gcc/expr.h

   1 /* Definitions for code generation pass of GNU compiler.
   2    Copyright (C) 1987-2015 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef GCC_EXPR_H
  21 #define GCC_EXPR_H
  22
  23 /* This is the 4th arg to `expand_expr'.
  24    EXPAND_STACK_PARM means we are possibly expanding a call param onto
  25    the stack.
  26    EXPAND_SUM means it is ok to return a PLUS rtx or MULT rtx.
  27    EXPAND_INITIALIZER is similar but also record any labels on forced_labels.
  28    EXPAND_CONST_ADDRESS means it is ok to return a MEM whose address
  29     is a constant that is not a legitimate address.
  30    EXPAND_WRITE means we are only going to write to the resulting rtx.
  31    EXPAND_MEMORY means we are interested in a memory result, even if
  32     the memory is constant and we could have propagated a constant value,
  33     or the memory is unaligned on a STRICT_ALIGNMENT target.  */
  34 enum expand_modifier {EXPAND_NORMAL = 0, EXPAND_STACK_PARM, EXPAND_SUM,
  35                       EXPAND_CONST_ADDRESS, EXPAND_INITIALIZER, EXPAND_WRITE,
  36                       EXPAND_MEMORY};
  37
  38 /* Prevent the compiler from deferring stack pops.  See
  39    inhibit_defer_pop for more information.  */
  40 #define NO_DEFER_POP (inhibit_defer_pop += 1)
  41
  42 /* Allow the compiler to defer stack pops.  See inhibit_defer_pop for
  43    more information.  */
  44 #define OK_DEFER_POP (inhibit_defer_pop -= 1)
  45 \f
  46 /* This structure is used to pass around information about exploded
  47    unary, binary and trinary expressions between expand_expr_real_1 and
  48    friends.  */
  49 typedef struct separate_ops
  50 {
  51   enum tree_code code;
  52   location_t location;
  53   tree type;
  54   tree op0, op1, op2;
  55 } *sepops;
  56 \f
  57 /* This is run during target initialization to set up which modes can be
  58    used directly in memory and to initialize the block move optab.  */
  59 extern void init_expr_target (void);
  60
  61 /* This is run at the start of compiling a function.  */
  62 extern void init_expr (void);
  63
  64 /* Emit some rtl insns to move data between rtx's, converting machine modes.
  65    Both modes must be floating or both fixed.  */
  66 extern void convert_move (rtx, rtx, int);
  67
  68 /* Convert an rtx to specified machine mode and return the result.  */
  69 extern rtx convert_to_mode (machine_mode, rtx, int);
  70
  71 /* Convert an rtx to MODE from OLDMODE and return the result.  */
  72 extern rtx convert_modes (machine_mode, machine_mode, rtx, int);
  73
  74 /* Emit code to move a block Y to a block X.  */
  75
  76 enum block_op_methods
  77 {
  78   BLOCK_OP_NORMAL,
  79   BLOCK_OP_NO_LIBCALL,
  80   BLOCK_OP_CALL_PARM,
  81   /* Like BLOCK_OP_NORMAL, but the libcall can be tail call optimized.  */
  82   BLOCK_OP_TAILCALL
  83 };
  84
  85 extern GTY(()) tree block_clear_fn;
  86 extern void init_block_move_fn (const char *);
  87 extern void init_block_clear_fn (const char *);
  88
  89 extern rtx emit_block_move (rtx, rtx, rtx, enum block_op_methods);
  90 extern rtx emit_block_move_via_libcall (rtx, rtx, rtx, bool);
  91 extern rtx emit_block_move_hints (rtx, rtx, rtx, enum block_op_methods,
  92                                   unsigned int, HOST_WIDE_INT,
  93                                   unsigned HOST_WIDE_INT,
  94                                   unsigned HOST_WIDE_INT,
  95                                   unsigned HOST_WIDE_INT);
  96 extern bool emit_storent_insn (rtx to, rtx from);
  97
  98 /* Copy all or part of a value X into registers starting at REGNO.
  99    The number of registers to be filled is NREGS.  */
 100 extern void move_block_to_reg (int, rtx, int, machine_mode);
 101
 102 /* Copy all or part of a BLKmode value X out of registers starting at REGNO.
