From: Junio C Hamano <gitster@pobox.com>
Date: Fri, 6 May 2011 18:00:36 +0000 (-0700)
Subject: Merge branch 'im/hashcmp-optim'
X-Git-Tag: v1.7.6-rc0~95
X-Git-Url: https://www.git.lorimer.id.au/gitweb.git/diff_plain/efa67bfd16f4260275654bc4194744dd65353350?hp=ac13e7c514d6790cc59041545f26b3f5da543b25

Merge branch 'im/hashcmp-optim'

* im/hashcmp-optim:
hashcmp(): inline memcmp() by hand to optimize
---

diff --git a/cache.h b/cache.h
index 5b896d9845..2b34116624 100644
--- a/cache.h
+++ b/cache.h
@@ -676,14 +676,24 @@ extern char *sha1_pack_name(const unsigned char *sha1);
 extern char *sha1_pack_index_name(const unsigned char *sha1);
 extern const char *find_unique_abbrev(const unsigned char *sha1, int);
 extern const unsigned char null_sha1[20];
-static inline int is_null_sha1(const unsigned char *sha1)
+
+static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2)
 {
-	return !memcmp(sha1, null_sha1, 20);
+	int i;
+
+	for (i = 0; i < 20; i++, sha1++, sha2++) {
+		if (*sha1 != *sha2)
+			return *sha1 - *sha2;
+	}
+
+	return 0;
 }
-static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2)
+
+static inline int is_null_sha1(const unsigned char *sha1)
 {
-	return memcmp(sha1, sha2, 20);
+	return !hashcmp(sha1, null_sha1);
 }
+
 static inline void hashcpy(unsigned char *sha_dst, const unsigned char *sha_src)
 {
 	memcpy(sha_dst, sha_src, 20);