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| author | Ian Lynagh <ian@well-typed.com> | 2012-09-19 22:37:01 +0100 |
|---|---|---|
| committer | Ian Lynagh <ian@well-typed.com> | 2012-09-19 22:37:01 +0100 |
| commit | fe5821233d439c35c441cfc6c9d2029e5fd01342 (patch) | |
| tree | dea7968ac9b9bb3698e6ee10a6ebfb2d72d8952d | |
| parent | 6a4d60a5e2ddcfafb30cfdf93c7a589398af054d (diff) | |
| download | haskell-fe5821233d439c35c441cfc6c9d2029e5fd01342.tar.gz | |
Make some uses of minBound/maxBound use the target Int/Word sizes
| -rw-r--r-- | compiler/prelude/PrelRules.lhs | 55 |
1 files changed, 28 insertions, 27 deletions
diff --git a/compiler/prelude/PrelRules.lhs b/compiler/prelude/PrelRules.lhs index 3f1236599a..aa4156bfdb 100644 --- a/compiler/prelude/PrelRules.lhs +++ b/compiler/prelude/PrelRules.lhs @@ -385,37 +385,38 @@ litEq is_eq = msum -- minBound, so we can replace such comparison with False. boundsCmp :: Comparison -> RuleM CoreExpr boundsCmp op = do + dflags <- getDynFlags [a, b] <- getArgs - liftMaybe $ mkRuleFn op a b + liftMaybe $ mkRuleFn dflags op a b data Comparison = Gt | Ge | Lt | Le -mkRuleFn :: Comparison -> CoreExpr -> CoreExpr -> Maybe CoreExpr -mkRuleFn Gt (Lit lit) _ | isMinBound lit = Just falseVal -mkRuleFn Le (Lit lit) _ | isMinBound lit = Just trueVal -mkRuleFn Ge _ (Lit lit) | isMinBound lit = Just trueVal -mkRuleFn Lt _ (Lit lit) | isMinBound lit = Just falseVal -mkRuleFn Ge (Lit lit) _ | isMaxBound lit = Just trueVal -mkRuleFn Lt (Lit lit) _ | isMaxBound lit = Just falseVal -mkRuleFn Gt _ (Lit lit) | isMaxBound lit = Just falseVal -mkRuleFn Le _ (Lit lit) | isMaxBound lit = Just trueVal -mkRuleFn _ _ _ = Nothing - -isMinBound :: Literal -> Bool -isMinBound (MachChar c) = c == minBound -isMinBound (MachInt i) = i == toInteger (minBound :: Int) -isMinBound (MachInt64 i) = i == toInteger (minBound :: Int64) -isMinBound (MachWord i) = i == toInteger (minBound :: Word) -isMinBound (MachWord64 i) = i == toInteger (minBound :: Word64) -isMinBound _ = False - -isMaxBound :: Literal -> Bool -isMaxBound (MachChar c) = c == maxBound -isMaxBound (MachInt i) = i == toInteger (maxBound :: Int) -isMaxBound (MachInt64 i) = i == toInteger (maxBound :: Int64) -isMaxBound (MachWord i) = i == toInteger (maxBound :: Word) -isMaxBound (MachWord64 i) = i == toInteger (maxBound :: Word64) -isMaxBound _ = False +mkRuleFn :: DynFlags -> Comparison -> CoreExpr -> CoreExpr -> Maybe CoreExpr +mkRuleFn dflags Gt (Lit lit) _ | isMinBound dflags lit = Just falseVal +mkRuleFn dflags Le (Lit lit) _ | isMinBound dflags lit = Just trueVal +mkRuleFn dflags Ge _ (Lit lit) | isMinBound dflags lit = Just trueVal +mkRuleFn dflags Lt _ (Lit lit) | isMinBound dflags lit = Just falseVal +mkRuleFn dflags Ge (Lit lit) _ | isMaxBound dflags lit = Just trueVal +mkRuleFn dflags Lt (Lit lit) _ | isMaxBound dflags lit = Just falseVal +mkRuleFn dflags Gt _ (Lit lit) | isMaxBound dflags lit = Just falseVal +mkRuleFn dflags Le _ (Lit lit) | isMaxBound dflags lit = Just trueVal +mkRuleFn _ _ _ _ = Nothing + +isMinBound :: DynFlags -> Literal -> Bool +isMinBound _ (MachChar c) = c == minBound +isMinBound dflags (MachInt i) = i == tARGET_MIN_INT dflags +isMinBound _ (MachInt64 i) = i == toInteger (minBound :: Int64) +isMinBound _ (MachWord i) = i == 0 +isMinBound _ (MachWord64 i) = i == 0 +isMinBound _ _ = False + +isMaxBound :: DynFlags -> Literal -> Bool +isMaxBound _ (MachChar c) = c == maxBound +isMaxBound dflags (MachInt i) = i == tARGET_MAX_INT dflags +isMaxBound _ (MachInt64 i) = i == toInteger (maxBound :: Int64) +isMaxBound dflags (MachWord i) = i == tARGET_MAX_WORD dflags +isMaxBound _ (MachWord64 i) = i == toInteger (maxBound :: Word64) +isMaxBound _ _ = False -- Note that we *don't* warn the user about overflow. It's not done at |