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 Free Software Foundation, Inc. 4 5This file is part of GCC. 6 7GCC is free software; you can redistribute it and/or modify it under 8the terms of the GNU General Public License as published by the Free 9Software Foundation; either version 2, or (at your option) any later 10version. 11 12GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13WARRANTY; without even the implied warranty of MERCHANTABILITY or 14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15for more details. 16 17You should have received a copy of the GNU General Public License 18along with GCC; see the file COPYING. If not, write to the Free 19Software Foundation, 59 Temple Place - Suite 330, Boston, MA 2002111-1307, USA. */ 21 22#include "config.h" 23#include "system.h" 24#include "rtl.h" 25#include "tree.h" 26#include "flags.h" 27#include "expr.h" 28#include "libfuncs.h" 29#include "function.h" 30#include "regs.h" 31#include "toplev.h" 32#include "output.h" 33#include "tm_p.h" 34#include "timevar.h" 35#include "sbitmap.h" 36 37#if !defined FUNCTION_OK_FOR_SIBCALL 38#define FUNCTION_OK_FOR_SIBCALL(DECL) 1 39#endif 40 41/* Decide whether a function's arguments should be processed 42 from first to last or from last to first. 43 44 They should if the stack and args grow in opposite directions, but 45 only if we have push insns. */ 46 47#ifdef PUSH_ROUNDING 48 49#if defined (STACK_GROWS_DOWNWARD) != defined (ARGS_GROW_DOWNWARD) 50#define PUSH_ARGS_REVERSED PUSH_ARGS 51#endif 52 53#endif 54 55#ifndef PUSH_ARGS_REVERSED 56#define PUSH_ARGS_REVERSED 0 57#endif 58 59#ifndef STACK_POINTER_OFFSET 60#define STACK_POINTER_OFFSET 0 61#endif 62 63/* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */ 64#define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT) 65 66/* Data structure and subroutines used within expand_call. */ 67 68struct arg_data 69{ 70 /* Tree node for this argument. */ 71 tree tree_value; 72 /* Mode for value; TYPE_MODE unless promoted. */ 73 enum machine_mode mode; 74 /* Current RTL value for argument, or 0 if it isn't precomputed. */ 75 rtx value; 76 /* Initially-compute RTL value for argument; only for const functions. */ 77 rtx initial_value; 78 /* Register to pass this argument in, 0 if passed on stack, or an 79 PARALLEL if the arg is to be copied into multiple non-contiguous 80 registers. */ 81 rtx reg; 82 /* Register to pass this argument in when generating tail call sequence. 83 This is not the same register as for normal calls on machines with 84 register windows. */ 85 rtx tail_call_reg; 86 /* If REG was promoted from the actual mode of the argument expression, 87 indicates whether the promotion is sign- or zero-extended. */ 88 int unsignedp; 89 /* Number of registers to use. 0 means put the whole arg in registers. 90 Also 0 if not passed in registers. */ 91 int partial; 92 /* Non-zero if argument must be passed on stack. 93 Note that some arguments may be passed on the stack 94 even though pass_on_stack is zero, just because FUNCTION_ARG says so. 95 pass_on_stack identifies arguments that *cannot* go in registers. */ 96 int pass_on_stack; 97 /* Offset of this argument from beginning of stack-args. */ 98 struct args_size offset; 99 /* Similar, but offset to the start of the stack slot. Different from 100 OFFSET if this arg pads downward. */ 101 struct args_size slot_offset; 102 /* Size of this argument on the stack, rounded up for any padding it gets, 103 parts of the argument passed in registers do not count. 104 If REG_PARM_STACK_SPACE is defined, then register parms 105 are counted here as well. */ 106 struct args_size size; 107 /* Location on the stack at which parameter should be stored. The store 108 has already been done if STACK == VALUE. */ 109 rtx stack; 110 /* Location on the stack of the start of this argument slot. This can 111 differ from STACK if this arg pads downward. This location is known 112 to be aligned to FUNCTION_ARG_BOUNDARY. */ 113 rtx stack_slot; 114 /* Place that this stack area has been saved, if needed. */ 115 rtx save_area; 116 /* If an argument's alignment does not permit direct copying into registers, 117 copy in smaller-sized pieces into pseudos. These are stored in a 118 block pointed to by this field. The next field says how many 119 word-sized pseudos we made. */ 120 rtx *aligned_regs; 121 int n_aligned_regs; 122 /* The amount that the stack pointer needs to be adjusted to 123 force alignment for the next argument. */ 124 struct args_size alignment_pad; 125}; 126 127/* A vector of one char per byte of stack space. A byte if non-zero if 128 the corresponding stack location has been used. 129 This vector is used to prevent a function call within an argument from 130 clobbering any stack already set up. */ 131static char *stack_usage_map; 132 133/* Size of STACK_USAGE_MAP. */ 134static int highest_outgoing_arg_in_use; 135 136/* A bitmap of virtual-incoming stack space. Bit is set if the corresponding 137 stack location's tail call argument has been already stored into the stack. 138 This bitmap is used to prevent sibling call optimization if function tries 139 to use parent's incoming argument slots when they have been already 140 overwritten with tail call arguments. */ 141static sbitmap stored_args_map; 142 143/* stack_arg_under_construction is nonzero when an argument may be 144 initialized with a constructor call (including a C function that 145 returns a BLKmode struct) and expand_call must take special action 146 to make sure the object being constructed does not overlap the 147 argument list for the constructor call. */ 148int stack_arg_under_construction; 149 150static int calls_function PARAMS ((tree, int)); 151static int calls_function_1 PARAMS ((tree, int)); 152 153/* Nonzero if this is a call to a `const' function. */ 154#define ECF_CONST 1 155/* Nonzero if this is a call to a `volatile' function. */ 156#define ECF_NORETURN 2 157/* Nonzero if this is a call to malloc or a related function. */ 158#define ECF_MALLOC 4 159/* Nonzero if it is plausible that this is a call to alloca. */ 160#define ECF_MAY_BE_ALLOCA 8 161/* Nonzero if this is a call to a function that won't throw an exception. */ 162#define ECF_NOTHROW 16 163/* Nonzero if this is a call to setjmp or a related function. */ 164#define ECF_RETURNS_TWICE 32 165/* Nonzero if this is a call to `longjmp'. */ 166#define ECF_LONGJMP 64 167/* Nonzero if this is a syscall that makes a new process in the image of 168 the current one. */ 169#define ECF_FORK_OR_EXEC 128 170#define ECF_SIBCALL 256 171/* Nonzero if this is a call to "pure" function (like const function, 172 but may read memory. */ 173#define ECF_PURE 512 174/* Nonzero if this is a call to a function that returns with the stack 175 pointer depressed. */ 176#define ECF_SP_DEPRESSED 1024 177/* Nonzero if this call is known to always return. */ 178#define ECF_ALWAYS_RETURN 2048 179/* Create libcall block around the call. */ 180#define ECF_LIBCALL_BLOCK 4096 181 182static void emit_call_1 PARAMS ((rtx, tree, tree, HOST_WIDE_INT, 183 HOST_WIDE_INT, HOST_WIDE_INT, rtx, 184 rtx, int, rtx, int, 185 CUMULATIVE_ARGS *)); 186static void precompute_register_parameters PARAMS ((int, 187 struct arg_data *, 188 int *)); 189static int store_one_arg PARAMS ((struct arg_data *, rtx, int, int, 190 int)); 191static void store_unaligned_arguments_into_pseudos PARAMS ((struct arg_data *, 192 int)); 193static int finalize_must_preallocate PARAMS ((int, int, 194 struct arg_data *, 195 struct args_size *)); 196static void precompute_arguments PARAMS ((int, int, 197 struct arg_data *)); 198static int compute_argument_block_size PARAMS ((int, 199 struct args_size *, 200 int)); 201static void initialize_argument_information PARAMS ((int, 202 struct arg_data *, 203 struct args_size *, 204 int, tree, tree, 205 CUMULATIVE_ARGS *, 206 int, rtx *, int *, 207 int *, int *)); 208static void compute_argument_addresses PARAMS ((struct arg_data *, 209 rtx, int)); 210static rtx rtx_for_function_call PARAMS ((tree, tree)); 211static void load_register_parameters PARAMS ((struct arg_data *, 212 int, rtx *, int)); 213static rtx emit_library_call_value_1 PARAMS ((int, rtx, rtx, 214 enum libcall_type, 215 enum machine_mode, 216 int, va_list)); 217static int special_function_p PARAMS ((tree, int)); 218static int flags_from_decl_or_type PARAMS ((tree)); 219static rtx try_to_integrate PARAMS ((tree, tree, rtx, 220 int, tree, rtx)); 221static int check_sibcall_argument_overlap_1 PARAMS ((rtx)); 222static int check_sibcall_argument_overlap PARAMS ((rtx, struct arg_data *)); 223 224static int combine_pending_stack_adjustment_and_call 225 PARAMS ((int, struct args_size *, int)); 226 227#ifdef REG_PARM_STACK_SPACE 228static rtx save_fixed_argument_area PARAMS ((int, rtx, int *, int *)); 229static void restore_fixed_argument_area PARAMS ((rtx, rtx, int, int)); 230#endif 231 232/* If WHICH is 1, return 1 if EXP contains a call to the built-in function 233 `alloca'. 234 235 If WHICH is 0, return 1 if EXP contains a call to any function. 236 Actually, we only need return 1 if evaluating EXP would require pushing 237 arguments on the stack, but that is too difficult to compute, so we just 238 assume any function call might require the stack. */ 239 240static tree calls_function_save_exprs; 241 242static int 243calls_function (exp, which) 244 tree exp; 245 int which; 246{ 247 int val; 248 249 calls_function_save_exprs = 0; 250 val = calls_function_1 (exp, which); 251 calls_function_save_exprs = 0; 252 return val; 253} 254 255/* Recursive function to do the work of above function. */ 256 257static int 258calls_function_1 (exp, which) 259 tree exp; 260 int which; 261{ 262 int i; 263 enum tree_code code = TREE_CODE (exp); 264 int class = TREE_CODE_CLASS (code); 265 int length = first_rtl_op (code); 266 267 /* If this code is language-specific, we don't know what it will do. */ 268 if ((int) code >= NUM_TREE_CODES) 269 return 1; 270 271 switch (code) 272 { 273 case CALL_EXPR: 274 if (which == 0) 275 return 1; 276 else if ((TREE_CODE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0)))) 277 == FUNCTION_TYPE) 278 && (TYPE_RETURNS_STACK_DEPRESSED 279 (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0)))))) 280 return 1; 281 else if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR 282 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0)) 283 == FUNCTION_DECL) 284 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0), 285 0) 286 & ECF_MAY_BE_ALLOCA)) 287 return 1; 288 289 break; 290 291 case CONSTRUCTOR: 292 { 293 tree tem; 294 295 for (tem = CONSTRUCTOR_ELTS (exp); tem != 0; tem = TREE_CHAIN (tem)) 296 if (calls_function_1 (TREE_VALUE (tem), which)) 297 return 1; 298 } 299 300 return 0; 301 302 case SAVE_EXPR: 303 if (SAVE_EXPR_RTL (exp) != 0) 304 return 0; 305 if (value_member (exp, calls_function_save_exprs)) 306 return 0; 307 calls_function_save_exprs = tree_cons (NULL_TREE, exp, 308 calls_function_save_exprs); 309 return (TREE_OPERAND (exp, 0) != 0 310 && calls_function_1 (TREE_OPERAND (exp, 0), which)); 311 312 case BLOCK: 313 { 314 tree local; 315 tree subblock; 316 317 for (local = BLOCK_VARS (exp); local; local = TREE_CHAIN (local)) 318 if (DECL_INITIAL (local) != 0 319 && calls_function_1 (DECL_INITIAL (local), which)) 320 return 1; 321 322 for (subblock = BLOCK_SUBBLOCKS (exp); 323 subblock; 324 subblock = TREE_CHAIN (subblock)) 325 if (calls_function_1 (subblock, which)) 326 return 1; 327 } 328 return 0; 329 330 case TREE_LIST: 331 for (; exp != 0; exp = TREE_CHAIN (exp)) 332 if (calls_function_1 (TREE_VALUE (exp), which)) 333 return 1; 334 return 0; 335 336 default: 337 break; 338 } 339 340 /* Only expressions, references, and blocks can contain calls. */ 341 if (! IS_EXPR_CODE_CLASS (class) && class != 'r' && class != 'b') 342 return 0; 343 344 for (i = 0; i < length; i++) 345 if (TREE_OPERAND (exp, i) != 0 346 && calls_function_1 (TREE_OPERAND (exp, i), which)) 347 return 1; 348 349 return 0; 350} 351 352/* Force FUNEXP into a form suitable for the address of a CALL, 353 and return that as an rtx. Also load the static chain register 354 if FNDECL is a nested function. 355 356 CALL_FUSAGE points to a variable holding the prospective 357 CALL_INSN_FUNCTION_USAGE information. */ 358 359rtx 360prepare_call_address (funexp, fndecl, call_fusage, reg_parm_seen, sibcallp) 361 rtx funexp; 362 tree fndecl; 363 rtx *call_fusage; 364 int reg_parm_seen; 365 int sibcallp; 366{ 367 rtx static_chain_value = 0; 368 369 funexp = protect_from_queue (funexp, 0); 370 371 if (fndecl != 0) 372 /* Get possible static chain value for nested function in C. */ 373 static_chain_value = lookup_static_chain (fndecl); 374 375 /* Make a valid memory address and copy constants thru pseudo-regs, 376 but not for a constant address if -fno-function-cse. */ 377 if (GET_CODE (funexp) != SYMBOL_REF) 378 /* If we are using registers for parameters, force the 379 function address into a register now. */ 380 funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen) 381 ? force_not_mem (memory_address (FUNCTION_MODE, funexp)) 382 : memory_address (FUNCTION_MODE, funexp)); 383 else if (! sibcallp) 384 { 385#ifndef NO_FUNCTION_CSE 386 if (optimize && ! flag_no_function_cse) 387#ifdef NO_RECURSIVE_FUNCTION_CSE 388 if (fndecl != current_function_decl) 389#endif 390 funexp = force_reg (Pmode, funexp); 391#endif 392 } 393 394 if (static_chain_value != 0) 395 { 396 emit_move_insn (static_chain_rtx, static_chain_value); 397 398 if (GET_CODE (static_chain_rtx) == REG) 399 use_reg (call_fusage, static_chain_rtx); 400 } 401 402 return funexp; 403} 404 405/* Generate instructions to call function FUNEXP, 406 and optionally pop the results. 407 The CALL_INSN is the first insn generated. 408 409 FNDECL is the declaration node of the function. This is given to the 410 macro RETURN_POPS_ARGS to determine whether this function pops its own args. 411 412 FUNTYPE is the data type of the function. This is given to the macro 413 RETURN_POPS_ARGS to determine whether this function pops its own args. 414 We used to allow an identifier for library functions, but that doesn't 415 work when the return type is an aggregate type and the calling convention 416 says that the pointer to this aggregate is to be popped by the callee. 417 418 STACK_SIZE is the number of bytes of arguments on the stack, 419 ROUNDED_STACK_SIZE is that number rounded up to 420 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is 421 both to put into the call insn and to generate explicit popping 422 code if necessary. 423 424 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value. 425 It is zero if this call doesn't want a structure value. 426 427 NEXT_ARG_REG is the rtx that results from executing 428 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1) 429 just after all the args have had their registers assigned. 430 This could be whatever you like, but normally it is the first 431 arg-register beyond those used for args in this call, 432 or 0 if all the arg-registers are used in this call. 433 It is passed on to `gen_call' so you can put this info in the call insn. 434 435 VALREG is a hard register in which a value is returned, 436 or 0 if the call does not return a value. 437 438 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before 439 the args to this call were processed. 440 We restore `inhibit_defer_pop' to that value. 441 442 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that 443 denote registers used by the called function. */ 444 445static void 446emit_call_1 (funexp, fndecl, funtype, stack_size, rounded_stack_size, 447 struct_value_size, next_arg_reg, valreg, old_inhibit_defer_pop, 448 call_fusage, ecf_flags, args_so_far) 449 rtx funexp; 450 tree fndecl ATTRIBUTE_UNUSED; 451 tree funtype ATTRIBUTE_UNUSED; 452 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED; 453 HOST_WIDE_INT rounded_stack_size; 454 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED; 455 rtx next_arg_reg ATTRIBUTE_UNUSED; 456 rtx valreg; 457 int old_inhibit_defer_pop; 458 rtx call_fusage; 459 int ecf_flags; 460 CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED; 461{ 462 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size); 463 rtx call_insn; 464 int already_popped = 0; 465 HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size); 466#if defined (HAVE_call) && defined (HAVE_call_value) 467 rtx struct_value_size_rtx; 468 struct_value_size_rtx = GEN_INT (struct_value_size); 469#endif 470 471#ifdef CALL_POPS_ARGS 472 n_popped += CALL_POPS_ARGS (* args_so_far); 473#endif 474 475 /* Ensure address is valid. SYMBOL_REF is already valid, so no need, 476 and we don't want to load it into a register as an optimization, 477 because prepare_call_address already did it if it should be done. */ 478 if (GET_CODE (funexp) != SYMBOL_REF) 479 funexp = memory_address (FUNCTION_MODE, funexp); 480 481#if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop) 482 if ((ecf_flags & ECF_SIBCALL) 483 && HAVE_sibcall_pop && HAVE_sibcall_value_pop 484 && (n_popped > 0 || stack_size == 0)) 485 { 486 rtx n_pop = GEN_INT (n_popped); 487 rtx pat; 488 489 /* If this subroutine pops its own args, record that in the call insn 490 if possible, for the sake of frame pointer elimination. */ 491 492 if (valreg) 493 pat = GEN_SIBCALL_VALUE_POP (valreg, 494 gen_rtx_MEM (FUNCTION_MODE, funexp), 495 rounded_stack_size_rtx, next_arg_reg, 496 n_pop); 497 else 498 pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp), 499 rounded_stack_size_rtx, next_arg_reg, n_pop); 500 501 emit_call_insn (pat); 502 already_popped = 1; 503 } 504 else 505#endif 506 507#if defined (HAVE_call_pop) && defined (HAVE_call_value_pop) 508 /* If the target has "call" or "call_value" insns, then prefer them 509 if no arguments are actually popped. If the target does not have 510 "call" or "call_value" insns, then we must use the popping versions 511 even if the call has no arguments to pop. */ 512#if defined (HAVE_call) && defined (HAVE_call_value) 513 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop 514 && n_popped > 0 && ! (ecf_flags & ECF_SP_DEPRESSED)) 515#else 516 if (HAVE_call_pop && HAVE_call_value_pop) 517#endif 518 { 519 rtx n_pop = GEN_INT (n_popped); 520 rtx pat; 521 522 /* If this subroutine pops its own args, record that in the call insn 523 if possible, for the sake of frame pointer elimination. */ 524 525 if (valreg) 526 pat = GEN_CALL_VALUE_POP (valreg, 527 gen_rtx_MEM (FUNCTION_MODE, funexp), 528 rounded_stack_size_rtx, next_arg_reg, n_pop); 529 else 530 pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp), 531 rounded_stack_size_rtx, next_arg_reg, n_pop); 532 533 emit_call_insn (pat); 534 already_popped = 1; 535 } 536 else 537#endif 538 539#if defined (HAVE_sibcall) && defined (HAVE_sibcall_value) 540 if ((ecf_flags & ECF_SIBCALL) 541 && HAVE_sibcall && HAVE_sibcall_value) 542 { 543 if (valreg) 544 emit_call_insn (GEN_SIBCALL_VALUE (valreg, 545 gen_rtx_MEM (FUNCTION_MODE, funexp), 546 rounded_stack_size_rtx, 547 next_arg_reg, NULL_RTX)); 548 else 549 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp), 550 rounded_stack_size_rtx, next_arg_reg, 551 struct_value_size_rtx)); 552 } 553 else 554#endif 555 556#if defined (HAVE_call) && defined (HAVE_call_value) 557 if (HAVE_call && HAVE_call_value) 558 { 559 if (valreg) 560 emit_call_insn (GEN_CALL_VALUE (valreg, 561 gen_rtx_MEM (FUNCTION_MODE, funexp), 562 rounded_stack_size_rtx, next_arg_reg, 563 NULL_RTX)); 564 else 565 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp), 566 rounded_stack_size_rtx, next_arg_reg, 567 struct_value_size_rtx)); 568 } 569 else 570#endif 571 abort (); 572 573 /* Find the CALL insn we just emitted. */ 574 for (call_insn = get_last_insn (); 575 call_insn && GET_CODE (call_insn) != CALL_INSN; 576 call_insn = PREV_INSN (call_insn)) 577 ; 578 579 if (! call_insn) 580 abort (); 581 582 /* Mark memory as used for "pure" function call. */ 583 if (ecf_flags & ECF_PURE) 584 call_fusage 585 = gen_rtx_EXPR_LIST 586 (VOIDmode, 587 gen_rtx_USE (VOIDmode, 588 gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode))), 589 call_fusage); 590 591 /* Put the register usage information on the CALL. If there is already 592 some usage information, put ours at the end. */ 593 if (CALL_INSN_FUNCTION_USAGE (call_insn)) 594 { 595 rtx link; 596 597 for (link = CALL_INSN_FUNCTION_USAGE (call_insn); XEXP (link, 1) != 0; 598 link = XEXP (link, 1)) 599 ; 600 601 XEXP (link, 1) = call_fusage; 602 } 603 else 604 CALL_INSN_FUNCTION_USAGE (call_insn) = call_fusage; 605 606 /* If this is a const call, then set the insn's unchanging bit. */ 607 if (ecf_flags & (ECF_CONST | ECF_PURE)) 608 CONST_OR_PURE_CALL_P (call_insn) = 1; 609 610 /* If this call can't throw, attach a REG_EH_REGION reg note to that 611 effect. */ 612 if (ecf_flags & ECF_NOTHROW) 613 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, const0_rtx, 614 REG_NOTES (call_insn)); 615 616 if (ecf_flags & ECF_NORETURN) 617 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_NORETURN, const0_rtx, 618 REG_NOTES (call_insn)); 619 if (ecf_flags & ECF_ALWAYS_RETURN) 620 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_ALWAYS_RETURN, const0_rtx, 621 REG_NOTES (call_insn)); 622 623 if (ecf_flags & ECF_RETURNS_TWICE) 624 { 625 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_SETJMP, const0_rtx, 626 REG_NOTES (call_insn)); 627 current_function_calls_setjmp = 1; 628 } 629 630 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0); 631 632 /* Restore this now, so that we do defer pops for this call's args 633 if the context of the call as a whole permits. */ 634 inhibit_defer_pop = old_inhibit_defer_pop; 635 636 if (n_popped > 0) 637 { 638 if (!already_popped) 639 CALL_INSN_FUNCTION_USAGE (call_insn) 640 = gen_rtx_EXPR_LIST (VOIDmode, 641 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx), 642 CALL_INSN_FUNCTION_USAGE (call_insn)); 643 rounded_stack_size -= n_popped; 644 rounded_stack_size_rtx = GEN_INT (rounded_stack_size); 645 stack_pointer_delta -= n_popped; 646 } 647 648 if (!ACCUMULATE_OUTGOING_ARGS) 649 { 650 /* If returning from the subroutine does not automatically pop the args, 651 we need an instruction to pop them sooner or later. 