1 /* Definitions for code generation pass of GNU compiler. 2 Copyright (C) 1987-2020 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 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 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 /* Expand a call to memcpy or memmove or memcmp, and return the result. */ 75 extern rtx emit_block_op_via_libcall (enum built_in_function, rtx, rtx, rtx, 76 bool); 77 78 static inline rtx 79 emit_block_copy_via_libcall (rtx dst, rtx src, rtx size, bool tailcall = false) 80 { 81 return emit_block_op_via_libcall (BUILT_IN_MEMCPY, dst, src, size, tailcall); 82 } 83 84 static inline rtx 85 emit_block_move_via_libcall (rtx dst, rtx src, rtx size, bool tailcall = false) 86 { 87 return emit_block_op_via_libcall (BUILT_IN_MEMMOVE, dst, src, size, tailcall); 88 } 89 90 static inline rtx 91 emit_block_comp_via_libcall (rtx dst, rtx src, rtx size, bool tailcall = false) 92 { 93 return emit_block_op_via_libcall (BUILT_IN_MEMCMP, dst, src, size, tailcall); 94 } 95 96 /* Emit code to move a block Y to a block X. */ 97 enum block_op_methods 98 { 99 BLOCK_OP_NORMAL, 100 BLOCK_OP_NO_LIBCALL, 101 BLOCK_OP_CALL_PARM, 102 /* Like BLOCK_OP_NORMAL, but the libcall can be tail call optimized. */ 103 BLOCK_OP_TAILCALL, 104 /* Like BLOCK_OP_NO_LIBCALL, but instead of emitting a libcall return 105 pc_rtx to indicate nothing has been emitted and let the caller handle 106 it. */ 107 BLOCK_OP_NO_LIBCALL_RET 108 }; 109 110 typedef rtx (*by_pieces_constfn) (void *, HOST_WIDE_INT, scalar_int_mode); 111 112 extern rtx emit_block_move (rtx, rtx, rtx, enum block_op_methods); 113 extern rtx emit_block_move_hints (rtx, rtx, rtx, enum block_op_methods, 114 unsigned int, HOST_WIDE_INT, 115 unsigned HOST_WIDE_INT, 116 unsigned HOST_WIDE_INT, 117 unsigned HOST_WIDE_INT, 118 bool bail_out_libcall = false, 119 bool *is_move_done = NULL, 120 bool might_overlap = false); 121 extern rtx emit_block_cmp_hints (rtx, rtx, rtx, tree, rtx, bool, 122 by_pieces_constfn, void *); 123 extern bool emit_storent_insn (rtx to, rtx from); 124 125 /* Copy all or part of a value X into registers starting at REGNO. 126 The number of registers to be filled is NREGS. */ 127 extern void move_block_to_reg (int, rtx, int, machine_mode); 128 129 /* Copy all or part of a BLKmode value X out of registers starting at REGNO. 130 The number of registers to be filled is NREGS. */ 131 extern void move_block_from_reg (int, rtx, int); 132 133 /* Generate a non-consecutive group of registers represented by a PARALLEL. */ 134 extern rtx gen_group_rtx (rtx); 135 136 /* Load a BLKmode value into non-consecutive registers represented by a 137 PARALLEL. */ 138 extern void emit_group_load (rtx, rtx, tree, poly_int64); 139 140 /* Similarly, but load into new temporaries. */ 141 extern rtx emit_group_load_into_temps (rtx, rtx, tree, poly_int64); 142 143 /* Move a non-consecutive group of registers represented by a PARALLEL into 144 a non-consecutive group of registers represented by a PARALLEL. */ 145 extern void emit_group_move (rtx, rtx); 146 147 /* Move a group of registers represented by a PARALLEL into pseudos. */ 148 extern rtx emit_group_move_into_temps (rtx); 149 150 /* Store a BLKmode value from non-consecutive registers represented by a 151 PARALLEL. */ 152 extern void emit_group_store (rtx, rtx, tree, poly_int64); 153 154 extern rtx maybe_emit_group_store (rtx, tree); 155 156 /* Mark REG