| blob | 8ae9899008843ae51b2699e41d52d3e2df95b648 |
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/>. */
58 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
59 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
61 /* Data structure and subroutines used within expand_call. */
63 struct arg_data
64 {
65 /* Tree node for this argument. */
66 tree tree_value;
67 /* Mode for value; TYPE_MODE unless promoted. */
68 machine_mode mode;
69 /* Current RTL value for argument, or 0 if it isn't precomputed. */
70 rtx value;
71 /* Initially-compute RTL value for argument; only for const functions. */
72 rtx initial_value;
73 /* Register to pass this argument in, 0 if passed on stack, or an
74 PARALLEL if the arg is to be copied into multiple non-contiguous
75 registers. */
76 rtx reg;
77 /* Register to pass this argument in when generating tail call sequence.
78 This is not the same register as for normal calls on machines with
79 register windows. */
80 rtx tail_call_reg;
81 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
82 form for emit_group_move. */
83 rtx parallel_value;
84 /* If value is passed in neither reg nor stack, this field holds a number
85 of a special slot to be used. */
86 rtx special_slot;
87 /* For pointer bounds hold an index of parm bounds are bound to. -1 if
88 there is no such pointer. */
90 /* If pointer_arg refers a structure, then pointer_offset holds an offset
91 of a pointer in this structure. */
93 /* If REG was promoted from the actual mode of the argument expression,
94 indicates whether the promotion is sign- or zero-extended. */
96 /* Number of bytes to put in registers. 0 means put the whole arg
97 in registers. Also 0 if not passed in registers. */
99 /* Nonzero if argument must be passed on stack.
100 Note that some arguments may be passed on the stack
101 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
102 pass_on_stack identifies arguments that *cannot* go in registers. */
104 /* Some fields packaged up for locate_and_pad_parm. */
106 /* Location on the stack at which parameter should be stored. The store
107 has already been done if STACK == VALUE. */
108 rtx stack;
109 /* Location on the stack of the start of this argument slot. This can
110 differ from STACK if this arg pads downward. This location is known
111 to be aligned to TARGET_FUNCTION_ARG_BOUNDARY. */
112 rtx stack_slot;
113 /* Place that this stack area has been saved, if needed. */
114 rtx save_area;
115 /* If an argument's alignment does not permit direct copying into registers,
116 copy in smaller-sized pieces into pseudos. These are stored in a
117 block pointed to by this field. The next field says how many
118 word-sized pseudos we made. */
121 };
123 /* A vector of one char per byte of stack space. A byte if nonzero if
124 the corresponding stack location has been used.
125 This vector is used to prevent a function call within an argument from
126 clobbering any stack already set up. */
129 /* Size of STACK_USAGE_MAP. */
132 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
133 stack location's tail call argument has been already stored into the stack.
134 This bitmap is used to prevent sibling call optimization if function tries
135 to use parent's incoming argument slots when they have been already
136 overwritten with tail call arguments. */
139 /* stack_arg_under_construction is nonzero when an argument may be
140 initialized with a constructor call (including a C function that
141 returns a BLKmode struct) and expand_call must take special action
142 to make sure the object being constructed does not overlap the
143 argument list for the constructor call. */
148 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);
212 /* Avoid long live ranges around function calls. */
218 /* Emit the runtime identification pattern. */
221 call_lab);
223 /* Statically predict the branch to very likely taken. */
228 /* Load the descriptor. */
237 POINTER_SIZE / BITS_PER_UNIT
246 {
249 }
251 /* Make sure we're not going to be overwritten below. */
253 }
255 /* If we are using registers for parameters, force the
256 function address into a register now. */
257 funexp = ((reg_parm_seen
261 }
262 else
263 {
264 /* funexp could be a SYMBOL_REF represents a function pointer which is
265 of ptr_mode. In this case, it should be converted into address mode
266 to be a valid address for memory rtx pattern. See PR 64971. */
271 {
274 }
275 }
280 {
281 rtx chain;
288 {
291 }
292 }
295 }
297 /* Generate instructions to call function FUNEXP,
298 and optionally pop the results.
299 The CALL_INSN is the first insn generated.
301 FNDECL is the declaration node of the function. This is given to the
302 hook TARGET_RETURN_POPS_ARGS to determine whether this function pops
303 its own args.
305 FUNTYPE is the data type of the function. This is given to the hook
306 TARGET_RETURN_POPS_ARGS to determine whether this function pops its
307 own args. We used to allow an identifier for library functions, but
308 that doesn't work when the return type is an aggregate type and the
309 calling convention says that the pointer to this aggregate is to be
310 popped by the callee.
312 STACK_SIZE is the number of bytes of arguments on the stack,
313 ROUNDED_STACK_SIZE is that number rounded up to
314 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
315 both to put into the call insn and to generate explicit popping
316 code if necessary.
318 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
319 It is zero if this call doesn't want a structure value.
321 NEXT_ARG_REG is the rtx that results from executing
322 targetm.calls.function_arg (&args_so_far, VOIDmode, void_type_node, true)
323 just after all the args have had their registers assigned.
324 This could be whatever you like, but normally it is the first
325 arg-register beyond those used for args in this call,
326 or 0 if all the arg-registers are used in this call.
327 It is passed on to `gen_call' so you can put this info in the call insn.
329 VALREG is a hard register in which a value is returned,
330 or 0 if the call does not return a value.
332 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
333 the args to this call were processed.
334 We restore `inhibit_defer_pop' to that value.
336 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
337 denote registers used by the called function. */
339 static void
341 tree funtype ATTRIBUTE_UNUSED,
342 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
343 HOST_WIDE_INT rounded_stack_size,
344 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
347 cumulative_args_t args_so_far ATTRIBUTE_UNUSED)
348 {
354 /* Sibling call patterns never pop arguments (no sibcall(_value)_pop
355 patterns exist). Any popping that the callee does on return will
356 be from our caller's frame rather than ours. */
358 {
361 #ifdef CALL_POPS_ARGS
363 #endif
364 }
366 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
367 and we don't want to load it into a register as an optimization,
368 because prepare_call_address already did it if it should be done. */
374 {
377 /* Although a built-in FUNCTION_DECL and its non-__builtin
378 counterpart compare equal and get a shared mem_attrs, they
379 produce different dump output in compare-debug compilations,
380 if an entry gets garbage collected in one compilation, then
381 adds a different (but equivalent) entry, while the other
382 doesn't run the garbage collector at the same spot and then
383 shares the mem_attr with the equivalent entry. */
385 {
389 }
392 }
397 {
400 rounded_stack_size_rtx,
402 else
405 }
406 /* If the target has "call" or "call_value" insns, then prefer them
407 if no arguments are actually popped. If the target does not have
408 "call" or "call_value" insns, then we must use the popping versions
409 even if the call has no arguments to pop. */
411 || !(valreg
414 {
417 /* If this subroutine pops its own args, record that in the call insn
418 if possible, for the sake of frame pointer elimination. */
422 rounded_stack_size_rtx,
424 else
429 }
430 else
431 {
435 else
438 }
441 /* Find the call we just emitted. */
444 /* Some target create a fresh MEM instead of reusing the one provided
445 above. Set its MEM_EXPR. */
452 /* Mark instrumented calls. */
456 /* Put the register usage information there. */
459 /* If this is a const call, then set the insn's unchanging bit. */
463 /* If this is a pure call, then set the insn's unchanging bit. */
467 /* If this is a const call, then set the insn's unchanging bit. */
471 /* Create a nothrow REG_EH_REGION note, if needed. */
478 {
481 }
485 /* Restore this now, so that we do defer pops for this call's args
486 if the context of the call as a whole permits. */
490 {
502 /* If popup is needed, stack realign must use DRAP */
505 }
506 /* For noreturn calls when not accumulating outgoing args force
507 REG_ARGS_SIZE note to prevent crossjumping of calls with different
508 args sizes. */
513 {
514 /* If returning from the subroutine does not automatically pop the args,
515 we need an instruction to pop them sooner or later.
516 Perhaps do it now; perhaps just record how much space to pop later.
518 If returning from the subroutine does pop the args, indicate that the
519 stack pointer will be changed. */
522 {
524 /* Just pretend we did the pop. */
529 else
531 }
532 }
533 /* When we accumulate outgoing args, we must avoid any stack manipulations.
534 Restore the stack pointer to its original value now. Usually
535 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
536 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
537 popping variants of functions exist as well.
539 ??? We may optimize similar to defer_pop above, but it is
540 probably not worthwhile.
542 ??? It will be worthwhile to enable combine_stack_adjustments even for
543 such machines. */
546 }
548 /* Determine if the function identified by FNDECL is one with
549 special properties we wish to know about. Modify FLAGS accordingly.
551 For example, if the function might return more than one time (setjmp), then
552 set ECF_RETURNS_TWICE.
554 Set ECF_MAY_BE_ALLOCA for any memory allocation function that might allocate
555 space from the stack such as alloca. */
557 static int
559 {
562 /* For instrumentation clones we want to derive flags
563 from the original name. */
570 /* Exclude functions not at the file scope, or not `extern',
571 since they are not the magic functions we would otherwise
572 think they are.
