gcc/reload.h

   1 /* Communication between reload.c and reload1.c.
   2    Copyright (C) 1987, 91-95, 97, 1998 Free Software Foundation, Inc.
   3
   4 This file is part of GNU CC.
   5
   6 GNU CC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU CC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU CC; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21
  22 /* If secondary reloads are the same for inputs and outputs, define those
  23    macros here.  */
  24
  25 #ifdef SECONDARY_RELOAD_CLASS
  26 #define SECONDARY_INPUT_RELOAD_CLASS(CLASS, MODE, X) \
  27   SECONDARY_RELOAD_CLASS (CLASS, MODE, X)
  28 #define SECONDARY_OUTPUT_RELOAD_CLASS(CLASS, MODE, X) \
  29   SECONDARY_RELOAD_CLASS (CLASS, MODE, X)
  30 #endif
  31
  32 /* If either macro is defined, show that we need secondary reloads.  */
  33 #if defined(SECONDARY_INPUT_RELOAD_CLASS) || defined(SECONDARY_OUTPUT_RELOAD_CLASS)
  34 #define HAVE_SECONDARY_RELOADS
  35 #endif
  36
  37 /* If MEMORY_MOVE_COST isn't defined, give it a default here.  */
  38 #ifndef MEMORY_MOVE_COST
  39 #ifdef HAVE_SECONDARY_RELOADS
  40 #define MEMORY_MOVE_COST(MODE,CLASS,IN) \
  41   (4 + memory_move_secondary_cost ((MODE), (CLASS), (IN)))
  42 #else
  43 #define MEMORY_MOVE_COST(MODE,CLASS,IN) 4
  44 #endif
  45 #endif
  46 extern int memory_move_secondary_cost PROTO ((enum machine_mode, enum reg_class, int));
  47
  48 /* See reload.c and reload1.c for comments on these variables.  */
  49
  50 /* Maximum number of reloads we can need.  */
  51 #define MAX_RELOADS (2 * MAX_RECOG_OPERANDS * (MAX_REGS_PER_ADDRESS + 1))
  52
  53 extern enum reg_class reload_address_base_reg_class;
  54 extern enum reg_class reload_address_index_reg_class;
  55 extern rtx reload_in[MAX_RELOADS];
  56 extern rtx reload_out[MAX_RELOADS];
  57 extern rtx reload_in_reg[MAX_RELOADS];
  58 extern enum reg_class reload_reg_class[MAX_RELOADS];
  59 extern enum machine_mode reload_inmode[MAX_RELOADS];
  60 extern enum machine_mode reload_outmode[MAX_RELOADS];
  61 extern char reload_optional[MAX_RELOADS];
  62 extern char reload_nongroup[MAX_RELOADS];
  63 extern int reload_inc[MAX_RELOADS];
  64 extern int reload_opnum[MAX_RELOADS];
  65 extern int reload_secondary_p[MAX_RELOADS];
  66 extern int reload_secondary_in_reload[MAX_RELOADS];
  67 extern int reload_secondary_out_reload[MAX_RELOADS];
  68 #ifdef MAX_INSN_CODE
  69 extern enum insn_code reload_secondary_in_icode[MAX_RELOADS];
  70 extern enum insn_code reload_secondary_out_icode[MAX_RELOADS];
  71 #endif
  72 extern int n_reloads;
  73
  74 extern 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
 100 enum 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
 109 extern enum reload_type reload_when_needed[MAX_RELOADS];
 110
 111 extern rtx *reg_equiv_constant;
 112 extern rtx *reg_equiv_memory_loc;
 113 extern rtx *reg_equiv_address;
 114 extern rtx *reg_equiv_mem;
 115
 116 /* All the "earlyclobber" operands of the current insn
 117    are recorded here.  */
 118 extern int n_earlyclobbers;
 119 extern rtx reload_earlyclobbers[MAX_RECOG_OPERANDS];
 120
 121 /* Save the number of operands.  */
 122 extern int reload_n_operands;
 123
 124 /* First uid used by insns created by reload in this function.
 125    Used in find_equiv_reg.  */
 126 extern 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
 132 extern char indirect_symref_ok;
 133
 134 /* Nonzero if an address (plus (reg frame_pointer) (reg ...)) is valid.  */
 135 extern char double_reg_address_ok;
 136
 137 #ifdef MAX_INSN_CODE
 138 /* These arrays record the insn_code of insns that may be needed to
 139    perform input and output reloads of special objects.  They provide a
 140    place to pass a scratch register.  */
 141 extern enum insn_code reload_in_optab[];
 142 extern enum insn_code reload_out_optab[];
 143 #endif
 144
 145 /* Functions from reload.c:  */
 146
 147 /* Return a memory location that will be used to copy X in mode MODE.
