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 "optabs.h"
  31 #include "libfuncs.h"
  32 #include "function.h"
  33 #include "regs.h"
  34 #include "toplev.h"
  35 #include "output.h"
  36 #include "tm_p.h"
  37 #include "timevar.h"
  38 #include "sbitmap.h"
  39 #include "langhooks.h"
  40 #include "target.h"
  41 #include "cgraph.h"
  42 #include "except.h"
  43
  44 #ifndef STACK_POINTER_OFFSET
  45 #define STACK_POINTER_OFFSET    0
  46 #endif
  47
  48 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits.  */
  49 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
  50
  51 /* Data structure and subroutines used within expand_call.  */
  52
  53 struct arg_data
  54 {
  55   /* Tree node for this argument.  */
  56   tree tree_value;
  57   /* Mode for value; TYPE_MODE unless promoted.  */
  58   enum machine_mode mode;
  59   /* Current RTL value for argument, or 0 if it isn't precomputed.  */
  60   rtx value;
  61   /* Initially-compute RTL value for argument; only for const functions.  */
  62   rtx initial_value;
  63   /* Register to pass this argument in, 0 if passed on stack, or an
  64      PARALLEL if the arg is to be copied into multiple non-contiguous
  65      registers.  */
  66   rtx reg;
  67   /* Register to pass this argument in when generating tail call sequence.
  68      This is not the same register as for normal calls on machines with
  69      register windows.  */
  70   rtx tail_call_reg;
  71   /* If REG was promoted from the actual mode of the argument expression,
  72      indicates whether the promotion is sign- or zero-extended.  */
  73   int unsignedp;
  74   /* Number of registers to use.  0 means put the whole arg in registers.
  75      Also 0 if not passed in registers.  */
  76   int partial;
  77   /* Nonzero if argument must be passed on stack.
  78      Note that some arguments may be passed on the stack
  79      even though pass_on_stack is zero, just because FUNCTION_ARG says so.
  80      pass_on_stack identifies arguments that *cannot* go in registers.  */
  81   int pass_on_stack;
  82   /* Some fields packaged up for locate_and_pad_parm.  */
  83   struct locate_and_pad_arg_data locate;
  84   /* Location on the stack at which parameter should be stored.  The store
  85      has already been done if STACK == VALUE.  */
  86   rtx stack;
  87   /* Location on the stack of the start of this argument slot.  This can
  88      differ from STACK if this arg pads downward.  This location is known
  89      to be aligned to FUNCTION_ARG_BOUNDARY.  */
  90   rtx stack_slot;
  91   /* Place that this stack area has been saved, if needed.  */
  92   rtx save_area;
  93   /* If an argument's alignment does not permit direct copying into registers,
  94      copy in smaller-sized pieces into pseudos.  These are stored in a
  95      block pointed to by this field.  The next field says how many
  96      word-sized pseudos we made.  */
  97   rtx *aligned_regs;
  98   int n_aligned_regs;
  99 };
 100
 101 /* A vector of one char per byte of stack space.  A byte if nonzero if
 102    the corresponding stack location has been used.
 103    This vector is used to prevent a function call within an argument from
 104    clobbering any stack already set up.  */
 105 static char *stack_usage_map;
 106
 107 /* Size of STACK_USAGE_MAP.  */
 108 static int highest_outgoing_arg_in_use;
 109
 110 /* A bitmap of virtual-incoming stack space.  Bit is set if the corresponding
 111    stack location's tail call argument has been already stored into the stack.
 112    This bitmap is used to prevent sibling call optimization if function tries
 113    to use parent's incoming argument slots when they have been already
 114    overwritten with tail call arguments.  */
 115 static sbitmap stored_args_map;
 116
 117 /* stack_arg_under_construction is nonzero when an argument may be
 118    initialized with a constructor call (including a C function that
 119    returns a BLKmode struct) and expand_call must take special action
 120    to make sure the object being constructed does not overlap the
 121    argument list for the constructor call.  */
 122 int stack_arg_under_construction;
 123
 124 static int calls_function (tree, int);
 125 static int calls_function_1 (tree, int);
 126
 127 static void emit_call_1 (rtx, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT,
 128                          HOST_WIDE_INT, rtx, rtx, int, rtx, int,
 129                          CUMULATIVE_ARGS *);
 130 static void precompute_register_parameters (int, struct arg_data *, int *);
 131 static int store_one_arg (struct arg_data *, rtx, int, int, int);
 132 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
 133 static int finalize_must_preallocate (int, int, struct arg_data *,
 134                                       struct args_size *);
 135 static void precompute_arguments (int, int, struct arg_data *);
 136 static int compute_argument_block_size (int, struct args_size *, int);
 137 static void initialize_argument_information (int, struct arg_data *,
 138                                              struct args_size *, int, tree,
 139                                              tree, CUMULATIVE_ARGS *, int,
 140                                              rtx *, int *, int *, int *);
 141 static void compute_argument_addresses (struct arg_data *, rtx, int);
 142 static rtx rtx_for_function_call (tree, tree);
 143 static void load_register_parameters (struct arg_data *, int, rtx *, int,
 144                                       int, int *);
 145 static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type,
 146                                       enum machine_mode, int, va_list);
 147 static int special_function_p (tree, int);
 148 static rtx try_to_integrate (tree, tree, rtx, int, tree, rtx);
 149 static int check_sibcall_argument_overlap_1 (rtx);
 150 static int check_sibcall_argument_overlap (rtx, struct arg_data *, int);
 151
 152 static int combine_pending_stack_adjustment_and_call (int, struct args_size *,
 153                                                       int);
 154 static tree fix_unsafe_tree (tree);
 155
 156 #ifdef REG_PARM_STACK_SPACE
 157 static rtx save_fixed_argument_area (int, rtx, int *, int *);
 158 static void restore_fixed_argument_area (rtx, rtx, int, int);
 159 #endif
 160 \f
 161 /* If WHICH is 1, return 1 if EXP contains a call to the built-in function
 162    `alloca'.
 163
 164    If WHICH is 0, return 1 if EXP contains a call to any function.
 165    Actually, we only need return 1 if evaluating EXP would require pushing
 166    arguments on the stack, but that is too difficult to compute, so we just
 167    assume any function call might require the stack.  */
 168
 169 static tree calls_function_save_exprs;
 170
 171 static int
 172 calls_function (tree exp, int which)
 173 {
 174   int val;
 175
 176   calls_function_save_exprs = 0;
 177   val = calls_function_1 (exp, which);
 178   calls_function_save_exprs = 0;
 179   return val;
 180 }
 181
 182 /* Recursive function to do the work of above function.  */
 183
 184 static int
 185 calls_function_1 (tree exp, int which)
 186 {
 187   int i;
 188   enum tree_code code = TREE_CODE (exp);
 189   int class = TREE_CODE_CLASS (code);
 190   int length = first_rtl_op (code);
 191
 192   /* If this code is language-specific, we don't know what it will do.  */
 193   if ((int) code >= NUM_TREE_CODES)
 194     return 1;
 195
 196   switch (code)
 197     {
 198     case CALL_EXPR:
 199       if (which == 0)
 200         return 1;
 201       else if ((TREE_CODE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))
 202                 == FUNCTION_TYPE)
 203                && (TYPE_RETURNS_STACK_DEPRESSED
 204                    (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))))
 205         return 1;
 206       else if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
 207                && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
 208                    == FUNCTION_DECL)
 209                && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
 210                                        0)
 211                    & ECF_MAY_BE_ALLOCA))
 212         return 1;
 213
 214       break;
 215
 216     case CONSTRUCTOR:
 217       {
 218         tree tem;
 219
 220         for (tem = CONSTRUCTOR_ELTS (exp); tem != 0; tem = TREE_CHAIN (tem))
 221           if (calls_function_1 (TREE_VALUE (tem), which))
 222             return 1;
 223       }
 224
 225       return 0;
 226
 227     case SAVE_EXPR:
 228       if (SAVE_EXPR_RTL (exp) != 0)
 229         return 0;
 230       if (value_member (exp, calls_function_save_exprs))
 231         return 0;
 232       calls_function_save_exprs = tree_cons (NULL_TREE, exp,
 233                                              calls_function_save_exprs);
 234       return (TREE_OPERAND (exp, 0) != 0
 235               && calls_function_1 (TREE_OPERAND (exp, 0), which));
 236
 237     case BLOCK:
 238       {
 239         tree local;
 240         tree subblock;
 241
 242         for (local = BLOCK_VARS (exp); local; local = TREE_CHAIN (local))
 243           if (DECL_INITIAL (local) != 0
 244               && calls_function_1 (DECL_INITIAL (local), which))
 245             return 1;
 246
 247         for (subblock = BLOCK_SUBBLOCKS (exp);
 248              subblock;
 249              subblock = TREE_CHAIN (subblock))
 250           if (calls_function_1 (subblock, which))
 251             return 1;
 252       }
 253       return 0;
 254
 255     case TREE_LIST:
 256       for (; exp != 0; exp = TREE_CHAIN (exp))
 257         if (calls_function_1 (TREE_VALUE (exp), which))
 258           return 1;
 259       return 0;
 260
 261     default:
 262       break;
 263     }
 264
 265   /* Only expressions, references, and blocks can contain calls.  */
 266   if (! IS_EXPR_CODE_CLASS (class) && class != 'r' && class != 'b')
 267     return 0;
 268
 269   for (i = 0; i < length; i++)
 270     if (TREE_OPERAND (exp, i) != 0
 271         && calls_function_1 (TREE_OPERAND (exp, i), which))
 272       return 1;
 273
 274   return 0;
 275 }
 276 \f
 277 /* Force FUNEXP into a form suitable for the address of a CALL,
 278    and return that as an rtx.  Also load the static chain register
 279    if FNDECL is a nested function.
 280
 281    CALL_FUSAGE points to a variable holding the prospective
 282    CALL_INSN_FUNCTION_USAGE information.  */
 283
 284 rtx
 285 prepare_call_address (rtx funexp, tree fndecl, rtx *call_fusage,
 286                       int reg_parm_seen, int sibcallp)
 287 {
 288   rtx static_chain_value = 0;
 289
 290   funexp = protect_from_queue (funexp, 0);
 291
 292   if (fndecl != 0)
 293     /* Get possible static chain value for nested function in C.  */
 294     static_chain_value = lookup_static_chain (fndecl);
 295
 296   /* Make a valid memory address and copy constants thru pseudo-regs,
 297      but not for a constant address if -fno-function-cse.  */
 298   if (GET_CODE (funexp) != SYMBOL_REF)
 299     /* If we are using registers for parameters, force the
 300        function address into a register now.  */
 301     funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
 302               ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
 303               : memory_address (FUNCTION_MODE, funexp));
 304   else if (! sibcallp)
 305     {
 306 #ifndef NO_FUNCTION_CSE
 307       if (optimize && ! flag_no_function_cse)
 308 #ifdef NO_RECURSIVE_FUNCTION_CSE
 309         if (fndecl != current_function_decl)
 310 #endif
 311           funexp = force_reg (Pmode, funexp);
 312 #endif
 313     }
 314
 315   if (static_chain_value != 0)
 316     {
 317       emit_move_insn (static_chain_rtx, static_chain_value);
 318
 319       if (GET_CODE (static_chain_rtx) == REG)
 320         use_reg (call_fusage, static_chain_rtx);
 321     }
 322
 323   return funexp;
 324 }
 325
 326 /* Generate instructions to call function FUNEXP,
 327    and optionally pop the results.
 328    The CALL_INSN is the first insn generated.
 329
 330    FNDECL is the declaration node of the function.  This is given to the
 331    macro RETURN_POPS_ARGS to determine whether this function pops its own args.
 332
 333    FUNTYPE is the data type of the function.  This is given to the macro
 334    RETURN_POPS_ARGS to determine whether this function pops its own args.
 335    We used to allow an identifier for library functions, but that doesn't
 336    work when the return type is an aggregate type and the calling convention
 337    says that the pointer to this aggregate is to be popped by the callee.
 338
 339    STACK_SIZE is the number of bytes of arguments on the stack,
 340    ROUNDED_STACK_SIZE is that number rounded up to
 341    PREFERRED_STACK_BOUNDARY; zero if the size is variable.  This is
 342    both to put into the call insn and to generate explicit popping
 343    code if necessary.
 344
 345    STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
 346    It is zero if this call doesn't want a structure value.
 347
 348    NEXT_ARG_REG is the rtx that results from executing
 349      FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
 350    just after all the args have had their registers assigned.
 351    This could be whatever you like, but normally it is the first
 352    arg-register beyond those used for args in this call,
 353    or 0 if all the arg-registers are used in this call.
 354    It is passed on to `gen_call' so you can put this info in the call insn.
 355
 356    VALREG is a hard register in which a value is returned,
 357    or 0 if the call does not return a value.
 358
 359    OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
 360    the args to this call were processed.
 361    We restore `inhibit_defer_pop' to that value.
 362
 363    CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
 364    denote registers used by the called function.  */
 365
 366 static void
 367 emit_call_1 (rtx funexp, tree fndecl ATTRIBUTE_UNUSED, tree funtype ATTRIBUTE_UNUSED,
 368              HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
 369              HOST_WIDE_INT rounded_stack_size,
 370              HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
 371              rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
 372              int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
 373              CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED)
 374 {
 375   rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
 376   rtx call_insn;
 377   int already_popped = 0;
 378   HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
 379 #if defined (HAVE_call) && defined (HAVE_call_value)
 380   rtx struct_value_size_rtx;
 381   struct_value_size_rtx = GEN_INT (struct_value_size);
 382 #endif
 383
 384 #ifdef CALL_POPS_ARGS
 385   n_popped += CALL_POPS_ARGS (* args_so_far);
 386 #endif
 387
 388   /* Ensure address is valid.  SYMBOL_REF is already valid, so no need,
 389      and we don't want to load it into a register as an optimization,
 390      because prepare_call_address already did it if it should be done.  */
 391   if (GET_CODE (funexp) != SYMBOL_REF)
 392     funexp = memory_address (FUNCTION_MODE, funexp);
 393
 394 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
 395   if ((ecf_flags & ECF_SIBCALL)
 396       && HAVE_sibcall_pop && HAVE_sibcall_value_pop
 397       && (n_popped > 0 || stack_size == 0))
 398     {
 399       rtx n_pop = GEN_INT (n_popped);
 400       rtx pat;
 401
 402       /* If this subroutine pops its own args, record that in the call insn
 403          if possible, for the sake of frame pointer elimination.  */
 404
 405       if (valreg)
 406         pat = GEN_SIBCALL_VALUE_POP (valreg,
 407                                      gen_rtx_MEM (FUNCTION_MODE, funexp),
 408                                      rounded_stack_size_rtx, next_arg_reg,
 409                                      n_pop);
 410       else
 411         pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
 412                                rounded_stack_size_rtx, next_arg_reg, n_pop);
 413
 414       emit_call_insn (pat);
 415       already_popped = 1;
 416     }
 417   else
 418 #endif
 419
 420 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
 421   /* If the target has "call" or "call_value" insns, then prefer them
 422      if no arguments are actually popped.  If the target does not have
 423      "call" or "call_value" insns, then we must use the popping versions
 424      even if the call has no arguments to pop.  */
 425 #if defined (HAVE_call) && defined (HAVE_call_value)
 426   if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
 427       && n_popped > 0 && ! (ecf_flags & ECF_SP_DEPRESSED))
 428 #else
 429   if (HAVE_call_pop && HAVE_call_value_pop)
 430 #endif
 431     {
 432       rtx n_pop = GEN_INT (n_popped);
 433       rtx pat;
 434
 435       /* If this subroutine pops its own args, record that in the call insn
 436          if possible, for the sake of frame pointer elimination.  */
 437
 438       if (valreg)
 439         pat = GEN_CALL_VALUE_POP (valreg,
 440                                   gen_rtx_MEM (FUNCTION_MODE, funexp),
 441                                   rounded_stack_size_rtx, next_arg_reg, n_pop);
 442       else
 443         pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
 444                             rounded_stack_size_rtx, next_arg_reg, n_pop);
 445
 446       emit_call_insn (pat);
 447       already_popped = 1;
 448     }
 449   else
 450 #endif
 451
 452 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
 453   if ((ecf_flags & ECF_SIBCALL)
 454       && HAVE_sibcall && HAVE_sibcall_value)
 455     {
 456       if (valreg)
 457         emit_call_insn (GEN_SIBCALL_VALUE (valreg,
 458                                            gen_rtx_MEM (FUNCTION_MODE, funexp),
 459                                            rounded_stack_size_rtx,
 460                                            next_arg_reg, NULL_RTX));
 461       else
 462         emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
 463                                      rounded_stack_size_rtx, next_arg_reg,
 464                                      struct_value_size_rtx));
 465     }
 466   else
 467 #endif
 468
 469 #if defined (HAVE_call) && defined (HAVE_call_value)
 470   if (HAVE_call && HAVE_call_value)
 471     {
 472       if (valreg)
 473         emit_call_insn (GEN_CALL_VALUE (valreg,
 474                                         gen_rtx_MEM (FUNCTION_MODE, funexp),
 475                                         rounded_stack_size_rtx, next_arg_reg,
 476                                         NULL_RTX));
 477       else
 478         emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
 479                                   rounded_stack_size_rtx, next_arg_reg,
 480                                   struct_value_size_rtx));
 481     }
 482   else
 483 #endif
 484     abort ();
 485
 486   /* Find the call we just emitted.  */
 487   call_insn = last_call_insn ();
 488
 489   /* Mark memory as used for "pure" function call.  */
 490   if (ecf_flags & ECF_PURE)
 491     call_fusage
 492       = gen_rtx_EXPR_LIST
 493         (VOIDmode,
 494          gen_rtx_USE (VOIDmode,
 495                       gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode))),
 496          call_fusage);
 497
 498   /* Put the register usage information there.  */
 499   add_function_usage_to (call_insn, call_fusage);
 500
 501   /* If this is a const call, then set the insn's unchanging bit.  */
 502   if (ecf_flags & (ECF_CONST | ECF_PURE))
 503     CONST_OR_PURE_CALL_P (call_insn) = 1;
 504
 505   /* If this call can't throw, attach a REG_EH_REGION reg note to that
 506      effect.  */
 507   if (ecf_flags & ECF_NOTHROW)
 508     REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, const0_rtx,
 509                                                REG_NOTES (call_insn));
 510   else
 511     note_eh_region_may_contain_throw ();
 512
 513   if (ecf_flags & ECF_NORETURN)
 514     REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_NORETURN, const0_rtx,
 515                                                REG_NOTES (call_insn));
 516   if (ecf_flags & ECF_ALWAYS_RETURN)
 517     REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_ALWAYS_RETURN, const0_rtx,
 518                                                REG_NOTES (call_insn));
 519
 520   if (ecf_flags & ECF_RETURNS_TWICE)
 521     {
 522       REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_SETJMP, const0_rtx,
 523                                                  REG_NOTES (call_insn));
 524       current_function_calls_setjmp = 1;
 525     }
 526
 527   SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
 528
 529   /* Restore this now, so that we do defer pops for this call's args
 530      if the context of the call as a whole permits.  */
 531   inhibit_defer_pop = old_inhibit_defer_pop;
 532
 533   /* Don't bother cleaning up after a noreturn function.  */
 534   if (ecf_flags & (ECF_NORETURN | ECF_LONGJMP))
 535     return;
 536
 537   if (n_popped > 0)
 538     {
 539       if (!already_popped)
 540         CALL_INSN_FUNCTION_USAGE (call_insn)
 541           = gen_rtx_EXPR_LIST (VOIDmode,
 542                                gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
 543                                CALL_INSN_FUNCTION_USAGE (call_insn));
 544       rounded_stack_size -= n_popped;
 545       rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
 546       stack_pointer_delta -= n_popped;
 547     }
 548
 549   if (!ACCUMULATE_OUTGOING_ARGS)
 550     {
 551       /* If returning from the subroutine does not automatically pop the args,
 552          we need an instruction to pop them sooner or later.
 553          Perhaps do it now; perhaps just record how much space to pop later.
 554
 555          If returning from the subroutine does pop the args, indicate that the
 556          stack pointer will be changed.  */
 557
 558       if (rounded_stack_size != 0)
 559         {
 560           if (ecf_flags & ECF_SP_DEPRESSED)
 561             /* Just pretend we did the pop.  */
 562             stack_pointer_delta -= rounded_stack_size;
 563           else if (flag_defer_pop && inhibit_defer_pop == 0
 564               && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
 565             pending_stack_adjust += rounded_stack_size;
 566           else
 567             adjust_stack (rounded_stack_size_rtx);
 568         }
 569     }
 570   /* When we accumulate outgoing args, we must avoid any stack manipulations.
 571      Restore the stack pointer to its original value now.  Usually
 572      ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
 573      On  i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
 574      popping variants of functions exist as well.
 575
 576      ??? We may optimize similar to defer_pop above, but it is
 577      probably not worthwhile.
