00001 /* Communication between reload.c and reload1.c. 00002 Copyright (C) 1987, 1991, 1992, 1993, 1994, 1995, 1997, 1998, 00003 1999, 2000, 2001, 2003, 2004 Free Software Foundation, Inc. 00004 00005 This file is part of GCC. 00006 00007 GCC is free software; you can redistribute it and/or modify it under 00008 the terms of the GNU General Public License as published by the Free 00009 Software Foundation; either version 2, or (at your option) any later 00010 version. 00011 00012 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 00013 WARRANTY; without even the implied warranty of MERCHANTABILITY or 00014 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 00015 for more details. 00016 00017 You should have received a copy of the GNU General Public License 00018 along with GCC; see the file COPYING. If not, write to the Free 00019 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 00020 02110-1301, USA. */ 00021 00022 00023 /* If secondary reloads are the same for inputs and outputs, define those 00024 macros here. */ 00025 00026 #ifdef SECONDARY_RELOAD_CLASS 00027 #define SECONDARY_INPUT_RELOAD_CLASS(CLASS, MODE, X) \ 00028 SECONDARY_RELOAD_CLASS (CLASS, MODE, X) 00029 #define SECONDARY_OUTPUT_RELOAD_CLASS(CLASS, MODE, X) \ 00030 SECONDARY_RELOAD_CLASS (CLASS, MODE, X) 00031 #endif 00032 00033 /* If MEMORY_MOVE_COST isn't defined, give it a default here. */ 00034 #ifndef MEMORY_MOVE_COST 00035 #define MEMORY_MOVE_COST(MODE,CLASS,IN) \ 00036 (4 + memory_move_secondary_cost ((MODE), (CLASS), (IN))) 00037 #endif 00038 extern int memory_move_secondary_cost (enum machine_mode, enum reg_class, int); 00039 00040 /* Maximum number of reloads we can need. */ 00041 #define MAX_RELOADS (2 * MAX_RECOG_OPERANDS * (MAX_REGS_PER_ADDRESS + 1)) 00042 00043 /* Encode the usage of a reload. The following codes are supported: 00044 00045 RELOAD_FOR_INPUT reload of an input operand 00046 RELOAD_FOR_OUTPUT likewise, for output 00047 RELOAD_FOR_INSN a reload that must not conflict with anything 00048 used in the insn, but may conflict with 00049 something used before or after the insn 00050 RELOAD_FOR_INPUT_ADDRESS reload for parts of the address of an object 00051 that is an input reload 00052 RELOAD_FOR_INPADDR_ADDRESS reload needed for RELOAD_FOR_INPUT_ADDRESS 00053 RELOAD_FOR_OUTPUT_ADDRESS like RELOAD_FOR INPUT_ADDRESS, for output 00054 RELOAD_FOR_OUTADDR_ADDRESS reload needed for RELOAD_FOR_OUTPUT_ADDRESS 00055 RELOAD_FOR_OPERAND_ADDRESS reload for the address of a non-reloaded 00056 operand; these don't conflict with 00057 any other addresses. 00058 RELOAD_FOR_OPADDR_ADDR reload needed for RELOAD_FOR_OPERAND_ADDRESS 00059 reloads; usually secondary reloads 00060 RELOAD_OTHER none of the above, usually multiple uses 00061 RELOAD_FOR_OTHER_ADDRESS reload for part of the address of an input 00062 that is marked RELOAD_OTHER. 00063 00064 This used to be "enum reload_when_needed" but some debuggers have trouble 00065 with an enum tag and variable of the same name. */ 00066 00067 enum reload_type 00068 { 00069 RELOAD_FOR_INPUT, RELOAD_FOR_OUTPUT, RELOAD_FOR_INSN, 00070 RELOAD_FOR_INPUT_ADDRESS, RELOAD_FOR_INPADDR_ADDRESS, 00071 RELOAD_FOR_OUTPUT_ADDRESS, RELOAD_FOR_OUTADDR_ADDRESS, 00072 RELOAD_FOR_OPERAND_ADDRESS, RELOAD_FOR_OPADDR_ADDR, 00073 RELOAD_OTHER, RELOAD_FOR_OTHER_ADDRESS 00074 }; 00075 00076 #ifdef GCC_INSN_CODES_H 00077 /* Each reload is recorded with a structure like this. */ 00078 struct reload 00079 { 00080 /* The value to reload from */ 00081 rtx in; 00082 /* Where to store reload-reg afterward if nec (often the same as 00083 reload_in) */ 00084 rtx out; 00085 00086 /* The class of registers to reload into. */ 00087 enum reg_class class; 00088 00089 /* The mode this operand should have when reloaded, on input. */ 00090 enum machine_mode inmode; 00091 /* The mode this operand should have when reloaded, on output. */ 00092 enum machine_mode outmode; 00093 00094 /* The mode of the reload register. */ 00095 enum machine_mode mode; 00096 00097 /* the largest number of registers this reload will require. */ 00098 unsigned int nregs; 00099 00100 /* Positive amount to increment or decrement by if 00101 reload_in is a PRE_DEC, PRE_INC, POST_DEC, POST_INC. 00102 Ignored otherwise (don't assume it is zero). */ 00103 int inc; 00104 /* A reg for which reload_in is the equivalent. 