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

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
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