reload.h revision 117395
1/* Communication between reload.c and reload1.c. 2 Copyright (C) 1987, 1991, 1992, 1993, 1994, 1995, 1997, 1998, 3 1999, 2000, 2001 Free Software Foundation, Inc. 4 5This file is part of GCC. 6 7GCC is free software; you can redistribute it and/or modify it under 8the terms of the GNU General Public License as published by the Free 9Software Foundation; either version 2, or (at your option) any later 10version. 11 12GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13WARRANTY; without even the implied warranty of MERCHANTABILITY or 14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15for more details. 16 17You should have received a copy of the GNU General Public License 18along with GCC; see the file COPYING. If not, write to the Free 19Software Foundation, 59 Temple Place - Suite 330, Boston, MA 2002111-1307, USA. */ 21 22 23/* If secondary reloads are the same for inputs and outputs, define those 24 macros here. */ 25 26#ifdef SECONDARY_RELOAD_CLASS 27#define SECONDARY_INPUT_RELOAD_CLASS(CLASS, MODE, X) \ 28 SECONDARY_RELOAD_CLASS (CLASS, MODE, X) 29#define SECONDARY_OUTPUT_RELOAD_CLASS(CLASS, MODE, X) \ 30 SECONDARY_RELOAD_CLASS (CLASS, MODE, X) 31#endif 32 33/* If either macro is defined, show that we need secondary reloads. */ 34#if defined(SECONDARY_INPUT_RELOAD_CLASS) || defined(SECONDARY_OUTPUT_RELOAD_CLASS) 35#define HAVE_SECONDARY_RELOADS 36#endif 37 38/* If MEMORY_MOVE_COST isn't defined, give it a default here. */ 39#ifndef MEMORY_MOVE_COST 40#ifdef HAVE_SECONDARY_RELOADS 41#define MEMORY_MOVE_COST(MODE,CLASS,IN) \ 42 (4 + memory_move_secondary_cost ((MODE), (CLASS), (IN))) 43#else 44#define MEMORY_MOVE_COST(MODE,CLASS,IN) 4 45#endif 46#endif 47extern int memory_move_secondary_cost PARAMS ((enum machine_mode, enum reg_class, int)); 48 49/* Maximum number of reloads we can need. */ 50#define MAX_RELOADS (2 * MAX_RECOG_OPERANDS * (MAX_REGS_PER_ADDRESS + 1)) 51 52/* Encode the usage of a reload. The following codes are supported: 53 54 RELOAD_FOR_INPUT reload of an input operand 55 RELOAD_FOR_OUTPUT likewise, for output 56 RELOAD_FOR_INSN a reload that must not conflict with anything 57 used in the insn, but may conflict with 58 something used before or after the insn 59 RELOAD_FOR_INPUT_ADDRESS reload for parts of the address of an object 60 that is an input reload 61 RELOAD_FOR_INPADDR_ADDRESS reload needed for RELOAD_FOR_INPUT_ADDRESS 62 RELOAD_FOR_OUTPUT_ADDRESS like RELOAD_FOR INPUT_ADDRESS, for output 63 RELOAD_FOR_OUTADDR_ADDRESS reload needed for RELOAD_FOR_OUTPUT_ADDRESS 64 RELOAD_FOR_OPERAND_ADDRESS reload for the address of a non-reloaded 65 operand; these don't conflict with 66 any other addresses. 67 RELOAD_FOR_OPADDR_ADDR reload needed for RELOAD_FOR_OPERAND_ADDRESS 68 reloads; usually secondary reloads 69 RELOAD_OTHER none of the above, usually multiple uses 70 RELOAD_FOR_OTHER_ADDRESS reload for part of the address of an input 71 that is marked RELOAD_OTHER. 72 73 This used to be "enum reload_when_needed" but some debuggers have trouble 74 with an enum tag and variable of the same name. */ 75 76enum reload_type 77{ 78 RELOAD_FOR_INPUT, RELOAD_FOR_OUTPUT, RELOAD_FOR_INSN, 79 RELOAD_FOR_INPUT_ADDRESS, RELOAD_FOR_INPADDR_ADDRESS, 80 RELOAD_FOR_OUTPUT_ADDRESS, RELOAD_FOR_OUTADDR_ADDRESS, 81 RELOAD_FOR_OPERAND_ADDRESS, RELOAD_FOR_OPADDR_ADDR, 82 RELOAD_OTHER, RELOAD_FOR_OTHER_ADDRESS 83}; 84 85#ifdef GCC_INSN_CODES_H 86/* Each reload is recorded with a structure like this. */ 87struct reload 88{ 89 /* The value to reload from */ 90 rtx in; 91 /* Where to store reload-reg afterward if nec (often the same as 92 reload_in) */ 93 rtx out; 94 95 /* The class of registers to reload into. */ 96 enum reg_class class; 97 98 /* The mode this operand should have when reloaded, on input. */ 99 enum machine_mode inmode; 100 /* The mode this operand should have when reloaded, on output. */ 101 enum machine_mode outmode; 102 103 /* The mode of the reload register. */ 104 enum machine_mode mode; 105 106 /* the largest number of registers this reload will require. */ 107 unsigned int nregs; 108 109 /* Positive amount to increment or decrement by if 110 reload_in is a PRE_DEC, PRE_INC, POST_DEC, POST_INC. 111 Ignored otherwise (don't assume it is zero). */ 112 int inc; 113 /* A reg for which reload_in is the equivalent. 