652 Perhaps do it now; perhaps just record how much space to pop later. 653 654 If returning from the subroutine does pop the args, indicate that the 655 stack pointer will be changed. */ 656 657 if (rounded_stack_size != 0) 658 { 659 if (ecf_flags & ECF_SP_DEPRESSED) 660 /* Just pretend we did the pop. */ 661 stack_pointer_delta -= rounded_stack_size; 662 else if (flag_defer_pop && inhibit_defer_pop == 0 663 && ! (ecf_flags & (ECF_CONST | ECF_PURE))) 664 pending_stack_adjust += rounded_stack_size; 665 else 666 adjust_stack (rounded_stack_size_rtx); 667 } 668 } 669 /* When we accumulate outgoing args, we must avoid any stack manipulations. 670 Restore the stack pointer to its original value now. Usually 671 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions. 672 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and 673 popping variants of functions exist as well. 674 675 ??? We may optimize similar to defer_pop above, but it is 676 probably not worthwhile. 677 678 ??? It will be worthwhile to enable combine_stack_adjustments even for 679 such machines. */ 680 else if (n_popped) 681 anti_adjust_stack (GEN_INT (n_popped)); 682} 683 684/* Determine if the function identified by NAME and FNDECL is one with 685 special properties we wish to know about. 686 687 For example, if the function might return more than one time (setjmp), then 688 set RETURNS_TWICE to a nonzero value. 689 690 Similarly set LONGJMP for if the function is in the longjmp family. 691 692 Set MALLOC for any of the standard memory allocation functions which 693 allocate from the heap. 694 695 Set MAY_BE_ALLOCA for any memory allocation function that might allocate 696 space from the stack such as alloca. */ 697 698static int 699special_function_p (fndecl, flags) 700 tree fndecl; 701 int flags; 702{ 703 if (! (flags & ECF_MALLOC) 704 && fndecl && DECL_NAME (fndecl) 705 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17 706 /* Exclude functions not at the file scope, or not `extern', 707 since they are not the magic functions we would otherwise 708 think they are. */ 709 && DECL_CONTEXT (fndecl) == NULL_TREE && TREE_PUBLIC (fndecl)) 710 { 711 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl)); 712 const char *tname = name; 713 714 /* We assume that alloca will always be called by name. It 715 makes no sense to pass it as a pointer-to-function to 716 anything that does not understand its behavior. */ 717 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6 718 && name[0] == 'a' 719 && ! strcmp (name, "alloca")) 720 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16 721 && name[0] == '_' 722 && ! strcmp (name, "__builtin_alloca")))) 723 flags |= ECF_MAY_BE_ALLOCA; 724 725 /* Disregard prefix _, __ or __x. */ 726 if (name[0] == '_') 727 { 728 if (name[1] == '_' && name[2] == 'x') 729 tname += 3; 730 else if (name[1] == '_') 731 tname += 2; 732 else 733 tname += 1; 734 } 735 736 if (tname[0] == 's') 737 { 738 if ((tname[1] == 'e' 739 && (! strcmp (tname, "setjmp") 740 || ! strcmp (tname, "setjmp_syscall"))) 741 || (tname[1] == 'i' 742 && ! strcmp (tname, "sigsetjmp")) 743 || (tname[1] == 'a' 744 && ! strcmp (tname, "savectx"))) 745 flags |= ECF_RETURNS_TWICE; 746 747 if (tname[1] == 'i' 748 && ! strcmp (tname, "siglongjmp")) 749 flags |= ECF_LONGJMP; 750 } 751 else if ((tname[0] == 'q' && tname[1] == 's' 752 && ! strcmp (tname, "qsetjmp")) 753 || (tname[0] == 'v' && tname[1] == 'f' 754 && ! strcmp (tname, "vfork"))) 755 flags |= ECF_RETURNS_TWICE; 756 757 else if (tname[0] == 'l' && tname[1] == 'o' 758 && ! strcmp (tname, "longjmp")) 759 flags |= ECF_LONGJMP; 760 761 else if ((tname[0] == 'f' && tname[1] == 'o' 762 && ! strcmp (tname, "fork")) 763 /* Linux specific: __clone. check NAME to insist on the 764 leading underscores, to avoid polluting the ISO / POSIX 765 namespace. */ 766 || (name[0] == '_' && name[1] == '_' 767 && ! strcmp (tname, "clone")) 768 || (tname[0] == 'e' && tname[1] == 'x' && tname[2] == 'e' 769 && tname[3] == 'c' && (tname[4] == 'l' || tname[4] == 'v') 770 && (tname[5] == '\0' 771 || ((tname[5] == 'p' || tname[5] == 'e') 772 && tname[6] == '\0')))) 773 flags |= ECF_FORK_OR_EXEC; 774 775 /* Do not add any more malloc-like functions to this list, 776 instead mark them as malloc functions using the malloc attribute. 777 Note, realloc is not suitable for attribute malloc since 778 it may return the same address across multiple calls. 779 C++ operator new is not suitable because it is not required 780 to return a unique pointer; indeed, the standard placement new 781 just returns its argument. */ 782 else if (TYPE_MODE (TREE_TYPE (TREE_TYPE (fndecl))) == Pmode 783 && (! strcmp (tname, "malloc") 784 || ! strcmp (tname, "calloc") 785 || ! strcmp (tname, "strdup"))) 786 flags |= ECF_MALLOC; 787 } 788 return flags; 789} 790 791/* Return nonzero when tree represent call to longjmp. */ 792 793int 794setjmp_call_p (fndecl) 795 tree fndecl; 796{ 797 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE; 798} 799 800/* Detect flags (function attributes) from the function decl or type node. */ 801 802static int 803flags_from_decl_or_type (exp) 804 tree exp; 805{ 806 int flags = 0; 807 tree type = exp; 808 /* ??? We can't set IS_MALLOC for function types? */ 809 if (DECL_P (exp)) 810 { 811 type = TREE_TYPE (exp); 812 813 /* The function exp may have the `malloc' attribute. */ 814 if (DECL_P (exp) && DECL_IS_MALLOC (exp)) 815 flags |= ECF_MALLOC; 816 817 /* The function exp may have the `pure' attribute. */ 818 if (DECL_P (exp) && DECL_IS_PURE (exp)) 819 flags |= ECF_PURE | ECF_LIBCALL_BLOCK; 820 821 if (TREE_NOTHROW (exp)) 822 flags |= ECF_NOTHROW; 823 } 824 825 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp)) 826 flags |= ECF_CONST | ECF_LIBCALL_BLOCK; 827 828 if (TREE_THIS_VOLATILE (exp)) 829 flags |= ECF_NORETURN; 830 831 /* Mark if the function returns with the stack pointer depressed. We 832 cannot consider it pure or constant in that case. */ 833 if (TREE_CODE (type) == FUNCTION_TYPE && TYPE_RETURNS_STACK_DEPRESSED (type)) 834 { 835 flags |= ECF_SP_DEPRESSED; 836 flags &= ~(ECF_PURE | ECF_CONST | ECF_LIBCALL_BLOCK); 837 } 838 839 return flags; 840} 841 842/* Precompute all register parameters as described by ARGS, storing values 843 into fields within the ARGS array. 844 845 NUM_ACTUALS indicates the total number elements in the ARGS array. 846 847 Set REG_PARM_SEEN if we encounter a register parameter. */ 848 849static void 850precompute_register_parameters (num_actuals, args, reg_parm_seen) 851 int num_actuals; 852 struct arg_data *args; 853 int *reg_parm_seen; 854{ 855 int i; 856 857 *reg_parm_seen = 0; 858 859 for (i = 0; i < num_actuals; i++) 860 if (args[i].reg != 0 && ! args[i].pass_on_stack) 861 { 862 *reg_parm_seen = 1; 863 864 if (args[i].value == 0) 865 { 866 push_temp_slots (); 867 args[i].value = expand_expr (args[i].tree_value, NULL_RTX, 868 VOIDmode, 0); 869 preserve_temp_slots (args[i].value); 870 pop_temp_slots (); 871 872 /* ANSI doesn't require a sequence point here, 873 but PCC has one, so this will avoid some problems. */ 874 emit_queue (); 875 } 876 877 /* If we are to promote the function arg to a wider mode, 878 do it now. */ 879 880 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value))) 881 args[i].value 882 = convert_modes (args[i].mode, 883 TYPE_MODE (TREE_TYPE (args[i].tree_value)), 884 args[i].value, args[i].unsignedp); 885 886 /* If the value is expensive, and we are inside an appropriately 887 short loop, put the value into a pseudo and then put the pseudo 888 into the hard reg. 889 890 For small register classes, also do this if this call uses 891 register parameters. This is to avoid reload conflicts while 892 loading the parameters registers. */ 893 894 if ((! (GET_CODE (args[i].value) == REG 895 || (GET_CODE (args[i].value) == SUBREG 896 && GET_CODE (SUBREG_REG (args[i].value)) == REG))) 897 && args[i].mode != BLKmode 898 && rtx_cost (args[i].value, SET) > COSTS_N_INSNS (1) 899 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen) 900 || preserve_subexpressions_p ())) 901 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value); 902 } 903} 904 905#ifdef REG_PARM_STACK_SPACE 906 907 /* The argument list is the property of the called routine and it 908 may clobber it. If the fixed area has been used for previous 909 parameters, we must save and restore it. */ 910 911static rtx 912save_fixed_argument_area (reg_parm_stack_space, argblock, 913 low_to_save, high_to_save) 914 int reg_parm_stack_space; 915 rtx argblock; 916 int *low_to_save; 917 int *high_to_save; 918{ 919 int i; 920 rtx save_area = NULL_RTX; 921 922 /* Compute the boundary of the that needs to be saved, if any. */ 923#ifdef ARGS_GROW_DOWNWARD 924 for (i = 0; i < reg_parm_stack_space + 1; i++) 925#else 926 for (i = 0; i < reg_parm_stack_space; i++) 927#endif 928 { 929 if (i >= highest_outgoing_arg_in_use 930 || stack_usage_map[i] == 0) 931 continue; 932 933 if (*low_to_save == -1) 934 *low_to_save = i; 935 936 *high_to_save = i; 937 } 938 939 if (*low_to_save >= 0) 940 { 941 int num_to_save = *high_to_save - *low_to_save + 1; 942 enum machine_mode save_mode 943 = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1); 944 rtx stack_area; 945 946 /* If we don't have the required alignment, must do this in BLKmode. */ 947 if ((*low_to_save & (MIN (GET_MODE_SIZE (save_mode), 948 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1))) 949 save_mode = BLKmode; 950 951#ifdef ARGS_GROW_DOWNWARD 952 stack_area 953 = gen_rtx_MEM (save_mode, 954 memory_address (save_mode, 955 plus_constant (argblock, 956 - *high_to_save))); 957#else 958 stack_area = gen_rtx_MEM (save_mode, 959 memory_address (save_mode, 960 plus_constant (argblock, 961 *low_to_save))); 962#endif 963 964 set_mem_align (stack_area, PARM_BOUNDARY); 965 if (save_mode == BLKmode) 966 { 967 save_area = assign_stack_temp (BLKmode, num_to_save, 0); 968 /* Cannot use emit_block_move here because it can be done by a 969 library call which in turn gets into this place again and deadly 970 infinite recursion happens. */ 971 move_by_pieces (validize_mem (save_area), stack_area, num_to_save, 972 PARM_BOUNDARY); 973 } 974 else 975 { 976 save_area = gen_reg_rtx (save_mode); 977 emit_move_insn (save_area, stack_area); 978 } 979 } 980 981 return save_area; 982} 983 984static void 985restore_fixed_argument_area (save_area, argblock, high_to_save, low_to_save) 986 rtx save_area; 987 rtx argblock; 988 int high_to_save; 989 int low_to_save; 990{ 991 enum machine_mode save_mode = GET_MODE (save_area); 992#ifdef ARGS_GROW_DOWNWARD 993 rtx stack_area 994 = gen_rtx_MEM (save_mode, 995 memory_address (save_mode, 996 plus_constant (argblock, 997 - high_to_save))); 998#else 999 rtx stack_area 1000 = gen_rtx_MEM (save_mode, 1001 memory_address (save_mode, 1002 plus_constant (argblock, 1003 low_to_save))); 1004#endif 1005 1006 if (save_mode != BLKmode) 1007 emit_move_insn (stack_area, save_area); 1008 else 1009 /* Cannot use emit_block_move here because it can be done by a library 1010 call which in turn gets into this place again and deadly infinite 1011 recursion happens. */ 1012 move_by_pieces (stack_area, validize_mem (save_area), 1013 high_to_save - low_to_save + 1, PARM_BOUNDARY); 1014} 1015#endif /* REG_PARM_STACK_SPACE */ 1016 1017/* If any elements in ARGS refer to parameters that are to be passed in 1018 registers, but not in memory, and whose alignment does not permit a 1019 direct copy into registers. Copy the values into a group of pseudos 1020 which we will later copy into the appropriate hard registers. 1021 1022 Pseudos for each unaligned argument will be stored into the array 1023 args[argnum].aligned_regs. The caller is responsible for deallocating 1024 the aligned_regs array if it is nonzero. */ 1025 1026static void 1027store_unaligned_arguments_into_pseudos (args, num_actuals) 1028 struct arg_data *args; 1029 int num_actuals; 1030{ 1031 int i, j; 1032 1033 for (i = 0; i < num_actuals; i++) 1034 if (args[i].reg != 0 && ! args[i].pass_on_stack 1035 && args[i].mode == BLKmode 1036 && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value)) 1037 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD))) 1038 { 1039 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value)); 1040 int big_endian_correction = 0; 1041 1042 args[i].n_aligned_regs 1043 = args[i].partial ? args[i].partial 1044 : (bytes + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD; 1045 1046 args[i].aligned_regs = (rtx *) xmalloc (sizeof (rtx) 1047 * args[i].n_aligned_regs); 1048 1049 /* Structures smaller than a word are aligned to the least 1050 significant byte (to the right). On a BYTES_BIG_ENDIAN machine, 1051 this means we must skip the empty high order bytes when 1052 calculating the bit offset. */ 1053 if (BYTES_BIG_ENDIAN 1054 && !FUNCTION_ARG_REG_LITTLE_ENDIAN 1055 && bytes < UNITS_PER_WORD) 1056 big_endian_correction = (BITS_PER_WORD - (bytes * BITS_PER_UNIT)); 1057 1058 for (j = 0; j < args[i].n_aligned_regs; j++) 1059 { 1060 rtx reg = gen_reg_rtx (word_mode); 1061 rtx word = operand_subword_force (args[i].value, j, BLKmode); 1062 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD); 1063 1064 args[i].aligned_regs[j] = reg; 1065 1066 /* There is no need to restrict this code to loading items 1067 in TYPE_ALIGN sized hunks. The bitfield instructions can 1068 load up entire word sized registers efficiently. 1069 1070 ??? This may not be needed anymore. 1071 We use to emit a clobber here but that doesn't let later 1072 passes optimize the instructions we emit. By storing 0 into 1073 the register later passes know the first AND to zero out the 1074 bitfield being set in the register is unnecessary. The store 1075 of 0 will be deleted as will at least the first AND. */ 1076 1077 emit_move_insn (reg, const0_rtx); 1078 1079 bytes -= bitsize / BITS_PER_UNIT; 1080 store_bit_field (reg, bitsize, big_endian_correction, word_mode, 1081 extract_bit_field (word, bitsize, 0, 1, NULL_RTX, 1082 word_mode, word_mode, 1083 BITS_PER_WORD), 1084 BITS_PER_WORD); 1085 } 1086 } 1087} 1088 1089/* Fill in ARGS_SIZE and ARGS array based on the parameters found in 1090 ACTPARMS. 1091 1092 NUM_ACTUALS is the total number of parameters. 1093 1094 N_NAMED_ARGS is the total number of named arguments. 1095 1096 FNDECL is the tree code for the target of this call (if known) 1097 1098 ARGS_SO_FAR holds state needed by the target to know where to place 1099 the next argument. 1100 1101 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved 1102 for arguments which are passed in registers. 1103 1104 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level 1105 and may be modified by this routine. 1106 1107 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer 1108 flags which may may be modified by this routine. */ 1109 1110static void 1111initialize_argument_information (num_actuals, args, args_size, n_named_args, 1112 actparms, fndecl, args_so_far, 1113 reg_parm_stack_space, old_stack_level, 1114 old_pending_adj, must_preallocate, 1115 ecf_flags) 1116 int num_actuals ATTRIBUTE_UNUSED; 1117 struct arg_data *args; 1118 struct args_size *args_size; 1119 int n_named_args ATTRIBUTE_UNUSED; 1120 tree actparms; 1121 tree fndecl; 1122 CUMULATIVE_ARGS *args_so_far; 1123 int reg_parm_stack_space; 1124 rtx *old_stack_level; 1125 int *old_pending_adj; 1126 int *must_preallocate; 1127 int *ecf_flags; 1128{ 1129 /* 1 if scanning parms front to back, -1 if scanning back to front. */ 1130 int inc; 1131 1132 /* Count arg position in order args appear. */ 1133 int argpos; 1134 1135 struct args_size alignment_pad; 1136 int i; 1137 tree p; 1138 1139 args_size->constant = 0; 1140 args_size->var = 0; 1141 1142 /* In this loop, we consider args in the order they are written. 1143 We fill up ARGS from the front or from the back if necessary 1144 so that in any case the first arg to be pushed ends up at the front. */ 1145 1146 if (PUSH_ARGS_REVERSED) 1147 { 1148 i = num_actuals - 1, inc = -1; 1149 /* In this case, must reverse order of args 1150 so that we compute and push the last arg first. */ 1151 } 1152 else 1153 { 1154 i = 0, inc = 1; 1155 } 1156 1157 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */ 1158 for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++) 1159 { 1160 tree type = TREE_TYPE (TREE_VALUE (p)); 1161 int unsignedp; 1162 enum machine_mode mode; 1163 1164 args[i].tree_value = TREE_VALUE (p); 1165 1166 /* Replace erroneous argument with constant zero. */ 1167 if (type == error_mark_node || !COMPLETE_TYPE_P (type)) 1168 args[i].tree_value = integer_zero_node, type = integer_type_node; 1169 1170 /* If TYPE is a transparent union, pass things the way we would 1171 pass the first field of the union. We have already verified that 1172 the modes are the same. */ 1173 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type)) 1174 type = TREE_TYPE (TYPE_FIELDS (type)); 1175 1176 /* Decide where to pass this arg. 1177 1178 args[i].reg is nonzero if all or part is passed in registers. 