1/* Communication between reload.c and reload1.c. 2 Copyright (C) 1987, 1991, 1992, 1993, 1994, 1995, 1997, 1998, 2000 3 Free Software Foundation, Inc. 4 5This file is part of GNU CC. 6 7GNU CC is free software; you can redistribute it and/or modify 8it under the terms of the GNU General Public License as published by 9the Free Software Foundation; either version 2, or (at your option) 10any later version. 11 12GNU CC is distributed in the hope that it will be useful, 13but WITHOUT ANY WARRANTY; without even the implied warranty of 14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15GNU General Public License for more details. 16 17You should have received a copy of the GNU General Public License 18along with GNU CC; see the file COPYING. If not, write to 19the Free Software Foundation, 59 Temple Place - Suite 330, 20Boston, MA 02111-1307, 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 PROTO ((enum machine_mode, enum reg_class, int)); 48 49/* See reload.c and reload1.c for comments on these variables. */ 50 51/* Maximum number of reloads we can need. */ 52#define MAX_RELOADS (2 * MAX_RECOG_OPERANDS * (MAX_REGS_PER_ADDRESS + 1)) 53 54extern rtx reload_in[MAX_RELOADS]; 55extern rtx reload_out[MAX_RELOADS]; 56extern rtx reload_in_reg[MAX_RELOADS]; 57extern rtx reload_out_reg[MAX_RELOADS]; 58extern enum reg_class reload_reg_class[MAX_RELOADS]; 59extern enum machine_mode reload_inmode[MAX_RELOADS]; 60extern enum machine_mode reload_outmode[MAX_RELOADS]; 61extern char reload_optional[MAX_RELOADS]; 62extern char reload_nongroup[MAX_RELOADS]; 63extern int reload_inc[MAX_RELOADS]; 64extern int reload_opnum[MAX_RELOADS]; 65extern int reload_secondary_p[MAX_RELOADS]; 66extern int reload_secondary_in_reload[MAX_RELOADS]; 67extern int reload_secondary_out_reload[MAX_RELOADS]; 68#ifdef MAX_INSN_CODE 69extern enum insn_code reload_secondary_in_icode[MAX_RELOADS]; 70extern enum insn_code reload_secondary_out_icode[MAX_RELOADS]; 71#endif 72extern int n_reloads; 73 74extern rtx reload_reg_rtx[MAX_RELOADS]; 75 76/* Encode the usage of a reload. The following codes are supported: 77 78 RELOAD_FOR_INPUT reload of an input operand 79 RELOAD_FOR_OUTPUT likewise, for output 80 RELOAD_FOR_INSN a reload that must not conflict with anything 81 used in the insn, but may conflict with 82 something used before or after the insn 83 RELOAD_FOR_INPUT_ADDRESS reload for parts of the address of an object 84 that is an input reload 85 RELOAD_FOR_INPADDR_ADDRESS reload needed for RELOAD_FOR_INPUT_ADDRESS 86 RELOAD_FOR_OUTPUT_ADDRESS like RELOAD_FOR INPUT_ADDRESS, for output 87 RELOAD_FOR_OUTADDR_ADDRESS reload needed for RELOAD_FOR_OUTPUT_ADDRESS 88 RELOAD_FOR_OPERAND_ADDRESS reload for the address of a non-reloaded 89 operand; these don't conflict with 90 any other addresses. 91 RELOAD_FOR_OPADDR_ADDR reload needed for RELOAD_FOR_OPERAND_ADDRESS 92 reloads; usually secondary reloads 93 RELOAD_OTHER none of the above, usually multiple uses 94 RELOAD_FOR_OTHER_ADDRESS reload for part of the address of an input 95 that is marked RELOAD_OTHER. 96 97 This used to be "enum reload_when_needed" but some debuggers have trouble 98 with an enum tag and variable of the same name. */ 99 100enum reload_type 101{ 102 RELOAD_FOR_INPUT, RELOAD_FOR_OUTPUT, RELOAD_FOR_INSN, 103 RELOAD_FOR_INPUT_ADDRESS, RELOAD_FOR_INPADDR_ADDRESS, 104 RELOAD_FOR_OUTPUT_ADDRESS, RELOAD_FOR_OUTADDR_ADDRESS, 105 RELOAD_FOR_OPERAND_ADDRESS, RELOAD_FOR_OPADDR_ADDR, 106 RELOAD_OTHER, RELOAD_FOR_OTHER_ADDRESS 107}; 108 109extern enum reload_type reload_when_needed[MAX_RELOADS]; 110 111extern rtx *reg_equiv_constant; 112extern rtx *reg_equiv_memory_loc; 113extern rtx *reg_equiv_address; 114extern rtx *reg_equiv_mem; 115 116/* All the "earlyclobber" operands of the current insn 117 are recorded here. */ 118extern int n_earlyclobbers; 119extern rtx reload_earlyclobbers[MAX_RECOG_OPERANDS]; 120 121/* Save the number of operands. */ 122extern int reload_n_operands; 123 124/* First uid used by insns created by reload in this function. 