1/* Communication between reload.c and reload1.c. 2 Copyright (C) 1987, 1991, 1992, 1993, 1994, 1995, 1997, 1998, 3 1999, 2000, 2001, 2003, 2004 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, 51 Franklin Street, Fifth Floor, Boston, MA 2002110-1301, 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 (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 GTY (()) struct varray_head_tag *reg_equiv_memory_loc_varray; 168extern rtx *reg_equiv_constant; 169extern rtx *reg_equiv_invariant; 170extern rtx *reg_equiv_memory_loc; 171extern rtx *reg_equiv_address; 172extern rtx *reg_equiv_mem; 173 174/* Element N is the list of insns that initialized reg N from its equivalent 175 constant or memory slot. */ 176extern GTY((length("reg_equiv_init_size"))) rtx *reg_equiv_init; 177 178/* The size of the previous array, for GC purposes. */ 179extern GTY(()) int reg_equiv_init_size; 180 181/* All the "earlyclobber" operands of the current insn 182 are recorded here. */ 183extern int n_earlyclobbers; 184extern rtx reload_earlyclobbers[MAX_RECOG_OPERANDS]; 185 186/* Save the number of operands. */ 187extern int reload_n_operands; 188 189/* First uid used by insns created by reload in this function. 190 Used in find_equiv_reg. */ 191extern int reload_first_uid; 192 193/* Nonzero if indirect addressing is supported when the innermost MEM is 194 of the form (MEM (SYMBOL_REF sym)). It is assumed that the level to 195 which these are valid is the same as spill_indirect_levels, above. */ 196 197extern char indirect_symref_ok; 198 199/* Nonzero if an address (plus (reg frame_pointer) (reg ...)) is valid. */ 200extern char double_reg_address_ok; 201 202extern int num_not_at_initial_offset; 203 204#if defined SET_HARD_REG_BIT && defined CLEAR_REG_SET 205/* This structure describes instructions which are relevant for reload. 206 Apart from all regular insns, this also includes CODE_LABELs, since they 207 must be examined for register elimination. */ 208struct insn_chain 209{ 210 /* Links to the neighbor instructions. */ 211 struct insn_chain *next, *prev; 212 213 /* Link through a chains set up by calculate_needs_all_insns, containing 214 all insns that need reloading. */ 215 struct insn_chain *next_need_reload; 216 217 /* The basic block this insn is in. */ 218 int block; 219 /* The rtx of the insn. */ 220 rtx insn; 221 /* Register life information: record all live hard registers, and all 222 live pseudos that have a hard register. */ 223 regset_head live_throughout; 224 regset_head dead_or_set; 225 226 /* Copies of the global variables computed by find_reloads. */ 227 struct reload *rld; 228 int n_reloads; 229 230 /* Indicates which registers have already been used for spills. */ 231 HARD_REG_SET used_spill_regs; 232 233 /* Nonzero if find_reloads said the insn requires reloading. */ 234 unsigned int need_reload:1; 235 /* Nonzero if find_reloads needs to be run during reload_as_needed to 236 perform modifications on any operands. */ 237 unsigned int need_operand_change:1; 238 /* Nonzero if eliminate_regs_in_insn said it requires eliminations. */ 239 unsigned int need_elim:1; 240 /* Nonzero if this insn was inserted by perform_caller_saves. */ 241 unsigned int is_caller_save_insn:1; 242}; 243 244/* A chain of insn_chain structures to describe all non-note insns in 245 a function. */ 246extern struct insn_chain *reload_insn_chain; 247 248/* Allocate a new insn_chain structure. */ 249extern struct insn_chain *new_insn_chain (void); 250 251extern void compute_use_by_pseudos (HARD_REG_SET *, regset); 252#endif 253 254/* Functions from reload.c: */ 255 256/* Return a memory location that will be used to copy X in mode MODE. 257 If we haven't already made a location for this mode in this insn, 258 call find_reloads_address on the location being returned. */ 259extern rtx get_secondary_mem (rtx, enum machine_mode, int, enum reload_type); 260 261/* Clear any secondary memory locations we've made. */ 262extern void clear_secondary_mem (void); 263 264/* Transfer all replacements that used to be in reload FROM to be in 265 reload TO. */ 266extern void transfer_replacements (int, int); 267 268/* IN_RTX is the value loaded by a reload that we now decided to inherit, 269 or a subpart of it. If we