On Thu, Feb 4, 2016 at 12:53 PM, Alan Lawrence
<alan.lawre...@foss.arm.com> wrote:
> On 04/02/16 09:53, Dominik Vogt wrote:
>>
>> On Wed, Feb 03, 2016 at 11:41:02AM +0000, Alan Lawrence wrote:
>>>
>>> On 26/01/16 12:23, Dominik Vogt wrote:
>>>>
>>>> On Mon, Dec 21, 2015 at 01:13:28PM +0000, Alan Lawrence wrote:
>>>>>
>>>>> ...the test passes with --param sra-max-scalarization-size-Ospeed.
>>>>>
>>>>> Verified on aarch64 and with stage1 compiler for hppa, powerpc, sparc,
>>>>> s390.
>>>>
>>>>
>>>> How did you test this on s390? For me, the test still fails
>>>> unless I add -march=z13 (s390x).
>>>
>>>
>>> Sorry for the slow response, was away last week. On x86 host, I built a
>>> compiler
>>>
>>> configure --enable-languages=c,c++,lto --target=s390-none-linux-gnu
>>
>> ^^^^
>> Looks like the test fails only on s390x (64-Bit ) without
>> -march=z13 but works on s390 (31-Bit).
>
>
> Ah, yes, I see. Loop is not unrolled for dom2, then vectorizer kicks in but
> vectorizes only the initialization/loading, and dom can't see the redundancy
> in
>
> MEM[(int[8] *)&a] = { 0, 1 };
> ...
> _23 = a[0];
>
> as they aren't reading equivalent chunks of memory.
Yep, only FRE/PRE know enough tricks to CSE this.
Richard.
> Same problem as on Alpha, and powerpc64 (without -mcpu=power7/power8).
>
> Powerpc chose to XFAIL rather than add -mcpu=power7, but I'm OK with any
> testsuite workaround here, such as yours.
>
> Cheers, Alan