114 If reload_in is a symbol_ref which came from 115 reg_equiv_constant, then this is the pseudo 116 which has that symbol_ref as equivalent. */ 117 rtx in_reg; 118 rtx out_reg; 119 120 /* Used in find_reload_regs to record the allocated register. */ 121 int regno; 122 /* This is the register to reload into. If it is zero when `find_reloads' 123 returns, you must find a suitable register in the class specified by 124 reload_reg_class, and store here an rtx for that register with mode from 125 reload_inmode or reload_outmode. */ 126 rtx reg_rtx; 127 /* The operand number being reloaded. This is used to group related reloads 128 and need not always be equal to the actual operand number in the insn, 129 though it current will be; for in-out operands, it is one of the two 130 operand numbers. */ 131 int opnum; 132 133 /* Gives the reload number of a secondary input reload, when needed; 134 otherwise -1. */ 135 int secondary_in_reload; 136 /* Gives the reload number of a secondary output reload, when needed; 137 otherwise -1. */ 138 int secondary_out_reload; 139 /* If a secondary input reload is required, gives the INSN_CODE that uses the 140 secondary reload as a scratch register, or CODE_FOR_nothing if the 141 secondary reload register is to be an intermediate register. */ 142 enum insn_code secondary_in_icode; 143 /* Likewise, for a secondary output reload. */ 144 enum insn_code secondary_out_icode; 145 146 /* Classifies reload as needed either for addressing an input reload, 147 addressing an output, for addressing a non-reloaded mem ref, or for 148 unspecified purposes (i.e., more than one of the above). */ 149 enum reload_type when_needed; 150 151 /* Nonzero for an optional reload. Optional reloads are ignored unless the 152 value is already sitting in a register. */ 153 unsigned int optional:1; 154 /* nonzero if this reload shouldn't be combined with another reload. */ 155 unsigned int nocombine:1; 156 /* Nonzero if this is a secondary register for one or more reloads. */ 157 unsigned int secondary_p:1; 158 /* Nonzero if this reload must use a register not already allocated to a 159 group. */ 160 unsigned int nongroup:1; 161}; 162 163extern struct reload rld[MAX_RELOADS]; 164extern int n_reloads; 165#endif 166 167extern rtx *reg_equiv_constant; 168extern rtx *reg_equiv_memory_loc; 169extern rtx *reg_equiv_address; 170extern rtx *reg_equiv_mem; 171 172/* All the "earlyclobber" operands of the current insn 173 are recorded here. */ 174extern int n_earlyclobbers; 175extern rtx reload_earlyclobbers[MAX_RECOG_OPERANDS]; 176 177/* Save the number of operands. */ 178extern int reload_n_operands; 179 180/* First uid used by insns created by reload in this function. 181 Used in find_equiv_reg. */ 182extern int reload_first_uid; 183 184/* Nonzero if indirect addressing is supported when the innermost MEM is 185 of the form (MEM (SYMBOL_REF sym)). It is assumed that the level to 186 which these are valid is the same as spill_indirect_levels, above. */ 187 188extern char indirect_symref_ok; 189 190/* Nonzero if an address (plus (reg frame_pointer) (reg ...)) is valid. */ 191extern char double_reg_address_ok; 192 193extern int num_not_at_initial_offset; 194 195struct needs 196{ 197 /* [0] is normal, [1] is nongroup. */ 198 short regs[2][N_REG_CLASSES]; 199 short groups[N_REG_CLASSES]; 200}; 201 202#if defined SET_HARD_REG_BIT && defined CLEAR_REG_SET 203/* This structure describes instructions which are relevant for reload. 