gcc/calls.c

   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
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 2, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to the Free
  19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20 02111-1307, USA.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "tm.h"
  26 #include "rtl.h"
  27 #include "tree.h"
  28 #include "flags.h"
  29 #include "expr.h"
  30 #include "libfuncs.h"
  31 #include "function.h"
  32 #include "regs.h"
  33 #include "toplev.h"
  34 #include "output.h"
  35 #include "tm_p.h"
  36 #include "timevar.h"
  37 #include "sbitmap.h"
  38 #include "langhooks.h"
  39 #include "target.h"
  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 #ifndef PUSH_ARGS_REVERSED
  50 #if defined (STACK_GROWS_DOWNWARD) != defined (ARGS_GROW_DOWNWARD)
  51 #define PUSH_ARGS_REVERSED  PUSH_ARGS
  52 #endif
  53 #endif
  54
  55 #endif
  56
  57 #ifndef PUSH_ARGS_REVERSED
  58 #define PUSH_ARGS_REVERSED 0
  59 #endif
  60
  61 #ifndef STACK_POINTER_OFFSET
  62 #define STACK_POINTER_OFFSET    0
  63 #endif
  64
  65 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits.  */
  66 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
  67
  68 /* Data structure and subroutines used within expand_call.  */
  69
  70 struct arg_data
  71 {
  72   /* Tree node for this argument.  */
  73   tree tree_value;
  74   /* Mode for value; TYPE_MODE unless promoted.  */
  75   enum machine_mode mode;
  76   /* Current RTL value for argument, or 0 if it isn't precomputed.  */
  77   rtx value;
  78   /* Initially-compute RTL value for argument; only for const functions.  */
  79   rtx initial_value;
  80   /* Register to pass this argument in, 0 if passed on stack, or an
  81      PARALLEL if the arg is to be copied into multiple non-contiguous
  82      registers.  */
  83   rtx reg;
  84   /* Register to pass this argument in when generating tail call sequence.
  85      This is not the same register as for normal calls on machines with
  86      register windows.  */
  87   rtx tail_call_reg;
  88   /* If REG was promoted from the actual mode of the argument expression,
  89      indicates whether the promotion is sign- or zero-extended.  */
  90   int unsignedp;
  91   /* Number of registers to use.  0 means put the whole arg in registers.
  92      Also 0 if not passed in registers.  */
  93   int partial;
  94   /* Nonzero if argument must be passed on stack.
  95      Note that some arguments may be passed on the stack
  96      even though pass_on_stack is zero, just because FUNCTION_ARG says so.
  97      pass_on_stack identifies arguments that *cannot* go in registers.  */
  98   int pass_on_stack;
  99   /* Offset of this argument from beginning of stack-args.  */
 100   struct args_size offset;
 101   /* Similar, but offset to the start of the stack slot.  Different from
 102      OFFSET if this arg pads downward.  */
 103   struct args_size slot_offset;
 104   /* Size of this argument on the stack, rounded up for any padding it gets,
 105      parts of the argument passed in registers do not count.
 106      If REG_PARM_STACK_SPACE is defined, then register parms
 107      are counted here as well.  */
 108   struct args_size size;
 109   /* Location on the stack at which parameter should be stored.  The store
 110      has already been done if STACK == VALUE.  */
 111   rtx stack;
 112   /* Location on the stack of the start of this argument slot.  This can
 113      differ from STACK if this arg pads downward.  This location is known
 114      to be aligned to FUNCTION_ARG_BOUNDARY.  */
 115   rtx stack_slot;
 116   /* Place that this stack area has been saved, if needed.  */
 117   rtx save_area;
 118   /* If an argument's alignment does not permit direct copying into registers,
 119      copy in smaller-sized pieces into pseudos.  These are stored in a
 120      block pointed to by this field.  The next field says how many
 121      word-sized pseudos we made.  */
 122   rtx *aligned_regs;
 123   int n_aligned_regs;
 124   /* The amount that the stack pointer needs to be adjusted to
 125      force alignment for the next argument.  */
 126   struct args_size alignment_pad;
 127 };
 128
 129 /* A vector of one char per byte of stack space.  A byte if nonzero if
 130    the corresponding stack location has been used.
 131    This vector is used to prevent a function call within an argument from
 132    clobbering any stack already set up.  */
 133 static char *stack_usage_map;
 134
 135 /* Size of STACK_USAGE_MAP.  */
 136 static int highest_outgoing_arg_in_use;
 137
 138 /* A bitmap of virtual-incoming stack space.  Bit is set if the corresponding
 139    stack location's tail call argument has been already stored into the stack.
 140    This bitmap is used to prevent sibling call optimization if function tries
 141    to use parent's incoming argument slots when they have been already
 142    overwritten with tail call arguments.  */
 143 static sbitmap stored_args_map;
 144
 145 /* stack_arg_under_construction is nonzero when an argument may be
 146    initialized with a constructor call (including a C function that
 147    returns a BLKmode struct) and expand_call must take special action
 148    to make sure the object being constructed does not overlap the
 149    argument list for the constructor call.  */
 150 int stack_arg_under_construction;
 151
 152 static int calls_function       PARAMS ((tree, int));
 153 static int calls_function_1     PARAMS ((tree, int));
 154
 155 static void emit_call_1         PARAMS ((rtx, tree, tree, HOST_WIDE_INT,
 156                                          HOST_WIDE_INT, HOST_WIDE_INT, rtx,
 157                                          rtx, int, rtx, int,
 158                                          CUMULATIVE_ARGS *));
 159 static void precompute_register_parameters      PARAMS ((int,
 160                                                          struct arg_data *,
 161                                                          int *));
 162 static int store_one_arg        PARAMS ((struct arg_data *, rtx, int, int,
 163                                          int));
 164 static void store_unaligned_arguments_into_pseudos PARAMS ((struct arg_data *,
 165                                                             int));
 166 static int finalize_must_preallocate            PARAMS ((int, int,
 167                                                          struct arg_data *,
 168                                                          struct args_size *));
 169 static void precompute_arguments                PARAMS ((int, int,
 170                                                          struct arg_data *));
 171 static int compute_argument_block_size          PARAMS ((int,
 172                                                          struct args_size *,
 173                                                          int));
 174 static void initialize_argument_information     PARAMS ((int,
 175                                                          struct arg_data *,
 176                                                          struct args_size *,
 177                                                          int, tree, tree,
 178                                                          CUMULATIVE_ARGS *,
 179                                                          int, rtx *, int *,
 180                                                          int *, int *));
 181 static void compute_argument_addresses          PARAMS ((struct arg_data *,
 182                                                          rtx, int));
 183 static rtx rtx_for_function_call                PARAMS ((tree, tree));
 184 static void load_register_parameters            PARAMS ((struct arg_data *,
 185                                                          int, rtx *, int));
 186 static rtx emit_library_call_value_1            PARAMS ((int, rtx, rtx,
 187                                                          enum libcall_type,
 188                                                          enum machine_mode,
 189                                                          int, va_list));
 190 static int special_function_p                   PARAMS ((tree, int));
 191 static rtx try_to_integrate                     PARAMS ((tree, tree, rtx,
 192                                                          int, tree, rtx));
 193 static int check_sibcall_argument_overlap_1     PARAMS ((rtx));
 194 static int check_sibcall_argument_overlap       PARAMS ((rtx, struct arg_data *));
 195
 196 static int combine_pending_stack_adjustment_and_call
 197                                                 PARAMS ((int, struct args_size *, int));
 198
 199 #ifdef REG_PARM_STACK_SPACE
 200 static rtx save_fixed_argument_area     PARAMS ((int, rtx, int *, int *));
 201 static void restore_fixed_argument_area PARAMS ((rtx, rtx, int, int));
 202 #endif
 203 \f
 204 /* If WHICH is 1, return 1 if EXP contains a call to the built-in function
 205    `alloca'.
 206
 207    If WHICH is 0, return 1 if EXP contains a call to any function.
 208    Actually, we only need return 1 if evaluating EXP would require pushing
 209    arguments on the stack, but that is too difficult to compute, so we just
 210    assume any function call might require the stack.  */
 211
 212 static tree calls_function_save_exprs;
 213
 214 static int
 215 calls_function (exp, which)
 216      tree exp;
 217      int which;
 218 {
 219   int val;
 220
 221   calls_function_save_exprs = 0;
 222   val = calls_function_1 (exp, which);
 223   calls_function_save_exprs = 0;
 224   return val;
 225 }
 226
 227 /* Recursive function to do the work of above function.  */
 228
 229 static int
 230 calls_function_1 (exp, which)
 231      tree exp;
 232      int which;
 233 {
 234   int i;
 235   enum tree_code code = TREE_CODE (exp);
 236   int class = TREE_CODE_CLASS (code);
 237   int length = first_rtl_op (code);
 238
 239   /* If this code is language-specific, we don't know what it will do.  */
 240   if ((int) code >= NUM_TREE_CODES)
 241     return 1;
 242
 243   switch (code)
 244     {
 245     case CALL_EXPR:
 246       if (which == 0)
 247         return 1;
 248       else if ((TREE_CODE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))
 249                 == FUNCTION_TYPE)
 250                && (TYPE_RETURNS_STACK_DEPRESSED
 251                    (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))))
 252         return 1;
 253       else if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
 254                && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
 255                    == FUNCTION_DECL)
 256                && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
 257                                        0)
 258                    & ECF_MAY_BE_ALLOCA))
 259         return 1;
 260
 261       break;
 262
 263     case CONSTRUCTOR:
 264       {
 265         tree tem;
 266
 267         for (tem = CONSTRUCTOR_ELTS (exp); tem != 0; tem = TREE_CHAIN (tem))
 268           if (calls_function_1 (TREE_VALUE (tem), which))
 269             return 1;
 270       }
 271
 272       return 0;
 273
 274     case SAVE_EXPR:
 275       if (SAVE_EXPR_RTL (exp) != 0)
 276         return 0;
 277       if (value_member (exp, calls_function_save_exprs))
 278         return 0;
 279       calls_function_save_exprs = tree_cons (NULL_TREE, exp,
 280                                              calls_function_save_exprs);
 281       return (TREE_OPERAND (exp, 0) != 0
 282               && calls_function_1 (TREE_OPERAND (exp, 0), which));
 283
 284     case BLOCK:
 285       {
 286         tree local;
 287         tree subblock;
 288
 289         for (local = BLOCK_VARS (exp); local; local = TREE_CHAIN (local))
 290           if (DECL_INITIAL (local) != 0
 291               && calls_function_1 (DECL_INITIAL (local), which))
 292             return 1;
 293
 294         for (subblock = BLOCK_SUBBLOCKS (exp);
 295              subblock;
 296              subblock = TREE_CHAIN (subblock))
 297           if (calls_function_1 (subblock, which))
 298             return 1;
 299       }
 300       return 0;
 301
 302     case TREE_LIST:
 303       for (; exp != 0; exp = TREE_CHAIN (exp))
 304         if (calls_function_1 (TREE_VALUE (exp), which))
 305           return 1;
 306       return 0;
 307
 308     default:
 309       break;
 310     }
 311
 312   /* Only expressions, references, and blocks can contain calls.  */
 313   if (! IS_EXPR_CODE_CLASS (class) && class != 'r' && class != 'b')
 314     return 0;
 315
 316   for (i = 0; i < length; i++)
 317     if (TREE_OPERAND (exp, i) != 0
 318         && calls_function_1 (TREE_OPERAND (exp, i), which))
 319       return 1;
 320
 321   return 0;
 322 }
 323 \f
 324 /* Force FUNEXP into a form suitable for the address of a CALL,
 325    and return that as an rtx.  Also load the static chain register
 326    if FNDECL is a nested function.
 327
 328    CALL_FUSAGE points to a variable holding the prospective
 329    CALL_INSN_FUNCTION_USAGE information.  */
 330
 331 rtx
 332 prepare_call_address (funexp, fndecl, call_fusage, reg_parm_seen, sibcallp)
 333      rtx funexp;
 334      tree fndecl;
 335      rtx *call_fusage;
 336      int reg_parm_seen;
 337      int sibcallp;
 338 {
 339   rtx static_chain_value = 0;
 340
 341   funexp = protect_from_queue (funexp, 0);
 342
 343   if (fndecl != 0)
 344     /* Get possible static chain value for nested function in C.  */
 345     static_chain_value = lookup_static_chain (fndecl);
 346
 347   /* Make a valid memory address and copy constants thru pseudo-regs,
 348      but not for a constant address if -fno-function-cse.  */
 349   if (GET_CODE (funexp) != SYMBOL_REF)
 350     /* If we are using registers for parameters, force the
 351        function address into a register now.  */
 352     funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
 353               ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
 354               : memory_address (FUNCTION_MODE, funexp));
 355   else if (! sibcallp)
 356     {
 357 #ifndef NO_FUNCTION_CSE
 358       if (optimize && ! flag_no_function_cse)
 359 #ifdef NO_RECURSIVE_FUNCTION_CSE
 360         if (fndecl != current_function_decl)
 361 #endif
 362           funexp = force_reg (Pmode, funexp);
 363 #endif
 364     }
 365
 366   if (static_chain_value != 0)
 367     {
 368       emit_move_insn (static_chain_rtx, static_chain_value);
 369
 370       if (GET_CODE (static_chain_rtx) == REG)
 371         use_reg (call_fusage, static_chain_rtx);
 372     }
 373
 374   return funexp;
 375 }
 376
 377 /* Generate instructions to call function FUNEXP,
 378    and optionally pop the results.
 379    The CALL_INSN is the first insn generated.
 380
 381    FNDECL is the declaration node of the function.  This is given to the
 382    macro RETURN_POPS_ARGS to determine whether this function pops its own args.
 383
 384    FUNTYPE is the data type of the function.  This is given to the macro
 385    RETURN_POPS_ARGS to determine whether this function pops its own args.
 386    We used to allow an identifier for library functions, but that doesn't
 387    work when the return type is an aggregate type and the calling convention
 388    says that the pointer to this aggregate is to be popped by the callee.
 389
 390    STACK_SIZE is the number of bytes of arguments on the stack,
 391    ROUNDED_STACK_SIZE is that number rounded up to
 392    PREFERRED_STACK_BOUNDARY; zero if the size is variable.  This is
 393    both to put into the call insn and to generate explicit popping
 394    code if necessary.
 395
 396    STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
 397    It is zero if this call doesn't want a structure value.
 398
 399    NEXT_ARG_REG is the rtx that results from executing
 400      FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
 401    just after all the args have had their registers assigned.
 402    This could be whatever you like, but normally it is the first
 403    arg-register beyond those used for args in this call,
 404    or 0 if all the arg-registers are used in this call.
 405    It is passed on to `gen_call' so you can put this info in the call insn.
 406
 407    VALREG is a hard register in which a value is returned,
 408    or 0 if the call does not return a value.
 409
 410    OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
 411    the args to this call were processed.
 412    We restore `inhibit_defer_pop' to that value.
 413
 414    CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
 415    denote registers used by the called function.  */
 416
 417 static void
 418 emit_call_1 (funexp, fndecl, funtype, stack_size, rounded_stack_size,
 419              struct_value_size, next_arg_reg, valreg, old_inhibit_defer_pop,
 420              call_fusage, ecf_flags, args_so_far)
 421      rtx funexp;
 422      tree fndecl ATTRIBUTE_UNUSED;
 423      tree funtype ATTRIBUTE_UNUSED;
 424      HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED;
 425      HOST_WIDE_INT rounded_stack_size;
 426      HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED;
 427      rtx next_arg_reg ATTRIBUTE_UNUSED;
 428      rtx valreg;
 429      int old_inhibit_defer_pop;
 430      rtx call_fusage;
 431      int ecf_flags;
 432      CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED;
 433 {
 434   rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
 435   rtx call_insn;
 436   int already_popped = 0;
 437   HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
 438 #if defined (HAVE_call) && defined (HAVE_call_value)
 439   rtx struct_value_size_rtx;
 440   struct_value_size_rtx = GEN_INT (struct_value_size);
 441 #endif
 442
 443 #ifdef CALL_POPS_ARGS
 444   n_popped += CALL_POPS_ARGS (* args_so_far);
 445 #endif
 446
 447   /* Ensure address is valid.  SYMBOL_REF is already valid, so no need,
 448      and we don't want to load it into a register as an optimization,
 449      because prepare_call_address already did it if it should be done.  */
 450   if (GET_CODE (funexp) != SYMBOL_REF)
 451     funexp = memory_address (FUNCTION_MODE, funexp);
 452
 453 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
 454   if ((ecf_flags & ECF_SIBCALL)
 455       && HAVE_sibcall_pop && HAVE_sibcall_value_pop
 456       && (n_popped > 0 || stack_size == 0))
 457     {
 458       rtx n_pop = GEN_INT (n_popped);
 459       rtx pat;
 460
 461       /* If this subroutine pops its own args, record that in the call insn
 462          if possible, for the sake of frame pointer elimination.  */
 463
 464       if (valreg)
 465         pat = GEN_SIBCALL_VALUE_POP (valreg,
 466                                      gen_rtx_MEM (FUNCTION_MODE, funexp),
 467                                      rounded_stack_size_rtx, next_arg_reg,
 468                                      n_pop);
 469       else
 470         pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
 471                                rounded_stack_size_rtx, next_arg_reg, n_pop);
 472
 473       emit_call_insn (pat);
 474       already_popped = 1;
 475     }
 476   else
 477 #endif
 478
 479 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
 480   /* If the target has "call" or "call_value" insns, then prefer them
 481      if no arguments are actually popped.  If the target does not have
 482      "call" or "call_value" insns, then we must use the popping versions
 483      even if the call has no arguments to pop.  */
 484 #if defined (HAVE_call) && defined (HAVE_call_value)
 485   if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
 486       && n_popped > 0 && ! (ecf_flags & ECF_SP_DEPRESSED))
 487 #else
 488   if (HAVE_call_pop && HAVE_call_value_pop)
 489 #endif
 490     {
 491       rtx n_pop = GEN_INT (n_popped);
 492       rtx pat;
 493
 494       /* If this subroutine pops its own args, record that in the call insn
 495          if possible, for the sake of frame pointer elimination.  */
 496
 497       if (valreg)
 498         pat = GEN_CALL_VALUE_POP (valreg,
 499                                   gen_rtx_MEM (FUNCTION_MODE, funexp),
 500                                   rounded_stack_size_rtx, next_arg_reg, n_pop);
 501       else
 502         pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
 503                             rounded_stack_size_rtx, next_arg_reg, n_pop);
 504
 505       emit_call_insn (pat);
 506       already_popped = 1;
 507     }
 508   else
 509 #endif
 510
 511 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
 512   if ((ecf_flags & ECF_SIBCALL)
 513       && HAVE_sibcall && HAVE_sibcall_value)
 514     {
 515       if (valreg)
 516         emit_call_insn (GEN_SIBCALL_VALUE (valreg,
 517                                            gen_rtx_MEM (FUNCTION_MODE, funexp),
 518                                            rounded_stack_size_rtx,
 519                                            next_arg_reg, NULL_RTX));
 520       else
 521         emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
 522                                      rounded_stack_size_rtx, next_arg_reg,
 523                                      struct_value_size_rtx));
 524     }
 525   else
 526 #endif
 527
 528 #if defined (HAVE_call) && defined (HAVE_call_value)
 529   if (HAVE_call && HAVE_call_value)
 530     {
 531       if (valreg)
 532         emit_call_insn (GEN_CALL_VALUE (valreg,
 533                                         gen_rtx_MEM (FUNCTION_MODE, funexp),
 534                                         rounded_stack_size_rtx, next_arg_reg,
 535                                         NULL_RTX));
 536       else
 537         emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
 538                                   rounded_stack_size_rtx, next_arg_reg,
 539                                   struct_value_size_rtx));
 540     }
 541   else
 542 #endif
 543     abort ();
 544
 545   /* Find the CALL insn we just emitted.  */
 546   for (call_insn = get_last_insn ();
 547        call_insn && GET_CODE (call_insn) != CALL_INSN;
 548        call_insn = PREV_INSN (call_insn))
 549     ;
 550
 551   if (! call_insn)
 552     abort ();
 553
 554   /* Mark memory as used for "pure" function call.  */
 555   if (ecf_flags & ECF_PURE)
 556     call_fusage
 557       = gen_rtx_EXPR_LIST
 558         (VOIDmode,
 559          gen_rtx_USE (VOIDmode,
 560                       gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode))),
 561          call_fusage);
 562
 563   /* Put the register usage information on the CALL.  If there is already
 564      some usage information, put ours at the end.  */
 565   if (CALL_INSN_FUNCTION_USAGE (call_insn))
 566     {
 567       rtx link;
 568
 569       for (link = CALL_INSN_FUNCTION_USAGE (call_insn); XEXP (link, 1) != 0;
 570            link = XEXP (link, 1))
 571         ;
 572
 573       XEXP (link, 1) = call_fusage;
 574     }
 575   else
 576     CALL_INSN_FUNCTION_USAGE (call_insn) = call_fusage;
 577
 578   /* If this is a const call, then set the insn's unchanging bit.  */
 579   if (ecf_flags & (ECF_CONST | ECF_PURE))
 580     CONST_OR_PURE_CALL_P (call_insn) = 1;
 581
 582   /* If this call can't throw, attach a REG_EH_REGION reg note to that
 583      effect.  */
 584   if (ecf_flags & ECF_NOTHROW)
 585     REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, const0_rtx,
 586                                                REG_NOTES (call_insn));
 587
 588   if (ecf_flags & ECF_NORETURN)
 589     REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_NORETURN, const0_rtx,
 590                                                REG_NOTES (call_insn));
 591   if (ecf_flags & ECF_ALWAYS_RETURN)
 592     REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_ALWAYS_RETURN, const0_rtx,
 593                                                REG_NOTES (call_insn));
 594
 595   if (ecf_flags & ECF_RETURNS_TWICE)
 596     {
 597       REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_SETJMP, const0_rtx,
 598                                                  REG_NOTES (call_insn));
 599       current_function_calls_setjmp = 1;
 600     }
 601
 602   SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
 603
 604   /* Restore this now, so that we do defer pops for this call's args
 605      if the context of the call as a whole permits.  */
 606   inhibit_defer_pop = old_inhibit_defer_pop;
 607
 608   if (n_popped > 0)
 609     {
 610       if (!already_popped)
 611         CALL_INSN_FUNCTION_USAGE (call_insn)
 612           = gen_rtx_EXPR_LIST (VOIDmode,
 613                                gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
 614                                CALL_INSN_FUNCTION_USAGE (call_insn));
 615       rounded_stack_size -= n_popped;
 616       rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
 617       stack_pointer_delta -= n_popped;
 618     }
 619
 620   if (!ACCUMULATE_OUTGOING_ARGS)
 621     {
 622       /* If returning from the subroutine does not automatically pop the args,
 623          we need an instruction to pop them sooner or later.
