calls.c revision 260139
1/* Convert function calls to rtl insns, for GNU C compiler. 2 Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 3 1999, 2000, 2001, 2002, 2003, 2004, 2005 4 Free Software Foundation, Inc. 5 6This file is part of GCC. 7 8GCC is free software; you can redistribute it and/or modify it under 9the terms of the GNU General Public License as published by the Free 10Software Foundation; either version 2, or (at your option) any later 11version. 12 13GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14WARRANTY; without even the implied warranty of MERCHANTABILITY or 15FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16for more details. 17 18You should have received a copy of the GNU General Public License 19along with GCC; see the file COPYING. If not, write to the Free 20Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 2102110-1301, USA. */ 22 23#include "config.h" 24#include "system.h" 25#include "coretypes.h" 26#include "tm.h" 27#include "rtl.h" 28#include "tree.h" 29#include "flags.h" 30#include "expr.h" 31#include "optabs.h" 32#include "libfuncs.h" 33#include "function.h" 34#include "regs.h" 35#include "toplev.h" 36#include "output.h" 37#include "tm_p.h" 38#include "timevar.h" 39#include "sbitmap.h" 40#include "langhooks.h" 41#include "target.h" 42#include "cgraph.h" 43#include "except.h" 44 45/* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */ 46#define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT) 47 48/* Data structure and subroutines used within expand_call. */ 49 50struct arg_data 51{ 52 /* Tree node for this argument. */ 53 tree tree_value; 54 /* Mode for value; TYPE_MODE unless promoted. */ 55 enum machine_mode mode; 56 /* Current RTL value for argument, or 0 if it isn't precomputed. */ 57 rtx value; 58 /* Initially-compute RTL value for argument; only for const functions. */ 59 rtx initial_value; 60 /* Register to pass this argument in, 0 if passed on stack, or an 61 PARALLEL if the arg is to be copied into multiple non-contiguous 62 registers. */ 63 rtx reg; 64 /* Register to pass this argument in when generating tail call sequence. 65 This is not the same register as for normal calls on machines with 66 register windows. */ 67 rtx tail_call_reg; 68 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct 69 form for emit_group_move. */ 70 rtx parallel_value; 71 /* If REG was promoted from the actual mode of the argument expression, 72 indicates whether the promotion is sign- or zero-extended. */ 73 int unsignedp; 74 /* Number of bytes to put in registers. 0 means put the whole arg 75 in registers. Also 0 if not passed in registers. */ 76 int partial; 77 /* Nonzero if argument must be passed on stack. 78 Note that some arguments may be passed on the stack 79 even though pass_on_stack is zero, just because FUNCTION_ARG says so. 80 pass_on_stack identifies arguments that *cannot* go in registers. */ 81 int pass_on_stack; 82 /* Some fields packaged up for locate_and_pad_parm. */ 83 struct locate_and_pad_arg_data locate; 84 /* Location on the stack at which parameter should be stored. The store 85 has already been done if STACK == VALUE. */ 86 rtx stack; 87 /* Location on the stack of the start of this argument slot. This can 88 differ from STACK if this arg pads downward. This location is known 89 to be aligned to FUNCTION_ARG_BOUNDARY. */ 90 rtx stack_slot; 91 /* Place that this stack area has been saved, if needed. */ 92 rtx save_area; 93 /* If an argument's alignment does not permit direct copying into registers, 94 copy in smaller-sized pieces into pseudos. These are stored in a 95 block pointed to by this field. The next field says how many 96 word-sized pseudos we made. */ 97 rtx *aligned_regs; 98 int n_aligned_regs; 99}; 100 101/* A vector of one char per byte of stack space. A byte if nonzero if 102 the corresponding stack location has been used. 103 This vector is used to prevent a function call within an argument from 104 clobbering any stack already set up. */ 105static char *stack_usage_map; 106 107/* Size of STACK_USAGE_MAP. */ 108static int highest_outgoing_arg_in_use; 109 110/* A bitmap of virtual-incoming stack space. Bit is set if the corresponding 111 stack location's tail call argument has been already stored into the stack. 112 This bitmap is used to prevent sibling call optimization if function tries 113 to use parent's incoming argument slots when they have been already 114 overwritten with tail call arguments. */ 115static sbitmap stored_args_map; 116 117/* stack_arg_under_construction is nonzero when an argument may be 118 initialized with a constructor call (including a C function that 119 returns a BLKmode struct) and expand_call must take special action 120 to make sure the object being constructed does not overlap the 121 argument list for the constructor call. */ 122static int stack_arg_under_construction; 123 124static void emit_call_1 (rtx, tree, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT, 125 HOST_WIDE_INT, rtx, rtx, int, rtx, int, 126 CUMULATIVE_ARGS *); 127static void precompute_register_parameters (int, struct arg_data *, int *); 128static int store_one_arg (struct arg_data *, rtx, int, int, int); 129static void store_unaligned_arguments_into_pseudos (struct arg_data *, int); 130static int finalize_must_preallocate (int, int, struct arg_data *, 131 struct args_size *); 132static void precompute_arguments (int, int, struct arg_data *); 133static int compute_argument_block_size (int, struct args_size *, int); 134static void initialize_argument_information (int, struct arg_data *, 135 struct args_size *, int, tree, 136 tree, CUMULATIVE_ARGS *, int, 137 rtx *, int *, int *, int *, 138 bool *, bool); 139static void compute_argument_addresses (struct arg_data *, rtx, int); 140static rtx rtx_for_function_call (tree, tree); 141static void load_register_parameters (struct arg_data *, int, rtx *, int, 142 int, int *); 143static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type, 144 enum machine_mode, int, va_list); 145static int special_function_p (tree, int); 146static int check_sibcall_argument_overlap_1 (rtx); 147static int check_sibcall_argument_overlap (rtx, struct arg_data *, int); 148 149static int combine_pending_stack_adjustment_and_call (int, struct args_size *, 150 unsigned int); 151static tree split_complex_values (tree); 152static tree split_complex_types (tree); 153 154#ifdef REG_PARM_STACK_SPACE 155static rtx save_fixed_argument_area (int, rtx, int *, int *); 156static void restore_fixed_argument_area (rtx, rtx, int, int); 157#endif 158 159/* Force FUNEXP into a form suitable for the address of a CALL, 160 and return that as an rtx. Also load the static chain register 161 if FNDECL is a nested function. 162 163 CALL_FUSAGE points to a variable holding the prospective 164 CALL_INSN_FUNCTION_USAGE information. */ 165 166rtx 167prepare_call_address (rtx funexp, rtx static_chain_value, 168 rtx *call_fusage, int reg_parm_seen, int sibcallp) 169{ 170 /* Make a valid memory address and copy constants through pseudo-regs, 171 but not for a constant address if -fno-function-cse. */ 172 if (GET_CODE (funexp) != SYMBOL_REF) 173 /* If we are using registers for parameters, force the 174 function address into a register now. */ 175 funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen) 176 ? force_not_mem (memory_address (FUNCTION_MODE, funexp)) 177 : memory_address (FUNCTION_MODE, funexp)); 178 else if (! sibcallp) 179 { 180#ifndef NO_FUNCTION_CSE 181 if (optimize && ! flag_no_function_cse) 182 funexp = force_reg (Pmode, funexp); 183#endif 184 } 185 186 if (static_chain_value != 0) 187 { 188 static_chain_value = convert_memory_address (Pmode, static_chain_value); 189 emit_move_insn (static_chain_rtx, static_chain_value); 190 191 if (REG_P (static_chain_rtx)) 192 use_reg (call_fusage, static_chain_rtx); 193 } 194 195 return funexp; 196} 197 198/* Generate instructions to call function FUNEXP, 199 and optionally pop the results. 200 The CALL_INSN is the first insn generated. 201 202 FNDECL is the declaration node of the function. This is given to the 203 macro RETURN_POPS_ARGS to determine whether this function pops its own args. 204 205 FUNTYPE is the data type of the function. This is given to the macro 206 RETURN_POPS_ARGS to determine whether this function pops its own args. 207 We used to allow an identifier for library functions, but that doesn't 208 work when the return type is an aggregate type and the calling convention 209 says that the pointer to this aggregate is to be popped by the callee. 210 211 STACK_SIZE is the number of bytes of arguments on the stack, 212 ROUNDED_STACK_SIZE is that number rounded up to 213 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is 214 both to put into the call insn and to generate explicit popping 215 code if necessary. 216 217 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value. 218 It is zero if this call doesn't want a structure value. 219 220 NEXT_ARG_REG is the rtx that results from executing 221 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1) 222 just after all the args have had their registers assigned. 223 This could be whatever you like, but normally it is the first 224 arg-register beyond those used for args in this call, 225 or 0 if all the arg-registers are used in this call. 226 It is passed on to `gen_call' so you can put this info in the call insn. 227 228 VALREG is a hard register in which a value is returned, 229 or 0 if the call does not return a value. 230 231 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before 232 the args to this call were processed. 233 We restore `inhibit_defer_pop' to that value. 234 235 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that 236 denote registers used by the called function. */ 237 238static void 239emit_call_1 (rtx funexp, tree fntree, tree fndecl ATTRIBUTE_UNUSED, 240 tree funtype ATTRIBUTE_UNUSED, 241 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED, 242 HOST_WIDE_INT rounded_stack_size, 243 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED, 244 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg, 245 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags, 246 CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED) 247{ 248 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size); 249 rtx call_insn; 250 int already_popped = 0; 251 HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size); 252#if defined (HAVE_call) && defined (HAVE_call_value) 253 rtx struct_value_size_rtx; 254 struct_value_size_rtx = GEN_INT (struct_value_size); 255#endif 256 257#ifdef CALL_POPS_ARGS 258 n_popped += CALL_POPS_ARGS (* args_so_far); 259#endif 260 261 /* Ensure address is valid. SYMBOL_REF is already valid, so no need, 262 and we don't want to load it into a register as an optimization, 263 because prepare_call_address already did it if it should be done. */ 264 if (GET_CODE (funexp) != SYMBOL_REF) 265 funexp = memory_address (FUNCTION_MODE, funexp); 266 267#if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop) 268 if ((ecf_flags & ECF_SIBCALL) 269 && HAVE_sibcall_pop && HAVE_sibcall_value_pop 270 && (n_popped > 0 || stack_size == 0)) 271 { 272 rtx n_pop = GEN_INT (n_popped); 273 rtx pat; 274 275 /* If this subroutine pops its own args, record that in the call insn 276 if possible, for the sake of frame pointer elimination. */ 277 278 if (valreg) 279 pat = GEN_SIBCALL_VALUE_POP (valreg, 280 gen_rtx_MEM (FUNCTION_MODE, funexp), 281 rounded_stack_size_rtx, next_arg_reg, 282 n_pop); 283 else 284 pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp), 285 rounded_stack_size_rtx, next_arg_reg, n_pop); 286 287 emit_call_insn (pat); 288 already_popped = 1; 289 } 290 else 291#endif 292 293#if defined (HAVE_call_pop) && defined (HAVE_call_value_pop) 294 /* If the target has "call" or "call_value" insns, then prefer them 295 if no arguments are actually popped. If the target does not have 296 "call" or "call_value" insns, then we must use the popping versions 297 even if the call has no arguments to pop. */ 298#if defined (HAVE_call) && defined (HAVE_call_value) 299 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop 300 && n_popped > 0 && ! (ecf_flags & ECF_SP_DEPRESSED)) 301#else 302 if (HAVE_call_pop && HAVE_call_value_pop) 303#endif 304 { 305 rtx n_pop = GEN_INT (n_popped); 306 rtx pat; 307 308 /* If this subroutine pops its own args, record that in the call insn 309 if possible, for the sake of frame pointer elimination. */ 310 311 if (valreg) 312 pat = GEN_CALL_VALUE_POP (valreg, 313 gen_rtx_MEM (FUNCTION_MODE, funexp), 314 rounded_stack_size_rtx, next_arg_reg, n_pop); 315 else 316 pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp), 317 rounded_stack_size_rtx, next_arg_reg, n_pop); 318 319 emit_call_insn (pat); 320 already_popped = 1; 321 } 322 else 323#endif 324 325#if defined (HAVE_sibcall) && defined (HAVE_sibcall_value) 326 if ((ecf_flags & ECF_SIBCALL) 327 && HAVE_sibcall && HAVE_sibcall_value) 328 { 329 if (valreg) 330 emit_call_insn (GEN_SIBCALL_VALUE (valreg, 331 gen_rtx_MEM (FUNCTION_MODE, funexp), 332 rounded_stack_size_rtx, 333 next_arg_reg, NULL_RTX)); 334 else 335 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp), 336 rounded_stack_size_rtx, next_arg_reg, 337 struct_value_size_rtx)); 338 } 339 else 340#endif 341 342#if defined (HAVE_call) && defined (HAVE_call_value) 343 if (HAVE_call && HAVE_call_value) 344 { 345 if (valreg) 346 emit_call_insn (GEN_CALL_VALUE (valreg, 347 gen_rtx_MEM (FUNCTION_MODE, funexp), 348 rounded_stack_size_rtx, next_arg_reg, 349 NULL_RTX)); 350 else 351 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp), 352 rounded_stack_size_rtx, next_arg_reg, 353 struct_value_size_rtx)); 354 } 355 else 356#endif 357 gcc_unreachable (); 358 359 /* Find the call we just emitted. */ 360 call_insn = last_call_insn (); 361 362 /* Mark memory as used for "pure" function call. */ 363 if (ecf_flags & ECF_PURE) 364 call_fusage 365 = gen_rtx_EXPR_LIST 366 (VOIDmode, 367 gen_rtx_USE (VOIDmode, 368 gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode))), 369 call_fusage); 370 371 /* Put the register usage information there. */ 372 add_function_usage_to (call_insn, call_fusage); 373 374 /* If this is a const call, then set the insn's unchanging bit. */ 375 if (ecf_flags & (ECF_CONST | ECF_PURE)) 376 CONST_OR_PURE_CALL_P (call_insn) = 1; 377 378 /* If this call can't throw, attach a REG_EH_REGION reg note to that 379 effect. */ 380 if (ecf_flags & ECF_NOTHROW) 381 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, const0_rtx, 382 REG_NOTES (call_insn)); 383 else 384 { 385 int rn = lookup_stmt_eh_region (fntree); 386 387 /* If rn < 0, then either (1) tree-ssa not used or (2) doesn't 388 throw, which we already took care of. */ 389 if (rn > 0) 390 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, GEN_INT (rn), 391 REG_NOTES (call_insn)); 392 note_current_region_may_contain_throw (); 393 } 394 395 if (ecf_flags & ECF_NORETURN) 396 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_NORETURN, const0_rtx, 397 REG_NOTES (call_insn)); 398 399 if (ecf_flags & ECF_RETURNS_TWICE) 400 { 401 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_SETJMP, const0_rtx, 402 REG_NOTES (call_insn)); 403 current_function_calls_setjmp = 1; 404 } 405 406 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0); 407 408 /* Restore this now, so that we do defer pops for this call's args 409 if the context of the call as a whole permits. */ 410 inhibit_defer_pop = old_inhibit_defer_pop; 411 412 if (n_popped > 0) 413 { 414 if (!already_popped) 415 CALL_INSN_FUNCTION_USAGE (call_insn) 416 = gen_rtx_EXPR_LIST (VOIDmode, 417 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx), 418 CALL_INSN_FUNCTION_USAGE (call_insn)); 419 rounded_stack_size -= n_popped; 420 rounded_stack_size_rtx = GEN_INT (rounded_stack_size); 421 stack_pointer_delta -= n_popped; 422 } 423 424 if (!ACCUMULATE_OUTGOING_ARGS) 425 { 426 /* If returning from the subroutine does not automatically pop the args, 427 we need an instruction to pop them sooner or later. 428 Perhaps do it now; perhaps just record how much space to pop later. 429 430 If returning from the subroutine does pop the args, indicate that the 431 stack pointer will be changed. */ 432 433 if (rounded_stack_size != 0) 434 { 435 if (ecf_flags & (ECF_SP_DEPRESSED | ECF_NORETURN)) 436 /* Just pretend we did the pop. */ 437 stack_pointer_delta -= rounded_stack_size; 438 else if (flag_defer_pop && inhibit_defer_pop == 0 439 && ! (ecf_flags & (ECF_CONST | ECF_PURE))) 440 pending_stack_adjust += rounded_stack_size; 441 else 442 adjust_stack (rounded_stack_size_rtx); 443 } 444 } 445 /* When we accumulate outgoing args, we must avoid any stack manipulations. 446 Restore the stack pointer to its original value now. Usually 447 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions. 448 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and 449 popping variants of functions exist as well. 450 451 ??? We may optimize similar to defer_pop above, but it is 452 probably not worthwhile. 453 454 ??? It will be worthwhile to enable combine_stack_adjustments even for 455 such machines. */ 456 else if (n_popped) 457 anti_adjust_stack (GEN_INT (n_popped)); 458} 459 460/* Determine if the function identified by NAME and FNDECL is one with 461 special properties we wish to know about. 462 463 For example, if the function might return more than one time (setjmp), then 464 set RETURNS_TWICE to a nonzero value. 465 466 Similarly set NORETURN if the function is in the longjmp family. 