gcc/expr.h

   1 /* Definitions for code generation pass of GNU compiler.
   2    Copyright (C) 1987, 1991, 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 /* The default branch cost is 1.  */
  23 #ifndef BRANCH_COST
  24 #define BRANCH_COST 1
  25 #endif
  26
  27 /* Macros to access the slots of a QUEUED rtx.
  28    Here rather than in rtl.h because only the expansion pass
  29    should ever encounter a QUEUED.  */
  30
  31 /* The variable for which an increment is queued.  */
  32 #define QUEUED_VAR(P) XEXP (P, 0)
  33 /* If the increment has been emitted, this is the insn
  34    that does the increment.  It is zero before the increment is emitted.
  35    If more than one insn is emitted, this is the first insn.  */
  36 #define QUEUED_INSN(P) XEXP (P, 1)
  37 /* If a pre-increment copy has been generated, this is the copy
  38    (it is a temporary reg).  Zero if no copy made yet.  */
  39 #define QUEUED_COPY(P) XEXP (P, 2)
  40 /* This is the body to use for the insn to do the increment.
  41    It is used to emit the increment.  */
  42 #define QUEUED_BODY(P) XEXP (P, 3)
  43 /* Next QUEUED in the queue.  */
  44 #define QUEUED_NEXT(P) XEXP (P, 4)
  45
  46 /* This is the 4th arg to `expand_expr'.
  47    EXPAND_STACK_PARM means we are possibly expanding a call param onto
  48    the stack.  Choosing a value of 2 isn't special;  It just allows
  49    some code optimization in store_expr.
  50    EXPAND_SUM means it is ok to return a PLUS rtx or MULT rtx.
  51    EXPAND_INITIALIZER is similar but also record any labels on forced_labels.
  52    EXPAND_CONST_ADDRESS means it is ok to return a MEM whose address
  53     is a constant that is not a legitimate address.
  54    EXPAND_WRITE means we are only going to write to the resulting rtx.  */
  55 enum expand_modifier {EXPAND_NORMAL = 0, EXPAND_STACK_PARM = 2, EXPAND_SUM,
  56                       EXPAND_CONST_ADDRESS, EXPAND_INITIALIZER, EXPAND_WRITE};
  57
  58 /* Prevent the compiler from deferring stack pops.  See
  59    inhibit_defer_pop for more information.  */
  60 #define NO_DEFER_POP (inhibit_defer_pop += 1)
  61
  62 /* Allow the compiler to defer stack pops.  See inhibit_defer_pop for
  63    more information.  */
  64 #define OK_DEFER_POP (inhibit_defer_pop -= 1)
  65 \f
  66 enum direction {none, upward, downward};
  67
  68 #ifdef TREE_CODE /* Don't lose if tree.h not included.  */
  69 /* Structure to record the size of a sequence of arguments
  70    as the sum of a tree-expression and a constant.  This structure is
  71    also used to store offsets from the stack, which might be negative,
  72    so the variable part must be ssizetype, not sizetype.  */
  73
  74 struct args_size
  75 {
  76   HOST_WIDE_INT constant;
  77   tree var;
  78 };
  79
  80 /* Package up various arg related fields of struct args for
  81    locate_and_pad_parm.  */
  82 struct locate_and_pad_arg_data
  83 {
  84   /* Size of this argument on the stack, rounded up for any padding it
  85      gets.  If REG_PARM_STACK_SPACE is defined, then register parms are
  86      counted here, otherwise they aren't.  */
  87   struct args_size size;
  88   /* Offset of this argument from beginning of stack-args.  */
  89   struct args_size offset;
  90   /* Offset to the start of the stack slot.  Different from OFFSET
  91      if this arg pads downward.  */
  92   struct args_size slot_offset;
  93   /* The amount that the stack pointer needs to be adjusted to
  94      force alignment for the next argument.  */
  95   struct args_size alignment_pad;
  96 };
  97 #endif
  98
  99 /* Add the value of the tree INC to the `struct args_size' TO.  */
 100
 101 #define ADD_PARM_SIZE(TO, INC)                          \
 102 do {                                                    \
 103   tree inc = (INC);                                     \
 104   if (host_integerp (inc, 0))                           \
 105     (TO).constant += tree_low_cst (inc, 0);             \
 106   else if ((TO).var == 0)                               \
 107     (TO).var = convert (ssizetype, inc);                \
