gcc/reload.h

   1 /* Communication between reload.c and reload1.c.
   2    Copyright (C) 1987, 1991, 1992, 1993, 1994 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, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20
  21 /* Add prototype support.  */
  22 #ifndef PROTO
  23 #if defined (USE_PROTOTYPES) ? USE_PROTOTYPES : defined (__STDC__)
  24 #define PROTO(ARGS) ARGS
  25 #else
  26 #define PROTO(ARGS) ()
  27 #endif
  28 #endif
  29
  30 #ifndef STDIO_PROTO
  31 #ifdef BUFSIZ
  32 #define STDIO_PROTO(ARGS) PROTO(ARGS)
  33 #else
  34 #define STDIO_PROTO(ARGS) ()
  35 #endif
  36 #endif
  37
  38 /* If secondary reloads are the same for inputs and outputs, define those
  39    macros here.  */
  40
  41 #ifdef SECONDARY_RELOAD_CLASS
  42 #define SECONDARY_INPUT_RELOAD_CLASS(CLASS, MODE, X) \
  43   SECONDARY_RELOAD_CLASS (CLASS, MODE, X)
  44 #define SECONDARY_OUTPUT_RELOAD_CLASS(CLASS, MODE, X) \
  45   SECONDARY_RELOAD_CLASS (CLASS, MODE, X)
  46 #endif
  47
  48 /* If either macro is defined, show that we need secondary reloads.  */
  49 #if defined(SECONDARY_INPUT_RELOAD_CLASS) || defined(SECONDARY_OUTPUT_RELOAD_CLASS)
  50 #define HAVE_SECONDARY_RELOADS
  51 #endif
  52
  53 /* See reload.c and reload1.c for comments on these variables.  */
  54
  55 /* Maximum number of reloads we can need.  */
  56 #define MAX_RELOADS (2 * MAX_RECOG_OPERANDS * (MAX_REGS_PER_ADDRESS + 1))
  57
  58 extern rtx reload_in[MAX_RELOADS];
  59 extern rtx reload_out[MAX_RELOADS];
  60 extern rtx reload_in_reg[MAX_RELOADS];
  61 extern enum reg_class reload_reg_class[MAX_RELOADS];
  62 extern enum machine_mode reload_inmode[MAX_RELOADS];
  63 extern enum machine_mode reload_outmode[MAX_RELOADS];
  64 extern char reload_optional[MAX_RELOADS];
  65 extern int reload_inc[MAX_RELOADS];
  66 extern int reload_opnum[MAX_RELOADS];
  67 extern int reload_secondary_p[MAX_RELOADS];
  68 extern int reload_secondary_in_reload[MAX_RELOADS];
  69 extern int reload_secondary_out_reload[MAX_RELOADS];
  70 #ifdef MAX_INSN_CODE
  71 extern enum insn_code reload_secondary_in_icode[MAX_RELOADS];
  72 extern enum insn_code reload_secondary_out_icode[MAX_RELOADS];
  73 #endif
  74 extern int n_reloads;
  75
  76 extern rtx reload_reg_rtx[MAX_RELOADS];
  77
  78 /* Encode the usage of a reload.  The following codes are supported:
  79
  80    RELOAD_FOR_INPUT             reload of an input operand
  81    RELOAD_FOR_OUTPUT            likewise, for output
  82    RELOAD_FOR_INSN              a reload that must not conflict with anything
  83                                 used in the insn, but may conflict with
  84                                 something used before or after the insn
  85    RELOAD_FOR_INPUT_ADDRESS     reload for parts of the address of an object
  86                                 that is an input reload
  87    RELOAD_FOR_OUTPUT_ADDRESS    likewise, for output reload
  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_OTHER                 none of the above, usually multiple uses
  92    RELOAD_FOR_OTHER_ADDRESS     reload for part of the address of an input
  93                                 that is marked RELOAD_OTHER.
  94
  95    This used to be "enum reload_when_needed" but some debuggers have trouble
  96    with an enum tag and variable of the same name.  */
  97
  98 enum reload_type
  99 {
 100   RELOAD_FOR_INPUT, RELOAD_FOR_OUTPUT, RELOAD_FOR_INSN,
 101   RELOAD_FOR_INPUT_ADDRESS, RELOAD_FOR_OUTPUT_ADDRESS,
 102   RELOAD_FOR_OPERAND_ADDRESS, RELOAD_OTHER, RELOAD_FOR_OTHER_ADDRESS
 103 };
 104
 105 extern enum reload_type reload_when_needed[MAX_RELOADS];
 106
 107 extern rtx *reg_equiv_constant;
 108 extern rtx *reg_equiv_memory_loc;
 109 extern rtx *reg_equiv_address;
 110 extern rtx *reg_equiv_mem;
 111
 112 /* All the "earlyclobber" operands of the current insn
 113    are recorded here.  */
 114 extern int n_earlyclobbers;
 115 extern rtx reload_earlyclobbers[MAX_RECOG_OPERANDS];
 116
 117 /* Save the number of operands.  */
 118 extern int reload_n_operands;
 119
 120 /* First uid used by insns created by reload in this function.
