RFR(M)(round 2): 8215902: Add support for SoftFloat-3e library

[Jakub Vaněk]

Hi Magnus and Erik,

I have added the link to the repository to README and I have removed
the link to the mailing list thread. I have also recreated the GitHub
repository. Now it is a fork of the mentioned repository with two extra
commits containing README and the build scripts.

New webrev URL: http://cr.openjdk.java.net/~jakvanek/8215902/webrev.04/
Bug: https://bugs.openjdk.java.net/browse/JDK-8215902

Regards,

Jakub

On 2019-01-15 at 15:05 +0100, Magnus Ihse Bursie wrote:
> On 2018-12-25 16:19, Jakub Vaněk wrote:
> > Hi,
> > 
> > please review this webrev. It is a successor of the softfloat-3
> > [patch]
> > thread (first email
> > 
http://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2018-November/031311.html
> > )
> > 
> > Changes since the last patch (v6):
> > 
> > - renamed --with-softloat* to --with-sflt* (it is more compact and
> > it
> >    corresponds to the old --with-sflt-lib=... option)
> > 
> > - license is now obtained via --with-sflt-license switch (so it is
> > not
> >    included in OpenJDK source tree)
> > 
> > - updated documentation (slight rewording, added the license
> > option)
> > 
> > - checks for default --with/--without behavior are in place again
> >    (I forgot them when I changed the way the library is detected)
> > 
> > - added a simple testcase - I found a disrepancy between softfloat
> > and
> >    system function behavior. When a float with bits 0x003FFFFF is
> >    added to 0x00000001, the correct result is 0x00400000, but the
> >    default software floating point implementation returns
> > 0x00000000.
> >    However I'm not sure where to put this test - now it is in
> >    test/hotspot/jtreg/compiler/floatingpoint.
> > 
> > - comments in code refer to CR 6757269 and newly JDK-8215902 too.
> > 
> > I have created a repository with SoftFloat-3e with build
> > configuration
> > specifically for OpenJDK on armel:
> > https://github.com/ev3dev-lang-java/softfloat-openjdk
> > 
> > I can add a link to it to the documentation.
> > 
> > Bug: https://bugs.openjdk.java.net/browse/JDK-8215902
> > Webrev: http://cr.openjdk.java.net/~jakvanek/8215902/webrev.02/
> 
> Hi Jakub,
> 
> In general this looks good.
> 
> Some comments:
> 
> I agree with Erik that you can add a link to your github project; 
> compiling SoftFloat is outside the scope of the OpenJDK build 
> instructions, but it can sure be helpful to lower the bar for users 
> wanting to do that. Just one question: any particular reason you
> didn't 
> create your github repo by forking the official 
> https://github.com/ucb-bar/berkeley-softfloat-3? That way, it would
> have 
> been easy for users to see that you were not adding any malicious or 
> suspicious code to the original SoftFloat distribution.
> 
> On the other hand, I think the link to 
> 
http://mail.openjdk.java.net/pipermail/aarch32-port-dev/2016-November/000611.html
>  
> is unnecessary and just creates clutter in the documentation. Please 
> remove it.
> 
> /Magnus
> > CI build: 
> > https://ci.adoptopenjdk.net/view/ev3dev/job/openjdk12_build_ev3_linux/67/
> > 
> > Cheers,
> > 
> > Jakub
> > 
> 
>