 578
 579      ??? It will be worthwhile to enable combine_stack_adjustments even for
 580      such machines.  */
 581   else if (n_popped)
 582     anti_adjust_stack (GEN_INT (n_popped));
 583 }
 584
 585 /* Determine if the function identified by NAME and FNDECL is one with
 586    special properties we wish to know about.
 587
 588    For example, if the function might return more than one time (setjmp), then
 589    set RETURNS_TWICE to a nonzero value.
 590
 591    Similarly set LONGJMP for if the function is in the longjmp family.
 592
 593    Set MAY_BE_ALLOCA for any memory allocation function that might allocate
 594    space from the stack such as alloca.  */
 595
 596 static int
 597 special_function_p (tree fndecl, int flags)
 598 {
 599   if (! (flags & ECF_MALLOC)
 600       && fndecl && DECL_NAME (fndecl)
 601       && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
 602       /* Exclude functions not at the file scope, or not `extern',
 603          since they are not the magic functions we would otherwise
 604          think they are.
 605          FIXME: this should be handled with attributes, not with this
 606          hacky imitation of DECL_ASSEMBLER_NAME.  It's (also) wrong
 607          because you can declare fork() inside a function if you
 608          wish.  */
 609       && (DECL_CONTEXT (fndecl) == NULL_TREE
 610           || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
 611       && TREE_PUBLIC (fndecl))
 612     {
 613       const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
 614       const char *tname = name;
 615
 616       /* We assume that alloca will always be called by name.  It
 617          makes no sense to pass it as a pointer-to-function to
 618          anything that does not understand its behavior.  */
 619       if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
 620             && name[0] == 'a'
 621             && ! strcmp (name, "alloca"))
 622            || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
 623                && name[0] == '_'
 624                && ! strcmp (name, "__builtin_alloca"))))
 625         flags |= ECF_MAY_BE_ALLOCA;
 626
 627       /* Disregard prefix _, __ or __x.  */
 628       if (name[0] == '_')
 629         {
 630           if (name[1] == '_' && name[2] == 'x')
 631             tname += 3;
 632           else if (name[1] == '_')
 633             tname += 2;
 634           else
 635             tname += 1;
 636         }
 637
 638       if (tname[0] == 's')
 639         {
 640           if ((tname[1] == 'e'
 641                && (! strcmp (tname, "setjmp")
 642                    || ! strcmp (tname, "setjmp_syscall")))
 643               || (tname[1] == 'i'
 644                   && ! strcmp (tname, "sigsetjmp"))
 645               || (tname[1] == 'a'
 646                   && ! strcmp (tname, "savectx")))
 647             flags |= ECF_RETURNS_TWICE;
 648
 649           if (tname[1] == 'i'
 650               && ! strcmp (tname, "siglongjmp"))
 651             flags |= ECF_LONGJMP;
 652         }
 653       else if ((tname[0] == 'q' && tname[1] == 's'
 654                 && ! strcmp (tname, "qsetjmp"))
 655                || (tname[0] == 'v' && tname[1] == 'f'
 656                    && ! strcmp (tname, "vfork")))
 657         flags |= ECF_RETURNS_TWICE;
 658
 659       else if (tname[0] == 'l' && tname[1] == 'o'
 660                && ! strcmp (tname, "longjmp"))
 661         flags |= ECF_LONGJMP;
 662
 663       else if ((tname[0] == 'f' && tname[1] == 'o'
 664                 && ! strcmp (tname, "fork"))
 665                /* Linux specific: __clone.  check NAME to insist on the
 666                   leading underscores, to avoid polluting the ISO / POSIX
 667                   namespace.  */
 668                || (name[0] == '_' && name[1] == '_'
 669                    && ! strcmp (tname, "clone"))
 670                || (tname[0] == 'e' && tname[1] == 'x' && tname[2] == 'e'
 671                    && tname[3] == 'c' && (tname[4] == 'l' || tname[4] == 'v')
 672                    && (tname[5] == '\0'
 673                        || ((tname[5] == 'p' || tname[5] == 'e')
 674                            && tname[6] == '\0'))))
 675         flags |= ECF_FORK_OR_EXEC;
 676     }
 677   return flags;
 678 }
 679
 680 /* Return nonzero when tree represent call to longjmp.  */
 681
 682 int
 683 setjmp_call_p (tree fndecl)
 684 {
 685   return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
 686 }
 687
 688 /* Return true when exp contains alloca call.  */
 689 bool
 690 alloca_call_p (tree exp)
 691 {
 692   if (TREE_CODE (exp) == CALL_EXPR
 693       && TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
 694       && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
 695           == FUNCTION_DECL)
 696       && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
 697                               0) & ECF_MAY_BE_ALLOCA))
 698     return true;
 699   return false;
 700 }
 701
 702 /* Detect flags (function attributes) from the function decl or type node.  */
 703
 704 int
 705 flags_from_decl_or_type (tree exp)
 706 {
 707   int flags = 0;
 708   tree type = exp;
 709
 710   if (DECL_P (exp))
 711     {
 712       struct cgraph_rtl_info *i = cgraph_rtl_info (exp);
 713       type = TREE_TYPE (exp);
 714
 715       if (i)
 716         {
 717           if (i->pure_function)
 718             flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
 719           if (i->const_function)
 720             flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
 721         }
 722
 723       /* The function exp may have the `malloc' attribute.  */
 724       if (DECL_IS_MALLOC (exp))
 725         flags |= ECF_MALLOC;
 726
 727       /* The function exp may have the `pure' attribute.  */
 728       if (DECL_IS_PURE (exp))
 729         flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
 730
 731       if (TREE_NOTHROW (exp))
 732         flags |= ECF_NOTHROW;
 733
 734       if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
 735         flags |= ECF_LIBCALL_BLOCK;
 736     }
 737
 738   if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
 739     flags |= ECF_CONST;
 740
 741   if (TREE_THIS_VOLATILE (exp))
 742     flags |= ECF_NORETURN;
 743
 744   /* Mark if the function returns with the stack pointer depressed.   We
 745      cannot consider it pure or constant in that case.  */
 746   if (TREE_CODE (type) == FUNCTION_TYPE && TYPE_RETURNS_STACK_DEPRESSED (type))
 747     {
 748       flags |= ECF_SP_DEPRESSED;
 749       flags &= ~(ECF_PURE | ECF_CONST | ECF_LIBCALL_BLOCK);
 750     }
 751
 752   return flags;
 753 }
 754
 755 /* Precompute all register parameters as described by ARGS, storing values
 756    into fields within the ARGS array.
 757
 758    NUM_ACTUALS indicates the total number elements in the ARGS array.
 759
 760    Set REG_PARM_SEEN if we encounter a register parameter.  */
 761
 762 static void
 763 precompute_register_parameters (int num_actuals, struct arg_data *args, int *reg_parm_seen)
 764 {
 765   int i;
 766
 767   *reg_parm_seen = 0;
 768
 769   for (i = 0; i < num_actuals; i++)
 770     if (args[i].reg != 0 && ! args[i].pass_on_stack)
 771       {
 772         *reg_parm_seen = 1;
 773
 774         if (args[i].value == 0)
 775           {
 776             push_temp_slots ();
 777             args[i].value = expand_expr (args[i].tree_value, NULL_RTX,
 778                                          VOIDmode, 0);
 779             preserve_temp_slots (args[i].value);
 780             pop_temp_slots ();
 781
 782             /* ANSI doesn't require a sequence point here,
 783                but PCC has one, so this will avoid some problems.  */
 784             emit_queue ();
 785           }
 786
 787         /* If the value is a non-legitimate constant, force it into a
 788            pseudo now.  TLS symbols sometimes need a call to resolve.  */
 789         if (CONSTANT_P (args[i].value)
 790             && !LEGITIMATE_CONSTANT_P (args[i].value))
 791           args[i].value = force_reg (args[i].mode, args[i].value);
 792
 793         /* If we are to promote the function arg to a wider mode,
 794            do it now.  */
 795
 796         if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
 797           args[i].value
 798             = convert_modes (args[i].mode,
 799                              TYPE_MODE (TREE_TYPE (args[i].tree_value)),
 800                              args[i].value, args[i].unsignedp);
 801
 802         /* If the value is expensive, and we are inside an appropriately
 803            short loop, put the value into a pseudo and then put the pseudo
 804            into the hard reg.
 805
 806            For small register classes, also do this if this call uses
 807            register parameters.  This is to avoid reload conflicts while
 808            loading the parameters registers.  */
 809
 810         if ((! (GET_CODE (args[i].value) == REG
 811                 || (GET_CODE (args[i].value) == SUBREG
 812                     && GET_CODE (SUBREG_REG (args[i].value)) == REG)))
 813             && args[i].mode != BLKmode
 814             && rtx_cost (args[i].value, SET) > COSTS_N_INSNS (1)
 815             && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
 816                 || preserve_subexpressions_p ()))
 817           args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
 818       }
 819 }
 820
 821 #ifdef REG_PARM_STACK_SPACE
 822
 823   /* The argument list is the property of the called routine and it
 824      may clobber it.  If the fixed area has been used for previous
 825      parameters, we must save and restore it.  */
 826
 827 static rtx
 828 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
 829 {
 830   int low;
 831   int high;
 832
 833   /* Compute the boundary of the area that needs to be saved, if any.  */
 834   high = reg_parm_stack_space;
 835 #ifdef ARGS_GROW_DOWNWARD
 836   high += 1;
 837 #endif
 838   if (high > highest_outgoing_arg_in_use)
 839     high = highest_outgoing_arg_in_use;
 840
 841   for (low = 0; low < high; low++)
 842     if (stack_usage_map[low] != 0)
 843       {
 844         int num_to_save;
 845         enum machine_mode save_mode;
 846         int delta;
 847         rtx stack_area;
 848         rtx save_area;
 849
 850         while (stack_usage_map[--high] == 0)
 851           ;
 852
 853         *low_to_save = low;
 854         *high_to_save = high;
 855
 856         num_to_save = high - low + 1;
 857         save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
 858
 859         /* If we don't have the required alignment, must do this
 860            in BLKmode.  */
 861         if ((low & (MIN (GET_MODE_SIZE (save_mode),
 862                          BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
 863           save_mode = BLKmode;
 864
 865 #ifdef ARGS_GROW_DOWNWARD
 866         delta = -high;
 867 #else
 868         delta = low;
 869 #endif
 870         stack_area = gen_rtx_MEM (save_mode,
 871                                   memory_address (save_mode,
 872                                                   plus_constant (argblock,
 873                                                                  delta)));
 874
 875         set_mem_align (stack_area, PARM_BOUNDARY);
 876         if (save_mode == BLKmode)
 877           {
 878             save_area = assign_stack_temp (BLKmode, num_to_save, 0);
 879             emit_block_move (validize_mem (save_area), stack_area,
 880                              GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
 881           }
 882         else
 883           {
 884             save_area = gen_reg_rtx (save_mode);
 885             emit_move_insn (save_area, stack_area);
 886           }
 887
 888         return save_area;
 889       }
 890
 891   return NULL_RTX;
 892 }
 893
 894 static void
 895 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
 896 {
 897   enum machine_mode save_mode = GET_MODE (save_area);
 898   int delta;
 899   rtx stack_area;
 900
 901 #ifdef ARGS_GROW_DOWNWARD
 902   delta = -high_to_save;
 903 #else
 904   delta = low_to_save;
 905 #endif
 906   stack_area = gen_rtx_MEM (save_mode,
 907                             memory_address (save_mode,
 908                                             plus_constant (argblock, delta)));
 909   set_mem_align (stack_area, PARM_BOUNDARY);
 910
 911   if (save_mode != BLKmode)
 912     emit_move_insn (stack_area, save_area);
 913   else
 914     emit_block_move (stack_area, validize_mem (save_area),
 915                      GEN_INT (high_to_save - low_to_save + 1),
 916                      BLOCK_OP_CALL_PARM);
 917 }
 918 #endif /* REG_PARM_STACK_SPACE */
 919
 920 /* If any elements in ARGS refer to parameters that are to be passed in
 921    registers, but not in memory, and whose alignment does not permit a
 922    direct copy into registers.  Copy the values into a group of pseudos
 923    which we will later copy into the appropriate hard registers.
 924
 925    Pseudos for each unaligned argument will be stored into the array
 926    args[argnum].aligned_regs.  The caller is responsible for deallocating
 927    the aligned_regs array if it is nonzero.  */
 928
 929 static void
 930 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
 931 {
 932   int i, j;
 933
 934   for (i = 0; i < num_actuals; i++)
 935     if (args[i].reg != 0 && ! args[i].pass_on_stack
 936         && args[i].mode == BLKmode
 937         && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
 938             < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
 939       {
 940         int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
 941         int nregs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
 942         int endian_correction = 0;
 943
 944         args[i].n_aligned_regs = args[i].partial ? args[i].partial : nregs;
 945         args[i].aligned_regs = xmalloc (sizeof (rtx) * args[i].n_aligned_regs);
 946
 947         /* Structures smaller than a word are normally aligned to the
 948            least significant byte.  On a BYTES_BIG_ENDIAN machine,
 949            this means we must skip the empty high order bytes when
 950            calculating the bit offset.  */
 951         if (bytes < UNITS_PER_WORD
 952 #ifdef BLOCK_REG_PADDING
 953             && (BLOCK_REG_PADDING (args[i].mode,
 954                                    TREE_TYPE (args[i].tree_value), 1)
 955                 == downward)
 956 #else
 957             && BYTES_BIG_ENDIAN
 958 #endif
 959             )
 960           endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
 961
 962         for (j = 0; j < args[i].n_aligned_regs; j++)
 963           {
 964             rtx reg = gen_reg_rtx (word_mode);
 965             rtx word = operand_subword_force (args[i].value, j, BLKmode);
 966             int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
 967
 968             args[i].aligned_regs[j] = reg;
 969             word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
 970                                       word_mode, word_mode, BITS_PER_WORD);
 971
 972             /* There is no need to restrict this code to loading items
 973                in TYPE_ALIGN sized hunks.  The bitfield instructions can
 974                load up entire word sized registers efficiently.
 975
 976                ??? This may not be needed anymore.
 977                We use to emit a clobber here but that doesn't let later
 978                passes optimize the instructions we emit.  By storing 0 into
 979                the register later passes know the first AND to zero out the
 980                bitfield being set in the register is unnecessary.  The store
 981                of 0 will be deleted as will at least the first AND.  */
 982
 983             emit_move_insn (reg, const0_rtx);
 984
 985             bytes -= bitsize / BITS_PER_UNIT;
 986             store_bit_field (reg, bitsize, endian_correction, word_mode,
 987                              word, BITS_PER_WORD);
 988           }
 989       }
 990 }
 991
 992 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
 993    ACTPARMS.
 994
 995    NUM_ACTUALS is the total number of parameters.
 996
 997    N_NAMED_ARGS is the total number of named arguments.
 998
 999    FNDECL is the tree code for the target of this call (if known)
1000
1001    ARGS_SO_FAR holds state needed by the target to know where to place
1002    the next argument.
1003
1004    REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1005    for arguments which are passed in registers.
1006
1007    OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1008    and may be modified by this routine.
1009
1010    OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1011    flags which may may be modified by this routine.  */
1012
1013 static void
1014 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
1015                                  struct arg_data *args,
1016                                  struct args_size *args_size,
1017                                  int n_named_args ATTRIBUTE_UNUSED,
1018                                  tree actparms, tree fndecl,
1019                                  CUMULATIVE_ARGS *args_so_far,
1020                                  int reg_parm_stack_space,
1021                                  rtx *old_stack_level, int *old_pending_adj,
1022                                  int *must_preallocate, int *ecf_flags)
1023 {
1024   /* 1 if scanning parms front to back, -1 if scanning back to front.  */
1025   int inc;
1026
1027   /* Count arg position in order args appear.  */
1028   int argpos;
1029
1030   int i;
1031   tree p;
1032
1033   args_size->constant = 0;
1034   args_size->var = 0;
1035
1036   /* In this loop, we consider args in the order they are written.
1037      We fill up ARGS from the front or from the back if necessary
1038      so that in any case the first arg to be pushed ends up at the front.  */
1039
1040   if (PUSH_ARGS_REVERSED)
1041     {
1042       i = num_actuals - 1, inc = -1;
1043       /* In this case, must reverse order of args
1044          so that we compute and push the last arg first.  */
1045     }
1046   else
1047     {
1048       i = 0, inc = 1;
1049     }
1050
1051   /* I counts args in order (to be) pushed; ARGPOS counts in order written.  */
1052   for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
1053     {
1054       tree type = TREE_TYPE (TREE_VALUE (p));
1055       int unsignedp;
1056       enum machine_mode mode;
1057
1058       args[i].tree_value = TREE_VALUE (p);
1059
1060       /* Replace erroneous argument with constant zero.  */
1061       if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1062         args[i].tree_value = integer_zero_node, type = integer_type_node;
1063
1064       /* If TYPE is a transparent union, pass things the way we would
1065          pass the first field of the union.  We have already verified that
1066          the modes are the same.  */
1067       if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
1068         type = TREE_TYPE (TYPE_FIELDS (type));
1069
1070       /* Decide where to pass this arg.
1071
1072          args[i].reg is nonzero if all or part is passed in registers.
1073
1074          args[i].partial is nonzero if part but not all is passed in registers,
1075          and the exact value says how many words are passed in registers.
1076
1077          args[i].pass_on_stack is nonzero if the argument must at least be
1078          computed on the stack.  It may then be loaded back into registers
1079          if args[i].reg is nonzero.
1080
1081          These decisions are driven by the FUNCTION_... macros and must agree
1082          with those made by function.c.  */
1083
1084       /* See if this argument should be passed by invisible reference.  */
1085       if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (type))
1086           || TREE_ADDRESSABLE (type)
1087 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
1088           || FUNCTION_ARG_PASS_BY_REFERENCE (*args_so_far, TYPE_MODE (type),
1089                                              type, argpos < n_named_args)
1090 #endif
1091           )
1092         {
1093           /* If we're compiling a thunk, pass through invisible
1094              references instead of making a copy.  */
1095           if (current_function_is_thunk
1096 #ifdef FUNCTION_ARG_CALLEE_COPIES
1097               || (FUNCTION_ARG_CALLEE_COPIES (*args_so_far, TYPE_MODE (type),
1098                                              type, argpos < n_named_args)
1099                   /* If it's in a register, we must make a copy of it too.  */
1100                   /* ??? Is this a sufficient test?  Is there a better one? */
1101                   && !(TREE_CODE (args[i].tree_value) == VAR_DECL
1102                        && REG_P (DECL_RTL (args[i].tree_value)))
1103                   && ! TREE_ADDRESSABLE (type))
1104 #endif
1105               )
1106             {
1107               /* C++ uses a TARGET_EXPR to indicate that we want to make a
1108                  new object from the argument.  If we are passing by
1109                  invisible reference, the callee will do that for us, so we
1110                  can strip off the TARGET_EXPR.  This is not always safe,
1111                  but it is safe in the only case where this is a useful
1112                  optimization; namely, when the argument is a plain object.
1113                  In that case, the frontend is just asking the backend to
1114                  make a bitwise copy of the argument.  */
1115
1116               if (TREE_CODE (args[i].tree_value) == TARGET_EXPR
1117                   && (DECL_P (TREE_OPERAND (args[i].tree_value, 1)))
1118                   && ! REG_P (DECL_RTL (TREE_OPERAND (args[i].tree_value, 1))))
1119                 args[i].tree_value = TREE_OPERAND (args[i].tree_value, 1);
1120
1121               args[i].tree_value = build1 (ADDR_EXPR,
1122                                            build_pointer_type (type),
1123                                            args[i].tree_value);
1124               type = build_pointer_type (type);
1125             }
1126           else if (TREE_CODE (args[i].tree_value) == TARGET_EXPR)
1127             {
1128               /* In the V3 C++ ABI, parameters are destroyed in the caller.
