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, 2 insertions, 3 deletions

diff --git a/universal.c b/universal.c
index 9558504317..9c7be3199e 100644
--- a/universal.c
+++ b/universal.c
@@ -304,12 +304,11 @@ Perl_sv_does_sv(pTHX_ SV *sv, SV *namesv, U32 flags)
 
     /* create a PV with value "isa", but with a special address
      * so that perl knows we're really doing "DOES" instead */
-    methodname = newSV_type(SVt_PV);
+    methodname = newSV_type_mortal(SVt_PV);
     SvLEN_set(methodname, 0);
     SvCUR_set(methodname, strlen(PL_isa_DOES));
     SvPVX(methodname) = (char *)PL_isa_DOES; /* discard 'const' qualifier */
     SvPOK_on(methodname);
-    sv_2mortal(methodname);
     call_sv(methodname, G_SCALAR | G_METHOD);
     SPAGAIN;
 
@@ -1126,7 +1125,7 @@ XS(XS_NamedCapture_TIEHASH)
                 flag = SvTRUE(mark[1]) ? RXapif_ALL : RXapif_ONE;
             mark += 2;
         }
-        ST(0) = sv_2mortal(newSV_type(SVt_IV));
+        ST(0) = newSV_type_mortal(SVt_IV);
         sv_setuv(newSVrv(ST(0), package), flag);
     }
     XSRETURN(1);