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simpler version of `luaK_tostack'

This commit is contained in:
Roberto Ierusalimschy 2000-04-17 11:05:34 -03:00
parent 870f61d299
commit 71219ccc39
1 changed files with 25 additions and 40 deletions
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65
lcode.c
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@ -1,5 +1,5 @@
/*
** $Id: lcode.c,v 1.25 2000/04/13 16:51:01 roberto Exp roberto $
** $Id: lcode.c,v 1.26 2000/04/14 17:47:24 roberto Exp roberto $
** Code generator for Lua
** See Copyright Notice in lua.h
*/
@ -311,54 +311,39 @@ static int code_label (FuncState *fs, OpCode op, int arg) {
}
static void jump_to_value (FuncState *fs, expdesc *v, Instruction previous) {
int p_nil = NO_JUMP; /* position of an eventual PUSHNIL */
int p_1 = NO_JUMP; /* position of an eventual PUSHINT */
int final; /* position after whole expression */
if (ISJUMP(previous)) {
luaK_concat(fs, &v->u.l.t, fs->pc-1); /* put `previous' in true list */
p_nil = code_label(fs, OP_PUSHNILJMP, 0);
p_1 = code_label(fs, OP_PUSHINT, 1);
}
else { /* still may need a PUSHNIL or a PUSHINT */
int need_nil = need_value(fs, v->u.l.f, OP_JMPONF);
int need_1 = need_value(fs, v->u.l.t, OP_JMPONT);
if (need_nil && need_1) {
int j = code_label(fs, OP_JMP, 0); /* skip both pushes */
p_nil = code_label(fs, OP_PUSHNILJMP, 0);
p_1 = code_label(fs, OP_PUSHINT, 1);
luaK_patchlist(fs, j, luaK_getlabel(fs));
luaK_deltastack(fs, -1); /* previous PUSHINT may be skipped */
}
else if (need_nil || need_1) {
int j = code_label(fs, OP_JMP, 0); /* skip one push */
if (need_nil)
p_nil = code_label(fs, OP_PUSHNIL, 1);
else /* need_1 */
p_1 = code_label(fs, OP_PUSHINT, 1);
luaK_patchlist(fs, j, luaK_getlabel(fs));
luaK_deltastack(fs, -1); /* previous PUSHs may be skipped */
}
}
final = luaK_getlabel(fs);
luaK_patchlistaux(fs, v->u.l.f, p_nil, OP_JMPONF, final);
luaK_patchlistaux(fs, v->u.l.t, p_1, OP_JMPONT, final);
v->u.l.f = v->u.l.t = NO_JUMP;
}
void luaK_tostack (LexState *ls, expdesc *v, int onlyone) {
FuncState *fs = ls->fs;
if (!discharge(fs, v)) { /* `v' is an expression? */
OpCode previous = GET_OPCODE(fs->f->code[fs->pc-1]);
LUA_ASSERT(L, previous != OP_SETLINE, "bad place to set line");
if (!ISJUMP(previous) && v->u.l.f == NO_JUMP && v->u.l.t == NO_JUMP) {
/* it is an expression without jumps */
/* expression has no jumps */
if (onlyone)
luaK_setcallreturns(fs, 1); /* call must return 1 value */
}
else /* expression has jumps... */
jump_to_value(fs, v, previous);
else { /* expression has jumps */
int final; /* position after whole expression */
int j = NO_JUMP; /* eventual jump over values */
int p_nil = NO_JUMP; /* position of an eventual PUSHNIL */
int p_1 = NO_JUMP; /* position of an eventual PUSHINT */
if (ISJUMP(previous) || need_value(fs, v->u.l.f, OP_JMPONF) ||
need_value(fs, v->u.l.t, OP_JMPONT)) {
/* expression need values */
if (ISJUMP(previous))
luaK_concat(fs, &v->u.l.t, fs->pc-1); /* put `previous' in t. list */
else {
j = code_label(fs, OP_JMP, 0); /* to jump over both pushes */
luaK_deltastack(fs, -1); /* next PUSHes may be skipped */
}
p_nil = code_label(fs, OP_PUSHNILJMP, 0);
p_1 = code_label(fs, OP_PUSHINT, 1);
luaK_patchlist(fs, j, luaK_getlabel(fs));
}
final = luaK_getlabel(fs);
luaK_patchlistaux(fs, v->u.l.f, p_nil, OP_JMPONF, final);
luaK_patchlistaux(fs, v->u.l.t, p_1, OP_JMPONT, final);
v->u.l.f = v->u.l.t = NO_JUMP;
}
}
}