 624          Perhaps do it now; perhaps just record how much space to pop later.
 625
 626          If returning from the subroutine does pop the args, indicate that the
 627          stack pointer will be changed.  */
 628
 629       if (rounded_stack_size != 0)
 630         {
 631           if (ecf_flags & ECF_SP_DEPRESSED)
 632             /* Just pretend we did the pop.  */
 633             stack_pointer_delta -= rounded_stack_size;
 634           else if (flag_defer_pop && inhibit_defer_pop == 0
 635               && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
 636             pending_stack_adjust += rounded_stack_size;
 637           else
 638             adjust_stack (rounded_stack_size_rtx);
 639         }
 640     }
 641   /* When we accumulate outgoing args, we must avoid any stack manipulations.
 642      Restore the stack pointer to its original value now.  Usually
 643      ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
 644      On  i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
 645      popping variants of functions exist as well.
 646
 647      ??? We may optimize similar to defer_pop above, but it is
 648      probably not worthwhile.
 649
 650      ??? It will be worthwhile to enable combine_stack_adjustments even for
 651      such machines.  */
 652   else if (n_popped)
 653     anti_adjust_stack (GEN_INT (n_popped));
 654 }
 655
 656 /* Determine if the function identified by NAME and FNDECL is one with
 657    special properties we wish to know about.
 658
 659    For example, if the function might return more than one time (setjmp), then
 660    set RETURNS_TWICE to a nonzero value.
 661
 662    Similarly set LONGJMP for if the function is in the longjmp family.
 663
 664    Set MALLOC for any of the standard memory allocation functions which
 665    allocate from the heap.
 666
 667    Set MAY_BE_ALLOCA for any memory allocation function that might allocate
 668    space from the stack such as alloca.  */
 669
 670 static int
 671 special_function_p (fndecl, flags)
 672      tree fndecl;
 673      int flags;
 674 {
 675   if (! (flags & ECF_MALLOC)
 676       && fndecl && DECL_NAME (fndecl)
 677       && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
 678       /* Exclude functions not at the file scope, or not `extern',
 679          since they are not the magic functions we would otherwise
 680          think they are.  */
 681       && DECL_CONTEXT (fndecl) == NULL_TREE && TREE_PUBLIC (fndecl))
 682     {
 683       const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
 684       const char *tname = name;
 685
 686       /* We assume that alloca will always be called by name.  It
 687          makes no sense to pass it as a pointer-to-function to
 688          anything that does not understand its behavior.  */
 689       if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
 690             && name[0] == 'a'
 691             && ! strcmp (name, "alloca"))
 692            || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
 693                && name[0] == '_'
 694                && ! strcmp (name, "__builtin_alloca"))))
 695         flags |= ECF_MAY_BE_ALLOCA;
 696
 697       /* Disregard prefix _, __ or __x.  */
 698       if (name[0] == '_')
 699         {
 700           if (name[1] == '_' && name[2] == 'x')
 701             tname += 3;
 702           else if (name[1] == '_')
 703             tname += 2;
 704           else
 705             tname += 1;
 706         }
 707
 708       if (tname[0] == 's')
 709         {
 710           if ((tname[1] == 'e'
 711                && (! strcmp (tname, "setjmp")
 712                    || ! strcmp (tname, "setjmp_syscall")))
 713               || (tname[1] == 'i'
 714                   && ! strcmp (tname, "sigsetjmp"))
 715               || (tname[1] == 'a'
 716                   && ! strcmp (tname, "savectx")))
 717             flags |= ECF_RETURNS_TWICE;
 718
 719           if (tname[1] == 'i'
 720               && ! strcmp (tname, "siglongjmp"))
 721             flags |= ECF_LONGJMP;
 722         }
 723       else if ((tname[0] == 'q' && tname[1] == 's'
 724                 && ! strcmp (tname, "qsetjmp"))
 725                || (tname[0] == 'v' && tname[1] == 'f'
 726                    && ! strcmp (tname, "vfork")))
 727         flags |= ECF_RETURNS_TWICE;
 728
 729       else if (tname[0] == 'l' && tname[1] == 'o'
 730                && ! strcmp (tname, "longjmp"))
 731         flags |= ECF_LONGJMP;
 732
 733       else if ((tname[0] == 'f' && tname[1] == 'o'
 734                 && ! strcmp (tname, "fork"))
 735                /* Linux specific: __clone.  check NAME to insist on the
 736                   leading underscores, to avoid polluting the ISO / POSIX
 737                   namespace.  */
 738                || (name[0] == '_' && name[1] == '_'
 739                    && ! strcmp (tname, "clone"))
 740                || (tname[0] == 'e' && tname[1] == 'x' && tname[2] == 'e'
 741                    && tname[3] == 'c' && (tname[4] == 'l' || tname[4] == 'v')
 742                    && (tname[5] == '\0'
 743                        || ((tname[5] == 'p' || tname[5] == 'e')
 744                            && tname[6] == '\0'))))
 745         flags |= ECF_FORK_OR_EXEC;
 746
 747       /* Do not add any more malloc-like functions to this list,
 748          instead mark them as malloc functions using the malloc attribute.
 749          Note, realloc is not suitable for attribute malloc since
 750          it may return the same address across multiple calls.
 751          C++ operator new is not suitable because it is not required
 752          to return a unique pointer; indeed, the standard placement new
 753          just returns its argument.  */
 754       else if (TYPE_MODE (TREE_TYPE (TREE_TYPE (fndecl))) == Pmode
 755                && (! strcmp (tname, "malloc")
 756                    || ! strcmp (tname, "calloc")
 757                    || ! strcmp (tname, "strdup")))
 758         flags |= ECF_MALLOC;
 759     }
 760   return flags;
 761 }
 762
 763 /* Return nonzero when tree represent call to longjmp.  */
 764
 765 int
 766 setjmp_call_p (fndecl)
 767      tree fndecl;
 768 {
 769   return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
 770 }
 771
 772 /* Return true when exp contains alloca call.  */
 773 bool
 774 alloca_call_p (exp)
 775      tree exp;
 776 {
 777   if (TREE_CODE (exp) == CALL_EXPR
 778       && TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
 779       && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
 780           == FUNCTION_DECL)
 781       && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
 782                               0) & ECF_MAY_BE_ALLOCA))
 783     return true;
 784   return false;
 785 }
 786
 787 /* Detect flags (function attributes) from the function decl or type node.  */
 788
 789 int
 790 flags_from_decl_or_type (exp)
 791      tree exp;
 792 {
 793   int flags = 0;
 794   tree type = exp;
 795   /* ??? We can't set IS_MALLOC for function types?  */
 796   if (DECL_P (exp))
 797     {
 798       type = TREE_TYPE (exp);
 799
 800       /* The function exp may have the `malloc' attribute.  */
 801       if (DECL_P (exp) && DECL_IS_MALLOC (exp))
 802         flags |= ECF_MALLOC;
 803
 804       /* The function exp may have the `pure' attribute.  */
 805       if (DECL_P (exp) && DECL_IS_PURE (exp))
 806         flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
 807
 808       if (TREE_NOTHROW (exp))
 809         flags |= ECF_NOTHROW;
 810     }
 811
 812   if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
 813     flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
 814
 815   if (TREE_THIS_VOLATILE (exp))
 816     flags |= ECF_NORETURN;
 817
 818   /* Mark if the function returns with the stack pointer depressed.   We
 819      cannot consider it pure or constant in that case.  */
 820   if (TREE_CODE (type) == FUNCTION_TYPE && TYPE_RETURNS_STACK_DEPRESSED (type))
 821     {
 822       flags |= ECF_SP_DEPRESSED;
 823       flags &= ~(ECF_PURE | ECF_CONST | ECF_LIBCALL_BLOCK);
 824     }
 825
 826   return flags;
 827 }
 828
 829 /* Precompute all register parameters as described by ARGS, storing values
 830    into fields within the ARGS array.
 831
 832    NUM_ACTUALS indicates the total number elements in the ARGS array.
 833
 834    Set REG_PARM_SEEN if we encounter a register parameter.  */
 835
 836 static void
 837 precompute_register_parameters (num_actuals, args, reg_parm_seen)
 838      int num_actuals;
 839      struct arg_data *args;
 840      int *reg_parm_seen;
 841 {
 842   int i;
 843
 844   *reg_parm_seen = 0;
 845
 846   for (i = 0; i < num_actuals; i++)
 847     if (args[i].reg != 0 && ! args[i].pass_on_stack)
 848       {
 849         *reg_parm_seen = 1;
 850
 851         if (args[i].value == 0)
 852           {
 853             push_temp_slots ();
 854             args[i].value = expand_expr (args[i].tree_value, NULL_RTX,
 855                                          VOIDmode, 0);
 856             preserve_temp_slots (args[i].value);
 857             pop_temp_slots ();
 858
 859             /* ANSI doesn't require a sequence point here,
 860                but PCC has one, so this will avoid some problems.  */
 861             emit_queue ();
 862           }
 863
 864         /* If the value is a non-legitimate constant, force it into a
 865            pseudo now.  TLS symbols sometimes need a call to resolve.  */
 866         if (CONSTANT_P (args[i].value)
 867             && !LEGITIMATE_CONSTANT_P (args[i].value))
 868           args[i].value = force_reg (args[i].mode, args[i].value);
 869
 870         /* If we are to promote the function arg to a wider mode,
 871            do it now.  */
 872
 873         if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
 874           args[i].value
 875             = convert_modes (args[i].mode,
 876                              TYPE_MODE (TREE_TYPE (args[i].tree_value)),
 877                              args[i].value, args[i].unsignedp);
 878
 879         /* If the value is expensive, and we are inside an appropriately
 880            short loop, put the value into a pseudo and then put the pseudo
 881            into the hard reg.
 882
 883            For small register classes, also do this if this call uses
 884            register parameters.  This is to avoid reload conflicts while
 885            loading the parameters registers.  */
 886
 887         if ((! (GET_CODE (args[i].value) == REG
 888                 || (GET_CODE (args[i].value) == SUBREG
 889                     && GET_CODE (SUBREG_REG (args[i].value)) == REG)))
 890             && args[i].mode != BLKmode
 891             && rtx_cost (args[i].value, SET) > COSTS_N_INSNS (1)
 892             && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
 893                 || preserve_subexpressions_p ()))
 894           args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
 895       }
 896 }
 897
 898 #ifdef REG_PARM_STACK_SPACE
 899
 900   /* The argument list is the property of the called routine and it
 901      may clobber it.  If the fixed area has been used for previous
 902      parameters, we must save and restore it.  */
 903
 904 static rtx
 905 save_fixed_argument_area (reg_parm_stack_space, argblock,
 906                           low_to_save, high_to_save)
 907      int reg_parm_stack_space;
 908      rtx argblock;
 909      int *low_to_save;
 910      int *high_to_save;
 911 {
 912   int i;
 913   rtx save_area = NULL_RTX;
 914
 915   /* Compute the boundary of the that needs to be saved, if any.  */
 916 #ifdef ARGS_GROW_DOWNWARD
 917   for (i = 0; i < reg_parm_stack_space + 1; i++)
 918 #else
 919   for (i = 0; i < reg_parm_stack_space; i++)
 920 #endif
 921     {
 922       if (i >= highest_outgoing_arg_in_use
 923           || stack_usage_map[i] == 0)
 924         continue;
 925
 926       if (*low_to_save == -1)
 927         *low_to_save = i;
 928
 929       *high_to_save = i;
 930     }
 931
 932   if (*low_to_save >= 0)
 933     {
 934       int num_to_save = *high_to_save - *low_to_save + 1;
 935       enum machine_mode save_mode
 936         = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
 937       rtx stack_area;
 938
 939       /* If we don't have the required alignment, must do this in BLKmode.  */
 940       if ((*low_to_save & (MIN (GET_MODE_SIZE (save_mode),
 941                                 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
 942         save_mode = BLKmode;
 943
 944 #ifdef ARGS_GROW_DOWNWARD
 945       stack_area
 946         = gen_rtx_MEM (save_mode,
 947                        memory_address (save_mode,
 948                                        plus_constant (argblock,
 949                                                       - *high_to_save)));
 950 #else
 951       stack_area = gen_rtx_MEM (save_mode,
 952                                 memory_address (save_mode,
 953                                                 plus_constant (argblock,
 954                                                                *low_to_save)));
 955 #endif
 956
 957       set_mem_align (stack_area, PARM_BOUNDARY);
 958       if (save_mode == BLKmode)
 959         {
 960           save_area = assign_stack_temp (BLKmode, num_to_save, 0);
 961           emit_block_move (validize_mem (save_area), stack_area,
 962                            GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
 963         }
 964       else
 965         {
 966           save_area = gen_reg_rtx (save_mode);
 967           emit_move_insn (save_area, stack_area);
 968         }
 969     }
 970
 971   return save_area;
 972 }
 973
 974 static void
 975 restore_fixed_argument_area (save_area, argblock, high_to_save, low_to_save)
 976      rtx save_area;
 977      rtx argblock;
 978      int high_to_save;
 979      int low_to_save;
 980 {
 981   enum machine_mode save_mode = GET_MODE (save_area);
 982 #ifdef ARGS_GROW_DOWNWARD
 983   rtx stack_area
 984     = gen_rtx_MEM (save_mode,
 985                    memory_address (save_mode,
 986                                    plus_constant (argblock,
 987                                                   - high_to_save)));
 988 #else
 989   rtx stack_area
 990     = gen_rtx_MEM (save_mode,
 991                    memory_address (save_mode,
 992                                    plus_constant (argblock,
 993                                                   low_to_save)));
 994 #endif
 995
 996   if (save_mode != BLKmode)
 997     emit_move_insn (stack_area, save_area);
 998   else
 999     emit_block_move (stack_area, validize_mem (save_area),
1000                      GEN_INT (high_to_save - low_to_save + 1),
1001                      BLOCK_OP_CALL_PARM);
1002 }
1003 #endif /* REG_PARM_STACK_SPACE */
1004
1005 /* If any elements in ARGS refer to parameters that are to be passed in
1006    registers, but not in memory, and whose alignment does not permit a
1007    direct copy into registers.  Copy the values into a group of pseudos
1008    which we will later copy into the appropriate hard registers.
1009
1010    Pseudos for each unaligned argument will be stored into the array
1011    args[argnum].aligned_regs.  The caller is responsible for deallocating
1012    the aligned_regs array if it is nonzero.  */
1013
1014 static void
1015 store_unaligned_arguments_into_pseudos (args, num_actuals)
1016      struct arg_data *args;
1017      int num_actuals;
1018 {
1019   int i, j;
1020
1021   for (i = 0; i < num_actuals; i++)
1022     if (args[i].reg != 0 && ! args[i].pass_on_stack
1023         && args[i].mode == BLKmode
1024         && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
1025             < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
1026       {
1027         int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1028         int big_endian_correction = 0;
1029
1030         args[i].n_aligned_regs
1031           = args[i].partial ? args[i].partial
1032             : (bytes + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1033
1034         args[i].aligned_regs = (rtx *) xmalloc (sizeof (rtx)
1035                                                 * args[i].n_aligned_regs);
1036
1037         /* Structures smaller than a word are aligned to the least
1038            significant byte (to the right).  On a BYTES_BIG_ENDIAN machine,
1039            this means we must skip the empty high order bytes when
1040            calculating the bit offset.  */
1041         if (BYTES_BIG_ENDIAN
1042             && bytes < UNITS_PER_WORD)
1043           big_endian_correction = (BITS_PER_WORD  - (bytes * BITS_PER_UNIT));
1044
1045         for (j = 0; j < args[i].n_aligned_regs; j++)
1046           {
1047             rtx reg = gen_reg_rtx (word_mode);
1048             rtx word = operand_subword_force (args[i].value, j, BLKmode);
1049             int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
1050
1051             args[i].aligned_regs[j] = reg;
1052
1053             /* There is no need to restrict this code to loading items
1054                in TYPE_ALIGN sized hunks.  The bitfield instructions can
1055                load up entire word sized registers efficiently.
1056
1057                ??? This may not be needed anymore.
1058                We use to emit a clobber here but that doesn't let later
1059                passes optimize the instructions we emit.  By storing 0 into
1060                the register later passes know the first AND to zero out the
1061                bitfield being set in the register is unnecessary.  The store
1062                of 0 will be deleted as will at least the first AND.  */
1063
1064             emit_move_insn (reg, const0_rtx);
1065
1066             bytes -= bitsize / BITS_PER_UNIT;
1067             store_bit_field (reg, bitsize, big_endian_correction, word_mode,
1068                              extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
1069                                                 word_mode, word_mode,
1070                                                 BITS_PER_WORD),
1071                              BITS_PER_WORD);
1072           }
1073       }
1074 }
1075
1076 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1077    ACTPARMS.
1078
1079    NUM_ACTUALS is the total number of parameters.
1080
1081    N_NAMED_ARGS is the total number of named arguments.
1082
1083    FNDECL is the tree code for the target of this call (if known)
1084
1085    ARGS_SO_FAR holds state needed by the target to know where to place
1086    the next argument.
1087
1088    REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1089    for arguments which are passed in registers.
1090
1091    OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1092    and may be modified by this routine.
1093
1094    OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1095    flags which may may be modified by this routine.  */
1096
1097 static void
1098 initialize_argument_information (num_actuals, args, args_size, n_named_args,
1099                                  actparms, fndecl, args_so_far,
1100                                  reg_parm_stack_space, old_stack_level,
1101                                  old_pending_adj, must_preallocate,
1102                                  ecf_flags)
1103      int num_actuals ATTRIBUTE_UNUSED;
1104      struct arg_data *args;
1105      struct args_size *args_size;
1106      int n_named_args ATTRIBUTE_UNUSED;
1107      tree actparms;
1108      tree fndecl;
1109      CUMULATIVE_ARGS *args_so_far;
1110      int reg_parm_stack_space;
1111      rtx *old_stack_level;
1112      int *old_pending_adj;
1113      int *must_preallocate;
1114      int *ecf_flags;
1115 {
1116   /* 1 if scanning parms front to back, -1 if scanning back to front.  */
1117   int inc;
1118
1119   /* Count arg position in order args appear.  */
1120   int argpos;
1121
1122   struct args_size alignment_pad;
1123   int i;
1124   tree p;
1125
1126   args_size->constant = 0;
1127   args_size->var = 0;
1128
1129   /* In this loop, we consider args in the order they are written.
1130      We fill up ARGS from the front or from the back if necessary
1131      so that in any case the first arg to be pushed ends up at the front.  */
1132
1133   if (PUSH_ARGS_REVERSED)
1134     {
1135       i = num_actuals - 1, inc = -1;
1136       /* In this case, must reverse order of args
1137          so that we compute and push the last arg first.  */
1138     }
1139   else
1140     {
1141       i = 0, inc = 1;
1142     }
1143
1144   /* I counts args in order (to be) pushed; ARGPOS counts in order written.  */
1145   for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
1146     {
1147       tree type = TREE_TYPE (TREE_VALUE (p));
1148       int unsignedp;
1149       enum machine_mode mode;
1150
1151       args[i].tree_value = TREE_VALUE (p);
1152
1153       /* Replace erroneous argument with constant zero.  */
1154       if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1155         args[i].tree_value = integer_zero_node, type = integer_type_node;
1156
1157       /* If TYPE is a transparent union, pass things the way we would
1158          pass the first field of the union.  We have already verified that
1159          the modes are the same.  */
1160       if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
1161         type = TREE_TYPE (TYPE_FIELDS (type));
1162
1163       /* Decide where to pass this arg.
