| blob | 6d5ef4e02a01cf37b41b6d78b66950127f5f0faf |
1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989-2017 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/>. */
56 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
57 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
59 /* Data structure and subroutines used within expand_call. */
61 struct arg_data
62 {
63 /* Tree node for this argument. */
64 tree tree_value;
65 /* Mode for value; TYPE_MODE unless promoted. */
66 machine_mode mode;
67 /* Current RTL value for argument, or 0 if it isn't precomputed. */
68 rtx value;
69 /* Initially-compute RTL value for argument; only for const functions. */
70 rtx initial_value;
71 /* Register to pass this argument in, 0 if passed on stack, or an
72 PARALLEL if the arg is to be copied into multiple non-contiguous
73 registers. */
74 rtx reg;
75 /* Register to pass this argument in when generating tail call sequence.
76 This is not the same register as for normal calls on machines with
77 register windows. */
78 rtx tail_call_reg;
79 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
80 form for emit_group_move. */
81 rtx parallel_value;
82 /* If value is passed in neither reg nor stack, this field holds a number
83 of a special slot to be used. */
84 rtx special_slot;
85 /* For pointer bounds hold an index of parm bounds are bound to. -1 if
86 there is no such pointer. */
88 /* If pointer_arg refers a structure, then pointer_offset holds an offset
89 of a pointer in this structure. */
91 /* If REG was promoted from the actual mode of the argument expression,
92 indicates whether the promotion is sign- or zero-extended. */
94 /* Number of bytes to put in registers. 0 means put the whole arg
95 in registers. Also 0 if not passed in registers. */
97 /* Nonzero if argument must be passed on stack.
98 Note that some arguments may be passed on the stack
99 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
100 pass_on_stack identifies arguments that *cannot* go in registers. */
102 /* Some fields packaged up for locate_and_pad_parm. */
104 /* Location on the stack at which parameter should be stored. The store
105 has already been done if STACK == VALUE. */
106 rtx stack;
107 /* Location on the stack of the start of this argument slot. This can
108 differ from STACK if this arg pads downward. This location is known
109 to be aligned to TARGET_FUNCTION_ARG_BOUNDARY. */
110 rtx stack_slot;
111 /* Place that this stack area has been saved, if needed. */
112 rtx save_area;
113 /* If an argument's alignment does not permit direct copying into registers,
114 copy in smaller-sized pieces into pseudos. These are stored in a
115 block pointed to by this field. The next field says how many
116 word-sized pseudos we made. */
119 };
121 /* A vector of one char per byte of stack space. A byte if nonzero if
122 the corresponding stack location has been used.
123 This vector is used to prevent a function call within an argument from
124 clobbering any stack already set up. */
127 /* Size of STACK_USAGE_MAP. */
130 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
131 stack location's tail call argument has been already stored into the stack.
132 This bitmap is used to prevent sibling call optimization if function tries
133 to use parent's incoming argument slots when they have been already
134 overwritten with tail call arguments. */
137 /* stack_arg_under_construction is nonzero when an argument may be
138 initialized with a constructor call (including a C function that
139 returns a BLKmode struct) and expand_call must take special action
140 to make sure the object being constructed does not overlap the
141 argument list for the constructor call. */
146 cumulative_args_t);
175 #ifdef REG_PARM_STACK_SPACE
178 #endif
179 \f
180 /* Force FUNEXP into a form suitable for the address of a CALL,
181 and return that as an rtx. Also load the static chain register
182 if FNDECL is a nested function.
184 CALL_FUSAGE points to a variable holding the prospective
185 CALL_INSN_FUNCTION_USAGE information. */
187 rtx
190 {
191 /* Make a valid memory address and copy constants through pseudo-regs,
192 but not for a constant address if -fno-function-cse. */
194 {
195 /* If it's an indirect call by descriptor, generate code to perform
196 runtime identification of the pointer and load the descriptor. */
198 {
203 fndecl_or_type
205 fndecl_or_type);
209 /* Avoid long live ranges around function calls. */
215 /* Emit the runtime identification pattern. */
218 call_lab);
220 /* Statically predict the branch to very likely taken. */
225 /* Load the descriptor. */
234 POINTER_SIZE / BITS_PER_UNIT
243 {
246 }
248 /* Make sure we're not going to be overwritten below. */
250 }
252 /* If we are using registers for parameters, force the
253 function address into a register now. */
254 funexp = ((reg_parm_seen
258 }
259 else
260 {
261 /* funexp could be a SYMBOL_REF represents a function pointer which is
262 of ptr_mode. In this case, it should be converted into address mode
263 to be a valid address for memory rtx pattern. See PR 64971. */
268 {
271 }
272 }
277 {
278 rtx chain;
285 {
288 }
289 }
292 }
294 /* Generate instructions to call function FUNEXP,
295 and optionally pop the results.
296 The CALL_INSN is the first insn generated.
298 FNDECL is the declaration node of the function. This is given to the
299 hook TARGET_RETURN_POPS_ARGS to determine whether this function pops
300 its own args.
302 FUNTYPE is the data type of the function. This is given to the hook
303 TARGET_RETURN_POPS_ARGS to determine whether this function pops its
304 own args. We used to allow an identifier for library functions, but
305 that doesn't work when the return type is an aggregate type and the
306 calling convention says that the pointer to this aggregate is to be
307 popped by the callee.
309 STACK_SIZE is the number of bytes of arguments on the stack,
310 ROUNDED_STACK_SIZE is that number rounded up to
311 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
312 both to put into the call insn and to generate explicit popping
313 code if necessary.
315 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
316 It is zero if this call doesn't want a structure value.
318 NEXT_ARG_REG is the rtx that results from executing
319 targetm.calls.function_arg (&args_so_far, VOIDmode, void_type_node, true)
320 just after all the args have had their registers assigned.
321 This could be whatever you like, but normally it is the first
322 arg-register beyond those used for args in this call,
323 or 0 if all the arg-registers are used in this call.
324 It is passed on to `gen_call' so you can put this info in the call insn.
326 VALREG is a hard register in which a value is returned,
327 or 0 if the call does not return a value.
329 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
330 the args to this call were processed.
331 We restore `inhibit_defer_pop' to that value.
333 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
334 denote registers used by the called function. */
336 static void
338 tree funtype ATTRIBUTE_UNUSED,
339 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
340 HOST_WIDE_INT rounded_stack_size,
341 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
344 cumulative_args_t args_so_far ATTRIBUTE_UNUSED)
345 {
351 /* Sibling call patterns never pop arguments (no sibcall(_value)_pop
352 patterns exist). Any popping that the callee does on return will
353 be from our caller's frame rather than ours. */
355 {
358 #ifdef CALL_POPS_ARGS
360 #endif
361 }
363 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
364 and we don't want to load it into a register as an optimization,
365 because prepare_call_address already did it if it should be done. */
371 {
374 /* Although a built-in FUNCTION_DECL and its non-__builtin
375 counterpart compare equal and get a shared mem_attrs, they
376 produce different dump output in compare-debug compilations,
377 if an entry gets garbage collected in one compilation, then
378 adds a different (but equivalent) entry, while the other
379 doesn't run the garbage collector at the same spot and then
380 shares the mem_attr with the equivalent entry. */
382 {
386 }
389 }
394 {
397 rounded_stack_size_rtx,
399 else
402 }
403 /* If the target has "call" or "call_value" insns, then prefer them
404 if no arguments are actually popped. If the target does not have
405 "call" or "call_value" insns, then we must use the popping versions
406 even if the call has no arguments to pop. */
408 || !(valreg
411 {
414 /* If this subroutine pops its own args, record that in the call insn
415 if possible, for the sake of frame pointer elimination. */
419 rounded_stack_size_rtx,
421 else
426 }
427 else
428 {
432 else
435 }
438 /* Find the call we just emitted. */
441 /* Some target create a fresh MEM instead of reusing the one provided
442 above. Set its MEM_EXPR. */
449 /* Mark instrumented calls. */
453 /* Put the register usage information there. */
456 /* If this is a const call, then set the insn's unchanging bit. */
460 /* If this is a pure call, then set the insn's unchanging bit. */
464 /* If this is a const call, then set the insn's unchanging bit. */
468 /* Create a nothrow REG_EH_REGION note, if needed. */
475 {
478 }
482 /* Restore this now, so that we do defer pops for this call's args
483 if the context of the call as a whole permits. */
487 {
499 /* If popup is needed, stack realign must use DRAP */
502 }
503 /* For noreturn calls when not accumulating outgoing args force
504 REG_ARGS_SIZE note to prevent crossjumping of calls with different
505 args sizes. */
510 {
511 /* If returning from the subroutine does not automatically pop the args,
512 we need an instruction to pop them sooner or later.
513 Perhaps do it now; perhaps just record how much space to pop later.
515 If returning from the subroutine does pop the args, indicate that the
516 stack pointer will be changed. */
519 {
521 /* Just pretend we did the pop. */
526 else
528 }
529 }
530 /* When we accumulate outgoing args, we must avoid any stack manipulations.
531 Restore the stack pointer to its original value now. Usually
532 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
533 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
534 popping variants of functions exist as well.
536 ??? We may optimize similar to defer_pop above, but it is
537 probably not worthwhile.
539 ??? It will be worthwhile to enable combine_stack_adjustments even for
540 such machines. */
543 }
545 /* Determine if the function identified by FNDECL is one with
546 special properties we wish to know about. Modify FLAGS accordingly.
548 For example, if the function might return more than one time (setjmp), then
549 set ECF_RETURNS_TWICE.
551 Set ECF_MAY_BE_ALLOCA for any memory allocation function that might allocate
552 space from the stack such as alloca. */
554 static int
556 {
559 /* For instrumentation clones we want to derive flags
560 from the original name. */
567 /* Exclude functions not at the file scope, or not `extern',
568 since they are not the magic functions we would otherwise
569 think they are.
