pp_entersub(): tweak some vars

make the scope of item be smaller;
don't assign +1 to MARK when we will shortly overwrite it;
use a local var to to store &GvAV(PL_defgv) to avoid recalculating it
use a _NN variant of SvREFCNT_inc

Shaves 2% off the object size of pp_entersub.

diff --git a/pp_hot.c b/pp_hot.c
index 6d44d90..7397a91 100644 (file)
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -2647,7 +2647,6 @@ try_autoload:
     if (!(CvISXSUB(cv))) {
        /* This path taken at least 75% of the time   */
        dMARK;
-       SSize_t items = SP - MARK;
        PADLIST * const padlist = CvPADLIST(cv);
         I32 depth;
 
@@ -2662,6 +2661,9 @@ try_autoload:
        PAD_SET_CUR_NOSAVE(padlist, depth);
        if (LIKELY(hasargs)) {
            AV *const av = MUTABLE_AV(PAD_SVl(0));
+            SSize_t items;
+            AV **defavp;
+
            if (UNLIKELY(AvREAL(av))) {
                /* @_ is normally not REAL--this should only ever
                 * happen when DB::sub() calls things that modify @_ */
@@ -2669,11 +2671,12 @@ try_autoload:
                AvREAL_off(av);
                AvREIFY_on(av);
            }
-           cx->blk_sub.savearray = GvAV(PL_defgv);
-           GvAV(PL_defgv) = MUTABLE_AV(SvREFCNT_inc_simple(av));
+           defavp = &GvAV(PL_defgv);
+           cx->blk_sub.savearray = *defavp;
+           *defavp = MUTABLE_AV(SvREFCNT_inc_simple_NN(av));
            CX_CURPAD_SAVE(cx->blk_sub);
            cx->blk_sub.argarray = av;
-           ++MARK;
+            items = SP - MARK;
 
            if (UNLIKELY(items - 1 > AvMAX(av))) {
                 SV **ary = AvALLOC(av);
@@ -2683,7 +2686,7 @@ try_autoload:
                 AvARRAY(av) = ary;
             }
 
-           Copy(MARK,AvARRAY(av),items,SV*);
+           Copy(MARK+1,AvARRAY(av),items,SV*);
            AvFILLp(av) = items - 1;
        
            MARK = AvARRAY(av);