Perl_newSV_type_mortal - new inline function introduced and used

There's no efficient way to create a mortal SV of any type other than
SVt_NULL (via sv_newmortal). The options are either to do:

* SV* sv = sv_newmortal; sv_upgrade(sv, SVt_SOMETYPE);
  but sv_upgrade is needlessly inefficient on new SVs.

* SV* sv = sv_2mortal(newSV_type(SVt_SOMETYPE)
  but this will perform runtime checks to see if (sv) and if (SvIMMORTAL(sv),
  and for a new SV we know that those answers will always be yes and no.

This commit adds a new inline function which is basically a mortalizing
wrapper around the now-inlined newSV_type.

1 files changed, 1 insertions, 2 deletions

diff --git a/av.c b/av.c
index 65c2246c62..335121a951 100644
--- a/av.c
+++ b/av.c
@@ -267,8 +267,7 @@ Perl_av_fetch(pTHX_ AV *av, SSize_t key, I32 lval)
                         return NULL;
             }
 
-            sv = sv_newmortal();
-            sv_upgrade(sv, SVt_PVLV);
+            sv = newSV_type_mortal(SVt_PVLV);
             mg_copy(MUTABLE_SV(av), sv, 0, key);
             if (!tied_magic) /* for regdata, force leavesub to make copies */
                 SvTEMP_off(sv);