From: Florian Ragwitz <rafl@debian.org>
Date: Sat, 22 Aug 2009 09:23:20 +0000 (+0200)
Subject: Backport another speedup tweak from bleadperl.
X-Git-Tag: 0.12_02~5
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=gitmo%2FClass-C3-XS.git;a=commitdiff_plain;h=3277bbc437306ad76a15c90b4271b4534ea633a5;hp=139e8d8c64758bcc77c21f067e1066ef1a918ea2

Backport another speedup tweak from bleadperl.
---

diff --git a/XS.xs b/XS.xs
index 0d22ac8..02f80ba 100644
--- a/XS.xs
+++ b/XS.xs
@@ -184,15 +184,16 @@ __mro_linear_isa_c3(pTHX_ HV* stash, HV* cache, I32 level)
                 SV** seq_ptr = AvARRAY(seq) + 1;
                 while(seq_items--) {
                     SV* const seqitem = *seq_ptr++;
-                    HE* const he = hv_fetch_ent(tails, seqitem, 0, 0);
-                    if(!he) {
-                        if(!hv_store_ent(tails, seqitem, newSViv(1), 0)) {
-                            croak("failed to store value in hash");
-                        }
-                    }
-                    else {
+                    /* LVALUE fetch will create a new undefined SV if necessary
+                     */
+                    HE* const he = hv_fetch_ent(tails, seqitem, 1, 0);
+                    if(he) {
                         SV* const val = HeVAL(he);
+                        /* This will increment undef to 1, which is what we
+                           want for a newly created entry.  */
                         sv_inc(val);
+                    } else {
+                        croak("failed to store value in hash");
                     }
                 }
             }