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, 2002, 2003 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 #include "cgraph.h"
  41
  42 /* Decide whether a function's arguments should be processed
  43    from first to last or from last to first.
  44
  45    They should if the stack and args grow in opposite directions, but
  46    only if we have push insns.  */
  47
  48 #ifdef PUSH_ROUNDING
  49
  50 #ifndef PUSH_ARGS_REVERSED
  51 #if defined (STACK_GROWS_DOWNWARD) != defined (ARGS_GROW_DOWNWARD)
  52 #define PUSH_ARGS_REVERSED  PUSH_ARGS
  53 #endif
  54 #endif
  55
  56 #endif
  57
  58 #ifndef PUSH_ARGS_REVERSED
  59 #define PUSH_ARGS_REVERSED 0
  60 #endif
  61
  62 #ifndef STACK_POINTER_OFFSET
  63 #define STACK_POINTER_OFFSET    0
  64 #endif
  65
  66 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits.  */
  67 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
  68
  69 /* Data structure and subroutines used within expand_call.  */
  70
  71 struct arg_data
  72 {
  73   /* Tree node for this argument.  */
  74   tree tree_value;
  75   /* Mode for value; TYPE_MODE unless promoted.  */
  76   enum machine_mode mode;
  77   /* Current RTL value for argument, or 0 if it isn't precomputed.  */
  78   rtx value;
  79   /* Initially-compute RTL value for argument; only for const functions.  */
  80   rtx initial_value;
  81   /* Register to pass this argument in, 0 if passed on stack, or an
  82      PARALLEL if the arg is to be copied into multiple non-contiguous
  83      registers.  */
  84   rtx reg;
  85   /* Register to pass this argument in when generating tail call sequence.
  86      This is not the same register as for normal calls on machines with
  87      register windows.  */
  88   rtx tail_call_reg;
  89   /* If REG was promoted from the actual mode of the argument expression,
  90      indicates whether the promotion is sign- or zero-extended.  */
  91   int unsignedp;
  92   /* Number of registers to use.  0 means put the whole arg in registers.
  93      Also 0 if not passed in registers.  */
  94   int partial;
  95   /* Nonzero if argument must be passed on stack.
  96      Note that some arguments may be passed on the stack
  97      even though pass_on_stack is zero, just because FUNCTION_ARG says so.
  98      pass_on_stack identifies arguments that *cannot* go in registers.  */
  99   int pass_on_stack;
 100   /* Offset of this argument from beginning of stack-args.  */
 101   struct args_size offset;
 102   /* Similar, but offset to the start of the stack slot.  Different from
 103      OFFSET if this arg pads downward.  */
 104   struct args_size slot_offset;
 105   /* Size of this argument on the stack, rounded up for any padding it gets,
 106      parts of the argument passed in registers do not count.
 107      If REG_PARM_STACK_SPACE is defined, then register parms
 108      are counted here as well.  */
 109   struct args_size size;
 110   /* Location on the stack at which parameter should be stored.  The store
 111      has already been done if STACK == VALUE.  */
 112   rtx stack;
 113   /* Location on the stack of the start of this argument slot.  This can
 114      differ from STACK if this arg pads downward.  This location is known
 115      to be aligned to FUNCTION_ARG_BOUNDARY.  */
 116   rtx stack_slot;
 117   /* Place that this stack area has been saved, if needed.  */
 118   rtx save_area;
 119   /* If an argument's alignment does not permit direct copying into registers,
 120      copy in smaller-sized pieces into pseudos.  These are stored in a
 121      block pointed to by this field.  The next field says how many
 122      word-sized pseudos we made.  */
 123   rtx *aligned_regs;
 124   int n_aligned_regs;
 125   /* The amount that the stack pointer needs to be adjusted to
 126      force alignment for the next argument.  */
 127   struct args_size alignment_pad;
 128 };
 129
 130 /* A vector of one char per byte of stack space.  A byte if nonzero if
 131    the corresponding stack location has been used.
 132    This vector is used to prevent a function call within an argument from
 133    clobbering any stack already set up.  */
 134 static char *stack_usage_map;
 135
 136 /* Size of STACK_USAGE_MAP.  */
 137 static int highest_outgoing_arg_in_use;
 138
 139 /* A bitmap of virtual-incoming stack space.  Bit is set if the corresponding
 140    stack location's tail call argument has been already stored into the stack.
 141    This bitmap is used to prevent sibling call optimization if function tries
 142    to use parent's incoming argument slots when they have been already
 143    overwritten with tail call arguments.  */
 144 static sbitmap stored_args_map;
 145
 146 /* stack_arg_under_construction is nonzero when an argument may be
 147    initialized with a constructor call (including a C function that
 148    returns a BLKmode struct) and expand_call must take special action
 149    to make sure the object being constructed does not overlap the
 150    argument list for the constructor call.  */
 151 int stack_arg_under_construction;
 152
 153 static int calls_function       PARAMS ((tree, int));
 154 static int calls_function_1     PARAMS ((tree, int));
 155
 156 static void emit_call_1         PARAMS ((rtx, tree, tree, HOST_WIDE_INT,
 157                                          HOST_WIDE_INT, HOST_WIDE_INT, rtx,
 158                                          rtx, int, rtx, int,
 159                                          CUMULATIVE_ARGS *));
 160 static void precompute_register_parameters      PARAMS ((int,
 161                                                          struct arg_data *,
 162                                                          int *));
 163 static int store_one_arg        PARAMS ((struct arg_data *, rtx, int, int,
 164                                          int));
 165 static void store_unaligned_arguments_into_pseudos PARAMS ((struct arg_data *,
 166                                                             int));
 167 static int finalize_must_preallocate            PARAMS ((int, int,
 168                                                          struct arg_data *,
 169                                                          struct args_size *));
 170 static void precompute_arguments                PARAMS ((int, int,
 171                                                          struct arg_data *));
 172 static int compute_argument_block_size          PARAMS ((int,
 173                                                          struct args_size *,
 174                                                          int));
 175 static void initialize_argument_information     PARAMS ((int,
 176                                                          struct arg_data *,
 177                                                          struct args_size *,
 178                                                          int, tree, tree,
 179                                                          CUMULATIVE_ARGS *,
 180                                                          int, rtx *, int *,
 181                                                          int *, int *));
 182 static void compute_argument_addresses          PARAMS ((struct arg_data *,
 183                                                          rtx, int));
 184 static rtx rtx_for_function_call                PARAMS ((tree, tree));
 185 static void load_register_parameters            PARAMS ((struct arg_data *,
 186                                                          int, rtx *, int,
 187                                                          int, int *));
 188 static rtx emit_library_call_value_1            PARAMS ((int, rtx, rtx,
 189                                                          enum libcall_type,
 190                                                          enum machine_mode,
 191                                                          int, va_list));
 192 static int special_function_p                   PARAMS ((tree, int));
 193 static rtx try_to_integrate                     PARAMS ((tree, tree, rtx,
 194                                                          int, tree, rtx));
 195 static int check_sibcall_argument_overlap_1     PARAMS ((rtx));
 196 static int check_sibcall_argument_overlap       PARAMS ((rtx, struct arg_data *,
 197                                                          int));
 198
 199 static int combine_pending_stack_adjustment_and_call
 200                                                 PARAMS ((int, struct args_size *, int));
 201 static tree fix_unsafe_tree             PARAMS ((tree));
 202
 203 #ifdef REG_PARM_STACK_SPACE
 204 static rtx save_fixed_argument_area     PARAMS ((int, rtx, int *, int *));
 205 static void restore_fixed_argument_area PARAMS ((rtx, rtx, int, int));
 206 #endif
 207 \f
 208 /* If WHICH is 1, return 1 if EXP contains a call to the built-in function
 209    `alloca'.
 210
 211    If WHICH is 0, return 1 if EXP contains a call to any function.
 212    Actually, we only need return 1 if evaluating EXP would require pushing
 213    arguments on the stack, but that is too difficult to compute, so we just
 214    assume any function call might require the stack.  */
 215
 216 static tree calls_function_save_exprs;
 217
 218 static int
 219 calls_function (exp, which)
 220      tree exp;
 221      int which;
 222 {
 223   int val;
 224
 225   calls_function_save_exprs = 0;
 226   val = calls_function_1 (exp, which);
 227   calls_function_save_exprs = 0;
 228   return val;
 229 }
 230
 231 /* Recursive function to do the work of above function.  */
 232
 233 static int
 234 calls_function_1 (exp, which)
 235      tree exp;
 236      int which;
 237 {
 238   int i;
 239   enum tree_code code = TREE_CODE (exp);
 240   int class = TREE_CODE_CLASS (code);
 241   int length = first_rtl_op (code);
 242
 243   /* If this code is language-specific, we don't know what it will do.  */
 244   if ((int) code >= NUM_TREE_CODES)
 245     return 1;
 246
 247   switch (code)
 248     {
 249     case CALL_EXPR:
 250       if (which == 0)
 251         return 1;
 252       else if ((TREE_CODE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))
 253                 == FUNCTION_TYPE)
 254                && (TYPE_RETURNS_STACK_DEPRESSED
 255                    (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))))
 256         return 1;
 257       else if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
 258                && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
 259                    == FUNCTION_DECL)
 260                && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
 261                                        0)
 262                    & ECF_MAY_BE_ALLOCA))
 263         return 1;
 264
 265       break;
 266
 267     case CONSTRUCTOR:
 268       {
 269         tree tem;
 270
 271         for (tem = CONSTRUCTOR_ELTS (exp); tem != 0; tem = TREE_CHAIN (tem))
 272           if (calls_function_1 (TREE_VALUE (tem), which))
 273             return 1;
 274       }
 275
 276       return 0;
 277
 278     case SAVE_EXPR:
 279       if (SAVE_EXPR_RTL (exp) != 0)
 280         return 0;
 281       if (value_member (exp, calls_function_save_exprs))
 282         return 0;
 283       calls_function_save_exprs = tree_cons (NULL_TREE, exp,
 284                                              calls_function_save_exprs);
 285       return (TREE_OPERAND (exp, 0) != 0
 286               && calls_function_1 (TREE_OPERAND (exp, 0), which));
 287
 288     case BLOCK:
 289       {
 290         tree local;
 291         tree subblock;
 292
 293         for (local = BLOCK_VARS (exp); local; local = TREE_CHAIN (local))
 294           if (DECL_INITIAL (local) != 0
 295               && calls_function_1 (DECL_INITIAL (local), which))
 296             return 1;
 297
 298         for (subblock = BLOCK_SUBBLOCKS (exp);
 299              subblock;
 300              subblock = TREE_CHAIN (subblock))
 301           if (calls_function_1 (subblock, which))
 302             return 1;
 303       }
 304       return 0;
 305
 306     case TREE_LIST:
 307       for (; exp != 0; exp = TREE_CHAIN (exp))
 308         if (calls_function_1 (TREE_VALUE (exp), which))
 309           return 1;
 310       return 0;
 311
 312     default:
 313       break;
 314     }
 315
 316   /* Only expressions, references, and blocks can contain calls.  */
 317   if (! IS_EXPR_CODE_CLASS (class) && class != 'r' && class != 'b')
 318     return 0;
 319
 320   for (i = 0; i < length; i++)
 321     if (TREE_OPERAND (exp, i) != 0
 322         && calls_function_1 (TREE_OPERAND (exp, i), which))
 323       return 1;
 324
 325   return 0;
 326 }
 327 \f
 328 /* Force FUNEXP into a form suitable for the address of a CALL,
 329    and return that as an rtx.  Also load the static chain register
 330    if FNDECL is a nested function.
 331
 332    CALL_FUSAGE points to a variable holding the prospective
 333    CALL_INSN_FUNCTION_USAGE information.  */
 334
 335 rtx
 336 prepare_call_address (funexp, fndecl, call_fusage, reg_parm_seen, sibcallp)
 337      rtx funexp;
 338      tree fndecl;
 339      rtx *call_fusage;
 340      int reg_parm_seen;
 341      int sibcallp;
 342 {
 343   rtx static_chain_value = 0;
 344
 345   funexp = protect_from_queue (funexp, 0);
 346
 347   if (fndecl != 0)
 348     /* Get possible static chain value for nested function in C.  */
 349     static_chain_value = lookup_static_chain (fndecl);
 350
 351   /* Make a valid memory address and copy constants thru pseudo-regs,
 352      but not for a constant address if -fno-function-cse.  */
 353   if (GET_CODE (funexp) != SYMBOL_REF)
 354     /* If we are using registers for parameters, force the
 355        function address into a register now.  */
 356     funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
 357               ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
 358               : memory_address (FUNCTION_MODE, funexp));
 359   else if (! sibcallp)
 360     {
 361 #ifndef NO_FUNCTION_CSE
 362       if (optimize && ! flag_no_function_cse)
 363 #ifdef NO_RECURSIVE_FUNCTION_CSE
 364         if (fndecl != current_function_decl)
 365 #endif
 366           funexp = force_reg (Pmode, funexp);
 367 #endif
 368     }
 369
 370   if (static_chain_value != 0)
 371     {
 372       emit_move_insn (static_chain_rtx, static_chain_value);
 373
 374       if (GET_CODE (static_chain_rtx) == REG)
 375         use_reg (call_fusage, static_chain_rtx);
 376     }
 377
 378   return funexp;
 379 }
 380
 381 /* Generate instructions to call function FUNEXP,
 382    and optionally pop the results.
 383    The CALL_INSN is the first insn generated.
 384
 385    FNDECL is the declaration node of the function.  This is given to the
 386    macro RETURN_POPS_ARGS to determine whether this function pops its own args.
 387
 388    FUNTYPE is the data type of the function.  This is given to the macro
 389    RETURN_POPS_ARGS to determine whether this function pops its own args.
 390    We used to allow an identifier for library functions, but that doesn't
 391    work when the return type is an aggregate type and the calling convention
 392    says that the pointer to this aggregate is to be popped by the callee.
 393
 394    STACK_SIZE is the number of bytes of arguments on the stack,
 395    ROUNDED_STACK_SIZE is that number rounded up to
 396    PREFERRED_STACK_BOUNDARY; zero if the size is variable.  This is
 397    both to put into the call insn and to generate explicit popping
 398    code if necessary.
 399
 400    STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
 401    It is zero if this call doesn't want a structure value.
 402
 403    NEXT_ARG_REG is the rtx that results from executing
 404      FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
 405    just after all the args have had their registers assigned.
 406    This could be whatever you like, but normally it is the first
 407    arg-register beyond those used for args in this call,
 408    or 0 if all the arg-registers are used in this call.
 409    It is passed on to `gen_call' so you can put this info in the call insn.
 410
 411    VALREG is a hard register in which a value is returned,
 412    or 0 if the call does not return a value.
 413
 414    OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
 415    the args to this call were processed.
 416    We restore `inhibit_defer_pop' to that value.
 417
 418    CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
 419    denote registers used by the called function.  */
 420
 421 static void
 422 emit_call_1 (funexp, fndecl, funtype, stack_size, rounded_stack_size,
 423              struct_value_size, next_arg_reg, valreg, old_inhibit_defer_pop,
 424              call_fusage, ecf_flags, args_so_far)
 425      rtx funexp;
 426      tree fndecl ATTRIBUTE_UNUSED;
 427      tree funtype ATTRIBUTE_UNUSED;
 428      HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED;
 429      HOST_WIDE_INT rounded_stack_size;
 430      HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED;
 431      rtx next_arg_reg ATTRIBUTE_UNUSED;
 432      rtx valreg;
 433      int old_inhibit_defer_pop;
 434      rtx call_fusage;
 435      int ecf_flags;
 436      CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED;
 437 {
 438   rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
 439   rtx call_insn;
 440   int already_popped = 0;
 441   HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
 442 #if defined (HAVE_call) && defined (HAVE_call_value)
 443   rtx struct_value_size_rtx;
 444   struct_value_size_rtx = GEN_INT (struct_value_size);
 445 #endif
 446
 447 #ifdef CALL_POPS_ARGS
 448   n_popped += CALL_POPS_ARGS (* args_so_far);
 449 #endif
 450
 451   /* Ensure address is valid.  SYMBOL_REF is already valid, so no need,
 452      and we don't want to load it into a register as an optimization,
 453      because prepare_call_address already did it if it should be done.  */
 454   if (GET_CODE (funexp) != SYMBOL_REF)
 455     funexp = memory_address (FUNCTION_MODE, funexp);
 456
 457 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
 458   if ((ecf_flags & ECF_SIBCALL)
 459       && HAVE_sibcall_pop && HAVE_sibcall_value_pop
 460       && (n_popped > 0 || stack_size == 0))
 461     {
 462       rtx n_pop = GEN_INT (n_popped);
 463       rtx pat;
 464
 465       /* If this subroutine pops its own args, record that in the call insn
 466          if possible, for the sake of frame pointer elimination.  */
 467
 468       if (valreg)
 469         pat = GEN_SIBCALL_VALUE_POP (valreg,
 470                                      gen_rtx_MEM (FUNCTION_MODE, funexp),
 471                                      rounded_stack_size_rtx, next_arg_reg,
 472                                      n_pop);
 473       else
 474         pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
 475                                rounded_stack_size_rtx, next_arg_reg, n_pop);
 476
 477       emit_call_insn (pat);
 478       already_popped = 1;
 479     }
 480   else
 481 #endif
 482
 483 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
 484   /* If the target has "call" or "call_value" insns, then prefer them
 485      if no arguments are actually popped.  If the target does not have
 486      "call" or "call_value" insns, then we must use the popping versions
 487      even if the call has no arguments to pop.  */
 488 #if defined (HAVE_call) && defined (HAVE_call_value)
 489   if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
 490       && n_popped > 0 && ! (ecf_flags & ECF_SP_DEPRESSED))
 491 #else
 492   if (HAVE_call_pop && HAVE_call_value_pop)
 493 #endif
 494     {
 495       rtx n_pop = GEN_INT (n_popped);
 496       rtx pat;
 497
 498       /* If this subroutine pops its own args, record that in the call insn
 499          if possible, for the sake of frame pointer elimination.  */
 500
 501       if (valreg)
 502         pat = GEN_CALL_VALUE_POP (valreg,
 503                                   gen_rtx_MEM (FUNCTION_MODE, funexp),
 504                                   rounded_stack_size_rtx, next_arg_reg, n_pop);
 505       else
 506         pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
 507                             rounded_stack_size_rtx, next_arg_reg, n_pop);
 508
 509       emit_call_insn (pat);
 510       already_popped = 1;
 511     }
 512   else
 513 #endif
 514
 515 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
 516   if ((ecf_flags & ECF_SIBCALL)
 517       && HAVE_sibcall && HAVE_sibcall_value)
 518     {
 519       if (valreg)
 520         emit_call_insn (GEN_SIBCALL_VALUE (valreg,
 521                                            gen_rtx_MEM (FUNCTION_MODE, funexp),
 522                                            rounded_stack_size_rtx,
 523                                            next_arg_reg, NULL_RTX));
 524       else
 525         emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
 526                                      rounded_stack_size_rtx, next_arg_reg,
 527                                      struct_value_size_rtx));
 528     }
 529   else
 530 #endif
 531
 532 #if defined (HAVE_call) && defined (HAVE_call_value)
 533   if (HAVE_call && HAVE_call_value)
 534     {
 535       if (valreg)
 536         emit_call_insn (GEN_CALL_VALUE (valreg,
 537                                         gen_rtx_MEM (FUNCTION_MODE, funexp),
 538                                         rounded_stack_size_rtx, next_arg_reg,
 539                                         NULL_RTX));
 540       else
 541         emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
 542                                   rounded_stack_size_rtx, next_arg_reg,
 543                                   struct_value_size_rtx));
 544     }
 545   else
 546 #endif
 547     abort ();
 548
 549   /* Find the CALL insn we just emitted.  */
 550   for (call_insn = get_last_insn ();
 551        call_insn && GET_CODE (call_insn) != CALL_INSN;
 552        call_insn = PREV_INSN (call_insn))
 553     ;
 554
 555   if (! call_insn)
 556     abort ();
 557
 558   /* Mark memory as used for "pure" function call.  */
 559   if (ecf_flags & ECF_PURE)
 560     call_fusage
 561       = gen_rtx_EXPR_LIST
 562         (VOIDmode,
 563          gen_rtx_USE (VOIDmode,
 564                       gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode))),
 565          call_fusage);
 566
 567   /* Put the register usage information on the CALL.  If there is already
 568      some usage information, put ours at the end.  */
 569   if (CALL_INSN_FUNCTION_USAGE (call_insn))
 570     {
 571       rtx link;
 572
 573       for (link = CALL_INSN_FUNCTION_USAGE (call_insn); XEXP (link, 1) != 0;
 574            link = XEXP (link, 1))
 575         ;
 576
 577       XEXP (link, 1) = call_fusage;
 578     }
 579   else
 580     CALL_INSN_FUNCTION_USAGE (call_insn) = call_fusage;
 581
 582   /* If this is a const call, then set the insn's unchanging bit.  */
 583   if (ecf_flags & (ECF_CONST | ECF_PURE))
 584     CONST_OR_PURE_CALL_P (call_insn) = 1;
 585
 586   /* If this call can't throw, attach a REG_EH_REGION reg note to that
 587      effect.  */
 588   if (ecf_flags & ECF_NOTHROW)
 589     REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, const0_rtx,
 590                                                REG_NOTES (call_insn));
 591
 592   if (ecf_flags & ECF_NORETURN)
 593     REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_NORETURN, const0_rtx,
 594                                                REG_NOTES (call_insn));
 595   if (ecf_flags & ECF_ALWAYS_RETURN)
 596     REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_ALWAYS_RETURN, const0_rtx,
 597                                                REG_NOTES (call_insn));
 598
 599   if (ecf_flags & ECF_RETURNS_TWICE)
 600     {
 601       REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_SETJMP, const0_rtx,
 602                                                  REG_NOTES (call_insn));
 603       current_function_calls_setjmp = 1;
 604     }
 605
 606   SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
 607
 608   /* Restore this now, so that we do defer pops for this call's args
 609      if the context of the call as a whole permits.  */
 610   inhibit_defer_pop = old_inhibit_defer_pop;
 611
 612   if (n_popped > 0)
 613     {
 614       if (!already_popped)
 615         CALL_INSN_FUNCTION_USAGE (call_insn)
 616           = gen_rtx_EXPR_LIST (VOIDmode,
 617                                gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
 618                                CALL_INSN_FUNCTION_USAGE (call_insn));
 619       rounded_stack_size -= n_popped;
 620       rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
 621       stack_pointer_delta -= n_popped;
 622     }
 623
 624   if (!ACCUMULATE_OUTGOING_ARGS)
 625     {
 626       /* If returning from the subroutine does not automatically pop the args,
 627          we need an instruction to pop them sooner or later.
