[PATCH 2/4] S390: Use 64bit instruction to check for copies of > 1MB with mvcle.

[Florian Weimer]

On 04/26/2016 02:07 PM, Stefan Liebler wrote:
> The __memcpy_default variant on s390 64bit calculates the number of
> 256byte blocks in a 64bit register and checks, if they exceed 1MB
> to jump to mvcle. Otherwise a mvc-loop is used. The compare-instruction
> only checks a 32bit value.
> This patch uses a 64bit compare.

This is purely an optimization, right?  Did the previous implementation 
still perform a complete copy (although perhaps in a less efficient way)?

Thanks,
Florian