 103    The number of registers to be filled is NREGS.  */
 104 extern void move_block_from_reg (int, rtx, int);
 105
 106 /* Generate a non-consecutive group of registers represented by a PARALLEL.  */
 107 extern rtx gen_group_rtx (rtx);
 108
 109 /* Load a BLKmode value into non-consecutive registers represented by a
 110    PARALLEL.  */
 111 extern void emit_group_load (rtx, rtx, tree, int);
 112
 113 /* Similarly, but load into new temporaries.  */
 114 extern rtx emit_group_load_into_temps (rtx, rtx, tree, int);
 115
 116 /* Move a non-consecutive group of registers represented by a PARALLEL into
 117    a non-consecutive group of registers represented by a PARALLEL.  */
 118 extern void emit_group_move (rtx, rtx);
 119
 120 /* Move a group of registers represented by a PARALLEL into pseudos.  */
 121 extern rtx emit_group_move_into_temps (rtx);
 122
 123 /* Store a BLKmode value from non-consecutive registers represented by a
 124    PARALLEL.  */
 125 extern void emit_group_store (rtx, rtx, tree, int);
 126
 127 extern rtx maybe_emit_group_store (rtx, tree);
 128
 129 /* Copy BLKmode object from a set of registers.  */
 130 extern void copy_blkmode_from_reg (rtx, rtx, tree);
 131
 132 /* Mark REG as holding a parameter for the next CALL_INSN.
 133    Mode is TYPE_MODE of the non-promoted parameter, or VOIDmode.  */
 134 extern void use_reg_mode (rtx *, rtx, machine_mode);
 135 extern void clobber_reg_mode (rtx *, rtx, machine_mode);
 136
 137 extern rtx copy_blkmode_to_reg (machine_mode, tree);
 138
 139 /* Mark REG as holding a parameter for the next CALL_INSN.  */
 140 static inline void
 141 use_reg (rtx *fusage, rtx reg)
 142 {
 143   use_reg_mode (fusage, reg, VOIDmode);
 144 }
 145
 146 /* Mark REG as clobbered by the call with FUSAGE as CALL_INSN_FUNCTION_USAGE.  */
 147 static inline void
 148 clobber_reg (rtx *fusage, rtx reg)
 149 {
 150   clobber_reg_mode (fusage, reg, VOIDmode);
 151 }
 152
 153 /* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
 154    for the next CALL_INSN.  */
 155 extern void use_regs (rtx *, int, int);
 156
 157 /* Mark a PARALLEL as holding a parameter for the next CALL_INSN.  */
 158 extern void use_group_regs (rtx *, rtx);
 159
 160 /* Write zeros through the storage of OBJECT.
 161    If OBJECT has BLKmode, SIZE is its length in bytes.  */
 162 extern rtx clear_storage (rtx, rtx, enum block_op_methods);
 163 extern rtx clear_storage_hints (rtx, rtx, enum block_op_methods,
 164                                 unsigned int, HOST_WIDE_INT,
 165                                 unsigned HOST_WIDE_INT,
 166                                 unsigned HOST_WIDE_INT,
 167                                 unsigned HOST_WIDE_INT);
 168 /* The same, but always output an library call.  */
 169 rtx set_storage_via_libcall (rtx, rtx, rtx, bool);
 170
 171 /* Expand a setmem pattern; return true if successful.  */
 172 extern bool set_storage_via_setmem (rtx, rtx, rtx, unsigned int,
 173                                     unsigned int, HOST_WIDE_INT,
 174                                     unsigned HOST_WIDE_INT,
 175                                     unsigned HOST_WIDE_INT,
 176                                     unsigned HOST_WIDE_INT);
 177
 178 extern unsigned HOST_WIDE_INT move_by_pieces_ninsns (unsigned HOST_WIDE_INT,
 179                                                      unsigned int,
 180                                                      unsigned int);
 181
 182 /* Return nonzero if it is desirable to store LEN bytes generated by
 183    CONSTFUN with several move instructions by store_by_pieces
 184    function.  CONSTFUNDATA is a pointer which will be passed as argument
 185    in every CONSTFUN call.
 186    ALIGN is maximum alignment we can assume.
 187    MEMSETP is true if this is a real memset/bzero, not a copy
 188    of a const string.  */
 189 extern int can_store_by_pieces (unsigned HOST_WIDE_INT,
 190                                 rtx (*) (void *, HOST_WIDE_INT,
 191                                          machine_mode),
 192                                 void *, unsigned int, bool);
 193
 194 /* Generate several move instructions to store LEN bytes generated by
 195    CONSTFUN to block TO.  (A MEM rtx with BLKmode).  CONSTFUNDATA is a
 196    pointer which will be passed as argument in every CONSTFUN call.
