Re: 7+ days of dogfood

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).

-- 
Steve