573 FIXME: this should be handled with attributes, not with this
574 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
575 because you can declare fork() inside a function if you
576 wish. */
580 {
584 /* We assume that alloca will always be called by name. It
585 makes no sense to pass it as a pointer-to-function to
586 anything that does not understand its behavior. */
592 /* Disregard prefix _ or __. */
594 {
597 else
599 }
601 /* ECF_RETURNS_TWICE is safe even for -ffreestanding. */
608 }
615 }
617 /* Similar to special_function_p; return a set of ERF_ flags for the
618 function FNDECL. */
619 static int
621 {
622 tree attr;
636 {
649 }
650 }
652 /* Return nonzero when FNDECL represents a call to setjmp. */
654 int
656 {
660 }
663 /* Return true if STMT may be an alloca call. */
665 bool
667 {
668 tree fndecl;
678 }
680 /* Return true if STMT is a builtin alloca call. */
682 bool
684 {
685 tree fndecl;
693 {
694 CASE_BUILT_IN_ALLOCA:
698 }
701 }
703 /* Return true when exp contains a builtin alloca call. */
705 bool
707 {
708 tree fndecl;
713 {
714 CASE_BUILT_IN_ALLOCA:
718 }
721 }
723 /* Return TRUE if FNDECL is either a TM builtin or a TM cloned
724 function. Return FALSE otherwise. */
726 static bool
728 {
736 {
738 {
781 }
782 }
784 }
786 /* Detect flags (function attributes) from the function decl or type node. */
788 int
790 {
794 {
795 /* The function exp may have the `malloc' attribute. */
799 /* The function exp may have the `returns_twice' attribute. */
803 /* Process the pure and const attributes. */
822 {
829 }
832 }
834 {
842 }
843 else
847 {
851 }
854 }
856 /* Detect flags from a CALL_EXPR. */
858 int
860 {
868 else
869 {
873 else
877 }
880 }
882 /* Return true if TYPE should be passed by invisible reference. */
884 bool
887 {
889 {
890 /* If this type contains non-trivial constructors, then it is
891 forbidden for the middle-end to create any new copies. */
895 /* GCC post 3.4 passes *all* variable sized types by reference. */
899 /* If a record type should be passed the same as its first (and only)
900 member, use the type and mode of that member. */
902 {
905 }
906 }
910 }
912 /* Return true if TYPE, which is passed by reference, should be callee
913 copied instead of caller copied. */
915 bool
918 {
922 named_arg);
923 }
926 /* Precompute all register parameters as described by ARGS, storing values
927 into fields within the ARGS array.
929 NUM_ACTUALS indicates the total number elements in the ARGS array.
931 Set REG_PARM_SEEN if we encounter a register parameter. */
933 static void
936 {
943 {
947 {
952 }
954 /* If we are to promote the function arg to a wider mode,
955 do it now. */
963 /* If the value is a non-legitimate constant, force it into a
964 pseudo now. TLS symbols sometimes need a call to resolve. */
969 /* If we're going to have to load the value by parts, pull the
970 parts into pseudos. The part extraction process can involve
971 non-trivial computation. */
973 {
978 }
980 /* If the value is expensive, and we are inside an appropriately
981 short loop, put the value into a pseudo and then put the pseudo
982 into the hard reg.
984 For small register classes, also do this if this call uses
985 register parameters. This is to avoid reload conflicts while
986 loading the parameters registers. */
995 && ((*reg_parm_seen
999 }
1000 }
1002 #ifdef REG_PARM_STACK_SPACE
1004 /* The argument list is the property of the called routine and it
1005 may clobber it. If the fixed area has been used for previous
1006 parameters, we must save and restore it. */
1008 static rtx
1009 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
1010 {
1014 /* Compute the boundary of the area that needs to be saved, if any. */
1024 {
1026 machine_mode save_mode;
1028 rtx addr;
1029 rtx stack_area;
1030 rtx save_area;
1033 ;
1040 /* If we don't have the required alignment, must do this
1041 in BLKmode. */
1042 scalar_int_mode imode;
1047 else
1052 else
1060 {
1064 }
1065 else
1066 {
1069 }
1072 }
1075 }
1077 static void
1079 {
1086 else
1095 else
1098 BLOCK_OP_CALL_PARM);
1099 }
1102 /* If any elements in ARGS refer to parameters that are to be passed in
1103 registers, but not in memory, and whose alignment does not permit a
1104 direct copy into registers. Copy the values into a group of pseudos
1105 which we will later copy into the appropriate hard registers.
1107 Pseudos for each unaligned argument will be stored into the array
1108 args[argnum].aligned_regs. The caller is responsible for deallocating
1109 the aligned_regs array if it is nonzero. */
1111 static void
1113 {
1123 {
1128 {
1131 }
1132 else
1133 {
1136 }
1140 /* Structures smaller than a word are normally aligned to the
1141 least significant byte. On a BYTES_BIG_ENDIAN machine,
1142 this means we must skip the empty high order bytes when
1143 calculating the bit offset. */
1145 #ifdef BLOCK_REG_PADDING
1149 #else
1150 && BYTES_BIG_ENDIAN
1151 #endif
1152 )
1156 {
1165 /* There is no need to restrict this code to loading items
1166 in TYPE_ALIGN sized hunks. The bitfield instructions can
1167 load up entire word sized registers efficiently.
1169 ??? This may not be needed anymore.
1170 We use to emit a clobber here but that doesn't let later
1171 passes optimize the instructions we emit. By storing 0 into
1172 the register later passes know the first AND to zero out the
1173 bitfield being set in the register is unnecessary. The store
1174 of 0 will be deleted as will at least the first AND. */
1181 }
1182 }
1183 }
1185 /* The limit set by -Walloc-larger-than=. */
1188 /* Initialize ALLOC_OBJECT_SIZE_LIMIT based on the -Walloc-size-larger-than=
1189 setting if the option is specified, or to the maximum object size if it
1190 is not. Return the initialized value. */
1192 static tree
1194 {
1196 {
1200 {
1204 unsigned HOST_WIDE_INT limit
1208 {
1210 {
1211 /* Numeric option arguments are at most INT_MAX. Make it
1212 possible to specify a larger value by accepting common
1213 suffixes. */
1240 else
1242 }
1245 {
1249 }
1250 }
1251 }
1252 }
1254 }
1256 /* Return true when EXP's range can be determined and set RANGE[] to it
1257 after adjusting it if necessary to make EXP a valid size argument to
1258 an allocation function declared with attribute alloc_size (whose
1259 argument may be signed), or to a string manipulation function like
1260 memset. */
1262 bool
1264 {
1266 {
1267 /* EXP is a constant. */
1270 }
1273 enum value_range_type range_type
1278 {
1279 /* No range information available. */
1283 }
1291 {
1293 {
1295 {
1296 /* EXP is not in a strictly negative range. That means
1297 it must be in some (not necessarily strictly) positive
1298 range which includes zero. Since in signed to unsigned
1299 conversions negative values end up converted to large
1300 positive values, and otherwise they are not valid sizes,
1301 the resulting range is in both cases [0, TYPE_MAX]. */
1304 }
1306 {
1307 /* EXP is not in a negative-positive range. That means EXP
1308 is either negative, or greater than max. Since negative
1309 sizes are invalid make the range [MAX + 1, TYPE_MAX]. */
1312 }
1313 else
1314 {
1317 }
1318 }
1320 {
1321 /* EXP is unsigned and not in the range [1, MAX]. That means
1322 it's either zero or greater than MAX. Even though 0 would
1323 normally be detected by -Walloc-zero set the range to
1324 [MAX, TYPE_MAX] so that when MAX is greater than the limit
1325 the whole range is diagnosed. */
1328 }
1329 else
1330 {
1333 }
1334 }
1340 }
1342 /* Diagnose a call EXP to function FN decorated with attribute alloc_size
1343 whose argument numbers given by IDX with values given by ARGS exceed
1344 the maximum object size or cause an unsigned oveflow (wrapping) when
1345 multiplied. When ARGS[0] is null the function does nothing. ARGS[1]
1346 may be null for functions like malloc, and non-null for those like
1347 calloc that are decorated with a two-argument attribute alloc_size. */
1349 void
1351 {
1352 /* The range each of the (up to) two arguments is known to be in. */
1355 /* Maximum object size set by -Walloc-size-larger-than= or SIZE_MAX / 2. */
1362 /* Validate each argument individually. */
1364 {
1366 {
1371 {
1375 }
1377 {
1378 /* Avoid issuing -Walloc-zero for allocation functions other
1379 than __builtin_alloca that are declared with attribute
1380 returns_nonnull because there's no portability risk. This
1381 avoids warning for such calls to libiberty's xmalloc and
1382 friends.
1383 Also avoid issuing the warning for calls to function named
1384 "alloca". */
1393 }
1395 {
1396 /* G++ emits calls to ::operator new[](SIZE_MAX) in C++98
1397 mode and with -fno-exceptions as a way to indicate array
1398 size overflow. There's no good way to detect C++98 here
1399 so avoid diagnosing these calls for all C++ modes. */
1408 "%Kargument %i value %qE exceeds "
1411 }
1412 }
1415 {
1416 /* Verify that the argument's range is not negative (including
1417 upper bound of zero). */
1420 {
1425 }
1427 {
1429 "%Kargument %i range [%E, %E] exceeds "
1433 maxobjsize);
1434 }
1435 }
1436 }
1441 /* For a two-argument alloc_size, validate the product of the two
1442 arguments if both of their values or ranges are known. */
1447 {
1448 /* Check for overflow in the product of a function decorated with
1449 attribute alloc_size (X, Y). */
1459 "%Kproduct %<%E * %E%> of arguments %i and %i "
1465 "%Kproduct %<%E * %E%> of arguments %i and %i "
1469 maxobjsize);
1472 {
1473 /* Print the full range of each of the two arguments to make
1474 it clear when it is, in fact, in a range and not constant. */
1481 }
1482 }
1485 {
1491 else
1494 }
1495 }
1497 /* If EXPR refers to a character array or pointer declared attribute
1498 nonstring return a decl for that array or pointer and set *REF to
1499 the referenced enclosing object or pointer. Otherwise returns
1500 null. */
1502 tree
1504 {
1507 {
1511 {
1517 }
1520 }
1536 }
1538 /* Warn about passing a non-string array/pointer to a function that
1539 expects a nul-terminated string argument. */
1541 void
1543 {
1549 /* The bound argument to a bounded string function like strncpy. */
1552 /* It's safe to call "bounded" string functions with a non-string
1553 argument since the functions provide an explicit bound for this
1554 purpose. */
1556 {
1572 }
1574 /* Determine the range of the bound argument (if specified). */
1579 /* Iterate over the built-in function's formal arguments and check
1580 each const char* against the actual argument. If the actual
1581 argument is declared attribute non-string issue a warning unless
1582 the argument's maximum length is bounded. */
1583 function_args_iterator it;
1587 {
1609 /* See if the destination is declared with attribute "nonstring". */
1624 {
1627 }
1635 "%qD argument %i declared attribute %<nonstring%> "
1646 }
1647 }
1649 /* Issue an error if CALL_EXPR was flagged as requiring
1650 tall-call optimization. */
1652 static void
1654 {
1660 }
1662 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1663 CALL_EXPR EXP.
