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