/*
** $Id: lcode.c,v 2.25.1.5 2011/01/31 14:53:16 roberto Exp $
** Code generator for Lua
** See Copyright Notice in lua.h
*/
#include <stdlib.h>
#define lcode_c
#define LUA_CORE
#include "lua.h"
#include "lcode.h"
#include "ldebug.h"
#include "ldo.h"
#include "lgc.h"
#include "llex.h"
#include "lmem.h"
#include "lobject.h"
#include "lopcodes.h"
#include "lparser.h"
#include "ltable.h"
#define hasjumps(e) ((e)->t != (e)->f)
static int isnumeral(expdesc *e) {
return (e->k == VKNUM && e->t == NO_JUMP && e->f == NO_JUMP);
}
void luaK_nil (FuncState *fs, int from, int n) {
Instruction *previous;
if (fs->pc > fs->lasttarget) { /* no jumps to current position? */
if (fs->pc == 0) { /* function start? */
if (from >= fs->nactvar)
return; /* positions are already clean */
}
else {
previous = &fs->f->code[fs->pc-1];
if (GET_OPCODE(*previous) == OP_LOADNIL) {
int pfrom = GETARG_A(*previous);
int pto = GETARG_B(*previous);
if (pfrom <= from && from <= pto+1) { /* can connect both? */
if (from+n-1 > pto)
SETARG_B(*previous, from+n-1);
return;
}
}
}
}
luaK_codeABC(fs, OP_LOADNIL, from, from+n-1, 0); /* else no optimization */
}
int luaK_jump (FuncState *fs) {
int jpc = fs->jpc; /* save list of jumps to here */
int j;
fs->jpc = NO_JUMP;
j = luaK_codeAsBx(fs, OP_JMP, 0, NO_JUMP);
luaK_concat(fs, &j, jpc); /* keep them on hold */
return j;
}
void luaK_ret (FuncState *fs, int first, int nret) {
luaK_codeABC(fs, OP_RETURN, first, nret+1, 0);
}
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