7+ days of dogfood
Anton Shterenlikht
mexas at bristol.ac.uk
Tue Feb 12 10:31:33 UTC 2013
From sgk at troutmask.apl.washington.edu Sun Feb 10 19:06:10 2013
On Sun, Feb 10, 2013 at 06:51:23PM +0000, Anton Shterenlikht wrote:
> Date: Sun, 10 Feb 2013 08:44:24 -0800
> From: Steve Kargl <sgk at troutmask.apl.washington.edu>
> To: Boris Samorodov <bsam at passap.ru>
> Subject: Re: 7+ days of dogfood
>
> > > FFLAGS = -O2 -pipe -march=native -mtune=native
> >
> > I don't like using "=" for FLAGS at make.conf...
> >
> > > FFLAGS+= -funroll-loops -ftree-vectorize
> >
> > ... as well as defaults overriding.
> >
>
> FFLAGS are the options used while compiling Fortran. Having
> spent years contributing to and testing gfortran, I am fairly
> comfortable with these options.
>
> Do you recommend these FFLAGS settings to all
> users of gfortran (via lang/gcc4x)?
>
Yes.
> For example, I use blas, lapack, slatec, atlas, etc.
> Should I use these FFLAGS too?
Without knowing what options you currently use, I cannot
make a concrete recommendation other than I've extensive
tested the above options with my own codes and the
Polyhedron testsuite. Oh, I do recommend that one should
avoid -ffast-math (unless one really understands what it
actually does).
You probably don't care, as you don't use ia64,
but just for the record, on ia64 r244834 with
# cat /etc/make.conf|grep FFLAGS
FFLAGS = -O2 -pipe -march=native -mtune=native
FFLAGS+= -funroll-loops -ftree-vectorize
#
I get building lapack:
gfortran47 -O2 -pipe -march=native -mtune=native -funroll-loops -ftree-vectorize -pg -c slatms.f -o slatms.o
gfortran47: error: unrecognized command line option '-march=native'
gfortran47: error: unrecognized argument in option '-mtune=native'
gfortran47: note: valid arguments to '-mtune=' are: itanium2 mckinley
This box is
CPU: Madison (1500 MHz Itanium 2)
so I guess I can try "-mtune=itanium2"
and probably have to drop "-march" completely.
Anyway, thank you for the recommendation.
Anton
--
Steve
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