1164
1165          args[i].reg is nonzero if all or part is passed in registers.
1166
1167          args[i].partial is nonzero if part but not all is passed in registers,
1168          and the exact value says how many words are passed in registers.
1169
1170          args[i].pass_on_stack is nonzero if the argument must at least be
1171          computed on the stack.  It may then be loaded back into registers
1172          if args[i].reg is nonzero.
1173
1174          These decisions are driven by the FUNCTION_... macros and must agree
1175          with those made by function.c.  */
1176
1177       /* See if this argument should be passed by invisible reference.  */
1178       if ((TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1179            && contains_placeholder_p (TYPE_SIZE (type)))
1180           || TREE_ADDRESSABLE (type)
1181 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
1182           || FUNCTION_ARG_PASS_BY_REFERENCE (*args_so_far, TYPE_MODE (type),
1183                                              type, argpos < n_named_args)
1184 #endif
1185           )
1186         {
1187           /* If we're compiling a thunk, pass through invisible
1188              references instead of making a copy.  */
1189           if (current_function_is_thunk
1190 #ifdef FUNCTION_ARG_CALLEE_COPIES
1191               || (FUNCTION_ARG_CALLEE_COPIES (*args_so_far, TYPE_MODE (type),
1192                                              type, argpos < n_named_args)
1193                   /* If it's in a register, we must make a copy of it too.  */
1194                   /* ??? Is this a sufficient test?  Is there a better one? */
1195                   && !(TREE_CODE (args[i].tree_value) == VAR_DECL
1196                        && REG_P (DECL_RTL (args[i].tree_value)))
1197                   && ! TREE_ADDRESSABLE (type))
1198 #endif
1199               )
1200             {
1201               /* C++ uses a TARGET_EXPR to indicate that we want to make a
1202                  new object from the argument.  If we are passing by
1203                  invisible reference, the callee will do that for us, so we
1204                  can strip off the TARGET_EXPR.  This is not always safe,
1205                  but it is safe in the only case where this is a useful
1206                  optimization; namely, when the argument is a plain object.
1207                  In that case, the frontend is just asking the backend to
1208                  make a bitwise copy of the argument.  */
1209
1210               if (TREE_CODE (args[i].tree_value) == TARGET_EXPR
1211                   && (DECL_P (TREE_OPERAND (args[i].tree_value, 1)))
1212                   && ! REG_P (DECL_RTL (TREE_OPERAND (args[i].tree_value, 1))))
1213                 args[i].tree_value = TREE_OPERAND (args[i].tree_value, 1);
1214
1215               args[i].tree_value = build1 (ADDR_EXPR,
1216                                            build_pointer_type (type),
1217                                            args[i].tree_value);
1218               type = build_pointer_type (type);
1219             }
1220           else if (TREE_CODE (args[i].tree_value) == TARGET_EXPR)
1221             {
1222               /* In the V3 C++ ABI, parameters are destroyed in the caller.
1223                  We implement this by passing the address of the temporary
1224                  rather than expanding it into another allocated slot.  */
1225               args[i].tree_value = build1 (ADDR_EXPR,
1226                                            build_pointer_type (type),
1227                                            args[i].tree_value);
1228               type = build_pointer_type (type);
1229             }
1230           else
1231             {
1232               /* We make a copy of the object and pass the address to the
1233                  function being called.  */
1234               rtx copy;
1235
1236               if (!COMPLETE_TYPE_P (type)
1237                   || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1238                   || (flag_stack_check && ! STACK_CHECK_BUILTIN
1239                       && (0 < compare_tree_int (TYPE_SIZE_UNIT (type),
1240                                                 STACK_CHECK_MAX_VAR_SIZE))))
1241                 {
1242                   /* This is a variable-sized object.  Make space on the stack
1243                      for it.  */
1244                   rtx size_rtx = expr_size (TREE_VALUE (p));
1245
1246                   if (*old_stack_level == 0)
1247                     {
1248                       emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1249                       *old_pending_adj = pending_stack_adjust;
1250                       pending_stack_adjust = 0;
1251                     }
1252
1253                   copy = gen_rtx_MEM (BLKmode,
1254                                       allocate_dynamic_stack_space
1255                                       (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1256                   set_mem_attributes (copy, type, 1);
1257                 }
1258               else
1259                 copy = assign_temp (type, 0, 1, 0);
1260
1261               store_expr (args[i].tree_value, copy, 0);
1262               *ecf_flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
1263
1264               args[i].tree_value = build1 (ADDR_EXPR,
1265                                            build_pointer_type (type),
1266                                            make_tree (type, copy));
1267               type = build_pointer_type (type);
1268             }
1269         }
1270
1271       mode = TYPE_MODE (type);
1272       unsignedp = TREE_UNSIGNED (type);
1273
1274 #ifdef PROMOTE_FUNCTION_ARGS
1275       mode = promote_mode (type, mode, &unsignedp, 1);
1276 #endif
1277
1278       args[i].unsignedp = unsignedp;
1279       args[i].mode = mode;
1280
1281       args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1282                                   argpos < n_named_args);
1283 #ifdef FUNCTION_INCOMING_ARG
1284       /* If this is a sibling call and the machine has register windows, the
1285          register window has to be unwinded before calling the routine, so
1286          arguments have to go into the incoming registers.  */
1287       args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1288                                                      argpos < n_named_args);
1289 #else
1290       args[i].tail_call_reg = args[i].reg;
1291 #endif
1292
1293 #ifdef FUNCTION_ARG_PARTIAL_NREGS
1294       if (args[i].reg)
1295         args[i].partial
1296           = FUNCTION_ARG_PARTIAL_NREGS (*args_so_far, mode, type,
1297                                         argpos < n_named_args);
1298 #endif
1299
1300       args[i].pass_on_stack = MUST_PASS_IN_STACK (mode, type);
1301
1302       /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1303          it means that we are to pass this arg in the register(s) designated
1304          by the PARALLEL, but also to pass it in the stack.  */
1305       if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1306           && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1307         args[i].pass_on_stack = 1;
1308
1309       /* If this is an addressable type, we must preallocate the stack
1310          since we must evaluate the object into its final location.
1311
1312          If this is to be passed in both registers and the stack, it is simpler
1313          to preallocate.  */
1314       if (TREE_ADDRESSABLE (type)
1315           || (args[i].pass_on_stack && args[i].reg != 0))
1316         *must_preallocate = 1;
1317
1318       /* If this is an addressable type, we cannot pre-evaluate it.  Thus,
1319          we cannot consider this function call constant.  */
1320       if (TREE_ADDRESSABLE (type))
1321         *ecf_flags &= ~ECF_LIBCALL_BLOCK;
1322
1323       /* Compute the stack-size of this argument.  */
1324       if (args[i].reg == 0 || args[i].partial != 0
1325           || reg_parm_stack_space > 0
1326           || args[i].pass_on_stack)
1327         locate_and_pad_parm (mode, type,
1328 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1329                              1,
1330 #else
1331                              args[i].reg != 0,
1332 #endif
1333                              fndecl, args_size, &args[i].offset,
1334                              &args[i].size, &alignment_pad);
1335
1336 #ifndef ARGS_GROW_DOWNWARD
1337       args[i].slot_offset = *args_size;
1338 #endif
1339
1340       args[i].alignment_pad = alignment_pad;
1341
1342       /* If a part of the arg was put into registers,
1343          don't include that part in the amount pushed.  */
1344       if (reg_parm_stack_space == 0 && ! args[i].pass_on_stack)
1345         args[i].size.constant -= ((args[i].partial * UNITS_PER_WORD)
1346                                   / (PARM_BOUNDARY / BITS_PER_UNIT)
1347                                   * (PARM_BOUNDARY / BITS_PER_UNIT));
1348
1349       /* Update ARGS_SIZE, the total stack space for args so far.  */
1350
1351       args_size->constant += args[i].size.constant;
1352       if (args[i].size.var)
1353         {
1354           ADD_PARM_SIZE (*args_size, args[i].size.var);
1355         }
1356
1357       /* Since the slot offset points to the bottom of the slot,
1358          we must record it after incrementing if the args grow down.  */
1359 #ifdef ARGS_GROW_DOWNWARD
1360       args[i].slot_offset = *args_size;
1361
1362       args[i].slot_offset.constant = -args_size->constant;
1363       if (args_size->var)
1364         SUB_PARM_SIZE (args[i].slot_offset, args_size->var);
1365 #endif
1366
1367       /* Increment ARGS_SO_FAR, which has info about which arg-registers
1368          have been used, etc.  */
1369
1370       FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1371                             argpos < n_named_args);
1372     }
1373 }
1374
1375 /* Update ARGS_SIZE to contain the total size for the argument block.
1376    Return the original constant component of the argument block's size.
1377
1378    REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1379    for arguments passed in registers.  */
1380
1381 static int
1382 compute_argument_block_size (reg_parm_stack_space, args_size,
1383                              preferred_stack_boundary)
1384      int reg_parm_stack_space;
1385      struct args_size *args_size;
1386      int preferred_stack_boundary ATTRIBUTE_UNUSED;
1387 {
1388   int unadjusted_args_size = args_size->constant;
1389
1390   /* For accumulate outgoing args mode we don't need to align, since the frame
1391      will be already aligned.  Align to STACK_BOUNDARY in order to prevent
1392      backends from generating misaligned frame sizes.  */
1393   if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1394     preferred_stack_boundary = STACK_BOUNDARY;
1395
1396   /* Compute the actual size of the argument block required.  The variable
1397      and constant sizes must be combined, the size may have to be rounded,
1398      and there may be a minimum required size.  */
1399
1400   if (args_size->var)
1401     {
1402       args_size->var = ARGS_SIZE_TREE (*args_size);
1403       args_size->constant = 0;
1404
1405       preferred_stack_boundary /= BITS_PER_UNIT;
1406       if (preferred_stack_boundary > 1)
1407         {
1408           /* We don't handle this case yet.  To handle it correctly we have
1409              to add the delta, round and subtract the delta.
1410              Currently no machine description requires this support.  */
1411           if (stack_pointer_delta & (preferred_stack_boundary - 1))
1412             abort ();
1413           args_size->var = round_up (args_size->var, preferred_stack_boundary);
1414         }
1415
1416       if (reg_parm_stack_space > 0)
1417         {
1418           args_size->var
1419             = size_binop (MAX_EXPR, args_size->var,
1420                           ssize_int (reg_parm_stack_space));
1421
1422 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1423           /* The area corresponding to register parameters is not to count in
1424              the size of the block we need.  So make the adjustment.  */
1425           args_size->var
1426             = size_binop (MINUS_EXPR, args_size->var,
1427                           ssize_int (reg_parm_stack_space));
1428 #endif
1429         }
1430     }
1431   else
1432     {
1433       preferred_stack_boundary /= BITS_PER_UNIT;
1434       if (preferred_stack_boundary < 1)
1435         preferred_stack_boundary = 1;
1436       args_size->constant = (((args_size->constant
1437                                + stack_pointer_delta
1438                                + preferred_stack_boundary - 1)
1439                               / preferred_stack_boundary
1440                               * preferred_stack_boundary)
1441                              - stack_pointer_delta);
1442
1443       args_size->constant = MAX (args_size->constant,
1444                                  reg_parm_stack_space);
1445
1446 #ifdef MAYBE_REG_PARM_STACK_SPACE
1447       if (reg_parm_stack_space == 0)
1448         args_size->constant = 0;
1449 #endif
1450
1451 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1452       args_size->constant -= reg_parm_stack_space;
1453 #endif
1454     }
1455   return unadjusted_args_size;
1456 }
1457
1458 /* Precompute parameters as needed for a function call.
1459
1460    FLAGS is mask of ECF_* constants.
1461
1462    NUM_ACTUALS is the number of arguments.
1463
1464    ARGS is an array containing information for each argument; this
1465    routine fills in the INITIAL_VALUE and VALUE fields for each
1466    precomputed argument.  */
1467
1468 static void
1469 precompute_arguments (flags, num_actuals, args)
1470      int flags;
1471      int num_actuals;
1472      struct arg_data *args;
1473 {
1474   int i;
1475
1476   /* If this function call is cse'able, precompute all the parameters.
1477      Note that if the parameter is constructed into a temporary, this will
1478      cause an additional copy because the parameter will be constructed
1479      into a temporary location and then copied into the outgoing arguments.
1480      If a parameter contains a call to alloca and this function uses the
1481      stack, precompute the parameter.  */
1482
1483   /* If we preallocated the stack space, and some arguments must be passed
1484      on the stack, then we must precompute any parameter which contains a
1485      function call which will store arguments on the stack.
1486      Otherwise, evaluating the parameter may clobber previous parameters
1487      which have already been stored into the stack.  (we have code to avoid
1488      such case by saving the outgoing stack arguments, but it results in
1489      worse code)  */
1490
1491   for (i = 0; i < num_actuals; i++)
1492     if ((flags & ECF_LIBCALL_BLOCK)
1493         || calls_function (args[i].tree_value, !ACCUMULATE_OUTGOING_ARGS))
1494       {
1495         enum machine_mode mode;
1496
1497         /* If this is an addressable type, we cannot pre-evaluate it.  */
1498         if (TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)))
1499           abort ();
1500
1501         args[i].value
1502           = expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0);
1503
1504         /* ANSI doesn't require a sequence point here,
1505            but PCC has one, so this will avoid some problems.  */
1506         emit_queue ();
1507
1508         args[i].initial_value = args[i].value
1509           = protect_from_queue (args[i].value, 0);
1510
1511         mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1512         if (mode != args[i].mode)
1513           {
1514             args[i].value
1515               = convert_modes (args[i].mode, mode,
1516                                args[i].value, args[i].unsignedp);
1517 #ifdef PROMOTE_FOR_CALL_ONLY
1518             /* CSE will replace this only if it contains args[i].value
1519                pseudo, so convert it down to the declared mode using
1520                a SUBREG.  */
1521             if (GET_CODE (args[i].value) == REG
1522                 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1523               {
1524                 args[i].initial_value
1525                   = gen_lowpart_SUBREG (mode, args[i].value);
1526                 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1527                 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1528                   args[i].unsignedp);
1529               }
1530 #endif
1531           }
1532       }
1533 }
1534
1535 /* Given the current state of MUST_PREALLOCATE and information about
1536    arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1537    compute and return the final value for MUST_PREALLOCATE.  */
1538
1539 static int
1540 finalize_must_preallocate (must_preallocate, num_actuals, args, args_size)
1541      int must_preallocate;
1542      int num_actuals;
1543      struct arg_data *args;
1544      struct args_size *args_size;
1545 {
1546   /* See if we have or want to preallocate stack space.
1547
1548      If we would have to push a partially-in-regs parm
1549      before other stack parms, preallocate stack space instead.
1550
1551      If the size of some parm is not a multiple of the required stack
1552      alignment, we must preallocate.
1553
1554      If the total size of arguments that would otherwise create a copy in
1555      a temporary (such as a CALL) is more than half the total argument list
1556      size, preallocation is faster.
1557
1558      Another reason to preallocate is if we have a machine (like the m88k)
1559      where stack alignment is required to be maintained between every
1560      pair of insns, not just when the call is made.  However, we assume here
1561      that such machines either do not have push insns (and hence preallocation
1562      would occur anyway) or the problem is taken care of with
1563      PUSH_ROUNDING.  */
1564
1565   if (! must_preallocate)
1566     {
1567       int partial_seen = 0;
1568       int copy_to_evaluate_size = 0;
1569       int i;
1570
1571       for (i = 0; i < num_actuals && ! must_preallocate; i++)
1572         {
1573           if (args[i].partial > 0 && ! args[i].pass_on_stack)
1574             partial_seen = 1;
1575           else if (partial_seen && args[i].reg == 0)
1576             must_preallocate = 1;
1577
1578           if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1579               && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1580                   || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1581                   || TREE_CODE (args[i].tree_value) == COND_EXPR
1582                   || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1583             copy_to_evaluate_size
1584               += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1585         }
1586
1587       if (copy_to_evaluate_size * 2 >= args_size->constant
1588           && args_size->constant > 0)
1589         must_preallocate = 1;
1590     }
1591   return must_preallocate;
1592 }
1593
1594 /* If we preallocated stack space, compute the address of each argument
1595    and store it into the ARGS array.
1596
1597    We need not ensure it is a valid memory address here; it will be
1598    validized when it is used.
1599
1600    ARGBLOCK is an rtx for the address of the outgoing arguments.  */
1601
1602 static void
1603 compute_argument_addresses (args, argblock, num_actuals)
1604      struct arg_data *args;
1605      rtx argblock;
1606      int num_actuals;
1607 {
1608   if (argblock)
1609     {
1610       rtx arg_reg = argblock;
1611       int i, arg_offset = 0;
1612
1613       if (GET_CODE (argblock) == PLUS)
1614         arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1615
1616       for (i = 0; i < num_actuals; i++)
1617         {
1618           rtx offset = ARGS_SIZE_RTX (args[i].offset);
1619           rtx slot_offset = ARGS_SIZE_RTX (args[i].slot_offset);
1620           rtx addr;
1621
1622           /* Skip this parm if it will not be passed on the stack.  */
1623           if (! args[i].pass_on_stack && args[i].reg != 0)
1624             continue;
1625
1626           if (GET_CODE (offset) == CONST_INT)
1627             addr = plus_constant (arg_reg, INTVAL (offset));
1628           else
1629             addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1630
1631           addr = plus_constant (addr, arg_offset);
1632           args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1633           set_mem_attributes (args[i].stack,
1634                               TREE_TYPE (args[i].tree_value), 1);
1635
1636           if (GET_CODE (slot_offset) == CONST_INT)
1637             addr = plus_constant (arg_reg, INTVAL (slot_offset));
1638           else
1639             addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1640
1641           addr = plus_constant (addr, arg_offset);
1642           args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1643           set_mem_attributes (args[i].stack_slot,
1644                               TREE_TYPE (args[i].tree_value), 1);
1645
1646           /* Function incoming arguments may overlap with sibling call
1647              outgoing arguments and we cannot allow reordering of reads
1648              from function arguments with stores to outgoing arguments
1649              of sibling calls.  */
1650           set_mem_alias_set (args[i].stack, 0);
1651           set_mem_alias_set (args[i].stack_slot, 0);
1652         }
1653     }
1654 }
1655
1656 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1657    in a call instruction.
1658
1659    FNDECL is the tree node for the target function.  For an indirect call
1660    FNDECL will be NULL_TREE.
1661
1662    EXP is the CALL_EXPR for this call.  */
1663
1664 static rtx
1665 rtx_for_function_call (fndecl, exp)
1666      tree fndecl;
1667      tree exp;
1668 {
1669   rtx funexp;
1670
1671   /* Get the function to call, in the form of RTL.  */
1672   if (fndecl)
1673     {
1674       /* If this is the first use of the function, see if we need to
1675          make an external definition for it.  */
1676       if (! TREE_USED (fndecl))
1677         {
1678           assemble_external (fndecl);
1679           TREE_USED (fndecl) = 1;
1680         }
1681
1682       /* Get a SYMBOL_REF rtx for the function address.  */
1683       funexp = XEXP (DECL_RTL (fndecl), 0);
1684     }
1685   else
1686     /* Generate an rtx (probably a pseudo-register) for the address.  */
1687     {
1688       push_temp_slots ();
1689       funexp = expand_expr (TREE_OPERAND (exp, 0), NULL_RTX, VOIDmode, 0);
1690       pop_temp_slots ();        /* FUNEXP can't be BLKmode.  */
1691       emit_queue ();
1692     }
1693   return funexp;
1694 }
1695
1696 /* Do the register loads required for any wholly-register parms or any
1697    parms which are passed both on the stack and in a register.  Their
1698    expressions were already evaluated.
