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 /* APPLE LOCAL blocks */ 2055 gcc_assert (POINTER_TYPE_P (funtype) || TREE_CODE (funtype) == BLOCK_POINTER_TYPE); 2056 funtype = TREE_TYPE (funtype); 2057 2058 /* Munge the tree to split complex arguments into their imaginary 2059 and real parts. */ 2060 if (targetm.calls.split_complex_arg) 2061 { 2062 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype)); 2063 actparms = split_complex_values (actparms); 2064 } 2065 else 2066 type_arg_types = TYPE_ARG_TYPES (funtype); 2067 2068 if (flags & ECF_MAY_BE_ALLOCA) 2069 current_function_calls_alloca = 1; 2070 2071 /* If struct_value_rtx is 0, it means pass the address 2072 as if it were an extra parameter. */ 2073 if (structure_value_addr && struct_value == 0) 2074 { 2075 /* If structure_value_addr is a REG other than 2076 virtual_outgoing_args_rtx, we can use always use it. If it 2077 is not a REG, we must always copy it into a register. 2078 If it is virtual_outgoing_args_rtx, we must copy it to another 2079 register in some cases. */ 2080 rtx temp = (!REG_P (structure_value_addr) 2081 || (ACCUMULATE_OUTGOING_ARGS 2082 && stack_arg_under_construction 2083 && structure_value_addr == virtual_outgoing_args_rtx) 2084 ? copy_addr_to_reg (convert_memory_address 2085 (Pmode, structure_value_addr)) 2086 : structure_value_addr); 2087 2088 actparms 2089 = tree_cons (error_mark_node, 2090 make_tree (build_pointer_type (TREE_TYPE (funtype)), 2091 temp), 2092 actparms); 2093 structure_value_addr_parm = 1; 2094 } 2095 2096 /* Count the arguments and set NUM_ACTUALS. */ 2097 for (p = actparms, num_actuals = 0; p; p = TREE_CHAIN (p)) 2098 num_actuals++; 2099 2100 /* Compute number of named args. 2101 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */ 2102 2103 if (type_arg_types != 0) 2104 n_named_args 2105 = (list_length (type_arg_types) 2106 /* Count the struct value address, if it is passed as a parm. */ 2107 + structure_value_addr_parm); 2108 else 2109 /* If we know nothing, treat all args as named. */ 2110 n_named_args = num_actuals; 2111 2112 /* Start updating where the next arg would go. 2113 2114 On some machines (such as the PA) indirect calls have a different 2115 calling convention than normal calls. The fourth argument in 2116 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call 2117 or not. */ 2118 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl, n_named_args); 2119 2120 /* Now possibly adjust the number of named args. 2121 Normally, don't include the last named arg if anonymous args follow. 2122 We do include the last named arg if 2123 targetm.calls.strict_argument_naming() returns nonzero. 2124 (If no anonymous args follow, the result of list_length is actually 2125 one too large. This is harmless.) 2126 2127 If targetm.calls.pretend_outgoing_varargs_named() returns 2128 nonzero, and targetm.calls.strict_argument_naming() returns zero, 2129 this machine will be able to place unnamed args that were passed 2130 in registers into the stack. So treat all args as named. This 2131 allows the insns emitting for a specific argument list to be 2132 independent of the function declaration. 2133 2134 If targetm.calls.pretend_outgoing_varargs_named() returns zero, 2135 we do not have any reliable way to pass unnamed args in 2136 registers, so we must force them into memory. */ 2137 2138 if (type_arg_types != 0 2139 && targetm.calls.strict_argument_naming (&args_so_far)) 2140 ; 2141 else if (type_arg_types != 0 2142 && ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far)) 2143 /* Don't include the last named arg. */ 2144 --n_named_args; 2145 else 2146 /* Treat all args as named. */ 2147 n_named_args = num_actuals; 2148 2149 /* Make a vector to hold all the information about each arg. */ 2150 args = alloca (num_actuals * sizeof (struct arg_data)); 2151 memset (args, 0, num_actuals * sizeof (struct arg_data)); 2152 2153 /* Build up entries in the ARGS array, compute the size of the 2154 arguments into ARGS_SIZE, etc. */ 2155 initialize_argument_information (num_actuals, args, &args_size, 2156 n_named_args, actparms, fndecl, 2157 &args_so_far, reg_parm_stack_space, 2158 &old_stack_level, &old_pending_adj, 2159 &must_preallocate, &flags, 2160 &try_tail_call, CALL_FROM_THUNK_P (exp)); 2161 2162 if (args_size.var) 2163 { 2164 /* If this function requires a variable-sized argument list, don't 2165 try to make a cse'able block for this call. We may be able to 2166 do this eventually, but it is too complicated to keep track of 2167 what insns go in the cse'able block and which don't. */ 2168 2169 flags &= ~ECF_LIBCALL_BLOCK; 2170 must_preallocate = 1; 2171 } 2172 2173 /* Now make final decision about preallocating stack space. */ 2174 must_preallocate = finalize_must_preallocate (must_preallocate, 2175 num_actuals, args, 2176 &args_size); 2177 2178 /* If the structure value address will reference the stack pointer, we 2179 must stabilize it. We don't need to do this if we know that we are 2180 not going to adjust the stack pointer in processing this call. */ 2181 2182 if (structure_value_addr 2183 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr) 2184 || reg_mentioned_p (virtual_outgoing_args_rtx, 2185 structure_value_addr)) 2186 && (args_size.var 2187 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant))) 2188 structure_value_addr = copy_to_reg (structure_value_addr); 2189 2190 /* Tail calls can make things harder to debug, and we've traditionally 2191 pushed these optimizations into -O2. Don't try if we're already 2192 expanding a call, as that means we're an argument. Don't try if 2193 there's cleanups, as we know there's code to follow the call. */ 2194 2195 if (currently_expanding_call++ != 0 2196 || !flag_optimize_sibling_calls 2197 || args_size.var 2198 || lookup_stmt_eh_region (exp) >= 0) 2199 try_tail_call = 0; 2200 2201 /* Rest of purposes for tail call optimizations to fail. */ 2202 if ( 2203#ifdef HAVE_sibcall_epilogue 2204 !HAVE_sibcall_epilogue 2205#else 2206 1 2207#endif 2208 || !try_tail_call 2209 /* Doing sibling call optimization needs some work, since 2210 structure_value_addr can be allocated on the stack. 2211 It does not seem worth the effort since few optimizable 2212 sibling calls will return a structure. */ 2213 || structure_value_addr != NULL_RTX 2214 /* Check whether the target is able to optimize the call 2215 into a sibcall. */ 2216 || !targetm.function_ok_for_sibcall (fndecl, exp) 2217 /* Functions that do not return exactly once may not be sibcall 2218 optimized. */ 2219 || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN)) 2220 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr))) 2221 /* If the called function is nested in the current one, it might access 2222 some of the caller's arguments, but could clobber them beforehand if 2223 the argument areas are shared. */ 2224 || (fndecl && decl_function_context (fndecl) == current_function_decl) 2225 /* If this function requires more stack slots than the current 2226 function, we cannot change it into a sibling call. 2227 current_function_pretend_args_size is not part of the 2228 stack allocated by our caller. */ 2229 || args_size.constant > (current_function_args_size 2230 - current_function_pretend_args_size) 2231 /* If the callee pops its own arguments, then it must pop exactly 2232 the same number of arguments as the current function. */ 2233 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant) 2234 != RETURN_POPS_ARGS (current_function_decl, 2235 TREE_TYPE (current_function_decl), 2236 current_function_args_size)) 2237 || !lang_hooks.decls.ok_for_sibcall (fndecl)) 2238 try_tail_call = 0; 2239 2240 /* Ensure current function's preferred stack boundary is at least 2241 what we need. We don't have to increase alignment for recursive 2242 functions. */ 2243 if (cfun->preferred_stack_boundary < preferred_stack_boundary 2244 && fndecl != current_function_decl) 2245 cfun->preferred_stack_boundary = preferred_stack_boundary; 2246 if (fndecl == current_function_decl) 2247 cfun->recursive_call_emit = true; 2248 2249 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT; 2250 2251 /* We want to make two insn chains; one for a sibling call, the other 2252 for a normal call. We will select one of the two chains after 2253 initial RTL generation is complete. */ 2254 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++) 2255 { 2256 int sibcall_failure = 0; 2257 /* We want to emit any pending stack adjustments before the tail 2258 recursion "call". That way we know any adjustment after the tail 2259 recursion call can be ignored if we indeed use the tail 2260 call expansion. */ 2261 int save_pending_stack_adjust = 0; 2262 int save_stack_pointer_delta = 0; 2263 rtx insns; 2264 rtx before_call, next_arg_reg; 2265 2266 if (pass == 0) 2267 { 2268 /* State variables we need to save and restore between 2269 iterations. */ 2270 save_pending_stack_adjust = pending_stack_adjust; 2271 save_stack_pointer_delta = stack_pointer_delta; 2272 } 2273 if (pass) 2274 flags &= ~ECF_SIBCALL; 2275 else 2276 flags |= ECF_SIBCALL; 2277 2278 /* Other state variables that we must reinitialize each time 2279 through the loop (that are not initialized by the loop itself). */ 2280 argblock = 0; 2281 call_fusage = 0; 2282 2283 /* Start a new sequence for the normal call case. 2284 2285 From this point on, if the sibling call fails, we want to set 2286 sibcall_failure instead of continuing the loop. */ 2287 start_sequence (); 2288 2289 /* Don't let pending stack adjusts add up to too much. 2290 Also, do all pending adjustments now if there is any chance 2291 this might be a call to alloca or if we are expanding a sibling 2292 call sequence or if we are calling a function that is to return 2293 with stack pointer depressed. 