Bug ID: JDK-8273021 C2: Improve Add and Xor ideal optimizations

Type: Enhancement
Component: hotspot
Sub-Component: compiler
Affected Version: 17,18

Priority: P4
Status: Resolved
Resolution: Fixed

Submitted: 2021-08-26
Updated: 2022-02-06
Resolved: 2021-09-13

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JDK 17	JDK 18
17.0.2Fixed	18 b15Fixed

Add the following identical equations for Add and Xor node, respectively.

~(x-1) => -x
~x + 1 => -x

Request the backport to 17u: The patch applies without conflicts. Low risk.

05-11-2021

Changeset: a73c06de Author: Yi Yang <yyang@openjdk.org> Date: 2021-09-13 02:10:45 +0000 URL: https://git.openjdk.java.net/jdk/commit/a73c06de2ac47033503189140c0f8ee61fcbceae

13-09-2021

Relates :	JDK-8279607 - Existing optimization "~x+1" -> "-x" can be generalized to "~x+c" -> "(c-1)-x".
Relates :	JDK-8273868 - Add IR tests for JDK-8273021