1179 1180 args[i].partial is nonzero if part but not all is passed in registers, 1181 and the exact value says how many words are passed in registers. 1182 1183 args[i].pass_on_stack is nonzero if the argument must at least be 1184 computed on the stack. It may then be loaded back into registers 1185 if args[i].reg is nonzero. 1186 1187 These decisions are driven by the FUNCTION_... macros and must agree 1188 with those made by function.c. */ 1189 1190 /* See if this argument should be passed by invisible reference. */ 1191 if ((TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST 1192 && contains_placeholder_p (TYPE_SIZE (type))) 1193 || TREE_ADDRESSABLE (type) 1194#ifdef FUNCTION_ARG_PASS_BY_REFERENCE 1195 || FUNCTION_ARG_PASS_BY_REFERENCE (*args_so_far, TYPE_MODE (type), 1196 type, argpos < n_named_args) 1197#endif 1198 ) 1199 { 1200 /* If we're compiling a thunk, pass through invisible 1201 references instead of making a copy. */ 1202 if (current_function_is_thunk 1203#ifdef FUNCTION_ARG_CALLEE_COPIES 1204 || (FUNCTION_ARG_CALLEE_COPIES (*args_so_far, TYPE_MODE (type), 1205 type, argpos < n_named_args) 1206 /* If it's in a register, we must make a copy of it too. */ 1207 /* ??? Is this a sufficient test? Is there a better one? */ 1208 && !(TREE_CODE (args[i].tree_value) == VAR_DECL 1209 && REG_P (DECL_RTL (args[i].tree_value))) 1210 && ! TREE_ADDRESSABLE (type)) 1211#endif 1212 ) 1213 { 1214 /* C++ uses a TARGET_EXPR to indicate that we want to make a 1215 new object from the argument. If we are passing by 1216 invisible reference, the callee will do that for us, so we 1217 can strip off the TARGET_EXPR. This is not always safe, 1218 but it is safe in the only case where this is a useful 1219 optimization; namely, when the argument is a plain object. 1220 In that case, the frontend is just asking the backend to 1221 make a bitwise copy of the argument. */ 1222 1223 if (TREE_CODE (args[i].tree_value) == TARGET_EXPR 1224 && (DECL_P (TREE_OPERAND (args[i].tree_value, 1))) 1225 && ! REG_P (DECL_RTL (TREE_OPERAND (args[i].tree_value, 1)))) 1226 args[i].tree_value = TREE_OPERAND (args[i].tree_value, 1); 1227 1228 args[i].tree_value = build1 (ADDR_EXPR, 1229 build_pointer_type (type), 1230 args[i].tree_value); 1231 type = build_pointer_type (type); 1232 } 1233 else if (TREE_CODE (args[i].tree_value) == TARGET_EXPR) 1234 { 1235 /* In the V3 C++ ABI, parameters are destroyed in the caller. 1236 We implement this by passing the address of the temporary 1237 rather than expanding it into another allocated slot. */ 1238 args[i].tree_value = build1 (ADDR_EXPR, 1239 build_pointer_type (type), 1240 args[i].tree_value); 1241 type = build_pointer_type (type); 1242 } 1243 else 1244 { 1245 /* We make a copy of the object and pass the address to the 1246 function being called. */ 1247 rtx copy; 1248 1249 if (!COMPLETE_TYPE_P (type) 1250 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST 1251 || (flag_stack_check && ! STACK_CHECK_BUILTIN 1252 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type), 1253 STACK_CHECK_MAX_VAR_SIZE)))) 1254 { 1255 /* This is a variable-sized object. Make space on the stack 1256 for it. */ 1257 rtx size_rtx = expr_size (TREE_VALUE (p)); 1258 1259 if (*old_stack_level == 0) 1260 { 1261 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX); 1262 *old_pending_adj = pending_stack_adjust; 1263 pending_stack_adjust = 0; 1264 } 1265 1266 copy = gen_rtx_MEM (BLKmode, 1267 allocate_dynamic_stack_space 1268 (size_rtx, NULL_RTX, TYPE_ALIGN (type))); 1269 set_mem_attributes (copy, type, 1); 1270 } 1271 else 1272 copy = assign_temp (type, 0, 1, 0); 1273 1274 store_expr (args[i].tree_value, copy, 0); 1275 *ecf_flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK); 1276 1277 args[i].tree_value = build1 (ADDR_EXPR, 1278 build_pointer_type (type), 1279 make_tree (type, copy)); 1280 type = build_pointer_type (type); 1281 } 1282 } 1283 1284 mode = TYPE_MODE (type); 1285 unsignedp = TREE_UNSIGNED (type); 1286 1287#ifdef PROMOTE_FUNCTION_ARGS 1288 mode = promote_mode (type, mode, &unsignedp, 1); 1289#endif 1290 1291 args[i].unsignedp = unsignedp; 1292 args[i].mode = mode; 1293 1294 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type, 1295 argpos < n_named_args); 1296#ifdef FUNCTION_INCOMING_ARG 1297 /* If this is a sibling call and the machine has register windows, the 1298 register window has to be unwinded before calling the routine, so 1299 arguments have to go into the incoming registers. */ 1300 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type, 1301 argpos < n_named_args); 1302#else 1303 args[i].tail_call_reg = args[i].reg; 1304#endif 1305 1306#ifdef FUNCTION_ARG_PARTIAL_NREGS 1307 if (args[i].reg) 1308 args[i].partial 1309 = FUNCTION_ARG_PARTIAL_NREGS (*args_so_far, mode, type, 1310 argpos < n_named_args); 1311#endif 1312 1313 args[i].pass_on_stack = MUST_PASS_IN_STACK (mode, type); 1314 1315 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]), 1316 it means that we are to pass this arg in the register(s) designated 1317 by the PARALLEL, but also to pass it in the stack. */ 1318 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL 1319 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0) 1320 args[i].pass_on_stack = 1; 1321 1322 /* If this is an addressable type, we must preallocate the stack 1323 since we must evaluate the object into its final location. 1324 1325 If this is to be passed in both registers and the stack, it is simpler 1326 to preallocate. */ 1327 if (TREE_ADDRESSABLE (type) 1328 || (args[i].pass_on_stack && args[i].reg != 0)) 1329 *must_preallocate = 1; 1330 1331 /* If this is an addressable type, we cannot pre-evaluate it. Thus, 1332 we cannot consider this function call constant. */ 1333 if (TREE_ADDRESSABLE (type)) 1334 *ecf_flags &= ~ECF_LIBCALL_BLOCK; 1335 1336 /* Compute the stack-size of this argument. */ 1337 if (args[i].reg == 0 || args[i].partial != 0 1338 || reg_parm_stack_space > 0 1339 || args[i].pass_on_stack) 1340 locate_and_pad_parm (mode, type, 1341#ifdef STACK_PARMS_IN_REG_PARM_AREA 1342 1, 1343#else 1344 args[i].reg != 0, 1345#endif 1346 fndecl, args_size, &args[i].offset, 1347 &args[i].size, &alignment_pad); 1348 1349#ifndef ARGS_GROW_DOWNWARD 1350 args[i].slot_offset = *args_size; 1351#endif 1352 1353 args[i].alignment_pad = alignment_pad; 1354 1355 /* If a part of the arg was put into registers, 1356 don't include that part in the amount pushed. */ 1357 if (reg_parm_stack_space == 0 && ! args[i].pass_on_stack) 1358 args[i].size.constant -= ((args[i].partial * UNITS_PER_WORD) 1359 / (PARM_BOUNDARY / BITS_PER_UNIT) 1360 * (PARM_BOUNDARY / BITS_PER_UNIT)); 1361 1362 /* Update ARGS_SIZE, the total stack space for args so far. */ 1363 1364 args_size->constant += args[i].size.constant; 1365 if (args[i].size.var) 1366 { 1367 ADD_PARM_SIZE (*args_size, args[i].size.var); 1368 } 1369 1370 /* Since the slot offset points to the bottom of the slot, 1371 we must record it after incrementing if the args grow down. */ 1372#ifdef ARGS_GROW_DOWNWARD 1373 args[i].slot_offset = *args_size; 1374 1375 args[i].slot_offset.constant = -args_size->constant; 1376 if (args_size->var) 1377 SUB_PARM_SIZE (args[i].slot_offset, args_size->var); 1378#endif 1379 1380 /* Increment ARGS_SO_FAR, which has info about which arg-registers 1381 have been used, etc. */ 1382 1383 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type, 1384 argpos < n_named_args); 1385 } 1386} 1387 1388/* Update ARGS_SIZE to contain the total size for the argument block. 1389 Return the original constant component of the argument block's size. 1390 1391 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved 1392 for arguments passed in registers. */ 1393 1394static int 1395compute_argument_block_size (reg_parm_stack_space, args_size, 1396 preferred_stack_boundary) 1397 int reg_parm_stack_space; 1398 struct args_size *args_size; 1399 int preferred_stack_boundary ATTRIBUTE_UNUSED; 1400{ 1401 int unadjusted_args_size = args_size->constant; 1402 1403 /* For accumulate outgoing args mode we don't need to align, since the frame 1404 will be already aligned. Align to STACK_BOUNDARY in order to prevent 1405 backends from generating misaligned frame sizes. */ 1406 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY) 1407 preferred_stack_boundary = STACK_BOUNDARY; 1408 1409 /* Compute the actual size of the argument block required. The variable 1410 and constant sizes must be combined, the size may have to be rounded, 1411 and there may be a minimum required size. */ 1412 1413 if (args_size->var) 1414 { 1415 args_size->var = ARGS_SIZE_TREE (*args_size); 1416 args_size->constant = 0; 1417 1418 preferred_stack_boundary /= BITS_PER_UNIT; 1419 if (preferred_stack_boundary > 1) 1420 { 1421 /* We don't handle this case yet. To handle it correctly we have 1422 to add the delta, round and subtract the delta. 1423 Currently no machine description requires this support. */ 1424 if (stack_pointer_delta & (preferred_stack_boundary - 1)) 1425 abort (); 1426 args_size->var = round_up (args_size->var, preferred_stack_boundary); 1427 } 1428 1429 if (reg_parm_stack_space > 0) 1430 { 1431 args_size->var 1432 = size_binop (MAX_EXPR, args_size->var, 1433 ssize_int (reg_parm_stack_space)); 1434 1435#ifndef OUTGOING_REG_PARM_STACK_SPACE 1436 /* The area corresponding to register parameters is not to count in 1437 the size of the block we need. So make the adjustment. */ 1438 args_size->var 1439 = size_binop (MINUS_EXPR, args_size->var, 1440 ssize_int (reg_parm_stack_space)); 1441#endif 1442 } 1443 } 1444 else 1445 { 1446 preferred_stack_boundary /= BITS_PER_UNIT; 1447 if (preferred_stack_boundary < 1) 1448 preferred_stack_boundary = 1; 1449 args_size->constant = (((args_size->constant 1450 + stack_pointer_delta 1451 + preferred_stack_boundary - 1) 1452 / preferred_stack_boundary 1453 * preferred_stack_boundary) 1454 - stack_pointer_delta); 1455 1456 args_size->constant = MAX (args_size->constant, 1457 reg_parm_stack_space); 1458 1459#ifdef MAYBE_REG_PARM_STACK_SPACE 1460 if (reg_parm_stack_space == 0) 1461 args_size->constant = 0; 1462#endif 1463 1464#ifndef OUTGOING_REG_PARM_STACK_SPACE 1465 args_size->constant -= reg_parm_stack_space; 1466#endif 1467 } 1468 return unadjusted_args_size; 1469} 1470 1471/* Precompute parameters as needed for a function call. 1472 1473 FLAGS is mask of ECF_* constants. 1474 1475 NUM_ACTUALS is the number of arguments. 1476 1477 ARGS is an array containing information for each argument; this 1478 routine fills in the INITIAL_VALUE and VALUE fields for each 1479 precomputed argument. */ 1480 1481static void 1482precompute_arguments (flags, num_actuals, args) 1483 int flags; 1484 int num_actuals; 1485 struct arg_data *args; 1486{ 1487 int i; 1488 1489 /* If this function call is cse'able, precompute all the parameters. 1490 Note that if the parameter is constructed into a temporary, this will 1491 cause an additional copy because the parameter will be constructed 1492 into a temporary location and then copied into the outgoing arguments. 1493 If a parameter contains a call to alloca and this function uses the 1494 stack, precompute the parameter. */ 1495 1496 /* If we preallocated the stack space, and some arguments must be passed 1497 on the stack, then we must precompute any parameter which contains a 1498 function call which will store arguments on the stack. 1499 Otherwise, evaluating the parameter may clobber previous parameters 1500 which have already been stored into the stack. (we have code to avoid 1501 such case by saving the outgoing stack arguments, but it results in 1502 worse code) */ 1503 1504 for (i = 0; i < num_actuals; i++) 1505 if ((flags & ECF_LIBCALL_BLOCK) 1506 || calls_function (args[i].tree_value, !ACCUMULATE_OUTGOING_ARGS)) 1507 { 1508 enum machine_mode mode; 1509 1510 /* If this is an addressable type, we cannot pre-evaluate it. */ 1511 if (TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))) 1512 abort (); 1513 1514 args[i].value 1515 = expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0); 1516 1517 /* ANSI doesn't require a sequence point here, 1518 but PCC has one, so this will avoid some problems. */ 1519 emit_queue (); 1520 1521 args[i].initial_value = args[i].value 1522 = protect_from_queue (args[i].value, 0); 1523 1524 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value)); 1525 if (mode != args[i].mode) 1526 { 1527 args[i].value 1528 = convert_modes (args[i].mode, mode, 1529 args[i].value, args[i].unsignedp); 1530#ifdef PROMOTE_FOR_CALL_ONLY 1531 /* CSE will replace this only if it contains args[i].value 1532 pseudo, so convert it down to the declared mode using 1533 a SUBREG. */ 1534 if (GET_CODE (args[i].value) == REG 1535 && GET_MODE_CLASS (args[i].mode) == MODE_INT) 1536 { 1537 args[i].initial_value 1538 = gen_lowpart_SUBREG (mode, args[i].value); 1539 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1; 1540 SUBREG_PROMOTED_UNSIGNED_P (args[i].initial_value) 1541 = args[i].unsignedp; 1542 } 1543#endif 1544 } 1545 } 1546} 1547 1548/* Given the current state of MUST_PREALLOCATE and information about 1549 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE, 1550 compute and return the final value for MUST_PREALLOCATE. */ 1551 1552static int 1553finalize_must_preallocate (must_preallocate, num_actuals, args, args_size) 1554 int must_preallocate; 1555 int num_actuals; 1556 struct arg_data *args; 1557 struct args_size *args_size; 1558{ 1559 /* See if we have or want to preallocate stack space. 1560 1561 If we would have to push a partially-in-regs parm 1562 before other stack parms, preallocate stack space instead. 1563 1564 If the size of some parm is not a multiple of the required stack 1565 alignment, we must preallocate. 1566 1567 If the total size of arguments that would otherwise create a copy in 1568 a temporary (such as a CALL) is more than half the total argument list 1569 size, preallocation is faster. 1570 1571 Another reason to preallocate is if we have a machine (like the m88k) 1572 where stack alignment is required to be maintained between every 1573 pair of insns, not just when the call is made. However, we assume here 1574 that such machines either do not have push insns (and hence preallocation 1575 would occur anyway) or the problem is taken care of with 1576 PUSH_ROUNDING. */ 1577 1578 if (! must_preallocate) 1579 { 1580 int partial_seen = 0; 1581 int copy_to_evaluate_size = 0; 1582 int i; 1583 1584 for (i = 0; i < num_actuals && ! must_preallocate; i++) 1585 { 1586 if (args[i].partial > 0 && ! args[i].pass_on_stack) 1587 partial_seen = 1; 1588 else if (partial_seen && args[i].reg == 0) 1589 must_preallocate = 1; 1590 1591 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode 1592 && (TREE_CODE (args[i].tree_value) == CALL_EXPR 1593 || TREE_CODE (args[i].tree_value) == TARGET_EXPR 1594 || TREE_CODE (args[i].tree_value) == COND_EXPR 1595 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)))) 1596 copy_to_evaluate_size 1597 += int_size_in_bytes (TREE_TYPE (args[i].tree_value)); 1598 } 1599 1600 if (copy_to_evaluate_size * 2 >= args_size->constant 1601 && args_size->constant > 0) 1602 must_preallocate = 1; 1603 } 1604 return must_preallocate; 1605} 1606 1607/* If we preallocated stack space, compute the address of each argument 1608 and store it into the ARGS array. 1609 1610 We need not ensure it is a valid memory address here; it will be 1611 validized when it is used. 1612 1613 ARGBLOCK is an rtx for the address of the outgoing arguments. */ 1614 1615static void 1616compute_argument_addresses (args, argblock, num_actuals) 1617 struct arg_data *args; 1618 rtx argblock; 1619 int num_actuals; 1620{ 1621 if (argblock) 1622 { 1623 rtx arg_reg = argblock; 1624 int i, arg_offset = 0; 1625 1626 if (GET_CODE (argblock) == PLUS) 1627 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1)); 1628 1629 for (i = 0; i < num_actuals; i++) 1630 { 1631 rtx offset = ARGS_SIZE_RTX (args[i].offset); 1632 rtx slot_offset = ARGS_SIZE_RTX (args[i].slot_offset); 1633 rtx addr; 1634 1635 /* Skip this parm if it will not be passed on the stack. */ 1636 if (! args[i].pass_on_stack && args[i].reg != 0) 1637 continue; 1638 1639 if (GET_CODE (offset) == CONST_INT) 1640 addr = plus_constant (arg_reg, INTVAL (offset)); 1641 else 1642 addr = gen_rtx_PLUS (Pmode, arg_reg, offset); 1643 1644 addr = plus_constant (addr, arg_offset); 1645 args[i].stack = gen_rtx_MEM (args[i].mode, addr); 1646 set_mem_attributes (args[i].stack, 1647 TREE_TYPE (args[i].tree_value), 1); 1648 1649 if (GET_CODE (slot_offset) == CONST_INT) 1650 addr = plus_constant (arg_reg, INTVAL (slot_offset)); 1651 else 1652 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset); 1653 1654 addr = plus_constant (addr, arg_offset); 1655 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr); 1656 set_mem_attributes (args[i].stack_slot, 1657 TREE_TYPE (args[i].tree_value), 1); 1658 1659 /* Function incoming arguments may overlap with sibling call 1660 outgoing arguments and we cannot allow reordering of reads 1661 from function arguments with stores to outgoing arguments 1662 of sibling calls. */ 1663 set_mem_alias_set (args[i].stack, 0); 1664 set_mem_alias_set (args[i].stack_slot, 0); 1665 } 1666 } 1667} 1668 1669/* Given a FNDECL and EXP, return an rtx suitable for use as a target address 1670 in a call instruction. 1671 1672 FNDECL is the tree node for the target function. For an indirect call 1673 FNDECL will be NULL_TREE. 1674 1675 EXP is the CALL_EXPR for this call. */ 1676 1677static rtx 1678rtx_for_function_call (fndecl, exp) 1679 tree fndecl; 1680 tree exp; 1681{ 1682 rtx funexp; 1683 1684 /* Get the function to call, in the form of RTL. */ 1685 if (fndecl) 1686 { 1687 /* If this is the first use of the function, see if we need to 1688 make an external definition for it. */ 1689 if (! TREE_USED (fndecl)) 1690 { 1691 assemble_external (fndecl); 1692 TREE_USED (fndecl) = 1; 1693 } 1694 1695 /* Get a SYMBOL_REF rtx for the function address. */ 1696 funexp = XEXP (DECL_RTL (fndecl), 0); 1697 } 1698 else 1699 /* Generate an rtx (probably a pseudo-register) for the address. */ 1700 { 1701 rtx funaddr; 1702 push_temp_slots (); 1703 funaddr = funexp 1704 = expand_expr (TREE_OPERAND (exp, 0), NULL_RTX, VOIDmode, 0); 1705 pop_temp_slots (); /* FUNEXP can't be BLKmode. */ 1706 emit_queue (); 1707 } 1708 return funexp; 1709} 1710 1711/* Do the register loads required for any wholly-register parms or any 1712 parms which are passed both on the stack and in a register. Their 1713 expressions were already evaluated. 