1129                  We implement this by passing the address of the temporary
1130                  rather than expanding it into another allocated slot.  */
1131               args[i].tree_value = build1 (ADDR_EXPR,
1132                                            build_pointer_type (type),
1133                                            args[i].tree_value);
1134               type = build_pointer_type (type);
1135             }
1136           else
1137             {
1138               /* We make a copy of the object and pass the address to the
1139                  function being called.  */
1140               rtx copy;
1141
1142               if (!COMPLETE_TYPE_P (type)
1143                   || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1144                   || (flag_stack_check && ! STACK_CHECK_BUILTIN
1145                       && (0 < compare_tree_int (TYPE_SIZE_UNIT (type),
1146                                                 STACK_CHECK_MAX_VAR_SIZE))))
1147                 {
1148                   /* This is a variable-sized object.  Make space on the stack
1149                      for it.  */
1150                   rtx size_rtx = expr_size (TREE_VALUE (p));
1151
1152                   if (*old_stack_level == 0)
1153                     {
1154                       emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1155                       *old_pending_adj = pending_stack_adjust;
1156                       pending_stack_adjust = 0;
1157                     }
1158
1159                   copy = gen_rtx_MEM (BLKmode,
1160                                       allocate_dynamic_stack_space
1161                                       (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1162                   set_mem_attributes (copy, type, 1);
1163                 }
1164               else
1165                 copy = assign_temp (type, 0, 1, 0);
1166
1167               store_expr (args[i].tree_value, copy, 0);
1168               *ecf_flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
1169
1170               args[i].tree_value = build1 (ADDR_EXPR,
1171                                            build_pointer_type (type),
1172                                            make_tree (type, copy));
1173               type = build_pointer_type (type);
1174             }
1175         }
1176
1177       mode = TYPE_MODE (type);
1178       unsignedp = TREE_UNSIGNED (type);
1179
1180 #ifdef PROMOTE_FUNCTION_ARGS
1181       mode = promote_mode (type, mode, &unsignedp, 1);
1182 #endif
1183
1184       args[i].unsignedp = unsignedp;
1185       args[i].mode = mode;
1186
1187       args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1188                                   argpos < n_named_args);
1189 #ifdef FUNCTION_INCOMING_ARG
1190       /* If this is a sibling call and the machine has register windows, the
1191          register window has to be unwinded before calling the routine, so
1192          arguments have to go into the incoming registers.  */
1193       args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1194                                                      argpos < n_named_args);
1195 #else
1196       args[i].tail_call_reg = args[i].reg;
1197 #endif
1198
1199 #ifdef FUNCTION_ARG_PARTIAL_NREGS
1200       if (args[i].reg)
1201         args[i].partial
1202           = FUNCTION_ARG_PARTIAL_NREGS (*args_so_far, mode, type,
1203                                         argpos < n_named_args);
1204 #endif
1205
1206       args[i].pass_on_stack = MUST_PASS_IN_STACK (mode, type);
1207
1208       /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1209          it means that we are to pass this arg in the register(s) designated
1210          by the PARALLEL, but also to pass it in the stack.  */
1211       if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1212           && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1213         args[i].pass_on_stack = 1;
1214
1215       /* If this is an addressable type, we must preallocate the stack
1216          since we must evaluate the object into its final location.
1217
1218          If this is to be passed in both registers and the stack, it is simpler
1219          to preallocate.  */
1220       if (TREE_ADDRESSABLE (type)
1221           || (args[i].pass_on_stack && args[i].reg != 0))
1222         *must_preallocate = 1;
1223
1224       /* If this is an addressable type, we cannot pre-evaluate it.  Thus,
1225          we cannot consider this function call constant.  */
1226       if (TREE_ADDRESSABLE (type))
1227         *ecf_flags &= ~ECF_LIBCALL_BLOCK;
1228
1229       /* Compute the stack-size of this argument.  */
1230       if (args[i].reg == 0 || args[i].partial != 0
1231           || reg_parm_stack_space > 0
1232           || args[i].pass_on_stack)
1233         locate_and_pad_parm (mode, type,
1234 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1235                              1,
1236 #else
1237                              args[i].reg != 0,
1238 #endif
1239                              args[i].pass_on_stack ? 0 : args[i].partial,
1240                              fndecl, args_size, &args[i].locate);
1241
1242       /* Update ARGS_SIZE, the total stack space for args so far.  */
1243
1244       args_size->constant += args[i].locate.size.constant;
1245       if (args[i].locate.size.var)
1246         ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1247
1248       /* Increment ARGS_SO_FAR, which has info about which arg-registers
1249          have been used, etc.  */
1250
1251       FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1252                             argpos < n_named_args);
1253     }
1254 }
1255
1256 /* Update ARGS_SIZE to contain the total size for the argument block.
1257    Return the original constant component of the argument block's size.
1258
1259    REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1260    for arguments passed in registers.  */
1261
1262 static int
1263 compute_argument_block_size (int reg_parm_stack_space,
1264                              struct args_size *args_size,
1265                              int preferred_stack_boundary ATTRIBUTE_UNUSED)
1266 {
1267   int unadjusted_args_size = args_size->constant;
1268
1269   /* For accumulate outgoing args mode we don't need to align, since the frame
1270      will be already aligned.  Align to STACK_BOUNDARY in order to prevent
1271      backends from generating misaligned frame sizes.  */
1272   if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1273     preferred_stack_boundary = STACK_BOUNDARY;
1274
1275   /* Compute the actual size of the argument block required.  The variable
1276      and constant sizes must be combined, the size may have to be rounded,
1277      and there may be a minimum required size.  */
1278
1279   if (args_size->var)
1280     {
1281       args_size->var = ARGS_SIZE_TREE (*args_size);
1282       args_size->constant = 0;
1283
1284       preferred_stack_boundary /= BITS_PER_UNIT;
1285       if (preferred_stack_boundary > 1)
1286         {
1287           /* We don't handle this case yet.  To handle it correctly we have
1288              to add the delta, round and subtract the delta.
1289              Currently no machine description requires this support.  */
1290           if (stack_pointer_delta & (preferred_stack_boundary - 1))
1291             abort ();
1292           args_size->var = round_up (args_size->var, preferred_stack_boundary);
1293         }
1294
1295       if (reg_parm_stack_space > 0)
1296         {
1297           args_size->var
1298             = size_binop (MAX_EXPR, args_size->var,
1299                           ssize_int (reg_parm_stack_space));
1300
1301 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1302           /* The area corresponding to register parameters is not to count in
1303              the size of the block we need.  So make the adjustment.  */
1304           args_size->var
1305             = size_binop (MINUS_EXPR, args_size->var,
1306                           ssize_int (reg_parm_stack_space));
1307 #endif
1308         }
1309     }
1310   else
1311     {
1312       preferred_stack_boundary /= BITS_PER_UNIT;
1313       if (preferred_stack_boundary < 1)
1314         preferred_stack_boundary = 1;
1315       args_size->constant = (((args_size->constant
1316                                + stack_pointer_delta
1317                                + preferred_stack_boundary - 1)
1318                               / preferred_stack_boundary
1319                               * preferred_stack_boundary)
1320                              - stack_pointer_delta);
1321
1322       args_size->constant = MAX (args_size->constant,
1323                                  reg_parm_stack_space);
1324
1325 #ifdef MAYBE_REG_PARM_STACK_SPACE
1326       if (reg_parm_stack_space == 0)
1327         args_size->constant = 0;
1328 #endif
1329
1330 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1331       args_size->constant -= reg_parm_stack_space;
1332 #endif
1333     }
1334   return unadjusted_args_size;
1335 }
1336
1337 /* Precompute parameters as needed for a function call.
1338
1339    FLAGS is mask of ECF_* constants.
1340
1341    NUM_ACTUALS is the number of arguments.
1342
1343    ARGS is an array containing information for each argument; this
1344    routine fills in the INITIAL_VALUE and VALUE fields for each
1345    precomputed argument.  */
1346
1347 static void
1348 precompute_arguments (int flags, int num_actuals, struct arg_data *args)
1349 {
1350   int i;
1351
1352   /* If this function call is cse'able, precompute all the parameters.
1353      Note that if the parameter is constructed into a temporary, this will
1354      cause an additional copy because the parameter will be constructed
1355      into a temporary location and then copied into the outgoing arguments.
1356      If a parameter contains a call to alloca and this function uses the
1357      stack, precompute the parameter.  */
1358
1359   /* If we preallocated the stack space, and some arguments must be passed
1360      on the stack, then we must precompute any parameter which contains a
1361      function call which will store arguments on the stack.
1362      Otherwise, evaluating the parameter may clobber previous parameters
1363      which have already been stored into the stack.  (we have code to avoid
1364      such case by saving the outgoing stack arguments, but it results in
1365      worse code)  */
1366
1367   for (i = 0; i < num_actuals; i++)
1368     if ((flags & ECF_LIBCALL_BLOCK)
1369         || calls_function (args[i].tree_value, !ACCUMULATE_OUTGOING_ARGS))
1370       {
1371         enum machine_mode mode;
1372
1373         /* If this is an addressable type, we cannot pre-evaluate it.  */
1374         if (TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)))
1375           abort ();
1376
1377         args[i].value
1378           = expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0);
1379
1380         /* ANSI doesn't require a sequence point here,
1381            but PCC has one, so this will avoid some problems.  */
1382         emit_queue ();
1383
1384         args[i].initial_value = args[i].value
1385           = protect_from_queue (args[i].value, 0);
1386
1387         mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1388         if (mode != args[i].mode)
1389           {
1390             args[i].value
1391               = convert_modes (args[i].mode, mode,
1392                                args[i].value, args[i].unsignedp);
1393 #ifdef PROMOTE_FOR_CALL_ONLY
1394             /* CSE will replace this only if it contains args[i].value
1395                pseudo, so convert it down to the declared mode using
1396                a SUBREG.  */
1397             if (GET_CODE (args[i].value) == REG
1398                 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1399               {
1400                 args[i].initial_value
1401                   = gen_lowpart_SUBREG (mode, args[i].value);
1402                 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1403                 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1404                   args[i].unsignedp);
1405               }
1406 #endif
1407           }
1408       }
1409 }
1410
1411 /* Given the current state of MUST_PREALLOCATE and information about
1412    arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1413    compute and return the final value for MUST_PREALLOCATE.  */
1414
1415 static int
1416 finalize_must_preallocate (int must_preallocate, int num_actuals, struct arg_data *args, struct args_size *args_size)
1417 {
1418   /* See if we have or want to preallocate stack space.
1419
1420      If we would have to push a partially-in-regs parm
1421      before other stack parms, preallocate stack space instead.
1422
1423      If the size of some parm is not a multiple of the required stack
1424      alignment, we must preallocate.
1425
1426      If the total size of arguments that would otherwise create a copy in
1427      a temporary (such as a CALL) is more than half the total argument list
1428      size, preallocation is faster.
1429
1430      Another reason to preallocate is if we have a machine (like the m88k)
1431      where stack alignment is required to be maintained between every
1432      pair of insns, not just when the call is made.  However, we assume here
1433      that such machines either do not have push insns (and hence preallocation
1434      would occur anyway) or the problem is taken care of with
1435      PUSH_ROUNDING.  */
1436
1437   if (! must_preallocate)
1438     {
1439       int partial_seen = 0;
1440       int copy_to_evaluate_size = 0;
1441       int i;
1442
1443       for (i = 0; i < num_actuals && ! must_preallocate; i++)
1444         {
1445           if (args[i].partial > 0 && ! args[i].pass_on_stack)
1446             partial_seen = 1;
1447           else if (partial_seen && args[i].reg == 0)
1448             must_preallocate = 1;
1449
1450           if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1451               && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1452                   || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1453                   || TREE_CODE (args[i].tree_value) == COND_EXPR
1454                   || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1455             copy_to_evaluate_size
1456               += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1457         }
1458
1459       if (copy_to_evaluate_size * 2 >= args_size->constant
1460           && args_size->constant > 0)
1461         must_preallocate = 1;
1462     }
1463   return must_preallocate;
1464 }
1465
1466 /* If we preallocated stack space, compute the address of each argument
1467    and store it into the ARGS array.
1468
1469    We need not ensure it is a valid memory address here; it will be
1470    validized when it is used.
1471
1472    ARGBLOCK is an rtx for the address of the outgoing arguments.  */
1473
1474 static void
1475 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1476 {
1477   if (argblock)
1478     {
1479       rtx arg_reg = argblock;
1480       int i, arg_offset = 0;
1481
1482       if (GET_CODE (argblock) == PLUS)
1483         arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1484
1485       for (i = 0; i < num_actuals; i++)
1486         {
1487           rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1488           rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1489           rtx addr;
1490
1491           /* Skip this parm if it will not be passed on the stack.  */
1492           if (! args[i].pass_on_stack && args[i].reg != 0)
1493             continue;
1494
1495           if (GET_CODE (offset) == CONST_INT)
1496             addr = plus_constant (arg_reg, INTVAL (offset));
1497           else
1498             addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1499
1500           addr = plus_constant (addr, arg_offset);
1501           args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1502           set_mem_align (args[i].stack, PARM_BOUNDARY);
1503           set_mem_attributes (args[i].stack,
1504                               TREE_TYPE (args[i].tree_value), 1);
1505
1506           if (GET_CODE (slot_offset) == CONST_INT)
1507             addr = plus_constant (arg_reg, INTVAL (slot_offset));
1508           else
1509             addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1510
1511           addr = plus_constant (addr, arg_offset);
1512           args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1513           set_mem_align (args[i].stack_slot, PARM_BOUNDARY);
1514           set_mem_attributes (args[i].stack_slot,
1515                               TREE_TYPE (args[i].tree_value), 1);
1516
1517           /* Function incoming arguments may overlap with sibling call
1518              outgoing arguments and we cannot allow reordering of reads
1519              from function arguments with stores to outgoing arguments
1520              of sibling calls.  */
1521           set_mem_alias_set (args[i].stack, 0);
1522           set_mem_alias_set (args[i].stack_slot, 0);
1523         }
1524     }
1525 }
1526
1527 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1528    in a call instruction.
1529
1530    FNDECL is the tree node for the target function.  For an indirect call
1531    FNDECL will be NULL_TREE.
1532
1533    ADDR is the operand 0 of CALL_EXPR for this call.  */
1534
1535 static rtx
1536 rtx_for_function_call (tree fndecl, tree addr)
1537 {
1538   rtx funexp;
1539
1540   /* Get the function to call, in the form of RTL.  */
1541   if (fndecl)
1542     {
1543       /* If this is the first use of the function, see if we need to
1544          make an external definition for it.  */
1545       if (! TREE_USED (fndecl))
1546         {
1547           assemble_external (fndecl);
1548           TREE_USED (fndecl) = 1;
1549         }
1550
1551       /* Get a SYMBOL_REF rtx for the function address.  */
1552       funexp = XEXP (DECL_RTL (fndecl), 0);
1553     }
1554   else
1555     /* Generate an rtx (probably a pseudo-register) for the address.  */
1556     {
1557       push_temp_slots ();
1558       funexp = expand_expr (addr, NULL_RTX, VOIDmode, 0);
1559       pop_temp_slots ();        /* FUNEXP can't be BLKmode.  */
1560       emit_queue ();
1561     }
1562   return funexp;
1563 }
1564
1565 /* Do the register loads required for any wholly-register parms or any
1566    parms which are passed both on the stack and in a register.  Their
1567    expressions were already evaluated.
1568
1569    Mark all register-parms as living through the call, putting these USE
1570    insns in the CALL_INSN_FUNCTION_USAGE field.
1571
1572    When IS_SIBCALL, perform the check_sibcall_overlap_argument_overlap
1573    checking, setting *SIBCALL_FAILURE if appropriate.  */
1574
1575 static void
1576 load_register_parameters (struct arg_data *args, int num_actuals,
1577                           rtx *call_fusage, int flags, int is_sibcall,
1578                           int *sibcall_failure)
1579 {
1580   int i, j;
1581
1582 #ifdef LOAD_ARGS_REVERSED
1583   for (i = num_actuals - 1; i >= 0; i--)
1584 #else
1585   for (i = 0; i < num_actuals; i++)
1586 #endif
1587     {
1588       rtx reg = ((flags & ECF_SIBCALL)
1589                  ? args[i].tail_call_reg : args[i].reg);
1590       if (reg)
1591         {
1592           int partial = args[i].partial;
1593           int nregs;
1594           int size = 0;
1595           rtx before_arg = get_last_insn ();
1596           /* Set to non-negative if must move a word at a time, even if just
1597              one word (e.g, partial == 1 && mode == DFmode).  Set to -1 if
1598              we just use a normal move insn.  This value can be zero if the
1599              argument is a zero size structure with no fields.  */
1600           nregs = -1;
1601           if (partial)
1602             nregs = partial;
1603           else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1604             {
1605               size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1606               nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1607             }
1608           else
1609             size = GET_MODE_SIZE (args[i].mode);
1610
1611           /* Handle calls that pass values in multiple non-contiguous
1612              locations.  The Irix 6 ABI has examples of this.  */
1613
1614           if (GET_CODE (reg) == PARALLEL)
1615             {
1616               tree type = TREE_TYPE (args[i].tree_value);
1617               emit_group_load (reg, args[i].value, type,
1618                                int_size_in_bytes (type));
1619             }
1620
1621           /* If simple case, just do move.  If normal partial, store_one_arg
1622              has already loaded the register for us.  In all other cases,
1623              load the register(s) from memory.  */
1624
1625           else if (nregs == -1
1626 #ifdef BLOCK_REG_PADDING
1627                    && !(size < UNITS_PER_WORD
1628                         && (args[i].locate.where_pad
1629                             == (BYTES_BIG_ENDIAN ? upward : downward)))
1630 #endif
1631                    )
1632             emit_move_insn (reg, args[i].value);
1633
1634           /* If we have pre-computed the values to put in the registers in
1635              the case of non-aligned structures, copy them in now.  */
1636
1637           else if (args[i].n_aligned_regs != 0)
1638             for (j = 0; j < args[i].n_aligned_regs; j++)
1639               emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1640                               args[i].aligned_regs[j]);
1641
1642           else if (partial == 0 || args[i].pass_on_stack)
1643             {
1644               rtx mem = validize_mem (args[i].value);
1645
1646 #ifdef BLOCK_REG_PADDING
1647               /* Handle case where we have a value that needs shifting
1648                  up to the msb.  eg. a QImode value and we're padding
1649                  upward on a BYTES_BIG_ENDIAN machine.  */
1650               if (nregs == -1)
1651                 {
1652                   rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1653                   rtx x;
1654                   int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1655                   x = expand_binop (word_mode, ashl_optab, mem,
1656                                     GEN_INT (shift), ri, 1, OPTAB_WIDEN);
1657                   if (x != ri)
1658                     emit_move_insn (ri, x);
1659                 }
1660
1661               /* Handle a BLKmode that needs shifting.  */
1662               else if (nregs == 1 && size < UNITS_PER_WORD
1663                        && args[i].locate.where_pad == downward)
1664                 {
1665                   rtx tem = operand_subword_force (mem, 0, args[i].mode);
1666                   rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1667                   rtx x = gen_reg_rtx (word_mode);
1668                   int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1669                   optab dir = BYTES_BIG_ENDIAN ? lshr_optab : ashl_optab;
1670
1671                   emit_move_insn (x, tem);
1672                   x = expand_binop (word_mode, dir, x, GEN_INT (shift),
1673                                     ri, 1, OPTAB_WIDEN);
1674                   if (x != ri)
1675                     emit_move_insn (ri, x);
1676                 }
1677               else
1678 #endif
1679                 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1680             }
1681
1682           /* When a parameter is a block, and perhaps in other cases, it is
1683              possible that it did a load from an argument slot that was
1684              already clobbered.  */
1685           if (is_sibcall
1686               && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1687             *sibcall_failure = 1;
1688
1689           /* Handle calls that pass values in multiple non-contiguous
1690              locations.  The Irix 6 ABI has examples of this.  */
1691           if (GET_CODE (reg) == PARALLEL)
1692             use_group_regs (call_fusage, reg);
1693           else if (nregs == -1)
1694             use_reg (call_fusage, reg);
1695           else
1696             use_regs (call_fusage, REGNO (reg), nregs == 0 ? 1 : nregs);
1697         }
1698     }
1699 }
1700
1701 /* Try to integrate function.  See expand_inline_function for documentation
1702    about the parameters.  */
1703
1704 static rtx
1705 try_to_integrate (tree fndecl, tree actparms, rtx target, int ignore,
1706                   tree type, rtx structure_value_addr)
1707 {
1708   rtx temp;
1709   rtx before_call;
1710   int i;
1711   rtx old_stack_level = 0;
1712   int reg_parm_stack_space = 0;
1713
1714 #ifdef REG_PARM_STACK_SPACE
1715 #ifdef MAYBE_REG_PARM_STACK_SPACE
1716   reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
1717 #else
1718   reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
1719 #endif
1720 #endif
1721
1722   before_call = get_last_insn ();
1723
1724   timevar_push (TV_INTEGRATION);
1725
1726   temp = expand_inline_function (fndecl, actparms, target,
1727                                  ignore, type,
1728                                  structure_value_addr);
1729
1730   timevar_pop (TV_INTEGRATION);
1731
1732   /* If inlining succeeded, return.  */
1733   if (temp != (rtx) (size_t) - 1)
1734     {
1735       if (ACCUMULATE_OUTGOING_ARGS)
1736         {
1737           /* If the outgoing argument list must be preserved, push
1738              the stack before executing the inlined function if it
1739              makes any calls.  */
1740
1741           i = reg_parm_stack_space;
1742           if (i > highest_outgoing_arg_in_use)
1743             i = highest_outgoing_arg_in_use;
1744           while (--i >= 0 && stack_usage_map[i] == 0)
1745             ;
1746
1747           if (stack_arg_under_construction || i >= 0)
1748             {
1749               rtx first_insn
1750                 = before_call ? NEXT_INSN (before_call) : get_insns ();
1751               rtx insn = NULL_RTX, seq;
1752
1753               /* Look for a call in the inline function code.
