The VAX is little endian for 32 bit numbers. It's only 64 bit double that are stored with the longwords reversed. The PDP-11 on the other hand did swap the (16 bit) words when storing a (32 bit) long, compared to little endian. -- Lennart On Sep 25, 2006, at 04:47 , Bulat Ziganshin wrote:
Hello Robert,
Monday, September 25, 2006, 12:09:13 PM, you wrote:
data ByteOrder = BigEndian | LittleEndian deriving ( Eq, Show, Read )
jfyi: there are (very rare) computers that are not LE nor BE. afaik, VAX was one - it has smth like 1032 byte order, mixing BE in 2-byte words and LE of 2-byte words in 4-byte word (or vice versa, i'm not sure)
flipEndian :: Integral a => a -> a flipEndian = wordConcat . reverse . toWord8s
a bit faster:
flipEndian n = let w1 = (n ) .&. 0xff w2 = (n >># 8) .&. 0xff w3 = (n >># 16) .&. 0xff w4 = (n >># 24) in (w1 <<# 24) .|. (w2 <<# 16) .|. (w3 <<# 8) .|. w4
#ifdef __GLASGOW_HASKELL__
(I# a) <<# (I# b) = (I# (a `iShiftL#` b)) (I# a) >># (I# b) = (I# (a `uncheckedIShiftRL#` b))
#else /* ! __GLASGOW_HASKELL__ */
a <<# b = a `shiftL` b a >># b = a `shiftR` b
#endif /* ! __GLASGOW_HASKELL__ */
-- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com
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