Integrated: 8317971: RISC-V: implement copySignF/D and signumF/D intrinsics

[Ilya Gavrilin]

On Fri, 13 Oct 2023 15:36:56 GMT, Ilya Gavrilin <igavrilin at openjdk.org> wrote:

> Hi all, please review this changes into risc-v floating point copysign and signum intrinsics.
> CopySign - returns first argument with the sign of second. On risc-v we have `fsgnj.x` instruction, which can implement this intrinsic.
> Signum - returns input value if it is +/- 0.0 or NaN, otherwise 1.0 with the sign of input value returned.  On risc-v we can use `fclass.x` to specify type of input value and return appropriate value.
> 
> Tests:
> Performance tests on t-head board:
> With intrinsics:
> 
> Benchmark                 (seed)   Mode  Cnt      Score      Error   Units
> MathBench.copySignDouble       0  thrpt    8  34156.580 ±   76.272  ops/ms
> MathBench.copySignFloat        0  thrpt    8  34181.731 ±   38.182  ops/ms
> MathBench.signumDouble         0  thrpt    8  31977.258 ± 1122.327  ops/ms
> MathBench.signumFloat          0  thrpt    8  31836.852 ±   56.013  ops/ms
> 
> Intrinsics turned off (`-XX:+UnlockDiagnosticVMOptions -XX:-UseCopySignIntrinsic -XX:-UseSignumIntrinsic`):
> 
> Benchmark                 (seed)   Mode  Cnt      Score      Error   Units
> MathBench.copySignDouble       0  thrpt    8  31000.996 ±  943.094  ops/ms
> MathBench.copySignFloat        0  thrpt    8  30678.016 ±   28.087  ops/ms
> MathBench.signumDouble         0  thrpt    8  25435.010 ± 2047.085  ops/ms
> MathBench.signumFloat          0  thrpt    8  25257.058 ±   79.175  ops/ms
> 
> Regression tests: tier1, hotspot:tier2 on risc-v board.
> 
> Also, changed name of one micro test: before we had: `sigNumDouble` and `signumFloat` tests, they does not matches to `signum` or `sigNum`. Now we have similar part: `signum`.
> Performance tests has been changed a bit, to check intrinsics result better, diff to modify tests:
> 
> diff --git a/test/micro/org/openjdk/bench/java/lang/MathBench.java b/test/micro/org/openjdk/bench/java/lang/MathBench.java
> index 6cd1353907e..0bee25366bf 100644
> --- a/test/micro/org/openjdk/bench/java/lang/MathBench.java
> +++ b/test/micro/org/openjdk/bench/java/lang/MathBench.java
> @@ -143,12 +143,12 @@ public double  ceilDouble() {
>  
>      @Benchmark
>      public double  copySignDouble() {
> -        return  Math.copySign(double81, doubleNegative12);
> +        return  Math.copySign(double81, doubleNegative12) + Math.copySign(double81, double2) + Math.copySign(double4Dot1, doubleNegative12);
>      }
>  
>      @Benchmark
>      public float  copySignFloat() {
> -        return  Math.copySign(floatNegative99, float1);
> +        return  Math.copySign(floatNegative99, float1) + Math.copySign(eFloat, float1) + Math.copySign...

This pull request has now been integrated.

Changeset: 5a97411f
Author:    Ilya Gavrilin <igavrilin at openjdk.org>
Committer: Vladimir Kempik <vkempik at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/5a97411f857b0bc9e70b417efa76a5fd5f887fe0
Stats:     90 lines in 5 files changed: 89 ins; 0 del; 1 mod

8317971: RISC-V: implement copySignF/D and signumF/D intrinsics

Reviewed-by: fyang, vkempik

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PR: https://git.openjdk.org/jdk/pull/16186