570 FIXME: this should be handled with attributes, not with this
571 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
572 because you can declare fork() inside a function if you
573 wish. */
577 {
581 /* We assume that alloca will always be called by name. It
582 makes no sense to pass it as a pointer-to-function to
583 anything that does not understand its behavior. */
589 /* Disregard prefix _ or __. */
591 {
594 else
596 }
598 /* ECF_RETURNS_TWICE is safe even for -ffreestanding. */
605 }
609 {
616 }
619 }
621 /* Similar to special_function_p; return a set of ERF_ flags for the
622 function FNDECL. */
623 static int
625 {
626 tree attr;
640 {
653 }
654 }
656 /* Return nonzero when FNDECL represents a call to setjmp. */
658 int
660 {
664 }
667 /* Return true if STMT may be an alloca call. */
669 bool
671 {
672 tree fndecl;
682 }
684 /* Return true if STMT is a builtin alloca call. */
686 bool
688 {
689 tree fndecl;
697 {
703 }
706 }
708 /* Return true when exp contains a builtin alloca call. */
710 bool
712 {
713 tree fndecl;
718 {
724 }
727 }
729 /* Return TRUE if FNDECL is either a TM builtin or a TM cloned
730 function. Return FALSE otherwise. */
732 static bool
734 {
742 {
744 {
787 }
788 }
790 }
792 /* Detect flags (function attributes) from the function decl or type node. */
794 int
796 {
800 {
801 /* The function exp may have the `malloc' attribute. */
805 /* The function exp may have the `returns_twice' attribute. */
809 /* Process the pure and const attributes. */
826 {
833 }
836 }
838 {
846 }
847 else
851 {
855 }
858 }
860 /* Detect flags from a CALL_EXPR. */
862 int
864 {
872 else
873 {
877 else
881 }
884 }
886 /* Return true if TYPE should be passed by invisible reference. */
888 bool
891 {
893 {
894 /* If this type contains non-trivial constructors, then it is
895 forbidden for the middle-end to create any new copies. */
899 /* GCC post 3.4 passes *all* variable sized types by reference. */
903 /* If a record type should be passed the same as its first (and only)
904 member, use the type and mode of that member. */
906 {
909 }
910 }
914 }
916 /* Return true if TYPE, which is passed by reference, should be callee
917 copied instead of caller copied. */
919 bool
922 {
926 named_arg);
927 }
930 /* Precompute all register parameters as described by ARGS, storing values
931 into fields within the ARGS array.
933 NUM_ACTUALS indicates the total number elements in the ARGS array.
935 Set REG_PARM_SEEN if we encounter a register parameter. */
937 static void
940 {
947 {
951 {
956 }
958 /* If we are to promote the function arg to a wider mode,
959 do it now. */
967 /* If the value is a non-legitimate constant, force it into a
968 pseudo now. TLS symbols sometimes need a call to resolve. */
973 /* If we're going to have to load the value by parts, pull the
974 parts into pseudos. The part extraction process can involve
975 non-trivial computation. */
977 {
982 }
984 /* If the value is expensive, and we are inside an appropriately
985 short loop, put the value into a pseudo and then put the pseudo
986 into the hard reg.
988 For small register classes, also do this if this call uses
989 register parameters. This is to avoid reload conflicts while
990 loading the parameters registers. */
999 && ((*reg_parm_seen
1003 }
1004 }
1006 #ifdef REG_PARM_STACK_SPACE
1008 /* The argument list is the property of the called routine and it
1009 may clobber it. If the fixed area has been used for previous
1010 parameters, we must save and restore it. */
1012 static rtx
1013 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
1014 {
1018 /* Compute the boundary of the area that needs to be saved, if any. */
1028 {
1030 machine_mode save_mode;
1032 rtx addr;
1033 rtx stack_area;
1034 rtx save_area;
1037 ;
1045 /* If we don't have the required alignment, must do this
1046 in BLKmode. */
1053 else
1061 {
1065 }
1066 else
1067 {
1070 }
1073 }
1076 }
1078 static void
1080 {
1087 else
1096 else
1099 BLOCK_OP_CALL_PARM);
1100 }
1103 /* If any elements in ARGS refer to parameters that are to be passed in
1104 registers, but not in memory, and whose alignment does not permit a
1105 direct copy into registers. Copy the values into a group of pseudos
1106 which we will later copy into the appropriate hard registers.
1108 Pseudos for each unaligned argument will be stored into the array
1109 args[argnum].aligned_regs. The caller is responsible for deallocating
1110 the aligned_regs array if it is nonzero. */
1112 static void
1114 {
1124 {
1129 {
1132 }
1133 else
1134 {
1137 }
1141 /* Structures smaller than a word are normally aligned to the
1142 least significant byte. On a BYTES_BIG_ENDIAN machine,
1143 this means we must skip the empty high order bytes when
1144 calculating the bit offset. */
1146 #ifdef BLOCK_REG_PADDING
1150 #else
1151 && BYTES_BIG_ENDIAN
1152 #endif
1153 )
1157 {
1166 /* There is no need to restrict this code to loading items
1167 in TYPE_ALIGN sized hunks. The bitfield instructions can
1168 load up entire word sized registers efficiently.
1170 ??? This may not be needed anymore.
1171 We use to emit a clobber here but that doesn't let later
1172 passes optimize the instructions we emit. By storing 0 into
1173 the register later passes know the first AND to zero out the
1174 bitfield being set in the register is unnecessary. The store
1175 of 0 will be deleted as will at least the first AND. */
1182 }
1183 }
1184 }
1186 /* The limit set by -Walloc-larger-than=. */
1189 /* Initialize ALLOC_OBJECT_SIZE_LIMIT based on the -Walloc-size-larger-than=
1190 setting if the option is specified, or to the maximum object size if it
1191 is not. Return the initialized value. */
1193 static tree
1195 {
1197 {
1201 {
1205 unsigned HOST_WIDE_INT limit
1209 {
1211 {
1212 /* Numeric option arguments are at most INT_MAX. Make it
1213 possible to specify a larger value by accepting common
1214 suffixes. */
1239 else
1241 }
1244 alloc_object_size_limit
1246 }
1247 }
1248 }
1250 }
1252 /* Return true when EXP's range can be determined and set RANGE[] to it
1253 after adjusting it if necessary to make EXP a valid size argument to
1254 an allocation function declared with attribute alloc_size (whose
1255 argument may be signed), or to a string manipulation function like
1256 memset. */
1258 bool
1260 {
1262 {
1263 /* EXP is a constant. */
1266 }
1269 enum value_range_type range_type
1274 {
1275 /* No range information available. */
1279 }
1289 {
1291 {
1293 {
1294 /* EXP is not in a strictly negative range. That means
1295 it must be in some (not necessarily strictly) positive
1296 range which includes zero. Since in signed to unsigned
1297 conversions negative values end up converted to large
1298 positive values, and otherwise they are not valid sizes,
1299 the resulting range is in both cases [0, TYPE_MAX]. */
1302 }
1304 {
1305 /* EXP is not in a negative-positive range. That means EXP
1306 is either negative, or greater than max. Since negative
1307 sizes are invalid make the range [MAX + 1, TYPE_MAX]. */
1310 }
1311 else
1312 {
1315 }
1316 }
1318 {
1319 /* EXP is unsigned and not in the range [1, MAX]. That means
1320 it's either zero or greater than MAX. Even though 0 would
1321 normally be detected by -Walloc-zero set the range to
1322 [MAX, TYPE_MAX] so that when MAX is greater than the limit
1323 the whole range is diagnosed. */
1326 }
1327 else
1328 {
1331 }
1332 }
1338 }
1340 /* Diagnose a call EXP to function FN decorated with attribute alloc_size
1341 whose argument numbers given by IDX with values given by ARGS exceed
1342 the maximum object size or cause an unsigned oveflow (wrapping) when
1343 multiplied. When ARGS[0] is null the function does nothing. ARGS[1]
1344 may be null for functions like malloc, and non-null for those like
1345 calloc that are decorated with a two-argument attribute alloc_size. */
1347 void
1349 {
1350 /* The range each of the (up to) two arguments is known to be in. */
1353 /* Maximum object size set by -Walloc-size-larger-than= or SIZE_MAX / 2. */
1360 /* Validate each argument individually. */
1362 {
1364 {
1369 {
1373 }
1375 {
1376 /* Avoid issuing -Walloc-zero for allocation functions other
1377 than __builtin_alloca that are declared with attribute
1378 returns_nonnull because there's no portability risk. This
1379 avoids warning for such calls to libiberty's xmalloc and
1380 friends.
1381 Also avoid issuing the warning for calls to function named
1382 "alloca". */
1391 }
1393 {
1394 /* G++ emits calls to ::operator new[](SIZE_MAX) in C++98
1395 mode and with -fno-exceptions as a way to indicate array
1396 size overflow. There's no good way to detect C++98 here
1397 so avoid diagnosing these calls for all C++ modes. */
1406 "%Kargument %i value %qE exceeds "
1409 }
1410 }
1413 {
1414 /* Verify that the argument's range is not negative (including
1415 upper bound of zero). */
1418 {
1423 }
1425 {
1427 "%Kargument %i range [%E, %E] exceeds "
1431 maxobjsize);
1432 }
1433 }
1434 }
1439 /* For a two-argument alloc_size, validate the product of the two
1440 arguments if both of their values or ranges are known. */
1445 {
1446 /* Check for overflow in the product of a function decorated with
1447 attribute alloc_size (X, Y). */
1457 "%Kproduct %<%E * %E%> of arguments %i and %i "
1463 "%Kproduct %<%E * %E%> of arguments %i and %i "
1467 maxobjsize);
1470 {
1471 /* Print the full range of each of the two arguments to make
1472 it clear when it is, in fact, in a range and not constant. */
1479 }
1480 }
1483 {
1489 else
1492 }
1493 }
1495 /* Issue an error if CALL_EXPR was flagged as requiring
1496 tall-call optimization. */
1498 static void
1500 {
1506 }
1508 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1509 CALL_EXPR EXP.
1511 NUM_ACTUALS is the total number of parameters.
1513 N_NAMED_ARGS is the total number of named arguments.
1515 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
1516 value, or null.
