gv_fetchpvn_flags ranks highly in the profile, and the ::/' scanning

loop is iterated over millions of times. Add a flag GV_NOTQUAL purely
as an optimisation, when the caller is passing in a string that is
known not to contain any package separators.

p4raw-id: //depot/perl@27053

1 files changed, 1 insertions, 1 deletions

diff --git a/util.c b/util.c
index 191773017c..636b06d922 100644
--- a/util.c
+++ b/util.c
@@ -2273,7 +2273,7 @@ Perl_my_popen(pTHX_ const char *cmd, const char *mode)
 	    PerlProc__exit(1);
 	}
 #endif	/* defined OS2 */
-	if ((tmpgv = gv_fetchpvs("$", GV_ADD, SVt_PV))) {
+	if ((tmpgv = gv_fetchpvs("$", GV_ADD|GV_NOTQUAL, SVt_PV))) {
 	    SvREADONLY_off(GvSV(tmpgv));
 	    sv_setiv(GvSV(tmpgv), PerlProc_getpid());
 	    SvREADONLY_on(GvSV(tmpgv));