1/* Communication between reload.c, reload1.c and the rest of compiler. 2 Copyright (C) 1987, 1991, 1992, 1993, 1994, 1995, 1997, 1998, 1999, 3 2000, 2001, 2003, 2004, 2007, 2008, 2010 4 Free Software Foundation, Inc. 5 6This file is part of GCC. 7 8GCC is free software; you can redistribute it and/or modify it under 9the terms of the GNU General Public License as published by the Free 10Software Foundation; either version 3, or (at your option) any later 11version. 12 13GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14WARRANTY; without even the implied warranty of MERCHANTABILITY or 15FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16for more details. 17 18You should have received a copy of the GNU General Public License 19along with GCC; see the file COPYING3. If not see 20<http://www.gnu.org/licenses/>. */ 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 MEMORY_MOVE_COST isn't defined, give it a default here. */ 34#ifndef MEMORY_MOVE_COST 35#define MEMORY_MOVE_COST(MODE,CLASS,IN) \ 36 (4 + memory_move_secondary_cost ((MODE), (CLASS), (IN))) 37#endif 38extern int memory_move_secondary_cost (enum machine_mode, enum reg_class, int); 39 40/* Maximum number of reloads we can need. */ 41#define MAX_RELOADS (2 * MAX_RECOG_OPERANDS * (MAX_REGS_PER_ADDRESS + 1)) 42 43/* Encode the usage of a reload. The following codes are supported: 44 45 RELOAD_FOR_INPUT reload of an input operand 46 RELOAD_FOR_OUTPUT likewise, for output 47 RELOAD_FOR_INSN a reload that must not conflict with anything 48 used in the insn, but may conflict with 49 something used before or after the insn 50 RELOAD_FOR_INPUT_ADDRESS reload for parts of the address of an object 51 that is an input reload 52 RELOAD_FOR_INPADDR_ADDRESS reload needed for RELOAD_FOR_INPUT_ADDRESS 53 RELOAD_FOR_OUTPUT_ADDRESS like RELOAD_FOR INPUT_ADDRESS, for output 54 RELOAD_FOR_OUTADDR_ADDRESS reload needed for RELOAD_FOR_OUTPUT_ADDRESS 55 RELOAD_FOR_OPERAND_ADDRESS reload for the address of a non-reloaded 56 operand; these don't conflict with 57 any other addresses. 58 RELOAD_FOR_OPADDR_ADDR reload needed for RELOAD_FOR_OPERAND_ADDRESS 59 reloads; usually secondary reloads 60 RELOAD_OTHER none of the above, usually multiple uses 61 RELOAD_FOR_OTHER_ADDRESS reload for part of the address of an input 62 that is marked RELOAD_OTHER. 63 64 This used to be "enum reload_when_needed" but some debuggers have trouble 65 with an enum tag and variable of the same name. */ 66 67enum reload_type 68{ 69 RELOAD_FOR_INPUT, RELOAD_FOR_OUTPUT, RELOAD_FOR_INSN, 70 RELOAD_FOR_INPUT_ADDRESS, RELOAD_FOR_INPADDR_ADDRESS, 71 RELOAD_FOR_OUTPUT_ADDRESS, RELOAD_FOR_OUTADDR_ADDRESS, 72 RELOAD_FOR_OPERAND_ADDRESS, RELOAD_FOR_OPADDR_ADDR, 73 RELOAD_OTHER, RELOAD_FOR_OTHER_ADDRESS 74}; 75 76#ifdef GCC_INSN_CODES_H 77/* Each reload is recorded with a structure like this. */ 78struct reload 79{ 80 /* The value to reload from */ 81 rtx in; 82 /* Where to store reload-reg afterward if nec (often the same as 83 reload_in) */ 84 rtx out; 85 86 /* The class of registers to reload into. */ 87 enum reg_class rclass; 88 89 /* The mode this operand should have when reloaded, on input. */ 90 enum machine_mode inmode; 91 /* The mode this operand should have when reloaded, on output. */ 92 enum machine_mode outmode; 93 94 /* The mode of the reload register. */ 95 enum machine_mode mode; 96 97 /* the largest number of registers this reload will require. */ 98 unsigned int nregs; 99 100 /* Positive amount to increment or decrement by if 101 reload_in is a PRE_DEC, PRE_INC, POST_DEC, POST_INC. 102 Ignored otherwise (don't assume it is zero). */ 103 int inc; 104 /* A reg for which reload_in is the equivalent. 105 If reload_in is a symbol_ref which came from 106 reg_equiv_constant, then this is the pseudo 107 which has that symbol_ref as equivalent. */ 108 rtx in_reg; 109 rtx out_reg; 110 111 /* Used in find_reload_regs to record the allocated register. */ 112 int regno; 113 /* This is the register to reload into. If it is zero when `find_reloads' 114 returns, you must find a suitable register in the class specified by 115 reload_reg_class, and store here an rtx for that register with mode from 116 reload_inmode or reload_outmode. */ 117 rtx reg_rtx; 118 /* The operand number being reloaded. This is used to group related reloads 119 and need not always be equal to the actual operand number in the insn, 120 though it current will be; for in-out operands, it is one of the two 121 