[llvm] r261039 - [X86] Fix a shrink-wrapping miscompile around __chkstk

[Hans Wennborg via llvm-commits]

r261136. Thanks

On Wed, Feb 17, 2016 at 10:57 AM, Reid Kleckner <rnk at google.com> wrote:
> Let's do it.
>
> On Wed, Feb 17, 2016 at 10:12 AM, Hans Wennborg <hans at chromium.org> wrote:
>>
>> Reid, what do you think about merging this to 3.8?
>>
>> On Tue, Feb 16, 2016 at 4:17 PM, Reid Kleckner via llvm-commits
>> <llvm-commits at lists.llvm.org> wrote:
>> > Author: rnk
>> > Date: Tue Feb 16 18:17:33 2016
>> > New Revision: 261039
>> >
>> > URL: http://llvm.org/viewvc/llvm-project?rev=261039&view=rev
>> > Log:
>> > [X86] Fix a shrink-wrapping miscompile around __chkstk
>> >
>> > __chkstk clobbers EAX. If EAX is live across the prologue, then we have
>> > to take extra steps to save it. We already had code to do this if EAX
>> > was a register parameter. This change adapts it to work when shrink
>> > wrapping is used.
>> >
>> > Modified:
>> >     llvm/trunk/lib/Target/X86/X86FrameLowering.cpp
>> >     llvm/trunk/test/CodeGen/X86/shrink-wrap-chkstk.ll
>
>