Request for review: 6896617: Optimize sun.nio.cs.ISO_8859_1$Encode.encodeArrayLoop() on x86

[Vitaly Davidovich]

Hi Vladimir,

encodeArray can be made static.

Also, what's the purpose of overflow flag? Once you detect overflow can't
you simply return the overflow result?

What's the key piece that allows jit to generate better code? Is it the
encodeArray which is nice, small, and isolated?

Thanks

Sent from my phone
On Jan 8, 2013 6:18 PM, "Vladimir Kozlov" <vladimir.kozlov at oracle.com>
wrote:

> http://cr.openjdk.java.net/~**kvn/6896617_jdk/webrev<http://cr.openjdk.java.net/~kvn/6896617_jdk/webrev>
>
> Move encoding loop into separate method for which VM will use intrinsic on
> x86. I want to get agreement on this jdk change before I submit VM part.
>
> This gives +1.6% performance improvement on SPECjAppServer2004 on x86.
> Note, even without intrinsic (on other platforms) JIT will produce better
> code for this loop.
>
> Thanks,
> Vladimir
>