os/os-android.h: use byte swap intrinsics if available

Signed-off-by: Omri Mor <omor1@asu.edu>

diff --git a/os/os-android.h b/os/os-android.h
index b59fac159ef47796e2860fccf464845116e074d1..1d11cccde42bdd8b1db35bf016ccb65d8f38ac62 100644 (file)
--- a/os/os-android.h
+++ b/os/os-android.h
@@ -20,6 +20,10 @@
 #include "binject.h"
 #include "../file.h"
 
+#ifndef __has_builtin         // Optional of course.
+  #define __has_builtin(x) 0  // Compatibility with non-clang compilers.
+#endif
+
 #define FIO_HAVE_DISK_UTIL
 #define FIO_HAVE_IOSCHED_SWITCH
 #define FIO_HAVE_IOPRIO
@@ -219,9 +223,19 @@ static inline long os_random_long(os_random_state_t *rs)
 #define FIO_O_NOATIME  0
 #endif
 
-#define fio_swap16(x)  __bswap_16(x)
-#define fio_swap32(x)  __bswap_32(x)
-#define fio_swap64(x)  __bswap_64(x)
+/* Check for GCC or Clang byte swap intrinsics */
+#if (__has_builtin(__builtin_bswap16) && __has_builtin(__builtin_bswap32) \
+     && __has_builtin(__builtin_bswap64)) || (__GNUC__ > 4 \
+     || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8)) /* fio_swapN */
+#define fio_swap16(x)  __builtin_bswap16(x)
+#define fio_swap32(x)  __builtin_bswap32(x)
+#define fio_swap64(x)  __builtin_bswap64(x)
+#else
+#include <byteswap.h>
+#define fio_swap16(x)  bswap_16(x)
+#define fio_swap32(x)  bswap_32(x)
+#define fio_swap64(x)  bswap_64(x)
+#endif /* fio_swapN */
 
 #define CACHE_LINE_FILE        \
        "/sys/devices/system/cpu/cpu0/cache/index0/coherency_line_size"