2294 Also do the adjustments before a throwing call, otherwise 2295 exception handling can fail; PR 19225. */ 2296 if (pending_stack_adjust >= 32 2297 || (pending_stack_adjust > 0 2298 && (flags & (ECF_MAY_BE_ALLOCA | ECF_SP_DEPRESSED))) 2299 || (pending_stack_adjust > 0 2300 && flag_exceptions && !(flags & ECF_NOTHROW)) 2301 || pass == 0) 2302 do_pending_stack_adjust (); 2303 2304 /* When calling a const function, we must pop the stack args right away, 2305 so that the pop is deleted or moved with the call. */ 2306 if (pass && (flags & ECF_LIBCALL_BLOCK)) 2307 NO_DEFER_POP; 2308 2309 /* Precompute any arguments as needed. */ 2310 if (pass) 2311 precompute_arguments (flags, num_actuals, args); 2312 2313 /* Now we are about to start emitting insns that can be deleted 2314 if a libcall is deleted. */ 2315 if (pass && (flags & (ECF_LIBCALL_BLOCK | ECF_MALLOC))) 2316 start_sequence (); 2317 2318 if (pass == 0 && cfun->stack_protect_guard) 2319 stack_protect_epilogue (); 2320 2321 adjusted_args_size = args_size; 2322 /* Compute the actual size of the argument block required. The variable 2323 and constant sizes must be combined, the size may have to be rounded, 2324 and there may be a minimum required size. When generating a sibcall 2325 pattern, do not round up, since we'll be re-using whatever space our 2326 caller provided. */ 2327 unadjusted_args_size 2328 = compute_argument_block_size (reg_parm_stack_space, 2329 &adjusted_args_size, 2330 (pass == 0 ? 0 2331 : preferred_stack_boundary)); 2332 2333 old_stack_allocated = stack_pointer_delta - pending_stack_adjust; 2334 2335 /* The argument block when performing a sibling call is the 2336 incoming argument block. */ 2337 if (pass == 0) 2338 { 2339 argblock = virtual_incoming_args_rtx; 2340 argblock 2341#ifdef STACK_GROWS_DOWNWARD 2342 = plus_constant (argblock, current_function_pretend_args_size); 2343#else 2344 = plus_constant (argblock, -current_function_pretend_args_size); 2345#endif 2346 stored_args_map = sbitmap_alloc (args_size.constant); 2347 sbitmap_zero (stored_args_map); 2348 } 2349 2350 /* If we have no actual push instructions, or shouldn't use them, 2351 make space for all args right now. */ 2352 else if (adjusted_args_size.var != 0) 2353 { 2354 if (old_stack_level == 0) 2355 { 2356 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX); 2357 old_stack_pointer_delta = stack_pointer_delta; 2358 old_pending_adj = pending_stack_adjust; 2359 pending_stack_adjust = 0; 2360 /* stack_arg_under_construction says whether a stack arg is 2361 being constructed at the old stack level. Pushing the stack 2362 gets a clean outgoing argument block. */ 2363 old_stack_arg_under_construction = stack_arg_under_construction; 2364 stack_arg_under_construction = 0; 2365 } 2366 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0); 2367 } 2368 else 2369 { 2370 /* Note that we must go through the motions of allocating an argument 2371 block even if the size is zero because we may be storing args 2372 in the area reserved for register arguments, which may be part of 2373 the stack frame. */ 2374 2375 int needed = adjusted_args_size.constant; 2376 2377 /* Store the maximum argument space used. It will be pushed by 2378 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow 2379 checking). */ 2380 2381 if (needed > current_function_outgoing_args_size) 2382 current_function_outgoing_args_size = needed; 2383 2384 if (must_preallocate) 2385 { 2386 if (ACCUMULATE_OUTGOING_ARGS) 2387 { 2388 /* Since the stack pointer will never be pushed, it is 2389 possible for the evaluation of a parm to clobber 2390 something we have already written to the stack. 2391 Since most function calls on RISC machines do not use 2392 the stack, this is uncommon, but must work correctly. 2393 2394 Therefore, we save any area of the stack that was already 2395 written and that we are using. Here we set up to do this 2396 by making a new stack usage map from the old one. The 2397 actual save will be done by store_one_arg. 2398 2399 Another approach might be to try to reorder the argument 2400 evaluations to avoid this conflicting stack usage. */ 2401 2402#ifndef OUTGOING_REG_PARM_STACK_SPACE 2403 /* Since we will be writing into the entire argument area, 2404 the map must be allocated for its entire size, not just 2405 the part that is the responsibility of the caller. */ 2406 needed += reg_parm_stack_space; 2407#endif 2408 2409#ifdef ARGS_GROW_DOWNWARD 2410 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, 2411 needed + 1); 2412#else 2413 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, 2414 needed); 2415#endif 2416 if (stack_usage_map_buf) 2417 free (stack_usage_map_buf); 2418 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use); 2419 stack_usage_map = stack_usage_map_buf; 2420 2421 if (initial_highest_arg_in_use) 2422 memcpy (stack_usage_map, initial_stack_usage_map, 2423 initial_highest_arg_in_use); 2424 2425 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use) 2426 memset (&stack_usage_map[initial_highest_arg_in_use], 0, 2427 (highest_outgoing_arg_in_use 2428 - initial_highest_arg_in_use)); 2429 needed = 0; 2430 2431 /* The address of the outgoing argument list must not be 2432 copied to a register here, because argblock would be left 2433 pointing to the wrong place after the call to 2434 allocate_dynamic_stack_space below. */ 2435 2436 argblock = virtual_outgoing_args_rtx; 2437 } 2438 else 2439 { 2440 if (inhibit_defer_pop == 0) 2441 { 2442 /* Try to reuse some or all of the pending_stack_adjust 2443 to get this space. */ 2444 needed 2445 = (combine_pending_stack_adjustment_and_call 2446 (unadjusted_args_size, 2447 &adjusted_args_size, 2448 preferred_unit_stack_boundary)); 2449 2450 /* combine_pending_stack_adjustment_and_call computes 2451 an adjustment before the arguments are allocated. 2452 Account for them and see whether or not the stack 2453 needs to go up or down. */ 2454 needed = unadjusted_args_size - needed; 2455 2456 if (needed < 0) 2457 { 2458 /* We're releasing stack space. */ 2459 /* ??? We can avoid any adjustment at all if we're 2460 already aligned. FIXME. */ 2461 pending_stack_adjust = -needed; 2462 do_pending_stack_adjust (); 2463 needed = 0; 2464 } 2465 else 2466 /* We need to allocate space. We'll do that in 2467 push_block below. */ 2468 pending_stack_adjust = 0; 2469 } 2470 2471 /* Special case this because overhead of `push_block' in 2472 this case is non-trivial. */ 2473 if (needed == 0) 2474 argblock = virtual_outgoing_args_rtx; 2475 else 2476 { 2477 argblock = push_block (GEN_INT (needed), 0, 0); 2478#ifdef ARGS_GROW_DOWNWARD 2479 argblock = plus_constant (argblock, needed); 2480#endif 2481 } 2482 2483 /* We only really need to call `copy_to_reg' in the case 2484 where push insns are going to be used to pass ARGBLOCK 2485 to a function call in ARGS. In that case, the stack 2486 pointer changes value from the allocation point to the 2487 call point, and hence the value of 2488 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might 2489 as well always do it. */ 2490 argblock = copy_to_reg (argblock); 2491 } 2492 } 2493 } 2494 2495 if (ACCUMULATE_OUTGOING_ARGS) 2496 { 2497 /* The save/restore code in store_one_arg handles all 2498 cases except one: a constructor call (including a C 2499 function returning a BLKmode struct) to initialize 2500 an argument. */ 2501 if (stack_arg_under_construction) 2502 { 2503#ifndef OUTGOING_REG_PARM_STACK_SPACE 2504 rtx push_size = GEN_INT (reg_parm_stack_space 2505 + adjusted_args_size.constant); 2506#else 2507 rtx push_size = GEN_INT (adjusted_args_size.constant); 2508#endif 2509 if (old_stack_level == 0) 2510 { 2511 emit_stack_save (SAVE_BLOCK, &old_stack_level, 2512 NULL_RTX); 2513 old_stack_pointer_delta = stack_pointer_delta; 2514 old_pending_adj = pending_stack_adjust; 2515 pending_stack_adjust = 0; 2516 /* stack_arg_under_construction says whether a stack 2517 arg is being constructed at the old stack level. 2518 Pushing the stack gets a clean outgoing argument 2519 block. */ 2520 old_stack_arg_under_construction 2521 = stack_arg_under_construction; 2522 stack_arg_under_construction = 0; 2523 /* Make a new map for the new argument list. */ 2524 if (stack_usage_map_buf) 2525 free (stack_usage_map_buf); 2526 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use); 2527 stack_usage_map = stack_usage_map_buf; 2528 memset (stack_usage_map, 0, highest_outgoing_arg_in_use); 2529 highest_outgoing_arg_in_use = 0; 2530 } 2531 allocate_dynamic_stack_space (push_size, NULL_RTX, 2532 BITS_PER_UNIT); 2533 } 2534 2535 /* If argument evaluation might modify the stack pointer, 2536 copy the address of the argument list to a register. */ 2537 for (i = 0; i < num_actuals; i++) 2538 if (args[i].pass_on_stack) 2539 { 2540 argblock = copy_addr_to_reg (argblock); 2541 break; 2542 } 2543 } 2544 2545 compute_argument_addresses (args, argblock, num_actuals); 2546 2547 /* If we push args individually in reverse order, perform stack alignment 2548 before the first push (the last arg). */ 2549 if (PUSH_ARGS_REVERSED && argblock == 0 2550 && adjusted_args_size.constant != unadjusted_args_size) 2551 { 2552 /* When the stack adjustment is pending, we get better code 2553 by combining the adjustments. */ 2554 if (pending_stack_adjust 2555 && ! (flags & ECF_LIBCALL_BLOCK) 2556 && ! inhibit_defer_pop) 2557 { 2558 pending_stack_adjust 2559 = (combine_pending_stack_adjustment_and_call 2560 (unadjusted_args_size, 2561 &adjusted_args_size, 2562 preferred_unit_stack_boundary)); 2563 do_pending_stack_adjust (); 2564 } 2565 else if (argblock == 0) 2566 anti_adjust_stack (GEN_INT (adjusted_args_size.constant 2567 - unadjusted_args_size)); 2568 } 2569 /* Now that the stack is properly aligned, pops can't safely 2570 be deferred during the evaluation of the arguments. */ 2571 NO_DEFER_POP; 2572 2573 funexp = rtx_for_function_call (fndecl, addr); 2574 2575 /* Figure out the register where the value, if any, will come back. */ 2576 valreg = 0; 2577 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode 2578 && ! structure_value_addr) 2579 { 2580 if (pcc_struct_value) 2581 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)), 2582 fndecl, NULL, (pass == 0)); 2583 else 2584 valreg = hard_function_value (TREE_TYPE (exp), fndecl, fntype, 2585 (pass == 0)); 2586 } 2587 2588 /* Precompute all register parameters. It isn't safe to compute anything 2589 once we have started filling any specific hard regs. */ 2590 precompute_register_parameters (num_actuals, args, ®_parm_seen); 2591 2592 if (TREE_OPERAND (exp, 2)) 2593 static_chain_value = expand_normal (TREE_OPERAND (exp, 2)); 2594 else 2595 static_chain_value = 0; 2596 2597#ifdef REG_PARM_STACK_SPACE 2598 /* Save the fixed argument area if it's part of the caller's frame and 2599 is clobbered by argument setup for this call. */ 2600 if (ACCUMULATE_OUTGOING_ARGS && pass) 2601 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock, 2602 &low_to_save, &high_to_save); 2603#endif 2604 2605 /* Now store (and compute if necessary) all non-register parms. 