
2627 num_actuals =
2630 /* Compute number of named args.
2631 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
2634 n_named_args
2636 /* Count the struct value address, if it is passed as a parm. */
2638 else
2639 /* If we know nothing, treat all args as named. */
2642 /* Start updating where the next arg would go.
2644 On some machines (such as the PA) indirect calls have a different
2645 calling convention than normal calls. The fourth argument in
2646 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2647 or not. */
2651 /* Now possibly adjust the number of named args.
2652 Normally, don't include the last named arg if anonymous args follow.
2653 We do include the last named arg if
2654 targetm.calls.strict_argument_naming() returns nonzero.
2655 (If no anonymous args follow, the result of list_length is actually
2656 one too large. This is harmless.)
2658 If targetm.calls.pretend_outgoing_varargs_named() returns
2659 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2660 this machine will be able to place unnamed args that were passed
2661 in registers into the stack. So treat all args as named. This
2662 allows the insns emitting for a specific argument list to be
2663 independent of the function declaration.
2665 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2666 we do not have any reliable way to pass unnamed args in
2667 registers, so we must force them into memory. */
2671 ;
2674 /* Don't include the last named arg. */
2676 else
2677 /* Treat all args as named. */
2680 /* Make a vector to hold all the information about each arg. */
2684 /* Build up entries in the ARGS array, compute the size of the
2685 arguments into ARGS_SIZE, etc. */
2697 /* Now make final decision about preallocating stack space. */
2702 /* If the structure value address will reference the stack pointer, we
2703 must stabilize it. We don't need to do this if we know that we are
2704 not going to adjust the stack pointer in processing this call. */
2709 structure_value_addr))
2714 /* Tail calls can make things harder to debug, and we've traditionally
2715 pushed these optimizations into -O2. Don't try if we're already
2716 expanding a call, as that means we're an argument. Don't try if
2717 there's cleanups, as we know there's code to follow the call. */
2720 || !flag_optimize_sibling_calls
2725 /* Rest of purposes for tail call optimizations to fail. */
2728 /* Doing sibling call optimization needs some work, since
2729 structure_value_addr can be allocated on the stack.
2730 It does not seem worth the effort since few optimizable
2731 sibling calls will return a structure. */
2733 #ifdef REG_PARM_STACK_SPACE
2734 /* If outgoing reg parm stack space changes, we can not do sibcall. */
2738 #endif
2739 /* Check whether the target is able to optimize the call
2740 into a sibcall. */
2742 /* Functions that do not return exactly once may not be sibcall
2743 optimized. */
2746 /* If the called function is nested in the current one, it might access
2747 some of the caller's arguments, but could clobber them beforehand if
2748 the argument areas are shared. */
2750 /* If this function requires more stack slots than the current
2751 function, we cannot change it into a sibling call.
2752 crtl->args.pretend_args_size is not part of the
2753 stack allocated by our caller. */
2756 /* If the callee pops its own arguments, then it must pop exactly
2757 the same number of arguments as the current function. */
2765 /* Check if caller and callee disagree in promotion of function
2766 return value. */
2768 {
2778 caller_promoted_mode
2782 callee_promoted_mode
2794 }
2796 /* Ensure current function's preferred stack boundary is at least
2797 what we need. Stack alignment may also increase preferred stack
2798 boundary. */
2801 else
2806 /* We want to make two insn chains; one for a sibling call, the other
2807 for a normal call. We will select one of the two chains after
2808 initial RTL generation is complete. */
2810 {
2812 /* We want to emit any pending stack adjustments before the tail
2813 recursion "call". That way we know any adjustment after the tail
2814 recursion call can be ignored if we indeed use the tail
2815 call expansion. */
2816 saved_pending_stack_adjust save;
2818 rtx next_arg_reg;
2821 {
2822 /* State variables we need to save and restore between
2823 iterations. */
2825 }
2828 else
2831 /* Other state variables that we must reinitialize each time
2832 through the loop (that are not initialized by the loop itself). */
2836 /* Start a new sequence for the normal call case.
2838 From this point on, if the sibling call fails, we want to set
2839 sibcall_failure instead of continuing the loop. */
2842 /* Don't let pending stack adjusts add up to too much.
2843 Also, do all pending adjustments now if there is any chance
2844 this might be a call to alloca or if we are expanding a sibling
2845 call sequence.