1754                  If DECL_SAVED_INSNS (fndecl)->outgoing_args_size is
1755                  nonzero then there is a call and it is not necessary
1756                  to scan the insns.  */
1757
1758               if (DECL_SAVED_INSNS (fndecl)->outgoing_args_size == 0)
1759                 for (insn = first_insn; insn; insn = NEXT_INSN (insn))
1760                   if (GET_CODE (insn) == CALL_INSN)
1761                     break;
1762
1763               if (insn)
1764                 {
1765                   /* Reserve enough stack space so that the largest
1766                      argument list of any function call in the inline
1767                      function does not overlap the argument list being
1768                      evaluated.  This is usually an overestimate because
1769                      allocate_dynamic_stack_space reserves space for an
1770                      outgoing argument list in addition to the requested
1771                      space, but there is no way to ask for stack space such
1772                      that an argument list of a certain length can be
1773                      safely constructed.
1774
1775                      Add the stack space reserved for register arguments, if
1776                      any, in the inline function.  What is really needed is the
1777                      largest value of reg_parm_stack_space in the inline
1778                      function, but that is not available.  Using the current
1779                      value of reg_parm_stack_space is wrong, but gives
1780                      correct results on all supported machines.  */
1781
1782                   int adjust = (DECL_SAVED_INSNS (fndecl)->outgoing_args_size
1783                                 + reg_parm_stack_space);
1784
1785                   start_sequence ();
1786                   emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
1787                   allocate_dynamic_stack_space (GEN_INT (adjust),
1788                                                 NULL_RTX, BITS_PER_UNIT);
1789                   seq = get_insns ();
1790                   end_sequence ();
1791                   emit_insn_before (seq, first_insn);
1792                   emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
1793                 }
1794             }
1795         }
1796
1797       /* If the result is equivalent to TARGET, return TARGET to simplify
1798          checks in store_expr.  They can be equivalent but not equal in the
1799          case of a function that returns BLKmode.  */
1800       if (temp != target && rtx_equal_p (temp, target))
1801         return target;
1802       return temp;
1803     }
1804
1805   /* If inlining failed, mark FNDECL as needing to be compiled
1806      separately after all.  If function was declared inline,
1807      give a warning.  */
1808   if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
1809       && optimize > 0 && !TREE_ADDRESSABLE (fndecl))
1810     {
1811       warning_with_decl (fndecl, "inlining failed in call to `%s'");
1812       warning ("called from here");
1813     }
1814   (*lang_hooks.mark_addressable) (fndecl);
1815   return (rtx) (size_t) - 1;
1816 }
1817
1818 /* We need to pop PENDING_STACK_ADJUST bytes.  But, if the arguments
1819    wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1820    bytes, then we would need to push some additional bytes to pad the
1821    arguments.  So, we compute an adjust to the stack pointer for an
1822    amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1823    bytes.  Then, when the arguments are pushed the stack will be perfectly
1824    aligned.  ARGS_SIZE->CONSTANT is set to the number of bytes that should
1825    be popped after the call.  Returns the adjustment.  */
1826
1827 static int
1828 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1829                                            struct args_size *args_size,
1830                                            int preferred_unit_stack_boundary)
1831 {
1832   /* The number of bytes to pop so that the stack will be
1833      under-aligned by UNADJUSTED_ARGS_SIZE bytes.  */
1834   HOST_WIDE_INT adjustment;
1835   /* The alignment of the stack after the arguments are pushed, if we
1836      just pushed the arguments without adjust the stack here.  */
1837   HOST_WIDE_INT unadjusted_alignment;
1838
1839   unadjusted_alignment
1840     = ((stack_pointer_delta + unadjusted_args_size)
1841        % preferred_unit_stack_boundary);
1842
1843   /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1844      as possible -- leaving just enough left to cancel out the
1845      UNADJUSTED_ALIGNMENT.  In other words, we want to ensure that the
1846      PENDING_STACK_ADJUST is non-negative, and congruent to
1847      -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY.  */
1848
1849   /* Begin by trying to pop all the bytes.  */
1850   unadjusted_alignment
1851     = (unadjusted_alignment
1852        - (pending_stack_adjust % preferred_unit_stack_boundary));
1853   adjustment = pending_stack_adjust;
1854   /* Push enough additional bytes that the stack will be aligned
1855      after the arguments are pushed.  */
1856   if (preferred_unit_stack_boundary > 1)
1857     {
1858       if (unadjusted_alignment > 0)
1859         adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1860       else
1861         adjustment += unadjusted_alignment;
1862     }
1863
1864   /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1865      bytes after the call.  The right number is the entire
1866      PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1867      by the arguments in the first place.  */
1868   args_size->constant
1869     = pending_stack_adjust - adjustment + unadjusted_args_size;
1870
1871   return adjustment;
1872 }
1873
1874 /* Scan X expression if it does not dereference any argument slots
1875    we already clobbered by tail call arguments (as noted in stored_args_map
1876    bitmap).
1877    Return nonzero if X expression dereferences such argument slots,
1878    zero otherwise.  */
1879
1880 static int
1881 check_sibcall_argument_overlap_1 (rtx x)
1882 {
1883   RTX_CODE code;
1884   int i, j;
1885   unsigned int k;
1886   const char *fmt;
1887
1888   if (x == NULL_RTX)
1889     return 0;
1890
1891   code = GET_CODE (x);
1892
1893   if (code == MEM)
1894     {
1895       if (XEXP (x, 0) == current_function_internal_arg_pointer)
1896         i = 0;
1897       else if (GET_CODE (XEXP (x, 0)) == PLUS
1898                && XEXP (XEXP (x, 0), 0) ==
1899                   current_function_internal_arg_pointer
1900                && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)
1901         i = INTVAL (XEXP (XEXP (x, 0), 1));
1902       else
1903         return 0;
1904
1905 #ifdef ARGS_GROW_DOWNWARD
1906       i = -i - GET_MODE_SIZE (GET_MODE (x));
1907 #endif
1908
1909       for (k = 0; k < GET_MODE_SIZE (GET_MODE (x)); k++)
1910         if (i + k < stored_args_map->n_bits
1911             && TEST_BIT (stored_args_map, i + k))
1912           return 1;
1913
1914       return 0;
1915     }
1916
1917   /* Scan all subexpressions.  */
1918   fmt = GET_RTX_FORMAT (code);
1919   for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1920     {
1921       if (*fmt == 'e')
1922         {
1923           if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1924             return 1;
1925         }
1926       else if (*fmt == 'E')
1927         {
1928           for (j = 0; j < XVECLEN (x, i); j++)
1929             if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1930               return 1;
1931         }
1932     }
1933   return 0;
1934 }
1935
1936 /* Scan sequence after INSN if it does not dereference any argument slots
1937    we already clobbered by tail call arguments (as noted in stored_args_map
1938    bitmap).  If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1939    stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1940    should be 0).  Return nonzero if sequence after INSN dereferences such argument
1941    slots, zero otherwise.  */
1942
1943 static int
1944 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1945 {
1946   int low, high;
1947
1948   if (insn == NULL_RTX)
1949     insn = get_insns ();
1950   else
1951     insn = NEXT_INSN (insn);
1952
1953   for (; insn; insn = NEXT_INSN (insn))
1954     if (INSN_P (insn)
1955         && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1956       break;
1957
1958   if (mark_stored_args_map)
1959     {
1960 #ifdef ARGS_GROW_DOWNWARD
1961       low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1962 #else
1963       low = arg->locate.slot_offset.constant;
1964 #endif
1965
1966       for (high = low + arg->locate.size.constant; low < high; low++)
1967         SET_BIT (stored_args_map, low);
1968     }
1969   return insn != NULL_RTX;
1970 }
1971
1972 static tree
1973 fix_unsafe_tree (tree t)
1974 {
1975   switch (unsafe_for_reeval (t))
1976     {
1977     case 0: /* Safe.  */
1978       break;
1979
1980     case 1: /* Mildly unsafe.  */
1981       t = unsave_expr (t);
1982       break;
1983
1984     case 2: /* Wildly unsafe.  */
1985       {
1986         tree var = build_decl (VAR_DECL, NULL_TREE,
1987                                TREE_TYPE (t));
1988         SET_DECL_RTL (var,
1989                       expand_expr (t, NULL_RTX, VOIDmode, EXPAND_NORMAL));
1990         t = var;
1991       }
1992       break;
1993
1994     default:
1995       abort ();
1996     }
1997   return t;
1998 }
1999
2000 /* Generate all the code for a function call
2001    and return an rtx for its value.
2002    Store the value in TARGET (specified as an rtx) if convenient.
2003    If the value is stored in TARGET then TARGET is returned.
2004    If IGNORE is nonzero, then we ignore the value of the function call.  */
2005
2006 rtx
2007 expand_call (tree exp, rtx target, int ignore)
2008 {
2009   /* Nonzero if we are currently expanding a call.  */
2010   static int currently_expanding_call = 0;
2011
2012   /* List of actual parameters.  */
2013   tree actparms = TREE_OPERAND (exp, 1);
2014   /* RTX for the function to be called.  */
2015   rtx funexp;
2016   /* Sequence of insns to perform a tail recursive "call".  */
2017   rtx tail_recursion_insns = NULL_RTX;
2018   /* Sequence of insns to perform a normal "call".  */
2019   rtx normal_call_insns = NULL_RTX;
2020   /* Sequence of insns to perform a tail recursive "call".  */
2021   rtx tail_call_insns = NULL_RTX;
2022   /* Data type of the function.  */
2023   tree funtype;
2024   tree type_arg_types;
2025   /* Declaration of the function being called,
2026      or 0 if the function is computed (not known by name).  */
2027   tree fndecl = 0;
2028   rtx insn;
2029   int try_tail_call = 1;
2030   int try_tail_recursion = 1;
2031   int pass;
2032
2033   /* Register in which non-BLKmode value will be returned,
2034      or 0 if no value or if value is BLKmode.  */
2035   rtx valreg;
2036   /* Address where we should return a BLKmode value;
2037      0 if value not BLKmode.  */
2038   rtx structure_value_addr = 0;
2039   /* Nonzero if that address is being passed by treating it as
2040      an extra, implicit first parameter.  Otherwise,
2041      it is passed by being copied directly into struct_value_rtx.  */
2042   int structure_value_addr_parm = 0;
2043   /* Size of aggregate value wanted, or zero if none wanted
2044      or if we are using the non-reentrant PCC calling convention
2045      or expecting the value in registers.  */
2046   HOST_WIDE_INT struct_value_size = 0;
2047   /* Nonzero if called function returns an aggregate in memory PCC style,
2048      by returning the address of where to find it.  */
2049   int pcc_struct_value = 0;
2050
2051   /* Number of actual parameters in this call, including struct value addr.  */
2052   int num_actuals;
2053   /* Number of named args.  Args after this are anonymous ones
2054      and they must all go on the stack.  */
2055   int n_named_args;
2056
2057   /* Vector of information about each argument.
2058      Arguments are numbered in the order they will be pushed,
2059      not the order they are written.  */
2060   struct arg_data *args;
2061
2062   /* Total size in bytes of all the stack-parms scanned so far.  */
2063   struct args_size args_size;
2064   struct args_size adjusted_args_size;
2065   /* Size of arguments before any adjustments (such as rounding).  */
2066   int unadjusted_args_size;
2067   /* Data on reg parms scanned so far.  */
2068   CUMULATIVE_ARGS args_so_far;
2069   /* Nonzero if a reg parm has been scanned.  */
2070   int reg_parm_seen;
2071   /* Nonzero if this is an indirect function call.  */
2072
2073   /* Nonzero if we must avoid push-insns in the args for this call.
2074      If stack space is allocated for register parameters, but not by the
2075      caller, then it is preallocated in the fixed part of the stack frame.
2076      So the entire argument block must then be preallocated (i.e., we
2077      ignore PUSH_ROUNDING in that case).  */
2078
2079   int must_preallocate = !PUSH_ARGS;
2080
2081   /* Size of the stack reserved for parameter registers.  */
2082   int reg_parm_stack_space = 0;
2083
2084   /* Address of space preallocated for stack parms
2085      (on machines that lack push insns), or 0 if space not preallocated.  */
2086   rtx argblock = 0;
2087
2088   /* Mask of ECF_ flags.  */
2089   int flags = 0;
2090   /* Nonzero if this is a call to an inline function.  */
2091   int is_integrable = 0;
2092 #ifdef REG_PARM_STACK_SPACE
2093   /* Define the boundary of the register parm stack space that needs to be
2094      saved, if any.  */
2095   int low_to_save, high_to_save;
2096   rtx save_area = 0;            /* Place that it is saved */
2097 #endif
2098
2099   int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2100   char *initial_stack_usage_map = stack_usage_map;
2101
2102   int old_stack_allocated;
2103
2104   /* State variables to track stack modifications.  */
2105   rtx old_stack_level = 0;
2106   int old_stack_arg_under_construction = 0;
2107   int old_pending_adj = 0;
2108   int old_inhibit_defer_pop = inhibit_defer_pop;
2109
2110   /* Some stack pointer alterations we make are performed via
2111      allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2112      which we then also need to save/restore along the way.  */
2113   int old_stack_pointer_delta = 0;
2114
2115   rtx call_fusage;
2116   tree p = TREE_OPERAND (exp, 0);
2117   tree addr = TREE_OPERAND (exp, 0);
2118   int i;
2119   /* The alignment of the stack, in bits.  */
2120   HOST_WIDE_INT preferred_stack_boundary;
2121   /* The alignment of the stack, in bytes.  */
2122   HOST_WIDE_INT preferred_unit_stack_boundary;
2123
2124   /* See if this is "nothrow" function call.  */
2125   if (TREE_NOTHROW (exp))
2126     flags |= ECF_NOTHROW;
2127
2128   /* See if we can find a DECL-node for the actual function.
2129      As a result, decide whether this is a call to an integrable function.  */
2130
2131   fndecl = get_callee_fndecl (exp);
2132   if (fndecl)
2133     {
2134       if (!flag_no_inline
2135           && fndecl != current_function_decl
2136           && DECL_INLINE (fndecl)
2137           && DECL_SAVED_INSNS (fndecl)
2138           && DECL_SAVED_INSNS (fndecl)->inlinable)
2139         is_integrable = 1;
2140       else if (! TREE_ADDRESSABLE (fndecl))
2141         {
2142           /* In case this function later becomes inlinable,
2143              record that there was already a non-inline call to it.
2144
2145              Use abstraction instead of setting TREE_ADDRESSABLE
2146              directly.  */
2147           if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
2148               && optimize > 0)
2149             {
2150               warning_with_decl (fndecl, "can't inline call to `%s'");
2151               warning ("called from here");
2152             }
2153           (*lang_hooks.mark_addressable) (fndecl);
2154         }
2155
2156       flags |= flags_from_decl_or_type (fndecl);
2157     }
2158
2159   /* If we don't have specific function to call, see if we have a
2160      attributes set in the type.  */
2161   else
2162     flags |= flags_from_decl_or_type (TREE_TYPE (TREE_TYPE (p)));
2163
2164   /* Warn if this value is an aggregate type,
2165      regardless of which calling convention we are using for it.  */
2166   if (warn_aggregate_return && AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2167     warning ("function call has aggregate value");
2168
2169   /* If the result of a pure or const function call is ignored (or void),
2170      and none of its arguments are volatile, we can avoid expanding the
2171      call and just evaluate the arguments for side-effects.  */
2172   if ((flags & (ECF_CONST | ECF_PURE))
2173       && (ignore || target == const0_rtx
2174           || TYPE_MODE (TREE_TYPE (exp)) == VOIDmode))
2175     {
2176       bool volatilep = false;
2177       tree arg;
2178
2179       for (arg = actparms; arg; arg = TREE_CHAIN (arg))
2180         if (TREE_THIS_VOLATILE (TREE_VALUE (arg)))
2181           {
2182             volatilep = true;
2183             break;
2184           }
2185
2186       if (! volatilep)
2187         {
2188           for (arg = actparms; arg; arg = TREE_CHAIN (arg))
2189             expand_expr (TREE_VALUE (arg), const0_rtx,
2190                          VOIDmode, EXPAND_NORMAL);
2191           return const0_rtx;
2192         }
2193     }
2194
2195 #ifdef REG_PARM_STACK_SPACE
2196 #ifdef MAYBE_REG_PARM_STACK_SPACE
2197   reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
2198 #else
2199   reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
2200 #endif
2201 #endif
2202
2203 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2204   if (reg_parm_stack_space > 0 && PUSH_ARGS)
2205     must_preallocate = 1;
2206 #endif
2207
2208   /* Set up a place to return a structure.  */
2209
2210   /* Cater to broken compilers.  */
2211   if (aggregate_value_p (exp))
2212     {
2213       /* This call returns a big structure.  */
2214       flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
2215
2216 #ifdef PCC_STATIC_STRUCT_RETURN
2217       {
2218         pcc_struct_value = 1;
2219         /* Easier than making that case work right.  */
2220         if (is_integrable)
2221           {
2222             /* In case this is a static function, note that it has been
2223                used.  */
2224             if (! TREE_ADDRESSABLE (fndecl))
2225               (*lang_hooks.mark_addressable) (fndecl);
2226             is_integrable = 0;
2227           }
2228       }
2229 #else /* not PCC_STATIC_STRUCT_RETURN */
2230       {
2231         struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2232
2233         if (CALL_EXPR_HAS_RETURN_SLOT_ADDR (exp))
2234           {
2235             /* The structure value address arg is already in actparms.
2236                Pull it out.  It might be nice to just leave it there, but
2237                we need to set structure_value_addr.  */
2238             tree return_arg = TREE_VALUE (actparms);
2239             actparms = TREE_CHAIN (actparms);
2240             structure_value_addr = expand_expr (return_arg, NULL_RTX,
2241                                                 VOIDmode, EXPAND_NORMAL);
2242           }
2243         else if (target && GET_CODE (target) == MEM)
2244           structure_value_addr = XEXP (target, 0);
2245         else
2246           {
2247             /* For variable-sized objects, we must be called with a target
2248                specified.  If we were to allocate space on the stack here,
2249                we would have no way of knowing when to free it.  */
2250             rtx d = assign_temp (TREE_TYPE (exp), 1, 1, 1);
2251
2252             mark_temp_addr_taken (d);
2253             structure_value_addr = XEXP (d, 0);
2254             target = 0;
2255           }
2256       }
2257 #endif /* not PCC_STATIC_STRUCT_RETURN */
2258     }
2259
2260   /* If called function is inline, try to integrate it.  */
2261
2262   if (is_integrable)
2263     {
2264       rtx temp = try_to_integrate (fndecl, actparms, target,
2265                                    ignore, TREE_TYPE (exp),
2266                                    structure_value_addr);
2267       if (temp != (rtx) (size_t) - 1)
2268         return temp;
2269     }
2270
2271   /* Figure out the amount to which the stack should be aligned.  */
2272   preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2273   if (fndecl)
2274     {
2275       struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2276       if (i && i->preferred_incoming_stack_boundary)
2277         preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2278     }
2279
2280   /* Operand 0 is a pointer-to-function; get the type of the function.  */
2281   funtype = TREE_TYPE (addr);
2282   if (! POINTER_TYPE_P (funtype))
2283     abort ();
2284   funtype = TREE_TYPE (funtype);
2285
2286   /* Munge the tree to split complex arguments into their imaginary
2287      and real parts.  */
2288   if (SPLIT_COMPLEX_ARGS)
2289     {
2290       type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2291       actparms = split_complex_values (actparms);
2292     }
2293   else
2294     type_arg_types = TYPE_ARG_TYPES (funtype);
2295
2296   /* See if this is a call to a function that can return more than once
2297      or a call to longjmp or malloc.  */
2298   flags |= special_function_p (fndecl, flags);
2299
2300   if (flags & ECF_MAY_BE_ALLOCA)
2301     current_function_calls_alloca = 1;
2302
2303   /* If struct_value_rtx is 0, it means pass the address
2304      as if it were an extra parameter.  */
2305   if (structure_value_addr && struct_value_rtx == 0)
2306     {
2307       /* If structure_value_addr is a REG other than
2308          virtual_outgoing_args_rtx, we can use always use it.  If it
2309          is not a REG, we must always copy it into a register.
2310          If it is virtual_outgoing_args_rtx, we must copy it to another
2311          register in some cases.  */
2312       rtx temp = (GET_CODE (structure_value_addr) != REG
2313                   || (ACCUMULATE_OUTGOING_ARGS
2314                       && stack_arg_under_construction
2315                       && structure_value_addr == virtual_outgoing_args_rtx)
2316                   ? copy_addr_to_reg (structure_value_addr)
2317                   : structure_value_addr);
2318
2319       actparms
2320         = tree_cons (error_mark_node,
2321                      make_tree (build_pointer_type (TREE_TYPE (funtype)),
2322                                 temp),
2323                      actparms);
2324       structure_value_addr_parm = 1;
2325     }
2326
2327   /* Count the arguments and set NUM_ACTUALS.  */
2328   for (p = actparms, num_actuals = 0; p; p = TREE_CHAIN (p))
2329     num_actuals++;
2330
2331   /* Compute number of named args.