1699
1700    Mark all register-parms as living through the call, putting these USE
1701    insns in the CALL_INSN_FUNCTION_USAGE field.  */
1702
1703 static void
1704 load_register_parameters (args, num_actuals, call_fusage, flags)
1705      struct arg_data *args;
1706      int num_actuals;
1707      rtx *call_fusage;
1708      int flags;
1709 {
1710   int i, j;
1711
1712 #ifdef LOAD_ARGS_REVERSED
1713   for (i = num_actuals - 1; i >= 0; i--)
1714 #else
1715   for (i = 0; i < num_actuals; i++)
1716 #endif
1717     {
1718       rtx reg = ((flags & ECF_SIBCALL)
1719                  ? args[i].tail_call_reg : args[i].reg);
1720       int partial = args[i].partial;
1721       int nregs;
1722
1723       if (reg)
1724         {
1725           /* Set to non-negative if must move a word at a time, even if just
1726              one word (e.g, partial == 1 && mode == DFmode).  Set to -1 if
1727              we just use a normal move insn.  This value can be zero if the
1728              argument is a zero size structure with no fields.  */
1729           nregs = (partial ? partial
1730                    : (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1731                       ? ((int_size_in_bytes (TREE_TYPE (args[i].tree_value))
1732                           + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)
1733                       : -1));
1734
1735           /* Handle calls that pass values in multiple non-contiguous
1736              locations.  The Irix 6 ABI has examples of this.  */
1737
1738           if (GET_CODE (reg) == PARALLEL)
1739             emit_group_load (reg, args[i].value,
1740                              int_size_in_bytes (TREE_TYPE (args[i].tree_value)));
1741
1742           /* If simple case, just do move.  If normal partial, store_one_arg
1743              has already loaded the register for us.  In all other cases,
1744              load the register(s) from memory.  */
1745
1746           else if (nregs == -1)
1747             emit_move_insn (reg, args[i].value);
1748
1749           /* If we have pre-computed the values to put in the registers in
1750              the case of non-aligned structures, copy them in now.  */
1751
1752           else if (args[i].n_aligned_regs != 0)
1753             for (j = 0; j < args[i].n_aligned_regs; j++)
1754               emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1755                               args[i].aligned_regs[j]);
1756
1757           else if (partial == 0 || args[i].pass_on_stack)
1758             move_block_to_reg (REGNO (reg),
1759                                validize_mem (args[i].value), nregs,
1760                                args[i].mode);
1761
1762           /* Handle calls that pass values in multiple non-contiguous
1763              locations.  The Irix 6 ABI has examples of this.  */
1764           if (GET_CODE (reg) == PARALLEL)
1765             use_group_regs (call_fusage, reg);
1766           else if (nregs == -1)
1767             use_reg (call_fusage, reg);
1768           else
1769             use_regs (call_fusage, REGNO (reg), nregs == 0 ? 1 : nregs);
1770         }
1771     }
1772 }
1773
1774 /* Try to integrate function.  See expand_inline_function for documentation
1775    about the parameters.  */
1776
1777 static rtx
1778 try_to_integrate (fndecl, actparms, target, ignore, type, structure_value_addr)
1779      tree fndecl;
1780      tree actparms;
1781      rtx target;
1782      int ignore;
1783      tree type;
1784      rtx structure_value_addr;
1785 {
1786   rtx temp;
1787   rtx before_call;
1788   int i;
1789   rtx old_stack_level = 0;
1790   int reg_parm_stack_space = 0;
1791
1792 #ifdef REG_PARM_STACK_SPACE
1793 #ifdef MAYBE_REG_PARM_STACK_SPACE
1794   reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
1795 #else
1796   reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
1797 #endif
1798 #endif
1799
1800   before_call = get_last_insn ();
1801
1802   timevar_push (TV_INTEGRATION);
1803
1804   temp = expand_inline_function (fndecl, actparms, target,
1805                                  ignore, type,
1806                                  structure_value_addr);
1807
1808   timevar_pop (TV_INTEGRATION);
1809
1810   /* If inlining succeeded, return.  */
1811   if (temp != (rtx) (size_t) - 1)
1812     {
1813       if (ACCUMULATE_OUTGOING_ARGS)
1814         {
1815           /* If the outgoing argument list must be preserved, push
1816              the stack before executing the inlined function if it
1817              makes any calls.  */
1818
1819           for (i = reg_parm_stack_space - 1; i >= 0; i--)
1820             if (i < highest_outgoing_arg_in_use && stack_usage_map[i] != 0)
1821               break;
1822
1823           if (stack_arg_under_construction || i >= 0)
1824             {
1825               rtx first_insn
1826                 = before_call ? NEXT_INSN (before_call) : get_insns ();
1827               rtx insn = NULL_RTX, seq;
1828
1829               /* Look for a call in the inline function code.
1830                  If DECL_SAVED_INSNS (fndecl)->outgoing_args_size is
1831                  nonzero then there is a call and it is not necessary
1832                  to scan the insns.  */
1833
1834               if (DECL_SAVED_INSNS (fndecl)->outgoing_args_size == 0)
1835                 for (insn = first_insn; insn; insn = NEXT_INSN (insn))
1836                   if (GET_CODE (insn) == CALL_INSN)
1837                     break;
1838
1839               if (insn)
1840                 {
1841                   /* Reserve enough stack space so that the largest
1842                      argument list of any function call in the inline
1843                      function does not overlap the argument list being
1844                      evaluated.  This is usually an overestimate because
1845                      allocate_dynamic_stack_space reserves space for an
1846                      outgoing argument list in addition to the requested
1847                      space, but there is no way to ask for stack space such
1848                      that an argument list of a certain length can be
1849                      safely constructed.
1850
1851                      Add the stack space reserved for register arguments, if
1852                      any, in the inline function.  What is really needed is the
1853                      largest value of reg_parm_stack_space in the inline
1854                      function, but that is not available.  Using the current
1855                      value of reg_parm_stack_space is wrong, but gives
1856                      correct results on all supported machines.  */
1857
1858                   int adjust = (DECL_SAVED_INSNS (fndecl)->outgoing_args_size
1859                                 + reg_parm_stack_space);
1860
1861                   start_sequence ();
1862                   emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
1863                   allocate_dynamic_stack_space (GEN_INT (adjust),
1864                                                 NULL_RTX, BITS_PER_UNIT);
1865                   seq = get_insns ();
1866                   end_sequence ();
1867                   emit_insn_before (seq, first_insn);
1868                   emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
1869                 }
1870             }
1871         }
1872
1873       /* If the result is equivalent to TARGET, return TARGET to simplify
1874          checks in store_expr.  They can be equivalent but not equal in the
1875          case of a function that returns BLKmode.  */
1876       if (temp != target && rtx_equal_p (temp, target))
1877         return target;
1878       return temp;
1879     }
1880
1881   /* If inlining failed, mark FNDECL as needing to be compiled
1882      separately after all.  If function was declared inline,
1883      give a warning.  */
1884   if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
1885       && optimize > 0 && !TREE_ADDRESSABLE (fndecl))
1886     {
1887       warning_with_decl (fndecl, "inlining failed in call to `%s'");
1888       warning ("called from here");
1889     }
1890   (*lang_hooks.mark_addressable) (fndecl);
1891   return (rtx) (size_t) - 1;
1892 }
1893
1894 /* We need to pop PENDING_STACK_ADJUST bytes.  But, if the arguments
1895    wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1896    bytes, then we would need to push some additional bytes to pad the
1897    arguments.  So, we compute an adjust to the stack pointer for an
1898    amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1899    bytes.  Then, when the arguments are pushed the stack will be perfectly
1900    aligned.  ARGS_SIZE->CONSTANT is set to the number of bytes that should
1901    be popped after the call.  Returns the adjustment.  */
1902
1903 static int
1904 combine_pending_stack_adjustment_and_call (unadjusted_args_size,
1905                                            args_size,
1906                                            preferred_unit_stack_boundary)
1907      int unadjusted_args_size;
1908      struct args_size *args_size;
1909      int preferred_unit_stack_boundary;
1910 {
1911   /* The number of bytes to pop so that the stack will be
1912      under-aligned by UNADJUSTED_ARGS_SIZE bytes.  */
1913   HOST_WIDE_INT adjustment;
1914   /* The alignment of the stack after the arguments are pushed, if we
1915      just pushed the arguments without adjust the stack here.  */
1916   HOST_WIDE_INT unadjusted_alignment;
1917
1918   unadjusted_alignment
1919     = ((stack_pointer_delta + unadjusted_args_size)
1920        % preferred_unit_stack_boundary);
1921
1922   /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1923      as possible -- leaving just enough left to cancel out the
1924      UNADJUSTED_ALIGNMENT.  In other words, we want to ensure that the
1925      PENDING_STACK_ADJUST is non-negative, and congruent to
1926      -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY.  */
1927
1928   /* Begin by trying to pop all the bytes.  */
1929   unadjusted_alignment
1930     = (unadjusted_alignment
1931        - (pending_stack_adjust % preferred_unit_stack_boundary));
1932   adjustment = pending_stack_adjust;
1933   /* Push enough additional bytes that the stack will be aligned
1934      after the arguments are pushed.  */
1935   if (preferred_unit_stack_boundary > 1)
1936     {
1937       if (unadjusted_alignment > 0)
1938         adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1939       else
1940         adjustment += unadjusted_alignment;
1941     }
1942
1943   /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1944      bytes after the call.  The right number is the entire
1945      PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1946      by the arguments in the first place.  */
1947   args_size->constant
1948     = pending_stack_adjust - adjustment + unadjusted_args_size;
1949
1950   return adjustment;
1951 }
1952
1953 /* Scan X expression if it does not dereference any argument slots
1954    we already clobbered by tail call arguments (as noted in stored_args_map
1955    bitmap).
1956    Return nonzero if X expression dereferences such argument slots,
1957    zero otherwise.  */
1958
1959 static int
1960 check_sibcall_argument_overlap_1 (x)
1961      rtx x;
1962 {
1963   RTX_CODE code;
1964   int i, j;
1965   unsigned int k;
1966   const char *fmt;
1967
1968   if (x == NULL_RTX)
1969     return 0;
1970
1971   code = GET_CODE (x);
1972
1973   if (code == MEM)
1974     {
1975       if (XEXP (x, 0) == current_function_internal_arg_pointer)
1976         i = 0;
1977       else if (GET_CODE (XEXP (x, 0)) == PLUS
1978                && XEXP (XEXP (x, 0), 0) ==
1979                   current_function_internal_arg_pointer
1980                && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)
1981         i = INTVAL (XEXP (XEXP (x, 0), 1));
1982       else
1983         return 0;
1984
1985 #ifdef ARGS_GROW_DOWNWARD
1986       i = -i - GET_MODE_SIZE (GET_MODE (x));
1987 #endif
1988
1989       for (k = 0; k < GET_MODE_SIZE (GET_MODE (x)); k++)
1990         if (i + k < stored_args_map->n_bits
1991             && TEST_BIT (stored_args_map, i + k))
1992           return 1;
1993
1994       return 0;
1995     }
1996
1997   /* Scan all subexpressions.  */
1998   fmt = GET_RTX_FORMAT (code);
1999   for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2000     {
2001       if (*fmt == 'e')
2002         {
2003           if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
2004             return 1;
2005         }
2006       else if (*fmt == 'E')
2007         {
2008           for (j = 0; j < XVECLEN (x, i); j++)
2009             if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
2010               return 1;
2011         }
2012     }
2013   return 0;
2014 }
2015
2016 /* Scan sequence after INSN if it does not dereference any argument slots
2017    we already clobbered by tail call arguments (as noted in stored_args_map
2018    bitmap).  Add stack slots for ARG to stored_args_map bitmap afterwards.
2019    Return nonzero if sequence after INSN dereferences such argument slots,
2020    zero otherwise.  */
2021
2022 static int
2023 check_sibcall_argument_overlap (insn, arg)
2024      rtx insn;
2025      struct arg_data *arg;
2026 {
2027   int low, high;
2028
2029   if (insn == NULL_RTX)
2030     insn = get_insns ();
2031   else
2032     insn = NEXT_INSN (insn);
2033
2034   for (; insn; insn = NEXT_INSN (insn))
2035     if (INSN_P (insn)
2036         && check_sibcall_argument_overlap_1 (PATTERN (insn)))
2037       break;
2038
2039 #ifdef ARGS_GROW_DOWNWARD
2040   low = -arg->slot_offset.constant - arg->size.constant;
2041 #else
2042   low = arg->slot_offset.constant;
2043 #endif
2044
2045   for (high = low + arg->size.constant; low < high; low++)
2046     SET_BIT (stored_args_map, low);
2047   return insn != NULL_RTX;
2048 }
2049
2050 /* Generate all the code for a function call
2051    and return an rtx for its value.
2052    Store the value in TARGET (specified as an rtx) if convenient.
2053    If the value is stored in TARGET then TARGET is returned.
2054    If IGNORE is nonzero, then we ignore the value of the function call.  */
2055
2056 rtx
2057 expand_call (exp, target, ignore)
2058      tree exp;
2059      rtx target;
2060      int ignore;
2061 {
2062   /* Nonzero if we are currently expanding a call.  */
2063   static int currently_expanding_call = 0;
2064
2065   /* List of actual parameters.  */
2066   tree actparms = TREE_OPERAND (exp, 1);
2067   /* RTX for the function to be called.  */
2068   rtx funexp;
2069   /* Sequence of insns to perform a tail recursive "call".  */
2070   rtx tail_recursion_insns = NULL_RTX;
2071   /* Sequence of insns to perform a normal "call".  */
2072   rtx normal_call_insns = NULL_RTX;
2073   /* Sequence of insns to perform a tail recursive "call".  */
2074   rtx tail_call_insns = NULL_RTX;
2075   /* Data type of the function.  */
2076   tree funtype;
2077   /* Declaration of the function being called,
2078      or 0 if the function is computed (not known by name).  */
2079   tree fndecl = 0;
2080   rtx insn;
2081   int try_tail_call = 1;
2082   int try_tail_recursion = 1;
2083   int pass;
2084
2085   /* Register in which non-BLKmode value will be returned,
2086      or 0 if no value or if value is BLKmode.  */
2087   rtx valreg;
2088   /* Address where we should return a BLKmode value;
2089      0 if value not BLKmode.  */
2090   rtx structure_value_addr = 0;
2091   /* Nonzero if that address is being passed by treating it as
2092      an extra, implicit first parameter.  Otherwise,
2093      it is passed by being copied directly into struct_value_rtx.  */
2094   int structure_value_addr_parm = 0;
2095   /* Size of aggregate value wanted, or zero if none wanted
2096      or if we are using the non-reentrant PCC calling convention
2097      or expecting the value in registers.  */
2098   HOST_WIDE_INT struct_value_size = 0;
2099   /* Nonzero if called function returns an aggregate in memory PCC style,
2100      by returning the address of where to find it.  */
2101   int pcc_struct_value = 0;
2102
2103   /* Number of actual parameters in this call, including struct value addr.  */
2104   int num_actuals;
2105   /* Number of named args.  Args after this are anonymous ones
2106      and they must all go on the stack.  */
2107   int n_named_args;
2108
2109   /* Vector of information about each argument.
2110      Arguments are numbered in the order they will be pushed,
2111      not the order they are written.  */
2112   struct arg_data *args;
2113
2114   /* Total size in bytes of all the stack-parms scanned so far.  */
2115   struct args_size args_size;
2116   struct args_size adjusted_args_size;
2117   /* Size of arguments before any adjustments (such as rounding).  */
2118   int unadjusted_args_size;
2119   /* Data on reg parms scanned so far.  */
2120   CUMULATIVE_ARGS args_so_far;
2121   /* Nonzero if a reg parm has been scanned.  */
2122   int reg_parm_seen;
2123   /* Nonzero if this is an indirect function call.  */
2124
2125   /* Nonzero if we must avoid push-insns in the args for this call.
2126      If stack space is allocated for register parameters, but not by the
2127      caller, then it is preallocated in the fixed part of the stack frame.
2128      So the entire argument block must then be preallocated (i.e., we
2129      ignore PUSH_ROUNDING in that case).  */
2130
2131   int must_preallocate = !PUSH_ARGS;
2132
2133   /* Size of the stack reserved for parameter registers.  */
2134   int reg_parm_stack_space = 0;
2135
2136   /* Address of space preallocated for stack parms
2137      (on machines that lack push insns), or 0 if space not preallocated.  */
2138   rtx argblock = 0;
2139
2140   /* Mask of ECF_ flags.  */
2141   int flags = 0;
2142   /* Nonzero if this is a call to an inline function.  */
2143   int is_integrable = 0;
2144 #ifdef REG_PARM_STACK_SPACE
2145   /* Define the boundary of the register parm stack space that needs to be
2146      save, if any.  */
2147   int low_to_save = -1, high_to_save;
2148   rtx save_area = 0;            /* Place that it is saved */
2149 #endif
2150
2151   int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2152   char *initial_stack_usage_map = stack_usage_map;
2153   int old_stack_arg_under_construction = 0;
2154
2155   rtx old_stack_level = 0;
2156   int old_pending_adj = 0;
2157   int old_inhibit_defer_pop = inhibit_defer_pop;
2158   int old_stack_allocated;
2159   rtx call_fusage;
2160   tree p = TREE_OPERAND (exp, 0);
2161   int i;
2162   /* The alignment of the stack, in bits.  */
2163   HOST_WIDE_INT preferred_stack_boundary;
2164   /* The alignment of the stack, in bytes.  */
2165   HOST_WIDE_INT preferred_unit_stack_boundary;
2166
2167   /* See if this is "nothrow" function call.  */
2168   if (TREE_NOTHROW (exp))
2169     flags |= ECF_NOTHROW;
2170
2171   /* See if we can find a DECL-node for the actual function.
2172      As a result, decide whether this is a call to an integrable function.  */
2173
2174   fndecl = get_callee_fndecl (exp);
2175   if (fndecl)
2176     {
2177       if (!flag_no_inline
2178           && fndecl != current_function_decl
2179           && DECL_INLINE (fndecl)
2180           && DECL_SAVED_INSNS (fndecl)
2181           && DECL_SAVED_INSNS (fndecl)->inlinable)
2182         is_integrable = 1;
2183       else if (! TREE_ADDRESSABLE (fndecl))
2184         {
2185           /* In case this function later becomes inlinable,
2186              record that there was already a non-inline call to it.
2187
2188              Use abstraction instead of setting TREE_ADDRESSABLE
2189              directly.  */
2190           if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
2191               && optimize > 0)
2192             {
2193               warning_with_decl (fndecl, "can't inline call to `%s'");
2194               warning ("called from here");
2195             }
2196           (*lang_hooks.mark_addressable) (fndecl);
2197         }
2198
2199       flags |= flags_from_decl_or_type (fndecl);
2200     }
2201
2202   /* If we don't have specific function to call, see if we have a
2203      attributes set in the type.  */
2204   else
2205     flags |= flags_from_decl_or_type (TREE_TYPE (TREE_TYPE (p)));
2206
2207 #ifdef REG_PARM_STACK_SPACE
2208 #ifdef MAYBE_REG_PARM_STACK_SPACE
2209   reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
2210 #else
2211   reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
2212 #endif
2213 #endif
2214
2215 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2216   if (reg_parm_stack_space > 0 && PUSH_ARGS)
2217     must_preallocate = 1;
2218 #endif
2219
2220   /* Warn if this value is an aggregate type,
2221      regardless of which calling convention we are using for it.  */
2222   if (warn_aggregate_return && AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2223     warning ("function call has aggregate value");
2224
2225   /* Set up a place to return a structure.  */
2226
2227   /* Cater to broken compilers.  */
2228   if (aggregate_value_p (exp))
2229     {
2230       /* This call returns a big structure.  */
2231       flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
2232
2233 #ifdef PCC_STATIC_STRUCT_RETURN
2234       {
2235         pcc_struct_value = 1;
2236         /* Easier than making that case work right.  */
2237         if (is_integrable)
2238           {
2239             /* In case this is a static function, note that it has been
2240                used.  */
2241             if (! TREE_ADDRESSABLE (fndecl))
2242               (*lang_hooks.mark_addressable) (fndecl);
2243             is_integrable = 0;
2244           }
2245       }
2246 #else /* not PCC_STATIC_STRUCT_RETURN */
2247       {
2248         struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2249
2250         if (CALL_EXPR_HAS_RETURN_SLOT_ADDR (exp))
2251           {
2252             /* The structure value address arg is already in actparms.
2253                Pull it out.  It might be nice to just leave it there, but
2254                we need to set structure_value_addr.  */
2255             tree return_arg = TREE_VALUE (actparms);
2256             actparms = TREE_CHAIN (actparms);
2257             structure_value_addr = expand_expr (return_arg, NULL_RTX,
2258                                                 VOIDmode, EXPAND_NORMAL);
2259           }
2260         else if (target && GET_CODE (target) == MEM)
2261           structure_value_addr = XEXP (target, 0);
2262         else
2263           {
2264             /* For variable-sized objects, we must be called with a target
2265                specified.  If we were to allocate space on the stack here,
2266                we would have no way of knowing when to free it.  */
2267             rtx d = assign_temp (TREE_TYPE (exp), 1, 1, 1);
2268
2269             mark_temp_addr_taken (d);
2270             structure_value_addr = XEXP (d, 0);
2271             target = 0;
2272           }
2273       }
2274 #endif /* not PCC_STATIC_STRUCT_RETURN */
2275     }
2276
2277   /* If called function is inline, try to integrate it.  */
2278
2279   if (is_integrable)
2280     {
2281       rtx temp = try_to_integrate (fndecl, actparms, target,
2282                                    ignore, TREE_TYPE (exp),
2283                                    structure_value_addr);
2284       if (temp != (rtx) (size_t) - 1)
2285         return temp;
2286     }
2287
2288   /* Figure out the amount to which the stack should be aligned.  */
2289   preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2290
2291   /* Operand 0 is a pointer-to-function; get the type of the function.  */
2292   funtype = TREE_TYPE (TREE_OPERAND (exp, 0));
2293   if (! POINTER_TYPE_P (funtype))
2294     abort ();
2295   funtype = TREE_TYPE (funtype);
2296
2297   /* See if this is a call to a function that can return more than once
2298      or a call to longjmp or malloc.  */
2299   flags |= special_function_p (fndecl, flags);
2300
2301   if (flags & ECF_MAY_BE_ALLOCA)
2302     current_function_calls_alloca = 1;
2303
2304   /* If struct_value_rtx is 0, it means pass the address
2305      as if it were an extra parameter.  */
2306   if (structure_value_addr && struct_value_rtx == 0)
2307     {
2308       /* If structure_value_addr is a REG other than
2309          virtual_outgoing_args_rtx, we can use always use it.  If it
2310          is not a REG, we must always copy it into a register.