 121    Used in find_equiv_reg.  */
 122 extern int reload_first_uid;
 123
 124 /* Nonzero if indirect addressing is supported when the innermost MEM is
 125    of the form (MEM (SYMBOL_REF sym)).  It is assumed that the level to
 126    which these are valid is the same as spill_indirect_levels, above.   */
 127
 128 extern char indirect_symref_ok;
 129
 130 /* Nonzero if an address (plus (reg frame_pointer) (reg ...)) is valid.  */
 131 extern char double_reg_address_ok;
 132
 133 #ifdef MAX_INSN_CODE
 134 /* These arrays record the insn_code of insns that may be needed to
 135    perform input and output reloads of special objects.  They provide a
 136    place to pass a scratch register.  */
 137 extern enum insn_code reload_in_optab[];
 138 extern enum insn_code reload_out_optab[];
 139 #endif
 140
 141 /* Functions from reload.c:  */
 142
 143 /* Return a memory location that will be used to copy X in mode MODE.
 144    If we haven't already made a location for this mode in this insn,
 145    call find_reloads_address on the location being returned.  */
 146 extern rtx get_secondary_mem PROTO((rtx, enum machine_mode,
 147                                     int, enum reload_type));
 148
 149 /* Clear any secondary memory locations we've made.  */
 150 extern void clear_secondary_mem PROTO((void));
 151
 152 /* Transfer all replacements that used to be in reload FROM to be in
 153    reload TO.  */
 154 extern void transfer_replacements PROTO((int, int));
 155
 156 /* Return 1 if ADDR is a valid memory address for mode MODE,
 157    and check that each pseudo reg has the proper kind of
 158    hard reg.  */
 159 extern int strict_memory_address_p PROTO((enum machine_mode, rtx));
 160
 161 /* Like rtx_equal_p except that it allows a REG and a SUBREG to match
 162    if they are the same hard reg, and has special hacks for
 163    autoincrement and autodecrement.  */
 164 extern int operands_match_p PROTO((rtx, rtx));
 165
 166 /* Return the number of times character C occurs in string S.  */
 167 extern int n_occurrences PROTO((int, char *));
 168
 169 /* Return 1 if altering OP will not modify the value of CLOBBER. */
 170 extern int safe_from_earlyclobber PROTO((rtx, rtx));
 171
 172 /* Search the body of INSN for values that need reloading and record them
 173    with push_reload.  REPLACE nonzero means record also where the values occur
 174    so that subst_reloads can be used.  */
 175 extern void find_reloads PROTO((rtx, int, int, int, short *));
 176
 177 /* Compute the sum of X and Y, making canonicalizations assumed in an
 178    address, namely: sum constant integers, surround the sum of two
 179    constants with a CONST, put the constant as the second operand, and
 180    group the constant on the outermost sum.  */
 181 extern rtx form_sum PROTO((rtx, rtx));
 182
 183 /* Substitute into the current INSN the registers into which we have reloaded
 184    the things that need reloading.  */
 185 extern void subst_reloads PROTO((void));
 186
 187 /* Make a copy of any replacements being done into X and move those copies
 188    to locations in Y, a copy of X.  We only look at the highest level of
 189    the RTL.  */
 190 extern void copy_replacements PROTO((rtx, rtx));
 191
 192 /* If LOC was scheduled to be replaced by something, return the replacement.
 193    Otherwise, return *LOC.  */
 194 extern rtx find_replacement PROTO((rtx *));
 195
 196 /* Return nonzero if register in range [REGNO, ENDREGNO)
 197    appears either explicitly or implicitly in X
 198    other than being stored into.  */
 199 extern int refers_to_regno_for_reload_p PROTO((int, int, rtx, rtx *));
 200
 201 /* Nonzero if modifying X will affect IN.  */
 202 extern int reg_overlap_mentioned_for_reload_p PROTO((rtx, rtx));
 203
 204 /* Return nonzero if anything in X contains a MEM.  Look also for pseudo
 205    registers.  */
 206 extern int refers_to_mem_for_reload_p PROTO((rtx));
 207
 208 /* Check the insns before INSN to see if there is a suitable register
 209    containing the same value as GOAL.  */
 210 extern rtx find_equiv_reg PROTO((rtx, rtx, enum reg_class, int, short *,
 211                                  int, enum machine_mode));
 212
 213 /* Return 1 if register REGNO is the subject of a clobber in insn INSN.  */
 214 extern int regno_clobbered_p PROTO((int, rtx));
 215
 216
 217 /* Functions in reload1.c:  */
 218
 219 /* Initialize the reload pass once per compilation.  */
 220 extern void init_reload PROTO((void));
 221
 222 /* The reload pass itself.  */
 223 extern int reload STDIO_PROTO((rtx, int, FILE *));
 224
 225 /* Mark the slots in regs_ever_live for the hard regs
 226    used by pseudo-reg number REGNO.  */
 227 extern void mark_home_live PROTO((int));
 228
 229 /* Scan X and replace any eliminable registers (such as fp) with a
 230    replacement (such as sp), plus an offset.  */
 231 extern rtx eliminate_regs PROTO((rtx, enum machine_mode, rtx));
 232
 233 /* Emit code to perform an input reload of IN to RELOADREG.  IN is from
 234    operand OPNUM with reload type TYPE.   */
 235 extern rtx gen_input_reload PROTO((rtx, rtx, int, enum reload_type));
 236
 237 /* Functions in caller-save.c:  */
 238
 239 /* Initialize for caller-save.  */
 240 extern void init_caller_save PROTO((void));
 241
 242 /* Initialize save areas by showing that we haven't allocated any yet.  */
 243 extern void init_save_areas PROTO((void));
 244
 245 /* Allocate save areas for any hard registers that might need saving.  */
 246 extern int setup_save_areas PROTO((int *));
 247
 248 /* Find the places where hard regs are live across calls and save them.  */
 249 extern void save_call_clobbered_regs PROTO((enum machine_mode));