Re: amd64 arch and optimization flags?

2014-02-11 Thread Thorsten Glaser
Tollef Fog Heen tfheen at err.no writes: ]] Jaromír Mikeš Aha ... so these default flags are added by compiler and they are not controlled by debian tools at all? Can I see somewhere default flags for different archs? run gcc -dumpspecs on the different platforms and you can see

Re: amd64 arch and optimization flags?

2014-02-10 Thread Felipe Sateler
On Sat, 08 Feb 2014 04:01:53 +0100, Vincent Lefevre wrote: On 2014-02-06 13:44:30 +, Felipe Sateler wrote: On Thu, 06 Feb 2014 00:47:54 +0100, Julian Taylor wrote: On 06.02.2014 00:39, Jaromír Mikeš wrote: -ffast-math this is dangerous it changes results, sometimes significantly

Re: amd64 arch and optimization flags?

2014-02-07 Thread peter green
this is dangerous it changes results, sometimes significantly (e.g. for complex numbers), only use if you don't care about correctness or have verified its still correct. IME, audio processing software can get away with it. Csound and its 400+ library of opcodes has been built with this

Re: amd64 arch and optimization flags?

2014-02-07 Thread Vincent Lefevre
On 2014-02-06 13:44:30 +, Felipe Sateler wrote: On Thu, 06 Feb 2014 00:47:54 +0100, Julian Taylor wrote: On 06.02.2014 00:39, Jaromír Mikeš wrote: -ffast-math this is dangerous it changes results, sometimes significantly (e.g. for complex numbers), only use if you don't care about

Re: amd64 arch and optimization flags?

2014-02-06 Thread Jaromír Mikeš
2014-02-06 Julian Taylor jtaylor.deb...@googlemail.com: On 06.02.2014 00:39, Jaromír Mikeš wrote: I would like to add some optimization flags for amd64 arch in some packages (mostly LV2 nad LADSPA plugins). I found these as candidates for amd64 arch: -msse -msse2 -mfpmath=sse

Re: amd64 arch and optimization flags?

2014-02-06 Thread Sylvestre Ledru
On 06/02/2014 10:22, Jaromír Mikeš wrote: 2014-02-06 Julian Taylor jtaylor.deb...@googlemail.com mailto:jtaylor.deb...@googlemail.com: On 06.02.2014 00:39, Jaromír Mikeš wrote: I would like to add some optimization flags for amd64 arch in some packages (mostly LV2 nad

Re: amd64 arch and optimization flags?

2014-02-06 Thread Jaromír Mikeš
2014-02-06 Sylvestre Ledru sylves...@debian.org: On 06/02/2014 10:22, Jaromír Mikeš wrote: 2014-02-06 Julian Taylor jtaylor.deb...@googlemail.com: On 06.02.2014 00:39, Jaromír Mikeš wrote: I would like to add some optimization flags for amd64 arch in some packages (mostly LV2 nad

Re: amd64 arch and optimization flags?

2014-02-06 Thread Tollef Fog Heen
]] Jaromír Mikeš Aha ... so these default flags are added by compiler and they are not controlled by debian tools at all? Can I see somewhere default flags for different archs? run gcc -dumpspecs on the different platforms and you can see them. -- Tollef Fog Heen UNIX is user friendly,

Re: amd64 arch and optimization flags?

2014-02-06 Thread Felipe Sateler
On Thu, 06 Feb 2014 00:47:54 +0100, Julian Taylor wrote: On 06.02.2014 00:39, Jaromír Mikeš wrote: Hi all, I would like to add some optimization flags for amd64 arch in some packages (mostly LV2 nad LADSPA plugins). I found these as candidates for amd64 arch: -msse -msse2 -mfpmath=sse

amd64 arch and optimization flags?

2014-02-05 Thread Jaromír Mikeš
Hi all, I would like to add some optimization flags for amd64 arch in some packages (mostly LV2 nad LADSPA plugins). I found these as candidates for amd64 arch: -msse -msse2 -mfpmath=sse -ffast-math -ftree-vectorize -mtune=generic Can some of them be safely added for amd64 or is just bad idea

Re: amd64 arch and optimization flags?

2014-02-05 Thread Julian Taylor
On 06.02.2014 00:39, Jaromír Mikeš wrote: Hi all, I would like to add some optimization flags for amd64 arch in some packages (mostly LV2 nad LADSPA plugins). I found these as candidates for amd64 arch: -msse -msse2 -mfpmath=sse this is enabled by default on amd64 -ffast-math