1518 FNDECL is the tree code for the target of this call (if known)
1520 ARGS_SO_FAR holds state needed by the target to know where to place
1521 the next argument.
1523 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1524 for arguments which are passed in registers.
1526 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1527 and may be modified by this routine.
1529 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1530 flags which may be modified by this routine.
1532 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
1533 that requires allocation of stack space.
1535 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
1536 the thunked-to function. */
1538 static void
1545 cumulative_args_t args_so_far,
1550 {
1554 /* Count arg position in order args appear. */
1564 /* In this loop, we consider args in the order they are written.
1565 We fill up ARGS from the back. */
1568 {
1570 call_expr_arg_iterator iter;
1571 tree arg;
1575 {
1577 j--;
1579 /* If we pass structure address then we need to
1580 create bounds for it. Since created bounds is
1581 a call statement, we expand it right here to avoid
1582 fixing all other places where it may be expanded. */
1584 {
1591 j--;
1592 }
1593 }
1596 {
1599 /* Remember last param with pointer and associate it
1600 with following pointer bounds. */
1603 {
1608 {
1611 }
1612 }
1616 {
1620 }
1622 {
1623 /* We expect bounds in instrumented calls only.
1624 Otherwise it is a sign we lost flag due to some optimization
1625 and may emit call args incorrectly. */
1628 /* For structures look for the next available pointer. */
1630 {
1637 /* Check we have no more pointers in the structure. */
1640 }
1643 /* Check we covered all pointers in the previous
1644 non bounds arg. */
1647 }
1648 else
1652 && argtype
1655 {
1658 j--;
1660 }
1661 else
1663 j--;
1664 argpos++;
1665 }
1669 }
1673 /* Extract attribute alloc_size and if set, store the indices of
1674 the corresponding arguments in ALLOC_IDX, and then the actual
1675 argument(s) at those indices in ALLOC_ARGS. */
1681 {
1686 }
1688 /* Array for up to the two attribute alloc_size arguments. */
1691 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1693 {
1696 machine_mode mode;
1698 /* Replace erroneous argument with constant zero. */
1702 /* If TYPE is a transparent union or record, pass things the way
1703 we would pass the first field of the union or record. We have
1704 already verified that the modes are the same. */
1709 /* Decide where to pass this arg.
1711 args[i].reg is nonzero if all or part is passed in registers.
1713 args[i].partial is nonzero if part but not all is passed in registers,
1714 and the exact value says how many bytes are passed in registers.
1716 args[i].pass_on_stack is nonzero if the argument must at least be
1717 computed on the stack. It may then be loaded back into registers
1718 if args[i].reg is nonzero.
1720 These decisions are driven by the FUNCTION_... macros and must agree
1721 with those made by function.c. */
1723 /* See if this argument should be passed by invisible reference. */
1726 {
1730 callee_copies
1734 /* If we're compiling a thunk, pass through invisible references
1735 instead of making a copy. */
1737 || (callee_copies
1742 {
1743 /* We may have turned the parameter value into an SSA name.
1744 Go back to the original parameter so we can take the
1745 address. */
1747 {
1751 }
1752 /* Argument setup code may have copied the value to register. We
1753 revert that optimization now because the tail call code must
1754 use the original location. */
1764 /* We can't use sibcalls if a callee-copied argument is
1765 stored in the current function's frame. */
1767 {
1770 "a callee-copied argument is"
1771 " stored in the current "
1773 }
1781 }
1782 else
1783 {
1784 /* We make a copy of the object and pass the address to the
1785 function being called. */
1786 rtx copy;
1793 {
1794 /* This is a variable-sized object. Make space on the stack
1795 for it. */
1799 {
1803 }
1805 /* We can pass TRUE as the 4th argument because we just
1806 saved the stack pointer and will restore it right after
1807 the call. */
1814 }
1815 else
1820 /* Just change the const function to pure and then let
1821 the next test clear the pure based on
1822 callee_copies. */
1824 {
1827 }
1837 "argument must be passed"
1839 }
1840 }
1853 {
1856 }
1858 /* If this is a sibling call and the machine has register windows, the
1859 register window has to be unwinded before calling the routine, so
1860 arguments have to go into the incoming registers. */
1865 else
1875 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1876 it means that we are to pass this arg in the register(s) designated
1877 by the PARALLEL, but also to pass it in the stack. */
1882 /* If this is an addressable type, we must preallocate the stack
1883 since we must evaluate the object into its final location.
1885 If this is to be passed in both registers and the stack, it is simpler
1886 to preallocate. */
1891 /* No stack allocation and padding for bounds. */
1893 ;
1894 /* Compute the stack-size of this argument. */
1899 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1901 #else
1903 #endif
1904 reg_parm_stack_space,
1907 #ifdef BLOCK_REG_PADDING
1908 else
1909 /* The argument is passed entirely in registers. See at which
1910 end it should be padded. */
1914 #endif
1916 /* Update ARGS_SIZE, the total stack space for args so far. */
1922 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1923 have been used, etc. */
1928 /* Store argument values for functions decorated with attribute
1929 alloc_size. */
1934 }
1937 {
1938 /* Check the arguments of functions decorated with attribute
1939 alloc_size. */
1941 }
1942 }
1944 /* Update ARGS_SIZE to contain the total size for the argument block.
1945 Return the original constant component of the argument block's size.
1947 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1948 for arguments passed in registers. */
1950 static int
1953 tree fndecl ATTRIBUTE_UNUSED,
1954 tree fntype ATTRIBUTE_UNUSED,
1956 {
1959 /* For accumulate outgoing args mode we don't need to align, since the frame
1960 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1961 backends from generating misaligned frame sizes. */
1965 /* Compute the actual size of the argument block required. The variable
1966 and constant sizes must be combined, the size may have to be rounded,
1967 and there may be a minimum required size. */
1970 {
1976 {
1977 /* We don't handle this case yet. To handle it correctly we have
1978 to add the delta, round and subtract the delta.
1979 Currently no machine description requires this support. */
1982 }
1985 {
1986 args_size->var
1990 /* The area corresponding to register parameters is not to count in
1991 the size of the block we need. So make the adjustment. */
1993 args_size->var
1996 }
1997 }
1998 else
1999 {
2004 + stack_pointer_delta
2006 / preferred_stack_boundary
2011 reg_parm_stack_space);
2015 }
2017 }
2019 /* Precompute parameters as needed for a function call.
2021 FLAGS is mask of ECF_* constants.
2023 NUM_ACTUALS is the number of arguments.
2025 ARGS is an array containing information for each argument; this
2026 routine fills in the INITIAL_VALUE and VALUE fields for each
2027 precomputed argument. */
2029 static void
2031 {
2034 /* If this is a libcall, then precompute all arguments so that we do not
2035 get extraneous instructions emitted as part of the libcall sequence. */
2037 /* If we preallocated the stack space, and some arguments must be passed
2038 on the stack, then we must precompute any parameter which contains a
2039 function call which will store arguments on the stack.
2040 Otherwise, evaluating the parameter may clobber previous parameters
2041 which have already been stored into the stack. (we have code to avoid
2042 such case by saving the outgoing stack arguments, but it results in
2043 worse code) */
2048 {
2049 tree type;
2050 machine_mode mode;
2055 /* If this is an addressable type, we cannot pre-evaluate it. */
2064 {
2070 /* CSE will replace this only if it contains args[i].value
2071 pseudo, so convert it down to the declared mode using
2072 a SUBREG. */
2076 {
2081 }
2082 }
2083 }
2084 }
2086 /* Given the current state of MUST_PREALLOCATE and information about
2087 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
2088 compute and return the final value for MUST_PREALLOCATE. */
2090 static int
2093 {
2094 /* See if we have or want to preallocate stack space.
2096 If we would have to push a partially-in-regs parm
2097 before other stack parms, preallocate stack space instead.
2099 If the size of some parm is not a multiple of the required stack
2100 alignment, we must preallocate.
2102 If the total size of arguments that would otherwise create a copy in
2103 a temporary (such as a CALL) is more than half the total argument list
2104 size, preallocation is faster.
2106 Another reason to preallocate is if we have a machine (like the m88k)
2107 where stack alignment is required to be maintained between every
2108 pair of insns, not just when the call is made. However, we assume here
2109 that such machines either do not have push insns (and hence preallocation
2110 would occur anyway) or the problem is taken care of with
2111 PUSH_ROUNDING. */
2114 {
2120 {
2125 /* We preallocate in case there are bounds passed
2126 in the bounds table to have precomputed address
2127 for bounds association. */
2137 copy_to_evaluate_size
2139 }
2144 }
2146 }
2148 /* If we preallocated stack space, compute the address of each argument
2149 and store it into the ARGS array.
2151 We need not ensure it is a valid memory address here; it will be
2152 validized when it is used.
2154 ARGBLOCK is an rtx for the address of the outgoing arguments. */
2156 static void
2158 {
2160 {
2168 {
2171 rtx addr;
2176 /* Skip this parm if it will not be passed on the stack. */
2182 /* Pointer Bounds are never passed on the stack. */
2188 else
2194 {
2195 /* Only part of the parameter is being passed on the stack.
2196 Generate a simple memory reference of the correct size. */
2202 }
2203 else
2204 {
2208 }
2214 {
2217 }
2222 else
2228 {
2229 /* Only part of the parameter is being passed on the stack.
2230 Generate a simple memory reference of the correct size.
2231 */
2234 }
2235 else
2236 {
2240 }
2243 /* Function incoming arguments may overlap with sibling call
2244 outgoing arguments and we cannot allow reordering of reads
2245 from function arguments with stores to outgoing arguments
2246 of sibling calls. */
2249 }
2250 }
2251 }
2253 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
2254 in a call instruction.