125 Used in find_equiv_reg. */ 126extern int reload_first_uid; 127 128/* Nonzero if indirect addressing is supported when the innermost MEM is 129 of the form (MEM (SYMBOL_REF sym)). It is assumed that the level to 130 which these are valid is the same as spill_indirect_levels, above. */ 131 132extern char indirect_symref_ok; 133 134/* Nonzero if an address (plus (reg frame_pointer) (reg ...)) is valid. */ 135extern char double_reg_address_ok; 136 137extern int num_not_at_initial_offset; 138 139#ifdef MAX_INSN_CODE 140/* These arrays record the insn_code of insns that may be needed to 141 perform input and output reloads of special objects. They provide a 142 place to pass a scratch register. */ 143extern enum insn_code reload_in_optab[]; 144extern enum insn_code reload_out_optab[]; 145#endif 146 147struct needs 148{ 149 /* [0] is normal, [1] is nongroup. */ 150 short regs[2][N_REG_CLASSES]; 151 short groups[N_REG_CLASSES]; 152}; 153 154#if defined SET_HARD_REG_BIT && defined CLEAR_REG_SET 155/* This structure describes instructions which are relevant for reload. 156 Apart from all regular insns, this also includes CODE_LABELs, since they 157 must be examined for register elimination. */ 158struct insn_chain 159{ 160 /* Links to the neighbour instructions. */ 161 struct insn_chain *next, *prev; 162 163 /* Link through a chains set up by calculate_needs_all_insns, containing 164 all insns that need reloading. */ 165 struct insn_chain *next_need_reload; 166 167 /* The basic block this insn is in. */ 168 int block; 169 /* The rtx of the insn. */ 170 rtx insn; 171 /* Register life information: record all live hard registers, and all 172 live pseudos that have a hard register. 173 This information is recorded for the point immediately before the insn 174 (in live_before), and for the point within the insn at which all 175 outputs have just been written to (in live_after). */ 176 regset live_before; 177 regset live_after; 178 179 /* For each class, size of group of consecutive regs 180 that is needed for the reloads of this class. */ 181 char group_size[N_REG_CLASSES]; 182 /* For each class, the machine mode which requires consecutive 183 groups of regs of that class. 184 If two different modes ever require groups of one class, 185 they must be the same size and equally restrictive for that class, 186 otherwise we can't handle the complexity. */ 187 enum machine_mode group_mode[N_REG_CLASSES]; 188 189 /* Indicates if a register was counted against the need for 190 groups. 0 means it can count against max_nongroup instead. */ 191 HARD_REG_SET counted_for_groups; 192 193 /* Indicates if a register was counted against the need for 194 non-groups. 0 means it can become part of a new group. 195 During choose_reload_regs, 1 here means don't use this reg 196 as part of a group, even if it seems to be otherwise ok. */ 197 HARD_REG_SET counted_for_nongroups; 198 199 /* Indicates which registers have already been used for spills. */ 200 HARD_REG_SET used_spill_regs; 201 202 /* Describe the needs for reload registers of this insn. */ 203 struct needs need; 204 205 /* Nonzero if find_reloads said the insn requires reloading. */ 206 unsigned int need_reload:1; 207 /* Nonzero if find_reloads needs to be run during reload_as_needed to 208 perform modifications on any operands. */ 209 unsigned int need_operand_change:1; 210 /* Nonzero if eliminate_regs_in_insn said it requires eliminations. */ 211 unsigned int need_elim:1; 212 /* Nonzero if this insn was inserted by perform_caller_saves. */ 213 unsigned int is_caller_save_insn:1; 214}; 215 216/* A chain of insn_chain structures to describe all non-note insns in 217 a function. */ 218extern struct insn_chain *reload_insn_chain; 219 220/* Allocate a new insn_chain structure. */ 221extern struct insn_chain *new_insn_chain PROTO((void)); 222 223extern void compute_use_by_pseudos PROTO((HARD_REG_SET *, regset)); 224#endif 225 226/* Functions from reload.c: */ 227 228/* Return a memory location that will be used to copy X in mode MODE. 229 If we haven't already made a location for this mode in this insn, 230 call find_reloads_address on the location being returned. */ 231extern rtx get_secondary_mem PROTO((rtx, enum machine_mode, 232 int, enum reload_type)); 233 234/* Clear any secondary memory locations we've made. */ 235extern void clear_secondary_mem PROTO((void)); 236 237/* Transfer all replacements that used to be in reload FROM to be in 238 reload TO. */ 239extern void transfer_replacements PROTO((int, int)); 240 241/* IN_RTX is the value loaded by a reload that we now decided to inherit, 242 or a subpart of it. If we have any replacements registered for IN_RTX, 243 chancel the reloads that were supposed