Commit d781517f authored by panne's avatar panne
Browse files

[project @ 2000-07-02 18:50:24 by panne]

Don't warn the user about integer overflow during constant folding
anymore. It's not done at runtime either, and compilation of
completely harmless things like

   ((124076834 :: Word32) + (2147483647 :: Word32))

yielded a warning.
parent ed481295
......@@ -15,8 +15,7 @@ module PrelRules ( primOpRule, builtinRules ) where
import CoreSyn
import Rules ( ProtoCoreRule(..) )
import Id ( idUnfolding, mkWildId, isDataConId_maybe )
import Literal ( Literal(..), isLitLitLit, mkMachInt, mkMachWord
, inIntRange, inWordRange, literalType
import Literal ( Literal(..), isLitLitLit, mkMachInt, mkMachWord, literalType
, word2IntLit, int2WordLit, char2IntLit, int2CharLit
, float2IntLit, int2FloatLit, double2IntLit, int2DoubleLit
, addr2IntLit, int2AddrLit, float2DoubleLit, double2FloatLit
......@@ -197,12 +196,12 @@ cmpOp cmp name l1 l2
negOp name (MachFloat f) = Just (name, mkFloatVal (-f))
negOp name (MachDouble d) = Just (name, mkDoubleVal (-d))
negOp name l@(MachInt i) = intResult name (ppr l) (-i)
negOp name l@(MachInt i) = intResult name (-i)
negOp name l = Nothing
--------------------------
intOp2 op name l1@(MachInt i1) l2@(MachInt i2)
= intResult name (ppr l1 <+> ppr l2) (i1 `op` i2)
= intResult name (i1 `op` i2)
intOp2 op name l1 l2 = Nothing -- Could find LitLit
intOp2Z op name (MachInt i1) (MachInt i2)
......@@ -212,8 +211,7 @@ intOp2Z op name l1 l2 = Nothing -- LitLit or zero dividend
--------------------------
-- Integer is not an instance of Bits, so we operate on Word64
wordBitOp2 op name l1@(MachWord w1) l2@(MachWord w2)
= wordResult name (ppr l1 <+> ppr l2)
((fromIntegral::Word64->Integer) (fromIntegral w1 `op` fromIntegral w2))
= Just (name, mkWordVal ((fromIntegral::Word64->Integer) (fromIntegral w1 `op` fromIntegral w2)))
wordBitOp2 op name l1 l2 = Nothing -- Could find LitLit
wordOp2Z op name (MachWord w1) (MachWord w2)
......@@ -276,31 +274,14 @@ do_lit_eq is_eq name lit expr
val_if_neq | is_eq = falseVal
| otherwise = trueVal
-- TODO: Merge intResult/wordResult
intResult name pp_args result
| not (inIntRange result)
-- Better tell the user that we've overflowed...
-- ..not that it stops us from actually folding!
= pprTrace "Warning:" (text "Integer overflow in:" <+> ppr name <+> pp_args)
Just (name, mkIntVal (squashInt result))
| otherwise
= Just (name, mkIntVal result)
wordResult name pp_args result
| not (inWordRange result)
-- Better tell the user that we've overflowed...
-- ..not that it stops us from actually folding!
= pprTrace "Warning:" (text "Word overflow in:" <+> ppr name <+> pp_args)
Just (name, mkWordVal (squashInt result))
| otherwise
= Just (name, mkWordVal result)
squashInt :: Integer -> Integer -- Squash into Int range
squashInt i = toInteger ((fromInteger i)::Int)
-- Note that we *don't* warn the user about overflow. It's not done at
-- runtime either, and compilation of completely harmless things like
-- ((124076834 :: Word32) + (2147483647 :: Word32))
-- would yield a warning. Instead we simply squash the value into the
-- Int range, but not in a way suitable for cross-compiling... :-(
intResult :: RuleName -> Integer -> Maybe (RuleName, CoreExpr)
intResult name result
= Just (name, mkIntVal (toInteger ((fromInteger result)::Int)))
\end{code}
......
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