Re: CVS commit: src/sys/arch

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

On Wed, Feb 05, 2014 at 11:43:21PM +0000, David Laight wrote:
> On Wed, Feb 05, 2014 at 03:09:59PM -0800, Matt Thomas wrote:
> > 
> > >> 
> > >> This breaks clang. Please do not depend on one SSE option disabling
> > >> another.
> > > 
> > > Without those flags I believe gcc might generate x87 instructions.
> > > Quite possibly even for amd64.
> > > See a very recent linux fix.
> > > Try searching for: Disable generation of traditional x87 instructions
> > 
> > I think Joerg is saying put in -mno-sse2 since that is not disabled
> > by -mno-sse when using clang.
> 
> with the gcc I'm looking at (if I'm reading to code properly):
> no-sse => no-sse2 => no-sse3 => no-ssse3 & no-sse4a => no-sse4_1
> => no-sse4_2 => no-avx => no-fma => no-fma4

While I mostly believe that -mno-sse will imply -mno-sse2, it is the one
I want to be explicit about since it is default feature of the amd64
platform.

Joerg