gcc/config/nds32/nds32-cost.c

   1 /* Subroutines used for calculate rtx costs of Andes NDS32 cpu for GNU compiler
   2    Copyright (C) 2012-2015 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 "tree.h"
  28 #include "rtl.h"
  29 #include "df.h"
  30 #include "alias.h"
  31 #include "stor-layout.h"
  32 #include "varasm.h"
  33 #include "calls.h"
  34 #include "regs.h"
  35 #include "insn-config.h"        /* Required by recog.h.  */
  36 #include "conditions.h"
  37 #include "output.h"
  38 #include "insn-attr.h"          /* For DFA state_t.  */
  39 #include "insn-codes.h"         /* For CODE_FOR_xxx.  */
  40 #include "reload.h"             /* For push_reload().  */
  41 #include "flags.h"
  42 #include "insn-config.h"
  43 #include "expmed.h"
  44 #include "dojump.h"
  45 #include "explow.h"
  46 #include "emit-rtl.h"
  47 #include "stmt.h"
  48 #include "expr.h"
  49 #include "recog.h"
  50 #include "diagnostic-core.h"
  51 #include "cfgrtl.h"
  52 #include "cfganal.h"
  53 #include "lcm.h"
  54 #include "cfgbuild.h"
  55 #include "cfgcleanup.h"
  56 #include "tm_p.h"
  57 #include "tm-constrs.h"
  58 #include "optabs.h"             /* For GEN_FCN.  */
  59 #include "target.h"
  60 #include "langhooks.h"          /* For add_builtin_function().  */
  61 #include "builtins.h"
  62
  63 /* ------------------------------------------------------------------------ */
  64
  65 bool
  66 nds32_rtx_costs_impl (rtx x,
  67                       machine_mode mode ATTRIBUTE_UNUSED,
  68                       int outer_code,
  69                       int opno ATTRIBUTE_UNUSED,
  70                       int *total,
  71                       bool speed)
  72 {
  73   int code = GET_CODE (x);
  74
  75   /* According to 'speed', goto suitable cost model section.  */
  76   if (speed)
  77     goto performance_cost;
  78   else
  79     goto size_cost;
  80
  81
  82 performance_cost:
  83   /* This is section for performance cost model.  */
  84
  85   /* In gcc/rtl.h, the default value of COSTS_N_INSNS(N) is N*4.
  86      We treat it as 4-cycle cost for each instruction
  87      under performance consideration.  */
  88   switch (code)
  89     {
  90     case SET:
  91       /* For 'SET' rtx, we need to return false
  92          so that it can recursively calculate costs.  */
  93       return false;
  94
  95     case USE:
  96       /* Used in combine.c as a marker.  */
  97       *total = 0;
  98       break;
  99
 100     case MULT:
 101       *total = COSTS_N_INSNS (1);
 102       break;
 103
 104     case DIV:
 105     case UDIV:
 106     case MOD:
 107     case UMOD:
 108       *total = COSTS_N_INSNS (7);
 109       break;
 110
 111     default:
 112       *total = COSTS_N_INSNS (1);
 113       break;
 114     }
 115
 116   return true;
 117
 118
 119 size_cost:
 120   /* This is section for size cost model.  */
 121
 122   /* In gcc/rtl.h, the default value of COSTS_N_INSNS(N) is N*4.
 123      We treat it as 4-byte cost for each instruction
 124      under code size consideration.  */
 125   switch (code)
 126     {
 127     case SET:
 128       /* For 'SET' rtx, we need to return false
 129          so that it can recursively calculate costs.  */
 130       return false;
 131
 132     case USE:
 133       /* Used in combine.c as a marker.  */
 134       *total = 0;
 135       break;
 136
 137     case CONST_INT:
 138       /* All instructions involving constant operation
 139          need to be considered for cost evaluation.  */
 140       if (outer_code == SET)
 141         {
 142           /* (set X imm5s), use movi55, 2-byte cost.
 143              (set X imm20s), use movi, 4-byte cost.
 144              (set X BIG_INT), use sethi/ori, 8-byte cost.  */
 145           if (satisfies_constraint_Is05 (x))
 146             *total = COSTS_N_INSNS (1) - 2;
 147           else if (satisfies_constraint_Is20 (x))
 148             *total = COSTS_N_INSNS (1);
 149           else
 150             *total = COSTS_N_INSNS (2);
 151         }
 152       else if (outer_code == PLUS || outer_code == MINUS)
 153         {
 154           /* Possible addi333/subi333 or subi45/addi45, 2-byte cost.