 108   else                                                  \
 109     (TO).var = size_binop (PLUS_EXPR, (TO).var,         \
 110                            convert (ssizetype, inc));   \
 111 } while (0)
 112
 113 #define SUB_PARM_SIZE(TO, DEC)                          \
 114 do {                                                    \
 115   tree dec = (DEC);                                     \
 116   if (host_integerp (dec, 0))                           \
 117     (TO).constant -= tree_low_cst (dec, 0);             \
 118   else if ((TO).var == 0)                               \
 119     (TO).var = size_binop (MINUS_EXPR, ssize_int (0),   \
 120                            convert (ssizetype, dec));   \
 121   else                                                  \
 122     (TO).var = size_binop (MINUS_EXPR, (TO).var,        \
 123                            convert (ssizetype, dec));   \
 124 } while (0)
 125
 126 /* Convert the implicit sum in a `struct args_size' into a tree
 127    of type ssizetype.  */
 128 #define ARGS_SIZE_TREE(SIZE)                                    \
 129 ((SIZE).var == 0 ? ssize_int ((SIZE).constant)                  \
 130  : size_binop (PLUS_EXPR, convert (ssizetype, (SIZE).var),      \
 131                ssize_int ((SIZE).constant)))
 132
 133 /* Convert the implicit sum in a `struct args_size' into an rtx.  */
 134 #define ARGS_SIZE_RTX(SIZE)                                     \
 135 ((SIZE).var == 0 ? GEN_INT ((SIZE).constant)                    \
 136  : expand_expr (ARGS_SIZE_TREE (SIZE), NULL_RTX, VOIDmode, 0))
 137
 138 /* Supply a default definition for FUNCTION_ARG_PADDING:
 139    usually pad upward, but pad short args downward on
 140    big-endian machines.  */
 141
 142 #ifndef FUNCTION_ARG_PADDING
 143 #define FUNCTION_ARG_PADDING(MODE, TYPE)                                \
 144   (! BYTES_BIG_ENDIAN                                                   \
 145    ? upward                                                             \
 146    : (((MODE) == BLKmode                                                \
 147        ? ((TYPE) && TREE_CODE (TYPE_SIZE (TYPE)) == INTEGER_CST         \
 148           && int_size_in_bytes (TYPE) < (PARM_BOUNDARY / BITS_PER_UNIT)) \
 149        : GET_MODE_BITSIZE (MODE) < PARM_BOUNDARY)                       \
 150       ? downward : upward))
 151 #endif
 152
 153 /* Supply a default definition for FUNCTION_ARG_BOUNDARY.  Normally, we let
 154    FUNCTION_ARG_PADDING, which also pads the length, handle any needed
 155    alignment.  */
 156
 157 #ifndef FUNCTION_ARG_BOUNDARY
 158 #define FUNCTION_ARG_BOUNDARY(MODE, TYPE)       PARM_BOUNDARY
 159 #endif
 160
 161 /* Define to nonzero if complex arguments should be split into their
 162    corresponding components.  */
 163 #ifndef SPLIT_COMPLEX_ARGS
 164 #define SPLIT_COMPLEX_ARGS 0
 165 #endif
 166 tree split_complex_types (tree);
 167 tree split_complex_values (tree);
 168
 169 /* Provide a default value for STRICT_ARGUMENT_NAMING.  */
 170 #ifndef STRICT_ARGUMENT_NAMING
 171 #define STRICT_ARGUMENT_NAMING 0
 172 #endif
 173
 174 /* Provide a default value for PRETEND_OUTGOING_VARARGS_NAMED.  */
 175 #ifdef SETUP_INCOMING_VARARGS
 176 #ifndef PRETEND_OUTGOING_VARARGS_NAMED
 177 #define PRETEND_OUTGOING_VARARGS_NAMED 1
 178 #endif
 179 #else
 180 /* It is an error to define PRETEND_OUTGOING_VARARGS_NAMED without
 181    defining SETUP_INCOMING_VARARGS.  */
 182 #define PRETEND_OUTGOING_VARARGS_NAMED 0
 183 #endif
 184
 185 /* Nonzero if we do not know how to pass TYPE solely in registers.  */
 186 extern bool default_must_pass_in_stack PARAMS((enum machine_mode, tree));
 187 #ifndef MUST_PASS_IN_STACK
 188 #define MUST_PASS_IN_STACK(MODE,TYPE) default_must_pass_in_stack(MODE, TYPE)
 189 #endif
 190
 191 /* Nonzero if type TYPE should be returned in memory.
 192    Most machines can use the following default definition.  */
 193
 194 #ifndef RETURN_IN_MEMORY
 195 #define RETURN_IN_MEMORY(TYPE) (TYPE_MODE (TYPE) == BLKmode)
 196 #endif
 197
 198 /* Supply a default definition of STACK_SAVEAREA_MODE for emit_stack_save.
