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