2256 FNDECL is the tree node for the target function. For an indirect call
2257 FNDECL will be NULL_TREE.
2259 ADDR is the operand 0 of CALL_EXPR for this call. */
2261 static rtx
2263 {
2264 rtx funexp;
2266 /* Get the function to call, in the form of RTL. */
2268 {
2272 /* Get a SYMBOL_REF rtx for the function address. */
2274 }
2275 else
2276 /* Generate an rtx (probably a pseudo-register) for the address. */
2277 {
2281 }
2283 }
2285 /* Internal state for internal_arg_pointer_based_exp and its helpers. */
2286 static struct
2287 {
2288 /* Last insn that has been scanned by internal_arg_pointer_based_exp_scan,
2289 or NULL_RTX if none has been scanned yet. */
2291 /* Vector indexed by REGNO - FIRST_PSEUDO_REGISTER, recording if a pseudo is
2292 based on crtl->args.internal_arg_pointer. The element is NULL_RTX if the
2293 pseudo isn't based on it, a CONST_INT offset if the pseudo is based on it
2294 with fixed offset, or PC if this is with variable or unknown offset. */
2300 /* Helper function for internal_arg_pointer_based_exp. Scan insns in
2301 the tail call sequence, starting with first insn that hasn't been
2302 scanned yet, and note for each pseudo on the LHS whether it is based
2303 on crtl->args.internal_arg_pointer or not, and what offset from that
2304 that pointer it has. */
2306 static void
2308 {
2313 else
2317 {
2320 {
2323 /* Punt on pseudos set multiple times. */
2328 else
2331 {
2333 internal_arg_pointer_exp_state.cache
2336 }
2337 }
2341 }
2344 }
2346 /* Compute whether RTL is based on crtl->args.internal_arg_pointer. Return
2347 NULL_RTX if RTL isn't based on it, a CONST_INT offset if RTL is based on
2348 it with fixed offset, or PC if this is with variable or unknown offset.
2349 TOPLEVEL is true if the function is invoked at the topmost level. */
2351 static rtx
2353 {
2364 {
2369 }
2371 /* When called at the topmost level, scan pseudo assignments in between the
2372 last scanned instruction in the tail call sequence and the latest insn
2373 in that sequence. */
2378 {
2384 }
2388 {
2394 }
2397 }
2399 /* Return true if and only if SIZE storage units (usually bytes)
2400 starting from address ADDR overlap with already clobbered argument
2401 area. This function is used to determine if we should give up a
2402 sibcall. */
2404 static bool
2406 {
2407 HOST_WIDE_INT i;
2408 rtx val;
2417 else
2422 else
2430 {
2437 }
2440 }
2442 /* Do the register loads required for any wholly-register parms or any
2443 parms which are passed both on the stack and in a register. Their
2444 expressions were already evaluated.
2446 Mark all register-parms as living through the call, putting these USE
2447 insns in the CALL_INSN_FUNCTION_USAGE field.
2449 When IS_SIBCALL, perform the check_sibcall_argument_overlap
2450 checking, setting *SIBCALL_FAILURE if appropriate. */
2452 static void
2456 {
2460 {
2464 {
2469 /* Set non-negative if we must move a word at a time, even if
2470 just one word (e.g, partial == 4 && mode == DFmode). Set
2471 to -1 if we just use a normal move insn. This value can be
2472 zero if the argument is a zero size structure. */
2475 ;
2477 {
2480 }
2482 {
2485 }
2486 else
2489 /* Handle calls that pass values in multiple non-contiguous
2490 locations. The Irix 6 ABI has examples of this. */
2495 /* If simple case, just do move. If normal partial, store_one_arg
2496 has already loaded the register for us. In all other cases,
2497 load the register(s) from memory. */
2500 {
2502 #ifdef BLOCK_REG_PADDING
2503 /* Handle case where we have a value that needs shifting
2504 up to the msb. eg. a QImode value and we're padding
2505 upward on a BYTES_BIG_ENDIAN machine. */
2509 {
2510 rtx x;
2513 /* Assigning REG here rather than a temp makes CALL_FUSAGE
2514 report the whole reg as used. Strictly speaking, the
2515 call only uses SIZE bytes at the msb end, but it doesn't
2516 seem worth generating rtl to say that. */
2521 }
2522 #endif
2523 }
2525 /* If we have pre-computed the values to put in the registers in
2526 the case of non-aligned structures, copy them in now. */
2534 {
2537 /* Check for overlap with already clobbered argument area,
2538 providing that this has non-zero size. */
2541 && (mem_overlaps_already_clobbered_arg_p
2548 else
2549 {
2563 }
2565 /* Handle a BLKmode that needs shifting. */
2567 #ifdef BLOCK_REG_PADDING
2569 #else
2570 && BYTES_BIG_ENDIAN
2571 #endif
2572 )
2573 {
2578 rtx x;
2583 }
2584 }
2586 /* When a parameter is a block, and perhaps in other cases, it is
2587 possible that it did a load from an argument slot that was
2588 already clobbered. */
2593 /* Handle calls that pass values in multiple non-contiguous
2594 locations. The Irix 6 ABI has examples of this. */
2602 }
2603 }
2604 }
2606 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
2607 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
2608 bytes, then we would need to push some additional bytes to pad the
2609 arguments. So, we compute an adjust to the stack pointer for an
2610 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
2611 bytes. Then, when the arguments are pushed the stack will be perfectly
2612 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
2613 be popped after the call. Returns the adjustment. */
2615 static int
2619 {
2620 /* The number of bytes to pop so that the stack will be
2621 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
2622 HOST_WIDE_INT adjustment;
2623 /* The alignment of the stack after the arguments are pushed, if we
2624 just pushed the arguments without adjust the stack here. */
2627 unadjusted_alignment
2631 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
2632 as possible -- leaving just enough left to cancel out the
2633 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
2634 PENDING_STACK_ADJUST is non-negative, and congruent to
2635 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
2637 /* Begin by trying to pop all the bytes. */
2638 unadjusted_alignment
2639 = (unadjusted_alignment
2642 /* Push enough additional bytes that the stack will be aligned
2643 after the arguments are pushed. */
2645 {
2648 else
2650 }
2652 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
2653 bytes after the call. The right number is the entire
2654 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
2655 by the arguments in the first place. */
2656 args_size->constant
2660 }
2662 /* Scan X expression if it does not dereference any argument slots
2663 we already clobbered by tail call arguments (as noted in stored_args_map
2664 bitmap).
2665 Return nonzero if X expression dereferences such argument slots,
2666 zero otherwise. */
2668 static int
2670 {
2671 RTX_CODE code;
2680 /* We need not check the operands of the CALL expression itself. */
2688 /* Scan all subexpressions. */
2691 {
2693 {
2696 }
2698 {
2702 }
2703 }
2705 }
2707 /* Scan sequence after INSN if it does not dereference any argument slots
2708 we already clobbered by tail call arguments (as noted in stored_args_map
2709 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
2710 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
2711 should be 0). Return nonzero if sequence after INSN dereferences such argument
2712 slots, zero otherwise. */
2714 static int
2717 {
2722 else
2731 {
2734 else
2739 }
2741 }
2743 /* Given that a function returns a value of mode MODE at the most
2744 significant end of hard register VALUE, shift VALUE left or right
2745 as specified by LEFT_P. Return true if some action was needed. */
2747 bool
2749 {
2750 HOST_WIDE_INT shift;
2757 /* Use ashr rather than lshr for right shifts. This is for the benefit
2758 of the MIPS port, which requires SImode values to be sign-extended
2759 when stored in 64-bit registers. */
2764 }
2766 /* If X is a likely-spilled register value, copy it to a pseudo
2767 register and return that register. Return X otherwise. */
2769 static rtx
2771 {
2772 rtx new_rtx;
2777 {
2778 /* Make sure that we generate a REG rather than a CONCAT.
2779 Moves into CONCATs can need nontrivial instructions,
2780 and the whole point of this function is to avoid
2781 using the hard register directly in such a situation. */
2787 }
2789 }
2791 /* Helper function for expand_call.
2792 Return false is EXP is not implementable as a sibling call. */
2794 static bool
2796 rtx structure_value_addr,
2797 tree funtype,
2799 tree fndecl,
2801 tree addr,
2803 {
2805 {
2806 maybe_complain_about_tail_call
2808 "machine description does not have"
2811 }
2813 /* Doing sibling call optimization needs some work, since
2814 structure_value_addr can be allocated on the stack.
2815 It does not seem worth the effort since few optimizable
2816 sibling calls will return a structure. */
2818 {
2821 }
2823 #ifdef REG_PARM_STACK_SPACE
2824 /* If outgoing reg parm stack space changes, we can not do sibcall. */
2828 {
2830 "inconsistent size of stack space"
2831 " allocated for arguments which are"
2834 }
2835 #endif
2837 /* Check whether the target is able to optimize the call
2838 into a sibcall. */
2840 {
2842 "target is not able to optimize the"
2845 }
2847 /* Functions that do not return exactly once may not be sibcall
2848 optimized. */
2850 {
2853 }
2855 {
2858 }
2861 {
2864 }
2866 /* If the called function is nested in the current one, it might access
2867 some of the caller's arguments, but could clobber them beforehand if
2868 the argument areas are shared. */
2870 {
2873 }
2875 /* If this function requires more stack slots than the current
2876 function, we cannot change it into a sibling call.
2877 crtl->args.pretend_args_size is not part of the
2878 stack allocated by our caller. */
2880 {
2882 "callee required more stack slots"
2885 }
2887 /* If the callee pops its own arguments, then it must pop exactly
2888 the same number of arguments as the current function. */
2893 {
2895 "inconsistent number of"
2898 }
2901 {
2905 }
2907 /* All checks passed. */
2909 }
2911 /* Generate all the code for a CALL_EXPR exp
2912 and return an rtx for its value.