 628          Perhaps do it now; perhaps just record how much space to pop later.
 629
 630          If returning from the subroutine does pop the args, indicate that the
 631          stack pointer will be changed.  */
 632
 633       if (rounded_stack_size != 0)
 634         {
 635           if (ecf_flags & ECF_SP_DEPRESSED)
 636             /* Just pretend we did the pop.  */
 637             stack_pointer_delta -= rounded_stack_size;
 638           else if (flag_defer_pop && inhibit_defer_pop == 0
 639               && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
 640             pending_stack_adjust += rounded_stack_size;
 641           else
 642             adjust_stack (rounded_stack_size_rtx);
 643         }
 644     }
 645   /* When we accumulate outgoing args, we must avoid any stack manipulations.
 646      Restore the stack pointer to its original value now.  Usually
 647      ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
 648      On  i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
 649      popping variants of functions exist as well.
 650
 651      ??? We may optimize similar to defer_pop above, but it is
 652      probably not worthwhile.
 653
 654      ??? It will be worthwhile to enable combine_stack_adjustments even for
 655      such machines.  */
 656   else if (n_popped)
 657     anti_adjust_stack (GEN_INT (n_popped));
 658 }
 659
 660 /* Determine if the function identified by NAME and FNDECL is one with
 661    special properties we wish to know about.
 662
 663    For example, if the function might return more than one time (setjmp), then
 664    set RETURNS_TWICE to a nonzero value.
 665
 666    Similarly set LONGJMP for if the function is in the longjmp family.
 667
 668    Set MALLOC for any of the standard memory allocation functions which
 669    allocate from the heap.
 670
 671    Set MAY_BE_ALLOCA for any memory allocation function that might allocate
 672    space from the stack such as alloca.  */
 673
 674 static int
 675 special_function_p (fndecl, flags)
 676      tree fndecl;
 677      int flags;
 678 {
 679   if (! (flags & ECF_MALLOC)
 680       && fndecl && DECL_NAME (fndecl)
 681       && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
 682       /* Exclude functions not at the file scope, or not `extern',
 683          since they are not the magic functions we would otherwise
 684          think they are.  */
 685       && DECL_CONTEXT (fndecl) == NULL_TREE && TREE_PUBLIC (fndecl))
 686     {
 687       const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
 688       const char *tname = name;
 689
 690       /* We assume that alloca will always be called by name.  It
 691          makes no sense to pass it as a pointer-to-function to
 692          anything that does not understand its behavior.  */
 693       if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
 694             && name[0] == 'a'
 695             && ! strcmp (name, "alloca"))
 696            || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
 697                && name[0] == '_'
 698                && ! strcmp (name, "__builtin_alloca"))))
 699         flags |= ECF_MAY_BE_ALLOCA;
 700
 701       /* Disregard prefix _, __ or __x.  */
 702       if (name[0] == '_')
 703         {
 704           if (name[1] == '_' && name[2] == 'x')
 705             tname += 3;
 706           else if (name[1] == '_')
 707             tname += 2;
 708           else
 709             tname += 1;
 710         }
 711
 712       if (tname[0] == 's')
 713         {
 714           if ((tname[1] == 'e'
 715                && (! strcmp (tname, "setjmp")
 716                    || ! strcmp (tname, "setjmp_syscall")))
 717               || (tname[1] == 'i'
 718                   && ! strcmp (tname, "sigsetjmp"))
 719               || (tname[1] == 'a'
 720                   && ! strcmp (tname, "savectx")))
 721             flags |= ECF_RETURNS_TWICE;
 722
 723           if (tname[1] == 'i'
 724               && ! strcmp (tname, "siglongjmp"))
 725             flags |= ECF_LONGJMP;
 726         }
 727       else if ((tname[0] == 'q' && tname[1] == 's'
 728                 && ! strcmp (tname, "qsetjmp"))
 729                || (tname[0] == 'v' && tname[1] == 'f'
 730                    && ! strcmp (tname, "vfork")))
 731         flags |= ECF_RETURNS_TWICE;
 732
 733       else if (tname[0] == 'l' && tname[1] == 'o'
 734                && ! strcmp (tname, "longjmp"))
 735         flags |= ECF_LONGJMP;
 736
 737       else if ((tname[0] == 'f' && tname[1] == 'o'
 738                 && ! strcmp (tname, "fork"))
 739                /* Linux specific: __clone.  check NAME to insist on the
 740                   leading underscores, to avoid polluting the ISO / POSIX
 741                   namespace.  */
 742                || (name[0] == '_' && name[1] == '_'
 743                    && ! strcmp (tname, "clone"))
 744                || (tname[0] == 'e' && tname[1] == 'x' && tname[2] == 'e'
 745                    && tname[3] == 'c' && (tname[4] == 'l' || tname[4] == 'v')
 746                    && (tname[5] == '\0'
 747                        || ((tname[5] == 'p' || tname[5] == 'e')
 748                            && tname[6] == '\0'))))
 749         flags |= ECF_FORK_OR_EXEC;
 750
 751       /* Do not add any more malloc-like functions to this list,
 752          instead mark them as malloc functions using the malloc attribute.
 753          Note, realloc is not suitable for attribute malloc since
 754          it may return the same address across multiple calls.
 755          C++ operator new is not suitable because it is not required
 756          to return a unique pointer; indeed, the standard placement new
 757          just returns its argument.  */
 758       else if (TYPE_MODE (TREE_TYPE (TREE_TYPE (fndecl))) == Pmode
 759                && (! strcmp (tname, "malloc")
 760                    || ! strcmp (tname, "calloc")
 761                    || ! strcmp (tname, "strdup")))
 762         flags |= ECF_MALLOC;
 763     }
 764   return flags;
 765 }
 766
 767 /* Return nonzero when tree represent call to longjmp.  */
 768
 769 int
 770 setjmp_call_p (fndecl)
 771      tree fndecl;
 772 {
 773   return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
 774 }
 775
 776 /* Return true when exp contains alloca call.  */
 777 bool
 778 alloca_call_p (exp)
 779      tree exp;
 780 {
 781   if (TREE_CODE (exp) == CALL_EXPR
 782       && TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
 783       && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
 784           == FUNCTION_DECL)
 785       && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
 786                               0) & ECF_MAY_BE_ALLOCA))
 787     return true;
 788   return false;
 789 }
 790
 791 /* Detect flags (function attributes) from the function decl or type node.  */
 792
 793 int
 794 flags_from_decl_or_type (exp)
 795      tree exp;
 796 {
 797   int flags = 0;
 798   tree type = exp;
 799   /* ??? We can't set IS_MALLOC for function types?  */
 800   if (DECL_P (exp))
 801     {
 802       struct cgraph_rtl_info *i = cgraph_rtl_info (exp);
 803       type = TREE_TYPE (exp);
 804
 805       if (i && i->pure_function)
 806         flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
 807       if (i && i->const_function)
 808         flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
 809
 810       /* The function exp may have the `malloc' attribute.  */
 811       if (DECL_P (exp) && DECL_IS_MALLOC (exp))
 812         flags |= ECF_MALLOC;
 813
 814       /* The function exp may have the `pure' attribute.  */
 815       if (DECL_P (exp) && DECL_IS_PURE (exp))
 816         flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
 817
 818       if (TREE_NOTHROW (exp))
 819         flags |= ECF_NOTHROW;
 820     }
 821
 822   if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
 823     flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
 824
 825   if (TREE_THIS_VOLATILE (exp))
 826     flags |= ECF_NORETURN;
 827
 828   /* Mark if the function returns with the stack pointer depressed.   We
 829      cannot consider it pure or constant in that case.  */
 830   if (TREE_CODE (type) == FUNCTION_TYPE && TYPE_RETURNS_STACK_DEPRESSED (type))
 831     {
 832       flags |= ECF_SP_DEPRESSED;
 833       flags &= ~(ECF_PURE | ECF_CONST | ECF_LIBCALL_BLOCK);
 834     }
 835
 836   return flags;
 837 }
 838
 839 /* Precompute all register parameters as described by ARGS, storing values
 840    into fields within the ARGS array.
 841
 842    NUM_ACTUALS indicates the total number elements in the ARGS array.
 843
 844    Set REG_PARM_SEEN if we encounter a register parameter.  */
 845
 846 static void
 847 precompute_register_parameters (num_actuals, args, reg_parm_seen)
 848      int num_actuals;
 849      struct arg_data *args;
 850      int *reg_parm_seen;
 851 {
 852   int i;
 853
 854   *reg_parm_seen = 0;
 855
 856   for (i = 0; i < num_actuals; i++)
 857     if (args[i].reg != 0 && ! args[i].pass_on_stack)
 858       {
 859         *reg_parm_seen = 1;
 860
 861         if (args[i].value == 0)
 862           {
 863             push_temp_slots ();
 864             args[i].value = expand_expr (args[i].tree_value, NULL_RTX,
 865                                          VOIDmode, 0);
 866             preserve_temp_slots (args[i].value);
 867             pop_temp_slots ();
 868
 869             /* ANSI doesn't require a sequence point here,
 870                but PCC has one, so this will avoid some problems.  */
 871             emit_queue ();
 872           }
 873
 874         /* If the value is a non-legitimate constant, force it into a
 875            pseudo now.  TLS symbols sometimes need a call to resolve.  */
 876         if (CONSTANT_P (args[i].value)
 877             && !LEGITIMATE_CONSTANT_P (args[i].value))
 878           args[i].value = force_reg (args[i].mode, args[i].value);
 879
 880         /* If we are to promote the function arg to a wider mode,
 881            do it now.  */
 882
 883         if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
 884           args[i].value
 885             = convert_modes (args[i].mode,
 886                              TYPE_MODE (TREE_TYPE (args[i].tree_value)),
 887                              args[i].value, args[i].unsignedp);
 888
 889         /* If the value is expensive, and we are inside an appropriately
 890            short loop, put the value into a pseudo and then put the pseudo
 891            into the hard reg.
 892
 893            For small register classes, also do this if this call uses
 894            register parameters.  This is to avoid reload conflicts while
 895            loading the parameters registers.  */
 896
 897         if ((! (GET_CODE (args[i].value) == REG
 898                 || (GET_CODE (args[i].value) == SUBREG
 899                     && GET_CODE (SUBREG_REG (args[i].value)) == REG)))
 900             && args[i].mode != BLKmode
 901             && rtx_cost (args[i].value, SET) > COSTS_N_INSNS (1)
 902             && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
 903                 || preserve_subexpressions_p ()))
 904           args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
 905       }
 906 }
 907
 908 #ifdef REG_PARM_STACK_SPACE
 909
 910   /* The argument list is the property of the called routine and it
 911      may clobber it.  If the fixed area has been used for previous
 912      parameters, we must save and restore it.  */
 913
 914 static rtx
 915 save_fixed_argument_area (reg_parm_stack_space, argblock,
 916                           low_to_save, high_to_save)
 917      int reg_parm_stack_space;
 918      rtx argblock;
 919      int *low_to_save;
 920      int *high_to_save;
 921 {
 922   int low;
 923   int high;
 924
 925   /* Compute the boundary of the area that needs to be saved, if any.  */
 926   high = reg_parm_stack_space;
 927 #ifdef ARGS_GROW_DOWNWARD
 928   high += 1;
 929 #endif
 930   if (high > highest_outgoing_arg_in_use)
 931     high = highest_outgoing_arg_in_use;
 932
 933   for (low = 0; low < high; low++)
 934     if (stack_usage_map[low] != 0)
 935       {
 936         int num_to_save;
 937         enum machine_mode save_mode;
 938         int delta;
 939         rtx stack_area;
 940         rtx save_area;
 941
 942         while (stack_usage_map[--high] == 0)
 943           ;
 944
 945         *low_to_save = low;
 946         *high_to_save = high;
 947
 948         num_to_save = high - low + 1;
 949         save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
 950
 951         /* If we don't have the required alignment, must do this
 952            in BLKmode.  */
 953         if ((low & (MIN (GET_MODE_SIZE (save_mode),
 954                          BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
 955           save_mode = BLKmode;
 956
 957 #ifdef ARGS_GROW_DOWNWARD
 958         delta = -high;
 959 #else
 960         delta = low;
 961 #endif
 962         stack_area = gen_rtx_MEM (save_mode,
 963                                   memory_address (save_mode,
 964                                                   plus_constant (argblock,
 965                                                                  delta)));
 966
 967         set_mem_align (stack_area, PARM_BOUNDARY);
 968         if (save_mode == BLKmode)
 969           {
 970             save_area = assign_stack_temp (BLKmode, num_to_save, 0);
 971             emit_block_move (validize_mem (save_area), stack_area,
 972                              GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
 973           }
 974         else
 975           {
 976             save_area = gen_reg_rtx (save_mode);
 977             emit_move_insn (save_area, stack_area);
 978           }
 979
 980         return save_area;
 981       }
 982
 983   return NULL_RTX;
 984 }
 985
 986 static void
 987 restore_fixed_argument_area (save_area, argblock, high_to_save, low_to_save)
 988      rtx save_area;
 989      rtx argblock;
 990      int high_to_save;
 991      int low_to_save;
 992 {
 993   enum machine_mode save_mode = GET_MODE (save_area);
 994   int delta;
 995   rtx stack_area;
 996
 997 #ifdef ARGS_GROW_DOWNWARD
 998   delta = -high_to_save;
 999 #else
1000   delta = low_to_save;
1001 #endif
1002   stack_area = gen_rtx_MEM (save_mode,
1003                             memory_address (save_mode,
1004                                             plus_constant (argblock, delta)));
1005   set_mem_align (stack_area, PARM_BOUNDARY);
1006
1007   if (save_mode != BLKmode)
1008     emit_move_insn (stack_area, save_area);
1009   else
1010     emit_block_move (stack_area, validize_mem (save_area),
1011                      GEN_INT (high_to_save - low_to_save + 1),
1012                      BLOCK_OP_CALL_PARM);
1013 }
1014 #endif /* REG_PARM_STACK_SPACE */
1015
1016 /* If any elements in ARGS refer to parameters that are to be passed in
1017    registers, but not in memory, and whose alignment does not permit a
1018    direct copy into registers.  Copy the values into a group of pseudos
1019    which we will later copy into the appropriate hard registers.
1020
1021    Pseudos for each unaligned argument will be stored into the array
1022    args[argnum].aligned_regs.  The caller is responsible for deallocating
1023    the aligned_regs array if it is nonzero.  */
1024
1025 static void
1026 store_unaligned_arguments_into_pseudos (args, num_actuals)
1027      struct arg_data *args;
1028      int num_actuals;
1029 {
1030   int i, j;
1031
1032   for (i = 0; i < num_actuals; i++)
1033     if (args[i].reg != 0 && ! args[i].pass_on_stack
1034         && args[i].mode == BLKmode
1035         && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
1036             < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
1037       {
1038         int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1039         int big_endian_correction = 0;
1040
1041         args[i].n_aligned_regs
1042           = args[i].partial ? args[i].partial
1043             : (bytes + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1044
1045         args[i].aligned_regs = (rtx *) xmalloc (sizeof (rtx)
1046                                                 * args[i].n_aligned_regs);
1047
1048         /* Structures smaller than a word are aligned to the least
1049            significant byte (to the right).  On a BYTES_BIG_ENDIAN machine,
1050            this means we must skip the empty high order bytes when
1051            calculating the bit offset.  */
1052         if (BYTES_BIG_ENDIAN
1053             && bytes < UNITS_PER_WORD)
1054           big_endian_correction = (BITS_PER_WORD  - (bytes * BITS_PER_UNIT));
1055
1056         for (j = 0; j < args[i].n_aligned_regs; j++)
1057           {
1058             rtx reg = gen_reg_rtx (word_mode);
1059             rtx word = operand_subword_force (args[i].value, j, BLKmode);
1060             int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
1061
1062             args[i].aligned_regs[j] = reg;
1063
1064             /* There is no need to restrict this code to loading items
1065                in TYPE_ALIGN sized hunks.  The bitfield instructions can
1066                load up entire word sized registers efficiently.
1067
1068                ??? This may not be needed anymore.
1069                We use to emit a clobber here but that doesn't let later
1070                passes optimize the instructions we emit.  By storing 0 into
1071                the register later passes know the first AND to zero out the
1072                bitfield being set in the register is unnecessary.  The store
1073                of 0 will be deleted as will at least the first AND.  */
1074
1075             emit_move_insn (reg, const0_rtx);
1076
1077             bytes -= bitsize / BITS_PER_UNIT;
1078             store_bit_field (reg, bitsize, big_endian_correction, word_mode,
1079                              extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
1080                                                 word_mode, word_mode,
1081                                                 BITS_PER_WORD),
1082                              BITS_PER_WORD);
1083           }
1084       }
1085 }
1086
1087 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1088    ACTPARMS.
1089
1090    NUM_ACTUALS is the total number of parameters.
1091
1092    N_NAMED_ARGS is the total number of named arguments.
1093
1094    FNDECL is the tree code for the target of this call (if known)
1095
1096    ARGS_SO_FAR holds state needed by the target to know where to place
1097    the next argument.
1098
1099    REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1100    for arguments which are passed in registers.
1101
1102    OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1103    and may be modified by this routine.
1104
1105    OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1106    flags which may may be modified by this routine.  */
1107
1108 static void
1109 initialize_argument_information (num_actuals, args, args_size, n_named_args,
1110                                  actparms, fndecl, args_so_far,
1111                                  reg_parm_stack_space, old_stack_level,
1112                                  old_pending_adj, must_preallocate,
1113                                  ecf_flags)
1114      int num_actuals ATTRIBUTE_UNUSED;
1115      struct arg_data *args;
1116      struct args_size *args_size;
1117      int n_named_args ATTRIBUTE_UNUSED;
1118      tree actparms;
1119      tree fndecl;
1120      CUMULATIVE_ARGS *args_so_far;
1121      int reg_parm_stack_space;
1122      rtx *old_stack_level;
1123      int *old_pending_adj;
1124      int *must_preallocate;
1125      int *ecf_flags;
1126 {
1127   /* 1 if scanning parms front to back, -1 if scanning back to front.  */
1128   int inc;
1129
1130   /* Count arg position in order args appear.  */
1131   int argpos;
1132
1133   struct args_size alignment_pad;
1134   int i;
1135   tree p;
1136
1137   args_size->constant = 0;
1138   args_size->var = 0;
1139
1140   /* In this loop, we consider args in the order they are written.
1141      We fill up ARGS from the front or from the back if necessary
1142      so that in any case the first arg to be pushed ends up at the front.  */
1143
1144   if (PUSH_ARGS_REVERSED)
1145     {
1146       i = num_actuals - 1, inc = -1;
1147       /* In this case, must reverse order of args
1148          so that we compute and push the last arg first.  */
1149     }
1150   else
1151     {
1152       i = 0, inc = 1;
1153     }
1154
1155   /* I counts args in order (to be) pushed; ARGPOS counts in order written.  */
1156   for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
1157     {
1158       tree type = TREE_TYPE (TREE_VALUE (p));
1159       int unsignedp;
1160       enum machine_mode mode;
1161
1162       args[i].tree_value = TREE_VALUE (p);
1163
1164       /* Replace erroneous argument with constant zero.  */
1165       if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1166         args[i].tree_value = integer_zero_node, type = integer_type_node;
1167
1168       /* If TYPE is a transparent union, pass things the way we would
1169          pass the first field of the union.  We have already verified that
1170          the modes are the same.  */
1171       if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
1172         type = TREE_TYPE (TYPE_FIELDS (type));
1173
1174       /* Decide where to pass this arg.
