On Wed, Mar 18, 2015 at 5:22 AM, Alan Modra <amo...@gmail.com> wrote:
> On Tue, Mar 17, 2015 at 01:28:41PM -0600, Jeff Law wrote:
>> On 03/14/2015 07:02 AM, Alan Modra wrote:
>> >     PR target/65408
>> >     PR target/58744
>> >     PR middle-end/36043
>> >     * calls.c (load_register_parameters): Don't load past end of
>> >     mem unless suitably aligned.
>> I think this is probably a stage1 item.  Richi, Jakub, Joseph, do any of you
>> think we should try to push this into gcc-5?
>
> Some (severity) background to PR65408.  The bug came from SAP HANA
> (en.wikipedia.org/wiki/SAP_HANA), a crash that happens on powerpc64
> and powerpc64le.  aarch64 would also be susceptible to the crash since
> it also loads 16 bytes for the 12-byte struct.  x86_64 only loads 12
> bytes (i386.c:construct_container generates a parallel with a DImode
> and SImode load).  However the underlying bug is there and hits x86_64
> too for the pr58744 and pr36043 testcases..

It's a very very very old bug though.  I'd be interested in any odd
code-generation difference for compiling, say, the linux kernel
(you _can_ get quite ugly code generated because of this fix).

I'm leaning towards waiting for stage1 and then consider a backport
to 5.1.

I'm sure the HAHA guys can work-around by forcing an extra temporary
on the stack and passing that.

Richard.

> --
> Alan Modra
> Australia Development Lab, IBM

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