Integrated: 8261671: X86 I2L conversion can be skipped for certain masked positive values

[Marcus G K Williams]

On Tue, 16 Feb 2021 16:13:48 GMT, Marcus G K Williams <github.com+168222+mgkwill at openjdk.org> wrote:

> 8261671: X86 I2L conversion can be skipped for certain masked positive values
> 
> For the following expression:
>  (long)(value & mask)
> Where value is of int type and mask is constant (power of two – 1), we can directly generate bzhi instruction to zero the upper bits instead of doing an andl, followed by movslq
> 
> Before:
> Benchmark Mode Cnt Score Error Units
> SkipIntToLongCast.skipMaskedSmallPositiveCast avgt 15 10.679 ± 1.496 ns/op
> 
> 
> After:
> Benchmark Mode Cnt Score Error Units
> SkipIntToLongCast.skipMaskedSmallPositiveCast avgt 15 7.870 ± 0.067 ns/op
> 
> Signed-off-by: Marcus G K Williams <marcus.williams at intel.com>

This pull request has now been integrated.

Changeset: 4f4ca0e7
Author:    Marcus G K Williams <marcus.williams at intel.com>
Committer: Sandhya Viswanathan <sviswanathan at openjdk.org>
URL:       https://git.openjdk.java.net/jdk/commit/4f4ca0e7
Stats:     370 lines in 7 files changed: 365 ins; 0 del; 5 mod

8261671: X86 I2L conversion can be skipped for certain masked positive values

Reviewed-by: kvn, neliasso, vlivanov

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PR: https://git.openjdk.java.net/jdk/pull/2590