00105 If reload_in is a symbol_ref which came from 00106 reg_equiv_constant, then this is the pseudo 00107 which has that symbol_ref as equivalent. */ 00108 rtx in_reg; 00109 rtx out_reg; 00110 00111 /* Used in find_reload_regs to record the allocated register. */ 00112 int regno; 00113 /* This is the register to reload into. If it is zero when `find_reloads' 00114 returns, you must find a suitable register in the class specified by 00115 reload_reg_class, and store here an rtx for that register with mode from 00116 reload_inmode or reload_outmode. */ 00117 rtx reg_rtx; 00118 /* The operand number being reloaded. This is used to group related reloads 00119 and need not always be equal to the actual operand number in the insn, 00120 though it current will be; for in-out operands, it is one of the two 00121 operand numbers. */ 00122 int opnum; 00123 00124 /* Gives the reload number of a secondary input reload, when needed; 00125 otherwise -1. */ 00126 int secondary_in_reload; 00127 /* Gives the reload number of a secondary output reload, when needed; 00128 otherwise -1. */ 00129 int secondary_out_reload; 00130 /* If a secondary input reload is required, gives the INSN_CODE that uses the 00131 secondary reload as a scratch register, or CODE_FOR_nothing if the 00132 secondary reload register is to be an intermediate register. */ 00133 enum insn_code secondary_in_icode; 00134 /* Likewise, for a secondary output reload. */ 00135 enum insn_code secondary_out_icode; 00136 00137 /* Classifies reload as needed either for addressing an input reload, 00138 addressing an output, for addressing a non-reloaded mem ref, or for 00139 unspecified purposes (i.e., more than one of the above). */ 00140 enum reload_type when_needed; 00141 00142 /* Nonzero for an optional reload. Optional reloads are ignored unless the 00143 value is already sitting in a register. */ 00144 unsigned int optional:1; 00145 /* nonzero if this reload shouldn't be combined with another reload. */ 00146 unsigned int nocombine:1; 00147 /* Nonzero if this is a secondary register for one or more reloads. */ 00148 unsigned int secondary_p:1; 00149 /* Nonzero if this reload must use a register not already allocated to a 00150 group. */ 00151 unsigned int nongroup:1; 00152 }; 00153 00154 extern struct reload rld[MAX_RELOADS]; 00155 extern int n_reloads; 00156 #endif 00157 00158 extern GTY (()) VEC(rtx,gc) *reg_equiv_memory_loc_vec; 00159 extern rtx *reg_equiv_constant; 00160 extern rtx *reg_equiv_invariant; 00161 extern rtx *reg_equiv_memory_loc; 00162 extern rtx *reg_equiv_address; 00163 extern rtx *reg_equiv_mem; 00164 extern rtx *reg_equiv_alt_mem_list; 00165 00166 /* Element N is the list of insns that initialized reg N from its equivalent 00167 constant or memory slot. */ 00168 extern GTY((length("reg_equiv_init_size"))) rtx *reg_equiv_init; 00169 00170 /* The size of the previous array, for GC purposes. */ 00171 extern GTY(()) int reg_equiv_init_size; 00172 00173 /* All the "earlyclobber" operands of the current insn 00174 are recorded here. */ 00175 extern int n_earlyclobbers; 00176 extern rtx reload_earlyclobbers[MAX_RECOG_OPERANDS]; 00177 00178 /* Save the number of operands. */ 00179 extern int reload_n_operands; 00180 00181 /* First uid used by insns created by reload in this function. 