467 468 Set MAY_BE_ALLOCA for any memory allocation function that might allocate 469 space from the stack such as alloca. */ 470 471static int 472special_function_p (tree fndecl, int flags) 473{ 474 if (fndecl && DECL_NAME (fndecl) 475 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17 476 /* Exclude functions not at the file scope, or not `extern', 477 since they are not the magic functions we would otherwise 478 think they are. 479 FIXME: this should be handled with attributes, not with this 480 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong 481 because you can declare fork() inside a function if you 482 wish. */ 483 && (DECL_CONTEXT (fndecl) == NULL_TREE 484 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL) 485 && TREE_PUBLIC (fndecl)) 486 { 487 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl)); 488 const char *tname = name; 489 490 /* We assume that alloca will always be called by name. It 491 makes no sense to pass it as a pointer-to-function to 492 anything that does not understand its behavior. */ 493 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6 494 && name[0] == 'a' 495 && ! strcmp (name, "alloca")) 496 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16 497 && name[0] == '_' 498 && ! strcmp (name, "__builtin_alloca")))) 499 flags |= ECF_MAY_BE_ALLOCA; 500 501 /* Disregard prefix _, __ or __x. */ 502 if (name[0] == '_') 503 { 504 if (name[1] == '_' && name[2] == 'x') 505 tname += 3; 506 else if (name[1] == '_') 507 tname += 2; 508 else 509 tname += 1; 510 } 511 512 if (tname[0] == 's') 513 { 514 if ((tname[1] == 'e' 515 && (! strcmp (tname, "setjmp") 516 || ! strcmp (tname, "setjmp_syscall"))) 517 || (tname[1] == 'i' 518 && ! strcmp (tname, "sigsetjmp")) 519 || (tname[1] == 'a' 520 && ! strcmp (tname, "savectx"))) 521 flags |= ECF_RETURNS_TWICE; 522 523 if (tname[1] == 'i' 524 && ! strcmp (tname, "siglongjmp")) 525 flags |= ECF_NORETURN; 526 } 527 else if ((tname[0] == 'q' && tname[1] == 's' 528 && ! strcmp (tname, "qsetjmp")) 529 || (tname[0] == 'v' && tname[1] == 'f' 530 && ! strcmp (tname, "vfork")) 531 || (tname[0] == 'g' && tname[1] == 'e' 532 && !strcmp (tname, "getcontext"))) 533 flags |= ECF_RETURNS_TWICE; 534 535 else if (tname[0] == 'l' && tname[1] == 'o' 536 && ! strcmp (tname, "longjmp")) 537 flags |= ECF_NORETURN; 538 } 539 540 return flags; 541} 542 543/* Return nonzero when FNDECL represents a call to setjmp. */ 544 545int 546setjmp_call_p (tree fndecl) 547{ 548 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE; 549} 550 551/* Return true when exp contains alloca call. */ 552bool 553alloca_call_p (tree exp) 554{ 555 if (TREE_CODE (exp) == CALL_EXPR 556 && TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR 557 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0)) 558 == FUNCTION_DECL) 559 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0), 560 0) & ECF_MAY_BE_ALLOCA)) 561 return true; 562 return false; 563} 564 565/* Detect flags (function attributes) from the function decl or type node. */ 566 567int 568flags_from_decl_or_type (tree exp) 569{ 570 int flags = 0; 571 tree type = exp; 572 573 if (DECL_P (exp)) 574 { 575 type = TREE_TYPE (exp); 576 577 /* The function exp may have the `malloc' attribute. */ 578 if (DECL_IS_MALLOC (exp)) 579 flags |= ECF_MALLOC; 580 581 /* The function exp may have the `returns_twice' attribute. */ 582 if (DECL_IS_RETURNS_TWICE (exp)) 583 flags |= ECF_RETURNS_TWICE; 584 585 /* The function exp may have the `pure' attribute. */ 586 if (DECL_IS_PURE (exp)) 587 flags |= ECF_PURE; 588 589 if (DECL_IS_NOVOPS (exp)) 590 flags |= ECF_NOVOPS; 591 592 if (TREE_NOTHROW (exp)) 593 flags |= ECF_NOTHROW; 594 595 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp)) 596 flags |= ECF_CONST; 597 598 flags = special_function_p (exp, flags); 599 } 600 else if (TYPE_P (exp) && TYPE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp)) 601 flags |= ECF_CONST; 602 603 if (TREE_THIS_VOLATILE (exp)) 604 flags |= ECF_NORETURN; 605 606 /* Mark if the function returns with the stack pointer depressed. We 607 cannot consider it pure or constant in that case. */ 608 if (TREE_CODE (type) == FUNCTION_TYPE && TYPE_RETURNS_STACK_DEPRESSED (type)) 609 { 610 flags |= ECF_SP_DEPRESSED; 611 flags &= ~(ECF_PURE | ECF_CONST); 612 } 613 614 return flags; 615} 616 617/* Detect flags from a CALL_EXPR. */ 618 619int 620call_expr_flags (tree t) 621{ 622 int flags; 623 tree decl = get_callee_fndecl (t); 624 625 if (decl) 626 flags = flags_from_decl_or_type (decl); 627 else 628 { 629 t = TREE_TYPE (TREE_OPERAND (t, 0)); 630 if (t && TREE_CODE (t) == POINTER_TYPE) 631 flags = flags_from_decl_or_type (TREE_TYPE (t)); 632 else 633 flags = 0; 634 } 635 636 return flags; 637} 638 639/* Precompute all register parameters as described by ARGS, storing values 640 into fields within the ARGS array. 641 642 NUM_ACTUALS indicates the total number elements in the ARGS array. 643 644 Set REG_PARM_SEEN if we encounter a register parameter. */ 645 646static void 647precompute_register_parameters (int num_actuals, struct arg_data *args, 648 int *reg_parm_seen) 649{ 650 int i; 651 652 *reg_parm_seen = 0; 653 654 for (i = 0; i < num_actuals; i++) 655 if (args[i].reg != 0 && ! args[i].pass_on_stack) 656 { 657 *reg_parm_seen = 1; 658 659 if (args[i].value == 0) 660 { 661 push_temp_slots (); 662 args[i].value = expand_normal (args[i].tree_value); 663 preserve_temp_slots (args[i].value); 664 pop_temp_slots (); 665 } 666 667 /* If the value is a non-legitimate constant, force it into a 668 pseudo now. TLS symbols sometimes need a call to resolve. */ 669 if (CONSTANT_P (args[i].value) 670 && !LEGITIMATE_CONSTANT_P (args[i].value)) 671 args[i].value = force_reg (args[i].mode, args[i].value); 672 673 /* If we are to promote the function arg to a wider mode, 674 do it now. */ 675 676 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value))) 677 args[i].value 678 = convert_modes (args[i].mode, 679 TYPE_MODE (TREE_TYPE (args[i].tree_value)), 680 args[i].value, args[i].unsignedp); 681 682 /* If we're going to have to load the value by parts, pull the 683 parts into pseudos. The part extraction process can involve 684 non-trivial computation. */ 685 if (GET_CODE (args[i].reg) == PARALLEL) 686 { 687 tree type = TREE_TYPE (args[i].tree_value); 688 args[i].parallel_value 689 = emit_group_load_into_temps (args[i].reg, args[i].value, 690 type, int_size_in_bytes (type)); 691 } 692 693 /* If the value is expensive, and we are inside an appropriately 694 short loop, put the value into a pseudo and then put the pseudo 695 into the hard reg. 696 697 For small register classes, also do this if this call uses 698 register parameters. This is to avoid reload conflicts while 699 loading the parameters registers. */ 700 701 else if ((! (REG_P (args[i].value) 702 || (GET_CODE (args[i].value) == SUBREG 703 && REG_P (SUBREG_REG (args[i].value))))) 704 && args[i].mode != BLKmode 705 && rtx_cost (args[i].value, SET) > COSTS_N_INSNS (1) 706 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen) 707 || optimize)) 708 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value); 709 } 710} 711 712#ifdef REG_PARM_STACK_SPACE 713 714 /* The argument list is the property of the called routine and it 715 may clobber it. If the fixed area has been used for previous 716 parameters, we must save and restore it. */ 717 718static rtx 719save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save) 720{ 721 int low; 722 int high; 723 724 /* Compute the boundary of the area that needs to be saved, if any. */ 725 high = reg_parm_stack_space; 726#ifdef ARGS_GROW_DOWNWARD 727 high += 1; 728#endif 729 if (high > highest_outgoing_arg_in_use) 730 high = highest_outgoing_arg_in_use; 731 732 for (low = 0; low < high; low++) 733 if (stack_usage_map[low] != 0) 734 { 735 int num_to_save; 736 enum machine_mode save_mode; 737 int delta; 738 rtx stack_area; 739 rtx save_area; 740 741 while (stack_usage_map[--high] == 0) 742 ; 743 744 *low_to_save = low; 745 *high_to_save = high; 746 747 num_to_save = high - low + 1; 748 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1); 749 750 /* If we don't have the required alignment, must do this 751 in BLKmode. */ 752 if ((low & (MIN (GET_MODE_SIZE (save_mode), 753 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1))) 754 save_mode = BLKmode; 755 756#ifdef ARGS_GROW_DOWNWARD 757 delta = -high; 758#else 759 delta = low; 760#endif 761 stack_area = gen_rtx_MEM (save_mode, 762 memory_address (save_mode, 763 plus_constant (argblock, 764 delta))); 765 766 set_mem_align (stack_area, PARM_BOUNDARY); 767 if (save_mode == BLKmode) 768 { 769 save_area = assign_stack_temp (BLKmode, num_to_save, 0); 770 emit_block_move (validize_mem (save_area), stack_area, 771 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM); 772 } 773 else 774 { 775 save_area = gen_reg_rtx (save_mode); 776 emit_move_insn (save_area, stack_area); 777 } 778 779 return save_area; 780 } 781 782 return NULL_RTX; 783} 784 785static void 786restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save) 787{ 788 enum machine_mode save_mode = GET_MODE (save_area); 789 int delta; 790 rtx stack_area; 791 792#ifdef ARGS_GROW_DOWNWARD 793 delta = -high_to_save; 794#else 795 delta = low_to_save; 796#endif 797 stack_area = gen_rtx_MEM (save_mode, 798 memory_address (save_mode, 799 plus_constant (argblock, delta))); 800 set_mem_align (stack_area, PARM_BOUNDARY); 801 802 if (save_mode != BLKmode) 803 emit_move_insn (stack_area, save_area); 804 else 805 emit_block_move (stack_area, validize_mem (save_area), 806 GEN_INT (high_to_save - low_to_save + 1), 807 BLOCK_OP_CALL_PARM); 808} 809#endif /* REG_PARM_STACK_SPACE */ 810 811/* If any elements in ARGS refer to parameters that are to be passed in 812 registers, but not in memory, and whose alignment does not permit a 813 direct copy into registers. Copy the values into a group of pseudos 814 which we will later copy into the appropriate hard registers. 815 816 Pseudos for each unaligned argument will be stored into the array 817 args[argnum].aligned_regs. The caller is responsible for deallocating 818 the aligned_regs array if it is nonzero. */ 819 820static void 821store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals) 822{ 823 int i, j; 824 825 for (i = 0; i < num_actuals; i++) 826 if (args[i].reg != 0 && ! args[i].pass_on_stack 827 && args[i].mode == BLKmode 828 && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value)) 829 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD))) 830 { 831 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value)); 832 int endian_correction = 0; 833 834 if (args[i].partial) 835 { 836 gcc_assert (args[i].partial % UNITS_PER_WORD == 0); 837 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD; 838 } 839 else 840 { 841 args[i].n_aligned_regs 842 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD; 843 } 844 845 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs); 846 847 /* Structures smaller than a word are normally aligned to the 848 least significant byte. On a BYTES_BIG_ENDIAN machine, 849 this means we must skip the empty high order bytes when 850 calculating the bit offset. */ 851 if (bytes < UNITS_PER_WORD 852#ifdef BLOCK_REG_PADDING 853 && (BLOCK_REG_PADDING (args[i].mode, 854 TREE_TYPE (args[i].tree_value), 1) 855 == downward) 856#else 857 && BYTES_BIG_ENDIAN 858#endif 859 ) 860 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT; 861 862 for (j = 0; j < args[i].n_aligned_regs; j++) 863 { 864 rtx reg = gen_reg_rtx (word_mode); 865 rtx word = operand_subword_force (args[i].value, j, BLKmode); 866 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD); 867 868 args[i].aligned_regs[j] = reg; 869 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX, 870 word_mode, word_mode); 871 872 /* There is no need to restrict this code to loading items 873 in TYPE_ALIGN sized hunks. The bitfield instructions can 874 load up entire word sized registers efficiently. 875 876 ??? This may not be needed anymore. 877 We use to emit a clobber here but that doesn't let later 878 passes optimize the instructions we emit. By storing 0 into 879 the register later passes know the first AND to zero out the 880 bitfield being set in the register is unnecessary. The store 881 of 0 will be deleted as will at least the first AND. */ 882 883 emit_move_insn (reg, const0_rtx); 884 885 bytes -= bitsize / BITS_PER_UNIT; 886 store_bit_field (reg, bitsize, endian_correction, word_mode, 887 word); 888 } 889 } 890} 891 892/* Fill in ARGS_SIZE and ARGS array based on the parameters found in 893 ACTPARMS. 894 895 NUM_ACTUALS is the total number of parameters. 896 897 N_NAMED_ARGS is the total number of named arguments. 898 899 FNDECL is the tree code for the target of this call (if known) 900 901 ARGS_SO_FAR holds state needed by the target to know where to place 902 the next argument. 903 904 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved 905 for arguments which are passed in registers. 906 907 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level 908 and may be modified by this routine. 909 910 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer 911 flags which may may be modified by this routine. 912 913 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference 914 that requires allocation of stack space. 915 916 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to 917 the thunked-to function. */ 918 919static void 920initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED, 921 struct arg_data *args, 922 struct args_size *args_size, 923 int n_named_args ATTRIBUTE_UNUSED, 924 tree actparms, tree fndecl, 925 CUMULATIVE_ARGS *args_so_far, 926 int reg_parm_stack_space, 927 rtx *old_stack_level, int *old_pending_adj, 928 int *must_preallocate, int *ecf_flags, 929 bool *may_tailcall, bool call_from_thunk_p) 930{ 931 /* 1 if scanning parms front to back, -1 if scanning back to front. */ 932 int inc; 933 934 /* Count arg position in order args appear. */ 935 int argpos; 936 937 int i; 938 tree p; 939 940 args_size->constant = 0; 941 args_size->var = 0; 942 943 /* In this loop, we consider args in the order they are written. 944 We fill up ARGS from the front or from the back if necessary 945 so that in any case the first arg to be pushed ends up at the front. */ 946 947 if (PUSH_ARGS_REVERSED) 948 { 949 i = num_actuals - 1, inc = -1; 950 /* In this case, must reverse order of args 951 so that we compute and push the last arg first. */ 952 } 953 else 954 { 955 i = 0, inc = 1; 956 } 957 958 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */ 959 for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++) 960 { 961 tree type = TREE_TYPE (TREE_VALUE (p)); 962 int unsignedp; 963 enum machine_mode mode; 964 965 args[i].tree_value = TREE_VALUE (p); 966 967 /* Replace erroneous argument with constant zero. */ 968 if (type == error_mark_node || !COMPLETE_TYPE_P (type)) 969 args[i].tree_value = integer_zero_node, type = integer_type_node; 970 971 /* If TYPE is a transparent union, pass things the way we would 972 pass the first field of the union. We have already verified that 973 the modes are the same. */ 974 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type)) 975 type = TREE_TYPE (TYPE_FIELDS (type)); 976 977 /* Decide where to pass this arg. 978 979 args[i].reg is nonzero if all or part is passed in registers. 980 981 args[i].partial is nonzero if part but not all is passed in registers, 982 and the exact value says how many bytes are passed in registers. 983 984 args[i].pass_on_stack is nonzero if the argument must at least be 985 computed on the stack. It may then be loaded back into registers 986 if args[i].reg is nonzero. 987 988 These decisions are driven by the FUNCTION_... macros and must agree 989 with those made by function.c. */ 990 991 /* See if this argument should be passed by invisible reference. */ 992 if (pass_by_reference (args_so_far, TYPE_MODE (type), 993 type, argpos < n_named_args)) 994 { 995 bool callee_copies; 996 tree base; 997 998 callee_copies 999 = reference_callee_copied (args_so_far, TYPE_MODE (type), 1000 type, argpos < n_named_args); 1001 1002 /* If we're compiling a thunk, pass through invisible references 1003 instead of making a copy. */ 1004 if (call_from_thunk_p 1005 || (callee_copies 1006 && !TREE_ADDRESSABLE (type) 1007 && (base = get_base_address (args[i].tree_value)) 1008 && (!DECL_P (base) || MEM_P (DECL_RTL (base))))) 1009 { 1010 /* We can't use sibcalls if a callee-copied argument is 1011 stored in the current function's frame. */ 1012 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base)) 1013 *may_tailcall = false; 1014 1015 args[i].tree_value = build_fold_addr_expr (args[i].tree_value); 1016 type = TREE_TYPE (args[i].tree_value); 1017 1018 *ecf_flags &= ~(ECF_CONST | ECF_LIBCALL_BLOCK); 1019 } 1020 else 1021 { 1022 /* We make a copy of the object and pass the address to the 1023 function being called. */ 1024 rtx copy; 1025 1026 if (!COMPLETE_TYPE_P (type) 1027 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST 1028 || (flag_stack_check && ! STACK_CHECK_BUILTIN 1029 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type), 1030 STACK_CHECK_MAX_VAR_SIZE)))) 1031 { 1032 /* This is a variable-sized object. Make space on the stack 1033 for it. */ 1034 rtx size_rtx = expr_size (TREE_VALUE (p)); 1035 1036 if (*old_stack_level == 0) 1037 { 1038 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX); 1039 *old_pending_adj = pending_stack_adjust; 1040 pending_stack_adjust = 0; 1041 } 1042 1043 copy = gen_rtx_MEM (BLKmode, 1044 allocate_dynamic_stack_space 1045 (size_rtx, NULL_RTX, TYPE_ALIGN (type))); 1046 set_mem_attributes (copy, type, 1); 1047 } 1048 else 1049 copy = assign_temp (type, 0, 1, 0); 1050 1051 store_expr (args[i].tree_value, copy, 0); 1052 1053 if (callee_copies) 1054 *ecf_flags &= ~(ECF_CONST | ECF_LIBCALL_BLOCK); 1055 else 1056 *ecf_flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK); 1057 1058 args[i].tree_value 1059 = build_fold_addr_expr (make_tree (type, copy)); 1060 type = TREE_TYPE (args[i].tree_value); 1061 *may_tailcall = false; 1062 } 1063 } 1064 1065 mode = TYPE_MODE (type); 1066 unsignedp = TYPE_UNSIGNED (type); 1067 1068 if (targetm.calls.promote_function_args (fndecl ? TREE_TYPE (fndecl) : 0)) 1069 mode = promote_mode (type, mode, &unsignedp, 1); 1070 1071 args[i].unsignedp = unsignedp; 1072 args[i].mode = mode; 1073 1074 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type, 1075 argpos < n_named_args); 1076#ifdef FUNCTION_INCOMING_ARG 1077 /* If this is a sibling call and the machine has register windows, the 1078 register window has to be unwinded before calling the routine, so 1079 arguments have to go into the incoming registers. */ 1080 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type, 1081 argpos < n_named_args); 1082#else 1083 args[i].tail_call_reg = args[i].reg; 1084#endif 1085 1086 if (args[i].reg) 1087 args[i].partial 1088 = targetm.calls.arg_partial_bytes (args_so_far, mode, type, 1089 argpos < n_named_args); 1090 1091 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type); 1092 1093 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]), 1094 it means that we are to pass this arg in the register(s) designated 1095 by the PARALLEL, but also to pass it in the stack. */ 1096 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL 1097 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0) 1098 args[i].pass_on_stack = 1; 1099 1100 /* If this is an addressable type, we must preallocate the stack 1101 since we must evaluate the object into its final location. 