[llvm] r309330 - [ConstantFolder] Don't try to fold gep when the idx is a vector.

[Davide Italiano via llvm-commits]

On Thu, Jul 27, 2017 at 3:20 PM, Davide Italiano via llvm-commits
<llvm-commits at lists.llvm.org> wrote:
> Author: davide
> Date: Thu Jul 27 15:20:44 2017
> New Revision: 309330
>
> URL: http://llvm.org/viewvc/llvm-project?rev=309330&view=rev
> Log:
> [ConstantFolder] Don't try to fold gep when the idx is a vector.
>
> The code in ConstantFoldGetElementPtr() assumes integers, and
> therefore it crashes trying to get the integer bidwith of a vector
> type (in this case <4 x i32>. I just changed the code to prevent
> the folding in case of vectors and I didn't bother to generalize
> as this doesn't seem to me something that really happens in
> practice, but I'm willing to change the patch if you think
> it's worth it.
> This is hard to trigger from -instsimplify or -instcombine
> only as the second instruction is dead, so the test uses loop-unroll.
>

Hans, David, can we consider merging this to 5.0?

Thanks,

--
Davide