[llvm-commits] [llvm] r66902 - /llvm/trunk/lib/Target/X86/X86FastISel.cpp

[Dan Gohman]

On Mar 13, 2009, at 12:28 PM, Duncan Sands wrote:

> Hi Dan,
>
>> X86SelectZExt, at least, currently assumes that the top bits in
>> the register holding an i1 value are zero.
>
> that sounds bogus.  A general rule is that extra bits hold rubbish
> values.  On the other hand, sometimes the nature of the extra bits
> is guaranteed, check out the remarks about getBooleanContents in
> SelectionDAGNodes.h.

Thanks. Looking into it, I believe you and Chris are right. I
just committed a patch which fixes the incorrect assumption.

Dan