r243851 - Fix invalid shufflevector operands

[John McCall via cfe-commits]

> On Aug 10, 2015, at 12:40 PM, Hans Wennborg <hans at chromium.org> wrote:
> On Fri, Aug 7, 2015 at 11:57 AM, Simon Pilgrim <llvm-dev at redking.me.uk> wrote:
>> On 06/08/2015 18:05, Hans Wennborg wrote:
>>> 
>>> On Sun, Aug 2, 2015 at 8:28 AM, Simon Pilgrim <llvm-dev at redking.me.uk>
>>> wrote:
>>>> 
>>>> Author: rksimon
>>>> Date: Sun Aug  2 10:28:10 2015
>>>> New Revision: 243851
>>>> 
>>>> URL: http://llvm.org/viewvc/llvm-project?rev=243851&view=rev
>>>> Log:
>>>> Fix invalid shufflevector operands
>>>> 
>>>> This patch fixes bug 23800 (
>>>> https://llvm.org/bugs/show_bug.cgi?id=23800#c2 ). There existed a case where
>>>> the index operand from extractelement was directly used to create a
>>>> shufflevector mask. Since the index can be of any integral type but the mask
>>>> must only contain 32 bit integers a 64 bit index operand led to an assertion
>>>> error later on.
>>>> 
>>>> Committed on behalf of mpflanzer (Moritz Pflanzer)
>>>> 
>>>> Differential Revision: http://reviews.llvm.org/D10838
>>> 
>>> Is this something we should merge to 3.7?
>> 
>> It is an edge case and not a regression - at best it would be a 'nice to
>> have'. But it would be a very straightforward merge.
> 
> John, what do you think? Should we merge this to 3.7?

Seems reasonable.  I’m comfortable with small patches that fix crashes.

John.