 199    Normally move_insn, so Pmode stack pointer.  */
 200
 201 #ifndef STACK_SAVEAREA_MODE
 202 #define STACK_SAVEAREA_MODE(LEVEL) Pmode
 203 #endif
 204
 205 /* Supply a default definition of STACK_SIZE_MODE for
 206    allocate_dynamic_stack_space.  Normally PLUS/MINUS, so word_mode.  */
 207
 208 #ifndef STACK_SIZE_MODE
 209 #define STACK_SIZE_MODE word_mode
 210 #endif
 211
 212 /* Provide default values for the macros controlling stack checking.  */
 213
 214 #ifndef STACK_CHECK_BUILTIN
 215 #define STACK_CHECK_BUILTIN 0
 216 #endif
 217
 218 /* The default interval is one page.  */
 219 #ifndef STACK_CHECK_PROBE_INTERVAL
 220 #define STACK_CHECK_PROBE_INTERVAL 4096
 221 #endif
 222
 223 /* The default is to do a store into the stack.  */
 224 #ifndef STACK_CHECK_PROBE_LOAD
 225 #define STACK_CHECK_PROBE_LOAD 0
 226 #endif
 227
 228 /* This value is arbitrary, but should be sufficient for most machines.  */
 229 #ifndef STACK_CHECK_PROTECT
 230 #define STACK_CHECK_PROTECT (75 * UNITS_PER_WORD)
 231 #endif
 232
 233 /* Make the maximum frame size be the largest we can and still only need
 234    one probe per function.  */
 235 #ifndef STACK_CHECK_MAX_FRAME_SIZE
 236 #define STACK_CHECK_MAX_FRAME_SIZE \
 237   (STACK_CHECK_PROBE_INTERVAL - UNITS_PER_WORD)
 238 #endif
 239
 240 /* This is arbitrary, but should be large enough everywhere.  */
 241 #ifndef STACK_CHECK_FIXED_FRAME_SIZE
 242 #define STACK_CHECK_FIXED_FRAME_SIZE (4 * UNITS_PER_WORD)
 243 #endif
 244
 245 /* Provide a reasonable default for the maximum size of an object to
 246    allocate in the fixed frame.  We may need to be able to make this
 247    controllable by the user at some point.  */
 248 #ifndef STACK_CHECK_MAX_VAR_SIZE
 249 #define STACK_CHECK_MAX_VAR_SIZE (STACK_CHECK_MAX_FRAME_SIZE / 100)
 250 #endif
 251 \f
 252 /* Functions from optabs.c, commonly used, and without need for the optabs
 253    tables:  */
 254
 255 /* Passed to expand_simple_binop and expand_binop to say which options
 256    to try to use if the requested operation can't be open-coded on the
 257    requisite mode.  Either OPTAB_LIB or OPTAB_LIB_WIDEN says try using
 258    a library call.  Either OPTAB_WIDEN or OPTAB_LIB_WIDEN says try
 259    using a wider mode.  OPTAB_MUST_WIDEN says try widening and don't
 260    try anything else.  */
 261
 262 enum optab_methods
 263 {
 264   OPTAB_DIRECT,
 265   OPTAB_LIB,
 266   OPTAB_WIDEN,
 267   OPTAB_LIB_WIDEN,
 268   OPTAB_MUST_WIDEN
 269 };
 270
 271 /* Generate code for a simple binary or unary operation.  "Simple" in
 272    this case means "can be unambiguously described by a (mode, code)
 273    pair and mapped to a single optab."  */
 274 extern rtx expand_simple_binop PARAMS ((enum machine_mode, enum rtx_code, rtx,
 275                                         rtx, rtx, int, enum optab_methods));
 276 extern rtx expand_simple_unop PARAMS ((enum machine_mode, enum rtx_code,
 277                                        rtx, rtx, int));
 278
 279 /* Report whether the machine description contains an insn which can
 280    perform the operation described by CODE and MODE.  */
 281 extern int have_insn_for PARAMS ((enum rtx_code, enum machine_mode));
 282
 283 /* Emit code to make a call to a constant function or a library call.  */
 284 extern void emit_libcall_block PARAMS ((rtx, rtx, rtx, rtx));
 285
 286 /* Create but don't emit one rtl instruction to perform certain operations.
 287    Modes must match; operands must meet the operation's predicates.
 288    Likewise for subtraction and for just copying.
 289    These do not call protect_from_queue; caller must do so.  */
 290 extern rtx gen_add2_insn PARAMS ((rtx, rtx));
 291 extern rtx gen_add3_insn PARAMS ((rtx, rtx, rtx));
 292 extern rtx gen_sub2_insn PARAMS ((rtx, rtx));
 293 extern rtx gen_sub3_insn PARAMS ((rtx, rtx, rtx));
 294 extern rtx gen_move_insn PARAMS ((rtx, rtx));
 295 extern int have_add2_insn PARAMS ((rtx, rtx));
 296 extern int have_sub2_insn PARAMS ((rtx, rtx));
 297
 298 /* Emit a pair of rtl insns to compare two rtx's and to jump
 299    to a label if the comparison is true.  */
 300 extern void emit_cmp_and_jump_insns PARAMS ((rtx, rtx, enum rtx_code, rtx,
 301                                              enum machine_mode, int, rtx));
 302
 303 /* Generate code to indirectly jump to a location given in the rtx LOC.  */
 304 extern void emit_indirect_jump PARAMS ((rtx));
 305
 306 #ifdef HAVE_conditional_move
 307 /* Emit a conditional move operation.  */
 308 rtx emit_conditional_move PARAMS ((rtx, enum rtx_code, rtx, rtx,
 309                                    enum machine_mode, rtx, rtx,
 310                                    enum machine_mode, int));
 311
 312 /* Return nonzero if the conditional move is supported.  */
 313 int can_conditionally_move_p PARAMS ((enum machine_mode mode));
 314
 315 #endif
 316 rtx emit_conditional_add PARAMS ((rtx, enum rtx_code, rtx, rtx,
 317                                   enum machine_mode, rtx, rtx,
 318                                   enum machine_mode, int));
 319
 320 \f
 321 /* Functions from expmed.c:  */
 322
 323 /* Arguments MODE, RTX: return an rtx for the negation of that value.