1714 1715 Mark all register-parms as living through the call, putting these USE 1716 insns in the CALL_INSN_FUNCTION_USAGE field. */ 1717 1718static void 1719load_register_parameters (args, num_actuals, call_fusage, flags) 1720 struct arg_data *args; 1721 int num_actuals; 1722 rtx *call_fusage; 1723 int flags; 1724{ 1725 int i, j; 1726 1727#ifdef LOAD_ARGS_REVERSED 1728 for (i = num_actuals - 1; i >= 0; i--) 1729#else 1730 for (i = 0; i < num_actuals; i++) 1731#endif 1732 { 1733 rtx reg = ((flags & ECF_SIBCALL) 1734 ? args[i].tail_call_reg : args[i].reg); 1735 int partial = args[i].partial; 1736 int nregs; 1737 1738 if (reg) 1739 { 1740 /* Set to non-negative if must move a word at a time, even if just 1741 one word (e.g, partial == 1 && mode == DFmode). Set to -1 if 1742 we just use a normal move insn. This value can be zero if the 1743 argument is a zero size structure with no fields. */ 1744 nregs = (partial ? partial 1745 : (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode 1746 ? ((int_size_in_bytes (TREE_TYPE (args[i].tree_value)) 1747 + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD) 1748 : -1)); 1749 1750 /* Handle calls that pass values in multiple non-contiguous 1751 locations. The Irix 6 ABI has examples of this. */ 1752 1753 if (GET_CODE (reg) == PARALLEL) 1754 emit_group_load (reg, args[i].value, 1755 int_size_in_bytes (TREE_TYPE (args[i].tree_value))); 1756 1757 /* If simple case, just do move. If normal partial, store_one_arg 1758 has already loaded the register for us. In all other cases, 1759 load the register(s) from memory. */ 1760 1761 else if (nregs == -1) 1762 emit_move_insn (reg, args[i].value); 1763 1764 /* If we have pre-computed the values to put in the registers in 1765 the case of non-aligned structures, copy them in now. */ 1766 1767 else if (args[i].n_aligned_regs != 0) 1768 for (j = 0; j < args[i].n_aligned_regs; j++) 1769 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j), 1770 args[i].aligned_regs[j]); 1771 1772 else if (partial == 0 || args[i].pass_on_stack) 1773 move_block_to_reg (REGNO (reg), 1774 validize_mem (args[i].value), nregs, 1775 args[i].mode); 1776 1777 /* Handle calls that pass values in multiple non-contiguous 1778 locations. The Irix 6 ABI has examples of this. */ 1779 if (GET_CODE (reg) == PARALLEL) 1780 use_group_regs (call_fusage, reg); 1781 else if (nregs == -1) 1782 use_reg (call_fusage, reg); 1783 else 1784 use_regs (call_fusage, REGNO (reg), nregs == 0 ? 1 : nregs); 1785 } 1786 } 1787} 1788 1789/* Try to integrate function. See expand_inline_function for documentation 1790 about the parameters. */ 1791 1792static rtx 1793try_to_integrate (fndecl, actparms, target, ignore, type, structure_value_addr) 1794 tree fndecl; 1795 tree actparms; 1796 rtx target; 1797 int ignore; 1798 tree type; 1799 rtx structure_value_addr; 1800{ 1801 rtx temp; 1802 rtx before_call; 1803 int i; 1804 rtx old_stack_level = 0; 1805 int reg_parm_stack_space = 0; 1806 1807#ifdef REG_PARM_STACK_SPACE 1808#ifdef MAYBE_REG_PARM_STACK_SPACE 1809 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE; 1810#else 1811 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl); 1812#endif 1813#endif 1814 1815 before_call = get_last_insn (); 1816 1817 timevar_push (TV_INTEGRATION); 1818 1819 temp = expand_inline_function (fndecl, actparms, target, 1820 ignore, type, 1821 structure_value_addr); 1822 1823 timevar_pop (TV_INTEGRATION); 1824 1825 /* If inlining succeeded, return. */ 1826 if (temp != (rtx) (size_t) - 1) 1827 { 1828 if (ACCUMULATE_OUTGOING_ARGS) 1829 { 1830 /* If the outgoing argument list must be preserved, push 1831 the stack before executing the inlined function if it 1832 makes any calls. */ 1833 1834 for (i = reg_parm_stack_space - 1; i >= 0; i--) 1835 if (i < highest_outgoing_arg_in_use && stack_usage_map[i] != 0) 1836 break; 1837 1838 if (stack_arg_under_construction || i >= 0) 1839 { 1840 rtx first_insn 1841 = before_call ? NEXT_INSN (before_call) : get_insns (); 1842 rtx insn = NULL_RTX, seq; 1843 1844 /* Look for a call in the inline function code. 1845 If DECL_SAVED_INSNS (fndecl)->outgoing_args_size is 1846 nonzero then there is a call and it is not necessary 1847 to scan the insns. */ 1848 1849 if (DECL_SAVED_INSNS (fndecl)->outgoing_args_size == 0) 1850 for (insn = first_insn; insn; insn = NEXT_INSN (insn)) 1851 if (GET_CODE (insn) == CALL_INSN) 1852 break; 1853 1854 if (insn) 1855 { 1856 /* Reserve enough stack space so that the largest 1857 argument list of any function call in the inline 1858 function does not overlap the argument list being 1859 evaluated. This is usually an overestimate because 1860 allocate_dynamic_stack_space reserves space for an 1861 outgoing argument list in addition to the requested 1862 space, but there is no way to ask for stack space such 1863 that an argument list of a certain length can be 1864 safely constructed. 1865 1866 Add the stack space reserved for register arguments, if 1867 any, in the inline function. What is really needed is the 1868 largest value of reg_parm_stack_space in the inline 1869 function, but that is not available. Using the current 1870 value of reg_parm_stack_space is wrong, but gives 1871 correct results on all supported machines. */ 1872 1873 int adjust = (DECL_SAVED_INSNS (fndecl)->outgoing_args_size 1874 + reg_parm_stack_space); 1875 1876 start_sequence (); 1877 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX); 1878 allocate_dynamic_stack_space (GEN_INT (adjust), 1879 NULL_RTX, BITS_PER_UNIT); 1880 seq = get_insns (); 1881 end_sequence (); 1882 emit_insns_before (seq, first_insn); 1883 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX); 1884 } 1885 } 1886 } 1887 1888 /* If the result is equivalent to TARGET, return TARGET to simplify 1889 checks in store_expr. They can be equivalent but not equal in the 1890 case of a function that returns BLKmode. */ 1891 if (temp != target && rtx_equal_p (temp, target)) 1892 return target; 1893 return temp; 1894 } 1895 1896 /* If inlining failed, mark FNDECL as needing to be compiled 1897 separately after all. If function was declared inline, 1898 give a warning. */ 1899 if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline 1900 && optimize > 0 && !TREE_ADDRESSABLE (fndecl)) 1901 { 1902 warning_with_decl (fndecl, "inlining failed in call to `%s'"); 1903 warning ("called from here"); 1904 } 1905 mark_addressable (fndecl); 1906 return (rtx) (size_t) - 1; 1907} 1908 1909/* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments 1910 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY 1911 bytes, then we would need to push some additional bytes to pad the 1912 arguments. So, we compute an adjust to the stack pointer for an 1913 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE 1914 bytes. Then, when the arguments are pushed the stack will be perfectly 1915 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should 1916 be popped after the call. Returns the adjustment. */ 1917 1918static int 1919combine_pending_stack_adjustment_and_call (unadjusted_args_size, 1920 args_size, 1921 preferred_unit_stack_boundary) 1922 int unadjusted_args_size; 1923 struct args_size *args_size; 1924 int preferred_unit_stack_boundary; 1925{ 1926 /* The number of bytes to pop so that the stack will be 1927 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */ 1928 HOST_WIDE_INT adjustment; 1929 /* The alignment of the stack after the arguments are pushed, if we 1930 just pushed the arguments without adjust the stack here. */ 1931 HOST_WIDE_INT unadjusted_alignment; 1932 1933 unadjusted_alignment 1934 = ((stack_pointer_delta + unadjusted_args_size) 1935 % preferred_unit_stack_boundary); 1936 1937 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes 1938 as possible -- leaving just enough left to cancel out the 1939 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the 1940 PENDING_STACK_ADJUST is non-negative, and congruent to 1941 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */ 1942 1943 /* Begin by trying to pop all the bytes. */ 1944 unadjusted_alignment 1945 = (unadjusted_alignment 1946 - (pending_stack_adjust % preferred_unit_stack_boundary)); 1947 adjustment = pending_stack_adjust; 1948 /* Push enough additional bytes that the stack will be aligned 1949 after the arguments are pushed. */ 1950 if (preferred_unit_stack_boundary > 1) 1951 { 1952 if (unadjusted_alignment > 0) 1953 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment; 1954 else 1955 adjustment += unadjusted_alignment; 1956 } 1957 1958 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of 1959 bytes after the call. The right number is the entire 1960 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required 1961 by the arguments in the first place. */ 1962 args_size->constant 1963 = pending_stack_adjust - adjustment + unadjusted_args_size; 1964 1965 return adjustment; 1966} 1967 1968/* Scan X expression if it does not dereference any argument slots 1969 we already clobbered by tail call arguments (as noted in stored_args_map 1970 bitmap). 1971 Return non-zero if X expression dereferences such argument slots, 1972 zero otherwise. */ 1973 1974static int 1975check_sibcall_argument_overlap_1 (x) 1976 rtx x; 1977{ 1978 RTX_CODE code; 1979 int i, j; 1980 unsigned int k; 1981 const char *fmt; 1982 1983 if (x == NULL_RTX) 1984 return 0; 1985 1986 code = GET_CODE (x); 1987 1988 if (code == MEM) 1989 { 1990 if (XEXP (x, 0) == current_function_internal_arg_pointer) 1991 i = 0; 1992 else if (GET_CODE (XEXP (x, 0)) == PLUS 1993 && XEXP (XEXP (x, 0), 0) == 1994 current_function_internal_arg_pointer 1995 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT) 1996 i = INTVAL (XEXP (XEXP (x, 0), 1)); 1997 else 1998 return 0; 1999 2000#ifdef ARGS_GROW_DOWNWARD 2001 i = -i - GET_MODE_SIZE (GET_MODE (x)); 2002#endif 2003 2004 for (k = 0; k < GET_MODE_SIZE (GET_MODE (x)); k++) 2005 if (i + k < stored_args_map->n_bits 2006 && TEST_BIT (stored_args_map, i + k)) 2007 return 1; 2008 2009 return 0; 2010 } 2011 2012 /* Scan all subexpressions. */ 2013 fmt = GET_RTX_FORMAT (code); 2014 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++) 2015 { 2016 if (*fmt == 'e') 2017 { 2018 if (check_sibcall_argument_overlap_1 (XEXP (x, i))) 2019 return 1; 2020 } 2021 else if (*fmt == 'E') 2022 { 2023 for (j = 0; j < XVECLEN (x, i); j++) 2024 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j))) 2025 return 1; 2026 } 2027 } 2028 return 0; 2029} 2030 2031/* Scan sequence after INSN if it does not dereference any argument slots 2032 we already clobbered by tail call arguments (as noted in stored_args_map 2033 bitmap). Add stack slots for ARG to stored_args_map bitmap afterwards. 2034 Return non-zero if sequence after INSN dereferences such argument slots, 2035 zero otherwise. */ 2036 2037static int 2038check_sibcall_argument_overlap (insn, arg) 2039 rtx insn; 2040 struct arg_data *arg; 2041{ 2042 int low, high; 2043 2044 if (insn == NULL_RTX) 2045 insn = get_insns (); 2046 else 2047 insn = NEXT_INSN (insn); 2048 2049 for (; insn; insn = NEXT_INSN (insn)) 2050 if (INSN_P (insn) 2051 && check_sibcall_argument_overlap_1 (PATTERN (insn))) 2052 break; 2053 2054#ifdef ARGS_GROW_DOWNWARD 2055 low = -arg->slot_offset.constant - arg->size.constant; 2056#else 2057 low = arg->slot_offset.constant; 2058#endif 2059 2060 for (high = low + arg->size.constant; low < high; low++) 2061 SET_BIT (stored_args_map, low); 2062 return insn != NULL_RTX; 2063} 2064 2065/* Generate all the code for a function call 2066 and return an rtx for its value. 2067 Store the value in TARGET (specified as an rtx) if convenient. 2068 If the value is stored in TARGET then TARGET is returned. 2069 If IGNORE is nonzero, then we ignore the value of the function call. */ 2070 2071rtx 2072expand_call (exp, target, ignore) 2073 tree exp; 2074 rtx target; 2075 int ignore; 2076{ 2077 /* Nonzero if we are currently expanding a call. */ 2078 static int currently_expanding_call = 0; 2079 2080 /* List of actual parameters. */ 2081 tree actparms = TREE_OPERAND (exp, 1); 2082 /* RTX for the function to be called. */ 2083 rtx funexp; 2084 /* Sequence of insns to perform a tail recursive "call". */ 2085 rtx tail_recursion_insns = NULL_RTX; 2086 /* Sequence of insns to perform a normal "call". */ 2087 rtx normal_call_insns = NULL_RTX; 2088 /* Sequence of insns to perform a tail recursive "call". */ 2089 rtx tail_call_insns = NULL_RTX; 2090 /* Data type of the function. */ 2091 tree funtype; 2092 /* Declaration of the function being called, 2093 or 0 if the function is computed (not known by name). */ 2094 tree fndecl = 0; 2095 rtx insn; 2096 int try_tail_call = 1; 2097 int try_tail_recursion = 1; 2098 int pass; 2099 2100 /* Register in which non-BLKmode value will be returned, 2101 or 0 if no value or if value is BLKmode. */ 2102 rtx valreg; 2103 /* Address where we should return a BLKmode value; 2104 0 if value not BLKmode. */ 2105 rtx structure_value_addr = 0; 2106 /* Nonzero if that address is being passed by treating it as 2107 an extra, implicit first parameter. Otherwise, 2108 it is passed by being copied directly into struct_value_rtx. */ 2109 int structure_value_addr_parm = 0; 2110 /* Size of aggregate value wanted, or zero if none wanted 2111 or if we are using the non-reentrant PCC calling convention 2112 or expecting the value in registers. */ 2113 HOST_WIDE_INT struct_value_size = 0; 2114 /* Nonzero if called function returns an aggregate in memory PCC style, 2115 by returning the address of where to find it. */ 2116 int pcc_struct_value = 0; 2117 2118 /* Number of actual parameters in this call, including struct value addr. */ 2119 int num_actuals; 2120 /* Number of named args. Args after this are anonymous ones 2121 and they must all go on the stack. */ 2122 int n_named_args; 2123 2124 /* Vector of information about each argument. 2125 Arguments are numbered in the order they will be pushed, 2126 not the order they are written. */ 2127 struct arg_data *args; 2128 2129 /* Total size in bytes of all the stack-parms scanned so far. */ 2130 struct args_size args_size; 2131 struct args_size adjusted_args_size; 2132 /* Size of arguments before any adjustments (such as rounding). */ 2133 int unadjusted_args_size; 2134 /* Data on reg parms scanned so far. */ 2135 CUMULATIVE_ARGS args_so_far; 2136 /* Nonzero if a reg parm has been scanned. */ 2137 int reg_parm_seen; 2138 /* Nonzero if this is an indirect function call. */ 2139 2140 /* Nonzero if we must avoid push-insns in the args for this call. 2141 If stack space is allocated for register parameters, but not by the 2142 caller, then it is preallocated in the fixed part of the stack frame. 2143 So the entire argument block must then be preallocated (i.e., we 2144 ignore PUSH_ROUNDING in that case). */ 2145 2146 int must_preallocate = !PUSH_ARGS; 2147 2148 /* Size of the stack reserved for parameter registers. */ 2149 int reg_parm_stack_space = 0; 2150 2151 /* Address of space preallocated for stack parms 2152 (on machines that lack push insns), or 0 if space not preallocated. */ 2153 rtx argblock = 0; 2154 2155 /* Mask of ECF_ flags. */ 2156 int flags = 0; 2157 /* Nonzero if this is a call to an inline function. */ 2158 int is_integrable = 0; 2159#ifdef REG_PARM_STACK_SPACE 2160 /* Define the boundary of the register parm stack space that needs to be 2161 save, if any. */ 2162 int low_to_save = -1, high_to_save; 2163 rtx save_area = 0; /* Place that it is saved */ 2164#endif 2165 2166 int initial_highest_arg_in_use = highest_outgoing_arg_in_use; 2167 char *initial_stack_usage_map = stack_usage_map; 2168 int old_stack_arg_under_construction = 0; 2169 2170 rtx old_stack_level = 0; 2171 int old_pending_adj = 0; 2172 int old_inhibit_defer_pop = inhibit_defer_pop; 2173 int old_stack_allocated; 2174 rtx call_fusage; 2175 tree p = TREE_OPERAND (exp, 0); 2176 int i; 2177 /* The alignment of the stack, in bits. */ 2178 HOST_WIDE_INT preferred_stack_boundary; 2179 /* The alignment of the stack, in bytes. */ 2180 HOST_WIDE_INT preferred_unit_stack_boundary; 2181 2182 /* See if this is "nothrow" function call. */ 2183 if (TREE_NOTHROW (exp)) 2184 flags |= ECF_NOTHROW; 2185 2186 /* See if we can find a DECL-node for the actual function. 2187 As a result, decide whether this is a call to an integrable function. */ 2188 2189 fndecl = get_callee_fndecl (exp); 2190 if (fndecl) 2191 { 2192 if (!flag_no_inline 2193 && fndecl != current_function_decl 2194 && DECL_INLINE (fndecl) 2195 && DECL_SAVED_INSNS (fndecl) 2196 && DECL_SAVED_INSNS (fndecl)->inlinable) 2197 is_integrable = 1; 2198 else if (! TREE_ADDRESSABLE (fndecl)) 2199 { 2200 /* In case this function later becomes inlinable, 2201 record that there was already a non-inline call to it. 2202 2203 Use abstraction instead of setting TREE_ADDRESSABLE 2204 directly. */ 2205 if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline 2206 && optimize > 0) 2207 { 2208 warning_with_decl (fndecl, "can't inline call to `%s'"); 2209 warning ("called from here"); 2210 } 2211 mark_addressable (fndecl); 2212 } 2213 2214 flags |= flags_from_decl_or_type (fndecl); 2215 } 2216 2217 /* If we don't have specific function to call, see if we have a 2218 attributes set in the type. */ 2219 else 2220 flags |= flags_from_decl_or_type (TREE_TYPE (TREE_TYPE (p))); 2221 2222#ifdef REG_PARM_STACK_SPACE 2223#ifdef MAYBE_REG_PARM_STACK_SPACE 2224 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE; 2225#else 2226 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl); 2227#endif 2228#endif 2229 2230#ifndef OUTGOING_REG_PARM_STACK_SPACE 2231 if (reg_parm_stack_space > 0 && PUSH_ARGS) 2232 must_preallocate = 1; 2233#endif 2234 2235 /* Warn if this value is an aggregate type, 2236 regardless of which calling convention we are using for it. */ 2237 if (warn_aggregate_return && AGGREGATE_TYPE_P (TREE_TYPE (exp))) 2238 warning ("function call has aggregate value"); 2239 2240 /* Set up a place to return a structure. */ 2241 2242 /* Cater to broken compilers. */ 2243 if (aggregate_value_p (exp)) 2244 { 2245 /* This call returns a big structure. */ 2246 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK); 2247 2248#ifdef PCC_STATIC_STRUCT_RETURN 2249 { 2250 pcc_struct_value = 1; 2251 /* Easier than making that case work right. */ 2252 if (is_integrable) 2253 { 2254 /* In case this is a static function, note that it has been 2255 used. */ 2256 if (! TREE_ADDRESSABLE (fndecl)) 2257 mark_addressable (fndecl); 2258 is_integrable = 0; 2259 } 2260 } 2261#else /* not PCC_STATIC_STRUCT_RETURN */ 2262 { 2263 struct_value_size = int_size_in_bytes (TREE_TYPE (exp)); 2264 2265 if (target && GET_CODE (target) == MEM) 2266 structure_value_addr = XEXP (target, 0); 2267 else 2268 { 2269 /* For variable-sized objects, we must be called with a target 2270 specified. If we were to allocate space on the stack here, 2271 we would have no way of knowing when to free it. */ 2272 rtx d = assign_temp (TREE_TYPE (exp), 1, 1, 1); 2273 2274 mark_temp_addr_taken (d); 2275 structure_value_addr = XEXP (d, 0); 2276 target = 0; 2277 } 2278 } 2279#endif /* not PCC_STATIC_STRUCT_RETURN */ 2280 } 2281 2282 /* If called function is inline, try to integrate it. */ 2283 2284 if (is_integrable) 2285 { 2286 rtx temp = try_to_integrate (fndecl, actparms, target, 2287 ignore, TREE_TYPE (exp), 2288 structure_value_addr); 2289 if (temp != (rtx) (size_t) - 1) 2290 return temp; 2291 } 2292 2293 /* Figure out the amount to which the stack should be aligned. */ 2294 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY; 2295 2296 /* Operand 0 is a pointer-to-function; get the type of the function. */ 2297 funtype = TREE_TYPE (TREE_OPERAND (exp, 0)); 2298 if (! POINTER_TYPE_P (funtype)) 2299 abort (); 2300 funtype = TREE_TYPE (funtype); 2301 2302 /* See if this is a call to a function that can return more than once 2303 or a call to longjmp or malloc. */ 2304 flags |= special_function_p (fndecl, flags); 2305 2306 if (flags & ECF_MAY_BE_ALLOCA) 2307 current_function_calls_alloca = 1; 2308 2309 /* If struct_value_rtx is 0, it means pass the address 2310 as if it were an extra parameter. */ 2311 if (structure_value_addr && struct_value_rtx == 0) 2312 { 2313 /* If structure_value_addr is a REG other than 2314 virtual_outgoing_args_rtx, we can use always use it. If it 2315 is not a REG, we must always copy it into a register. 