2846 Also do the adjustments before a throwing call, otherwise
2847 exception handling can fail; PR 19225. */
2856 /* Precompute any arguments as needed. */
2860 /* Now we are about to start emitting insns that can be deleted
2861 if a libcall is deleted. */
2869 /* Compute the actual size of the argument block required. The variable
2870 and constant sizes must be combined, the size may have to be rounded,
2871 and there may be a minimum required size. When generating a sibcall
2872 pattern, do not round up, since we'll be re-using whatever space our
2873 caller provided. */
2874 unadjusted_args_size
2883 /* The argument block when performing a sibling call is the
2884 incoming argument block. */
2886 {
2889 argblock
2891 else
2892 argblock
2897 }
2899 /* If we have no actual push instructions, or shouldn't use them,
2900 make space for all args right now. */
2902 {
2904 {
2909 /* stack_arg_under_construction says whether a stack arg is
2910 being constructed at the old stack level. Pushing the stack
2911 gets a clean outgoing argument block. */
2914 }
2918 }
2919 else
2920 {
2921 /* Note that we must go through the motions of allocating an argument
2922 block even if the size is zero because we may be storing args
2923 in the area reserved for register arguments, which may be part of
2924 the stack frame. */
2928 /* Store the maximum argument space used. It will be pushed by
2929 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2930 checking). */
2936 {
2938 {
2939 /* Since the stack pointer will never be pushed, it is
2940 possible for the evaluation of a parm to clobber
2941 something we have already written to the stack.
2942 Since most function calls on RISC machines do not use
2943 the stack, this is uncommon, but must work correctly.
2945 Therefore, we save any area of the stack that was already
2946 written and that we are using. Here we set up to do this
2947 by making a new stack usage map from the old one. The
2948 actual save will be done by store_one_arg.
2950 Another approach might be to try to reorder the argument
2951 evaluations to avoid this conflicting stack usage. */
2953 /* Since we will be writing into the entire argument area,
2954 the map must be allocated for its entire size, not just
2955 the part that is the responsibility of the caller. */
2960 highest_outgoing_arg_in_use
2962 else
2963 highest_outgoing_arg_in_use
2972 initial_highest_arg_in_use);
2976 (highest_outgoing_arg_in_use
2980 /* The address of the outgoing argument list must not be
2981 copied to a register here, because argblock would be left
2982 pointing to the wrong place after the call to
2983 allocate_dynamic_stack_space below. */
2986 }
2987 else
2988 {
2990 {
2991 /* Try to reuse some or all of the pending_stack_adjust
2992 to get this space. */
2993 needed
2994 = (combine_pending_stack_adjustment_and_call
2997 preferred_unit_stack_boundary));
2999 /* combine_pending_stack_adjustment_and_call computes
3000 an adjustment before the arguments are allocated.
3001 Account for them and see whether or not the stack
3002 needs to go up or down. */
3006 {
3007 /* We're releasing stack space. */
3008 /* ??? We can avoid any adjustment at all if we're
3009 already aligned. FIXME. */
3013 }
3014 else
3015 /* We need to allocate space. We'll do that in
3016 push_block below. */
3018 }
3020 /* Special case this because overhead of `push_block' in
3021 this case is non-trivial. */
3024 else
3025 {
3029 }
3031 /* We only really need to call `copy_to_reg' in the case
3032 where push insns are going to be used to pass ARGBLOCK
3033 to a function call in ARGS. In that case, the stack
3034 pointer changes value from the allocation point to the
3035 call point, and hence the value of
3036 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
3037 as well always do it. */
3039 }
3040 }
3041 }
3044 {
3045 /* The save/restore code in store_one_arg handles all
3046 cases except one: a constructor call (including a C
3047 function returning a BLKmode struct) to initialize
3048 an argument. */
3050 {
3051 rtx push_size
3057 {
3062 /* stack_arg_under_construction says whether a stack
3063 arg is being constructed at the old stack level.
3064 Pushing the stack gets a clean outgoing argument
3065 block. */
3066 old_stack_arg_under_construction
3069 /* Make a new map for the new argument list. */
3074 }
3075 /* We can pass TRUE as the 4th argument because we just
3076 saved the stack pointer and will restore it right after
3077 the call. */
3080 }
3082 /* If argument evaluation might modify the stack pointer,
3083 copy the address of the argument list to a register. */
3086 {
3089 }
3090 }
3094 /* Stack is properly aligned, pops can't safely be deferred during
3095 the evaluation of the arguments. */
3096 NO_DEFER_POP;
3098 /* Precompute all register parameters. It isn't safe to compute
3099 anything once we have started filling any specific hard regs.
