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implementation of BREAK

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This commit is contained in:
Roberto Ierusalimschy
2000-04-05 14:51:58 -03:00
parent 9f734094f9
commit 22329e4cdf
6 changed files with 168 additions and 117 deletions
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92
lcode.c
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@@ -1,5 +1,5 @@
/*
** $Id: lcode.c,v 1.18 2000/03/24 17:26:08 roberto Exp roberto $
** $Id: lcode.c,v 1.19 2000/04/04 20:48:44 roberto Exp roberto $
** Code generator for Lua
** See Copyright Notice in lua.h
*/
@@ -23,6 +23,18 @@ void luaK_error (LexState *ls, const char *msg) {
luaX_error(ls, msg, ls->token);
}
/*
** 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 CREATE_0(OP_END); /* no optimizations after an `END' */
}
int luaK_code (FuncState *fs, Instruction i, int delta) {
luaK_deltastack(fs, delta);
@@ -48,19 +60,6 @@ int luaK_AB(FuncState *fs, OpCode o, int a, int b, int d) {
}
/*
** 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 CREATE_0(OP_END); /* no optimizations after an `END' */
}
static Instruction prepare (FuncState *fs, Instruction i, int delta) {
Instruction previous = previous_instruction(fs);
luaK_code(fs, i, delta);
@@ -154,7 +153,7 @@ static void luaK_setlocal (FuncState *fs, int l) {
static void luaK_eq (FuncState *fs) {
/* PUSHNIL 1; JMPEQ -> NOT (a==nil) */
Instruction previous = prepare(fs, CREATE_S(OP_JMPEQ, 0), -2);
Instruction previous = prepare(fs, CREATE_S(OP_JMPEQ, NO_JUMP), -2);
if (previous == CREATE_U(OP_PUSHNIL, 1)) {
setprevious(fs, CREATE_0(OP_NOT));
luaK_deltastack(fs, 1); /* undo delta from `prepare' */
@@ -164,13 +163,18 @@ static void luaK_eq (FuncState *fs) {
static void luaK_neq (FuncState *fs) {
/* PUSHNIL 1; JMPNEQ -> JMPT (a~=nil) */
Instruction previous = prepare(fs, CREATE_S(OP_JMPNEQ, 0), -2);
Instruction previous = prepare(fs, CREATE_S(OP_JMPNEQ, NO_JUMP), -2);
if (previous == CREATE_U(OP_PUSHNIL, 1)) {
setprevious(fs, CREATE_S(OP_JMPT, 0));
setprevious(fs, CREATE_S(OP_JMPT, NO_JUMP));
}
}
int luaK_jump (FuncState *fs) {
return luaK_S(fs, OP_JMP, NO_JUMP, 0);
}
void luaK_retcode (FuncState *fs, int nlocals, int nexps) {
Instruction previous = prepare(fs, CREATE_U(OP_RETURN, nlocals), 0);
if (nexps > 0 && GET_OPCODE(previous) == OP_CALL) {
@@ -192,12 +196,13 @@ static void luaK_pushnil (FuncState *fs, int n) {
}
void luaK_fixjump (FuncState *fs, int pc, int dest) {
static void luaK_fixjump (FuncState *fs, int pc, int dest) {
Instruction *jmp = &fs->f->code[pc];
if (dest == NO_JUMP)
SETARG_S(*jmp, 0); /* absolute value to represent end of list */
SETARG_S(*jmp, NO_JUMP); /* point to itself to represent end of list */
else { /* jump is relative to position following jump instruction */
int offset = dest-(pc+1);
LUA_ASSERT(L, offset != NO_JUMP, "cannot link to itself");
if (abs(offset) > MAXARG_S)
luaK_error(fs->ls, "control structure too long");
SETARG_S(*jmp, offset);
@@ -207,7 +212,7 @@ void luaK_fixjump (FuncState *fs, int pc, int dest) {
static int luaK_getjump (FuncState *fs, int pc) {
int offset = GETARG_S(fs->f->code[pc]);
if (offset == 0)
if (offset == NO_JUMP) /* point to itself represents end of list */
return NO_JUMP; /* end of list */
else
return (pc+1)+offset; /* turn offset into absolute position */
@@ -225,11 +230,11 @@ int luaK_getlabel (FuncState *fs) {
void luaK_deltastack (FuncState *fs, int delta) {
fs->stacksize += delta;
