[llvm] r257730 - [X86] Don't alter HasOpaqueSPAdjustment after we've relied on it

[Hans Wennborg via llvm-commits]

Thanks! Merged in r257779.

On Thu, Jan 14, 2016 at 9:51 AM, Nadav Rotem <nrotem at apple.com> wrote:
> Yes. This is OK.
>
>> On Jan 14, 2016, at 9:47 AM, Hans Wennborg <hans at chromium.org> wrote:
>>
>> I'd like to merge this to 3.8. Nadav, is this OK for you as code owner?
>>
>> Thanks,
>> Hans
>>
>> On Wed, Jan 13, 2016 at 5:20 PM, David Majnemer via llvm-commits
>> <llvm-commits at lists.llvm.org> wrote:
>>> Author: majnemer
>>> Date: Wed Jan 13 19:20:03 2016
>>> New Revision: 257730
>>>
>>> URL: http://llvm.org/viewvc/llvm-project?rev=257730&view=rev
>>> Log:
>>> [X86] Don't alter HasOpaqueSPAdjustment after we've relied on it
>>>
>>> We rely on HasOpaqueSPAdjustment not changing after we've calculated
>>> things based on it.  Things like whether or not we can use 'rep;movs' to
>>> copy bytes around, that sort of thing.  If it changes, invariants in the
>>> backend will quietly break.  This situation arose when we had a call to
>>> memcpy *and* a COPY of the FLAGS register where we would attempt to
>>> reference local variables using %esi, a register that was clobbered by
>>> the 'rep;movs'.
>>>
>>> This fixes PR26124.
>