1665 NUM_ACTUALS is the total number of parameters.
1667 N_NAMED_ARGS is the total number of named arguments.
1669 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
1670 value, or null.
1672 FNDECL is the tree code for the target of this call (if known)
1674 ARGS_SO_FAR holds state needed by the target to know where to place
1675 the next argument.
1677 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1678 for arguments which are passed in registers.
1680 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1681 and may be modified by this routine.
1683 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1684 flags which may be modified by this routine.
1686 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
1687 that requires allocation of stack space.
1689 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
1690 the thunked-to function. */
1692 static void
1699 cumulative_args_t args_so_far,
1704 {
1708 /* Count arg position in order args appear. */
1718 /* In this loop, we consider args in the order they are written.
1719 We fill up ARGS from the back. */
1722 {
1724 call_expr_arg_iterator iter;
1725 tree arg;
1729 {
1731 j--;
1733 /* If we pass structure address then we need to
1734 create bounds for it. Since created bounds is
1735 a call statement, we expand it right here to avoid
1736 fixing all other places where it may be expanded. */
1738 {
1745 j--;
1746 }
1747 }
1750 {
1753 /* Remember last param with pointer and associate it
1754 with following pointer bounds. */
1757 {
1762 {
1765 }
1766 }
1770 {
1774 }
1776 {
1777 /* We expect bounds in instrumented calls only.
1778 Otherwise it is a sign we lost flag due to some optimization
1779 and may emit call args incorrectly. */
1782 /* For structures look for the next available pointer. */
1784 {
1791 /* Check we have no more pointers in the structure. */
1794 }
1797 /* Check we covered all pointers in the previous
1798 non bounds arg. */
1801 }
1802 else
1806 && argtype
1809 {
1812 j--;
1814 }
1815 else
1817 j--;
1818 argpos++;
1819 }
1823 }
1827 /* Extract attribute alloc_size and if set, store the indices of
1828 the corresponding arguments in ALLOC_IDX, and then the actual
1829 argument(s) at those indices in ALLOC_ARGS. */
1835 {
1840 }
1842 /* Array for up to the two attribute alloc_size arguments. */
1845 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1847 {
1850 machine_mode mode;
1852 /* Replace erroneous argument with constant zero. */
1856 /* If TYPE is a transparent union or record, pass things the way
1857 we would pass the first field of the union or record. We have
1858 already verified that the modes are the same. */
1863 /* Decide where to pass this arg.
1865 args[i].reg is nonzero if all or part is passed in registers.
1867 args[i].partial is nonzero if part but not all is passed in registers,
1868 and the exact value says how many bytes are passed in registers.
1870 args[i].pass_on_stack is nonzero if the argument must at least be
1871 computed on the stack. It may then be loaded back into registers
1872 if args[i].reg is nonzero.
1874 These decisions are driven by the FUNCTION_... macros and must agree
1875 with those made by function.c. */
1877 /* See if this argument should be passed by invisible reference. */
1880 {
1884 callee_copies
1888 /* If we're compiling a thunk, pass through invisible references
1889 instead of making a copy. */
1891 || (callee_copies
1896 {
1897 /* We may have turned the parameter value into an SSA name.
1898 Go back to the original parameter so we can take the
1899 address. */
1901 {
1905 }
1906 /* Argument setup code may have copied the value to register. We
1907 revert that optimization now because the tail call code must
1908 use the original location. */
1918 /* We can't use sibcalls if a callee-copied argument is
1919 stored in the current function's frame. */
1921 {
1924 "a callee-copied argument is"
1925 " stored in the current "
1927 }
1935 }
1936 else
1937 {
1938 /* We make a copy of the object and pass the address to the
1939 function being called. */
1940 rtx copy;
1947 {
1948 /* This is a variable-sized object. Make space on the stack
1949 for it. */
1953 {
1957 }
1959 /* We can pass TRUE as the 4th argument because we just
1960 saved the stack pointer and will restore it right after
1961 the call. */
1965 max_int_size_in_bytes
1970 }
1971 else
1976 /* Just change the const function to pure and then let
1977 the next test clear the pure based on
1978 callee_copies. */
1980 {
1983 }
1993 "argument must be passed"
1995 }
1996 }
2011 {
2014 }
2016 /* If this is a sibling call and the machine has register windows, the
2017 register window has to be unwinded before calling the routine, so
2018 arguments have to go into the incoming registers. */
2023 else
2033 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
2034 it means that we are to pass this arg in the register(s) designated
2035 by the PARALLEL, but also to pass it in the stack. */
2040 /* If this is an addressable type, we must preallocate the stack
2041 since we must evaluate the object into its final location.
2043 If this is to be passed in both registers and the stack, it is simpler
2044 to preallocate. */
2049 /* No stack allocation and padding for bounds. */
2051 ;
2052 /* Compute the stack-size of this argument. */
2057 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2059 #else
2061 #endif
2062 reg_parm_stack_space,
2065 #ifdef BLOCK_REG_PADDING
2066 else
2067 /* The argument is passed entirely in registers. See at which
2068 end it should be padded. */
2072 #endif
2074 /* Update ARGS_SIZE, the total stack space for args so far. */
2080 /* Increment ARGS_SO_FAR, which has info about which arg-registers
2081 have been used, etc. */
2086 /* Store argument values for functions decorated with attribute
2087 alloc_size. */
2092 }
2095 {
2096 /* Check the arguments of functions decorated with attribute
2097 alloc_size. */
2099 }
2101 /* Detect passing non-string arguments to functions expecting
2102 nul-terminated strings. */
2104 }
2106 /* Update ARGS_SIZE to contain the total size for the argument block.
2107 Return the original constant component of the argument block's size.
2109 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
2110 for arguments passed in registers. */
2112 static int
2115 tree fndecl ATTRIBUTE_UNUSED,
2116 tree fntype ATTRIBUTE_UNUSED,
2118 {
2121 /* For accumulate outgoing args mode we don't need to align, since the frame
2122 will be already aligned. Align to STACK_BOUNDARY in order to prevent
2123 backends from generating misaligned frame sizes. */
2127 /* Compute the actual size of the argument block required. The variable
2128 and constant sizes must be combined, the size may have to be rounded,
2129 and there may be a minimum required size. */
2132 {
2138 {
2139 /* We don't handle this case yet. To handle it correctly we have
2140 to add the delta, round and subtract the delta.
2141 Currently no machine description requires this support. */
2144 }
2147 {
2148 args_size->var
2152 /* The area corresponding to register parameters is not to count in
2153 the size of the block we need. So make the adjustment. */
2155 args_size->var
2158 }
2159 }
2160 else
2161 {
2166 + stack_pointer_delta
2168 / preferred_stack_boundary
2173 reg_parm_stack_space);
2177 }
2179 }
2181 /* Precompute parameters as needed for a function call.
2183 FLAGS is mask of ECF_* constants.
2185 NUM_ACTUALS is the number of arguments.
2187 ARGS is an array containing information for each argument; this
2188 routine fills in the INITIAL_VALUE and VALUE fields for each
2189 precomputed argument. */
2191 static void
2193 {
2196 /* If this is a libcall, then precompute all arguments so that we do not
2197 get extraneous instructions emitted as part of the libcall sequence. */
2199 /* If we preallocated the stack space, and some arguments must be passed
2200 on the stack, then we must precompute any parameter which contains a
2201 function call which will store arguments on the stack.
2202 Otherwise, evaluating the parameter may clobber previous parameters
2203 which have already been stored into the stack. (we have code to avoid
2204 such case by saving the outgoing stack arguments, but it results in
2205 worse code) */
2210 {
2211 tree type;
2212 machine_mode mode;
2217 /* If this is an addressable type, we cannot pre-evaluate it. */
2226 {
2232 /* CSE will replace this only if it contains args[i].value
2233 pseudo, so convert it down to the declared mode using
2234 a SUBREG. */
2238 {
2243 }
2244 }
2245 }
2246 }
2248 /* Given the current state of MUST_PREALLOCATE and information about
2249 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
2250 compute and return the final value for MUST_PREALLOCATE. */
2252 static int
2255 {
2256 /* See if we have or want to preallocate stack space.
2258 If we would have to push a partially-in-regs parm
2259 before other stack parms, preallocate stack space instead.
2261 If the size of some parm is not a multiple of the required stack
2262 alignment, we must preallocate.
2264 If the total size of arguments that would otherwise create a copy in
2265 a temporary (such as a CALL) is more than half the total argument list
2266 size, preallocation is faster.
2268 Another reason to preallocate is if we have a machine (like the m88k)
2269 where stack alignment is required to be maintained between every
2270 pair of insns, not just when the call is made. However, we assume here
2271 that such machines either do not have push insns (and hence preallocation
2272 would occur anyway) or the problem is taken care of with
2273 PUSH_ROUNDING. */
2276 {
2282 {
2287 /* We preallocate in case there are bounds passed
2288 in the bounds table to have precomputed address
2289 for bounds association. */
2299 copy_to_evaluate_size
2301 }
2306 }
2308 }
2310 /* If we preallocated stack space, compute the address of each argument
2311 and store it into the ARGS array.
2313 We need not ensure it is a valid memory address here; it will be
2314 validized when it is used.
2316 ARGBLOCK is an rtx for the address of the outgoing arguments. */
2318 static void
2320 {
2322 {
2330 {
2333 rtx addr;
2338 /* Skip this parm if it will not be passed on the stack. */
2344 /* Pointer Bounds are never passed on the stack. */
2352 {
2353 /* Only part of the parameter is being passed on the stack.
2354 Generate a simple memory reference of the correct size. */
2360 }
2361 else
2362 {
2366 }
2372 {
2375 }
2382 {
2383 /* Only part of the parameter is being passed on the stack.
