RFR: 8210416: [linux] Poor StrictMath performance due to non-optimized compilation
david.holmes at oracle.com
Wed Sep 5 21:32:50 UTC 2018
Might as well raise this here too as it's really a build philosophy
issue. Shouldn't flags like -ffp-contract=off (and the existing AIX
-qfloat=nomaf) be toolchain specific rather than platform specific?
On 5/09/2018 11:12 PM, Severin Gehwolf wrote:
> Cross-posting this review-thread on core-libs-dev and build-dev as this
> is a build change, but affects fdlibm which is core-libs.
> With JDK-8170153 optimization for fdlibm code has been turned on for
> ppc64 s390 and aarch64. This patch intends to turn it on on all arches
> on Linux. I've not observed any precision issues. Is there a good
> reason to not use -O3 -ffp-contract=off everywhere?
> Bug: https://bugs.openjdk.java.net/browse/JDK-8210416
> webrev: http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8210416/webrev.01/
> Testing: - java/lang/Math, java/lang/StrictMath tests (all pass).
> - Currently running through submit repo.
> A simple micro benchmark from JDK-8170153 shows these numbers for
> Function | before | after
> sin | 0m33.382s | 0m18.731s
> cos | 0m31.562s | 0m18.796s
> tan | 0m33.657s | 0m21.093s
> atan | 0m5.714s | 0m4.902s
> log | 0m6.212s | 0m4.439s
> log10 | 0m7.946s | 0m5.543s
> sqrt | 0m0.481s | 0m0.449s
> cbrt | 0m5.295s | 0m5.214s
> tanh | 0m1.404s | 0m1.307s
> log1p | 0m6.457s | 0m5.131s
> IEEEremainder | 0m10.629s | 0m6.048s
> atan2 | 0m8.037s | 0m5.668s
> hypot | 0m2.171s | 0m2.147s
More information about the core-libs-dev