| blob | 537b34818a6c6a57af9fbeb13f035368b9135cda |
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/>. */
59 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
60 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
62 /* Data structure and subroutines used within expand_call. */
64 struct arg_data
65 {
66 /* Tree node for this argument. */
67 tree tree_value;
68 /* Mode for value; TYPE_MODE unless promoted. */
69 machine_mode mode;
70 /* Current RTL value for argument, or 0 if it isn't precomputed. */
71 rtx value;
72 /* Initially-compute RTL value for argument; only for const functions. */
73 rtx initial_value;
74 /* Register to pass this argument in, 0 if passed on stack, or an
75 PARALLEL if the arg is to be copied into multiple non-contiguous
76 registers. */
77 rtx reg;
78 /* Register to pass this argument in when generating tail call sequence.
79 This is not the same register as for normal calls on machines with
80 register windows. */
81 rtx tail_call_reg;
82 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
83 form for emit_group_move. */
84 rtx parallel_value;
85 /* If value is passed in neither reg nor stack, this field holds a number
86 of a special slot to be used. */
87 rtx special_slot;
88 /* For pointer bounds hold an index of parm bounds are bound to. -1 if
89 there is no such pointer. */
91 /* If pointer_arg refers a structure, then pointer_offset holds an offset
92 of a pointer in this structure. */
94 /* If REG was promoted from the actual mode of the argument expression,
95 indicates whether the promotion is sign- or zero-extended. */
97 /* Number of bytes to put in registers. 0 means put the whole arg
98 in registers. Also 0 if not passed in registers. */
100 /* Nonzero if argument must be passed on stack.
101 Note that some arguments may be passed on the stack
102 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
103 pass_on_stack identifies arguments that *cannot* go in registers. */
105 /* Some fields packaged up for locate_and_pad_parm. */
107 /* Location on the stack at which parameter should be stored. The store
108 has already been done if STACK == VALUE. */
109 rtx stack;
110 /* Location on the stack of the start of this argument slot. This can
111 differ from STACK if this arg pads downward. This location is known
112 to be aligned to TARGET_FUNCTION_ARG_BOUNDARY. */
113 rtx stack_slot;
114 /* Place that this stack area has been saved, if needed. */
115 rtx save_area;
116 /* If an argument's alignment does not permit direct copying into registers,
117 copy in smaller-sized pieces into pseudos. These are stored in a
118 block pointed to by this field. The next field says how many
119 word-sized pseudos we made. */
122 };
124 /* A vector of one char per byte of stack space. A byte if nonzero if
125 the corresponding stack location has been used.
126 This vector is used to prevent a function call within an argument from
127 clobbering any stack already set up. */
130 /* Size of STACK_USAGE_MAP. */
133 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
134 stack location's tail call argument has been already stored into the stack.
135 This bitmap is used to prevent sibling call optimization if function tries
136 to use parent's incoming argument slots when they have been already
137 overwritten with tail call arguments. */
140 /* stack_arg_under_construction is nonzero when an argument may be
141 initialized with a constructor call (including a C function that
142 returns a BLKmode struct) and expand_call must take special action
143 to make sure the object being constructed does not overlap the
144 argument list for the constructor call. */
149 cumulative_args_t);
176 #ifdef REG_PARM_STACK_SPACE
179 #endif
180 \f
181 /* Force FUNEXP into a form suitable for the address of a CALL,
182 and return that as an rtx. Also load the static chain register
183 if FNDECL is a nested function.
185 CALL_FUSAGE points to a variable holding the prospective
186 CALL_INSN_FUNCTION_USAGE information. */
188 rtx
191 {
192 /* Make a valid memory address and copy constants through pseudo-regs,
193 but not for a constant address if -fno-function-cse. */
195 {
196 /* If it's an indirect call by descriptor, generate code to perform
197 runtime identification of the pointer and load the descriptor. */
199 {
204 fndecl_or_type
206 fndecl_or_type);
213 /* Avoid long live ranges around function calls. */
219 /* Emit the runtime identification pattern. */
222 call_lab);
224 /* Statically predict the branch to very likely taken. */
229 /* Load the descriptor. */
238 POINTER_SIZE / BITS_PER_UNIT
247 {
250 }
252 /* Make sure we're not going to be overwritten below. */
254 }
256 /* If we are using registers for parameters, force the
257 function address into a register now. */
258 funexp = ((reg_parm_seen
262 }
263 else
264 {
265 /* funexp could be a SYMBOL_REF represents a function pointer which is
266 of ptr_mode. In this case, it should be converted into address mode
267 to be a valid address for memory rtx pattern. See PR 64971. */
272 {
275 }
276 }
281 {
282 rtx chain;
289 {
292 }
293 }
296 }
298 /* Generate instructions to call function FUNEXP,
299 and optionally pop the results.
300 The CALL_INSN is the first insn generated.
302 FNDECL is the declaration node of the function. This is given to the
303 hook TARGET_RETURN_POPS_ARGS to determine whether this function pops
304 its own args.
306 FUNTYPE is the data type of the function. This is given to the hook
307 TARGET_RETURN_POPS_ARGS to determine whether this function pops its
308 own args. We used to allow an identifier for library functions, but
309 that doesn't work when the return type is an aggregate type and the
310 calling convention says that the pointer to this aggregate is to be
311 popped by the callee.
313 STACK_SIZE is the number of bytes of arguments on the stack,
314 ROUNDED_STACK_SIZE is that number rounded up to
315 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
316 both to put into the call insn and to generate explicit popping
317 code if necessary.
319 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
320 It is zero if this call doesn't want a structure value.
322 NEXT_ARG_REG is the rtx that results from executing
323 targetm.calls.function_arg (&args_so_far, VOIDmode, void_type_node, true)
324 just after all the args have had their registers assigned.
325 This could be whatever you like, but normally it is the first
326 arg-register beyond those used for args in this call,
327 or 0 if all the arg-registers are used in this call.
328 It is passed on to `gen_call' so you can put this info in the call insn.
330 VALREG is a hard register in which a value is returned,
331 or 0 if the call does not return a value.
333 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
334 the args to this call were processed.
335 We restore `inhibit_defer_pop' to that value.
337 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
338 denote registers used by the called function. */
340 static void
342 tree funtype ATTRIBUTE_UNUSED,
343 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
344 HOST_WIDE_INT rounded_stack_size,
345 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
348 cumulative_args_t args_so_far ATTRIBUTE_UNUSED)
349 {
355 /* Sibling call patterns never pop arguments (no sibcall(_value)_pop
356 patterns exist). Any popping that the callee does on return will
357 be from our caller's frame rather than ours. */
359 {
362 #ifdef CALL_POPS_ARGS
364 #endif
365 }
367 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
368 and we don't want to load it into a register as an optimization,
369 because prepare_call_address already did it if it should be done. */
375 {
378 /* Although a built-in FUNCTION_DECL and its non-__builtin
379 counterpart compare equal and get a shared mem_attrs, they
380 produce different dump output in compare-debug compilations,
381 if an entry gets garbage collected in one compilation, then
382 adds a different (but equivalent) entry, while the other
383 doesn't run the garbage collector at the same spot and then
384 shares the mem_attr with the equivalent entry. */
386 {
390 }
393 }
398 {
401 rounded_stack_size_rtx,
403 else
406 }
407 /* If the target has "call" or "call_value" insns, then prefer them
408 if no arguments are actually popped. If the target does not have
409 "call" or "call_value" insns, then we must use the popping versions
410 even if the call has no arguments to pop. */
412 || !(valreg
415 {
418 /* If this subroutine pops its own args, record that in the call insn
419 if possible, for the sake of frame pointer elimination. */
423 rounded_stack_size_rtx,
425 else
430 }
431 else
432 {
436 else
439 }
442 /* Find the call we just emitted. */
445 /* Some target create a fresh MEM instead of reusing the one provided
446 above. Set its MEM_EXPR. */
453 /* Mark instrumented calls. */
457 /* Put the register usage information there. */
460 /* If this is a const call, then set the insn's unchanging bit. */
464 /* If this is a pure call, then set the insn's unchanging bit. */
468 /* If this is a const call, then set the insn's unchanging bit. */
472 /* Create a nothrow REG_EH_REGION note, if needed. */
479 {
482 }
486 /* Restore this now, so that we do defer pops for this call's args
487 if the context of the call as a whole permits. */
491 {
503 /* If popup is needed, stack realign must use DRAP */
506 }
507 /* For noreturn calls when not accumulating outgoing args force
508 REG_ARGS_SIZE note to prevent crossjumping of calls with different
509 args sizes. */
514 {
515 /* If returning from the subroutine does not automatically pop the args,
516 we need an instruction to pop them sooner or later.
517 Perhaps do it now; perhaps just record how much space to pop later.
519 If returning from the subroutine does pop the args, indicate that the
520 stack pointer will be changed. */
523 {
525 /* Just pretend we did the pop. */
530 else
532 }
533 }
534 /* When we accumulate outgoing args, we must avoid any stack manipulations.
535 Restore the stack pointer to its original value now. Usually
536 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
537 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
538 popping variants of functions exist as well.
540 ??? We may optimize similar to defer_pop above, but it is
541 probably not worthwhile.
543 ??? It will be worthwhile to enable combine_stack_adjustments even for
544 such machines. */
547 }
549 /* Determine if the function identified by FNDECL is one with
550 special properties we wish to know about. Modify FLAGS accordingly.
552 For example, if the function might return more than one time (setjmp), then
553 set ECF_RETURNS_TWICE.
555 Set ECF_MAY_BE_ALLOCA for any memory allocation function that might allocate
556 space from the stack such as alloca. */
558 static int
560 {
563 /* For instrumentation clones we want to derive flags
564 from the original name. */
571 /* Exclude functions not at the file scope, or not `extern',
572 since they are not the magic functions we would otherwise
573 think they are.