3100 TLS symbols sometimes need a call to resolve. Precompute
3101 register parameters before any stack pointer manipulation
3102 to avoid unaligned stack in the called function. */
3105 OK_DEFER_POP;
3107 /* Perform stack alignment before the first push (the last arg). */
3111 {
3112 /* When the stack adjustment is pending, we get better code
3113 by combining the adjustments. */
3116 {
3117 pending_stack_adjust
3118 = (combine_pending_stack_adjustment_and_call
3121 preferred_unit_stack_boundary));
3123 }
3127 }
3128 /* Now that the stack is properly aligned, pops can't safely
3129 be deferred during the evaluation of the arguments. */
3130 NO_DEFER_POP;
3132 /* Record the maximum pushed stack space size. We need to delay
3133 doing it this far to take into account the optimization done
3134 by combine_pending_stack_adjustment_and_call. */
3136 && !ACCUMULATE_OUTGOING_ARGS
3137 && pass
3139 {
3143 }
3149 else
3152 #ifdef REG_PARM_STACK_SPACE
3153 /* Save the fixed argument area if it's part of the caller's frame and
3154 is clobbered by argument setup for this call. */
3158 #endif
3160 /* Now store (and compute if necessary) all non-register parms.
3161 These come before register parms, since they can require block-moves,
3162 which could clobber the registers used for register parms.
3163 Parms which have partial registers are not stored here,
3164 but we do preallocate space here if they want that. */
3167 {
3168 /* Delay bounds until all other args are stored. */
3172 {
3175 /* We don't allow passing huge (> 2^30 B) arguments
3176 by value. It would cause an overflow later on. */
3179 {
3182 }
3186 reg_parm_stack_space)
3191 }
3194 call_fusage
3197 call_fusage);
3198 }
3200 /* If we have a parm that is passed in registers but not in memory
3201 and whose alignment does not permit a direct copy into registers,
3202 make a group of pseudos that correspond to each register that we
3203 will later fill. */
3207 /* Now store any partially-in-registers parm.
3208 This is the last place a block-move can happen. */
3212 {
3215 /* On targets with weird calling conventions (e.g. PA) it's
3216 hard to ensure that all cases of argument overlap between
3217 stack and registers work. Play it safe and bail out. */
3219 {
3222 }
3226 reg_parm_stack_space)
3231 }
3236 {
3239 }
3243 /* Figure out the register where the value, if any, will come back. */
3248 {
3250 {
3257 }
3258 else
3259 {
3264 fndecl,
3266 }
3268 /* If VALREG is a PARALLEL whose first member has a zero
3269 offset, use that. This is for targets such as m68k that
3270 return the same value in multiple places. */
3272 {
3279 }
3280 }
3282 /* Store all bounds not passed in registers. */
3284 {
3289 ? NULL
3291 }
3293 /* If register arguments require space on the stack and stack space
3294 was not preallocated, allocate stack space here for arguments
3295 passed in registers. */
3297 && !ACCUMULATE_OUTGOING_ARGS
3301 /* Pass the function the address in which to return a
3302 structure value. */
3304 {
3305 structure_value_addr
3310 NULL_RTX)));
3314 }
3324 /* Save a pointer to the last insn before the call, so that we can
3325 later safely search backwards to find the CALL_INSN. */
3328 /* Set up next argument register. For sibling calls on machines
3329 with register windows this should be the incoming register. */
3332 VOIDmode,
3333 void_type_node,
3335 else
3341 {
3347 && valreg
3350 call_fusage
3353 call_fusage);
3354 }
3355 /* All arguments and registers used for the call must be set up by
3356 now! */
3358 /* Stack must be properly aligned now. */
3362 /* Generate the actual call instruction. */
3369 {
3373 {
3377 }
3380 }
3382 /* If the call setup or the call itself overlaps with anything
3383 of the argument setup we probably clobbered our call address.
