[cfe-dev] Signed overflow and vectors?

[Eli Friedman]

On Fri, May 6, 2011 at 11:45 AM, Chris Lattner <clattner at apple.com> wrote:
>
> On May 5, 2011, at 12:00 PM, Eli Friedman wrote:
>
> Looking at http://llvm.org/bugs/show_bug.cgi?id=9850 , I realized that
> we are setting nsw flags on vector instructions.  To fix that bug, at
> the very least, we need to fix *mmintrin.h to not use instructions
> with undefined overflow behavior.  But generally, do we want to be
> setting nsw on vector addition/subtraction/etc. generated by clang?
>
> I think "no", we shouldn't be setting these on vector operations.

Done in r131000.

-Eli