574 FIXME: this should be handled with attributes, not with this
575 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
576 because you can declare fork() inside a function if you
577 wish. */
581 {
585 /* We assume that alloca will always be called by name. It
586 makes no sense to pass it as a pointer-to-function to
587 anything that does not understand its behavior. */
593 /* Disregard prefix _ or __. */
595 {
598 else
600 }
602 /* ECF_RETURNS_TWICE is safe even for -ffreestanding. */
609 }
616 }
618 /* Similar to special_function_p; return a set of ERF_ flags for the
619 function FNDECL. */
620 static int
622 {
623 tree attr;
637 {
650 }
651 }
653 /* Return nonzero when FNDECL represents a call to setjmp. */
655 int
657 {
661 }
664 /* Return true if STMT may be an alloca call. */
666 bool
668 {
669 tree fndecl;
679 }
681 /* Return true if STMT is a builtin alloca call. */
683 bool
685 {
686 tree fndecl;
694 {
695 CASE_BUILT_IN_ALLOCA:
699 }
702 }
704 /* Return true when exp contains a builtin alloca call. */
706 bool
708 {
709 tree fndecl;
714 {
715 CASE_BUILT_IN_ALLOCA:
719 }
722 }
724 /* Return TRUE if FNDECL is either a TM builtin or a TM cloned
725 function. Return FALSE otherwise. */
727 static bool
729 {
737 {
739 {
782 }
783 }
785 }
787 /* Detect flags (function attributes) from the function decl or type node. */
789 int
791 {
795 {
796 /* The function exp may have the `malloc' attribute. */
800 /* The function exp may have the `returns_twice' attribute. */
804 /* Process the pure and const attributes. */
823 {
830 }
833 }
835 {
843 }
844 else
848 {
852 }
855 }
857 /* Detect flags from a CALL_EXPR. */
859 int
861 {
869 else
870 {
874 else
878 }
881 }
883 /* Return true if TYPE should be passed by invisible reference. */
885 bool
888 {
890 {
891 /* If this type contains non-trivial constructors, then it is
892 forbidden for the middle-end to create any new copies. */
896 /* GCC post 3.4 passes *all* variable sized types by reference. */
900 /* If a record type should be passed the same as its first (and only)
901 member, use the type and mode of that member. */
903 {
906 }
907 }
911 }
913 /* Return true if TYPE, which is passed by reference, should be callee
914 copied instead of caller copied. */
916 bool
919 {
923 named_arg);
924 }
927 /* Precompute all register parameters as described by ARGS, storing values
928 into fields within the ARGS array.
930 NUM_ACTUALS indicates the total number elements in the ARGS array.
932 Set REG_PARM_SEEN if we encounter a register parameter. */
934 static void
937 {
944 {
948 {
953 }
955 /* If we are to promote the function arg to a wider mode,
956 do it now. */
964 /* If the value is a non-legitimate constant, force it into a
965 pseudo now. TLS symbols sometimes need a call to resolve. */
970 /* If we're going to have to load the value by parts, pull the
971 parts into pseudos. The part extraction process can involve
972 non-trivial computation. */
974 {
979 }
981 /* If the value is expensive, and we are inside an appropriately
982 short loop, put the value into a pseudo and then put the pseudo
983 into the hard reg.
985 For small register classes, also do this if this call uses
986 register parameters. This is to avoid reload conflicts while
987 loading the parameters registers. */
996 && ((*reg_parm_seen
1000 }
1001 }
1003 #ifdef REG_PARM_STACK_SPACE
1005 /* The argument list is the property of the called routine and it
1006 may clobber it. If the fixed area has been used for previous
1007 parameters, we must save and restore it. */
1009 static rtx
1010 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
1011 {
1015 /* Compute the boundary of the area that needs to be saved, if any. */
1025 {
1027 machine_mode save_mode;
1029 rtx addr;
1030 rtx stack_area;
1031 rtx save_area;
1034 ;
1041 /* If we don't have the required alignment, must do this
1042 in BLKmode. */
1043 scalar_int_mode imode;
1048 else
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. */
1241 else
1243 }
1246 {
1249 alloc_object_size_limit
1251 }
1252 }
1253 }
1254 }
1256 }
1258 /* Return true when EXP's range can be determined and set RANGE[] to it
1259 after adjusting it if necessary to make EXP a represents a valid size
1260 of object, or a valid size argument to an allocation function declared
1261 with attribute alloc_size (whose argument may be signed), or to a string
1262 manipulation function like memset. When ALLOW_ZERO is true, allow
1263 returning a range of [0, 0] for a size in an anti-range [1, N] where
1264 N > PTRDIFF_MAX. A zero range is a (nearly) invalid argument to
1265 allocation functions like malloc but it is a valid argument to
1266 functions like memset. */
1268 bool
1270 {
1272 {
1273 /* EXP is a constant. */
1276 }
1286 else
1290 {
1292 {
1293 /* Use the full range of the type of the expression when
1294 no value range information is available. */
1298 }
1303 }
1310 {
1312 {
1314 {
1315 /* EXP is not in a strictly negative range. That means
1316 it must be in some (not necessarily strictly) positive
1317 range which includes zero. Since in signed to unsigned
1318 conversions negative values end up converted to large
1319 positive values, and otherwise they are not valid sizes,
1320 the resulting range is in both cases [0, TYPE_MAX]. */
1323 }
1325 {
1326 /* EXP is not in a negative-positive range. That means EXP
1327 is either negative, or greater than max. Since negative
1328 sizes are invalid make the range [MAX + 1, TYPE_MAX]. */
1331 }
1332 else
1333 {
1336 }
1337 }
1339 {
1340 /* EXP is unsigned and not in the range [1, MAX]. That means
1341 it's either zero or greater than MAX. Even though 0 would
1342 normally be detected by -Walloc-zero, unless ALLOW_ZERO
1343 is true, set the range to [MAX, TYPE_MAX] so that when MAX
1344 is greater than the limit the whole range is diagnosed. */
1347 else
1348 {
1351 }
1352 }
1353 else
1354 {
1357 }
1358 }
1364 }
1366 /* Diagnose a call EXP to function FN decorated with attribute alloc_size
1367 whose argument numbers given by IDX with values given by ARGS exceed
1368 the maximum object size or cause an unsigned oveflow (wrapping) when
1369 multiplied. When ARGS[0] is null the function does nothing. ARGS[1]
1370 may be null for functions like malloc, and non-null for those like
1371 calloc that are decorated with a two-argument attribute alloc_size. */
1373 void
1375 {
1376 /* The range each of the (up to) two arguments is known to be in. */
1379 /* Maximum object size set by -Walloc-size-larger-than= or SIZE_MAX / 2. */
1386 /* Validate each argument individually. */
1388 {
1390 {
1395 {
1399 }
1401 {
1402 /* Avoid issuing -Walloc-zero for allocation functions other
1403 than __builtin_alloca that are declared with attribute
1404 returns_nonnull because there's no portability risk. This
1405 avoids warning for such calls to libiberty's xmalloc and
1406 friends.
1407 Also avoid issuing the warning for calls to function named
1408 "alloca". */
1417 }
1419 {
1420 /* G++ emits calls to ::operator new[](SIZE_MAX) in C++98
1421 mode and with -fno-exceptions as a way to indicate array
1422 size overflow. There's no good way to detect C++98 here
1423 so avoid diagnosing these calls for all C++ modes. */
1432 "%Kargument %i value %qE exceeds "
1435 }
1436 }
1439 {
1440 /* Verify that the argument's range is not negative (including
1441 upper bound of zero). */
1444 {
1449 }
1451 {
1453 "%Kargument %i range [%E, %E] exceeds "
1457 maxobjsize);
1458 }
1459 }
1460 }
1465 /* For a two-argument alloc_size, validate the product of the two
1466 arguments if both of their values or ranges are known. */
1471 {
1472 /* Check for overflow in the product of a function decorated with
1473 attribute alloc_size (X, Y). */
1483 "%Kproduct %<%E * %E%> of arguments %i and %i "
1489 "%Kproduct %<%E * %E%> of arguments %i and %i "
1493 maxobjsize);
1496 {
1497 /* Print the full range of each of the two arguments to make
1498 it clear when it is, in fact, in a range and not constant. */
1505 }
1506 }
1509 {
1515 else
1518 }
1519 }
1521 /* If EXPR refers to a character array or pointer declared attribute
1522 nonstring return a decl for that array or pointer and set *REF to
1523 the referenced enclosing object or pointer. Otherwise returns
1524 null. */
1526 tree
1528 {
1531 {
1535 {
1541 }
1544 }
1560 }
1562 /* Warn about passing a non-string array/pointer to a function that
1563 expects a nul-terminated string argument. */
1565 void
1567 {
1573 /* The bound argument to a bounded string function like strncpy. */
1576 /* It's safe to call "bounded" string functions with a non-string
1577 argument since the functions provide an explicit bound for this
1578 purpose. */
1580 {
1596 }
1598 /* Determine the range of the bound argument (if specified). */
1603 /* Iterate over the built-in function's formal arguments and check
1604 each const char* against the actual argument. If the actual
1605 argument is declared attribute non-string issue a warning unless
1606 the argument's maximum length is bounded. */
1607 function_args_iterator it;
1611 {
1633 /* See if the destination is declared with attribute "nonstring". */
1648 {
1651 }
1659 "%qD argument %i declared attribute %<nonstring%> "
1670 }
1671 }
1673 /* Issue an error if CALL_EXPR was flagged as requiring
1674 tall-call optimization. */
1676 static void
1678 {
1684 }
1686 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1687 CALL_EXPR EXP.
1689 NUM_ACTUALS is the total number of parameters.
1691 N_NAMED_ARGS is the total number of named arguments.
1693 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
1694 value, or null.
1696 FNDECL is the tree code for the target of this call (if known)
1698 ARGS_SO_FAR holds state needed by the target to know where to place
1699 the next argument.
1701 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1702 for arguments which are passed in registers.
1704 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1705 and may be modified by this routine.
1707 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1708 flags which may be modified by this routine.
