* Re: 01/03: gnu: Add QD.
[not found] ` <20180202143849.080E924648@vcs0.savannah.gnu.org>
@ 2018-02-04 3:55 ` Mark H Weaver
2018-02-05 4:04 ` Eric Bavier
0 siblings, 1 reply; 5+ messages in thread
From: Mark H Weaver @ 2018-02-04 3:55 UTC (permalink / raw)
To: Eric Bavier; +Cc: guix-devel
Hi Eric,
ericbavier@centurylink.net (Eric Bavier) writes:
> bavier pushed a commit to branch master
> in repository guix.
>
> commit cbc084e1a7c25d1c8944bcb20a989f795acdb096
> Author: Eric Bavier <bavier@cray.com>
> Date: Wed Jan 31 13:55:37 2018 -0600
>
> gnu: Add QD.
[...]
> +(define-public qd
> + (package
> + (name "qd")
> + (version "2.3.18")
> + (source (origin
> + (method url-fetch)
> + (uri (string-append "http://crd.lbl.gov/~dhbailey/mpdist/qd-"
> + version ".tar.gz"))
> + (sha256
> + (base32
> + "0vkihcj9fyv2cycq8515713gbs3yskhmivy8bznvx72i6ddnn2c1"))))
> + (build-system gnu-build-system)
> + (native-inputs
> + `(("gfortran" ,gfortran)))
> + (arguments
> + `(#:configure-flags `("--disable-enable_fma" ;weird :/
"weird :/" is not a very useful comment. Can you change it to explain
why you added this flag? It seems unfortunate to disable fused
multiply-add for this kind of library.
Mark
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: 01/03: gnu: Add QD.
2018-02-04 3:55 ` 01/03: gnu: Add QD Mark H Weaver
@ 2018-02-05 4:04 ` Eric Bavier
2018-02-05 11:04 ` Ludovic Courtès
2018-02-06 1:24 ` Mark H Weaver
0 siblings, 2 replies; 5+ messages in thread
From: Eric Bavier @ 2018-02-05 4:04 UTC (permalink / raw)
To: Mark H Weaver; +Cc: guix-devel
On Sat, 03 Feb 2018 22:55:56 -0500
Mark H Weaver <mhw@netris.org> wrote:
> Hi Eric,
>
> ericbavier@centurylink.net (Eric Bavier) writes:
> > bavier pushed a commit to branch master
> > in repository guix.
> >
> > commit cbc084e1a7c25d1c8944bcb20a989f795acdb096
> > Author: Eric Bavier <bavier@cray.com>
> > Date: Wed Jan 31 13:55:37 2018 -0600
> >
> > gnu: Add QD.
> [...]
> > +(define-public qd
> > + (package
> > + (name "qd")
> > + (version "2.3.18")
> > + (source (origin
> > + (method url-fetch)
> > + (uri (string-append "http://crd.lbl.gov/~dhbailey/mpdist/qd-"
> > + version ".tar.gz"))
> > + (sha256
> > + (base32
> > + "0vkihcj9fyv2cycq8515713gbs3yskhmivy8bznvx72i6ddnn2c1"))))
> > + (build-system gnu-build-system)
> > + (native-inputs
> > + `(("gfortran" ,gfortran)))
> > + (arguments
> > + `(#:configure-flags `("--disable-enable_fma" ;weird :/
>
> "weird :/" is not a very useful comment.
Sorry. I thought it was obvious it was in reference to the
"disable-enable" bit.
> Can you change it to explain
> why you added this flag? It seems unfortunate to disable fused
> multiply-add for this kind of library.
The library does not support runtime ISA detection. I thought FMAs are
something we don't support in our baseline x86-64 builds?
`~Eric
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: 01/03: gnu: Add QD.
2018-02-05 4:04 ` Eric Bavier
@ 2018-02-05 11:04 ` Ludovic Courtès
2018-02-06 1:24 ` Mark H Weaver
1 sibling, 0 replies; 5+ messages in thread
From: Ludovic Courtès @ 2018-02-05 11:04 UTC (permalink / raw)
To: Eric Bavier; +Cc: guix-devel
Eric Bavier <ericbavier@centurylink.net> skribis:
> On Sat, 03 Feb 2018 22:55:56 -0500
> Mark H Weaver <mhw@netris.org> wrote:
>
>> Hi Eric,
>>
>> ericbavier@centurylink.net (Eric Bavier) writes:
>> > bavier pushed a commit to branch master
>> > in repository guix.
>> >
>> > commit cbc084e1a7c25d1c8944bcb20a989f795acdb096
>> > Author: Eric Bavier <bavier@cray.com>
>> > Date: Wed Jan 31 13:55:37 2018 -0600
>> >
>> > gnu: Add QD.
>> [...]