1175
1176          args[i].reg is nonzero if all or part is passed in registers.
1177
1178          args[i].partial is nonzero if part but not all is passed in registers,
1179          and the exact value says how many words are passed in registers.
1180
1181          args[i].pass_on_stack is nonzero if the argument must at least be
1182          computed on the stack.  It may then be loaded back into registers
1183          if args[i].reg is nonzero.
1184
1185          These decisions are driven by the FUNCTION_... macros and must agree
1186          with those made by function.c.  */
1187
1188       /* See if this argument should be passed by invisible reference.  */
1189       if ((TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1190            && contains_placeholder_p (TYPE_SIZE (type)))
1191           || TREE_ADDRESSABLE (type)
1192 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
1193           || FUNCTION_ARG_PASS_BY_REFERENCE (*args_so_far, TYPE_MODE (type),
1194                                              type, argpos < n_named_args)
1195 #endif
1196           )
1197         {
1198           /* If we're compiling a thunk, pass through invisible
1199              references instead of making a copy.  */
1200           if (current_function_is_thunk
1201 #ifdef FUNCTION_ARG_CALLEE_COPIES
1202               || (FUNCTION_ARG_CALLEE_COPIES (*args_so_far, TYPE_MODE (type),
1203                                              type, argpos < n_named_args)
1204                   /* If it's in a register, we must make a copy of it too.  */
1205                   /* ??? Is this a sufficient test?  Is there a better one? */
1206                   && !(TREE_CODE (args[i].tree_value) == VAR_DECL
1207                        && REG_P (DECL_RTL (args[i].tree_value)))
1208                   && ! TREE_ADDRESSABLE (type))
1209 #endif
1210               )
1211             {
1212               /* C++ uses a TARGET_EXPR to indicate that we want to make a
1213                  new object from the argument.  If we are passing by
1214                  invisible reference, the callee will do that for us, so we
1215                  can strip off the TARGET_EXPR.  This is not always safe,
1216                  but it is safe in the only case where this is a useful
1217                  optimization; namely, when the argument is a plain object.
1218                  In that case, the frontend is just asking the backend to
1219                  make a bitwise copy of the argument.  */
1220
1221               if (TREE_CODE (args[i].tree_value) == TARGET_EXPR
1222                   && (DECL_P (TREE_OPERAND (args[i].tree_value, 1)))
1223                   && ! REG_P (DECL_RTL (TREE_OPERAND (args[i].tree_value, 1))))
1224                 args[i].tree_value = TREE_OPERAND (args[i].tree_value, 1);
1225
1226               args[i].tree_value = build1 (ADDR_EXPR,
1227                                            build_pointer_type (type),
1228                                            args[i].tree_value);
1229               type = build_pointer_type (type);
1230             }
1231           else if (TREE_CODE (args[i].tree_value) == TARGET_EXPR)
1232             {
1233               /* In the V3 C++ ABI, parameters are destroyed in the caller.
1234                  We implement this by passing the address of the temporary
1235                  rather than expanding it into another allocated slot.  */
1236               args[i].tree_value = build1 (ADDR_EXPR,
1237                                            build_pointer_type (type),
1238                                            args[i].tree_value);
1239               type = build_pointer_type (type);
1240             }
1241           else
1242             {
1243               /* We make a copy of the object and pass the address to the
1244                  function being called.  */
1245               rtx copy;
1246
1247               if (!COMPLETE_TYPE_P (type)
1248                   || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1249                   || (flag_stack_check && ! STACK_CHECK_BUILTIN
1250                       && (0 < compare_tree_int (TYPE_SIZE_UNIT (type),
1251                                                 STACK_CHECK_MAX_VAR_SIZE))))
1252                 {
1253                   /* This is a variable-sized object.  Make space on the stack
1254                      for it.  */
1255                   rtx size_rtx = expr_size (TREE_VALUE (p));
1256
1257                   if (*old_stack_level == 0)
1258                     {
1259                       emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1260                       *old_pending_adj = pending_stack_adjust;
1261                       pending_stack_adjust = 0;
1262                     }
1263
1264                   copy = gen_rtx_MEM (BLKmode,
1265                                       allocate_dynamic_stack_space
1266                                       (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1267                   set_mem_attributes (copy, type, 1);
1268                 }
1269               else
1270                 copy = assign_temp (type, 0, 1, 0);
1271
1272               store_expr (args[i].tree_value, copy, 0);
1273               *ecf_flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
1274
1275               args[i].tree_value = build1 (ADDR_EXPR,
1276                                            build_pointer_type (type),
1277                                            make_tree (type, copy));
1278               type = build_pointer_type (type);
1279             }
1280         }
1281
1282       mode = TYPE_MODE (type);
1283       unsignedp = TREE_UNSIGNED (type);
1284
1285 #ifdef PROMOTE_FUNCTION_ARGS
1286       mode = promote_mode (type, mode, &unsignedp, 1);
1287 #endif
1288
1289       args[i].unsignedp = unsignedp;
1290       args[i].mode = mode;
1291
1292       args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1293                                   argpos < n_named_args);
1294 #ifdef FUNCTION_INCOMING_ARG
1295       /* If this is a sibling call and the machine has register windows, the
1296          register window has to be unwinded before calling the routine, so
1297          arguments have to go into the incoming registers.  */
1298       args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1299                                                      argpos < n_named_args);
1300 #else
1301       args[i].tail_call_reg = args[i].reg;
1302 #endif
1303
1304 #ifdef FUNCTION_ARG_PARTIAL_NREGS
1305       if (args[i].reg)
1306         args[i].partial
1307           = FUNCTION_ARG_PARTIAL_NREGS (*args_so_far, mode, type,
1308                                         argpos < n_named_args);
1309 #endif
1310
1311       args[i].pass_on_stack = MUST_PASS_IN_STACK (mode, type);
1312
1313       /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1314          it means that we are to pass this arg in the register(s) designated
1315          by the PARALLEL, but also to pass it in the stack.  */
1316       if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1317           && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1318         args[i].pass_on_stack = 1;
1319
1320       /* If this is an addressable type, we must preallocate the stack
1321          since we must evaluate the object into its final location.
1322
1323          If this is to be passed in both registers and the stack, it is simpler
1324          to preallocate.  */
1325       if (TREE_ADDRESSABLE (type)
1326           || (args[i].pass_on_stack && args[i].reg != 0))
1327         *must_preallocate = 1;
1328
1329       /* If this is an addressable type, we cannot pre-evaluate it.  Thus,
1330          we cannot consider this function call constant.  */
1331       if (TREE_ADDRESSABLE (type))
1332         *ecf_flags &= ~ECF_LIBCALL_BLOCK;
1333
1334       /* Compute the stack-size of this argument.  */
1335       if (args[i].reg == 0 || args[i].partial != 0
1336           || reg_parm_stack_space > 0
1337           || args[i].pass_on_stack)
1338         locate_and_pad_parm (mode, type,
1339 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1340                              1,
1341 #else
1342                              args[i].reg != 0,
1343 #endif
1344                              fndecl, args_size, &args[i].offset,
1345                              &args[i].size, &alignment_pad);
1346
1347 #ifndef ARGS_GROW_DOWNWARD
1348       args[i].slot_offset = *args_size;
1349 #endif
1350
1351       args[i].alignment_pad = alignment_pad;
1352
1353       /* If a part of the arg was put into registers,
1354          don't include that part in the amount pushed.  */
1355       if (reg_parm_stack_space == 0 && ! args[i].pass_on_stack)
1356         args[i].size.constant -= ((args[i].partial * UNITS_PER_WORD)
1357                                   / (PARM_BOUNDARY / BITS_PER_UNIT)
1358                                   * (PARM_BOUNDARY / BITS_PER_UNIT));
1359
1360       /* Update ARGS_SIZE, the total stack space for args so far.  */
1361
1362       args_size->constant += args[i].size.constant;
1363       if (args[i].size.var)
1364         {
1365           ADD_PARM_SIZE (*args_size, args[i].size.var);
1366         }
1367
1368       /* Since the slot offset points to the bottom of the slot,
1369          we must record it after incrementing if the args grow down.  */
1370 #ifdef ARGS_GROW_DOWNWARD
1371       args[i].slot_offset = *args_size;
1372
1373       args[i].slot_offset.constant = -args_size->constant;
1374       if (args_size->var)
1375         SUB_PARM_SIZE (args[i].slot_offset, args_size->var);
1376 #endif
1377
1378       /* Increment ARGS_SO_FAR, which has info about which arg-registers
1379          have been used, etc.  */
1380
1381       FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1382                             argpos < n_named_args);
1383     }
1384 }
1385
1386 /* Update ARGS_SIZE to contain the total size for the argument block.
1387    Return the original constant component of the argument block's size.
1388
1389    REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1390    for arguments passed in registers.  */
1391
1392 static int
1393 compute_argument_block_size (reg_parm_stack_space, args_size,
1394                              preferred_stack_boundary)
1395      int reg_parm_stack_space;
1396      struct args_size *args_size;
1397      int preferred_stack_boundary ATTRIBUTE_UNUSED;
1398 {
1399   int unadjusted_args_size = args_size->constant;
1400
1401   /* For accumulate outgoing args mode we don't need to align, since the frame
1402      will be already aligned.  Align to STACK_BOUNDARY in order to prevent
1403      backends from generating misaligned frame sizes.  */
1404   if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1405     preferred_stack_boundary = STACK_BOUNDARY;
1406
1407   /* Compute the actual size of the argument block required.  The variable
1408      and constant sizes must be combined, the size may have to be rounded,
1409      and there may be a minimum required size.  */
1410
1411   if (args_size->var)
1412     {
1413       args_size->var = ARGS_SIZE_TREE (*args_size);
1414       args_size->constant = 0;
1415
1416       preferred_stack_boundary /= BITS_PER_UNIT;
1417       if (preferred_stack_boundary > 1)
1418         {
1419           /* We don't handle this case yet.  To handle it correctly we have
1420              to add the delta, round and subtract the delta.
1421              Currently no machine description requires this support.  */
1422           if (stack_pointer_delta & (preferred_stack_boundary - 1))
1423             abort ();
1424           args_size->var = round_up (args_size->var, preferred_stack_boundary);
1425         }
1426
1427       if (reg_parm_stack_space > 0)
1428         {
1429           args_size->var
1430             = size_binop (MAX_EXPR, args_size->var,
1431                           ssize_int (reg_parm_stack_space));
1432
1433 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1434           /* The area corresponding to register parameters is not to count in
1435              the size of the block we need.  So make the adjustment.  */
1436           args_size->var
1437             = size_binop (MINUS_EXPR, args_size->var,
1438                           ssize_int (reg_parm_stack_space));
1439 #endif
1440         }
1441     }
1442   else
1443     {
1444       preferred_stack_boundary /= BITS_PER_UNIT;
1445       if (preferred_stack_boundary < 1)
1446         preferred_stack_boundary = 1;
1447       args_size->constant = (((args_size->constant
1448                                + stack_pointer_delta
1449                                + preferred_stack_boundary - 1)
1450                               / preferred_stack_boundary
1451                               * preferred_stack_boundary)
1452                              - stack_pointer_delta);
1453
1454       args_size->constant = MAX (args_size->constant,
1455                                  reg_parm_stack_space);
1456
1457 #ifdef MAYBE_REG_PARM_STACK_SPACE
1458       if (reg_parm_stack_space == 0)
1459         args_size->constant = 0;
1460 #endif
1461
1462 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1463       args_size->constant -= reg_parm_stack_space;
1464 #endif
1465     }
1466   return unadjusted_args_size;
1467 }
1468
1469 /* Precompute parameters as needed for a function call.
1470
1471    FLAGS is mask of ECF_* constants.
1472
1473    NUM_ACTUALS is the number of arguments.
1474
1475    ARGS is an array containing information for each argument; this
1476    routine fills in the INITIAL_VALUE and VALUE fields for each
1477    precomputed argument.  */
1478
1479 static void
1480 precompute_arguments (flags, num_actuals, args)
1481      int flags;
1482      int num_actuals;
1483      struct arg_data *args;
1484 {
1485   int i;
1486
1487   /* If this function call is cse'able, precompute all the parameters.
1488      Note that if the parameter is constructed into a temporary, this will
1489      cause an additional copy because the parameter will be constructed
1490      into a temporary location and then copied into the outgoing arguments.
1491      If a parameter contains a call to alloca and this function uses the
1492      stack, precompute the parameter.  */
1493
1494   /* If we preallocated the stack space, and some arguments must be passed
1495      on the stack, then we must precompute any parameter which contains a
1496      function call which will store arguments on the stack.
1497      Otherwise, evaluating the parameter may clobber previous parameters
1498      which have already been stored into the stack.  (we have code to avoid
1499      such case by saving the outgoing stack arguments, but it results in
1500      worse code)  */
1501
1502   for (i = 0; i < num_actuals; i++)
1503     if ((flags & ECF_LIBCALL_BLOCK)
1504         || calls_function (args[i].tree_value, !ACCUMULATE_OUTGOING_ARGS))
1505       {
1506         enum machine_mode mode;
1507
1508         /* If this is an addressable type, we cannot pre-evaluate it.  */
1509         if (TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)))
1510           abort ();
1511
1512         args[i].value
1513           = expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0);
1514
1515         /* ANSI doesn't require a sequence point here,
1516            but PCC has one, so this will avoid some problems.  */
1517         emit_queue ();
1518
1519         args[i].initial_value = args[i].value
1520           = protect_from_queue (args[i].value, 0);
1521
1522         mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1523         if (mode != args[i].mode)
1524           {
1525             args[i].value
1526               = convert_modes (args[i].mode, mode,
1527                                args[i].value, args[i].unsignedp);
1528 #ifdef PROMOTE_FOR_CALL_ONLY
1529             /* CSE will replace this only if it contains args[i].value
1530                pseudo, so convert it down to the declared mode using
1531                a SUBREG.  */
1532             if (GET_CODE (args[i].value) == REG
1533                 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1534               {
1535                 args[i].initial_value
1536                   = gen_lowpart_SUBREG (mode, args[i].value);
1537                 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1538                 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1539                   args[i].unsignedp);
1540               }
1541 #endif
1542           }
1543       }
1544 }
1545
1546 /* Given the current state of MUST_PREALLOCATE and information about
1547    arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1548    compute and return the final value for MUST_PREALLOCATE.  */
1549
1550 static int
1551 finalize_must_preallocate (must_preallocate, num_actuals, args, args_size)
1552      int must_preallocate;
1553      int num_actuals;
1554      struct arg_data *args;
1555      struct args_size *args_size;
1556 {
1557   /* See if we have or want to preallocate stack space.
1558
1559      If we would have to push a partially-in-regs parm
1560      before other stack parms, preallocate stack space instead.
1561
1562      If the size of some parm is not a multiple of the required stack
1563      alignment, we must preallocate.
1564
1565      If the total size of arguments that would otherwise create a copy in
1566      a temporary (such as a CALL) is more than half the total argument list
1567      size, preallocation is faster.
1568
1569      Another reason to preallocate is if we have a machine (like the m88k)
1570      where stack alignment is required to be maintained between every
1571      pair of insns, not just when the call is made.  However, we assume here
1572      that such machines either do not have push insns (and hence preallocation
1573      would occur anyway) or the problem is taken care of with
1574      PUSH_ROUNDING.  */
1575
1576   if (! must_preallocate)
1577     {
1578       int partial_seen = 0;
1579       int copy_to_evaluate_size = 0;
1580       int i;
1581
1582       for (i = 0; i < num_actuals && ! must_preallocate; i++)
1583         {
1584           if (args[i].partial > 0 && ! args[i].pass_on_stack)
1585             partial_seen = 1;
1586           else if (partial_seen && args[i].reg == 0)
1587             must_preallocate = 1;
1588
1589           if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1590               && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1591                   || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1592                   || TREE_CODE (args[i].tree_value) == COND_EXPR
1593                   || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1594             copy_to_evaluate_size
1595               += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1596         }
1597
1598       if (copy_to_evaluate_size * 2 >= args_size->constant
1599           && args_size->constant > 0)
1600         must_preallocate = 1;
1601     }
1602   return must_preallocate;
1603 }
1604
1605 /* If we preallocated stack space, compute the address of each argument
1606    and store it into the ARGS array.
1607
1608    We need not ensure it is a valid memory address here; it will be
1609    validized when it is used.
1610
1611    ARGBLOCK is an rtx for the address of the outgoing arguments.  */
1612
1613 static void
1614 compute_argument_addresses (args, argblock, num_actuals)
1615      struct arg_data *args;
1616      rtx argblock;
1617      int num_actuals;
1618 {
1619   if (argblock)
1620     {
1621       rtx arg_reg = argblock;
1622       int i, arg_offset = 0;
1623
1624       if (GET_CODE (argblock) == PLUS)
1625         arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1626
1627       for (i = 0; i < num_actuals; i++)
1628         {
1629           rtx offset = ARGS_SIZE_RTX (args[i].offset);
1630           rtx slot_offset = ARGS_SIZE_RTX (args[i].slot_offset);
1631           rtx addr;
1632
1633           /* Skip this parm if it will not be passed on the stack.  */
1634           if (! args[i].pass_on_stack && args[i].reg != 0)
1635             continue;
1636
1637           if (GET_CODE (offset) == CONST_INT)
1638             addr = plus_constant (arg_reg, INTVAL (offset));
1639           else
1640             addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1641
1642           addr = plus_constant (addr, arg_offset);
1643           args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1644           set_mem_align (args[i].stack, PARM_BOUNDARY);
1645           set_mem_attributes (args[i].stack,
1646                               TREE_TYPE (args[i].tree_value), 1);
1647
1648           if (GET_CODE (slot_offset) == CONST_INT)
1649             addr = plus_constant (arg_reg, INTVAL (slot_offset));
1650           else
1651             addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1652
1653           addr = plus_constant (addr, arg_offset);
1654           args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1655           set_mem_align (args[i].stack_slot, PARM_BOUNDARY);
1656           set_mem_attributes (args[i].stack_slot,
1657                               TREE_TYPE (args[i].tree_value), 1);
1658
1659           /* Function incoming arguments may overlap with sibling call
1660              outgoing arguments and we cannot allow reordering of reads
1661              from function arguments with stores to outgoing arguments
1662              of sibling calls.  */
1663           set_mem_alias_set (args[i].stack, 0);
1664           set_mem_alias_set (args[i].stack_slot, 0);
1665         }
1666     }
1667 }
1668
1669 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1670    in a call instruction.
1671
1672    FNDECL is the tree node for the target function.  For an indirect call
1673    FNDECL will be NULL_TREE.
1674
1675    ADDR is the operand 0 of CALL_EXPR for this call.  */
1676
1677 static rtx
1678 rtx_for_function_call (fndecl, addr)
1679      tree fndecl;
1680      tree addr;
1681 {
1682   rtx funexp;
1683
1684   /* Get the function to call, in the form of RTL.  */
1685   if (fndecl)
1686     {
1687       /* If this is the first use of the function, see if we need to
1688          make an external definition for it.  */
1689       if (! TREE_USED (fndecl))
1690         {
1691           assemble_external (fndecl);
1692           TREE_USED (fndecl) = 1;
1693         }
1694
1695       /* Get a SYMBOL_REF rtx for the function address.  */
1696       funexp = XEXP (DECL_RTL (fndecl), 0);
1697     }
1698   else
1699     /* Generate an rtx (probably a pseudo-register) for the address.  */
1700     {
1701       push_temp_slots ();
1702       funexp = expand_expr (addr, NULL_RTX, VOIDmode, 0);
1703       pop_temp_slots ();        /* FUNEXP can't be BLKmode.  */
1704       emit_queue ();
1705     }
1706   return funexp;
1707 }
1708
1709 /* Do the register loads required for any wholly-register parms or any
1710    parms which are passed both on the stack and in a register.  Their
1711    expressions were already evaluated.
1712
1713    Mark all register-parms as living through the call, putting these USE
1714    insns in the CALL_INSN_FUNCTION_USAGE field.