2316 If it is virtual_outgoing_args_rtx, we must copy it to another 2317 register in some cases. */ 2318 rtx temp = (GET_CODE (structure_value_addr) != REG 2319 || (ACCUMULATE_OUTGOING_ARGS 2320 && stack_arg_under_construction 2321 && structure_value_addr == virtual_outgoing_args_rtx) 2322 ? copy_addr_to_reg (structure_value_addr) 2323 : structure_value_addr); 2324 2325 actparms 2326 = tree_cons (error_mark_node, 2327 make_tree (build_pointer_type (TREE_TYPE (funtype)), 2328 temp), 2329 actparms); 2330 structure_value_addr_parm = 1; 2331 } 2332 2333 /* Count the arguments and set NUM_ACTUALS. */ 2334 for (p = actparms, num_actuals = 0; p; p = TREE_CHAIN (p)) 2335 num_actuals++; 2336 2337 /* Compute number of named args. 2338 Normally, don't include the last named arg if anonymous args follow. 2339 We do include the last named arg if STRICT_ARGUMENT_NAMING is nonzero. 2340 (If no anonymous args follow, the result of list_length is actually 2341 one too large. This is harmless.) 2342 2343 If PRETEND_OUTGOING_VARARGS_NAMED is set and STRICT_ARGUMENT_NAMING is 2344 zero, this machine will be able to place unnamed args that were 2345 passed in registers into the stack. So treat all args as named. 2346 This allows the insns emitting for a specific argument list to be 2347 independent of the function declaration. 2348 2349 If PRETEND_OUTGOING_VARARGS_NAMED is not set, we do not have any 2350 reliable way to pass unnamed args in registers, so we must force 2351 them into memory. */ 2352 2353 if ((STRICT_ARGUMENT_NAMING 2354 || ! PRETEND_OUTGOING_VARARGS_NAMED) 2355 && TYPE_ARG_TYPES (funtype) != 0) 2356 n_named_args 2357 = (list_length (TYPE_ARG_TYPES (funtype)) 2358 /* Don't include the last named arg. */ 2359 - (STRICT_ARGUMENT_NAMING ? 0 : 1) 2360 /* Count the struct value address, if it is passed as a parm. */ 2361 + structure_value_addr_parm); 2362 else 2363 /* If we know nothing, treat all args as named. */ 2364 n_named_args = num_actuals; 2365 2366 /* Start updating where the next arg would go. 2367 2368 On some machines (such as the PA) indirect calls have a different 2369 calling convention than normal calls. The last argument in 2370 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call 2371 or not. */ 2372 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, (fndecl == 0)); 2373 2374 /* Make a vector to hold all the information about each arg. */ 2375 args = (struct arg_data *) alloca (num_actuals * sizeof (struct arg_data)); 2376 memset ((char *) args, 0, num_actuals * sizeof (struct arg_data)); 2377 2378 /* Build up entries in the ARGS array, compute the size of the 2379 arguments into ARGS_SIZE, etc. */ 2380 initialize_argument_information (num_actuals, args, &args_size, 2381 n_named_args, actparms, fndecl, 2382 &args_so_far, reg_parm_stack_space, 2383 &old_stack_level, &old_pending_adj, 2384 &must_preallocate, &flags); 2385 2386 if (args_size.var) 2387 { 2388 /* If this function requires a variable-sized argument list, don't 2389 try to make a cse'able block for this call. We may be able to 2390 do this eventually, but it is too complicated to keep track of 2391 what insns go in the cse'able block and which don't. */ 2392 2393 flags &= ~ECF_LIBCALL_BLOCK; 2394 must_preallocate = 1; 2395 } 2396 2397 /* Now make final decision about preallocating stack space. */ 2398 must_preallocate = finalize_must_preallocate (must_preallocate, 2399 num_actuals, args, 2400 &args_size); 2401 2402 /* If the structure value address will reference the stack pointer, we 2403 must stabilize it. We don't need to do this if we know that we are 2404 not going to adjust the stack pointer in processing this call. */ 2405 2406 if (structure_value_addr 2407 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr) 2408 || reg_mentioned_p (virtual_outgoing_args_rtx, 2409 structure_value_addr)) 2410 && (args_size.var 2411 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant))) 2412 structure_value_addr = copy_to_reg (structure_value_addr); 2413 2414 /* Tail calls can make things harder to debug, and we're traditionally 2415 pushed these optimizations into -O2. Don't try if we're already 2416 expanding a call, as that means we're an argument. Don't try if 2417 there's cleanups, as we know there's code to follow the call. 2418 2419 If rtx_equal_function_value_matters is false, that means we've 2420 finished with regular parsing. Which means that some of the 2421 machinery we use to generate tail-calls is no longer in place. 2422 This is most often true of sjlj-exceptions, which we couldn't 2423 tail-call to anyway. */ 2424 2425 if (currently_expanding_call++ != 0 2426 || !flag_optimize_sibling_calls 2427 || !rtx_equal_function_value_matters 2428 || any_pending_cleanups (1) 2429 || args_size.var) 2430 try_tail_call = try_tail_recursion = 0; 2431 2432 /* Tail recursion fails, when we are not dealing with recursive calls. */ 2433 if (!try_tail_recursion 2434 || TREE_CODE (TREE_OPERAND (exp, 0)) != ADDR_EXPR 2435 || TREE_OPERAND (TREE_OPERAND (exp, 0), 0) != current_function_decl) 2436 try_tail_recursion = 0; 2437 2438 /* Rest of purposes for tail call optimizations to fail. */ 2439 if ( 2440#ifdef HAVE_sibcall_epilogue 2441 !HAVE_sibcall_epilogue 2442#else 2443 1 2444#endif 2445 || !try_tail_call 2446 /* Doing sibling call optimization needs some work, since 2447 structure_value_addr can be allocated on the stack. 2448 It does not seem worth the effort since few optimizable 2449 sibling calls will return a structure. */ 2450 || structure_value_addr != NULL_RTX 2451 /* If the register holding the address is a callee saved 2452 register, then we lose. We have no way to prevent that, 2453 so we only allow calls to named functions. */ 2454 /* ??? This could be done by having the insn constraints 2455 use a register class that is all call-clobbered. Any 2456 reload insns generated to fix things up would appear 2457 before the sibcall_epilogue. */ 2458 || fndecl == NULL_TREE 2459 || (flags & (ECF_RETURNS_TWICE | ECF_LONGJMP)) 2460 || TREE_THIS_VOLATILE (fndecl) 2461 || !FUNCTION_OK_FOR_SIBCALL (fndecl) 2462 /* If this function requires more stack slots than the current 2463 function, we cannot change it into a sibling call. */ 2464 || args_size.constant > current_function_args_size 2465 /* If the callee pops its own arguments, then it must pop exactly 2466 the same number of arguments as the current function. */ 2467 || RETURN_POPS_ARGS (fndecl, funtype, args_size.constant) 2468 != RETURN_POPS_ARGS (current_function_decl, 2469 TREE_TYPE (current_function_decl), 2470 current_function_args_size)) 2471 try_tail_call = 0; 2472 2473 if (try_tail_call || try_tail_recursion) 2474 { 2475 int end, inc; 2476 actparms = NULL_TREE; 2477 /* Ok, we're going to give the tail call the old college try. 2478 This means we're going to evaluate the function arguments 2479 up to three times. There are two degrees of badness we can 2480 encounter, those that can be unsaved and those that can't. 2481 (See unsafe_for_reeval commentary for details.) 2482 2483 Generate a new argument list. Pass safe arguments through 2484 unchanged. For the easy badness wrap them in UNSAVE_EXPRs. 2485 For hard badness, evaluate them now and put their resulting 2486 rtx in a temporary VAR_DECL. 2487 2488 initialize_argument_information has ordered the array for the 2489 order to be pushed, and we must remember this when reconstructing 2490 the original argument order. */ 2491 2492 if (PUSH_ARGS_REVERSED) 2493 { 2494 inc = 1; 2495 i = 0; 2496 end = num_actuals; 2497 } 2498 else 2499 { 2500 inc = -1; 2501 i = num_actuals - 1; 2502 end = -1; 2503 } 2504 2505 for (; i != end; i += inc) 2506 { 2507 switch (unsafe_for_reeval (args[i].tree_value)) 2508 { 2509 case 0: /* Safe. */ 2510 break; 2511 2512 case 1: /* Mildly unsafe. */ 2513 args[i].tree_value = unsave_expr (args[i].tree_value); 2514 break; 2515 2516 case 2: /* Wildly unsafe. */ 2517 { 2518 tree var = build_decl (VAR_DECL, NULL_TREE, 2519 TREE_TYPE (args[i].tree_value)); 2520 SET_DECL_RTL (var, 2521 expand_expr (args[i].tree_value, NULL_RTX, 2522 VOIDmode, EXPAND_NORMAL)); 2523 args[i].tree_value = var; 2524 } 2525 break; 2526 2527 default: 2528 abort (); 2529 } 2530 /* We need to build actparms for optimize_tail_recursion. We can 2531 safely trash away TREE_PURPOSE, since it is unused by this 2532 function. */ 2533 if (try_tail_recursion) 2534 actparms = tree_cons (NULL_TREE, args[i].tree_value, actparms); 2535 } 2536 /* Expanding one of those dangerous arguments could have added 2537 cleanups, but otherwise give it a whirl. */ 2538 if (any_pending_cleanups (1)) 2539 try_tail_call = try_tail_recursion = 0; 2540 } 2541 2542 /* Generate a tail recursion sequence when calling ourselves. */ 2543 2544 if (try_tail_recursion) 2545 { 2546 /* We want to emit any pending stack adjustments before the tail 2547 recursion "call". That way we know any adjustment after the tail 2548 recursion call can be ignored if we indeed use the tail recursion 2549 call expansion. */ 2550 int save_pending_stack_adjust = pending_stack_adjust; 2551 int save_stack_pointer_delta = stack_pointer_delta; 2552 2553 /* Emit any queued insns now; otherwise they would end up in 2554 only one of the alternates. */ 2555 emit_queue (); 2556 2557 /* Use a new sequence to hold any RTL we generate. We do not even 2558 know if we will use this RTL yet. The final decision can not be 2559 made until after RTL generation for the entire function is 2560 complete. */ 2561 start_sequence (); 2562 /* If expanding any of the arguments creates cleanups, we can't 2563 do a tailcall. So, we'll need to pop the pending cleanups 2564 list. If, however, all goes well, and there are no cleanups 2565 then the call to expand_start_target_temps will have no 2566 effect. */ 2567 expand_start_target_temps (); 2568 if (optimize_tail_recursion (actparms, get_last_insn ())) 2569 { 2570 if (any_pending_cleanups (1)) 2571 try_tail_call = try_tail_recursion = 0; 2572 else 2573 tail_recursion_insns = get_insns (); 2574 } 2575 expand_end_target_temps (); 2576 end_sequence (); 2577 2578 /* Restore the original pending stack adjustment for the sibling and 2579 normal call cases below. */ 2580 pending_stack_adjust = save_pending_stack_adjust; 2581 stack_pointer_delta = save_stack_pointer_delta; 2582 } 2583 2584 if (profile_arc_flag && (flags & ECF_FORK_OR_EXEC)) 2585 { 2586 /* A fork duplicates the profile information, and an exec discards 2587 it. We can't rely on fork/exec to be paired. So write out the 2588 profile information we have gathered so far, and clear it. */ 2589 /* ??? When Linux's __clone is called with CLONE_VM set, profiling 2590 is subject to race conditions, just as with multithreaded 2591 programs. */ 2592 2593 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__bb_fork_func"), 2594 LCT_ALWAYS_RETURN, 2595 VOIDmode, 0); 2596 } 2597 2598 /* Ensure current function's preferred stack boundary is at least 2599 what we need. We don't have to increase alignment for recursive 2600 functions. */ 2601 if (cfun->preferred_stack_boundary < preferred_stack_boundary 2602 && fndecl != current_function_decl) 2603 cfun->preferred_stack_boundary = preferred_stack_boundary; 2604 2605 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT; 2606 2607 function_call_count++; 2608 2609 /* We want to make two insn chains; one for a sibling call, the other 2610 for a normal call. We will select one of the two chains after 2611 initial RTL generation is complete. */ 2612 for (pass = 0; pass < 2; pass++) 2613 { 2614 int sibcall_failure = 0; 2615 /* We want to emit any pending stack adjustments before the tail 2616 recursion "call". That way we know any adjustment after the tail 2617 recursion call can be ignored if we indeed use the tail recursion 2618 call expansion. */ 2619 int save_pending_stack_adjust = 0; 2620 int save_stack_pointer_delta = 0; 2621 rtx insns; 2622 rtx before_call, next_arg_reg; 2623 2624 if (pass == 0) 2625 { 2626 if (! try_tail_call) 2627 continue; 2628 2629 /* Emit any queued insns now; otherwise they would end up in 2630 only one of the alternates. */ 2631 emit_queue (); 2632 2633 /* State variables we need to save and restore between 2634 iterations. */ 2635 save_pending_stack_adjust = pending_stack_adjust; 2636 save_stack_pointer_delta = stack_pointer_delta; 2637 } 2638 if (pass) 2639 flags &= ~ECF_SIBCALL; 2640 else 2641 flags |= ECF_SIBCALL; 2642 2643 /* Other state variables that we must reinitialize each time 2644 through the loop (that are not initialized by the loop itself). */ 2645 argblock = 0; 2646 call_fusage = 0; 2647 2648 /* Start a new sequence for the normal call case. 2649 2650 From this point on, if the sibling call fails, we want to set 2651 sibcall_failure instead of continuing the loop. */ 2652 start_sequence (); 2653 2654 if (pass == 0) 2655 { 2656 /* We know at this point that there are not currently any 2657 pending cleanups. If, however, in the process of evaluating 2658 the arguments we were to create some, we'll need to be 2659 able to get rid of them. */ 2660 expand_start_target_temps (); 2661 } 2662 2663 /* Don't let pending stack adjusts add up to too much. 2664 Also, do all pending adjustments now if there is any chance 2665 this might be a call to alloca or if we are expanding a sibling 2666 call sequence or if we are calling a function that is to return 2667 with stack pointer depressed. */ 2668 if (pending_stack_adjust >= 32 2669 || (pending_stack_adjust > 0 2670 && (flags & (ECF_MAY_BE_ALLOCA | ECF_SP_DEPRESSED))) 2671 || pass == 0) 2672 do_pending_stack_adjust (); 2673 2674 /* When calling a const function, we must pop the stack args right away, 2675 so that the pop is deleted or moved with the call. */ 2676 if (pass && (flags & ECF_LIBCALL_BLOCK)) 2677 NO_DEFER_POP; 2678 2679#ifdef FINAL_REG_PARM_STACK_SPACE 2680 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant, 2681 args_size.var); 2682#endif 2683 /* Precompute any arguments as needed. */ 2684 if (pass) 2685 precompute_arguments (flags, num_actuals, args); 2686 2687 /* Now we are about to start emitting insns that can be deleted 2688 if a libcall is deleted. */ 2689 if (pass && (flags & (ECF_LIBCALL_BLOCK | ECF_MALLOC))) 2690 start_sequence (); 2691 2692 adjusted_args_size = args_size; 2693 /* Compute the actual size of the argument block required. The variable 2694 and constant sizes must be combined, the size may have to be rounded, 2695 and there may be a minimum required size. When generating a sibcall 2696 pattern, do not round up, since we'll be re-using whatever space our 2697 caller provided. */ 2698 unadjusted_args_size 2699 = compute_argument_block_size (reg_parm_stack_space, 2700 &adjusted_args_size, 2701 (pass == 0 ? 0 2702 : preferred_stack_boundary)); 2703 2704 old_stack_allocated = stack_pointer_delta - pending_stack_adjust; 2705 2706 /* The argument block when performing a sibling call is the 2707 incoming argument block. */ 2708 if (pass == 0) 2709 { 2710 argblock = virtual_incoming_args_rtx; 2711 stored_args_map = sbitmap_alloc (args_size.constant); 2712 sbitmap_zero (stored_args_map); 2713 } 2714 2715 /* If we have no actual push instructions, or shouldn't use them, 2716 make space for all args right now. */ 2717 else if (adjusted_args_size.var != 0) 2718 { 2719 if (old_stack_level == 0) 2720 { 2721 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX); 2722 old_pending_adj = pending_stack_adjust; 2723 pending_stack_adjust = 0; 2724 /* stack_arg_under_construction says whether a stack arg is 2725 being constructed at the old stack level. Pushing the stack 2726 gets a clean outgoing argument block. */ 2727 old_stack_arg_under_construction = stack_arg_under_construction; 2728 stack_arg_under_construction = 0; 2729 } 2730 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0); 2731 } 2732 else 2733 { 2734 /* Note that we must go through the motions of allocating an argument 2735 block even if the size is zero because we may be storing args 2736 in the area reserved for register arguments, which may be part of 2737 the stack frame. */ 2738 2739 int needed = adjusted_args_size.constant; 2740 2741 /* Store the maximum argument space used. It will be pushed by 2742 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow 2743 checking). */ 2744 2745 if (needed > current_function_outgoing_args_size) 2746 current_function_outgoing_args_size = needed; 2747 2748 if (must_preallocate) 2749 { 2750 if (ACCUMULATE_OUTGOING_ARGS) 2751 { 2752 /* Since the stack pointer will never be pushed, it is 2753 possible for the evaluation of a parm to clobber 2754 something we have already written to the stack. 2755 Since most function calls on RISC machines do not use 2756 the stack, this is uncommon, but must work correctly. 2757 2758 Therefore, we save any area of the stack that was already 2759 written and that we are using. Here we set up to do this 2760 by making a new stack usage map from the old one. The 2761 actual save will be done by store_one_arg. 2762 2763 Another approach might be to try to reorder the argument 2764 evaluations to avoid this conflicting stack usage. */ 2765 2766#ifndef OUTGOING_REG_PARM_STACK_SPACE 2767 /* Since we will be writing into the entire argument area, 2768 the map must be allocated for its entire size, not just 2769 the part that is the responsibility of the caller. */ 2770 needed += reg_parm_stack_space; 2771#endif 2772 2773#ifdef ARGS_GROW_DOWNWARD 2774 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, 2775 needed + 1); 2776#else 2777 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, 2778 needed); 2779#endif 2780 stack_usage_map 2781 = (char *) alloca (highest_outgoing_arg_in_use); 2782 2783 if (initial_highest_arg_in_use) 2784 memcpy (stack_usage_map, initial_stack_usage_map, 2785 initial_highest_arg_in_use); 2786 2787 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use) 2788 memset (&stack_usage_map[initial_highest_arg_in_use], 0, 2789 (highest_outgoing_arg_in_use 2790 - initial_highest_arg_in_use)); 2791 needed = 0; 2792 2793 /* The address of the outgoing argument list must not be 2794 copied to a register here, because argblock would be left 2795 pointing to the wrong place after the call to 2796 allocate_dynamic_stack_space below. */ 2797 2798 argblock = virtual_outgoing_args_rtx; 2799 } 2800 else 2801 { 2802 if (inhibit_defer_pop == 0) 2803 { 2804 /* Try to reuse some or all of the pending_stack_adjust 2805 to get this space. */ 2806 needed 2807 = (combine_pending_stack_adjustment_and_call 2808 (unadjusted_args_size, 2809 &adjusted_args_size, 2810 preferred_unit_stack_boundary)); 2811 2812 /* combine_pending_stack_adjustment_and_call computes 2813 an adjustment before the arguments are allocated. 