2606 These come before register parms, since they can require block-moves, 2607 which could clobber the registers used for register parms. 2608 Parms which have partial registers are not stored here, 2609 but we do preallocate space here if they want that. */ 2610 2611 for (i = 0; i < num_actuals; i++) 2612 if (args[i].reg == 0 || args[i].pass_on_stack) 2613 { 2614 rtx before_arg = get_last_insn (); 2615 2616 if (store_one_arg (&args[i], argblock, flags, 2617 adjusted_args_size.var != 0, 2618 reg_parm_stack_space) 2619 || (pass == 0 2620 && check_sibcall_argument_overlap (before_arg, 2621 &args[i], 1))) 2622 sibcall_failure = 1; 2623 2624 if (flags & ECF_CONST 2625 && args[i].stack 2626 && args[i].value == args[i].stack) 2627 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, 2628 gen_rtx_USE (VOIDmode, 2629 args[i].value), 2630 call_fusage); 2631 } 2632 2633 /* If we have a parm that is passed in registers but not in memory 2634 and whose alignment does not permit a direct copy into registers, 2635 make a group of pseudos that correspond to each register that we 2636 will later fill. */ 2637 if (STRICT_ALIGNMENT) 2638 store_unaligned_arguments_into_pseudos (args, num_actuals); 2639 2640 /* Now store any partially-in-registers parm. 2641 This is the last place a block-move can happen. */ 2642 if (reg_parm_seen) 2643 for (i = 0; i < num_actuals; i++) 2644 if (args[i].partial != 0 && ! args[i].pass_on_stack) 2645 { 2646 rtx before_arg = get_last_insn (); 2647 2648 if (store_one_arg (&args[i], argblock, flags, 2649 adjusted_args_size.var != 0, 2650 reg_parm_stack_space) 2651 || (pass == 0 2652 && check_sibcall_argument_overlap (before_arg, 2653 &args[i], 1))) 2654 sibcall_failure = 1; 2655 } 2656 2657 /* If we pushed args in forward order, perform stack alignment 2658 after pushing the last arg. */ 2659 if (!PUSH_ARGS_REVERSED && argblock == 0) 2660 anti_adjust_stack (GEN_INT (adjusted_args_size.constant 2661 - unadjusted_args_size)); 2662 2663 /* If register arguments require space on the stack and stack space 2664 was not preallocated, allocate stack space here for arguments 2665 passed in registers. */ 2666#ifdef OUTGOING_REG_PARM_STACK_SPACE 2667 if (!ACCUMULATE_OUTGOING_ARGS 2668 && must_preallocate == 0 && reg_parm_stack_space > 0) 2669 anti_adjust_stack (GEN_INT (reg_parm_stack_space)); 2670#endif 2671 2672 /* Pass the function the address in which to return a 2673 structure value. */ 2674 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm) 2675 { 2676 structure_value_addr 2677 = convert_memory_address (Pmode, structure_value_addr); 2678 emit_move_insn (struct_value, 2679 force_reg (Pmode, 2680 force_operand (structure_value_addr, 2681 NULL_RTX))); 2682 2683 if (REG_P (struct_value)) 2684 use_reg (&call_fusage, struct_value); 2685 } 2686 2687 funexp = prepare_call_address (funexp, static_chain_value, 2688 &call_fusage, reg_parm_seen, pass == 0); 2689 2690 load_register_parameters (args, num_actuals, &call_fusage, flags, 2691 pass == 0, &sibcall_failure); 2692 2693 /* Save a pointer to the last insn before the call, so that we can 2694 later safely search backwards to find the CALL_INSN. */ 2695 before_call = get_last_insn (); 2696 2697 /* Set up next argument register. For sibling calls on machines 2698 with register windows this should be the incoming register. */ 2699#ifdef FUNCTION_INCOMING_ARG 2700 if (pass == 0) 2701 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode, 2702 void_type_node, 1); 2703 else 2704#endif 2705 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode, 2706 void_type_node, 1); 2707 2708 /* All arguments and registers used for the call must be set up by 2709 now! */ 2710 2711 /* Stack must be properly aligned now. */ 2712 gcc_assert (!pass 2713 || !(stack_pointer_delta % preferred_unit_stack_boundary)); 2714 2715 /* Generate the actual call instruction. */ 2716 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size, 2717 adjusted_args_size.constant, struct_value_size, 2718 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage, 2719 flags, & args_so_far); 2720 2721 /* If a non-BLKmode value is returned at the most significant end 2722 of a register, shift the register right by the appropriate amount 2723 and update VALREG accordingly. BLKmode values are handled by the 2724 group load/store machinery below. */ 2725 if (!structure_value_addr 2726 && !pcc_struct_value 2727 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode 2728 && targetm.calls.return_in_msb (TREE_TYPE (exp))) 2729 { 2730 if (shift_return_value (TYPE_MODE (TREE_TYPE (exp)), false, valreg)) 2731 sibcall_failure = 1; 2732 valreg = gen_rtx_REG (TYPE_MODE (TREE_TYPE (exp)), REGNO (valreg)); 2733 } 2734 2735 /* If call is cse'able, make appropriate pair of reg-notes around it. 2736 Test valreg so we don't crash; may safely ignore `const' 2737 if return type is void. Disable for PARALLEL return values, because 2738 we have no way to move such values into a pseudo register. */ 2739 if (pass && (flags & ECF_LIBCALL_BLOCK)) 2740 { 2741 rtx insns; 2742 rtx insn; 2743 bool failed = valreg == 0 || GET_CODE (valreg) == PARALLEL; 2744 2745 insns = get_insns (); 2746 2747 /* Expansion of block moves possibly introduced a loop that may 2748 not appear inside libcall block. */ 2749 for (insn = insns; insn; insn = NEXT_INSN (insn)) 2750 if (JUMP_P (insn)) 2751 failed = true; 2752 2753 if (failed) 2754 { 2755 end_sequence (); 2756 emit_insn (insns); 2757 } 2758 else 2759 { 2760 rtx note = 0; 2761 rtx temp = gen_reg_rtx (GET_MODE (valreg)); 2762 2763 /* Mark the return value as a pointer if needed. */ 2764 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE) 2765 mark_reg_pointer (temp, 2766 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp)))); 2767 2768 end_sequence (); 2769 if (flag_unsafe_math_optimizations 2770 && fndecl 2771 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL 2772 && (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRT 2773 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRTF 2774 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRTL)) 2775 note = gen_rtx_fmt_e (SQRT, 2776 GET_MODE (temp), 2777 args[0].initial_value); 2778 else 2779 { 2780 /* Construct an "equal form" for the value which 2781 mentions all the arguments in order as well as 2782 the function name. */ 2783 for (i = 0; i < num_actuals; i++) 2784 note = gen_rtx_EXPR_LIST (VOIDmode, 2785 args[i].initial_value, note); 2786 note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note); 2787 2788 if (flags & ECF_PURE) 2789 note = gen_rtx_EXPR_LIST (VOIDmode, 2790 gen_rtx_USE (VOIDmode, 2791 gen_rtx_MEM (BLKmode, 2792 gen_rtx_SCRATCH (VOIDmode))), 2793 note); 2794 } 2795 emit_libcall_block (insns, temp, valreg, note); 2796 2797 valreg = temp; 2798 } 2799 } 2800 else if (pass && (flags & ECF_MALLOC)) 2801 { 2802 rtx temp = gen_reg_rtx (GET_MODE (valreg)); 2803 rtx last, insns; 2804 2805 /* The return value from a malloc-like function is a pointer. */ 2806 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE) 2807 mark_reg_pointer (temp, BIGGEST_ALIGNMENT); 2808 2809 emit_move_insn (temp, valreg); 2810 2811 /* The return value from a malloc-like function can not alias 2812 anything else. */ 2813 last = get_last_insn (); 2814 REG_NOTES (last) = 2815 gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last)); 2816 2817 /* Write out the sequence. */ 2818 insns = get_insns (); 2819 end_sequence (); 2820 emit_insn (insns); 2821 valreg = temp; 2822 } 2823 2824 /* For calls to `setjmp', etc., inform flow.c it should complain 2825 if nonvolatile values are live. For functions that cannot return, 2826 inform flow that control does not fall through. */ 2827 2828 if ((flags & ECF_NORETURN) || pass == 0) 2829 { 2830 /* The barrier must be emitted 2831 immediately after the CALL_INSN. Some ports emit more 2832 than just a CALL_INSN above, so we must search for it here. */ 2833 2834 rtx last = get_last_insn (); 2835 while (!CALL_P (last)) 2836 { 2837 last = PREV_INSN (last); 2838 /* There was no CALL_INSN? */ 2839 gcc_assert (last != before_call); 2840 } 2841 2842 emit_barrier_after (last); 2843 2844 /* Stack adjustments after a noreturn call are dead code. 2845 However when NO_DEFER_POP is in effect, we must preserve 2846 stack_pointer_delta. */ 2847 if (inhibit_defer_pop == 0) 2848 { 2849 stack_pointer_delta = old_stack_allocated; 2850 pending_stack_adjust = 0; 2851 } 2852 } 2853 2854 /* If value type not void, return an rtx for the value. */ 2855 2856 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode 2857 || ignore) 2858 target = const0_rtx; 2859 else if (structure_value_addr) 2860 { 2861 if (target == 0 || !MEM_P (target)) 2862 { 2863 target 2864 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), 2865 memory_address (TYPE_MODE (TREE_TYPE (exp)), 2866 structure_value_addr)); 2867 set_mem_attributes (target, exp, 1); 2868 } 2869 } 2870 else if (pcc_struct_value) 2871 { 2872 /* This is the special C++ case where we need to 2873 know what the true target was. We take care to 2874 never use this value more than once in one expression. */ 2875 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), 2876 copy_to_reg (valreg)); 2877 set_mem_attributes (target, exp, 1); 2878 } 2879 /* Handle calls that return values in multiple non-contiguous locations. 