From eadf2aaaffa7a35e7f67b150ce0d57f2c17b9231 Mon Sep 17 00:00:00 2001 From: Roberto Ierusalimschy Date: Fri, 15 Jun 2001 16:17:33 -0300 Subject: small optimizations --- lvm.c | 72 +++++++++++++++++++++++++++++++++++++------------------------------ 1 file changed, 40 insertions(+), 32 deletions(-) (limited to 'lvm.c') diff --git a/lvm.c b/lvm.c index 5cadb252..3b17a0ad 100644 --- a/lvm.c +++ b/lvm.c @@ -1,5 +1,5 @@ /* -** $Id: lvm.c,v 1.183 2001/06/08 19:20:02 roberto Exp roberto $ +** $Id: lvm.c,v 1.184 2001/06/11 14:56:42 roberto Exp roberto $ ** Lua virtual machine ** See Copyright Notice in lua.h */ @@ -106,17 +106,17 @@ void luaV_Lclosure (lua_State *L, Proto *l, int nelems) { } -static void callTM (lua_State *L, Closure *f, const l_char *fmt, ...) { +/* maximum stack used by a call to a tag method (func + args) */ +#define MAXSTACK_TM 4 + +static StkId callTM (lua_State *L, Closure *f, const l_char *fmt, ...) { va_list argp; StkId base = L->top; - StkId result = NULL; /* result position */ + lua_assert(strlen(fmt)+1 <= MAXSTACK_TM); + luaD_checkstack(L, MAXSTACK_TM); va_start(argp, fmt); setclvalue(L->top, f); /* push function */ - incr_top; - if (*fmt == l_c('r')) { - fmt++; - result = va_arg(argp, TObject *); /* result position */ - } + L->top++; while (*fmt) { if (*fmt++ == l_c('o')) { setobj(L->top, va_arg(argp, TObject *)); @@ -125,17 +125,24 @@ static void callTM (lua_State *L, Closure *f, const l_char *fmt, ...) { lua_assert(*(fmt-1) == l_c('s')); setsvalue(L->top, va_arg(argp, TString *)); } - incr_top; + L->top++; } luaD_call(L, base); - if (result) { /* need result? */ - if (L->top == base) /* are there valid results? */ - setnilvalue(result); /* function had no results */ - else - setobj(result, base); /* get first result */ + va_end(argp); + return base; +} + + +#define setTM(L, base) (L->top = (base)) + +static void setTMresult (lua_State *L, TObject *result, StkId base) { + if (L->top == base) { /* are there valid results? */ + setnilvalue(result); /* function had no results */ + } + else { + setobj(result, base); /* get first result */ } L->top = base; /* restore top */ - va_end(argp); } @@ -164,7 +171,7 @@ void luaV_gettable (lua_State *L, StkId t, TObject *key, StkId res) { if (tm == NULL) /* no tag method? */ luaG_typeerror(L, t, l_s("index")); } - callTM(L, tm, l_s("roo"), res, t, key); + setTMresult(L, res, callTM(L, tm, l_s("oo"), t, key)); } @@ -187,7 +194,7 @@ void luaV_settable (lua_State *L, StkId t, TObject *key, StkId val) { if (tm == NULL) /* no tag method? */ luaG_typeerror(L, t, l_s("index")); } - callTM(L, tm, l_s("ooo"), t, key, val); + setTM(L, callTM(L, tm, l_s("ooo"), t, key, val)); } @@ -197,8 +204,9 @@ void luaV_getglobal (lua_State *L, TString *name, StkId res) { if (!HAS_TM_GETGLOBAL(L, ttype(value)) || /* is there a tag method? */ (tm = luaT_gettmbyObj(G(L), value, TM_GETGLOBAL)) == NULL) { setobj(res, value); /* default behavior */ - } else - callTM(L, tm, l_s("rso"), res, name, value); + } + else + setTMresult(L, res, callTM(L, tm, l_s("so"), name, value)); } @@ -208,8 +216,9 @@ void luaV_setglobal (lua_State *L, TString *name, StkId val) { if (!HAS_TM_SETGLOBAL(L, ttype(oldvalue)) || /* no tag methods? */ (tm = luaT_gettmbyObj(G(L), oldvalue, TM_SETGLOBAL)) == NULL) { setobj(oldvalue, val); /* raw set */ - } else - callTM(L, tm, l_s("soo"), name, oldvalue, val); + } + else + setTM(L, callTM(L, tm, l_s("soo"), name, oldvalue, val)); } @@ -226,7 +235,7 @@ static int call_binTM (lua_State *L, const TObject *p1, const TObject *p2, } } opname = luaS_new(L, luaT_eventname[event]); - callTM(L, tm, l_s("roos"), res, p1, p2, opname); + setTMresult(L, res, callTM(L, tm, l_s("oos"), p1, p2, opname)); return 1; } @@ -566,15 +575,16 @@ StkId luaV_execute (lua_State *L, const Closure *cl, StkId base) { return ra; } case OP_FORPREP: { - int jmp = GETARG_sBc(i); if (luaV_tonumber(ra, ra) == NULL) luaD_error(L, l_s("`for' initial value must be a number")); if (luaV_tonumber(ra+1, ra+1) == NULL) luaD_error(L, l_s("`for' limit must be a number")); if (luaV_tonumber(ra+2, ra+2) == NULL) luaD_error(L, l_s("`for' step must be a number")); - pc += -jmp; /* `jump' to loop end (delta is negated here) */ nvalue(ra) -= nvalue(ra+2);/* decrement index (to be incremented) */ + pc += -GETARG_sBc(i); /* `jump' to loop end (delta is negated here) */ + /* store in `ra+1' total number of repetitions */ + nvalue(ra+1) = ((nvalue(ra+1)-nvalue(ra))/nvalue(ra+2)); /* go through */ } case OP_FORLOOP: { @@ -582,28 +592,26 @@ StkId luaV_execute (lua_State *L, const Closure *cl, StkId base) { ttype(ra+2) == LUA_TNUMBER); if (ttype(ra) != LUA_TNUMBER) luaD_error(L, l_s("`for' index must be a number")); - nvalue(ra) += nvalue(ra+2); /* increment index */ - if (nvalue(ra+2) > 0 ? - nvalue(ra) <= nvalue(ra+1) : - nvalue(ra) >= nvalue(ra+1)) + if (--nvalue(ra+1) >= 0) { + nvalue(ra) += nvalue(ra+2); /* increment index */ dojump(pc, i); /* repeat loop */ + } break; } case OP_TFORPREP: { - int jmp = GETARG_sBc(i); if (ttype(ra) != LUA_TTABLE) luaD_error(L, l_s("`for' table must be a table")); setnvalue(ra+1, -1); /* initial index */ setnilvalue(ra+2); setnilvalue(ra+3); - pc += -jmp; /* `jump' to loop end (delta is negated here) */ + pc += -GETARG_sBc(i); /* `jump' to loop end (delta is negated here) */ /* go through */ } case OP_TFORLOOP: { Hash *t; int n; - runtime_check(L, ttype(ra) == LUA_TTABLE); - runtime_check(L, ttype(ra+1) == LUA_TNUMBER); + runtime_check(L, ttype(ra) == LUA_TTABLE && + ttype(ra+1) == LUA_TNUMBER); t = hvalue(ra); n = (int)nvalue(ra+1); n = luaH_nexti(t, n); -- cgit v1.2.3-55-g6feb