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Date:      Wed, 16 Jul 2003 11:17:58 +1000 (EST)
From:      Bruce Evans <bde@zeta.org.au>
To:        David Schultz <das@FreeBSD.org>
Cc:        cvs-all@FreeBSD.org
Subject:   Re: cvs commit: src/contrib/gcc/config/i386 freebsd.h
Message-ID:  <20030716110439.M13786@gamplex.bde.org>
In-Reply-To: <20030715060049.GA33856@HAL9000.homeunix.com>
References:  <200307121933.h6CJXYsP069815@repoman.freebsd.org> <20030715060049.GA33856@HAL9000.homeunix.com>

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On Mon, 14 Jul 2003, David Schultz wrote:

> On Sat, Jul 12, 2003, Alexander Kabaev wrote:
> > kan         2003/07/12 12:33:34 PDT
> >
> >   FreeBSD src repository
> >
> >   Modified files:
> >     contrib/gcc/config/i386 freebsd.h
> >   Log:
> >   Do not override FP rounding options for 32bit platforms. amd64 doesn't
> >   need this.
>
> You mean for 64-bit platforms, right?  Does this mean that gcc's
> problems with FP precision and constant evaluation have been
> fixed, at least for amd64?  I understand there have been some
> improvements in this area in gcc 3.3.

Right.  It just means that the override is broken for the TARGET_64BIT
case.  amd64 seems to need the code for the same reasons as i386 (the
npx control word is set to round to 53-bit precision).  The override
informs gcc of this, but it apparently causes problems for the 64-bit
case.  This seems to be the only improvement in this area.  i386.md
still bogusly says that the i387 has non-widening FP operations
(SF + SF -> SF, etc.), so casts and assignments don't narrow widened
FP results on i386's.

Bruce



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