to load them. 244 Return non-zero if we chanceled any reloads. */ 245extern int remove_address_replacements PROTO((rtx in_rtx)); 246 247/* Like rtx_equal_p except that it allows a REG and a SUBREG to match 248 if they are the same hard reg, and has special hacks for 249 autoincrement and autodecrement. */ 250extern int operands_match_p PROTO((rtx, rtx)); 251 252/* Return 1 if altering OP will not modify the value of CLOBBER. */ 253extern int safe_from_earlyclobber PROTO((rtx, rtx)); 254 255/* Search the body of INSN for values that need reloading and record them 256 with push_reload. REPLACE nonzero means record also where the values occur 257 so that subst_reloads can be used. */ 258extern int find_reloads PROTO((rtx, int, int, int, short *)); 259 260/* Compute the sum of X and Y, making canonicalizations assumed in an 261 address, namely: sum constant integers, surround the sum of two 262 constants with a CONST, put the constant as the second operand, and 263 group the constant on the outermost sum. */ 264extern rtx form_sum PROTO((rtx, rtx)); 265 266/* Substitute into the current INSN the registers into which we have reloaded 267 the things that need reloading. */ 268extern void subst_reloads PROTO((void)); 269 270/* Make a copy of any replacements being done into X and move those copies 271 to locations in Y, a copy of X. We only look at the highest level of 272 the RTL. */ 273extern void copy_replacements PROTO((rtx, rtx)); 274 275/* Change any replacements being done to *X to be done to *Y */ 276extern void move_replacements PROTO((rtx *x, rtx *y)); 277 278/* If LOC was scheduled to be replaced by something, return the replacement. 279 Otherwise, return *LOC. */ 280extern rtx find_replacement PROTO((rtx *)); 281 282/* Return nonzero if register in range [REGNO, ENDREGNO) 283 appears either explicitly or implicitly in X 284 other than being stored into. */ 285extern int refers_to_regno_for_reload_p PROTO((int, int, rtx, rtx *)); 286 287/* Nonzero if modifying X will affect IN. */ 288extern int reg_overlap_mentioned_for_reload_p PROTO((rtx, rtx)); 289 290/* Return nonzero if anything in X contains a MEM. Look also for pseudo 291 registers. */ 292extern int refers_to_mem_for_reload_p PROTO((rtx)); 293 294/* Check the insns before INSN to see if there is a suitable register 295 containing the same value as GOAL. */ 296extern rtx find_equiv_reg PROTO((rtx, rtx, enum reg_class, int, short *, 297 int, enum machine_mode)); 298 299/* Return 1 if register REGNO is the subject of a clobber in insn INSN. */ 300extern int regno_clobbered_p PROTO((int, rtx, enum machine_mode, int)); 301 302/* Functions in reload1.c: */ 303 304extern int reloads_conflict PROTO ((int, int)); 305 306int count_occurrences PROTO((rtx, rtx)); 307 308/* Initialize the reload pass once per compilation. */ 309extern void init_reload PROTO((void)); 310 311/* The reload pass itself. */ 312extern int reload PROTO((rtx, int, FILE *)); 313 314/* Mark the slots in regs_ever_live for the hard regs 315 used by pseudo-reg number REGNO. */ 316extern void mark_home_live PROTO((int)); 317 318/* Scan X and replace any eliminable registers (such as fp) with a 319 replacement (such as sp), plus an offset. */ 320extern rtx eliminate_regs PROTO((rtx, enum machine_mode, rtx)); 321 322/* Emit code to perform a reload from IN (which may be a reload register) to 323 OUT (which may also be a reload register). IN or OUT is from operand 324 OPNUM with reload type TYPE. */ 325extern rtx gen_reload PROTO((rtx, rtx, int, enum reload_type)); 326 327/* Deallocate the reload register used by reload number R. */ 328extern void deallocate_reload_reg PROTO((int r)); 329 330/* Functions in caller-save.c: */ 331 332/* Initialize for caller-save. */ 333extern void init_caller_save PROTO((void)); 334 335/* Initialize save areas by showing that we haven't allocated any yet. */ 336extern void init_save_areas PROTO((void)); 337 338/* Allocate save areas for any hard registers that might need saving. */ 339extern void setup_save_areas PROTO((void)); 340 341/* Find the places where hard regs are live across calls and save them. */ 342extern void save_call_clobbered_regs PROTO((void)); 343 344/* Replace (subreg (reg)) with the appropriate (reg) for any operands. */ 345extern void cleanup_subreg_operands PROTO ((rtx)); 346 347extern int earlyclobber_operand_p PROTO((rtx)); 348