1710 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
1711 that requires allocation of stack space.
1713 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
1714 the thunked-to function. */
1716 static void
1723 cumulative_args_t args_so_far,
1728 {
1732 /* Count arg position in order args appear. */
1742 /* In this loop, we consider args in the order they are written.
1743 We fill up ARGS from the back. */
1746 {
1748 call_expr_arg_iterator iter;
1749 tree arg;
1753 {
1755 j--;
1757 /* If we pass structure address then we need to
1758 create bounds for it. Since created bounds is
1759 a call statement, we expand it right here to avoid
1760 fixing all other places where it may be expanded. */
1762 {
1769 j--;
1770 }
1771 }
1774 {
1777 /* Remember last param with pointer and associate it
1778 with following pointer bounds. */
1781 {
1786 {
1789 }
1790 }
1794 {
1798 }
1800 {
1801 /* We expect bounds in instrumented calls only.
1802 Otherwise it is a sign we lost flag due to some optimization
1803 and may emit call args incorrectly. */
1806 /* For structures look for the next available pointer. */
1808 {
1815 /* Check we have no more pointers in the structure. */
1818 }
1821 /* Check we covered all pointers in the previous
1822 non bounds arg. */
1825 }
1826 else
1830 && argtype
1833 {
1836 j--;
1838 }
1839 else
1841 j--;
1842 argpos++;
1843 }
1847 }
1851 /* Extract attribute alloc_size and if set, store the indices of
1852 the corresponding arguments in ALLOC_IDX, and then the actual
1853 argument(s) at those indices in ALLOC_ARGS. */
1859 {
1864 }
1866 /* Array for up to the two attribute alloc_size arguments. */
1869 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1871 {
1874 machine_mode mode;
1876 /* Replace erroneous argument with constant zero. */
1880 /* If TYPE is a transparent union or record, pass things the way
1881 we would pass the first field of the union or record. We have
1882 already verified that the modes are the same. */
1887 /* Decide where to pass this arg.
1889 args[i].reg is nonzero if all or part is passed in registers.
1891 args[i].partial is nonzero if part but not all is passed in registers,
1892 and the exact value says how many bytes are passed in registers.
1894 args[i].pass_on_stack is nonzero if the argument must at least be
1895 computed on the stack. It may then be loaded back into registers
1896 if args[i].reg is nonzero.
1898 These decisions are driven by the FUNCTION_... macros and must agree
1899 with those made by function.c. */
1901 /* See if this argument should be passed by invisible reference. */
1904 {
1908 callee_copies
1912 /* If we're compiling a thunk, pass through invisible references
1913 instead of making a copy. */
1915 || (callee_copies
1920 {
1921 /* We may have turned the parameter value into an SSA name.
1922 Go back to the original parameter so we can take the
1923 address. */
1925 {
1929 }
1930 /* Argument setup code may have copied the value to register. We
1931 revert that optimization now because the tail call code must
1932 use the original location. */
1942 /* We can't use sibcalls if a callee-copied argument is
1943 stored in the current function's frame. */
1945 {
1948 "a callee-copied argument is"
1949 " stored in the current "
1951 }
1959 }
1960 else
1961 {
1962 /* We make a copy of the object and pass the address to the
1963 function being called. */
1964 rtx copy;
1971 {
1972 /* This is a variable-sized object. Make space on the stack
1973 for it. */
1977 {
1981 }
1983 /* We can pass TRUE as the 4th argument because we just
1984 saved the stack pointer and will restore it right after
1985 the call. */
1989 max_int_size_in_bytes
1994 }
1995 else
2000 /* Just change the const function to pure and then let
2001 the next test clear the pure based on
2002 callee_copies. */
2004 {
2007 }
2017 "argument must be passed"
2019 }
2020 }
2035 {
2038 }
2040 /* If this is a sibling call and the machine has register windows, the
2041 register window has to be unwinded before calling the routine, so
2042 arguments have to go into the incoming registers. */
2047 else
2057 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
2058 it means that we are to pass this arg in the register(s) designated
2059 by the PARALLEL, but also to pass it in the stack. */
2064 /* If this is an addressable type, we must preallocate the stack
2065 since we must evaluate the object into its final location.
2067 If this is to be passed in both registers and the stack, it is simpler
2068 to preallocate. */
2073 /* No stack allocation and padding for bounds. */
2075 ;
2076 /* Compute the stack-size of this argument. */
2081 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2083 #else
2085 #endif
2086 reg_parm_stack_space,
2089 #ifdef BLOCK_REG_PADDING
2090 else
2091 /* The argument is passed entirely in registers. See at which
2092 end it should be padded. */
2096 #endif
2098 /* Update ARGS_SIZE, the total stack space for args so far. */
2104 /* Increment ARGS_SO_FAR, which has info about which arg-registers
2105 have been used, etc. */
2110 /* Store argument values for functions decorated with attribute
2111 alloc_size. */
2116 }
2119 {
2120 /* Check the arguments of functions decorated with attribute
2121 alloc_size. */
2123 }
2125 /* Detect passing non-string arguments to functions expecting
2126 nul-terminated strings. */
2128 }
2130 /* Update ARGS_SIZE to contain the total size for the argument block.
2131 Return the original constant component of the argument block's size.
2133 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
2134 for arguments passed in registers. */
2136 static int
2139 tree fndecl ATTRIBUTE_UNUSED,
2140 tree fntype ATTRIBUTE_UNUSED,
2142 {
2145 /* For accumulate outgoing args mode we don't need to align, since the frame
2146 will be already aligned. Align to STACK_BOUNDARY in order to prevent
2147 backends from generating misaligned frame sizes. */
2151 /* Compute the actual size of the argument block required. The variable
2152 and constant sizes must be combined, the size may have to be rounded,
2153 and there may be a minimum required size. */
2156 {
2162 {
2163 /* We don't handle this case yet. To handle it correctly we have
2164 to add the delta, round and subtract the delta.
2165 Currently no machine description requires this support. */
2168 }
2171 {
2172 args_size->var
2176 /* The area corresponding to register parameters is not to count in
2177 the size of the block we need. So make the adjustment. */
2179 args_size->var
2182 }
2183 }
2184 else
2185 {
2190 + stack_pointer_delta
2192 / preferred_stack_boundary
2197 reg_parm_stack_space);
2201 }
2203 }
2205 /* Precompute parameters as needed for a function call.
2207 FLAGS is mask of ECF_* constants.
2209 NUM_ACTUALS is the number of arguments.
2211 ARGS is an array containing information for each argument; this
2212 routine fills in the INITIAL_VALUE and VALUE fields for each
2213 precomputed argument. */
2215 static void
2217 {
2220 /* If this is a libcall, then precompute all arguments so that we do not
2221 get extraneous instructions emitted as part of the libcall sequence. */
2223 /* If we preallocated the stack space, and some arguments must be passed
2224 on the stack, then we must precompute any parameter which contains a
2225 function call which will store arguments on the stack.
2226 Otherwise, evaluating the parameter may clobber previous parameters
2227 which have already been stored into the stack. (we have code to avoid
2228 such case by saving the outgoing stack arguments, but it results in
2229 worse code) */
2234 {
2235 tree type;
2236 machine_mode mode;
2241 /* If this is an addressable type, we cannot pre-evaluate it. */
2250 {
2256 /* CSE will replace this only if it contains args[i].value
2257 pseudo, so convert it down to the declared mode using
2258 a SUBREG. */
2262 {
2267 }
2268 }
2269 }
2270 }
2272 /* Given the current state of MUST_PREALLOCATE and information about
2273 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
2274 compute and return the final value for MUST_PREALLOCATE. */
2276 static int
2279 {
2280 /* See if we have or want to preallocate stack space.
2282 If we would have to push a partially-in-regs parm
2283 before other stack parms, preallocate stack space instead.
2285 If the size of some parm is not a multiple of the required stack
2286 alignment, we must preallocate.
2288 If the total size of arguments that would otherwise create a copy in
2289 a temporary (such as a CALL) is more than half the total argument list
2290 size, preallocation is faster.
2292 Another reason to preallocate is if we have a machine (like the m88k)
2293 where stack alignment is required to be maintained between every
2294 pair of insns, not just when the call is made. However, we assume here
2295 that such machines either do not have push insns (and hence preallocation
2296 would occur anyway) or the problem is taken care of with
2297 PUSH_ROUNDING. */
2300 {
2306 {
2311 /* We preallocate in case there are bounds passed
2312 in the bounds table to have precomputed address
2313 for bounds association. */
2323 copy_to_evaluate_size
2325 }
2330 }
2332 }
2334 /* If we preallocated stack space, compute the address of each argument
2335 and store it into the ARGS array.
2337 We need not ensure it is a valid memory address here; it will be
2338 validized when it is used.
2340 ARGBLOCK is an rtx for the address of the outgoing arguments. */
2342 static void
2344 {
2346 {
2354 {
2357 rtx addr;
2362 /* Skip this parm if it will not be passed on the stack. */
2371 /* Pointer Bounds are never passed on the stack. */
2379 {
2380 /* Only part of the parameter is being passed on the stack.
2381 Generate a simple memory reference of the correct size. */
2387 }
2388 else
2389 {
2393 }
2399 {
2402 }
2409 {
2410 /* Only part of the parameter is being passed on the stack.
2411 Generate a simple memory reference of the correct size.
2412 */
2415 }
2416 else
2417 {
2421 }
2424 /* Function incoming arguments may overlap with sibling call
2425 outgoing arguments and we cannot allow reordering of reads
2426 from function arguments with stores to outgoing arguments
2427 of sibling calls. */
2430 }
2431 }
2432 }
2434 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
2435 in a call instruction.
