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in 'luaD_poscall', there is no need to compute 'firstResult' when 'nres==0'

pull/19/head
Roberto Ierusalimschy 7 years ago
parent
de53c2ec7e
commit
02ed0b2c30
3 changed files with 48 additions and 51 deletions
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  1. 69
      ldo.c
  2. 5
      ldo.h
  3. 25
      lvm.c

69
ldo.c
View File

@ -1,5 +1,5 @@
/*
** $Id: ldo.c,v 2.199 2018/03/07 16:26:01 roberto Exp roberto $
** $Id: ldo.c,v 2.200 2018/03/16 15:33:34 roberto Exp roberto $
** Stack and Call structure of Lua
** See Copyright Notice in lua.h
*/
@ -319,14 +319,15 @@ void luaD_hookcall (lua_State *L, CallInfo *ci) {
}
static void rethook (lua_State *L, CallInfo *ci, StkId firstres, int nres) {
static StkId rethook (lua_State *L, CallInfo *ci, StkId firstres, int nres) {
ptrdiff_t oldtop = savestack(L, L->top); /* hook may change top */
int delta = 0;
if (isLuacode(ci)) {
Proto *p = clLvalue(s2v(ci->func))->p;
if (p->is_vararg)
delta = ci->u.l.nextraargs + p->numparams + 1;
if (L->top < ci->top)
L->top = ci->top; /* correct top */
L->top = ci->top; /* correct top to run hook */
}
if (L->hookmask & LUA_MASKRET) { /* is return hook on? */
int ftransfer;
@ -337,6 +338,7 @@ static void rethook (lua_State *L, CallInfo *ci, StkId firstres, int nres) {
}
if (isLua(ci->previous))
L->oldpc = ci->previous->u.l.savedpc; /* update 'oldpc' */
return restorestack(L, oldtop);
}
@ -363,40 +365,33 @@ void luaD_tryfuncTM (lua_State *L, StkId func) {
** expressions, multiple results for tail calls/single parameters)
** separated.
*/
static void moveresults (lua_State *L, StkId firstResult, StkId res,
int nres, int wanted) {
static void moveresults (lua_State *L, StkId res, int nres, int wanted) {
switch (wanted) { /* handle typical cases separately */
case 0: break; /* nothing to move */
case 1: { /* one result needed */
case 0: /* no values needed */
L->top = res;
break;
case 1: /* one value needed */
if (nres == 0) /* no results? */
setnilvalue(s2v(res)); /* adjust with nil */
else
setobjs2s(L, res, firstResult); /* move it to proper place */
setobjs2s(L, res, L->top - nres); /* move it to proper place */
L->top = res + 1;
break;
}
case LUA_MULTRET: {
case LUA_MULTRET:
wanted = nres; /* we want all results */
/* FALLTHROUGH */
default: { /* multiple results */
StkId firstresult = L->top - nres; /* index of first result */
int i;
for (i = 0; i < nres; i++) /* move all results to correct place */
setobjs2s(L, res + i, firstResult + i);
wanted = nres; /* it wanted what it had */
break;
}
default: {
int i;
if (wanted <= nres) { /* enough results? */
for (i = 0; i < wanted; i++) /* move wanted results to correct place */
setobjs2s(L, res + i, firstResult + i);
}
else { /* not enough results; use all of them plus nils */
for (i = 0; i < nres; i++) /* move all results to correct place */
setobjs2s(L, res + i, firstResult + i);
for (; i < wanted; i++) /* complete wanted number of results */
setnilvalue(s2v(res + i));
}
/* move all results to correct place */
for (i = 0; i < nres && i < wanted; i++)
setobjs2s(L, res + i, firstresult + i);
for (; i < wanted; i++) /* complete wanted number of results */
setnilvalue(s2v(res + i));
L->top = res + wanted; /* top points after the last result */
break;
}
}
L->top = res + wanted; /* top points after the last result */
}
@ -404,15 +399,12 @@ static void moveresults (lua_State *L, StkId firstResult, StkId res,
** Finishes a function call: calls hook if necessary, removes CallInfo,
** moves current number of results to proper place.
*/
void luaD_poscall (lua_State *L, CallInfo *ci, StkId firstResult, int nres) {
if (L->hookmask) {
ptrdiff_t fr = savestack(L, firstResult); /* hook may change stack */
rethook(L, ci, firstResult, nres);
firstResult = restorestack(L, fr);
}
void luaD_poscall (lua_State *L, CallInfo *ci, int nres) {
if (L->hookmask)
L->top = rethook(L, ci, L->top - nres, nres);
L->ci = ci->previous; /* back to caller */
/* move results to proper place */
moveresults(L, firstResult, ci->func, nres, ci->nresults);
moveresults(L, ci->func, nres, ci->nresults);
}
@ -477,7 +469,7 @@ void luaD_call (lua_State *L, StkId func, int nresults) {
n = (*f)(L); /* do the actual call */
lua_lock(L);
api_checknelems(L, n);
luaD_poscall(L, ci, L->top - n, n);
luaD_poscall(L, ci, n);
break;
}
case LUA_TLCL: { /* Lua function */
@ -540,7 +532,7 @@ static void finishCcall (lua_State *L, int status) {
n = (*ci->u.c.k)(L, status, ci->u.c.ctx); /* call continuation function */
lua_lock(L);
api_checknelems(L, n);
luaD_poscall(L, ci, L->top - n, n); /* finish 'luaD_call' */
luaD_poscall(L, ci, n); /* finish 'luaD_call' */
}
@ -642,9 +634,8 @@ static void resume (lua_State *L, void *ud) {
n = (*ci->u.c.k)(L, LUA_YIELD, ci->u.c.ctx); /* call continuation */
lua_lock(L);
api_checknelems(L, n);
firstArg = L->top - n; /* yield results come from continuation */
}
luaD_poscall(L, ci, firstArg, n); /* finish 'luaD_call' */
luaD_poscall(L, ci, n); /* finish 'luaD_call' */
}
unroll(L, NULL); /* run continuation */
}