2880 The Irix 6 ABI has examples of this. */ 2881 else if (GET_CODE (valreg) == PARALLEL) 2882 { 2883 if (target == 0) 2884 { 2885 /* This will only be assigned once, so it can be readonly. */ 2886 tree nt = build_qualified_type (TREE_TYPE (exp), 2887 (TYPE_QUALS (TREE_TYPE (exp)) 2888 | TYPE_QUAL_CONST)); 2889 2890 target = assign_temp (nt, 0, 1, 1); 2891 } 2892 2893 if (! rtx_equal_p (target, valreg)) 2894 emit_group_store (target, valreg, TREE_TYPE (exp), 2895 int_size_in_bytes (TREE_TYPE (exp))); 2896 2897 /* We can not support sibling calls for this case. */ 2898 sibcall_failure = 1; 2899 } 2900 else if (target 2901 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp)) 2902 && GET_MODE (target) == GET_MODE (valreg)) 2903 { 2904 bool may_overlap = false; 2905 2906 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard 2907 reg to a plain register. */ 2908 if (REG_P (valreg) 2909 && HARD_REGISTER_P (valreg) 2910 && CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (REGNO (valreg))) 2911 && !(REG_P (target) && !HARD_REGISTER_P (target))) 2912 valreg = copy_to_reg (valreg); 2913 2914 /* If TARGET is a MEM in the argument area, and we have 2915 saved part of the argument area, then we can't store 2916 directly into TARGET as it may get overwritten when we 2917 restore the argument save area below. Don't work too 2918 hard though and simply force TARGET to a register if it 2919 is a MEM; the optimizer is quite likely to sort it out. */ 2920 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target)) 2921 for (i = 0; i < num_actuals; i++) 2922 if (args[i].save_area) 2923 { 2924 may_overlap = true; 2925 break; 2926 } 2927 2928 if (may_overlap) 2929 target = copy_to_reg (valreg); 2930 else 2931 { 2932 /* TARGET and VALREG cannot be equal at this point 2933 because the latter would not have 2934 REG_FUNCTION_VALUE_P true, while the former would if 2935 it were referring to the same register. 2936 2937 If they refer to the same register, this move will be 2938 a no-op, except when function inlining is being 2939 done. */ 2940 emit_move_insn (target, valreg); 2941 2942 /* If we are setting a MEM, this code must be executed. 2943 Since it is emitted after the call insn, sibcall 2944 optimization cannot be performed in that case. */ 2945 if (MEM_P (target)) 2946 sibcall_failure = 1; 2947 } 2948 } 2949 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode) 2950 { 2951 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp)); 2952 2953 /* We can not support sibling calls for this case. */ 2954 sibcall_failure = 1; 2955 } 2956 else 2957 target = copy_to_reg (valreg); 2958 2959 if (targetm.calls.promote_function_return(funtype)) 2960 { 2961 /* If we promoted this return value, make the proper SUBREG. 2962 TARGET might be const0_rtx here, so be careful. */ 2963 if (REG_P (target) 2964 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode 2965 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp))) 2966 { 2967 tree type = TREE_TYPE (exp); 2968 int unsignedp = TYPE_UNSIGNED (type); 2969 int offset = 0; 2970 enum machine_mode pmode; 2971 2972 pmode = promote_mode (type, TYPE_MODE (type), &unsignedp, 1); 2973 /* If we don't promote as expected, something is wrong. */ 2974 gcc_assert (GET_MODE (target) == pmode); 2975 2976 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN) 2977 && (GET_MODE_SIZE (GET_MODE (target)) 2978 > GET_MODE_SIZE (TYPE_MODE (type)))) 2979 { 2980 offset = GET_MODE_SIZE (GET_MODE (target)) 2981 - GET_MODE_SIZE (TYPE_MODE (type)); 2982 if (! BYTES_BIG_ENDIAN) 2983 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD; 2984 else if (! WORDS_BIG_ENDIAN) 2985 offset %= UNITS_PER_WORD; 2986 } 2987 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset); 2988 SUBREG_PROMOTED_VAR_P (target) = 1; 2989 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp); 2990 } 2991 } 2992 2993 /* If size of args is variable or this was a constructor call for a stack 2994 argument, restore saved stack-pointer value. */ 2995 2996 if (old_stack_level && ! (flags & ECF_SP_DEPRESSED)) 2997 { 2998 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX); 2999 stack_pointer_delta = old_stack_pointer_delta; 3000 pending_stack_adjust = old_pending_adj; 3001 old_stack_allocated = stack_pointer_delta - pending_stack_adjust; 3002 stack_arg_under_construction = old_stack_arg_under_construction; 3003 highest_outgoing_arg_in_use = initial_highest_arg_in_use; 3004 stack_usage_map = initial_stack_usage_map; 3005 sibcall_failure = 1; 3006 } 3007 else if (ACCUMULATE_OUTGOING_ARGS && pass) 3008 { 3009#ifdef REG_PARM_STACK_SPACE 3010 if (save_area) 3011 restore_fixed_argument_area (save_area, argblock, 3012 high_to_save, low_to_save); 3013#endif 3014 3015 /* If we saved any argument areas, restore them. */ 3016 for (i = 0; i < num_actuals; i++) 3017 if (args[i].save_area) 3018 { 3019 enum machine_mode save_mode = GET_MODE (args[i].save_area); 3020 rtx stack_area 3021 = gen_rtx_MEM (save_mode, 3022 memory_address (save_mode, 3023 XEXP (args[i].stack_slot, 0))); 3024 3025 if (save_mode != BLKmode) 3026 emit_move_insn (stack_area, args[i].save_area); 3027 else 3028 emit_block_move (stack_area, args[i].save_area, 3029 GEN_INT (args[i].locate.size.constant), 3030 BLOCK_OP_CALL_PARM); 3031 } 3032 3033 highest_outgoing_arg_in_use = initial_highest_arg_in_use; 3034 stack_usage_map = initial_stack_usage_map; 3035 } 3036 3037 /* If this was alloca, record the new stack level for nonlocal gotos. 3038 Check for the handler slots since we might not have a save area 3039 for non-local gotos. */ 3040 3041 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0) 3042 update_nonlocal_goto_save_area (); 3043 3044 /* Free up storage we no longer need. */ 3045 for (i = 0; i < num_actuals; ++i) 3046 if (args[i].aligned_regs) 3047 free (args[i].aligned_regs); 3048 3049 insns = get_insns (); 3050 end_sequence (); 3051 3052 if (pass == 0) 3053 { 3054 tail_call_insns = insns; 3055 3056 /* Restore the pending stack adjustment now that we have 3057 finished generating the sibling call sequence. */ 3058 3059 pending_stack_adjust = save_pending_stack_adjust; 3060 stack_pointer_delta = save_stack_pointer_delta; 3061 3062 /* Prepare arg structure for next iteration. */ 3063 for (i = 0; i < num_actuals; i++) 3064 { 3065 args[i].value = 0; 3066 args[i].aligned_regs = 0; 3067 args[i].stack = 0; 3068 } 3069 3070 sbitmap_free (stored_args_map); 3071 } 3072 else 3073 { 3074 normal_call_insns = insns; 3075 3076 /* Verify that we've deallocated all the stack we used. */ 3077 gcc_assert ((flags & ECF_NORETURN) 3078 || (old_stack_allocated 3079 == stack_pointer_delta - pending_stack_adjust)); 3080 } 3081 3082 /* If something prevents making this a sibling call, 3083 zero out the sequence. */ 3084 if (sibcall_failure) 3085 tail_call_insns = NULL_RTX; 3086 else 3087 break; 3088 } 3089 3090 /* If tail call production succeeded, we need to remove REG_EQUIV notes on 3091 arguments too, as argument area is now clobbered by the call. */ 3092 if (tail_call_insns) 3093 { 3094 emit_insn (tail_call_insns); 3095 cfun->tail_call_emit = true; 3096 } 3097 else 3098 emit_insn (normal_call_insns); 3099 3100 currently_expanding_call--; 3101 3102 /* If this function returns with the stack pointer depressed, ensure 3103 this block saves and restores the stack pointer, show it was 3104 changed, and adjust for any outgoing arg space. */ 3105 if (flags & ECF_SP_DEPRESSED) 3106 { 3107 clear_pending_stack_adjust (); 3108 emit_insn (gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx)); 3109 emit_move_insn (virtual_stack_dynamic_rtx, stack_pointer_rtx); 3110 } 3111 3112 if (stack_usage_map_buf) 3113 free (stack_usage_map_buf); 3114 3115 return target; 3116} 3117 3118/* A sibling call sequence invalidates any REG_EQUIV notes made for 3119 this function's incoming arguments. 3120 3121 At the start of RTL generation we know the only REG_EQUIV notes 3122 in the rtl chain are those for incoming arguments, so we can look 3123 for REG_EQUIV notes between the start of the function and the 3124 NOTE_INSN_FUNCTION_BEG. 3125 3126 This is (slight) overkill. We could keep track of the highest 3127 argument we clobber and be more selective in removing notes, but it 3128 does not seem to be worth the effort. */ 3129 3130void 3131fixup_tail_calls (void) 3132{ 3133 rtx insn; 3134 3135 for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) 3136 { 3137 /* There are never REG_EQUIV notes for the incoming arguments 3138 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */ 3139 if (NOTE_P (insn) 3140 && NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG) 3141 break; 3142 3143 while (1) 3144 { 3145 rtx note = find_reg_note (insn, REG_EQUIV, 0); 3146 if (note) 3147 { 3148 /* Remove the note and keep looking at the notes for 3149 this insn. */ 3150 remove_note (insn, note); 3151 continue; 3152 } 3153 break; 3154 } 3155 } 3156} 3157 3158/* Traverse an argument list in VALUES and expand all complex 3159 arguments into their components. */ 3160static tree 3161split_complex_values (tree values) 3162{ 3163 tree p; 3164 3165 /* Before allocating memory, check for the common case of no complex. */ 3166 for (p = values; p; p = TREE_CHAIN (p)) 3167 { 3168 tree type = TREE_TYPE (TREE_VALUE (p)); 3169 if (type && TREE_CODE (type) == COMPLEX_TYPE 3170 && targetm.calls.split_complex_arg (type)) 3171 goto found; 3172 } 3173 return values; 3174 3175 found: 3176 values = copy_list (values); 3177 3178 for (p = values; p; p = TREE_CHAIN (p)) 3179 { 3180 tree complex_value = TREE_VALUE (p); 3181 tree complex_type; 3182 3183 complex_type = TREE_TYPE (complex_value); 3184 if (!complex_type) 3185 continue; 3186 3187 if (TREE_CODE (complex_type) == COMPLEX_TYPE 3188 && targetm.calls.split_complex_arg (complex_type)) 3189 { 3190 tree subtype; 3191 tree real, imag, next; 3192 3193 subtype = TREE_TYPE (complex_type); 3194 complex_value = save_expr (complex_value); 3195 real = build1 (REALPART_EXPR, subtype, complex_value); 3196 imag = build1 (IMAGPART_EXPR, subtype, complex_value); 3197 3198 TREE_VALUE (p) = real; 3199 next = TREE_CHAIN (p); 3200 imag = build_tree_list (NULL_TREE, imag); 3201 TREE_CHAIN (p) = imag; 3202 TREE_CHAIN (imag) = next; 3203 3204 /* Skip the newly created node. */ 3205 p = TREE_CHAIN (p); 3206 } 3207 } 3208 3209 return values; 3210} 3211 3212/* Traverse a list of TYPES and expand all complex types into their 3213 components. */ 3214static tree 3215split_complex_types (tree types) 3216{ 3217 tree p; 3218 3219 /* Before allocating memory, check for the common case of no complex. */ 3220 for (p = types; p; p = TREE_CHAIN (p)) 3221 { 3222 tree type = TREE_VALUE (p); 3223 if (TREE_CODE (type) == COMPLEX_TYPE 3224 && targetm.calls.split_complex_arg (type)) 3225 goto found; 3226 } 3227 return types; 3228 3229 found: 3230 types = copy_list (types); 3231 3232 for (p = types; p; p = TREE_CHAIN (p)) 3233 { 3234 tree complex_type = TREE_VALUE (p); 3235 3236 if (TREE_CODE (complex_type) == COMPLEX_TYPE 3237 && targetm.calls.split_complex_arg (complex_type)) 3238 { 3239 tree next, imag; 3240 3241 /* Rewrite complex type with component type. */ 3242 TREE_VALUE (p) = TREE_TYPE (complex_type); 3243 next = TREE_CHAIN (p); 3244 3245 /* Add another component type for the imaginary part. */ 3246 imag = build_tree_list (NULL_TREE, TREE_VALUE (p)); 3247 TREE_CHAIN (p) = imag; 3248 TREE_CHAIN (imag) = next; 3249 3250 /* Skip the newly created node. */ 3251 p = TREE_CHAIN (p); 3252 } 3253 } 3254 3255 return types; 3256} 3257 3258/* Output a library call to function FUN (a SYMBOL_REF rtx). 3259 The RETVAL parameter specifies whether return value needs to be saved, other 3260 parameters are documented in the emit_library_call function below. */ 3261 3262static rtx 3263emit_library_call_value_1 (int retval, rtx orgfun, rtx value, 3264 enum libcall_type fn_type, 3265 enum machine_mode outmode, int nargs, va_list p) 3266{ 3267 /* Total size in bytes of all the stack-parms scanned so far. */ 3268 struct args_size args_size; 3269 /* Size of arguments before any adjustments (such as rounding). */ 3270 struct args_size original_args_size; 3271 int argnum; 3272 rtx fun; 3273 int inc; 3274 int count; 3275 rtx argblock = 0; 3276 CUMULATIVE_ARGS args_so_far; 3277 struct arg 3278 { 3279 rtx value; 3280 enum machine_mode mode; 3281 rtx reg; 3282 int partial; 3283 struct locate_and_pad_arg_data locate; 3284 rtx save_area; 3285 }; 3286 struct arg *argvec; 3287 int old_inhibit_defer_pop = inhibit_defer_pop; 3288 rtx call_fusage = 0; 3289 rtx mem_value = 0; 3290 rtx valreg; 3291 int pcc_struct_value = 0; 3292 int struct_value_size = 0; 3293 int flags; 3294 int reg_parm_stack_space = 0; 3295 int needed; 3296 rtx before_call; 3297 tree tfom; /* type_for_mode (outmode, 0) */ 3298 3299#ifdef REG_PARM_STACK_SPACE 3300 /* Define the boundary of the register parm stack space that needs to be 3301 save, if any. */ 3302 int low_to_save, high_to_save; 3303 rtx save_area = 0; /* Place that it is saved. */ 3304#endif 3305 3306 /* Size of the stack reserved for parameter registers. */ 3307 int initial_highest_arg_in_use = highest_outgoing_arg_in_use; 3308 char *initial_stack_usage_map = stack_usage_map; 3309 char *stack_usage_map_buf = NULL; 3310 3311 rtx struct_value = targetm.calls.struct_value_rtx (0, 0); 3312 3313#ifdef REG_PARM_STACK_SPACE 3314 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0); 3315#endif 3316 3317 /* By default, library functions can not throw. */ 3318 flags = ECF_NOTHROW; 3319 3320 switch (fn_type) 3321 { 3322 case LCT_NORMAL: 3323 break; 3324 case LCT_CONST: 3325 flags |= ECF_CONST; 3326 break; 3327 case LCT_PURE: 3328 flags |= ECF_PURE; 3329 break; 3330 case LCT_CONST_MAKE_BLOCK: 3331 flags |= ECF_CONST | ECF_LIBCALL_BLOCK; 3332 break; 3333 case LCT_PURE_MAKE_BLOCK: 3334 flags |= ECF_PURE | ECF_LIBCALL_BLOCK; 3335 break; 3336 case LCT_NORETURN: 3337 flags |= ECF_NORETURN; 3338 break; 3339 case LCT_THROW: 3340 flags = ECF_NORETURN; 3341 break; 3342 case LCT_RETURNS_TWICE: 3343 flags = ECF_RETURNS_TWICE; 3344 break; 3345 } 3346 fun = orgfun; 3347 3348 /* Ensure current function's preferred stack boundary is at least 3349 what we need. */ 3350 if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY) 3351 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY; 3352 3353 /* If this kind of value comes back in memory, 3354 decide where in memory it should come back. */ 3355 if (outmode != VOIDmode) 3356 { 3357 tfom = lang_hooks.types.type_for_mode (outmode, 0); 3358 if (aggregate_value_p (tfom, 0)) 3359 { 3360#ifdef PCC_STATIC_STRUCT_RETURN 3361 rtx pointer_reg 3362 = hard_function_value (build_pointer_type (tfom), 0, 0, 0); 3363 mem_value = gen_rtx_MEM (outmode, pointer_reg); 3364 pcc_struct_value = 1; 3365 if (value == 0) 3366 value = gen_reg_rtx (outmode); 3367#else /* not PCC_STATIC_STRUCT_RETURN */ 3368 struct_value_size = GET_MODE_SIZE (outmode); 3369 if (value != 0 && MEM_P (value)) 3370 mem_value = value; 3371 else 3372 mem_value = assign_temp (tfom, 0, 1, 1); 3373#endif 3374 /* This call returns a big structure. */ 3375 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK); 3376 } 3377 } 3378 else 3379 tfom = void_type_node; 3380 3381 /* ??? Unfinished: must pass the memory address as an argument. */ 3382 3383 /* Copy all the libcall-arguments out of the varargs data 3384 and into a vector ARGVEC. 3385 3386 Compute how to pass each argument. We only support a very small subset 3387 of the full argument passing conventions to limit complexity here since 3388 library functions shouldn't have many args. */ 3389 3390 argvec = alloca ((nargs + 1) * sizeof (struct arg)); 3391 memset (argvec, 0, (nargs + 1) * sizeof (struct arg)); 3392 3393#ifdef INIT_CUMULATIVE_LIBCALL_ARGS 3394 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun); 3395#else 3396 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0, nargs); 3397#endif 3398 3399 args_size.constant = 0; 3400 args_size.var = 0; 3401 3402 count = 0; 3403 3404 /* Now we are about to start emitting insns that can be deleted 3405 if a libcall is deleted. */ 3406 if (flags & ECF_LIBCALL_BLOCK) 3407 start_sequence (); 3408 3409 push_temp_slots (); 3410 3411 /* If there's a structure value address to be passed, 3412 either pass it in the special place, or pass it as an extra argument. */ 3413 if (mem_value && struct_value == 0 && ! pcc_struct_value) 3414 { 3415 rtx addr = XEXP (mem_value, 0); 3416 3417 nargs++; 3418 3419 /* Make sure it is a reasonable operand for a move or push insn. */ 3420 if (!REG_P (addr) && !MEM_P (addr) 3421 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr))) 3422 addr = force_operand (addr, NULL_RTX); 3423 3424 argvec[count].value = addr; 3425 argvec[count].mode = Pmode; 3426 argvec[count].partial = 0; 3427 3428 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1); 3429 gcc_assert (targetm.calls.arg_partial_bytes (&args_so_far, Pmode, 3430 NULL_TREE, 1) == 0); 3431 3432 locate_and_pad_parm (Pmode, NULL_TREE, 3433#ifdef STACK_PARMS_IN_REG_PARM_AREA 3434 1, 3435#else 3436 argvec[count].reg != 0, 3437#endif 3438 0, NULL_TREE, &args_size, &argvec[count].locate); 3439 3440 if (argvec[count].reg == 0 || argvec[count].partial != 0 3441 || reg_parm_stack_space > 0) 3442 args_size.constant += argvec[count].locate.size.constant; 3443 3444 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1); 3445 3446 count++; 3447 } 3448 3449 for (; count < nargs; count++) 3450 { 3451 rtx val = va_arg (p, rtx); 3452 enum machine_mode mode = va_arg (p, enum machine_mode); 3453 3454 /* We cannot convert the arg value to the mode the library wants here; 3455 must do it earlier where we know the signedness of the arg. */ 3456 gcc_assert (mode != BLKmode 3457 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode)); 3458 3459 /* Make sure it is a reasonable operand for a move or push insn. */ 3460 if (!REG_P (val) && !MEM_P (val) 3461 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val))) 3462 val = force_operand (val, NULL_RTX); 3463 3464 if (pass_by_reference (&args_so_far, mode, NULL_TREE, 1)) 3465 { 3466 rtx slot; 3467 int must_copy 3468 = !reference_callee_copied (&args_so_far, mode, NULL_TREE, 1); 3469 3470 /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure 3471 functions, so we have to pretend this isn't such a function. */ 3472 if (flags & ECF_LIBCALL_BLOCK) 3473 { 3474 rtx insns = get_insns (); 3475 end_sequence (); 3476 emit_insn (insns); 3477 } 3478 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK); 3479 3480 /* If this was a CONST function, it is now PURE since 3481 it now reads memory. */ 3482 if (flags & ECF_CONST) 3483 { 3484 flags &= ~ECF_CONST; 3485 flags |= ECF_PURE; 3486 } 3487 3488 if (GET_MODE (val) == MEM && !must_copy) 3489 slot = val; 3490 else 3491 { 3492 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0), 3493 0, 1, 1); 3494 emit_move_insn (slot, val); 3495 } 3496 3497 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, 3498 gen_rtx_USE (VOIDmode, slot), 3499 call_fusage); 3500 if (must_copy) 3501 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, 3502 gen_rtx_CLOBBER (VOIDmode, 3503 slot), 3504 call_fusage); 3505 3506 mode = Pmode; 3507 val = force_operand (XEXP (slot, 0), NULL_RTX); 3508 } 3509 3510 argvec[count].value = val; 3511 argvec[count].mode = mode; 3512 3513 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1); 3514 3515 argvec[count].partial 