2332      Normally, don't include the last named arg if anonymous args follow.
2333      We do include the last named arg if STRICT_ARGUMENT_NAMING is nonzero.
2334      (If no anonymous args follow, the result of list_length is actually
2335      one too large.  This is harmless.)
2336
2337      If PRETEND_OUTGOING_VARARGS_NAMED is set and STRICT_ARGUMENT_NAMING is
2338      zero, this machine will be able to place unnamed args that were
2339      passed in registers into the stack.  So treat all args as named.
2340      This allows the insns emitting for a specific argument list to be
2341      independent of the function declaration.
2342
2343      If PRETEND_OUTGOING_VARARGS_NAMED is not set, we do not have any
2344      reliable way to pass unnamed args in registers, so we must force
2345      them into memory.  */
2346
2347   if ((STRICT_ARGUMENT_NAMING
2348        || ! PRETEND_OUTGOING_VARARGS_NAMED)
2349       && type_arg_types != 0)
2350     n_named_args
2351       = (list_length (type_arg_types)
2352          /* Don't include the last named arg.  */
2353          - (STRICT_ARGUMENT_NAMING ? 0 : 1)
2354          /* Count the struct value address, if it is passed as a parm.  */
2355          + structure_value_addr_parm);
2356   else
2357     /* If we know nothing, treat all args as named.  */
2358     n_named_args = num_actuals;
2359
2360   /* Start updating where the next arg would go.
2361
2362      On some machines (such as the PA) indirect calls have a different
2363      calling convention than normal calls.  The last argument in
2364      INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2365      or not.  */
2366   INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl);
2367
2368   /* Make a vector to hold all the information about each arg.  */
2369   args = alloca (num_actuals * sizeof (struct arg_data));
2370   memset (args, 0, num_actuals * sizeof (struct arg_data));
2371
2372   /* Build up entries in the ARGS array, compute the size of the
2373      arguments into ARGS_SIZE, etc.  */
2374   initialize_argument_information (num_actuals, args, &args_size,
2375                                    n_named_args, actparms, fndecl,
2376                                    &args_so_far, reg_parm_stack_space,
2377                                    &old_stack_level, &old_pending_adj,
2378                                    &must_preallocate, &flags);
2379
2380   if (args_size.var)
2381     {
2382       /* If this function requires a variable-sized argument list, don't
2383          try to make a cse'able block for this call.  We may be able to
2384          do this eventually, but it is too complicated to keep track of
2385          what insns go in the cse'able block and which don't.  */
2386
2387       flags &= ~ECF_LIBCALL_BLOCK;
2388       must_preallocate = 1;
2389     }
2390
2391   /* Now make final decision about preallocating stack space.  */
2392   must_preallocate = finalize_must_preallocate (must_preallocate,
2393                                                 num_actuals, args,
2394                                                 &args_size);
2395
2396   /* If the structure value address will reference the stack pointer, we
2397      must stabilize it.  We don't need to do this if we know that we are
2398      not going to adjust the stack pointer in processing this call.  */
2399
2400   if (structure_value_addr
2401       && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2402           || reg_mentioned_p (virtual_outgoing_args_rtx,
2403                               structure_value_addr))
2404       && (args_size.var
2405           || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2406     structure_value_addr = copy_to_reg (structure_value_addr);
2407
2408   /* Tail calls can make things harder to debug, and we're traditionally
2409      pushed these optimizations into -O2.  Don't try if we're already
2410      expanding a call, as that means we're an argument.  Don't try if
2411      there's cleanups, as we know there's code to follow the call.
2412
2413      If rtx_equal_function_value_matters is false, that means we've
2414      finished with regular parsing.  Which means that some of the
2415      machinery we use to generate tail-calls is no longer in place.
2416      This is most often true of sjlj-exceptions, which we couldn't
2417      tail-call to anyway.  */
2418
2419   if (currently_expanding_call++ != 0
2420       || !flag_optimize_sibling_calls
2421       || !rtx_equal_function_value_matters
2422       || any_pending_cleanups ()
2423       || args_size.var)
2424     try_tail_call = try_tail_recursion = 0;
2425
2426   /* Tail recursion fails, when we are not dealing with recursive calls.  */
2427   if (!try_tail_recursion
2428       || TREE_CODE (addr) != ADDR_EXPR
2429       || TREE_OPERAND (addr, 0) != current_function_decl)
2430     try_tail_recursion = 0;
2431
2432   /*  Rest of purposes for tail call optimizations to fail.  */
2433   if (
2434 #ifdef HAVE_sibcall_epilogue
2435       !HAVE_sibcall_epilogue
2436 #else
2437       1
2438 #endif
2439       || !try_tail_call
2440       /* Doing sibling call optimization needs some work, since
2441          structure_value_addr can be allocated on the stack.
2442          It does not seem worth the effort since few optimizable
2443          sibling calls will return a structure.  */
2444       || structure_value_addr != NULL_RTX
2445       /* Check whether the target is able to optimize the call
2446          into a sibcall.  */
2447       || !(*targetm.function_ok_for_sibcall) (fndecl, exp)
2448       /* Functions that do not return exactly once may not be sibcall
2449          optimized.  */
2450       || (flags & (ECF_RETURNS_TWICE | ECF_LONGJMP | ECF_NORETURN))
2451       || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2452       /* If the called function is nested in the current one, it might access
2453          some of the caller's arguments, but could clobber them beforehand if
2454          the argument areas are shared.  */
2455       || (fndecl && decl_function_context (fndecl) == current_function_decl)
2456       /* If this function requires more stack slots than the current
2457          function, we cannot change it into a sibling call.  */
2458       || args_size.constant > current_function_args_size
2459       /* If the callee pops its own arguments, then it must pop exactly
2460          the same number of arguments as the current function.  */
2461       || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2462           != RETURN_POPS_ARGS (current_function_decl,
2463                                TREE_TYPE (current_function_decl),
2464                                current_function_args_size))
2465       || !(*lang_hooks.decls.ok_for_sibcall) (fndecl))
2466     try_tail_call = 0;
2467
2468   if (try_tail_call || try_tail_recursion)
2469     {
2470       int end, inc;
2471       actparms = NULL_TREE;
2472       /* Ok, we're going to give the tail call the old college try.
2473          This means we're going to evaluate the function arguments
2474          up to three times.  There are two degrees of badness we can
2475          encounter, those that can be unsaved and those that can't.
2476          (See unsafe_for_reeval commentary for details.)
2477
2478          Generate a new argument list.  Pass safe arguments through
2479          unchanged.  For the easy badness wrap them in UNSAVE_EXPRs.
2480          For hard badness, evaluate them now and put their resulting
2481          rtx in a temporary VAR_DECL.
2482
2483          initialize_argument_information has ordered the array for the
2484          order to be pushed, and we must remember this when reconstructing
2485          the original argument order.  */
2486
2487       if (PUSH_ARGS_REVERSED)
2488         {
2489           inc = 1;
2490           i = 0;
2491           end = num_actuals;
2492         }
2493       else
2494         {
2495           inc = -1;
2496           i = num_actuals - 1;
2497           end = -1;
2498         }
2499
2500       for (; i != end; i += inc)
2501         {
2502           args[i].tree_value = fix_unsafe_tree (args[i].tree_value);
2503           /* We need to build actparms for optimize_tail_recursion.  We can
2504              safely trash away TREE_PURPOSE, since it is unused by this
2505              function.  */
2506           if (try_tail_recursion)
2507             actparms = tree_cons (NULL_TREE, args[i].tree_value, actparms);
2508         }
2509       /* Do the same for the function address if it is an expression.  */
2510       if (!fndecl)
2511         addr = fix_unsafe_tree (addr);
2512       /* Expanding one of those dangerous arguments could have added
2513          cleanups, but otherwise give it a whirl.  */
2514       if (any_pending_cleanups ())
2515         try_tail_call = try_tail_recursion = 0;
2516     }
2517
2518   /* Generate a tail recursion sequence when calling ourselves.  */
2519
2520   if (try_tail_recursion)
2521     {
2522       /* We want to emit any pending stack adjustments before the tail
2523          recursion "call".  That way we know any adjustment after the tail
2524          recursion call can be ignored if we indeed use the tail recursion
2525          call expansion.  */
2526       int save_pending_stack_adjust = pending_stack_adjust;
2527       int save_stack_pointer_delta = stack_pointer_delta;
2528
2529       /* Emit any queued insns now; otherwise they would end up in
2530          only one of the alternates.  */
2531       emit_queue ();
2532
2533       /* Use a new sequence to hold any RTL we generate.  We do not even
2534          know if we will use this RTL yet.  The final decision can not be
2535          made until after RTL generation for the entire function is
2536          complete.  */
2537       start_sequence ();
2538       /* If expanding any of the arguments creates cleanups, we can't
2539          do a tailcall.  So, we'll need to pop the pending cleanups
2540          list.  If, however, all goes well, and there are no cleanups
2541          then the call to expand_start_target_temps will have no
2542          effect.  */
2543       expand_start_target_temps ();
2544       if (optimize_tail_recursion (actparms, get_last_insn ()))
2545         {
2546           if (any_pending_cleanups ())
2547             try_tail_call = try_tail_recursion = 0;
2548           else
2549             tail_recursion_insns = get_insns ();
2550         }
2551       expand_end_target_temps ();
2552       end_sequence ();
2553
2554       /* Restore the original pending stack adjustment for the sibling and
2555          normal call cases below.  */
2556       pending_stack_adjust = save_pending_stack_adjust;
2557       stack_pointer_delta = save_stack_pointer_delta;
2558     }
2559
2560   if (profile_arc_flag && (flags & ECF_FORK_OR_EXEC))
2561     {
2562       /* A fork duplicates the profile information, and an exec discards
2563          it.  We can't rely on fork/exec to be paired.  So write out the
2564          profile information we have gathered so far, and clear it.  */
2565       /* ??? When Linux's __clone is called with CLONE_VM set, profiling
2566          is subject to race conditions, just as with multithreaded
2567          programs.  */
2568
2569       emit_library_call (gcov_flush_libfunc, LCT_ALWAYS_RETURN, VOIDmode, 0);
2570     }
2571
2572   /* Ensure current function's preferred stack boundary is at least
2573      what we need.  We don't have to increase alignment for recursive
2574      functions.  */
2575   if (cfun->preferred_stack_boundary < preferred_stack_boundary
2576       && fndecl != current_function_decl)
2577     cfun->preferred_stack_boundary = preferred_stack_boundary;
2578   if (fndecl == current_function_decl)
2579     cfun->recursive_call_emit = true;
2580
2581   preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2582
2583   function_call_count++;
2584
2585   /* We want to make two insn chains; one for a sibling call, the other
2586      for a normal call.  We will select one of the two chains after
2587      initial RTL generation is complete.  */
2588   for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2589     {
2590       int sibcall_failure = 0;
2591       /* We want to emit any pending stack adjustments before the tail
2592          recursion "call".  That way we know any adjustment after the tail
2593          recursion call can be ignored if we indeed use the tail recursion
2594          call expansion.  */
2595       int save_pending_stack_adjust = 0;
2596       int save_stack_pointer_delta = 0;
2597       rtx insns;
2598       rtx before_call, next_arg_reg;
2599
2600       if (pass == 0)
2601         {
2602           /* Emit any queued insns now; otherwise they would end up in
2603              only one of the alternates.  */
2604           emit_queue ();
2605
2606           /* State variables we need to save and restore between
2607              iterations.  */
2608           save_pending_stack_adjust = pending_stack_adjust;
2609           save_stack_pointer_delta = stack_pointer_delta;
2610         }
2611       if (pass)
2612         flags &= ~ECF_SIBCALL;
2613       else
2614         flags |= ECF_SIBCALL;
2615
2616       /* Other state variables that we must reinitialize each time
2617          through the loop (that are not initialized by the loop itself).  */
2618       argblock = 0;
2619       call_fusage = 0;
2620
2621       /* Start a new sequence for the normal call case.
2622
2623          From this point on, if the sibling call fails, we want to set
2624          sibcall_failure instead of continuing the loop.  */
2625       start_sequence ();
2626
2627       if (pass == 0)
2628         {
2629           /* We know at this point that there are not currently any
2630              pending cleanups.  If, however, in the process of evaluating
2631              the arguments we were to create some, we'll need to be
2632              able to get rid of them.  */
2633           expand_start_target_temps ();
2634         }
2635
2636       /* Don't let pending stack adjusts add up to too much.
2637          Also, do all pending adjustments now if there is any chance
2638          this might be a call to alloca or if we are expanding a sibling
2639          call sequence or if we are calling a function that is to return
2640          with stack pointer depressed.  */
2641       if (pending_stack_adjust >= 32
2642           || (pending_stack_adjust > 0
2643               && (flags & (ECF_MAY_BE_ALLOCA | ECF_SP_DEPRESSED)))
2644           || pass == 0)
2645         do_pending_stack_adjust ();
2646
2647       /* When calling a const function, we must pop the stack args right away,
2648          so that the pop is deleted or moved with the call.  */
2649       if (pass && (flags & ECF_LIBCALL_BLOCK))
2650         NO_DEFER_POP;
2651
2652 #ifdef FINAL_REG_PARM_STACK_SPACE
2653       reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
2654                                                          args_size.var);
2655 #endif
2656       /* Precompute any arguments as needed.  */
2657       if (pass)
2658         precompute_arguments (flags, num_actuals, args);
2659
2660       /* Now we are about to start emitting insns that can be deleted
2661          if a libcall is deleted.  */
2662       if (pass && (flags & (ECF_LIBCALL_BLOCK | ECF_MALLOC)))
2663         start_sequence ();
2664
2665       adjusted_args_size = args_size;
2666       /* Compute the actual size of the argument block required.  The variable
2667          and constant sizes must be combined, the size may have to be rounded,
2668          and there may be a minimum required size.  When generating a sibcall
2669          pattern, do not round up, since we'll be re-using whatever space our
2670          caller provided.  */
2671       unadjusted_args_size
2672         = compute_argument_block_size (reg_parm_stack_space,
2673                                        &adjusted_args_size,
2674                                        (pass == 0 ? 0
2675                                         : preferred_stack_boundary));
2676
2677       old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2678
2679       /* The argument block when performing a sibling call is the
2680          incoming argument block.  */
2681       if (pass == 0)
2682         {
2683           argblock = virtual_incoming_args_rtx;
2684           argblock
2685 #ifdef STACK_GROWS_DOWNWARD
2686             = plus_constant (argblock, current_function_pretend_args_size);
2687 #else
2688             = plus_constant (argblock, -current_function_pretend_args_size);
2689 #endif
2690           stored_args_map = sbitmap_alloc (args_size.constant);
2691           sbitmap_zero (stored_args_map);
2692         }
2693
2694       /* If we have no actual push instructions, or shouldn't use them,
2695          make space for all args right now.  */
2696       else if (adjusted_args_size.var != 0)
2697         {
2698           if (old_stack_level == 0)
2699             {
2700               emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2701               old_stack_pointer_delta = stack_pointer_delta;
2702               old_pending_adj = pending_stack_adjust;
2703               pending_stack_adjust = 0;
2704               /* stack_arg_under_construction says whether a stack arg is
2705                  being constructed at the old stack level.  Pushing the stack
2706                  gets a clean outgoing argument block.  */
2707               old_stack_arg_under_construction = stack_arg_under_construction;
2708               stack_arg_under_construction = 0;
2709             }
2710           argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2711         }
2712       else
2713         {
2714           /* Note that we must go through the motions of allocating an argument
2715              block even if the size is zero because we may be storing args
2716              in the area reserved for register arguments, which may be part of
2717              the stack frame.  */
2718
2719           int needed = adjusted_args_size.constant;
2720
2721           /* Store the maximum argument space used.  It will be pushed by
2722              the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2723              checking).  */
2724
2725           if (needed > current_function_outgoing_args_size)
2726             current_function_outgoing_args_size = needed;
2727
2728           if (must_preallocate)
2729             {
2730               if (ACCUMULATE_OUTGOING_ARGS)
2731                 {
2732                   /* Since the stack pointer will never be pushed, it is
2733                      possible for the evaluation of a parm to clobber
2734                      something we have already written to the stack.
2735                      Since most function calls on RISC machines do not use
2736                      the stack, this is uncommon, but must work correctly.
2737
2738                      Therefore, we save any area of the stack that was already
2739                      written and that we are using.  Here we set up to do this
2740                      by making a new stack usage map from the old one.  The
2741                      actual save will be done by store_one_arg.
2742
2743                      Another approach might be to try to reorder the argument
2744                      evaluations to avoid this conflicting stack usage.  */
2745
2746 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2747                   /* Since we will be writing into the entire argument area,
2748                      the map must be allocated for its entire size, not just
2749                      the part that is the responsibility of the caller.  */
2750                   needed += reg_parm_stack_space;
2751 #endif
2752
2753 #ifdef ARGS_GROW_DOWNWARD
2754                   highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2755                                                      needed + 1);
2756 #else
2757                   highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2758                                                      needed);
2759 #endif
2760                   stack_usage_map = alloca (highest_outgoing_arg_in_use);
2761
2762                   if (initial_highest_arg_in_use)
2763                     memcpy (stack_usage_map, initial_stack_usage_map,
2764                             initial_highest_arg_in_use);
2765
2766                   if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2767                     memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2768                            (highest_outgoing_arg_in_use
2769                             - initial_highest_arg_in_use));
2770                   needed = 0;
2771
2772                   /* The address of the outgoing argument list must not be
2773                      copied to a register here, because argblock would be left
2774                      pointing to the wrong place after the call to
2775                      allocate_dynamic_stack_space below.  */
2776
2777                   argblock = virtual_outgoing_args_rtx;
2778                 }
2779               else
2780                 {
2781                   if (inhibit_defer_pop == 0)
2782                     {
2783                       /* Try to reuse some or all of the pending_stack_adjust
2784                          to get this space.  */
2785                       needed
2786                         = (combine_pending_stack_adjustment_and_call
2787                            (unadjusted_args_size,
2788                             &adjusted_args_size,
2789                             preferred_unit_stack_boundary));
2790
2791                       /* combine_pending_stack_adjustment_and_call computes
2792                          an adjustment before the arguments are allocated.
2793                          Account for them and see whether or not the stack
2794                          needs to go up or down.  */
2795                       needed = unadjusted_args_size - needed;
2796
2797                       if (needed < 0)
2798                         {
2799                           /* We're releasing stack space.  */
2800                           /* ??? We can avoid any adjustment at all if we're
2801                              already aligned.  FIXME.  */
2802                           pending_stack_adjust = -needed;
2803                           do_pending_stack_adjust ();
2804                           needed = 0;
2805                         }
2806                       else
2807                         /* We need to allocate space.  We'll do that in
2808                            push_block below.  */
2809                         pending_stack_adjust = 0;
2810                     }
2811
2812                   /* Special case this because overhead of `push_block' in
2813                      this case is non-trivial.  */
2814                   if (needed == 0)
2815                     argblock = virtual_outgoing_args_rtx;
2816                   else
2817                     {
2818                       argblock = push_block (GEN_INT (needed), 0, 0);
2819 #ifdef ARGS_GROW_DOWNWARD
2820                       argblock = plus_constant (argblock, needed);
2821 #endif
2822                     }
2823
2824                   /* We only really need to call `copy_to_reg' in the case
2825                      where push insns are going to be used to pass ARGBLOCK
2826                      to a function call in ARGS.  In that case, the stack
2827                      pointer changes value from the allocation point to the
2828                      call point, and hence the value of
2829                      VIRTUAL_OUTGOING_ARGS_RTX changes as well.  But might
2830                      as well always do it.  */
2831                   argblock = copy_to_reg (argblock);
2832                 }
2833             }
2834         }
2835
2836       if (ACCUMULATE_OUTGOING_ARGS)
2837         {
2838           /* The save/restore code in store_one_arg handles all
2839              cases except one: a constructor call (including a C
2840              function returning a BLKmode struct) to initialize
2841              an argument.  */
2842           if (stack_arg_under_construction)
2843             {
2844 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2845               rtx push_size = GEN_INT (reg_parm_stack_space
2846                                        + adjusted_args_size.constant);
2847 #else
2848               rtx push_size = GEN_INT (adjusted_args_size.constant);
2849 #endif
2850               if (old_stack_level == 0)
2851                 {
2852                   emit_stack_save (SAVE_BLOCK, &old_stack_level,
2853                                    NULL_RTX);
2854                   old_stack_pointer_delta = stack_pointer_delta;
2855                   old_pending_adj = pending_stack_adjust;
2856                   pending_stack_adjust = 0;
2857                   /* stack_arg_under_construction says whether a stack
2858                      arg is being constructed at the old stack level.