3384 In that case we can't do sibcalls. */
3389 /* If a non-BLKmode value is returned at the most significant end
3390 of a register, shift the register right by the appropriate amount
3391 and update VALREG accordingly. BLKmode values are handled by the
3392 group load/store machinery below. */
3394 && !pcc_struct_value
3399 {
3403 }
3406 {
3410 /* The return value from a malloc-like function is a pointer. */
3416 /* The return value from a malloc-like function can not alias
3417 anything else. */
3421 /* Write out the sequence. */
3426 }
3428 /* For calls to `setjmp', etc., inform
3429 function.c:setjmp_warnings that it should complain if
3430 nonvolatile values are live. For functions that cannot
3431 return, inform flow that control does not fall through. */
3434 {
3435 /* The barrier must be emitted
3436 immediately after the CALL_INSN. Some ports emit more
3437 than just a CALL_INSN above, so we must search for it here. */
3441 {
3443 /* There was no CALL_INSN? */
3445 }
3449 /* Stack adjustments after a noreturn call are dead code.
3450 However when NO_DEFER_POP is in effect, we must preserve
3451 stack_pointer_delta. */
3453 {
3456 }
3457 }
3459 /* If value type not void, return an rtx for the value. */
3465 {
3467 {
3468 target
3471 structure_value_addr));
3473 }
3474 }
3476 {
3477 /* This is the special C++ case where we need to
3478 know what the true target was. We take care to
3479 never use this value more than once in one expression. */
3483 }
3484 /* Handle calls that return values in multiple non-contiguous locations.
3485 The Irix 6 ABI has examples of this. */
3487 {
3491 ;
3493 /* Handle the result of a emit_group_move_into_temps
3494 call in the previous pass. */
3496 else
3499 }
3503 {
3506 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
3507 reg to a plain register. */
3511 /* If TARGET is a MEM in the argument area, and we have
3512 saved part of the argument area, then we can't store
3513 directly into TARGET as it may get overwritten when we
3514 restore the argument save area below. Don't work too
3515 hard though and simply force TARGET to a register if it
3516 is a MEM; the optimizer is quite likely to sort it out. */
3520 {
3523 }
3527 else
3528 {
3529 /* TARGET and VALREG cannot be equal at this point
3530 because the latter would not have
3531 REG_FUNCTION_VALUE_P true, while the former would if
3532 it were referring to the same register.
3534 If they refer to the same register, this move will be
3535 a no-op, except when function inlining is being
3536 done. */
3539 /* If we are setting a MEM, this code must be executed.
3540 Since it is emitted after the call insn, sibcall
3541 optimization cannot be performed in that case. */
3544 }
3545 }
3546 else
3549 /* If we promoted this return value, make the proper SUBREG.
3550 TARGET might be const0_rtx here, so be careful. */
3554 {
3558 machine_mode pmode;
3560 /* Ensure we promote as expected, and get the new unsignedness. */
3568 {
3575 }
3580 }
3582 /* If size of args is variable or this was a constructor call for a stack
3583 argument, restore saved stack-pointer value. */
3586 {
3600 }
3602 {
3603 #ifdef REG_PARM_STACK_SPACE
3607 #endif
3609 /* If we saved any argument areas, restore them. */
3612 {
3614 rtx stack_area
3621 else
3624 BLOCK_OP_CALL_PARM);
3625 }
3629 }
3631 /* If this was alloca, record the new stack level. */
3635 /* Free up storage we no longer need. */
3645 {
3648 /* Restore the pending stack adjustment now that we have
3649 finished generating the sibling call sequence. */
3653 /* Prepare arg structure for next iteration. */
3655 {
3659 }
3664 }
3665 else
3666 {
3669 /* Verify that we've deallocated all the stack we used. */
3671 || (old_stack_allocated
3673 }
3675 /* If something prevents making this a sibling call,
3676 zero out the sequence. */
3679 else
3681 }
3683 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
3684 arguments too, as argument area is now clobbered by the call. */
3686 {
3689 }
3690 else
3693 currently_expanding_call--;
3697 /* Join result with returned bounds so caller may use them if needed. */
3701 }
3703 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3704 this function's incoming arguments.