 324    May emit insns.  */
 325 extern rtx negate_rtx PARAMS ((enum machine_mode, rtx));
 326
 327 /* Expand a logical AND operation.  */
 328 extern rtx expand_and PARAMS ((enum machine_mode, rtx, rtx, rtx));
 329
 330 /* Emit a store-flag operation.  */
 331 extern rtx emit_store_flag PARAMS ((rtx, enum rtx_code, rtx, rtx,
 332                                     enum machine_mode, int, int));
 333
 334 /* Like emit_store_flag, but always succeeds.  */
 335 extern rtx emit_store_flag_force PARAMS ((rtx, enum rtx_code, rtx, rtx,
 336                                           enum machine_mode, int, int));
 337
 338 /* Functions from loop.c:  */
 339
 340 /* Given an insn and condition, return a canonical description of
 341    the test being made.  */
 342 extern rtx canonicalize_condition PARAMS ((rtx, rtx, int, rtx *, rtx));
 343
 344 /* Given a JUMP_INSN, return a canonical description of the test
 345    being made.  */
 346 extern rtx get_condition PARAMS ((rtx, rtx *));
 347
 348 /* Generate a conditional trap instruction.  */
 349 extern rtx gen_cond_trap PARAMS ((enum rtx_code, rtx, rtx, rtx));
 350 \f
 351 /* Functions from builtins.c:  */
 352 extern rtx expand_builtin PARAMS ((tree, rtx, rtx, enum machine_mode, int));
 353 extern void std_expand_builtin_va_start PARAMS ((tree, rtx));
 354 extern rtx std_expand_builtin_va_arg PARAMS ((tree, tree));
 355 extern rtx expand_builtin_va_arg PARAMS ((tree, tree));
 356 extern void default_init_builtins PARAMS ((void));
 357 extern rtx default_expand_builtin PARAMS ((tree, rtx, rtx,
 358                                            enum machine_mode, int));
 359 extern void expand_builtin_setjmp_setup PARAMS ((rtx, rtx));
 360 extern void expand_builtin_setjmp_receiver PARAMS ((rtx));
 361 extern void expand_builtin_longjmp PARAMS ((rtx, rtx));
 362 extern rtx expand_builtin_saveregs PARAMS ((void));
 363 extern void expand_builtin_trap PARAMS ((void));
 364 extern HOST_WIDE_INT get_varargs_alias_set PARAMS ((void));
 365 extern HOST_WIDE_INT get_frame_alias_set PARAMS ((void));
 366 extern void record_base_value           PARAMS ((unsigned int, rtx, int));
 367 extern void record_alias_subset         PARAMS ((HOST_WIDE_INT,
 368                                                  HOST_WIDE_INT));
 369 extern HOST_WIDE_INT new_alias_set              PARAMS ((void));
 370 extern int can_address_p                PARAMS ((tree));
 371 \f
 372 /* Functions from expr.c:  */
 373
 374 /* This is run once per compilation to set up which modes can be used
 375    directly in memory and to initialize the block move optab.  */
 376 extern void init_expr_once PARAMS ((void));
 377
 378 /* This is run at the start of compiling a function.  */
 379 extern void init_expr PARAMS ((void));
 380
 381 /* This is run at the end of compiling a function.  */
 382 extern void finish_expr_for_function PARAMS ((void));
 383
 384 /* Use protect_from_queue to convert a QUEUED expression
 385    into something that you can put immediately into an instruction.  */
 386 extern rtx protect_from_queue PARAMS ((rtx, int));
 387
 388 /* Perform all the pending incrementations.  */
 389 extern void emit_queue PARAMS ((void));
 390
 391 /* Tell if something has a queued subexpression.  */
 392 extern int queued_subexp_p PARAMS ((rtx));
 393
 394 /* Emit some rtl insns to move data between rtx's, converting machine modes.
 395    Both modes must be floating or both fixed.  */
 396 extern void convert_move PARAMS ((rtx, rtx, int));
 397
 398 /* Convert an rtx to specified machine mode and return the result.  */
 399 extern rtx convert_to_mode PARAMS ((enum machine_mode, rtx, int));
 400
 401 /* Convert an rtx to MODE from OLDMODE and return the result.  */
 402 extern rtx convert_modes PARAMS ((enum machine_mode, enum machine_mode,
 403                                   rtx, int));
 404
 405 /* Emit code to move a block Y to a block X.  */
 406
 407 enum block_op_methods
 408 {
 409   BLOCK_OP_NORMAL,
 410   BLOCK_OP_NO_LIBCALL,
 411   BLOCK_OP_CALL_PARM
 412 };
 413
 414 extern void init_block_move_fn PARAMS ((const char *));
 415 extern void init_block_clear_fn PARAMS ((const char *));
 416
 417 extern rtx emit_block_move PARAMS ((rtx, rtx, rtx, enum block_op_methods));
 418
 419 /* Copy all or part of a value X into registers starting at REGNO.
 420    The number of registers to be filled is NREGS.  */
 421 extern void move_block_to_reg PARAMS ((int, rtx, int, enum machine_mode));
 422
 423 /* Copy all or part of a BLKmode value X out of registers starting at REGNO.