as holding a parameter for the next CALL_INSN. 157 Mode is TYPE_MODE of the non-promoted parameter, or VOIDmode. */ 158 extern void use_reg_mode (rtx *, rtx, machine_mode); 159 extern void clobber_reg_mode (rtx *, rtx, machine_mode); 160 161 extern rtx copy_blkmode_to_reg (machine_mode, tree); 162 163 /* Mark REG as holding a parameter for the next CALL_INSN. */ 164 static inline void 165 use_reg (rtx *fusage, rtx reg) 166 { 167 use_reg_mode (fusage, reg, VOIDmode); 168 } 169 170 /* Mark REG as clobbered by the call with FUSAGE as CALL_INSN_FUNCTION_USAGE. */ 171 static inline void 172 clobber_reg (rtx *fusage, rtx reg) 173 { 174 clobber_reg_mode (fusage, reg, VOIDmode); 175 } 176 177 /* Mark NREGS consecutive regs, starting at REGNO, as holding parameters 178 for the next CALL_INSN. */ 179 extern void use_regs (rtx *, int, int); 180 181 /* Mark a PARALLEL as holding a parameter for the next CALL_INSN. */ 182 extern void use_group_regs (rtx *, rtx); 183 184 #ifdef GCC_INSN_CODES_H 185 extern rtx expand_cmpstrn_or_cmpmem (insn_code, rtx, rtx, rtx, tree, rtx, 186 HOST_WIDE_INT); 187 #endif 188 189 /* Write zeros through the storage of OBJECT. 190 If OBJECT has BLKmode, SIZE is its length in bytes. */ 191 extern rtx clear_storage (rtx, rtx, enum block_op_methods); 192 extern rtx clear_storage_hints (rtx, rtx, enum block_op_methods, 193 unsigned int, HOST_WIDE_INT, 194 unsigned HOST_WIDE_INT, 195 unsigned HOST_WIDE_INT, 196 unsigned HOST_WIDE_INT); 197 /* The same, but always output an library call. */ 198 extern rtx set_storage_via_libcall (rtx, rtx, rtx, bool = false); 199 200 /* Expand a setmem pattern; return true if successful. */ 201 extern bool set_storage_via_setmem (rtx, rtx, rtx, unsigned int, 202 unsigned int, HOST_WIDE_INT, 203 unsigned HOST_WIDE_INT, 204 unsigned HOST_WIDE_INT, 205 unsigned HOST_WIDE_INT); 206 207 /* Return nonzero if it is desirable to store LEN bytes generated by 208 CONSTFUN with several move instructions by store_by_pieces 209 function. CONSTFUNDATA is a pointer which will be passed as argument 210 in every CONSTFUN call. 211 ALIGN is maximum alignment we can assume. 212 MEMSETP is true if this is a real memset/bzero, not a copy 213 of a const string. */ 214 extern int can_store_by_pieces (unsigned HOST_WIDE_INT, 215 by_pieces_constfn, 216 void *, unsigned int, bool); 217 218 /* Generate several move instructions to store LEN bytes generated by 219 CONSTFUN to block TO. (A MEM rtx with BLKmode). CONSTFUNDATA is a 220 pointer which will be passed as argument in every CONSTFUN call. 221 ALIGN is maximum alignment we can assume. 222 MEMSETP is true if this is a real memset/bzero, not a copy. 223 Returns TO + LEN. */ 224 extern rtx store_by_pieces (rtx, unsigned HOST_WIDE_INT, by_pieces_constfn, 225 void *, unsigned int, bool, memop_ret); 226 227 /* Emit insns to set X from Y. */ 228 extern rtx_insn *emit_move_insn (rtx, rtx); 229 extern rtx_insn *gen_move_insn (rtx, rtx); 230 231 /* Emit insns to set X from Y, with no frills. */ 232 extern rtx_insn *emit_move_insn_1 (rtx, rtx); 233 234 extern rtx_insn *emit_move_complex_push (machine_mode, rtx, rtx); 235 extern rtx_insn *emit_move_complex_parts (rtx, rtx); 236 extern rtx read_complex_part (rtx, bool); 237 extern void write_complex_part (rtx, rtx, bool); 238 extern rtx read_complex_part (rtx, bool); 239 extern rtx emit_move_resolve_push (machine_mode, rtx); 240 241 /* Push a