Checking for SSE / SSE2 support
 

In a program, does anyone know how one would check for SSE / SSE2 support being enabled in the OS without using exception handling/signals?

Thanks for any help!!
drivingon9

You might want to check out the code MPlayer uses for runtime cpu detection.

Would it be possible to just read in /proc/cpuinfo and search for "sse" or sse2"

Using /proc/cpuinfo is implicitly discouraged by the kernel folks, since the API may change in a nanosecond and is thus not stable, even though it has been for a longish while. Under 2.6, sysfs might have the CPU flags somewhere in an easy-to-parse place, but I doubt it.

See the mplayer program for how it detects SSE and SSE2.

Re: Checking for SSE / SSE2 support
 

Unfortunately, MPlayer uses signal handling. It executes an SSE/SSE2 instructions and catches the exception if the OS doesn't handle it. I was wondering if there was a cleaner way to do it.

Thanks.

Use the assembler instruction CPUID

I found a small C program here that does pretty much exactly what you want:
http://www-ti.informatik.uni-tuebing...heim/software/

Martin

Can't do that.

CPUID will tell you whether the CPU supports SSE/SSE2, but not the OS.
The OS (linux in this case) can have SSE and/or SSE2 disabled.

:confused:
That was new to me. What do you mean by that? Is it possible for the OS to turn off certain instructions in the CPU, or is it just a question of whether the shared libs are compiled with SSE support?

Martin