[riscv-port] Integrated: 8279292: riscv: Intrinsify multiplyToLen and squareToLen

[Feilong Jiang]

On Mon, 27 Dec 2021 08:25:22 GMT, Feilong Jiang <fjiang at openjdk.org> wrote:

> BigInteger intrinsic: MultiplyToLen and SquareToLen intrinsic are missed in current vm. They should be implemented.
> The JMH tests show that the MultiplyToLen intrinsic improve the performance by up to 2x ~ 3x and the SquareToLen intrinsic improve the performance by up to 1.8x ~ 2x when the length of BigInteger changed from 1 to 5000, compared with that of C2.
> 
> Full jtreg tests on qemu and hotspot/jdk tier1 test on Unmathced are passed without new failures.
> 
> JMH tests and results on D1 and Unmatched list as follows:
> [MyBenchmark.txt](https://github.com/openjdk/riscv-port/files/7779255/MyBenchmark.txt)
> 
> [squareToLen_unmatched.txt](https://github.com/openjdk/riscv-port/files/7779247/squareToLen_unmatched.txt)
> [squareToLen_d1.txt](https://github.com/openjdk/riscv-port/files/7779248/squareToLen_d1.txt)
> [multiplyToLen_unmatched.txt](https://github.com/openjdk/riscv-port/files/7779249/multiplyToLen_unmatched.txt)
> [multiplyToLen_d1.txt](https://github.com/openjdk/riscv-port/files/7779250/multiplyToLen_d1.txt)

This pull request has now been integrated.

Changeset: b396cdda
Author:    Feilong Jiang <fjiang at openjdk.org>
Committer: Fei Yang <fyang at openjdk.org>
URL:       https://git.openjdk.java.net/riscv-port/commit/b396cdda88b703918fe89d80261b08bb22c64e76
Stats:     595 lines in 4 files changed: 589 ins; 0 del; 6 mod

8279292: riscv: Intrinsify multiplyToLen and squareToLen

Co-authored-by: Taiping Guo <guotaiping1 at huawei.com>
Reviewed-by: fyang

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PR: https://git.openjdk.java.net/riscv-port/pull/38