commit e247c3ada3ff47a1352927e797263137f4e02e0e
parent b5dc2f9b0c57fef5f72152973938ff5265366dcd
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 20 Jul 2015 15:24:24 -0300
implementation of fast track for gettable operations
Diffstat:
| M | lapi.c | | | 48 | ++++++++++++++++++++++++++++++------------------ |
| M | lvm.c | | | 32 | +++++++++++++++----------------- |
| M | lvm.h | | | 28 | +++++++++++++++++++++++++--- |
3 files changed, 70 insertions(+), 38 deletions(-)
diff --git a/lapi.c b/lapi.c
@@ -1,5 +1,5 @@
/*
-** $Id: lapi.c,v 2.249 2015/04/06 12:23:48 roberto Exp roberto $
+** $Id: lapi.c,v 2.250 2015/06/18 14:19:52 roberto Exp roberto $
** Lua API
** See Copyright Notice in lua.h
*/
@@ -579,16 +579,27 @@ LUA_API int lua_pushthread (lua_State *L) {
*/
+static int auxgetstr (lua_State *L, const TValue *t, const char *k) {
+ const TValue *aux;
+ TString *str = luaS_new(L, k);
+ if (luaV_fastget(L, t, str, aux, luaH_getstr)) {
+ setobj2s(L, L->top, aux);
+ api_incr_top(L);
+ }
+ else {
+ setsvalue2s(L, L->top, str);
+ api_incr_top(L);
+ luaV_finishget(L, t, L->top - 1, L->top - 1, aux);
+ }
+ lua_unlock(L);
+ return ttnov(L->top - 1);
+}
+
+
LUA_API int lua_getglobal (lua_State *L, const char *name) {
Table *reg = hvalue(&G(L)->l_registry);
- const TValue *gt; /* global table */
lua_lock(L);
- gt = luaH_getint(reg, LUA_RIDX_GLOBALS);
- setsvalue2s(L, L->top, luaS_new(L, name));
- api_incr_top(L);
- luaV_gettable(L, gt, L->top - 1, L->top - 1);
- lua_unlock(L);
- return ttnov(L->top - 1);
+ return auxgetstr(L, luaH_getint(reg, LUA_RIDX_GLOBALS), name);
}
@@ -603,24 +614,25 @@ LUA_API int lua_gettable (lua_State *L, int idx) {
LUA_API int lua_getfield (lua_State *L, int idx, const char *k) {
- StkId t;
lua_lock(L);
- t = index2addr(L, idx);
- setsvalue2s(L, L->top, luaS_new(L, k));
- api_incr_top(L);
- luaV_gettable(L, t, L->top - 1, L->top - 1);
- lua_unlock(L);
- return ttnov(L->top - 1);
+ return auxgetstr(L, index2addr(L, idx), k);
}
LUA_API int lua_geti (lua_State *L, int idx, lua_Integer n) {
StkId t;
+ const TValue *aux;
lua_lock(L);
t = index2addr(L, idx);
- setivalue(L->top, n);
- api_incr_top(L);
- luaV_gettable(L, t, L->top - 1, L->top - 1);
+ if (luaV_fastget(L, t, n, aux, luaH_getint)) {
+ setobj2s(L, L->top, aux);
+ api_incr_top(L);
+ }
+ else {
+ setivalue(L->top, n);
+ api_incr_top(L);
+ luaV_finishget(L, t, L->top - 1, L->top - 1, aux);
+ }
lua_unlock(L);
return ttnov(L->top - 1);
}
diff --git a/lvm.c b/lvm.c
@@ -1,5 +1,5 @@
/*
-** $Id: lvm.c,v 2.246 2015/06/25 14:00:01 roberto Exp roberto $
+** $Id: lvm.c,v 2.247 2015/07/04 16:31:03 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -153,30 +153,28 @@ static int forlimit (const TValue *obj, lua_Integer *p, lua_Integer step,
/*
-** Main function for table access (invoking metamethods if needed).