3516 = targetm.calls.arg_partial_bytes (&args_so_far, mode, NULL_TREE, 1); 3517 3518 locate_and_pad_parm (mode, NULL_TREE, 3519#ifdef STACK_PARMS_IN_REG_PARM_AREA 3520 1, 3521#else 3522 argvec[count].reg != 0, 3523#endif 3524 argvec[count].partial, 3525 NULL_TREE, &args_size, &argvec[count].locate); 3526 3527 gcc_assert (!argvec[count].locate.size.var); 3528 3529 if (argvec[count].reg == 0 || argvec[count].partial != 0 3530 || reg_parm_stack_space > 0) 3531 args_size.constant += argvec[count].locate.size.constant; 3532 3533 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1); 3534 } 3535 3536 /* If this machine requires an external definition for library 3537 functions, write one out. */ 3538 assemble_external_libcall (fun); 3539 3540 original_args_size = args_size; 3541 args_size.constant = (((args_size.constant 3542 + stack_pointer_delta 3543 + STACK_BYTES - 1) 3544 / STACK_BYTES 3545 * STACK_BYTES) 3546 - stack_pointer_delta); 3547 3548 args_size.constant = MAX (args_size.constant, 3549 reg_parm_stack_space); 3550 3551#ifndef OUTGOING_REG_PARM_STACK_SPACE 3552 args_size.constant -= reg_parm_stack_space; 3553#endif 3554 3555 if (args_size.constant > current_function_outgoing_args_size) 3556 current_function_outgoing_args_size = args_size.constant; 3557 3558 if (ACCUMULATE_OUTGOING_ARGS) 3559 { 3560 /* Since the stack pointer will never be pushed, it is possible for 3561 the evaluation of a parm to clobber something we have already 3562 written to the stack. Since most function calls on RISC machines 3563 do not use the stack, this is uncommon, but must work correctly. 3564 3565 Therefore, we save any area of the stack that was already written 3566 and that we are using. Here we set up to do this by making a new 3567 stack usage map from the old one. 3568 3569 Another approach might be to try to reorder the argument 3570 evaluations to avoid this conflicting stack usage. */ 3571 3572 needed = args_size.constant; 3573 3574#ifndef OUTGOING_REG_PARM_STACK_SPACE 3575 /* Since we will be writing into the entire argument area, the 3576 map must be allocated for its entire size, not just the part that 3577 is the responsibility of the caller. */ 3578 needed += reg_parm_stack_space; 3579#endif 3580 3581#ifdef ARGS_GROW_DOWNWARD 3582 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, 3583 needed + 1); 3584#else 3585 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, 3586 needed); 3587#endif 3588 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use); 3589 stack_usage_map = stack_usage_map_buf; 3590 3591 if (initial_highest_arg_in_use) 3592 memcpy (stack_usage_map, initial_stack_usage_map, 3593 initial_highest_arg_in_use); 3594 3595 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use) 3596 memset (&stack_usage_map[initial_highest_arg_in_use], 0, 3597 highest_outgoing_arg_in_use - initial_highest_arg_in_use); 3598 needed = 0; 3599 3600 /* We must be careful to use virtual regs before they're instantiated, 3601 and real regs afterwards. Loop optimization, for example, can create 3602 new libcalls after we've instantiated the virtual regs, and if we 3603 use virtuals anyway, they won't match the rtl patterns. */ 3604 3605 if (virtuals_instantiated) 3606 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET); 3607 else 3608 argblock = virtual_outgoing_args_rtx; 3609 } 3610 else 3611 { 3612 if (!PUSH_ARGS) 3613 argblock = push_block (GEN_INT (args_size.constant), 0, 0); 3614 } 3615 3616 /* If we push args individually in reverse order, perform stack alignment 3617 before the first push (the last arg). */ 3618 if (argblock == 0 && PUSH_ARGS_REVERSED) 3619 anti_adjust_stack (GEN_INT (args_size.constant 3620 - original_args_size.constant)); 3621 3622 if (PUSH_ARGS_REVERSED) 3623 { 3624 inc = -1; 3625 argnum = nargs - 1; 3626 } 3627 else 3628 { 3629 inc = 1; 3630 argnum = 0; 3631 } 3632 3633#ifdef REG_PARM_STACK_SPACE 3634 if (ACCUMULATE_OUTGOING_ARGS) 3635 { 3636 /* The argument list is the property of the called routine and it 3637 may clobber it. If the fixed area has been used for previous 3638 parameters, we must save and restore it. */ 3639 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock, 3640 &low_to_save, &high_to_save); 3641 } 3642#endif 3643 3644 /* Push the args that need to be pushed. */ 3645 3646 /* ARGNUM indexes the ARGVEC array in the order in which the arguments 3647 are to be pushed. */ 3648 for (count = 0; count < nargs; count++, argnum += inc) 3649 { 3650 enum machine_mode mode = argvec[argnum].mode; 3651 rtx val = argvec[argnum].value; 3652 rtx reg = argvec[argnum].reg; 3653 int partial = argvec[argnum].partial; 3654 int lower_bound = 0, upper_bound = 0, i; 3655 3656 if (! (reg != 0 && partial == 0)) 3657 { 3658 if (ACCUMULATE_OUTGOING_ARGS) 3659 { 3660 /* If this is being stored into a pre-allocated, fixed-size, 3661 stack area, save any previous data at that location. */ 3662 3663#ifdef ARGS_GROW_DOWNWARD 3664 /* stack_slot is negative, but we want to index stack_usage_map 3665 with positive values. */ 3666 upper_bound = -argvec[argnum].locate.offset.constant + 1; 3667 lower_bound = upper_bound - argvec[argnum].locate.size.constant; 3668#else 3669 lower_bound = argvec[argnum].locate.offset.constant; 3670 upper_bound = lower_bound + argvec[argnum].locate.size.constant; 3671#endif 3672 3673 i = lower_bound; 3674 /* Don't worry about things in the fixed argument area; 3675 it has already been saved. */ 3676 if (i < reg_parm_stack_space) 3677 i = reg_parm_stack_space; 3678 while (i < upper_bound && stack_usage_map[i] == 0) 3679 i++; 3680 3681 if (i < upper_bound) 3682 { 3683 /* We need to make a save area. */ 3684 unsigned int size 3685 = argvec[argnum].locate.size.constant * BITS_PER_UNIT; 3686 enum machine_mode save_mode 3687 = mode_for_size (size, MODE_INT, 1); 3688 rtx adr 3689 = plus_constant (argblock, 3690 argvec[argnum].locate.offset.constant); 3691 rtx stack_area 3692 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr)); 3693 3694 if (save_mode == BLKmode) 3695 { 3696 argvec[argnum].save_area 3697 = assign_stack_temp (BLKmode, 3698 argvec[argnum].locate.size.constant, 3699 0); 3700 3701 emit_block_move (validize_mem (argvec[argnum].save_area), 3702 stack_area, 3703 GEN_INT (argvec[argnum].locate.size.constant), 3704 BLOCK_OP_CALL_PARM); 3705 } 3706 else 3707 { 3708 argvec[argnum].save_area = gen_reg_rtx (save_mode); 3709 3710 emit_move_insn (argvec[argnum].save_area, stack_area); 3711 } 3712 } 3713 } 3714 3715 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY, 3716 partial, reg, 0, argblock, 3717 GEN_INT (argvec[argnum].locate.offset.constant), 3718 reg_parm_stack_space, 3719 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad)); 3720 3721 /* Now mark the segment we just used. */ 3722 if (ACCUMULATE_OUTGOING_ARGS) 3723 for (i = lower_bound; i < upper_bound; i++) 3724 stack_usage_map[i] = 1; 3725 3726 NO_DEFER_POP; 3727 3728 if (flags & ECF_CONST) 3729 { 3730 rtx use; 3731 3732 /* Indicate argument access so that alias.c knows that these 3733 values are live. */ 3734 if (argblock) 3735 use = plus_constant (argblock, 3736 argvec[argnum].locate.offset.constant); 3737 else 3738 /* When arguments are pushed, trying to tell alias.c where 3739 exactly this argument is won't work, because the 3740 auto-increment causes confusion. So we merely indicate 3741 that we access something with a known mode somewhere on 3742 the stack. */ 3743 use = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx, 3744 gen_rtx_SCRATCH (Pmode)); 3745 use = gen_rtx_MEM (argvec[argnum].mode, use); 3746 use = gen_rtx_USE (VOIDmode, use); 3747 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage); 3748 } 3749 } 3750 } 3751 3752 /* If we pushed args in forward order, perform stack alignment 3753 after pushing the last arg. */ 3754 if (argblock == 0 && !PUSH_ARGS_REVERSED) 3755 anti_adjust_stack (GEN_INT (args_size.constant 3756 - original_args_size.constant)); 3757 3758 if (PUSH_ARGS_REVERSED) 3759 argnum = nargs - 1; 3760 else 3761 argnum = 0; 3762 3763 fun = prepare_call_address (fun, NULL, &call_fusage, 0, 0); 3764 3765 /* Now load any reg parms into their regs. */ 3766 3767 /* ARGNUM indexes the ARGVEC array in the order in which the arguments 3768 are to be pushed. */ 3769 for (count = 0; count < nargs; count++, argnum += inc) 3770 { 3771 enum machine_mode mode = argvec[argnum].mode; 3772 rtx val = argvec[argnum].value; 3773 rtx reg = argvec[argnum].reg; 3774 int partial = argvec[argnum].partial; 3775 3776 /* Handle calls that pass values in multiple non-contiguous 3777 locations. The PA64 has examples of this for library calls. */ 3778 if (reg != 0 && GET_CODE (reg) == PARALLEL) 3779 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode)); 3780 else if (reg != 0 && partial == 0) 3781 emit_move_insn (reg, val); 3782 3783 NO_DEFER_POP; 3784 } 3785 3786 /* Any regs containing parms remain in use through the call. */ 3787 for (count = 0; count < nargs; count++) 3788 { 3789 rtx reg = argvec[count].reg; 3790 if (reg != 0 && GET_CODE (reg) == PARALLEL) 3791 use_group_regs (&call_fusage, reg); 3792 else if (reg != 0) 3793 use_reg (&call_fusage, reg); 3794 } 3795 3796 /* Pass the function the address in which to return a structure value. */ 3797 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value) 3798 { 3799 emit_move_insn (struct_value, 3800 force_reg (Pmode, 3801 force_operand (XEXP (mem_value, 0), 3802 NULL_RTX))); 3803 if (REG_P (struct_value)) 3804 use_reg (&call_fusage, struct_value); 3805 } 3806 3807 /* Don't allow popping to be deferred, since then 3808 cse'ing of library calls could delete a call and leave the pop. */ 3809 NO_DEFER_POP; 3810 valreg = (mem_value == 0 && outmode != VOIDmode 3811 ? hard_libcall_value (outmode) : NULL_RTX); 3812 3813 /* Stack must be properly aligned now. */ 3814 gcc_assert (!