3706 At the start of RTL generation we know the only REG_EQUIV notes
3707 in the rtl chain are those for incoming arguments, so we can look
3708 for REG_EQUIV notes between the start of the function and the
3709 NOTE_INSN_FUNCTION_BEG.
3711 This is (slight) overkill. We could keep track of the highest
3712 argument we clobber and be more selective in removing notes, but it
3713 does not seem to be worth the effort. */
3715 void
3717 {
3721 {
3722 rtx note;
3724 /* There are never REG_EQUIV notes for the incoming arguments
3725 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
3735 }
3736 }
3738 /* Traverse a list of TYPES and expand all complex types into their
3739 components. */
3740 static tree
3742 {
3743 tree p;
3745 /* Before allocating memory, check for the common case of no complex. */
3747 {
3752 }
3755 found:
3759 {
3764 {
3767 /* Rewrite complex type with component type. */
3771 /* Add another component type for the imaginary part. */
3776 /* Skip the newly created node. */
3778 }
3779 }
3782 }
3783 \f
3784 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3785 The RETVAL parameter specifies whether return value needs to be saved, other
3786 parameters are documented in the emit_library_call function below. */
3788 static rtx
3792 {
3793 /* Total size in bytes of all the stack-parms scanned so far. */
3795 /* Size of arguments before any adjustments (such as rounding). */
3798 rtx fun;
3799 /* Todo, choose the correct decl type of orgfun. Sadly this information
3800 isn't present here, so we default to native calling abi here. */
3805 CUMULATIVE_ARGS args_so_far_v;
3806 cumulative_args_t args_so_far;
3807 struct arg
3808 {
3809 rtx value;
3810 machine_mode mode;
3811 rtx reg;
3814 rtx save_area;
3815 };
3820 rtx valreg;
3830 #ifdef REG_PARM_STACK_SPACE
3831 /* Define the boundary of the register parm stack space that needs to be
3832 save, if any. */
3835 #endif
3837 /* Size of the stack reserved for parameter registers. */
3844 #ifdef REG_PARM_STACK_SPACE
3846 #endif
3848 /* By default, library functions can not throw. */
3852 {
3870 }
3873 /* Ensure current function's preferred stack boundary is at least
3874 what we need. */
3878 /* If this kind of value comes back in memory,
3879 decide where in memory it should come back. */
3881 {
3884 {
3885 #ifdef PCC_STATIC_STRUCT_RETURN
3886 rtx pointer_reg
3896 else
3898 #endif
3899 /* This call returns a big structure. */
3901 }
3902 }
3903 else
3906 /* ??? Unfinished: must pass the memory address as an argument. */
3908 /* Copy all the libcall-arguments out of the varargs data
3909 and into a vector ARGVEC.
3911 Compute how to pass each argument. We only support a very small subset
3912 of the full argument passing conventions to limit complexity here since
3913 library functions shouldn't have many args. */
3918 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3920 #else
3922 #endif
3932 /* If there's a structure value address to be passed,
3933 either pass it in the special place, or pass it as an extra argument. */
3935 {
3938 nargs++;
3940 /* Make sure it is a reasonable operand for a move or push insn. */
3956 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3958 #else
3960 #endif
3970 count++;
3971 }
3974 {
3979 /* We cannot convert the arg value to the mode the library wants here;
3980 must do it earlier where we know the signedness of the arg. */
3984 /* Make sure it is a reasonable operand for a move or push insn. */
3990 {
3991 rtx slot;
3992 int must_copy
3995 /* If this was a CONST function, it is now PURE since it now
3996 reads memory. */
3998 {
4001 }
4004 {
4009 }
4010 else
4011 {
4015 }
4019 call_fusage);
4023 slot),
4024 call_fusage);
4028 }
4042 {
4044 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4046 #else
4048 #endif
4053 }
4054 #ifdef BLOCK_REG_PADDING
4055 else
4056 /* The argument is passed entirely in registers. See at which
4057 end it should be padded. */
4061 #endif
4064 }
4066 /* If this machine requires an external definition for library
4067 functions, write one out. */
4072 + stack_pointer_delta
4074 / STACK_BYTES
4079 reg_parm_stack_space);
4088 {
4092 }
4095 {
4096 /* Since the stack pointer will never be pushed, it is possible for
4097 the evaluation of a parm to clobber something we have already
4098 written to the stack. Since most function calls on RISC machines
4099 do not use the stack, this is uncommon, but must work correctly.
4101 Therefore, we save any area of the stack that was already written
4102 and that we are using. Here we set up to do this by making a new
4103 stack usage map from the old one.
