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