2859                      Pushing the stack gets a clean outgoing argument
2860                      block.  */
2861                   old_stack_arg_under_construction
2862                     = stack_arg_under_construction;
2863                   stack_arg_under_construction = 0;
2864                   /* Make a new map for the new argument list.  */
2865                   stack_usage_map = alloca (highest_outgoing_arg_in_use);
2866                   memset (stack_usage_map, 0, highest_outgoing_arg_in_use);
2867                   highest_outgoing_arg_in_use = 0;
2868                 }
2869               allocate_dynamic_stack_space (push_size, NULL_RTX,
2870                                             BITS_PER_UNIT);
2871             }
2872
2873           /* If argument evaluation might modify the stack pointer,
2874              copy the address of the argument list to a register.  */
2875           for (i = 0; i < num_actuals; i++)
2876             if (args[i].pass_on_stack)
2877               {
2878                 argblock = copy_addr_to_reg (argblock);
2879                 break;
2880               }
2881         }
2882
2883       compute_argument_addresses (args, argblock, num_actuals);
2884
2885       /* If we push args individually in reverse order, perform stack alignment
2886          before the first push (the last arg).  */
2887       if (PUSH_ARGS_REVERSED && argblock == 0
2888           && adjusted_args_size.constant != unadjusted_args_size)
2889         {
2890           /* When the stack adjustment is pending, we get better code
2891              by combining the adjustments.  */
2892           if (pending_stack_adjust
2893               && ! (flags & ECF_LIBCALL_BLOCK)
2894               && ! inhibit_defer_pop)
2895             {
2896               pending_stack_adjust
2897                 = (combine_pending_stack_adjustment_and_call
2898                    (unadjusted_args_size,
2899                     &adjusted_args_size,
2900                     preferred_unit_stack_boundary));
2901               do_pending_stack_adjust ();
2902             }
2903           else if (argblock == 0)
2904             anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2905                                         - unadjusted_args_size));
2906         }
2907       /* Now that the stack is properly aligned, pops can't safely
2908          be deferred during the evaluation of the arguments.  */
2909       NO_DEFER_POP;
2910
2911       funexp = rtx_for_function_call (fndecl, addr);
2912
2913       /* Figure out the register where the value, if any, will come back.  */
2914       valreg = 0;
2915       if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2916           && ! structure_value_addr)
2917         {
2918           if (pcc_struct_value)
2919             valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2920                                           fndecl, (pass == 0));
2921           else
2922             valreg = hard_function_value (TREE_TYPE (exp), fndecl, (pass == 0));
2923         }
2924
2925       /* Precompute all register parameters.  It isn't safe to compute anything
2926          once we have started filling any specific hard regs.  */
2927       precompute_register_parameters (num_actuals, args, &reg_parm_seen);
2928
2929 #ifdef REG_PARM_STACK_SPACE
2930       /* Save the fixed argument area if it's part of the caller's frame and
2931          is clobbered by argument setup for this call.  */
2932       if (ACCUMULATE_OUTGOING_ARGS && pass)
2933         save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2934                                               &low_to_save, &high_to_save);
2935 #endif
2936
2937       /* Now store (and compute if necessary) all non-register parms.
2938          These come before register parms, since they can require block-moves,
2939          which could clobber the registers used for register parms.
2940          Parms which have partial registers are not stored here,
2941          but we do preallocate space here if they want that.  */
2942
2943       for (i = 0; i < num_actuals; i++)
2944         if (args[i].reg == 0 || args[i].pass_on_stack)
2945           {
2946             rtx before_arg = get_last_insn ();
2947
2948             if (store_one_arg (&args[i], argblock, flags,
2949                                adjusted_args_size.var != 0,
2950                                reg_parm_stack_space)
2951                 || (pass == 0
2952                     && check_sibcall_argument_overlap (before_arg,
2953                                                        &args[i], 1)))
2954               sibcall_failure = 1;
2955           }
2956
2957       /* If we have a parm that is passed in registers but not in memory
2958          and whose alignment does not permit a direct copy into registers,
2959          make a group of pseudos that correspond to each register that we
2960          will later fill.  */
2961       if (STRICT_ALIGNMENT)
2962         store_unaligned_arguments_into_pseudos (args, num_actuals);
2963
2964       /* Now store any partially-in-registers parm.
2965          This is the last place a block-move can happen.  */
2966       if (reg_parm_seen)
2967         for (i = 0; i < num_actuals; i++)
2968           if (args[i].partial != 0 && ! args[i].pass_on_stack)
2969             {
2970               rtx before_arg = get_last_insn ();
2971
2972               if (store_one_arg (&args[i], argblock, flags,
2973                                  adjusted_args_size.var != 0,
2974                                  reg_parm_stack_space)
2975                   || (pass == 0
2976                       && check_sibcall_argument_overlap (before_arg,
2977                                                          &args[i], 1)))
2978                 sibcall_failure = 1;
2979             }
2980
2981       /* If we pushed args in forward order, perform stack alignment
2982          after pushing the last arg.  */
2983       if (!PUSH_ARGS_REVERSED && argblock == 0)
2984         anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2985                                     - unadjusted_args_size));
2986
2987       /* If register arguments require space on the stack and stack space
2988          was not preallocated, allocate stack space here for arguments
2989          passed in registers.  */
2990 #ifdef OUTGOING_REG_PARM_STACK_SPACE
2991       if (!ACCUMULATE_OUTGOING_ARGS
2992           && must_preallocate == 0 && reg_parm_stack_space > 0)
2993         anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2994 #endif
2995
2996       /* Pass the function the address in which to return a
2997          structure value.  */
2998       if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2999         {
3000 #ifdef POINTERS_EXTEND_UNSIGNED
3001           if (GET_MODE (structure_value_addr) != Pmode)
3002             structure_value_addr = convert_memory_address
3003                                         (Pmode, structure_value_addr);
3004 #endif
3005           emit_move_insn (struct_value_rtx,
3006                           force_reg (Pmode,
3007                                      force_operand (structure_value_addr,
3008                                                     NULL_RTX)));
3009
3010           if (GET_CODE (struct_value_rtx) == REG)
3011             use_reg (&call_fusage, struct_value_rtx);
3012         }
3013
3014       funexp = prepare_call_address (funexp, fndecl, &call_fusage,
3015                                      reg_parm_seen, pass == 0);
3016
3017       load_register_parameters (args, num_actuals, &call_fusage, flags,
3018                                 pass == 0, &sibcall_failure);
3019
3020       /* Perform postincrements before actually calling the function.  */
3021       emit_queue ();
3022
3023       /* Save a pointer to the last insn before the call, so that we can
3024          later safely search backwards to find the CALL_INSN.  */
3025       before_call = get_last_insn ();
3026
3027       /* Set up next argument register.  For sibling calls on machines
3028          with register windows this should be the incoming register.  */
3029 #ifdef FUNCTION_INCOMING_ARG
3030       if (pass == 0)
3031         next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
3032                                               void_type_node, 1);
3033       else
3034 #endif
3035         next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
3036                                      void_type_node, 1);
3037
3038       /* All arguments and registers used for the call must be set up by
3039          now!  */
3040
3041       /* Stack must be properly aligned now.  */
3042       if (pass && stack_pointer_delta % preferred_unit_stack_boundary)
3043         abort ();
3044
3045       /* Generate the actual call instruction.  */
3046       emit_call_1 (funexp, fndecl, funtype, unadjusted_args_size,
3047                    adjusted_args_size.constant, struct_value_size,
3048                    next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
3049                    flags, & args_so_far);
3050
3051       /* If call is cse'able, make appropriate pair of reg-notes around it.
3052          Test valreg so we don't crash; may safely ignore `const'
3053          if return type is void.  Disable for PARALLEL return values, because
3054          we have no way to move such values into a pseudo register.  */
3055       if (pass && (flags & ECF_LIBCALL_BLOCK))
3056         {
3057           rtx insns;
3058
3059           if (valreg == 0 || GET_CODE (valreg) == PARALLEL)
3060             {
3061               insns = get_insns ();
3062               end_sequence ();
3063               emit_insn (insns);
3064             }
3065           else
3066             {
3067               rtx note = 0;
3068               rtx temp = gen_reg_rtx (GET_MODE (valreg));
3069
3070               /* Mark the return value as a pointer if needed.  */
3071               if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3072                 mark_reg_pointer (temp,
3073                                   TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))));
3074
3075               /* Construct an "equal form" for the value which mentions all the
3076                  arguments in order as well as the function name.  */
3077               for (i = 0; i < num_actuals; i++)
3078                 note = gen_rtx_EXPR_LIST (VOIDmode,
3079                                           args[i].initial_value, note);
3080               note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note);
3081
3082               insns = get_insns ();
3083               end_sequence ();
3084
3085               if (flags & ECF_PURE)
3086                 note = gen_rtx_EXPR_LIST (VOIDmode,
3087                         gen_rtx_USE (VOIDmode,
3088                                      gen_rtx_MEM (BLKmode,
3089                                                   gen_rtx_SCRATCH (VOIDmode))),
3090                         note);
3091
3092               emit_libcall_block (insns, temp, valreg, note);
3093
3094               valreg = temp;
3095             }
3096         }
3097       else if (pass && (flags & ECF_MALLOC))
3098         {
3099           rtx temp = gen_reg_rtx (GET_MODE (valreg));
3100           rtx last, insns;
3101
3102           /* The return value from a malloc-like function is a pointer.  */
3103           if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3104             mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
3105
3106           emit_move_insn (temp, valreg);
3107
3108           /* The return value from a malloc-like function can not alias
3109              anything else.  */
3110           last = get_last_insn ();
3111           REG_NOTES (last) =
3112             gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last));
3113
3114           /* Write out the sequence.  */
3115           insns = get_insns ();
3116           end_sequence ();
3117           emit_insn (insns);
3118           valreg = temp;
3119         }
3120
3121       /* For calls to `setjmp', etc., inform flow.c it should complain
3122          if nonvolatile values are live.  For functions that cannot return,
3123          inform flow that control does not fall through.  */
3124
3125       if ((flags & (ECF_NORETURN | ECF_LONGJMP)) || pass == 0)
3126         {
3127           /* The barrier must be emitted
3128              immediately after the CALL_INSN.  Some ports emit more
3129              than just a CALL_INSN above, so we must search for it here.  */
3130
3131           rtx last = get_last_insn ();
3132           while (GET_CODE (last) != CALL_INSN)
3133             {
3134               last = PREV_INSN (last);
3135               /* There was no CALL_INSN?  */
3136               if (last == before_call)
3137                 abort ();
3138             }
3139
3140           emit_barrier_after (last);
3141
3142           /* Stack adjustments after a noreturn call are dead code.  */
3143           stack_pointer_delta = old_stack_allocated;
3144           pending_stack_adjust = 0;
3145         }
3146
3147       if (flags & ECF_LONGJMP)
3148         current_function_calls_longjmp = 1;
3149
3150       /* If value type not void, return an rtx for the value.  */
3151
3152       /* If there are cleanups to be called, don't use a hard reg as target.
3153          We need to double check this and see if it matters anymore.  */
3154       if (any_pending_cleanups ())
3155         {
3156           if (target && REG_P (target)
3157               && REGNO (target) < FIRST_PSEUDO_REGISTER)
3158             target = 0;
3159           sibcall_failure = 1;
3160         }
3161
3162       if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
3163           || ignore)
3164         target = const0_rtx;
3165       else if (structure_value_addr)
3166         {
3167           if (target == 0 || GET_CODE (target) != MEM)
3168             {
3169               target
3170                 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3171                                memory_address (TYPE_MODE (TREE_TYPE (exp)),
3172                                                structure_value_addr));
3173               set_mem_attributes (target, exp, 1);
3174             }
3175         }
3176       else if (pcc_struct_value)
3177         {
3178           /* This is the special C++ case where we need to
3179              know what the true target was.  We take care to
3180              never use this value more than once in one expression.  */
3181           target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3182                                 copy_to_reg (valreg));
3183           set_mem_attributes (target, exp, 1);
3184         }
3185       /* Handle calls that return values in multiple non-contiguous locations.
3186          The Irix 6 ABI has examples of this.  */
3187       else if (GET_CODE (valreg) == PARALLEL)
3188         {
3189           if (target == 0)
3190             {
3191               /* This will only be assigned once, so it can be readonly.  */
3192               tree nt = build_qualified_type (TREE_TYPE (exp),
3193                                               (TYPE_QUALS (TREE_TYPE (exp))
3194                                                | TYPE_QUAL_CONST));
3195
3196               target = assign_temp (nt, 0, 1, 1);
3197               preserve_temp_slots (target);
3198             }
3199
3200           if (! rtx_equal_p (target, valreg))
3201             emit_group_store (target, valreg, TREE_TYPE (exp),
3202                               int_size_in_bytes (TREE_TYPE (exp)));
3203
3204           /* We can not support sibling calls for this case.  */
3205           sibcall_failure = 1;
3206         }
3207       else if (target
3208                && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
3209                && GET_MODE (target) == GET_MODE (valreg))
3210         {
3211           /* TARGET and VALREG cannot be equal at this point because the
3212              latter would not have REG_FUNCTION_VALUE_P true, while the
3213              former would if it were referring to the same register.
3214
3215              If they refer to the same register, this move will be a no-op,
3216              except when function inlining is being done.  */
3217           emit_move_insn (target, valreg);
3218
3219           /* If we are setting a MEM, this code must be executed.  Since it is
3220              emitted after the call insn, sibcall optimization cannot be
3221              performed in that case.  */
3222           if (GET_CODE (target) == MEM)
3223             sibcall_failure = 1;
3224         }
3225       else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
3226         {
3227           target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
3228
3229           /* We can not support sibling calls for this case.  */
3230           sibcall_failure = 1;
3231         }
3232       else
3233         target = copy_to_reg (valreg);
3234
3235 #ifdef PROMOTE_FUNCTION_RETURN
3236       /* If we promoted this return value, make the proper SUBREG.  TARGET
3237          might be const0_rtx here, so be careful.  */
3238       if (GET_CODE (target) == REG
3239           && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
3240           && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
3241         {
3242           tree type = TREE_TYPE (exp);
3243           int unsignedp = TREE_UNSIGNED (type);
3244           int offset = 0;
3245
3246           /* If we don't promote as expected, something is wrong.  */
3247           if (GET_MODE (target)
3248               != promote_mode (type, TYPE_MODE (type), &unsignedp, 1))
3249             abort ();
3250
3251         if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3252             && GET_MODE_SIZE (GET_MODE (target))
3253                > GET_MODE_SIZE (TYPE_MODE (type)))
3254           {
3255             offset = GET_MODE_SIZE (GET_MODE (target))
3256                      - GET_MODE_SIZE (TYPE_MODE (type));
3257             if (! BYTES_BIG_ENDIAN)
3258               offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3259             else if (! WORDS_BIG_ENDIAN)
3260               offset %= UNITS_PER_WORD;
3261           }
3262           target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3263           SUBREG_PROMOTED_VAR_P (target) = 1;
3264           SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3265         }
3266 #endif
3267
3268       /* If size of args is variable or this was a constructor call for a stack
3269          argument, restore saved stack-pointer value.  */
3270
3271       if (old_stack_level && ! (flags & ECF_SP_DEPRESSED))
3272         {
3273           emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3274           stack_pointer_delta = old_stack_pointer_delta;
3275           pending_stack_adjust = old_pending_adj;
3276           stack_arg_under_construction = old_stack_arg_under_construction;
3277           highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3278           stack_usage_map = initial_stack_usage_map;
3279           sibcall_failure = 1;
3280         }
3281       else if (ACCUMULATE_OUTGOING_ARGS && pass)
3282         {
3283 #ifdef REG_PARM_STACK_SPACE
3284           if (save_area)
3285             restore_fixed_argument_area (save_area, argblock,
3286                                          high_to_save, low_to_save);
3287 #endif
3288
3289           /* If we saved any argument areas, restore them.  */
3290           for (i = 0; i < num_actuals; i++)
3291             if (args[i].save_area)
3292               {
3293                 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3294                 rtx stack_area
3295                   = gen_rtx_MEM (save_mode,
3296                                  memory_address (save_mode,
3297                                                  XEXP (args[i].stack_slot, 0)));
3298
3299                 if (save_mode != BLKmode)
3300                   emit_move_insn (stack_area, args[i].save_area);
3301                 else
3302                   emit_block_move (stack_area, args[i].save_area,
3303                                    GEN_INT (args[i].locate.size.constant),
3304                                    BLOCK_OP_CALL_PARM);
3305               }
3306
3307           highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3308           stack_usage_map = initial_stack_usage_map;
3309         }
3310
3311       /* If this was alloca, record the new stack level for nonlocal gotos.
3312          Check for the handler slots since we might not have a save area
3313          for non-local gotos.  */
3314
3315       if ((flags & ECF_MAY_BE_ALLOCA) && nonlocal_goto_handler_slots != 0)
3316         emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
3317
3318       /* Free up storage we no longer need.  */
3319       for (i = 0; i < num_actuals; ++i)
3320         if (args[i].aligned_regs)
3321           free (args[i].aligned_regs);
3322
3323       if (pass == 0)
3324         {
3325           /* Undo the fake expand_start_target_temps we did earlier.  If
3326              there had been any cleanups created, we've already set
3327              sibcall_failure.  */
3328           expand_end_target_temps ();
3329         }
3330
3331       /* If this function is returning into a memory location marked as
3332          readonly, it means it is initializing that location. We normally treat
3333          functions as not clobbering such locations, so we need to specify that
3334          this one does. We do this by adding the appropriate CLOBBER to the
3335          CALL_INSN function usage list.  This cannot be done by emitting a
3336          standalone CLOBBER after the call because the latter would be ignored
3337          by at least the delay slot scheduling pass. We do this now instead of
3338          adding to call_fusage before the call to emit_call_1 because TARGET
3339          may be modified in the meantime.  */
3340       if (structure_value_addr != 0 && target != 0
3341           && GET_CODE (target) == MEM && RTX_UNCHANGING_P (target))
3342         add_function_usage_to
3343           (last_call_insn (),
3344            gen_rtx_EXPR_LIST (VOIDmode, gen_rtx_CLOBBER (VOIDmode, target),
3345                               NULL_RTX));
3346
3347       insns = get_insns ();
3348       end_sequence ();
3349
3350       if (pass == 0)
3351         {
3352           tail_call_insns = insns;
3353
3354           /* Restore the pending stack adjustment now that we have
3355              finished generating the sibling call sequence.  */
3356
3357           pending_stack_adjust = save_pending_stack_adjust;
3358           stack_pointer_delta = save_stack_pointer_delta;
3359
3360           /* Prepare arg structure for next iteration.  */
3361           for (i = 0; i < num_actuals; i++)
3362             {
3363               args[i].value = 0;
3364               args[i].aligned_regs = 0;
3365               args[i].stack = 0;
3366             }
3367
3368           sbitmap_free (stored_args_map);
3369         }
3370       else
3371         {
3372           normal_call_insns = insns;
3373
3374           /* Verify that we've deallocated all the stack we used.  */
3375           if (! (flags & (ECF_NORETURN | ECF_LONGJMP))
3376               && old_stack_allocated != stack_pointer_delta
3377                                         - pending_stack_adjust)
3378             abort ();
3379         }
3380
3381       /* If something prevents making this a sibling call,
3382          zero out the sequence.  */
3383       if (sibcall_failure)
3384         tail_call_insns = NULL_RTX;
3385     }
3386
3387   /* The function optimize_sibling_and_tail_recursive_calls doesn't
3388      handle CALL_PLACEHOLDERs inside other CALL_PLACEHOLDERs.  This
3389      can happen if the arguments to this function call an inline
3390      function who's expansion contains another CALL_PLACEHOLDER.
3391
3392      If there are any C_Ps in any of these sequences, replace them
3393      with their normal call.  */
3394
3395   for (insn = normal_call_insns; insn; insn = NEXT_INSN (insn))
3396     if (GET_CODE (insn) == CALL_INSN
3397         && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3398       replace_call_placeholder (insn, sibcall_use_normal);
3399
3400   for (insn = tail_call_insns; insn; insn = NEXT_INSN (insn))
3401     if (GET_CODE (insn) == CALL_INSN
3402         && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3403       replace_call_placeholder (insn, sibcall_use_normal);
3404
3405   for (insn = tail_recursion_insns; insn; insn = NEXT_INSN (insn))
3406     if (GET_CODE (insn) == CALL_INSN
3407         && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3408       replace_call_placeholder (insn, sibcall_use_normal);
3409
3410   /* If this was a potential tail recursion site, then emit a
3411      CALL_PLACEHOLDER with the normal and the tail recursion streams.
3412      One of them will be selected later.  */
3413   if (tail_recursion_insns || tail_call_insns)
3414     {
3415       /* The tail recursion label must be kept around.  We could expose
3416          its use in the CALL_PLACEHOLDER, but that creates unwanted edges
3417          and makes determining true tail recursion sites difficult.