204 Apart from all regular insns, this also includes CODE_LABELs, since they 205 must be examined for register elimination. */ 206struct insn_chain 207{ 208 /* Links to the neighbor instructions. */ 209 struct insn_chain *next, *prev; 210 211 /* Link through a chains set up by calculate_needs_all_insns, containing 212 all insns that need reloading. */ 213 struct insn_chain *next_need_reload; 214 215 /* The basic block this insn is in. */ 216 int block; 217 /* The rtx of the insn. */ 218 rtx insn; 219 /* Register life information: record all live hard registers, and all 220 live pseudos that have a hard register. */ 221 regset_head live_throughout; 222 regset_head dead_or_set; 223 224 /* Copies of the global variables computed by find_reloads. */ 225 struct reload *rld; 226 int n_reloads; 227 228 /* Indicates which registers have already been used for spills. */ 229 HARD_REG_SET used_spill_regs; 230 231 /* Describe the needs for reload registers of this insn. */ 232 struct needs need; 233 234 /* Nonzero if find_reloads said the insn requires reloading. */ 235 unsigned int need_reload:1; 236 /* Nonzero if find_reloads needs to be run during reload_as_needed to 237 perform modifications on any operands. */ 238 unsigned int need_operand_change:1; 239 /* Nonzero if eliminate_regs_in_insn said it requires eliminations. */ 240 unsigned int need_elim:1; 241 /* Nonzero if this insn was inserted by perform_caller_saves. */ 242 unsigned int is_caller_save_insn:1; 243}; 244 245/* A chain of insn_chain structures to describe all non-note insns in 246 a function. */ 247extern struct insn_chain *reload_insn_chain; 248 249/* Allocate a new insn_chain structure. */ 250extern struct insn_chain *new_insn_chain PARAMS ((void)); 251 252extern void compute_use_by_pseudos PARAMS ((HARD_REG_SET *, regset)); 253#endif 254 255/* Functions from reload.c: */ 256 257/* Return a memory location that will be used to copy X in mode MODE. 258 If we haven't already made a location for this mode in this insn, 259 call find_reloads_address on the location being returned. */ 260extern rtx get_secondary_mem PARAMS ((rtx, enum machine_mode, 261 int, enum reload_type)); 262 263/* Clear any secondary memory locations we've made. */ 264extern void clear_secondary_mem PARAMS ((void)); 265 266/* Transfer all replacements that used to be in reload FROM to be in 267 reload TO. */ 268extern void transfer_replacements PARAMS ((int, int)); 269 270/* IN_RTX is the value loaded by a reload that we now decided to inherit, 271 or a subpart of it. If we have any replacements registered for IN_RTX, 272 chancel the reloads that were supposed to load them. 273 Return nonzero if we chanceled any reloads. */ 274extern int remove_address_replacements PARAMS ((rtx in_rtx)); 275 276/* Like rtx_equal_p except that it allows a REG and a SUBREG to match 277 if they are the same hard reg, and has special hacks for 278 autoincrement and autodecrement. */ 279extern int operands_match_p PARAMS ((rtx, rtx)); 280 281/* Return 1 if altering OP will not modify the value of CLOBBER. */ 282extern int safe_from_earlyclobber PARAMS ((rtx, rtx)); 283 284/* Search the body of INSN for values that need reloading and record them 285 with push_reload. REPLACE nonzero means record also where the values occur 286 so that subst_reloads can be used. */ 287extern int find_reloads PARAMS ((rtx, int, int, int, short *)); 288 289/* Compute the sum of X and Y, making canonicalizations assumed in an 290 address, namely: sum constant integers, surround the sum of two 291 constants with a CONST, put the constant as the second operand, and 292 group the constant on the outermost sum. */ 293extern rtx form_sum