if (delta > 0 && fs->stacksize > fs->f->maxstacksize) {
if (fs->stacksize > MAXSTACK)
fs->stacklevel += delta;
if (delta > 0 && fs->stacklevel > fs->f->maxstacksize) {
if (fs->stacklevel > MAXSTACK)
luaK_error(fs->ls, "function or expression too complex");
fs->f->maxstacksize = fs->stacksize;
fs->f->maxstacksize = fs->stacklevel;
}
}
@@ -357,29 +362,16 @@ static OpCode invertjump (OpCode op) {
}
static void luaK_jump (FuncState *fs, OpCode jump) {
Instruction previous = prepare(fs, CREATE_S(jump, 0), -1);
static void luaK_condjump (FuncState *fs, OpCode jump) {
Instruction previous = prepare(fs, CREATE_S(jump, NO_JUMP), -1);
switch (GET_OPCODE(previous)) {
case OP_NOT: previous = CREATE_S(invertjump(jump), 0); break;
case OP_PUSHNIL: /* optimize `repeat until nil' */
if (GETARG_U(previous) == 1 && jump == OP_JMPF) {
previous = CREATE_S(OP_JMP, 0);
break;
}
else return; /* do not set previous */
case OP_NOT: previous = CREATE_S(invertjump(jump), NO_JUMP); break;
default: return;
}
setprevious(fs, previous);
}
static void insert_last (FuncState *fs, int *list) {
int first = *list;
*list = fs->pc-1; /* insert last instruction in the list */
luaK_fixjump(fs, *list, first);
}
static void luaK_patchlistaux (FuncState *fs, int list, int target,
OpCode special, int special_target) {
Instruction *code = fs->f->code;
@@ -414,7 +406,7 @@ static int need_value (FuncState *fs, int list, OpCode hasvalue) {
}
static void concatlists (FuncState *fs, int *l1, int l2) {
void luaK_concat (FuncState *fs, int *l1, int l2) {
if (*l1 == NO_JUMP)
*l1 = l2;
else {
@@ -446,8 +438,8 @@ static void luaK_testgo (FuncState *fs, expdesc *v, int invert, OpCode jump) {
SET_OPCODE(*previous, invertjump(GET_OPCODE(*previous)));
}
else
luaK_jump(fs, jump);
insert_last(fs, exitlist);
luaK_condjump(fs, jump);
luaK_concat(fs, exitlist, fs->pc-1); /* insert last jump in `exitlist' */
luaK_patchlist(fs, *golist, luaK_getlabel(fs));
*golist = NO_JUMP;
}
@@ -478,7 +470,7 @@ void luaK_tostack (LexState *ls, expdesc *v, int onlyone) {
int p_1 = 0; /* position of an eventual PUSHINT */
int final; /* position after whole expression */
if (ISJUMP(previous)) {
insert_last(fs, &v->u.l.t); /* put `previous' in true list */
luaK_concat(fs, &v->u.l.t, fs->pc-1); /* put `previous' in true list */
p_nil = luaK_0(fs, OP_PUSHNILJMP, 0);
p_1 = luaK_S(fs, OP_PUSHINT, 1, 1);
}
@@ -544,13 +536,13 @@ void luaK_posfix (LexState *ls, int op, expdesc *v1, expdesc *v2) {
LUA_ASSERT(ls->L, v1->u.l.t == NO_JUMP, "list must be closed");
discharge1(fs, v2);
v1->u.l.t = v2->u.l.t;
concatlists(fs, &v1->u.l.f, v2->u.l.f);
luaK_concat(fs, &v1->u.l.f, v2->u.l.f);
}
else if (op == TK_OR) {
LUA_ASSERT(ls->L, v1->u.l.f == NO_JUMP, "list must be closed");
discharge1(fs, v2);
v1->u.l.f = v2->u.l.f;
concatlists(fs, &v1->u.l.t, v2->u.l.t);
luaK_concat(fs, &v1->u.l.t, v2->u.l.t);
}
else {
luaK_tostack(ls, v2, 1); /* `v2' must be a value */
@@ -563,10 +555,10 @@ void luaK_posfix (LexState *ls, int op, expdesc *v1, expdesc *v2) {
case TK_CONC: luaK_conc(fs); break;
case TK_EQ: luaK_eq(fs); break;
case TK_NE: luaK_neq(fs); break;
case '>': luaK_S(fs, OP_JMPGT, 0, -2); break;
case '<': luaK_S(fs, OP_JMPLT, 0, -2); break;
case TK_GE: luaK_S(fs, OP_JMPGE, 0, -2); break;
case TK_LE: luaK_S(fs, OP_JMPLE, 0, -2); break;
case '>': luaK_S(fs, OP_JMPGT, NO_JUMP, -2); break;
case '<': luaK_S(fs, OP_JMPLT, NO_JUMP, -2); break;
case TK_GE: luaK_S(fs, OP_JMPGE, NO_JUMP, -2); break;
case TK_LE: luaK_S(fs, OP_JMPLE, NO_JUMP, -2); break;
}
}
}