2913 Store the value in TARGET (specified as an rtx) if convenient.
2914 If the value is stored in TARGET then TARGET is returned.
2915 If IGNORE is nonzero, then we ignore the value of the function call. */
2917 rtx
2919 {
2920 /* Nonzero if we are currently expanding a call. */
2923 /* RTX for the function to be called. */
2924 rtx funexp;
2925 /* Sequence of insns to perform a normal "call". */
2927 /* Sequence of insns to perform a tail "call". */
2929 /* Data type of the function. */
2930 tree funtype;
2931 tree type_arg_types;
2932 tree rettype;
2933 /* Declaration of the function being called,
2934 or 0 if the function is computed (not known by name). */
2936 /* The type of the function being called. */
2937 tree fntype;
2942 /* Register in which non-BLKmode value will be returned,
2943 or 0 if no value or if value is BLKmode. */
2944 rtx valreg;
2945 /* Register(s) in which bounds are returned. */
2947 /* Address where we should return a BLKmode value;
2948 0 if value not BLKmode. */
2950 /* Nonzero if that address is being passed by treating it as
2951 an extra, implicit first parameter. Otherwise,
2952 it is passed by being copied directly into struct_value_rtx. */
2954 /* Holds the value of implicit argument for the struct value. */
2956 /* Size of aggregate value wanted, or zero if none wanted
2957 or if we are using the non-reentrant PCC calling convention
2958 or expecting the value in registers. */
2960 /* Nonzero if called function returns an aggregate in memory PCC style,
2961 by returning the address of where to find it. */
2965 /* Number of actual parameters in this call, including struct value addr. */
2967 /* Number of named args. Args after this are anonymous ones
2968 and they must all go on the stack. */
2970 /* Number of complex actual arguments that need to be split. */
2973 /* Vector of information about each argument.
2974 Arguments are numbered in the order they will be pushed,
2975 not the order they are written. */
2978 /* Total size in bytes of all the stack-parms scanned so far. */
2981 /* Size of arguments before any adjustments (such as rounding). */
2983 /* Data on reg parms scanned so far. */
2984 CUMULATIVE_ARGS args_so_far_v;
2985 cumulative_args_t args_so_far;
2986 /* Nonzero if a reg parm has been scanned. */
2988 /* Nonzero if this is an indirect function call. */
2990 /* Nonzero if we must avoid push-insns in the args for this call.
2991 If stack space is allocated for register parameters, but not by the
2992 caller, then it is preallocated in the fixed part of the stack frame.
2993 So the entire argument block must then be preallocated (i.e., we
2994 ignore PUSH_ROUNDING in that case). */
2998 /* Size of the stack reserved for parameter registers. */
3001 /* Address of space preallocated for stack parms
3002 (on machines that lack push insns), or 0 if space not preallocated. */
3005 /* Mask of ECF_ and ERF_ flags. */
3008 #ifdef REG_PARM_STACK_SPACE
3009 /* Define the boundary of the register parm stack space that needs to be
3010 saved, if any. */
3013 #endif
3021 /* State variables to track stack modifications. */
3027 /* Some stack pointer alterations we make are performed via
3028 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
3029 which we then also need to save/restore along the way. */
3032 rtx call_fusage;
3035 /* The alignment of the stack, in bits. */
3037 /* The alignment of the stack, in bytes. */
3039 /* The static chain value to use for this call. */
3040 rtx static_chain_value;
3041 /* See if this is "nothrow" function call. */
3045 /* See if we can find a DECL-node for the actual function, and get the
3046 function attributes (flags) from the function decl or type node. */
3049 {
3053 }
3054 else
3055 {
3060 }
3065 /* Warn if this value is an aggregate type,
3066 regardless of which calling convention we are using for it. */
3070 /* If the result of a non looping pure or const function call is
3071 ignored (or void), and none of its arguments are volatile, we can
3072 avoid expanding the call and just evaluate the arguments for
3073 side-effects. */
3078 {
3080 tree arg;
3081 call_expr_arg_iterator iter;
3085 {
3088 }
3091 {
3095 }
3096 }
3098 #ifdef REG_PARM_STACK_SPACE
3100 #endif
3106 /* Set up a place to return a structure. */
3108 /* Cater to broken compilers. */
3110 {
3111 /* This call returns a big structure. */
3114 #ifdef PCC_STATIC_STRUCT_RETURN
3115 {
3117 }
3119 {
3122 /* Even if it is semantically safe to use the target as the return
3123 slot, it may be not sufficiently aligned for the return type. */
3125 && target
3131 else
3132 {
3133 /* For variable-sized objects, we must be called with a target
3134 specified. If we were to allocate space on the stack here,
3135 we would have no way of knowing when to free it. */
3139 }
3140 }
3142 }
3144 /* Figure out the amount to which the stack should be aligned. */
3147 {
3149 /* Without automatic stack alignment, we can't increase preferred
3150 stack boundary. With automatic stack alignment, it is
3151 unnecessary since unless we can guarantee that all callers will
3152 align the outgoing stack properly, callee has to align its
3153 stack anyway. */
3158 }
3160 /* Operand 0 is a pointer-to-function; get the type of the function. */
3165 /* Count whether there are actual complex arguments that need to be split
3166 into their real and imaginary parts. Munge the type_arg_types
3167 appropriately here as well. */
3169 {
3170 call_expr_arg_iterator iter;
3171 tree arg;
3173 {
3177 num_complex_actuals++;
3178 }
3180 }
3181 else
3187 /* If struct_value_rtx is 0, it means pass the address
3188 as if it were an extra parameter. Put the argument expression
3189 in structure_value_addr_value. */
3191 {
3192 /* If structure_value_addr is a REG other than
3193 virtual_outgoing_args_rtx, we can use always use it. If it
3194 is not a REG, we must always copy it into a register.
3195 If it is virtual_outgoing_args_rtx, we must copy it to another
3196 register in some cases. */
3198 || (ACCUMULATE_OUTGOING_ARGS
3199 && stack_arg_under_construction
3205 structure_value_addr_value =
3208 }
3210 /* Count the arguments and set NUM_ACTUALS. */
3211 num_actuals =
3214 /* Compute number of named args.
3215 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
3218 n_named_args
3220 /* Count the struct value address, if it is passed as a parm. */
3222 else
3223 /* If we know nothing, treat all args as named. */
3226 /* Start updating where the next arg would go.
3228 On some machines (such as the PA) indirect calls have a different
3229 calling convention than normal calls. The fourth argument in
3230 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
3231 or not. */
3235 /* Now possibly adjust the number of named args.
3236 Normally, don't include the last named arg if anonymous args follow.
3237 We do include the last named arg if
3238 targetm.calls.strict_argument_naming() returns nonzero.
3239 (If no anonymous args follow, the result of list_length is actually
3240 one too large. This is harmless.)
3242 If targetm.calls.pretend_outgoing_varargs_named() returns
3243 nonzero, and targetm.calls.strict_argument_naming() returns zero,
3244 this machine will be able to place unnamed args that were passed
3245 in registers into the stack. So treat all args as named. This
3246 allows the insns emitting for a specific argument list to be
3247 independent of the function declaration.
3249 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
3250 we do not have any reliable way to pass unnamed args in
3251 registers, so we must force them into memory. */
3255 ;
3258 /* Don't include the last named arg. */
3260 else
3261 /* Treat all args as named. */
3264 /* Make a vector to hold all the information about each arg. */
3267 /* Build up entries in the ARGS array, compute the size of the
3268 arguments into ARGS_SIZE, etc. */
3280 /* Now make final decision about preallocating stack space. */
3285 /* If the structure value address will reference the stack pointer, we
3286 must stabilize it. We don't need to do this if we know that we are
3287 not going to adjust the stack pointer in processing this call. */
3292 structure_value_addr))
3297 /* Tail calls can make things harder to debug, and we've traditionally
3298 pushed these optimizations into -O2. Don't try if we're already
3299 expanding a call, as that means we're an argument. Don't try if
3300 there's cleanups, as we know there's code to follow the call. */
3303 || !flag_optimize_sibling_calls
3308 /* If the user has marked the function as requiring tail-call
3309 optimization, attempt it. */
3313 /* Rest of purposes for tail call optimizations to fail. */
3316 structure_value_addr,
3317 funtype,
3318 reg_parm_stack_space,
3319 fndecl,
3322 /* Check if caller and callee disagree in promotion of function
3323 return value. */
3325 {
3335 caller_promoted_mode
3339 callee_promoted_mode
3350 {
3353 "caller and callee disagree in"
3354 " promotion of function"
3356 }
3357 }
3359 /* Ensure current function's preferred stack boundary is at least
3360 what we need. Stack alignment may also increase preferred stack
3361 boundary. */
3364 else
3369 /* We want to make two insn chains; one for a sibling call, the other
3370 for a normal call. We will select one of the two chains after
3371 initial RTL generation is complete. */
3373 {
3375 /* We want to emit any pending stack adjustments before the tail
3376 recursion "call". That way we know any adjustment after the tail
3377 recursion call can be ignored if we indeed use the tail
3378 call expansion. */
3379 saved_pending_stack_adjust save;
3381 rtx next_arg_reg;
3384 {
3385 /* State variables we need to save and restore between
3386 iterations. */
3388 }
3391 else
3394 /* Other state variables that we must reinitialize each time
3395 through the loop (that are not initialized by the loop itself). */
3399 /* Start a new sequence for the normal call case.
3401 From this point on, if the sibling call fails, we want to set
3402 sibcall_failure instead of continuing the loop. */
3405 /* Don't let pending stack adjusts add up to too much.
3406 Also, do all pending adjustments now if there is any chance
3407 this might be a call to alloca or if we are expanding a sibling
3408 call sequence.
