hv.* - disable unshared keys except when requested

This disables the new unshared hash key logic by default. People
who wish to try it out can enable it at build time with

    -DPERL_USE_UNSHARED_KEYS_IN_LARGE_HASHES

in the configure process.

1 files changed, 7 insertions, 0 deletions

diff --git a/hv.h b/hv.h
index bd81e5750c..2c5e796d9b 100644
--- a/hv.h
+++ b/hv.h
@@ -28,6 +28,13 @@
 #   define PERL_HASH_ITER_BUCKET(iter)      (((iter)->xhv_riter) ^ ((iter)->xhv_rand))
 #endif
 
+#ifdef PERL_USE_UNSHARED_KEYS_IN_LARGE_HASHES
+#define LARGE_HASH_HEURISTIC(hv,new_max) S_large_hash_heuristic(aTHX_ (hv), (new_max))
+#else
+#define LARGE_HASH_HEURISTIC(hv,new_max) 0
+#endif
+
+
 /* entry in hash value chain */
 struct he {
     /* Keep hent_next first in this structure, because sv_free_arenas take