4105 Another approach might be to try to reorder the argument
4106 evaluations to avoid this conflicting stack usage. */
4110 /* Since we will be writing into the entire argument area, the
4111 map must be allocated for its entire size, not just the part that
4112 is the responsibility of the caller. */
4119 else
4127 initial_highest_arg_in_use);
4134 /* We must be careful to use virtual regs before they're instantiated,
4135 and real regs afterwards. Loop optimization, for example, can create
4136 new libcalls after we've instantiated the virtual regs, and if we
4137 use virtuals anyway, they won't match the rtl patterns. */
4141 STACK_POINTER_OFFSET);
4142 else
4144 }
4145 else
4146 {
4149 }
4151 /* We push args individually in reverse order, perform stack alignment
4152 before the first push (the last arg). */
4159 #ifdef REG_PARM_STACK_SPACE
4161 {
4162 /* The argument list is the property of the called routine and it
4163 may clobber it. If the fixed area has been used for previous
4164 parameters, we must save and restore it. */
4167 }
4168 #endif
4170 /* When expanding a normal call, args are stored in push order,
4171 which is the reverse of what we have here. */
4175 {
4178 }
4182 /* Push the args that need to be pushed. */
4186 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4187 are to be pushed. */
4189 {
4198 {
4199 rtx use;
4202 {
4203 /* If this is being stored into a pre-allocated, fixed-size,
4204 stack area, save any previous data at that location. */
4207 {
4208 /* stack_slot is negative, but we want to index stack_usage_map
4209 with positive values. */
4212 }
4213 else
4214 {
4217 }
4220 /* Don't worry about things in the fixed argument area;
4221 it has already been saved. */
4225 i++;
4228 {
4229 /* We need to make a save area. */
4230 unsigned int size
4232 machine_mode save_mode
4234 rtx adr
4237 rtx stack_area
4241 {
4245 );
4249 stack_area,
4251 BLOCK_OP_CALL_PARM);
4252 }
4253 else
4254 {
4258 }
4259 }
4260 }
4265 reg_parm_stack_space,
4268 /* Now mark the segment we just used. */
4273 NO_DEFER_POP;
4275 /* Indicate argument access so that alias.c knows that these
4276 values are live. */
4282 else
4283 {
4284 /* When arguments are pushed, trying to tell alias.c where
4285 exactly this argument is won't work, because the
4286 auto-increment causes confusion. So we merely indicate
4287 that we access something with a known mode somewhere on
4288 the stack. */
4292 }
4296 }
4297 }
4303 /* Now load any reg parms into their regs. */
4305 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4306 are to be pushed. */
4308 {
4313 #ifdef BLOCK_REG_PADDING
4315 #endif
4317 /* Handle calls that pass values in multiple non-contiguous
4318 locations. The PA64 has examples of this for library calls. */
4322 {
4324 #ifdef BLOCK_REG_PADDING
4327 /* Copied from load_register_parameters. */
4329 /* Handle case where we have a value that needs shifting
4330 up to the msb. eg. a QImode value and we're padding
4331 upward on a BYTES_BIG_ENDIAN machine. */
4335 {
4336 rtx x;
4339 /* Assigning REG here rather than a temp makes CALL_FUSAGE
4340 report the whole reg as used. Strictly speaking, the
4341 call only uses SIZE bytes at the msb end, but it doesn't
4342 seem worth generating rtl to say that. */
4347 }
4348 #endif
4349 }
4351 NO_DEFER_POP;
4352 }
4354 /* Any regs containing parms remain in use through the call. */
4356 {
4361 {
4364 {
4369 }
4370 else
4372 }
4373 }
4375 /* Pass the function the address in which to return a structure value. */
4377 {
4381 NULL_RTX)));
4384 }
4386 /* Don't allow popping to be deferred, since then
4387 cse'ing of library calls could delete a call and leave the pop. */
4388 NO_DEFER_POP;
4392 /* Stack must be properly aligned now. */
4398 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
4399 will set inhibit_defer_pop to that value. */
4400 /* The return type is needed to decide how many bytes the function pops.
