[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH] xen/x86: Fix up rules when forcing -mno-sse

On Wed, Aug 12, 2015 at 10:38 AM, Jan Beulich <JBeulich@xxxxxxxx> wrote:
>>>> On 12.08.15 at 17:23, <cardoe@xxxxxxxxxx> wrote:
>> From: Nathan Rossi <nathan.rossi@xxxxxxxxxx>
>> * When forcing -mno-sse specify -mfpmath=387 to avoid the fallback
>>   warning
> "the fallback warning" being what? I've never seen any, and I don't
> think I've ever heard anyone else say there was one.
> Apart from that I don't think -mfpmath=387 is what we want - we'd
> better tell the compiler to not use x87 registers at all.
> Jan

I guess I jumped the gun a bit. When targeting a corei7 based chip, Yocto uses
the following CFLAGS for the packages it builds:

-march=corei7 -mtune=corei7 -mfpmath=sse -msse4.2

The issue is the -mfpmath value.

Doug Goldstein

Xen-devel mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.