gcc/config/nds32/nds32-cost.c

   1 /* Subroutines used for calculate rtx costs of Andes NDS32 cpu for GNU compiler
   2    Copyright (C) 2012-2016 Free Software Foundation, Inc.
   3    Contributed by Andes Technology Corporation.
   4
   5    This file is part of GCC.
   6
   7    GCC is free software; you can redistribute it and/or modify it
   8    under the terms of the GNU General Public License as published
   9    by the Free Software Foundation; either version 3, or (at your
  10    option) any later version.
  11
  12    GCC is distributed in the hope that it will be useful, but WITHOUT
  13    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  15    License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with GCC; see the file COPYING3.  If not see
  19    <http://www.gnu.org/licenses/>.  */
  20
  21 /* ------------------------------------------------------------------------ */
  22
  23 #include "config.h"
  24 #include "system.h"
  25 #include "coretypes.h"
  26 #include "backend.h"
  27 #include "target.h"
  28 #include "rtl.h"
  29 #include "tree.h"
  30 #include "tm_p.h"
  31 #include "optabs.h"             /* For GEN_FCN.  */
  32 #include "recog.h"
  33 #include "tm-constrs.h"
  34
  35 /* ------------------------------------------------------------------------ */
  36
  37 bool
  38 nds32_rtx_costs_impl (rtx x,
  39                       machine_mode mode ATTRIBUTE_UNUSED,
  40                       int outer_code,
  41                       int opno ATTRIBUTE_UNUSED,
  42                       int *total,
  43                       bool speed)
  44 {
  45   int code = GET_CODE (x);
  46
  47   /* According to 'speed', goto suitable cost model section.  */
  48   if (speed)
  49     goto performance_cost;
  50   else
  51     goto size_cost;
  52
  53
  54 performance_cost:
  55   /* This is section for performance cost model.  */
  56
  57   /* In gcc/rtl.h, the default value of COSTS_N_INSNS(N) is N*4.
  58      We treat it as 4-cycle cost for each instruction
  59      under performance consideration.  */
  60   switch (code)
  61     {
  62     case SET:
  63       /* For 'SET' rtx, we need to return false
  64          so that it can recursively calculate costs.  */
  65       return false;
  66
  67     case USE:
  68       /* Used in combine.c as a marker.  */
  69       *total = 0;
  70       break;
  71
  72     case MULT:
  73       *total = COSTS_N_INSNS (1);
  74       break;
  75
  76     case DIV:
  77     case UDIV:
  78     case MOD:
  79     case UMOD:
  80       *total = COSTS_N_INSNS (7);
  81       break;
  82
  83     default:
  84       *total = COSTS_N_INSNS (1);
  85       break;
  86     }
  87
  88   return true;
  89
  90
  91 size_cost:
  92   /* This is section for size cost model.  */
  93
  94   /* In gcc/rtl.h, the default value of COSTS_N_INSNS(N) is N*4.
  95      We treat it as 4-byte cost for each instruction
  96      under code size consideration.  */
  97   switch (code)
  98     {
  99     case SET:
 100       /* For 'SET' rtx, we need to return false
 101          so that it can recursively calculate costs.  */
 102       return false;
 103
 104     case USE:
 105       /* Used in combine.c as a marker.  */
 106       *total = 0;
 107       break;
 108
 109     case CONST_INT:
 110       /* All instructions involving constant operation
 111          need to be considered for cost evaluation.  */
 112       if (outer_code == SET)
 113         {
 114           /* (set X imm5s), use movi55, 2-byte cost.
 115              (set X imm20s), use movi, 4-byte cost.
 116              (set X BIG_INT), use sethi/ori, 8-byte cost.  */
 117           if (satisfies_constraint_Is05 (x))
 118             *total = COSTS_N_INSNS (1) - 2;
 119           else if (satisfies_constraint_Is20 (x))
 120             *total = COSTS_N_INSNS (1);
 121           else
 122             *total = COSTS_N_INSNS (2);
 123         }
 124       else if (outer_code == PLUS || outer_code == MINUS)
 125         {
 126           /* Possible addi333/subi333 or subi45/addi45, 2-byte cost.