(stack_pointer_delta 3815 & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1))); 3816 3817 before_call = get_last_insn (); 3818 3819 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which 3820 will set inhibit_defer_pop to that value. */ 3821 /* The return type is needed to decide how many bytes the function pops. 3822 Signedness plays no role in that, so for simplicity, we pretend it's 3823 always signed. We also assume that the list of arguments passed has 3824 no impact, so we pretend it is unknown. */ 3825 3826 emit_call_1 (fun, NULL, 3827 get_identifier (XSTR (orgfun, 0)), 3828 build_function_type (tfom, NULL_TREE), 3829 original_args_size.constant, args_size.constant, 3830 struct_value_size, 3831 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1), 3832 valreg, 3833 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far); 3834 3835 /* For calls to `setjmp', etc., inform flow.c it should complain 3836 if nonvolatile values are live. For functions that cannot return, 3837 inform flow that control does not fall through. */ 3838 3839 if (flags & ECF_NORETURN) 3840 { 3841 /* The barrier note must be emitted 3842 immediately after the CALL_INSN. Some ports emit more than 3843 just a CALL_INSN above, so we must search for it here. */ 3844 3845 rtx last = get_last_insn (); 3846 while (!CALL_P (last)) 3847 { 3848 last = PREV_INSN (last); 3849 /* There was no CALL_INSN? */ 3850 gcc_assert (last != before_call); 3851 } 3852 3853 emit_barrier_after (last); 3854 } 3855 3856 /* Now restore inhibit_defer_pop to its actual original value. */ 3857 OK_DEFER_POP; 3858 3859 /* If call is cse'able, make appropriate pair of reg-notes around it. 3860 Test valreg so we don't crash; may safely ignore `const' 3861 if return type is void. Disable for PARALLEL return values, because 3862 we have no way to move such values into a pseudo register. */ 3863 if (flags & ECF_LIBCALL_BLOCK) 3864 { 3865 rtx insns; 3866 3867 if (valreg == 0) 3868 { 3869 insns = get_insns (); 3870 end_sequence (); 3871 emit_insn (insns); 3872 } 3873 else 3874 { 3875 rtx note = 0; 3876 rtx temp; 3877 int i; 3878 3879 if (GET_CODE (valreg) == PARALLEL) 3880 { 3881 temp = gen_reg_rtx (outmode); 3882 emit_group_store (temp, valreg, NULL_TREE, 3883 GET_MODE_SIZE (outmode)); 3884 valreg = temp; 3885 } 3886 3887 temp = gen_reg_rtx (GET_MODE (valreg)); 3888 3889 /* Construct an "equal form" for the value which mentions all the 3890 arguments in order as well as the function name. */ 3891 for (i = 0; i < nargs; i++) 3892 note = gen_rtx_EXPR_LIST (VOIDmode, argvec[i].value, note); 3893 note = gen_rtx_EXPR_LIST (VOIDmode, fun, note); 3894 3895 insns = get_insns (); 3896 end_sequence (); 3897 3898 if (flags & ECF_PURE) 3899 note = gen_rtx_EXPR_LIST (VOIDmode, 3900 gen_rtx_USE (VOIDmode, 3901 gen_rtx_MEM (BLKmode, 3902 gen_rtx_SCRATCH (VOIDmode))), 3903 note); 3904 3905 emit_libcall_block (insns, temp, valreg, note); 3906 3907 valreg = temp; 3908 } 3909 } 3910 pop_temp_slots (); 3911 3912 /* Copy the value to the right place. */ 3913 if (outmode != VOIDmode && retval) 3914 { 3915 if (mem_value) 3916 { 3917 if (value == 0) 3918 value = mem_value; 3919 if (value != mem_value) 3920 emit_move_insn (value, mem_value); 3921 } 3922 else if (GET_CODE (valreg) == PARALLEL) 3923 { 3924 if (value == 0) 3925 value = gen_reg_rtx (outmode); 3926 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode)); 3927 } 3928 else if (value != 0) 3929 emit_move_insn (value, valreg); 3930 else 3931 value = valreg; 3932 } 3933 3934 if (ACCUMULATE_OUTGOING_ARGS) 3935 { 3936#ifdef REG_PARM_STACK_SPACE 3937 if (save_area) 3938 restore_fixed_argument_area (save_area, argblock, 3939 high_to_save, low_to_save); 3940#endif 3941 3942 /* If we saved any argument areas, restore them. */ 3943 for (count = 0; count < nargs; count++) 3944 if (argvec[count].save_area) 3945 { 3946 enum machine_mode save_mode = GET_MODE (argvec[count].save_area); 3947 rtx adr = plus_constant (argblock, 3948 argvec[count].locate.offset.constant); 3949 rtx stack_area = gen_rtx_MEM (save_mode, 3950 memory_address (save_mode, adr)); 3951 3952 if (save_mode == BLKmode) 3953 emit_block_move (stack_area, 3954 validize_mem (argvec[count].save_area), 3955 GEN_INT (argvec[count].locate.size.constant), 3956 BLOCK_OP_CALL_PARM); 3957 else 3958 emit_move_insn (stack_area, argvec[count].save_area); 3959 } 3960 3961 highest_outgoing_arg_in_use = initial_highest_arg_in_use; 3962 stack_usage_map = initial_stack_usage_map; 3963 } 3964 3965 if (stack_usage_map_buf) 3966 free (stack_usage_map_buf); 3967 3968 return value; 3969 3970} 3971 3972/* Output a library call to function FUN (a SYMBOL_REF rtx) 3973 (emitting the queue unless NO_QUEUE is nonzero), 3974 for a value of mode OUTMODE, 3975 with NARGS different arguments, passed as alternating rtx values 3976 and machine_modes to convert them to. 3977 3978 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const' 3979 calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls 3980 which should be enclosed in REG_LIBCALL/REG_RETVAL notes, 3981 LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in 3982 REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)), 3983 or other LCT_ value for other types of library calls. */ 3984 3985void 3986emit_library_call (rtx orgfun, enum libcall_type fn_type, 3987 enum machine_mode outmode, int nargs, ...) 3988{ 3989 va_list p; 3990 3991 va_start (p, nargs); 3992 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p); 3993 va_end (p); 3994} 3995 3996/* Like emit_library_call except that an extra argument, VALUE, 3997 comes second and says where to store the result. 3998 (If VALUE is zero, this function chooses a convenient way 3999 to return the value. 4000 4001 This function returns an rtx for where the value is to be found. 4002 If VALUE is nonzero, VALUE is returned. */ 4003 4004rtx 4005emit_library_call_value (rtx orgfun, rtx value, 4006 enum libcall_type fn_type, 4007 enum machine_mode outmode, int nargs, ...) 4008{ 4009 rtx result; 4010 va_list p; 4011 4012 va_start (p, nargs); 4013 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode, 4014 nargs, p); 4015 va_end (p); 4016 4017 return result; 4018} 4019 4020/* Store a single argument for a function call 4021 into the register or memory area where it must be passed. 4022 *ARG describes the argument value and where to pass it. 4023 4024 ARGBLOCK is the address of the stack-block for all the arguments, 4025 or 0 on a machine where arguments are pushed individually. 4026 4027 MAY_BE_ALLOCA nonzero says this could be a call to `alloca' 4028 so must be careful about how the stack is used. 4029 4030 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing 4031 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate 4032 that we need not worry about saving and restoring the stack. 4033 4034 FNDECL is the declaration of the function we are calling. 4035 4036 Return nonzero if this arg should cause sibcall failure, 4037 zero otherwise. */ 4038 4039static int 4040store_one_arg (struct arg_data *arg, rtx argblock, int flags, 4041 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space) 4042{ 4043 tree pval = arg->tree_value; 4044 rtx reg = 0; 4045 int partial = 0; 4046 int used = 0; 4047 int i, lower_bound = 0, upper_bound = 0; 4048 int sibcall_failure = 0; 4049 4050 if (TREE_CODE (pval) == ERROR_MARK) 4051 return 1; 4052 4053 /* Push a new temporary level for any temporaries we make for 4054 this argument. */ 4055 push_temp_slots (); 4056 4057 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)) 4058 { 4059 /* If this is being stored into a pre-allocated, fixed-size, stack area, 4060 save any previous data at that location. */ 4061 if (argblock && ! variable_size && arg->stack) 4062 { 4063#ifdef ARGS_GROW_DOWNWARD 4064 /* stack_slot is negative, but we want to index stack_usage_map 4065 with positive values. */ 4066 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS) 4067 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1; 4068 else 4069 upper_bound = 0; 4070 4071 lower_bound = upper_bound - arg->locate.size.constant; 4072#else 4073 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS) 4074 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)); 4075 else 4076 lower_bound = 0; 4077 4078 upper_bound = lower_bound + arg->locate.size.constant; 4079#endif 4080 4081 i = lower_bound; 4082 /* Don't worry about things in the fixed argument area; 4083 it has already been saved. */ 4084 if (i < reg_parm_stack_space) 4085 i = reg_parm_stack_space; 4086 while (i < upper_bound && stack_usage_map[i] == 0) 4087 i++; 4088 4089 if (i < upper_bound) 4090 { 4091 /* We need to make a save area. */ 4092 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT; 4093 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1); 4094 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0)); 4095 rtx stack_area = gen_rtx_MEM (save_mode, adr); 4096 4097 if (save_mode == BLKmode) 4098 { 4099 tree ot = TREE_TYPE (arg->tree_value); 4100 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot) 4101 | TYPE_QUAL_CONST)); 4102 4103 arg->save_area = assign_temp (nt, 0, 1, 1); 4104 preserve_temp_slots (arg->save_area); 4105 emit_block_move (validize_mem (arg->save_area), stack_area, 4106 GEN_INT (arg->locate.size.constant), 4107 BLOCK_OP_CALL_PARM); 4108 } 4109 else 4110 { 4111 arg->save_area = gen_reg_rtx (save_mode); 4112 emit_move_insn (arg->save_area, stack_area); 4113 } 4114 } 4115 } 4116 } 4117 4118 /* If this isn't going to be placed on both the stack and in registers, 4119 set up the register and number of words. */ 4120 if (! arg->pass_on_stack) 4121 { 4122 if (flags & ECF_SIBCALL) 4123 reg = arg->tail_call_reg; 4124 else 4125 reg = arg->reg; 4126 partial = arg->partial; 4127 } 4128 4129 /* Being passed entirely in a register. We shouldn't be called in 4130 this case. */ 4131 gcc_assert (reg == 0 || partial != 0); 4132 4133 /* If this arg needs special alignment, don't load the registers 4134 here. */ 4135 if (arg->n_aligned_regs != 0) 4136 reg = 0; 4137 4138 /* If this is being passed partially in a register, we can't evaluate 4139 it directly into its stack slot. Otherwise, we can. */ 4140 if (arg->value == 0) 4141 { 4142 /* stack_arg_under_construction is nonzero if a function argument is 4143 being evaluated directly into the outgoing argument list and 4144 expand_call must take special action to preserve the argument list 4145 if it is called recursively. 