This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: powerpc-eabi-gcc no implicit FPU usage
- From: Mark Mitchell <mark at codesourcery dot com>
- To: Robert Grimm <rfgrimm at gmail dot com>
- Cc: David Edelsohn <dje dot gcc at gmail dot com>, gcc at gcc dot gnu dot org
- Date: Thu, 20 May 2010 09:21:43 -0700
- Subject: Re: powerpc-eabi-gcc no implicit FPU usage
- References: <5522DE9B-4FBC-4199-B143-102763034AFD@gmail.com> <303e1d291001160523t59af08e1q109f45e08ba3157@mail.gmail.com> <5431D733-3FA6-4C99-A455-AF0E1104A8F1@gmail.com>
Robert Grimm wrote:
> Actually, I saw some old posts that talked about a -fno-implicit-fp option
[I know this is a very old post, but I noticed it in old email and felt
it might still be useful to reply.]
CodeSourcery has a -fno-implicit-fp option that does exactly what you
have requested in some of our compilers. We use this particularly in
the context of VxWorks; on VxWorks, the kernel will only save/restore
floating-point registers across task switches for tasks that are
designated as floating-point tasks. Therefore, using an FPR in a
non-floating-point task is a bug.
Because there is so much VxWorks code out there that does not use
-msoft-float, it's not practical to require that programmers use
-msoft-float for all files, and then explicitly turn on hard-float for
floating-point tasks. We offered to contribute this code, but the FSF
GCC maintainers decided not to accept it.
--
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713