2814 Account for them and see whether or not the stack 2815 needs to go up or down. */ 2816 needed = unadjusted_args_size - needed; 2817 2818 if (needed < 0) 2819 { 2820 /* We're releasing stack space. */ 2821 /* ??? We can avoid any adjustment at all if we're 2822 already aligned. FIXME. */ 2823 pending_stack_adjust = -needed; 2824 do_pending_stack_adjust (); 2825 needed = 0; 2826 } 2827 else 2828 /* We need to allocate space. We'll do that in 2829 push_block below. */ 2830 pending_stack_adjust = 0; 2831 } 2832 2833 /* Special case this because overhead of `push_block' in 2834 this case is non-trivial. */ 2835 if (needed == 0) 2836 argblock = virtual_outgoing_args_rtx; 2837 else 2838 argblock = push_block (GEN_INT (needed), 0, 0); 2839 2840 /* We only really need to call `copy_to_reg' in the case 2841 where push insns are going to be used to pass ARGBLOCK 2842 to a function call in ARGS. In that case, the stack 2843 pointer changes value from the allocation point to the 2844 call point, and hence the value of 2845 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might 2846 as well always do it. */ 2847 argblock = copy_to_reg (argblock); 2848 2849 /* The save/restore code in store_one_arg handles all 2850 cases except one: a constructor call (including a C 2851 function returning a BLKmode struct) to initialize 2852 an argument. */ 2853 if (stack_arg_under_construction) 2854 { 2855#ifndef OUTGOING_REG_PARM_STACK_SPACE 2856 rtx push_size = GEN_INT (reg_parm_stack_space 2857 + adjusted_args_size.constant); 2858#else 2859 rtx push_size = GEN_INT (adjusted_args_size.constant); 2860#endif 2861 if (old_stack_level == 0) 2862 { 2863 emit_stack_save (SAVE_BLOCK, &old_stack_level, 2864 NULL_RTX); 2865 old_pending_adj = pending_stack_adjust; 2866 pending_stack_adjust = 0; 2867 /* stack_arg_under_construction says whether a stack 2868 arg is being constructed at the old stack level. 2869 Pushing the stack gets a clean outgoing argument 2870 block. */ 2871 old_stack_arg_under_construction 2872 = stack_arg_under_construction; 2873 stack_arg_under_construction = 0; 2874 /* Make a new map for the new argument list. */ 2875 stack_usage_map = (char *) 2876 alloca (highest_outgoing_arg_in_use); 2877 memset (stack_usage_map, 0, highest_outgoing_arg_in_use); 2878 highest_outgoing_arg_in_use = 0; 2879 } 2880 allocate_dynamic_stack_space (push_size, NULL_RTX, 2881 BITS_PER_UNIT); 2882 } 2883 /* If argument evaluation might modify the stack pointer, 2884 copy the address of the argument list to a register. */ 2885 for (i = 0; i < num_actuals; i++) 2886 if (args[i].pass_on_stack) 2887 { 2888 argblock = copy_addr_to_reg (argblock); 2889 break; 2890 } 2891 } 2892 } 2893 } 2894 2895 compute_argument_addresses (args, argblock, num_actuals); 2896 2897 /* If we push args individually in reverse order, perform stack alignment 2898 before the first push (the last arg). */ 2899 if (PUSH_ARGS_REVERSED && argblock == 0 2900 && adjusted_args_size.constant != unadjusted_args_size) 2901 { 2902 /* When the stack adjustment is pending, we get better code 2903 by combining the adjustments. */ 2904 if (pending_stack_adjust 2905 && ! (flags & ECF_LIBCALL_BLOCK) 2906 && ! inhibit_defer_pop) 2907 { 2908 pending_stack_adjust 2909 = (combine_pending_stack_adjustment_and_call 2910 (unadjusted_args_size, 2911 &adjusted_args_size, 2912 preferred_unit_stack_boundary)); 2913 do_pending_stack_adjust (); 2914 } 2915 else if (argblock == 0) 2916 anti_adjust_stack (GEN_INT (adjusted_args_size.constant 2917 - unadjusted_args_size)); 2918 } 2919 /* Now that the stack is properly aligned, pops can't safely 2920 be deferred during the evaluation of the arguments. */ 2921 NO_DEFER_POP; 2922 2923 funexp = rtx_for_function_call (fndecl, exp); 2924 2925 /* Figure out the register where the value, if any, will come back. */ 2926 valreg = 0; 2927 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode 2928 && ! structure_value_addr) 2929 { 2930 if (pcc_struct_value) 2931 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)), 2932 fndecl, (pass == 0)); 2933 else 2934 valreg = hard_function_value (TREE_TYPE (exp), fndecl, (pass == 0)); 2935 } 2936 2937 /* Precompute all register parameters. It isn't safe to compute anything 2938 once we have started filling any specific hard regs. */ 2939 precompute_register_parameters (num_actuals, args, ®_parm_seen); 2940 2941#ifdef REG_PARM_STACK_SPACE 2942 /* Save the fixed argument area if it's part of the caller's frame and 2943 is clobbered by argument setup for this call. */ 2944 if (ACCUMULATE_OUTGOING_ARGS && pass) 2945 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock, 2946 &low_to_save, &high_to_save); 2947#endif 2948 2949 /* Now store (and compute if necessary) all non-register parms. 2950 These come before register parms, since they can require block-moves, 2951 which could clobber the registers used for register parms. 2952 Parms which have partial registers are not stored here, 2953 but we do preallocate space here if they want that. */ 2954 2955 for (i = 0; i < num_actuals; i++) 2956 if (args[i].reg == 0 || args[i].pass_on_stack) 2957 { 2958 rtx before_arg = get_last_insn (); 2959 2960 if (store_one_arg (&args[i], argblock, flags, 2961 adjusted_args_size.var != 0, 2962 reg_parm_stack_space) 2963 || (pass == 0 2964 && check_sibcall_argument_overlap (before_arg, 2965 &args[i]))) 2966 sibcall_failure = 1; 2967 } 2968 2969 /* If we have a parm that is passed in registers but not in memory 2970 and whose alignment does not permit a direct copy into registers, 2971 make a group of pseudos that correspond to each register that we 2972 will later fill. */ 2973 if (STRICT_ALIGNMENT) 2974 store_unaligned_arguments_into_pseudos (args, num_actuals); 2975 2976 /* Now store any partially-in-registers parm. 2977 This is the last place a block-move can happen. */ 2978 if (reg_parm_seen) 2979 for (i = 0; i < num_actuals; i++) 2980 if (args[i].partial != 0 && ! args[i].pass_on_stack) 2981 { 2982 rtx before_arg = get_last_insn (); 2983 2984 if (store_one_arg (&args[i], argblock, flags, 2985 adjusted_args_size.var != 0, 2986 reg_parm_stack_space) 2987 || (pass == 0 2988 && check_sibcall_argument_overlap (before_arg, 2989 &args[i]))) 2990 sibcall_failure = 1; 2991 } 2992 2993 /* If we pushed args in forward order, perform stack alignment 2994 after pushing the last arg. */ 2995 if (!PUSH_ARGS_REVERSED && argblock == 0) 2996 anti_adjust_stack (GEN_INT (adjusted_args_size.constant 2997 - unadjusted_args_size)); 2998 2999 /* If register arguments require space on the stack and stack space 3000 was not preallocated, allocate stack space here for arguments 3001 passed in registers. */ 3002#ifdef OUTGOING_REG_PARM_STACK_SPACE 3003 if (!ACCUMULATE_OUTGOING_ARGS 3004 && must_preallocate == 0 && reg_parm_stack_space > 0) 3005 anti_adjust_stack (GEN_INT (reg_parm_stack_space)); 3006#endif 3007 3008 /* Pass the function the address in which to return a 3009 structure value. */ 3010 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm) 3011 { 3012 emit_move_insn (struct_value_rtx, 3013 force_reg (Pmode, 3014 force_operand (structure_value_addr, 3015 NULL_RTX))); 3016 3017 if (GET_CODE (struct_value_rtx) == REG) 3018 use_reg (&call_fusage, struct_value_rtx); 3019 } 3020 3021 funexp = prepare_call_address (funexp, fndecl, &call_fusage, 3022 reg_parm_seen, pass == 0); 3023 3024 load_register_parameters (args, num_actuals, &call_fusage, flags); 3025 3026 /* Perform postincrements before actually calling the function. */ 3027 emit_queue (); 3028 3029 /* Save a pointer to the last insn before the call, so that we can 3030 later safely search backwards to find the CALL_INSN. */ 3031 before_call = get_last_insn (); 3032 3033 /* Set up next argument register. For sibling calls on machines 3034 with register windows this should be the incoming register. */ 3035#ifdef FUNCTION_INCOMING_ARG 3036 if (pass == 0) 3037 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode, 3038 void_type_node, 1); 3039 else 3040#endif 3041 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode, 3042 void_type_node, 1); 3043 3044 /* All arguments and registers used for the call must be set up by 3045 now! */ 3046 3047 /* Stack must be properly aligned now. */ 3048 if (pass && stack_pointer_delta % preferred_unit_stack_boundary) 3049 abort (); 3050 3051 /* Generate the actual call instruction. */ 3052 emit_call_1 (funexp, fndecl, funtype, unadjusted_args_size, 3053 adjusted_args_size.constant, struct_value_size, 3054 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage, 3055 flags, & args_so_far); 3056 3057 /* Verify that we've deallocated all the stack we used. */ 3058 if (pass 3059 && old_stack_allocated != stack_pointer_delta - pending_stack_adjust) 3060 abort (); 3061 3062 /* If call is cse'able, make appropriate pair of reg-notes around it. 3063 Test valreg so we don't crash; may safely ignore `const' 3064 if return type is void. Disable for PARALLEL return values, because 3065 we have no way to move such values into a pseudo register. */ 3066 if (pass && (flags & ECF_LIBCALL_BLOCK)) 3067 { 3068 rtx insns; 3069 3070 if (valreg == 0 || GET_CODE (valreg) == PARALLEL) 3071 { 3072 insns = get_insns (); 3073 end_sequence (); 3074 emit_insns (insns); 3075 } 3076 else 3077 { 3078 rtx note = 0; 3079 rtx temp = gen_reg_rtx (GET_MODE (valreg)); 3080 3081 /* Mark the return value as a pointer if needed. */ 3082 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE) 3083 mark_reg_pointer (temp, 3084 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp)))); 3085 3086 /* Construct an "equal form" for the value which mentions all the 3087 arguments in order as well as the function name. */ 3088 for (i = 0; i < num_actuals; i++) 3089 note = gen_rtx_EXPR_LIST (VOIDmode, 3090 args[i].initial_value, note); 3091 note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note); 3092 3093 insns = get_insns (); 3094 end_sequence (); 3095 3096 if (flags & ECF_PURE) 3097 note = gen_rtx_EXPR_LIST (VOIDmode, 3098 gen_rtx_USE (VOIDmode, 3099 gen_rtx_MEM (BLKmode, 3100 gen_rtx_SCRATCH (VOIDmode))), 3101 note); 3102 3103 emit_libcall_block (insns, temp, valreg, note); 3104 3105 valreg = temp; 3106 } 3107 } 3108 else if (pass && (flags & ECF_MALLOC)) 3109 { 3110 rtx temp = gen_reg_rtx (GET_MODE (valreg)); 3111 rtx last, insns; 3112 3113 /* The return value from a malloc-like function is a pointer. */ 3114 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE) 3115 mark_reg_pointer (temp, BIGGEST_ALIGNMENT); 3116 3117 emit_move_insn (temp, valreg); 3118 3119 /* The return value from a malloc-like function can not alias 3120 anything else. */ 3121 last = get_last_insn (); 3122 REG_NOTES (last) = 3123 gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last)); 3124 3125 /* Write out the sequence. */ 3126 insns = get_insns (); 3127 end_sequence (); 3128 emit_insns (insns); 3129 valreg = temp; 3130 } 3131 3132 /* For calls to `setjmp', etc., inform flow.c it should complain 3133 if nonvolatile values are live. For functions that cannot return, 3134 inform flow that control does not fall through. */ 3135 3136 if ((flags & (ECF_NORETURN | ECF_LONGJMP)) || pass == 0) 3137 { 3138 /* The barrier must be emitted 3139 immediately after the CALL_INSN. Some ports emit more 3140 than just a CALL_INSN above, so we must search for it here. */ 3141 3142 rtx last = get_last_insn (); 3143 while (GET_CODE (last) != CALL_INSN) 3144 { 3145 last = PREV_INSN (last); 3146 /* There was no CALL_INSN? */ 3147 if (last == before_call) 3148 abort (); 3149 } 3150 3151 emit_barrier_after (last); 3152 } 3153 3154 if (flags & ECF_LONGJMP) 3155 current_function_calls_longjmp = 1; 3156 3157 /* If this function is returning into a memory location marked as 3158 readonly, it means it is initializing that location. But we normally 3159 treat functions as not clobbering such locations, so we need to 3160 specify that this one does. */ 3161 if (target != 0 && GET_CODE (target) == MEM 3162 && structure_value_addr != 0 && RTX_UNCHANGING_P (target)) 3163 emit_insn (gen_rtx_CLOBBER (VOIDmode, target)); 3164 3165 /* If value type not void, return an rtx for the value. */ 3166 3167 /* If there are cleanups to be called, don't use a hard reg as target. 3168 We need to double check this and see if it matters anymore. */ 3169 if (any_pending_cleanups (1)) 3170 { 3171 if (target && REG_P (target) 3172 && REGNO (target) < FIRST_PSEUDO_REGISTER) 3173 target = 0; 3174 sibcall_failure = 1; 3175 } 3176 3177 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode 3178 || ignore) 3179 target = const0_rtx; 3180 else if (structure_value_addr) 3181 { 3182 if (target == 0 || GET_CODE (target) != MEM) 3183 { 3184 target 3185 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), 3186 memory_address (TYPE_MODE (TREE_TYPE (exp)), 3187 structure_value_addr)); 3188 set_mem_attributes (target, exp, 1); 3189 } 3190 } 3191 else if (pcc_struct_value) 3192 { 3193 /* This is the special C++ case where we need to 3194 know what the true target was. We take care to 3195 never use this value more than once in one expression. */ 3196 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)), 3197 copy_to_reg (valreg)); 3198 set_mem_attributes (target, exp, 1); 3199 } 3200 /* Handle calls that return values in multiple non-contiguous locations. 3201 The Irix 6 ABI has examples of this. */ 3202 else if (GET_CODE (valreg) == PARALLEL) 3203 { 3204 if (target == 0) 3205 { 3206 /* This will only be assigned once, so it can be readonly. */ 3207 tree nt = build_qualified_type (TREE_TYPE (exp), 3208 (TYPE_QUALS (TREE_TYPE (exp)) 3209 | TYPE_QUAL_CONST)); 3210 3211 target = assign_temp (nt, 0, 1, 1); 3212 preserve_temp_slots (target); 3213 } 3214 3215 if (! rtx_equal_p (target, valreg)) 3216 emit_group_store (target, valreg, 3217 int_size_in_bytes (TREE_TYPE (exp))); 3218 3219 /* We can not support sibling calls for this case. */ 3220 sibcall_failure = 1; 3221 } 3222 else if (target 3223 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp)) 3224 && GET_MODE (target) == GET_MODE (valreg)) 3225 { 3226 /* TARGET and VALREG cannot be equal at this point because the 3227 latter would not have REG_FUNCTION_VALUE_P true, while the 3228 former would if it were referring to the same register. 3229 3230 If they refer to the same register, this move will be a no-op, 3231 except when function inlining is being done. */ 3232 emit_move_insn (target, valreg); 3233 } 3234 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode) 3235 { 3236 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp)); 3237 3238 /* We can not support sibling calls for this case. */ 3239 sibcall_failure = 1; 3240 } 3241 else 3242 target = copy_to_reg (valreg); 3243 3244#ifdef PROMOTE_FUNCTION_RETURN 3245 /* If we promoted this return value, make the proper SUBREG. TARGET 3246 might be const0_rtx here, so be careful. */ 3247 if (GET_CODE (target) == REG 3248 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode 3249 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp))) 3250 { 3251 tree type = TREE_TYPE (exp); 3252 int unsignedp = TREE_UNSIGNED (type); 3253 int offset = 0; 3254 3255 /* If we don't promote as expected, something is wrong. */ 3256 if (GET_MODE (target) 3257 != promote_mode (type, TYPE_MODE (type), &unsignedp, 1)) 3258 abort (); 3259 3260 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN) 3261 && GET_MODE_SIZE (GET_MODE (target)) 3262 > GET_MODE_SIZE (TYPE_MODE (type))) 3263 { 3264 offset = GET_MODE_SIZE (GET_MODE (target)) 3265 - GET_MODE_SIZE (TYPE_MODE (type)); 3266 if (! BYTES_BIG_ENDIAN) 3267 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD; 3268 else if (! WORDS_BIG_ENDIAN) 3269 offset %= UNITS_PER_WORD; 3270 } 3271 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset); 3272 SUBREG_PROMOTED_VAR_P (target) = 1; 3273 SUBREG_PROMOTED_UNSIGNED_P (target) = unsignedp; 3274 } 3275#endif 3276 3277 /* If size of args is variable or this was a constructor call for a stack 3278 argument, restore saved stack-pointer value. */ 3279 3280 if (old_stack_level && ! (flags & ECF_SP_DEPRESSED)) 3281 { 3282 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX); 3283 pending_stack_adjust = old_pending_adj; 3284 stack_arg_under_construction = old_stack_arg_under_construction; 3285 highest_outgoing_arg_in_use = initial_highest_arg_in_use; 3286 stack_usage_map = initial_stack_usage_map; 3287 sibcall_failure = 1; 3288 } 3289 else if (ACCUMULATE_OUTGOING_ARGS && pass) 3290 { 3291#ifdef REG_PARM_STACK_SPACE 3292 if (save_area) 3293 { 3294 restore_fixed_argument_area (save_area, argblock, 3295 high_to_save, low_to_save); 3296 } 3297#endif 3298 3299 /* If we saved any argument areas, restore them. */ 3300 for (i = 0; i < num_actuals; i++) 3301 if (args[i].save_area) 3302 { 3303 enum machine_mode save_mode = GET_MODE (args[i].save_area); 3304 rtx stack_area 3305 = gen_rtx_MEM (save_mode, 3306 memory_address (save_mode, 3307 XEXP (args[i].stack_slot, 0))); 3308 3309 if (save_mode != BLKmode) 3310 emit_move_insn (stack_area, args[i].save_area); 3311 else 3312 emit_block_move (stack_area, 3313 validize_mem (args[i].save_area), 3314 GEN_INT (args[i].size.constant)); 3315 } 3316 3317 highest_outgoing_arg_in_use = initial_highest_arg_in_use; 3318 stack_usage_map = initial_stack_usage_map; 3319 } 3320 3321 /* If this was alloca, record the new stack level for nonlocal gotos. 3322 Check for the handler slots since we might not have a save area 3323 for non-local gotos. */ 3324 3325 if ((flags & ECF_MAY_BE_ALLOCA) && nonlocal_goto_handler_slots != 0) 3326 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX); 3327 3328 /* Free up storage we no longer need. */ 3329 for (i = 0; i < num_actuals; ++i) 3330 if (args[i].aligned_regs) 3331 free (args[i].aligned_regs); 3332 3333 if (pass == 0) 3334 { 3335 /* Undo the fake expand_start_target_temps we did earlier. If 3336 there had been any cleanups created, we've already set 3337 sibcall_failure. */ 3338 expand_end_target_temps (); 3339 } 3340 3341 insns = get_insns (); 3342 end_sequence (); 3343 3344 if (pass == 0) 3345 { 3346 tail_call_insns = insns; 3347 3348 /* Restore the pending stack adjustment now that we have 3349 finished generating the sibling call sequence. */ 3350 3351 pending_stack_adjust = save_pending_stack_adjust; 3352 stack_pointer_delta = save_stack_pointer_delta; 3353 3354 /* Prepare arg structure for next iteration. */ 3355 for (i = 0; i < num_actuals; i++) 3356 { 3357 args[i].value = 0; 3358 args[i].aligned_regs = 0; 3359 args[i].stack = 0; 3360 } 3361 3362 sbitmap_free (stored_args_map); 3363 } 3364 else 3365 normal_call_insns = insns; 3366 3367 /* If something prevents making this a sibling call, 3368 zero out the sequence. */ 3369 if (sibcall_failure) 3370 tail_call_insns = NULL_RTX; 3371 } 3372 3373 /* The function optimize_sibling_and_tail_recursive_calls doesn't 3374 handle CALL_PLACEHOLDERs inside other CALL_PLACEHOLDERs. This 3375 can happen if the arguments to this function call an inline 3376 function who's expansion contains another CALL_PLACEHOLDER. 3377 3378 If there are any C_Ps in any of these sequences, replace them 3379 with their normal call. */ 3380 3381 for (insn = normal_call_insns; insn; insn = NEXT_INSN (insn)) 3382 if (GET_CODE (insn) == CALL_INSN 3383 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER) 3384 replace_call_placeholder (insn, sibcall_use_normal); 3385 3386 for (insn = tail_call_insns; insn; insn = NEXT_INSN (insn)) 3387 if (GET_CODE (insn) == CALL_INSN 3388 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER) 3389 replace_call_placeholder (insn, sibcall_use_normal); 3390 3391 for (insn = tail_recursion_insns; insn; insn = NEXT_INSN (insn)) 3392 if (GET_CODE (insn) == CALL_INSN 3393 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER) 3394 replace_call_placeholder (insn, sibcall_use_normal); 3395 3396 /* If this was a potential tail recursion site, then emit a 3397 CALL_PLACEHOLDER with the normal and the tail recursion streams. 