1102 1103 If this is to be passed in both registers and the stack, it is simpler 1104 to preallocate. */ 1105 if (TREE_ADDRESSABLE (type) 1106 || (args[i].pass_on_stack && args[i].reg != 0)) 1107 *must_preallocate = 1; 1108 1109 /* If this is an addressable type, we cannot pre-evaluate it. Thus, 1110 we cannot consider this function call constant. */ 1111 if (TREE_ADDRESSABLE (type)) 1112 *ecf_flags &= ~ECF_LIBCALL_BLOCK; 1113 1114 /* Compute the stack-size of this argument. */ 1115 if (args[i].reg == 0 || args[i].partial != 0 1116 || reg_parm_stack_space > 0 1117 || args[i].pass_on_stack) 1118 locate_and_pad_parm (mode, type, 1119#ifdef STACK_PARMS_IN_REG_PARM_AREA 1120 1, 1121#else 1122 args[i].reg != 0, 1123#endif 1124 args[i].pass_on_stack ? 0 : args[i].partial, 1125 fndecl, args_size, &args[i].locate); 1126#ifdef BLOCK_REG_PADDING 1127 else 1128 /* The argument is passed entirely in registers. See at which 1129 end it should be padded. */ 1130 args[i].locate.where_pad = 1131 BLOCK_REG_PADDING (mode, type, 1132 int_size_in_bytes (type) <= UNITS_PER_WORD); 1133#endif 1134 1135 /* Update ARGS_SIZE, the total stack space for args so far. */ 1136 1137 args_size->constant += args[i].locate.size.constant; 1138 if (args[i].locate.size.var) 1139 ADD_PARM_SIZE (*args_size, args[i].locate.size.var); 1140 1141 /* Increment ARGS_SO_FAR, which has info about which arg-registers 1142 have been used, etc. */ 1143 1144 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type, 1145 argpos < n_named_args); 1146 } 1147} 1148 1149/* Update ARGS_SIZE to contain the total size for the argument block. 1150 Return the original constant component of the argument block's size. 1151 1152 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved 1153 for arguments passed in registers. */ 1154 1155static int 1156compute_argument_block_size (int reg_parm_stack_space, 1157 struct args_size *args_size, 1158 int preferred_stack_boundary ATTRIBUTE_UNUSED) 1159{ 1160 int unadjusted_args_size = args_size->constant; 1161 1162 /* For accumulate outgoing args mode we don't need to align, since the frame 1163 will be already aligned. Align to STACK_BOUNDARY in order to prevent 1164 backends from generating misaligned frame sizes. */ 1165 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY) 1166 preferred_stack_boundary = STACK_BOUNDARY; 1167 1168 /* Compute the actual size of the argument block required. The variable 1169 and constant sizes must be combined, the size may have to be rounded, 1170 and there may be a minimum required size. */ 1171 1172 if (args_size->var) 1173 { 1174 args_size->var = ARGS_SIZE_TREE (*args_size); 1175 args_size->constant = 0; 1176 1177 preferred_stack_boundary /= BITS_PER_UNIT; 1178 if (preferred_stack_boundary > 1) 1179 { 1180 /* We don't handle this case yet. To handle it correctly we have 1181 to add the delta, round and subtract the delta. 1182 Currently no machine description requires this support. */ 1183 gcc_assert (!(stack_pointer_delta & (preferred_stack_boundary - 1))); 1184 args_size->var = round_up (args_size->var, preferred_stack_boundary); 1185 } 1186 1187 if (reg_parm_stack_space > 0) 1188 { 1189 args_size->var 1190 = size_binop (MAX_EXPR, args_size->var, 1191 ssize_int (reg_parm_stack_space)); 1192 1193#ifndef OUTGOING_REG_PARM_STACK_SPACE 1194 /* The area corresponding to register parameters is not to count in 1195 the size of the block we need. So make the adjustment. */ 1196 args_size->var 1197 = size_binop (MINUS_EXPR, args_size->var, 1198 ssize_int (reg_parm_stack_space)); 1199#endif 1200 } 1201 } 1202 else 1203 { 1204 preferred_stack_boundary /= BITS_PER_UNIT; 1205 if (preferred_stack_boundary < 1) 1206 preferred_stack_boundary = 1; 1207 args_size->constant = (((args_size->constant 1208 + stack_pointer_delta 1209 + preferred_stack_boundary - 1) 1210 / preferred_stack_boundary 1211 * preferred_stack_boundary) 1212 - stack_pointer_delta); 1213 1214 args_size->constant = MAX (args_size->constant, 1215 reg_parm_stack_space); 1216 1217#ifndef OUTGOING_REG_PARM_STACK_SPACE 1218 args_size->constant -= reg_parm_stack_space; 1219#endif 1220 } 1221 return unadjusted_args_size; 1222} 1223 1224/* Precompute parameters as needed for a function call. 1225 1226 FLAGS is mask of ECF_* constants. 1227 1228 NUM_ACTUALS is the number of arguments. 1229 1230 ARGS is an array containing information for each argument; this 1231 routine fills in the INITIAL_VALUE and VALUE fields for each 1232 precomputed argument. */ 1233 1234static void 1235precompute_arguments (int flags, int num_actuals, struct arg_data *args) 1236{ 1237 int i; 1238 1239 /* If this is a libcall, then precompute all arguments so that we do not 1240 get extraneous instructions emitted as part of the libcall sequence. */ 1241 1242 /* If we preallocated the stack space, and some arguments must be passed 1243 on the stack, then we must precompute any parameter which contains a 1244 function call which will store arguments on the stack. 1245 Otherwise, evaluating the parameter may clobber previous parameters 1246 which have already been stored into the stack. (we have code to avoid 1247 such case by saving the outgoing stack arguments, but it results in 1248 worse code) */ 1249 if ((flags & ECF_LIBCALL_BLOCK) == 0 && !ACCUMULATE_OUTGOING_ARGS) 1250 return; 1251 1252 for (i = 0; i < num_actuals; i++) 1253 { 1254 enum machine_mode mode; 1255 1256 if ((flags & ECF_LIBCALL_BLOCK) == 0 1257 && TREE_CODE (args[i].tree_value) != CALL_EXPR) 1258 continue; 1259 1260 /* If this is an addressable type, we cannot pre-evaluate it. */ 1261 gcc_assert (!TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))); 1262 1263 args[i].initial_value = args[i].value 1264 = expand_normal (args[i].tree_value); 1265 1266 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value)); 1267 if (mode != args[i].mode) 1268 { 1269 args[i].value 1270 = convert_modes (args[i].mode, mode, 1271 args[i].value, args[i].unsignedp); 1272#if defined(PROMOTE_FUNCTION_MODE) && !defined(PROMOTE_MODE) 1273 /* CSE will replace this only if it contains args[i].value 1274 pseudo, so convert it down to the declared mode using 1275 a SUBREG. */ 1276 if (REG_P (args[i].value) 1277 && GET_MODE_CLASS (args[i].mode) == MODE_INT) 1278 { 1279 args[i].initial_value 1280 = gen_lowpart_SUBREG (mode, args[i].value); 1281 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1; 1282 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value, 1283 args[i].unsignedp); 1284 } 1285#endif 1286 } 1287 } 1288} 1289 1290/* Given the current state of MUST_PREALLOCATE and information about 1291 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE, 1292 compute and return the final value for MUST_PREALLOCATE. */ 1293 1294static int 1295finalize_must_preallocate (int must_preallocate, int num_actuals, struct arg_data *args, struct args_size *args_size) 1296{ 1297 /* See if we have or want to preallocate stack space. 1298 1299 If we would have to push a partially-in-regs parm 1300 before other stack parms, preallocate stack space instead. 1301 1302 If the size of some parm is not a multiple of the required stack 1303 alignment, we must preallocate. 1304 1305 If the total size of arguments that would otherwise create a copy in 1306 a temporary (such as a CALL) is more than half the total argument list 1307 size, preallocation is faster. 1308 1309 Another reason to preallocate is if we have a machine (like the m88k) 1310 where stack alignment is required to be maintained between every 1311 pair of insns, not just when the call is made. However, we assume here 1312 that such machines either do not have push insns (and hence preallocation 1313 would occur anyway) or the problem is taken care of with 1314 PUSH_ROUNDING. */ 1315 1316 if (! must_preallocate) 1317 { 1318 int partial_seen = 0; 1319 int copy_to_evaluate_size = 0; 1320 int i; 1321 1322 for (i = 0; i < num_actuals && ! must_preallocate; i++) 1323 { 1324 if (args[i].partial > 0 && ! args[i].pass_on_stack) 1325 partial_seen = 1; 1326 else if (partial_seen && args[i].reg == 0) 1327 must_preallocate = 1; 1328 1329 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode 1330 && (TREE_CODE (args[i].tree_value) == CALL_EXPR 1331 || TREE_CODE (args[i].tree_value) == TARGET_EXPR 1332 || TREE_CODE (args[i].tree_value) == COND_EXPR 1333 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)))) 1334 copy_to_evaluate_size 1335 += int_size_in_bytes (TREE_TYPE (args[i].tree_value)); 1336 } 1337 1338 if (copy_to_evaluate_size * 2 >= args_size->constant 1339 && args_size->constant > 0) 1340 must_preallocate = 1; 1341 } 1342 return must_preallocate; 1343} 1344 1345/* If we preallocated stack space, compute the address of each argument 1346 and store it into the ARGS array. 1347 1348 We need not ensure it is a valid memory address here; it will be 1349 validized when it is used. 1350 1351 ARGBLOCK is an rtx for the address of the outgoing arguments. */ 1352 1353static void 1354compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals) 1355{ 1356 if (argblock) 1357 { 1358 rtx arg_reg = argblock; 1359 int i, arg_offset = 0; 1360 1361 if (GET_CODE (argblock) == PLUS) 1362 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1)); 1363 1364 for (i = 0; i < num_actuals; i++) 1365 { 1366 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset); 1367 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset); 1368 rtx addr; 1369 unsigned int align, boundary; 1370 unsigned int units_on_stack = 0; 1371 enum machine_mode partial_mode = VOIDmode; 1372 1373 /* Skip this parm if it will not be passed on the stack. */ 1374 if (! args[i].pass_on_stack 1375 && args[i].reg != 0 1376 && args[i].partial == 0) 1377 continue; 1378 1379 if (GET_CODE (offset) == CONST_INT) 1380 addr = plus_constant (arg_reg, INTVAL (offset)); 1381 else 1382 addr = gen_rtx_PLUS (Pmode, arg_reg, offset); 1383 1384 addr = plus_constant (addr, arg_offset); 1385 1386 if (args[i].partial != 0) 1387 { 1388 /* Only part of the parameter is being passed on the stack. 1389 Generate a simple memory reference of the correct size. */ 1390 units_on_stack = args[i].locate.size.constant; 1391 partial_mode = mode_for_size (units_on_stack * BITS_PER_UNIT, 1392 MODE_INT, 1); 1393 args[i].stack = gen_rtx_MEM (partial_mode, addr); 1394 set_mem_size (args[i].stack, GEN_INT (units_on_stack)); 1395 } 1396 else 1397 { 1398 args[i].stack = gen_rtx_MEM (args[i].mode, addr); 1399 set_mem_attributes (args[i].stack, 1400 TREE_TYPE (args[i].tree_value), 1); 1401 } 1402 align = BITS_PER_UNIT; 1403 boundary = args[i].locate.boundary; 1404 if (args[i].locate.where_pad != downward) 1405 align = boundary; 1406 else if (GET_CODE (offset) == CONST_INT) 1407 { 1408 align = INTVAL (offset) * BITS_PER_UNIT | boundary; 1409 align = align & -align; 1410 } 1411 set_mem_align (args[i].stack, align); 1412 1413 if (GET_CODE (slot_offset) == CONST_INT) 1414 addr = plus_constant (arg_reg, INTVAL (slot_offset)); 1415 else 1416 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset); 1417 1418 addr = plus_constant (addr, arg_offset); 1419 1420 if (args[i].partial != 0) 1421 { 1422 /* Only part of the parameter is being passed on the stack. 1423 Generate a simple memory reference of the correct size. */ 1424 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr); 1425 set_mem_size (args[i].stack_slot, GEN_INT (units_on_stack)); 1426 } 1427 else 1428 { 1429 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr); 1430 set_mem_attributes (args[i].stack_slot, 1431 TREE_TYPE (args[i].tree_value), 1); 1432 } 1433 set_mem_align (args[i].stack_slot, args[i].locate.boundary); 1434 1435 /* Function incoming arguments may overlap with sibling call 1436 outgoing arguments and we cannot allow reordering of reads 1437 from function arguments with stores to outgoing arguments 1438 of sibling calls. */ 1439 set_mem_alias_set (args[i].stack, 0); 1440 set_mem_alias_set (args[i].stack_slot, 0); 1441 } 1442 } 1443} 1444 1445/* Given a FNDECL and EXP, return an rtx suitable for use as a target address 1446 in a call instruction. 1447 1448 FNDECL is the tree node for the target function. For an indirect call 1449 FNDECL will be NULL_TREE. 1450 1451 ADDR is the operand 0 of CALL_EXPR for this call. */ 1452 1453static rtx 1454rtx_for_function_call (tree fndecl, tree addr) 1455{ 1456 rtx funexp; 1457 1458 /* Get the function to call, in the form of RTL. */ 1459 if (fndecl) 1460 { 1461 /* If this is the first use of the function, see if we need to 1462 make an external definition for it. */ 1463 if (! TREE_USED (fndecl)) 1464 { 1465 assemble_external (fndecl); 1466 TREE_USED (fndecl) = 1; 1467 } 1468 1469 /* Get a SYMBOL_REF rtx for the function address. */ 1470 funexp = XEXP (DECL_RTL (fndecl), 0); 1471 } 1472 else 1473 /* Generate an rtx (probably a pseudo-register) for the address. */ 1474 { 1475 push_temp_slots (); 1476 funexp = expand_normal (addr); 1477 pop_temp_slots (); /* FUNEXP can't be BLKmode. */ 1478 } 1479 return funexp; 1480} 1481 1482/* Return true if and only if SIZE storage units (usually bytes) 1483 starting from address ADDR overlap with already clobbered argument 1484 area. This function is used to determine if we should give up a 1485 sibcall. */ 1486 1487static bool 1488mem_overlaps_already_clobbered_arg_p (rtx addr, unsigned HOST_WIDE_INT size) 1489{ 1490 HOST_WIDE_INT i; 1491 1492 if (addr == current_function_internal_arg_pointer) 1493 i = 0; 1494 else if (GET_CODE (addr) == PLUS 1495 && XEXP (addr, 0) == current_function_internal_arg_pointer 1496 && GET_CODE (XEXP (addr, 1)) == CONST_INT) 1497 i = INTVAL (XEXP (addr, 1)); 1498 /* Return true for arg pointer based indexed addressing. */ 1499 else if (GET_CODE (addr) == PLUS 1500 && (XEXP (addr, 0) == current_function_internal_arg_pointer 1501 || XEXP (addr, 1) == current_function_internal_arg_pointer)) 1502 return true; 1503 else 1504 return false; 1505 1506#ifdef ARGS_GROW_DOWNWARD 1507 i = -i - size; 1508#endif 1509 if (size > 0) 1510 { 1511 unsigned HOST_WIDE_INT k; 1512 1513 for (k = 0; k < size; k++) 1514 if (i + k < stored_args_map->n_bits 1515 && TEST_BIT (stored_args_map, i + k)) 1516 return true; 1517 } 1518 1519 return false; 1520} 1521 1522/* Do the register loads required for any wholly-register parms or any 1523 parms which are passed both on the stack and in a register. Their 1524 expressions were already evaluated. 1525 1526 Mark all register-parms as living through the call, putting these USE 1527 insns in the CALL_INSN_FUNCTION_USAGE field. 1528 1529 When IS_SIBCALL, perform the check_sibcall_argument_overlap 1530 checking, setting *SIBCALL_FAILURE if appropriate. */ 1531 1532static void 1533load_register_parameters (struct arg_data *args, int num_actuals, 1534 rtx *call_fusage, int flags, int is_sibcall, 1535 int *sibcall_failure) 1536{ 1537 int i, j; 1538 1539 for (i = 0; i < num_actuals; i++) 1540 { 1541 rtx reg = ((flags & ECF_SIBCALL) 1542 ? args[i].tail_call_reg : args[i].reg); 1543 if (reg) 1544 { 1545 int partial = args[i].partial; 1546 int nregs; 1547 int size = 0; 1548 rtx before_arg = get_last_insn (); 1549 /* Set non-negative if we must move a word at a time, even if 1550 just one word (e.g, partial == 4 && mode == DFmode). Set 1551 to -1 if we just use a normal move insn. This value can be 1552 zero if the argument is a zero size structure. */ 1553 nregs = -1; 1554 if (GET_CODE (reg) == PARALLEL) 1555 ; 1556 else if (partial) 1557 { 1558 gcc_assert (partial % UNITS_PER_WORD == 0); 1559 nregs = partial / UNITS_PER_WORD; 1560 } 1561 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode) 1562 { 1563 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value)); 1564 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD; 1565 } 1566 else 1567 size = GET_MODE_SIZE (args[i].mode); 1568 1569 /* Handle calls that pass values in multiple non-contiguous 1570 locations. The Irix 6 ABI has examples of this. */ 1571 1572 if (GET_CODE (reg) == PARALLEL) 1573 emit_group_move (reg, args[i].parallel_value); 1574 1575 /* If simple case, just do move. If normal partial, store_one_arg 1576 has already loaded the register for us. In all other cases, 1577 load the register(s) from memory. */ 1578 1579 else if (nregs == -1) 1580 { 1581 emit_move_insn (reg, args[i].value); 1582#ifdef BLOCK_REG_PADDING 1583 /* Handle case where we have a value that needs shifting 1584 up to the msb. eg. a QImode value and we're padding 1585 upward on a BYTES_BIG_ENDIAN machine. */ 1586 if (size < UNITS_PER_WORD 1587 && (args[i].locate.where_pad 1588 == (BYTES_BIG_ENDIAN ? upward : downward))) 1589 { 1590 rtx x; 1591 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT; 1592 1593 /* Assigning REG here rather than a temp makes CALL_FUSAGE 1594 report the whole reg as used. Strictly speaking, the 1595 call only uses SIZE bytes at the msb end, but it doesn't 1596 seem worth generating rtl to say that. */ 1597 reg = gen_rtx_REG (word_mode, REGNO (reg)); 1598 x = expand_shift (LSHIFT_EXPR, word_mode, reg, 1599 build_int_cst (NULL_TREE, shift), 1600 reg, 1); 1601 if (x != reg) 1602 emit_move_insn (reg, x); 1603 } 1604#endif 1605 } 1606 1607 /* If we have pre-computed the values to put in the registers in 1608 the case of non-aligned structures, copy them in now. */ 1609 1610 else if (args[i].n_aligned_regs != 0) 1611 for (j = 0; j < args[i].n_aligned_regs; j++) 1612 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j), 1613 args[i].aligned_regs[j]); 1614 1615 else if (partial == 0 || args[i].pass_on_stack) 1616 { 1617 rtx mem = validize_mem (args[i].value); 1618 1619 /* Check for overlap with already clobbered argument area. */ 1620 if (is_sibcall 1621 && mem_overlaps_already_clobbered_arg_p (XEXP (args[i].value, 0), 1622 size)) 1623 *sibcall_failure = 1; 1624 1625 /* Handle a BLKmode that needs shifting. */ 1626 if (nregs == 1 && size < UNITS_PER_WORD 1627#ifdef BLOCK_REG_PADDING 1628 && args[i].locate.where_pad == downward 1629#else 1630 && BYTES_BIG_ENDIAN 1631#endif 1632 ) 1633 { 1634 rtx tem = operand_subword_force (mem, 0, args[i].mode); 1635 rtx ri = gen_rtx_REG (word_mode, REGNO (reg)); 1636 rtx x = gen_reg_rtx (word_mode); 1637 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT; 1638 enum tree_code dir = BYTES_BIG_ENDIAN ? RSHIFT_EXPR 1639 : LSHIFT_EXPR; 1640 1641 emit_move_insn (x, tem); 1642 x = expand_shift (dir, word_mode, x, 1643 build_int_cst (NULL_TREE, shift), 1644 ri, 1); 1645 if (x != ri) 1646 emit_move_insn (ri, x); 1647 } 1648 else 1649 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode); 1650 } 1651 1652 /* When a parameter is a block, and perhaps in other cases, it is 1653 possible that it did a load from an argument slot that was 1654 already clobbered. */ 1655 if (is_sibcall 1656 && check_sibcall_argument_overlap (before_arg, &args[i], 0)) 1657 *sibcall_failure = 1; 1658 1659 /* Handle calls that pass values in multiple non-contiguous 1660 locations. The Irix 6 ABI has examples of this. */ 1661 if (GET_CODE (reg) == PARALLEL) 1662 use_group_regs (call_fusage, reg); 1663 else if (nregs == -1) 1664 use_reg (call_fusage, reg); 1665 else if (nregs > 0) 1666 use_regs (call_fusage, REGNO (reg), nregs); 1667 } 1668 } 1669} 1670 1671/* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments 1672 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY 1673 bytes, then we would need to push some additional bytes to pad the 1674 arguments. So, we compute an adjust to the stack pointer for an 1675 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE 1676 bytes. Then, when the arguments are pushed the stack will be perfectly 1677 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should 1678 be popped after the call. Returns the adjustment. */ 1679 1680static int 1681combine_pending_stack_adjustment_and_call (int unadjusted_args_size, 1682 struct args_size *args_size, 1683 unsigned int preferred_unit_stack_boundary) 1684{ 1685 /* The number of bytes to pop so that the stack will be 1686 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */ 1687 HOST_WIDE_INT adjustment; 1688 /* The alignment of the stack after the arguments are pushed, if we 1689 just pushed the arguments without adjust the stack here. */ 1690 unsigned HOST_WIDE_INT unadjusted_alignment; 1691 1692 unadjusted_alignment 1693 = ((stack_pointer_delta + unadjusted_args_size) 1694 % preferred_unit_stack_boundary); 1695 1696 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes 1697 as possible -- leaving just enough left to cancel out the 1698 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the 1699 PENDING_STACK_ADJUST is non-negative, and congruent to 1700 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */ 1701 1702 /* Begin by trying to pop all the bytes. */ 1703 unadjusted_alignment 1704 = (unadjusted_alignment 1705 - (pending_stack_adjust % preferred_unit_stack_boundary)); 1706 adjustment = pending_stack_adjust; 1707 /* Push enough additional bytes that the stack will be aligned 1708 after the arguments are pushed. */ 1709 if (preferred_unit_stack_boundary > 1) 1710 { 1711 if (unadjusted_alignment > 0) 1712 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment; 1713 else 1714 adjustment += unadjusted_alignment; 1715 } 1716 1717 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of 1718 bytes after the call. The right number is the entire 1719 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required 1720 by the arguments in the first place. */ 1721 args_size->constant 1722 = pending_stack_adjust - adjustment + unadjusted_args_size; 1723 1724 return adjustment; 1725} 1726 1727/* Scan X expression if it does not dereference any argument slots 1728 we already clobbered by tail call arguments (as noted in stored_args_map 1729 bitmap). 1730 Return nonzero if X expression dereferences such argument slots, 1731 zero otherwise. */ 1732 1733static int 1734check_sibcall_argument_overlap_1 (rtx x) 1735{ 1736 RTX_CODE code; 1737 int i, j; 1738 const char *fmt; 1739 1740 if (x == NULL_RTX) 1741 return 0; 1742 1743 code = GET_CODE (x); 1744 1745 if (code == MEM) 1746 return mem_overlaps_already_clobbered_arg_p (XEXP (x, 0), 1747 GET_MODE_SIZE (GET_MODE (x))); 1748 1749 /* Scan all subexpressions. */ 1750 fmt = GET_RTX_FORMAT (code); 1751 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++) 1752 { 1753 if (*fmt == 'e') 1754 { 1755 if (check_sibcall_argument_overlap_1 (XEXP (x, i))) 1756 return 1; 1757 } 1758 else if (*fmt == 'E') 1759 { 1760 for (j = 0; j < XVECLEN (x, i); j++) 1761 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j))) 1762 return 1; 1763 } 1764 } 1765 return 0; 1766} 1767 1768/* Scan sequence after INSN if it does not dereference any argument slots 1769 we already clobbered by tail call arguments (as noted in stored_args_map 1770 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to 1771 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP 1772 should be 0). Return nonzero if sequence after INSN dereferences such argument 1773 slots, zero otherwise. */ 1774 1775static int 1776check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map) 1777{ 1778 int low, high; 1779 1780 if (insn == NULL_RTX) 1781 insn = get_insns (); 1782 else 1783 insn = NEXT_INSN (insn); 1784 1785 for (; insn; insn = NEXT_INSN (insn)) 1786 if (INSN_P (insn) 1787 && check_sibcall_argument_overlap_1 (PATTERN (insn))) 1788 break; 1789 1790 if (mark_stored_args_map) 1791 { 1792#ifdef ARGS_GROW_DOWNWARD 1793 low = -arg->locate.slot_offset.constant - arg->locate.size.constant; 1794#else 1795 low = arg->locate.slot_offset.constant; 1796#endif 1797 1798 for (high = low + arg->locate.size.constant; low < high; low++) 1799 SET_BIT (stored_args_map, low); 1800 } 1801 return insn != NULL_RTX; 1802} 1803 1804/* Given that a function returns a value of mode MODE at the most 1805 significant end of hard register VALUE, shift VALUE left or right 1806 as specified by LEFT_P. Return true if some action was needed. */ 1807 1808bool 1809shift_return_value (enum machine_mode mode, bool left_p, rtx value) 1810{ 1811 HOST_WIDE_INT shift; 1812 1813 gcc_assert (REG_P (value) && HARD_REGISTER_P (value)); 1814 shift = GET_MODE_BITSIZE (GET_MODE (value)) - GET_MODE_BITSIZE (mode); 1815 if (shift == 0) 1816 return false; 1817 1818 /* Use ashr rather than lshr for right shifts. This is for the benefit 1819 of the MIPS port, which requires SImode values to be sign-extended 1820 when stored in 64-bit registers. */ 1821 if (!force_expand_binop (GET_MODE (value), left_p ? ashl_optab : ashr_optab, 1822 value, GEN_INT (shift), value, 1, OPTAB_WIDEN)) 1823 gcc_unreachable (); 1824 return true; 1825} 1826 1827/* Generate all the code for a function call 1828 and return an rtx for its value. 1829 Store the value in TARGET (specified as an rtx) if convenient. 1830 If the value is stored in TARGET then TARGET is returned. 1831 If IGNORE is nonzero, then we ignore the value of the function call. */ 1832 1833rtx 1834expand_call (tree exp, rtx target, int ignore) 1835{ 1836 /* Nonzero if we are currently expanding a call. */ 1837 static int currently_expanding_call = 0; 1838 1839 /* List of actual parameters. */ 1840 tree actparms = TREE_OPERAND (exp, 1); 1841 /* RTX for the function to be called. */ 1842 rtx funexp; 1843 /* Sequence of insns to perform a normal "call". */ 1844 rtx normal_call_insns = NULL_RTX; 1845 /* Sequence of insns to perform a tail "call". */ 1846 rtx tail_call_insns = NULL_RTX; 1847 /* Data type of the function. */ 1848 tree funtype; 1849 tree type_arg_types; 1850 /* Declaration of the function being called, 1851 or 0 if the function is computed (not known by name). */ 1852 tree fndecl = 0; 1853 /* The type of the function being called. */ 1854 tree fntype; 1855 bool try_tail_call = CALL_EXPR_TAILCALL (exp); 1856 int pass; 1857 1858 /* Register in which non-BLKmode value will be returned, 1859 or 0 if no value or if value is BLKmode. */ 1860 rtx valreg; 1861 /* Address where we should return a BLKmode value; 1862 0 if value not BLKmode. */ 1863 rtx structure_value_addr = 0; 1864 /* Nonzero if that address is being passed by treating it as 1865 an extra, implicit first parameter. Otherwise, 1866 it is passed by being copied directly into struct_value_rtx. */ 1867 int structure_value_addr_parm = 0; 1868 /* Size of aggregate value wanted, or zero if none wanted 1869 or if we are using the non-reentrant PCC calling convention 1870 or expecting the value in registers. */ 1871 HOST_WIDE_INT struct_value_size = 0; 1872 /* Nonzero if called function returns an aggregate in memory PCC style, 1873 by returning the address of where to find it. */ 1874 int pcc_struct_value = 0; 1875 rtx struct_value = 0; 1876 1877 /* Number of actual parameters in this call, including struct value addr. */ 1878 int num_actuals; 1879 /* Number of named args. Args after this are anonymous ones 1880 and they must all go on the stack. */ 1881 int n_named_args; 1882 1883 /* Vector of information about each argument. 1884 Arguments are numbered in the order they will be pushed, 1885 not the order they are written. */ 1886 struct arg_data *args; 1887 1888 /* Total size in bytes of all the stack-parms scanned so far. */ 1889 struct args_size args_size; 1890 struct args_size adjusted_args_size; 1891 /* Size of arguments before any adjustments (such as rounding). */ 1892 int unadjusted_args_size; 1893 /* Data on reg parms scanned so far. */ 1894 CUMULATIVE_ARGS args_so_far; 1895 /* Nonzero if a reg parm has been scanned. */ 1896 int reg_parm_seen; 1897 /* Nonzero if this is an indirect function call. */ 1898 1899 /* Nonzero if we must avoid push-insns in the args for this call. 1900 If stack space is allocated for register parameters, but not by the 1901 caller, then it is preallocated in the fixed part of the stack frame. 1902 So the entire argument block must then be preallocated (i.e., we 1903 ignore PUSH_ROUNDING in that case). */ 1904 1905 int must_preallocate = !PUSH_ARGS; 1906 1907 /* Size of the stack reserved for parameter registers. */ 1908 int reg_parm_stack_space = 0; 1909 1910 /* Address of space preallocated for stack parms 1911 (on machines that lack push insns), or 0 if space not preallocated. */ 1912 rtx argblock = 0; 1913 1914 /* Mask of ECF_ flags. */ 1915 int flags = 0; 1916#ifdef REG_PARM_STACK_SPACE 1917 /* Define the boundary of the register parm stack space that needs to be 1918 saved, if any. */ 1919 int low_to_save, high_to_save; 1920 rtx save_area = 0; /* Place that it is saved */ 1921#endif 1922 1923 int initial_highest_arg_in_use = highest_outgoing_arg_in_use; 1924 char *initial_stack_usage_map = stack_usage_map; 1925 char *stack_usage_map_buf = NULL; 1926 1927 int old_stack_allocated; 1928 1929 /* State variables to track stack modifications. */ 1930 rtx old_stack_level = 0; 1931 int old_stack_arg_under_construction = 0; 1932 int old_pending_adj = 0; 1933 int old_inhibit_defer_pop = inhibit_defer_pop; 1934 1935 /* Some stack pointer alterations we make are performed via 1936 allocate_dynamic_stack_space. This modifies the stack_pointer_delta, 1937 which we then also need to save/restore along the way. */ 1938 int old_stack_pointer_delta = 0; 1939 1940 rtx call_fusage; 1941 tree p = TREE_OPERAND (exp, 0); 1942 tree addr = TREE_OPERAND (exp, 0); 1943 int i; 1944 /* The alignment of the stack, in bits. */ 1945 unsigned HOST_WIDE_INT preferred_stack_boundary; 1946 /* The alignment of the stack, in bytes. */ 1947 unsigned HOST_WIDE_INT preferred_unit_stack_boundary; 1948 /* The static chain value to use for this call. */ 1949 rtx static_chain_value; 1950 /* See if this is "nothrow" function call. */ 1951 if (TREE_NOTHROW (exp)) 1952 flags |= ECF_NOTHROW; 1953 1954 /* See if we can find a DECL-node for the actual function, and get the 1955 function attributes (flags) from the function decl or type node. */ 1956 fndecl = get_callee_fndecl (exp); 1957 if (fndecl) 1958 { 1959 fntype = TREE_TYPE (fndecl); 1960 flags |= flags_from_decl_or_type (fndecl); 1961 } 1962 else 1963 { 1964 fntype = TREE_TYPE (TREE_TYPE (p)); 1965 flags |= flags_from_decl_or_type (fntype); 1966 } 1967 1968 struct_value = targetm.calls.struct_value_rtx (fntype, 0); 1969 1970 /* Warn if this value is an aggregate type, 1971 regardless of which calling convention we are using for it. */ 1972 if (AGGREGATE_TYPE_P (TREE_TYPE (exp))) 1973 warning (OPT_Waggregate_return, "function call has aggregate value"); 1974 1975 /* If the result of a pure or const function call is ignored (or void), 1976 and none of its arguments are volatile, we can avoid expanding the 1977 call and just evaluate the arguments for side-effects. */ 1978 if ((flags & (ECF_CONST | ECF_PURE)) 1979 && (ignore || target == const0_rtx 1980 || TYPE_MODE (TREE_TYPE (exp)) == VOIDmode)) 1981 { 1982 bool volatilep = false; 1983 tree arg; 1984 1985 for (arg = actparms; arg; arg = TREE_CHAIN (arg)) 1986 if (TREE_THIS_VOLATILE (TREE_VALUE (arg))) 1987 { 1988 volatilep = true; 1989 break; 1990 } 1991 1992 if (! volatilep) 1993 { 1994 for (arg = actparms; arg; arg = TREE_CHAIN (arg)) 1995 expand_expr (TREE_VALUE (arg), const0_rtx, 1996 VOIDmode, EXPAND_NORMAL); 1997 return const0_rtx; 1998 } 1999 } 2000 2001#ifdef REG_PARM_STACK_SPACE 2002 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl); 2003#endif 2004 2005#ifndef OUTGOING_REG_PARM_STACK_SPACE 2006 if (reg_parm_stack_space > 0 && PUSH_ARGS) 2007 must_preallocate = 1; 2008#endif 2009 2010 /* Set up a place to return a structure. */ 2011 2012 /* Cater to broken compilers. */ 2013 if (aggregate_value_p (exp, fndecl)) 2014 { 2015 /* This call returns a big structure. */ 2016 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK); 2017 2018#ifdef PCC_STATIC_STRUCT_RETURN 2019 { 2020 pcc_struct_value = 1; 2021 } 2022#else /* not PCC_STATIC_STRUCT_RETURN */ 2023 { 2024 struct_value_size = int_size_in_bytes (TREE_TYPE (exp)); 2025 2026 if (target && MEM_P (target) && CALL_EXPR_RETURN_SLOT_OPT (exp)) 2027 structure_value_addr = XEXP (target, 0); 2028 else 2029 { 2030 /* For variable-sized objects, we must be called with a target 2031 specified. If we were to allocate space on the stack here, 2032 we would have no way of knowing when to free it. */ 2033 rtx d = assign_temp (TREE_TYPE (exp), 0, 1, 1); 2034 2035 mark_temp_addr_taken (d); 2036 structure_value_addr = XEXP (d, 0); 2037 target = 0; 2038 } 2039 } 2040#endif /* not PCC_STATIC_STRUCT_RETURN */ 2041 } 2042 2043 /* Figure out the amount to which the stack should be aligned. */ 2044 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY; 2045 if (fndecl) 2046 { 2047 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl); 2048 if (i && i->preferred_incoming_stack_boundary) 2049 preferred_stack_boundary = i->preferred_incoming_stack_boundary; 2050 } 2051 2052 /* Operand 0 is a pointer-to-function; get the type of the function. */ 2053 funtype = TREE_TYPE (addr); 2054 gcc_assert (POINTER_TYPE_P (funtype)); 2055 funtype = TREE_TYPE (funtype); 2056 2057 /* Munge the tree to split complex arguments into their imaginary 2058 and real parts. */ 2059 if (targetm.calls.split_complex_arg) 2060 { 2061 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype)); 2062 actparms = split_complex_values (actparms); 2063 } 2064 else 2065 type_arg_types = TYPE_ARG_TYPES (funtype); 2066 2067 if (flags & ECF_MAY_BE_ALLOCA) 2068 current_function_calls_alloca = 1; 2069 2070 /* If struct_value_rtx is 0, it means pass the address 2071 as if it were an extra parameter. */ 2072 if (structure_value_addr && struct_value == 0) 2073 { 2074 /* If structure_value_addr is a REG other than 2075 virtual_outgoing_args_rtx, we can use always use it. If it 2076 is not a REG, we must always copy it into a register. 2077 If it is virtual_outgoing_args_rtx, we must copy it to another 2078 register in some cases. */ 2079 rtx temp = (!REG_P (structure_value_addr) 2080 || (ACCUMULATE_OUTGOING_ARGS 2081 && stack_arg_under_construction 2082 && structure_value_addr == virtual_outgoing_args_rtx) 2083 ? copy_addr_to_reg (convert_memory_address 2084 (Pmode, structure_value_addr)) 2085 : structure_value_addr); 2086 2087 actparms 2088 = tree_cons (error_mark_node, 2089 make_tree (build_pointer_type (TREE_TYPE (funtype)), 2090 temp), 2091 actparms); 2092 structure_value_addr_parm = 1; 2093 } 2094 2095 /* Count the arguments and set NUM_ACTUALS. */ 2096 for (p = actparms, num_actuals = 0; p; p = TREE_CHAIN (p)) 2097 num_actuals++; 2098 2099 /* Compute number of named args. 2100 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */ 2101 2102 if (type_arg_types != 0) 2103 n_named_args 2104 = (list_length (type_arg_types) 2105 /* Count the struct value address, if it is passed as a parm. */ 2106 + structure_value_addr_parm); 2107 else 2108 /* If we know nothing, treat all args as named. */ 2109 n_named_args = num_actuals; 2110 2111 /* Start updating where the next arg would go. 2112 2113 On some machines (such as the PA) indirect calls have a different 2114 calling convention than normal calls. The fourth argument in 2115 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call 2116 or not. */ 2117 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl, n_named_args); 2118 2119 /* Now possibly adjust the number of named args. 2120 Normally, don't include the last named arg if anonymous args follow. 2121 We do include the last named arg if 2122 targetm.calls.strict_argument_naming() returns nonzero. 2123 (If no anonymous args follow, the result of list_length is actually 2124 one too large. This is harmless.) 2125 2126 If targetm.calls.pretend_outgoing_varargs_named() returns 2127 nonzero, and targetm.calls.strict_argument_naming() returns zero, 2128 this machine will be able to place unnamed args that were passed 2129 in registers into the stack. So treat all args as named. This 2130 allows the insns emitting for a specific argument list to be 2131 independent of the function declaration. 2132 2133 If targetm.calls.pretend_outgoing_varargs_named() returns zero, 2134 we do not have any reliable way to pass unnamed args in 2135 registers, so we must force them into memory. */ 2136 2137 if (type_arg_types != 0 2138 && targetm.calls.strict_argument_naming (&args_so_far)) 2139 ; 2140 else if (type_arg_types != 0 2141 && ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far)) 2142 /* Don't include the last named arg. */ 2143 --n_named_args; 2144 else 2145 /* Treat all args as named. */ 2146 n_named_args = num_actuals; 2147 2148 /* Make a vector to hold all the information about each arg. */ 2149 args = alloca (num_actuals * sizeof (struct arg_data)); 2150 memset (args, 0, num_actuals * sizeof (struct arg_data)); 2151 2152 /* Build up entries in the ARGS array, compute the size of the 2153 arguments into ARGS_SIZE, etc. */ 2154 initialize_argument_information (num_actuals, args, &args_size, 2155 n_named_args, actparms, fndecl, 2156 &args_so_far, reg_parm_stack_space, 2157 &old_stack_level, &old_pending_adj, 2158 &must_preallocate, &flags, 2159 &try_tail_call, CALL_FROM_THUNK_P (exp)); 2160 2161 if (args_size.var) 2162 { 2163 /* If this function requires a variable-sized argument list, don't 2164 try to make a cse'able block for this call. We may be able to 2165 do this eventually, but it is too complicated to keep track of 2166 what insns go in the cse'able block and which don't. */ 2167 2168 flags &= ~ECF_LIBCALL_BLOCK; 2169 must_preallocate = 1; 2170 } 2171 2172 /* Now make final decision about preallocating stack space. */ 2173 must_preallocate = finalize_must_preallocate (must_preallocate, 2174 num_actuals, args, 2175 &args_size); 2176 2177 /* If the structure value address will reference the stack pointer, we 2178 must stabilize it. We don't need to do this if we know that we are 2179 not going to adjust the stack pointer in processing this call. */ 2180 2181 if (structure_value_addr 2182 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr) 2183 || reg_mentioned_p (virtual_outgoing_args_rtx, 2184 structure_value_addr)) 2185 && (args_size.var 2186 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant))) 2187 structure_value_addr = copy_to_reg (structure_value_addr); 2188 2189 /* Tail calls can make things harder to debug, and we've traditionally 2190 pushed these optimizations into -O2. Don't try if we're already 2191 expanding a call, as that means we're an argument. Don't try if 2192 there's cleanups, as we know there's code to follow the call. */ 2193 2194 if (currently_expanding_call++ != 0 2195 || !flag_optimize_sibling_calls 2196 || args_size.var 2197 || lookup_stmt_eh_region (exp) >= 0) 2198 try_tail_call = 0; 2199 2200 /* Rest of purposes for tail call optimizations to fail. */ 2201 if ( 2202#ifdef HAVE_sibcall_epilogue 2203 !HAVE_sibcall_epilogue 2204#else 2205 1 2206#endif 2207 || !try_tail_call 2208 /* Doing sibling call optimization needs some work, since 2209 structure_value_addr can be allocated on the stack. 