>> > +(define-public qd
>> > + (package
>> > + (name "qd")
>> > + (version "2.3.18")
>> > + (source (origin
>> > + (method url-fetch)
>> > + (uri (string-append "http://crd.lbl.gov/~dhbailey/mpdist/qd-"
>> > + version ".tar.gz"))
>> > + (sha256
>> > + (base32
>> > + "0vkihcj9fyv2cycq8515713gbs3yskhmivy8bznvx72i6ddnn2c1"))))
>> > + (build-system gnu-build-system)
>> > + (native-inputs
>> > + `(("gfortran" ,gfortran)))
>> > + (arguments
>> > + `(#:configure-flags `("--disable-enable_fma" ;weird :/
>>
>> "weird :/" is not a very useful comment.
>
> Sorry. I thought it was obvious it was in reference to the
> "disable-enable" bit.
>
>> Can you change it to explain
>> why you added this flag? It seems unfortunate to disable fused
>> multiply-add for this kind of library.
>
> The library does not support runtime ISA detection. I thought FMAs are
> something we don't support in our baseline x86-64 builds?
Indeed.
Ludo'.
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: 01/03: gnu: Add QD.
2018-02-05 4:04 ` Eric Bavier
2018-02-05 11:04 ` Ludovic Courtès
@ 2018-02-06 1:24 ` Mark H Weaver
2018-02-06 14:27 ` Eric Bavier
1 sibling, 1 reply; 5+ messages in thread
From: Mark H Weaver @ 2018-02-06 1:24 UTC (permalink / raw)
To: Eric Bavier; +Cc: guix-devel
Hi Eric,
Eric Bavier <ericbavier@centurylink.net> writes:
> On Sat, 03 Feb 2018 22:55:56 -0500
> Mark H Weaver <mhw@netris.org> wrote:
>
>> ericbavier@centurylink.net (Eric Bavier) writes:
>> > + `(#:configure-flags `("--disable-enable_fma" ;weird :/
>>
>> "weird :/" is not a very useful comment.
>
> Sorry. I thought it was obvious it was in reference to the
> "disable-enable" bit.
I thought that might be the case, but I was still curious why you were
disabling FMA support, and the comment didn't help.
>> Can you change it to explain
>> why you added this flag? It seems unfortunate to disable fused
>> multiply-add for this kind of library.
>
> The library does not support runtime ISA detection. I thought FMAs are
> something we don't support in our baseline x86-64 builds?
Indeed. I was surprised to learn that FMAs are only supported in very
recent Intel processors. My Yeeloong with MIPS-based Loongson 2F
processor from 2008 includes support for FMA instructions, and I guessed
that Intel had them long before, but actually Intel didn't add them
until several years later.
Mark
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: 01/03: gnu: Add QD.
2018-02-06 1:24 ` Mark H Weaver
@ 2018-02-06 14:27 ` Eric Bavier
0 siblings, 0 replies; 5+ messages in thread
From: Eric Bavier @ 2018-02-06 14:27 UTC (permalink / raw)
To: Mark H Weaver; +Cc: guix-devel
On Mon, 05 Feb 2018 20:24:45 -0500
Mark H Weaver <mhw@netris.org> wrote:
> Hi Eric,
>
> Eric Bavier <ericbavier@centurylink.net> writes:
>
> > On Sat, 03 Feb 2018 22:55:56 -0500
> > Mark H Weaver <mhw@netris.org> wrote:
> >
> >> ericbavier@centurylink.net (Eric Bavier) writes:
> >> > + `(#:configure-flags `("--disable-enable_fma" ;weird :/
> >>
> >> "weird :/" is not a very useful comment.
> >
> > Sorry. I thought it was obvious it was in reference to the
> > "disable-enable" bit.
>
> I thought that might be the case, but I was still curious why you were
> disabling FMA support, and the comment didn't help.
Sorry about the confusion. I'll revise it to something more
informative. I usually try to refrain from "witty" comments.
>
> >> Can you change it to explain
> >> why you added this flag? It seems unfortunate to disable fused
> >> multiply-add for this kind of library.
> >
> > The library does not support runtime ISA detection. I thought FMAs are
> > something we don't support in our baseline x86-64 builds?
>
> Indeed. I was surprised to learn that FMAs are only supported in very
> recent Intel processors. My Yeeloong with MIPS-based Loongson 2F
> processor from 2008 includes support for FMA instructions, and I guessed
> that Intel had them long before, but actually Intel didn't add them
> until several years later.
AMD also had a 4-argument FMA instruction much sooner.
Thank you for the attention to this matter,
`~Eric
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2018-02-06 14:27 UTC | newest]
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[not found] ` <20180202143849.080E924648@vcs0.savannah.gnu.org>
2018-02-04 3:55 ` 01/03: gnu: Add QD Mark H Weaver
2018-02-05 4:04 ` Eric Bavier
2018-02-05 11:04 ` Ludovic Courtès
2018-02-06 1:24 ` Mark H Weaver
2018-02-06 14:27 ` Eric Bavier
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