4401 Signedness plays no role in that, so for simplicity, we pretend it's
4402 always signed. We also assume that the list of arguments passed has
4403 no impact, so we pretend it is unknown. */
4409 struct_value_size,
4412 valreg,
4416 {
4421 }
4423 /* Right-shift returned value if necessary. */
4427 {
4430 }
4434 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
4435 that it should complain if nonvolatile values are live. For
4436 functions that cannot return, inform flow that control does not
4437 fall through. */
4439 {
4440 /* The barrier note must be emitted
4441 immediately after the CALL_INSN. Some ports emit more than
4442 just a CALL_INSN above, so we must search for it here. */
4445 {
4447 /* There was no CALL_INSN? */
4449 }
4452 }
4454 /* Consider that "regular" libcalls, i.e. all of them except for LCT_THROW
4455 and LCT_RETURNS_TWICE, cannot perform non-local gotos. */
4457 {
4460 {
4462 /* There was no CALL_INSN? */
4464 }
4467 }
4469 /* Now restore inhibit_defer_pop to its actual original value. */
4470 OK_DEFER_POP;
4474 /* Copy the value to the right place. */
4476 {
4478 {
4483 }
4485 {
4489 }
4490 else
4491 {
4492 /* Convert to the proper mode if a promotion has been active. */
4494 {
4501 }
4505 else
4507 }
4508 }
4511 {
4512 #ifdef REG_PARM_STACK_SPACE
4516 #endif
4518 /* If we saved any argument areas, restore them. */
4521 {
4530 validize_mem
4533 BLOCK_OP_CALL_PARM);
4534 else
4536 }
4540 }
4546 }
4547 \f
4548 /* Output a library call to function FUN (a SYMBOL_REF rtx)
4549 (emitting the queue unless NO_QUEUE is nonzero),
4550 for a value of mode OUTMODE,
4551 with NARGS different arguments, passed as alternating rtx values
4552 and machine_modes to convert them to.
4554 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
4555 `const' calls, LCT_PURE for `pure' calls, or other LCT_ value for
4556 other types of library calls. */
4558 void
4561 {
4567 }
4568 \f
4569 /* Like emit_library_call except that an extra argument, VALUE,
4570 comes second and says where to store the result.
4571 (If VALUE is zero, this function chooses a convenient way
4572 to return the value.
4574 This function returns an rtx for where the value is to be found.
4575 If VALUE is nonzero, VALUE is returned. */
4577 rtx
4581 {
4582 rtx result;
4591 }
4592 \f
4594 /* Store pointer bounds argument ARG into Bounds Table entry
4595 associated with PARM. */
4596 static void
4598 {
4601 /* We may pass bounds not associated with any pointer. */
4603 {
4607 }
4608 /* Find pointer associated with bounds and where it is
4609 passed. */
4610 else
4611 {
4613 {
4617 }
4619 {
4627 else
4628 {
4631 }
4632 }
4633 else
4634 {
4643 else
4645 }
4646 }
4648 /* Expand bounds. */
4653 }
4655 /* Store a single argument for a function call
4656 into the register or memory area where it must be passed.
4657 *ARG describes the argument value and where to pass it.
4659 ARGBLOCK is the address of the stack-block for all the arguments,
4660 or 0 on a machine where arguments are pushed individually.
4662 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4663 so must be careful about how the stack is used.
4665 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4666 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4667 that we need not worry about saving and restoring the stack.
4669 FNDECL is the declaration of the function we are calling.
4671 Return nonzero if this arg should cause sibcall failure,
4672 zero otherwise. */
4674 static int
4677 {
4688 /* Push a new temporary level for any temporaries we make for
4689 this argument. */
4693 {
4694 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4695 save any previous data at that location. */
4697 {
4699 {
4700 /* stack_slot is negative, but we want to index stack_usage_map
4701 with positive values. */
4704 else
4708 }
4709 else
4710 {
4713 else
4717 }
4720 /* Don't worry about things in the fixed argument area;
4721 it has already been saved. */
4725 i++;
4728 {
4729 /* We need to make a save area. */
4736 {
4737 arg->save_area
4741 stack_area,
4743 BLOCK_OP_CALL_PARM);
4744 }
4745 else
4746 {
4749 }
4750 }
4751 }
4752 }
4754 /* If this isn't going to be placed on both the stack and in registers,
4755 set up the register and number of words. */
4757 {
4760 else
4763 }
4765 /* Being passed entirely in a register. We shouldn't be called in
4766 this case. */
4769 /* If this arg needs special alignment, don't load the registers
4770 here. */
4774 /* If this is being passed partially in a register, we can't evaluate
4775 it directly into its stack slot. Otherwise, we can. */
4777 {
4778 /* stack_arg_under_construction is nonzero if a function argument is
4779 being evaluated directly into the outgoing argument list and
4780 expand_call must take special action to preserve the argument list
4781 if it is called recursively.
4783 For scalar function arguments stack_usage_map is sufficient to
4784 determine which stack slots must be saved and restored. Scalar
4785 arguments in general have pass_on_stack == 0.
4787 If this argument is initialized by a function which takes the
4788 address of the argument (a C++ constructor or a C function
4789 returning a BLKmode structure), then stack_usage_map is
4790 insufficient and expand_call must push the stack around the
4791 function call. Such arguments have pass_on_stack == 1.