PARAMS ((rtx, rtx)); 294 295/* Substitute into the current INSN the registers into which we have reloaded 296 the things that need reloading. */ 297extern void subst_reloads PARAMS ((rtx)); 298 299/* Make a copy of any replacements being done into X and move those copies 300 to locations in Y, a copy of X. We only look at the highest level of 301 the RTL. */ 302extern void copy_replacements PARAMS ((rtx, rtx)); 303 304/* Change any replacements being done to *X to be done to *Y */ 305extern void move_replacements PARAMS ((rtx *x, rtx *y)); 306 307/* If LOC was scheduled to be replaced by something, return the replacement. 308 Otherwise, return *LOC. */ 309extern rtx find_replacement PARAMS ((rtx *)); 310 311/* Return nonzero if register in range [REGNO, ENDREGNO) 312 appears either explicitly or implicitly in X 313 other than being stored into. */ 314extern int refers_to_regno_for_reload_p PARAMS ((unsigned int, unsigned int, 315 rtx, rtx *)); 316 317/* Nonzero if modifying X will affect IN. */ 318extern int reg_overlap_mentioned_for_reload_p PARAMS ((rtx, rtx)); 319 320/* Return nonzero if anything in X contains a MEM. Look also for pseudo 321 registers. */ 322extern int refers_to_mem_for_reload_p PARAMS ((rtx)); 323 324/* Check the insns before INSN to see if there is a suitable register 325 containing the same value as GOAL. */ 326extern rtx find_equiv_reg PARAMS ((rtx, rtx, enum reg_class, int, short *, 327 int, enum machine_mode)); 328 329/* Return 1 if register REGNO is the subject of a clobber in insn INSN. */ 330extern int regno_clobbered_p PARAMS ((unsigned int, rtx, enum machine_mode, 331 int)); 332 333/* Return 1 if X is an operand of an insn that is being earlyclobbered. */ 334extern int earlyclobber_operand_p PARAMS ((rtx)); 335 336/* Record one reload that needs to be performed. */ 337extern int push_reload PARAMS ((rtx, rtx, rtx *, rtx *, enum reg_class, 338 enum machine_mode, enum machine_mode, 339 int, int, int, enum reload_type)); 340 341/* Functions in reload1.c: */ 342 343extern void reload_cse_regs PARAMS ((rtx)); 344extern int reloads_conflict PARAMS ((int, int)); 345 346/* Initialize the reload pass once per compilation. */ 347extern void init_reload PARAMS ((void)); 348 349/* The reload pass itself. */ 350extern int reload PARAMS ((rtx, int)); 351 352/* Mark the slots in regs_ever_live for the hard regs 353 used by pseudo-reg number REGNO. */ 354extern void mark_home_live PARAMS ((int)); 355 356/* Scan X and replace any eliminable registers (such as fp) with a 357 replacement (such as sp), plus an offset. */ 358extern rtx eliminate_regs PARAMS ((rtx, enum machine_mode, rtx)); 359 360/* Emit code to perform a reload from IN (which may be a reload register) to 361 OUT (which may also be a reload register). IN or OUT is from operand 362 OPNUM with reload type TYPE. */ 363extern rtx gen_reload PARAMS ((rtx, rtx, int, enum reload_type)); 364 365/* Deallocate the reload register used by reload number R. */ 366extern void deallocate_reload_reg PARAMS ((int r)); 367 368/* Functions in caller-save.c: */ 369 370/* Initialize for caller-save. */ 371extern void init_caller_save PARAMS ((void)); 372 373/* Initialize save areas by showing that we haven't allocated any yet. */ 374extern void init_save_areas PARAMS ((void)); 375 376/* Allocate save areas for any hard registers that might need saving. */ 377extern void setup_save_areas PARAMS ((void)); 378 379/* Find the places where hard regs are live across calls and save them. */ 380extern void save_call_clobbered_regs PARAMS ((void)); 381 382/* Replace (subreg (reg)) with the appropriate (reg) for any operands. */ 383extern void cleanup_subreg_operands PARAMS ((rtx)); 384 385/* Debugging support. */ 386extern void debug_reload_to_stream PARAMS ((FILE *)); 387extern void debug_reload PARAMS ((void)); 388