2384 Generate a simple memory reference of the correct size.
2385 */
2388 }
2389 else
2390 {
2394 }
2397 /* Function incoming arguments may overlap with sibling call
2398 outgoing arguments and we cannot allow reordering of reads
2399 from function arguments with stores to outgoing arguments
2400 of sibling calls. */
2403 }
2404 }
2405 }
2407 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
2408 in a call instruction.
2410 FNDECL is the tree node for the target function. For an indirect call
2411 FNDECL will be NULL_TREE.
2413 ADDR is the operand 0 of CALL_EXPR for this call. */
2415 static rtx
2417 {
2418 rtx funexp;
2420 /* Get the function to call, in the form of RTL. */
2422 {
2426 /* Get a SYMBOL_REF rtx for the function address. */
2428 }
2429 else
2430 /* Generate an rtx (probably a pseudo-register) for the address. */
2431 {
2435 }
2437 }
2439 /* Internal state for internal_arg_pointer_based_exp and its helpers. */
2440 static struct
2441 {
2442 /* Last insn that has been scanned by internal_arg_pointer_based_exp_scan,
2443 or NULL_RTX if none has been scanned yet. */
2445 /* Vector indexed by REGNO - FIRST_PSEUDO_REGISTER, recording if a pseudo is
2446 based on crtl->args.internal_arg_pointer. The element is NULL_RTX if the
2447 pseudo isn't based on it, a CONST_INT offset if the pseudo is based on it
2448 with fixed offset, or PC if this is with variable or unknown offset. */
2454 /* Helper function for internal_arg_pointer_based_exp. Scan insns in
2455 the tail call sequence, starting with first insn that hasn't been
2456 scanned yet, and note for each pseudo on the LHS whether it is based
2457 on crtl->args.internal_arg_pointer or not, and what offset from that
2458 that pointer it has. */
2460 static void
2462 {
2467 else
2471 {
2474 {
2477 /* Punt on pseudos set multiple times. */
2482 else
2485 {
2487 internal_arg_pointer_exp_state.cache
2490 }
2491 }
2495 }
2498 }
2500 /* Compute whether RTL is based on crtl->args.internal_arg_pointer. Return
2501 NULL_RTX if RTL isn't based on it, a CONST_INT offset if RTL is based on
2502 it with fixed offset, or PC if this is with variable or unknown offset.
2503 TOPLEVEL is true if the function is invoked at the topmost level. */
2505 static rtx
2507 {
2518 {
2523 }
2525 /* When called at the topmost level, scan pseudo assignments in between the
2526 last scanned instruction in the tail call sequence and the latest insn
2527 in that sequence. */
2532 {
2538 }
2542 {
2548 }
2551 }
2553 /* Return true if and only if SIZE storage units (usually bytes)
2554 starting from address ADDR overlap with already clobbered argument
2555 area. This function is used to determine if we should give up a
2556 sibcall. */
2558 static bool
2560 {
2561 HOST_WIDE_INT i;
2562 rtx val;
2571 else
2576 else
2584 {
2591 }
2594 }
2596 /* Do the register loads required for any wholly-register parms or any
2597 parms which are passed both on the stack and in a register. Their
2598 expressions were already evaluated.
2600 Mark all register-parms as living through the call, putting these USE
2601 insns in the CALL_INSN_FUNCTION_USAGE field.
2603 When IS_SIBCALL, perform the check_sibcall_argument_overlap
2604 checking, setting *SIBCALL_FAILURE if appropriate. */
2606 static void
2610 {
2614 {
2618 {
2623 /* Set non-negative if we must move a word at a time, even if
2624 just one word (e.g, partial == 4 && mode == DFmode). Set
2625 to -1 if we just use a normal move insn. This value can be
2626 zero if the argument is a zero size structure. */
2629 ;
2631 {
2634 }
2636 {
2639 }
2640 else
2643 /* Handle calls that pass values in multiple non-contiguous
2644 locations. The Irix 6 ABI has examples of this. */
2649 /* If simple case, just do move. If normal partial, store_one_arg
2650 has already loaded the register for us. In all other cases,
2651 load the register(s) from memory. */
2654 {
2656 #ifdef BLOCK_REG_PADDING
2657 /* Handle case where we have a value that needs shifting
2658 up to the msb. eg. a QImode value and we're padding
2659 upward on a BYTES_BIG_ENDIAN machine. */
2663 {
2664 rtx x;
2667 /* Assigning REG here rather than a temp makes CALL_FUSAGE
2668 report the whole reg as used. Strictly speaking, the
2669 call only uses SIZE bytes at the msb end, but it doesn't
2670 seem worth generating rtl to say that. */
2675 }
2676 #endif
2677 }
2679 /* If we have pre-computed the values to put in the registers in
2680 the case of non-aligned structures, copy them in now. */
2688 {
2691 /* Check for overlap with already clobbered argument area,
2692 providing that this has non-zero size. */
2695 && (mem_overlaps_already_clobbered_arg_p
2702 else
2703 {
2712 NULL);
2718 }
2720 /* Handle a BLKmode that needs shifting. */
2722 #ifdef BLOCK_REG_PADDING
2724 #else
2725 && BYTES_BIG_ENDIAN
2726 #endif
2727 )
2728 {
2733 rtx x;
2738 }
2739 }
2741 /* When a parameter is a block, and perhaps in other cases, it is
2742 possible that it did a load from an argument slot that was
2743 already clobbered. */
2748 /* Handle calls that pass values in multiple non-contiguous
2749 locations. The Irix 6 ABI has examples of this. */
2757 }
2758 }
2759 }
2761 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
2762 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
2763 bytes, then we would need to push some additional bytes to pad the
2764 arguments. So, we compute an adjust to the stack pointer for an
2765 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
2766 bytes. Then, when the arguments are pushed the stack will be perfectly
2767 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
2768 be popped after the call. Returns the adjustment. */
2770 static int
2774 {
2775 /* The number of bytes to pop so that the stack will be
2776 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
2777 HOST_WIDE_INT adjustment;
2778 /* The alignment of the stack after the arguments are pushed, if we
2779 just pushed the arguments without adjust the stack here. */
2782 unadjusted_alignment
2786 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
2787 as possible -- leaving just enough left to cancel out the
2788 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
2789 PENDING_STACK_ADJUST is non-negative, and congruent to
2790 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
2792 /* Begin by trying to pop all the bytes. */
2793 unadjusted_alignment
2794 = (unadjusted_alignment
2797 /* Push enough additional bytes that the stack will be aligned
2798 after the arguments are pushed. */
2802 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
2803 bytes after the call. The right number is the entire
2804 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
2805 by the arguments in the first place. */
2806 args_size->constant
2810 }
2812 /* Scan X expression if it does not dereference any argument slots
2813 we already clobbered by tail call arguments (as noted in stored_args_map
2814 bitmap).
2815 Return nonzero if X expression dereferences such argument slots,
2816 zero otherwise. */
2818 static int
2820 {
2821 RTX_CODE code;
2830 /* We need not check the operands of the CALL expression itself. */
2838 /* Scan all subexpressions. */
2841 {
2843 {
2846 }
2848 {
2852 }
2853 }
2855 }
2857 /* Scan sequence after INSN if it does not dereference any argument slots
2858 we already clobbered by tail call arguments (as noted in stored_args_map
2859 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
2860 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
2861 should be 0). Return nonzero if sequence after INSN dereferences such argument
2862 slots, zero otherwise. */
2864 static int
2867 {
2872 else
2881 {
2884 else
2889 }
2891 }
2893 /* Given that a function returns a value of mode MODE at the most
2894 significant end of hard register VALUE, shift VALUE left or right
2895 as specified by LEFT_P. Return true if some action was needed. */
2897 bool
2899 {
2900 HOST_WIDE_INT shift;
2907 /* Use ashr rather than lshr for right shifts. This is for the benefit
2908 of the MIPS port, which requires SImode values to be sign-extended
2909 when stored in 64-bit registers. */
2914 }
2916 /* If X is a likely-spilled register value, copy it to a pseudo
2917 register and return that register. Return X otherwise. */
2919 static rtx
2921 {
2922 rtx new_rtx;
2927 {
2928 /* Make sure that we generate a REG rather than a CONCAT.
2929 Moves into CONCATs can need nontrivial instructions,
2930 and the whole point of this function is to avoid
2931 using the hard register directly in such a situation. */
2937 }
2939 }
2941 /* Helper function for expand_call.
2942 Return false is EXP is not implementable as a sibling call. */
2944 static bool
2946 rtx structure_value_addr,
2947 tree funtype,
2949 tree fndecl,
2951 tree addr,
2953 {
2955 {
2956 maybe_complain_about_tail_call
2958 "machine description does not have"
2961 }
2963 /* Doing sibling call optimization needs some work, since
2964 structure_value_addr can be allocated on the stack.
2965 It does not seem worth the effort since few optimizable
2966 sibling calls will return a structure. */
2968 {
2971 }
2973 #ifdef REG_PARM_STACK_SPACE
2974 /* If outgoing reg parm stack space changes, we can not do sibcall. */
2978 {
2980 "inconsistent size of stack space"
2981 " allocated for arguments which are"
2984 }
2985 #endif
2987 /* Check whether the target is able to optimize the call
2988 into a sibcall. */
2990 {
2992 "target is not able to optimize the"
2995 }
2997 /* Functions that do not return exactly once may not be sibcall
2998 optimized. */
3000 {
3003 }
3005 {
3008 }
3011 {
3014 }
3016 /* If the called function is nested in the current one, it might access
3017 some of the caller's arguments, but could clobber them beforehand if
3018 the argument areas are shared. */
3020 {
3023 }
3025 /* If this function requires more stack slots than the current
3026 function, we cannot change it into a sibling call.
3027 crtl->args.pretend_args_size is not part of the
3028 stack allocated by our caller. */
3030 {
3032 "callee required more stack slots"
3035 }
3037 /* If the callee pops its own arguments, then it must pop exactly
3038 the same number of arguments as the current function. */
3043 {
3045 "inconsistent number of"
3048 }
3051 {
3055 }
3057 /* All checks passed. */
3059 }
3061 /* Generate all the code for a CALL_EXPR exp
3062 and return an rtx for its value.
