FIX #1916: don't try to convert float constants to int in CMM optimizer

diff --git a/compiler/cmm/CmmOpt.hs b/compiler/cmm/CmmOpt.hs
index 320f0a5..7c88add 100644 (file)
--- a/compiler/cmm/CmmOpt.hs
+++ b/compiler/cmm/CmmOpt.hs
@@ -341,7 +341,8 @@ cmmMachOpFold cmp [CmmMachOp conv [x], CmmLit (CmmInt i _)]
   = cmmMachOpFold narrow_cmp [x, CmmLit (CmmInt narrow_i rep)]
  where
     maybe_conversion (MO_U_Conv from _) = Just (from, narrowU)
   = cmmMachOpFold narrow_cmp [x, CmmLit (CmmInt narrow_i rep)]
  where
     maybe_conversion (MO_U_Conv from _) = Just (from, narrowU)

-    maybe_conversion (MO_S_Conv from _) = Just (from, narrowS)
+    maybe_conversion (MO_S_Conv from _)
+        | not (isFloatingRep from) = Just (from, narrowS)

     maybe_conversion _ = Nothing
     
     maybe_comparison (MO_U_Gt _) rep = Just (MO_U_Gt rep)
     maybe_conversion _ = Nothing
     
     maybe_comparison (MO_U_Gt _) rep = Just (MO_U_Gt rep)