util.h: backout 06badf7d10dc and 2c9645c0a582 for big-endian breakage
authorSiddharth Agarwal <sid0@fb.com>
Mon, 30 Sep 2013 12:36:26 -0700
changeset 19833 1935e8383a9e
parent 19832 0c02d8e7bbc4
child 19834 80633eac7b9d
util.h: backout 06badf7d10dc and 2c9645c0a582 for big-endian breakage getbe32 and putbe32 need to behave differently on big-endian and little-endian systems. On big-endian ones, they should be roughly equivalent to the identity function with a cast, but on little-endian ones they should reverse the order of the bytes. That is achieved by the original definition, but __builtin_bswap32 and _byteswap_ulong, as the names suggest, swap bytes around unconditionally. There was no measurable performance improvement, so there's no point adding extra complexity with even more ifdefs for endianncess.
mercurial/util.h
--- a/mercurial/util.h	Mon Sep 30 12:38:08 2013 -0700
+++ b/mercurial/util.h	Mon Sep 30 12:36:26 2013 -0700
@@ -151,17 +151,6 @@
 #define inline __inline
 #endif
 
-#if defined(_MSC_VER) && (_MSC_VER >= 1300)
-static inline uint32_t getbe32(const char *c)
-{
-	return _byteswap_ulong(*(uint32_t *)c);
-}
-#elif __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)
-static inline uint32_t getbe32(const char *c)
-{
-	return __builtin_bswap32(*(uint32_t *)c);
-}
-#else
 static inline uint32_t getbe32(const char *c)
 {
 	const unsigned char *d = (const unsigned char *)c;
@@ -171,21 +160,7 @@
 		(d[2] << 8) |
 		(d[3]));
 }
-#endif
 
-#if defined(_MSC_VER) && (_MSC_VER >= 1300)
-static inline void putbe32(uint32_t x, char *c)
-{
-	x = _byteswap_ulong(x);
-	*(uint32_t *)c = x;
-}
-#elif __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)
-static inline void putbe32(uint32_t x, char *c)
-{
-	x = __builtin_bswap32(x);
-	*(uint32_t *)c = x;
-}
-#else
 static inline void putbe32(uint32_t x, char *c)
 {
 	c[0] = (x >> 24) & 0xff;
@@ -193,6 +168,5 @@
 	c[2] = (x >> 8) & 0xff;
 	c[3] = (x) & 0xff;
 }
-#endif
 
 #endif /* _HG_UTIL_H_ */