1715
1716    When IS_SIBCALL, perform the check_sibcall_overlap_argument_overlap
1717    checking, setting *SIBCALL_FAILURE if appropriate.  */
1718
1719 static void
1720 load_register_parameters (args, num_actuals, call_fusage, flags,
1721                             is_sibcall, sibcall_failure)
1722      struct arg_data *args;
1723      int num_actuals;
1724      rtx *call_fusage;
1725      int flags;
1726      int is_sibcall;
1727      int *sibcall_failure;
1728 {
1729   int i, j;
1730
1731 #ifdef LOAD_ARGS_REVERSED
1732   for (i = num_actuals - 1; i >= 0; i--)
1733 #else
1734   for (i = 0; i < num_actuals; i++)
1735 #endif
1736     {
1737       rtx reg = ((flags & ECF_SIBCALL)
1738                  ? args[i].tail_call_reg : args[i].reg);
1739       int partial = args[i].partial;
1740       int nregs;
1741
1742       if (reg)
1743         {
1744           rtx before_arg = get_last_insn ();
1745           /* Set to non-negative if must move a word at a time, even if just
1746              one word (e.g, partial == 1 && mode == DFmode).  Set to -1 if
1747              we just use a normal move insn.  This value can be zero if the
1748              argument is a zero size structure with no fields.  */
1749           nregs = (partial ? partial
1750                    : (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1751                       ? ((int_size_in_bytes (TREE_TYPE (args[i].tree_value))
1752                           + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)
1753                       : -1));
1754
1755           /* Handle calls that pass values in multiple non-contiguous
1756              locations.  The Irix 6 ABI has examples of this.  */
1757
1758           if (GET_CODE (reg) == PARALLEL)
1759             emit_group_load (reg, args[i].value,
1760                              int_size_in_bytes (TREE_TYPE (args[i].tree_value)));
1761
1762           /* If simple case, just do move.  If normal partial, store_one_arg
1763              has already loaded the register for us.  In all other cases,
1764              load the register(s) from memory.  */
1765
1766           else if (nregs == -1)
1767             emit_move_insn (reg, args[i].value);
1768
1769           /* If we have pre-computed the values to put in the registers in
1770              the case of non-aligned structures, copy them in now.  */
1771
1772           else if (args[i].n_aligned_regs != 0)
1773             for (j = 0; j < args[i].n_aligned_regs; j++)
1774               emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1775                               args[i].aligned_regs[j]);
1776
1777           else if (partial == 0 || args[i].pass_on_stack)
1778             move_block_to_reg (REGNO (reg),
1779                                validize_mem (args[i].value), nregs,
1780                                args[i].mode);
1781
1782           /* When a parameter is a block, and perhaps in other cases, it is
1783              possible that it did a load from an argument slot that was
1784              already clobbered.  */
1785           if (is_sibcall
1786               && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1787             *sibcall_failure = 1;
1788
1789           /* Handle calls that pass values in multiple non-contiguous
1790              locations.  The Irix 6 ABI has examples of this.  */
1791           if (GET_CODE (reg) == PARALLEL)
1792             use_group_regs (call_fusage, reg);
1793           else if (nregs == -1)
1794             use_reg (call_fusage, reg);
1795           else
1796             use_regs (call_fusage, REGNO (reg), nregs == 0 ? 1 : nregs);
1797         }
1798     }
1799 }
1800
1801 /* Try to integrate function.  See expand_inline_function for documentation
1802    about the parameters.  */
1803
1804 static rtx
1805 try_to_integrate (fndecl, actparms, target, ignore, type, structure_value_addr)
1806      tree fndecl;
1807      tree actparms;
1808      rtx target;
1809      int ignore;
1810      tree type;
1811      rtx structure_value_addr;
1812 {
1813   rtx temp;
1814   rtx before_call;
1815   int i;
1816   rtx old_stack_level = 0;
1817   int reg_parm_stack_space = 0;
1818
1819 #ifdef REG_PARM_STACK_SPACE
1820 #ifdef MAYBE_REG_PARM_STACK_SPACE
1821   reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
1822 #else
1823   reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
1824 #endif
1825 #endif
1826
1827   before_call = get_last_insn ();
1828
1829   timevar_push (TV_INTEGRATION);
1830
1831   temp = expand_inline_function (fndecl, actparms, target,
1832                                  ignore, type,
1833                                  structure_value_addr);
1834
1835   timevar_pop (TV_INTEGRATION);
1836
1837   /* If inlining succeeded, return.  */
1838   if (temp != (rtx) (size_t) - 1)
1839     {
1840       if (ACCUMULATE_OUTGOING_ARGS)
1841         {
1842           /* If the outgoing argument list must be preserved, push
1843              the stack before executing the inlined function if it
1844              makes any calls.  */
1845
1846           i = reg_parm_stack_space;
1847           if (i > highest_outgoing_arg_in_use)
1848             i = highest_outgoing_arg_in_use;
1849           while (--i >= 0 && stack_usage_map[i] == 0)
1850             ;
1851
1852           if (stack_arg_under_construction || i >= 0)
1853             {
1854               rtx first_insn
1855                 = before_call ? NEXT_INSN (before_call) : get_insns ();
1856               rtx insn = NULL_RTX, seq;
1857
1858               /* Look for a call in the inline function code.
1859                  If DECL_SAVED_INSNS (fndecl)->outgoing_args_size is
1860                  nonzero then there is a call and it is not necessary
1861                  to scan the insns.  */
1862
1863               if (DECL_SAVED_INSNS (fndecl)->outgoing_args_size == 0)
1864                 for (insn = first_insn; insn; insn = NEXT_INSN (insn))
1865                   if (GET_CODE (insn) == CALL_INSN)
1866                     break;
1867
1868               if (insn)
1869                 {
1870                   /* Reserve enough stack space so that the largest
1871                      argument list of any function call in the inline
1872                      function does not overlap the argument list being
1873                      evaluated.  This is usually an overestimate because
1874                      allocate_dynamic_stack_space reserves space for an
1875                      outgoing argument list in addition to the requested
1876                      space, but there is no way to ask for stack space such
1877                      that an argument list of a certain length can be
1878                      safely constructed.
1879
1880                      Add the stack space reserved for register arguments, if
1881                      any, in the inline function.  What is really needed is the
1882                      largest value of reg_parm_stack_space in the inline
1883                      function, but that is not available.  Using the current
1884                      value of reg_parm_stack_space is wrong, but gives
1885                      correct results on all supported machines.  */
1886
1887                   int adjust = (DECL_SAVED_INSNS (fndecl)->outgoing_args_size
1888                                 + reg_parm_stack_space);
1889
1890                   start_sequence ();
1891                   emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
1892                   allocate_dynamic_stack_space (GEN_INT (adjust),
1893                                                 NULL_RTX, BITS_PER_UNIT);
1894                   seq = get_insns ();
1895                   end_sequence ();
1896                   emit_insn_before (seq, first_insn);
1897                   emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
1898                 }
1899             }
1900         }
1901
1902       /* If the result is equivalent to TARGET, return TARGET to simplify
1903          checks in store_expr.  They can be equivalent but not equal in the
1904          case of a function that returns BLKmode.  */
1905       if (temp != target && rtx_equal_p (temp, target))
1906         return target;
1907       return temp;
1908     }
1909
1910   /* If inlining failed, mark FNDECL as needing to be compiled
1911      separately after all.  If function was declared inline,
1912      give a warning.  */
1913   if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
1914       && optimize > 0 && !TREE_ADDRESSABLE (fndecl))
1915     {
1916       warning_with_decl (fndecl, "inlining failed in call to `%s'");
1917       warning ("called from here");
1918     }
1919   (*lang_hooks.mark_addressable) (fndecl);
1920   return (rtx) (size_t) - 1;
1921 }
1922
1923 /* We need to pop PENDING_STACK_ADJUST bytes.  But, if the arguments
1924    wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1925    bytes, then we would need to push some additional bytes to pad the
1926    arguments.  So, we compute an adjust to the stack pointer for an
1927    amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1928    bytes.  Then, when the arguments are pushed the stack will be perfectly
1929    aligned.  ARGS_SIZE->CONSTANT is set to the number of bytes that should
1930    be popped after the call.  Returns the adjustment.  */
1931
1932 static int
1933 combine_pending_stack_adjustment_and_call (unadjusted_args_size,
1934                                            args_size,
1935                                            preferred_unit_stack_boundary)
1936      int unadjusted_args_size;
1937      struct args_size *args_size;
1938      int preferred_unit_stack_boundary;
1939 {
1940   /* The number of bytes to pop so that the stack will be
1941      under-aligned by UNADJUSTED_ARGS_SIZE bytes.  */
1942   HOST_WIDE_INT adjustment;
1943   /* The alignment of the stack after the arguments are pushed, if we
1944      just pushed the arguments without adjust the stack here.  */
1945   HOST_WIDE_INT unadjusted_alignment;
1946
1947   unadjusted_alignment
1948     = ((stack_pointer_delta + unadjusted_args_size)
1949        % preferred_unit_stack_boundary);
1950
1951   /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1952      as possible -- leaving just enough left to cancel out the
1953      UNADJUSTED_ALIGNMENT.  In other words, we want to ensure that the
1954      PENDING_STACK_ADJUST is non-negative, and congruent to
1955      -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY.  */
1956
1957   /* Begin by trying to pop all the bytes.  */
1958   unadjusted_alignment
1959     = (unadjusted_alignment
1960        - (pending_stack_adjust % preferred_unit_stack_boundary));
1961   adjustment = pending_stack_adjust;
1962   /* Push enough additional bytes that the stack will be aligned
1963      after the arguments are pushed.  */
1964   if (preferred_unit_stack_boundary > 1)
1965     {
1966       if (unadjusted_alignment > 0)
1967         adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1968       else
1969         adjustment += unadjusted_alignment;
1970     }
1971
1972   /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1973      bytes after the call.  The right number is the entire
1974      PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1975      by the arguments in the first place.  */
1976   args_size->constant
1977     = pending_stack_adjust - adjustment + unadjusted_args_size;
1978
1979   return adjustment;
1980 }
1981
1982 /* Scan X expression if it does not dereference any argument slots
1983    we already clobbered by tail call arguments (as noted in stored_args_map
1984    bitmap).
1985    Return nonzero if X expression dereferences such argument slots,
1986    zero otherwise.  */
1987
1988 static int
1989 check_sibcall_argument_overlap_1 (x)
1990      rtx x;
1991 {
1992   RTX_CODE code;
1993   int i, j;
1994   unsigned int k;
1995   const char *fmt;
1996
1997   if (x == NULL_RTX)
1998     return 0;
1999
2000   code = GET_CODE (x);
2001
2002   if (code == MEM)
2003     {
2004       if (XEXP (x, 0) == current_function_internal_arg_pointer)
2005         i = 0;
2006       else if (GET_CODE (XEXP (x, 0)) == PLUS
2007                && XEXP (XEXP (x, 0), 0) ==
2008                   current_function_internal_arg_pointer
2009                && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)
2010         i = INTVAL (XEXP (XEXP (x, 0), 1));
2011       else
2012         return 0;
2013
2014 #ifdef ARGS_GROW_DOWNWARD
2015       i = -i - GET_MODE_SIZE (GET_MODE (x));
2016 #endif
2017
2018       for (k = 0; k < GET_MODE_SIZE (GET_MODE (x)); k++)
2019         if (i + k < stored_args_map->n_bits
2020             && TEST_BIT (stored_args_map, i + k))
2021           return 1;
2022
2023       return 0;
2024     }
2025
2026   /* Scan all subexpressions.  */
2027   fmt = GET_RTX_FORMAT (code);
2028   for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2029     {
2030       if (*fmt == 'e')
2031         {
2032           if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
2033             return 1;
2034         }
2035       else if (*fmt == 'E')
2036         {
2037           for (j = 0; j < XVECLEN (x, i); j++)
2038             if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
2039               return 1;
2040         }
2041     }
2042   return 0;
2043 }
2044
2045 /* Scan sequence after INSN if it does not dereference any argument slots
2046    we already clobbered by tail call arguments (as noted in stored_args_map
2047    bitmap).  If MARK_STORED_ARGS_MAP, add stack slots for ARG to
2048    stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
2049    should be 0).  Return nonzero if sequence after INSN dereferences such argument
2050    slots, zero otherwise.  */
2051
2052 static int
2053 check_sibcall_argument_overlap (insn, arg, mark_stored_args_map)
2054      rtx insn;
2055      struct arg_data *arg;
2056      int mark_stored_args_map;
2057 {
2058   int low, high;
2059
2060   if (insn == NULL_RTX)
2061     insn = get_insns ();
2062   else
2063     insn = NEXT_INSN (insn);
2064
2065   for (; insn; insn = NEXT_INSN (insn))
2066     if (INSN_P (insn)
2067         && check_sibcall_argument_overlap_1 (PATTERN (insn)))
2068       break;
2069
2070   if (mark_stored_args_map)
2071     {
2072 #ifdef ARGS_GROW_DOWNWARD
2073       low = -arg->slot_offset.constant - arg->size.constant;
2074 #else
2075       low = arg->slot_offset.constant;
2076 #endif
2077
2078       for (high = low + arg->size.constant; low < high; low++)
2079         SET_BIT (stored_args_map, low);
2080     }
2081   return insn != NULL_RTX;
2082 }
2083
2084 static tree
2085 fix_unsafe_tree (t)
2086      tree t;
2087 {
2088   switch (unsafe_for_reeval (t))
2089     {
2090     case 0: /* Safe.  */
2091       break;
2092
2093     case 1: /* Mildly unsafe.  */
2094       t = unsave_expr (t);
2095       break;
2096
2097     case 2: /* Wildly unsafe.  */
2098       {
2099         tree var = build_decl (VAR_DECL, NULL_TREE,
2100                                TREE_TYPE (t));
2101         SET_DECL_RTL (var,
2102                       expand_expr (t, NULL_RTX, VOIDmode, EXPAND_NORMAL));
2103         t = var;
2104       }
2105       break;
2106
2107     default:
2108       abort ();
2109     }
2110   return t;
2111 }
2112
2113 /* Generate all the code for a function call
2114    and return an rtx for its value.
2115    Store the value in TARGET (specified as an rtx) if convenient.
2116    If the value is stored in TARGET then TARGET is returned.
2117    If IGNORE is nonzero, then we ignore the value of the function call.  */
2118
2119 rtx
2120 expand_call (exp, target, ignore)
2121      tree exp;
2122      rtx target;
2123      int ignore;
2124 {
2125   /* Nonzero if we are currently expanding a call.  */
2126   static int currently_expanding_call = 0;
2127
2128   /* List of actual parameters.  */
2129   tree actparms = TREE_OPERAND (exp, 1);
2130   /* RTX for the function to be called.  */
2131   rtx funexp;
2132   /* Sequence of insns to perform a tail recursive "call".  */
2133   rtx tail_recursion_insns = NULL_RTX;
2134   /* Sequence of insns to perform a normal "call".  */
2135   rtx normal_call_insns = NULL_RTX;
2136   /* Sequence of insns to perform a tail recursive "call".  */
2137   rtx tail_call_insns = NULL_RTX;
2138   /* Data type of the function.  */
2139   tree funtype;
2140   /* Declaration of the function being called,
2141      or 0 if the function is computed (not known by name).  */
2142   tree fndecl = 0;
2143   rtx insn;
2144   int try_tail_call = 1;
2145   int try_tail_recursion = 1;
2146   int pass;
2147
2148   /* Register in which non-BLKmode value will be returned,
2149      or 0 if no value or if value is BLKmode.  */
2150   rtx valreg;
2151   /* Address where we should return a BLKmode value;
2152      0 if value not BLKmode.  */
2153   rtx structure_value_addr = 0;
2154   /* Nonzero if that address is being passed by treating it as
2155      an extra, implicit first parameter.  Otherwise,
2156      it is passed by being copied directly into struct_value_rtx.  */
2157   int structure_value_addr_parm = 0;
2158   /* Size of aggregate value wanted, or zero if none wanted
2159      or if we are using the non-reentrant PCC calling convention
2160      or expecting the value in registers.  */
2161   HOST_WIDE_INT struct_value_size = 0;
2162   /* Nonzero if called function returns an aggregate in memory PCC style,
2163      by returning the address of where to find it.  */
2164   int pcc_struct_value = 0;
2165
2166   /* Number of actual parameters in this call, including struct value addr.  */
2167   int num_actuals;
2168   /* Number of named args.  Args after this are anonymous ones
2169      and they must all go on the stack.  */
2170   int n_named_args;
2171
2172   /* Vector of information about each argument.
2173      Arguments are numbered in the order they will be pushed,
2174      not the order they are written.  */
2175   struct arg_data *args;
2176
2177   /* Total size in bytes of all the stack-parms scanned so far.  */
2178   struct args_size args_size;
2179   struct args_size adjusted_args_size;
2180   /* Size of arguments before any adjustments (such as rounding).  */
2181   int unadjusted_args_size;
2182   /* Data on reg parms scanned so far.  */
2183   CUMULATIVE_ARGS args_so_far;
2184   /* Nonzero if a reg parm has been scanned.  */
2185   int reg_parm_seen;
2186   /* Nonzero if this is an indirect function call.  */
2187
2188   /* Nonzero if we must avoid push-insns in the args for this call.
2189      If stack space is allocated for register parameters, but not by the
2190      caller, then it is preallocated in the fixed part of the stack frame.
2191      So the entire argument block must then be preallocated (i.e., we
2192      ignore PUSH_ROUNDING in that case).  */
2193
2194   int must_preallocate = !PUSH_ARGS;
2195
2196   /* Size of the stack reserved for parameter registers.  */
2197   int reg_parm_stack_space = 0;
2198
2199   /* Address of space preallocated for stack parms
2200      (on machines that lack push insns), or 0 if space not preallocated.  */
2201   rtx argblock = 0;
2202
2203   /* Mask of ECF_ flags.  */
2204   int flags = 0;
2205   /* Nonzero if this is a call to an inline function.  */
2206   int is_integrable = 0;
2207 #ifdef REG_PARM_STACK_SPACE
2208   /* Define the boundary of the register parm stack space that needs to be
2209      saved, if any.  */
2210   int low_to_save, high_to_save;
2211   rtx save_area = 0;            /* Place that it is saved */
2212 #endif
2213
2214   int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2215   char *initial_stack_usage_map = stack_usage_map;
2216   int old_stack_arg_under_construction = 0;
2217
2218   rtx old_stack_level = 0;
2219   int old_pending_adj = 0;
2220   int old_inhibit_defer_pop = inhibit_defer_pop;
2221   int old_stack_allocated;
2222   rtx call_fusage;
2223   tree p = TREE_OPERAND (exp, 0);
2224   tree addr = TREE_OPERAND (exp, 0);
2225   int i;
2226   /* The alignment of the stack, in bits.  */
2227   HOST_WIDE_INT preferred_stack_boundary;
2228   /* The alignment of the stack, in bytes.  */
2229   HOST_WIDE_INT preferred_unit_stack_boundary;
2230
2231   /* See if this is "nothrow" function call.  */
2232   if (TREE_NOTHROW (exp))
2233     flags |= ECF_NOTHROW;
2234
2235   /* See if we can find a DECL-node for the actual function.
2236      As a result, decide whether this is a call to an integrable function.  */
2237
2238   fndecl = get_callee_fndecl (exp);
2239   if (fndecl)
2240     {
2241       if (!flag_no_inline
2242           && fndecl != current_function_decl
2243           && DECL_INLINE (fndecl)
2244           && DECL_SAVED_INSNS (fndecl)
2245           && DECL_SAVED_INSNS (fndecl)->inlinable)
2246         is_integrable = 1;
2247       else if (! TREE_ADDRESSABLE (fndecl))
2248         {
2249           /* In case this function later becomes inlinable,
2250              record that there was already a non-inline call to it.
2251
2252              Use abstraction instead of setting TREE_ADDRESSABLE
2253              directly.  */
2254           if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
2255               && optimize > 0)
2256             {
2257               warning_with_decl (fndecl, "can't inline call to `%s'");
2258               warning ("called from here");
2259             }
2260           (*lang_hooks.mark_addressable) (fndecl);
2261         }
2262
2263       flags |= flags_from_decl_or_type (fndecl);
2264     }
2265
2266   /* If we don't have specific function to call, see if we have a
2267      attributes set in the type.  */
2268   else
2269     flags |= flags_from_decl_or_type (TREE_TYPE (TREE_TYPE (p)));
2270
2271 #ifdef REG_PARM_STACK_SPACE
2272 #ifdef MAYBE_REG_PARM_STACK_SPACE
2273   reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
2274 #else
2275   reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
2276 #endif
2277 #endif
2278
2279 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2280   if (reg_parm_stack_space > 0 && PUSH_ARGS)
2281     must_preallocate = 1;
2282 #endif
2283
2284   /* Warn if this value is an aggregate type,
2285      regardless of which calling convention we are using for it.  */
2286   if (warn_aggregate_return && AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2287     warning ("function call has aggregate value");
2288
2289   /* Set up a place to return a structure.  */
2290
2291   /* Cater to broken compilers.  */
2292   if (aggregate_value_p (exp))
2293     {
2294       /* This call returns a big structure.  */
2295       flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
2296
2297 #ifdef PCC_STATIC_STRUCT_RETURN
2298       {
2299         pcc_struct_value = 1;
2300         /* Easier than making that case work right.  */
2301         if (is_integrable)
2302           {
2303             /* In case this is a static function, note that it has been
2304                used.  */
2305             if (! TREE_ADDRESSABLE (fndecl))
2306               (*lang_hooks.mark_addressable) (fndecl);
2307             is_integrable = 0;
2308           }
2309       }
2310 #else /* not PCC_STATIC_STRUCT_RETURN */
2311       {
2312         struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2313
2314         if (CALL_EXPR_HAS_RETURN_SLOT_ADDR (exp))
2315           {
2316             /* The structure value address arg is already in actparms.