block of length SIZE (perhaps variable) 242 and return an rtx to address the beginning of the block. */ 243 extern rtx push_block (rtx, poly_int64, int); 244 245 /* Generate code to push something onto the stack, given its mode and type. */ 246 extern bool emit_push_insn (rtx, machine_mode, tree, rtx, unsigned int, 247 int, rtx, poly_int64, rtx, rtx, int, rtx, bool); 248 249 /* Extract the accessible bit-range from a COMPONENT_REF. */ 250 extern void get_bit_range (poly_uint64_pod *, poly_uint64_pod *, tree, 251 poly_int64_pod *, tree *); 252 253 /* Expand an assignment that stores the value of FROM into TO. */ 254 extern void expand_assignment (tree, tree, bool); 255 256 /* Generate code for computing expression EXP, 257 and storing the value into TARGET. 258 If SUGGEST_REG is nonzero, copy the value through a register 259 and return that register, if that is possible. */ 260 extern rtx store_expr (tree, rtx, int, bool, bool); 261 262 /* Given an rtx that may include add and multiply operations, 263 generate them as insns and return a pseudo-reg containing the value. 264 Useful after calling expand_expr with 1 as sum_ok. */ 265 extern rtx force_operand (rtx, rtx); 266 267 /* Work horses for expand_expr. */ 268 extern rtx expand_expr_real (tree, rtx, machine_mode, 269 enum expand_modifier, rtx *, bool); 270 extern rtx expand_expr_real_1 (tree, rtx, machine_mode, 271 enum expand_modifier, rtx *, bool); 272 extern rtx expand_expr_real_2 (sepops, rtx, machine_mode, 273 enum expand_modifier); 274 275 /* Generate code for computing expression EXP. 276 An rtx for the computed value is returned. The value is never null. 277 In the case of a void EXP, const0_rtx is returned. */ 278 static inline rtx 279 expand_expr (tree exp, rtx target, machine_mode mode, 280 enum expand_modifier modifier) 281 { 282 return expand_expr_real (exp, target, mode, modifier, NULL, false); 283 } 284 285 static inline rtx 286 expand_normal (tree exp) 287 { 288 return expand_expr_real (exp, NULL_RTX, VOIDmode, EXPAND_NORMAL, NULL, false); 289 } 290 291 292 /* Return the tree node and offset if a given argument corresponds to 293 a string constant. */ 294 extern tree string_constant (tree, tree *, tree *, tree *); 295 296 extern enum tree_code maybe_optimize_mod_cmp (enum tree_code, tree *, tree *); 297 298 /* Two different ways of generating switch statements. */ 299 extern int try_casesi (tree, tree, tree, tree, rtx, rtx, rtx, profile_probability); 300 extern int try_tablejump (tree, tree, tree, tree, rtx, rtx, profile_probability); 301 302 extern int safe_from_p (const_rtx, tree, int); 303 304 /* Get the personality libfunc for a function decl. */ 305 rtx get_personality_function (tree); 306 307 /* Determine whether the LEN bytes can be moved by using several move 308 instructions. Return nonzero if a call to move_by_pieces should 309 succeed. */ 310 extern bool can_move_by_pieces (unsigned HOST_WIDE_INT, unsigned int); 311 312 extern unsigned HOST_WIDE_INT highest_pow2_factor (const_tree); 313 314 extern bool categorize_ctor_elements (const_tree, HOST_WIDE_INT *, 315 HOST_WIDE_INT *, HOST_WIDE_INT *, 316 bool *); 317 318 extern void expand_operands (tree, tree, rtx, rtx*, rtx*, 319 enum expand_modifier); 320 321 /* rtl.h and tree.h were included. */ 322 /* Return an rtx for the size in bytes of the value of an expr. */ 323 extern rtx expr_size (tree); 324 325 #endif /* GCC_EXPR_H */ 326