2437 FNDECL is the tree node for the target function. For an indirect call
2438 FNDECL will be NULL_TREE.
2440 ADDR is the operand 0 of CALL_EXPR for this call. */
2442 static rtx
2444 {
2445 rtx funexp;
2447 /* Get the function to call, in the form of RTL. */
2449 {
2453 /* Get a SYMBOL_REF rtx for the function address. */
2455 }
2456 else
2457 /* Generate an rtx (probably a pseudo-register) for the address. */
2458 {
2462 }
2464 }
2466 /* Return the static chain for this function, if any. */
2468 rtx
2470 {
2475 }
2477 /* Internal state for internal_arg_pointer_based_exp and its helpers. */
2478 static struct
2479 {
2480 /* Last insn that has been scanned by internal_arg_pointer_based_exp_scan,
2481 or NULL_RTX if none has been scanned yet. */
2483 /* Vector indexed by REGNO - FIRST_PSEUDO_REGISTER, recording if a pseudo is
2484 based on crtl->args.internal_arg_pointer. The element is NULL_RTX if the
2485 pseudo isn't based on it, a CONST_INT offset if the pseudo is based on it
2486 with fixed offset, or PC if this is with variable or unknown offset. */
2492 /* Helper function for internal_arg_pointer_based_exp. Scan insns in
2493 the tail call sequence, starting with first insn that hasn't been
2494 scanned yet, and note for each pseudo on the LHS whether it is based
2495 on crtl->args.internal_arg_pointer or not, and what offset from that
2496 that pointer it has. */
2498 static void
2500 {
2505 else
2509 {
2512 {
2515 /* Punt on pseudos set multiple times. */
2520 else
2523 {
2525 internal_arg_pointer_exp_state.cache
2528 }
2529 }
2533 }
2536 }
2538 /* Compute whether RTL is based on crtl->args.internal_arg_pointer. Return
2539 NULL_RTX if RTL isn't based on it, a CONST_INT offset if RTL is based on
2540 it with fixed offset, or PC if this is with variable or unknown offset.
2541 TOPLEVEL is true if the function is invoked at the topmost level. */
2543 static rtx
2545 {
2556 {
2561 }
2563 /* When called at the topmost level, scan pseudo assignments in between the
2564 last scanned instruction in the tail call sequence and the latest insn
2565 in that sequence. */
2570 {
2576 }
2580 {
2586 }
2589 }
2591 /* Return true if and only if SIZE storage units (usually bytes)
2592 starting from address ADDR overlap with already clobbered argument
2593 area. This function is used to determine if we should give up a
2594 sibcall. */
2596 static bool
2598 {
2599 HOST_WIDE_INT i;
2600 rtx val;
2609 else
2614 else
2622 {
2629 }
2632 }
2634 /* Do the register loads required for any wholly-register parms or any
2635 parms which are passed both on the stack and in a register. Their
2636 expressions were already evaluated.
2638 Mark all register-parms as living through the call, putting these USE
2639 insns in the CALL_INSN_FUNCTION_USAGE field.
2641 When IS_SIBCALL, perform the check_sibcall_argument_overlap
2642 checking, setting *SIBCALL_FAILURE if appropriate. */
2644 static void
2648 {
2652 {
2656 {
2661 /* Set non-negative if we must move a word at a time, even if
2662 just one word (e.g, partial == 4 && mode == DFmode). Set
2663 to -1 if we just use a normal move insn. This value can be
2664 zero if the argument is a zero size structure. */
2667 ;
2669 {
2672 }
2674 {
2677 }
2678 else
2681 /* Handle calls that pass values in multiple non-contiguous
2682 locations. The Irix 6 ABI has examples of this. */
2687 /* If simple case, just do move. If normal partial, store_one_arg
2688 has already loaded the register for us. In all other cases,
2689 load the register(s) from memory. */
2692 {
2694 #ifdef BLOCK_REG_PADDING
2695 /* Handle case where we have a value that needs shifting
2696 up to the msb. eg. a QImode value and we're padding
2697 upward on a BYTES_BIG_ENDIAN machine. */
2701 {
2702 rtx x;
2705 /* Assigning REG here rather than a temp makes CALL_FUSAGE
2706 report the whole reg as used. Strictly speaking, the
2707 call only uses SIZE bytes at the msb end, but it doesn't
2708 seem worth generating rtl to say that. */
2713 }
2714 #endif
2715 }
2717 /* If we have pre-computed the values to put in the registers in
2718 the case of non-aligned structures, copy them in now. */
2726 {
2729 /* Check for overlap with already clobbered argument area,
2730 providing that this has non-zero size. */
2733 && (mem_overlaps_already_clobbered_arg_p
2740 else
2741 {
2750 NULL);
2756 }
2758 /* Handle a BLKmode that needs shifting. */
2760 #ifdef BLOCK_REG_PADDING
2762 #else
2763 && BYTES_BIG_ENDIAN
2764 #endif
2765 )
2766 {
2771 rtx x;
2776 }
2777 }
2779 /* When a parameter is a block, and perhaps in other cases, it is
2780 possible that it did a load from an argument slot that was
2781 already clobbered. */
2786 /* Handle calls that pass values in multiple non-contiguous
2787 locations. The Irix 6 ABI has examples of this. */
2795 }
2796 }
2797 }
2799 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
2800 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
2801 bytes, then we would need to push some additional bytes to pad the
2802 arguments. So, we compute an adjust to the stack pointer for an
2803 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
2804 bytes. Then, when the arguments are pushed the stack will be perfectly
2805 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
2806 be popped after the call. Returns the adjustment. */
2808 static int
2812 {
2813 /* The number of bytes to pop so that the stack will be
2814 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
2815 HOST_WIDE_INT adjustment;
2816 /* The alignment of the stack after the arguments are pushed, if we
2817 just pushed the arguments without adjust the stack here. */
2820 unadjusted_alignment
2824 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
2825 as possible -- leaving just enough left to cancel out the
2826 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
2827 PENDING_STACK_ADJUST is non-negative, and congruent to
2828 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
2830 /* Begin by trying to pop all the bytes. */
2831 unadjusted_alignment
2832 = (unadjusted_alignment
2835 /* Push enough additional bytes that the stack will be aligned
2836 after the arguments are pushed. */
2840 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
2841 bytes after the call. The right number is the entire
2842 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
2843 by the arguments in the first place. */
2844 args_size->constant
2848 }
2850 /* Scan X expression if it does not dereference any argument slots
2851 we already clobbered by tail call arguments (as noted in stored_args_map
2852 bitmap).
2853 Return nonzero if X expression dereferences such argument slots,
2854 zero otherwise. */
2856 static int
2858 {
2859 RTX_CODE code;
2868 /* We need not check the operands of the CALL expression itself. */
2876 /* Scan all subexpressions. */
2879 {
2881 {
2884 }
2886 {
2890 }
2891 }
2893 }
2895 /* Scan sequence after INSN if it does not dereference any argument slots
2896 we already clobbered by tail call arguments (as noted in stored_args_map
2897 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
2898 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
2899 should be 0). Return nonzero if sequence after INSN dereferences such argument
2900 slots, zero otherwise. */
2902 static int
2905 {
2910 else
2919 {
2922 else
2927 }
2929 }
2931 /* Given that a function returns a value of mode MODE at the most
2932 significant end of hard register VALUE, shift VALUE left or right
2933 as specified by LEFT_P. Return true if some action was needed. */
2935 bool
2937 {
2938 HOST_WIDE_INT shift;
2946 /* Use ashr rather than lshr for right shifts. This is for the benefit
2947 of the MIPS port, which requires SImode values to be sign-extended
2948 when stored in 64-bit registers. */
2954 }
2956 /* If X is a likely-spilled register value, copy it to a pseudo
2957 register and return that register. Return X otherwise. */
2959 static rtx
2961 {
2962 rtx new_rtx;
2967 {
2968 /* Make sure that we generate a REG rather than a CONCAT.
2969 Moves into CONCATs can need nontrivial instructions,
2970 and the whole point of this function is to avoid
2971 using the hard register directly in such a situation. */
2977 }
2979 }
2981 /* Helper function for expand_call.
2982 Return false is EXP is not implementable as a sibling call. */
2984 static bool
2986 rtx structure_value_addr,
2987 tree funtype,
2989 tree fndecl,
2991 tree addr,
2993 {
2995 {
2996 maybe_complain_about_tail_call
2998 "machine description does not have"
3001 }
3003 /* Doing sibling call optimization needs some work, since
3004 structure_value_addr can be allocated on the stack.
3005 It does not seem worth the effort since few optimizable
3006 sibling calls will return a structure. */
3008 {
3011 }
3013 #ifdef REG_PARM_STACK_SPACE
3014 /* If outgoing reg parm stack space changes, we can not do sibcall. */
3018 {
3020 "inconsistent size of stack space"
3021 " allocated for arguments which are"
3024 }
3025 #endif
3027 /* Check whether the target is able to optimize the call
3028 into a sibcall. */
3030 {
3032 "target is not able to optimize the"
3035 }
3037 /* Functions that do not return exactly once may not be sibcall
3038 optimized. */
3040 {
3043 }
3045 {
3048 }
3051 {
3054 }
3056 /* If the called function is nested in the current one, it might access
3057 some of the caller's arguments, but could clobber them beforehand if
3058 the argument areas are shared. */
3060 {
3063 }
3065 /* If this function requires more stack slots than the current
3066 function, we cannot change it into a sibling call.
3067 crtl->args.pretend_args_size is not part of the
3068 stack allocated by our caller. */
3070 {
3072 "callee required more stack slots"
3075 }
3077 /* If the callee pops its own arguments, then it must pop exactly
3078 the same number of arguments as the current function. */
3083 {
3085 "inconsistent number of"
3088 }
3091 {
3095 }
3097 /* All checks passed. */
3099 }
3101 /* Generate all the code for a CALL_EXPR exp
3102 and return an rtx for its value.
