8210425: [x86] sharedRuntimeTrig/sharedRuntimeTrans compiled without optimization

Erik Joelsson erik.joelsson at oracle.com
Wed Sep 12 17:02:06 UTC 2018

Hello Severin,

In configure, we now set FDLIBM_CFLAGS based on toolchain type and 
capabilities. In JvmOverrideFiles.gmk, the use of it is still 
conditional on Linux. I don't think it should be. We already have the 
conditionals we need.


On 2018-09-12 05:44, Severin Gehwolf wrote:
> Hi,
> Updated webrev since fdlibm build change seems to have settled:
> http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8210425/webrev.02/
> Optimization is being done at level -O2 (CXX_O_FLAG_NORM) with
> -ffp-contract=off when the toolchain (gcc/clang at this point)
> supports it. Otherwise no optimization will be done. Those overrides
> are no longer in an x86 specific block. Thus, ppc64, aarch64, s390x
> will get correct settings too.
> How does this look?
> Thanks,
> Severin
> On Wed, 2018-09-12 at 07:16 +0000, Schmidt, Lutz wrote:
>> I totally agree with Andrew's statement. FP calculations should be
>> evaluated as the programmer wrote them down. All fiddling around with
>> sequence or rounding is evil. You lose reproducibility of results.
>> Regards,
>> Lutz
>> On 08.09.18, 11:26, "hotspot-dev on behalf of Andrew Haley" <hotspot-dev-bounces at openjdk.java.net on behalf of aph at redhat.com> wrote:
>>      On 09/06/2018 03:32 PM, Severin Gehwolf wrote:
>>      > Right. I should note that ppc64, s390x and aarch64 ports don't have
>>      > this optimization turned off as those overrides are in a x86 specific
>>      > block. It appears it hasn't caused issues for these ports so far.
>>      That's just dumb luck. We really should turn off the merging of FP
>>      operations on all platforms.
>>      --
>>      Andrew Haley
>>      Java Platform Lead Engineer
>>      Red Hat UK Ltd. <https://www.redhat.com>
>>      EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671

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