unify PERL_HASH and PERL_HASH_INTERNAL

Those two macros expand into two large, almost identical chunks of code.
The only difference between the two is the source of the hash seed.
So parameterize this into a new PERL_HASH_INTERNAL_() macro.

Also, there are a couple of places in hv.c that do the rough equivalent of

    if (HvREHASH(hv))
	key = PERL_HASH_INTERNAL(...)
    else
	key = PERL_HASH(...)

which incorporates two complete macro expansions into the code.
Reorganise them to be

    key = PERL_HASH_INTERNAL_(..., HvREHASH(hv))

diff --git a/hv.c b/hv.c
index a37ed09..c4eba5c 100644 (file)
--- a/hv.c
+++ b/hv.c
@@ -604,21 +604,18 @@ Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
        }
     }
 
-    if (HvREHASH(hv)) {
-       PERL_HASH_INTERNAL(hash, key, klen);
-       /* We don't have a pointer to the hv, so we have to replicate the
-          flag into every HEK, so that hv_iterkeysv can see it.  */
-       /* And yes, you do need this even though you are not "storing" because
-          you can flip the flags below if doing an lval lookup.  (And that
-          was put in to give the semantics Andreas was expecting.)  */
+    if (HvREHASH(hv) || (!hash && !(keysv && (SvIsCOW_shared_hash(keysv)))))
+       PERL_HASH_INTERNAL_(hash, key, klen, HvREHASH(hv));
+    else if (!hash)
+       hash = SvSHARED_HASH(keysv);
+
+    /* We don't have a pointer to the hv, so we have to replicate the
+       flag into every HEK, so that hv_iterkeysv can see it.
+       And yes, you do need this even though you are not "storing" because
+       you can flip the flags below if doing an lval lookup.  (And that
+       was put in to give the semantics Andreas was expecting.)  */
+    if (HvREHASH(hv))
        flags |= HVhek_REHASH;
-    } else if (!hash) {
-        if (keysv && (SvIsCOW_shared_hash(keysv))) {
-            hash = SvSHARED_HASH(keysv);
-        } else {
-            PERL_HASH(hash, key, klen);
-        }
-    }
 
     masked_flags = (flags & HVhek_MASK);
 
@@ -970,15 +967,10 @@ S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
         HvHASKFLAGS_on(MUTABLE_SV(hv));
     }
 
-    if (HvREHASH(hv)) {
-       PERL_HASH_INTERNAL(hash, key, klen);
-    } else if (!hash) {
-        if (keysv && (SvIsCOW_shared_hash(keysv))) {
-            hash = SvSHARED_HASH(keysv);
-        } else {
-            PERL_HASH(hash, key, klen);
-        }
-    }
+    if (HvREHASH(hv) || (!hash && !(keysv && (SvIsCOW_shared_hash(keysv)))))
+       PERL_HASH_INTERNAL_(hash, key, klen, HvREHASH(hv));
+    else if (!hash)
+       hash = SvSHARED_HASH(keysv);
 
     masked_flags = (k_flags & HVhek_MASK);
 

diff --git a/hv.h b/hv.h
index eae1e70..358c8d8 100644 (file)
--- a/hv.h
+++ b/hv.h
@@ -127,30 +127,23 @@ struct xpvhv {
 #       define PERL_HASH_SEED  0
 #   endif
 #endif
-#define PERL_HASH(hash,str,len) \
-     STMT_START        { \
-       register const char * const s_PeRlHaSh_tmp = str; \
-       register const unsigned char *s_PeRlHaSh = (const unsigned char *)s_PeRlHaSh_tmp; \
-       register I32 i_PeRlHaSh = len; \
-       register U32 hash_PeRlHaSh = PERL_HASH_SEED; \
-       while (i_PeRlHaSh--) { \
-           hash_PeRlHaSh += *s_PeRlHaSh++; \
-           hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
-           hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
-       } \
-       hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
-       hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
-       (hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
-    } STMT_END
+
+#define PERL_HASH(hash,str,len) PERL_HASH_INTERNAL_(hash,str,len,0)
 
 /* Only hv.c and mod_perl should be doing this.  */
 #ifdef PERL_HASH_INTERNAL_ACCESS
-#define PERL_HASH_INTERNAL(hash,str,len) \
+#define PERL_HASH_INTERNAL(hash,str,len) PERL_HASH_INTERNAL_(hash,str,len,1)
+#endif
+
+/* Common base for PERL_HASH and PERL_HASH_INTERNAL that parameterises
+ * the source of the seed. Not for direct use outside of hv.c. */
+
+#define PERL_HASH_INTERNAL_(hash,str,len,internal) \
      STMT_START        { \
        register const char * const s_PeRlHaSh_tmp = str; \
        register const unsigned char *s_PeRlHaSh = (const unsigned char *)s_PeRlHaSh_tmp; \
        register I32 i_PeRlHaSh = len; \
-       register U32 hash_PeRlHaSh = PL_rehash_seed; \
+       register U32 hash_PeRlHaSh = (internal ? PL_rehash_seed : PERL_HASH_SEED); \
        while (i_PeRlHaSh--) { \
            hash_PeRlHaSh += *s_PeRlHaSh++; \
            hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
@@ -160,7 +153,6 @@ struct xpvhv {
        hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
        (hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
     } STMT_END
-#endif
 
 /*
 =head1 Hash Manipulation Functions