4146 4147 For scalar function arguments stack_usage_map is sufficient to 4148 determine which stack slots must be saved and restored. Scalar 4149 arguments in general have pass_on_stack == 0. 4150 4151 If this argument is initialized by a function which takes the 4152 address of the argument (a C++ constructor or a C function 4153 returning a BLKmode structure), then stack_usage_map is 4154 insufficient and expand_call must push the stack around the 4155 function call. Such arguments have pass_on_stack == 1. 4156 4157 Note that it is always safe to set stack_arg_under_construction, 4158 but this generates suboptimal code if set when not needed. */ 4159 4160 if (arg->pass_on_stack) 4161 stack_arg_under_construction++; 4162 4163 arg->value = expand_expr (pval, 4164 (partial 4165 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode) 4166 ? NULL_RTX : arg->stack, 4167 VOIDmode, EXPAND_STACK_PARM); 4168 4169 /* If we are promoting object (or for any other reason) the mode 4170 doesn't agree, convert the mode. */ 4171 4172 if (arg->mode != TYPE_MODE (TREE_TYPE (pval))) 4173 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)), 4174 arg->value, arg->unsignedp); 4175 4176 if (arg->pass_on_stack) 4177 stack_arg_under_construction--; 4178 } 4179 4180 /* Check for overlap with already clobbered argument area. */ 4181 if ((flags & ECF_SIBCALL) 4182 && MEM_P (arg->value) 4183 && mem_overlaps_already_clobbered_arg_p (XEXP (arg->value, 0), 4184 arg->locate.size.constant)) 4185 sibcall_failure = 1; 4186 4187 /* Don't allow anything left on stack from computation 4188 of argument to alloca. */ 4189 if (flags & ECF_MAY_BE_ALLOCA) 4190 do_pending_stack_adjust (); 4191 4192 if (arg->value == arg->stack) 4193 /* If the value is already in the stack slot, we are done. */ 4194 ; 4195 else if (arg->mode != BLKmode) 4196 { 4197 int size; 4198 4199 /* Argument is a scalar, not entirely passed in registers. 4200 (If part is passed in registers, arg->partial says how much 4201 and emit_push_insn will take care of putting it there.) 4202 4203 Push it, and if its size is less than the 4204 amount of space allocated to it, 4205 also bump stack pointer by the additional space. 4206 Note that in C the default argument promotions 4207 will prevent such mismatches. */ 4208 4209 size = GET_MODE_SIZE (arg->mode); 4210 /* Compute how much space the push instruction will push. 4211 On many machines, pushing a byte will advance the stack 4212 pointer by a halfword. */ 4213#ifdef PUSH_ROUNDING 4214 size = PUSH_ROUNDING (size); 4215#endif 4216 used = size; 4217 4218 /* Compute how much space the argument should get: 4219 round up to a multiple of the alignment for arguments. */ 4220 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval))) 4221 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1) 4222 / (PARM_BOUNDARY / BITS_PER_UNIT)) 4223 * (PARM_BOUNDARY / BITS_PER_UNIT)); 4224 4225 /* This isn't already where we want it on the stack, so put it there. 4226 This can either be done with push or copy insns. */ 4227 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX, 4228 PARM_BOUNDARY, partial, reg, used - size, argblock, 4229 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space, 4230 ARGS_SIZE_RTX (arg->locate.alignment_pad)); 4231 4232 /* Unless this is a partially-in-register argument, the argument is now 4233 in the stack. */ 4234 if (partial == 0) 4235 arg->value = arg->stack; 4236 } 4237 else 4238 { 4239 /* BLKmode, at least partly to be pushed. */ 4240 4241 unsigned int parm_align; 4242 int excess; 4243 rtx size_rtx; 4244 4245 /* Pushing a nonscalar. 4246 If part is passed in registers, PARTIAL says how much 4247 and emit_push_insn will take care of putting it there. */ 4248 4249 /* Round its size up to a multiple 4250 of the allocation unit for arguments. */ 4251 4252 if (arg->locate.size.var != 0) 4253 { 4254 excess = 0; 4255 size_rtx = ARGS_SIZE_RTX (arg->locate.size); 4256 } 4257 else 4258 { 4259 /* PUSH_ROUNDING has no effect on us, because emit_push_insn 4260 for BLKmode is careful to avoid it. */ 4261 excess = (arg->locate.size.constant 4262 - int_size_in_bytes (TREE_TYPE (pval)) 4263 + partial); 4264 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)), 4265 NULL_RTX, TYPE_MODE (sizetype), 0); 4266 } 4267 4268 parm_align = arg->locate.boundary; 4269 4270 /* When an argument is padded down, the block is aligned to 4271 PARM_BOUNDARY, but the actual argument isn't. */ 4272 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward) 4273 { 4274 if (arg->locate.size.var) 4275 parm_align = BITS_PER_UNIT; 4276 else if (excess) 4277 { 4278 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT; 4279 parm_align = MIN (parm_align, excess_align); 4280 } 4281 } 4282 4283 if ((flags & ECF_SIBCALL) && MEM_P (arg->value)) 4284 { 4285 /* emit_push_insn might not work properly if arg->value and 4286 argblock + arg->locate.offset areas overlap. */ 4287 rtx x = arg->value; 4288 int i = 0; 4289 4290 if (XEXP (x, 0) == current_function_internal_arg_pointer 4291 || (GET_CODE (XEXP (x, 0)) == PLUS 4292 && XEXP (XEXP (x, 0), 0) == 4293 current_function_internal_arg_pointer 4294 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)) 4295 { 4296 if (XEXP (x, 0) != current_function_internal_arg_pointer) 4297 i = INTVAL (XEXP (XEXP (x, 0), 1)); 4298 4299 /* expand_call should ensure this. */ 4300 gcc_assert (!arg->locate.offset.var 4301 && arg->locate.size.var == 0 4302 && GET_CODE (size_rtx) == CONST_INT); 4303 4304 if (arg->locate.offset.constant > i) 4305 { 4306 if (arg->locate.offset.constant < i + INTVAL (size_rtx)) 4307 sibcall_failure = 1; 4308 } 4309 else if (arg->locate.offset.constant < i) 4310 { 4311 /* Use arg->locate.size.constant instead of size_rtx 4312 because we only care about the part of the argument 4313 on the stack. */ 4314 if (i < (arg->locate.offset.constant 4315 + arg->locate.size.constant)) 4316 sibcall_failure = 1; 4317 } 4318 else 4319 { 4320 /* Even though they appear to be at the same location, 4321 if part of the outgoing argument is in registers, 4322 they aren't really at the same location. Check for 4323 this by making sure that the incoming size is the 4324 same as the outgoing size. */ 4325 if (arg->locate.size.constant != INTVAL (size_rtx)) 4326 sibcall_failure = 1; 4327 } 4328 } 4329 } 4330 4331 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx, 4332 parm_align, partial, reg, excess, argblock, 4333 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space, 4334 ARGS_SIZE_RTX (arg->locate.alignment_pad)); 4335 4336 /* Unless this is a partially-in-register argument, the argument is now 4337 in the stack. 4338 4339 ??? Unlike the case above, in which we want the actual 4340 address of the data, so that we can load it directly into a 4341 register, here we want the address of the stack slot, so that 4342 it's properly aligned for word-by-word copying or something 4343 like that. It's not clear that this is always correct. */ 4344 if (partial == 0) 4345 arg->value = arg->stack_slot; 4346 } 4347 4348 if (arg->reg && GET_CODE (arg->reg) == PARALLEL) 4349 { 4350 tree type = TREE_TYPE (arg->tree_value); 4351 arg->parallel_value 4352 = emit_group_load_into_temps (arg->reg, arg->value, type, 4353 int_size_in_bytes (type)); 4354 } 4355 4356 /* Mark all slots this store used. */ 4357 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL) 4358 && argblock && ! variable_size && arg->stack) 4359 for (i = lower_bound; i < upper_bound; i++) 4360 stack_usage_map[i] = 1; 4361 4362 /* Once we have pushed something, pops can't safely 4363 be deferred during the rest of the arguments. */ 4364 NO_DEFER_POP; 4365 4366 /* Free any temporary slots made in processing this argument. Show 4367 that we might have taken the address of something and pushed that 4368 as an operand. */ 4369 preserve_temp_slots (NULL_RTX); 4370 free_temp_slots (); 4371 pop_temp_slots (); 4372 4373 return sibcall_failure; 4374} 4375 4376/* Nonzero if we do not know how to pass TYPE solely in registers. */ 4377 4378bool 4379must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED, 4380 tree type) 4381{ 4382 if (!type) 4383 return false; 4384 4385 /* If the type has variable size... */ 4386 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST) 4387 return true; 4388 4389 /* If the type is marked as addressable (it is required 4390 to be constructed into the stack)... */ 4391 if (TREE_ADDRESSABLE (type)) 4392 return true; 4393 4394 return false; 4395} 4396 4397/* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one 4398 takes trailing padding of a structure into account. */ 4399/* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */ 4400 4401bool 4402must_pass_in_stack_var_size_or_pad (enum machine_mode mode, tree type) 4403{ 4404 if (!type) 4405 return false; 4406 4407 /* If the type has variable size... */ 4408 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST) 4409 return true; 4410 4411 /* If the type is marked as addressable (it is required 4412 to be constructed into the stack)... */ 4413 if (TREE_ADDRESSABLE (type)) 4414 return true; 4415 4416 /* If the padding and mode of the type is such that a copy into 4417 a register would put it into the wrong part of the register. */ 4418 if (mode == BLKmode 4419 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT) 4420 && (FUNCTION_ARG_PADDING (mode, type) 4421 == (BYTES_BIG_ENDIAN ? upward : downward))) 4422 return true; 4423 4424 return false; 4425} 4426