3063 Store the value in TARGET (specified as an rtx) if convenient.
3064 If the value is stored in TARGET then TARGET is returned.
3065 If IGNORE is nonzero, then we ignore the value of the function call. */
3067 rtx
3069 {
3070 /* Nonzero if we are currently expanding a call. */
3073 /* RTX for the function to be called. */
3074 rtx funexp;
3075 /* Sequence of insns to perform a normal "call". */
3077 /* Sequence of insns to perform a tail "call". */
3079 /* Data type of the function. */
3080 tree funtype;
3081 tree type_arg_types;
3082 tree rettype;
3083 /* Declaration of the function being called,
3084 or 0 if the function is computed (not known by name). */
3086 /* The type of the function being called. */
3087 tree fntype;
3092 /* Register in which non-BLKmode value will be returned,
3093 or 0 if no value or if value is BLKmode. */
3094 rtx valreg;
3095 /* Register(s) in which bounds are returned. */
3097 /* Address where we should return a BLKmode value;
3098 0 if value not BLKmode. */
3100 /* Nonzero if that address is being passed by treating it as
3101 an extra, implicit first parameter. Otherwise,
3102 it is passed by being copied directly into struct_value_rtx. */
3104 /* Holds the value of implicit argument for the struct value. */
3106 /* Size of aggregate value wanted, or zero if none wanted
3107 or if we are using the non-reentrant PCC calling convention
3108 or expecting the value in registers. */
3110 /* Nonzero if called function returns an aggregate in memory PCC style,
3111 by returning the address of where to find it. */
3115 /* Number of actual parameters in this call, including struct value addr. */
3117 /* Number of named args. Args after this are anonymous ones
3118 and they must all go on the stack. */
3120 /* Number of complex actual arguments that need to be split. */
3123 /* Vector of information about each argument.
3124 Arguments are numbered in the order they will be pushed,
3125 not the order they are written. */
3128 /* Total size in bytes of all the stack-parms scanned so far. */
3131 /* Size of arguments before any adjustments (such as rounding). */
3133 /* Data on reg parms scanned so far. */
3134 CUMULATIVE_ARGS args_so_far_v;
3135 cumulative_args_t args_so_far;
3136 /* Nonzero if a reg parm has been scanned. */
3138 /* Nonzero if this is an indirect function call. */
3140 /* Nonzero if we must avoid push-insns in the args for this call.
3141 If stack space is allocated for register parameters, but not by the
3142 caller, then it is preallocated in the fixed part of the stack frame.
3143 So the entire argument block must then be preallocated (i.e., we
3144 ignore PUSH_ROUNDING in that case). */
3148 /* Size of the stack reserved for parameter registers. */
3151 /* Address of space preallocated for stack parms
3152 (on machines that lack push insns), or 0 if space not preallocated. */
3155 /* Mask of ECF_ and ERF_ flags. */
3158 #ifdef REG_PARM_STACK_SPACE
3159 /* Define the boundary of the register parm stack space that needs to be
3160 saved, if any. */
3163 #endif
3171 /* State variables to track stack modifications. */
3177 /* Some stack pointer alterations we make are performed via
3178 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
3179 which we then also need to save/restore along the way. */
3182 rtx call_fusage;
3185 /* The alignment of the stack, in bits. */
3187 /* The alignment of the stack, in bytes. */
3189 /* The static chain value to use for this call. */
3190 rtx static_chain_value;
3191 /* See if this is "nothrow" function call. */
3195 /* See if we can find a DECL-node for the actual function, and get the
3196 function attributes (flags) from the function decl or type node. */
3199 {
3203 }
3204 else
3205 {
3210 }
3215 /* Warn if this value is an aggregate type,
3216 regardless of which calling convention we are using for it. */
3220 /* If the result of a non looping pure or const function call is
3221 ignored (or void), and none of its arguments are volatile, we can
3222 avoid expanding the call and just evaluate the arguments for
3223 side-effects. */
3228 {
3230 tree arg;
3231 call_expr_arg_iterator iter;
3235 {
3238 }
3241 {
3245 }
3246 }
3248 #ifdef REG_PARM_STACK_SPACE
3250 #endif
3256 /* Set up a place to return a structure. */
3258 /* Cater to broken compilers. */
3260 {
3261 /* This call returns a big structure. */
3264 #ifdef PCC_STATIC_STRUCT_RETURN
3265 {
3267 }
3269 {
3272 /* Even if it is semantically safe to use the target as the return
3273 slot, it may be not sufficiently aligned for the return type. */
3275 && target
3281 else
3282 {
3283 /* For variable-sized objects, we must be called with a target
3284 specified. If we were to allocate space on the stack here,
3285 we would have no way of knowing when to free it. */
3289 }
3290 }
3292 }
3294 /* Figure out the amount to which the stack should be aligned. */
3297 {
3299 /* Without automatic stack alignment, we can't increase preferred
3300 stack boundary. With automatic stack alignment, it is
3301 unnecessary since unless we can guarantee that all callers will
3302 align the outgoing stack properly, callee has to align its
3303 stack anyway. */
3308 }
3310 /* Operand 0 is a pointer-to-function; get the type of the function. */
3315 /* Count whether there are actual complex arguments that need to be split
3316 into their real and imaginary parts. Munge the type_arg_types
3317 appropriately here as well. */
3319 {
3320 call_expr_arg_iterator iter;
3321 tree arg;
3323 {
3327 num_complex_actuals++;
3328 }
3330 }
3331 else
3337 /* If struct_value_rtx is 0, it means pass the address
3338 as if it were an extra parameter. Put the argument expression
3339 in structure_value_addr_value. */
3341 {
3342 /* If structure_value_addr is a REG other than
3343 virtual_outgoing_args_rtx, we can use always use it. If it
3344 is not a REG, we must always copy it into a register.
3345 If it is virtual_outgoing_args_rtx, we must copy it to another
3346 register in some cases. */
3348 || (ACCUMULATE_OUTGOING_ARGS
3349 && stack_arg_under_construction
3355 structure_value_addr_value =
3358 }
3360 /* Count the arguments and set NUM_ACTUALS. */
3361 num_actuals =
3364 /* Compute number of named args.
3365 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
3368 n_named_args
3370 /* Count the struct value address, if it is passed as a parm. */
3372 else
3373 /* If we know nothing, treat all args as named. */
3376 /* Start updating where the next arg would go.
3378 On some machines (such as the PA) indirect calls have a different
3379 calling convention than normal calls. The fourth argument in
3380 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
3381 or not. */
3385 /* Now possibly adjust the number of named args.
3386 Normally, don't include the last named arg if anonymous args follow.
3387 We do include the last named arg if
3388 targetm.calls.strict_argument_naming() returns nonzero.
3389 (If no anonymous args follow, the result of list_length is actually
3390 one too large. This is harmless.)
3392 If targetm.calls.pretend_outgoing_varargs_named() returns
3393 nonzero, and targetm.calls.strict_argument_naming() returns zero,
3394 this machine will be able to place unnamed args that were passed
3395 in registers into the stack. So treat all args as named. This
3396 allows the insns emitting for a specific argument list to be
3397 independent of the function declaration.
3399 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
3400 we do not have any reliable way to pass unnamed args in
3401 registers, so we must force them into memory. */
3405 ;
3408 /* Don't include the last named arg. */
3410 else
3411 /* Treat all args as named. */
3414 /* Make a vector to hold all the information about each arg. */
3417 /* Build up entries in the ARGS array, compute the size of the
3418 arguments into ARGS_SIZE, etc. */
3430 /* Now make final decision about preallocating stack space. */
3435 /* If the structure value address will reference the stack pointer, we
3436 must stabilize it. We don't need to do this if we know that we are
3437 not going to adjust the stack pointer in processing this call. */
3442 structure_value_addr))
3447 /* Tail calls can make things harder to debug, and we've traditionally
3448 pushed these optimizations into -O2. Don't try if we're already
3449 expanding a call, as that means we're an argument. Don't try if
3450 there's cleanups, as we know there's code to follow the call. */
3453 || !flag_optimize_sibling_calls
3458 /* If the user has marked the function as requiring tail-call
3459 optimization, attempt it. */
3463 /* Rest of purposes for tail call optimizations to fail. */
3466 structure_value_addr,
3467 funtype,
3468 reg_parm_stack_space,
3469 fndecl,
3472 /* Check if caller and callee disagree in promotion of function
3473 return value. */
3475 {
3485 caller_promoted_mode
3489 callee_promoted_mode
3499 {
3502 "caller and callee disagree in"
3503 " promotion of function"
3505 }
3506 }
3508 /* Ensure current function's preferred stack boundary is at least
3509 what we need. Stack alignment may also increase preferred stack
3510 boundary. */
3513 else
3518 /* We want to make two insn chains; one for a sibling call, the other
3519 for a normal call. We will select one of the two chains after
3520 initial RTL generation is complete. */
3522 {
3524 /* We want to emit any pending stack adjustments before the tail
3525 recursion "call". That way we know any adjustment after the tail
3526 recursion call can be ignored if we indeed use the tail
3527 call expansion. */
3528 saved_pending_stack_adjust save;
3530 rtx next_arg_reg;
3533 {
3534 /* State variables we need to save and restore between
3535 iterations. */
3537 }
3540 else
3543 /* Other state variables that we must reinitialize each time
3544 through the loop (that are not initialized by the loop itself). */
3548 /* Start a new sequence for the normal call case.
3550 From this point on, if the sibling call fails, we want to set
3551 sibcall_failure instead of continuing the loop. */
3554 /* Don't let pending stack adjusts add up to too much.
3555 Also, do all pending adjustments now if there is any chance
3556 this might be a call to alloca or if we are expanding a sibling
3557 call sequence.
