X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Futils%2FFastTypes.lhs;h=ab5ae460d4709c2a8303cc8c91988d97845b848b;hb=1a7d1b77334529ca96ed4cbc03fcb5f55dc2de4a;hp=bcea61de7805b27d891b74771568923ea714c334;hpb=da72bd5d852ac0e01a00f5d54030a958fbcf72dc;p=ghc-hetmet.git

diff --git a/compiler/utils/FastTypes.lhs b/compiler/utils/FastTypes.lhs
index bcea61d..ab5ae46 100644
--- a/compiler/utils/FastTypes.lhs
+++ b/compiler/utils/FastTypes.lhs
@@ -4,6 +4,13 @@
 \section{Fast integers and booleans}
 
 \begin{code}
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
 module FastTypes (
     FastInt, _ILIT, iBox, iUnbox,
     (+#), (-#), (*#), quotFastInt, negateFastInt,
@@ -34,6 +41,8 @@ fastBool True  = 1#
 fastBool False = 0#
 isFastTrue x = x ==# 1#
 
+-- note that fastOr and fastAnd are strict in both arguments
+-- since they are unboxed
 fastOr 1# _ = 1#
 fastOr 0# x = x
 
@@ -60,11 +69,16 @@ negateFastInt = negate
 type FastBool = Bool
 fastBool x = x
 isFastTrue x = x
-fastOr = (||)
-fastAnd = (&&)
+-- make sure these are as strict as the unboxed version,
+-- so that the performance characteristics match
+fastOr False False = False
+fastOr _ _ = True
+fastAnd True True = True
+fastAnd _ _ = False
 
 --These are among the type-signatures necessary for !ghc to compile
 -- but break ghc (can't give a signature for an import...)
+--Note that the comparisons actually do return Bools not FastBools.
 (+#) :: FastInt -> FastInt -> FastInt
 (-#) :: FastInt -> FastInt -> FastInt
 (*#) :: FastInt -> FastInt -> FastInt
@@ -75,19 +89,6 @@ fastAnd = (&&)
 (>#) :: FastInt -> FastInt -> Bool
 
 #endif /* ! __GLASGOW_HASKELL__ */
--- however it's still possible to check that these are
--- valid signatures nonetheless (e.g., ==# returns Bool
--- not FastBool/Int# !)
-_signatures =
- ( (+#) :: FastInt -> FastInt -> FastInt
- , (-#) :: FastInt -> FastInt -> FastInt
- , (*#) :: FastInt -> FastInt -> FastInt
- , (==#) :: FastInt -> FastInt -> Bool
- , (<#) :: FastInt -> FastInt -> Bool
- , (<=#) :: FastInt -> FastInt -> Bool
- , (>=#) :: FastInt -> FastInt -> Bool
- , (>#) :: FastInt -> FastInt -> Bool
- )
 
 -- type-signatures will improve the non-ghc-specific versions
 -- and keep things accurate (and ABLE to compile!)