From f8279f6cd8bf22245be30649df5a2d19d868e114 Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Fri, 5 Jul 2002 15:27:39 -0300
Subject: optimizations for gettable (temporary)
---
lvm.c | 98 +++++++++++++++++++++++++++++++++++++++++++++----------------------
1 file changed, 66 insertions(+), 32 deletions(-)
(limited to 'lvm.c')
diff --git a/lvm.c b/lvm.c
index d61953fe..0e643f7f 100644
--- a/lvm.c
+++ b/lvm.c
@@ -1,5 +1,5 @@
/*
-** $Id: lvm.c,v 1.242 2002/06/24 14:11:14 roberto Exp roberto $
+** $Id: lvm.c,v 1.243 2002/06/24 15:07:21 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -32,7 +32,7 @@
/* limit for table tag-method chains (to avoid loops) */
-#define MAXTAGLOOP 10000
+#define MAXTAGLOOP 100
static void luaV_checkGC (lua_State *L, StkId top) {
@@ -108,34 +108,46 @@ static void callTM (lua_State *L, const TObject *f,
}
+static const TObject *luaV_index (lua_State *L, const TObject *t,
+ TObject *key, int loop) {
+ const TObject *tm = fasttm(L, hvalue(t)->metatable, TM_INDEX);
+ if (tm == NULL) return &luaO_nilobject; /* no TM */
+ if (ttype(tm) == LUA_TFUNCTION) {
+ callTMres(L, tm, t, key);
+ return L->top;
+ }
+ else return luaV_gettable(L, tm, key, loop);
+}
+
+static const TObject *luaV_getnotable (lua_State *L, const TObject *t,
+ TObject *key, int loop) {
+ const TObject *tm = luaT_gettmbyobj(L, t, TM_GETTABLE);
+ if (ttype(tm) == LUA_TNIL)
+ luaG_typeerror(L, t, "index");
+ if (ttype(tm) == LUA_TFUNCTION) {
+ callTMres(L, tm, t, key);
+ return L->top;
+ }
+ else return luaV_gettable(L, tm, key, loop);
+}
+
+
/*
** Function to index a table.
** Receives the table at `t' and the key at `key'.
** leaves the result at `res'.
*/
-const TObject *luaV_gettable (lua_State *L, const TObject *t, TObject *key) {
- const TObject *tm;
- int loop = 0;
- do {
- if (ttype(t) == LUA_TTABLE) { /* `t' is a table? */
- Table *h = hvalue(t);
- const TObject *v = luaH_get(h, key); /* do a primitive get */
- if (ttype(v) != LUA_TNIL || /* result is no nil? */
- (tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */
- return v;
- }
- /* else will try the tag method */
- }
- else if (ttype(tm = luaT_gettmbyobj(L, t, TM_GETTABLE)) == LUA_TNIL)
- luaG_typeerror(L, t, "index");
- if (ttype(tm) == LUA_TFUNCTION) {
- callTMres(L, tm, t, key);
- return L->top;
- }
- t = tm; /* else repeat access with `tm' */
- } while (++loop <= MAXTAGLOOP);
- luaG_runerror(L, "loop in gettable");
- return NULL; /* to avoid warnings */
+const TObject *luaV_gettable (lua_State *L, const TObject *t, TObject *key,
+ int loop) {
+ if (loop > MAXTAGLOOP)
+ luaG_runerror(L, "loop in gettable");
+ if (ttype(t) == LUA_TTABLE) { /* `t' is a table? */
+ Table *h = hvalue(t);
+ const TObject *v = luaH_get(h, key); /* do a primitive get */
+ if (ttype(v) != LUA_TNIL) return v;
+ else return luaV_index(L, t, key, loop+1);
+ }
+ else return luaV_getnotable(L, t, key, loop+1);
}
@@ -392,12 +404,26 @@ StkId luaV_execute (lua_State *L) {
break;
}
case OP_GETGLOBAL: {
- lua_assert(ttype(KBx(i)) == LUA_TSTRING && ttype(&cl->g) == LUA_TTABLE);
- setobj(RA(i), luaV_gettable(L, &cl->g, KBx(i)));
+ StkId rb = KBx(i);
+ const TObject *v;
+ lua_assert(ttype(rb) == LUA_TSTRING && ttype(&cl->g) == LUA_TTABLE);
+ v = luaH_getstr(hvalue(&cl->g), tsvalue(rb));
+ if (ttype(v) != LUA_TNIL) { setobj(ra, v); }
+ else
+ setobj(RA(i), luaV_index(L, &cl->g, rb, 0));
break;
}
case OP_GETTABLE: {
- setobj(RA(i), luaV_gettable(L, RB(i), RKC(i)));
+ StkId rb = RB(i);
+ TObject *rc = RKC(i);
+ if (ttype(rb) == LUA_TTABLE) {
+ const TObject *v = luaH_get(hvalue(rb), rc);
+ if (ttype(v) != LUA_TNIL) { setobj(ra, v); }
+ else
+ setobj(RA(i), luaV_index(L, rb, rc, 0));
+ }
+ else
+ setobj(RA(i), luaV_getnotable(L, rb, rc, 0));
break;
}
case OP_SETGLOBAL: {
@@ -423,8 +449,17 @@ StkId luaV_execute (lua_State *L) {
}
case OP_SELF: {
StkId rb = RB(i);
+ TObject *rc = RKC(i);
+ runtime_check(L, ttype(rc) == LUA_TSTRING);
setobj(ra+1, rb);
- setobj(RA(i), luaV_gettable(L, rb, RKC(i)));
+ if (ttype(rb) == LUA_TTABLE) {
+ const TObject *v = luaH_getstr(hvalue(rb), tsvalue(rc));
+ if (ttype(v) != LUA_TNIL) { setobj(ra, v); }
+ else
+ setobj(RA(i), luaV_index(L, rb, rc, 0));
+ }
+ else
+ setobj(RA(i), luaV_getnotable(L, rb, rc, 0));
break;
}
case OP_ADD: {
@@ -620,11 +655,10 @@ StkId luaV_execute (lua_State *L) {
else dojump(pc, GETARG_sBx(*pc) + 1); /* else jump back */
break;
}
- case OP_TFORPREP: {
+ case OP_TFORPREP: { /* for compatibility only */
if (ttype(ra) == LUA_TTABLE) {
setobj(ra+1, ra);
- setsvalue(ra, luaS_new(L, "next"));
- setobj(RA(i), luaV_gettable(L, gt(L), ra));
+ setobj(ra, luaH_getstr(hvalue(gt(L)), luaS_new(L, "next")));
}
dojump(pc, GETARG_sBx(i));
break;
--
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