Bug in CmmOpt

Two bugs are demonstrated by the following code. The first one is wrong code generated for the comparison, and the second is the panic (see the comment):

module Test where
import GHC.Base

utf8DecodeChar# :: Addr# -> Bool -> Bool
{-# NOINLINE utf8DecodeChar# #-}
utf8DecodeChar# a# fred =
  case () of 
    _ | word2Int# (indexWord8OffAddr# a# 0#) <=# 0x7F# -> True

-- Omitting the next line gives an ASSERT error:
-- ghc-6.9: panic! (the 'impossible' happened)
--   (GHC version 6.9 for x86_64-unknown-linux):
-- 	ASSERT failed! file nativeGen/MachCodeGen.hs line 1049
-- %MO_S_Le_I8(I8[R2], 127 :: I8)
      | fred -> True

      | otherwise -> False

Trac metadata

Trac field	Value
Version	6.8.2
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system	Unknown
Architecture	Unknown