operand numbers. */ 122 int opnum; 123 124 /* Gives the reload number of a secondary input reload, when needed; 125 otherwise -1. */ 126 int secondary_in_reload; 127 /* Gives the reload number of a secondary output reload, when needed; 128 otherwise -1. */ 129 int secondary_out_reload; 130 /* If a secondary input reload is required, gives the INSN_CODE that uses the 131 secondary reload as a scratch register, or CODE_FOR_nothing if the 132 secondary reload register is to be an intermediate register. */ 133 enum insn_code secondary_in_icode; 134 /* Likewise, for a secondary output reload. */ 135 enum insn_code secondary_out_icode; 136 137 /* Classifies reload as needed either for addressing an input reload, 138 addressing an output, for addressing a non-reloaded mem ref, or for 139 unspecified purposes (i.e., more than one of the above). */ 140 enum reload_type when_needed; 141 142 /* Nonzero for an optional reload. Optional reloads are ignored unless the 143 value is already sitting in a register. */ 144 unsigned int optional:1; 145 /* nonzero if this reload shouldn't be combined with another reload. */ 146 unsigned int nocombine:1; 147 /* Nonzero if this is a secondary register for one or more reloads. */ 148 unsigned int secondary_p:1; 149 /* Nonzero if this reload must use a register not already allocated to a 150 group. */ 151 unsigned int nongroup:1; 152}; 153 154extern struct reload rld[MAX_RELOADS]; 155extern int n_reloads; 156#endif 157 158extern GTY (()) VEC(rtx,gc) *reg_equiv_memory_loc_vec; 159extern rtx *reg_equiv_constant; 160extern rtx *reg_equiv_invariant; 161extern rtx *reg_equiv_memory_loc; 162extern rtx *reg_equiv_address; 163extern rtx *reg_equiv_mem; 164extern rtx *reg_equiv_alt_mem_list; 165 166/* Element N is the list of insns that initialized reg N from its equivalent 167 constant or memory slot. */ 168extern GTY((length("reg_equiv_init_size"))) rtx *reg_equiv_init; 169 170/* The size of the previous array, for GC purposes. */ 171extern GTY(()) int reg_equiv_init_size; 172 173/* All the "earlyclobber" operands of the current insn 174 are recorded here. */ 175extern int n_earlyclobbers; 176extern rtx reload_earlyclobbers[MAX_RECOG_OPERANDS]; 177 178/* Save the number of operands. */ 179extern int reload_n_operands; 180 181/* First uid used by insns created by reload in this function. 182 Used in find_equiv_reg. */ 183extern int reload_first_uid; 184 185/* Nonzero if indirect addressing is supported when the innermost MEM is 186 of the form (MEM (SYMBOL_REF sym)). It is assumed that the level to 187 which these are valid is the same as spill_indirect_levels, above. */ 188 189extern char indirect_symref_ok; 190 191/* Nonzero if an address (plus (reg frame_pointer) (reg ...)) is valid. */ 192extern char double_reg_address_ok; 193 194extern int num_not_at_initial_offset; 195 196#if defined SET_HARD_REG_BIT && defined CLEAR_REG_SET 197/* This structure describes instructions which are relevant for reload. 198 Apart from all regular insns, this also includes CODE_LABELs, since they 199 must be examined for register elimination. */ 200struct insn_chain 201{ 202 /* Links to the neighbor instructions. */ 203 struct insn_chain *next, *prev; 204 205 /* Link through a chains set up by calculate_needs_all_insns, containing 206 all insns that need reloading. */ 207 struct insn_chain *next_need_reload; 208 209 /* The rtx of the insn. */ 210 rtx insn; 211 212 /* The basic block this insn is in. */ 213 int block; 214 215 /* Nonzero if find_reloads said the insn requires reloading. */ 216 unsigned int need_reload:1; 217 /* Nonzero if find_reloads needs to be run during reload_as_needed to 218 perform modifications on any operands. */ 219 unsigned int need_operand_change:1; 220 /* Nonzero if eliminate_regs_in_insn said it requires eliminations. */ 221 unsigned int need_elim:1; 222 /* Nonzero if this insn was inserted by perform_caller_saves. */ 223 unsigned int is_caller_save_insn:1; 224 225 /* Register life information: record all live hard registers, and 226 all live pseudos that have a hard register. This set also 227 contains pseudos spilled by IRA. */ 228 regset_head live_throughout; 229 regset_head dead_or_set; 230 231 /* Copies of the global variables computed by find_reloads. */ 232 struct reload *rld; 233 int n_reloads; 234 235 /* Indicates which registers have already been used for spills. */ 236 HARD_REG_SET used_spill_regs; 237}; 238 239/* A chain of insn_chain structures to