RFR 8203628: Optimize (masked) byte memory comparisons on x86

Aleksey Shipilev shade at redhat.com
Tue May 22 15:13:32 UTC 2018

On 05/22/2018 05:10 PM, Aleksey Shipilev wrote:
> So, currently it gets compiled using the temporary register, when we could use the indirect memory
> operands, thus avoiding the temp. It gets worse when mask is involved, and we would have another
> addl on this path. The optimization works well when GC barriers are frequent and/or the register
> pressure is high, because we have both denser code and more available registers. When registers are
> abundant and CPU

(one GC pause later)

...is not spectrally melted down, the impact is close to zero.


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