2317                Pull it out.  It might be nice to just leave it there, but
2318                we need to set structure_value_addr.  */
2319             tree return_arg = TREE_VALUE (actparms);
2320             actparms = TREE_CHAIN (actparms);
2321             structure_value_addr = expand_expr (return_arg, NULL_RTX,
2322                                                 VOIDmode, EXPAND_NORMAL);
2323           }
2324         else if (target && GET_CODE (target) == MEM)
2325           structure_value_addr = XEXP (target, 0);
2326         else
2327           {
2328             /* For variable-sized objects, we must be called with a target
2329                specified.  If we were to allocate space on the stack here,
2330                we would have no way of knowing when to free it.  */
2331             rtx d = assign_temp (TREE_TYPE (exp), 1, 1, 1);
2332
2333             mark_temp_addr_taken (d);
2334             structure_value_addr = XEXP (d, 0);
2335             target = 0;
2336           }
2337       }
2338 #endif /* not PCC_STATIC_STRUCT_RETURN */
2339     }
2340
2341   /* If called function is inline, try to integrate it.  */
2342
2343   if (is_integrable)
2344     {
2345       rtx temp = try_to_integrate (fndecl, actparms, target,
2346                                    ignore, TREE_TYPE (exp),
2347                                    structure_value_addr);
2348       if (temp != (rtx) (size_t) - 1)
2349         return temp;
2350     }
2351
2352   /* Figure out the amount to which the stack should be aligned.  */
2353   preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2354   if (fndecl)
2355     {
2356       struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2357       if (i && i->preferred_incoming_stack_boundary)
2358         preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2359     }
2360
2361   /* Operand 0 is a pointer-to-function; get the type of the function.  */
2362   funtype = TREE_TYPE (addr);
2363   if (! POINTER_TYPE_P (funtype))
2364     abort ();
2365   funtype = TREE_TYPE (funtype);
2366
2367   /* See if this is a call to a function that can return more than once
2368      or a call to longjmp or malloc.  */
2369   flags |= special_function_p (fndecl, flags);
2370
2371   if (flags & ECF_MAY_BE_ALLOCA)
2372     current_function_calls_alloca = 1;
2373
2374   /* If struct_value_rtx is 0, it means pass the address
2375      as if it were an extra parameter.  */
2376   if (structure_value_addr && struct_value_rtx == 0)
2377     {
2378       /* If structure_value_addr is a REG other than
2379          virtual_outgoing_args_rtx, we can use always use it.  If it
2380          is not a REG, we must always copy it into a register.
2381          If it is virtual_outgoing_args_rtx, we must copy it to another
2382          register in some cases.  */
2383       rtx temp = (GET_CODE (structure_value_addr) != REG
2384                   || (ACCUMULATE_OUTGOING_ARGS
2385                       && stack_arg_under_construction
2386                       && structure_value_addr == virtual_outgoing_args_rtx)
2387                   ? copy_addr_to_reg (structure_value_addr)
2388                   : structure_value_addr);
2389
2390       actparms
2391         = tree_cons (error_mark_node,
2392                      make_tree (build_pointer_type (TREE_TYPE (funtype)),
2393                                 temp),
2394                      actparms);
2395       structure_value_addr_parm = 1;
2396     }
2397
2398   /* Count the arguments and set NUM_ACTUALS.  */
2399   for (p = actparms, num_actuals = 0; p; p = TREE_CHAIN (p))
2400     num_actuals++;
2401
2402   /* Compute number of named args.
2403      Normally, don't include the last named arg if anonymous args follow.
2404      We do include the last named arg if STRICT_ARGUMENT_NAMING is nonzero.
2405      (If no anonymous args follow, the result of list_length is actually
2406      one too large.  This is harmless.)
2407
2408      If PRETEND_OUTGOING_VARARGS_NAMED is set and STRICT_ARGUMENT_NAMING is
2409      zero, this machine will be able to place unnamed args that were
2410      passed in registers into the stack.  So treat all args as named.
2411      This allows the insns emitting for a specific argument list to be
2412      independent of the function declaration.
2413
2414      If PRETEND_OUTGOING_VARARGS_NAMED is not set, we do not have any
2415      reliable way to pass unnamed args in registers, so we must force
2416      them into memory.  */
2417
2418   if ((STRICT_ARGUMENT_NAMING
2419        || ! PRETEND_OUTGOING_VARARGS_NAMED)
2420       && TYPE_ARG_TYPES (funtype) != 0)
2421     n_named_args
2422       = (list_length (TYPE_ARG_TYPES (funtype))
2423          /* Don't include the last named arg.  */
2424          - (STRICT_ARGUMENT_NAMING ? 0 : 1)
2425          /* Count the struct value address, if it is passed as a parm.  */
2426          + structure_value_addr_parm);
2427   else
2428     /* If we know nothing, treat all args as named.  */
2429     n_named_args = num_actuals;
2430
2431   /* Start updating where the next arg would go.
2432
2433      On some machines (such as the PA) indirect calls have a different
2434      calling convention than normal calls.  The last argument in
2435      INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2436      or not.  */
2437   INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl);
2438
2439   /* Make a vector to hold all the information about each arg.  */
2440   args = (struct arg_data *) alloca (num_actuals * sizeof (struct arg_data));
2441   memset ((char *) args, 0, num_actuals * sizeof (struct arg_data));
2442
2443   /* Build up entries in the ARGS array, compute the size of the
2444      arguments into ARGS_SIZE, etc.  */
2445   initialize_argument_information (num_actuals, args, &args_size,
2446                                    n_named_args, actparms, fndecl,
2447                                    &args_so_far, reg_parm_stack_space,
2448                                    &old_stack_level, &old_pending_adj,
2449                                    &must_preallocate, &flags);
2450
2451   if (args_size.var)
2452     {
2453       /* If this function requires a variable-sized argument list, don't
2454          try to make a cse'able block for this call.  We may be able to
2455          do this eventually, but it is too complicated to keep track of
2456          what insns go in the cse'able block and which don't.  */
2457
2458       flags &= ~ECF_LIBCALL_BLOCK;
2459       must_preallocate = 1;
2460     }
2461
2462   /* Now make final decision about preallocating stack space.  */
2463   must_preallocate = finalize_must_preallocate (must_preallocate,
2464                                                 num_actuals, args,
2465                                                 &args_size);
2466
2467   /* If the structure value address will reference the stack pointer, we
2468      must stabilize it.  We don't need to do this if we know that we are
2469      not going to adjust the stack pointer in processing this call.  */
2470
2471   if (structure_value_addr
2472       && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2473           || reg_mentioned_p (virtual_outgoing_args_rtx,
2474                               structure_value_addr))
2475       && (args_size.var
2476           || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2477     structure_value_addr = copy_to_reg (structure_value_addr);
2478
2479   /* Tail calls can make things harder to debug, and we're traditionally
2480      pushed these optimizations into -O2.  Don't try if we're already
2481      expanding a call, as that means we're an argument.  Don't try if
2482      there's cleanups, as we know there's code to follow the call.
2483
2484      If rtx_equal_function_value_matters is false, that means we've
2485      finished with regular parsing.  Which means that some of the
2486      machinery we use to generate tail-calls is no longer in place.
2487      This is most often true of sjlj-exceptions, which we couldn't
2488      tail-call to anyway.  */
2489
2490   if (currently_expanding_call++ != 0
2491       || !flag_optimize_sibling_calls
2492       || !rtx_equal_function_value_matters
2493       || any_pending_cleanups (1)
2494       || args_size.var)
2495     try_tail_call = try_tail_recursion = 0;
2496
2497   /* Tail recursion fails, when we are not dealing with recursive calls.  */
2498   if (!try_tail_recursion
2499       || TREE_CODE (addr) != ADDR_EXPR
2500       || TREE_OPERAND (addr, 0) != current_function_decl)
2501     try_tail_recursion = 0;
2502
2503   /*  Rest of purposes for tail call optimizations to fail.  */
2504   if (
2505 #ifdef HAVE_sibcall_epilogue
2506       !HAVE_sibcall_epilogue
2507 #else
2508       1
2509 #endif
2510       || !try_tail_call
2511       /* Doing sibling call optimization needs some work, since
2512          structure_value_addr can be allocated on the stack.
2513          It does not seem worth the effort since few optimizable
2514          sibling calls will return a structure.  */
2515       || structure_value_addr != NULL_RTX
2516       /* Check whether the target is able to optimize the call
2517          into a sibcall.  */
2518       || !(*targetm.function_ok_for_sibcall) (fndecl, exp)
2519       /* Functions that do not return exactly once may not be sibcall
2520          optimized.  */
2521       || (flags & (ECF_RETURNS_TWICE | ECF_LONGJMP | ECF_NORETURN))
2522       || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2523       /* If this function requires more stack slots than the current
2524          function, we cannot change it into a sibling call.  */
2525       || args_size.constant > current_function_args_size
2526       /* If the callee pops its own arguments, then it must pop exactly
2527          the same number of arguments as the current function.  */
2528       || RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2529          != RETURN_POPS_ARGS (current_function_decl,
2530                               TREE_TYPE (current_function_decl),
2531                               current_function_args_size))
2532     try_tail_call = 0;
2533
2534   if (try_tail_call || try_tail_recursion)
2535     {
2536       int end, inc;
2537       actparms = NULL_TREE;
2538       /* Ok, we're going to give the tail call the old college try.
2539          This means we're going to evaluate the function arguments
2540          up to three times.  There are two degrees of badness we can
2541          encounter, those that can be unsaved and those that can't.
2542          (See unsafe_for_reeval commentary for details.)
2543
2544          Generate a new argument list.  Pass safe arguments through
2545          unchanged.  For the easy badness wrap them in UNSAVE_EXPRs.
2546          For hard badness, evaluate them now and put their resulting
2547          rtx in a temporary VAR_DECL.
2548
2549          initialize_argument_information has ordered the array for the
2550          order to be pushed, and we must remember this when reconstructing
2551          the original argument order.  */
2552
2553       if (PUSH_ARGS_REVERSED)
2554         {
2555           inc = 1;
2556           i = 0;
2557           end = num_actuals;
2558         }
2559       else
2560         {
2561           inc = -1;
2562           i = num_actuals - 1;
2563           end = -1;
2564         }
2565
2566       for (; i != end; i += inc)
2567         {
2568           args[i].tree_value = fix_unsafe_tree (args[i].tree_value);
2569           /* We need to build actparms for optimize_tail_recursion.  We can
2570              safely trash away TREE_PURPOSE, since it is unused by this
2571              function.  */
2572           if (try_tail_recursion)
2573             actparms = tree_cons (NULL_TREE, args[i].tree_value, actparms);
2574         }
2575       /* Do the same for the function address if it is an expression.  */
2576       if (!fndecl)
2577         addr = fix_unsafe_tree (addr);
2578       /* Expanding one of those dangerous arguments could have added
2579          cleanups, but otherwise give it a whirl.  */
2580       if (any_pending_cleanups (1))
2581         try_tail_call = try_tail_recursion = 0;
2582     }
2583
2584   /* Generate a tail recursion sequence when calling ourselves.  */
2585
2586   if (try_tail_recursion)
2587     {
2588       /* We want to emit any pending stack adjustments before the tail
2589          recursion "call".  That way we know any adjustment after the tail
2590          recursion call can be ignored if we indeed use the tail recursion
2591          call expansion.  */
2592       int save_pending_stack_adjust = pending_stack_adjust;
2593       int save_stack_pointer_delta = stack_pointer_delta;
2594
2595       /* Emit any queued insns now; otherwise they would end up in
2596          only one of the alternates.  */
2597       emit_queue ();
2598
2599       /* Use a new sequence to hold any RTL we generate.  We do not even
2600          know if we will use this RTL yet.  The final decision can not be
2601          made until after RTL generation for the entire function is
2602          complete.  */
2603       start_sequence ();
2604       /* If expanding any of the arguments creates cleanups, we can't
2605          do a tailcall.  So, we'll need to pop the pending cleanups
2606          list.  If, however, all goes well, and there are no cleanups
2607          then the call to expand_start_target_temps will have no
2608          effect.  */
2609       expand_start_target_temps ();
2610       if (optimize_tail_recursion (actparms, get_last_insn ()))
2611         {
2612           if (any_pending_cleanups (1))
2613             try_tail_call = try_tail_recursion = 0;
2614           else
2615             tail_recursion_insns = get_insns ();
2616         }
2617       expand_end_target_temps ();
2618       end_sequence ();
2619
2620       /* Restore the original pending stack adjustment for the sibling and
2621          normal call cases below.  */
2622       pending_stack_adjust = save_pending_stack_adjust;
2623       stack_pointer_delta = save_stack_pointer_delta;
2624     }
2625
2626   if (profile_arc_flag && (flags & ECF_FORK_OR_EXEC))
2627     {
2628       /* A fork duplicates the profile information, and an exec discards
2629          it.  We can't rely on fork/exec to be paired.  So write out the
2630          profile information we have gathered so far, and clear it.  */
2631       /* ??? When Linux's __clone is called with CLONE_VM set, profiling
2632          is subject to race conditions, just as with multithreaded
2633          programs.  */
2634
2635       emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__gcov_flush"),
2636                          LCT_ALWAYS_RETURN,
2637                          VOIDmode, 0);
2638     }
2639
2640   /* Ensure current function's preferred stack boundary is at least
2641      what we need.  We don't have to increase alignment for recursive
2642      functions.  */
2643   if (cfun->preferred_stack_boundary < preferred_stack_boundary
2644       && fndecl != current_function_decl)
2645     cfun->preferred_stack_boundary = preferred_stack_boundary;
2646   if (fndecl == current_function_decl)
2647     cfun->recursive_call_emit = true;
2648
2649   preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2650
2651   function_call_count++;
2652
2653   /* We want to make two insn chains; one for a sibling call, the other
2654      for a normal call.  We will select one of the two chains after
2655      initial RTL generation is complete.  */
2656   for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2657     {
2658       int sibcall_failure = 0;
2659       /* We want to emit any pending stack adjustments before the tail
2660          recursion "call".  That way we know any adjustment after the tail
2661          recursion call can be ignored if we indeed use the tail recursion
2662          call expansion.  */
2663       int save_pending_stack_adjust = 0;
2664       int save_stack_pointer_delta = 0;
2665       rtx insns;
2666       rtx before_call, next_arg_reg;
2667
2668       if (pass == 0)
2669         {
2670           /* Emit any queued insns now; otherwise they would end up in
2671              only one of the alternates.  */
2672           emit_queue ();
2673
2674           /* State variables we need to save and restore between
2675              iterations.  */
2676           save_pending_stack_adjust = pending_stack_adjust;
2677           save_stack_pointer_delta = stack_pointer_delta;
2678         }
2679       if (pass)
2680         flags &= ~ECF_SIBCALL;
2681       else
2682         flags |= ECF_SIBCALL;
2683
2684       /* Other state variables that we must reinitialize each time
2685          through the loop (that are not initialized by the loop itself).  */
2686       argblock = 0;
2687       call_fusage = 0;
2688
2689       /* Start a new sequence for the normal call case.
2690
2691          From this point on, if the sibling call fails, we want to set
2692          sibcall_failure instead of continuing the loop.  */
2693       start_sequence ();
2694
2695       if (pass == 0)
2696         {
2697           /* We know at this point that there are not currently any
2698              pending cleanups.  If, however, in the process of evaluating
2699              the arguments we were to create some, we'll need to be
2700              able to get rid of them.  */
2701           expand_start_target_temps ();
2702         }
2703
2704       /* Don't let pending stack adjusts add up to too much.
2705          Also, do all pending adjustments now if there is any chance
2706          this might be a call to alloca or if we are expanding a sibling
2707          call sequence or if we are calling a function that is to return
2708          with stack pointer depressed.  */
2709       if (pending_stack_adjust >= 32
2710           || (pending_stack_adjust > 0
2711               && (flags & (ECF_MAY_BE_ALLOCA | ECF_SP_DEPRESSED)))
2712           || pass == 0)
2713         do_pending_stack_adjust ();
2714
2715       /* When calling a const function, we must pop the stack args right away,
2716          so that the pop is deleted or moved with the call.  */
2717       if (pass && (flags & ECF_LIBCALL_BLOCK))
2718         NO_DEFER_POP;
2719
2720 #ifdef FINAL_REG_PARM_STACK_SPACE
2721       reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
2722                                                          args_size.var);
2723 #endif
2724       /* Precompute any arguments as needed.  */
2725       if (pass)
2726         precompute_arguments (flags, num_actuals, args);
2727
2728       /* Now we are about to start emitting insns that can be deleted
2729          if a libcall is deleted.  */
2730       if (pass && (flags & (ECF_LIBCALL_BLOCK | ECF_MALLOC)))
2731         start_sequence ();
2732
2733       adjusted_args_size = args_size;
2734       /* Compute the actual size of the argument block required.  The variable
2735          and constant sizes must be combined, the size may have to be rounded,
2736          and there may be a minimum required size.  When generating a sibcall
2737          pattern, do not round up, since we'll be re-using whatever space our
2738          caller provided.  */
2739       unadjusted_args_size
2740         = compute_argument_block_size (reg_parm_stack_space,
2741                                        &adjusted_args_size,
2742                                        (pass == 0 ? 0
2743                                         : preferred_stack_boundary));
2744
2745       old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2746
2747       /* The argument block when performing a sibling call is the
2748          incoming argument block.  */
2749       if (pass == 0)
2750         {
2751           argblock = virtual_incoming_args_rtx;
2752           argblock
2753 #ifdef STACK_GROWS_DOWNWARD
2754             = plus_constant (argblock, current_function_pretend_args_size);
2755 #else
2756             = plus_constant (argblock, -current_function_pretend_args_size);
2757 #endif
2758           stored_args_map = sbitmap_alloc (args_size.constant);
2759           sbitmap_zero (stored_args_map);
2760         }
2761
2762       /* If we have no actual push instructions, or shouldn't use them,
2763          make space for all args right now.  */
2764       else if (adjusted_args_size.var != 0)
2765         {
2766           if (old_stack_level == 0)
2767             {
2768               emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2769               old_pending_adj = pending_stack_adjust;
2770               pending_stack_adjust = 0;
2771               /* stack_arg_under_construction says whether a stack arg is
2772                  being constructed at the old stack level.  Pushing the stack
2773                  gets a clean outgoing argument block.  */
2774               old_stack_arg_under_construction = stack_arg_under_construction;
2775               stack_arg_under_construction = 0;
2776             }
2777           argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2778         }
2779       else
2780         {
2781           /* Note that we must go through the motions of allocating an argument
2782              block even if the size is zero because we may be storing args
2783              in the area reserved for register arguments, which may be part of
2784              the stack frame.  */
2785
2786           int needed = adjusted_args_size.constant;
2787
2788           /* Store the maximum argument space used.  It will be pushed by
2789              the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2790              checking).  */
2791
2792           if (needed > current_function_outgoing_args_size)
2793             current_function_outgoing_args_size = needed;
2794
2795           if (must_preallocate)
2796             {
2797               if (ACCUMULATE_OUTGOING_ARGS)
2798                 {
2799                   /* Since the stack pointer will never be pushed, it is
2800                      possible for the evaluation of a parm to clobber
2801                      something we have already written to the stack.
2802                      Since most function calls on RISC machines do not use
2803                      the stack, this is uncommon, but must work correctly.
2804
2805                      Therefore, we save any area of the stack that was already
2806                      written and that we are using.  Here we set up to do this
2807                      by making a new stack usage map from the old one.  The
2808                      actual save will be done by store_one_arg.
2809
2810                      Another approach might be to try to reorder the argument
2811                      evaluations to avoid this conflicting stack usage.  */
2812
2813 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2814                   /* Since we will be writing into the entire argument area,
2815                      the map must be allocated for its entire size, not just
2816                      the part that is the responsibility of the caller.  */
2817                   needed += reg_parm_stack_space;
2818 #endif
2819
2820 #ifdef ARGS_GROW_DOWNWARD
2821                   highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2822                                                      needed + 1);
2823 #else
2824                   highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2825                                                      needed);
2826 #endif
2827                   stack_usage_map
2828                     = (char *) alloca (highest_outgoing_arg_in_use);
2829
2830                   if (initial_highest_arg_in_use)
2831                     memcpy (stack_usage_map, initial_stack_usage_map,
2832                             initial_highest_arg_in_use);
2833
2834                   if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2835                     memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2836                            (highest_outgoing_arg_in_use
2837                             - initial_highest_arg_in_use));
2838                   needed = 0;
2839
2840                   /* The address of the outgoing argument list must not be
2841                      copied to a register here, because argblock would be left
2842                      pointing to the wrong place after the call to
2843                      allocate_dynamic_stack_space below.  */
2844
2845                   argblock = virtual_outgoing_args_rtx;
2846                 }
2847               else
2848                 {
2849                   if (inhibit_defer_pop == 0)
2850                     {
2851                       /* Try to reuse some or all of the pending_stack_adjust
2852                          to get this space.  */
2853                       needed
2854                         = (combine_pending_stack_adjustment_and_call
2855                            (unadjusted_args_size,
2856                             &adjusted_args_size,
2857                             preferred_unit_stack_boundary));
2858
2859                       /* combine_pending_stack_adjustment_and_call computes
2860                          an adjustment before the arguments are allocated.
