[riscv-port] Integrated: 8278192: riscv: remove unnecessary instruct of DecodeNKlass in C2

[Yadong Wang]

On Fri, 3 Dec 2021 08:20:17 GMT, Yadong Wang <yadongwang at openjdk.org> wrote:

> There are two instructs for DecodeNKlass in C2, and the difference is only that which temporary register operand is used by them, xheapbase, t0 or t1. It's too complicated and the effect is almost invisible. So we just simplify the pattern by using a temporary register from the register allocation.
> Hotspot and jdk tier1 passed on the unmatched board. And all jtreg tests were tested on qemu without new failures.

This pull request has now been integrated.

Changeset: 63b0d52d
Author:    Yadong Wang <yadongwang at openjdk.org>
Committer: Fei Yang <fyang at openjdk.org>
URL:       https://git.openjdk.java.net/riscv-port/commit/63b0d52d287cb2a8f3bb1aa3a7eeff89645b9615
Stats:     69 lines in 4 files changed: 3 ins; 48 del; 18 mod

8278192: riscv: remove unnecessary instruct of DecodeNKlass in C2

Reviewed-by: fyang

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PR: https://git.openjdk.java.net/riscv-port/pull/22