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small improvements

This commit is contained in:
Roberto Ierusalimschy 2002-01-18 15:39:40 -02:00
parent 448517e47e
commit b38e594ed7
1 changed files with 6 additions and 21 deletions
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27
lcode.c
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@ -31,27 +31,15 @@ void luaK_error (LexState *ls, const char *msg) {
} }
/*
** Returns the the previous instruction, for optimizations.
** If there is a jump target between this and the current instruction,
** returns a dummy instruction to avoid wrong optimizations.
*/
static Instruction previous_instruction (FuncState *fs) {
if (fs->pc > fs->lasttarget) /* no jumps to current position? */
return fs->f->code[fs->pc-1]; /* returns previous instruction */
else
return cast(Instruction, -1);/* invalid instruction avoids optimizations */
}
void luaK_nil (FuncState *fs, int from, int n) { void luaK_nil (FuncState *fs, int from, int n) {
Instruction previous = previous_instruction(fs); Instruction *previous;
if (GET_OPCODE(previous) == OP_LOADNIL) { if (fs->pc > fs->lasttarget && /* no jumps to current position? */
int pfrom = GETARG_A(previous); GET_OPCODE(*(previous = &fs->f->code[fs->pc-1])) == OP_LOADNIL) {
int pto = GETARG_B(previous); int pfrom = GETARG_A(*previous);
int pto = GETARG_B(*previous);
if (pfrom <= from && from <= pto+1) { /* can connect both? */ if (pfrom <= from && from <= pto+1) { /* can connect both? */
if (from+n-1 > pto) if (from+n-1 > pto)
SETARG_B(fs->f->code[fs->pc-1], from+n-1); SETARG_B(*previous, from+n-1);
return; return;
} }
} }
@ -126,8 +114,6 @@ static int luaK_getjump (FuncState *fs, int pc) {
static Instruction *getjumpcontrol (FuncState *fs, int pc) { static Instruction *getjumpcontrol (FuncState *fs, int pc) {
Instruction *pi = &fs->f->code[pc]; Instruction *pi = &fs->f->code[pc];
OpCode op = GET_OPCODE(*pi);
lua_assert(op == OP_JMP || op == OP_FORLOOP || op == OP_TFORLOOP);
if (pc >= 1 && testOpMode(GET_OPCODE(*(pi-1)), OpModeT)) if (pc >= 1 && testOpMode(GET_OPCODE(*(pi-1)), OpModeT))
return pi-1; return pi-1;
else else
@ -790,7 +776,6 @@ static int luaK_code (FuncState *fs, Instruction i) {
luaM_growvector(fs->L, f->code, fs->pc, f->sizecode, Instruction, luaM_growvector(fs->L, f->code, fs->pc, f->sizecode, Instruction,
MAX_INT, "code size overflow"); MAX_INT, "code size overflow");
f->code[fs->pc] = i; f->code[fs->pc] = i;
/*printf("free: %d ", fs->freereg); printopcode(f, fs->pc);*/
return fs->pc++; return fs->pc++;
} }