 424    The number of registers to be filled is NREGS.  */
 425 extern void move_block_from_reg PARAMS ((int, rtx, int));
 426
 427 /* Generate a non-consecutive group of registers represented by a PARALLEL.  */
 428 extern rtx gen_group_rtx PARAMS ((rtx));
 429
 430 /* Load a BLKmode value into non-consecutive registers represented by a
 431    PARALLEL.  */
 432 extern void emit_group_load PARAMS ((rtx, rtx, int));
 433
 434 /* Move a non-consecutive group of registers represented by a PARALLEL into
 435    a non-consecutive group of registers represented by a PARALLEL.  */
 436 extern void emit_group_move PARAMS ((rtx, rtx));
 437
 438 /* Store a BLKmode value from non-consecutive registers represented by a
 439    PARALLEL.  */
 440 extern void emit_group_store PARAMS ((rtx, rtx, int));
 441
 442 #ifdef TREE_CODE
 443 /* Copy BLKmode object from a set of registers.  */
 444 extern rtx copy_blkmode_from_reg PARAMS ((rtx, rtx, tree));
 445 #endif
 446
 447 /* Mark REG as holding a parameter for the next CALL_INSN.  */
 448 extern void use_reg PARAMS ((rtx *, rtx));
 449
 450 /* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
 451    for the next CALL_INSN.  */
 452 extern void use_regs PARAMS ((rtx *, int, int));
 453
 454 /* Mark a PARALLEL as holding a parameter for the next CALL_INSN.  */
 455 extern void use_group_regs PARAMS ((rtx *, rtx));
 456
 457 /* Write zeros through the storage of OBJECT.
 458    If OBJECT has BLKmode, SIZE is its length in bytes.  */
 459 extern rtx clear_storage PARAMS ((rtx, rtx));
 460
 461 /* Determine whether the LEN bytes can be moved by using several move
 462    instructions.  Return nonzero if a call to move_by_pieces should
 463    succeed.  */
 464 extern int can_move_by_pieces PARAMS ((unsigned HOST_WIDE_INT, unsigned int));
 465
 466 /* Return nonzero if it is desirable to store LEN bytes generated by
 467    CONSTFUN with several move instructions by store_by_pieces
 468    function.  CONSTFUNDATA is a pointer which will be passed as argument
 469    in every CONSTFUN call.
 470    ALIGN is maximum alignment we can assume.  */
 471 extern int can_store_by_pieces PARAMS ((unsigned HOST_WIDE_INT,
 472                                         rtx (*) (PTR, HOST_WIDE_INT,
 473                                                  enum machine_mode),
 474                                         PTR, unsigned int));
 475
 476 /* Generate several move instructions to store LEN bytes generated by
 477    CONSTFUN to block TO.  (A MEM rtx with BLKmode).  CONSTFUNDATA is a
 478    pointer which will be passed as argument in every CONSTFUN call.
 479    ALIGN is maximum alignment we can assume.
 480    Returns TO + LEN.  */
 481 extern rtx store_by_pieces PARAMS ((rtx, unsigned HOST_WIDE_INT,
 482                                     rtx (*) (PTR, HOST_WIDE_INT,
 483                                              enum machine_mode),
 484                                     PTR, unsigned int, int));
 485
 486 /* Emit insns to set X from Y.  */
 487 extern rtx emit_move_insn PARAMS ((rtx, rtx));
 488
 489 /* Emit insns to set X from Y, with no frills.  */
 490 extern rtx emit_move_insn_1 PARAMS ((rtx, rtx));
 491
 492 /* Push a block of length SIZE (perhaps variable)
 493    and return an rtx to address the beginning of the block.  */
 494 extern rtx push_block PARAMS ((rtx, int, int));
 495
 496 #ifdef TREE_CODE
 497 /* Generate code to push something onto the stack, given its mode and type.  */
 498 extern void emit_push_insn PARAMS ((rtx, enum machine_mode, tree, rtx,
 499                                     unsigned int, int, rtx, int, rtx, rtx,
 500                                     int, rtx));
 501
 502 /* Expand an assignment that stores the value of FROM into TO.  */
 503 extern rtx expand_assignment PARAMS ((tree, tree, int, int));
 504
 505 /* Generate code for computing expression EXP,
 506    and storing the value into TARGET.
 507    If SUGGEST_REG is nonzero, copy the value through a register
 508    and return that register, if that is possible.  */
 509 extern rtx store_expr PARAMS ((tree, rtx, int));
 510 #endif
 511
 512 /* Given an rtx that may include add and multiply operations,
 513    generate them as insns and return a pseudo-reg containing the value.
 514    Useful after calling expand_expr with 1 as sum_ok.  */
 515 extern rtx force_operand PARAMS ((rtx, rtx));
 516
 517 /* Return an object on the placeholder list that matches EXP, a
 518    PLACEHOLDER_EXPR.  An object "matches" if it is of the type of the
 519    PLACEHOLDER_EXPR or a pointer type to it.  For further information, see
 520    tree.def.  If no such object is found, abort.  If PLIST is nonzero, it is
 521    a location which initially points to a starting location in the
 522    placeholder list (zero means start of the list) and where a pointer into
 523    the placeholder list at which the object is found is placed.  */
 524 extern tree find_placeholder PARAMS ((tree, tree *));
 525
 526 /* Generate code for computing expression EXP.
