diff options
Diffstat (limited to 'lcode.c')
| -rw-r--r-- | lcode.c | 65 |
1 files changed, 25 insertions, 40 deletions
| @@ -1,5 +1,5 @@ | |||
| 1 | /* | 1 | /* |
| 2 | ** $Id: lcode.c,v 1.25 2000/04/13 16:51:01 roberto Exp roberto $ | 2 | ** $Id: lcode.c,v 1.26 2000/04/14 17:47:24 roberto Exp roberto $ |
| 3 | ** Code generator for Lua | 3 | ** Code generator for Lua |
| 4 | ** See Copyright Notice in lua.h | 4 | ** See Copyright Notice in lua.h |
| 5 | */ | 5 | */ |
| @@ -311,54 +311,39 @@ static int code_label (FuncState *fs, OpCode op, int arg) { | |||
| 311 | } | 311 | } |
| 312 | 312 | ||
| 313 | 313 | ||
| 314 | static void jump_to_value (FuncState *fs, expdesc *v, Instruction previous) { | ||
| 315 | int p_nil = NO_JUMP; /* position of an eventual PUSHNIL */ | ||
| 316 | int p_1 = NO_JUMP; /* position of an eventual PUSHINT */ | ||
| 317 | int final; /* position after whole expression */ | ||
| 318 | if (ISJUMP(previous)) { | ||
| 319 | luaK_concat(fs, &v->u.l.t, fs->pc-1); /* put `previous' in true list */ | ||
| 320 | p_nil = code_label(fs, OP_PUSHNILJMP, 0); | ||
| 321 | p_1 = code_label(fs, OP_PUSHINT, 1); | ||
| 322 | } | ||
| 323 | else { /* still may need a PUSHNIL or a PUSHINT */ | ||
| 324 | int need_nil = need_value(fs, v->u.l.f, OP_JMPONF); | ||
| 325 | int need_1 = need_value(fs, v->u.l.t, OP_JMPONT); | ||
| 326 | if (need_nil && need_1) { | ||
| 327 | int j = code_label(fs, OP_JMP, 0); /* skip both pushes */ | ||
| 328 | p_nil = code_label(fs, OP_PUSHNILJMP, 0); | ||
| 329 | p_1 = code_label(fs, OP_PUSHINT, 1); | ||
| 330 | luaK_patchlist(fs, j, luaK_getlabel(fs)); | ||
| 331 | luaK_deltastack(fs, -1); /* previous PUSHINT may be skipped */ | ||
| 332 | } | ||
| 333 | else if (need_nil || need_1) { | ||
| 334 | int j = code_label(fs, OP_JMP, 0); /* skip one push */ | ||
| 335 | if (need_nil) | ||
| 336 | p_nil = code_label(fs, OP_PUSHNIL, 1); | ||
| 337 | else /* need_1 */ | ||
| 338 | p_1 = code_label(fs, OP_PUSHINT, 1); | ||
| 339 | luaK_patchlist(fs, j, luaK_getlabel(fs)); | ||
| 340 | luaK_deltastack(fs, -1); /* previous PUSHs may be skipped */ | ||
| 341 | } | ||
| 342 | } | ||
| 343 | final = luaK_getlabel(fs); | ||
| 344 | luaK_patchlistaux(fs, v->u.l.f, p_nil, OP_JMPONF, final); | ||
| 345 | luaK_patchlistaux(fs, v->u.l.t, p_1, OP_JMPONT, final); | ||
| 346 | v->u.l.f = v->u.l.t = NO_JUMP; | ||
| 347 | } | ||
| 348 | |||
| 349 | |||
| 350 | void luaK_tostack (LexState *ls, expdesc *v, int onlyone) { | 314 | void luaK_tostack (LexState *ls, expdesc *v, int onlyone) { |
| 351 | FuncState *fs = ls->fs; | 315 | FuncState *fs = ls->fs; |
| 352 | if (!discharge(fs, v)) { /* `v' is an expression? */ | 316 | if (!discharge(fs, v)) { /* `v' is an expression? */ |
| 353 | OpCode previous = GET_OPCODE(fs->f->code[fs->pc-1]); | 317 | OpCode previous = GET_OPCODE(fs->f->code[fs->pc-1]); |
| 354 | LUA_ASSERT(L, previous != OP_SETLINE, "bad place to set line"); | 318 | LUA_ASSERT(L, previous != OP_SETLINE, "bad place to set line"); |
| 355 | if (!ISJUMP(previous) && v->u.l.f == NO_JUMP && v->u.l.t == NO_JUMP) { | 319 | if (!ISJUMP(previous) && v->u.l.f == NO_JUMP && v->u.l.t == NO_JUMP) { |
| 356 | /* it is an expression without jumps */ | 320 | /* expression has no jumps */ |
| 357 | if (onlyone) | 321 | if (onlyone) |
| 358 | luaK_setcallreturns(fs, 1); /* call must return 1 value */ | 322 | luaK_setcallreturns(fs, 1); /* call must return 1 value */ |
| 359 | } | 323 | } |
| 360 | else /* expression has jumps... */ | 324 | else { /* expression has jumps */ |
| 361 | jump_to_value(fs, v, previous); | 325 | int final; /* position after whole expression */ |
| 326 | int j = NO_JUMP; /* eventual jump over values */ | ||
| 327 | int p_nil = NO_JUMP; /* position of an eventual PUSHNIL */ | ||
| 328 | int p_1 = NO_JUMP; /* position of an eventual PUSHINT */ | ||
| 329 | if (ISJUMP(previous) || need_value(fs, v->u.l.f, OP_JMPONF) || | ||
| 330 | need_value(fs, v->u.l.t, OP_JMPONT)) { | ||
| 331 | /* expression need values */ | ||
| 332 | if (ISJUMP(previous)) | ||
| 333 | luaK_concat(fs, &v->u.l.t, fs->pc-1); /* put `previous' in t. list */ | ||
| 334 | else { | ||
| 335 | j = code_label(fs, OP_JMP, 0); /* to jump over both pushes */ | ||
| 336 | luaK_deltastack(fs, -1); /* next PUSHes may be skipped */ | ||
| 337 | } | ||
| 338 | p_nil = code_label(fs, OP_PUSHNILJMP, 0); | ||
| 339 | p_1 = code_label(fs, OP_PUSHINT, 1); | ||
| 340 | luaK_patchlist(fs, j, luaK_getlabel(fs)); | ||
| 341 | } | ||
| 342 | final = luaK_getlabel(fs); | ||
| 343 | luaK_patchlistaux(fs, v->u.l.f, p_nil, OP_JMPONF, final); | ||
| 344 | luaK_patchlistaux(fs, v->u.l.t, p_1, OP_JMPONT, final); | ||
| 345 | v->u.l.f = v->u.l.t = NO_JUMP; | ||
| 346 | } | ||
| 362 | } | 347 | } |
| 363 | } | 348 | } |
| 364 | 349 | ||