2861                          Account for them and see whether or not the stack
2862                          needs to go up or down.  */
2863                       needed = unadjusted_args_size - needed;
2864
2865                       if (needed < 0)
2866                         {
2867                           /* We're releasing stack space.  */
2868                           /* ??? We can avoid any adjustment at all if we're
2869                              already aligned.  FIXME.  */
2870                           pending_stack_adjust = -needed;
2871                           do_pending_stack_adjust ();
2872                           needed = 0;
2873                         }
2874                       else
2875                         /* We need to allocate space.  We'll do that in
2876                            push_block below.  */
2877                         pending_stack_adjust = 0;
2878                     }
2879
2880                   /* Special case this because overhead of `push_block' in
2881                      this case is non-trivial.  */
2882                   if (needed == 0)
2883                     argblock = virtual_outgoing_args_rtx;
2884                   else
2885                     argblock = push_block (GEN_INT (needed), 0, 0);
2886
2887                   /* We only really need to call `copy_to_reg' in the case
2888                      where push insns are going to be used to pass ARGBLOCK
2889                      to a function call in ARGS.  In that case, the stack
2890                      pointer changes value from the allocation point to the
2891                      call point, and hence the value of
2892                      VIRTUAL_OUTGOING_ARGS_RTX changes as well.  But might
2893                      as well always do it.  */
2894                   argblock = copy_to_reg (argblock);
2895
2896                   /* The save/restore code in store_one_arg handles all
2897                      cases except one: a constructor call (including a C
2898                      function returning a BLKmode struct) to initialize
2899                      an argument.  */
2900                   if (stack_arg_under_construction)
2901                     {
2902 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2903                       rtx push_size = GEN_INT (reg_parm_stack_space
2904                                                + adjusted_args_size.constant);
2905 #else
2906                       rtx push_size = GEN_INT (adjusted_args_size.constant);
2907 #endif
2908                       if (old_stack_level == 0)
2909                         {
2910                           emit_stack_save (SAVE_BLOCK, &old_stack_level,
2911                                            NULL_RTX);
2912                           old_pending_adj = pending_stack_adjust;
2913                           pending_stack_adjust = 0;
2914                           /* stack_arg_under_construction says whether a stack
2915                              arg is being constructed at the old stack level.
2916                              Pushing the stack gets a clean outgoing argument
2917                              block.  */
2918                           old_stack_arg_under_construction
2919                             = stack_arg_under_construction;
2920                           stack_arg_under_construction = 0;
2921                           /* Make a new map for the new argument list.  */
2922                           stack_usage_map = (char *)
2923                             alloca (highest_outgoing_arg_in_use);
2924                           memset (stack_usage_map, 0, highest_outgoing_arg_in_use);
2925                           highest_outgoing_arg_in_use = 0;
2926                         }
2927                       allocate_dynamic_stack_space (push_size, NULL_RTX,
2928                                                     BITS_PER_UNIT);
2929                     }
2930                   /* If argument evaluation might modify the stack pointer,
2931                      copy the address of the argument list to a register.  */
2932                   for (i = 0; i < num_actuals; i++)
2933                     if (args[i].pass_on_stack)
2934                       {
2935                         argblock = copy_addr_to_reg (argblock);
2936                         break;
2937                       }
2938                 }
2939             }
2940         }
2941
2942       compute_argument_addresses (args, argblock, num_actuals);
2943
2944       /* If we push args individually in reverse order, perform stack alignment
2945          before the first push (the last arg).  */
2946       if (PUSH_ARGS_REVERSED && argblock == 0
2947           && adjusted_args_size.constant != unadjusted_args_size)
2948         {
2949           /* When the stack adjustment is pending, we get better code
2950              by combining the adjustments.  */
2951           if (pending_stack_adjust
2952               && ! (flags & ECF_LIBCALL_BLOCK)
2953               && ! inhibit_defer_pop)
2954             {
2955               pending_stack_adjust
2956                 = (combine_pending_stack_adjustment_and_call
2957                    (unadjusted_args_size,
2958                     &adjusted_args_size,
2959                     preferred_unit_stack_boundary));
2960               do_pending_stack_adjust ();
2961             }
2962           else if (argblock == 0)
2963             anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2964                                         - unadjusted_args_size));
2965         }
2966       /* Now that the stack is properly aligned, pops can't safely
2967          be deferred during the evaluation of the arguments.  */
2968       NO_DEFER_POP;
2969
2970       funexp = rtx_for_function_call (fndecl, addr);
2971
2972       /* Figure out the register where the value, if any, will come back.  */
2973       valreg = 0;
2974       if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2975           && ! structure_value_addr)
2976         {
2977           if (pcc_struct_value)
2978             valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2979                                           fndecl, (pass == 0));
2980           else
2981             valreg = hard_function_value (TREE_TYPE (exp), fndecl, (pass == 0));
2982         }
2983
2984       /* Precompute all register parameters.  It isn't safe to compute anything
2985          once we have started filling any specific hard regs.  */
2986       precompute_register_parameters (num_actuals, args, &reg_parm_seen);
2987
2988 #ifdef REG_PARM_STACK_SPACE
2989       /* Save the fixed argument area if it's part of the caller's frame and
2990          is clobbered by argument setup for this call.  */
2991       if (ACCUMULATE_OUTGOING_ARGS && pass)
2992         save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2993                                               &low_to_save, &high_to_save);
2994 #endif
2995
2996       /* Now store (and compute if necessary) all non-register parms.
2997          These come before register parms, since they can require block-moves,
2998          which could clobber the registers used for register parms.
2999          Parms which have partial registers are not stored here,
3000          but we do preallocate space here if they want that.  */
3001
3002       for (i = 0; i < num_actuals; i++)
3003         if (args[i].reg == 0 || args[i].pass_on_stack)
3004           {
3005             rtx before_arg = get_last_insn ();
3006
3007             if (store_one_arg (&args[i], argblock, flags,
3008                                adjusted_args_size.var != 0,
3009                                reg_parm_stack_space)
3010                 || (pass == 0
3011                     && check_sibcall_argument_overlap (before_arg,
3012                                                        &args[i], 1)))
3013               sibcall_failure = 1;
3014           }
3015
3016       /* If we have a parm that is passed in registers but not in memory
3017          and whose alignment does not permit a direct copy into registers,
3018          make a group of pseudos that correspond to each register that we
3019          will later fill.  */
3020       if (STRICT_ALIGNMENT)
3021         store_unaligned_arguments_into_pseudos (args, num_actuals);
3022
3023       /* Now store any partially-in-registers parm.
3024          This is the last place a block-move can happen.  */
3025       if (reg_parm_seen)
3026         for (i = 0; i < num_actuals; i++)
3027           if (args[i].partial != 0 && ! args[i].pass_on_stack)
3028             {
3029               rtx before_arg = get_last_insn ();
3030
3031               if (store_one_arg (&args[i], argblock, flags,
3032                                  adjusted_args_size.var != 0,
3033                                  reg_parm_stack_space)
3034                   || (pass == 0
3035                       && check_sibcall_argument_overlap (before_arg,
3036                                                          &args[i], 1)))
3037                 sibcall_failure = 1;
3038             }
3039
3040       /* If we pushed args in forward order, perform stack alignment
3041          after pushing the last arg.  */
3042       if (!PUSH_ARGS_REVERSED && argblock == 0)
3043         anti_adjust_stack (GEN_INT (adjusted_args_size.constant
3044                                     - unadjusted_args_size));
3045
3046       /* If register arguments require space on the stack and stack space
3047          was not preallocated, allocate stack space here for arguments
3048          passed in registers.  */
3049 #ifdef OUTGOING_REG_PARM_STACK_SPACE
3050       if (!ACCUMULATE_OUTGOING_ARGS
3051           && must_preallocate == 0 && reg_parm_stack_space > 0)
3052         anti_adjust_stack (GEN_INT (reg_parm_stack_space));
3053 #endif
3054
3055       /* Pass the function the address in which to return a
3056          structure value.  */
3057       if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
3058         {
3059           emit_move_insn (struct_value_rtx,
3060                           force_reg (Pmode,
3061                                      force_operand (structure_value_addr,
3062                                                     NULL_RTX)));
3063
3064           if (GET_CODE (struct_value_rtx) == REG)
3065             use_reg (&call_fusage, struct_value_rtx);
3066         }
3067
3068       funexp = prepare_call_address (funexp, fndecl, &call_fusage,
3069                                      reg_parm_seen, pass == 0);
3070
3071       load_register_parameters (args, num_actuals, &call_fusage, flags,
3072                                 pass == 0, &sibcall_failure);
3073
3074       /* Perform postincrements before actually calling the function.  */
3075       emit_queue ();
3076
3077       /* Save a pointer to the last insn before the call, so that we can
3078          later safely search backwards to find the CALL_INSN.  */
3079       before_call = get_last_insn ();
3080
3081       /* Set up next argument register.  For sibling calls on machines
3082          with register windows this should be the incoming register.  */
3083 #ifdef FUNCTION_INCOMING_ARG
3084       if (pass == 0)
3085         next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
3086                                               void_type_node, 1);
3087       else
3088 #endif
3089         next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
3090                                      void_type_node, 1);
3091
3092       /* All arguments and registers used for the call must be set up by
3093          now!  */
3094
3095       /* Stack must be properly aligned now.  */
3096       if (pass && stack_pointer_delta % preferred_unit_stack_boundary)
3097         abort ();
3098
3099       /* Generate the actual call instruction.  */
3100       emit_call_1 (funexp, fndecl, funtype, unadjusted_args_size,
3101                    adjusted_args_size.constant, struct_value_size,
3102                    next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
3103                    flags, & args_so_far);
3104
3105       /* Verify that we've deallocated all the stack we used.  */
3106       if (pass
3107           && old_stack_allocated != stack_pointer_delta - pending_stack_adjust)
3108         abort ();
3109
3110       /* If call is cse'able, make appropriate pair of reg-notes around it.
3111          Test valreg so we don't crash; may safely ignore `const'
3112          if return type is void.  Disable for PARALLEL return values, because
3113          we have no way to move such values into a pseudo register.  */
3114       if (pass && (flags & ECF_LIBCALL_BLOCK))
3115         {
3116           rtx insns;
3117
3118           if (valreg == 0 || GET_CODE (valreg) == PARALLEL)
3119             {
3120               insns = get_insns ();
3121               end_sequence ();
3122               emit_insn (insns);
3123             }
3124           else
3125             {
3126               rtx note = 0;
3127               rtx temp = gen_reg_rtx (GET_MODE (valreg));
3128
3129               /* Mark the return value as a pointer if needed.  */
3130               if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3131                 mark_reg_pointer (temp,
3132                                   TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))));
3133
3134               /* Construct an "equal form" for the value which mentions all the
3135                  arguments in order as well as the function name.  */
3136               for (i = 0; i < num_actuals; i++)
3137                 note = gen_rtx_EXPR_LIST (VOIDmode,
3138                                           args[i].initial_value, note);
3139               note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note);
3140
3141               insns = get_insns ();
3142               end_sequence ();
3143
3144               if (flags & ECF_PURE)
3145                 note = gen_rtx_EXPR_LIST (VOIDmode,
3146                         gen_rtx_USE (VOIDmode,
3147                                      gen_rtx_MEM (BLKmode,
3148                                                   gen_rtx_SCRATCH (VOIDmode))),
3149                         note);
3150
3151               emit_libcall_block (insns, temp, valreg, note);
3152
3153               valreg = temp;
3154             }
3155         }
3156       else if (pass && (flags & ECF_MALLOC))
3157         {
3158           rtx temp = gen_reg_rtx (GET_MODE (valreg));
3159           rtx last, insns;
3160
3161           /* The return value from a malloc-like function is a pointer.  */
3162           if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3163             mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
3164
3165           emit_move_insn (temp, valreg);
3166
3167           /* The return value from a malloc-like function can not alias
3168              anything else.  */
3169           last = get_last_insn ();
3170           REG_NOTES (last) =
3171             gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last));
3172
3173           /* Write out the sequence.  */
3174           insns = get_insns ();
3175           end_sequence ();
3176           emit_insn (insns);
3177           valreg = temp;
3178         }
3179
3180       /* For calls to `setjmp', etc., inform flow.c it should complain
3181          if nonvolatile values are live.  For functions that cannot return,
3182          inform flow that control does not fall through.  */
3183
3184       if ((flags & (ECF_NORETURN | ECF_LONGJMP)) || pass == 0)
3185         {
3186           /* The barrier must be emitted
3187              immediately after the CALL_INSN.  Some ports emit more
3188              than just a CALL_INSN above, so we must search for it here.  */
3189
3190           rtx last = get_last_insn ();
3191           while (GET_CODE (last) != CALL_INSN)
3192             {
3193               last = PREV_INSN (last);
3194               /* There was no CALL_INSN?  */
3195               if (last == before_call)
3196                 abort ();
3197             }
3198
3199           emit_barrier_after (last);
3200         }
3201
3202       if (flags & ECF_LONGJMP)
3203         current_function_calls_longjmp = 1;
3204
3205       /* If this function is returning into a memory location marked as
3206          readonly, it means it is initializing that location.  But we normally
3207          treat functions as not clobbering such locations, so we need to
3208          specify that this one does.  */
3209       if (target != 0 && GET_CODE (target) == MEM
3210           && structure_value_addr != 0 && RTX_UNCHANGING_P (target))
3211         emit_insn (gen_rtx_CLOBBER (VOIDmode, target));
3212
3213       /* If value type not void, return an rtx for the value.  */
3214
3215       /* If there are cleanups to be called, don't use a hard reg as target.
3216          We need to double check this and see if it matters anymore.  */
3217       if (any_pending_cleanups (1))
3218         {
3219           if (target && REG_P (target)
3220               && REGNO (target) < FIRST_PSEUDO_REGISTER)
3221             target = 0;
3222           sibcall_failure = 1;
3223         }
3224
3225       if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
3226           || ignore)
3227         target = const0_rtx;
3228       else if (structure_value_addr)
3229         {
3230           if (target == 0 || GET_CODE (target) != MEM)
3231             {
3232               target
3233                 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3234                                memory_address (TYPE_MODE (TREE_TYPE (exp)),
3235                                                structure_value_addr));
3236               set_mem_attributes (target, exp, 1);
3237             }
3238         }
3239       else if (pcc_struct_value)
3240         {
3241           /* This is the special C++ case where we need to
3242              know what the true target was.  We take care to
3243              never use this value more than once in one expression.  */
3244           target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3245                                 copy_to_reg (valreg));
3246           set_mem_attributes (target, exp, 1);
3247         }
3248       /* Handle calls that return values in multiple non-contiguous locations.
3249          The Irix 6 ABI has examples of this.  */
3250       else if (GET_CODE (valreg) == PARALLEL)
3251         {
3252           if (target == 0)
3253             {
3254               /* This will only be assigned once, so it can be readonly.  */
3255               tree nt = build_qualified_type (TREE_TYPE (exp),
3256                                               (TYPE_QUALS (TREE_TYPE (exp))
3257                                                | TYPE_QUAL_CONST));
3258
3259               target = assign_temp (nt, 0, 1, 1);
3260               preserve_temp_slots (target);
3261             }
3262
3263           if (! rtx_equal_p (target, valreg))
3264             emit_group_store (target, valreg,
3265                               int_size_in_bytes (TREE_TYPE (exp)));
3266
3267           /* We can not support sibling calls for this case.  */
3268           sibcall_failure = 1;
3269         }
3270       else if (target
3271                && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
3272                && GET_MODE (target) == GET_MODE (valreg))
3273         {
3274           /* TARGET and VALREG cannot be equal at this point because the
3275              latter would not have REG_FUNCTION_VALUE_P true, while the
3276              former would if it were referring to the same register.
3277
3278              If they refer to the same register, this move will be a no-op,
3279              except when function inlining is being done.  */
3280           emit_move_insn (target, valreg);
3281         }
3282       else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
3283         {
3284           target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
3285
3286           /* We can not support sibling calls for this case.  */
3287           sibcall_failure = 1;
3288         }
3289       else
3290         target = copy_to_reg (valreg);
3291
3292 #ifdef PROMOTE_FUNCTION_RETURN
3293       /* If we promoted this return value, make the proper SUBREG.  TARGET
3294          might be const0_rtx here, so be careful.  */
3295       if (GET_CODE (target) == REG
3296           && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
3297           && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
3298         {
3299           tree type = TREE_TYPE (exp);
3300           int unsignedp = TREE_UNSIGNED (type);
3301           int offset = 0;
3302
3303           /* If we don't promote as expected, something is wrong.  */
3304           if (GET_MODE (target)
3305               != promote_mode (type, TYPE_MODE (type), &unsignedp, 1))
3306             abort ();
3307
3308         if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3309             && GET_MODE_SIZE (GET_MODE (target))
3310                > GET_MODE_SIZE (TYPE_MODE (type)))
3311           {
3312             offset = GET_MODE_SIZE (GET_MODE (target))
3313                      - GET_MODE_SIZE (TYPE_MODE (type));
3314             if (! BYTES_BIG_ENDIAN)
3315               offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3316             else if (! WORDS_BIG_ENDIAN)
3317               offset %= UNITS_PER_WORD;
3318           }
3319           target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3320           SUBREG_PROMOTED_VAR_P (target) = 1;
3321           SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3322         }
3323 #endif
3324
3325       /* If size of args is variable or this was a constructor call for a stack
3326          argument, restore saved stack-pointer value.  */
3327
3328       if (old_stack_level && ! (flags & ECF_SP_DEPRESSED))
3329         {
3330           emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3331           pending_stack_adjust = old_pending_adj;
3332           stack_arg_under_construction = old_stack_arg_under_construction;
3333           highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3334           stack_usage_map = initial_stack_usage_map;
3335           sibcall_failure = 1;
3336         }
3337       else if (ACCUMULATE_OUTGOING_ARGS && pass)
3338         {
3339 #ifdef REG_PARM_STACK_SPACE
3340           if (save_area)
3341             restore_fixed_argument_area (save_area, argblock,
3342                                          high_to_save, low_to_save);
3343 #endif
3344
3345           /* If we saved any argument areas, restore them.  */
3346           for (i = 0; i < num_actuals; i++)
3347             if (args[i].save_area)
3348               {
3349                 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3350                 rtx stack_area
3351                   = gen_rtx_MEM (save_mode,
3352                                  memory_address (save_mode,
3353                                                  XEXP (args[i].stack_slot, 0)));
3354
3355                 if (save_mode != BLKmode)
3356                   emit_move_insn (stack_area, args[i].save_area);
3357                 else
3358                   emit_block_move (stack_area, args[i].save_area,
3359                                    GEN_INT (args[i].size.constant),
3360                                    BLOCK_OP_CALL_PARM);
3361               }
3362
3363           highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3364           stack_usage_map = initial_stack_usage_map;
3365         }
3366
3367       /* If this was alloca, record the new stack level for nonlocal gotos.
3368          Check for the handler slots since we might not have a save area
3369          for non-local gotos.  */
3370
3371       if ((flags & ECF_MAY_BE_ALLOCA) && nonlocal_goto_handler_slots != 0)
3372         emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
3373
3374       /* Free up storage we no longer need.  */
3375       for (i = 0; i < num_actuals; ++i)
3376         if (args[i].aligned_regs)
3377           free (args[i].aligned_regs);
3378
3379       if (pass == 0)
3380         {
3381           /* Undo the fake expand_start_target_temps we did earlier.  If
3382              there had been any cleanups created, we've already set
3383              sibcall_failure.  */
3384           expand_end_target_temps ();
3385         }
3386
3387       insns = get_insns ();
3388       end_sequence ();
3389
3390       if (pass == 0)
3391         {
3392           tail_call_insns = insns;
3393
3394           /* Restore the pending stack adjustment now that we have
3395              finished generating the sibling call sequence.  */
3396
3397           pending_stack_adjust = save_pending_stack_adjust;
3398           stack_pointer_delta = save_stack_pointer_delta;
3399
3400           /* Prepare arg structure for next iteration.  */
3401           for (i = 0; i < num_actuals; i++)
3402             {
3403               args[i].value = 0;
3404               args[i].aligned_regs = 0;
3405               args[i].stack = 0;
3406             }
3407
3408           sbitmap_free (stored_args_map);
3409         }
3410       else
3411         normal_call_insns = insns;
3412
3413       /* If something prevents making this a sibling call,
3414          zero out the sequence.  */
3415       if (sibcall_failure)
3416         tail_call_insns = NULL_RTX;
3417     }
3418
3419   /* The function optimize_sibling_and_tail_recursive_calls doesn't
3420      handle CALL_PLACEHOLDERs inside other CALL_PLACEHOLDERs.  This
3421      can happen if the arguments to this function call an inline
3422      function who's expansion contains another CALL_PLACEHOLDER.