3103 Store the value in TARGET (specified as an rtx) if convenient.
3104 If the value is stored in TARGET then TARGET is returned.
3105 If IGNORE is nonzero, then we ignore the value of the function call. */
3107 rtx
3109 {
3110 /* Nonzero if we are currently expanding a call. */
3113 /* RTX for the function to be called. */
3114 rtx funexp;
3115 /* Sequence of insns to perform a normal "call". */
3117 /* Sequence of insns to perform a tail "call". */
3119 /* Data type of the function. */
3120 tree funtype;
3121 tree type_arg_types;
3122 tree rettype;
3123 /* Declaration of the function being called,
3124 or 0 if the function is computed (not known by name). */
3126 /* The type of the function being called. */
3127 tree fntype;
3132 /* Register in which non-BLKmode value will be returned,
3133 or 0 if no value or if value is BLKmode. */
3134 rtx valreg;
3135 /* Register(s) in which bounds are returned. */
3137 /* Address where we should return a BLKmode value;
3138 0 if value not BLKmode. */
3140 /* Nonzero if that address is being passed by treating it as
3141 an extra, implicit first parameter. Otherwise,
3142 it is passed by being copied directly into struct_value_rtx. */
3144 /* Holds the value of implicit argument for the struct value. */
3146 /* Size of aggregate value wanted, or zero if none wanted
3147 or if we are using the non-reentrant PCC calling convention
3148 or expecting the value in registers. */
3150 /* Nonzero if called function returns an aggregate in memory PCC style,
3151 by returning the address of where to find it. */
3155 /* Number of actual parameters in this call, including struct value addr. */
3157 /* Number of named args. Args after this are anonymous ones
3158 and they must all go on the stack. */
3160 /* Number of complex actual arguments that need to be split. */
3163 /* Vector of information about each argument.
3164 Arguments are numbered in the order they will be pushed,
3165 not the order they are written. */
3168 /* Total size in bytes of all the stack-parms scanned so far. */
3171 /* Size of arguments before any adjustments (such as rounding). */
3173 /* Data on reg parms scanned so far. */
3174 CUMULATIVE_ARGS args_so_far_v;
3175 cumulative_args_t args_so_far;
3176 /* Nonzero if a reg parm has been scanned. */
3178 /* Nonzero if this is an indirect function call. */
3180 /* Nonzero if we must avoid push-insns in the args for this call.
3181 If stack space is allocated for register parameters, but not by the
3182 caller, then it is preallocated in the fixed part of the stack frame.
3183 So the entire argument block must then be preallocated (i.e., we
3184 ignore PUSH_ROUNDING in that case). */
3188 /* Size of the stack reserved for parameter registers. */
3191 /* Address of space preallocated for stack parms
3192 (on machines that lack push insns), or 0 if space not preallocated. */
3195 /* Mask of ECF_ and ERF_ flags. */
3198 #ifdef REG_PARM_STACK_SPACE
3199 /* Define the boundary of the register parm stack space that needs to be
3200 saved, if any. */
3203 #endif
3211 /* State variables to track stack modifications. */
3217 /* Some stack pointer alterations we make are performed via
3218 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
3219 which we then also need to save/restore along the way. */
3222 rtx call_fusage;
3225 /* The alignment of the stack, in bits. */
3227 /* The alignment of the stack, in bytes. */
3229 /* The static chain value to use for this call. */
3230 rtx static_chain_value;
3231 /* See if this is "nothrow" function call. */
3235 /* See if we can find a DECL-node for the actual function, and get the
3236 function attributes (flags) from the function decl or type node. */
3239 {
3243 }
3244 else
3245 {
3250 }
3255 /* Warn if this value is an aggregate type,
3256 regardless of which calling convention we are using for it. */
3260 /* If the result of a non looping pure or const function call is
3261 ignored (or void), and none of its arguments are volatile, we can
3262 avoid expanding the call and just evaluate the arguments for
3263 side-effects. */
3268 {
3270 tree arg;
3271 call_expr_arg_iterator iter;
3275 {
3278 }
3281 {
3285 }
3286 }
3288 #ifdef REG_PARM_STACK_SPACE
3290 #endif
3296 /* Set up a place to return a structure. */
3298 /* Cater to broken compilers. */
3300 {
3301 /* This call returns a big structure. */
3304 #ifdef PCC_STATIC_STRUCT_RETURN
3305 {
3307 }
3309 {
3312 /* Even if it is semantically safe to use the target as the return
3313 slot, it may be not sufficiently aligned for the return type. */
3315 && target
3321 else
3322 {
3323 /* For variable-sized objects, we must be called with a target
3324 specified. If we were to allocate space on the stack here,
3325 we would have no way of knowing when to free it. */
3329 }
3330 }
3332 }
3334 /* Figure out the amount to which the stack should be aligned. */
3337 {
3339 /* Without automatic stack alignment, we can't increase preferred
3340 stack boundary. With automatic stack alignment, it is
3341 unnecessary since unless we can guarantee that all callers will
3342 align the outgoing stack properly, callee has to align its
3343 stack anyway. */
3348 }
3350 /* Operand 0 is a pointer-to-function; get the type of the function. */
3355 /* Count whether there are actual complex arguments that need to be split
3356 into their real and imaginary parts. Munge the type_arg_types
3357 appropriately here as well. */
3359 {
3360 call_expr_arg_iterator iter;
3361 tree arg;
3363 {
3367 num_complex_actuals++;
3368 }
3370 }
3371 else
3377 /* If struct_value_rtx is 0, it means pass the address
3378 as if it were an extra parameter. Put the argument expression
3379 in structure_value_addr_value. */
3381 {
3382 /* If structure_value_addr is a REG other than
3383 virtual_outgoing_args_rtx, we can use always use it. If it
3384 is not a REG, we must always copy it into a register.
3385 If it is virtual_outgoing_args_rtx, we must copy it to another
3386 register in some cases. */
3388 || (ACCUMULATE_OUTGOING_ARGS
3389 && stack_arg_under_construction
3395 structure_value_addr_value =
3398 }
3400 /* Count the arguments and set NUM_ACTUALS. */
3401 num_actuals =
3404 /* Compute number of named args.
3405 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
3408 n_named_args
3410 /* Count the struct value address, if it is passed as a parm. */
3412 else
3413 /* If we know nothing, treat all args as named. */
3416 /* Start updating where the next arg would go.
3418 On some machines (such as the PA) indirect calls have a different
3419 calling convention than normal calls. The fourth argument in
3420 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
3421 or not. */
3425 /* Now possibly adjust the number of named args.
3426 Normally, don't include the last named arg if anonymous args follow.
3427 We do include the last named arg if
3428 targetm.calls.strict_argument_naming() returns nonzero.
3429 (If no anonymous args follow, the result of list_length is actually
3430 one too large. This is harmless.)
3432 If targetm.calls.pretend_outgoing_varargs_named() returns
3433 nonzero, and targetm.calls.strict_argument_naming() returns zero,
3434 this machine will be able to place unnamed args that were passed
3435 in registers into the stack. So treat all args as named. This
3436 allows the insns emitting for a specific argument list to be
3437 independent of the function declaration.
3439 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
3440 we do not have any reliable way to pass unnamed args in
3441 registers, so we must force them into memory. */
3445 ;
3448 /* Don't include the last named arg. */
3450 else
3451 /* Treat all args as named. */
3454 /* Make a vector to hold all the information about each arg. */
3457 /* Build up entries in the ARGS array, compute the size of the
3458 arguments into ARGS_SIZE, etc. */
3470 /* Now make final decision about preallocating stack space. */
3475 /* If the structure value address will reference the stack pointer, we
3476 must stabilize it. We don't need to do this if we know that we are
3477 not going to adjust the stack pointer in processing this call. */
3482 structure_value_addr))
3487 /* Tail calls can make things harder to debug, and we've traditionally
3488 pushed these optimizations into -O2. Don't try if we're already
3489 expanding a call, as that means we're an argument. Don't try if
3490 there's cleanups, as we know there's code to follow the call. */
3493 || !flag_optimize_sibling_calls
3498 /* If the user has marked the function as requiring tail-call
3499 optimization, attempt it. */
3503 /* Rest of purposes for tail call optimizations to fail. */
3506 structure_value_addr,
3507 funtype,
3508 reg_parm_stack_space,
3509 fndecl,
3512 /* Check if caller and callee disagree in promotion of function
3513 return value. */
3515 {
3525 caller_promoted_mode
3529 callee_promoted_mode
3539 {
3542 "caller and callee disagree in"
3543 " promotion of function"
3545 }
3546 }
3548 /* Ensure current function's preferred stack boundary is at least
3549 what we need. Stack alignment may also increase preferred stack
3550 boundary. */
3553 else
3558 /* We want to make two insn chains; one for a sibling call, the other
3559 for a normal call. We will select one of the two chains after
3560 initial RTL generation is complete. */
3562 {
3564 /* We want to emit any pending stack adjustments before the tail
3565 recursion "call". That way we know any adjustment after the tail
3566 recursion call can be ignored if we indeed use the tail
3567 call expansion. */
3568 saved_pending_stack_adjust save;
3570 rtx next_arg_reg;
3573 {
3574 /* State variables we need to save and restore between
3575 iterations. */
3577 }
3580 else
3583 /* Other state variables that we must reinitialize each time
3584 through the loop (that are not initialized by the loop itself). */
3588 /* Start a new sequence for the normal call case.
3590 From this point on, if the sibling call fails, we want to set
3591 sibcall_failure instead of continuing the loop. */
3594 /* Don't let pending stack adjusts add up to too much.
3595 Also, do all pending adjustments now if there is any chance
3596 this might be a call to alloca or if we are expanding a sibling
3597 call sequence.
