> 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...
Ilya Gavrilin has updated the pull request incrementally with one additional
commit since the last revision:
Changed branch inside signum implementation
-------------
Changes:
- all: https://git.openjdk.org/jdk/pull/16186/files
- new: https://git.openjdk.org/jdk/pull/16186/files/c0a2ab95..867d6e8e
Webrevs:
- full: https://webrevs.openjdk.org/?repo=jdk&pr=16186&range=03
- incr: https://webrevs.openjdk.org/?repo=jdk&pr=16186&range=02-03
Stats: 10 lines in 1 file changed: 3 ins; 5 del; 2 mod
Patch: https://git.openjdk.org/jdk/pull/16186.diff
Fetch: git fetch https://git.openjdk.org/jdk.git pull/16186/head:pull/16186
PR: https://git.openjdk.org/jdk/pull/16186