3558 Also do the adjustments before a throwing call, otherwise
3559 exception handling can fail; PR 19225. */
3568 /* Precompute any arguments as needed. */
3572 /* Now we are about to start emitting insns that can be deleted
3573 if a libcall is deleted. */
3583 /* Compute the actual size of the argument block required. The variable
3584 and constant sizes must be combined, the size may have to be rounded,
3585 and there may be a minimum required size. When generating a sibcall
3586 pattern, do not round up, since we'll be re-using whatever space our
3587 caller provided. */
3588 unadjusted_args_size
3597 /* The argument block when performing a sibling call is the
3598 incoming argument block. */
3600 {
3603 argblock
3605 else
3606 argblock
3611 }
3613 /* If we have no actual push instructions, or shouldn't use them,
3614 make space for all args right now. */
3616 {
3618 {
3623 /* stack_arg_under_construction says whether a stack arg is
3624 being constructed at the old stack level. Pushing the stack
3625 gets a clean outgoing argument block. */
3628 }
3632 }
3633 else
3634 {
3635 /* Note that we must go through the motions of allocating an argument
3636 block even if the size is zero because we may be storing args
3637 in the area reserved for register arguments, which may be part of
3638 the stack frame. */
3642 /* Store the maximum argument space used. It will be pushed by
3643 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
3644 checking). */
3650 {
3652 {
3653 /* Since the stack pointer will never be pushed, it is
3654 possible for the evaluation of a parm to clobber
3655 something we have already written to the stack.
3656 Since most function calls on RISC machines do not use
3657 the stack, this is uncommon, but must work correctly.
3659 Therefore, we save any area of the stack that was already
3660 written and that we are using. Here we set up to do this
3661 by making a new stack usage map from the old one. The
3662 actual save will be done by store_one_arg.
3664 Another approach might be to try to reorder the argument
3665 evaluations to avoid this conflicting stack usage. */
3667 /* Since we will be writing into the entire argument area,
3668 the map must be allocated for its entire size, not just
3669 the part that is the responsibility of the caller. */
3674 highest_outgoing_arg_in_use
3676 else
3677 highest_outgoing_arg_in_use
3686 initial_highest_arg_in_use);
3690 (highest_outgoing_arg_in_use
3694 /* The address of the outgoing argument list must not be
3695 copied to a register here, because argblock would be left
3696 pointing to the wrong place after the call to
3697 allocate_dynamic_stack_space below. */
3700 }
3701 else
3702 {
3704 {
3705 /* Try to reuse some or all of the pending_stack_adjust
3706 to get this space. */
3707 needed
3708 = (combine_pending_stack_adjustment_and_call
3711 preferred_unit_stack_boundary));
3713 /* combine_pending_stack_adjustment_and_call computes
3714 an adjustment before the arguments are allocated.
3715 Account for them and see whether or not the stack
3716 needs to go up or down. */
3720 {
3721 /* We're releasing stack space. */
3722 /* ??? We can avoid any adjustment at all if we're
3723 already aligned. FIXME. */
3727 }
3728 else
3729 /* We need to allocate space. We'll do that in
3730 push_block below. */
3732 }
3734 /* Special case this because overhead of `push_block' in
3735 this case is non-trivial. */
3738 else
3739 {
3743 }
3745 /* We only really need to call `copy_to_reg' in the case
3746 where push insns are going to be used to pass ARGBLOCK
3747 to a function call in ARGS. In that case, the stack
3748 pointer changes value from the allocation point to the
3749 call point, and hence the value of
3750 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
3751 as well always do it. */
3753 }
3754 }
3755 }
3758 {
3759 /* The save/restore code in store_one_arg handles all
3760 cases except one: a constructor call (including a C
3761 function returning a BLKmode struct) to initialize
3762 an argument. */
3764 {
3765 rtx push_size
3771 {
3776 /* stack_arg_under_construction says whether a stack
3777 arg is being constructed at the old stack level.
3778 Pushing the stack gets a clean outgoing argument
3779 block. */
3780 old_stack_arg_under_construction
3783 /* Make a new map for the new argument list. */
3788 }
3789 /* We can pass TRUE as the 4th argument because we just
3790 saved the stack pointer and will restore it right after
3791 the call. */
3794 }
3796 /* If argument evaluation might modify the stack pointer,
3797 copy the address of the argument list to a register. */
3800 {
3803 }
3804 }
3808 /* Stack is properly aligned, pops can't safely be deferred during
3809 the evaluation of the arguments. */
3810 NO_DEFER_POP;
3812 /* Precompute all register parameters. It isn't safe to compute
3813 anything once we have started filling any specific hard regs.
3814 TLS symbols sometimes need a call to resolve. Precompute
3815 register parameters before any stack pointer manipulation
3816 to avoid unaligned stack in the called function. */
3819 OK_DEFER_POP;
3821 /* Perform stack alignment before the first push (the last arg). */
3825 {
3826 /* When the stack adjustment is pending, we get better code
3827 by combining the adjustments. */
3830 {
3831 pending_stack_adjust
3832 = (combine_pending_stack_adjustment_and_call
3835 preferred_unit_stack_boundary));
3837 }
3841 }
3842 /* Now that the stack is properly aligned, pops can't safely
3843 be deferred during the evaluation of the arguments. */
3844 NO_DEFER_POP;
3846 /* Record the maximum pushed stack space size. We need to delay
3847 doing it this far to take into account the optimization done
3848 by combine_pending_stack_adjustment_and_call. */
3850 && !ACCUMULATE_OUTGOING_ARGS
3851 && pass
3853 {
3857 }
3863 else
3866 #ifdef REG_PARM_STACK_SPACE
3867 /* Save the fixed argument area if it's part of the caller's frame and
3868 is clobbered by argument setup for this call. */
3872 #endif
3874 /* Now store (and compute if necessary) all non-register parms.
3875 These come before register parms, since they can require block-moves,
3876 which could clobber the registers used for register parms.
3877 Parms which have partial registers are not stored here,
3878 but we do preallocate space here if they want that. */
3881 {
3882 /* Delay bounds until all other args are stored. */
3886 {
3889 /* We don't allow passing huge (> 2^30 B) arguments
3890 by value. It would cause an overflow later on. */
3893 {
3896 }
3900 reg_parm_stack_space)
3905 }
3908 call_fusage
3911 call_fusage);
3912 }
3914 /* If we have a parm that is passed in registers but not in memory
3915 and whose alignment does not permit a direct copy into registers,
3916 make a group of pseudos that correspond to each register that we
3917 will later fill. */
3921 /* Now store any partially-in-registers parm.
3922 This is the last place a block-move can happen. */
3926 {
3929 /* On targets with weird calling conventions (e.g. PA) it's
3930 hard to ensure that all cases of argument overlap between
3931 stack and registers work. Play it safe and bail out. */
3933 {
3936 }
3940 reg_parm_stack_space)
3945 }
3950 {
3953 }
3957 /* Figure out the register where the value, if any, will come back. */
3962 {
3964 {
3971 }
3972 else
3973 {
3978 fndecl,
3980 }
3982 /* If VALREG is a PARALLEL whose first member has a zero
3983 offset, use that. This is for targets such as m68k that
3984 return the same value in multiple places. */
3986 {
3993 }
3994 }
3996 /* Store all bounds not passed in registers. */
3998 {
4003 ? NULL
4005 }
4007 /* If register arguments require space on the stack and stack space
4008 was not preallocated, allocate stack space here for arguments
4009 passed in registers. */
4011 && !ACCUMULATE_OUTGOING_ARGS
4015 /* Pass the function the address in which to return a
4016 structure value. */
4018 {
4019 structure_value_addr
4024 NULL_RTX)));
4028 }
4038 /* Save a pointer to the last insn before the call, so that we can
4039 later safely search backwards to find the CALL_INSN. */
4042 /* Set up next argument register. For sibling calls on machines
4043 with register windows this should be the incoming register. */
4046 VOIDmode,
4047 void_type_node,
4049 else
4055 {
4061 && valreg
4064 call_fusage
4067 call_fusage);
4068 }
4069 /* All arguments and registers used for the call must be set up by
4070 now! */
4072 /* Stack must be properly aligned now. */
4076 /* Generate the actual call instruction. */
4083 {
4087 {
4091 }
4094 }
4096 /* If the call setup or the call itself overlaps with anything
4097 of the argument setup we probably clobbered our call address.
4098 In that case we can't do sibcalls. */
4103 /* If a non-BLKmode value is returned at the most significant end
4104 of a register, shift the register right by the appropriate amount
4105 and update VALREG accordingly. BLKmode values are handled by the
4106 group load/store machinery below. */
4108 && !pcc_struct_value
4113 {
4117 }
4120 {
4124 /* The return value from a malloc-like function is a pointer. */
4130 /* The return value from a malloc-like function can not alias
4131 anything else. */
4135 /* Write out the sequence. */
4140 }
4142 /* For calls to `setjmp', etc., inform
4143 function.c:setjmp_warnings that it should complain if
4144 nonvolatile values are live. For functions that cannot
4145 return, inform flow that control does not fall through. */
4148 {
4149 /* The barrier must be emitted
4150 immediately after the CALL_INSN. Some ports emit more
4151 than just a CALL_INSN above, so we must search for it here. */
4155 {
4157 /* There was no CALL_INSN? */
4159 }
4163 /* Stack adjustments after a noreturn call are dead code.
4164 However when NO_DEFER_POP is in effect, we must preserve
4165 stack_pointer_delta. */
4167 {
4170 }
4171 }
4173 /* If value type not void, return an rtx for the value. */
4179 {
4181 {
4182 target
4185 structure_value_addr));
4187 }
4188 }
4190 {
4191 /* This is the special C++ case where we need to
4192 know what the true target was. We take care to
4193 never use this value more than once in one expression. */
4197 }
4198 /* Handle calls that return values in multiple non-contiguous locations.