 197    ALIGN is maximum alignment we can assume.
 198    MEMSETP is true if this is a real memset/bzero, not a copy.
 199    Returns TO + LEN.  */
 200 extern rtx store_by_pieces (rtx, unsigned HOST_WIDE_INT,
 201                             rtx (*) (void *, HOST_WIDE_INT, machine_mode),
 202                             void *, unsigned int, bool, int);
 203
 204 /* Emit insns to set X from Y.  */
 205 extern rtx_insn *emit_move_insn (rtx, rtx);
 206 extern rtx_insn *gen_move_insn (rtx, rtx);
 207 extern rtx gen_move_insn_uncast (rtx, rtx);
 208
 209 /* Emit insns to set X from Y, with no frills.  */
 210 extern rtx_insn *emit_move_insn_1 (rtx, rtx);
 211
 212 extern rtx_insn *emit_move_complex_push (machine_mode, rtx, rtx);
 213 extern rtx_insn *emit_move_complex_parts (rtx, rtx);
 214 extern void write_complex_part (rtx, rtx, bool);
 215 extern rtx emit_move_resolve_push (machine_mode, rtx);
 216
 217 /* Push a block of length SIZE (perhaps variable)
 218    and return an rtx to address the beginning of the block.  */
 219 extern rtx push_block (rtx, int, int);
 220
 221 /* Generate code to push something onto the stack, given its mode and type.  */
 222 extern bool emit_push_insn (rtx, machine_mode, tree, rtx, unsigned int,
 223                             int, rtx, int, rtx, rtx, int, rtx, bool);
 224
 225 /* Expand an assignment that stores the value of FROM into TO.  */
 226 extern void expand_assignment (tree, tree, bool);
 227
 228 /* Generate code for computing expression EXP,
 229    and storing the value into TARGET.
 230    If SUGGEST_REG is nonzero, copy the value through a register
 231    and return that register, if that is possible.  */
 232 extern rtx store_expr_with_bounds (tree, rtx, int, bool, tree);
 233 extern rtx store_expr (tree, rtx, int, bool);
 234
 235 /* Given an rtx that may include add and multiply operations,
 236    generate them as insns and return a pseudo-reg containing the value.
 237    Useful after calling expand_expr with 1 as sum_ok.  */
 238 extern rtx force_operand (rtx, rtx);
 239
 240 /* Work horses for expand_expr.  */
 241 extern rtx expand_expr_real (tree, rtx, machine_mode,
 242                              enum expand_modifier, rtx *, bool);
 243 extern rtx expand_expr_real_1 (tree, rtx, machine_mode,
 244                                enum expand_modifier, rtx *, bool);
 245 extern rtx expand_expr_real_2 (sepops, rtx, machine_mode,
 246                                enum expand_modifier);
 247
 248 /* Generate code for computing expression EXP.
 249    An rtx for the computed value is returned.  The value is never null.
 250    In the case of a void EXP, const0_rtx is returned.  */
 251 static inline rtx
 252 expand_expr (tree exp, rtx target, machine_mode mode,
 253              enum expand_modifier modifier)
 254 {
 255   return expand_expr_real (exp, target, mode, modifier, NULL, false);
 256 }
 257
 258 static inline rtx
 259 expand_normal (tree exp)
 260 {
 261   return expand_expr_real (exp, NULL_RTX, VOIDmode, EXPAND_NORMAL, NULL, false);
 262 }
 263
 264
 265 /* Return the tree node and offset if a given argument corresponds to
 266    a string constant.  */
 267 extern tree string_constant (tree, tree *);
 268
 269 /* Two different ways of generating switch statements.  */
 270 extern int try_casesi (tree, tree, tree, tree, rtx, rtx, rtx, int);
 271 extern int try_tablejump (tree, tree, tree, tree, rtx, rtx, int);
 272
 273 extern int safe_from_p (const_rtx, tree, int);
 274
 275 /* Get the personality libfunc for a function decl.  */
 276 rtx get_personality_function (tree);
 277
 278 /* Determine whether the LEN bytes can be moved by using several move
 279    instructions.  Return nonzero if a call to move_by_pieces should
 280    succeed.  */
 281 extern int can_move_by_pieces (unsigned HOST_WIDE_INT, unsigned int);
 282
 283 extern unsigned HOST_WIDE_INT highest_pow2_factor (const_tree);
 284
 285 extern bool categorize_ctor_elements (const_tree, HOST_WIDE_INT *,
 286                                       HOST_WIDE_INT *, bool *);
 287
 288 extern void expand_operands (tree, tree, rtx, rtx*, rtx*,
 289                              enum expand_modifier);
 290
 291 /* rtl.h and tree.h were included.  */
 292 /* Return an rtx for the size in bytes of the value of an expr.  */
 293 extern rtx expr_size (tree);
 294
 295 #endif /* GCC_EXPR_H */