gcc/reload.h

   1 /* Communication between reload.c and reload1.c.
   2    Copyright (C) 1987, 91, 92, 93, 94, 95, 1997 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 /* See reload.c and reload1.c for comments on these variables.  */
  38
  39 /* Maximum number of reloads we can need.  */
  40 #define MAX_RELOADS (2 * MAX_RECOG_OPERANDS * (MAX_REGS_PER_ADDRESS + 1))
  41
  42 extern enum reg_class reload_address_base_reg_class;
  43 extern enum reg_class reload_address_index_reg_class;
  44 extern rtx reload_in[MAX_RELOADS];
  45 extern rtx reload_out[MAX_RELOADS];
  46 extern rtx reload_in_reg[MAX_RELOADS];
  47 extern enum reg_class reload_reg_class[MAX_RELOADS];
  48 extern enum machine_mode reload_inmode[MAX_RELOADS];
  49 extern enum machine_mode reload_outmode[MAX_RELOADS];
  50 extern char reload_optional[MAX_RELOADS];
  51 extern int reload_inc[MAX_RELOADS];
  52 extern int reload_opnum[MAX_RELOADS];
  53 extern int reload_secondary_p[MAX_RELOADS];
  54 extern int reload_secondary_in_reload[MAX_RELOADS];
  55 extern int reload_secondary_out_reload[MAX_RELOADS];
  56 #ifdef MAX_INSN_CODE
  57 extern enum insn_code reload_secondary_in_icode[MAX_RELOADS];
  58 extern enum insn_code reload_secondary_out_icode[MAX_RELOADS];
  59 #endif
  60 extern int n_reloads;
  61
  62 extern rtx reload_reg_rtx[MAX_RELOADS];
  63
  64 /* Encode the usage of a reload.  The following codes are supported:
  65
  66    RELOAD_FOR_INPUT             reload of an input operand
  67    RELOAD_FOR_OUTPUT            likewise, for output
  68    RELOAD_FOR_INSN              a reload that must not conflict with anything
  69                                 used in the insn, but may conflict with
  70                                 something used before or after the insn
  71    RELOAD_FOR_INPUT_ADDRESS     reload for parts of the address of an object
  72                                 that is an input reload
  73    RELOAD_FOR_INPADDR_ADDRESS   reload needed for RELOAD_FOR_INPUT_ADDRESS
  74    RELOAD_FOR_OUTPUT_ADDRESS    like RELOAD_FOR INPUT_ADDRESS, for output
  75    RELOAD_FOR_OUTADDR_ADDRESS   reload needed for RELOAD_FOR_OUTPUT_ADDRESS
  76    RELOAD_FOR_OPERAND_ADDRESS   reload for the address of a non-reloaded
  77                                 operand; these don't conflict with
  78                                 any other addresses.
  79    RELOAD_FOR_OPADDR_ADDR       reload needed for RELOAD_FOR_OPERAND_ADDRESS
  80                                 reloads; usually secondary reloads
  81    RELOAD_OTHER                 none of the above, usually multiple uses
  82    RELOAD_FOR_OTHER_ADDRESS     reload for part of the address of an input
  83                                 that is marked RELOAD_OTHER.
  84
  85    This used to be "enum reload_when_needed" but some debuggers have trouble
  86    with an enum tag and variable of the same name.  */
  87
  88 enum reload_type
  89 {
  90   RELOAD_FOR_INPUT, RELOAD_FOR_OUTPUT, RELOAD_FOR_INSN,
  91   RELOAD_FOR_INPUT_ADDRESS, RELOAD_FOR_INPADDR_ADDRESS,
  92   RELOAD_FOR_OUTPUT_ADDRESS, RELOAD_FOR_OUTADDR_ADDRESS,
  93   RELOAD_FOR_OPERAND_ADDRESS, RELOAD_FOR_OPADDR_ADDR,
  94   RELOAD_OTHER, RELOAD_FOR_OTHER_ADDRESS
  95 };
  96
  97 extern enum reload_type reload_when_needed[MAX_RELOADS];
  98
  99 extern rtx *reg_equiv_constant;
 100 extern rtx *reg_equiv_memory_loc;
 101 extern rtx *reg_equiv_address;
 102 extern rtx *reg_equiv_mem;
 103
 104 /* All the "earlyclobber" operands of the current insn
 105    are recorded here.  */
 106 extern int n_earlyclobbers;
 107 extern rtx reload_earlyclobbers[MAX_RECOG_OPERANDS];
 108
 109 /* Save the number of operands.  */
 110 extern int reload_n_operands;
 111
 112 /* First uid used by insns created by reload in this function.
 113    Used in find_equiv_reg.  */
 114 extern int reload_first_uid;
 115
 116 /* Nonzero if indirect addressing is supported when the innermost MEM is
 117    of the form (MEM (SYMBOL_REF sym)).  It is assumed that the level to
 118    which these are valid is the same as spill_indirect_levels, above.   */
 119
 120 extern char indirect_symref_ok;
 121
 122 /* Nonzero if an address (plus (reg frame_pointer) (reg ...)) is valid.  */
 123 extern char double_reg_address_ok;
 124
 125 #ifdef MAX_INSN_CODE
 126 /* These arrays record the insn_code of insns that may be needed to
 127    perform input and output reloads of special objects.  They provide a
 128    place to pass a scratch register.  */
 129 extern enum insn_code reload_in_optab[];
 130 extern enum insn_code reload_out_optab[];
 131 #endif
 132
 133 /* Functions from reload.c:  */
 134
 135 /* Return a memory location that will be used to copy X in mode MODE.
