PPC.Ppr: Shift by 32 bits is not allowed.

Hi,

when compiling vector-algorithms on powerpc, I get

[ 7 of 10] Compiling Data.Vector.Algorithms.Tim ( src/Data/Vector/Algorithms/Tim.hs, dist-ghc/build/Data/Vector/Algorithms/Tim.o )
ghc: panic! (the 'impossible' happened)
  (GHC version 7.10.2 for powerpc-unknown-linux):
	PPC.Ppr: Shift by 32 bits is not allowed.

I do not get this error on other 32bit architectures.

The offending code seems to be

minrun :: Int -> Int
minrun n0 = (n0 `unsafeShiftR` extra) + if (lowMask .&. n0) > 0 then 1 else 0
 where
 -- smear the bits down from the most significant bit
 !n1 = n0 .|. unsafeShiftR n0 1
 !n2 = n1 .|. unsafeShiftR n1 2
 !n3 = n2 .|. unsafeShiftR n2 4
 !n4 = n3 .|. unsafeShiftR n3 8
 !n5 = n4 .|. unsafeShiftR n4 16
 !n6 = n5 .|. unsafeShiftR n5 32

The call to panic was introduced by Erik in the fix for #5900 (closed).

Is the code at fault, or the compiler?

Trac metadata

Trac field	Value
Version	7.10.2
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler (CodeGen)
Test case
Differential revisions
BlockedBy
Related
Blocking
CC	erikd
Operating system
Architecture