3418
3419          So we set LABEL_PRESERVE_P here, then clear it when we select
3420          one of the call sequences after rtl generation is complete.  */
3421       if (tail_recursion_insns)
3422         LABEL_PRESERVE_P (tail_recursion_label) = 1;
3423       emit_call_insn (gen_rtx_CALL_PLACEHOLDER (VOIDmode, normal_call_insns,
3424                                                 tail_call_insns,
3425                                                 tail_recursion_insns,
3426                                                 tail_recursion_label));
3427     }
3428   else
3429     emit_insn (normal_call_insns);
3430
3431   currently_expanding_call--;
3432
3433   /* If this function returns with the stack pointer depressed, ensure
3434      this block saves and restores the stack pointer, show it was
3435      changed, and adjust for any outgoing arg space.  */
3436   if (flags & ECF_SP_DEPRESSED)
3437     {
3438       clear_pending_stack_adjust ();
3439       emit_insn (gen_rtx (CLOBBER, VOIDmode, stack_pointer_rtx));
3440       emit_move_insn (virtual_stack_dynamic_rtx, stack_pointer_rtx);
3441       save_stack_pointer ();
3442     }
3443
3444   return target;
3445 }
3446
3447 /* Traverse an argument list in VALUES and expand all complex
3448    arguments into their components.  */
3449 tree
3450 split_complex_values (tree values)
3451 {
3452   tree p;
3453
3454   values = copy_list (values);
3455
3456   for (p = values; p; p = TREE_CHAIN (p))
3457     {
3458       tree complex_value = TREE_VALUE (p);
3459       tree complex_type;
3460
3461       complex_type = TREE_TYPE (complex_value);
3462       if (!complex_type)
3463         continue;
3464
3465       if (TREE_CODE (complex_type) == COMPLEX_TYPE)
3466         {
3467           tree subtype;
3468           tree real, imag, next;
3469
3470           subtype = TREE_TYPE (complex_type);
3471           complex_value = save_expr (complex_value);
3472           real = build1 (REALPART_EXPR, subtype, complex_value);
3473           imag = build1 (IMAGPART_EXPR, subtype, complex_value);
3474
3475           TREE_VALUE (p) = real;
3476           next = TREE_CHAIN (p);
3477           imag = build_tree_list (NULL_TREE, imag);
3478           TREE_CHAIN (p) = imag;
3479           TREE_CHAIN (imag) = next;
3480
3481           /* Skip the newly created node.  */
3482           p = TREE_CHAIN (p);
3483         }
3484     }
3485
3486   return values;
3487 }
3488
3489 /* Traverse a list of TYPES and expand all complex types into their
3490    components.  */
3491 tree
3492 split_complex_types (tree types)
3493 {
3494   tree p;
3495
3496   types = copy_list (types);
3497
3498   for (p = types; p; p = TREE_CHAIN (p))
3499     {
3500       tree complex_type = TREE_VALUE (p);
3501
3502       if (TREE_CODE (complex_type) == COMPLEX_TYPE)
3503         {
3504           tree next, imag;
3505
3506           /* Rewrite complex type with component type.  */
3507           TREE_VALUE (p) = TREE_TYPE (complex_type);
3508           next = TREE_CHAIN (p);
3509
3510           /* Add another component type for the imaginary part.  */
3511           imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3512           TREE_CHAIN (p) = imag;
3513           TREE_CHAIN (imag) = next;
3514
3515           /* Skip the newly created node.  */
3516           p = TREE_CHAIN (p);
3517         }
3518     }
3519
3520   return types;
3521 }
3522 \f
3523 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3524    The RETVAL parameter specifies whether return value needs to be saved, other
3525    parameters are documented in the emit_library_call function below.  */
3526
3527 static rtx
3528 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3529                            enum libcall_type fn_type,
3530                            enum machine_mode outmode, int nargs, va_list p)
3531 {
3532   /* Total size in bytes of all the stack-parms scanned so far.  */
3533   struct args_size args_size;
3534   /* Size of arguments before any adjustments (such as rounding).  */
3535   struct args_size original_args_size;
3536   int argnum;
3537   rtx fun;
3538   int inc;
3539   int count;
3540   rtx argblock = 0;
3541   CUMULATIVE_ARGS args_so_far;
3542   struct arg
3543   {
3544     rtx value;
3545     enum machine_mode mode;
3546     rtx reg;
3547     int partial;
3548     struct locate_and_pad_arg_data locate;
3549     rtx save_area;
3550   };
3551   struct arg *argvec;
3552   int old_inhibit_defer_pop = inhibit_defer_pop;
3553   rtx call_fusage = 0;
3554   rtx mem_value = 0;
3555   rtx valreg;
3556   int pcc_struct_value = 0;
3557   int struct_value_size = 0;
3558   int flags;
3559   int reg_parm_stack_space = 0;
3560   int needed;
3561   rtx before_call;
3562   tree tfom;                    /* type_for_mode (outmode, 0) */
3563
3564 #ifdef REG_PARM_STACK_SPACE
3565   /* Define the boundary of the register parm stack space that needs to be
3566      save, if any.  */
3567   int low_to_save, high_to_save;
3568   rtx save_area = 0;            /* Place that it is saved.  */
3569 #endif
3570
3571   /* Size of the stack reserved for parameter registers.  */
3572   int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3573   char *initial_stack_usage_map = stack_usage_map;
3574
3575 #ifdef REG_PARM_STACK_SPACE
3576 #ifdef MAYBE_REG_PARM_STACK_SPACE
3577   reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
3578 #else
3579   reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3580 #endif
3581 #endif
3582
3583   /* By default, library functions can not throw.  */
3584   flags = ECF_NOTHROW;
3585
3586   switch (fn_type)
3587     {
3588     case LCT_NORMAL:
3589       break;
3590     case LCT_CONST:
3591       flags |= ECF_CONST;
3592       break;
3593     case LCT_PURE:
3594       flags |= ECF_PURE;
3595       break;
3596     case LCT_CONST_MAKE_BLOCK:
3597       flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
3598       break;
3599     case LCT_PURE_MAKE_BLOCK:
3600       flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
3601       break;
3602     case LCT_NORETURN:
3603       flags |= ECF_NORETURN;
3604       break;
3605     case LCT_THROW:
3606       flags = ECF_NORETURN;
3607       break;
3608     case LCT_ALWAYS_RETURN:
3609       flags = ECF_ALWAYS_RETURN;
3610       break;
3611     case LCT_RETURNS_TWICE:
3612       flags = ECF_RETURNS_TWICE;
3613       break;
3614     }
3615   fun = orgfun;
3616
3617   /* Ensure current function's preferred stack boundary is at least
3618      what we need.  */
3619   if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3620     cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3621
3622   /* If this kind of value comes back in memory,
3623      decide where in memory it should come back.  */
3624   if (outmode != VOIDmode)
3625     {
3626       tfom = (*lang_hooks.types.type_for_mode) (outmode, 0);
3627       if (aggregate_value_p (tfom))
3628         {
3629 #ifdef PCC_STATIC_STRUCT_RETURN
3630           rtx pointer_reg
3631             = hard_function_value (build_pointer_type (tfom), 0, 0);
3632           mem_value = gen_rtx_MEM (outmode, pointer_reg);
3633           pcc_struct_value = 1;
3634           if (value == 0)
3635             value = gen_reg_rtx (outmode);
3636 #else /* not PCC_STATIC_STRUCT_RETURN */
3637           struct_value_size = GET_MODE_SIZE (outmode);
3638           if (value != 0 && GET_CODE (value) == MEM)
3639             mem_value = value;
3640           else
3641             mem_value = assign_temp (tfom, 0, 1, 1);
3642 #endif
3643           /* This call returns a big structure.  */
3644           flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3645         }
3646     }
3647   else
3648     tfom = void_type_node;
3649
3650   /* ??? Unfinished: must pass the memory address as an argument.  */
3651
3652   /* Copy all the libcall-arguments out of the varargs data
3653      and into a vector ARGVEC.
3654
3655      Compute how to pass each argument.  We only support a very small subset
3656      of the full argument passing conventions to limit complexity here since
3657      library functions shouldn't have many args.  */
3658
3659   argvec = alloca ((nargs + 1) * sizeof (struct arg));
3660   memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3661
3662 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3663   INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3664 #else
3665   INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0);
3666 #endif
3667
3668   args_size.constant = 0;
3669   args_size.var = 0;
3670
3671   count = 0;
3672
3673   /* Now we are about to start emitting insns that can be deleted
3674      if a libcall is deleted.  */
3675   if (flags & ECF_LIBCALL_BLOCK)
3676     start_sequence ();
3677
3678   push_temp_slots ();
3679
3680   /* If there's a structure value address to be passed,
3681      either pass it in the special place, or pass it as an extra argument.  */
3682   if (mem_value && struct_value_rtx == 0 && ! pcc_struct_value)
3683     {
3684       rtx addr = XEXP (mem_value, 0);
3685       nargs++;
3686
3687       /* Make sure it is a reasonable operand for a move or push insn.  */
3688       if (GET_CODE (addr) != REG && GET_CODE (addr) != MEM
3689           && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3690         addr = force_operand (addr, NULL_RTX);
3691
3692       argvec[count].value = addr;
3693       argvec[count].mode = Pmode;
3694       argvec[count].partial = 0;
3695
3696       argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3697 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3698       if (FUNCTION_ARG_PARTIAL_NREGS (args_so_far, Pmode, NULL_TREE, 1))
3699         abort ();
3700 #endif
3701
3702       locate_and_pad_parm (Pmode, NULL_TREE,
3703 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3704                            1,
3705 #else
3706                            argvec[count].reg != 0,
3707 #endif
3708                            0, NULL_TREE, &args_size, &argvec[count].locate);
3709
3710       if (argvec[count].reg == 0 || argvec[count].partial != 0
3711           || reg_parm_stack_space > 0)
3712         args_size.constant += argvec[count].locate.size.constant;
3713
3714       FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3715
3716       count++;
3717     }
3718
3719   for (; count < nargs; count++)
3720     {
3721       rtx val = va_arg (p, rtx);
3722       enum machine_mode mode = va_arg (p, enum machine_mode);
3723
3724       /* We cannot convert the arg value to the mode the library wants here;
3725          must do it earlier where we know the signedness of the arg.  */
3726       if (mode == BLKmode
3727           || (GET_MODE (val) != mode && GET_MODE (val) != VOIDmode))
3728         abort ();
3729
3730       /* On some machines, there's no way to pass a float to a library fcn.
3731          Pass it as a double instead.  */
3732 #ifdef LIBGCC_NEEDS_DOUBLE
3733       if (LIBGCC_NEEDS_DOUBLE && mode == SFmode)
3734         val = convert_modes (DFmode, SFmode, val, 0), mode = DFmode;
3735 #endif
3736
3737       /* There's no need to call protect_from_queue, because
3738          either emit_move_insn or emit_push_insn will do that.  */
3739
3740       /* Make sure it is a reasonable operand for a move or push insn.  */
3741       if (GET_CODE (val) != REG && GET_CODE (val) != MEM
3742           && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3743         val = force_operand (val, NULL_RTX);
3744
3745 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
3746       if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, mode, NULL_TREE, 1))
3747         {
3748           rtx slot;
3749           int must_copy = 1
3750 #ifdef FUNCTION_ARG_CALLEE_COPIES
3751             && ! FUNCTION_ARG_CALLEE_COPIES (args_so_far, mode,
3752                                              NULL_TREE, 1)
3753 #endif
3754             ;
3755
3756           /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure
3757              functions, so we have to pretend this isn't such a function.  */
3758           if (flags & ECF_LIBCALL_BLOCK)
3759             {
3760               rtx insns = get_insns ();
3761               end_sequence ();
3762               emit_insn (insns);
3763             }
3764           flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3765
3766           /* If this was a CONST function, it is now PURE since
3767              it now reads memory.  */
3768           if (flags & ECF_CONST)
3769             {
3770               flags &= ~ECF_CONST;
3771               flags |= ECF_PURE;
3772             }
3773
3774           if (GET_MODE (val) == MEM && ! must_copy)
3775             slot = val;
3776           else if (must_copy)
3777             {
3778               slot = assign_temp ((*lang_hooks.types.type_for_mode) (mode, 0),
3779                                   0, 1, 1);
3780               emit_move_insn (slot, val);
3781             }
3782           else
3783             {
3784               tree type = (*lang_hooks.types.type_for_mode) (mode, 0);
3785
3786               slot
3787                 = gen_rtx_MEM (mode,
3788                                expand_expr (build1 (ADDR_EXPR,
3789                                                     build_pointer_type (type),
3790                                                     make_tree (type, val)),
3791                                             NULL_RTX, VOIDmode, 0));
3792             }
3793
3794           call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3795                                            gen_rtx_USE (VOIDmode, slot),
3796                                            call_fusage);
3797           if (must_copy)
3798             call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3799                                              gen_rtx_CLOBBER (VOIDmode,
3800                                                               slot),
3801                                              call_fusage);
3802
3803           mode = Pmode;
3804           val = force_operand (XEXP (slot, 0), NULL_RTX);
3805         }
3806 #endif
3807
3808       argvec[count].value = val;
3809       argvec[count].mode = mode;
3810
3811       argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3812
3813 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3814       argvec[count].partial
3815         = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode, NULL_TREE, 1);
3816 #else
3817       argvec[count].partial = 0;
3818 #endif
3819
3820       locate_and_pad_parm (mode, NULL_TREE,
3821 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3822                            1,
3823 #else
3824                            argvec[count].reg != 0,
3825 #endif
3826                            argvec[count].partial,
3827                            NULL_TREE, &args_size, &argvec[count].locate);
3828
3829       if (argvec[count].locate.size.var)
3830         abort ();
3831
3832       if (argvec[count].reg == 0 || argvec[count].partial != 0
3833           || reg_parm_stack_space > 0)
3834         args_size.constant += argvec[count].locate.size.constant;
3835
3836       FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3837     }
3838
3839 #ifdef FINAL_REG_PARM_STACK_SPACE
3840   reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
3841                                                      args_size.var);
3842 #endif
3843   /* If this machine requires an external definition for library
3844      functions, write one out.  */
3845   assemble_external_libcall (fun);
3846
3847   original_args_size = args_size;
3848   args_size.constant = (((args_size.constant
3849                           + stack_pointer_delta
3850                           + STACK_BYTES - 1)
3851                           / STACK_BYTES
3852                           * STACK_BYTES)
3853                          - stack_pointer_delta);
3854
3855   args_size.constant = MAX (args_size.constant,
3856                             reg_parm_stack_space);
3857
3858 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3859   args_size.constant -= reg_parm_stack_space;
3860 #endif
3861
3862   if (args_size.constant > current_function_outgoing_args_size)
3863     current_function_outgoing_args_size = args_size.constant;
3864
3865   if (ACCUMULATE_OUTGOING_ARGS)
3866     {
3867       /* Since the stack pointer will never be pushed, it is possible for
3868          the evaluation of a parm to clobber something we have already
3869          written to the stack.  Since most function calls on RISC machines
3870          do not use the stack, this is uncommon, but must work correctly.
3871
3872          Therefore, we save any area of the stack that was already written
3873          and that we are using.  Here we set up to do this by making a new
3874          stack usage map from the old one.
3875
3876          Another approach might be to try to reorder the argument
3877          evaluations to avoid this conflicting stack usage.  */
3878
3879       needed = args_size.constant;
3880
3881 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3882       /* Since we will be writing into the entire argument area, the
3883          map must be allocated for its entire size, not just the part that
3884          is the responsibility of the caller.  */
3885       needed += reg_parm_stack_space;
3886 #endif
3887
3888 #ifdef ARGS_GROW_DOWNWARD
3889       highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3890                                          needed + 1);
3891 #else
3892       highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3893                                          needed);
3894 #endif
3895       stack_usage_map = alloca (highest_outgoing_arg_in_use);
3896
3897       if (initial_highest_arg_in_use)
3898         memcpy (stack_usage_map, initial_stack_usage_map,
3899                 initial_highest_arg_in_use);
3900
3901       if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3902         memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3903                highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3904       needed = 0;
3905
3906       /* We must be careful to use virtual regs before they're instantiated,
3907          and real regs afterwards.  Loop optimization, for example, can create
3908          new libcalls after we've instantiated the virtual regs, and if we
3909          use virtuals anyway, they won't match the rtl patterns.  */
3910
3911       if (virtuals_instantiated)
3912         argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3913       else
3914         argblock = virtual_outgoing_args_rtx;
3915     }
3916   else
3917     {
3918       if (!PUSH_ARGS)
3919         argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3920     }
3921
3922   /* If we push args individually in reverse order, perform stack alignment
3923      before the first push (the last arg).  */
3924   if (argblock == 0 && PUSH_ARGS_REVERSED)
3925     anti_adjust_stack (GEN_INT (args_size.constant
3926                                 - original_args_size.constant));
3927
3928   if (PUSH_ARGS_REVERSED)
3929     {
3930       inc = -1;
3931       argnum = nargs - 1;
3932     }
3933   else
3934     {
3935       inc = 1;
3936       argnum = 0;
3937     }
3938
3939 #ifdef REG_PARM_STACK_SPACE
3940   if (ACCUMULATE_OUTGOING_ARGS)
3941     {
3942       /* The argument list is the property of the called routine and it
3943          may clobber it.  If the fixed area has been used for previous
3944          parameters, we must save and restore it.  */
3945       save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3946                                             &low_to_save, &high_to_save);
3947     }
3948 #endif
3949
3950   /* Push the args that need to be pushed.  */
3951
3952   /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3953      are to be pushed.  */
3954   for (count = 0; count < nargs; count++, argnum += inc)
3955     {
3956       enum machine_mode mode = argvec[argnum].mode;
3957       rtx val = argvec[argnum].value;
3958       rtx reg = argvec[argnum].reg;
3959       int partial = argvec[argnum].partial;
3960       int lower_bound = 0, upper_bound = 0, i;
3961
3962       if (! (reg != 0 && partial == 0))
3963         {
3964           if (ACCUMULATE_OUTGOING_ARGS)
3965             {
3966               /* If this is being stored into a pre-allocated, fixed-size,
3967                  stack area, save any previous data at that location.  */
3968
3969 #ifdef ARGS_GROW_DOWNWARD
3970               /* stack_slot is negative, but we want to index stack_usage_map
3971                  with positive values.  */
3972               upper_bound = -argvec[argnum].locate.offset.constant + 1;
3973               lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3974 #else
3975               lower_bound = argvec[argnum].locate.offset.constant;
3976               upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3977 #endif
3978
3979               i = lower_bound;
3980               /* Don't worry about things in the fixed argument area;
3981                  it has already been saved.  */
3982               if (i < reg_parm_stack_space)
3983                 i = reg_parm_stack_space;
3984               while (i < upper_bound && stack_usage_map[i] == 0)
3985                 i++;
3986
3987               if (i < upper_bound)
3988                 {
3989                   /* We need to make a save area.  */
3990                   unsigned int size
3991                     = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
3992                   enum machine_mode save_mode
3993                     = mode_for_size (size, MODE_INT, 1);
3994                   rtx adr
3995                     = plus_constant (argblock,
3996                                      argvec[argnum].locate.offset.constant);
3997                   rtx stack_area
3998                     = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
3999                   argvec[argnum].save_area = gen_reg_rtx (save_mode);
4000
4001                   emit_move_insn (argvec[argnum].save_area, stack_area);
4002                 }
4003             }
4004
4005           emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
4006                           partial, reg, 0, argblock,
4007                           GEN_INT (argvec[argnum].locate.offset.constant),
4008                           reg_parm_stack_space,
4009                           ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
4010
4011           /* Now mark the segment we just used.  */
4012           if (ACCUMULATE_OUTGOING_ARGS)
4013             for (i = lower_bound; i < upper_bound; i++)
4014               stack_usage_map[i] = 1;
4015
4016           NO_DEFER_POP;
4017         }
4018     }
4019
4020   /* If we pushed args in forward order, perform stack alignment
4021      after pushing the last arg.  */
4022   if (argblock == 0 && !PUSH_ARGS_REVERSED)
4023     anti_adjust_stack (GEN_INT (args_size.constant
4024                                 - original_args_size.constant));
4025
4026   if (PUSH_ARGS_REVERSED)
4027     argnum = nargs - 1;
4028   else
4029     argnum = 0;
4030
4031   fun = prepare_call_address (fun, NULL_TREE, &call_fusage, 0, 0);
4032
4033   /* Now load any reg parms into their regs.  */
4034
4035   /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4036      are to be pushed.  */
4037   for (count = 0; count < nargs; count++, argnum += inc)
4038     {
4039       rtx val = argvec[argnum].value;
4040       rtx reg = argvec[argnum].reg;
4041       int partial = argvec[argnum].partial;
4042
4043       /* Handle calls that pass values in multiple non-contiguous
4044          locations.  The PA64 has examples of this for library calls.  */
4045       if (reg != 0 && GET_CODE (reg) == PARALLEL)
4046         emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (GET_MODE (val)));
4047       else if (reg != 0 && partial == 0)
4048         emit_move_insn (reg, val);
4049
4050       NO_DEFER_POP;
4051     }
4052
4053   /* Any regs containing parms remain in use through the call.  */
4054   for (count = 0; count < nargs; count++)
4055     {
4056       rtx reg = argvec[count].reg;
4057       if (reg != 0 && GET_CODE (reg) == PARALLEL)
4058         use_group_regs (&call_fusage, reg);
4059       else if (reg != 0)
4060         use_reg (&call_fusage, reg);
4061     }
4062
4063   /* Pass the function the address in which to return a structure value.  */
4064   if (mem_value != 0 && struct_value_rtx != 0 && ! pcc_struct_value)
4065     {
4066       emit_move_insn (struct_value_rtx,
4067                       force_reg (Pmode,
4068                                  force_operand (XEXP (mem_value, 0),
4069                                                 NULL_RTX)));
4070       if (GET_CODE (struct_value_rtx) == REG)
4071         use_reg (&call_fusage, struct_value_rtx);
4072     }
4073
4074   /* Don't allow popping to be deferred, since then
4075      cse'ing of library calls could delete a call and leave the pop.  */
4076   NO_DEFER_POP;
4077   valreg = (mem_value == 0 && outmode != VOIDmode
4078             ? hard_libcall_value (outmode) : NULL_RTX);
4079
4080   /* Stack must be properly aligned now.  */
4081   if (stack_pointer_delta & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1))
4082     abort ();
4083
4084   before_call = get_last_insn ();
4085
4086   /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
4087      will set inhibit_defer_pop to that value.  */
4088   /* The return type is needed to decide how many bytes the function pops.