4793 Note that it is always safe to set stack_arg_under_construction,
4794 but this generates suboptimal code if set when not needed. */
4797 stack_arg_under_construction++;
4800 (partial
4805 /* If we are promoting object (or for any other reason) the mode
4806 doesn't agree, convert the mode. */
4813 stack_arg_under_construction--;
4814 }
4816 /* Check for overlap with already clobbered argument area. */
4823 /* Don't allow anything left on stack from computation
4824 of argument to alloca. */
4829 /* If the value is already in the stack slot, we are done. */
4830 ;
4832 {
4836 /* Argument is a scalar, not entirely passed in registers.
4837 (If part is passed in registers, arg->partial says how much
4838 and emit_push_insn will take care of putting it there.)
4840 Push it, and if its size is less than the
4841 amount of space allocated to it,
4842 also bump stack pointer by the additional space.
4843 Note that in C the default argument promotions
4844 will prevent such mismatches. */
4847 /* Compute how much space the push instruction will push.
4848 On many machines, pushing a byte will advance the stack
4849 pointer by a halfword. */
4850 #ifdef PUSH_ROUNDING
4852 #endif
4855 /* Compute how much space the argument should get:
4856 round up to a multiple of the alignment for arguments. */
4862 /* Compute the alignment of the pushed argument. */
4865 {
4868 {
4871 }
4872 }
4874 /* This isn't already where we want it on the stack, so put it there.
4875 This can either be done with push or copy insns. */
4882 /* Unless this is a partially-in-register argument, the argument is now
4883 in the stack. */
4886 }
4887 else
4888 {
4889 /* BLKmode, at least partly to be pushed. */
4893 rtx size_rtx;
4895 /* Pushing a nonscalar.
4896 If part is passed in registers, PARTIAL says how much
4897 and emit_push_insn will take care of putting it there. */
4899 /* Round its size up to a multiple
4900 of the allocation unit for arguments. */
4903 {
4906 }
4907 else
4908 {
4909 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
4910 for BLKmode is careful to avoid it. */
4916 EXPAND_NORMAL);
4917 }
4921 /* When an argument is padded down, the block is aligned to
4922 PARM_BOUNDARY, but the actual argument isn't. */
4924 {
4928 {
4931 }
4932 }
4935 {
4936 /* emit_push_insn might not work properly if arg->value and
4937 argblock + arg->locate.offset areas overlap. */
4946 {
4950 /* arg.locate doesn't contain the pretend_args_size offset,
4951 it's part of argblock. Ensure we don't count it in I. */
4954 else
4957 /* expand_call should ensure this. */
4963 {
4966 }
4968 {
4969 /* Use arg->locate.size.constant instead of size_rtx
4970 because we only care about the part of the argument
4971 on the stack. */
4975 }
4976 else
4977 {
4978 /* Even though they appear to be at the same location,
4979 if part of the outgoing argument is in registers,
4980 they aren't really at the same location. Check for
4981 this by making sure that the incoming size is the
4982 same as the outgoing size. */
4985 }
4986 }
4987 }
4994 /* Unless this is a partially-in-register argument, the argument is now
4995 in the stack.
4997 ??? Unlike the case above, in which we want the actual
4998 address of the data, so that we can load it directly into a
4999 register, here we want the address of the stack slot, so that
5000 it's properly aligned for word-by-word copying or something
5001 like that. It's not clear that this is always correct. */
5004 }
5007 {
5009 arg->parallel_value
5012 }
5014 /* Mark all slots this store used. */
5020 /* Once we have pushed something, pops can't safely
5021 be deferred during the rest of the arguments. */
5022 NO_DEFER_POP;
5024 /* Free any temporary slots made in processing this argument. */
5028 }
5030 /* Nonzero if we do not know how to pass TYPE solely in registers. */
5032 bool
5034 const_tree type)
5035 {
5039 /* If the type has variable size... */
5043 /* If the type is marked as addressable (it is required
5044 to be constructed into the stack)... */
5049 }
5051 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
5052 takes trailing padding of a structure into account. */
5053 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
5055 bool
5057 {
5061 /* If the type has variable size... */
5065 /* If the type is marked as addressable (it is required
5066 to be constructed into the stack)... */
5070 /* If the padding and mode of the type is such that a copy into
5071 a register would put it into the wrong part of the register. */
5079 }