00182 Used in find_equiv_reg. */ 00183 extern int reload_first_uid; 00184 00185 /* Nonzero if indirect addressing is supported when the innermost MEM is 00186 of the form (MEM (SYMBOL_REF sym)). It is assumed that the level to 00187 which these are valid is the same as spill_indirect_levels, above. */ 00188 00189 extern char indirect_symref_ok; 00190 00191 /* Nonzero if an address (plus (reg frame_pointer) (reg ...)) is valid. */ 00192 extern char double_reg_address_ok; 00193 00194 extern int num_not_at_initial_offset; 00195 00196 #if defined SET_HARD_REG_BIT && defined CLEAR_REG_SET 00197 /* This structure describes instructions which are relevant for reload. 00198 Apart from all regular insns, this also includes CODE_LABELs, since they 00199 must be examined for register elimination. */ 00200 struct insn_chain 00201 { 00202 /* Links to the neighbor instructions. */ 00203 struct insn_chain *next, *prev; 00204 00205 /* Link through a chains set up by calculate_needs_all_insns, containing 00206 all insns that need reloading. */ 00207 struct insn_chain *next_need_reload; 00208 00209 /* The basic block this insn is in. */ 00210 int block; 00211 /* The rtx of the insn. */ 00212 rtx insn; 00213 /* Register life information: record all live hard registers, and all 00214 live pseudos that have a hard register. */ 00215 regset_head live_throughout; 00216 regset_head dead_or_set; 00217 00218 /* Copies of the global variables computed by find_reloads. */ 00219 struct reload *rld; 00220 int n_reloads; 00221 00222 /* Indicates which registers have already been used for spills. */ 00223 HARD_REG_SET used_spill_regs; 00224 00225 /* Nonzero if find_reloads said the insn requires reloading. */ 00226 unsigned int need_reload:1; 00227 /* Nonzero if find_reloads needs to be run during reload_as_needed to 00228 perform modifications on any operands. */ 00229 unsigned int need_operand_change:1; 00230 /* Nonzero if eliminate_regs_in_insn said it requires eliminations. */ 00231 unsigned int need_elim:1; 00232 /* Nonzero if this insn was inserted by perform_caller_saves. */ 00233 unsigned int is_caller_save_insn:1; 00234 }; 00235 00236 /* A chain of insn_chain structures to describe all non-note insns in 00237 a function. */ 00238 extern struct insn_chain *reload_insn_chain; 00239 00240 /* Allocate a new insn_chain structure. */ 00241 extern struct insn_chain *new_insn_chain (void); 00242 00243 extern void compute_use_by_pseudos (HARD_REG_SET *, regset); 00244 #endif 00245 00246 /* Functions from reload.c: */ 00247 00248 extern enum reg_class secondary_reload_class (bool, enum reg_class, 00249 enum machine_mode, rtx); 00250 00251 #ifdef GCC_INSN_CODES_H 00252 extern enum reg_class scratch_reload_class (enum insn_code); 00253 #endif 00254 00255 /* Return a memory location that will be used to copy X in mode MODE. 00256 If we haven't already made a location for this mode in this insn, 00257 call find_reloads_address on the location being returned. */ 00258 extern rtx get_secondary_mem (rtx, enum machine_mode, int, enum reload_type); 00259 00260 /* Clear any secondary memory locations we've made. */ 00261 extern void clear_secondary_mem (void); 00262 00263 /* Transfer all replacements that used to be in reload FROM to be in 00264 reload TO. */ 00265 extern void transfer_replacements (int, int); 00266 00267 /* IN_RTX is the value loaded by a reload that we now decided to inherit, 00268 or a subpart of it. If we have any replacements registered for IN_RTX, 00269 cancel the reloads that were supposed to load them. 00270 Return nonzero if we canceled any reloads. */ 00271 extern int remove_address_replacements (rtx in_rtx); 00272 00273 /* Like rtx_equal_p except that it allows a REG and a SUBREG to match 00274 if they are the same hard reg, and has special hacks for 00275 autoincrement and autodecrement. */ 00276 extern int operands_match_p (rtx, rtx); 00277 00278 /* Return 1 if altering OP will not modify the value of CLOBBER. */ 00279 extern int safe_from_earlyclobber (rtx, rtx); 00280 00281 /* Search the body