Re: CVS commit: src/sys/arch

[David Laight <david%l8s.co.uk@localhost>]

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

You either need all of them, and the one that the next sub-version
of the cpu/compiler add, or you assume that the first ones imply the
latter - at least to some degree.

        David

-- 
David Laight: david%l8s.co.uk@localhost