1 files changed, 32 insertions, 6 deletions
diff --git a/include/llvm/Support/SwapByteOrder.h b/include/llvm/Support/SwapByteOrder.h
index 06a447a27c2a..6cec87006c02 100644
--- a/include/llvm/Support/SwapByteOrder.h
+++ b/include/llvm/Support/SwapByteOrder.h
@@ -22,9 +22,37 @@
 #include <stdlib.h>
 #endif
 
+#if defined(__linux__) || defined(__GNU__) || defined(__HAIKU__)
+#include <endian.h>
+#elif defined(_AIX)
+#include <sys/machine.h>
+#elif defined(__sun)
+/* Solaris provides _BIG_ENDIAN/_LITTLE_ENDIAN selector in sys/types.h */
+#include <sys/types.h>
+#define BIG_ENDIAN 4321
+#define LITTLE_ENDIAN 1234
+#if defined(_BIG_ENDIAN)
+#define BYTE_ORDER BIG_ENDIAN
+#else
+#define BYTE_ORDER LITTLE_ENDIAN
+#endif
+#else
+#if !defined(BYTE_ORDER) && !defined(_WIN32)
+#include <machine/endian.h>
+#endif
+#endif
+
 namespace llvm {
 namespace sys {
 
+#if defined(BYTE_ORDER) && defined(BIG_ENDIAN) && BYTE_ORDER == BIG_ENDIAN
+constexpr bool IsBigEndianHost = true;
+#else
+constexpr bool IsBigEndianHost = false;
+#endif
+
+static const bool IsLittleEndianHost = !IsBigEndianHost;
+
 /// SwapByteOrder_16 - This function returns a byte-swapped representation of
 /// the 16-bit argument.
 inline uint16_t SwapByteOrder_16(uint16_t value) {
@@ -39,10 +67,9 @@ inline uint16_t SwapByteOrder_16(uint16_t value) {
 #endif
 }
 
-/// SwapByteOrder_32 - This function returns a byte-swapped representation of
-/// the 32-bit argument.
+/// This function returns a byte-swapped representation of the 32-bit argument.
 inline uint32_t SwapByteOrder_32(uint32_t value) {
-#if defined(__llvm__) || (LLVM_GNUC_PREREQ(4, 3, 0) && !defined(__ICC))
+#if defined(__llvm__) || (defined(__GNUC__) && !defined(__ICC))
   return __builtin_bswap32(value);
 #elif defined(_MSC_VER) && !defined(_DEBUG)
   return _byteswap_ulong(value);
@@ -55,10 +82,9 @@ inline uint32_t SwapByteOrder_32(uint32_t value) {
 #endif
 }
 
-/// SwapByteOrder_64 - This function returns a byte-swapped representation of
-/// the 64-bit argument.
+/// This function returns a byte-swapped representation of the 64-bit argument.
 inline uint64_t SwapByteOrder_64(uint64_t value) {
-#if defined(__llvm__) || (LLVM_GNUC_PREREQ(4, 3, 0) && !defined(__ICC))
+#if defined(__llvm__) || (defined(__GNUC__) && !defined(__ICC))
   return __builtin_bswap64(value);
 #elif defined(_MSC_VER) && !defined(_DEBUG)
   return _byteswap_uint64(value);