2311          If it is virtual_outgoing_args_rtx, we must copy it to another
2312          register in some cases.  */
2313       rtx temp = (GET_CODE (structure_value_addr) != REG
2314                   || (ACCUMULATE_OUTGOING_ARGS
2315                       && stack_arg_under_construction
2316                       && structure_value_addr == virtual_outgoing_args_rtx)
2317                   ? copy_addr_to_reg (structure_value_addr)
2318                   : structure_value_addr);
2319
2320       actparms
2321         = tree_cons (error_mark_node,
2322                      make_tree (build_pointer_type (TREE_TYPE (funtype)),
2323                                 temp),
2324                      actparms);
2325       structure_value_addr_parm = 1;
2326     }
2327
2328   /* Count the arguments and set NUM_ACTUALS.  */
2329   for (p = actparms, num_actuals = 0; p; p = TREE_CHAIN (p))
2330     num_actuals++;
2331
2332   /* Compute number of named args.
2333      Normally, don't include the last named arg if anonymous args follow.
2334      We do include the last named arg if STRICT_ARGUMENT_NAMING is nonzero.
2335      (If no anonymous args follow, the result of list_length is actually
2336      one too large.  This is harmless.)
2337
2338      If PRETEND_OUTGOING_VARARGS_NAMED is set and STRICT_ARGUMENT_NAMING is
2339      zero, this machine will be able to place unnamed args that were
2340      passed in registers into the stack.  So treat all args as named.
2341      This allows the insns emitting for a specific argument list to be
2342      independent of the function declaration.
2343
2344      If PRETEND_OUTGOING_VARARGS_NAMED is not set, we do not have any
2345      reliable way to pass unnamed args in registers, so we must force
2346      them into memory.  */
2347
2348   if ((STRICT_ARGUMENT_NAMING
2349        || ! PRETEND_OUTGOING_VARARGS_NAMED)
2350       && TYPE_ARG_TYPES (funtype) != 0)
2351     n_named_args
2352       = (list_length (TYPE_ARG_TYPES (funtype))
2353          /* Don't include the last named arg.  */
2354          - (STRICT_ARGUMENT_NAMING ? 0 : 1)
2355          /* Count the struct value address, if it is passed as a parm.  */
2356          + structure_value_addr_parm);
2357   else
2358     /* If we know nothing, treat all args as named.  */
2359     n_named_args = num_actuals;
2360
2361   /* Start updating where the next arg would go.
2362
2363      On some machines (such as the PA) indirect calls have a different
2364      calling convention than normal calls.  The last argument in
2365      INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2366      or not.  */
2367   INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, (fndecl == 0));
2368
2369   /* Make a vector to hold all the information about each arg.  */
2370   args = (struct arg_data *) alloca (num_actuals * sizeof (struct arg_data));
2371   memset ((char *) args, 0, num_actuals * sizeof (struct arg_data));
2372
2373   /* Build up entries in the ARGS array, compute the size of the
2374      arguments into ARGS_SIZE, etc.  */
2375   initialize_argument_information (num_actuals, args, &args_size,
2376                                    n_named_args, actparms, fndecl,
2377                                    &args_so_far, reg_parm_stack_space,
2378                                    &old_stack_level, &old_pending_adj,
2379                                    &must_preallocate, &flags);
2380
2381   if (args_size.var)
2382     {
2383       /* If this function requires a variable-sized argument list, don't
2384          try to make a cse'able block for this call.  We may be able to
2385          do this eventually, but it is too complicated to keep track of
2386          what insns go in the cse'able block and which don't.  */
2387
2388       flags &= ~ECF_LIBCALL_BLOCK;
2389       must_preallocate = 1;
2390     }
2391
2392   /* Now make final decision about preallocating stack space.  */
2393   must_preallocate = finalize_must_preallocate (must_preallocate,
2394                                                 num_actuals, args,
2395                                                 &args_size);
2396
2397   /* If the structure value address will reference the stack pointer, we
2398      must stabilize it.  We don't need to do this if we know that we are
2399      not going to adjust the stack pointer in processing this call.  */
2400
2401   if (structure_value_addr
2402       && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2403           || reg_mentioned_p (virtual_outgoing_args_rtx,
2404                               structure_value_addr))
2405       && (args_size.var
2406           || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2407     structure_value_addr = copy_to_reg (structure_value_addr);
2408
2409   /* Tail calls can make things harder to debug, and we're traditionally
2410      pushed these optimizations into -O2.  Don't try if we're already
2411      expanding a call, as that means we're an argument.  Don't try if
2412      there's cleanups, as we know there's code to follow the call.
2413
2414      If rtx_equal_function_value_matters is false, that means we've
2415      finished with regular parsing.  Which means that some of the
2416      machinery we use to generate tail-calls is no longer in place.
2417      This is most often true of sjlj-exceptions, which we couldn't
2418      tail-call to anyway.  */
2419
2420   if (currently_expanding_call++ != 0
2421       || !flag_optimize_sibling_calls
2422       || !rtx_equal_function_value_matters
2423       || any_pending_cleanups (1)
2424       || args_size.var)
2425     try_tail_call = try_tail_recursion = 0;
2426
2427   /* Tail recursion fails, when we are not dealing with recursive calls.  */
2428   if (!try_tail_recursion
2429       || TREE_CODE (TREE_OPERAND (exp, 0)) != ADDR_EXPR
2430       || TREE_OPERAND (TREE_OPERAND (exp, 0), 0) != current_function_decl)
2431     try_tail_recursion = 0;
2432
2433   /*  Rest of purposes for tail call optimizations to fail.  */
2434   if (
2435 #ifdef HAVE_sibcall_epilogue
2436       !HAVE_sibcall_epilogue
2437 #else
2438       1
2439 #endif
2440       || !try_tail_call
2441       /* Doing sibling call optimization needs some work, since
2442          structure_value_addr can be allocated on the stack.
2443          It does not seem worth the effort since few optimizable
2444          sibling calls will return a structure.  */
2445       || structure_value_addr != NULL_RTX
2446       /* Check whether the target is able to optimize the call
2447          into a sibcall.  */
2448       || !(*targetm.function_ok_for_sibcall) (fndecl, exp)
2449       /* Functions that do not return exactly once may not be sibcall
2450          optimized.  */
2451       || (flags & (ECF_RETURNS_TWICE | ECF_LONGJMP | ECF_NORETURN))
2452       || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))
2453       /* If this function requires more stack slots than the current
2454          function, we cannot change it into a sibling call.  */
2455       || args_size.constant > current_function_args_size
2456       /* If the callee pops its own arguments, then it must pop exactly
2457          the same number of arguments as the current function.  */
2458       || RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2459          != RETURN_POPS_ARGS (current_function_decl,
2460                               TREE_TYPE (current_function_decl),
2461                               current_function_args_size))
2462     try_tail_call = 0;
2463
2464   if (try_tail_call || try_tail_recursion)
2465     {
2466       int end, inc;
2467       actparms = NULL_TREE;
2468       /* Ok, we're going to give the tail call the old college try.
2469          This means we're going to evaluate the function arguments
2470          up to three times.  There are two degrees of badness we can
2471          encounter, those that can be unsaved and those that can't.
2472          (See unsafe_for_reeval commentary for details.)
2473
2474          Generate a new argument list.  Pass safe arguments through
2475          unchanged.  For the easy badness wrap them in UNSAVE_EXPRs.
2476          For hard badness, evaluate them now and put their resulting
2477          rtx in a temporary VAR_DECL.
2478
2479          initialize_argument_information has ordered the array for the
2480          order to be pushed, and we must remember this when reconstructing
2481          the original argument order.  */
2482
2483       if (PUSH_ARGS_REVERSED)
2484         {
2485           inc = 1;
2486           i = 0;
2487           end = num_actuals;
2488         }
2489       else
2490         {
2491           inc = -1;
2492           i = num_actuals - 1;
2493           end = -1;
2494         }
2495
2496       for (; i != end; i += inc)
2497         {
2498           switch (unsafe_for_reeval (args[i].tree_value))
2499             {
2500             case 0: /* Safe.  */
2501               break;
2502
2503             case 1: /* Mildly unsafe.  */
2504               args[i].tree_value = unsave_expr (args[i].tree_value);
2505               break;
2506
2507             case 2: /* Wildly unsafe.  */
2508               {
2509                 tree var = build_decl (VAR_DECL, NULL_TREE,
2510                                        TREE_TYPE (args[i].tree_value));
2511                 SET_DECL_RTL (var,
2512                               expand_expr (args[i].tree_value, NULL_RTX,
2513                                            VOIDmode, EXPAND_NORMAL));
2514                 args[i].tree_value = var;
2515               }
2516               break;
2517
2518             default:
2519               abort ();
2520             }
2521           /* We need to build actparms for optimize_tail_recursion.  We can
2522              safely trash away TREE_PURPOSE, since it is unused by this
2523              function.  */
2524           if (try_tail_recursion)
2525             actparms = tree_cons (NULL_TREE, args[i].tree_value, actparms);
2526         }
2527       /* Expanding one of those dangerous arguments could have added
2528          cleanups, but otherwise give it a whirl.  */
2529       if (any_pending_cleanups (1))
2530         try_tail_call = try_tail_recursion = 0;
2531     }
2532
2533   /* Generate a tail recursion sequence when calling ourselves.  */
2534
2535   if (try_tail_recursion)
2536     {
2537       /* We want to emit any pending stack adjustments before the tail
2538          recursion "call".  That way we know any adjustment after the tail
2539          recursion call can be ignored if we indeed use the tail recursion
2540          call expansion.  */
2541       int save_pending_stack_adjust = pending_stack_adjust;
2542       int save_stack_pointer_delta = stack_pointer_delta;
2543
2544       /* Emit any queued insns now; otherwise they would end up in
2545          only one of the alternates.  */
2546       emit_queue ();
2547
2548       /* Use a new sequence to hold any RTL we generate.  We do not even
2549          know if we will use this RTL yet.  The final decision can not be
2550          made until after RTL generation for the entire function is
2551          complete.  */
2552       start_sequence ();
2553       /* If expanding any of the arguments creates cleanups, we can't
2554          do a tailcall.  So, we'll need to pop the pending cleanups
2555          list.  If, however, all goes well, and there are no cleanups
2556          then the call to expand_start_target_temps will have no
2557          effect.  */
2558       expand_start_target_temps ();
2559       if (optimize_tail_recursion (actparms, get_last_insn ()))
2560         {
2561           if (any_pending_cleanups (1))
2562             try_tail_call = try_tail_recursion = 0;
2563           else
2564             tail_recursion_insns = get_insns ();
2565         }
2566       expand_end_target_temps ();
2567       end_sequence ();
2568
2569       /* Restore the original pending stack adjustment for the sibling and
2570          normal call cases below.  */
2571       pending_stack_adjust = save_pending_stack_adjust;
2572       stack_pointer_delta = save_stack_pointer_delta;
2573     }
2574
2575   if (profile_arc_flag && (flags & ECF_FORK_OR_EXEC))
2576     {
2577       /* A fork duplicates the profile information, and an exec discards
2578          it.  We can't rely on fork/exec to be paired.  So write out the
2579          profile information we have gathered so far, and clear it.  */
2580       /* ??? When Linux's __clone is called with CLONE_VM set, profiling
2581          is subject to race conditions, just as with multithreaded
2582          programs.  */
2583
2584       emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__gcov_flush"),
2585                          LCT_ALWAYS_RETURN,
2586                          VOIDmode, 0);
2587     }
2588
2589   /* Ensure current function's preferred stack boundary is at least
2590      what we need.  We don't have to increase alignment for recursive
2591      functions.  */
2592   if (cfun->preferred_stack_boundary < preferred_stack_boundary
2593       && fndecl != current_function_decl)
2594     cfun->preferred_stack_boundary = preferred_stack_boundary;
2595
2596   preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2597
2598   function_call_count++;
2599
2600   /* We want to make two insn chains; one for a sibling call, the other
2601      for a normal call.  We will select one of the two chains after
2602      initial RTL generation is complete.  */
2603   for (pass = 0; pass < 2; pass++)
2604     {
2605       int sibcall_failure = 0;
2606       /* We want to emit any pending stack adjustments before the tail
2607          recursion "call".  That way we know any adjustment after the tail
2608          recursion call can be ignored if we indeed use the tail recursion
2609          call expansion.  */
2610       int save_pending_stack_adjust = 0;
2611       int save_stack_pointer_delta = 0;
2612       rtx insns;
2613       rtx before_call, next_arg_reg;
2614
2615       if (pass == 0)
2616         {
2617           if (! try_tail_call)
2618             continue;
2619
2620           /* Emit any queued insns now; otherwise they would end up in
2621              only one of the alternates.  */
2622           emit_queue ();
2623
2624           /* State variables we need to save and restore between
2625              iterations.  */
2626           save_pending_stack_adjust = pending_stack_adjust;
2627           save_stack_pointer_delta = stack_pointer_delta;
2628         }
2629       if (pass)
2630         flags &= ~ECF_SIBCALL;
2631       else
2632         flags |= ECF_SIBCALL;
2633
2634       /* Other state variables that we must reinitialize each time
2635          through the loop (that are not initialized by the loop itself).  */
2636       argblock = 0;
2637       call_fusage = 0;
2638
2639       /* Start a new sequence for the normal call case.
2640
2641          From this point on, if the sibling call fails, we want to set
2642          sibcall_failure instead of continuing the loop.  */
2643       start_sequence ();
2644
2645       if (pass == 0)
2646         {
2647           /* We know at this point that there are not currently any
2648              pending cleanups.  If, however, in the process of evaluating
2649              the arguments we were to create some, we'll need to be
2650              able to get rid of them.  */
2651           expand_start_target_temps ();
2652         }
2653
2654       /* Don't let pending stack adjusts add up to too much.
2655          Also, do all pending adjustments now if there is any chance
2656          this might be a call to alloca or if we are expanding a sibling
2657          call sequence or if we are calling a function that is to return
2658          with stack pointer depressed.  */
2659       if (pending_stack_adjust >= 32
2660           || (pending_stack_adjust > 0
2661               && (flags & (ECF_MAY_BE_ALLOCA | ECF_SP_DEPRESSED)))
2662           || pass == 0)
2663         do_pending_stack_adjust ();
2664
2665       /* When calling a const function, we must pop the stack args right away,
2666          so that the pop is deleted or moved with the call.  */
2667       if (pass && (flags & ECF_LIBCALL_BLOCK))
2668         NO_DEFER_POP;
2669
2670 #ifdef FINAL_REG_PARM_STACK_SPACE
2671       reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
2672                                                          args_size.var);
2673 #endif
2674       /* Precompute any arguments as needed.  */
2675       if (pass)
2676         precompute_arguments (flags, num_actuals, args);
2677
2678       /* Now we are about to start emitting insns that can be deleted
2679          if a libcall is deleted.  */
2680       if (pass && (flags & (ECF_LIBCALL_BLOCK | ECF_MALLOC)))
2681         start_sequence ();
2682
2683       adjusted_args_size = args_size;
2684       /* Compute the actual size of the argument block required.  The variable
2685          and constant sizes must be combined, the size may have to be rounded,
2686          and there may be a minimum required size.  When generating a sibcall
2687          pattern, do not round up, since we'll be re-using whatever space our
2688          caller provided.  */
2689       unadjusted_args_size
2690         = compute_argument_block_size (reg_parm_stack_space,
2691                                        &adjusted_args_size,
2692                                        (pass == 0 ? 0
2693                                         : preferred_stack_boundary));
2694
2695       old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2696
2697       /* The argument block when performing a sibling call is the
2698          incoming argument block.  */
2699       if (pass == 0)
2700         {
2701           argblock = virtual_incoming_args_rtx;
2702           argblock
2703 #ifdef STACK_GROWS_DOWNWARD
2704             = plus_constant (argblock, current_function_pretend_args_size);
2705 #else
2706             = plus_constant (argblock, -current_function_pretend_args_size);
2707 #endif
2708           stored_args_map = sbitmap_alloc (args_size.constant);
2709           sbitmap_zero (stored_args_map);
2710         }
2711
2712       /* If we have no actual push instructions, or shouldn't use them,
2713          make space for all args right now.  */
2714       else if (adjusted_args_size.var != 0)
2715         {
2716           if (old_stack_level == 0)
2717             {
2718               emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2719               old_pending_adj = pending_stack_adjust;
2720               pending_stack_adjust = 0;
2721               /* stack_arg_under_construction says whether a stack arg is
2722                  being constructed at the old stack level.  Pushing the stack
2723                  gets a clean outgoing argument block.  */
2724               old_stack_arg_under_construction = stack_arg_under_construction;
2725               stack_arg_under_construction = 0;
2726             }
2727           argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2728         }
2729       else
2730         {
2731           /* Note that we must go through the motions of allocating an argument
2732              block even if the size is zero because we may be storing args
2733              in the area reserved for register arguments, which may be part of
2734              the stack frame.  */
2735
2736           int needed = adjusted_args_size.constant;
2737
2738           /* Store the maximum argument space used.  It will be pushed by
2739              the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2740              checking).  */
2741
2742           if (needed > current_function_outgoing_args_size)
2743             current_function_outgoing_args_size = needed;
2744
2745           if (must_preallocate)
2746             {
2747               if (ACCUMULATE_OUTGOING_ARGS)
2748                 {
2749                   /* Since the stack pointer will never be pushed, it is
2750                      possible for the evaluation of a parm to clobber
2751                      something we have already written to the stack.
2752                      Since most function calls on RISC machines do not use
2753                      the stack, this is uncommon, but must work correctly.
2754
2755                      Therefore, we save any area of the stack that was already
2756                      written and that we are using.  Here we set up to do this
2757                      by making a new stack usage map from the old one.  The
2758                      actual save will be done by store_one_arg.
2759
2760                      Another approach might be to try to reorder the argument
2761                      evaluations to avoid this conflicting stack usage.  */
2762
2763 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2764                   /* Since we will be writing into the entire argument area,
2765                      the map must be allocated for its entire size, not just
2766                      the part that is the responsibility of the caller.  */
2767                   needed += reg_parm_stack_space;
2768 #endif
2769
2770 #ifdef ARGS_GROW_DOWNWARD
2771                   highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2772                                                      needed + 1);
2773 #else
2774                   highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2775                                                      needed);
2776 #endif
2777                   stack_usage_map
2778                     = (char *) alloca (highest_outgoing_arg_in_use);
2779
2780                   if (initial_highest_arg_in_use)
2781                     memcpy (stack_usage_map, initial_stack_usage_map,
2782                             initial_highest_arg_in_use);
2783
2784                   if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2785                     memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2786                            (highest_outgoing_arg_in_use
2787                             - initial_highest_arg_in_use));
2788                   needed = 0;
2789
2790                   /* The address of the outgoing argument list must not be
2791                      copied to a register here, because argblock would be left
2792                      pointing to the wrong place after the call to
2793                      allocate_dynamic_stack_space below.  */
2794
2795                   argblock = virtual_outgoing_args_rtx;
2796                 }
2797               else
2798                 {
2799                   if (inhibit_defer_pop == 0)
2800                     {
2801                       /* Try to reuse some or all of the pending_stack_adjust
2802                          to get this space.  */
2803                       needed
2804                         = (combine_pending_stack_adjustment_and_call
2805                            (unadjusted_args_size,
2806                             &adjusted_args_size,
2807                             preferred_unit_stack_boundary));
2808
2809                       /* combine_pending_stack_adjustment_and_call computes
2810                          an adjustment before the arguments are allocated.
2811                          Account for them and see whether or not the stack
2812                          needs to go up or down.  */
2813                       needed = unadjusted_args_size - needed;
2814
2815                       if (needed < 0)
2816                         {
2817                           /* We're releasing stack space.  */
2818                           /* ??? We can avoid any adjustment at all if we're
2819                              already aligned.  FIXME.  */
2820                           pending_stack_adjust = -needed;
2821                           do_pending_stack_adjust ();
2822                           needed = 0;
2823                         }
2824                       else
2825                         /* We need to allocate space.  We'll do that in
2826                            push_block below.  */
2827                         pending_stack_adjust = 0;
2828                     }
2829
2830                   /* Special case this because overhead of `push_block' in
2831                      this case is non-trivial.  */
2832                   if (needed == 0)
2833                     argblock = virtual_outgoing_args_rtx;
2834                   else
2835                     argblock = push_block (GEN_INT (needed), 0, 0);
2836
2837                   /* We only really need to call `copy_to_reg' in the case
2838                      where push insns are going to be used to pass ARGBLOCK
2839                      to a function call in ARGS.  In that case, the stack
2840                      pointer changes value from the allocation point to the
2841                      call point, and hence the value of
2842                      VIRTUAL_OUTGOING_ARGS_RTX changes as well.  But might
2843                      as well always do it.  */
2844                   argblock = copy_to_reg (argblock);
2845
2846                   /* The save/restore code in store_one_arg handles all
2847                      cases except one: a constructor call (including a C
2848                      function returning a BLKmode struct) to initialize
2849                      an argument.  */
2850                   if (stack_arg_under_construction)
2851                     {
2852 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2853                       rtx push_size = GEN_INT (reg_parm_stack_space
2854                                                + adjusted_args_size.constant);
2855 #else
2856                       rtx push_size = GEN_INT (adjusted_args_size.constant);
2857 #endif
2858                       if (old_stack_level == 0)
2859                         {
2860                           emit_stack_save (SAVE_BLOCK, &old_stack_level,
2861                                            NULL_RTX);
2862                           old_pending_adj = pending_stack_adjust;
2863                           pending_stack_adjust = 0;
2864                           /* stack_arg_under_construction says whether a stack
2865                              arg is being constructed at the old stack level.
