use __BYTE_ORDER__ macro to detect endianness when available

BUG=skia:

Change-Id: Iff27097c248a643319e930a6212c5a7155bd0064
Reviewed-on: https://skia-review.googlesource.com/5280
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Klein <mtklein@chromium.org>

diff --git a/include/core/SkPreConfig.h b/include/core/SkPreConfig.h
index b165ae1..0e6f787 100644 (file)
--- a/include/core/SkPreConfig.h
+++ b/include/core/SkPreConfig.h
@@ -72,7 +72,11 @@
 //////////////////////////////////////////////////////////////////////
 
 #if !defined(SK_CPU_BENDIAN) && !defined(SK_CPU_LENDIAN)
-    #if defined(__sparc) || defined(__sparc__) || \
+    #if defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
+        #define SK_CPU_BENDIAN
+    #elif defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
+        #define SK_CPU_LENDIAN
+    #elif defined(__sparc) || defined(__sparc__) || \
       defined(_POWER) || defined(__powerpc__) || \
       defined(__ppc__) || defined(__hppa) || \
       defined(__PPC__) || defined(__PPC64__) || \