[project @ 2005-05-03 10:29:19 by simonmar]

MO_S_Conv folding: fold floating-point literals properly

diff --git a/ghc/compiler/nativeGen/AsmCodeGen.lhs b/ghc/compiler/nativeGen/AsmCodeGen.lhs
index cb2d4f7..43eed18 100644 (file)
--- a/ghc/compiler/nativeGen/AsmCodeGen.lhs
+++ b/ghc/compiler/nativeGen/AsmCodeGen.lhs
@@ -547,9 +547,13 @@ cmmMachOpFold op arg@[CmmLit (CmmInt x rep)]
        -- "from" type, in order to truncate to the correct size.
        -- The final narrow/widen to the destination type
        -- is implicit in the CmmLit.
-      MO_S_Conv from to -> CmmLit (CmmInt (narrowS from x) to)
+      MO_S_Conv from to
+          | isFloatingRep to -> CmmLit (CmmFloat (fromInteger x) to)
+          | otherwise        -> CmmLit (CmmInt (narrowS from x) to)
       MO_U_Conv from to -> CmmLit (CmmInt (narrowU from x) to)
-      _  -> panic "cmmMachOpFold: unknown unary op"
+
+      _ -> panic "cmmMachOpFold: unknown unary op"
+
 
 -- Eliminate conversion NOPs
 cmmMachOpFold (MO_S_Conv rep1 rep2) [x] | rep1 == rep2 = x
@@ -576,10 +580,14 @@ cmmMachOpFold conv_outer args@[CmmMachOp conv_inner [x]]
        | otherwise ->
            CmmMachOp conv_outer args
   where
-       isIntConversion (MO_U_Conv rep1 rep2) = Just (rep1,rep2,False)
-       isIntConversion (MO_S_Conv rep1 rep2) = Just (rep1,rep2,True)
+       isIntConversion (MO_U_Conv rep1 rep2) 
+         | not (isFloatingRep rep1) && not (isFloatingRep rep2) 
+         = Just (rep1,rep2,False)
+       isIntConversion (MO_S_Conv rep1 rep2)
+         | not (isFloatingRep rep1) && not (isFloatingRep rep2) 
+         = Just (rep1,rep2,True)
        isIntConversion _ = Nothing
- 
+
        intconv True  = MO_S_Conv
        intconv False = MO_U_Conv