[endianess] fix some issues on non supported arches

Crypto/Internal/CompatPrim.hs

@@ -24,6 +24,9 @@ module Crypto.Internal.CompatPrim
     ) where
 
 import GHC.Prim
+#if !defined(ARCH_IS_LITTLE_ENDIAN) && !defined(ARCH_IS_BIG_ENDIAN)
+import Data.Memory.Endian (getSystemEndianness, Endianness(..))
+#endif
 
 -- | byteswap Word# to or from Big Endian
 --
@@ -31,8 +34,10 @@ import GHC.Prim
 be32Prim :: Word# -> Word#
 #ifdef ARCH_IS_LITTLE_ENDIAN
 be32Prim = byteswap32Prim
+#elif defined(ARCH_IS_BIG_ENDIAN)
+be32Prim = id
 #else
-be32Prim w = w
+be32Prim w = if getSystemEndianness == LittleEndian then byteswap32Prim w else w
 #endif
 
 -- | byteswap Word# to or from Little Endian
@@ -41,8 +46,10 @@ be32Prim w = w
 le32Prim :: Word# -> Word#
 #ifdef ARCH_IS_LITTLE_ENDIAN
 le32Prim w = w
-#else
+#elif defined(ARCH_IS_BIG_ENDIAN)
 le32Prim = byteswap32Prim
+#else
+le32Prim w = if getSystemEndianness == LittleEndian then w else byteswap32Prim w
 #endif
 
 -- | Simple compatibility for byteswap the lower 32 bits of a Word#
@@ -69,11 +76,24 @@ convert4To32 a b c d = or# (or# c1 c2) (or# c3 c4)
         !c2 = uncheckedShiftL# b 16#
         !c3 = uncheckedShiftL# c 8#
         !c4 = d
-#else
+#elif defined(ARCH_IS_BIG_ENDIAN)
         !c1 = uncheckedShiftL# d 24#
         !c2 = uncheckedShiftL# c 16#
         !c3 = uncheckedShiftL# b 8#
         !c4 = a
+#else
+        !c1
+            | getSystemEndianness == LittleEndian = uncheckedShiftL# a 24#
+            | otherwise                           = uncheckedShiftL# d 24#
+        !c2
+            | getSystemEndianness == LittleEndian = uncheckedShiftL# b 16#
+            | otherwise                           = uncheckedShiftL# c 16#
+        !c3
+            | getSystemEndianness == LittleEndian = uncheckedShiftL# c 8#
+            | otherwise                           = uncheckedShiftL# b 8#
+        !c4
+            | getSystemEndianness == LittleEndian = d
+            | otherwise                           = a
 #endif
 
 -- | Simple wrapper to handle pre 7.8 and future, where