sdcc/src/z80/peeph-z80.def

   1 // peeph-z80.def - Z80 peephole rules
   2 //
   3 // Some of these peepholes could be potentially moved to peeph.def, but a
   4 // GBZ80 expert should have a look at them before.
   5 //
   6 // (c) Philipp Klaus Krause (pkk@spth.de, philipp@colecovision.eu) 2006 - 2020
   7 //
   8 // This program is free software; you can redistribute it and/or modify it
   9 // under the terms of the GNU General Public License as published by the
  10 // Free Software Foundation; either version 2, or (at your option) any
  11 // later version.
  12 //
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17 //
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  21
  22 replace restart {
  23         xor     a, a
  24         ld      %1 (%2), a
  25 } by {
  26         ld      %1 (%2), #0
  27         ; peephole 178 direct load zero constant to memory addressed by index register
  28 } if notUsed('a'), canAssign(%1 %2 '#0')