[llvm-commits] [llvm] r89639 - in /llvm/trunk: lib/Transforms/Scalar/InstructionCombining.cpp test/Transforms/InstCombine/compare-signs.ll

[Chris Lattner]

On Nov 23, 2009, at 12:33 AM, Duncan Sands wrote:

>>>> + if (KnownZeroLHS.countLeadingOnes() == BitWidth-1 &&
>>>> + KnownZeroRHS.countLeadingOnes() == BitWidth-1) {
>>> 
>>> == -> >= :)
>> 
>> Nope, look again!
>> 
>> +        APInt TypeMask(APInt::getHighBitsSet(BitWidth, BitWidth-1));
>> 
>> Thus, it will never return a knownzero with all bits set. :)
> 
> Ha ha, you got me there!

Please add a comment.  Obviously it isn't clear what is going on here.