3423
3424      If there are any C_Ps in any of these sequences, replace them
3425      with their normal call.  */
3426
3427   for (insn = normal_call_insns; insn; insn = NEXT_INSN (insn))
3428     if (GET_CODE (insn) == CALL_INSN
3429         && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3430       replace_call_placeholder (insn, sibcall_use_normal);
3431
3432   for (insn = tail_call_insns; insn; insn = NEXT_INSN (insn))
3433     if (GET_CODE (insn) == CALL_INSN
3434         && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3435       replace_call_placeholder (insn, sibcall_use_normal);
3436
3437   for (insn = tail_recursion_insns; insn; insn = NEXT_INSN (insn))
3438     if (GET_CODE (insn) == CALL_INSN
3439         && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3440       replace_call_placeholder (insn, sibcall_use_normal);
3441
3442   /* If this was a potential tail recursion site, then emit a
3443      CALL_PLACEHOLDER with the normal and the tail recursion streams.
3444      One of them will be selected later.  */
3445   if (tail_recursion_insns || tail_call_insns)
3446     {
3447       /* The tail recursion label must be kept around.  We could expose
3448          its use in the CALL_PLACEHOLDER, but that creates unwanted edges
3449          and makes determining true tail recursion sites difficult.
3450
3451          So we set LABEL_PRESERVE_P here, then clear it when we select
3452          one of the call sequences after rtl generation is complete.  */
3453       if (tail_recursion_insns)
3454         LABEL_PRESERVE_P (tail_recursion_label) = 1;
3455       emit_call_insn (gen_rtx_CALL_PLACEHOLDER (VOIDmode, normal_call_insns,
3456                                                 tail_call_insns,
3457                                                 tail_recursion_insns,
3458                                                 tail_recursion_label));
3459     }
3460   else
3461     emit_insn (normal_call_insns);
3462
3463   currently_expanding_call--;
3464
3465   /* If this function returns with the stack pointer depressed, ensure
3466      this block saves and restores the stack pointer, show it was
3467      changed, and adjust for any outgoing arg space.  */
3468   if (flags & ECF_SP_DEPRESSED)
3469     {
3470       clear_pending_stack_adjust ();
3471       emit_insn (gen_rtx (CLOBBER, VOIDmode, stack_pointer_rtx));
3472       emit_move_insn (virtual_stack_dynamic_rtx, stack_pointer_rtx);
3473       save_stack_pointer ();
3474     }
3475
3476   return target;
3477 }
3478 \f
3479 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3480    The RETVAL parameter specifies whether return value needs to be saved, other
3481    parameters are documented in the emit_library_call function below.  */
3482
3483 static rtx
3484 emit_library_call_value_1 (retval, orgfun, value, fn_type, outmode, nargs, p)
3485      int retval;
3486      rtx orgfun;
3487      rtx value;
3488      enum libcall_type fn_type;
3489      enum machine_mode outmode;
3490      int nargs;
3491      va_list p;
3492 {
3493   /* Total size in bytes of all the stack-parms scanned so far.  */
3494   struct args_size args_size;
3495   /* Size of arguments before any adjustments (such as rounding).  */
3496   struct args_size original_args_size;
3497   int argnum;
3498   rtx fun;
3499   int inc;
3500   int count;
3501   struct args_size alignment_pad;
3502   rtx argblock = 0;
3503   CUMULATIVE_ARGS args_so_far;
3504   struct arg
3505   {
3506     rtx value;
3507     enum machine_mode mode;
3508     rtx reg;
3509     int partial;
3510     struct args_size offset;
3511     struct args_size size;
3512     rtx save_area;
3513   };
3514   struct arg *argvec;
3515   int old_inhibit_defer_pop = inhibit_defer_pop;
3516   rtx call_fusage = 0;
3517   rtx mem_value = 0;
3518   rtx valreg;
3519   int pcc_struct_value = 0;
3520   int struct_value_size = 0;
3521   int flags;
3522   int reg_parm_stack_space = 0;
3523   int needed;
3524   rtx before_call;
3525   tree tfom;                    /* type_for_mode (outmode, 0) */
3526
3527 #ifdef REG_PARM_STACK_SPACE
3528   /* Define the boundary of the register parm stack space that needs to be
3529      save, if any.  */
3530   int low_to_save, high_to_save;
3531   rtx save_area = 0;            /* Place that it is saved.  */
3532 #endif
3533
3534   /* Size of the stack reserved for parameter registers.  */
3535   int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3536   char *initial_stack_usage_map = stack_usage_map;
3537
3538 #ifdef REG_PARM_STACK_SPACE
3539 #ifdef MAYBE_REG_PARM_STACK_SPACE
3540   reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
3541 #else
3542   reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3543 #endif
3544 #endif
3545
3546   /* By default, library functions can not throw.  */
3547   flags = ECF_NOTHROW;
3548
3549   switch (fn_type)
3550     {
3551     case LCT_NORMAL:
3552       break;
3553     case LCT_CONST:
3554       flags |= ECF_CONST;
3555       break;
3556     case LCT_PURE:
3557       flags |= ECF_PURE;
3558       break;
3559     case LCT_CONST_MAKE_BLOCK:
3560       flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
3561       break;
3562     case LCT_PURE_MAKE_BLOCK:
3563       flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
3564       break;
3565     case LCT_NORETURN:
3566       flags |= ECF_NORETURN;
3567       break;
3568     case LCT_THROW:
3569       flags = ECF_NORETURN;
3570       break;
3571     case LCT_ALWAYS_RETURN:
3572       flags = ECF_ALWAYS_RETURN;
3573       break;
3574     case LCT_RETURNS_TWICE:
3575       flags = ECF_RETURNS_TWICE;
3576       break;
3577     }
3578   fun = orgfun;
3579
3580   /* Ensure current function's preferred stack boundary is at least
3581      what we need.  */
3582   if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3583     cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3584
3585   /* If this kind of value comes back in memory,
3586      decide where in memory it should come back.  */
3587   if (outmode != VOIDmode)
3588     {
3589       tfom = (*lang_hooks.types.type_for_mode) (outmode, 0);
3590       if (aggregate_value_p (tfom))
3591         {
3592 #ifdef PCC_STATIC_STRUCT_RETURN
3593           rtx pointer_reg
3594             = hard_function_value (build_pointer_type (tfom), 0, 0);
3595           mem_value = gen_rtx_MEM (outmode, pointer_reg);
3596           pcc_struct_value = 1;
3597           if (value == 0)
3598             value = gen_reg_rtx (outmode);
3599 #else /* not PCC_STATIC_STRUCT_RETURN */
3600           struct_value_size = GET_MODE_SIZE (outmode);
3601           if (value != 0 && GET_CODE (value) == MEM)
3602             mem_value = value;
3603           else
3604             mem_value = assign_temp (tfom, 0, 1, 1);
3605 #endif
3606           /* This call returns a big structure.  */
3607           flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3608         }
3609     }
3610   else
3611     tfom = void_type_node;
3612
3613   /* ??? Unfinished: must pass the memory address as an argument.  */
3614
3615   /* Copy all the libcall-arguments out of the varargs data
3616      and into a vector ARGVEC.
3617
3618      Compute how to pass each argument.  We only support a very small subset
3619      of the full argument passing conventions to limit complexity here since
3620      library functions shouldn't have many args.  */
3621
3622   argvec = (struct arg *) alloca ((nargs + 1) * sizeof (struct arg));
3623   memset ((char *) argvec, 0, (nargs + 1) * sizeof (struct arg));
3624
3625 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3626   INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3627 #else
3628   INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0);
3629 #endif
3630
3631   args_size.constant = 0;
3632   args_size.var = 0;
3633
3634   count = 0;
3635
3636   /* Now we are about to start emitting insns that can be deleted
3637      if a libcall is deleted.  */
3638   if (flags & ECF_LIBCALL_BLOCK)
3639     start_sequence ();
3640
3641   push_temp_slots ();
3642
3643   /* If there's a structure value address to be passed,
3644      either pass it in the special place, or pass it as an extra argument.  */
3645   if (mem_value && struct_value_rtx == 0 && ! pcc_struct_value)
3646     {
3647       rtx addr = XEXP (mem_value, 0);
3648       nargs++;
3649
3650       /* Make sure it is a reasonable operand for a move or push insn.  */
3651       if (GET_CODE (addr) != REG && GET_CODE (addr) != MEM
3652           && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3653         addr = force_operand (addr, NULL_RTX);
3654
3655       argvec[count].value = addr;
3656       argvec[count].mode = Pmode;
3657       argvec[count].partial = 0;
3658
3659       argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3660 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3661       if (FUNCTION_ARG_PARTIAL_NREGS (args_so_far, Pmode, NULL_TREE, 1))
3662         abort ();
3663 #endif
3664
3665       locate_and_pad_parm (Pmode, NULL_TREE,
3666 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3667                            1,
3668 #else
3669                            argvec[count].reg != 0,
3670 #endif
3671                            NULL_TREE, &args_size, &argvec[count].offset,
3672                            &argvec[count].size, &alignment_pad);
3673
3674       if (argvec[count].reg == 0 || argvec[count].partial != 0
3675           || reg_parm_stack_space > 0)
3676         args_size.constant += argvec[count].size.constant;
3677
3678       FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3679
3680       count++;
3681     }
3682
3683   for (; count < nargs; count++)
3684     {
3685       rtx val = va_arg (p, rtx);
3686       enum machine_mode mode = va_arg (p, enum machine_mode);
3687
3688       /* We cannot convert the arg value to the mode the library wants here;
3689          must do it earlier where we know the signedness of the arg.  */
3690       if (mode == BLKmode
3691           || (GET_MODE (val) != mode && GET_MODE (val) != VOIDmode))
3692         abort ();
3693
3694       /* On some machines, there's no way to pass a float to a library fcn.
3695          Pass it as a double instead.  */
3696 #ifdef LIBGCC_NEEDS_DOUBLE
3697       if (LIBGCC_NEEDS_DOUBLE && mode == SFmode)
3698         val = convert_modes (DFmode, SFmode, val, 0), mode = DFmode;
3699 #endif
3700
3701       /* There's no need to call protect_from_queue, because
3702          either emit_move_insn or emit_push_insn will do that.  */
3703
3704       /* Make sure it is a reasonable operand for a move or push insn.  */
3705       if (GET_CODE (val) != REG && GET_CODE (val) != MEM
3706           && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3707         val = force_operand (val, NULL_RTX);
3708
3709 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
3710       if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, mode, NULL_TREE, 1))
3711         {
3712           rtx slot;
3713           int must_copy = 1
3714 #ifdef FUNCTION_ARG_CALLEE_COPIES
3715             && ! FUNCTION_ARG_CALLEE_COPIES (args_so_far, mode,
3716                                              NULL_TREE, 1)
3717 #endif
3718             ;
3719
3720           /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure
3721              functions, so we have to pretend this isn't such a function.  */
3722           if (flags & ECF_LIBCALL_BLOCK)
3723             {
3724               rtx insns = get_insns ();
3725               end_sequence ();
3726               emit_insn (insns);
3727             }
3728           flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3729
3730           /* If this was a CONST function, it is now PURE since
3731              it now reads memory.  */
3732           if (flags & ECF_CONST)
3733             {
3734               flags &= ~ECF_CONST;
3735               flags |= ECF_PURE;
3736             }
3737
3738           if (GET_MODE (val) == MEM && ! must_copy)
3739             slot = val;
3740           else if (must_copy)
3741             {
3742               slot = assign_temp ((*lang_hooks.types.type_for_mode) (mode, 0),
3743                                   0, 1, 1);
3744               emit_move_insn (slot, val);
3745             }
3746           else
3747             {
3748               tree type = (*lang_hooks.types.type_for_mode) (mode, 0);
3749
3750               slot
3751                 = gen_rtx_MEM (mode,
3752                                expand_expr (build1 (ADDR_EXPR,
3753                                                     build_pointer_type (type),
3754                                                     make_tree (type, val)),
3755                                             NULL_RTX, VOIDmode, 0));
3756             }
3757
3758           call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3759                                            gen_rtx_USE (VOIDmode, slot),
3760                                            call_fusage);
3761           if (must_copy)
3762             call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3763                                              gen_rtx_CLOBBER (VOIDmode,
3764                                                               slot),
3765                                              call_fusage);
3766
3767           mode = Pmode;
3768           val = force_operand (XEXP (slot, 0), NULL_RTX);
3769         }
3770 #endif
3771
3772       argvec[count].value = val;
3773       argvec[count].mode = mode;
3774
3775       argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3776
3777 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3778       argvec[count].partial
3779         = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode, NULL_TREE, 1);
3780 #else
3781       argvec[count].partial = 0;
3782 #endif
3783
3784       locate_and_pad_parm (mode, NULL_TREE,
3785 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3786                            1,
3787 #else
3788                            argvec[count].reg != 0,
3789 #endif
3790                            NULL_TREE, &args_size, &argvec[count].offset,
3791                            &argvec[count].size, &alignment_pad);
3792
3793       if (argvec[count].size.var)
3794         abort ();
3795
3796       if (reg_parm_stack_space == 0 && argvec[count].partial)
3797         argvec[count].size.constant -= argvec[count].partial * UNITS_PER_WORD;
3798
3799       if (argvec[count].reg == 0 || argvec[count].partial != 0
3800           || reg_parm_stack_space > 0)
3801         args_size.constant += argvec[count].size.constant;
3802
3803       FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3804     }
3805
3806 #ifdef FINAL_REG_PARM_STACK_SPACE
3807   reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
3808                                                      args_size.var);
3809 #endif
3810   /* If this machine requires an external definition for library
3811      functions, write one out.  */
3812   assemble_external_libcall (fun);
3813
3814   original_args_size = args_size;
3815   args_size.constant = (((args_size.constant
3816                           + stack_pointer_delta
3817                           + STACK_BYTES - 1)
3818                           / STACK_BYTES
3819                           * STACK_BYTES)
3820                          - stack_pointer_delta);
3821
3822   args_size.constant = MAX (args_size.constant,
3823                             reg_parm_stack_space);
3824
3825 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3826   args_size.constant -= reg_parm_stack_space;
3827 #endif
3828
3829   if (args_size.constant > current_function_outgoing_args_size)
3830     current_function_outgoing_args_size = args_size.constant;
3831
3832   if (ACCUMULATE_OUTGOING_ARGS)
3833     {
3834       /* Since the stack pointer will never be pushed, it is possible for
3835          the evaluation of a parm to clobber something we have already
3836          written to the stack.  Since most function calls on RISC machines
3837          do not use the stack, this is uncommon, but must work correctly.
3838
3839          Therefore, we save any area of the stack that was already written
3840          and that we are using.  Here we set up to do this by making a new
3841          stack usage map from the old one.
3842
3843          Another approach might be to try to reorder the argument
3844          evaluations to avoid this conflicting stack usage.  */
3845
3846       needed = args_size.constant;
3847
3848 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3849       /* Since we will be writing into the entire argument area, the
3850          map must be allocated for its entire size, not just the part that
3851          is the responsibility of the caller.  */
3852       needed += reg_parm_stack_space;
3853 #endif
3854
3855 #ifdef ARGS_GROW_DOWNWARD
3856       highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3857                                          needed + 1);
3858 #else
3859       highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3860                                          needed);
3861 #endif
3862       stack_usage_map = (char *) alloca (highest_outgoing_arg_in_use);
3863
3864       if (initial_highest_arg_in_use)
3865         memcpy (stack_usage_map, initial_stack_usage_map,
3866                 initial_highest_arg_in_use);
3867
3868       if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3869         memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3870                highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3871       needed = 0;
3872
3873       /* We must be careful to use virtual regs before they're instantiated,
3874          and real regs afterwards.  Loop optimization, for example, can create
3875          new libcalls after we've instantiated the virtual regs, and if we
3876          use virtuals anyway, they won't match the rtl patterns.  */
3877
3878       if (virtuals_instantiated)
3879         argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3880       else
3881         argblock = virtual_outgoing_args_rtx;
3882     }
3883   else
3884     {
3885       if (!PUSH_ARGS)
3886         argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3887     }
3888
3889   /* If we push args individually in reverse order, perform stack alignment
3890      before the first push (the last arg).  */
3891   if (argblock == 0 && PUSH_ARGS_REVERSED)
3892     anti_adjust_stack (GEN_INT (args_size.constant
3893                                 - original_args_size.constant));
3894
3895   if (PUSH_ARGS_REVERSED)
3896     {
3897       inc = -1;
3898       argnum = nargs - 1;
3899     }
3900   else
3901     {
3902       inc = 1;
3903       argnum = 0;
3904     }
3905
3906 #ifdef REG_PARM_STACK_SPACE
3907   if (ACCUMULATE_OUTGOING_ARGS)
3908     {
3909       /* The argument list is the property of the called routine and it
3910          may clobber it.  If the fixed area has been used for previous
3911          parameters, we must save and restore it.  */
3912       save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3913                                             &low_to_save, &high_to_save);
3914     }
3915 #endif
3916
3917   /* Push the args that need to be pushed.  */
3918
3919   /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3920      are to be pushed.  */
3921   for (count = 0; count < nargs; count++, argnum += inc)
3922     {
3923       enum machine_mode mode = argvec[argnum].mode;
3924       rtx val = argvec[argnum].value;
3925       rtx reg = argvec[argnum].reg;
3926       int partial = argvec[argnum].partial;
3927       int lower_bound = 0, upper_bound = 0, i;
3928
3929       if (! (reg != 0 && partial == 0))
3930         {
3931           if (ACCUMULATE_OUTGOING_ARGS)
3932             {
3933               /* If this is being stored into a pre-allocated, fixed-size,
3934                  stack area, save any previous data at that location.  */
3935
3936 #ifdef ARGS_GROW_DOWNWARD
3937               /* stack_slot is negative, but we want to index stack_usage_map
3938                  with positive values.  */
3939               upper_bound = -argvec[argnum].offset.constant + 1;
3940               lower_bound = upper_bound - argvec[argnum].size.constant;
3941 #else
3942               lower_bound = argvec[argnum].offset.constant;
3943               upper_bound = lower_bound + argvec[argnum].size.constant;
3944 #endif
3945
3946               i = lower_bound;
3947               /* Don't worry about things in the fixed argument area;
3948                  it has already been saved.  */
3949               if (i < reg_parm_stack_space)
3950                 i = reg_parm_stack_space;
3951               while (i < upper_bound && stack_usage_map[i] == 0)
3952                 i++;
3953
3954               if (i < upper_bound)
3955                 {
3956                   /* We need to make a save area.  See what mode we can make
3957                      it.  */
3958                   enum machine_mode save_mode
3959                     = mode_for_size (argvec[argnum].size.constant
3960                                      * BITS_PER_UNIT,
3961                                      MODE_INT, 1);
3962                   rtx stack_area
3963                     = gen_rtx_MEM
3964                       (save_mode,
3965                        memory_address
3966                        (save_mode,
3967                         plus_constant (argblock,
3968                                        argvec[argnum].offset.constant)));
3969                   argvec[argnum].save_area = gen_reg_rtx (save_mode);
3970
3971                   emit_move_insn (argvec[argnum].save_area, stack_area);
3972                 }
3973             }
3974
3975           emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
3976                           partial, reg, 0, argblock,
3977                           GEN_INT (argvec[argnum].offset.constant),
3978                           reg_parm_stack_space, ARGS_SIZE_RTX (alignment_pad));
3979
3980           /* Now mark the segment we just used.  */
3981           if (ACCUMULATE_OUTGOING_ARGS)
3982             for (i = lower_bound; i < upper_bound; i++)
3983               stack_usage_map[i] = 1;
3984
3985           NO_DEFER_POP;
3986         }
3987     }
3988
3989   /* If we pushed args in forward order, perform stack alignment
3990      after pushing the last arg.  */
3991   if (argblock == 0 && !PUSH_ARGS_REVERSED)
3992     anti_adjust_stack (GEN_INT (args_size.constant
3993                                 - original_args_size.constant));
3994
3995   if (PUSH_ARGS_REVERSED)
3996     argnum = nargs - 1;
3997   else
3998     argnum = 0;
3999
4000   fun = prepare_call_address (fun, NULL_TREE, &call_fusage, 0, 0);
4001
4002   /* Now load any reg parms into their regs.  */
4003
4004   /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4005      are to be pushed.  */
4006   for (count = 0; count < nargs; count++, argnum += inc)
4007     {
4008       rtx val = argvec[argnum].value;
4009       rtx reg = argvec[argnum].reg;
4010       int partial = argvec[argnum].partial;
4011
4012       /* Handle calls that pass values in multiple non-contiguous
4013          locations.  The PA64 has examples of this for library calls.  */
4014       if (reg != 0 && GET_CODE (reg) == PARALLEL)
4015         emit_group_load (reg, val, GET_MODE_SIZE (GET_MODE (val)));
4016       else if (reg != 0 && partial == 0)
4017         emit_move_insn (reg, val);
4018
4019       NO_DEFER_POP;
4020     }
4021
4022   /* Any regs containing parms remain in use through the call.  */
4023   for (count = 0; count < nargs; count++)
4024     {
4025       rtx reg = argvec[count].reg;
4026       if (reg != 0 && GET_CODE (reg) == PARALLEL)
4027         use_group_regs (&call_fusage, reg);
4028       else if (reg != 0)
4029         use_reg (&call_fusage, reg);
4030     }
4031
4032   /* Pass the function the address in which to return a structure value.  */
4033   if (mem_value != 0 && struct_value_rtx != 0 && ! pcc_struct_value)
4034     {
4035       emit_move_insn (struct_value_rtx,
4036                       force_reg (Pmode,
4037                                  force_operand (XEXP (mem_value, 0),
4038                                                 NULL_RTX)));
4039       if (GET_CODE (struct_value_rtx) == REG)
4040         use_reg (&call_fusage, struct_value_rtx);
4041     }
4042
4043   /* Don't allow popping to be deferred, since then
4044      cse'ing of library calls could delete a call and leave the pop.  */
4045   NO_DEFER_POP;
4046   valreg = (mem_value == 0 && outmode != VOIDmode
4047             ? hard_libcall_value (outmode) : NULL_RTX);
4048
4049   /* Stack must be properly aligned now.  */
4050   if (stack_pointer_delta & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1))
4051     abort ();
4052
4053   before_call = get_last_insn ();
4054
4055   /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
4056      will set inhibit_defer_pop to that value.  */
4057   /* The return type is needed to decide how many bytes the function pops.