 155              General case, cost 1 instruction with 4-byte.  */
 156           if (satisfies_constraint_Iu05 (x))
 157             *total = COSTS_N_INSNS (1) - 2;
 158           else
 159             *total = COSTS_N_INSNS (1);
 160         }
 161       else if (outer_code == ASHIFT)
 162         {
 163           /* Possible slli333, 2-byte cost.
 164              General case, cost 1 instruction with 4-byte.  */
 165           if (satisfies_constraint_Iu03 (x))
 166             *total = COSTS_N_INSNS (1) - 2;
 167           else
 168             *total = COSTS_N_INSNS (1);
 169         }
 170       else if (outer_code == ASHIFTRT || outer_code == LSHIFTRT)
 171         {
 172           /* Possible srai45 or srli45, 2-byte cost.
 173              General case, cost 1 instruction with 4-byte.  */
 174           if (satisfies_constraint_Iu05 (x))
 175             *total = COSTS_N_INSNS (1) - 2;
 176           else
 177             *total = COSTS_N_INSNS (1);
 178         }
 179       else
 180         {
 181           /* For other cases, simply set it 4-byte cost.  */
 182           *total = COSTS_N_INSNS (1);
 183         }
 184       break;
 185
 186     case CONST_DOUBLE:
 187       /* It requires high part and low part processing, set it 8-byte cost.  */
 188       *total = COSTS_N_INSNS (2);
 189       break;
 190
 191     default:
 192       /* For other cases, generally we set it 4-byte cost
 193          and stop resurively traversing.  */
 194       *total = COSTS_N_INSNS (1);
 195       break;
 196     }
 197
 198   return true;
 199 }
 200
 201 int
 202 nds32_address_cost_impl (rtx address,
 203                          machine_mode mode ATTRIBUTE_UNUSED,
 204                          addr_space_t as ATTRIBUTE_UNUSED,
 205                          bool speed)
 206 {
 207   rtx plus0, plus1;
 208   enum rtx_code code;
 209
 210   code = GET_CODE (address);
 211
 212   /* According to 'speed', goto suitable cost model section.  */
 213   if (speed)
 214     goto performance_cost;
 215   else
 216     goto size_cost;
 217
 218 performance_cost:
 219   /* This is section for performance cost model.  */
 220
 221   /* FALLTHRU, currently we use same cost model as size_cost.  */
 222
 223 size_cost:
 224   /* This is section for size cost model.  */
 225
 226   switch (code)
 227     {
 228     case POST_MODIFY:
 229     case POST_INC:
 230     case POST_DEC:
 231       /* We encourage that rtx contains
 232          POST_MODIFY/POST_INC/POST_DEC behavior.  */
 233       return 0;
 234
 235     case SYMBOL_REF:
 236       /* We can have gp-relative load/store for symbol_ref.
 237          Have it 4-byte cost.  */
 238       return COSTS_N_INSNS (1);
 239
 240     case CONST:
 241       /* It is supposed to be the pattern (const (plus symbol_ref const_int)).
 242          Have it 4-byte cost.  */
 243       return COSTS_N_INSNS (1);
 244
 245     case REG:
 246       /* Simply return 4-byte costs.  */
 247       return COSTS_N_INSNS (1);
 248
 249     case PLUS:
 250       /* We do not need to check if the address is a legitimate address,
 251          because this hook is never called with an invalid address.
 252          But we better check the range of
 253          const_int value for cost, if it exists.  */
 254       plus0 = XEXP (address, 0);
 255       plus1 = XEXP (address, 1);
 256
 257       if (REG_P (plus0) && CONST_INT_P (plus1))
 258         {
 259           /* If it is possible to be lwi333/swi333 form,
 260              make it 2-byte cost.  */
 261           if (satisfies_constraint_Iu05 (plus1))
 262             return (COSTS_N_INSNS (1) - 2);
 263           else
 264             return COSTS_N_INSNS (1);
 265         }
 266
 267       /* For other 'plus' situation, make it cost 4-byte.  */
 268       return COSTS_N_INSNS (1);
 269
 270     default:
 271       break;
 272     }
 273
 274   return COSTS_N_INSNS (4);
 275 }
 276
 277 /* ------------------------------------------------------------------------ */