3598 Also do the adjustments before a throwing call, otherwise
3599 exception handling can fail; PR 19225. */
3608 /* Precompute any arguments as needed. */
3612 /* Now we are about to start emitting insns that can be deleted
3613 if a libcall is deleted. */
3623 /* Compute the actual size of the argument block required. The variable
3624 and constant sizes must be combined, the size may have to be rounded,
3625 and there may be a minimum required size. When generating a sibcall
3626 pattern, do not round up, since we'll be re-using whatever space our
3627 caller provided. */
3628 unadjusted_args_size
3637 /* The argument block when performing a sibling call is the
3638 incoming argument block. */
3640 {
3643 argblock
3645 else
3646 argblock
3651 }
3653 /* If we have no actual push instructions, or shouldn't use them,
3654 make space for all args right now. */
3656 {
3658 {
3663 /* stack_arg_under_construction says whether a stack arg is
3664 being constructed at the old stack level. Pushing the stack
3665 gets a clean outgoing argument block. */
3668 }
3672 }
3673 else
3674 {
3675 /* Note that we must go through the motions of allocating an argument
3676 block even if the size is zero because we may be storing args
3677 in the area reserved for register arguments, which may be part of
3678 the stack frame. */
3682 /* Store the maximum argument space used. It will be pushed by
3683 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
3684 checking). */
3690 {
3692 {
3693 /* Since the stack pointer will never be pushed, it is
3694 possible for the evaluation of a parm to clobber
3695 something we have already written to the stack.
3696 Since most function calls on RISC machines do not use
3697 the stack, this is uncommon, but must work correctly.
3699 Therefore, we save any area of the stack that was already
3700 written and that we are using. Here we set up to do this
3701 by making a new stack usage map from the old one. The
3702 actual save will be done by store_one_arg.
3704 Another approach might be to try to reorder the argument
3705 evaluations to avoid this conflicting stack usage. */
3707 /* Since we will be writing into the entire argument area,
3708 the map must be allocated for its entire size, not just
3709 the part that is the responsibility of the caller. */
3714 highest_outgoing_arg_in_use
3716 else
3717 highest_outgoing_arg_in_use
3726 initial_highest_arg_in_use);
3730 (highest_outgoing_arg_in_use
3734 /* The address of the outgoing argument list must not be
3735 copied to a register here, because argblock would be left
3736 pointing to the wrong place after the call to
3737 allocate_dynamic_stack_space below. */
3740 }
3741 else
3742 {
3744 {
3745 /* Try to reuse some or all of the pending_stack_adjust
3746 to get this space. */
3747 needed
3748 = (combine_pending_stack_adjustment_and_call
3751 preferred_unit_stack_boundary));
3753 /* combine_pending_stack_adjustment_and_call computes
3754 an adjustment before the arguments are allocated.
3755 Account for them and see whether or not the stack
3756 needs to go up or down. */
3760 {
3761 /* We're releasing stack space. */
3762 /* ??? We can avoid any adjustment at all if we're
3763 already aligned. FIXME. */
3767 }
3768 else
3769 /* We need to allocate space. We'll do that in
3770 push_block below. */
3772 }
3774 /* Special case this because overhead of `push_block' in
3775 this case is non-trivial. */
3778 else
3779 {
3783 }
3785 /* We only really need to call `copy_to_reg' in the case
3786 where push insns are going to be used to pass ARGBLOCK
3787 to a function call in ARGS. In that case, the stack
3788 pointer changes value from the allocation point to the
3789 call point, and hence the value of
3790 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
3791 as well always do it. */
3793 }
3794 }
3795 }
3798 {
3799 /* The save/restore code in store_one_arg handles all
3800 cases except one: a constructor call (including a C
3801 function returning a BLKmode struct) to initialize
3802 an argument. */
3804 {
3805 rtx push_size
3811 {
3816 /* stack_arg_under_construction says whether a stack
3817 arg is being constructed at the old stack level.
3818 Pushing the stack gets a clean outgoing argument
3819 block. */
3820 old_stack_arg_under_construction
3823 /* Make a new map for the new argument list. */
3828 }
3829 /* We can pass TRUE as the 4th argument because we just
3830 saved the stack pointer and will restore it right after
3831 the call. */
3834 }
3836 /* If argument evaluation might modify the stack pointer,
3837 copy the address of the argument list to a register. */
3840 {
3843 }
3844 }
3848 /* Stack is properly aligned, pops can't safely be deferred during
3849 the evaluation of the arguments. */
3850 NO_DEFER_POP;
3852 /* Precompute all register parameters. It isn't safe to compute
3853 anything once we have started filling any specific hard regs.
3854 TLS symbols sometimes need a call to resolve. Precompute
3855 register parameters before any stack pointer manipulation
3856 to avoid unaligned stack in the called function. */
3859 OK_DEFER_POP;
3861 /* Perform stack alignment before the first push (the last arg). */
3865 {
3866 /* When the stack adjustment is pending, we get better code
3867 by combining the adjustments. */
3870 {
3871 pending_stack_adjust
3872 = (combine_pending_stack_adjustment_and_call
3875 preferred_unit_stack_boundary));
3877 }
3881 }
3882 /* Now that the stack is properly aligned, pops can't safely
3883 be deferred during the evaluation of the arguments. */
3884 NO_DEFER_POP;
3886 /* Record the maximum pushed stack space size. We need to delay
3887 doing it this far to take into account the optimization done
3888 by combine_pending_stack_adjustment_and_call. */
3890 && !ACCUMULATE_OUTGOING_ARGS
3891 && pass
3893 {
3897 }
3903 else
3906 #ifdef REG_PARM_STACK_SPACE
3907 /* Save the fixed argument area if it's part of the caller's frame and
3908 is clobbered by argument setup for this call. */
3912 #endif
3914 /* Now store (and compute if necessary) all non-register parms.
3915 These come before register parms, since they can require block-moves,
3916 which could clobber the registers used for register parms.
3917 Parms which have partial registers are not stored here,
3918 but we do preallocate space here if they want that. */
3921 {
3922 /* Delay bounds until all other args are stored. */
3926 {
3929 /* We don't allow passing huge (> 2^30 B) arguments
3930 by value. It would cause an overflow later on. */
3933 {
3936 }
3940 reg_parm_stack_space)
3945 }
3948 call_fusage
3951 call_fusage);
3952 }
3954 /* If we have a parm that is passed in registers but not in memory
3955 and whose alignment does not permit a direct copy into registers,
3956 make a group of pseudos that correspond to each register that we
3957 will later fill. */
3961 /* Now store any partially-in-registers parm.
3962 This is the last place a block-move can happen. */
3966 {
3969 /* On targets with weird calling conventions (e.g. PA) it's
3970 hard to ensure that all cases of argument overlap between
3971 stack and registers work. Play it safe and bail out. */
3973 {
3976 }
3980 reg_parm_stack_space)
3985 }
3990 {
3993 }
3997 /* Figure out the register where the value, if any, will come back. */
4002 {
4004 {
4011 }
4012 else
4013 {
4018 fndecl,
4020 }
4022 /* If VALREG is a PARALLEL whose first member has a zero
4023 offset, use that. This is for targets such as m68k that
4024 return the same value in multiple places. */
4026 {
4033 }
4034 }
4036 /* Store all bounds not passed in registers. */
4038 {
4043 ? NULL
4045 }
4047 /* If register arguments require space on the stack and stack space
4048 was not preallocated, allocate stack space here for arguments
4049 passed in registers. */
4051 && !ACCUMULATE_OUTGOING_ARGS
4055 /* Pass the function the address in which to return a
4056 structure value. */
4058 {
4059 structure_value_addr
4064 NULL_RTX)));
4068 }
4078 /* Save a pointer to the last insn before the call, so that we can
4079 later safely search backwards to find the CALL_INSN. */
4082 /* Set up next argument register. For sibling calls on machines
4083 with register windows this should be the incoming register. */
4086 VOIDmode,
4087 void_type_node,
4089 else
4095 {
4101 && valreg
4104 call_fusage
4107 call_fusage);
4108 }
4109 /* All arguments and registers used for the call must be set up by
4110 now! */
4112 /* Stack must be properly aligned now. */
4116 /* Generate the actual call instruction. */
4123 {
4127 {
4131 }
4134 }
4136 /* If the call setup or the call itself overlaps with anything
4137 of the argument setup we probably clobbered our call address.
4138 In that case we can't do sibcalls. */
4143 /* If a non-BLKmode value is returned at the most significant end
4144 of a register, shift the register right by the appropriate amount
4145 and update VALREG accordingly. BLKmode values are handled by the
4146 group load/store machinery below. */
4148 && !pcc_struct_value
4153 {
4157 }
4160 {
4164 /* The return value from a malloc-like function is a pointer. */
4170 /* The return value from a malloc-like function can not alias
4171 anything else. */
4175 /* Write out the sequence. */
4180 }
4182 /* For calls to `setjmp', etc., inform
4183 function.c:setjmp_warnings that it should complain if
4184 nonvolatile values are live. For functions that cannot
4185 return, inform flow that control does not fall through. */
4188 {
4189 /* The barrier must be emitted
4190 immediately after the CALL_INSN. Some ports emit more
4191 than just a CALL_INSN above, so we must search for it here. */
4195 {
4197 /* There was no CALL_INSN? */
4199 }
4203 /* Stack adjustments after a noreturn call are dead code.
4204 However when NO_DEFER_POP is in effect, we must preserve
4205 stack_pointer_delta. */
4207 {
4210 }
4211 }
4213 /* If value type not void, return an rtx for the value. */
4219 {
4221 {
4222 target
4225 structure_value_addr));
4227 }
4228 }
4230 {
4231 /* This is the special C++ case where we need to
4232 know what the true target was. We take care to
4233 never use this value more than once in one expression. */
4237 }
4238 /* Handle calls that return values in multiple non-contiguous locations.
4239 The Irix 6 ABI has examples of this. */
4241 {
4245 ;
4247 /* Handle the result of a emit_group_move_into_temps
4248 call in the previous pass. */
4250 else
4253 }
4257 {
4260 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
4261 reg to a plain register. */
4265 /* If TARGET is a MEM in the argument area, and we have
4266 saved part of the argument area, then we can't store
4267 directly into TARGET as it may get overwritten when we
4268 restore the argument save area below. Don't work too
4269 hard though and simply force TARGET to a register if it
4270 is a MEM; the optimizer is quite likely to sort it out. */
4274 {
4277 }
4281 else
4282 {
4283 /* TARGET and VALREG cannot be equal at this point
4284 because the latter would not have
4285 REG_FUNCTION_VALUE_P true, while the former would if
4286 it were referring to the same register.