5
ldo.h
View File

@ -1,5 +1,5 @@
/*
** $Id: ldo.h,v 2.42 2018/02/15 15:34:29 roberto Exp roberto $
** $Id: ldo.h,v 2.43 2018/02/17 19:29:29 roberto Exp roberto $
** Stack and Call structure of Lua
** See Copyright Notice in lua.h
*/
@ -61,8 +61,7 @@ LUAI_FUNC void luaD_callnoyield (lua_State *L, StkId func, int nResults);
LUAI_FUNC void luaD_tryfuncTM (lua_State *L, StkId func);
LUAI_FUNC int luaD_pcall (lua_State *L, Pfunc func, void *u,
ptrdiff_t oldtop, ptrdiff_t ef);
LUAI_FUNC void luaD_poscall (lua_State *L, CallInfo *ci, StkId firstResult,
int nres);
LUAI_FUNC void luaD_poscall (lua_State *L, CallInfo *ci, int nres);
LUAI_FUNC int luaD_reallocstack (lua_State *L, int newsize, int raiseerror);
LUAI_FUNC int luaD_growstack (lua_State *L, int n, int raiseerror);
LUAI_FUNC void luaD_shrinkstack (lua_State *L);

25
lvm.c
View File

@ -1,5 +1,5 @@
/*
** $Id: lvm.c,v 2.353 2018/04/04 14:23:41 roberto Exp roberto $
** $Id: lvm.c,v 2.354 2018/05/02 18:17:59 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@ -1591,7 +1591,7 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
ra = RA(i);
}
ci->func -= delta;
luaD_poscall(L, ci, ra, cast_int(L->top - ra));
luaD_poscall(L, ci, cast_int(L->top - ra));
return;
}
else { /* Lua tail call */
@ -1602,20 +1602,25 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
vmbreak;
}
vmcase(OP_RETURN) {
int b = GETARG_B(i);
int n = (b != 0 ? b - 1 : cast_int(L->top - ra));
int n = GETARG_B(i) - 1; /* number of results */
if (n < 0) /* not fixed? */
n = cast_int(L->top - ra); /* get what is available */
else
L->top = ra + n; /* set call for 'luaD_poscall' */
if (TESTARG_k(i)) {
int nparams1 = GETARG_C(i);
if (nparams1) /* vararg function? */
ci->func -= ci->u.l.nextraargs + nparams1;
luaF_close(L, base); /* there may be open upvalues */
}
halfProtect(luaD_poscall(L, ci, ra, n));
halfProtect(luaD_poscall(L, ci, n));
return;
}
vmcase(OP_RETURN0) {
if (L->hookmask)
halfProtect(luaD_poscall(L, ci, ra, 0)); /* no hurry... */
if (L->hookmask) {
L->top = ra;
halfProtect(luaD_poscall(L, ci, 0)); /* no hurry... */
}
else {
int nres = ci->nresults;
L->ci = ci->previous; /* back to caller */
@ -1626,8 +1631,10 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
return;
}
vmcase(OP_RETURN1) {
if (L->hookmask)
halfProtect(luaD_poscall(L, ci, ra, 1)); /* no hurry... */
if (L->hookmask) {
L->top = ra + 1;
halfProtect(luaD_poscall(L, ci, 1)); /* no hurry... */
}
else {
int nres = ci->nresults;
L->ci = ci->previous; /* back to caller */

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