 136    If we haven't already made a location for this mode in this insn,
 137    call find_reloads_address on the location being returned.  */
 138 extern rtx get_secondary_mem PROTO((rtx, enum machine_mode,
 139                                     int, enum reload_type));
 140
 141 /* Clear any secondary memory locations we've made.  */
 142 extern void clear_secondary_mem PROTO((void));
 143
 144 /* Transfer all replacements that used to be in reload FROM to be in
 145    reload TO.  */
 146 extern void transfer_replacements PROTO((int, int));
 147
 148 /* Return 1 if ADDR is a valid memory address for mode MODE,
 149    and check that each pseudo reg has the proper kind of
 150    hard reg.  */
 151 extern int strict_memory_address_p PROTO((enum machine_mode, rtx));
 152
 153 /* Like rtx_equal_p except that it allows a REG and a SUBREG to match
 154    if they are the same hard reg, and has special hacks for
 155    autoincrement and autodecrement.  */
 156 extern int operands_match_p PROTO((rtx, rtx));
 157
 158 /* Return the number of times character C occurs in string S.  */
 159 extern int n_occurrences PROTO((int, char *));
 160
 161 /* Return 1 if altering OP will not modify the value of CLOBBER. */
 162 extern int safe_from_earlyclobber PROTO((rtx, rtx));
 163
 164 /* Search the body of INSN for values that need reloading and record them
 165    with push_reload.  REPLACE nonzero means record also where the values occur
 166    so that subst_reloads can be used.  */
 167 extern void find_reloads PROTO((rtx, int, int, int, short *));
 168
 169 /* Compute the sum of X and Y, making canonicalizations assumed in an
 170    address, namely: sum constant integers, surround the sum of two
 171    constants with a CONST, put the constant as the second operand, and
 172    group the constant on the outermost sum.  */
 173 extern rtx form_sum PROTO((rtx, rtx));
 174
 175 /* Substitute into the current INSN the registers into which we have reloaded
 176    the things that need reloading.  */
 177 extern void subst_reloads PROTO((void));
 178
 179 /* Make a copy of any replacements being done into X and move those copies
 180    to locations in Y, a copy of X.  We only look at the highest level of
 181    the RTL.  */
 182 extern void copy_replacements PROTO((rtx, rtx));
 183
 184 /* If LOC was scheduled to be replaced by something, return the replacement.
 185    Otherwise, return *LOC.  */
 186 extern rtx find_replacement PROTO((rtx *));
 187
 188 /* Return nonzero if register in range [REGNO, ENDREGNO)
 189    appears either explicitly or implicitly in X
 190    other than being stored into.  */
 191 extern int refers_to_regno_for_reload_p PROTO((int, int, rtx, rtx *));
 192
 193 /* Nonzero if modifying X will affect IN.  */
 194 extern int reg_overlap_mentioned_for_reload_p PROTO((rtx, rtx));
 195
 196 /* Return nonzero if anything in X contains a MEM.  Look also for pseudo
 197    registers.  */
 198 extern int refers_to_mem_for_reload_p PROTO((rtx));
 199
 200 /* Check the insns before INSN to see if there is a suitable register
 201    containing the same value as GOAL.  */
 202 extern rtx find_equiv_reg PROTO((rtx, rtx, enum reg_class, int, short *,
 203                                  int, enum machine_mode));
 204
 205 /* Return 1 if register REGNO is the subject of a clobber in insn INSN.  */
 206 extern int regno_clobbered_p PROTO((int, rtx));
 207
 208
 209 /* Functions in reload1.c:  */
 210
 211 /* Initialize the reload pass once per compilation.  */
 212 extern void init_reload PROTO((void));
 213
 214 /* The reload pass itself.  */
 215 extern int reload STDIO_PROTO((rtx, int, FILE *));
 216
 217 /* Mark the slots in regs_ever_live for the hard regs
 218    used by pseudo-reg number REGNO.  */
 219 extern void mark_home_live PROTO((int));
 220
 221 /* Scan X and replace any eliminable registers (such as fp) with a
 222    replacement (such as sp), plus an offset.  */
 223 extern rtx eliminate_regs PROTO((rtx, enum machine_mode, rtx, int));
 224
 225 /* Emit code to perform a reload from IN (which may be a reload register) to
 226    OUT (which may also be a reload register).  IN or OUT is from operand
 227    OPNUM with reload type TYPE.  */
 228 extern rtx gen_reload PROTO((rtx, rtx, int, enum reload_type));
 229
 230 /* Functions in caller-save.c:  */
 231
 232 /* Initialize for caller-save.  */
 233 extern void init_caller_save PROTO((void));
 234
 235 /* Initialize save areas by showing that we haven't allocated any yet.  */
 236 extern void init_save_areas PROTO((void));
 237
 238 /* Allocate save areas for any hard registers that might need saving.  */
 239 extern int setup_save_areas PROTO((int *));
 240
 241 /* Find the places where hard regs are live across calls and save them.  */
 242 extern void save_call_clobbered_regs PROTO((enum machine_mode));