Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 21 Mar 2003 21:14:43 -0800
From:      David Schultz <das@FreeBSD.ORG>
To:        Till Riedel <till@f111.hadiko.de>
Cc:        freebsd-current@FreeBSD.ORG
Subject:   Re: libm problem
Message-ID:  <20030322051443.GA13854@HAL9000.homeunix.com>
In-Reply-To: <20030322005435.GA8393@f111.hadiko.de>
References:  <20030318173051.GA2322@f111.hadiko.de> <20030319131317.GA670@HAL9000.homeunix.com> <20030321235237.GA8097@f111.hadiko.de> <20030322111233.F4471@gamplex.bde.org> <20030322005435.GA8393@f111.hadiko.de>

next in thread | previous in thread | raw e-mail | index | archive | help
Thus spake Till Riedel <till@f111.hadiko.de>:
> I now know the thing that makes it break.
> 
> cc -O2 -pipe -mcpu=pentiumpro -c /usr/src/lib/msun/src/e_pow.c
> works fine!
> cc -O0 -pipe -march=pentium4 -c /usr/src/lib/msun/src/e_pow.c
> ... works
> but...
> cc -O -pipe -march=pentium4 -c /usr/src/lib/msun/src/e_pow.c
> breaks it. Hey its only gcc :-), nothing to worry about.
> I think that 0 is nice number: so why don't optimize everithing to down it.
> -O seems to minimize numbers not calculation time. Does anyone know the
> flag to turn that off.

If you have the time and inclination, I suggest reporting this
problem to the gcc folks.  For now, don't use Pentium 4
optimizations.  Not only are they apparently broken, they also
generate slower code than you get by optimizing for a PPro, or
even a 386.

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20030322051443.GA13854>