have any replacements registered for IN_RTX, 270 cancel the reloads that were supposed to load them. 271 Return nonzero if we canceled any reloads. */ 272extern int remove_address_replacements (rtx in_rtx); 273 274/* Like rtx_equal_p except that it allows a REG and a SUBREG to match 275 if they are the same hard reg, and has special hacks for 276 autoincrement and autodecrement. */ 277extern int operands_match_p (rtx, rtx); 278 279/* Return 1 if altering OP will not modify the value of CLOBBER. */ 280extern int safe_from_earlyclobber (rtx, rtx); 281 282/* Search the body of INSN for values that need reloading and record them 283 with push_reload. REPLACE nonzero means record also where the values occur 284 so that subst_reloads can be used. */ 285extern int find_reloads (rtx, int, int, int, short *); 286 287/* Compute the sum of X and Y, making canonicalizations assumed in an 288 address, namely: sum constant integers, surround the sum of two 289 constants with a CONST, put the constant as the second operand, and 290 group the constant on the outermost sum. */ 291extern rtx form_sum (rtx, rtx); 292 293/* Substitute into the current INSN the registers into which we have reloaded 294 the things that need reloading. */ 295extern void subst_reloads (rtx); 296 297/* Make a copy of any replacements being done into X and move those copies 298 to locations in Y, a copy of X. We only look at the highest level of 299 the RTL. */ 300extern void copy_replacements (rtx, rtx); 301 302/* Change any replacements being done to *X to be done to *Y */ 303extern void move_replacements (rtx *x, rtx *y); 304 305/* If LOC was scheduled to be replaced by something, return the replacement. 306 Otherwise, return *LOC. */ 307extern rtx find_replacement (rtx *); 308 309/* Nonzero if modifying X will affect IN. */ 310extern int reg_overlap_mentioned_for_reload_p (rtx, rtx); 311 312/* Check the insns before INSN to see if there is a suitable register 313 containing the same value as GOAL. */ 314extern rtx find_equiv_reg (rtx, rtx, enum reg_class, int, short *, 315 int, enum machine_mode); 316 317/* Return 1 if register REGNO is the subject of a clobber in insn INSN. */ 318extern int regno_clobbered_p (unsigned int, rtx, enum machine_mode, int); 319 320/* Return 1 if X is an operand of an insn that is being earlyclobbered. */ 321extern int earlyclobber_operand_p (rtx); 322 323/* Record one reload that needs to be performed. */ 324extern int push_reload (rtx, rtx, rtx *, rtx *, enum reg_class, 325 enum machine_mode, enum machine_mode, 326 int, int, int, enum reload_type); 327 328/* Functions in postreload.c: */ 329extern void reload_cse_regs (rtx); 330 331/* Functions in reload1.c: */ 332 333/* Initialize the reload pass once per compilation. */ 334extern void init_reload (void); 335 336/* The reload pass itself. */ 337extern int reload (rtx, int); 338 339/* Mark the slots in regs_ever_live for the hard regs 340 used by pseudo-reg number REGNO. */ 341extern void mark_home_live (int); 342 343/* Scan X and replace any eliminable registers (such as fp) with a 344 replacement (such as sp), plus an offset. */ 345extern rtx eliminate_regs (rtx, enum machine_mode, rtx); 346 347/* Deallocate the reload register used by reload number R. */ 348extern void deallocate_reload_reg (int r); 349 350/* Functions in caller-save.c: */ 351 352/* Initialize for caller-save. */ 353extern void init_caller_save (void); 354 355/* Initialize save areas by showing that we haven't allocated any yet. */ 356extern void init_save_areas (void); 357 358/* Allocate save areas for any hard registers that might need saving. */ 359extern void setup_save_areas (void); 360 361/* Find the places where hard regs are live across calls and save them. */ 362extern void save_call_clobbered_regs (void); 363 364/* Replace (subreg (reg)) with the appropriate (reg) for any operands. */ 365extern void cleanup_subreg_operands (rtx); 366 367/* Debugging support. */ 368extern void debug_reload_to_stream (FILE *); 369extern void debug_reload (void); 370 371/* Compute the actual register we should reload to, in case we're 372 reloading to/from a register that is wider than a word. */ 373extern rtx reload_adjust_reg_for_mode (rtx, enum machine_mode); 374