How to disable SIMD extensions (mmx, sse3, ...)?

How to disable SIMD extensions (mmx, sse3, ...)?

[Mauro Ziliani]

Hi all.

I'm working with a Geode LX800, porting an old application Debian-based 
into Yocto Thud.

I need to disable some multimedia SIMD extensions for gcc compiler.

Where I can do this?

I suppose I have to disable SIMD extensions in 
conf/machine/geode_lx800.conf file (the machine descriptor file), but I 
cannot find any document about.


Can you help me?

MZ

Re: How to disable SIMD extensions (mmx, sse3, ...)?

[Adrian Bunk]

On Tue, Jun 04, 2019 at 09:08:49AM +0200, Mauro Ziliani wrote:
> Hi all.

Hi Mauro,

> I'm working with a Geode LX800, porting an old application Debian-based into
> Yocto Thud.

I assume you are aware that the Geode LX is should still work with the 
latest Debian releases.

> I need to disable some multimedia SIMD extensions for gcc compiler.

Why do you want to also disable MMX?
The AMD Geode LX does support MMX (and 3DNow!).

> Where I can do this?
> 
> I suppose I have to disable SIMD extensions in conf/machine/geode_lx800.conf
> file (the machine descriptor file), but I cannot find any document about.
> 
> Can you help me?

Passing -march=geode to the compiler should enable exactly the 
instructions supported by the CPU.

> MZ

cu
Adrian

-- 

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       "Only a promise," Lao Er said.
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