On 2018-09-06 03:12, Severin Gehwolf wrote:
Hi David,
On Thu, 2018-09-06 at 07:32 +1000, David Holmes wrote:
Hi Severin,
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?
Looks like Clang has -ffp-contract:
https://clang.llvm.org/docs/ClangCommandLineReference.html#cmdoption-clang-ffp-contract
Is there any other (supported) toolchain other than gcc and clang on
linux? As for AIX I suppose there is only on supported toolchain?
We don't have a big variety of toolchain/platform combinations that we
actively support no, but we still try to be conscious of when a flag is
toolchain specific and when it's platform specific. There is certainly
interest in using other compilers on Linux, and GCC could potentially be
used on other platforms as well. Until we actually try it, it can be
hard to know for sure if a flag actually applies in other cases for the
toolchain and/or platform, but we can at least try our best guess.
/Erik
Thanks,
Severin
Thanks,
David
On 5/09/2018 11:12 PM, Severin Gehwolf wrote:
Hi,
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[1] shows these numbers
for
StrictMath:
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
Thoughts?
Thanks,
Severin
