diff options
| author | Reid Barton <rwbarton@gmail.com> | 2013-09-07 21:07:30 -0400 |
|---|---|---|
| committer | Austin Seipp <austin@well-typed.com> | 2013-09-15 13:01:12 -0500 |
| commit | acaa1c873d6d0657b8b918f8d38927d5667329ac (patch) | |
| tree | d80655c0e0b7b2ec0ab8952c42d18201cdb14fcc /libraries/base/GHC/Word.hs | |
| parent | fa3440945f2519325867c8fe4dbc66aca9c6a7f7 (diff) | |
| download | haskell-acaa1c873d6d0657b8b918f8d38927d5667329ac.tar.gz | |
byteSwap16/32: Narrow the result to 16/32 bits
According to primops.txt.pp, the BSwap16Op and BSwap32Op primops
leave the higher bytes of their results undefined. We must clear
those higher bytes here before storing the result in a Word16/32.
Signed-off-by: Austin Seipp <austin@well-typed.com>
Diffstat (limited to 'libraries/base/GHC/Word.hs')
| -rw-r--r-- | libraries/base/GHC/Word.hs | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/libraries/base/GHC/Word.hs b/libraries/base/GHC/Word.hs index 3419a24d58..47710118b5 100644 --- a/libraries/base/GHC/Word.hs +++ b/libraries/base/GHC/Word.hs @@ -304,7 +304,7 @@ instance FiniteBits Word16 where finiteBitSize _ = 16 byteSwap16 :: Word16 -> Word16 -byteSwap16 (W16# w#) = W16# (byteSwap16# w#) +byteSwap16 (W16# w#) = W16# (narrow16Word# (byteSwap16# w#)) {-# RULES "fromIntegral/Word8->Word16" fromIntegral = \(W8# x#) -> W16# x# @@ -531,7 +531,7 @@ instance Read Word32 where #endif byteSwap32 :: Word32 -> Word32 -byteSwap32 (W32# w#) = W32# (byteSwap32# w#) +byteSwap32 (W32# w#) = W32# (narrow32Word# (byteSwap32# w#)) ------------------------------------------------------------------------ -- type Word64 |