3409 Also do the adjustments before a throwing call, otherwise
3410 exception handling can fail; PR 19225. */
3419 /* Precompute any arguments as needed. */
3423 /* Now we are about to start emitting insns that can be deleted
3424 if a libcall is deleted. */
3434 /* Compute the actual size of the argument block required. The variable
3435 and constant sizes must be combined, the size may have to be rounded,
3436 and there may be a minimum required size. When generating a sibcall
3437 pattern, do not round up, since we'll be re-using whatever space our
3438 caller provided. */
3439 unadjusted_args_size
3448 /* The argument block when performing a sibling call is the
3449 incoming argument block. */
3451 {
3454 argblock
3456 else
3457 argblock
3462 }
3464 /* If we have no actual push instructions, or shouldn't use them,
3465 make space for all args right now. */
3467 {
3469 {
3474 /* stack_arg_under_construction says whether a stack arg is
3475 being constructed at the old stack level. Pushing the stack
3476 gets a clean outgoing argument block. */
3479 }
3483 }
3484 else
3485 {
3486 /* Note that we must go through the motions of allocating an argument
3487 block even if the size is zero because we may be storing args
3488 in the area reserved for register arguments, which may be part of
3489 the stack frame. */
3493 /* Store the maximum argument space used. It will be pushed by
3494 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
3495 checking). */
3501 {
3503 {
3504 /* Since the stack pointer will never be pushed, it is
3505 possible for the evaluation of a parm to clobber
3506 something we have already written to the stack.
3507 Since most function calls on RISC machines do not use
3508 the stack, this is uncommon, but must work correctly.
3510 Therefore, we save any area of the stack that was already
3511 written and that we are using. Here we set up to do this
3512 by making a new stack usage map from the old one. The
3513 actual save will be done by store_one_arg.
3515 Another approach might be to try to reorder the argument
3516 evaluations to avoid this conflicting stack usage. */
3518 /* Since we will be writing into the entire argument area,
3519 the map must be allocated for its entire size, not just
3520 the part that is the responsibility of the caller. */
3525 highest_outgoing_arg_in_use
3527 else
3528 highest_outgoing_arg_in_use
3537 initial_highest_arg_in_use);
3541 (highest_outgoing_arg_in_use
3545 /* The address of the outgoing argument list must not be
3546 copied to a register here, because argblock would be left
3547 pointing to the wrong place after the call to
3548 allocate_dynamic_stack_space below. */
3551 }
3552 else
3553 {
3555 {
3556 /* Try to reuse some or all of the pending_stack_adjust
3557 to get this space. */
3558 needed
3559 = (combine_pending_stack_adjustment_and_call
3562 preferred_unit_stack_boundary));
3564 /* combine_pending_stack_adjustment_and_call computes
3565 an adjustment before the arguments are allocated.
3566 Account for them and see whether or not the stack
3567 needs to go up or down. */
3571 {
3572 /* We're releasing stack space. */
3573 /* ??? We can avoid any adjustment at all if we're
3574 already aligned. FIXME. */
3578 }
3579 else
3580 /* We need to allocate space. We'll do that in
3581 push_block below. */
3583 }
3585 /* Special case this because overhead of `push_block' in
3586 this case is non-trivial. */
3589 else
3590 {
3594 }
3596 /* We only really need to call `copy_to_reg' in the case
3597 where push insns are going to be used to pass ARGBLOCK
3598 to a function call in ARGS. In that case, the stack
3599 pointer changes value from the allocation point to the
3600 call point, and hence the value of
3601 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
3602 as well always do it. */
3604 }
3605 }
3606 }
3609 {
3610 /* The save/restore code in store_one_arg handles all
3611 cases except one: a constructor call (including a C
3612 function returning a BLKmode struct) to initialize
3613 an argument. */
3615 {
3616 rtx push_size
3622 {
3627 /* stack_arg_under_construction says whether a stack
3628 arg is being constructed at the old stack level.
3629 Pushing the stack gets a clean outgoing argument
3630 block. */
3631 old_stack_arg_under_construction
3634 /* Make a new map for the new argument list. */
3639 }
3640 /* We can pass TRUE as the 4th argument because we just
3641 saved the stack pointer and will restore it right after
3642 the call. */
3645 }
3647 /* If argument evaluation might modify the stack pointer,
3648 copy the address of the argument list to a register. */
3651 {
3654 }
3655 }
3659 /* Stack is properly aligned, pops can't safely be deferred during
3660 the evaluation of the arguments. */
3661 NO_DEFER_POP;
3663 /* Precompute all register parameters. It isn't safe to compute
3664 anything once we have started filling any specific hard regs.
3665 TLS symbols sometimes need a call to resolve. Precompute
3666 register parameters before any stack pointer manipulation
3667 to avoid unaligned stack in the called function. */
3670 OK_DEFER_POP;
3672 /* Perform stack alignment before the first push (the last arg). */
3676 {
3677 /* When the stack adjustment is pending, we get better code
3678 by combining the adjustments. */
3681 {
3682 pending_stack_adjust
3683 = (combine_pending_stack_adjustment_and_call
3686 preferred_unit_stack_boundary));
3688 }
3692 }
3693 /* Now that the stack is properly aligned, pops can't safely
3694 be deferred during the evaluation of the arguments. */
3695 NO_DEFER_POP;
3697 /* Record the maximum pushed stack space size. We need to delay
3698 doing it this far to take into account the optimization done
3699 by combine_pending_stack_adjustment_and_call. */
3701 && !ACCUMULATE_OUTGOING_ARGS
3702 && pass
3704 {
3708 }
3714 else
3717 #ifdef REG_PARM_STACK_SPACE
3718 /* Save the fixed argument area if it's part of the caller's frame and
3719 is clobbered by argument setup for this call. */
3723 #endif
3725 /* Now store (and compute if necessary) all non-register parms.
3726 These come before register parms, since they can require block-moves,
3727 which could clobber the registers used for register parms.
3728 Parms which have partial registers are not stored here,
3729 but we do preallocate space here if they want that. */
3732 {
3733 /* Delay bounds until all other args are stored. */
3737 {
3740 /* We don't allow passing huge (> 2^30 B) arguments
3741 by value. It would cause an overflow later on. */
3744 {
3747 }
3751 reg_parm_stack_space)
3756 }
3759 call_fusage
3762 call_fusage);
3763 }
3765 /* If we have a parm that is passed in registers but not in memory
3766 and whose alignment does not permit a direct copy into registers,
3767 make a group of pseudos that correspond to each register that we
3768 will later fill. */
3772 /* Now store any partially-in-registers parm.
3773 This is the last place a block-move can happen. */
3777 {
3780 /* On targets with weird calling conventions (e.g. PA) it's
3781 hard to ensure that all cases of argument overlap between
3782 stack and registers work. Play it safe and bail out. */
3784 {
3787 }
3791 reg_parm_stack_space)
3796 }
3801 {
3804 }
3808 /* Figure out the register where the value, if any, will come back. */
3813 {
3815 {
3822 }
3823 else
3824 {
3829 fndecl,
3831 }
3833 /* If VALREG is a PARALLEL whose first member has a zero
3834 offset, use that. This is for targets such as m68k that
3835 return the same value in multiple places. */
3837 {
3844 }
3845 }
3847 /* Store all bounds not passed in registers. */
3849 {
3854 ? NULL
3856 }
3858 /* If register arguments require space on the stack and stack space
3859 was not preallocated, allocate stack space here for arguments
3860 passed in registers. */
3862 && !ACCUMULATE_OUTGOING_ARGS
3866 /* Pass the function the address in which to return a
3867 structure value. */
3869 {
3870 structure_value_addr
3875 NULL_RTX)));
3879 }
3889 /* Save a pointer to the last insn before the call, so that we can
3890 later safely search backwards to find the CALL_INSN. */
3893 /* Set up next argument register. For sibling calls on machines
3894 with register windows this should be the incoming register. */
3897 VOIDmode,
3898 void_type_node,
3900 else
3906 {
3912 && valreg
3915 call_fusage
3918 call_fusage);
3919 }
3920 /* All arguments and registers used for the call must be set up by
3921 now! */
3923 /* Stack must be properly aligned now. */
3927 /* Generate the actual call instruction. */
3934 {
3938 {
3942 }
3945 }
3947 /* If the call setup or the call itself overlaps with anything
3948 of the argument setup we probably clobbered our call address.
3949 In that case we can't do sibcalls. */
3954 /* If a non-BLKmode value is returned at the most significant end
3955 of a register, shift the register right by the appropriate amount
3956 and update VALREG accordingly. BLKmode values are handled by the
3957 group load/store machinery below. */
3959 && !pcc_struct_value
3964 {
3968 }
3971 {
3975 /* The return value from a malloc-like function is a pointer. */
3981 /* The return value from a malloc-like function can not alias
3982 anything else. */
3986 /* Write out the sequence. */
3991 }
3993 /* For calls to `setjmp', etc., inform
3994 function.c:setjmp_warnings that it should complain if
3995 nonvolatile values are live. For functions that cannot
3996 return, inform flow that control does not fall through. */
3999 {
4000 /* The barrier must be emitted
4001 immediately after the CALL_INSN. Some ports emit more
4002 than just a CALL_INSN above, so we must search for it here. */
4006 {
4008 /* There was no CALL_INSN? */
4010 }
4014 /* Stack adjustments after a noreturn call are dead code.
4015 However when NO_DEFER_POP is in effect, we must preserve
4016 stack_pointer_delta. */
4018 {
4021 }
4022 }
4024 /* If value type not void, return an rtx for the value. */
4030 {
4032 {
4033 target
4036 structure_value_addr));
4038 }
4039 }
4041 {
4042 /* This is the special C++ case where we need to
4043 know what the true target was. We take care to
4044 never use this value more than once in one expression. */
4048 }
4049 /* Handle calls that return values in multiple non-contiguous locations.
4050 The Irix 6 ABI has examples of this. */
4052 {
4056 ;
4058 /* Handle the result of a emit_group_move_into_temps
4059 call in the previous pass. */
4061 else
4064 }
4068 {
4071 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
4072 reg to a plain register. */
4076 /* If TARGET is a MEM in the argument area, and we have
4077 saved part of the argument area, then we can't store
4078 directly into TARGET as it may get overwritten when we
4079 restore the argument save area below. Don't work too
4080 hard though and simply force TARGET to a register if it
4081 is a MEM; the optimizer is quite likely to sort it out. */
4085 {
4088 }
4092 else
4093 {
4094 /* TARGET and VALREG cannot be equal at this point
4095 because the latter would not have
4096 REG_FUNCTION_VALUE_P true, while the former would if
4097 it were referring to the same register.