2210 It does not seem worth the effort since few optimizable 2211 sibling calls will return a structure. */ 2212 || structure_value_addr != NULL_RTX 2213 /* Check whether the target is able to optimize the call 2214 into a sibcall. */ 2215 || !targetm.function_ok_for_sibcall (fndecl, exp) 2216 /* Functions that do not return exactly once may not be sibcall 2217 optimized. */ 2218 || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN)) 2219 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr))) 2220 /* If the called function is nested in the current one, it might access 2221 some of the caller's arguments, but could clobber them beforehand if 2222 the argument areas are shared. */ 2223 || (fndecl && decl_function_context (fndecl) == current_function_decl) 2224 /* If this function requires more stack slots than the current 2225 function, we cannot change it into a sibling call. 2226 current_function_pretend_args_size is not part of the 2227 stack allocated by our caller. */ 2228 || args_size.constant > (current_function_args_size 2229 - current_function_pretend_args_size) 2230 /* If the callee pops its own arguments, then it must pop exactly 2231 the same number of arguments as the current function. */ 2232 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant) 2233 != RETURN_POPS_ARGS (current_function_decl, 2234 TREE_TYPE (current_function_decl), 2235 current_function_args_size)) 2236 || !lang_hooks.decls.ok_for_sibcall (fndecl)) 2237 try_tail_call = 0; 2238 2239 /* Ensure current function's preferred stack boundary is at least 2240 what we need. We don't have to increase alignment for recursive 2241 functions. */ 2242 if (cfun->preferred_stack_boundary < preferred_stack_boundary 2243 && fndecl != current_function_decl) 2244 cfun->preferred_stack_boundary = preferred_stack_boundary; 2245 if (fndecl == current_function_decl) 2246 cfun->recursive_call_emit = true; 2247 2248 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT; 2249 2250 /* We want to make two insn chains; one for a sibling call, the other 2251 for a normal call. We will select one of the two chains after 2252 initial RTL generation is complete. */ 2253 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++) 2254 { 2255 int sibcall_failure = 0; 2256 /* We want to emit any pending stack adjustments before the tail 2257 recursion "call". That way we know any adjustment after the tail 2258 recursion call can be ignored if we indeed use the tail 2259 call expansion. */ 2260 int save_pending_stack_adjust = 0; 2261 int save_stack_pointer_delta = 0; 2262 rtx insns; 2263 rtx before_call, next_arg_reg; 2264 2265 if (pass == 0) 2266 { 2267 /* State variables we need to save and restore between 2268 iterations. */ 2269 save_pending_stack_adjust = pending_stack_adjust; 2270 save_stack_pointer_delta = stack_pointer_delta; 2271 } 2272 if (pass) 2273 flags &= ~ECF_SIBCALL; 2274 else 2275 flags |= ECF_SIBCALL; 2276 2277 /* Other state variables that we must reinitialize each time 2278 through the loop (that are not initialized by the loop itself). */ 2279 argblock = 0; 2280 call_fusage = 0; 2281 2282 /* Start a new sequence for the normal call case. 2283 2284 From this point on, if the sibling call fails, we want to set 2285 sibcall_failure instead of continuing the loop. */ 2286 start_sequence (); 2287 2288 /* Don't let pending stack adjusts add up to too much. 2289 Also, do all pending adjustments now if there is any chance 2290 this might be a call to alloca or if we are expanding a sibling 2291 call sequence or if we are calling a function that is to return 2292 with stack pointer depressed. 2293 Also do the adjustments before a throwing call, otherwise 2294 exception handling can fail; PR 19225. */ 2295 if (pending_stack_adjust >= 32 2296 || (pending_stack_adjust > 0 2297 && (flags & (ECF_MAY_BE_ALLOCA | ECF_SP_DEPRESSED))) 2298 || (pending_stack_adjust > 0 2299 && flag_exceptions && !(flags & ECF_NOTHROW)) 2300 || pass == 0) 2301 do_pending_stack_adjust (); 2302 2303 /* When calling a const function, we must pop the stack args right away, 2304 so that the pop is deleted or moved with the call. */ 2305 if (pass && (flags & ECF_LIBCALL_BLOCK)) 2306 NO_DEFER_POP; 2307 2308 /* Precompute any arguments as needed. */ 2309 if (pass) 2310 precompute_arguments (flags, num_actuals, args); 2311 2312 /* Now we are about to start emitting insns that can be deleted 2313 if a libcall is deleted. */ 2314 if (pass && (flags & (ECF_LIBCALL_BLOCK | ECF_MALLOC))) 2315 start_sequence (); 2316 2317 if (pass == 0 && cfun->stack_protect_guard) 2318 stack_protect_epilogue (); 2319 2320 adjusted_args_size = args_size; 2321 /* Compute the actual size of the argument block required. The variable 2322 and constant sizes must be combined, the size may have to be rounded, 2323 and there may be a minimum required size. When generating a sibcall 2324 pattern, do not round up, since we'll be re-using whatever space our 2325 caller provided. */ 2326 unadjusted_args_size 2327 = compute_argument_block_size (reg_parm_stack_space, 2328 &adjusted_args_size, 2329 (pass == 0 ? 0 2330 : preferred_stack_boundary)); 2331 2332 old_stack_allocated = stack_pointer_delta - pending_stack_adjust; 2333 2334 /* The argument block when performing a sibling call is the 2335 incoming argument block. */ 2336 if (pass == 0) 2337 { 2338 argblock = virtual_incoming_args_rtx; 2339 argblock 2340#ifdef STACK_GROWS_DOWNWARD 2341 = plus_constant (argblock, current_function_pretend_args_size); 2342#else 2343 = plus_constant (argblock, -current_function_pretend_args_size); 2344#endif 2345 stored_args_map = sbitmap_alloc (args_size.constant); 2346 sbitmap_zero (stored_args_map); 2347 } 2348 2349 /* If we have no actual push instructions, or shouldn't use them, 2350 make space for all args right now. */ 2351 else if (adjusted_args_size.var != 0) 2352 { 2353 if (old_stack_level == 0) 2354 { 2355 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX); 2356 old_stack_pointer_delta = stack_pointer_delta; 2357 old_pending_adj = pending_stack_adjust; 2358 pending_stack_adjust = 0; 2359 /* stack_arg_under_construction says whether a stack arg is 2360 being constructed at the old stack level. Pushing the stack 2361 gets a clean outgoing argument block. */ 2362 old_stack_arg_under_construction = stack_arg_under_construction; 2363 stack_arg_under_construction = 0; 2364 } 2365 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0); 2366 } 2367 else 2368 { 2369 /* Note that we must go through the motions of allocating an argument 2370 block even if the size is zero because we may be storing args 2371 in the area reserved for register arguments, which may be part of 2372 the stack frame. */ 2373 2374 int needed = adjusted_args_size.constant; 2375 2376 /* Store the maximum argument space used. It will be pushed by 2377 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow 2378 checking). */ 2379 2380 if (needed > current_function_outgoing_args_size) 2381 current_function_outgoing_args_size = needed; 2382 2383 if (must_preallocate) 2384 { 2385 if (ACCUMULATE_OUTGOING_ARGS) 2386 { 2387 /* Since the stack pointer will never be pushed, it is 2388 possible for the evaluation of a parm to clobber 2389 something we have already written to the stack. 2390 Since most function calls on RISC machines do not use 2391 the stack, this is uncommon, but must work correctly. 2392 2393 Therefore, we save any area of the stack that was already 2394 written and that we are using. Here we set up to do this 2395 by making a new stack usage map from the old one. The 2396 actual save will be done by store_one_arg. 2397 2398 Another approach might be to try to reorder the argument 2399 evaluations to avoid this conflicting stack usage. */ 2400 2401#ifndef OUTGOING_REG_PARM_STACK_SPACE 2402 /* Since we will be writing into the entire argument area, 2403 the map must be allocated for its entire size, not just 2404 the part that is the responsibility of the caller. */ 2405 needed += reg_parm_stack_space; 2406#endif 2407 2408#ifdef ARGS_GROW_DOWNWARD 2409 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, 2410 needed + 1); 2411#else 2412 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, 2413 needed); 2414#endif 2415 if (stack_usage_map_buf) 2416 free (stack_usage_map_buf); 2417 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use); 2418 stack_usage_map = stack_usage_map_buf; 2419 2420 if (initial_highest_arg_in_use) 2421 memcpy (stack_usage_map, initial_stack_usage_map, 2422 initial_highest_arg_in_use); 2423 2424 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use) 2425 memset (&stack_usage_map[initial_highest_arg_in_use], 0, 2426 (highest_outgoing_arg_in_use 2427 - initial_highest_arg_in_use)); 2428 needed = 0; 2429 2430 /* The address of the outgoing argument list must not be 2431 copied to a register here, because argblock would be left 2432 pointing to the wrong place after the call to 2433 allocate_dynamic_stack_space below. */ 2434 2435 argblock = virtual_outgoing_args_rtx; 2436 } 2437 else 2438 { 2439 if (inhibit_defer_pop == 0) 2440 { 2441 /* Try to reuse some or all of the pending_stack_adjust 2442 to get this space. */ 2443 needed 2444 = (combine_pending_stack_adjustment_and_call 2445 (unadjusted_args_size, 2446 &adjusted_args_size, 2447 preferred_unit_stack_boundary)); 2448 2449 /* combine_pending_stack_adjustment_and_call computes 2450 an adjustment before the arguments are allocated. 2451 Account for them and see whether or not the stack 2452 needs to go up or down. */ 2453 needed = unadjusted_args_size - needed; 2454 2455 if (needed < 0) 2456 { 2457 /* We're releasing stack space. */ 2458 /* ??? We can avoid any adjustment at all if we're 2459 already aligned. FIXME. */ 2460 pending_stack_adjust = -needed; 2461 do_pending_stack_adjust (); 2462 needed = 0; 2463 } 2464 else 2465 /* We need to allocate space. We'll do that in 2466 push_block below. */ 2467 pending_stack_adjust = 0; 2468 } 2469 2470 /* Special case this because overhead of `push_block' in 2471 this case is non-trivial. */ 2472 if (needed == 0) 2473 argblock = virtual_outgoing_args_rtx; 2474 else 2475 { 2476 argblock = push_block (GEN_INT (needed), 0, 0); 2477#ifdef ARGS_GROW_DOWNWARD 2478 argblock = plus_constant (argblock, needed); 2479#endif 2480 } 2481 2482 /* We only really need to call `copy_to_reg' in the case 2483 where push insns are going to be used to pass ARGBLOCK 2484 to a function call in ARGS. In that case, the stack 2485 pointer changes value from the allocation point to the 2486 call point, and hence the value of 2487 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might 2488 as well always do it. */ 2489 argblock = copy_to_reg (argblock); 2490 } 2491 } 2492 } 2493 2494 if (ACCUMULATE_OUTGOING_ARGS) 2495 { 2496 /* The save/restore code in store_one_arg handles all 2497 cases except one: a constructor call (including a C 2498 function returning a BLKmode struct) to initialize 2499 an argument. */ 2500 if (stack_arg_under_construction) 2501 { 2502#ifndef OUTGOING_REG_PARM_STACK_SPACE 2503 rtx push_size = GEN_INT (reg_parm_stack_space 2504 + adjusted_args_size.constant); 2505#else 2506 rtx push_size = GEN_INT (adjusted_args_size.constant); 2507#endif 2508 if (old_stack_level == 0) 2509 { 2510 emit_stack_save (SAVE_BLOCK, &old_stack_level, 2511 NULL_RTX); 2512 old_stack_pointer_delta = stack_pointer_delta; 2513 old_pending_adj = pending_stack_adjust; 2514 pending_stack_adjust = 0; 2515 /* stack_arg_under_construction says whether a stack 2516 arg is being constructed at the old stack level. 2517 Pushing the stack gets a clean outgoing argument 2518 block. */ 2519 old_stack_arg_under_construction 2520 = stack_arg_under_construction; 2521 stack_arg_under_construction = 0; 2522 /* Make a new map for the new argument list. */ 2523 if (stack_usage_map_buf) 2524 free (stack_usage_map_buf); 2525 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use); 2526 stack_usage_map = stack_usage_map_buf; 2527 memset (stack_usage_map, 0, highest_outgoing_arg_in_use); 2528 highest_outgoing_arg_in_use = 0; 2529 } 2530 allocate_dynamic_stack_space (push_size, NULL_RTX, 2531 BITS_PER_UNIT); 2532 } 2533 2534 /* If argument evaluation might modify the stack pointer, 2535 copy the address of the argument list to a register. */ 2536 for (i = 0; i < num_actuals; i++) 2537 if (args[i].pass_on_stack) 2538 { 2539 argblock = copy_addr_to_reg (argblock); 2540 break; 2541 } 2542 } 2543 2544 compute_argument_addresses (args, argblock, num_actuals); 2545 2546 /* If we push args individually in reverse order, perform stack alignment 2547 before the first push (the last arg). */ 2548 if (PUSH_ARGS_REVERSED && argblock == 0 2549 && adjusted_args_size.constant != unadjusted_args_size) 2550 { 2551 /* When the stack adjustment is pending, we get better code 2552 by combining the adjustments. */ 2553 if (pending_stack_adjust 2554 && ! (flags & ECF_LIBCALL_BLOCK) 2555 && ! inhibit_defer_pop) 2556 { 2557 pending_stack_adjust 2558 = (combine_pending_stack_adjustment_and_call 2559 (unadjusted_args_size, 2560 &adjusted_args_size, 2561 preferred_unit_stack_boundary)); 2562 do_pending_stack_adjust (); 2563 } 2564 else if (argblock == 0) 2565 anti_adjust_stack (GEN_INT (adjusted_args_size.constant 2566 - unadjusted_args_size)); 2567 } 2568 /* Now that the stack is properly aligned, pops can't safely 2569 be deferred during the evaluation of the arguments. */ 2570 NO_DEFER_POP; 2571 2572 funexp = rtx_for_function_call (fndecl, addr); 2573 2574 /* Figure out the register where the value, if any, will come back. */ 2575 valreg = 0; 2576 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode 2577 && ! structure_value_addr) 2578 { 2579 if (pcc_struct_value) 2580 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)), 2581 fndecl, NULL, (pass == 0)); 2582 else 2583 valreg = hard_function_value (TREE_TYPE (exp), fndecl, fntype, 2584 (pass == 0)); 2585 } 2586 2587 /* Precompute all register parameters. It isn't safe to compute anything 2588 once we have started filling any specific hard regs. */ 2589 precompute_register_parameters (num_actuals, args, ®_parm_seen); 2590 2591 if (TREE_OPERAND (exp, 2)) 2592 static_chain_value = expand_normal (TREE_OPERAND (exp, 2)); 2593 else 2594 static_chain_value = 0; 2595 2596#ifdef REG_PARM_STACK_SPACE 2597 /* Save the fixed argument area if it's part of the caller's frame and 2598 is clobbered by argument setup for this call. */ 2599 if (ACCUMULATE_OUTGOING_ARGS && pass) 2600 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock, 2601 &low_to_save, &high_to_save); 2602#endif 2603 2604 /* Now store (and compute if necessary) all non-register parms. 2605 These come before register parms, since they can require block-moves, 2606 which could clobber the registers used for register parms. 2607 Parms which have partial registers are not stored here, 2608 but we do preallocate space here if they want that. */ 2609 2610 for (i = 0; i < num_actuals; i++) 2611 if (args[i].reg == 0 || args[i].pass_on_stack) 2612 { 2613 rtx before_arg = get_last_insn (); 2614 2615 if (store_one_arg (&args[i], argblock, flags, 2616 adjusted_args_size.var != 0, 2617 reg_parm_stack_space) 2618 || (pass == 0 2619 && check_sibcall_argument_overlap (before_arg, 2620 &args[i], 1))) 2621 sibcall_failure = 1; 2622 2623 if (flags & ECF_CONST 2624 && args[i].stack 2625 && args[i].value == args[i].stack) 2626 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, 2627 gen_rtx_USE (VOIDmode, 2628 args[i].value), 2629 call_fusage); 2630 } 2631 2632 /* If we have a parm that is passed in registers but not in memory 2633 and whose alignment does not permit a direct copy into registers, 2634 make a group of pseudos that correspond to each register that we 2635 will later fill. */ 2636 if (STRICT_ALIGNMENT) 2637 store_unaligned_arguments_into_pseudos (args, num_actuals); 2638 2639 /* Now store any partially-in-registers parm. 2640 This is the last place a block-move can happen. */ 2641 if (reg_parm_seen) 2642 for (i = 0; i < num_actuals; i++) 2643 if (args[i].partial != 0 && ! args[i].pass_on_stack) 2644 { 2645 rtx before_arg = get_last_insn (); 2646 2647 if (store_one_arg (&args[i], argblock, flags, 2648 adjusted_args_size.var != 0, 2649 reg_parm_stack_space) 2650 || (pass == 0 2651 && check_sibcall_argument_overlap (before_arg, 2652 &args[i], 1))) 2653 sibcall_failure = 1; 2654 } 2655 2656 /* If we pushed args in forward order, perform stack alignment 2657 after pushing the last arg. */ 2658 if (!PUSH_ARGS_REVERSED && argblock == 0) 2659 anti_adjust_stack (GEN_INT (adjusted_args_size.constant 2660 - unadjusted_args_size)); 2661 2662 /* If register arguments require space on the stack and stack space 2663 was not preallocated, allocate stack space here for arguments 2664 passed in registers. */ 2665#ifdef OUTGOING_REG_PARM_STACK_SPACE 2666 if (!ACCUMULATE_OUTGOING_ARGS 2667 && must_preallocate == 0 && reg_parm_stack_space > 0) 2668 anti_adjust_stack (GEN_INT (reg_parm_stack_space)); 2669#endif 2670 2671 /* Pass the function the address in which to return a 2672 structure value. */ 2673 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm) 2674 { 2675 structure_value_addr 2676 = convert_memory_address (Pmode, structure_value_addr); 2677 emit_move_insn (struct_value, 2678 force_reg (Pmode, 2679 force_operand (structure_value_addr, 2680 NULL_RTX))); 2681 2682 if (REG_P (struct_value)) 2683 use_reg (&call_fusage, struct_value); 2684 } 2685 2686 funexp = prepare_call_address (funexp, static_chain_value, 2687 &call_fusage, reg_parm_seen, pass == 0); 2688 2689 load_register_parameters (args, num_actuals, &call_fusage, flags, 2690 pass == 0, &sibcall_failure); 2691 2692 /* Save a pointer to the last insn before the call, so that we can 2693 later safely search backwards to find the CALL_INSN. */ 2694 before_call = get_last_insn (); 2695 2696 /* Set up next argument register. For sibling calls on machines 2697 with register windows this should be the incoming register. */ 2698#ifdef FUNCTION_INCOMING_ARG 2699 if (pass == 0) 2700 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode, 2701 void_type_node, 1); 2702 else 2703#endif 2704 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode, 2705 void_type_node, 1); 2706 2707 /* All arguments and registers used for the call must be set up by 2708 now! */ 2709 2710 /* Stack must be properly aligned now. */ 2711 gcc_assert (!pass 2712 || !