RFR: 8240772: x86_64: Pre-generate Assembler::popa, pusha and vzeroupper

Vladimir Kozlov vladimir.kozlov at oracle.com
Wed Mar 11 22:35:36 UTC 2020


Nice!

Thanks,
Vladimir

On 3/11/20 2:36 PM, Claes Redestad wrote:
> On 2020-03-11 19:29, Vladimir Kozlov wrote:
>>
>> That leads to question. Claes, what was the reason you used loop instead of memcpy for vzeroupper?
> 
> For UseAXV <= 2 then vzeroupper is 3 bytes, so the loop simply used
> fewer instructions. It doesn't seem to matter much in the end, so let's
> favor simplicity.
> 
> Final(?) version: http://cr.openjdk.java.net/~redestad/8240772/open.02/
> 
> /Claes


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