4288 If they refer to the same register, this move will be
4289 a no-op, except when function inlining is being
4290 done. */
4293 /* If we are setting a MEM, this code must be executed.
4294 Since it is emitted after the call insn, sibcall
4295 optimization cannot be performed in that case. */
4298 }
4299 }
4300 else
4303 /* If we promoted this return value, make the proper SUBREG.
4304 TARGET might be const0_rtx here, so be careful. */
4308 {
4311 machine_mode pmode;
4313 /* Ensure we promote as expected, and get the new unsignedness. */
4323 }
4325 /* If size of args is variable or this was a constructor call for a stack
4326 argument, restore saved stack-pointer value. */
4329 {
4343 }
4345 {
4346 #ifdef REG_PARM_STACK_SPACE
4350 #endif
4352 /* If we saved any argument areas, restore them. */
4355 {
4357 rtx stack_area
4364 else
4367 BLOCK_OP_CALL_PARM);
4368 }
4372 }
4374 /* If this was alloca, record the new stack level. */
4378 /* Free up storage we no longer need. */
4388 {
4391 /* Restore the pending stack adjustment now that we have
4392 finished generating the sibling call sequence. */
4396 /* Prepare arg structure for next iteration. */
4398 {
4402 }
4407 }
4408 else
4409 {
4412 /* Verify that we've deallocated all the stack we used. */
4414 || (old_stack_allocated
4416 }
4418 /* If something prevents making this a sibling call,
4419 zero out the sequence. */
4422 else
4424 }
4426 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
4427 arguments too, as argument area is now clobbered by the call. */
4429 {
4432 }
4433 else
4434 {
4437 /* Ideally we'd emit a message for all of the ways that it could
4438 have failed. */
4440 }
4442 currently_expanding_call--;
4447 /* Join result with returned bounds so caller may use them if needed. */
4451 }
4453 /* A sibling call sequence invalidates any REG_EQUIV notes made for
4454 this function's incoming arguments.
4456 At the start of RTL generation we know the only REG_EQUIV notes
4457 in the rtl chain are those for incoming arguments, so we can look
4458 for REG_EQUIV notes between the start of the function and the
4459 NOTE_INSN_FUNCTION_BEG.
4461 This is (slight) overkill. We could keep track of the highest
4462 argument we clobber and be more selective in removing notes, but it
4463 does not seem to be worth the effort. */
4465 void
4467 {
4471 {
4472 rtx note;
4474 /* There are never REG_EQUIV notes for the incoming arguments
4475 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
4485 }
4486 }
4488 /* Traverse a list of TYPES and expand all complex types into their
4489 components. */
4490 static tree
4492 {
4493 tree p;
4495 /* Before allocating memory, check for the common case of no complex. */
4497 {
4502 }
4505 found:
4509 {
4514 {
4517 /* Rewrite complex type with component type. */
4521 /* Add another component type for the imaginary part. */
4526 /* Skip the newly created node. */
4528 }
4529 }
4532 }
4533 \f
4534 /* Output a library call to function ORGFUN (a SYMBOL_REF rtx)
4535 for a value of mode OUTMODE,
4536 with NARGS different arguments, passed as ARGS.
4537 Store the return value if RETVAL is nonzero: store it in VALUE if
4538 VALUE is nonnull, otherwise pick a convenient location. In either
4539 case return the location of the stored value.
4541 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
4542 `const' calls, LCT_PURE for `pure' calls, or another LCT_ value for
4543 other types of library calls. */
4545 rtx
4549 {
4550 /* Total size in bytes of all the stack-parms scanned so far. */
4552 /* Size of arguments before any adjustments (such as rounding). */
4555 rtx fun;
4556 /* Todo, choose the correct decl type of orgfun. Sadly this information
4557 isn't present here, so we default to native calling abi here. */
4562 CUMULATIVE_ARGS args_so_far_v;
4563 cumulative_args_t args_so_far;
4564 struct arg
4565 {
4566 rtx value;
4567 machine_mode mode;
4568 rtx reg;
4571 rtx save_area;
4572 };
4577 rtx valreg;
4587 #ifdef REG_PARM_STACK_SPACE
4588 /* Define the boundary of the register parm stack space that needs to be
4589 save, if any. */
4592 #endif
4594 /* Size of the stack reserved for parameter registers. */
4601 #ifdef REG_PARM_STACK_SPACE
4603 #endif
4605 /* By default, library functions cannot throw. */
4609 {
4627 }
4630 /* Ensure current function's preferred stack boundary is at least
4631 what we need. */
4635 /* If this kind of value comes back in memory,
4636 decide where in memory it should come back. */
4638 {
4641 {
4642 #ifdef PCC_STATIC_STRUCT_RETURN
4643 rtx pointer_reg
4653 else
4655 #endif
4656 /* This call returns a big structure. */
4658 }
4659 }
4660 else
4663 /* ??? Unfinished: must pass the memory address as an argument. */
4665 /* Copy all the libcall-arguments out of the varargs data
4666 and into a vector ARGVEC.
4668 Compute how to pass each argument. We only support a very small subset
4669 of the full argument passing conventions to limit complexity here since
4670 library functions shouldn't have many args. */
4675 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
4677 #else
4679 #endif
4689 /* If there's a structure value address to be passed,
4690 either pass it in the special place, or pass it as an extra argument. */
4692 {
4695 nargs++;
4697 /* Make sure it is a reasonable operand for a move or push insn. */
4713 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4715 #else
4717 #endif
4727 count++;
4728 }
4731 {
4736 /* We cannot convert the arg value to the mode the library wants here;
4737 must do it earlier where we know the signedness of the arg. */
4741 /* Make sure it is a reasonable operand for a move or push insn. */
4747 {
4748 rtx slot;
4749 int must_copy
4752 /* If this was a CONST function, it is now PURE since it now
4753 reads memory. */
4755 {
4758 }
4761 {
4766 }
4767 else
4768 {
4772 }
4776 call_fusage);
4780 slot),
4781 call_fusage);
4785 }
4799 {
4801 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4803 #else
4805 #endif
4810 }
4811 #ifdef BLOCK_REG_PADDING
4812 else
4813 /* The argument is passed entirely in registers. See at which
4814 end it should be padded. */
4818 #endif
4821 }
4823 /* If this machine requires an external definition for library
4824 functions, write one out. */
4829 + stack_pointer_delta
4831 / STACK_BYTES
4836 reg_parm_stack_space);
4845 {
4849 }
4852 {
4853 /* Since the stack pointer will never be pushed, it is possible for
4854 the evaluation of a parm to clobber something we have already
4855 written to the stack. Since most function calls on RISC machines
4856 do not use the stack, this is uncommon, but must work correctly.
4858 Therefore, we save any area of the stack that was already written
4859 and that we are using. Here we set up to do this by making a new
4860 stack usage map from the old one.
4862 Another approach might be to try to reorder the argument
4863 evaluations to avoid this conflicting stack usage. */
4867 /* Since we will be writing into the entire argument area, the
4868 map must be allocated for its entire size, not just the part that
4869 is the responsibility of the caller. */
4876 else
4884 initial_highest_arg_in_use);
4891 /* We must be careful to use virtual regs before they're instantiated,
4892 and real regs afterwards. Loop optimization, for example, can create
4893 new libcalls after we've instantiated the virtual regs, and if we
4894 use virtuals anyway, they won't match the rtl patterns. */
4898 STACK_POINTER_OFFSET);
4899 else
4901 }
4902 else
4903 {
4906 }
4908 /* We push args individually in reverse order, perform stack alignment
4909 before the first push (the last arg). */
4916 #ifdef REG_PARM_STACK_SPACE
4918 {
4919 /* The argument list is the property of the called routine and it
4920 may clobber it. If the fixed area has been used for previous
4921 parameters, we must save and restore it. */
4924 }
4925 #endif
4927 /* When expanding a normal call, args are stored in push order,
4928 which is the reverse of what we have here. */
4932 {
4935 }
4939 /* Push the args that need to be pushed. */
4943 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4944 are to be pushed. */
4946 {
4955 {
4956 rtx use;
4959 {
4960 /* If this is being stored into a pre-allocated, fixed-size,
4961 stack area, save any previous data at that location. */
4964 {
4965 /* stack_slot is negative, but we want to index stack_usage_map
4966 with positive values. */
4969 }
4970 else
4971 {
4974 }
4977 /* Don't worry about things in the fixed argument area;
4978 it has already been saved. */
4982 i++;
4985 {
4986 /* We need to make a save area. */
4987 unsigned int size
4989 machine_mode save_mode
4991 rtx adr
4994 rtx stack_area
4998 {
5002 );
5006 stack_area,
5008 BLOCK_OP_CALL_PARM);
5009 }
5010 else
5011 {
5015 }
5016 }
5017 }
5022 reg_parm_stack_space,
5025 /* Now mark the segment we just used. */
5030 NO_DEFER_POP;
5032 /* Indicate argument access so that alias.c knows that these
5033 values are live. */
5039 else
5040 {
5041 /* When arguments are pushed, trying to tell alias.c where
5042 exactly this argument is won't work, because the
5043 auto-increment causes confusion. So we merely indicate
5044 that we access something with a known mode somewhere on
5045 the stack. */
5049 }
5053 }
5054 }
5060 /* Now load any reg parms into their regs. */
5062 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5063 are to be pushed. */
5065 {
5070 #ifdef BLOCK_REG_PADDING
5072 #endif
5074 /* Handle calls that pass values in multiple non-contiguous
5075 locations. The PA64 has examples of this for library calls. */
5079 {
5081 #ifdef BLOCK_REG_PADDING
5084 /* Copied from load_register_parameters. */
5086 /* Handle case where we have a value that needs shifting
5087 up to the msb. eg. a QImode value and we're padding
5088 upward on a BYTES_BIG_ENDIAN machine. */
5092 {
5093 rtx x;
5096 /* Assigning REG here rather than a temp makes CALL_FUSAGE
5097 report the whole reg as used. Strictly speaking, the
5098 call only uses SIZE bytes at the msb end, but it doesn't
5099 seem worth generating rtl to say that. */
5104 }
5105 #endif
5106 }
5108 NO_DEFER_POP;
5109 }
5111 /* Any regs containing parms remain in use through the call. */
5113 {
5118 {
5121 {
5126 }
5127 else
5129 }
5130 }
5132 /* Pass the function the address in which to return a structure value. */
5134 {
5138 NULL_RTX)));
5141 }
5143 /* Don't allow popping to be deferred, since then
5144 cse'ing of library calls could delete a call and leave the pop. */
5145 NO_DEFER_POP;
5149 /* Stack must be properly aligned now. */
5155 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
5156 will set inhibit_defer_pop to that value. */
5157 /* The return type is needed to decide how many bytes the function pops.
