optimization for "while 1" and "repeat until nil"

This commit is contained in:
Roberto Ierusalimschy 2000-03-17 11:46:04 -03:00
parent 2c8e28d75a
commit da7eb34cd6

21
lcode.c
View File

@ -1,5 +1,5 @@
/*
** $Id: lcode.c,v 1.13 2000/03/16 18:03:09 roberto Exp roberto $
** $Id: lcode.c,v 1.14 2000/03/17 13:09:46 roberto Exp roberto $
** Code generator for Lua
** See Copyright Notice in lua.h
*/
@ -337,8 +337,23 @@ static OpCode invertjump (OpCode op) {
static void luaK_jump (FuncState *fs, OpCode jump) {
Instruction previous = prepare(fs, CREATE_S(jump, 0), -1);
if (previous == CREATE_0(OP_NOT))
setprevious(fs, CREATE_S(invertjump(jump), 0));
switch (GET_OPCODE(previous)) {
case OP_NOT: previous = CREATE_S(invertjump(jump), 0); break;
case OP_PUSHINT:
if (jump == OP_IFTJMP) {
previous = CREATE_S(OP_JMP, 0);
break;
}
else return; /* do not set previous */
case OP_PUSHNIL:
if (jump == OP_IFFJMP) {
previous = CREATE_S(OP_JMP, 0);
break;
}
else return; /* do not set previous */
default: return;
}
setprevious(fs, previous);
}