4089      Signedness plays no role in that, so for simplicity, we pretend it's
4090      always signed.  We also assume that the list of arguments passed has
4091      no impact, so we pretend it is unknown.  */
4092
4093   emit_call_1 (fun,
4094                get_identifier (XSTR (orgfun, 0)),
4095                build_function_type (tfom, NULL_TREE),
4096                original_args_size.constant, args_size.constant,
4097                struct_value_size,
4098                FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
4099                valreg,
4100                old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
4101
4102   /* For calls to `setjmp', etc., inform flow.c it should complain
4103      if nonvolatile values are live.  For functions that cannot return,
4104      inform flow that control does not fall through.  */
4105
4106   if (flags & (ECF_NORETURN | ECF_LONGJMP))
4107     {
4108       /* The barrier note must be emitted
4109          immediately after the CALL_INSN.  Some ports emit more than
4110          just a CALL_INSN above, so we must search for it here.  */
4111
4112       rtx last = get_last_insn ();
4113       while (GET_CODE (last) != CALL_INSN)
4114         {
4115           last = PREV_INSN (last);
4116           /* There was no CALL_INSN?  */
4117           if (last == before_call)
4118             abort ();
4119         }
4120
4121       emit_barrier_after (last);
4122     }
4123
4124   /* Now restore inhibit_defer_pop to its actual original value.  */
4125   OK_DEFER_POP;
4126
4127   /* If call is cse'able, make appropriate pair of reg-notes around it.
4128      Test valreg so we don't crash; may safely ignore `const'
4129      if return type is void.  Disable for PARALLEL return values, because
4130      we have no way to move such values into a pseudo register.  */
4131   if (flags & ECF_LIBCALL_BLOCK)
4132     {
4133       rtx insns;
4134
4135       if (valreg == 0)
4136         {
4137           insns = get_insns ();
4138           end_sequence ();
4139           emit_insn (insns);
4140         }
4141       else
4142         {
4143           rtx note = 0;
4144           rtx temp;
4145           int i;
4146
4147           if (GET_CODE (valreg) == PARALLEL)
4148             {
4149               temp = gen_reg_rtx (outmode);
4150               emit_group_store (temp, valreg, NULL_TREE, outmode);
4151               valreg = temp;
4152             }
4153
4154           temp = gen_reg_rtx (GET_MODE (valreg));
4155
4156           /* Construct an "equal form" for the value which mentions all the
4157              arguments in order as well as the function name.  */
4158           for (i = 0; i < nargs; i++)
4159             note = gen_rtx_EXPR_LIST (VOIDmode, argvec[i].value, note);
4160           note = gen_rtx_EXPR_LIST (VOIDmode, fun, note);
4161
4162           insns = get_insns ();
4163           end_sequence ();
4164
4165           if (flags & ECF_PURE)
4166             note = gen_rtx_EXPR_LIST (VOIDmode,
4167                         gen_rtx_USE (VOIDmode,
4168                                      gen_rtx_MEM (BLKmode,
4169                                                   gen_rtx_SCRATCH (VOIDmode))),
4170                         note);
4171
4172           emit_libcall_block (insns, temp, valreg, note);
4173
4174           valreg = temp;
4175         }
4176     }
4177   pop_temp_slots ();
4178
4179   /* Copy the value to the right place.  */
4180   if (outmode != VOIDmode && retval)
4181     {
4182       if (mem_value)
4183         {
4184           if (value == 0)
4185             value = mem_value;
4186           if (value != mem_value)
4187             emit_move_insn (value, mem_value);
4188         }
4189       else if (GET_CODE (valreg) == PARALLEL)
4190         {
4191           if (value == 0)
4192             value = gen_reg_rtx (outmode);
4193           emit_group_store (value, valreg, NULL_TREE, outmode);
4194         }
4195       else if (value != 0)
4196         emit_move_insn (value, valreg);
4197       else
4198         value = valreg;
4199     }
4200
4201   if (ACCUMULATE_OUTGOING_ARGS)
4202     {
4203 #ifdef REG_PARM_STACK_SPACE
4204       if (save_area)
4205         restore_fixed_argument_area (save_area, argblock,
4206                                      high_to_save, low_to_save);
4207 #endif
4208
4209       /* If we saved any argument areas, restore them.  */
4210       for (count = 0; count < nargs; count++)
4211         if (argvec[count].save_area)
4212           {
4213             enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
4214             rtx adr = plus_constant (argblock,
4215                                      argvec[count].locate.offset.constant);
4216             rtx stack_area = gen_rtx_MEM (save_mode,
4217                                           memory_address (save_mode, adr));
4218
4219             emit_move_insn (stack_area, argvec[count].save_area);
4220           }
4221
4222       highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4223       stack_usage_map = initial_stack_usage_map;
4224     }
4225
4226   return value;
4227
4228 }
4229 \f
4230 /* Output a library call to function FUN (a SYMBOL_REF rtx)
4231    (emitting the queue unless NO_QUEUE is nonzero),
4232    for a value of mode OUTMODE,
4233    with NARGS different arguments, passed as alternating rtx values
4234    and machine_modes to convert them to.
4235    The rtx values should have been passed through protect_from_queue already.
4236
4237    FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const'
4238    calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls
4239    which should be enclosed in REG_LIBCALL/REG_RETVAL notes,
4240    LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in
4241    REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)),
4242    or other LCT_ value for other types of library calls.  */
4243
4244 void
4245 emit_library_call (rtx orgfun, enum libcall_type fn_type,
4246                    enum machine_mode outmode, int nargs, ...)
4247 {
4248   va_list p;
4249
4250   va_start (p, nargs);
4251   emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
4252   va_end (p);
4253 }
4254 \f
4255 /* Like emit_library_call except that an extra argument, VALUE,
4256    comes second and says where to store the result.
4257    (If VALUE is zero, this function chooses a convenient way
4258    to return the value.
4259
4260    This function returns an rtx for where the value is to be found.
4261    If VALUE is nonzero, VALUE is returned.  */
4262
4263 rtx
4264 emit_library_call_value (rtx orgfun, rtx value,
4265                          enum libcall_type fn_type,
4266                          enum machine_mode outmode, int nargs, ...)
4267 {
4268   rtx result;
4269   va_list p;
4270
4271   va_start (p, nargs);
4272   result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
4273                                       nargs, p);
4274   va_end (p);
4275
4276   return result;
4277 }
4278 \f
4279 /* Store a single argument for a function call
4280    into the register or memory area where it must be passed.
4281    *ARG describes the argument value and where to pass it.
4282
4283    ARGBLOCK is the address of the stack-block for all the arguments,
4284    or 0 on a machine where arguments are pushed individually.
4285
4286    MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4287    so must be careful about how the stack is used.
4288
4289    VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4290    argument stack.  This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4291    that we need not worry about saving and restoring the stack.
4292
4293    FNDECL is the declaration of the function we are calling.
4294
4295    Return nonzero if this arg should cause sibcall failure,
4296    zero otherwise.  */
4297
4298 static int
4299 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
4300                int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
4301 {
4302   tree pval = arg->tree_value;
4303   rtx reg = 0;
4304   int partial = 0;
4305   int used = 0;
4306   int i, lower_bound = 0, upper_bound = 0;
4307   int sibcall_failure = 0;
4308
4309   if (TREE_CODE (pval) == ERROR_MARK)
4310     return 1;
4311
4312   /* Push a new temporary level for any temporaries we make for
4313      this argument.  */
4314   push_temp_slots ();
4315
4316   if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4317     {
4318       /* If this is being stored into a pre-allocated, fixed-size, stack area,
4319          save any previous data at that location.  */
4320       if (argblock && ! variable_size && arg->stack)
4321         {
4322 #ifdef ARGS_GROW_DOWNWARD
4323           /* stack_slot is negative, but we want to index stack_usage_map
4324              with positive values.  */
4325           if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4326             upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4327           else
4328             upper_bound = 0;
4329
4330           lower_bound = upper_bound - arg->locate.size.constant;
4331 #else
4332           if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4333             lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4334           else
4335             lower_bound = 0;
4336
4337           upper_bound = lower_bound + arg->locate.size.constant;
4338 #endif
4339
4340           i = lower_bound;
4341           /* Don't worry about things in the fixed argument area;
4342              it has already been saved.  */
4343           if (i < reg_parm_stack_space)
4344             i = reg_parm_stack_space;
4345           while (i < upper_bound && stack_usage_map[i] == 0)
4346             i++;
4347
4348           if (i < upper_bound)
4349             {
4350               /* We need to make a save area.  */
4351               unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4352               enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4353               rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4354               rtx stack_area = gen_rtx_MEM (save_mode, adr);
4355
4356               if (save_mode == BLKmode)
4357                 {
4358                   tree ot = TREE_TYPE (arg->tree_value);
4359                   tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4360                                                        | TYPE_QUAL_CONST));
4361
4362                   arg->save_area = assign_temp (nt, 0, 1, 1);
4363                   preserve_temp_slots (arg->save_area);
4364                   emit_block_move (validize_mem (arg->save_area), stack_area,
4365                                    expr_size (arg->tree_value),
4366                                    BLOCK_OP_CALL_PARM);
4367                 }
4368               else
4369                 {
4370                   arg->save_area = gen_reg_rtx (save_mode);
4371                   emit_move_insn (arg->save_area, stack_area);
4372                 }
4373             }
4374         }
4375     }
4376
4377   /* If this isn't going to be placed on both the stack and in registers,
4378      set up the register and number of words.  */
4379   if (! arg->pass_on_stack)
4380     {
4381       if (flags & ECF_SIBCALL)
4382         reg = arg->tail_call_reg;
4383       else
4384         reg = arg->reg;
4385       partial = arg->partial;
4386     }
4387
4388   if (reg != 0 && partial == 0)
4389     /* Being passed entirely in a register.  We shouldn't be called in
4390        this case.  */
4391     abort ();
4392
4393   /* If this arg needs special alignment, don't load the registers
4394      here.  */
4395   if (arg->n_aligned_regs != 0)
4396     reg = 0;
4397
4398   /* If this is being passed partially in a register, we can't evaluate
4399      it directly into its stack slot.  Otherwise, we can.  */
4400   if (arg->value == 0)
4401     {
4402       /* stack_arg_under_construction is nonzero if a function argument is
4403          being evaluated directly into the outgoing argument list and
4404          expand_call must take special action to preserve the argument list
4405          if it is called recursively.
4406
4407          For scalar function arguments stack_usage_map is sufficient to
4408          determine which stack slots must be saved and restored.  Scalar
4409          arguments in general have pass_on_stack == 0.
4410
4411          If this argument is initialized by a function which takes the
4412          address of the argument (a C++ constructor or a C function
4413          returning a BLKmode structure), then stack_usage_map is
4414          insufficient and expand_call must push the stack around the
4415          function call.  Such arguments have pass_on_stack == 1.
4416
4417          Note that it is always safe to set stack_arg_under_construction,
4418          but this generates suboptimal code if set when not needed.  */
4419
4420       if (arg->pass_on_stack)
4421         stack_arg_under_construction++;
4422
4423       arg->value = expand_expr (pval,
4424                                 (partial
4425                                  || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4426                                 ? NULL_RTX : arg->stack,
4427                                 VOIDmode, EXPAND_STACK_PARM);
4428
4429       /* If we are promoting object (or for any other reason) the mode
4430          doesn't agree, convert the mode.  */
4431
4432       if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4433         arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4434                                     arg->value, arg->unsignedp);
4435
4436       if (arg->pass_on_stack)
4437         stack_arg_under_construction--;
4438     }
4439
4440   /* Don't allow anything left on stack from computation
4441      of argument to alloca.  */
4442   if (flags & ECF_MAY_BE_ALLOCA)
4443     do_pending_stack_adjust ();
4444
4445   if (arg->value == arg->stack)
4446     /* If the value is already in the stack slot, we are done.  */
4447     ;
4448   else if (arg->mode != BLKmode)
4449     {
4450       int size;
4451
4452       /* Argument is a scalar, not entirely passed in registers.
4453          (If part is passed in registers, arg->partial says how much
4454          and emit_push_insn will take care of putting it there.)
4455
4456          Push it, and if its size is less than the
4457          amount of space allocated to it,
4458          also bump stack pointer by the additional space.
4459          Note that in C the default argument promotions
4460          will prevent such mismatches.  */
4461
4462       size = GET_MODE_SIZE (arg->mode);
4463       /* Compute how much space the push instruction will push.
4464          On many machines, pushing a byte will advance the stack
4465          pointer by a halfword.  */
4466 #ifdef PUSH_ROUNDING
4467       size = PUSH_ROUNDING (size);
4468 #endif
4469       used = size;
4470
4471       /* Compute how much space the argument should get:
4472          round up to a multiple of the alignment for arguments.  */
4473       if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4474         used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4475                  / (PARM_BOUNDARY / BITS_PER_UNIT))
4476                 * (PARM_BOUNDARY / BITS_PER_UNIT));
4477
4478       /* This isn't already where we want it on the stack, so put it there.
4479          This can either be done with push or copy insns.  */
4480       emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4481                       PARM_BOUNDARY, partial, reg, used - size, argblock,
4482                       ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4483                       ARGS_SIZE_RTX (arg->locate.alignment_pad));
4484
4485       /* Unless this is a partially-in-register argument, the argument is now
4486          in the stack.  */
4487       if (partial == 0)
4488         arg->value = arg->stack;
4489     }
4490   else
4491     {
4492       /* BLKmode, at least partly to be pushed.  */
4493
4494       unsigned int parm_align;
4495       int excess;
4496       rtx size_rtx;
4497
4498       /* Pushing a nonscalar.
4499          If part is passed in registers, PARTIAL says how much
4500          and emit_push_insn will take care of putting it there.  */
4501
4502       /* Round its size up to a multiple
4503          of the allocation unit for arguments.  */
4504
4505       if (arg->locate.size.var != 0)
4506         {
4507           excess = 0;
4508           size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4509         }
4510       else
4511         {
4512           /* PUSH_ROUNDING has no effect on us, because
4513              emit_push_insn for BLKmode is careful to avoid it.  */
4514           excess = (arg->locate.size.constant
4515                     - int_size_in_bytes (TREE_TYPE (pval))
4516                     + partial * UNITS_PER_WORD);
4517           size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4518                                   NULL_RTX, TYPE_MODE (sizetype), 0);
4519         }
4520
4521       /* Some types will require stricter alignment, which will be
4522          provided for elsewhere in argument layout.  */
4523       parm_align = MAX (PARM_BOUNDARY, TYPE_ALIGN (TREE_TYPE (pval)));
4524
4525       /* When an argument is padded down, the block is aligned to
4526          PARM_BOUNDARY, but the actual argument isn't.  */
4527       if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4528         {
4529           if (arg->locate.size.var)
4530             parm_align = BITS_PER_UNIT;
4531           else if (excess)
4532             {
4533               unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4534               parm_align = MIN (parm_align, excess_align);
4535             }
4536         }
4537
4538       if ((flags & ECF_SIBCALL) && GET_CODE (arg->value) == MEM)
4539         {
4540           /* emit_push_insn might not work properly if arg->value and
4541              argblock + arg->locate.offset areas overlap.  */
4542           rtx x = arg->value;
4543           int i = 0;
4544
4545           if (XEXP (x, 0) == current_function_internal_arg_pointer
4546               || (GET_CODE (XEXP (x, 0)) == PLUS
4547                   && XEXP (XEXP (x, 0), 0) ==
4548                      current_function_internal_arg_pointer
4549                   && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4550             {
4551               if (XEXP (x, 0) != current_function_internal_arg_pointer)
4552                 i = INTVAL (XEXP (XEXP (x, 0), 1));
4553
4554               /* expand_call should ensure this */
4555               if (arg->locate.offset.var || GET_CODE (size_rtx) != CONST_INT)
4556                 abort ();
4557
4558               if (arg->locate.offset.constant > i)
4559                 {
4560                   if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4561                     sibcall_failure = 1;
4562                 }
4563               else if (arg->locate.offset.constant < i)
4564                 {
4565                   if (i < arg->locate.offset.constant + INTVAL (size_rtx))
4566                     sibcall_failure = 1;
4567                 }
4568             }
4569         }
4570
4571       emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4572                       parm_align, partial, reg, excess, argblock,
4573                       ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4574                       ARGS_SIZE_RTX (arg->locate.alignment_pad));
4575
4576       /* Unless this is a partially-in-register argument, the argument is now
4577          in the stack.
4578
4579          ??? Unlike the case above, in which we want the actual
4580          address of the data, so that we can load it directly into a
4581          register, here we want the address of the stack slot, so that
4582          it's properly aligned for word-by-word copying or something
4583          like that.  It's not clear that this is always correct.  */
4584       if (partial == 0)
4585         arg->value = arg->stack_slot;
4586     }
4587
4588   /* Mark all slots this store used.  */
4589   if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4590       && argblock && ! variable_size && arg->stack)
4591     for (i = lower_bound; i < upper_bound; i++)
4592       stack_usage_map[i] = 1;
4593
4594   /* Once we have pushed something, pops can't safely
4595      be deferred during the rest of the arguments.  */
4596   NO_DEFER_POP;
4597
4598   /* ANSI doesn't require a sequence point here,
4599      but PCC has one, so this will avoid some problems.  */
4600   emit_queue ();
4601
4602   /* Free any temporary slots made in processing this argument.  Show
4603      that we might have taken the address of something and pushed that
4604      as an operand.  */
4605   preserve_temp_slots (NULL_RTX);
4606   free_temp_slots ();
4607   pop_temp_slots ();
4608
4609   return sibcall_failure;
4610 }
4611
4612 /* Nonzero if we do not know how to pass TYPE solely in registers.
4613    We cannot do so in the following cases:
4614
4615    - if the type has variable size
4616    - if the type is marked as addressable (it is required to be constructed
4617      into the stack)
4618    - if the padding and mode of the type is such that a copy into a register
4619      would put it into the wrong part of the register.
4620
4621    Which padding can't be supported depends on the byte endianness.
4622
4623    A value in a register is implicitly padded at the most significant end.
4624    On a big-endian machine, that is the lower end in memory.
4625    So a value padded in memory at the upper end can't go in a register.
4626    For a little-endian machine, the reverse is true.  */
4627
4628 bool
4629 default_must_pass_in_stack (enum machine_mode mode, tree type)
4630 {
4631   if (!type)
4632     return false;
4633
4634   /* If the type has variable size...  */
4635   if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4636     return true;
4637
4638   /* If the type is marked as addressable (it is required
4639      to be constructed into the stack)...  */
4640   if (TREE_ADDRESSABLE (type))
4641     return true;
4642
4643   /* If the padding and mode of the type is such that a copy into
4644      a register would put it into the wrong part of the register.  */
4645   if (mode == BLKmode
4646       && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4647       && (FUNCTION_ARG_PADDING (mode, type)
4648           == (BYTES_BIG_ENDIAN ? upward : downward)))
4649     return true;
4650
4651   return false;
4652 }