4199 The Irix 6 ABI has examples of this. */
4201 {
4205 ;
4207 /* Handle the result of a emit_group_move_into_temps
4208 call in the previous pass. */
4210 else
4213 }
4217 {
4220 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
4221 reg to a plain register. */
4225 /* If TARGET is a MEM in the argument area, and we have
4226 saved part of the argument area, then we can't store
4227 directly into TARGET as it may get overwritten when we
4228 restore the argument save area below. Don't work too
4229 hard though and simply force TARGET to a register if it
4230 is a MEM; the optimizer is quite likely to sort it out. */
4234 {
4237 }
4241 else
4242 {
4243 /* TARGET and VALREG cannot be equal at this point
4244 because the latter would not have
4245 REG_FUNCTION_VALUE_P true, while the former would if
4246 it were referring to the same register.
4248 If they refer to the same register, this move will be
4249 a no-op, except when function inlining is being
4250 done. */
4253 /* If we are setting a MEM, this code must be executed.
4254 Since it is emitted after the call insn, sibcall
4255 optimization cannot be performed in that case. */
4258 }
4259 }
4260 else
4263 /* If we promoted this return value, make the proper SUBREG.
4264 TARGET might be const0_rtx here, so be careful. */
4268 {
4271 machine_mode pmode;
4273 /* Ensure we promote as expected, and get the new unsignedness. */
4283 }
4285 /* If size of args is variable or this was a constructor call for a stack
4286 argument, restore saved stack-pointer value. */
4289 {
4303 }
4305 {
4306 #ifdef REG_PARM_STACK_SPACE
4310 #endif
4312 /* If we saved any argument areas, restore them. */
4315 {
4317 rtx stack_area
4324 else
4327 BLOCK_OP_CALL_PARM);
4328 }
4332 }
4334 /* If this was alloca, record the new stack level. */
4338 /* Free up storage we no longer need. */
4348 {
4351 /* Restore the pending stack adjustment now that we have
4352 finished generating the sibling call sequence. */
4356 /* Prepare arg structure for next iteration. */
4358 {
4362 }
4367 }
4368 else
4369 {
4372 /* Verify that we've deallocated all the stack we used. */
4374 || (old_stack_allocated
4376 }
4378 /* If something prevents making this a sibling call,
4379 zero out the sequence. */
4382 else
4384 }
4386 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
4387 arguments too, as argument area is now clobbered by the call. */
4389 {
4392 }
4393 else
4394 {
4397 /* Ideally we'd emit a message for all of the ways that it could
4398 have failed. */
4400 }
4402 currently_expanding_call--;
4407 /* Join result with returned bounds so caller may use them if needed. */
4411 }
4413 /* A sibling call sequence invalidates any REG_EQUIV notes made for
4414 this function's incoming arguments.
4416 At the start of RTL generation we know the only REG_EQUIV notes
4417 in the rtl chain are those for incoming arguments, so we can look
4418 for REG_EQUIV notes between the start of the function and the
4419 NOTE_INSN_FUNCTION_BEG.
4421 This is (slight) overkill. We could keep track of the highest
4422 argument we clobber and be more selective in removing notes, but it
4423 does not seem to be worth the effort. */
4425 void
4427 {
4431 {
4432 rtx note;
4434 /* There are never REG_EQUIV notes for the incoming arguments
4435 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
4445 }
4446 }
4448 /* Traverse a list of TYPES and expand all complex types into their
4449 components. */
4450 static tree
4452 {
4453 tree p;
4455 /* Before allocating memory, check for the common case of no complex. */
4457 {
4462 }
4465 found:
4469 {
4474 {
4477 /* Rewrite complex type with component type. */
4481 /* Add another component type for the imaginary part. */
4486 /* Skip the newly created node. */
4488 }
4489 }
4492 }
4493 \f
4494 /* Output a library call to function ORGFUN (a SYMBOL_REF rtx)
4495 for a value of mode OUTMODE,
4496 with NARGS different arguments, passed as ARGS.
4497 Store the return value if RETVAL is nonzero: store it in VALUE if
4498 VALUE is nonnull, otherwise pick a convenient location. In either
4499 case return the location of the stored value.
4501 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
4502 `const' calls, LCT_PURE for `pure' calls, or another LCT_ value for
4503 other types of library calls. */
4505 rtx
4509 {
4510 /* Total size in bytes of all the stack-parms scanned so far. */
4512 /* Size of arguments before any adjustments (such as rounding). */
4515 rtx fun;
4516 /* Todo, choose the correct decl type of orgfun. Sadly this information
4517 isn't present here, so we default to native calling abi here. */
4522 CUMULATIVE_ARGS args_so_far_v;
4523 cumulative_args_t args_so_far;
4524 struct arg
4525 {
4526 rtx value;
4527 machine_mode mode;
4528 rtx reg;
4531 rtx save_area;
4532 };
4537 rtx valreg;
4547 #ifdef REG_PARM_STACK_SPACE
4548 /* Define the boundary of the register parm stack space that needs to be
4549 save, if any. */
4552 #endif
4554 /* Size of the stack reserved for parameter registers. */
4561 #ifdef REG_PARM_STACK_SPACE
4563 #endif
4565 /* By default, library functions cannot throw. */
4569 {
4587 }
4590 /* Ensure current function's preferred stack boundary is at least
4591 what we need. */
4595 /* If this kind of value comes back in memory,
4596 decide where in memory it should come back. */
4598 {
4601 {
4602 #ifdef PCC_STATIC_STRUCT_RETURN
4603 rtx pointer_reg
4613 else
4615 #endif
4616 /* This call returns a big structure. */
4618 }
4619 }
4620 else
4623 /* ??? Unfinished: must pass the memory address as an argument. */
4625 /* Copy all the libcall-arguments out of the varargs data
4626 and into a vector ARGVEC.
4628 Compute how to pass each argument. We only support a very small subset
4629 of the full argument passing conventions to limit complexity here since
4630 library functions shouldn't have many args. */
4635 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
4637 #else
4639 #endif
4649 /* If there's a structure value address to be passed,
4650 either pass it in the special place, or pass it as an extra argument. */
4652 {
4655 nargs++;
4657 /* Make sure it is a reasonable operand for a move or push insn. */
4673 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4675 #else
4677 #endif
4687 count++;
4688 }
4691 {
4696 /* We cannot convert the arg value to the mode the library wants here;
4697 must do it earlier where we know the signedness of the arg. */
4701 /* Make sure it is a reasonable operand for a move or push insn. */
4707 {
4708 rtx slot;
4709 int must_copy
4712 /* If this was a CONST function, it is now PURE since it now
4713 reads memory. */
4715 {
4718 }
4721 {
4726 }
4727 else
4728 {
4732 }
4736 call_fusage);
4740 slot),
4741 call_fusage);
4745 }
4759 {
4761 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4763 #else
4765 #endif
4770 }
4771 #ifdef BLOCK_REG_PADDING
4772 else
4773 /* The argument is passed entirely in registers. See at which
4774 end it should be padded. */
4778 #endif
4781 }
4783 /* If this machine requires an external definition for library
4784 functions, write one out. */
4789 + stack_pointer_delta
4791 / STACK_BYTES
4796 reg_parm_stack_space);
4805 {
4809 }
4812 {
4813 /* Since the stack pointer will never be pushed, it is possible for
4814 the evaluation of a parm to clobber something we have already
4815 written to the stack. Since most function calls on RISC machines
4816 do not use the stack, this is uncommon, but must work correctly.
4818 Therefore, we save any area of the stack that was already written
4819 and that we are using. Here we set up to do this by making a new
4820 stack usage map from the old one.
4822 Another approach might be to try to reorder the argument
4823 evaluations to avoid this conflicting stack usage. */
4827 /* Since we will be writing into the entire argument area, the
4828 map must be allocated for its entire size, not just the part that
4829 is the responsibility of the caller. */
4836 else
4844 initial_highest_arg_in_use);
4851 /* We must be careful to use virtual regs before they're instantiated,
4852 and real regs afterwards. Loop optimization, for example, can create
4853 new libcalls after we've instantiated the virtual regs, and if we
4854 use virtuals anyway, they won't match the rtl patterns. */
4858 STACK_POINTER_OFFSET);
4859 else
4861 }
4862 else
4863 {
4866 }
4868 /* We push args individually in reverse order, perform stack alignment
4869 before the first push (the last arg). */
4876 #ifdef REG_PARM_STACK_SPACE
4878 {
4879 /* The argument list is the property of the called routine and it
4880 may clobber it. If the fixed area has been used for previous
4881 parameters, we must save and restore it. */
4884 }
4885 #endif
4887 /* When expanding a normal call, args are stored in push order,
4888 which is the reverse of what we have here. */
4892 {
4895 }
4899 /* Push the args that need to be pushed. */
4903 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4904 are to be pushed. */
4906 {
4915 {
4916 rtx use;
4919 {
4920 /* If this is being stored into a pre-allocated, fixed-size,
4921 stack area, save any previous data at that location. */
4924 {
4925 /* stack_slot is negative, but we want to index stack_usage_map
4926 with positive values. */
4929 }
4930 else
4931 {
4934 }
4937 /* Don't worry about things in the fixed argument area;
4938 it has already been saved. */
4942 i++;
4945 {
4946 /* We need to make a save area. */
4947 unsigned int size
4949 machine_mode save_mode
4951 rtx adr
4954 rtx stack_area
4958 {
4962 );
4966 stack_area,
4968 BLOCK_OP_CALL_PARM);
4969 }
4970 else
4971 {
4975 }
4976 }
4977 }
4982 reg_parm_stack_space,
4985 /* Now mark the segment we just used. */
4990 NO_DEFER_POP;
4992 /* Indicate argument access so that alias.c knows that these
4993 values are live. */
4999 else
5000 {
5001 /* When arguments are pushed, trying to tell alias.c where
5002 exactly this argument is won't work, because the
5003 auto-increment causes confusion. So we merely indicate
5004 that we access something with a known mode somewhere on
5005 the stack. */
5009 }
5013 }
5014 }
5020 /* Now load any reg parms into their regs. */
5022 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5023 are to be pushed. */
5025 {
5030 #ifdef BLOCK_REG_PADDING
5032 #endif
5034 /* Handle calls that pass values in multiple non-contiguous
5035 locations. The PA64 has examples of this for library calls. */
5039 {
5041 #ifdef BLOCK_REG_PADDING
5044 /* Copied from load_register_parameters. */
5046 /* Handle case where we have a value that needs shifting
5047 up to the msb. eg. a QImode value and we're padding
5048 upward on a BYTES_BIG_ENDIAN machine. */
5052 {
5053 rtx x;
5056 /* Assigning REG here rather than a temp makes CALL_FUSAGE
5057 report the whole reg as used. Strictly speaking, the
5058 call only uses SIZE bytes at the msb end, but it doesn't
5059 seem worth generating rtl to say that. */
5064 }
5065 #endif
5066 }
5068 NO_DEFER_POP;
5069 }
5071 /* Any regs containing parms remain in use through the call. */
5073 {
5078 {
5081 {
5086 }
5087 else
5089 }
5090 }
5092 /* Pass the function the address in which to return a structure value. */
5094 {
5098 NULL_RTX)));
5101 }
5103 /* Don't allow popping to be deferred, since then
5104 cse'ing of library calls could delete a call and leave the pop. */
5105 NO_DEFER_POP;
5109 /* Stack must be properly aligned now. */
5115 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
5116 will set inhibit_defer_pop to that value. */
5117 /* The return type is needed to decide how many bytes the function pops.