 527    An rtx for the computed value is returned.  The value is never null.
 528    In the case of a void EXP, const0_rtx is returned.  */
 529 extern rtx expand_expr PARAMS ((tree, rtx, enum machine_mode,
 530                                 enum expand_modifier));
 531
 532 /* At the start of a function, record that we have no previously-pushed
 533    arguments waiting to be popped.  */
 534 extern void init_pending_stack_adjust PARAMS ((void));
 535
 536 /* When exiting from function, if safe, clear out any pending stack adjust
 537    so the adjustment won't get done.  */
 538 extern void clear_pending_stack_adjust PARAMS ((void));
 539
 540 /* Pop any previously-pushed arguments that have not been popped yet.  */
 541 extern void do_pending_stack_adjust PARAMS ((void));
 542
 543 #ifdef TREE_CODE
 544 /* Return the tree node and offset if a given argument corresponds to
 545    a string constant.  */
 546 extern tree string_constant PARAMS ((tree, tree *));
 547
 548 /* Generate code to evaluate EXP and jump to LABEL if the value is zero.  */
 549 extern void jumpifnot PARAMS ((tree, rtx));
 550
 551 /* Generate code to evaluate EXP and jump to LABEL if the value is nonzero.  */
 552 extern void jumpif PARAMS ((tree, rtx));
 553
 554 /* Generate code to evaluate EXP and jump to IF_FALSE_LABEL if
 555    the result is zero, or IF_TRUE_LABEL if the result is one.  */
 556 extern void do_jump PARAMS ((tree, rtx, rtx));
 557 #endif
 558
 559 /* Generate rtl to compare two rtx's, will call emit_cmp_insn.  */
 560 extern rtx compare_from_rtx PARAMS ((rtx, rtx, enum rtx_code, int,
 561                                      enum machine_mode, rtx));
 562 extern void do_compare_rtx_and_jump PARAMS ((rtx, rtx, enum rtx_code, int,
 563                                              enum machine_mode, rtx,
 564                                              rtx, rtx));
 565
 566 /* Two different ways of generating switch statements.  */
 567 extern int try_casesi    PARAMS ((tree, tree, tree, tree, rtx, rtx));
 568 extern int try_tablejump PARAMS ((tree, tree, tree, tree, rtx, rtx));
 569
 570 /* Smallest number of adjacent cases before we use a jump table.
 571    XXX Should be a target hook.  */
 572 extern unsigned int case_values_threshold PARAMS ((void));
 573
 574 \f
 575 #ifdef TREE_CODE
 576 /* rtl.h and tree.h were included.  */
 577 /* Return an rtx for the size in bytes of the value of an expr.  */
 578 extern rtx expr_size PARAMS ((tree));
 579
 580 /* Return a wide integer for the size in bytes of the value of EXP, or -1
 581    if the size can vary or is larger than an integer.  */
 582 extern HOST_WIDE_INT int_expr_size PARAMS ((tree));
 583
 584 extern rtx lookup_static_chain PARAMS ((tree));
 585
 586 /* Convert a stack slot address ADDR valid in function FNDECL
 587    into an address valid in this function (using a static chain).  */
 588 extern rtx fix_lexical_addr PARAMS ((rtx, tree));
 589
 590 /* Return the address of the trampoline for entering nested fn FUNCTION.  */
 591 extern rtx trampoline_address PARAMS ((tree));
 592
 593 /* Return an rtx that refers to the value returned by a function
 594    in its original home.  This becomes invalid if any more code is emitted.  */
 595 extern rtx hard_function_value PARAMS ((tree, tree, int));
 596
 597 extern rtx prepare_call_address PARAMS ((rtx, tree, rtx *, int, int));
 598
 599 extern rtx expand_call PARAMS ((tree, rtx, int));
 600
 601 extern rtx expand_shift PARAMS ((enum tree_code, enum machine_mode, rtx, tree,
 602                                  rtx, int));
 603 extern rtx expand_divmod PARAMS ((int, enum tree_code, enum machine_mode, rtx,
 604                                   rtx, rtx, int));
 605 extern void locate_and_pad_parm PARAMS ((enum machine_mode, tree, int, int,
 606                                          tree, struct args_size *,
 607                                          struct locate_and_pad_arg_data *));
 608 extern rtx expand_inline_function PARAMS ((tree, tree, rtx, int, tree, rtx));
 609
 610 /* Return the CODE_LABEL rtx for a LABEL_DECL, creating it if necessary.  */
 611 extern rtx label_rtx PARAMS ((tree));
 612
 613 /* As label_rtx, but additionally the label is placed on the forced label
 614    list of its containing function (i.e. it is treated as reachable even
 615    if how is not obvious).  */
 616 extern rtx force_label_rtx PARAMS ((tree));
 617 #endif
 618
 619 /* Indicate how an input argument register was promoted.  */
 620 extern rtx promoted_input_arg PARAMS ((unsigned int, enum machine_mode *,
 621                                        int *));
 622
 623 /* Return an rtx like arg but sans any constant terms.
 624    Returns the original rtx if it has no constant terms.
 625    The constant terms are added and stored via a second arg.  */
 626 extern rtx eliminate_constant_term PARAMS ((rtx, rtx *));
 627
 628 /* Convert arg to a valid memory address for specified machine mode,
 629    by emitting insns to perform arithmetic if nec.  */
 630 extern rtx memory_address PARAMS ((enum machine_mode, rtx));
 631
 632 /* Like `memory_address' but pretent `flag_force_addr' is 0.  */
 633 extern rtx memory_address_noforce PARAMS ((enum machine_mode, rtx));
 634
 635 /* Set the alias set of MEM to SET.  */
 636 extern void set_mem_alias_set PARAMS ((rtx, HOST_WIDE_INT));
 637
 638 /* Set the alignment of MEM to ALIGN bits.  */
 639 extern void set_mem_align PARAMS ((rtx, unsigned int));
 640
 641 /* Set the expr for MEM to EXPR.  */
 642 extern void set_mem_expr PARAMS ((rtx, tree));
 643
 644 /* Set the offset for MEM to OFFSET.  */
 645 extern void set_mem_offset PARAMS ((rtx, rtx));
 646
 647 /* Set the size for MEM to SIZE.  */
 648 extern void set_mem_size PARAMS ((rtx, rtx));
 649
 650 /* Return a memory reference like MEMREF, but with its mode changed
 651    to MODE and its address changed to ADDR.