(stack_pointer_delta % preferred_unit_stack_boundary)); 2713 2714 /* Generate the actual call instruction. */ 2715 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size, 2716 adjusted_args_size.constant, struct_value_size, 2717 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage, 2718 flags, & args_so_far); 2719 2720 /* If a non-BLKmode value is returned at the most significant end 2721 of a register, shift the register right by the appropriate amount 2722 and update VALREG accordingly. BLKmode values are handled by the 2723 group load/store machinery below. */ 2724 if (!structure_value_addr 2725 && !pcc_struct_value 2726 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode 2727 && targetm.calls.return_in_msb (TREE_TYPE (exp))) 2728 { 2729 if (shift_return_value (TYPE_MODE (TREE_TYPE (exp)), false, valreg)) 2730 sibcall_failure = 1; 2731 valreg = gen_rtx_REG (TYPE_MODE (TREE_TYPE (exp)), REGNO (valreg)); 2732 } 2733 2734 /* If call is cse'able, make appropriate pair of reg-notes around it. 2735 Test valreg so we don't crash; may safely ignore `const' 2736 if return type is void. Disable for PARALLEL return values, because 2737 we have no way to move such values into a pseudo register. */ 2738 if (pass && (flags & ECF_LIBCALL_BLOCK)) 2739 { 2740 rtx insns; 2741 rtx insn; 2742 bool failed = valreg == 0 || GET_CODE (valreg) == PARALLEL; 2743 2744 insns = get_insns (); 2745 2746 /* Expansion of block moves possibly introduced a loop that may 2747 not appear inside libcall block. */ 2748 for (insn = insns; insn; insn = NEXT_INSN (insn)) 2749 if (JUMP_P (insn)) 2750 failed = true; 2751 2752 if (failed) 2753 { 2754 end_sequence (); 2755 emit_insn (insns); 2756 } 2757 else 2758 { 2759 rtx note = 0; 2760 rtx temp = gen_reg_rtx (GET_MODE (valreg)); 2761 2762 /* Mark the return value as a pointer if needed. */ 2763 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE) 2764 mark_reg_pointer (temp, 2765 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp)))); 2766 2767 end_sequence (); 2768 if (flag_unsafe_math_optimizations 2769 && fndecl 2770 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL 2771 && (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRT 2772 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRTF 2773 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRTL)) 2774 note = gen_rtx_fmt_e (SQRT, 2775 GET_MODE (temp), 2776 args[0].initial_value); 2777 else 2778 { 2779 /* Construct an "equal form" for the value which 2780 mentions all the arguments in order as well as 2781 the function name. */ 2782 for (i = 0; i < num_actuals; i++) 2783 note = gen_rtx_EXPR_LIST (VOIDmode, 2784 args[i].initial_value, note); 2785 note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note); 2786 2787 if (flags & ECF_PURE) 2788 note = gen_rtx_EXPR_LIST (VOIDmode, 2789 gen_rtx_USE (VOIDmode, 2790 gen_rtx_MEM (BLKmode, 2791 gen_rtx_SCRATCH (VOIDmode))), 2792 note); 2793 } 2794 emit_libcall_block (insns, temp, valreg, note); 2795 2796 valreg = temp; 2797 } 2798 } 2799 else if (pass && (flags & ECF_MALLOC)) 2800 { 2801 rtx temp = gen_reg_rtx (GET_MODE (valreg)); 2802 rtx last, insns; 2803 2804 /* The return value from a malloc-like function is a pointer. */ 2805 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE) 2806 mark_reg_pointer (temp, BIGGEST_ALIGNMENT); 2807 2808 emit_move_insn (temp, valreg); 2809 2810 /* The return value from a malloc-like function can not alias 2811 anything else. */ 2812 last = get_last_insn (); 2813 REG_NOTES (last) = 2814 gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last)); 2815 2816 /* Write out the sequence. */ 2817 insns = get_insns (); 2818 end_sequence (); 2819 emit_insn (insns); 2820 valreg = temp; 2821 } 2822 2823 /* For calls to `setjmp', etc., inform flow.c it should complain 2824 if nonvolatile values are live. For functions that cannot return, 2825 inform flow that control does not fall through. */ 2826 2827 if ((flags & ECF_NORETURN) || pass == 0) 2828 { 2829 /* The barrier must be emitted 2830 immediately after the CALL_INSN. Some ports emit more 2831 than just a CALL_INSN above, so we must search for it here. */ 2832 2833 rtx last = get_last_insn (); 2834 while (!CALL_P (last)) 2835 { 2836 last = PREV_INSN (last); 2837 /* There was no CALL_INSN? */ 2838 gcc_assert (last != before_call); 2839 } 2840 2841 emit_barrier_after (last); 2842 2843 /* Stack adjustments after a noreturn call are dead code. 2844 However when NO_DEFER_POP is in effect, we must preserve 2845 stack_pointer_delta. */ 2846 if (inhibit_defer_pop == 0) 2847 { 2848 stack_pointer_delta = old_stack_allocated; 2849 pending_stack_adjust = 0; 2850 } 2851 } 2852 2853 /* If value type not void, return an rtx for the value. */ 2854 2855 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode 2856 || ignore) 2857 target = const0_rtx; 2858 else if (structure_value_addr) 2859 { 2860 if (target == 0 || !MEM_P (target)) 2861 { 2862 target 2863 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), 2864 memory_address (TYPE_MODE (TREE_TYPE (exp)), 2865 structure_value_addr)); 2866 set_mem_attributes (target, exp, 1); 2867 } 2868 } 2869 else if (pcc_struct_value) 2870 { 2871 /* This is the special C++ case where we need to 2872 know what the true target was. We take care to 2873 never use this value more than once in one expression. */ 2874 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), 2875 copy_to_reg (valreg)); 2876 set_mem_attributes (target, exp, 1); 2877 } 2878 /* Handle calls that return values in multiple non-contiguous locations. 2879 The Irix 6 ABI has examples of this. */ 2880 else if (GET_CODE (valreg) == PARALLEL) 2881 { 2882 if (target == 0) 2883 { 2884 /* This will only be assigned once, so it can be readonly. */ 2885 tree nt = build_qualified_type (TREE_TYPE (exp), 2886 (TYPE_QUALS (TREE_TYPE (exp)) 2887 | TYPE_QUAL_CONST)); 2888 2889 target = assign_temp (nt, 0, 1, 1); 2890 } 2891 2892 if (! rtx_equal_p (target, valreg)) 2893 emit_group_store (target, valreg, TREE_TYPE (exp), 2894 int_size_in_bytes (TREE_TYPE (exp))); 2895 2896 /* We can not support sibling calls for this case. */ 2897 sibcall_failure = 1; 2898 } 2899 else if (target 2900 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp)) 2901 && GET_MODE (target) == GET_MODE (valreg)) 2902 { 2903 bool may_overlap = false; 2904 2905 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard 2906 reg to a plain register. */ 2907 if (REG_P (valreg) 2908 && HARD_REGISTER_P (valreg) 2909 && CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (REGNO (valreg))) 2910 && !(REG_P (target) && !HARD_REGISTER_P (target))) 2911 valreg = copy_to_reg (valreg); 2912 2913 /* If TARGET is a MEM in the argument area, and we have 2914 saved part of the argument area, then we can't store 2915 directly into TARGET as it may get overwritten when we 2916 restore the argument save area below. Don't work too 2917 hard though and simply force TARGET to a register if it 2918 is a MEM; the optimizer is quite likely to sort it out. */ 2919 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target)) 2920 for (i = 0; i < num_actuals; i++) 2921 if (args[i].save_area) 2922 { 2923 may_overlap = true; 2924 break; 2925 } 2926 2927 if (may_overlap) 2928 target = copy_to_reg (valreg); 2929 else 2930 { 2931 /* TARGET and VALREG cannot be equal at this point 2932 because the latter would not have 2933 REG_FUNCTION_VALUE_P true, while the former would if 2934 it were referring to the same register. 2935 2936 If they refer to the same register, this move will be 2937 a no-op, except when function inlining is being 2938 done. */ 2939 emit_move_insn (target, valreg); 2940 2941 /* If we are setting a MEM, this code must be executed. 2942 Since it is emitted after the call insn, sibcall 2943 optimization cannot be performed in that case. */ 2944 if (MEM_P (target)) 2945 sibcall_failure = 1; 2946 } 2947 } 2948 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode) 2949 { 2950 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp)); 2951 2952 /* We can not support sibling calls for this case. */ 2953 sibcall_failure = 1; 2954 } 2955 else 2956 target = copy_to_reg (valreg); 2957 2958 if (targetm.calls.promote_function_return(funtype)) 2959 { 2960 /* If we promoted this return value, make the proper SUBREG. 2961 TARGET might be const0_rtx here, so be careful. */ 2962 if (REG_P (target) 2963 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode 2964 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp))) 2965 { 2966 tree type = TREE_TYPE (exp); 2967 int unsignedp = TYPE_UNSIGNED (type); 2968 int offset = 0; 2969 enum machine_mode pmode; 2970 2971 pmode = promote_mode (type, TYPE_MODE (type), &unsignedp, 1); 2972 /* If we don't promote as expected, something is wrong. */ 2973 gcc_assert (GET_MODE (target) == pmode); 2974 2975 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN) 2976 && (GET_MODE_SIZE (GET_MODE (target)) 2977 > GET_MODE_SIZE (TYPE_MODE (type)))) 2978 { 2979 offset = GET_MODE_SIZE (GET_MODE (target)) 2980 - GET_MODE_SIZE (TYPE_MODE (type)); 2981 if (! BYTES_BIG_ENDIAN) 2982 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD; 2983 else if (! WORDS_BIG_ENDIAN) 2984 offset %= UNITS_PER_WORD; 2985 } 2986 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset); 2987 SUBREG_PROMOTED_VAR_P (target) = 1; 2988 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp); 2989 } 2990 } 2991 2992 /* If size of args is variable or this was a constructor call for a stack 2993 argument, restore saved stack-pointer value. */ 2994 2995 if (old_stack_level && ! (flags & ECF_SP_DEPRESSED)) 2996 { 2997 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX); 2998 stack_pointer_delta = old_stack_pointer_delta; 2999 pending_stack_adjust = old_pending_adj; 3000 old_stack_allocated = stack_pointer_delta - pending_stack_adjust; 3001 stack_arg_under_construction = old_stack_arg_under_construction; 3002 highest_outgoing_arg_in_use = initial_highest_arg_in_use; 3003 stack_usage_map = initial_stack_usage_map; 3004 sibcall_failure = 1; 3005 } 3006 else if (ACCUMULATE_OUTGOING_ARGS && pass) 3007 { 3008#ifdef REG_PARM_STACK_SPACE 3009 if (save_area) 3010 restore_fixed_argument_area (save_area, argblock, 3011 high_to_save, low_to_save); 3012#endif 3013 3014 /* If we saved any argument areas, restore them. */ 3015 for (i = 0; i < num_actuals; i++) 3016 if (args[i].save_area) 3017 { 3018 enum machine_mode save_mode = GET_MODE (args[i].save_area); 3019 rtx stack_area 3020 = gen_rtx_MEM (save_mode, 3021 memory_address (save_mode, 3022 XEXP (args[i].stack_slot, 0))); 3023 3024 if (save_mode != BLKmode) 3025 emit_move_insn (stack_area, args[i].save_area); 3026 else 3027 emit_block_move (stack_area, args[i].save_area, 3028 GEN_INT (args[i].locate.size.constant), 3029 BLOCK_OP_CALL_PARM); 3030 } 3031 3032 highest_outgoing_arg_in_use = initial_highest_arg_in_use; 3033 stack_usage_map = initial_stack_usage_map; 3034 } 3035 3036 /* If this was alloca, record the new stack level for nonlocal gotos. 3037 Check for the handler slots since we might not have a save area 3038 for non-local gotos. */ 3039 3040 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0) 3041 update_nonlocal_goto_save_area (); 3042 3043 /* Free up storage we no longer need. */ 3044 for (i = 0; i < num_actuals; ++i) 3045 if (args[i].aligned_regs) 3046 free (args[i].aligned_regs); 3047 3048 insns = get_insns (); 3049 end_sequence (); 3050 3051 if (pass == 0) 3052 { 3053 tail_call_insns = insns; 3054 3055 /* Restore the pending stack adjustment now that we have 3056 finished generating the sibling call sequence. */ 3057 3058 pending_stack_adjust = save_pending_stack_adjust; 3059 stack_pointer_delta = save_stack_pointer_delta; 3060 3061 /* Prepare arg structure for next iteration. */ 3062 for (i = 0; i < num_actuals; i++) 3063 { 3064 args[i].value = 0; 3065 args[i].aligned_regs = 0; 3066 args[i].stack = 0; 3067 } 3068 3069 sbitmap_free (stored_args_map); 3070 } 3071 else 3072 { 3073 normal_call_insns = insns; 3074 3075 /* Verify that we've deallocated all the stack we used. */ 3076 gcc_assert ((flags & ECF_NORETURN) 3077 || (old_stack_allocated 3078 == stack_pointer_delta - pending_stack_adjust)); 3079 } 3080 3081 /* If something prevents making this a sibling call, 3082 zero out the sequence. */ 3083 if (sibcall_failure) 3084 tail_call_insns = NULL_RTX; 3085 else 3086 break; 3087 } 3088 3089 /* If tail call production succeeded, we need to remove REG_EQUIV notes on 3090 arguments too, as argument area is now clobbered by the call. */ 3091 if (tail_call_insns) 3092 { 3093 emit_insn (tail_call_insns); 3094 cfun->tail_call_emit = true; 3095 } 3096 else 3097 emit_insn (normal_call_insns); 3098 3099 currently_expanding_call--; 3100 3101 /* If this function returns with the stack pointer depressed, ensure 3102 this block saves and restores the stack pointer, show it was 3103 changed, and adjust for any outgoing arg space. */ 3104 if (flags & ECF_SP_DEPRESSED) 3105 { 3106 clear_pending_stack_adjust (); 3107 emit_insn (gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx)); 3108 emit_move_insn (virtual_stack_dynamic_rtx, stack_pointer_rtx); 3109 } 3110 3111 if (stack_usage_map_buf) 3112 free (stack_usage_map_buf); 3113 3114 return target; 3115} 3116 3117/* A sibling call sequence invalidates any REG_EQUIV notes made for 3118 this function's incoming arguments. 3119 3120 At the start of RTL generation we know the only REG_EQUIV notes 3121 in the rtl chain are those for incoming arguments, so we can look 3122 for REG_EQUIV notes between the start of the function and the 3123 NOTE_INSN_FUNCTION_BEG. 3124 3125 This is (slight) overkill. We could keep track of the highest 3126 argument we clobber and be more selective in removing notes, but it 3127 does not seem to be worth the effort. */ 3128 3129void 3130fixup_tail_calls (void) 3131{ 3132 rtx insn; 3133 3134 for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) 3135 { 3136 /* There are never REG_EQUIV notes for the incoming arguments 3137 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */ 3138 if (NOTE_P (insn) 3139 && NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG) 3140 break; 3141 3142 while (1) 3143 { 3144 rtx note = find_reg_note (insn, REG_EQUIV, 0); 3145 if (note) 3146 { 3147 /* Remove the note and keep looking at the notes for 3148 this insn. */ 3149 remove_note (insn, note); 3150 continue; 3151 } 3152 break; 3153 } 3154 } 3155} 3156 3157/* Traverse an argument list in VALUES and expand all complex 3158 arguments into their components. */ 3159static tree 3160split_complex_values (tree values) 3161{ 3162 tree p; 3163 3164 /* Before allocating memory, check for the common case of no complex. */ 3165 for (p = values; p; p = TREE_CHAIN (p)) 3166 { 3167 tree type = TREE_TYPE (TREE_VALUE (p)); 3168 if (type && TREE_CODE (type) == COMPLEX_TYPE 3169 && targetm.calls.split_complex_arg (type)) 3170 goto found; 3171 } 3172 return values; 3173 3174 found: 3175 values = copy_list (values); 3176 3177 for (p = values; p; p = TREE_CHAIN (p)) 3178 { 3179 tree complex_value = TREE_VALUE (p); 3180 tree complex_type; 3181 3182 complex_type = TREE_TYPE (complex_value); 3183 if (!complex_type) 3184 continue; 3185 3186 if (TREE_CODE (complex_type) == COMPLEX_TYPE 3187 && targetm.calls.split_complex_arg (complex_type)) 3188 { 3189 tree subtype; 3190 tree real, imag, next; 3191 3192 subtype = TREE_TYPE (complex_type); 3193 complex_value = save_expr (complex_value); 3194 real = build1 (REALPART_EXPR, subtype, complex_value); 3195 imag = build1 (IMAGPART_EXPR, subtype, complex_value); 3196 3197 TREE_VALUE (p) = real; 3198 next = TREE_CHAIN (p); 3199 imag = build_tree_list (NULL_TREE, imag); 3200 TREE_CHAIN (p) = imag; 3201 TREE_CHAIN (imag) = next; 3202 3203 /* Skip the newly created node. */ 3204 p = TREE_CHAIN (p); 3205 } 3206 } 3207 3208 return values; 3209} 3210 3211/* Traverse a list of TYPES and expand all complex types into their 3212 components. */ 3213static tree 3214split_complex_types (tree types) 3215{ 3216 tree p; 3217 3218 /* Before allocating memory, check for the common case of no complex. */ 3219 for (p = types; p; p = TREE_CHAIN (p)) 3220 { 3221 tree type = TREE_VALUE (p); 3222 if (TREE_CODE (type) == COMPLEX_TYPE 3223 && targetm.calls.split_complex_arg (type)) 3224 goto found; 3225 } 3226 return types; 3227 3228 found: 3229 types = copy_list (types); 3230 3231 for (p = types; p; p = TREE_CHAIN (p)) 3232 { 3233 tree complex_type = TREE_VALUE (p); 3234 3235 if (TREE_CODE (complex_type) == COMPLEX_TYPE 3236 && targetm.calls.split_complex_arg (complex_type)) 3237 { 3238 tree next, imag; 3239 3240 /* Rewrite complex type with component type. */ 3241 TREE_VALUE (p) = TREE_TYPE (complex_type); 3242 next = TREE_CHAIN (p); 3243 3244 /* Add another component type for the imaginary part. */ 3245 imag = build_tree_list (NULL_TREE, TREE_VALUE (p)); 3246 TREE_CHAIN (p) = imag; 3247 TREE_CHAIN (imag) = next; 3248 3249 /* Skip the newly created node. */ 3250 p = TREE_CHAIN (p); 3251 } 3252 } 3253 3254 return types; 3255} 3256 3257/* Output a library call to function FUN (a SYMBOL_REF rtx). 