3398 One of them will be selected later. */ 3399 if (tail_recursion_insns || tail_call_insns) 3400 { 3401 /* The tail recursion label must be kept around. We could expose 3402 its use in the CALL_PLACEHOLDER, but that creates unwanted edges 3403 and makes determining true tail recursion sites difficult. 3404 3405 So we set LABEL_PRESERVE_P here, then clear it when we select 3406 one of the call sequences after rtl generation is complete. */ 3407 if (tail_recursion_insns) 3408 LABEL_PRESERVE_P (tail_recursion_label) = 1; 3409 emit_call_insn (gen_rtx_CALL_PLACEHOLDER (VOIDmode, normal_call_insns, 3410 tail_call_insns, 3411 tail_recursion_insns, 3412 tail_recursion_label)); 3413 } 3414 else 3415 emit_insns (normal_call_insns); 3416 3417 currently_expanding_call--; 3418 3419 /* If this function returns with the stack pointer depressed, ensure 3420 this block saves and restores the stack pointer, show it was 3421 changed, and adjust for any outgoing arg space. */ 3422 if (flags & ECF_SP_DEPRESSED) 3423 { 3424 clear_pending_stack_adjust (); 3425 emit_insn (gen_rtx (CLOBBER, VOIDmode, stack_pointer_rtx)); 3426 emit_move_insn (virtual_stack_dynamic_rtx, stack_pointer_rtx); 3427 save_stack_pointer (); 3428 } 3429 3430 return target; 3431} 3432 3433/* Output a library call to function FUN (a SYMBOL_REF rtx). 3434 The RETVAL parameter specifies whether return value needs to be saved, other 3435 parameters are documented in the emit_library_call function below. */ 3436 3437static rtx 3438emit_library_call_value_1 (retval, orgfun, value, fn_type, outmode, nargs, p) 3439 int retval; 3440 rtx orgfun; 3441 rtx value; 3442 enum libcall_type fn_type; 3443 enum machine_mode outmode; 3444 int nargs; 3445 va_list p; 3446{ 3447 /* Total size in bytes of all the stack-parms scanned so far. */ 3448 struct args_size args_size; 3449 /* Size of arguments before any adjustments (such as rounding). */ 3450 struct args_size original_args_size; 3451 int argnum; 3452 rtx fun; 3453 int inc; 3454 int count; 3455 struct args_size alignment_pad; 3456 rtx argblock = 0; 3457 CUMULATIVE_ARGS args_so_far; 3458 struct arg 3459 { 3460 rtx value; 3461 enum machine_mode mode; 3462 rtx reg; 3463 int partial; 3464 struct args_size offset; 3465 struct args_size size; 3466 rtx save_area; 3467 }; 3468 struct arg *argvec; 3469 int old_inhibit_defer_pop = inhibit_defer_pop; 3470 rtx call_fusage = 0; 3471 rtx mem_value = 0; 3472 rtx valreg; 3473 int pcc_struct_value = 0; 3474 int struct_value_size = 0; 3475 int flags; 3476 int reg_parm_stack_space = 0; 3477 int needed; 3478 rtx before_call; 3479 3480#ifdef REG_PARM_STACK_SPACE 3481 /* Define the boundary of the register parm stack space that needs to be 3482 save, if any. */ 3483 int low_to_save = -1, high_to_save = 0; 3484 rtx save_area = 0; /* Place that it is saved. */ 3485#endif 3486 3487 /* Size of the stack reserved for parameter registers. */ 3488 int initial_highest_arg_in_use = highest_outgoing_arg_in_use; 3489 char *initial_stack_usage_map = stack_usage_map; 3490 3491#ifdef REG_PARM_STACK_SPACE 3492#ifdef MAYBE_REG_PARM_STACK_SPACE 3493 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE; 3494#else 3495 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0); 3496#endif 3497#endif 3498 3499 /* By default, library functions can not throw. */ 3500 flags = ECF_NOTHROW; 3501 3502 switch (fn_type) 3503 { 3504 case LCT_NORMAL: 3505 break; 3506 case LCT_CONST: 3507 flags |= ECF_CONST; 3508 break; 3509 case LCT_PURE: 3510 flags |= ECF_PURE; 3511 break; 3512 case LCT_CONST_MAKE_BLOCK: 3513 flags |= ECF_CONST | ECF_LIBCALL_BLOCK; 3514 break; 3515 case LCT_PURE_MAKE_BLOCK: 3516 flags |= ECF_PURE | ECF_LIBCALL_BLOCK; 3517 break; 3518 case LCT_NORETURN: 3519 flags |= ECF_NORETURN; 3520 break; 3521 case LCT_THROW: 3522 flags = ECF_NORETURN; 3523 break; 3524 case LCT_ALWAYS_RETURN: 3525 flags = ECF_ALWAYS_RETURN; 3526 break; 3527 case LCT_RETURNS_TWICE: 3528 flags = ECF_RETURNS_TWICE; 3529 break; 3530 } 3531 fun = orgfun; 3532 3533 /* Ensure current function's preferred stack boundary is at least 3534 what we need. */ 3535 if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY) 3536 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY; 3537 3538 /* If this kind of value comes back in memory, 3539 decide where in memory it should come back. */ 3540 if (outmode != VOIDmode && aggregate_value_p (type_for_mode (outmode, 0))) 3541 { 3542#ifdef PCC_STATIC_STRUCT_RETURN 3543 rtx pointer_reg 3544 = hard_function_value (build_pointer_type (type_for_mode (outmode, 0)), 3545 0, 0); 3546 mem_value = gen_rtx_MEM (outmode, pointer_reg); 3547 pcc_struct_value = 1; 3548 if (value == 0) 3549 value = gen_reg_rtx (outmode); 3550#else /* not PCC_STATIC_STRUCT_RETURN */ 3551 struct_value_size = GET_MODE_SIZE (outmode); 3552 if (value != 0 && GET_CODE (value) == MEM) 3553 mem_value = value; 3554 else 3555 mem_value = assign_temp (type_for_mode (outmode, 0), 0, 1, 1); 3556#endif 3557 3558 /* This call returns a big structure. */ 3559 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK); 3560 } 3561 3562 /* ??? Unfinished: must pass the memory address as an argument. */ 3563 3564 /* Copy all the libcall-arguments out of the varargs data 3565 and into a vector ARGVEC. 3566 3567 Compute how to pass each argument. We only support a very small subset 3568 of the full argument passing conventions to limit complexity here since 3569 library functions shouldn't have many args. */ 3570 3571 argvec = (struct arg *) alloca ((nargs + 1) * sizeof (struct arg)); 3572 memset ((char *) argvec, 0, (nargs + 1) * sizeof (struct arg)); 3573 3574#ifdef INIT_CUMULATIVE_LIBCALL_ARGS 3575 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun); 3576#else 3577 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0); 3578#endif 3579 3580 args_size.constant = 0; 3581 args_size.var = 0; 3582 3583 count = 0; 3584 3585 /* Now we are about to start emitting insns that can be deleted 3586 if a libcall is deleted. */ 3587 if (flags & ECF_LIBCALL_BLOCK) 3588 start_sequence (); 3589 3590 push_temp_slots (); 3591 3592 /* If there's a structure value address to be passed, 3593 either pass it in the special place, or pass it as an extra argument. */ 3594 if (mem_value && struct_value_rtx == 0 && ! pcc_struct_value) 3595 { 3596 rtx addr = XEXP (mem_value, 0); 3597 nargs++; 3598 3599 /* Make sure it is a reasonable operand for a move or push insn. */ 3600 if (GET_CODE (addr) != REG && GET_CODE (addr) != MEM 3601 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr))) 3602 addr = force_operand (addr, NULL_RTX); 3603 3604 argvec[count].value = addr; 3605 argvec[count].mode = Pmode; 3606 argvec[count].partial = 0; 3607 3608 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1); 3609#ifdef FUNCTION_ARG_PARTIAL_NREGS 3610 if (FUNCTION_ARG_PARTIAL_NREGS (args_so_far, Pmode, NULL_TREE, 1)) 3611 abort (); 3612#endif 3613 3614 locate_and_pad_parm (Pmode, NULL_TREE, 3615#ifdef STACK_PARMS_IN_REG_PARM_AREA 3616 1, 3617#else 3618 argvec[count].reg != 0, 3619#endif 3620 NULL_TREE, &args_size, &argvec[count].offset, 3621 &argvec[count].size, &alignment_pad); 3622 3623 if (argvec[count].reg == 0 || argvec[count].partial != 0 3624 || reg_parm_stack_space > 0) 3625 args_size.constant += argvec[count].size.constant; 3626 3627 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1); 3628 3629 count++; 3630 } 3631 3632 for (; count < nargs; count++) 3633 { 3634 rtx val = va_arg (p, rtx); 3635 enum machine_mode mode = va_arg (p, enum machine_mode); 3636 3637 /* We cannot convert the arg value to the mode the library wants here; 3638 must do it earlier where we know the signedness of the arg. */ 3639 if (mode == BLKmode 3640 || (GET_MODE (val) != mode && GET_MODE (val) != VOIDmode)) 3641 abort (); 3642 3643 /* On some machines, there's no way to pass a float to a library fcn. 3644 Pass it as a double instead. */ 3645#ifdef LIBGCC_NEEDS_DOUBLE 3646 if (LIBGCC_NEEDS_DOUBLE && mode == SFmode) 3647 val = convert_modes (DFmode, SFmode, val, 0), mode = DFmode; 3648#endif 3649 3650 /* There's no need to call protect_from_queue, because 3651 either emit_move_insn or emit_push_insn will do that. */ 3652 3653 /* Make sure it is a reasonable operand for a move or push insn. */ 3654 if (GET_CODE (val) != REG && GET_CODE (val) != MEM 3655 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val))) 3656 val = force_operand (val, NULL_RTX); 3657 3658#ifdef FUNCTION_ARG_PASS_BY_REFERENCE 3659 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, mode, NULL_TREE, 1)) 3660 { 3661 rtx slot; 3662 int must_copy = 1 3663#ifdef FUNCTION_ARG_CALLEE_COPIES 3664 && ! FUNCTION_ARG_CALLEE_COPIES (args_so_far, mode, 3665 NULL_TREE, 1) 3666#endif 3667 ; 3668
|
3677 if (GET_MODE (val) == MEM && ! must_copy) 3678 slot = val; 3679 else if (must_copy) 3680 { 3681 slot = assign_temp (type_for_mode (mode, 0), 0, 1, 1); 3682 emit_move_insn (slot, val); 3683 } 3684 else 3685 { 3686 tree type = type_for_mode (mode, 0); 3687 3688 slot = gen_rtx_MEM (mode, 3689 expand_expr (build1 (ADDR_EXPR, 3690 build_pointer_type 3691 (type), 3692 make_tree (type, val)), 3693 NULL_RTX, VOIDmode, 0)); 3694 } 3695 3696 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, 3697 gen_rtx_USE (VOIDmode, slot), 3698 call_fusage); 3699 if (must_copy) 3700 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, 3701 gen_rtx_CLOBBER (VOIDmode, 3702 slot), 3703 call_fusage); 3704 3705 mode = Pmode; 3706 val = force_operand (XEXP (slot, 0), NULL_RTX); 3707 } 3708#endif 3709 3710 argvec[count].value = val; 3711 argvec[count].mode = mode; 3712 3713 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1); 3714 3715#ifdef FUNCTION_ARG_PARTIAL_NREGS 3716 argvec[count].partial 3717 = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode, NULL_TREE, 1); 3718#else 3719 argvec[count].partial = 0; 3720#endif 3721 3722 locate_and_pad_parm (mode, NULL_TREE, 3723#ifdef STACK_PARMS_IN_REG_PARM_AREA 3724 1, 3725#else 3726 argvec[count].reg != 0, 3727#endif 3728 NULL_TREE, &args_size, &argvec[count].offset, 3729 &argvec[count].size, &alignment_pad); 3730 3731 if (argvec[count].size.var) 3732 abort (); 3733 3734 if (reg_parm_stack_space == 0 && argvec[count].partial) 3735 argvec[count].size.constant -= argvec[count].partial * UNITS_PER_WORD; 3736 3737 if (argvec[count].reg == 0 || argvec[count].partial != 0 3738 || reg_parm_stack_space > 0) 3739 args_size.constant += argvec[count].size.constant; 3740 3741 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1); 3742 } 3743 3744#ifdef FINAL_REG_PARM_STACK_SPACE 3745 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant, 3746 args_size.var); 3747#endif 3748 /* If this machine requires an external definition for library 3749 functions, write one out. */ 3750 assemble_external_libcall (fun); 3751 3752 original_args_size = args_size; 3753 args_size.constant = (((args_size.constant 3754 + stack_pointer_delta 3755 + STACK_BYTES - 1) 3756 / STACK_BYTES 3757 * STACK_BYTES) 3758 - stack_pointer_delta); 3759 3760 args_size.constant = MAX (args_size.constant, 3761 reg_parm_stack_space); 3762 3763#ifndef OUTGOING_REG_PARM_STACK_SPACE 3764 args_size.constant -= reg_parm_stack_space; 3765#endif 3766 3767 if (args_size.constant > current_function_outgoing_args_size) 3768 current_function_outgoing_args_size = args_size.constant; 3769 3770 if (ACCUMULATE_OUTGOING_ARGS) 3771 { 3772 /* Since the stack pointer will never be pushed, it is possible for 3773 the evaluation of a parm to clobber something we have already 3774 written to the stack. Since most function calls on RISC machines 3775 do not use the stack, this is uncommon, but must work correctly. 3776 3777 Therefore, we save any area of the stack that was already written 3778 and that we are using. Here we set up to do this by making a new 3779 stack usage map from the old one. 3780 3781 Another approach might be to try to reorder the argument 3782 evaluations to avoid this conflicting stack usage. */ 3783 3784 needed = args_size.constant; 3785 3786#ifndef OUTGOING_REG_PARM_STACK_SPACE 3787 /* Since we will be writing into the entire argument area, the 3788 map must be allocated for its entire size, not just the part that 3789 is the responsibility of the caller. */ 3790 needed += reg_parm_stack_space; 3791#endif 3792 3793#ifdef ARGS_GROW_DOWNWARD 3794 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, 3795 needed + 1); 3796#else 3797 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, 3798 needed); 3799#endif 3800 stack_usage_map = (char *) alloca (highest_outgoing_arg_in_use); 3801 3802 if (initial_highest_arg_in_use) 3803 memcpy (stack_usage_map, initial_stack_usage_map, 3804 initial_highest_arg_in_use); 3805 3806 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use) 3807 memset (&stack_usage_map[initial_highest_arg_in_use], 0, 3808 highest_outgoing_arg_in_use - initial_highest_arg_in_use); 3809 needed = 0; 3810 3811 /* We must be careful to use virtual regs before they're instantiated, 3812 and real regs afterwards. Loop optimization, for example, can create 3813 new libcalls after we've instantiated the virtual regs, and if we 3814 use virtuals anyway, they won't match the rtl patterns. */ 3815 3816 if (virtuals_instantiated) 3817 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET); 3818 else 3819 argblock = virtual_outgoing_args_rtx; 3820 } 3821 else 3822 { 3823 if (!PUSH_ARGS) 3824 argblock = push_block (GEN_INT (args_size.constant), 0, 0); 3825 } 3826 3827 /* If we push args individually in reverse order, perform stack alignment 3828 before the first push (the last arg). */ 3829 if (argblock == 0 && PUSH_ARGS_REVERSED) 3830 anti_adjust_stack (GEN_INT (args_size.constant 3831 - original_args_size.constant)); 3832 3833 if (PUSH_ARGS_REVERSED) 3834 { 3835 inc = -1; 3836 argnum = nargs - 1; 3837 } 3838 else 3839 { 3840 inc = 1; 3841 argnum = 0; 3842 } 3843 3844#ifdef REG_PARM_STACK_SPACE 3845 if (ACCUMULATE_OUTGOING_ARGS) 3846 { 3847 /* The argument list is the property of the called routine and it 3848 may clobber it. If the fixed area has been used for previous 3849 parameters, we must save and restore it. 3850 3851 Here we compute the boundary of the that needs to be saved, if any. */ 3852 3853#ifdef ARGS_GROW_DOWNWARD 3854 for (count = 0; count < reg_parm_stack_space + 1; count++) 3855#else 3856 for (count = 0; count < reg_parm_stack_space; count++) 3857#endif 3858 { 3859 if (count >= highest_outgoing_arg_in_use 3860 || stack_usage_map[count] == 0) 3861 continue; 3862 3863 if (low_to_save == -1) 3864 low_to_save = count; 3865 3866 high_to_save = count; 3867 } 3868 3869 if (low_to_save >= 0) 3870 { 3871 int num_to_save = high_to_save - low_to_save + 1; 3872 enum machine_mode save_mode 3873 = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1); 3874 rtx stack_area; 3875 3876 /* If we don't have the required alignment, must do this in BLKmode. */ 3877 if ((low_to_save & (MIN (GET_MODE_SIZE (save_mode), 3878 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1))) 3879 save_mode = BLKmode; 3880 3881#ifdef ARGS_GROW_DOWNWARD 3882 stack_area = gen_rtx_MEM (save_mode, 3883 memory_address (save_mode, 3884 plus_constant (argblock, 3885 -high_to_save))); 3886#else 3887 stack_area = gen_rtx_MEM (save_mode, 3888 memory_address (save_mode, 3889 plus_constant (argblock, 3890 low_to_save))); 3891#endif 3892 if (save_mode == BLKmode) 3893 { 3894 save_area = assign_stack_temp (BLKmode, num_to_save, 0); 3895 set_mem_align (save_area, PARM_BOUNDARY); 3896 emit_block_move (validize_mem (save_area), stack_area, 3897 GEN_INT (num_to_save)); 3898 } 3899 else 3900 { 3901 save_area = gen_reg_rtx (save_mode); 3902 emit_move_insn (save_area, stack_area); 3903 } 3904 } 3905 } 3906#endif 3907 3908 /* Push the args that need to be pushed. */ 3909 3910 /* ARGNUM indexes the ARGVEC array in the order in which the arguments 3911 are to be pushed. */ 3912 for (count = 0; count < nargs; count++, argnum += inc) 3913 { 3914 enum machine_mode mode = argvec[argnum].mode; 3915 rtx val = argvec[argnum].value; 3916 rtx reg = argvec[argnum].reg; 3917 int partial = argvec[argnum].partial; 3918 int lower_bound = 0, upper_bound = 0, i; 3919 3920 if (! (reg != 0 && partial == 0)) 3921 { 3922 if (ACCUMULATE_OUTGOING_ARGS) 3923 { 3924 /* If this is being stored into a pre-allocated, fixed-size, 3925 stack area, save any previous data at that location. */ 3926 3927#ifdef ARGS_GROW_DOWNWARD 3928 /* stack_slot is negative, but we want to index stack_usage_map 3929 with positive values. */ 3930 upper_bound = -argvec[argnum].offset.constant + 1; 3931 lower_bound = upper_bound - argvec[argnum].size.constant; 3932#else 3933 lower_bound = argvec[argnum].offset.constant; 3934 upper_bound = lower_bound + argvec[argnum].size.constant; 3935#endif 3936 3937 for (i = lower_bound; i < upper_bound; i++) 3938 if (stack_usage_map[i] 3939 /* Don't store things in the fixed argument area at this 3940 point; it has already been saved. */ 3941 && i > reg_parm_stack_space) 3942 break; 3943 3944 if (i != upper_bound) 3945 { 3946 /* We need to make a save area. See what mode we can make 3947 it. */ 3948 enum machine_mode save_mode 3949 = mode_for_size (argvec[argnum].size.constant 3950 * BITS_PER_UNIT, 3951 MODE_INT, 1); 3952 rtx stack_area 3953 = gen_rtx_MEM 3954 (save_mode, 3955 memory_address 3956 (save_mode, 3957 plus_constant (argblock, 3958 argvec[argnum].offset.constant))); 3959 argvec[argnum].save_area = gen_reg_rtx (save_mode); 3960 3961 emit_move_insn (argvec[argnum].save_area, stack_area); 3962 } 3963 } 3964 3965 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, 0, partial, reg, 0, 3966 argblock, GEN_INT (argvec[argnum].offset.constant), 3967 reg_parm_stack_space, ARGS_SIZE_RTX (alignment_pad)); 3968 3969 /* Now mark the segment we just used. */ 3970 if (ACCUMULATE_OUTGOING_ARGS) 3971 for (i = lower_bound; i < upper_bound; i++) 3972 stack_usage_map[i] = 1; 3973 3974 NO_DEFER_POP; 3975 } 3976 } 3977 3978 /* If we pushed args in forward order, perform stack alignment 3979 after pushing the last arg. */ 3980 if (argblock == 0 && !PUSH_ARGS_REVERSED) 3981 anti_adjust_stack (GEN_INT (args_size.constant 3982 - original_args_size.constant)); 3983 3984 if (PUSH_ARGS_REVERSED) 3985 argnum = nargs - 1; 3986 else 3987 argnum = 0; 3988 3989 fun = prepare_call_address (fun, NULL_TREE, &call_fusage, 0, 0); 3990 3991 /* Now load any reg parms into their regs. */ 3992 3993 /* ARGNUM indexes the ARGVEC array in the order in which the arguments 3994 are to be pushed. */ 3995 for (count = 0; count < nargs; count++, argnum += inc) 3996 { 3997 rtx val = argvec[argnum].value; 3998 rtx reg = argvec[argnum].reg; 3999 int partial = argvec[argnum].partial; 4000 4001 /* Handle calls that pass values in multiple non-contiguous 4002 locations. The PA64 has examples of this for library calls. */ 4003 if (reg != 0 && GET_CODE (reg) == PARALLEL) 4004 emit_group_load (reg, val, GET_MODE_SIZE (GET_MODE (val))); 4005 else if (reg != 0 && partial == 0) 4006 emit_move_insn (reg, val); 4007 4008 NO_DEFER_POP; 4009 } 4010 4011 /* Any regs containing parms remain in use through the call. */ 4012 for (count = 0; count < nargs; count++) 4013 { 4014 rtx reg = argvec[count].reg; 4015 if (reg != 0 && GET_CODE (reg) == PARALLEL) 4016 use_group_regs (&call_fusage, reg); 4017 else if (reg != 0) 4018 use_reg (&call_fusage, reg); 4019 } 4020 4021 /* Pass the function the address in which to return a structure value. */ 4022 if (mem_value != 0 && struct_value_rtx != 0 && ! pcc_struct_value) 4023 { 4024 emit_move_insn (struct_value_rtx, 4025 force_reg (Pmode, 4026 