Hash lookup of constant strings optimization:

Introduce SvREADONLY && SvFAKE to flag an SV which has SvPVX pointing
to string table (as per sharepvn). Add newSV_pvn_share to create such
a thing. Make hv.c compare addresses of strings and skip string compare
if equal. Make method_named and helem ops use these shared-string SVs
when arg is constant. Make keys op return shared-string SVs (less clearly
a win).

p4raw-id: //depot/perl@7016

1 files changed, 8 insertions, 1 deletions

diff --git a/perlapi.c b/perlapi.c
index 3257fecabb..496fcc9318 100644
--- a/perlapi.c
+++ b/perlapi.c
@@ -1,4 +1,4 @@
-/* !!!!!!!   DO NOT EDIT THIS FILE   !!!!!!! 
+/* !!!!!!!   DO NOT EDIT THIS FILE   !!!!!!!
    This file is built by embed.pl from data in embed.pl, pp.sym, intrpvar.h,
    perlvars.h and thrdvar.h.  Any changes made here will be lost!
 */
@@ -2015,6 +2015,13 @@ Perl_newSVpvn(pTHXo_ const char* s, STRLEN len)
     return ((CPerlObj*)pPerl)->Perl_newSVpvn(s, len);
 }
 
+#undef  Perl_newSVpvn_share
+SV*
+Perl_newSVpvn_share(pTHXo_ const char* s, STRLEN len, U32 hash)
+{
+    return ((CPerlObj*)pPerl)->Perl_newSVpvn_share(s, len, hash);
+}
+
 #undef  Perl_newSVpvf
 SV*
 Perl_newSVpvf(pTHXo_ const char* pat, ...)