2866                              Pushing the stack gets a clean outgoing argument
2867                              block.  */
2868                           old_stack_arg_under_construction
2869                             = stack_arg_under_construction;
2870                           stack_arg_under_construction = 0;
2871                           /* Make a new map for the new argument list.  */
2872                           stack_usage_map = (char *)
2873                             alloca (highest_outgoing_arg_in_use);
2874                           memset (stack_usage_map, 0, highest_outgoing_arg_in_use);
2875                           highest_outgoing_arg_in_use = 0;
2876                         }
2877                       allocate_dynamic_stack_space (push_size, NULL_RTX,
2878                                                     BITS_PER_UNIT);
2879                     }
2880                   /* If argument evaluation might modify the stack pointer,
2881                      copy the address of the argument list to a register.  */
2882                   for (i = 0; i < num_actuals; i++)
2883                     if (args[i].pass_on_stack)
2884                       {
2885                         argblock = copy_addr_to_reg (argblock);
2886                         break;
2887                       }
2888                 }
2889             }
2890         }
2891
2892       compute_argument_addresses (args, argblock, num_actuals);
2893
2894       /* If we push args individually in reverse order, perform stack alignment
2895          before the first push (the last arg).  */
2896       if (PUSH_ARGS_REVERSED && argblock == 0
2897           && adjusted_args_size.constant != unadjusted_args_size)
2898         {
2899           /* When the stack adjustment is pending, we get better code
2900              by combining the adjustments.  */
2901           if (pending_stack_adjust
2902               && ! (flags & ECF_LIBCALL_BLOCK)
2903               && ! inhibit_defer_pop)
2904             {
2905               pending_stack_adjust
2906                 = (combine_pending_stack_adjustment_and_call
2907                    (unadjusted_args_size,
2908                     &adjusted_args_size,
2909                     preferred_unit_stack_boundary));
2910               do_pending_stack_adjust ();
2911             }
2912           else if (argblock == 0)
2913             anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2914                                         - unadjusted_args_size));
2915         }
2916       /* Now that the stack is properly aligned, pops can't safely
2917          be deferred during the evaluation of the arguments.  */
2918       NO_DEFER_POP;
2919
2920       funexp = rtx_for_function_call (fndecl, exp);
2921
2922       /* Figure out the register where the value, if any, will come back.  */
2923       valreg = 0;
2924       if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2925           && ! structure_value_addr)
2926         {
2927           if (pcc_struct_value)
2928             valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2929                                           fndecl, (pass == 0));
2930           else
2931             valreg = hard_function_value (TREE_TYPE (exp), fndecl, (pass == 0));
2932         }
2933
2934       /* Precompute all register parameters.  It isn't safe to compute anything
2935          once we have started filling any specific hard regs.  */
2936       precompute_register_parameters (num_actuals, args, &reg_parm_seen);
2937
2938 #ifdef REG_PARM_STACK_SPACE
2939       /* Save the fixed argument area if it's part of the caller's frame and
2940          is clobbered by argument setup for this call.  */
2941       if (ACCUMULATE_OUTGOING_ARGS && pass)
2942         save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2943                                               &low_to_save, &high_to_save);
2944 #endif
2945
2946       /* Now store (and compute if necessary) all non-register parms.
2947          These come before register parms, since they can require block-moves,
2948          which could clobber the registers used for register parms.
2949          Parms which have partial registers are not stored here,
2950          but we do preallocate space here if they want that.  */
2951
2952       for (i = 0; i < num_actuals; i++)
2953         if (args[i].reg == 0 || args[i].pass_on_stack)
2954           {
2955             rtx before_arg = get_last_insn ();
2956
2957             if (store_one_arg (&args[i], argblock, flags,
2958                                adjusted_args_size.var != 0,
2959                                reg_parm_stack_space)
2960                 || (pass == 0
2961                     && check_sibcall_argument_overlap (before_arg,
2962                                                        &args[i])))
2963               sibcall_failure = 1;
2964           }
2965
2966       /* If we have a parm that is passed in registers but not in memory
2967          and whose alignment does not permit a direct copy into registers,
2968          make a group of pseudos that correspond to each register that we
2969          will later fill.  */
2970       if (STRICT_ALIGNMENT)
2971         store_unaligned_arguments_into_pseudos (args, num_actuals);
2972
2973       /* Now store any partially-in-registers parm.
2974          This is the last place a block-move can happen.  */
2975       if (reg_parm_seen)
2976         for (i = 0; i < num_actuals; i++)
2977           if (args[i].partial != 0 && ! args[i].pass_on_stack)
2978             {
2979               rtx before_arg = get_last_insn ();
2980
2981               if (store_one_arg (&args[i], argblock, flags,
2982                                  adjusted_args_size.var != 0,
2983                                  reg_parm_stack_space)
2984                   || (pass == 0
2985                       && check_sibcall_argument_overlap (before_arg,
2986                                                          &args[i])))
2987                 sibcall_failure = 1;
2988             }
2989
2990       /* If we pushed args in forward order, perform stack alignment
2991          after pushing the last arg.  */
2992       if (!PUSH_ARGS_REVERSED && argblock == 0)
2993         anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2994                                     - unadjusted_args_size));
2995
2996       /* If register arguments require space on the stack and stack space
2997          was not preallocated, allocate stack space here for arguments
2998          passed in registers.  */
2999 #ifdef OUTGOING_REG_PARM_STACK_SPACE
3000       if (!ACCUMULATE_OUTGOING_ARGS
3001           && must_preallocate == 0 && reg_parm_stack_space > 0)
3002         anti_adjust_stack (GEN_INT (reg_parm_stack_space));
3003 #endif
3004
3005       /* Pass the function the address in which to return a
3006          structure value.  */
3007       if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
3008         {
3009           emit_move_insn (struct_value_rtx,
3010                           force_reg (Pmode,
3011                                      force_operand (structure_value_addr,
3012                                                     NULL_RTX)));
3013
3014           if (GET_CODE (struct_value_rtx) == REG)
3015             use_reg (&call_fusage, struct_value_rtx);
3016         }
3017
3018       funexp = prepare_call_address (funexp, fndecl, &call_fusage,
3019                                      reg_parm_seen, pass == 0);
3020
3021       load_register_parameters (args, num_actuals, &call_fusage, flags);
3022
3023       /* Perform postincrements before actually calling the function.  */
3024       emit_queue ();
3025
3026       /* Save a pointer to the last insn before the call, so that we can
3027          later safely search backwards to find the CALL_INSN.  */
3028       before_call = get_last_insn ();
3029
3030       /* Set up next argument register.  For sibling calls on machines
3031          with register windows this should be the incoming register.  */
3032 #ifdef FUNCTION_INCOMING_ARG
3033       if (pass == 0)
3034         next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
3035                                               void_type_node, 1);
3036       else
3037 #endif
3038         next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
3039                                      void_type_node, 1);
3040
3041       /* All arguments and registers used for the call must be set up by
3042          now!  */
3043
3044       /* Stack must be properly aligned now.  */
3045       if (pass && stack_pointer_delta % preferred_unit_stack_boundary)
3046         abort ();
3047
3048       /* Generate the actual call instruction.  */
3049       emit_call_1 (funexp, fndecl, funtype, unadjusted_args_size,
3050                    adjusted_args_size.constant, struct_value_size,
3051                    next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
3052                    flags, & args_so_far);
3053
3054       /* Verify that we've deallocated all the stack we used.  */
3055       if (pass
3056           && old_stack_allocated != stack_pointer_delta - pending_stack_adjust)
3057         abort ();
3058
3059       /* If call is cse'able, make appropriate pair of reg-notes around it.
3060          Test valreg so we don't crash; may safely ignore `const'
3061          if return type is void.  Disable for PARALLEL return values, because
3062          we have no way to move such values into a pseudo register.  */
3063       if (pass && (flags & ECF_LIBCALL_BLOCK))
3064         {
3065           rtx insns;
3066
3067           if (valreg == 0 || GET_CODE (valreg) == PARALLEL)
3068             {
3069               insns = get_insns ();
3070               end_sequence ();
3071               emit_insn (insns);
3072             }
3073           else
3074             {
3075               rtx note = 0;
3076               rtx temp = gen_reg_rtx (GET_MODE (valreg));
3077
3078               /* Mark the return value as a pointer if needed.  */
3079               if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3080                 mark_reg_pointer (temp,
3081                                   TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))));
3082
3083               /* Construct an "equal form" for the value which mentions all the
3084                  arguments in order as well as the function name.  */
3085               for (i = 0; i < num_actuals; i++)
3086                 note = gen_rtx_EXPR_LIST (VOIDmode,
3087                                           args[i].initial_value, note);
3088               note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note);
3089
3090               insns = get_insns ();
3091               end_sequence ();
3092
3093               if (flags & ECF_PURE)
3094                 note = gen_rtx_EXPR_LIST (VOIDmode,
3095                         gen_rtx_USE (VOIDmode,
3096                                      gen_rtx_MEM (BLKmode,
3097                                                   gen_rtx_SCRATCH (VOIDmode))),
3098                         note);
3099
3100               emit_libcall_block (insns, temp, valreg, note);
3101
3102               valreg = temp;
3103             }
3104         }
3105       else if (pass && (flags & ECF_MALLOC))
3106         {
3107           rtx temp = gen_reg_rtx (GET_MODE (valreg));
3108           rtx last, insns;
3109
3110           /* The return value from a malloc-like function is a pointer.  */
3111           if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3112             mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
3113
3114           emit_move_insn (temp, valreg);
3115
3116           /* The return value from a malloc-like function can not alias
3117              anything else.  */
3118           last = get_last_insn ();
3119           REG_NOTES (last) =
3120             gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last));
3121
3122           /* Write out the sequence.  */
3123           insns = get_insns ();
3124           end_sequence ();
3125           emit_insn (insns);
3126           valreg = temp;
3127         }
3128
3129       /* For calls to `setjmp', etc., inform flow.c it should complain
3130          if nonvolatile values are live.  For functions that cannot return,
3131          inform flow that control does not fall through.  */
3132
3133       if ((flags & (ECF_NORETURN | ECF_LONGJMP)) || pass == 0)
3134         {
3135           /* The barrier must be emitted
3136              immediately after the CALL_INSN.  Some ports emit more
3137              than just a CALL_INSN above, so we must search for it here.  */
3138
3139           rtx last = get_last_insn ();
3140           while (GET_CODE (last) != CALL_INSN)
3141             {
3142               last = PREV_INSN (last);
3143               /* There was no CALL_INSN?  */
3144               if (last == before_call)
3145                 abort ();
3146             }
3147
3148           emit_barrier_after (last);
3149         }
3150
3151       if (flags & ECF_LONGJMP)
3152         current_function_calls_longjmp = 1;
3153
3154       /* If this function is returning into a memory location marked as
3155          readonly, it means it is initializing that location.  But we normally
3156          treat functions as not clobbering such locations, so we need to
3157          specify that this one does.  */
3158       if (target != 0 && GET_CODE (target) == MEM
3159           && structure_value_addr != 0 && RTX_UNCHANGING_P (target))
3160         emit_insn (gen_rtx_CLOBBER (VOIDmode, target));
3161
3162       /* If value type not void, return an rtx for the value.  */
3163
3164       /* If there are cleanups to be called, don't use a hard reg as target.
3165          We need to double check this and see if it matters anymore.  */
3166       if (any_pending_cleanups (1))
3167         {
3168           if (target && REG_P (target)
3169               && REGNO (target) < FIRST_PSEUDO_REGISTER)
3170             target = 0;
3171           sibcall_failure = 1;
3172         }
3173
3174       if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
3175           || ignore)
3176         target = const0_rtx;
3177       else if (structure_value_addr)
3178         {
3179           if (target == 0 || GET_CODE (target) != MEM)
3180             {
3181               target
3182                 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3183                                memory_address (TYPE_MODE (TREE_TYPE (exp)),
3184                                                structure_value_addr));
3185               set_mem_attributes (target, exp, 1);
3186             }
3187         }
3188       else if (pcc_struct_value)
3189         {
3190           /* This is the special C++ case where we need to
3191              know what the true target was.  We take care to
3192              never use this value more than once in one expression.  */
3193           target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3194                                 copy_to_reg (valreg));
3195           set_mem_attributes (target, exp, 1);
3196         }
3197       /* Handle calls that return values in multiple non-contiguous locations.
3198          The Irix 6 ABI has examples of this.  */
3199       else if (GET_CODE (valreg) == PARALLEL)
3200         {
3201           if (target == 0)
3202             {
3203               /* This will only be assigned once, so it can be readonly.  */
3204               tree nt = build_qualified_type (TREE_TYPE (exp),
3205                                               (TYPE_QUALS (TREE_TYPE (exp))
3206                                                | TYPE_QUAL_CONST));
3207
3208               target = assign_temp (nt, 0, 1, 1);
3209               preserve_temp_slots (target);
3210             }
3211
3212           if (! rtx_equal_p (target, valreg))
3213             emit_group_store (target, valreg,
3214                               int_size_in_bytes (TREE_TYPE (exp)));
3215
3216           /* We can not support sibling calls for this case.  */
3217           sibcall_failure = 1;
3218         }
3219       else if (target
3220                && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
3221                && GET_MODE (target) == GET_MODE (valreg))
3222         {
3223           /* TARGET and VALREG cannot be equal at this point because the
3224              latter would not have REG_FUNCTION_VALUE_P true, while the
3225              former would if it were referring to the same register.
3226
3227              If they refer to the same register, this move will be a no-op,
3228              except when function inlining is being done.  */
3229           emit_move_insn (target, valreg);
3230         }
3231       else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
3232         {
3233           target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
3234
3235           /* We can not support sibling calls for this case.  */
3236           sibcall_failure = 1;
3237         }
3238       else
3239         target = copy_to_reg (valreg);
3240
3241 #ifdef PROMOTE_FUNCTION_RETURN
3242       /* If we promoted this return value, make the proper SUBREG.  TARGET
3243          might be const0_rtx here, so be careful.  */
3244       if (GET_CODE (target) == REG
3245           && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
3246           && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
3247         {
3248           tree type = TREE_TYPE (exp);
3249           int unsignedp = TREE_UNSIGNED (type);
3250           int offset = 0;
3251
3252           /* If we don't promote as expected, something is wrong.  */
3253           if (GET_MODE (target)
3254               != promote_mode (type, TYPE_MODE (type), &unsignedp, 1))
3255             abort ();
3256
3257         if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3258             && GET_MODE_SIZE (GET_MODE (target))
3259                > GET_MODE_SIZE (TYPE_MODE (type)))
3260           {
3261             offset = GET_MODE_SIZE (GET_MODE (target))
3262                      - GET_MODE_SIZE (TYPE_MODE (type));
3263             if (! BYTES_BIG_ENDIAN)
3264               offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3265             else if (! WORDS_BIG_ENDIAN)
3266               offset %= UNITS_PER_WORD;
3267           }
3268           target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3269           SUBREG_PROMOTED_VAR_P (target) = 1;
3270           SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3271         }
3272 #endif
3273
3274       /* If size of args is variable or this was a constructor call for a stack
3275          argument, restore saved stack-pointer value.  */
3276
3277       if (old_stack_level && ! (flags & ECF_SP_DEPRESSED))
3278         {
3279           emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3280           pending_stack_adjust = old_pending_adj;
3281           stack_arg_under_construction = old_stack_arg_under_construction;
3282           highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3283           stack_usage_map = initial_stack_usage_map;
3284           sibcall_failure = 1;
3285         }
3286       else if (ACCUMULATE_OUTGOING_ARGS && pass)
3287         {
3288 #ifdef REG_PARM_STACK_SPACE
3289           if (save_area)
3290             {
3291               restore_fixed_argument_area (save_area, argblock,
3292                                            high_to_save, low_to_save);
3293             }
3294 #endif
3295
3296           /* If we saved any argument areas, restore them.  */
3297           for (i = 0; i < num_actuals; i++)
3298             if (args[i].save_area)
3299               {
3300                 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3301                 rtx stack_area
3302                   = gen_rtx_MEM (save_mode,
3303                                  memory_address (save_mode,
3304                                                  XEXP (args[i].stack_slot, 0)));
3305
3306                 if (save_mode != BLKmode)
3307                   emit_move_insn (stack_area, args[i].save_area);
3308                 else
3309                   emit_block_move (stack_area, args[i].save_area,
3310                                    GEN_INT (args[i].size.constant),
3311                                    BLOCK_OP_CALL_PARM);
3312               }
3313
3314           highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3315           stack_usage_map = initial_stack_usage_map;
3316         }
3317
3318       /* If this was alloca, record the new stack level for nonlocal gotos.
3319          Check for the handler slots since we might not have a save area
3320          for non-local gotos.  */
3321
3322       if ((flags & ECF_MAY_BE_ALLOCA) && nonlocal_goto_handler_slots != 0)
3323         emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
3324
3325       /* Free up storage we no longer need.  */
3326       for (i = 0; i < num_actuals; ++i)
3327         if (args[i].aligned_regs)
3328           free (args[i].aligned_regs);
3329
3330       if (pass == 0)
3331         {
3332           /* Undo the fake expand_start_target_temps we did earlier.  If
3333              there had been any cleanups created, we've already set
3334              sibcall_failure.  */
3335           expand_end_target_temps ();
3336         }
3337
3338       insns = get_insns ();
3339       end_sequence ();
3340
3341       if (pass == 0)
3342         {
3343           tail_call_insns = insns;
3344
3345           /* Restore the pending stack adjustment now that we have
3346              finished generating the sibling call sequence.  */
3347
3348           pending_stack_adjust = save_pending_stack_adjust;
3349           stack_pointer_delta = save_stack_pointer_delta;
3350
3351           /* Prepare arg structure for next iteration.  */
3352           for (i = 0; i < num_actuals; i++)
3353             {
3354               args[i].value = 0;
3355               args[i].aligned_regs = 0;
3356               args[i].stack = 0;
3357             }
3358
3359           sbitmap_free (stored_args_map);
3360         }
3361       else
3362         normal_call_insns = insns;
3363
3364       /* If something prevents making this a sibling call,
3365          zero out the sequence.  */
3366       if (sibcall_failure)
3367         tail_call_insns = NULL_RTX;
3368     }
3369
3370   /* The function optimize_sibling_and_tail_recursive_calls doesn't
3371      handle CALL_PLACEHOLDERs inside other CALL_PLACEHOLDERs.  This
3372      can happen if the arguments to this function call an inline
3373      function who's expansion contains another CALL_PLACEHOLDER.
3374
3375      If there are any C_Ps in any of these sequences, replace them
3376      with their normal call.  */
3377
3378   for (insn = normal_call_insns; insn; insn = NEXT_INSN (insn))
3379     if (GET_CODE (insn) == CALL_INSN
3380         && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3381       replace_call_placeholder (insn, sibcall_use_normal);
3382
3383   for (insn = tail_call_insns; insn; insn = NEXT_INSN (insn))
3384     if (GET_CODE (insn) == CALL_INSN
3385         && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3386       replace_call_placeholder (insn, sibcall_use_normal);
3387
3388   for (insn = tail_recursion_insns; insn; insn = NEXT_INSN (insn))
3389     if (GET_CODE (insn) == CALL_INSN
3390         && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3391       replace_call_placeholder (insn, sibcall_use_normal);
3392
3393   /* If this was a potential tail recursion site, then emit a
3394      CALL_PLACEHOLDER with the normal and the tail recursion streams.
3395      One of them will be selected later.  */
3396   if (tail_recursion_insns || tail_call_insns)
3397     {
3398       /* The tail recursion label must be kept around.  We could expose
3399          its use in the CALL_PLACEHOLDER, but that creates unwanted edges
3400          and makes determining true tail recursion sites difficult.