 127              General case, cost 1 instruction with 4-byte.  */
 128           if (satisfies_constraint_Iu05 (x))
 129             *total = COSTS_N_INSNS (1) - 2;
 130           else
 131             *total = COSTS_N_INSNS (1);
 132         }
 133       else if (outer_code == ASHIFT)
 134         {
 135           /* Possible slli333, 2-byte cost.
 136              General case, cost 1 instruction with 4-byte.  */
 137           if (satisfies_constraint_Iu03 (x))
 138             *total = COSTS_N_INSNS (1) - 2;
 139           else
 140             *total = COSTS_N_INSNS (1);
 141         }
 142       else if (outer_code == ASHIFTRT || outer_code == LSHIFTRT)
 143         {
 144           /* Possible srai45 or srli45, 2-byte cost.
 145              General case, cost 1 instruction with 4-byte.  */
 146           if (satisfies_constraint_Iu05 (x))
 147             *total = COSTS_N_INSNS (1) - 2;
 148           else
 149             *total = COSTS_N_INSNS (1);
 150         }
 151       else
 152         {
 153           /* For other cases, simply set it 4-byte cost.  */
 154           *total = COSTS_N_INSNS (1);
 155         }
 156       break;
 157
 158     case CONST_DOUBLE:
 159       /* It requires high part and low part processing, set it 8-byte cost.  */
 160       *total = COSTS_N_INSNS (2);
 161       break;
 162
 163     default:
 164       /* For other cases, generally we set it 4-byte cost
 165          and stop resurively traversing.  */
 166       *total = COSTS_N_INSNS (1);
 167       break;
 168     }
 169
 170   return true;
 171 }
 172
 173 int
 174 nds32_address_cost_impl (rtx address,
 175                          machine_mode mode ATTRIBUTE_UNUSED,
 176                          addr_space_t as ATTRIBUTE_UNUSED,
 177                          bool speed)
 178 {
 179   rtx plus0, plus1;
 180   enum rtx_code code;
 181
 182   code = GET_CODE (address);
 183
 184   /* According to 'speed', goto suitable cost model section.  */
 185   if (speed)
 186     goto performance_cost;
 187   else
 188     goto size_cost;
 189
 190 performance_cost:
 191   /* This is section for performance cost model.  */
 192
 193   /* FALLTHRU, currently we use same cost model as size_cost.  */
 194
 195 size_cost:
 196   /* This is section for size cost model.  */
 197
 198   switch (code)
 199     {
 200     case POST_MODIFY:
 201     case POST_INC:
 202     case POST_DEC:
 203       /* We encourage that rtx contains
 204          POST_MODIFY/POST_INC/POST_DEC behavior.  */
 205       return 0;
 206
 207     case SYMBOL_REF:
 208       /* We can have gp-relative load/store for symbol_ref.
 209          Have it 4-byte cost.  */
 210       return COSTS_N_INSNS (1);
 211
 212     case CONST:
 213       /* It is supposed to be the pattern (const (plus symbol_ref const_int)).
 214          Have it 4-byte cost.  */
 215       return COSTS_N_INSNS (1);
 216
 217     case REG:
 218       /* Simply return 4-byte costs.  */
 219       return COSTS_N_INSNS (1);
 220
 221     case PLUS:
 222       /* We do not need to check if the address is a legitimate address,
 223          because this hook is never called with an invalid address.
 224          But we better check the range of
 225          const_int value for cost, if it exists.  */
 226       plus0 = XEXP (address, 0);
 227       plus1 = XEXP (address, 1);
 228
 229       if (REG_P (plus0) && CONST_INT_P (plus1))
 230         {
 231           /* If it is possible to be lwi333/swi333 form,
 232              make it 2-byte cost.  */
 233           if (satisfies_constraint_Iu05 (plus1))
 234             return (COSTS_N_INSNS (1) - 2);
 235           else
 236             return COSTS_N_INSNS (1);
 237         }
 238
 239       /* For other 'plus' situation, make it cost 4-byte.  */
 240       return COSTS_N_INSNS (1);
 241
 242     default:
 243       break;
 244     }
 245
 246   return COSTS_N_INSNS (4);
 247 }
 248
 249 /* ------------------------------------------------------------------------ */