 652    (VOIDmode means don't change the mode.
 653    NULL for ADDR means don't change the address.)  */
 654 extern rtx change_address PARAMS ((rtx, enum machine_mode, rtx));
 655
 656 /* Return a memory reference like MEMREF, but with its mode changed
 657    to MODE and its address offset by OFFSET bytes.  */
 658 #define adjust_address(MEMREF, MODE, OFFSET) \
 659   adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1)
 660
 661 /* Likewise, but the reference is not required to be valid.  */
 662 #define adjust_address_nv(MEMREF, MODE, OFFSET) \
 663   adjust_address_1 (MEMREF, MODE, OFFSET, 0, 1)
 664
 665 /* Return a memory reference like MEMREF, but with its mode changed
 666    to MODE and its address changed to ADDR, which is assumed to be
 667    increased by OFFSET bytes from MEMREF.  */
 668 #define adjust_automodify_address(MEMREF, MODE, ADDR, OFFSET) \
 669   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 1)
 670
 671 /* Likewise, but the reference is not required to be valid.  */
 672 #define adjust_automodify_address_nv(MEMREF, MODE, ADDR, OFFSET) \
 673   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 0)
 674
 675 extern rtx adjust_address_1 PARAMS ((rtx, enum machine_mode, HOST_WIDE_INT,
 676                                      int, int));
 677 extern rtx adjust_automodify_address_1 PARAMS ((rtx, enum machine_mode,
 678                                                 rtx, HOST_WIDE_INT, int));
 679
 680 /* Return a memory reference like MEMREF, but whose address is changed by
 681    adding OFFSET, an RTX, to it.  POW2 is the highest power of two factor
 682    known to be in OFFSET (possibly 1).  */
 683 extern rtx offset_address PARAMS ((rtx, rtx, unsigned HOST_WIDE_INT));
 684
 685 /* Return a memory reference like MEMREF, but with its address changed to
 686    ADDR.  The caller is asserting that the actual piece of memory pointed
 687    to is the same, just the form of the address is being changed, such as
 688    by putting something into a register.  */
 689 extern rtx replace_equiv_address PARAMS ((rtx, rtx));
 690
 691 /* Likewise, but the reference is not required to be valid.  */
 692 extern rtx replace_equiv_address_nv PARAMS ((rtx, rtx));
 693
 694 /* Return a memory reference like MEMREF, but with its mode widened to
 695    MODE and adjusted by OFFSET.  */
 696 extern rtx widen_memory_access PARAMS ((rtx, enum machine_mode, HOST_WIDE_INT));
 697
 698 /* Return a memory reference like MEMREF, but which is known to have a
 699    valid address.  */
 700 extern rtx validize_mem PARAMS ((rtx));
 701
 702 #ifdef TREE_CODE
 703 /* Given REF, either a MEM or a REG, and T, either the type of X or
 704    the expression corresponding to REF, set RTX_UNCHANGING_P if
 705    appropriate.  */
 706 extern void maybe_set_unchanging PARAMS ((rtx, tree));
 707
 708 /* Given REF, a MEM, and T, either the type of X or the expression
 709    corresponding to REF, set the memory attributes.  OBJECTP is nonzero
 710    if we are making a new object of this type.  */
 711 extern void set_mem_attributes PARAMS ((rtx, tree, int));
 712
 713 /* Similar, except that BITPOS has not yet been applied to REF, so if
 714    we alter MEM_OFFSET according to T then we should subtract BITPOS
 715    expecting that it'll be added back in later.  */
 716 extern void set_mem_attributes_minus_bitpos PARAMS ((rtx, tree, int,
 717                                                      HOST_WIDE_INT));
 718 #endif
 719
 720 /* Assemble the static constant template for function entry trampolines.  */
 721 extern rtx assemble_trampoline_template PARAMS ((void));
 722
 723 /* Given rtx, return new rtx whose address won't be affected by
 724    any side effects.  It has been copied to a new temporary reg.  */
 725 extern rtx stabilize PARAMS ((rtx));
 726
 727 /* Given an rtx, copy all regs it refers to into new temps
 728    and return a modified copy that refers to the new temps.  */
 729 extern rtx copy_all_regs PARAMS ((rtx));
 730
 731 /* Copy given rtx to a new temp reg and return that.  */
 732 extern rtx copy_to_reg PARAMS ((rtx));
 733
 734 /* Like copy_to_reg but always make the reg Pmode.  */
 735 extern rtx copy_addr_to_reg PARAMS ((rtx));
 736
 737 /* Like copy_to_reg but always make the reg the specified mode MODE.  */
 738 extern rtx copy_to_mode_reg PARAMS ((enum machine_mode, rtx));
 739
 740 /* Copy given rtx to given temp reg and return that.  */
 741 extern rtx copy_to_suggested_reg PARAMS ((rtx, rtx, enum machine_mode));
 742
 743 /* Copy a value to a register if it isn't already a register.
