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Re: RFC: Define __FPMATH_387__ and __FPMATH_SSE__
- From: "Richard Guenther" <richard dot guenther at gmail dot com>
- To: "H. J. Lu" <hjl at lucon dot org>
- Cc: gcc at gcc dot gnu dot org, "GNU C Library" <libc-alpha at sources dot redhat dot com>
- Date: Thu, 2 Mar 2006 16:08:54 +0100
- Subject: Re: RFC: Define __FPMATH_387__ and __FPMATH_SSE__
- References: <20060302145712.GA27830@lucon.org>
On 3/2/06, H. J. Lu <email@example.com> wrote:
> With this patch:
> gcc no longer mixes SSE and x387 math by default. However glibc
> still assumes gcc mixes SSE and x387 math. The x86-64 FP control
> routines in glibc change both SSE and x387 units, which is no
> longer necessary with the newer gcc. But glibc has no way to know
> if gcc mixes SSE and x387 math. I am proposing to define
> __FPMATH_387__ if x387 math is used and define __FPMATH_SSE__ if
> SSE math is used, respectively. If 2 units are used, both will
> be defined. Glibc can have sets math unit control routines and
> only call the ones be using.
Which routines are you referring to? I can only find
which only touches x387 unit. I think it would make sense to add gcc builtins
for status/control word changes, though.