3401
3402          So we set LABEL_PRESERVE_P here, then clear it when we select
3403          one of the call sequences after rtl generation is complete.  */
3404       if (tail_recursion_insns)
3405         LABEL_PRESERVE_P (tail_recursion_label) = 1;
3406       emit_call_insn (gen_rtx_CALL_PLACEHOLDER (VOIDmode, normal_call_insns,
3407                                                 tail_call_insns,
3408                                                 tail_recursion_insns,
3409                                                 tail_recursion_label));
3410     }
3411   else
3412     emit_insn (normal_call_insns);
3413
3414   currently_expanding_call--;
3415
3416   /* If this function returns with the stack pointer depressed, ensure
3417      this block saves and restores the stack pointer, show it was
3418      changed, and adjust for any outgoing arg space.  */
3419   if (flags & ECF_SP_DEPRESSED)
3420     {
3421       clear_pending_stack_adjust ();
3422       emit_insn (gen_rtx (CLOBBER, VOIDmode, stack_pointer_rtx));
3423       emit_move_insn (virtual_stack_dynamic_rtx, stack_pointer_rtx);
3424       save_stack_pointer ();
3425     }
3426
3427   return target;
3428 }
3429 \f
3430 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3431    The RETVAL parameter specifies whether return value needs to be saved, other
3432    parameters are documented in the emit_library_call function below.  */
3433
3434 static rtx
3435 emit_library_call_value_1 (retval, orgfun, value, fn_type, outmode, nargs, p)
3436      int retval;
3437      rtx orgfun;
3438      rtx value;
3439      enum libcall_type fn_type;
3440      enum machine_mode outmode;
3441      int nargs;
3442      va_list p;
3443 {
3444   /* Total size in bytes of all the stack-parms scanned so far.  */
3445   struct args_size args_size;
3446   /* Size of arguments before any adjustments (such as rounding).  */
3447   struct args_size original_args_size;
3448   int argnum;
3449   rtx fun;
3450   int inc;
3451   int count;
3452   struct args_size alignment_pad;
3453   rtx argblock = 0;
3454   CUMULATIVE_ARGS args_so_far;
3455   struct arg
3456   {
3457     rtx value;
3458     enum machine_mode mode;
3459     rtx reg;
3460     int partial;
3461     struct args_size offset;
3462     struct args_size size;
3463     rtx save_area;
3464   };
3465   struct arg *argvec;
3466   int old_inhibit_defer_pop = inhibit_defer_pop;
3467   rtx call_fusage = 0;
3468   rtx mem_value = 0;
3469   rtx valreg;
3470   int pcc_struct_value = 0;
3471   int struct_value_size = 0;
3472   int flags;
3473   int reg_parm_stack_space = 0;
3474   int needed;
3475   rtx before_call;
3476   tree tfom;                    /* type_for_mode (outmode, 0) */
3477
3478 #ifdef REG_PARM_STACK_SPACE
3479   /* Define the boundary of the register parm stack space that needs to be
3480      save, if any.  */
3481   int low_to_save = -1, high_to_save = 0;
3482   rtx save_area = 0;            /* Place that it is saved.  */
3483 #endif
3484
3485   /* Size of the stack reserved for parameter registers.  */
3486   int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3487   char *initial_stack_usage_map = stack_usage_map;
3488
3489 #ifdef REG_PARM_STACK_SPACE
3490 #ifdef MAYBE_REG_PARM_STACK_SPACE
3491   reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
3492 #else
3493   reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3494 #endif
3495 #endif
3496
3497   /* By default, library functions can not throw.  */
3498   flags = ECF_NOTHROW;
3499
3500   switch (fn_type)
3501     {
3502     case LCT_NORMAL:
3503       break;
3504     case LCT_CONST:
3505       flags |= ECF_CONST;
3506       break;
3507     case LCT_PURE:
3508       flags |= ECF_PURE;
3509       break;
3510     case LCT_CONST_MAKE_BLOCK:
3511       flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
3512       break;
3513     case LCT_PURE_MAKE_BLOCK:
3514       flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
3515       break;
3516     case LCT_NORETURN:
3517       flags |= ECF_NORETURN;
3518       break;
3519     case LCT_THROW:
3520       flags = ECF_NORETURN;
3521       break;
3522     case LCT_ALWAYS_RETURN:
3523       flags = ECF_ALWAYS_RETURN;
3524       break;
3525     case LCT_RETURNS_TWICE:
3526       flags = ECF_RETURNS_TWICE;
3527       break;
3528     }
3529   fun = orgfun;
3530
3531   /* Ensure current function's preferred stack boundary is at least
3532      what we need.  */
3533   if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3534     cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3535
3536   /* If this kind of value comes back in memory,
3537      decide where in memory it should come back.  */
3538   if (outmode != VOIDmode)
3539     {
3540       tfom = (*lang_hooks.types.type_for_mode) (outmode, 0);
3541       if (aggregate_value_p (tfom))
3542         {
3543 #ifdef PCC_STATIC_STRUCT_RETURN
3544           rtx pointer_reg
3545             = hard_function_value (build_pointer_type (tfom), 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 (tfom, 0, 1, 1);
3556 #endif
3557           /* This call returns a big structure.  */
3558           flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3559         }
3560     }
3561   else
3562     tfom = void_type_node;
3563
3564   /* ??? Unfinished: must pass the memory address as an argument.  */
3565
3566   /* Copy all the libcall-arguments out of the varargs data
3567      and into a vector ARGVEC.
3568
3569      Compute how to pass each argument.  We only support a very small subset
3570      of the full argument passing conventions to limit complexity here since
3571      library functions shouldn't have many args.  */
3572
3573   argvec = (struct arg *) alloca ((nargs + 1) * sizeof (struct arg));
3574   memset ((char *) argvec, 0, (nargs + 1) * sizeof (struct arg));
3575
3576 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3577   INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3578 #else
3579   INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0);
3580 #endif
3581
3582   args_size.constant = 0;
3583   args_size.var = 0;
3584
3585   count = 0;
3586
3587   /* Now we are about to start emitting insns that can be deleted
3588      if a libcall is deleted.  */
3589   if (flags & ECF_LIBCALL_BLOCK)
3590     start_sequence ();
3591
3592   push_temp_slots ();
3593
3594   /* If there's a structure value address to be passed,
3595      either pass it in the special place, or pass it as an extra argument.  */
3596   if (mem_value && struct_value_rtx == 0 && ! pcc_struct_value)
3597     {
3598       rtx addr = XEXP (mem_value, 0);
3599       nargs++;
3600
3601       /* Make sure it is a reasonable operand for a move or push insn.  */
3602       if (GET_CODE (addr) != REG && GET_CODE (addr) != MEM
3603           && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3604         addr = force_operand (addr, NULL_RTX);
3605
3606       argvec[count].value = addr;
3607       argvec[count].mode = Pmode;
3608       argvec[count].partial = 0;
3609
3610       argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3611 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3612       if (FUNCTION_ARG_PARTIAL_NREGS (args_so_far, Pmode, NULL_TREE, 1))
3613         abort ();
3614 #endif
3615
3616       locate_and_pad_parm (Pmode, NULL_TREE,
3617 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3618                            1,
3619 #else
3620                            argvec[count].reg != 0,
3621 #endif
3622                            NULL_TREE, &args_size, &argvec[count].offset,
3623                            &argvec[count].size, &alignment_pad);
3624
3625       if (argvec[count].reg == 0 || argvec[count].partial != 0
3626           || reg_parm_stack_space > 0)
3627         args_size.constant += argvec[count].size.constant;
3628
3629       FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3630
3631       count++;
3632     }
3633
3634   for (; count < nargs; count++)
3635     {
3636       rtx val = va_arg (p, rtx);
3637       enum machine_mode mode = va_arg (p, enum machine_mode);
3638
3639       /* We cannot convert the arg value to the mode the library wants here;
3640          must do it earlier where we know the signedness of the arg.  */
3641       if (mode == BLKmode
3642           || (GET_MODE (val) != mode && GET_MODE (val) != VOIDmode))
3643         abort ();
3644
3645       /* On some machines, there's no way to pass a float to a library fcn.
3646          Pass it as a double instead.  */
3647 #ifdef LIBGCC_NEEDS_DOUBLE
3648       if (LIBGCC_NEEDS_DOUBLE && mode == SFmode)
3649         val = convert_modes (DFmode, SFmode, val, 0), mode = DFmode;
3650 #endif
3651
3652       /* There's no need to call protect_from_queue, because
3653          either emit_move_insn or emit_push_insn will do that.  */
3654
3655       /* Make sure it is a reasonable operand for a move or push insn.  */
3656       if (GET_CODE (val) != REG && GET_CODE (val) != MEM
3657           && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3658         val = force_operand (val, NULL_RTX);
3659
3660 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
3661       if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, mode, NULL_TREE, 1))
3662         {
3663           rtx slot;
3664           int must_copy = 1
3665 #ifdef FUNCTION_ARG_CALLEE_COPIES
3666             && ! FUNCTION_ARG_CALLEE_COPIES (args_so_far, mode,
3667                                              NULL_TREE, 1)
3668 #endif
3669             ;
3670
3671           /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure
3672              functions, so we have to pretend this isn't such a function.  */
3673           if (flags & ECF_LIBCALL_BLOCK)
3674             {
3675               rtx insns = get_insns ();
3676               end_sequence ();
3677               emit_insn (insns);
3678             }
3679           flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3680
3681           /* If this was a CONST function, it is now PURE since
3682              it now reads memory.  */
3683           if (flags & ECF_CONST)
3684             {
3685               flags &= ~ECF_CONST;
3686               flags |= ECF_PURE;
3687             }
3688
3689           if (GET_MODE (val) == MEM && ! must_copy)
3690             slot = val;
3691           else if (must_copy)
3692             {
3693               slot = assign_temp ((*lang_hooks.types.type_for_mode) (mode, 0),
3694                                   0, 1, 1);
3695               emit_move_insn (slot, val);
3696             }
3697           else
3698             {
3699               tree type = (*lang_hooks.types.type_for_mode) (mode, 0);
3700
3701               slot = gen_rtx_MEM (mode,
3702                                   expand_expr (build1 (ADDR_EXPR,
3703                                                        build_pointer_type
3704                                                        (type),
3705                                                        make_tree (type, val)),
3706                                                NULL_RTX, VOIDmode, 0));
3707             }
3708
3709           call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3710                                            gen_rtx_USE (VOIDmode, slot),
3711                                            call_fusage);
3712           if (must_copy)
3713             call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3714                                              gen_rtx_CLOBBER (VOIDmode,
3715                                                               slot),
3716                                              call_fusage);
3717
3718           mode = Pmode;
3719           val = force_operand (XEXP (slot, 0), NULL_RTX);
3720         }
3721 #endif
3722
3723       argvec[count].value = val;
3724       argvec[count].mode = mode;
3725
3726       argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3727
3728 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3729       argvec[count].partial
3730         = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode, NULL_TREE, 1);
3731 #else
3732       argvec[count].partial = 0;
3733 #endif
3734
3735       locate_and_pad_parm (mode, NULL_TREE,
3736 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3737                            1,
3738 #else
3739                            argvec[count].reg != 0,
3740 #endif
3741                            NULL_TREE, &args_size, &argvec[count].offset,
3742                            &argvec[count].size, &alignment_pad);
3743
3744       if (argvec[count].size.var)
3745         abort ();
3746
3747       if (reg_parm_stack_space == 0 && argvec[count].partial)
3748         argvec[count].size.constant -= argvec[count].partial * UNITS_PER_WORD;
3749
3750       if (argvec[count].reg == 0 || argvec[count].partial != 0
3751           || reg_parm_stack_space > 0)
3752         args_size.constant += argvec[count].size.constant;
3753
3754       FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3755     }
3756
3757 #ifdef FINAL_REG_PARM_STACK_SPACE
3758   reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
3759                                                      args_size.var);
3760 #endif
3761   /* If this machine requires an external definition for library
3762      functions, write one out.  */
3763   assemble_external_libcall (fun);
3764
3765   original_args_size = args_size;
3766   args_size.constant = (((args_size.constant
3767                           + stack_pointer_delta
3768                           + STACK_BYTES - 1)
3769                           / STACK_BYTES
3770                           * STACK_BYTES)
3771                          - stack_pointer_delta);
3772
3773   args_size.constant = MAX (args_size.constant,
3774                             reg_parm_stack_space);
3775
3776 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3777   args_size.constant -= reg_parm_stack_space;
3778 #endif
3779
3780   if (args_size.constant > current_function_outgoing_args_size)
3781     current_function_outgoing_args_size = args_size.constant;
3782
3783   if (ACCUMULATE_OUTGOING_ARGS)
3784     {
3785       /* Since the stack pointer will never be pushed, it is possible for
3786          the evaluation of a parm to clobber something we have already
3787          written to the stack.  Since most function calls on RISC machines
3788          do not use the stack, this is uncommon, but must work correctly.
3789
3790          Therefore, we save any area of the stack that was already written
3791          and that we are using.  Here we set up to do this by making a new
3792          stack usage map from the old one.
3793
3794          Another approach might be to try to reorder the argument
3795          evaluations to avoid this conflicting stack usage.  */
3796
3797       needed = args_size.constant;
3798
3799 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3800       /* Since we will be writing into the entire argument area, the
3801          map must be allocated for its entire size, not just the part that
3802          is the responsibility of the caller.  */
3803       needed += reg_parm_stack_space;
3804 #endif
3805
3806 #ifdef ARGS_GROW_DOWNWARD
3807       highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3808                                          needed + 1);
3809 #else
3810       highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3811                                          needed);
3812 #endif
3813       stack_usage_map = (char *) alloca (highest_outgoing_arg_in_use);
3814
3815       if (initial_highest_arg_in_use)
3816         memcpy (stack_usage_map, initial_stack_usage_map,
3817                 initial_highest_arg_in_use);
3818
3819       if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3820         memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3821                highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3822       needed = 0;
3823
3824       /* We must be careful to use virtual regs before they're instantiated,
3825          and real regs afterwards.  Loop optimization, for example, can create
3826          new libcalls after we've instantiated the virtual regs, and if we
3827          use virtuals anyway, they won't match the rtl patterns.  */
3828
3829       if (virtuals_instantiated)
3830         argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3831       else
3832         argblock = virtual_outgoing_args_rtx;
3833     }
3834   else
3835     {
3836       if (!PUSH_ARGS)
3837         argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3838     }
3839
3840   /* If we push args individually in reverse order, perform stack alignment
3841      before the first push (the last arg).  */
3842   if (argblock == 0 && PUSH_ARGS_REVERSED)
3843     anti_adjust_stack (GEN_INT (args_size.constant
3844                                 - original_args_size.constant));
3845
3846   if (PUSH_ARGS_REVERSED)
3847     {
3848       inc = -1;
3849       argnum = nargs - 1;
3850     }
3851   else
3852     {
3853       inc = 1;
3854       argnum = 0;
3855     }
3856
3857 #ifdef REG_PARM_STACK_SPACE
3858   if (ACCUMULATE_OUTGOING_ARGS)
3859     {
3860       /* The argument list is the property of the called routine and it
3861          may clobber it.  If the fixed area has been used for previous
3862          parameters, we must save and restore it.
3863
3864          Here we compute the boundary of the that needs to be saved, if any.  */
3865
3866 #ifdef ARGS_GROW_DOWNWARD
3867       for (count = 0; count < reg_parm_stack_space + 1; count++)
3868 #else
3869       for (count = 0; count < reg_parm_stack_space; count++)
3870 #endif
3871         {
3872           if (count >= highest_outgoing_arg_in_use
3873               || stack_usage_map[count] == 0)
3874             continue;
3875
3876           if (low_to_save == -1)
3877             low_to_save = count;
3878
3879           high_to_save = count;
3880         }
3881
3882       if (low_to_save >= 0)
3883         {
3884           int num_to_save = high_to_save - low_to_save + 1;
3885           enum machine_mode save_mode
3886             = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
3887           rtx stack_area;
3888
3889           /* If we don't have the required alignment, must do this in BLKmode.  */
3890           if ((low_to_save & (MIN (GET_MODE_SIZE (save_mode),
3891                                    BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
3892             save_mode = BLKmode;
3893
3894 #ifdef ARGS_GROW_DOWNWARD
3895           stack_area = gen_rtx_MEM (save_mode,
3896                                     memory_address (save_mode,
3897                                                     plus_constant (argblock,
3898                                                                    -high_to_save)));
3899 #else
3900           stack_area = gen_rtx_MEM (save_mode,
3901                                     memory_address (save_mode,
3902                                                     plus_constant (argblock,
3903                                                                    low_to_save)));
3904 #endif
3905           if (save_mode == BLKmode)
3906             {
3907               save_area = assign_stack_temp (BLKmode, num_to_save, 0);
3908               set_mem_align (save_area, PARM_BOUNDARY);
3909               emit_block_move (save_area, stack_area, GEN_INT (num_to_save),
3910                                BLOCK_OP_CALL_PARM);
3911             }
3912           else
3913             {
3914               save_area = gen_reg_rtx (save_mode);
3915               emit_move_insn (save_area, stack_area);
3916             }
3917         }
3918     }
3919 #endif
3920
3921   /* Push the args that need to be pushed.  */
3922
3923   /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3924      are to be pushed.  */
3925   for (count = 0; count < nargs; count++, argnum += inc)
3926     {
3927       enum machine_mode mode = argvec[argnum].mode;
3928       rtx val = argvec[argnum].value;
3929       rtx reg = argvec[argnum].reg;
3930       int partial = argvec[argnum].partial;
3931       int lower_bound = 0, upper_bound = 0, i;
3932
3933       if (! (reg != 0 && partial == 0))
3934         {
3935           if (ACCUMULATE_OUTGOING_ARGS)
3936             {
3937               /* If this is being stored into a pre-allocated, fixed-size,
3938                  stack area, save any previous data at that location.  */
3939
3940 #ifdef ARGS_GROW_DOWNWARD
3941               /* stack_slot is negative, but we want to index stack_usage_map
3942                  with positive values.  */
3943               upper_bound = -argvec[argnum].offset.constant + 1;
3944               lower_bound = upper_bound - argvec[argnum].size.constant;
3945 #else
3946               lower_bound = argvec[argnum].offset.constant;
3947               upper_bound = lower_bound + argvec[argnum].size.constant;
3948 #endif
3949
3950               for (i = lower_bound; i < upper_bound; i++)
3951                 if (stack_usage_map[i]
3952                     /* Don't store things in the fixed argument area at this
3953                        point; it has already been saved.  */
3954                     && i > reg_parm_stack_space)
3955                   break;
3956
3957               if (i != upper_bound)
3958                 {
3959                   /* We need to make a save area.  See what mode we can make
3960                      it.  */
3961                   enum machine_mode save_mode
3962                     = mode_for_size (argvec[argnum].size.constant
3963                                      * BITS_PER_UNIT,
3964                                      MODE_INT, 1);
3965                   rtx stack_area
3966                     = gen_rtx_MEM
3967                       (save_mode,
3968                        memory_address
3969                        (save_mode,
3970                         plus_constant (argblock,
3971                                        argvec[argnum].offset.constant)));
3972                   argvec[argnum].save_area = gen_reg_rtx (save_mode);
3973
3974                   emit_move_insn (argvec[argnum].save_area, stack_area);
3975                 }
3976             }
3977
3978           emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
3979                           partial, reg, 0, argblock,
3980                           GEN_INT (argvec[argnum].offset.constant),
3981                           reg_parm_stack_space, ARGS_SIZE_RTX (alignment_pad));
3982
3983           /* Now mark the segment we just used.  */
3984           if (ACCUMULATE_OUTGOING_ARGS)
3985             for (i = lower_bound; i < upper_bound; i++)
3986               stack_usage_map[i] = 1;
3987
3988           NO_DEFER_POP;
3989         }
3990     }
3991
3992   /* If we pushed args in forward order, perform stack alignment
3993      after pushing the last arg.  */
3994   if (argblock == 0 && !PUSH_ARGS_REVERSED)
3995     anti_adjust_stack (GEN_INT (args_size.constant
3996                                 - original_args_size.constant));
3997
3998   if (PUSH_ARGS_REVERSED)
3999     argnum = nargs - 1;
4000   else
4001     argnum = 0;
4002
4003   fun = prepare_call_address (fun, NULL_TREE, &call_fusage, 0, 0);
4004
4005   /* Now load any reg parms into their regs.  */
4006
4007   /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4008      are to be pushed.  */
4009   for (count = 0; count < nargs; count++, argnum += inc)
4010     {
4011       rtx val = argvec[argnum].value;
4012       rtx reg = argvec[argnum].reg;
4013       int partial = argvec[argnum].partial;
4014
4015       /* Handle calls that pass values in multiple non-contiguous
4016          locations.  The PA64 has examples of this for library calls.  */
4017       if (reg != 0 && GET_CODE (reg) == PARALLEL)
4018         emit_group_load (reg, val, GET_MODE_SIZE (GET_MODE (val)));
4019       else if (reg != 0 && partial == 0)
4020         emit_move_insn (reg, val);
4021
4022       NO_DEFER_POP;
4023     }
4024
4025   /* Any regs containing parms remain in use through the call.  */
4026   for (count = 0; count < nargs; count++)
4027     {
4028       rtx reg = argvec[count].reg;
4029       if (reg != 0 && GET_CODE (reg) == PARALLEL)
4030         use_group_regs (&call_fusage, reg);
4031       else if (reg != 0)
4032         use_reg (&call_fusage, reg);
4033     }
4034
4035   /* Pass the function the address in which to return a structure value.  */
4036   if (mem_value != 0 && struct_value_rtx != 0 && ! pcc_struct_value)
4037     {
4038       emit_move_insn (struct_value_rtx,
4039                       force_reg (Pmode,
4040                                  force_operand (XEXP (mem_value, 0),
4041                                                 NULL_RTX)));
4042       if (GET_CODE (struct_value_rtx) == REG)
4043         use_reg (&call_fusage, struct_value_rtx);
4044     }
4045
4046   /* Don't allow popping to be deferred, since then
4047      cse'ing of library calls could delete a call and leave the pop.  */
4048   NO_DEFER_POP;
4049   valreg = (mem_value == 0 && outmode != VOIDmode
4050             ? hard_libcall_value (outmode) : NULL_RTX);
4051
4052   /* Stack must be properly aligned now.  */
4053   if (stack_pointer_delta & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1))
4054     abort ();
4055
4056   before_call = get_last_insn ();
4057
4058   /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
4059      will set inhibit_defer_pop to that value.  */
4060   /* The return type is needed to decide how many bytes the function pops.
