fenv.h support for alpha?

[Dave Huang]

I was trying to build ffmpeg3 from pkgsrc on NetBSD/alpha, and got this error:

In file included from libavfilter/vf_drawtext.c:40:0:
/usr/include/fenv.h:31:2: error: #error "fenv.h is currently not supported for this architecture"
#error "fenv.h is currently not supported for this architecture"
^

Back in 2014, Martin Husemann mentioned that he was planning to look at
adding support:
http://mail-index.netbsd.org/port-alpha/2014/03/07/msg000695.html

There's also this PR 49997 about the lack of fenv.h support on various
architectures: http://gnats.netbsd.org/49997

Has there been any progress on this since then? What's involved in
adding support? I seem to recall hearing that the Alpha doesn't fully
implement the IEEE FP standard, and that it needs some software
assistance--is the problem that we need to write that software?
--
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[Havard Eidnes]

> I was trying to build ffmpeg3 from pkgsrc on NetBSD/alpha, and got this error:
>
> In file included from libavfilter/vf_drawtext.c:40:0:
> /usr/include/fenv.h:31:2: error: #error "fenv.h is currently not supported for this architecture"
> #error "fenv.h is currently not supported for this architecture"
> ^
>
> Back in 2014, Martin Husemann mentioned that he was planning to look at
> adding support:
> http://mail-index.netbsd.org/port-alpha/2014/03/07/msg000695.html
>
> There's also this PR 49997 about the lack of fenv.h support on various
> architectures: http://gnats.netbsd.org/49997

The specific package mentioned here is lang/perl5, where I last
year added a patch to work around this problem, ref. the commit
message which says (among others):

Add a Configure test to verify that including <fenv.h> doesn't produce
a build error, as it will in quite few cases on NetBSD on archs which
are not amd64, i386 or sparc in NetBSD 6.x. If the test build fails,
pretend we don't have fenv.h.

As for the more generic problem and the progress (or lack thereof) of
dealing "properly" with this I'll leave to others to answer for. If I
recall correctly, we're a bit special in that we have <fenv.h> but not
all of our ports actually implement it, so packages with configure
tests which just check for the presence of <fenv.h> will fall on their
faces later, as you've noted.

Regards,

- Håvard

[Martin Husemann]

On Wed, Jun 08, 2016 at 12:15:22PM -0500, Dave Huang wrote:
> Back in 2014, Martin Husemann mentioned that he was planning to look at
> adding support:
> http://mail-index.netbsd.org/port-alpha/2014/03/07/msg000695.html

Oops, I thought I had done that, will dig for the changes...

Martin