 148    If we haven't already made a location for this mode in this insn,
 149    call find_reloads_address on the location being returned.  */
 150 extern rtx get_secondary_mem PROTO((rtx, enum machine_mode,
 151                                     int, enum reload_type));
 152
 153 /* Clear any secondary memory locations we've made.  */
 154 extern void clear_secondary_mem PROTO((void));
 155
 156 /* Transfer all replacements that used to be in reload FROM to be in
 157    reload TO.  */
 158 extern void transfer_replacements PROTO((int, int));
 159
 160 /* Remove all replacements in reload FROM.  */
 161 extern void remove_replacements PROTO((int));
 162
 163 /* Like rtx_equal_p except that it allows a REG and a SUBREG to match
 164    if they are the same hard reg, and has special hacks for
 165    autoincrement and autodecrement.  */
 166 extern int operands_match_p PROTO((rtx, rtx));
 167
 168 /* Return the number of times character C occurs in string S.  */
 169 extern int n_occurrences PROTO((int, char *));
 170
 171 /* Return 1 if altering OP will not modify the value of CLOBBER. */
 172 extern int safe_from_earlyclobber PROTO((rtx, rtx));
 173
 174 /* Search the body of INSN for values that need reloading and record them
 175    with push_reload.  REPLACE nonzero means record also where the values occur
 176    so that subst_reloads can be used.  */
 177 extern void find_reloads PROTO((rtx, int, int, int, short *));
 178
 179 /* Compute the sum of X and Y, making canonicalizations assumed in an
 180    address, namely: sum constant integers, surround the sum of two
 181    constants with a CONST, put the constant as the second operand, and
 182    group the constant on the outermost sum.  */
 183 extern rtx form_sum PROTO((rtx, rtx));
 184
 185 /* Substitute into the current INSN the registers into which we have reloaded
 186    the things that need reloading.  */
 187 extern void subst_reloads PROTO((void));
 188
 189 /* Make a copy of any replacements being done into X and move those copies
 190    to locations in Y, a copy of X.  We only look at the highest level of
 191    the RTL.  */
 192 extern void copy_replacements PROTO((rtx, rtx));
 193
 194 /* Change any replacements being done to *X to be done to *Y */
 195 extern void move_replacements PROTO((rtx *x, rtx *y));
 196
 197 /* If LOC was scheduled to be replaced by something, return the replacement.
 198    Otherwise, return *LOC.  */
 199 extern rtx find_replacement PROTO((rtx *));
 200
 201 /* Return nonzero if register in range [REGNO, ENDREGNO)
 202    appears either explicitly or implicitly in X
 203    other than being stored into.  */
 204 extern int refers_to_regno_for_reload_p PROTO((int, int, rtx, rtx *));
 205
 206 /* Nonzero if modifying X will affect IN.  */
 207 extern int reg_overlap_mentioned_for_reload_p PROTO((rtx, rtx));
 208
 209 /* Return nonzero if anything in X contains a MEM.  Look also for pseudo
 210    registers.  */
 211 extern int refers_to_mem_for_reload_p PROTO((rtx));
 212
 213 /* Check the insns before INSN to see if there is a suitable register
 214    containing the same value as GOAL.  */
 215 extern rtx find_equiv_reg PROTO((rtx, rtx, enum reg_class, int, short *,
 216                                  int, enum machine_mode));
 217
 218 /* Return 1 if register REGNO is the subject of a clobber in insn INSN.  */
 219 extern int regno_clobbered_p PROTO((int, rtx));
 220
 221 /* Functions in reload1.c:  */
 222
 223 extern int reloads_conflict             PROTO ((int, int));
 224
 225 int count_occurrences            PROTO((rtx, rtx));
 226
 227 /* Initialize the reload pass once per compilation.  */
 228 extern void init_reload PROTO((void));
 229
 230 /* The reload pass itself.  */
 231 extern int reload PROTO((rtx, int, FILE *));
 232
 233 /* Mark the slots in regs_ever_live for the hard regs
 234    used by pseudo-reg number REGNO.  */
 235 extern void mark_home_live PROTO((int));
 236
 237 /* Scan X and replace any eliminable registers (such as fp) with a
 238    replacement (such as sp), plus an offset.  */
 239 extern rtx eliminate_regs PROTO((rtx, enum machine_mode, rtx));
 240
 241 /* Emit code to perform a reload from IN (which may be a reload register) to
 242    OUT (which may also be a reload register).  IN or OUT is from operand
 243    OPNUM with reload type TYPE.  */
 244 extern rtx gen_reload PROTO((rtx, rtx, int, enum reload_type));
 245
 246 /* Functions in caller-save.c:  */
 247
 248 /* Initialize for caller-save.  */
 249 extern void init_caller_save PROTO((void));
 250
 251 /* Initialize save areas by showing that we haven't allocated any yet.  */
 252 extern void init_save_areas PROTO((void));
 253
 254 /* Allocate save areas for any hard registers that might need saving.  */
 255 extern int setup_save_areas PROTO((int *));
 256
 257 /* Find the places where hard regs are live across calls and save them.  */
 258 extern void save_call_clobbered_regs PROTO((enum machine_mode));