4058      Signedness plays no role in that, so for simplicity, we pretend it's
4059      always signed.  We also assume that the list of arguments passed has
4060      no impact, so we pretend it is unknown.  */
4061
4062   emit_call_1 (fun,
4063                get_identifier (XSTR (orgfun, 0)),
4064                build_function_type (tfom, NULL_TREE),
4065                original_args_size.constant, args_size.constant,
4066                struct_value_size,
4067                FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
4068                valreg,
4069                old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
4070
4071   /* For calls to `setjmp', etc., inform flow.c it should complain
4072      if nonvolatile values are live.  For functions that cannot return,
4073      inform flow that control does not fall through.  */
4074
4075   if (flags & (ECF_NORETURN | ECF_LONGJMP))
4076     {
4077       /* The barrier note must be emitted
4078          immediately after the CALL_INSN.  Some ports emit more than
4079          just a CALL_INSN above, so we must search for it here.  */
4080
4081       rtx last = get_last_insn ();
4082       while (GET_CODE (last) != CALL_INSN)
4083         {
4084           last = PREV_INSN (last);
4085           /* There was no CALL_INSN?  */
4086           if (last == before_call)
4087             abort ();
4088         }
4089
4090       emit_barrier_after (last);
4091     }
4092
4093   /* Now restore inhibit_defer_pop to its actual original value.  */
4094   OK_DEFER_POP;
4095
4096   /* If call is cse'able, make appropriate pair of reg-notes around it.
4097      Test valreg so we don't crash; may safely ignore `const'
4098      if return type is void.  Disable for PARALLEL return values, because
4099      we have no way to move such values into a pseudo register.  */
4100   if (flags & ECF_LIBCALL_BLOCK)
4101     {
4102       rtx insns;
4103
4104       if (valreg == 0)
4105         {
4106           insns = get_insns ();
4107           end_sequence ();
4108           emit_insn (insns);
4109         }
4110       else
4111         {
4112           rtx note = 0;
4113           rtx temp;
4114           int i;
4115
4116           if (GET_CODE (valreg) == PARALLEL)
4117             {
4118               temp = gen_reg_rtx (outmode);
4119               emit_group_store (temp, valreg, outmode);
4120               valreg = temp;
4121             }
4122
4123           temp = gen_reg_rtx (GET_MODE (valreg));
4124
4125           /* Construct an "equal form" for the value which mentions all the
4126              arguments in order as well as the function name.  */
4127           for (i = 0; i < nargs; i++)
4128             note = gen_rtx_EXPR_LIST (VOIDmode, argvec[i].value, note);
4129           note = gen_rtx_EXPR_LIST (VOIDmode, fun, note);
4130
4131           insns = get_insns ();
4132           end_sequence ();
4133
4134           if (flags & ECF_PURE)
4135             note = gen_rtx_EXPR_LIST (VOIDmode,
4136                         gen_rtx_USE (VOIDmode,
4137                                      gen_rtx_MEM (BLKmode,
4138                                                   gen_rtx_SCRATCH (VOIDmode))),
4139                         note);
4140
4141           emit_libcall_block (insns, temp, valreg, note);
4142
4143           valreg = temp;
4144         }
4145     }
4146   pop_temp_slots ();
4147
4148   /* Copy the value to the right place.  */
4149   if (outmode != VOIDmode && retval)
4150     {
4151       if (mem_value)
4152         {
4153           if (value == 0)
4154             value = mem_value;
4155           if (value != mem_value)
4156             emit_move_insn (value, mem_value);
4157         }
4158       else if (GET_CODE (valreg) == PARALLEL)
4159         {
4160           if (value == 0)
4161             value = gen_reg_rtx (outmode);
4162           emit_group_store (value, valreg, outmode);
4163         }
4164       else if (value != 0)
4165         emit_move_insn (value, valreg);
4166       else
4167         value = valreg;
4168     }
4169
4170   if (ACCUMULATE_OUTGOING_ARGS)
4171     {
4172 #ifdef REG_PARM_STACK_SPACE
4173       if (save_area)
4174         restore_fixed_argument_area (save_area, argblock,
4175                                      high_to_save, low_to_save);
4176 #endif
4177
4178       /* If we saved any argument areas, restore them.  */
4179       for (count = 0; count < nargs; count++)
4180         if (argvec[count].save_area)
4181           {
4182             enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
4183             rtx stack_area
4184               = gen_rtx_MEM (save_mode,
4185                              memory_address
4186                              (save_mode,
4187                               plus_constant (argblock,
4188                                              argvec[count].offset.constant)));
4189
4190             emit_move_insn (stack_area, argvec[count].save_area);
4191           }
4192
4193       highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4194       stack_usage_map = initial_stack_usage_map;
4195     }
4196
4197   return value;
4198
4199 }
4200 \f
4201 /* Output a library call to function FUN (a SYMBOL_REF rtx)
4202    (emitting the queue unless NO_QUEUE is nonzero),
4203    for a value of mode OUTMODE,
4204    with NARGS different arguments, passed as alternating rtx values
4205    and machine_modes to convert them to.
4206    The rtx values should have been passed through protect_from_queue already.
4207
4208    FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const'
4209    calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls
4210    which should be enclosed in REG_LIBCALL/REG_RETVAL notes,
4211    LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in
4212    REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)),
4213    or other LCT_ value for other types of library calls.  */
4214
4215 void
4216 emit_library_call VPARAMS((rtx orgfun, enum libcall_type fn_type,
4217                            enum machine_mode outmode, int nargs, ...))
4218 {
4219   VA_OPEN (p, nargs);
4220   VA_FIXEDARG (p, rtx, orgfun);
4221   VA_FIXEDARG (p, int, fn_type);
4222   VA_FIXEDARG (p, enum machine_mode, outmode);
4223   VA_FIXEDARG (p, int, nargs);
4224
4225   emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
4226
4227   VA_CLOSE (p);
4228 }
4229 \f
4230 /* Like emit_library_call except that an extra argument, VALUE,
4231    comes second and says where to store the result.
4232    (If VALUE is zero, this function chooses a convenient way
4233    to return the value.
4234
4235    This function returns an rtx for where the value is to be found.
4236    If VALUE is nonzero, VALUE is returned.  */
4237
4238 rtx
4239 emit_library_call_value VPARAMS((rtx orgfun, rtx value,
4240                                  enum libcall_type fn_type,
4241                                  enum machine_mode outmode, int nargs, ...))
4242 {
4243   rtx result;
4244
4245   VA_OPEN (p, nargs);
4246   VA_FIXEDARG (p, rtx, orgfun);
4247   VA_FIXEDARG (p, rtx, value);
4248   VA_FIXEDARG (p, int, fn_type);
4249   VA_FIXEDARG (p, enum machine_mode, outmode);
4250   VA_FIXEDARG (p, int, nargs);
4251
4252   result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
4253                                       nargs, p);
4254
4255   VA_CLOSE (p);
4256
4257   return result;
4258 }
4259 \f
4260 /* Store a single argument for a function call
4261    into the register or memory area where it must be passed.
4262    *ARG describes the argument value and where to pass it.
4263
4264    ARGBLOCK is the address of the stack-block for all the arguments,
4265    or 0 on a machine where arguments are pushed individually.
4266
4267    MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4268    so must be careful about how the stack is used.
4269
4270    VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4271    argument stack.  This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4272    that we need not worry about saving and restoring the stack.
4273
4274    FNDECL is the declaration of the function we are calling.
4275
4276    Return nonzero if this arg should cause sibcall failure,
4277    zero otherwise.  */
4278
4279 static int
4280 store_one_arg (arg, argblock, flags, variable_size, reg_parm_stack_space)
4281      struct arg_data *arg;
4282      rtx argblock;
4283      int flags;
4284      int variable_size ATTRIBUTE_UNUSED;
4285      int reg_parm_stack_space;
4286 {
4287   tree pval = arg->tree_value;
4288   rtx reg = 0;
4289   int partial = 0;
4290   int used = 0;
4291   int i, lower_bound = 0, upper_bound = 0;
4292   int sibcall_failure = 0;
4293
4294   if (TREE_CODE (pval) == ERROR_MARK)
4295     return 1;
4296
4297   /* Push a new temporary level for any temporaries we make for
4298      this argument.  */
4299   push_temp_slots ();
4300
4301   if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4302     {
4303       /* If this is being stored into a pre-allocated, fixed-size, stack area,
4304          save any previous data at that location.  */
4305       if (argblock && ! variable_size && arg->stack)
4306         {
4307 #ifdef ARGS_GROW_DOWNWARD
4308           /* stack_slot is negative, but we want to index stack_usage_map
4309              with positive values.  */
4310           if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4311             upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4312           else
4313             upper_bound = 0;
4314
4315           lower_bound = upper_bound - arg->size.constant;
4316 #else
4317           if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4318             lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4319           else
4320             lower_bound = 0;
4321
4322           upper_bound = lower_bound + arg->size.constant;
4323 #endif
4324
4325           i = lower_bound;
4326           /* Don't worry about things in the fixed argument area;
4327              it has already been saved.  */
4328           if (i < reg_parm_stack_space)
4329             i = reg_parm_stack_space;
4330           while (i < upper_bound && stack_usage_map[i] == 0)
4331             i++;
4332
4333           if (i < upper_bound)
4334             {
4335               /* We need to make a save area.  See what mode we can make it.  */
4336               enum machine_mode save_mode
4337                 = mode_for_size (arg->size.constant * BITS_PER_UNIT, MODE_INT, 1);
4338               rtx stack_area
4339                 = gen_rtx_MEM (save_mode,
4340                                memory_address (save_mode,
4341                                                XEXP (arg->stack_slot, 0)));
4342
4343               if (save_mode == BLKmode)
4344                 {
4345                   tree ot = TREE_TYPE (arg->tree_value);
4346                   tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4347                                                        | TYPE_QUAL_CONST));
4348
4349                   arg->save_area = assign_temp (nt, 0, 1, 1);
4350                   preserve_temp_slots (arg->save_area);
4351                   emit_block_move (validize_mem (arg->save_area), stack_area,
4352                                    expr_size (arg->tree_value),
4353                                    BLOCK_OP_CALL_PARM);
4354                 }
4355               else
4356                 {
4357                   arg->save_area = gen_reg_rtx (save_mode);
4358                   emit_move_insn (arg->save_area, stack_area);
4359                 }
4360             }
4361         }
4362     }
4363
4364   /* If this isn't going to be placed on both the stack and in registers,
4365      set up the register and number of words.  */
4366   if (! arg->pass_on_stack)
4367     {
4368       if (flags & ECF_SIBCALL)
4369         reg = arg->tail_call_reg;
4370       else
4371         reg = arg->reg;
4372       partial = arg->partial;
4373     }
4374
4375   if (reg != 0 && partial == 0)
4376     /* Being passed entirely in a register.  We shouldn't be called in
4377        this case.  */
4378     abort ();
4379
4380   /* If this arg needs special alignment, don't load the registers
4381      here.  */
4382   if (arg->n_aligned_regs != 0)
4383     reg = 0;
4384
4385   /* If this is being passed partially in a register, we can't evaluate
4386      it directly into its stack slot.  Otherwise, we can.  */
4387   if (arg->value == 0)
4388     {
4389       /* stack_arg_under_construction is nonzero if a function argument is
4390          being evaluated directly into the outgoing argument list and
4391          expand_call must take special action to preserve the argument list
4392          if it is called recursively.
4393
4394          For scalar function arguments stack_usage_map is sufficient to
4395          determine which stack slots must be saved and restored.  Scalar
4396          arguments in general have pass_on_stack == 0.
4397
4398          If this argument is initialized by a function which takes the
4399          address of the argument (a C++ constructor or a C function
4400          returning a BLKmode structure), then stack_usage_map is
4401          insufficient and expand_call must push the stack around the
4402          function call.  Such arguments have pass_on_stack == 1.
4403
4404          Note that it is always safe to set stack_arg_under_construction,
4405          but this generates suboptimal code if set when not needed.  */
4406
4407       if (arg->pass_on_stack)
4408         stack_arg_under_construction++;
4409
4410       arg->value = expand_expr (pval,
4411                                 (partial
4412                                  || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4413                                 ? NULL_RTX : arg->stack,
4414                                 VOIDmode, EXPAND_STACK_PARM);
4415
4416       /* If we are promoting object (or for any other reason) the mode
4417          doesn't agree, convert the mode.  */
4418
4419       if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4420         arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4421                                     arg->value, arg->unsignedp);
4422
4423       if (arg->pass_on_stack)
4424         stack_arg_under_construction--;
4425     }
4426
4427   /* Don't allow anything left on stack from computation
4428      of argument to alloca.  */
4429   if (flags & ECF_MAY_BE_ALLOCA)
4430     do_pending_stack_adjust ();
4431
4432   if (arg->value == arg->stack)
4433     /* If the value is already in the stack slot, we are done.  */
4434     ;
4435   else if (arg->mode != BLKmode)
4436     {
4437       int size;
4438
4439       /* Argument is a scalar, not entirely passed in registers.
4440          (If part is passed in registers, arg->partial says how much
4441          and emit_push_insn will take care of putting it there.)
4442
4443          Push it, and if its size is less than the
4444          amount of space allocated to it,
4445          also bump stack pointer by the additional space.
4446          Note that in C the default argument promotions
4447          will prevent such mismatches.  */
4448
4449       size = GET_MODE_SIZE (arg->mode);
4450       /* Compute how much space the push instruction will push.
4451          On many machines, pushing a byte will advance the stack
4452          pointer by a halfword.  */
4453 #ifdef PUSH_ROUNDING
4454       size = PUSH_ROUNDING (size);
4455 #endif
4456       used = size;
4457
4458       /* Compute how much space the argument should get:
4459          round up to a multiple of the alignment for arguments.  */
4460       if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4461         used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4462                  / (PARM_BOUNDARY / BITS_PER_UNIT))
4463                 * (PARM_BOUNDARY / BITS_PER_UNIT));
4464
4465       /* This isn't already where we want it on the stack, so put it there.
4466          This can either be done with push or copy insns.  */
4467       emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4468                       PARM_BOUNDARY, partial, reg, used - size, argblock,
4469                       ARGS_SIZE_RTX (arg->offset), reg_parm_stack_space,
4470                       ARGS_SIZE_RTX (arg->alignment_pad));
4471
4472       /* Unless this is a partially-in-register argument, the argument is now
4473          in the stack.  */
4474       if (partial == 0)
4475         arg->value = arg->stack;
4476     }
4477   else
4478     {
4479       /* BLKmode, at least partly to be pushed.  */
4480
4481       unsigned int parm_align;
4482       int excess;
4483       rtx size_rtx;
4484
4485       /* Pushing a nonscalar.
4486          If part is passed in registers, PARTIAL says how much
4487          and emit_push_insn will take care of putting it there.  */
4488
4489       /* Round its size up to a multiple
4490          of the allocation unit for arguments.  */
4491
4492       if (arg->size.var != 0)
4493         {
4494           excess = 0;
4495           size_rtx = ARGS_SIZE_RTX (arg->size);
4496         }
4497       else
4498         {
4499           /* PUSH_ROUNDING has no effect on us, because
4500              emit_push_insn for BLKmode is careful to avoid it.  */
4501           excess = (arg->size.constant - int_size_in_bytes (TREE_TYPE (pval))
4502                     + partial * UNITS_PER_WORD);
4503           size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4504                                   NULL_RTX, TYPE_MODE (sizetype), 0);
4505         }
4506
4507       /* Some types will require stricter alignment, which will be
4508          provided for elsewhere in argument layout.  */
4509       parm_align = MAX (PARM_BOUNDARY, TYPE_ALIGN (TREE_TYPE (pval)));
4510
4511       /* When an argument is padded down, the block is aligned to
4512          PARM_BOUNDARY, but the actual argument isn't.  */
4513       if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4514         {
4515           if (arg->size.var)
4516             parm_align = BITS_PER_UNIT;
4517           else if (excess)
4518             {
4519               unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4520               parm_align = MIN (parm_align, excess_align);
4521             }
4522         }
4523
4524       if ((flags & ECF_SIBCALL) && GET_CODE (arg->value) == MEM)
4525         {
4526           /* emit_push_insn might not work properly if arg->value and
4527              argblock + arg->offset areas overlap.  */
4528           rtx x = arg->value;
4529           int i = 0;
4530
4531           if (XEXP (x, 0) == current_function_internal_arg_pointer
4532               || (GET_CODE (XEXP (x, 0)) == PLUS
4533                   && XEXP (XEXP (x, 0), 0) ==
4534                      current_function_internal_arg_pointer
4535                   && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4536             {
4537               if (XEXP (x, 0) != current_function_internal_arg_pointer)
4538                 i = INTVAL (XEXP (XEXP (x, 0), 1));
4539
4540               /* expand_call should ensure this */
4541               if (arg->offset.var || GET_CODE (size_rtx) != CONST_INT)
4542                 abort ();
4543
4544               if (arg->offset.constant > i)
4545                 {
4546                   if (arg->offset.constant < i + INTVAL (size_rtx))
4547                     sibcall_failure = 1;
4548                 }
4549               else if (arg->offset.constant < i)
4550                 {
4551                   if (i < arg->offset.constant + INTVAL (size_rtx))
4552                     sibcall_failure = 1;
4553                 }
4554             }
4555         }
4556
4557       emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4558                       parm_align, partial, reg, excess, argblock,
4559                       ARGS_SIZE_RTX (arg->offset), reg_parm_stack_space,
4560                       ARGS_SIZE_RTX (arg->alignment_pad));
4561
4562       /* Unless this is a partially-in-register argument, the argument is now
4563          in the stack.
4564
4565          ??? Unlike the case above, in which we want the actual
4566          address of the data, so that we can load it directly into a
4567          register, here we want the address of the stack slot, so that
4568          it's properly aligned for word-by-word copying or something
4569          like that.  It's not clear that this is always correct.  */
4570       if (partial == 0)
4571         arg->value = arg->stack_slot;
4572     }
4573
4574   /* Mark all slots this store used.  */
4575   if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4576       && argblock && ! variable_size && arg->stack)
4577     for (i = lower_bound; i < upper_bound; i++)
4578       stack_usage_map[i] = 1;
4579
4580   /* Once we have pushed something, pops can't safely
4581      be deferred during the rest of the arguments.  */
4582   NO_DEFER_POP;
4583
4584   /* ANSI doesn't require a sequence point here,
4585      but PCC has one, so this will avoid some problems.  */
4586   emit_queue ();
4587
4588   /* Free any temporary slots made in processing this argument.  Show
4589      that we might have taken the address of something and pushed that
4590      as an operand.  */
4591   preserve_temp_slots (NULL_RTX);
4592   free_temp_slots ();
4593   pop_temp_slots ();
4594
4595   return sibcall_failure;
4596 }
4597
4598 /* Nonzero if we do not know how to pass TYPE solely in registers.
4599    We cannot do so in the following cases:
4600
4601    - if the type has variable size
4602    - if the type is marked as addressable (it is required to be constructed
4603      into the stack)
4604    - if the padding and mode of the type is such that a copy into a register
4605      would put it into the wrong part of the register.
4606
4607    Which padding can't be supported depends on the byte endianness.
4608
4609    A value in a register is implicitly padded at the most significant end.
4610    On a big-endian machine, that is the lower end in memory.
4611    So a value padded in memory at the upper end can't go in a register.
4612    For a little-endian machine, the reverse is true.  */
4613
4614 bool
4615 default_must_pass_in_stack (mode, type)
4616      enum machine_mode mode;
4617      tree type;
4618 {
4619   if (!type)
4620     return false;
4621
4622   /* If the type has variable size...  */
4623   if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4624     return true;
4625
4626   /* If the type is marked as addressable (it is required
4627      to be constructed into the stack)...  */
4628   if (TREE_ADDRESSABLE (type))
4629     return true;
4630
4631   /* If the padding and mode of the type is such that a copy into
4632      a register would put it into the wrong part of the register.  */
4633   if (mode == BLKmode
4634       && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4635       && (FUNCTION_ARG_PADDING (mode, type)
4636           == (BYTES_BIG_ENDIAN ? upward : downward)))
4637     return true;
4638
4639   return false;
4640 }