3258 The RETVAL parameter specifies whether return value needs to be saved, other 3259 parameters are documented in the emit_library_call function below. */ 3260 3261static rtx 3262emit_library_call_value_1 (int retval, rtx orgfun, rtx value, 3263 enum libcall_type fn_type, 3264 enum machine_mode outmode, int nargs, va_list p) 3265{ 3266 /* Total size in bytes of all the stack-parms scanned so far. */ 3267 struct args_size args_size; 3268 /* Size of arguments before any adjustments (such as rounding). */ 3269 struct args_size original_args_size; 3270 int argnum; 3271 rtx fun; 3272 int inc; 3273 int count; 3274 rtx argblock = 0; 3275 CUMULATIVE_ARGS args_so_far; 3276 struct arg 3277 { 3278 rtx value; 3279 enum machine_mode mode; 3280 rtx reg; 3281 int partial; 3282 struct locate_and_pad_arg_data locate; 3283 rtx save_area; 3284 }; 3285 struct arg *argvec; 3286 int old_inhibit_defer_pop = inhibit_defer_pop; 3287 rtx call_fusage = 0; 3288 rtx mem_value = 0; 3289 rtx valreg; 3290 int pcc_struct_value = 0; 3291 int struct_value_size = 0; 3292 int flags; 3293 int reg_parm_stack_space = 0; 3294 int needed; 3295 rtx before_call; 3296 tree tfom; /* type_for_mode (outmode, 0) */ 3297 3298#ifdef REG_PARM_STACK_SPACE 3299 /* Define the boundary of the register parm stack space that needs to be 3300 save, if any. */ 3301 int low_to_save, high_to_save; 3302 rtx save_area = 0; /* Place that it is saved. */ 3303#endif 3304 3305 /* Size of the stack reserved for parameter registers. */ 3306 int initial_highest_arg_in_use = highest_outgoing_arg_in_use; 3307 char *initial_stack_usage_map = stack_usage_map; 3308 char *stack_usage_map_buf = NULL; 3309 3310 rtx struct_value = targetm.calls.struct_value_rtx (0, 0); 3311 3312#ifdef REG_PARM_STACK_SPACE 3313 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0); 3314#endif 3315 3316 /* By default, library functions can not throw. */ 3317 flags = ECF_NOTHROW; 3318 3319 switch (fn_type) 3320 { 3321 case LCT_NORMAL: 3322 break; 3323 case LCT_CONST: 3324 flags |= ECF_CONST; 3325 break; 3326 case LCT_PURE: 3327 flags |= ECF_PURE; 3328 break; 3329 case LCT_CONST_MAKE_BLOCK: 3330 flags |= ECF_CONST | ECF_LIBCALL_BLOCK; 3331 break; 3332 case LCT_PURE_MAKE_BLOCK: 3333 flags |= ECF_PURE | ECF_LIBCALL_BLOCK; 3334 break; 3335 case LCT_NORETURN: 3336 flags |= ECF_NORETURN; 3337 break; 3338 case LCT_THROW: 3339 flags = ECF_NORETURN; 3340 break; 3341 case LCT_RETURNS_TWICE: 3342 flags = ECF_RETURNS_TWICE; 3343 break; 3344 } 3345 fun = orgfun; 3346 3347 /* Ensure current function's preferred stack boundary is at least 3348 what we need. */ 3349 if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY) 3350 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY; 3351 3352 /* If this kind of value comes back in memory, 3353 decide where in memory it should come back. */ 3354 if (outmode != VOIDmode) 3355 { 3356 tfom = lang_hooks.types.type_for_mode (outmode, 0); 3357 if (aggregate_value_p (tfom, 0)) 3358 { 3359#ifdef PCC_STATIC_STRUCT_RETURN 3360 rtx pointer_reg 3361 = hard_function_value (build_pointer_type (tfom), 0, 0, 0); 3362 mem_value = gen_rtx_MEM (outmode, pointer_reg); 3363 pcc_struct_value = 1; 3364 if (value == 0) 3365 value = gen_reg_rtx (outmode); 3366#else /* not PCC_STATIC_STRUCT_RETURN */ 3367 struct_value_size = GET_MODE_SIZE (outmode); 3368 if (value != 0 && MEM_P (value)) 3369 mem_value = value; 3370 else 3371 mem_value = assign_temp (tfom, 0, 1, 1); 3372#endif 3373 /* This call returns a big structure. */ 3374 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK); 3375 } 3376 } 3377 else 3378 tfom = void_type_node; 3379 3380 /* ??? Unfinished: must pass the memory address as an argument. */ 3381 3382 /* Copy all the libcall-arguments out of the varargs data 3383 and into a vector ARGVEC. 3384 3385 Compute how to pass each argument. We only support a very small subset 3386 of the full argument passing conventions to limit complexity here since 3387 library functions shouldn't have many args. */ 3388 3389 argvec = alloca ((nargs + 1) * sizeof (struct arg)); 3390 memset (argvec, 0, (nargs + 1) * sizeof (struct arg)); 3391 3392#ifdef INIT_CUMULATIVE_LIBCALL_ARGS 3393 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun); 3394#else 3395 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0, nargs); 3396#endif 3397 3398 args_size.constant = 0; 3399 args_size.var = 0; 3400 3401 count = 0; 3402 3403 /* Now we are about to start emitting insns that can be deleted 3404 if a libcall is deleted. */ 3405 if (flags & ECF_LIBCALL_BLOCK) 3406 start_sequence (); 3407 3408 push_temp_slots (); 3409 3410 /* If there's a structure value address to be passed, 3411 either pass it in the special place, or pass it as an extra argument. */ 3412 if (mem_value && struct_value == 0 && ! pcc_struct_value) 3413 { 3414 rtx addr = XEXP (mem_value, 0); 3415 3416 nargs++; 3417 3418 /* Make sure it is a reasonable operand for a move or push insn. */ 3419 if (!REG_P (addr) && !MEM_P (addr) 3420 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr))) 3421 addr = force_operand (addr, NULL_RTX); 3422 3423 argvec[count].value = addr; 3424 argvec[count].mode = Pmode; 3425 argvec[count].partial = 0; 3426 3427 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1); 3428 gcc_assert (targetm.calls.arg_partial_bytes (&args_so_far, Pmode, 3429 NULL_TREE, 1) == 0); 3430 3431 locate_and_pad_parm (Pmode, NULL_TREE, 3432#ifdef STACK_PARMS_IN_REG_PARM_AREA 3433 1, 3434#else 3435 argvec[count].reg != 0, 3436#endif 3437 0, NULL_TREE, &args_size, &argvec[count].locate); 3438 3439 if (argvec[count].reg == 0 || argvec[count].partial != 0 3440 || reg_parm_stack_space > 0) 3441 args_size.constant += argvec[count].locate.size.constant; 3442 3443 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1); 3444 3445 count++; 3446 } 3447 3448 for (; count < nargs; count++) 3449 { 3450 rtx val = va_arg (p, rtx); 3451 enum machine_mode mode = va_arg (p, enum machine_mode); 3452 3453 /* We cannot convert the arg value to the mode the library wants here; 3454 must do it earlier where we know the signedness of the arg. */ 3455 gcc_assert (mode != BLKmode 3456 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode)); 3457 3458 /* Make sure it is a reasonable operand for a move or push insn. */ 3459 if (!REG_P (val) && !MEM_P (val) 3460 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val))) 3461 val = force_operand (val, NULL_RTX); 3462 3463 if (pass_by_reference (&args_so_far, mode, NULL_TREE, 1)) 3464 { 3465 rtx slot; 3466 int must_copy 3467 = !reference_callee_copied (&args_so_far, mode, NULL_TREE, 1); 3468 3469 /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure 3470 functions, so we have to pretend this isn't such a function. */ 3471 if (flags & ECF_LIBCALL_BLOCK) 3472 { 3473 rtx insns = get_insns (); 3474 end_sequence (); 3475 emit_insn (insns); 3476 } 3477 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK); 3478 3479 /* If this was a CONST function, it is now PURE since 3480 it now reads memory. */ 3481 if (flags & ECF_CONST) 3482 { 3483 flags &= ~ECF_CONST; 3484 flags |= ECF_PURE; 3485 } 3486 3487 if (GET_MODE (val) == MEM && !must_copy) 3488 slot = val; 3489 else 3490 { 3491 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0), 3492 0, 1, 1); 3493 emit_move_insn (slot, val); 3494 } 3495 3496 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, 3497 gen_rtx_USE (VOIDmode, slot), 3498 call_fusage); 3499 if (must_copy) 3500 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, 3501 gen_rtx_CLOBBER (VOIDmode, 3502 slot), 3503 call_fusage); 3504 3505 mode = Pmode; 3506 val = force_operand (XEXP (slot, 0), NULL_RTX); 3507 } 3508 3509 argvec[count].value = val; 3510 argvec[count].mode = mode; 3511 3512 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1); 3513 3514 argvec[count].partial 3515 = targetm.calls.arg_partial_bytes (&args_so_far, mode, NULL_TREE, 1); 3516 3517 locate_and_pad_parm (mode, NULL_TREE, 3518#ifdef STACK_PARMS_IN_REG_PARM_AREA 3519 1, 3520#else 3521 argvec[count].reg != 0, 3522#endif 3523 argvec[count].partial, 3524 NULL_TREE, &args_size, &argvec[count].locate); 3525 3526 gcc_assert (!argvec[count].locate.size.var); 3527 3528 if (argvec[count].reg == 0 || argvec[count].partial != 0 3529 || reg_parm_stack_space > 0) 3530 args_size.constant += argvec[count].locate.size.constant; 3531 3532 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1); 3533 } 3534 3535 /* If this machine requires an external definition for library 3536 functions, write one out. */ 3537 assemble_external_libcall (fun); 3538 3539 original_args_size = args_size; 3540 args_size.constant = (((args_size.constant 3541 + stack_pointer_delta 3542 + STACK_BYTES - 1) 3543 / STACK_BYTES 3544 * STACK_BYTES) 3545 - stack_pointer_delta); 3546 3547 args_size.constant = MAX (args_size.constant, 3548 reg_parm_stack_space); 3549 3550#ifndef OUTGOING_REG_PARM_STACK_SPACE 3551 args_size.constant -= reg_parm_stack_space; 3552#endif 3553 3554 if (args_size.constant > current_function_outgoing_args_size) 3555 current_function_outgoing_args_size = args_size.constant; 3556 3557 if (ACCUMULATE_OUTGOING_ARGS) 3558 { 3559 /* Since the stack pointer will never be pushed, it is possible for 3560 the evaluation of a parm to clobber something we have already 3561 written to the stack. Since most function calls on RISC machines 3562 do not use the stack, this is uncommon, but must work correctly. 3563 3564 Therefore, we save any area of the stack that was already written 3565 and that we are using. Here we set up to do this by making a new 3566 stack usage map from the old one. 3567 3568 Another approach might be to try to reorder the argument 3569 evaluations to avoid this conflicting stack usage. */ 3570 3571 needed = args_size.constant; 3572 3573#ifndef OUTGOING_REG_PARM_STACK_SPACE 3574 /* Since we will be writing into the entire argument area, the 3575 map must be allocated for its entire size, not just the part that 3576 is the responsibility of the caller. */ 3577 needed += reg_parm_stack_space; 3578#endif 3579 3580#ifdef ARGS_GROW_DOWNWARD 3581 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, 3582 needed + 1); 3583#else 3584 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, 3585 needed); 3586#endif 3587 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use); 3588 stack_usage_map = stack_usage_map_buf; 3589 3590 if (initial_highest_arg_in_use) 3591 memcpy (stack_usage_map, initial_stack_usage_map, 3592 initial_highest_arg_in_use); 3593 3594 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use) 3595 memset (&stack_usage_map[initial_highest_arg_in_use], 0, 3596 highest_outgoing_arg_in_use - initial_highest_arg_in_use); 3597 needed = 0; 3598 3599 /* We must be careful to use virtual regs before they're instantiated, 3600 and real regs afterwards. Loop optimization, for example, can create 3601 new libcalls after we've instantiated the virtual regs, and if we 3602 use virtuals anyway, they won't match the rtl patterns. */ 3603 3604 if (virtuals_instantiated) 3605 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET); 3606 else 3607 argblock = virtual_outgoing_args_rtx; 3608 } 3609 else 3610 { 3611 if (!PUSH_ARGS) 3612 argblock = push_block (GEN_INT (args_size.constant), 0, 0); 3613 } 3614 3615 /* If we push args individually in reverse order, perform stack alignment 3616 before the first push (the last arg). */ 3617 if (argblock == 0 && PUSH_ARGS_REVERSED) 3618 anti_adjust_stack (GEN_INT (args_size.constant 3619 - original_args_size.constant)); 3620 3621 if (PUSH_ARGS_REVERSED) 3622 { 3623 inc = -1; 3624 argnum = nargs - 1; 3625 } 3626 else 3627 { 3628 inc = 1; 3629 argnum = 0; 3630 } 3631 3632#ifdef REG_PARM_STACK_SPACE 3633 if (ACCUMULATE_OUTGOING_ARGS) 3634 { 3635 /* The argument list is the property of the called routine and it 3636 may clobber it. If the fixed area has been used for previous 3637 parameters, we must save and restore it. */ 3638 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock, 3639 &low_to_save, &high_to_save); 3640 } 3641#endif 3642 3643 /* Push the args that need to be pushed. */ 3644 3645 /* ARGNUM indexes the ARGVEC array in the order in which the arguments 3646 are to be pushed. */ 3647 for (count = 0; count < nargs; count++, argnum += inc) 3648 { 3649 enum machine_mode mode = argvec[argnum].mode; 3650 rtx val = argvec[argnum].value; 3651 rtx reg = argvec[argnum].reg; 3652 int partial = argvec[argnum].partial; 3653 int lower_bound = 0, upper_bound = 0, i; 3654 3655 if (! (reg != 0 && partial == 0)) 3656 { 3657 if (ACCUMULATE_OUTGOING_ARGS) 3658 { 3659 /* If this is being stored into a pre-allocated, fixed-size, 3660 stack area, save any previous data at that location. */ 3661 3662#ifdef ARGS_GROW_DOWNWARD 3663 /* stack_slot is negative, but we want to index stack_usage_map 3664 with positive values. */ 3665 upper_bound = -argvec[argnum].locate.offset.constant + 1; 3666 lower_bound = upper_bound - argvec[argnum].locate.size.constant; 3667#else 3668 lower_bound = argvec[argnum].locate.offset.constant; 3669 upper_bound = lower_bound + argvec[argnum].locate.size.constant; 3670#endif 3671 3672 i = lower_bound; 3673 /* Don't worry about things in the fixed argument area; 3674 it has already been saved. */ 3675 if (i < reg_parm_stack_space) 3676 i = reg_parm_stack_space; 3677 while (i < upper_bound && stack_usage_map[i] == 0) 3678 i++; 3679 3680 if (i < upper_bound) 3681 { 3682 /* We need to make a save area. */ 3683 unsigned int size 3684 = argvec[argnum].locate.size.constant * BITS_PER_UNIT; 3685 enum machine_mode save_mode 3686 = mode_for_size (size, MODE_INT, 1); 3687 rtx adr 3688 = plus_constant (argblock, 3689 argvec[argnum].locate.offset.constant); 3690 rtx stack_area 3691 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr)); 3692 3693 if (save_mode == BLKmode) 3694 { 3695 argvec[argnum].save_area 3696 = assign_stack_temp (BLKmode, 3697 argvec[argnum].locate.size.constant, 3698 0); 3699 3700 emit_block_move (validize_mem (argvec[argnum].save_area), 3701 stack_area, 3702 GEN_INT (argvec[argnum].locate.size.constant), 3703 BLOCK_OP_CALL_PARM); 3704 } 3705 else 3706 { 3707 argvec[argnum].save_area = gen_reg_rtx (save_mode); 3708 3709 emit_move_insn (argvec[argnum].save_area, stack_area); 3710 } 3711 } 3712 } 3713 3714 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY, 3715 partial, reg, 0, argblock, 3716 GEN_INT (argvec[argnum].locate.offset.constant), 3717 reg_parm_stack_space, 3718 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad)); 3719 3720 /* Now mark the segment we just used. */ 3721 if (ACCUMULATE_OUTGOING_ARGS) 3722 for (i = lower_bound; i < upper_bound; i++) 3723 stack_usage_map[i] = 1; 3724 3725 NO_DEFER_POP; 3726 3727 if (flags & ECF_CONST) 3728 { 3729 rtx use; 3730 3731 /* Indicate argument access so that alias.c knows that these 3732 values are live. */ 3733 if (argblock) 3734 use = plus_constant (argblock, 3735 argvec[argnum].locate.offset.constant); 3736 else 3737 /* When arguments are pushed, trying to tell alias.c where 3738 exactly this argument is won't work, because the 3739 auto-increment causes confusion. So we merely indicate 3740 that we access something with a known mode somewhere on 3741 the stack. */ 3742 use = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx, 3743 gen_rtx_SCRATCH (Pmode)); 3744 use = gen_rtx_MEM (argvec[argnum].mode, use); 3745 use = gen_rtx_USE (VOIDmode, use); 3746 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage); 3747 } 3748 } 3749 } 3750 3751 /* If we pushed args in forward order, perform stack alignment 3752 after pushing the last arg. */ 3753 if (argblock == 0 && !PUSH_ARGS_REVERSED) 3754 anti_adjust_stack (GEN_INT (args_size.constant 3755 - original_args_size.constant)); 3756 3757 if (PUSH_ARGS_REVERSED) 3758 argnum = nargs - 1; 3759 else 3760 argnum = 0; 3761 3762 fun = prepare_call_address (fun, NULL, &call_fusage, 0, 0); 3763 3764 /* Now load any reg parms into their regs. */ 3765 3766 /* ARGNUM indexes the ARGVEC array in the order in which the arguments 3767 are to be pushed. */ 3768 for (count = 0; count < nargs; count++, argnum += inc) 3769 { 3770 enum machine_mode mode = argvec[argnum].mode; 3771 rtx val = argvec[argnum].value; 3772 rtx reg = argvec[argnum].reg; 3773 int partial = argvec[argnum].partial; 3774 3775 /* Handle calls that pass values in multiple non-contiguous 3776 locations. The PA64 has examples of this for library calls. */ 3777 if (reg != 0 && GET_CODE (reg) == PARALLEL) 3778 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode)); 3779 else if (reg != 0 && partial == 0) 3780 emit_move_insn (reg, val); 3781 3782 NO_DEFER_POP; 3783 } 3784 3785 /* Any regs containing parms remain in use through the call. */ 3786 for (count = 0; count < nargs; count++) 3787 { 3788 rtx reg = argvec[count].reg; 3789 if (reg != 0 && GET_CODE (reg) == PARALLEL) 3790 use_group_regs (&call_fusage, reg); 3791 else if (reg != 0) 3792 use_reg (&call_fusage, reg); 3793 } 3794 3795 /* Pass the function the address in which to return a structure value. */ 3796 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value) 3797 { 3798 emit_move_insn (struct_value, 3799 force_reg (Pmode, 3800 force_operand (XEXP (mem_value, 0), 3801 NULL_RTX))); 3802 if (REG_P (struct_value)) 3803 use_reg (&call_fusage, struct_value); 3804 } 3805 3806 /* Don't allow popping to be deferred, since then 3807 cse'ing of library calls could delete a call and leave the pop. */ 3808 NO_DEFER_POP; 3809 valreg = (mem_value == 0 && outmode != VOIDmode 3810 ? hard_libcall_value (outmode) : NULL_RTX); 3811 3812 /* Stack must be properly aligned now. */ 3813 gcc_assert (!