-** Compute 'val = t[key]'
+** Complete a table access: if 't' is a table, 'tm' has its metamethod;
+** otherwise, 'tm' is NULL.
*/
-void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) {
+void luaV_finishget (lua_State *L, const TValue *t, TValue *key, StkId val,
+ const TValue *tm) {
int loop; /* counter to avoid infinite loops */
+ lua_assert(tm != NULL || !ttistable(t));
for (loop = 0; loop < MAXTAGLOOP; loop++) {
- const TValue *tm;
- if (ttistable(t)) { /* 't' is a table? */
- Table *h = hvalue(t);
- const TValue *res = luaH_get(h, key); /* do a primitive get */
- if (!ttisnil(res) || /* result is not nil? */
- (tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */
- setobj2s(L, val, res); /* result is the raw get */
- return;
- }
- /* else will try metamethod */
+ if (tm == NULL) { /* no metamethod (from a table)? */
+ if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
+ luaG_typeerror(L, t, "index"); /* no metamethod */
}
- else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
- luaG_typeerror(L, t, "index"); /* no metamethod */
if (ttisfunction(tm)) { /* metamethod is a function */
- luaT_callTM(L, tm, t, key, val, 1);
+ luaT_callTM(L, tm, t, key, val, 1); /* call it */
return;
}
t = tm; /* else repeat access over 'tm' */
+ if (luaV_fastget(L,t,key,tm,luaH_get)) { /* try fast track */
+ setobj2s(L, val, tm); /* done */
+ return;
+ }
+ /* else repeat */
}
luaG_runerror(L, "gettable chain too long; possible loop");
}
diff --git a/lvm.h b/lvm.h
@@ -1,5 +1,5 @@
/*
-** $Id: lvm.h,v 2.34 2014/08/01 17:24:02 roberto Exp roberto $
+** $Id: lvm.h,v 2.35 2015/02/20 14:27:53 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -48,13 +48,35 @@
#define luaV_rawequalobj(t1,t2) luaV_equalobj(NULL,t1,t2)
+/*
+** fast track for 'gettable': 1 means 'aux' points to resulted value;
+** 0 means 'aux' is metamethod (if 't' is a table) or NULL. 'f' is
+** the raw get function to use.
+*/
+#define luaV_fastget(L,t,k,aux,f) \
+ (!ttistable(t) \
+ ? (aux = NULL, 0) /* not a table; 'aux' is NULL and result is 0 */ \
+ : (aux = f(hvalue(t), k), /* else, do raw access */ \
+ !ttisnil(aux) ? 1 /* result not nil? 'aux' has it */ \
+ : (aux = fasttm(L, hvalue(t)->metatable, TM_INDEX), /* get metamethod */\
+ aux != NULL ? 0 /* has metamethod? must call it */ \
+ : (aux = luaO_nilobject, 1)))) /* else, final result is nil */
+
+/*
+** standard implementation for 'gettable'
+*/
+#define luaV_gettable(L,t,k,v) { const TValue *aux; \
+ if (luaV_fastget(L,t,k,aux,luaH_get)) { setobj2s(L, v, aux); } \
+ else luaV_finishget(L,t,k,v,aux); }
+
+
LUAI_FUNC int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2);
LUAI_FUNC int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r);
LUAI_FUNC int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r);
LUAI_FUNC int luaV_tonumber_ (const TValue *obj, lua_Number *n);
LUAI_FUNC int luaV_tointeger (const TValue *obj, lua_Integer *p, int mode);
-LUAI_FUNC void luaV_gettable (lua_State *L, const TValue *t, TValue *key,
- StkId val);
+LUAI_FUNC void luaV_finishget (lua_State *L, const TValue *t, TValue *key,
+ StkId val, const TValue *tm);
LUAI_FUNC void luaV_settable (lua_State *L, const TValue *t, TValue *key,
StkId val);
LUAI_FUNC void luaV_finishOp (lua_State *L);