4061      Signedness plays no role in that, so for simplicity, we pretend it's
4062      always signed.  We also assume that the list of arguments passed has
4063      no impact, so we pretend it is unknown.  */
4064
4065   emit_call_1 (fun,
4066                get_identifier (XSTR (orgfun, 0)),
4067                build_function_type (tfom, NULL_TREE),
4068                original_args_size.constant, args_size.constant,
4069                struct_value_size,
4070                FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
4071                valreg,
4072                old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
4073
4074   /* For calls to `setjmp', etc., inform flow.c it should complain
4075      if nonvolatile values are live.  For functions that cannot return,
4076      inform flow that control does not fall through.  */
4077
4078   if (flags & (ECF_NORETURN | ECF_LONGJMP))
4079     {
4080       /* The barrier note must be emitted
4081          immediately after the CALL_INSN.  Some ports emit more than
4082          just a CALL_INSN above, so we must search for it here.  */
4083
4084       rtx last = get_last_insn ();
4085       while (GET_CODE (last) != CALL_INSN)
4086         {
4087           last = PREV_INSN (last);
4088           /* There was no CALL_INSN?  */
4089           if (last == before_call)
4090             abort ();
4091         }
4092
4093       emit_barrier_after (last);
4094     }
4095
4096   /* Now restore inhibit_defer_pop to its actual original value.  */
4097   OK_DEFER_POP;
4098
4099   /* If call is cse'able, make appropriate pair of reg-notes around it.
4100      Test valreg so we don't crash; may safely ignore `const'
4101      if return type is void.  Disable for PARALLEL return values, because
4102      we have no way to move such values into a pseudo register.  */
4103   if (flags & ECF_LIBCALL_BLOCK)
4104     {
4105       rtx insns;
4106
4107       if (valreg == 0 || GET_CODE (valreg) == PARALLEL)
4108         {
4109           insns = get_insns ();
4110           end_sequence ();
4111           emit_insn (insns);
4112         }
4113       else
4114         {
4115           rtx note = 0;
4116           rtx temp = gen_reg_rtx (GET_MODE (valreg));
4117           int i;
4118
4119           /* Construct an "equal form" for the value which mentions all the
4120              arguments in order as well as the function name.  */
4121           for (i = 0; i < nargs; i++)
4122             note = gen_rtx_EXPR_LIST (VOIDmode, argvec[i].value, note);
4123           note = gen_rtx_EXPR_LIST (VOIDmode, fun, note);
4124
4125           insns = get_insns ();
4126           end_sequence ();
4127
4128           if (flags & ECF_PURE)
4129             note = gen_rtx_EXPR_LIST (VOIDmode,
4130                         gen_rtx_USE (VOIDmode,
4131                                      gen_rtx_MEM (BLKmode,
4132                                                   gen_rtx_SCRATCH (VOIDmode))),
4133                         note);
4134
4135           emit_libcall_block (insns, temp, valreg, note);
4136
4137           valreg = temp;
4138         }
4139     }
4140   pop_temp_slots ();
4141
4142   /* Copy the value to the right place.  */
4143   if (outmode != VOIDmode && retval)
4144     {
4145       if (mem_value)
4146         {
4147           if (value == 0)
4148             value = mem_value;
4149           if (value != mem_value)
4150             emit_move_insn (value, mem_value);
4151         }
4152       else if (value != 0)
4153         emit_move_insn (value, valreg);
4154       else
4155         value = valreg;
4156     }
4157
4158   if (ACCUMULATE_OUTGOING_ARGS)
4159     {
4160 #ifdef REG_PARM_STACK_SPACE
4161       if (save_area)
4162         {
4163           enum machine_mode save_mode = GET_MODE (save_area);
4164 #ifdef ARGS_GROW_DOWNWARD
4165           rtx stack_area
4166             = gen_rtx_MEM (save_mode,
4167                            memory_address (save_mode,
4168                                            plus_constant (argblock,
4169                                                           - high_to_save)));
4170 #else
4171           rtx stack_area
4172             = gen_rtx_MEM (save_mode,
4173                            memory_address (save_mode,
4174                                            plus_constant (argblock, low_to_save)));
4175 #endif
4176
4177           set_mem_align (stack_area, PARM_BOUNDARY);
4178           if (save_mode != BLKmode)
4179             emit_move_insn (stack_area, save_area);
4180           else
4181             emit_block_move (stack_area, save_area,
4182                              GEN_INT (high_to_save - low_to_save + 1),
4183                              BLOCK_OP_CALL_PARM);
4184         }
4185 #endif
4186
4187       /* If we saved any argument areas, restore them.  */
4188       for (count = 0; count < nargs; count++)
4189         if (argvec[count].save_area)
4190           {
4191             enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
4192             rtx stack_area
4193               = gen_rtx_MEM (save_mode,
4194                              memory_address
4195                              (save_mode,
4196                               plus_constant (argblock,
4197                                              argvec[count].offset.constant)));
4198
4199             emit_move_insn (stack_area, argvec[count].save_area);
4200           }
4201
4202       highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4203       stack_usage_map = initial_stack_usage_map;
4204     }
4205
4206   return value;
4207
4208 }
4209 \f
4210 /* Output a library call to function FUN (a SYMBOL_REF rtx)
4211    (emitting the queue unless NO_QUEUE is nonzero),
4212    for a value of mode OUTMODE,
4213    with NARGS different arguments, passed as alternating rtx values
4214    and machine_modes to convert them to.
4215    The rtx values should have been passed through protect_from_queue already.
4216
4217    FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const'
4218    calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls
4219    which should be enclosed in REG_LIBCALL/REG_RETVAL notes,
4220    LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in
4221    REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)),
4222    or other LCT_ value for other types of library calls.  */
4223
4224 void
4225 emit_library_call VPARAMS((rtx orgfun, enum libcall_type fn_type,
4226                            enum machine_mode outmode, int nargs, ...))
4227 {
4228   VA_OPEN (p, nargs);
4229   VA_FIXEDARG (p, rtx, orgfun);
4230   VA_FIXEDARG (p, int, fn_type);
4231   VA_FIXEDARG (p, enum machine_mode, outmode);
4232   VA_FIXEDARG (p, int, nargs);
4233
4234   emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
4235
4236   VA_CLOSE (p);
4237 }
4238 \f
4239 /* Like emit_library_call except that an extra argument, VALUE,
4240    comes second and says where to store the result.
4241    (If VALUE is zero, this function chooses a convenient way
4242    to return the value.
4243
4244    This function returns an rtx for where the value is to be found.
4245    If VALUE is nonzero, VALUE is returned.  */
4246
4247 rtx
4248 emit_library_call_value VPARAMS((rtx orgfun, rtx value,
4249                                  enum libcall_type fn_type,
4250                                  enum machine_mode outmode, int nargs, ...))
4251 {
4252   rtx result;
4253
4254   VA_OPEN (p, nargs);
4255   VA_FIXEDARG (p, rtx, orgfun);
4256   VA_FIXEDARG (p, rtx, value);
4257   VA_FIXEDARG (p, int, fn_type);
4258   VA_FIXEDARG (p, enum machine_mode, outmode);
4259   VA_FIXEDARG (p, int, nargs);
4260
4261   result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
4262                                       nargs, p);
4263
4264   VA_CLOSE (p);
4265
4266   return result;
4267 }
4268 \f
4269 /* Store a single argument for a function call
4270    into the register or memory area where it must be passed.
4271    *ARG describes the argument value and where to pass it.
4272
4273    ARGBLOCK is the address of the stack-block for all the arguments,
4274    or 0 on a machine where arguments are pushed individually.
4275
4276    MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4277    so must be careful about how the stack is used.
4278
4279    VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4280    argument stack.  This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4281    that we need not worry about saving and restoring the stack.
4282
4283    FNDECL is the declaration of the function we are calling.
4284
4285    Return nonzero if this arg should cause sibcall failure,
4286    zero otherwise.  */
4287
4288 static int
4289 store_one_arg (arg, argblock, flags, variable_size, reg_parm_stack_space)
4290      struct arg_data *arg;
4291      rtx argblock;
4292      int flags;
4293      int variable_size ATTRIBUTE_UNUSED;
4294      int reg_parm_stack_space;
4295 {
4296   tree pval = arg->tree_value;
4297   rtx reg = 0;
4298   int partial = 0;
4299   int used = 0;
4300   int i, lower_bound = 0, upper_bound = 0;
4301   int sibcall_failure = 0;
4302
4303   if (TREE_CODE (pval) == ERROR_MARK)
4304     return 1;
4305
4306   /* Push a new temporary level for any temporaries we make for
4307      this argument.  */
4308   push_temp_slots ();
4309
4310   if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4311     {
4312       /* If this is being stored into a pre-allocated, fixed-size, stack area,
4313          save any previous data at that location.  */
4314       if (argblock && ! variable_size && arg->stack)
4315         {
4316 #ifdef ARGS_GROW_DOWNWARD
4317           /* stack_slot is negative, but we want to index stack_usage_map
4318              with positive values.  */
4319           if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4320             upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4321           else
4322             upper_bound = 0;
4323
4324           lower_bound = upper_bound - arg->size.constant;
4325 #else
4326           if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4327             lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4328           else
4329             lower_bound = 0;
4330
4331           upper_bound = lower_bound + arg->size.constant;
4332 #endif
4333
4334           for (i = lower_bound; i < upper_bound; i++)
4335             if (stack_usage_map[i]
4336                 /* Don't store things in the fixed argument area at this point;
4337                    it has already been saved.  */
4338                 && i > reg_parm_stack_space)
4339               break;
4340
4341           if (i != upper_bound)
4342             {
4343               /* We need to make a save area.  See what mode we can make it.  */
4344               enum machine_mode save_mode
4345                 = mode_for_size (arg->size.constant * BITS_PER_UNIT, MODE_INT, 1);
4346               rtx stack_area
4347                 = gen_rtx_MEM (save_mode,
4348                                memory_address (save_mode,
4349                                                XEXP (arg->stack_slot, 0)));
4350
4351               if (save_mode == BLKmode)
4352                 {
4353                   tree ot = TREE_TYPE (arg->tree_value);
4354                   tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4355                                                        | TYPE_QUAL_CONST));
4356
4357                   arg->save_area = assign_temp (nt, 0, 1, 1);
4358                   preserve_temp_slots (arg->save_area);
4359                   emit_block_move (validize_mem (arg->save_area), stack_area,
4360                                    expr_size (arg->tree_value),
4361                                    BLOCK_OP_CALL_PARM);
4362                 }
4363               else
4364                 {
4365                   arg->save_area = gen_reg_rtx (save_mode);
4366                   emit_move_insn (arg->save_area, stack_area);
4367                 }
4368             }
4369         }
4370       /* Now that we have saved any slots that will be overwritten by this
4371          store, mark all slots this store will use.  We must do this before
4372          we actually expand the argument since the expansion itself may
4373          trigger library calls which might need to use the same stack slot.  */
4374       if (argblock && ! variable_size && arg->stack)
4375         for (i = lower_bound; i < upper_bound; i++)
4376           stack_usage_map[i] = 1;
4377     }
4378
4379   /* If this isn't going to be placed on both the stack and in registers,
4380      set up the register and number of words.  */
4381   if (! arg->pass_on_stack)
4382     {
4383       if (flags & ECF_SIBCALL)
4384         reg = arg->tail_call_reg;
4385       else
4386         reg = arg->reg;
4387       partial = arg->partial;
4388     }
4389
4390   if (reg != 0 && partial == 0)
4391     /* Being passed entirely in a register.  We shouldn't be called in
4392        this case.  */
4393     abort ();
4394
4395   /* If this arg needs special alignment, don't load the registers
4396      here.  */
4397   if (arg->n_aligned_regs != 0)
4398     reg = 0;
4399
4400   /* If this is being passed partially in a register, we can't evaluate
4401      it directly into its stack slot.  Otherwise, we can.  */
4402   if (arg->value == 0)
4403     {
4404       /* stack_arg_under_construction is nonzero if a function argument is
4405          being evaluated directly into the outgoing argument list and
4406          expand_call must take special action to preserve the argument list
4407          if it is called recursively.
4408
4409          For scalar function arguments stack_usage_map is sufficient to
4410          determine which stack slots must be saved and restored.  Scalar
4411          arguments in general have pass_on_stack == 0.
4412
4413          If this argument is initialized by a function which takes the
4414          address of the argument (a C++ constructor or a C function
4415          returning a BLKmode structure), then stack_usage_map is
4416          insufficient and expand_call must push the stack around the
4417          function call.  Such arguments have pass_on_stack == 1.
4418
4419          Note that it is always safe to set stack_arg_under_construction,
4420          but this generates suboptimal code if set when not needed.  */
4421
4422       if (arg->pass_on_stack)
4423         stack_arg_under_construction++;
4424
4425       arg->value = expand_expr (pval,
4426                                 (partial
4427                                  || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4428                                 ? NULL_RTX : arg->stack,
4429                                 VOIDmode, 0);
4430
4431       /* If we are promoting object (or for any other reason) the mode
4432          doesn't agree, convert the mode.  */
4433
4434       if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4435         arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4436                                     arg->value, arg->unsignedp);
4437
4438       if (arg->pass_on_stack)
4439         stack_arg_under_construction--;
4440     }
4441
4442   /* Don't allow anything left on stack from computation
4443      of argument to alloca.  */
4444   if (flags & ECF_MAY_BE_ALLOCA)
4445     do_pending_stack_adjust ();
4446
4447   if (arg->value == arg->stack)
4448     /* If the value is already in the stack slot, we are done.  */
4449     ;
4450   else if (arg->mode != BLKmode)
4451     {
4452       int size;
4453
4454       /* Argument is a scalar, not entirely passed in registers.
4455          (If part is passed in registers, arg->partial says how much
4456          and emit_push_insn will take care of putting it there.)
4457
4458          Push it, and if its size is less than the
4459          amount of space allocated to it,
4460          also bump stack pointer by the additional space.
4461          Note that in C the default argument promotions
4462          will prevent such mismatches.  */
4463
4464       size = GET_MODE_SIZE (arg->mode);
4465       /* Compute how much space the push instruction will push.
4466          On many machines, pushing a byte will advance the stack
4467          pointer by a halfword.  */
4468 #ifdef PUSH_ROUNDING
4469       size = PUSH_ROUNDING (size);
4470 #endif
4471       used = size;
4472
4473       /* Compute how much space the argument should get:
4474          round up to a multiple of the alignment for arguments.  */
4475       if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4476         used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4477                  / (PARM_BOUNDARY / BITS_PER_UNIT))
4478                 * (PARM_BOUNDARY / BITS_PER_UNIT));
4479
4480       /* This isn't already where we want it on the stack, so put it there.
4481          This can either be done with push or copy insns.  */
4482       emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4483                       PARM_BOUNDARY, partial, reg, used - size, argblock,
4484                       ARGS_SIZE_RTX (arg->offset), reg_parm_stack_space,
4485                       ARGS_SIZE_RTX (arg->alignment_pad));
4486
4487       /* Unless this is a partially-in-register argument, the argument is now
4488          in the stack.  */
4489       if (partial == 0)
4490         arg->value = arg->stack;
4491     }
4492   else
4493     {
4494       /* BLKmode, at least partly to be pushed.  */
4495
4496       unsigned int parm_align;
4497       int excess;
4498       rtx size_rtx;
4499
4500       /* Pushing a nonscalar.
4501          If part is passed in registers, PARTIAL says how much
4502          and emit_push_insn will take care of putting it there.  */
4503
4504       /* Round its size up to a multiple
4505          of the allocation unit for arguments.  */
4506
4507       if (arg->size.var != 0)
4508         {
4509           excess = 0;
4510           size_rtx = ARGS_SIZE_RTX (arg->size);
4511         }
4512       else
4513         {
4514           /* PUSH_ROUNDING has no effect on us, because
4515              emit_push_insn for BLKmode is careful to avoid it.  */
4516           excess = (arg->size.constant - int_size_in_bytes (TREE_TYPE (pval))
4517                     + partial * UNITS_PER_WORD);
4518           size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4519                                   NULL_RTX, TYPE_MODE (sizetype), 0);
4520         }
4521
4522       /* Some types will require stricter alignment, which will be
4523          provided for elsewhere in argument layout.  */
4524       parm_align = MAX (PARM_BOUNDARY, TYPE_ALIGN (TREE_TYPE (pval)));
4525
4526       /* When an argument is padded down, the block is aligned to
4527          PARM_BOUNDARY, but the actual argument isn't.  */
4528       if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4529         {
4530           if (arg->size.var)
4531             parm_align = BITS_PER_UNIT;
4532           else if (excess)
4533             {
4534               unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4535               parm_align = MIN (parm_align, excess_align);
4536             }
4537         }
4538
4539       if ((flags & ECF_SIBCALL) && GET_CODE (arg->value) == MEM)
4540         {
4541           /* emit_push_insn might not work properly if arg->value and
4542              argblock + arg->offset areas overlap.  */
4543           rtx x = arg->value;
4544           int i = 0;
4545
4546           if (XEXP (x, 0) == current_function_internal_arg_pointer
4547               || (GET_CODE (XEXP (x, 0)) == PLUS
4548                   && XEXP (XEXP (x, 0), 0) ==
4549                      current_function_internal_arg_pointer
4550                   && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4551             {
4552               if (XEXP (x, 0) != current_function_internal_arg_pointer)
4553                 i = INTVAL (XEXP (XEXP (x, 0), 1));
4554
4555               /* expand_call should ensure this */
4556               if (arg->offset.var || GET_CODE (size_rtx) != CONST_INT)
4557                 abort ();
4558
4559               if (arg->offset.constant > i)
4560                 {
4561                   if (arg->offset.constant < i + INTVAL (size_rtx))
4562                     sibcall_failure = 1;
4563                 }
4564               else if (arg->offset.constant < i)
4565                 {
4566                   if (i < arg->offset.constant + INTVAL (size_rtx))
4567                     sibcall_failure = 1;
4568                 }
4569             }
4570         }
4571
4572       /* Special handling is required if part of the parameter lies in the
4573          register parameter area.  The argument may be copied into the stack
4574          slot using memcpy(), but the original contents of the register
4575          parameter area will be restored after the memcpy() call.
4576
4577          To ensure that the part that lies in the register parameter area
4578          is copied correctly, we emit a separate push for that part.  This
4579          push should be small enough to avoid a call to memcpy().  */
4580 #ifndef STACK_PARMS_IN_REG_PARM_AREA
4581       if (arg->reg && arg->pass_on_stack)
4582 #else
4583       if (1)
4584 #endif
4585         {
4586           if (arg->offset.constant < reg_parm_stack_space && arg->offset.var)
4587             error ("variable offset is passed partially in stack and in reg");
4588           else if (arg->offset.constant < reg_parm_stack_space && arg->size.var)
4589             error ("variable size is passed partially in stack and in reg");
4590           else if (arg->offset.constant < reg_parm_stack_space
4591               && ((arg->offset.constant + arg->size.constant)
4592                    > reg_parm_stack_space))
4593           {
4594             rtx size_rtx1 = GEN_INT (reg_parm_stack_space - arg->offset.constant);
4595             emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx1,
4596                             parm_align, partial, reg, excess, argblock,
4597                             ARGS_SIZE_RTX (arg->offset), reg_parm_stack_space,
4598                             ARGS_SIZE_RTX (arg->alignment_pad));
4599           }
4600         }
4601
4602
4603       emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4604                       parm_align, partial, reg, excess, argblock,
4605                       ARGS_SIZE_RTX (arg->offset), reg_parm_stack_space,
4606                       ARGS_SIZE_RTX (arg->alignment_pad));
4607
4608       /* Unless this is a partially-in-register argument, the argument is now
4609          in the stack.
4610
4611          ??? Unlike the case above, in which we want the actual
4612          address of the data, so that we can load it directly into a
4613          register, here we want the address of the stack slot, so that
4614          it's properly aligned for word-by-word copying or something
4615          like that.  It's not clear that this is always correct.  */
4616       if (partial == 0)
4617         arg->value = arg->stack_slot;
4618     }
4619
4620   /* Once we have pushed something, pops can't safely
4621      be deferred during the rest of the arguments.  */
4622   NO_DEFER_POP;
4623
4624   /* ANSI doesn't require a sequence point here,
4625      but PCC has one, so this will avoid some problems.  */
4626   emit_queue ();
4627
4628   /* Free any temporary slots made in processing this argument.  Show
4629      that we might have taken the address of something and pushed that
4630      as an operand.  */
4631   preserve_temp_slots (NULL_RTX);
4632   free_temp_slots ();
4633   pop_temp_slots ();
4634
4635   return sibcall_failure;
4636 }