of INSN for values that need reloading and record them 00282 with push_reload. REPLACE nonzero means record also where the values occur 00283 so that subst_reloads can be used. */ 00284 extern int find_reloads (rtx, int, int, int, short *); 00285 00286 /* Compute the sum of X and Y, making canonicalizations assumed in an 00287 address, namely: sum constant integers, surround the sum of two 00288 constants with a CONST, put the constant as the second operand, and 00289 group the constant on the outermost sum. */ 00290 extern rtx form_sum (rtx, rtx); 00291 00292 /* Substitute into the current INSN the registers into which we have reloaded 00293 the things that need reloading. */ 00294 extern void subst_reloads (rtx); 00295 00296 /* Make a copy of any replacements being done into X and move those copies 00297 to locations in Y, a copy of X. We only look at the highest level of 00298 the RTL. */ 00299 extern void copy_replacements (rtx, rtx); 00300 00301 /* Change any replacements being done to *X to be done to *Y */ 00302 extern void move_replacements (rtx *x, rtx *y); 00303 00304 /* If LOC was scheduled to be replaced by something, return the replacement. 00305 Otherwise, return *LOC. */ 00306 extern rtx find_replacement (rtx *); 00307 00308 /* Nonzero if modifying X will affect IN. */ 00309 extern int reg_overlap_mentioned_for_reload_p (rtx, rtx); 00310 00311 /* Check the insns before INSN to see if there is a suitable register 00312 containing the same value as GOAL. */ 00313 extern rtx find_equiv_reg (rtx, rtx, enum reg_class, int, short *, 00314 int, enum machine_mode); 00315 00316 /* Return 1 if register REGNO is the subject of a clobber in insn INSN. */ 00317 extern int regno_clobbered_p (unsigned int, rtx, enum machine_mode, int); 00318 00319 /* Return 1 if X is an operand of an insn that is being earlyclobbered. */ 00320 extern int earlyclobber_operand_p (rtx); 00321 00322 /* Record one reload that needs to be performed. */ 00323 extern int push_reload (rtx, rtx, rtx *, rtx *, enum reg_class, 00324 enum machine_mode, enum machine_mode, 00325 int, int, int, enum reload_type); 00326 00327 /* Functions in postreload.c: */ 00328 extern void reload_cse_regs (rtx); 00329 00330 /* Functions in reload1.c: */ 00331 00332 /* Initialize the reload pass once per compilation. */ 00333 extern void init_reload (void); 00334 00335 /* The reload pass itself. */ 00336 extern int reload (rtx, int); 00337 00338 /* Mark the slots in regs_ever_live for the hard regs 00339 used by pseudo-reg number REGNO. */ 00340 extern void mark_home_live (int); 00341 00342 /* Scan X and replace any eliminable registers (such as fp) with a 00343 replacement (such as sp), plus an offset. */ 00344 extern rtx eliminate_regs (rtx, enum machine_mode, rtx); 00345 00346 /* Deallocate the reload register used by reload number R. */ 00347 extern void deallocate_reload_reg (int r); 00348 00349 /* Functions in caller-save.c: */ 00350 00351 /* Initialize for caller-save. */ 00352 extern void init_caller_save (void); 00353 00354 /* Initialize save areas by showing that we haven't allocated any yet. */ 00355 extern void init_save_areas (void); 00356 00357 /* Allocate save areas for any hard registers that might need saving. */ 00358 extern void setup_save_areas (void); 00359 00360 /* Find the places where hard regs are live across calls and save them. */ 00361 extern void save_call_clobbered_regs (void); 00362 00363 /* Replace (subreg (reg)) with the appropriate (reg) for any operands. */ 00364 extern void cleanup_subreg_operands (rtx); 00365 00366 /* Debugging support. */ 00367 extern void debug_reload_to_stream (FILE *); 00368 extern void debug_reload (void); 00369 00370 /* Compute the actual register we should reload to, in case we're 00371 reloading to/from a register that is wider than a word. */ 00372 extern rtx reload_adjust_reg_for_mode (rtx, enum machine_mode);
1.5.6