summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--cache.h22
1 files changed, 12 insertions, 10 deletions
diff --git a/cache.h b/cache.h
index 2ead61f05a..85a8e7b101 100644
--- a/cache.h
+++ b/cache.h
@@ -1024,16 +1024,12 @@ extern const struct object_id null_oid;
static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2)
{
/*
- * This is a temporary optimization hack. By asserting the size here,
- * we let the compiler know that it's always going to be 20, which lets
- * it turn this fixed-size memcmp into a few inline instructions.
- *
- * This will need to be extended or ripped out when we learn about
- * hashes of different sizes.
+ * Teach the compiler that there are only two possibilities of hash size
+ * here, so that it can optimize for this case as much as possible.
*/
- if (the_hash_algo->rawsz != 20)
- BUG("hash size not yet supported by hashcmp");
- return memcmp(sha1, sha2, the_hash_algo->rawsz);
+ if (the_hash_algo->rawsz == GIT_MAX_RAWSZ)
+ return memcmp(sha1, sha2, GIT_MAX_RAWSZ);
+ return memcmp(sha1, sha2, GIT_SHA1_RAWSZ);
}
static inline int oidcmp(const struct object_id *oid1, const struct object_id *oid2)
@@ -1043,7 +1039,13 @@ static inline int oidcmp(const struct object_id *oid1, const struct object_id *o
static inline int hasheq(const unsigned char *sha1, const unsigned char *sha2)
{
- return !hashcmp(sha1, sha2);
+ /*
+ * We write this here instead of deferring to hashcmp so that the
+ * compiler can properly inline it and avoid calling memcmp.
+ */
+ if (the_hash_algo->rawsz == GIT_MAX_RAWSZ)
+ return !memcmp(sha1, sha2, GIT_MAX_RAWSZ);
+ return !memcmp(sha1, sha2, GIT_SHA1_RAWSZ);
}
static inline int oideq(const struct object_id *oid1, const struct object_id *oid2)