Bug ID: JDK-8254872 Optimize Rotate on AArch64

JDK-8254872 : Optimize Rotate on AArch64

Type: Enhancement
Component: hotspot
Sub-Component: compiler
Affected Version: 16

Priority: P4
Status: Resolved
Resolution: Fixed
OS: generic
CPU: aarch64

Submitted: 2020-10-16
Updated: 2020-12-01
Resolved: 2020-11-17

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JDK 16
16 b25Fixed

Related Reports

Relates :	JDK-8256438 - AArch64: Implement match rules with ROR shift register value
Relates :	JDK-8256478 - C2 compilation fails with assert(t1->isa_long()) failed: Type must be a long
Relates :	JDK-8256823 - C2 compilation fails with "assert(isShiftCount(imm8 >> 1)) failed: illegal shift count"

Description

Intel created a patch to intrinsify Integer/Long.rotateX APIs [1]. New IR nodes are introduced, we can do it in AArch64. 
Considering GVN folds relevant operation patterns into a single Rotate node, the final code[3] removes intrinsics.



[1] http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2020-July/038963.html
[2] https://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2020-July/039048.html
[3] https://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2020-August/039324.html

Comments

Changeset: 30a2ad55 Author: Eric Liu <eric.c.liu@arm.com> Committer: Nick Gasson <ngasson@openjdk.org> Date: 2020-11-17 01:55:09 +0000 URL: https://github.com/openjdk/jdk/commit/30a2ad55

17-11-2020