(stack_pointer_delta 3814 & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1))); 3815 3816 before_call = get_last_insn (); 3817 3818 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which 3819 will set inhibit_defer_pop to that value. */ 3820 /* The return type is needed to decide how many bytes the function pops. 3821 Signedness plays no role in that, so for simplicity, we pretend it's 3822 always signed. We also assume that the list of arguments passed has 3823 no impact, so we pretend it is unknown. */ 3824 3825 emit_call_1 (fun, NULL, 3826 get_identifier (XSTR (orgfun, 0)), 3827 build_function_type (tfom, NULL_TREE), 3828 original_args_size.constant, args_size.constant, 3829 struct_value_size, 3830 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1), 3831 valreg, 3832 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far); 3833 3834 /* For calls to `setjmp', etc., inform flow.c it should complain 3835 if nonvolatile values are live. For functions that cannot return, 3836 inform flow that control does not fall through. */ 3837 3838 if (flags & ECF_NORETURN) 3839 { 3840 /* The barrier note must be emitted 3841 immediately after the CALL_INSN. Some ports emit more than 3842 just a CALL_INSN above, so we must search for it here. */ 3843 3844 rtx last = get_last_insn (); 3845 while (!CALL_P (last)) 3846 { 3847 last = PREV_INSN (last); 3848 /* There was no CALL_INSN? */ 3849 gcc_assert (last != before_call); 3850 } 3851 3852 emit_barrier_after (last); 3853 } 3854 3855 /* Now restore inhibit_defer_pop to its actual original value. */ 3856 OK_DEFER_POP; 3857 3858 /* If call is cse'able, make appropriate pair of reg-notes around it. 3859 Test valreg so we don't crash; may safely ignore `const' 3860 if return type is void. Disable for PARALLEL return values, because 3861 we have no way to move such values into a pseudo register. */ 3862 if (flags & ECF_LIBCALL_BLOCK) 3863 { 3864 rtx insns; 3865 3866 if (valreg == 0) 3867 { 3868 insns = get_insns (); 3869 end_sequence (); 3870 emit_insn (insns); 3871 } 3872 else 3873 { 3874 rtx note = 0; 3875 rtx temp; 3876 int i; 3877 3878 if (GET_CODE (valreg) == PARALLEL) 3879 { 3880 temp = gen_reg_rtx (outmode); 3881 emit_group_store (temp, valreg, NULL_TREE, 3882 GET_MODE_SIZE (outmode)); 3883 valreg = temp; 3884 } 3885 3886 temp = gen_reg_rtx (GET_MODE (valreg)); 3887 3888 /* Construct an "equal form" for the value which mentions all the 3889 arguments in order as well as the function name. */ 3890 for (i = 0; i < nargs; i++) 3891 note = gen_rtx_EXPR_LIST (VOIDmode, argvec[i].value, note); 3892 note = gen_rtx_EXPR_LIST (VOIDmode, fun, note); 3893 3894 insns = get_insns (); 3895 end_sequence (); 3896 3897 if (flags & ECF_PURE) 3898 note = gen_rtx_EXPR_LIST (VOIDmode, 3899 gen_rtx_USE (VOIDmode, 3900 gen_rtx_MEM (BLKmode, 3901 gen_rtx_SCRATCH (VOIDmode))), 3902 note); 3903 3904 emit_libcall_block (insns, temp, valreg, note); 3905 3906 valreg = temp; 3907 } 3908 } 3909 pop_temp_slots (); 3910 3911 /* Copy the value to the right place. */ 3912 if (outmode != VOIDmode && retval) 3913 { 3914 if (mem_value) 3915 { 3916 if (value == 0) 3917 value = mem_value; 3918 if (value != mem_value) 3919 emit_move_insn (value, mem_value); 3920 } 3921 else if (GET_CODE (valreg) == PARALLEL) 3922 { 3923 if (value == 0) 3924 value = gen_reg_rtx (outmode); 3925 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode)); 3926 } 3927 else if (value != 0) 3928 emit_move_insn (value, valreg); 3929 else 3930 value = valreg; 3931 } 3932 3933 if (ACCUMULATE_OUTGOING_ARGS) 3934 { 3935#ifdef REG_PARM_STACK_SPACE 3936 if (save_area) 3937 restore_fixed_argument_area (save_area, argblock, 3938 high_to_save, low_to_save); 3939#endif 3940 3941 /* If we saved any argument areas, restore them. */ 3942 for (count = 0; count < nargs; count++) 3943 if (argvec[count].save_area) 3944 { 3945 enum machine_mode save_mode = GET_MODE (argvec[count].save_area); 3946 rtx adr = plus_constant (argblock, 3947 argvec[count].locate.offset.constant); 3948 rtx stack_area = gen_rtx_MEM (save_mode, 3949 memory_address (save_mode, adr)); 3950 3951 if (save_mode == BLKmode) 3952 emit_block_move (stack_area, 3953 validize_mem (argvec[count].save_area), 3954 GEN_INT (argvec[count].locate.size.constant), 3955 BLOCK_OP_CALL_PARM); 3956 else 3957 emit_move_insn (stack_area, argvec[count].save_area); 3958 } 3959 3960 highest_outgoing_arg_in_use = initial_highest_arg_in_use; 3961 stack_usage_map = initial_stack_usage_map; 3962 } 3963 3964 if (stack_usage_map_buf) 3965 free (stack_usage_map_buf); 3966 3967 return value; 3968 3969} 3970 3971/* Output a library call to function FUN (a SYMBOL_REF rtx) 3972 (emitting the queue unless NO_QUEUE is nonzero), 3973 for a value of mode OUTMODE, 3974 with NARGS different arguments, passed as alternating rtx values 3975 and machine_modes to convert them to. 3976 3977 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const' 3978 calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls 3979 which should be enclosed in REG_LIBCALL/REG_RETVAL notes, 3980 LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in 3981 REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)), 3982 or other LCT_ value for other types of library calls. */ 3983 3984void 3985emit_library_call (rtx orgfun, enum libcall_type fn_type, 3986 enum machine_mode outmode, int nargs, ...) 3987{ 3988 va_list p; 3989 3990 va_start (p, nargs); 3991 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p); 3992 va_end (p); 3993} 3994 3995/* Like emit_library_call except that an extra argument, VALUE, 3996 comes second and says where to store the result. 3997 (If VALUE is zero, this function chooses a convenient way 3998 to return the value. 3999 4000 This function returns an rtx for where the value is to be found. 4001 If VALUE is nonzero, VALUE is returned. */ 4002 4003rtx 4004emit_library_call_value (rtx orgfun, rtx value, 4005 enum libcall_type fn_type, 4006 enum machine_mode outmode, int nargs, ...) 4007{ 4008 rtx result; 4009 va_list p; 4010 4011 va_start (p, nargs); 4012 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode, 4013 nargs, p); 4014 va_end (p); 4015 4016 return result; 4017} 4018 4019/* Store a single argument for a function call 4020 into the register or memory area where it must be passed. 4021 *ARG describes the argument value and where to pass it. 4022 4023 ARGBLOCK is the address of the stack-block for all the arguments, 4024 or 0 on a machine where arguments are pushed individually. 4025 4026 MAY_BE_ALLOCA nonzero says this could be a call to `alloca' 4027 so must be careful about how the stack is used. 4028 4029 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing 4030 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate 4031 that we need not worry about saving and restoring the stack. 4032 4033 FNDECL is the declaration of the function we are calling. 4034 4035 Return nonzero if this arg should cause sibcall failure, 4036 zero otherwise. */ 4037 4038static int 4039store_one_arg (struct arg_data *arg, rtx argblock, int flags, 4040 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space) 4041{ 4042 tree pval = arg->tree_value; 4043 rtx reg = 0; 4044 int partial = 0; 4045 int used = 0; 4046 int i, lower_bound = 0, upper_bound = 0; 4047 int sibcall_failure = 0; 4048 4049 if (TREE_CODE (pval) == ERROR_MARK) 4050 return 1; 4051 4052 /* Push a new temporary level for any temporaries we make for 4053 this argument. */ 4054 push_temp_slots (); 4055 4056 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)) 4057 { 4058 /* If this is being stored into a pre-allocated, fixed-size, stack area, 4059 save any previous data at that location. */ 4060 if (argblock && ! variable_size && arg->stack) 4061 { 4062#ifdef ARGS_GROW_DOWNWARD 4063 /* stack_slot is negative, but we want to index stack_usage_map 4064 with positive values. */ 4065 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS) 4066 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1; 4067 else 4068 upper_bound = 0; 4069 4070 lower_bound = upper_bound - arg->locate.size.constant; 4071#else 4072 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS) 4073 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)); 4074 else 4075 lower_bound = 0; 4076 4077 upper_bound = lower_bound + arg->locate.size.constant; 4078#endif 4079 4080 i = lower_bound; 4081 /* Don't worry about things in the fixed argument area; 4082 it has already been saved. */ 4083 if (i < reg_parm_stack_space) 4084 i = reg_parm_stack_space; 4085 while (i < upper_bound && stack_usage_map[i] == 0) 4086 i++; 4087 4088 if (i < upper_bound) 4089 { 4090 /* We need to make a save area. */ 4091 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT; 4092 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1); 4093 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0)); 4094 rtx stack_area = gen_rtx_MEM (save_mode, adr); 4095 4096 if (save_mode == BLKmode) 4097 { 4098 tree ot = TREE_TYPE (arg->tree_value); 4099 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot) 4100 | TYPE_QUAL_CONST)); 4101 4102 arg->save_area = assign_temp (nt, 0, 1, 1); 4103 preserve_temp_slots (arg->save_area); 4104 emit_block_move (validize_mem (arg->save_area), stack_area, 4105 GEN_INT (arg->locate.size.constant), 4106 BLOCK_OP_CALL_PARM); 4107 } 4108 else 4109 { 4110 arg->save_area = gen_reg_rtx (save_mode); 4111 emit_move_insn (arg->save_area, stack_area); 4112 } 4113 } 4114 } 4115 } 4116 4117 /* If this isn't going to be placed on both the stack and in registers, 4118 set up the register and number of words. */ 4119 if (! arg->pass_on_stack) 4120 { 4121 if (flags & ECF_SIBCALL) 4122 reg = arg->tail_call_reg; 4123 else 4124 reg = arg->reg; 4125 partial = arg->partial; 4126 } 4127 4128 /* Being passed entirely in a register. We shouldn't be called in 4129 this case. */ 4130 gcc_assert (reg == 0 || partial != 0); 4131 4132 /* If this arg needs special alignment, don't load the registers 4133 here. */ 4134 if (arg->n_aligned_regs != 0) 4135 reg = 0; 4136 4137 /* If this is being passed partially in a register, we can't evaluate 4138 it directly into its stack slot. Otherwise, we can. */ 4139 if (arg->value == 0) 4140 { 4141 /* stack_arg_under_construction is nonzero if a function argument is 4142 being evaluated directly into the outgoing argument list and 4143 expand_call must take special action to preserve the argument list 4144 if it is called recursively. 4145 4146 For scalar function arguments stack_usage_map is sufficient to 4147 determine which stack slots must be saved and restored. Scalar 4148 arguments in general have pass_on_stack == 0. 4149 4150 If this argument is initialized by a function which takes the 4151 address of the argument (a C++ constructor or a C function 4152 returning a BLKmode structure), then stack_usage_map is 4153 insufficient and expand_call must push the stack around the 4154 function call. Such arguments have pass_on_stack == 1. 4155 4156 Note that it is always safe to set stack_arg_under_construction, 4157 but this generates suboptimal code if set when not needed. */ 4158 4159 if (arg->pass_on_stack) 4160 stack_arg_under_construction++; 4161 4162 arg->value = expand_expr (pval, 4163 (partial 4164 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode) 4165 ? NULL_RTX : arg->stack, 4166 VOIDmode, EXPAND_STACK_PARM); 4167 4168 /* If we are promoting object (or for any other reason) the mode 4169 doesn't agree, convert the mode. */ 4170 4171 if (arg->mode != TYPE_MODE (TREE_TYPE (pval))) 4172 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)), 4173 arg->value, arg->unsignedp); 4174 4175 if (arg->pass_on_stack) 4176 stack_arg_under_construction--; 4177 } 4178 4179 /* Check for overlap with already clobbered argument area. */ 4180 if ((flags & ECF_SIBCALL) 4181 && MEM_P (arg->value) 4182 && mem_overlaps_already_clobbered_arg_p (XEXP (arg->value, 0), 4183 arg->locate.size.constant)) 4184 sibcall_failure = 1; 4185 4186 /* Don't allow anything left on stack from computation 4187 of argument to alloca. */ 4188 if (flags & ECF_MAY_BE_ALLOCA) 4189 do_pending_stack_adjust (); 4190 4191 if (arg->value == arg->stack) 4192 /* If the value is already in the stack slot, we are done. */ 4193 ; 4194 else if (arg->mode != BLKmode) 4195 { 4196 int size; 4197 4198 /* Argument is a scalar, not entirely passed in registers. 4199 (If part is passed in registers, arg->partial says how much 4200 and emit_push_insn will take care of putting it there.) 4201 4202 Push it, and if its size is less than the 4203 amount of space allocated to it, 4204 also bump stack pointer by the additional space. 4205 Note that in C the default argument promotions 4206 will prevent such mismatches. */ 4207 4208 size = GET_MODE_SIZE (arg->mode); 4209 /* Compute how much space the push instruction will push. 4210 On many machines, pushing a byte will advance the stack 4211 pointer by a halfword. */ 4212#ifdef PUSH_ROUNDING 4213 size = PUSH_ROUNDING (size); 4214#endif 4215 used = size; 4216 4217 /* Compute how much space the argument should get: 4218 round up to a multiple of the alignment for arguments. */ 4219 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval))) 4220 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1) 4221 / (PARM_BOUNDARY / BITS_PER_UNIT)) 4222 * (PARM_BOUNDARY / BITS_PER_UNIT)); 4223 4224 /* This isn't already where we want it on the stack, so put it there. 4225 This can either be done with push or copy insns. */ 4226 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX, 4227 PARM_BOUNDARY, partial, reg, used - size, argblock, 4228 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space, 4229 ARGS_SIZE_RTX (arg->locate.alignment_pad)); 4230 4231 /* Unless this is a partially-in-register argument, the argument is now 4232 in the stack. */ 4233 if (partial == 0) 4234 arg->value = arg->stack; 4235 } 4236 else 4237 { 4238 /* BLKmode, at least partly to be pushed. */ 4239 4240 unsigned int parm_align; 4241 int excess; 4242 rtx size_rtx; 4243 4244 /* Pushing a nonscalar. 4245 If part is passed in registers, PARTIAL says how much 4246 and emit_push_insn will take care of putting it there. */ 4247 4248 /* Round its size up to a multiple 4249 of the allocation unit for arguments. */ 4250 4251 if (arg->locate.size.var != 0) 4252 { 4253 excess = 0; 4254 size_rtx = ARGS_SIZE_RTX (arg->locate.size); 4255 } 4256 else 4257 { 4258 /* PUSH_ROUNDING has no effect on us, because emit_push_insn 4259 for BLKmode is careful to avoid it. */ 4260 excess = (arg->locate.size.constant 4261 - int_size_in_bytes (TREE_TYPE (pval)) 4262 + partial); 4263 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)), 4264 NULL_RTX, TYPE_MODE (sizetype), 0); 4265 } 4266 4267 parm_align = arg->locate.boundary; 4268 4269 /* When an argument is padded down, the block is aligned to 4270 PARM_BOUNDARY, but the actual argument isn't. */ 4271 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward) 4272 { 4273 if (arg->locate.size.var) 4274 parm_align = BITS_PER_UNIT; 4275 else if (excess) 4276 { 4277 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT; 4278 parm_align = MIN (parm_align, excess_align); 4279 } 4280 } 4281 4282 if ((flags & ECF_SIBCALL) && MEM_P (arg->value)) 4283 { 4284 /* emit_push_insn might not work properly if arg->value and 4285 argblock + arg->locate.offset areas overlap. */ 4286 rtx x = arg->value; 4287 int i = 0; 4288 4289 if (XEXP (x, 0) == current_function_internal_arg_pointer 4290 || (GET_CODE (XEXP (x, 0)) == PLUS 4291 && XEXP (XEXP (x, 0), 0) == 4292 current_function_internal_arg_pointer 4293 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)) 4294 { 4295 if (XEXP (x, 0) != current_function_internal_arg_pointer) 4296 i = INTVAL (XEXP (XEXP (x, 0), 1)); 4297 4298 /* expand_call should ensure this. */ 4299 gcc_assert (!arg->locate.offset.var 4300 && arg->locate.size.var == 0 4301 && GET_CODE (size_rtx) == CONST_INT); 4302 4303 if (arg->locate.offset.constant > i) 4304 { 4305 if (arg->locate.offset.constant < i + INTVAL (size_rtx)) 4306 sibcall_failure = 1; 4307 } 4308 else if (arg->locate.offset.constant < i) 4309 { 4310 /* Use arg->locate.size.constant instead of size_rtx 4311 because we only care about the part of the argument 4312 on the stack. */ 4313 if (i < (arg->locate.offset.constant 4314 + arg->locate.size.constant)) 4315 sibcall_failure = 1; 4316 } 4317 else 4318 { 4319 /* Even though they appear to be at the same location, 4320 if part of the outgoing argument is in registers, 4321 they aren't really at the same location. Check for 4322 this by making sure that the incoming size is the 4323 same as the outgoing size. */ 4324 if (arg->locate.size.constant != INTVAL (size_rtx)) 4325 sibcall_failure = 1; 4326 } 4327 } 4328 } 4329 4330 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx, 4331 parm_align, partial, reg, excess, argblock, 4332 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space, 4333 ARGS_SIZE_RTX (arg->locate.alignment_pad)); 4334 4335 /* Unless this is a partially-in-register argument, the argument is now 4336 in the stack. 4337 4338 ??? Unlike the case above, in which we want the actual 4339 address of the data, so that we can load it directly into a 4340 register, here we want the address of the stack slot, so that 4341 it's properly aligned for word-by-word copying or something 4342 like that. It's not clear that this is always correct. */ 4343 if (partial == 0) 4344 arg->value = arg->stack_slot; 4345 } 4346 4347 if (arg->reg && GET_CODE (arg->reg) == PARALLEL) 4348 { 4349 tree type = TREE_TYPE (arg->tree_value); 4350 arg->parallel_value 4351 = emit_group_load_into_temps (arg->reg, arg->value, type, 4352 int_size_in_bytes (type)); 4353 } 4354 4355 /* Mark all slots this store used. */ 4356 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL) 4357 && argblock && ! variable_size && arg->stack) 4358 for (i = lower_bound; i < upper_bound; i++) 4359 stack_usage_map[i] = 1; 4360 4361 /* Once we have pushed something, pops can't safely 4362 be deferred during the rest of the arguments. */ 4363 NO_DEFER_POP; 4364 4365 /* Free any temporary slots made in processing this argument. Show 4366 that we might have taken the address of something and pushed that 4367 as an operand. */ 4368 preserve_temp_slots (NULL_RTX); 4369 free_temp_slots (); 4370 pop_temp_slots (); 4371 4372 return sibcall_failure; 4373} 4374 4375/* Nonzero if we do not know how to pass TYPE solely in registers. */ 4376 4377bool 4378must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED, 4379 tree type) 4380{ 4381 if (!type) 4382 return false; 4383 4384 /* If the type has variable size... */ 4385 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST) 4386 return true; 4387 4388 /* If the type is marked as addressable (it is required 4389 to be constructed into the stack)... */ 4390 if (TREE_ADDRESSABLE (type)) 4391 return true; 4392 4393 return false; 4394} 4395 4396/* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one 4397 takes trailing padding of a structure into account. */ 4398/* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */ 4399 4400bool 4401must_pass_in_stack_var_size_or_pad (enum machine_mode mode, tree type) 4402{ 4403 if (!type) 4404 return false; 4405 4406 /* If the type has variable size... */ 4407 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST) 4408 return true; 4409 4410 /* If the type is marked as addressable (it is required 4411 to be constructed into the stack)... */ 4412 if (TREE_ADDRESSABLE (type)) 4413 return true; 4414 4415 /* If the padding and mode of the type is such that a copy into 4416 a register would put it into the wrong part of the register. */ 4417 if (mode == BLKmode 4418 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT) 4419 && (FUNCTION_ARG_PADDING (mode, type) 4420 == (BYTES_BIG_ENDIAN ? upward : downward))) 4421 return true; 4422 4423 return false; 4424} 4425