4099 If they refer to the same register, this move will be
4100 a no-op, except when function inlining is being
4101 done. */
4104 /* If we are setting a MEM, this code must be executed.
4105 Since it is emitted after the call insn, sibcall
4106 optimization cannot be performed in that case. */
4109 }
4110 }
4111 else
4114 /* If we promoted this return value, make the proper SUBREG.
4115 TARGET might be const0_rtx here, so be careful. */
4119 {
4123 machine_mode pmode;
4125 /* Ensure we promote as expected, and get the new unsignedness. */
4133 {
4140 }
4145 }
4147 /* If size of args is variable or this was a constructor call for a stack
4148 argument, restore saved stack-pointer value. */
4151 {
4165 }
4167 {
4168 #ifdef REG_PARM_STACK_SPACE
4172 #endif
4174 /* If we saved any argument areas, restore them. */
4177 {
4179 rtx stack_area
4186 else
4189 BLOCK_OP_CALL_PARM);
4190 }
4194 }
4196 /* If this was alloca, record the new stack level. */
4200 /* Free up storage we no longer need. */
4210 {
4213 /* Restore the pending stack adjustment now that we have
4214 finished generating the sibling call sequence. */
4218 /* Prepare arg structure for next iteration. */
4220 {
4224 }
4229 }
4230 else
4231 {
4234 /* Verify that we've deallocated all the stack we used. */
4236 || (old_stack_allocated
4238 }
4240 /* If something prevents making this a sibling call,
4241 zero out the sequence. */
4244 else
4246 }
4248 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
4249 arguments too, as argument area is now clobbered by the call. */
4251 {
4254 }
4255 else
4256 {
4259 /* Ideally we'd emit a message for all of the ways that it could
4260 have failed. */
4262 }
4264 currently_expanding_call--;
4269 /* Join result with returned bounds so caller may use them if needed. */
4273 }
4275 /* A sibling call sequence invalidates any REG_EQUIV notes made for
4276 this function's incoming arguments.
4278 At the start of RTL generation we know the only REG_EQUIV notes
4279 in the rtl chain are those for incoming arguments, so we can look
4280 for REG_EQUIV notes between the start of the function and the
4281 NOTE_INSN_FUNCTION_BEG.
4283 This is (slight) overkill. We could keep track of the highest
4284 argument we clobber and be more selective in removing notes, but it
4285 does not seem to be worth the effort. */
4287 void
4289 {
4293 {
4294 rtx note;
4296 /* There are never REG_EQUIV notes for the incoming arguments
4297 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
4307 }
4308 }
4310 /* Traverse a list of TYPES and expand all complex types into their
4311 components. */
4312 static tree
4314 {
4315 tree p;
4317 /* Before allocating memory, check for the common case of no complex. */
4319 {
4324 }
4327 found:
4331 {
4336 {
4339 /* Rewrite complex type with component type. */
4343 /* Add another component type for the imaginary part. */
4348 /* Skip the newly created node. */
4350 }
4351 }
4354 }
4355 \f
4356 /* Output a library call to function FUN (a SYMBOL_REF rtx).
4357 The RETVAL parameter specifies whether return value needs to be saved, other
4358 parameters are documented in the emit_library_call function below. */
4360 static rtx
4364 {
4365 /* Total size in bytes of all the stack-parms scanned so far. */
4367 /* Size of arguments before any adjustments (such as rounding). */
4370 rtx fun;
4371 /* Todo, choose the correct decl type of orgfun. Sadly this information
4372 isn't present here, so we default to native calling abi here. */
4377 CUMULATIVE_ARGS args_so_far_v;
4378 cumulative_args_t args_so_far;
4379 struct arg
4380 {
4381 rtx value;
4382 machine_mode mode;
4383 rtx reg;
4386 rtx save_area;
4387 };
4392 rtx valreg;
4402 #ifdef REG_PARM_STACK_SPACE
4403 /* Define the boundary of the register parm stack space that needs to be
4404 save, if any. */
4407 #endif
4409 /* Size of the stack reserved for parameter registers. */
4416 #ifdef REG_PARM_STACK_SPACE
4418 #endif
4420 /* By default, library functions cannot throw. */
4424 {
4442 }
4445 /* Ensure current function's preferred stack boundary is at least
4446 what we need. */
4450 /* If this kind of value comes back in memory,
4451 decide where in memory it should come back. */
4453 {
4456 {
4457 #ifdef PCC_STATIC_STRUCT_RETURN
4458 rtx pointer_reg
4468 else
4470 #endif
4471 /* This call returns a big structure. */
4473 }
4474 }
4475 else
4478 /* ??? Unfinished: must pass the memory address as an argument. */
4480 /* Copy all the libcall-arguments out of the varargs data
4481 and into a vector ARGVEC.
4483 Compute how to pass each argument. We only support a very small subset
4484 of the full argument passing conventions to limit complexity here since
4485 library functions shouldn't have many args. */
4490 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
4492 #else
4494 #endif
4504 /* If there's a structure value address to be passed,
4505 either pass it in the special place, or pass it as an extra argument. */
4507 {
4510 nargs++;
4512 /* Make sure it is a reasonable operand for a move or push insn. */
4528 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4530 #else
4532 #endif
4542 count++;
4543 }
4546 {
4551 /* We cannot convert the arg value to the mode the library wants here;
4552 must do it earlier where we know the signedness of the arg. */
4556 /* Make sure it is a reasonable operand for a move or push insn. */
4562 {
4563 rtx slot;
4564 int must_copy
4567 /* If this was a CONST function, it is now PURE since it now
4568 reads memory. */
4570 {
4573 }
4576 {
4581 }
4582 else
4583 {
4587 }
4591 call_fusage);
4595 slot),
4596 call_fusage);
4600 }
4614 {
4616 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4618 #else
4620 #endif
4625 }
4626 #ifdef BLOCK_REG_PADDING
4627 else
4628 /* The argument is passed entirely in registers. See at which
4629 end it should be padded. */
4633 #endif
4636 }
4638 /* If this machine requires an external definition for library
4639 functions, write one out. */
4644 + stack_pointer_delta
4646 / STACK_BYTES
4651 reg_parm_stack_space);
4660 {
4664 }
4667 {
4668 /* Since the stack pointer will never be pushed, it is possible for
4669 the evaluation of a parm to clobber something we have already
4670 written to the stack. Since most function calls on RISC machines
4671 do not use the stack, this is uncommon, but must work correctly.
4673 Therefore, we save any area of the stack that was already written
4674 and that we are using. Here we set up to do this by making a new
4675 stack usage map from the old one.
4677 Another approach might be to try to reorder the argument
4678 evaluations to avoid this conflicting stack usage. */
4682 /* Since we will be writing into the entire argument area, the
4683 map must be allocated for its entire size, not just the part that
4684 is the responsibility of the caller. */
4691 else
4699 initial_highest_arg_in_use);
4706 /* We must be careful to use virtual regs before they're instantiated,
4707 and real regs afterwards. Loop optimization, for example, can create
4708 new libcalls after we've instantiated the virtual regs, and if we
4709 use virtuals anyway, they won't match the rtl patterns. */
4713 STACK_POINTER_OFFSET);
4714 else
4716 }
4717 else
4718 {
4721 }
4723 /* We push args individually in reverse order, perform stack alignment
4724 before the first push (the last arg). */
4731 #ifdef REG_PARM_STACK_SPACE
4733 {
4734 /* The argument list is the property of the called routine and it
4735 may clobber it. If the fixed area has been used for previous
4736 parameters, we must save and restore it. */
4739 }
4740 #endif
4742 /* When expanding a normal call, args are stored in push order,
4743 which is the reverse of what we have here. */
4747 {
4750 }
4754 /* Push the args that need to be pushed. */
4758 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4759 are to be pushed. */
4761 {
4770 {
4771 rtx use;
4774 {
4775 /* If this is being stored into a pre-allocated, fixed-size,
4776 stack area, save any previous data at that location. */
4779 {
4780 /* stack_slot is negative, but we want to index stack_usage_map
4781 with positive values. */
4784 }
4785 else
4786 {
4789 }
4792 /* Don't worry about things in the fixed argument area;
4793 it has already been saved. */
4797 i++;
4800 {
4801 /* We need to make a save area. */
4802 unsigned int size
4804 machine_mode save_mode
4806 rtx adr
4809 rtx stack_area
4813 {
4817 );
4821 stack_area,
4823 BLOCK_OP_CALL_PARM);
4824 }
4825 else
4826 {
4830 }
4831 }
4832 }
4837 reg_parm_stack_space,
4840 /* Now mark the segment we just used. */
4845 NO_DEFER_POP;
4847 /* Indicate argument access so that alias.c knows that these
4848 values are live. */
4854 else
4855 {
4856 /* When arguments are pushed, trying to tell alias.c where
4857 exactly this argument is won't work, because the
4858 auto-increment causes confusion. So we merely indicate
4859 that we access something with a known mode somewhere on
4860 the stack. */
4864 }
4868 }
4869 }
4875 /* Now load any reg parms into their regs. */
4877 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4878 are to be pushed. */
4880 {
4885 #ifdef BLOCK_REG_PADDING
4887 #endif
4889 /* Handle calls that pass values in multiple non-contiguous
4890 locations. The PA64 has examples of this for library calls. */
4894 {
4896 #ifdef BLOCK_REG_PADDING
4899 /* Copied from load_register_parameters. */
4901 /* Handle case where we have a value that needs shifting
4902 up to the msb. eg. a QImode value and we're padding
4903 upward on a BYTES_BIG_ENDIAN machine. */
4907 {
4908 rtx x;
4911 /* Assigning REG here rather than a temp makes CALL_FUSAGE
4912 report the whole reg as used. Strictly speaking, the
4913 call only uses SIZE bytes at the msb end, but it doesn't
4914 seem worth generating rtl to say that. */
4919 }
4920 #endif
4921 }
4923 NO_DEFER_POP;
4924 }
4926 /* Any regs containing parms remain in use through the call. */
4928 {
4933 {
4936 {
4941 }
4942 else
4944 }
4945 }
4947 /* Pass the function the address in which to return a structure value. */
4949 {
4953 NULL_RTX)));
4956 }
4958 /* Don't allow popping to be deferred, since then
4959 cse'ing of library calls could delete a call and leave the pop. */
4960 NO_DEFER_POP;
4964 /* Stack must be properly aligned now. */
4970 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
4971 will set inhibit_defer_pop to that value. */
4972 /* The return type is needed to decide how many bytes the function pops.
