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