8210425: [x86] sharedRuntimeTrig/sharedRuntimeTrans compiled without optimization

[Severin Gehwolf]

Hi Erik,

On Wed, 2018-09-12 at 10:02 -0700, Erik Joelsson wrote:
> 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.

Thanks for the review. Updated webrev:
http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8210425/webrev.03/

I wasn't sure whether the precompiled headers handling for gcc/clang is
right and was reluctant to move it out of the linux conditional. The
assumption on my end is that if headers are compiled with -O3, we can't
used them for any other opt level. It should still all work. Thoughts?

Thanks,
Severin

> 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
> > >      
> > > 
> 
>