5158 Signedness plays no role in that, so for simplicity, we pretend it's
5159 always signed. We also assume that the list of arguments passed has
5160 no impact, so we pretend it is unknown. */
5166 struct_value_size,
5169 valreg,
5173 {
5178 }
5180 /* Right-shift returned value if necessary. */
5184 {
5187 }
5191 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
5192 that it should complain if nonvolatile values are live. For
5193 functions that cannot return, inform flow that control does not
5194 fall through. */
5196 {
5197 /* The barrier note must be emitted
5198 immediately after the CALL_INSN. Some ports emit more than
5199 just a CALL_INSN above, so we must search for it here. */
5202 {
5204 /* There was no CALL_INSN? */
5206 }
5209 }
5211 /* Consider that "regular" libcalls, i.e. all of them except for LCT_THROW
5212 and LCT_RETURNS_TWICE, cannot perform non-local gotos. */
5214 {
5217 {
5219 /* There was no CALL_INSN? */
5221 }
5224 }
5226 /* Now restore inhibit_defer_pop to its actual original value. */
5227 OK_DEFER_POP;
5231 /* Copy the value to the right place. */
5233 {
5235 {
5240 }
5242 {
5246 }
5247 else
5248 {
5249 /* Convert to the proper mode if a promotion has been active. */
5251 {
5258 }
5262 else
5264 }
5265 }
5268 {
5269 #ifdef REG_PARM_STACK_SPACE
5273 #endif
5275 /* If we saved any argument areas, restore them. */
5278 {
5287 validize_mem
5290 BLOCK_OP_CALL_PARM);
5291 else
5293 }
5297 }
5303 }
5304 \f
5306 /* Store pointer bounds argument ARG into Bounds Table entry
5307 associated with PARM. */
5308 static void
5310 {
5313 /* We may pass bounds not associated with any pointer. */
5315 {
5319 }
5320 /* Find pointer associated with bounds and where it is
5321 passed. */
5322 else
5323 {
5325 {
5329 }
5331 {
5339 else
5340 {
5343 }
5344 }
5345 else
5346 {
5355 else
5357 }
5358 }
5360 /* Expand bounds. */
5365 }
5367 /* Store a single argument for a function call
5368 into the register or memory area where it must be passed.
5369 *ARG describes the argument value and where to pass it.
5371 ARGBLOCK is the address of the stack-block for all the arguments,
5372 or 0 on a machine where arguments are pushed individually.
5374 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
5375 so must be careful about how the stack is used.
5377 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
5378 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
5379 that we need not worry about saving and restoring the stack.
5381 FNDECL is the declaration of the function we are calling.
5383 Return nonzero if this arg should cause sibcall failure,
5384 zero otherwise. */
5386 static int
5389 {
5400 /* Push a new temporary level for any temporaries we make for
5401 this argument. */
5405 {
5406 /* If this is being stored into a pre-allocated, fixed-size, stack area,
5407 save any previous data at that location. */
5409 {
5411 {
5412 /* stack_slot is negative, but we want to index stack_usage_map
5413 with positive values. */
5416 else
5420 }
5421 else
5422 {
5425 else
5429 }
5432 /* Don't worry about things in the fixed argument area;
5433 it has already been saved. */
5437 i++;
5440 {
5441 /* We need to make a save area. */
5443 machine_mode save_mode
5449 {
5450 arg->save_area
5454 stack_area,
5456 BLOCK_OP_CALL_PARM);
5457 }
5458 else
5459 {
5462 }
5463 }
5464 }
5465 }
5467 /* If this isn't going to be placed on both the stack and in registers,
5468 set up the register and number of words. */
5470 {
5473 else
5476 }
5478 /* Being passed entirely in a register. We shouldn't be called in
5479 this case. */
5482 /* If this arg needs special alignment, don't load the registers
5483 here. */
5487 /* If this is being passed partially in a register, we can't evaluate
5488 it directly into its stack slot. Otherwise, we can. */
5490 {
5491 /* stack_arg_under_construction is nonzero if a function argument is
5492 being evaluated directly into the outgoing argument list and
5493 expand_call must take special action to preserve the argument list
5494 if it is called recursively.
5496 For scalar function arguments stack_usage_map is sufficient to
5497 determine which stack slots must be saved and restored. Scalar
5498 arguments in general have pass_on_stack == 0.
5500 If this argument is initialized by a function which takes the
5501 address of the argument (a C++ constructor or a C function
5502 returning a BLKmode structure), then stack_usage_map is
5503 insufficient and expand_call must push the stack around the
5504 function call. Such arguments have pass_on_stack == 1.
5506 Note that it is always safe to set stack_arg_under_construction,
5507 but this generates suboptimal code if set when not needed. */
5510 stack_arg_under_construction++;
5513 (partial
5518 /* If we are promoting object (or for any other reason) the mode
5519 doesn't agree, convert the mode. */
5526 stack_arg_under_construction--;
5527 }
5529 /* Check for overlap with already clobbered argument area. */
5536 /* Don't allow anything left on stack from computation
5537 of argument to alloca. */
5542 /* If the value is already in the stack slot, we are done. */
5543 ;
5545 {
5549 /* Argument is a scalar, not entirely passed in registers.
5550 (If part is passed in registers, arg->partial says how much
5551 and emit_push_insn will take care of putting it there.)
5553 Push it, and if its size is less than the
5554 amount of space allocated to it,
5555 also bump stack pointer by the additional space.
5556 Note that in C the default argument promotions
5557 will prevent such mismatches. */
5561 else
5564 /* Compute how much space the push instruction will push.
5565 On many machines, pushing a byte will advance the stack
5566 pointer by a halfword. */
5567 #ifdef PUSH_ROUNDING
5569 #endif
5572 /* Compute how much space the argument should get:
5573 round up to a multiple of the alignment for arguments. */
5580 /* Compute the alignment of the pushed argument. */
5584 {
5587 {
5590 }
5591 }
5593 /* This isn't already where we want it on the stack, so put it there.
5594 This can either be done with push or copy insns. */
5599 reg_parm_stack_space,
5603 /* Unless this is a partially-in-register argument, the argument is now
5604 in the stack. */
5607 }
5608 else
5609 {
5610 /* BLKmode, at least partly to be pushed. */
5614 rtx size_rtx;
5616 /* Pushing a nonscalar.
5617 If part is passed in registers, PARTIAL says how much
5618 and emit_push_insn will take care of putting it there. */
5620 /* Round its size up to a multiple
5621 of the allocation unit for arguments. */
5624 {
5627 }
5628 else
5629 {
5630 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
5631 for BLKmode is careful to avoid it. */
5637 EXPAND_NORMAL);
5638 }
5642 /* When an argument is padded down, the block is aligned to
5643 PARM_BOUNDARY, but the actual argument isn't. */
5646 {
5650 {
5653 }
5654 }
5657 {
5658 /* emit_push_insn might not work properly if arg->value and
5659 argblock + arg->locate.offset areas overlap. */
5668 {
5672 /* arg.locate doesn't contain the pretend_args_size offset,
5673 it's part of argblock. Ensure we don't count it in I. */
5676 else
5679 /* expand_call should ensure this. */
5685 {
5688 }
5690 {
5691 /* Use arg->locate.size.constant instead of size_rtx
5692 because we only care about the part of the argument
5693 on the stack. */
5697 }
5698 else
5699 {
5700 /* Even though they appear to be at the same location,
5701 if part of the outgoing argument is in registers,
5702 they aren't really at the same location. Check for
5703 this by making sure that the incoming size is the
5704 same as the outgoing size. */
5707 }
5708 }
5709 }
5715 reg_parm_stack_space,
5718 /* Unless this is a partially-in-register argument, the argument is now
5719 in the stack.
5721 ??? Unlike the case above, in which we want the actual
5722 address of the data, so that we can load it directly into a
5723 register, here we want the address of the stack slot, so that
5724 it's properly aligned for word-by-word copying or something
5725 like that. It's not clear that this is always correct. */
5728 }
5731 {
5733 arg->parallel_value
5736 }
5738 /* Mark all slots this store used. */
5744 /* Once we have pushed something, pops can't safely
5745 be deferred during the rest of the arguments. */
5746 NO_DEFER_POP;
5748 /* Free any temporary slots made in processing this argument. */
5752 }
5754 /* Nonzero if we do not know how to pass TYPE solely in registers. */
5756 bool
5758 const_tree type)
5759 {
5763 /* If the type has variable size... */
5767 /* If the type is marked as addressable (it is required
5768 to be constructed into the stack)... */
5773 }
5775 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
5776 takes trailing padding of a structure into account. */
5777 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
5779 bool
5781 {
5785 /* If the type has variable size... */
5789 /* If the type is marked as addressable (it is required
5790 to be constructed into the stack)... */
5797 /* If the padding and mode of the type is such that a copy into
5798 a register would put it into the wrong part of the register. */
5806 }
5808 /* Tell the garbage collector about GTY markers in this source file. */