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 |