Re: [Valgrind-developers] Valgrind, PPC and CPU detection

[Bart V. A. <bar...@gm...>]

On Mon, Dec 22, 2008 at 2:34 PM, Julian Seward <js...@ac...> wrote:
>
>> Has it already been considered before to use the value of the PVR
>> register for PPC instruction set detection in Valgrind ?
>
> No.  I didn't know of its existence.  Is the instruction usable from
> user space?
>
> In fact the SIGILL scheme works pretty well most of the time, afaics,
> and means we don't have to drag around a big table listing all known
> PowerPC/POWER CPUs.  Is there a specific difficulty with the SIGILL
> scheme?

I'm not sure the PVR register is directly accessible from user space,
but recent kernels make this information available through
/proc/cpuinfo:

$ cat /proc/cpuinfo
...
processor       : 3
cpu             : Cell Broadband Engine, altivec supported
clock           : 3200.000000MHz
revision        : 5.1 (pvr 0070 0501)
...

The reason I was asking about the PVR register is because apparently
some PowerPC CPU's are not yet supported by Valgrind -- see e.g.
http://bugs.kde.org/show_bug.cgi?id=176926.

Bart.