force_operand (XEXP (mem_value, 0), 4027 NULL_RTX))); 4028 if (GET_CODE (struct_value_rtx) == REG) 4029 use_reg (&call_fusage, struct_value_rtx); 4030 } 4031 4032 /* Don't allow popping to be deferred, since then 4033 cse'ing of library calls could delete a call and leave the pop. */ 4034 NO_DEFER_POP; 4035 valreg = (mem_value == 0 && outmode != VOIDmode 4036 ? hard_libcall_value (outmode) : NULL_RTX); 4037 4038 /* Stack must be properly aligned now. */ 4039 if (stack_pointer_delta & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1)) 4040 abort (); 4041 4042 before_call = get_last_insn (); 4043 4044 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which 4045 will set inhibit_defer_pop to that value. */ 4046 /* The return type is needed to decide how many bytes the function pops. 4047 Signedness plays no role in that, so for simplicity, we pretend it's 4048 always signed. We also assume that the list of arguments passed has 4049 no impact, so we pretend it is unknown. */ 4050 4051 emit_call_1 (fun, 4052 get_identifier (XSTR (orgfun, 0)), 4053 build_function_type (outmode == VOIDmode ? void_type_node 4054 : type_for_mode (outmode, 0), NULL_TREE), 4055 original_args_size.constant, args_size.constant, 4056 struct_value_size, 4057 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1), 4058 valreg, 4059 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far); 4060 4061 /* For calls to `setjmp', etc., inform flow.c it should complain 4062 if nonvolatile values are live. For functions that cannot return, 4063 inform flow that control does not fall through. */ 4064 4065 if (flags & (ECF_NORETURN | ECF_LONGJMP)) 4066 { 4067 /* The barrier note must be emitted 4068 immediately after the CALL_INSN. Some ports emit more than 4069 just a CALL_INSN above, so we must search for it here. */ 4070 4071 rtx last = get_last_insn (); 4072 while (GET_CODE (last) != CALL_INSN) 4073 { 4074 last = PREV_INSN (last); 4075 /* There was no CALL_INSN? */ 4076 if (last == before_call) 4077 abort (); 4078 } 4079 4080 emit_barrier_after (last); 4081 } 4082 4083 /* Now restore inhibit_defer_pop to its actual original value. */ 4084 OK_DEFER_POP; 4085 4086 /* If call is cse'able, make appropriate pair of reg-notes around it. 4087 Test valreg so we don't crash; may safely ignore `const' 4088 if return type is void. Disable for PARALLEL return values, because 4089 we have no way to move such values into a pseudo register. */ 4090 if (flags & ECF_LIBCALL_BLOCK) 4091 { 4092 rtx insns; 4093 4094 if (valreg == 0 || GET_CODE (valreg) == PARALLEL) 4095 { 4096 insns = get_insns (); 4097 end_sequence (); 4098 emit_insns (insns); 4099 } 4100 else 4101 { 4102 rtx note = 0; 4103 rtx temp = gen_reg_rtx (GET_MODE (valreg)); 4104 int i; 4105 4106 /* Construct an "equal form" for the value which mentions all the 4107 arguments in order as well as the function name. */ 4108 for (i = 0; i < nargs; i++) 4109 note = gen_rtx_EXPR_LIST (VOIDmode, argvec[i].value, note); 4110 note = gen_rtx_EXPR_LIST (VOIDmode, fun, note); 4111 4112 insns = get_insns (); 4113 end_sequence (); 4114 4115 if (flags & ECF_PURE) 4116 note = gen_rtx_EXPR_LIST (VOIDmode, 4117 gen_rtx_USE (VOIDmode, 4118 gen_rtx_MEM (BLKmode, 4119 gen_rtx_SCRATCH (VOIDmode))), 4120 note); 4121 4122 emit_libcall_block (insns, temp, valreg, note); 4123 4124 valreg = temp; 4125 } 4126 } 4127 pop_temp_slots (); 4128 4129 /* Copy the value to the right place. */ 4130 if (outmode != VOIDmode && retval) 4131 { 4132 if (mem_value) 4133 { 4134 if (value == 0) 4135 value = mem_value; 4136 if (value != mem_value) 4137 emit_move_insn (value, mem_value); 4138 } 4139 else if (value != 0) 4140 emit_move_insn (value, hard_libcall_value (outmode)); 4141 else 4142 value = hard_libcall_value (outmode); 4143 } 4144 4145 if (ACCUMULATE_OUTGOING_ARGS) 4146 { 4147#ifdef REG_PARM_STACK_SPACE 4148 if (save_area) 4149 { 4150 enum machine_mode save_mode = GET_MODE (save_area); 4151#ifdef ARGS_GROW_DOWNWARD 4152 rtx stack_area 4153 = gen_rtx_MEM (save_mode, 4154 memory_address (save_mode, 4155 plus_constant (argblock, 4156 - high_to_save))); 4157#else 4158 rtx stack_area 4159 = gen_rtx_MEM (save_mode, 4160 memory_address (save_mode, 4161 plus_constant (argblock, low_to_save))); 4162#endif 4163 4164 set_mem_align (stack_area, PARM_BOUNDARY); 4165 if (save_mode != BLKmode) 4166 emit_move_insn (stack_area, save_area); 4167 else 4168 emit_block_move (stack_area, validize_mem (save_area), 4169 GEN_INT (high_to_save - low_to_save + 1)); 4170 } 4171#endif 4172 4173 /* If we saved any argument areas, restore them. */ 4174 for (count = 0; count < nargs; count++) 4175 if (argvec[count].save_area) 4176 { 4177 enum machine_mode save_mode = GET_MODE (argvec[count].save_area); 4178 rtx stack_area 4179 = gen_rtx_MEM (save_mode, 4180 memory_address 4181 (save_mode, 4182 plus_constant (argblock, 4183 argvec[count].offset.constant))); 4184 4185 emit_move_insn (stack_area, argvec[count].save_area); 4186 } 4187 4188 highest_outgoing_arg_in_use = initial_highest_arg_in_use; 4189 stack_usage_map = initial_stack_usage_map; 4190 } 4191 4192 return value; 4193 4194} 4195 4196/* Output a library call to function FUN (a SYMBOL_REF rtx) 4197 (emitting the queue unless NO_QUEUE is nonzero), 4198 for a value of mode OUTMODE, 4199 with NARGS different arguments, passed as alternating rtx values 4200 and machine_modes to convert them to. 4201 The rtx values should have been passed through protect_from_queue already. 4202 4203 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const' 4204 calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls 4205 which should be enclosed in REG_LIBCALL/REG_RETVAL notes, 4206 LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in 4207 REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)), 4208 or other LCT_ value for other types of library calls. */ 4209 4210void 4211emit_library_call VPARAMS((rtx orgfun, enum libcall_type fn_type, 4212 enum machine_mode outmode, int nargs, ...)) 4213{ 4214 VA_OPEN (p, nargs); 4215 VA_FIXEDARG (p, rtx, orgfun); 4216 VA_FIXEDARG (p, int, fn_type); 4217 VA_FIXEDARG (p, enum machine_mode, outmode); 4218 VA_FIXEDARG (p, int, nargs); 4219 4220 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p); 4221 4222 VA_CLOSE (p); 4223} 4224 4225/* Like emit_library_call except that an extra argument, VALUE, 4226 comes second and says where to store the result. 4227 (If VALUE is zero, this function chooses a convenient way 4228 to return the value. 4229 4230 This function returns an rtx for where the value is to be found. 4231 If VALUE is nonzero, VALUE is returned. */ 4232 4233rtx 4234emit_library_call_value VPARAMS((rtx orgfun, rtx value, 4235 enum libcall_type fn_type, 4236 enum machine_mode outmode, int nargs, ...)) 4237{ 4238 rtx result; 4239 4240 VA_OPEN (p, nargs); 4241 VA_FIXEDARG (p, rtx, orgfun); 4242 VA_FIXEDARG (p, rtx, value); 4243 VA_FIXEDARG (p, int, fn_type); 4244 VA_FIXEDARG (p, enum machine_mode, outmode); 4245 VA_FIXEDARG (p, int, nargs); 4246 4247 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode, 4248 nargs, p); 4249 4250 VA_CLOSE (p); 4251 4252 return result; 4253} 4254 4255/* Store a single argument for a function call 4256 into the register or memory area where it must be passed. 4257 *ARG describes the argument value and where to pass it. 4258 4259 ARGBLOCK is the address of the stack-block for all the arguments, 4260 or 0 on a machine where arguments are pushed individually. 4261 4262 MAY_BE_ALLOCA nonzero says this could be a call to `alloca' 4263 so must be careful about how the stack is used. 4264 4265 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing 4266 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate 4267 that we need not worry about saving and restoring the stack. 4268 4269 FNDECL is the declaration of the function we are calling. 4270 4271 Return non-zero if this arg should cause sibcall failure, 4272 zero otherwise. */ 4273 4274static int 4275store_one_arg (arg, argblock, flags, variable_size, reg_parm_stack_space) 4276 struct arg_data *arg; 4277 rtx argblock; 4278 int flags; 4279 int variable_size ATTRIBUTE_UNUSED; 4280 int reg_parm_stack_space; 4281{ 4282 tree pval = arg->tree_value; 4283 rtx reg = 0; 4284 int partial = 0; 4285 int used = 0; 4286 int i, lower_bound = 0, upper_bound = 0; 4287 int sibcall_failure = 0; 4288 4289 if (TREE_CODE (pval) == ERROR_MARK) 4290 return 1; 4291 4292 /* Push a new temporary level for any temporaries we make for 4293 this argument. */ 4294 push_temp_slots (); 4295 4296 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)) 4297 { 4298 /* If this is being stored into a pre-allocated, fixed-size, stack area, 4299 save any previous data at that location. */ 4300 if (argblock && ! variable_size && arg->stack) 4301 { 4302#ifdef ARGS_GROW_DOWNWARD 4303 /* stack_slot is negative, but we want to index stack_usage_map 4304 with positive values. */ 4305 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS) 4306 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1; 4307 else 4308 upper_bound = 0; 4309 4310 lower_bound = upper_bound - arg->size.constant; 4311#else 4312 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS) 4313 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)); 4314 else 4315 lower_bound = 0; 4316 4317 upper_bound = lower_bound + arg->size.constant; 4318#endif 4319 4320 for (i = lower_bound; i < upper_bound; i++) 4321 if (stack_usage_map[i] 4322 /* Don't store things in the fixed argument area at this point; 4323 it has already been saved. */ 4324 && i > reg_parm_stack_space) 4325 break; 4326 4327 if (i != upper_bound) 4328 { 4329 /* We need to make a save area. See what mode we can make it. */ 4330 enum machine_mode save_mode 4331 = mode_for_size (arg->size.constant * BITS_PER_UNIT, MODE_INT, 1); 4332 rtx stack_area 4333 = gen_rtx_MEM (save_mode, 4334 memory_address (save_mode, 4335 XEXP (arg->stack_slot, 0))); 4336 4337 if (save_mode == BLKmode) 4338 { 4339 tree ot = TREE_TYPE (arg->tree_value); 4340 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot) 4341 | TYPE_QUAL_CONST)); 4342 4343 arg->save_area = assign_temp (nt, 0, 1, 1); 4344 preserve_temp_slots (arg->save_area); 4345 emit_block_move (validize_mem (arg->save_area), stack_area, 4346 expr_size (arg->tree_value)); 4347 } 4348 else 4349 { 4350 arg->save_area = gen_reg_rtx (save_mode); 4351 emit_move_insn (arg->save_area, stack_area); 4352 } 4353 } 4354 } 4355 /* Now that we have saved any slots that will be overwritten by this 4356 store, mark all slots this store will use. We must do this before 4357 we actually expand the argument since the expansion itself may 4358 trigger library calls which might need to use the same stack slot. */ 4359 if (argblock && ! variable_size && arg->stack) 4360 for (i = lower_bound; i < upper_bound; i++) 4361 stack_usage_map[i] = 1; 4362 } 4363 4364 /* If this isn't going to be placed on both the stack and in registers, 4365 set up the register and number of words. */ 4366 if (! arg->pass_on_stack) 4367 { 4368 if (flags & ECF_SIBCALL) 4369 reg = arg->tail_call_reg; 4370 else 4371 reg = arg->reg; 4372 partial = arg->partial; 4373 } 4374 4375 if (reg != 0 && partial == 0) 4376 /* Being passed entirely in a register. We shouldn't be called in 4377 this case. */ 4378 abort (); 4379 4380 /* If this arg needs special alignment, don't load the registers 4381 here. */ 4382 if (arg->n_aligned_regs != 0) 4383 reg = 0; 4384 4385 /* If this is being passed partially in a register, we can't evaluate 4386 it directly into its stack slot. Otherwise, we can. */ 4387 if (arg->value == 0) 4388 { 4389 /* stack_arg_under_construction is nonzero if a function argument is 4390 being evaluated directly into the outgoing argument list and 4391 expand_call must take special action to preserve the argument list 4392 if it is called recursively. 4393 4394 For scalar function arguments stack_usage_map is sufficient to 4395 determine which stack slots must be saved and restored. Scalar 4396 arguments in general have pass_on_stack == 0. 4397 4398 If this argument is initialized by a function which takes the 4399 address of the argument (a C++ constructor or a C function 4400 returning a BLKmode structure), then stack_usage_map is 4401 insufficient and expand_call must push the stack around the 4402 function call. Such arguments have pass_on_stack == 1. 4403 4404 Note that it is always safe to set stack_arg_under_construction, 4405 but this generates suboptimal code if set when not needed. */ 4406 4407 if (arg->pass_on_stack) 4408 stack_arg_under_construction++; 4409 4410 arg->value = expand_expr (pval, 4411 (partial 4412 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode) 4413 ? NULL_RTX : arg->stack, 4414 VOIDmode, 0); 4415 4416 /* If we are promoting object (or for any other reason) the mode 4417 doesn't agree, convert the mode. */ 4418 4419 if (arg->mode != TYPE_MODE (TREE_TYPE (pval))) 4420 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)), 4421 arg->value, arg->unsignedp); 4422 4423 if (arg->pass_on_stack) 4424 stack_arg_under_construction--; 4425 } 4426 4427 /* Don't allow anything left on stack from computation 4428 of argument to alloca. */ 4429 if (flags & ECF_MAY_BE_ALLOCA) 4430 do_pending_stack_adjust (); 4431 4432 if (arg->value == arg->stack) 4433 /* If the value is already in the stack slot, we are done. */ 4434 ; 4435 else if (arg->mode != BLKmode) 4436 { 4437 int size; 4438 4439 /* Argument is a scalar, not entirely passed in registers. 4440 (If part is passed in registers, arg->partial says how much 4441 and emit_push_insn will take care of putting it there.) 4442 4443 Push it, and if its size is less than the 4444 amount of space allocated to it, 4445 also bump stack pointer by the additional space. 4446 Note that in C the default argument promotions 4447 will prevent such mismatches. */ 4448 4449 size = GET_MODE_SIZE (arg->mode); 4450 /* Compute how much space the push instruction will push. 4451 On many machines, pushing a byte will advance the stack 4452 pointer by a halfword. */ 4453#ifdef PUSH_ROUNDING 4454 size = PUSH_ROUNDING (size); 4455#endif 4456 used = size; 4457 4458 /* Compute how much space the argument should get: 4459 round up to a multiple of the alignment for arguments. */ 4460 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval))) 4461 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1) 4462 / (PARM_BOUNDARY / BITS_PER_UNIT)) 4463 * (PARM_BOUNDARY / BITS_PER_UNIT)); 4464 4465 /* This isn't already where we want it on the stack, so put it there. 4466 This can either be done with push or copy insns. */ 4467 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX, 0, 4468 partial, reg, used - size, argblock, 4469 ARGS_SIZE_RTX (arg->offset), reg_parm_stack_space, 4470 ARGS_SIZE_RTX (arg->alignment_pad)); 4471 4472 /* Unless this is a partially-in-register argument, the argument is now 4473 in the stack. */ 4474 if (partial == 0) 4475 arg->value = arg->stack; 4476 } 4477 else 4478 { 4479 /* BLKmode, at least partly to be pushed. */ 4480 4481 int excess; 4482 rtx size_rtx; 4483 4484 /* Pushing a nonscalar. 4485 If part is passed in registers, PARTIAL says how much 4486 and emit_push_insn will take care of putting it there. */ 4487 4488 /* Round its size up to a multiple 4489 of the allocation unit for arguments. */ 4490 4491 if (arg->size.var != 0) 4492 { 4493 excess = 0; 4494 size_rtx = ARGS_SIZE_RTX (arg->size); 4495 } 4496 else 4497 { 4498 /* PUSH_ROUNDING has no effect on us, because 4499 emit_push_insn for BLKmode is careful to avoid it. */ 4500 excess = (arg->size.constant - int_size_in_bytes (TREE_TYPE (pval)) 4501 + partial * UNITS_PER_WORD); 4502 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)), 4503 NULL_RTX, TYPE_MODE (sizetype), 0); 4504 } 4505 4506 if ((flags & ECF_SIBCALL) && GET_CODE (arg->value) == MEM) 4507 { 4508 /* emit_push_insn might not work properly if arg->value and 4509 argblock + arg->offset areas overlap. */ 4510 rtx x = arg->value; 4511 int i = 0; 4512 4513 if (XEXP (x, 0) == current_function_internal_arg_pointer 4514 || (GET_CODE (XEXP (x, 0)) == PLUS 4515 && XEXP (XEXP (x, 0), 0) == 4516 current_function_internal_arg_pointer 4517 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)) 4518 { 4519 if (XEXP (x, 0) != current_function_internal_arg_pointer) 4520 i = INTVAL (XEXP (XEXP (x, 0), 1)); 4521 4522 /* expand_call should ensure this */ 4523 if (arg->offset.var || GET_CODE (size_rtx) != CONST_INT) 4524 abort (); 4525 4526 if (arg->offset.constant > i) 4527 { 4528 if (arg->offset.constant < i + INTVAL (size_rtx)) 4529 sibcall_failure = 1; 4530 } 4531 else if (arg->offset.constant < i) 4532 { 4533 if (i < arg->offset.constant + INTVAL (size_rtx)) 4534 sibcall_failure = 1; 4535 } 4536 } 4537 } 4538 4539 /* Special handling is required if part of the parameter lies in the 4540 register parameter area. The argument may be copied into the stack 4541 slot using memcpy(), but the original contents of the register 4542 parameter area will be restored after the memcpy() call. 4543 4544 To ensure that the part that lies in the register parameter area 4545 is copied correctly, we emit a separate push for that part. This 4546 push should be small enough to avoid a call to memcpy(). */ 4547#ifndef STACK_PARMS_IN_REG_PARM_AREA 4548 if (arg->reg && arg->pass_on_stack) 4549#else 4550 if (1) 4551#endif 4552 { 4553 if (arg->offset.constant < reg_parm_stack_space && arg->offset.var) 4554 error ("variable offset is passed partially in stack and in reg"); 4555 else if (arg->offset.constant < reg_parm_stack_space && arg->size.var) 4556 error ("variable size is passed partially in stack and in reg"); 4557 else if (arg->offset.constant < reg_parm_stack_space 4558 && ((arg->offset.constant + arg->size.constant) 4559 > reg_parm_stack_space)) 4560 { 4561 rtx size_rtx1 = GEN_INT (reg_parm_stack_space - arg->offset.constant); 4562 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx1, 4563 TYPE_ALIGN (TREE_TYPE (pval)), partial, reg, 4564 excess, argblock, ARGS_SIZE_RTX (arg->offset), 4565 reg_parm_stack_space, 4566 ARGS_SIZE_RTX (arg->alignment_pad)); 4567 } 4568 } 4569 4570 4571 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx, 4572 TYPE_ALIGN (TREE_TYPE (pval)), partial, reg, excess, 4573 argblock, ARGS_SIZE_RTX (arg->offset), 4574 reg_parm_stack_space, 4575 ARGS_SIZE_RTX (arg->alignment_pad)); 4576 4577 /* Unless this is a partially-in-register argument, the argument is now 4578 in the stack. 4579 4580 ??? Unlike the case above, in which we want the actual 4581 address of the data, so that we can load it directly into a 4582 register, here we want the address of the stack slot, so that 4583 it's properly aligned for word-by-word copying or something 4584 like that. It's not clear that this is always correct. */ 4585 if (partial == 0) 4586 arg->value = arg->stack_slot; 4587 } 4588 4589 /* Once we have pushed something, pops can't safely 4590 be deferred during the rest of the arguments. */ 4591 NO_DEFER_POP; 4592 4593 /* ANSI doesn't require a sequence point here, 4594 but PCC has one, so this will avoid some problems. */ 4595 emit_queue (); 4596 4597 /* Free any temporary slots made in processing this argument. Show 4598 that we might have taken the address of something and pushed that 4599 as an operand. */ 4600 preserve_temp_slots (NULL_RTX); 4601 free_temp_slots (); 4602 pop_temp_slots (); 4603 4604 return sibcall_failure; 4605}
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