AMD xop check support

Question

I have next problem:
I have some tests related to xop check with using some Bulldozer (xop) instructions.
And I must run this tests only on Bulldozer processors.
How can I check that my processor supports xop instruction at compile-time?

Language: C, Os: Linux;

You mean you want to check if the machine you are compiling on has XOP? — Mysticial, Nov 08 '12 at 07:15
You will need a USB crystal ball in order to determine at compile-time what the CPU will eventually be at run-time. — Paul R, Nov 08 '12 at 07:17

Olaf Dietsche · Answer 1 · 2012-11-08T22:19:45.403

0

You cannot test at compile time, but you can compile for AMD Bulldozer using:

$ gcc -march=bdver1 -mtune=bdver1 ...

See: http://gcc.gnu.org/gcc-4.6/changes.html

If your build machine is your target machine, look into /proc/cpuinfo.

edited Nov 08 '12 at 22:19

answered Nov 08 '12 at 07:17

Olaf Dietsche

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score 0 · Answer 2 · answered Nov 08 '12 at 07:28

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You can write a program that checks CPUID and use the output of that program while compiling:
gcc $(cpuid_test) my_prog.c

where cpuid_test returns '-march=bdver1' or -DXOP_SUPPORT=1

answered Nov 08 '12 at 07:28

Aki Suihkonen

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score 0 · Answer 3 · answered Nov 09 '12 at 00:22

If a source is compiled with -march=bdver1 (which enables XOP support among other things), the preprocessor macro __XOP__ will be defined to 1.

You can test at compile time for XOP with

#ifdef __XOP__
     ...XOP code path here...
#else
     ...non XOP code here...
#endif

AMD xop check support

3 Answers3