#ifndef INCHASH_H
#define INCHASH_H 1
-#include "config.h"
-#include "system.h"
-#include "coretypes.h"
-#include "hashtab.h"
/* This file implements an incremential hash function ADT, to be used
by code that incrementially hashes a lot of unrelated data
Currently it just implements the plain old jhash based
incremental hash from gcc's tree.c. */
-extern hashval_t iterative_hash_host_wide_int (HOST_WIDE_INT, hashval_t);
-extern hashval_t iterative_hash_hashval_t (hashval_t, hashval_t);
+hashval_t iterative_hash_host_wide_int (HOST_WIDE_INT, hashval_t);
+hashval_t iterative_hash_hashval_t (hashval_t, hashval_t);
namespace inchash
{
}
/* Hash in pointer PTR. */
- void add_ptr (void *ptr)
+ void add_ptr (const void *ptr)
{
add (&ptr, sizeof (ptr));
}
{
if (a.end() > b.end())
{
- merge (b);
+ merge (b);
merge (a);
}
else
{
- merge (a);
- merge (b);
+ merge (a);
+ merge (b);
}
}
}
+/* Borrowed from hashtab.c iterative_hash implementation. */
+#define mix(a,b,c) \
+{ \
+ a -= b; a -= c; a ^= (c>>13); \
+ b -= c; b -= a; b ^= (a<< 8); \
+ c -= a; c -= b; c ^= ((b&0xffffffff)>>13); \
+ a -= b; a -= c; a ^= ((c&0xffffffff)>>12); \
+ b -= c; b -= a; b = (b ^ (a<<16)) & 0xffffffff; \
+ c -= a; c -= b; c = (c ^ (b>> 5)) & 0xffffffff; \
+ a -= b; a -= c; a = (a ^ (c>> 3)) & 0xffffffff; \
+ b -= c; b -= a; b = (b ^ (a<<10)) & 0xffffffff; \
+ c -= a; c -= b; c = (c ^ (b>>15)) & 0xffffffff; \
+}
+
+
+/* Produce good hash value combining VAL and VAL2. */
+inline
+hashval_t
+iterative_hash_hashval_t (hashval_t val, hashval_t val2)
+{
+ /* the golden ratio; an arbitrary value. */
+ hashval_t a = 0x9e3779b9;
+
+ mix (a, val, val2);
+ return val2;
+}
+
+/* Produce good hash value combining VAL and VAL2. */
+
+inline
+hashval_t
+iterative_hash_host_wide_int (HOST_WIDE_INT val, hashval_t val2)
+{
+ if (sizeof (HOST_WIDE_INT) == sizeof (hashval_t))
+ return iterative_hash_hashval_t (val, val2);
+ else
+ {
+ hashval_t a = (hashval_t) val;
+ /* Avoid warnings about shifting of more than the width of the type on
+ hosts that won't execute this path. */
+ int zero = 0;
+ hashval_t b = (hashval_t) (val >> (sizeof (hashval_t) * 8 + zero));
+ mix (a, b, val2);
+ if (sizeof (HOST_WIDE_INT) > 2 * sizeof (hashval_t))
+ {
+ hashval_t a = (hashval_t) (val >> (sizeof (hashval_t) * 16 + zero));
+ hashval_t b = (hashval_t) (val >> (sizeof (hashval_t) * 24 + zero));
+ mix (a, b, val2);
+ }
+ return val2;
+ }
+}
+
#endif