describe all non-note insns in 240 a function. */ 241extern struct insn_chain *reload_insn_chain; 242 243/* Allocate a new insn_chain structure. */ 244extern struct insn_chain *new_insn_chain (void); 245 246extern void compute_use_by_pseudos (HARD_REG_SET *, regset); 247#endif 248 249/* Functions from reload.c: */ 250 251extern enum reg_class secondary_reload_class (bool, enum reg_class, 252 enum machine_mode, rtx); 253 254#ifdef GCC_INSN_CODES_H 255extern enum reg_class scratch_reload_class (enum insn_code); 256#endif 257 258/* Return a memory location that will be used to copy X in mode MODE. 259 If we haven't already made a location for this mode in this insn, 260 call find_reloads_address on the location being returned. */ 261extern rtx get_secondary_mem (rtx, enum machine_mode, int, enum reload_type); 262 263/* Clear any secondary memory locations we've made. */ 264extern void clear_secondary_mem (void); 265 266/* Transfer all replacements that used to be in reload FROM to be in 267 reload TO. */ 268extern void transfer_replacements (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 cancel the reloads that were supposed to load them. 273 Return nonzero if we canceled any reloads. */ 274extern int remove_address_replacements (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 (rtx, rtx); 280 281/* Return 1 if altering OP will not modify the value of CLOBBER. */ 282extern int safe_from_earlyclobber (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 (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 (enum machine_mode, 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 (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 (rtx, rtx); 303 304/* Change any replacements being done to *X to be done to *Y */ 305extern void move_replacements (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 (rtx *); 310 311/* Nonzero if modifying X will affect IN. */ 312extern int reg_overlap_mentioned_for_reload_p (rtx, rtx); 313 314/* Check the insns before INSN to see if there is a suitable register 315 containing the same value as GOAL. */ 316extern rtx find_equiv_reg (rtx, rtx, enum reg_class, int, short *, 317 int, enum machine_mode); 318 319/* Return 1 if register REGNO is the subject of a clobber in insn INSN. */ 320extern int regno_clobbered_p (unsigned int, rtx, enum machine_mode, int); 321 322/* Return 1 if X is an operand of an insn that is being earlyclobbered. */ 323extern int earlyclobber_operand_p (rtx); 324 325/* Record one reload that needs to be performed. */ 326extern int push_reload (rtx, rtx, rtx *, rtx *, enum reg_class, 327 enum machine_mode, enum machine_mode, 328 int, int, int, enum reload_type); 329 330/* Functions in postreload.c: */ 331extern void reload_cse_regs (rtx); 332 333/* Functions in reload1.c: */ 334 335/* Initialize the reload pass once per compilation. */ 336extern void init_reload (void); 337 338/* The reload pass itself. */ 339extern int reload (rtx, int); 340 341/* Mark the slots in regs_ever_live for the hard regs 342 used by pseudo-reg number REGNO. */ 343extern void mark_home_live (int); 344 345/* Scan X and replace any eliminable registers (such as fp) with a 346 replacement (such as sp), plus an offset. */ 347extern rtx eliminate_regs (rtx, enum machine_mode, rtx); 348extern bool elimination_target_reg_p (rtx); 349 350/* Deallocate the reload register used by reload number R. */ 351extern void deallocate_reload_reg (int r); 352 353/* True if caller-save has been reinitialized. */ 354extern bool caller_save_initialized_p; 355 356/* Functions in caller-save.c: */ 357 358/* Initialize for caller-save. */ 359extern void init_caller_save (void); 360 361/* Initialize save areas by showing that we haven't allocated any yet. */ 362extern void init_save_areas (void); 363 364/* Allocate save areas for any hard registers that might need saving. */ 365extern void setup_save_areas (void); 366 367/* Find the places where hard regs are live across calls and save them. */ 368extern void save_call_clobbered_regs (void); 369 370/* Replace (subreg (reg)) with the appropriate (reg) for any operands. */ 371extern void cleanup_subreg_operands (rtx); 372 373/* Debugging support. */ 374extern void debug_reload_to_stream (FILE *); 375extern void debug_reload (void); 376 377/* Compute the actual register we should reload to, in case we're 378 reloading to/from a register that is wider than a word. */ 379extern rtx reload_adjust_reg_for_mode (rtx, enum machine_mode); 380