4973 Signedness plays no role in that, so for simplicity, we pretend it's
4974 always signed. We also assume that the list of arguments passed has
4975 no impact, so we pretend it is unknown. */
4981 struct_value_size,
4984 valreg,
4988 {
4993 }
4995 /* Right-shift returned value if necessary. */
4999 {
5002 }
5006 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
5007 that it should complain if nonvolatile values are live. For
5008 functions that cannot return, inform flow that control does not
5009 fall through. */
5011 {
5012 /* The barrier note must be emitted
5013 immediately after the CALL_INSN. Some ports emit more than
5014 just a CALL_INSN above, so we must search for it here. */
5017 {
5019 /* There was no CALL_INSN? */
5021 }
5024 }
5026 /* Consider that "regular" libcalls, i.e. all of them except for LCT_THROW
5027 and LCT_RETURNS_TWICE, cannot perform non-local gotos. */
5029 {
5032 {
5034 /* There was no CALL_INSN? */
5036 }
5039 }
5041 /* Now restore inhibit_defer_pop to its actual original value. */
5042 OK_DEFER_POP;
5046 /* Copy the value to the right place. */
5048 {
5050 {
5055 }
5057 {
5061 }
5062 else
5063 {
5064 /* Convert to the proper mode if a promotion has been active. */
5066 {
5073 }
5077 else
5079 }
5080 }
5083 {
5084 #ifdef REG_PARM_STACK_SPACE
5088 #endif
5090 /* If we saved any argument areas, restore them. */
5093 {
5102 validize_mem
5105 BLOCK_OP_CALL_PARM);
5106 else
5108 }
5112 }
5118 }
5119 \f
5120 /* Output a library call to function FUN (a SYMBOL_REF rtx)
5121 (emitting the queue unless NO_QUEUE is nonzero),
5122 for a value of mode OUTMODE,
5123 with NARGS different arguments, passed as alternating rtx values
5124 and machine_modes to convert them to.
5126 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
5127 `const' calls, LCT_PURE for `pure' calls, or other LCT_ value for
5128 other types of library calls. */
5130 void
5133 {
5139 }
5140 \f
5141 /* Like emit_library_call except that an extra argument, VALUE,
5142 comes second and says where to store the result.
5143 (If VALUE is zero, this function chooses a convenient way
5144 to return the value.
5146 This function returns an rtx for where the value is to be found.
5147 If VALUE is nonzero, VALUE is returned. */
5149 rtx
5153 {
5154 rtx result;
5163 }
5164 \f
5166 /* Store pointer bounds argument ARG into Bounds Table entry
5167 associated with PARM. */
5168 static void
5170 {
5173 /* We may pass bounds not associated with any pointer. */
5175 {
5179 }
5180 /* Find pointer associated with bounds and where it is
5181 passed. */
5182 else
5183 {
5185 {
5189 }
5191 {
5199 else
5200 {
5203 }
5204 }
5205 else
5206 {
5215 else
5217 }
5218 }
5220 /* Expand bounds. */
5225 }
5227 /* Store a single argument for a function call
5228 into the register or memory area where it must be passed.
5229 *ARG describes the argument value and where to pass it.
5231 ARGBLOCK is the address of the stack-block for all the arguments,
5232 or 0 on a machine where arguments are pushed individually.
5234 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
5235 so must be careful about how the stack is used.
5237 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
5238 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
5239 that we need not worry about saving and restoring the stack.
5241 FNDECL is the declaration of the function we are calling.
5243 Return nonzero if this arg should cause sibcall failure,
5244 zero otherwise. */
5246 static int
5249 {
5260 /* Push a new temporary level for any temporaries we make for
5261 this argument. */
5265 {
5266 /* If this is being stored into a pre-allocated, fixed-size, stack area,
5267 save any previous data at that location. */
5269 {
5271 {
5272 /* stack_slot is negative, but we want to index stack_usage_map
5273 with positive values. */
5276 else
5280 }
5281 else
5282 {
5285 else
5289 }
5292 /* Don't worry about things in the fixed argument area;
5293 it has already been saved. */
5297 i++;
5300 {
5301 /* We need to make a save area. */
5308 {
5309 arg->save_area
5313 stack_area,
5315 BLOCK_OP_CALL_PARM);
5316 }
5317 else
5318 {
5321 }
5322 }
5323 }
5324 }
5326 /* If this isn't going to be placed on both the stack and in registers,
5327 set up the register and number of words. */
5329 {
5332 else
5335 }
5337 /* Being passed entirely in a register. We shouldn't be called in
5338 this case. */
5341 /* If this arg needs special alignment, don't load the registers
5342 here. */
5346 /* If this is being passed partially in a register, we can't evaluate
5347 it directly into its stack slot. Otherwise, we can. */
5349 {
5350 /* stack_arg_under_construction is nonzero if a function argument is
5351 being evaluated directly into the outgoing argument list and
5352 expand_call must take special action to preserve the argument list
5353 if it is called recursively.
5355 For scalar function arguments stack_usage_map is sufficient to
5356 determine which stack slots must be saved and restored. Scalar
5357 arguments in general have pass_on_stack == 0.
5359 If this argument is initialized by a function which takes the
5360 address of the argument (a C++ constructor or a C function
5361 returning a BLKmode structure), then stack_usage_map is
5362 insufficient and expand_call must push the stack around the
5363 function call. Such arguments have pass_on_stack == 1.
5365 Note that it is always safe to set stack_arg_under_construction,
5366 but this generates suboptimal code if set when not needed. */
5369 stack_arg_under_construction++;
5372 (partial
5377 /* If we are promoting object (or for any other reason) the mode
5378 doesn't agree, convert the mode. */
5385 stack_arg_under_construction--;
5386 }
5388 /* Check for overlap with already clobbered argument area. */
5395 /* Don't allow anything left on stack from computation
5396 of argument to alloca. */
5401 /* If the value is already in the stack slot, we are done. */
5402 ;
5404 {
5408 /* Argument is a scalar, not entirely passed in registers.
5409 (If part is passed in registers, arg->partial says how much
5410 and emit_push_insn will take care of putting it there.)
5412 Push it, and if its size is less than the
5413 amount of space allocated to it,
5414 also bump stack pointer by the additional space.
5415 Note that in C the default argument promotions
5416 will prevent such mismatches. */
5419 /* Compute how much space the push instruction will push.
5420 On many machines, pushing a byte will advance the stack
5421 pointer by a halfword. */
5422 #ifdef PUSH_ROUNDING
5424 #endif
5427 /* Compute how much space the argument should get:
5428 round up to a multiple of the alignment for arguments. */
5434 /* Compute the alignment of the pushed argument. */
5437 {
5440 {
5443 }
5444 }
5446 /* This isn't already where we want it on the stack, so put it there.
5447 This can either be done with push or copy insns. */
5454 /* Unless this is a partially-in-register argument, the argument is now
5455 in the stack. */
5458 }
5459 else
5460 {
5461 /* BLKmode, at least partly to be pushed. */
5465 rtx size_rtx;
5467 /* Pushing a nonscalar.
5468 If part is passed in registers, PARTIAL says how much
5469 and emit_push_insn will take care of putting it there. */
5471 /* Round its size up to a multiple
5472 of the allocation unit for arguments. */
5475 {
5478 }
5479 else
5480 {
5481 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
5482 for BLKmode is careful to avoid it. */
5488 EXPAND_NORMAL);
5489 }
5493 /* When an argument is padded down, the block is aligned to
5494 PARM_BOUNDARY, but the actual argument isn't. */
5496 {
5500 {
5503 }
5504 }
5507 {
5508 /* emit_push_insn might not work properly if arg->value and
5509 argblock + arg->locate.offset areas overlap. */
5518 {
5522 /* arg.locate doesn't contain the pretend_args_size offset,
5523 it's part of argblock. Ensure we don't count it in I. */
5526 else
5529 /* expand_call should ensure this. */
5535 {
5538 }
5540 {
5541 /* Use arg->locate.size.constant instead of size_rtx
5542 because we only care about the part of the argument
5543 on the stack. */
5547 }
5548 else
5549 {
5550 /* Even though they appear to be at the same location,
5551 if part of the outgoing argument is in registers,
5552 they aren't really at the same location. Check for
5553 this by making sure that the incoming size is the
5554 same as the outgoing size. */
5557 }
5558 }
5559 }
5566 /* Unless this is a partially-in-register argument, the argument is now
5567 in the stack.
5569 ??? Unlike the case above, in which we want the actual
5570 address of the data, so that we can load it directly into a
5571 register, here we want the address of the stack slot, so that
5572 it's properly aligned for word-by-word copying or something
5573 like that. It's not clear that this is always correct. */
5576 }
5579 {
5581 arg->parallel_value
5584 }
5586 /* Mark all slots this store used. */
5592 /* Once we have pushed something, pops can't safely
5593 be deferred during the rest of the arguments. */
5594 NO_DEFER_POP;
5596 /* Free any temporary slots made in processing this argument. */
5600 }
5602 /* Nonzero if we do not know how to pass TYPE solely in registers. */
5604 bool
5606 const_tree type)
5607 {
5611 /* If the type has variable size... */
5615 /* If the type is marked as addressable (it is required
5616 to be constructed into the stack)... */
5621 }
5623 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
5624 takes trailing padding of a structure into account. */
5625 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
5627 bool
5629 {
5633 /* If the type has variable size... */
5637 /* If the type is marked as addressable (it is required
5638 to be constructed into the stack)... */
5642 /* If the padding and mode of the type is such that a copy into
5643 a register would put it into the wrong part of the register. */
5651 }