[PATCH] Don't write beyond destination in __mempcpy_avx512_no_vzeroupper (bug 23196)

[Florian Weimer]

On 05/22/2018 02:17 PM, Andreas Schwab wrote:
> On Mai 22 2018, "H.J. Lu"<hjl.tools@gmail.com>  wrote:
> 
>> The modified test does't fail on Skylake server with unchanged
>> memmove-avx512-no-vzeroupper.S.   Can you modify the test
>> so that it fails with the original memmove-avx512-no-vzeroupper.S
>> on Skylake server?

> How to do that?  I have tested it on a Xeon Phi (whateve that means)
> where it failed without the fix.

It has to do with copy sizes and relation to the cache size.  I had to 
adjust your reproducer to make it fail on KNL, basically increasing the 
copy size by a factor of 10.

Thanks,
Florian