[LLVMdev] confusion w.r.t. scalar evolution and nuw

[David Majnemer]

On Wed, Jan 14, 2015 at 10:14 PM, Sanjoy Das <sanjoy at playingwithpointers.com
> wrote:

> > We are permitted to turn 'sub nsw i32 %x, 1' into 'add nsw i32 %x, -1'
>
> nsw also has the same problem:
>
> sub nsw int_min, int_min is 0 but
> add nsw int_min, (-int_min) is poison
>

Right, it doesn't work with all values.  I was specifically referring to
the %x and -1 case.


>
> -- Sanjoy
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20150114/9fa6a110/attachment.html>