Use faster byte swapping when compiling with MSVC

[git.git] / compat / bswap.h

diff --git a/compat/bswap.h b/compat/bswap.h
index 7246a12c6eee9411d694b9022c0f21af9a6d4de5..279e0b48b15e091fc0ca975c3efbd461ab02c149 100644 (file)
--- a/compat/bswap.h
+++ b/compat/bswap.h
@@ -9,7 +9,7 @@
  * Default version that the compiler ought to optimize properly with
  * constant values.
  */
-static inline unsigned int default_swab32(unsigned int val)
+static inline uint32_t default_swab32(uint32_t val)
 {
        return (((val & 0xff000000) >> 24) |
                ((val & 0x00ff0000) >>  8) |
@@ -20,7 +20,7 @@ static inline unsigned int default_swab32(unsigned int val)
 #if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
 
 #define bswap32(x) ({ \
-       unsigned int __res; \
+       uint32_t __res; \
        if (__builtin_constant_p(x)) { \
                __res = default_swab32(x); \
        } else { \
@@ -28,6 +28,16 @@ static inline unsigned int default_swab32(unsigned int val)
        } \
        __res; })
 
+#elif defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64))
+
+#include <stdlib.h>
+
+#define bswap32(x) _byteswap_ulong(x)
+
+#endif
+
+#ifdef bswap32
+
 #undef ntohl
 #undef htonl
 #define ntohl(x) bswap32(x)