Re: 01/03: gnu: Add QD.
On Mon, 05 Feb 2018 20:24:45 -0500 Mark H Weaverwrote: > Hi Eric, > > Eric Bavier writes: > > > On Sat, 03 Feb 2018 22:55:56 -0500 > > Mark H Weaver wrote: > > > >> ericbav...@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
Re: 01/03: gnu: Add QD.
Hi Eric, Eric Bavierwrites: > On Sat, 03 Feb 2018 22:55:56 -0500 > Mark H Weaver wrote: > >> ericbav...@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
Re: 01/03: gnu: Add QD.
Eric Bavierskribis: > On Sat, 03 Feb 2018 22:55:56 -0500 > Mark H Weaver wrote: > >> Hi Eric, >> >> ericbav...@centurylink.net (Eric Bavier) writes: >> > bavier pushed a commit to branch master >> > in repository guix. >> > >> > commit cbc084e1a7c25d1c8944bcb20a989f795acdb096 >> > Author: Eric Bavier >> > 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'.
Re: 01/03: gnu: Add QD.
On Sat, 03 Feb 2018 22:55:56 -0500 Mark H Weaverwrote: > Hi Eric, > > ericbav...@centurylink.net (Eric Bavier) writes: > > bavier pushed a commit to branch master > > in repository guix. > > > > commit cbc084e1a7c25d1c8944bcb20a989f795acdb096 > > Author: Eric Bavier > > 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
Re: 01/03: gnu: Add QD.
Hi Eric, ericbav...@centurylink.net (Eric Bavier) writes: > bavier pushed a commit to branch master > in repository guix. > > commit cbc084e1a7c25d1c8944bcb20a989f795acdb096 > Author: Eric Bavier> 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