5118 Signedness plays no role in that, so for simplicity, we pretend it's
5119 always signed. We also assume that the list of arguments passed has
5120 no impact, so we pretend it is unknown. */
5126 struct_value_size,
5129 valreg,
5133 {
5138 }
5140 /* Right-shift returned value if necessary. */
5144 {
5147 }
5151 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
5152 that it should complain if nonvolatile values are live. For
5153 functions that cannot return, inform flow that control does not
5154 fall through. */
5156 {
5157 /* The barrier note must be emitted
5158 immediately after the CALL_INSN. Some ports emit more than
5159 just a CALL_INSN above, so we must search for it here. */
5162 {
5164 /* There was no CALL_INSN? */
5166 }
5169 }
5171 /* Consider that "regular" libcalls, i.e. all of them except for LCT_THROW
5172 and LCT_RETURNS_TWICE, cannot perform non-local gotos. */
5174 {
5177 {
5179 /* There was no CALL_INSN? */
5181 }
5184 }
5186 /* Now restore inhibit_defer_pop to its actual original value. */
5187 OK_DEFER_POP;
5191 /* Copy the value to the right place. */
5193 {
5195 {
5200 }
5202 {
5206 }
5207 else
5208 {
5209 /* Convert to the proper mode if a promotion has been active. */
5211 {
5218 }
5222 else
5224 }
5225 }
5228 {
5229 #ifdef REG_PARM_STACK_SPACE
5233 #endif
5235 /* If we saved any argument areas, restore them. */
5238 {
5247 validize_mem
5250 BLOCK_OP_CALL_PARM);
5251 else
5253 }
5257 }
5263 }
5264 \f
5266 /* Store pointer bounds argument ARG into Bounds Table entry
5267 associated with PARM. */
5268 static void
5270 {
5273 /* We may pass bounds not associated with any pointer. */
5275 {
5279 }
5280 /* Find pointer associated with bounds and where it is
5281 passed. */
5282 else
5283 {
5285 {
5289 }
5291 {
5299 else
5300 {
5303 }
5304 }
5305 else
5306 {
5315 else
5317 }
5318 }
5320 /* Expand bounds. */
5325 }
5327 /* Store a single argument for a function call
5328 into the register or memory area where it must be passed.
5329 *ARG describes the argument value and where to pass it.
5331 ARGBLOCK is the address of the stack-block for all the arguments,
5332 or 0 on a machine where arguments are pushed individually.
5334 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
5335 so must be careful about how the stack is used.
5337 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
5338 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
5339 that we need not worry about saving and restoring the stack.
5341 FNDECL is the declaration of the function we are calling.
5343 Return nonzero if this arg should cause sibcall failure,
5344 zero otherwise. */
5346 static int
5349 {
5360 /* Push a new temporary level for any temporaries we make for
5361 this argument. */
5365 {
5366 /* If this is being stored into a pre-allocated, fixed-size, stack area,
5367 save any previous data at that location. */
5369 {
5371 {
5372 /* stack_slot is negative, but we want to index stack_usage_map
5373 with positive values. */
5376 else
5380 }
5381 else
5382 {
5385 else
5389 }
5392 /* Don't worry about things in the fixed argument area;
5393 it has already been saved. */
5397 i++;
5400 {
5401 /* We need to make a save area. */
5403 machine_mode save_mode
5409 {
5410 arg->save_area
5414 stack_area,
5416 BLOCK_OP_CALL_PARM);
5417 }
5418 else
5419 {
5422 }
5423 }
5424 }
5425 }
5427 /* If this isn't going to be placed on both the stack and in registers,
5428 set up the register and number of words. */
5430 {
5433 else
5436 }
5438 /* Being passed entirely in a register. We shouldn't be called in
5439 this case. */
5442 /* If this arg needs special alignment, don't load the registers
5443 here. */
5447 /* If this is being passed partially in a register, we can't evaluate
5448 it directly into its stack slot. Otherwise, we can. */
5450 {
5451 /* stack_arg_under_construction is nonzero if a function argument is
5452 being evaluated directly into the outgoing argument list and
5453 expand_call must take special action to preserve the argument list
5454 if it is called recursively.
5456 For scalar function arguments stack_usage_map is sufficient to
5457 determine which stack slots must be saved and restored. Scalar
5458 arguments in general have pass_on_stack == 0.
5460 If this argument is initialized by a function which takes the
5461 address of the argument (a C++ constructor or a C function
5462 returning a BLKmode structure), then stack_usage_map is
5463 insufficient and expand_call must push the stack around the
5464 function call. Such arguments have pass_on_stack == 1.
5466 Note that it is always safe to set stack_arg_under_construction,
5467 but this generates suboptimal code if set when not needed. */
5470 stack_arg_under_construction++;
5473 (partial
5478 /* If we are promoting object (or for any other reason) the mode
5479 doesn't agree, convert the mode. */
5486 stack_arg_under_construction--;
5487 }
5489 /* Check for overlap with already clobbered argument area. */
5496 /* Don't allow anything left on stack from computation
5497 of argument to alloca. */
5502 /* If the value is already in the stack slot, we are done. */
5503 ;
5505 {
5509 /* Argument is a scalar, not entirely passed in registers.
5510 (If part is passed in registers, arg->partial says how much
5511 and emit_push_insn will take care of putting it there.)
5513 Push it, and if its size is less than the
5514 amount of space allocated to it,
5515 also bump stack pointer by the additional space.
5516 Note that in C the default argument promotions
5517 will prevent such mismatches. */
5521 else
5524 /* Compute how much space the push instruction will push.
5525 On many machines, pushing a byte will advance the stack
5526 pointer by a halfword. */
5527 #ifdef PUSH_ROUNDING
5529 #endif
5532 /* Compute how much space the argument should get:
5533 round up to a multiple of the alignment for arguments. */
5540 /* Compute the alignment of the pushed argument. */
5544 {
5547 {
5550 }
5551 }
5553 /* This isn't already where we want it on the stack, so put it there.
5554 This can either be done with push or copy insns. */
5559 reg_parm_stack_space,
5563 /* Unless this is a partially-in-register argument, the argument is now
5564 in the stack. */
5567 }
5568 else
5569 {
5570 /* BLKmode, at least partly to be pushed. */
5574 rtx size_rtx;
5576 /* Pushing a nonscalar.
5577 If part is passed in registers, PARTIAL says how much
5578 and emit_push_insn will take care of putting it there. */
5580 /* Round its size up to a multiple
5581 of the allocation unit for arguments. */
5584 {
5587 }
5588 else
5589 {
5590 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
5591 for BLKmode is careful to avoid it. */
5597 EXPAND_NORMAL);
5598 }
5602 /* When an argument is padded down, the block is aligned to
5603 PARM_BOUNDARY, but the actual argument isn't. */
5606 {
5610 {
5613 }
5614 }
5617 {
5618 /* emit_push_insn might not work properly if arg->value and
5619 argblock + arg->locate.offset areas overlap. */
5628 {
5632 /* arg.locate doesn't contain the pretend_args_size offset,
5633 it's part of argblock. Ensure we don't count it in I. */
5636 else
5639 /* expand_call should ensure this. */
5645 {
5648 }
5650 {
5651 /* Use arg->locate.size.constant instead of size_rtx
5652 because we only care about the part of the argument
5653 on the stack. */
5657 }
5658 else
5659 {
5660 /* Even though they appear to be at the same location,
5661 if part of the outgoing argument is in registers,
5662 they aren't really at the same location. Check for
5663 this by making sure that the incoming size is the
5664 same as the outgoing size. */
5667 }
5668 }
5669 }
5675 reg_parm_stack_space,
5678 /* Unless this is a partially-in-register argument, the argument is now
5679 in the stack.
5681 ??? Unlike the case above, in which we want the actual
5682 address of the data, so that we can load it directly into a
5683 register, here we want the address of the stack slot, so that
5684 it's properly aligned for word-by-word copying or something
5685 like that. It's not clear that this is always correct. */
5688 }
5691 {
5693 arg->parallel_value
5696 }
5698 /* Mark all slots this store used. */
5704 /* Once we have pushed something, pops can't safely
5705 be deferred during the rest of the arguments. */
5706 NO_DEFER_POP;
5708 /* Free any temporary slots made in processing this argument. */
5712 }
5714 /* Nonzero if we do not know how to pass TYPE solely in registers. */
5716 bool
5718 const_tree type)
5719 {
5723 /* If the type has variable size... */
5727 /* If the type is marked as addressable (it is required
5728 to be constructed into the stack)... */
5733 }
5735 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
5736 takes trailing padding of a structure into account. */
5737 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
5739 bool
5741 {
5745 /* If the type has variable size... */
5749 /* If the type is marked as addressable (it is required
5750 to be constructed into the stack)... */
5757 /* If the padding and mode of the type is such that a copy into
5758 a register would put it into the wrong part of the register. */
5766 }
5768 /* Tell the garbage collector about GTY markers in this source file. */