[llvm] r228525 - Correctly combine alias.scope metadata by a union instead of intersecting

[Hans Wennborg]

Hal,

Björn marked this as a 3.6 regression in PR22507. Is this commit okay
for merging?

Thanks,
Hans

On Sun, Feb 8, 2015 at 9:07 AM, Bjorn Steinbrink <bsteinbr at gmail.com> wrote:
> Author: bsteinbr
> Date: Sun Feb  8 11:07:14 2015
> New Revision: 228525
>
> URL: http://llvm.org/viewvc/llvm-project?rev=228525&view=rev
> Log:
> Correctly combine alias.scope metadata by a union instead of intersecting
>
> Summary:
> The alias.scope metadata represents sets of things an instruction might
> alias with. When generically combining the metadata from two
> instructions the result must be the union of the original sets, because
> the new instruction might alias with anything any of the original
> instructions aliased with.