 744    Args are mode (in case value is a constant) and the value.  */
 745 extern rtx force_reg PARAMS ((enum machine_mode, rtx));
 746
 747 /* Return given rtx, copied into a new temp reg if it was in memory.  */
 748 extern rtx force_not_mem PARAMS ((rtx));
 749
 750 #ifdef TREE_CODE
 751 /* Return mode and signedness to use when object is promoted.  */
 752 extern enum machine_mode promote_mode PARAMS ((tree, enum machine_mode,
 753                                                int *, int));
 754 #endif
 755
 756 /* Remove some bytes from the stack.  An rtx says how many.  */
 757 extern void adjust_stack PARAMS ((rtx));
 758
 759 /* Add some bytes to the stack.  An rtx says how many.  */
 760 extern void anti_adjust_stack PARAMS ((rtx));
 761
 762 /* This enum is used for the following two functions.  */
 763 enum save_level {SAVE_BLOCK, SAVE_FUNCTION, SAVE_NONLOCAL};
 764
 765 /* Save the stack pointer at the specified level.  */
 766 extern void emit_stack_save PARAMS ((enum save_level, rtx *, rtx));
 767
 768 /* Restore the stack pointer from a save area of the specified level.  */
 769 extern void emit_stack_restore PARAMS ((enum save_level, rtx, rtx));
 770
 771 /* Allocate some space on the stack dynamically and return its address.  An rtx
 772    says how many bytes.  */
 773 extern rtx allocate_dynamic_stack_space PARAMS ((rtx, rtx, int));
 774
 775 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
 776    FIRST is a constant and size is a Pmode RTX.  These are offsets from the
 777    current stack pointer.  STACK_GROWS_DOWNWARD says whether to add or
 778    subtract from the stack.  If SIZE is constant, this is done
 779    with a fixed number of probes.  Otherwise, we must make a loop.  */
 780 extern void probe_stack_range PARAMS ((HOST_WIDE_INT, rtx));
 781
 782 /* Return an rtx that refers to the value returned by a library call
 783    in its original home.  This becomes invalid if any more code is emitted.  */
 784 extern rtx hard_libcall_value PARAMS ((enum machine_mode));
 785
 786 /* Given an rtx, return an rtx for a value rounded up to a multiple
 787    of STACK_BOUNDARY / BITS_PER_UNIT.  */
 788 extern rtx round_push PARAMS ((rtx));
 789
 790 /* Return the mode desired by operand N of a particular bitfield
 791    insert/extract insn, or MAX_MACHINE_MODE if no such insn is
 792    available.  */
 793
 794 enum extraction_pattern { EP_insv, EP_extv, EP_extzv };
 795 extern enum machine_mode
 796 mode_for_extraction PARAMS ((enum extraction_pattern, int));
 797
 798 extern rtx store_bit_field PARAMS ((rtx, unsigned HOST_WIDE_INT,
 799                                     unsigned HOST_WIDE_INT,
 800                                     enum machine_mode, rtx, HOST_WIDE_INT));
 801 extern rtx extract_bit_field PARAMS ((rtx, unsigned HOST_WIDE_INT,
 802                                       unsigned HOST_WIDE_INT, int, rtx,
 803                                       enum machine_mode, enum machine_mode,
 804                                       HOST_WIDE_INT));
 805 extern rtx expand_mult PARAMS ((enum machine_mode, rtx, rtx, rtx, int));
 806 extern bool const_mult_add_overflow_p PARAMS ((rtx, rtx, rtx, enum machine_mode, int));
 807 extern rtx expand_mult_add PARAMS ((rtx, rtx, rtx, rtx,enum machine_mode, int));
 808 extern rtx expand_mult_highpart_adjust PARAMS ((enum machine_mode, rtx, rtx, rtx, rtx, int));
 809
 810 extern rtx assemble_static_space PARAMS ((unsigned HOST_WIDE_INT));
 811 extern int safe_from_p PARAMS ((rtx, tree, int));
 812
 813 /* Call this once to initialize the contents of the optabs
 814    appropriately for the current target machine.  */
 815 extern void init_optabs                         PARAMS ((void));
 816 extern void init_all_optabs                     PARAMS ((void));
 817
 818 /* Call this to initialize an optab function entry.  */
 819 extern rtx init_one_libfunc                     PARAMS ((const char *));
 820
 821 extern void do_jump_by_parts_equality_rtx       PARAMS ((rtx, rtx, rtx));
 822 extern void do_jump_by_parts_greater_rtx        PARAMS ((enum machine_mode,
 823                                                          int, rtx, rtx, rtx,
 824                                                          rtx));
 825
 826 #ifdef TREE_CODE   /* Don't lose if tree.h not included.  */
 827 extern void mark_seen_cases                     PARAMS ((tree, unsigned char *,
 828                                                          HOST_WIDE_INT, int));
 829 #endif
 830
 831 extern int vector_mode_valid_p          PARAMS ((enum machine_mode));
 832
 833 extern tree placeholder_list;