CODEWITHSUNDEEP
ccross-platformcpuid
Fire Lancer
Fire Lancer

Reputation: 30145

Detecting CPU capability without assembly

I've been looking at ways to determine the CPU, and its capabilities (e.g. SEE, SSE2, etc).

However all the ways I've found involved assembly code using the cpuid instruction. Given the different ways of doing assembly in C/C++ between compilers and even targets (no inline assembly for 64-bit targets under VC), I'd rather avoid that.

Is there some simple library around, or OS functions (for both Windows and Linux) for getting this information?

Currently I'm only interested in platforms using the x86 and x86-64 CPU's, and I definitely need to support at least AMD and Intel.

Upvotes: 4

Views: 1179

Answers (4)

phuclv
phuclv

Reputation: 41962

You can use cpuinfo which is a cross-platform CPU information library

Check if the host CPU supports x86 AVX

cpuinfo_initialize();
if (cpuinfo_has_x86_avx()) {
    avx_implementation(arguments);
}

Pin thread to cores sharing L2 cache with the current core (Linux or Android)

cpuinfo_initialize();
cpu_set_t cpu_set;
CPU_ZERO(&cpu_set);
const struct cpuinfo_cache* current_l2 = cpuinfo_get_current_processor()->cache.l2;
for (uint32_t i = 0; i < current_l2->processor_count; i++) {
    CPU_SET(cpuinfo_get_processor(current_l2->processor_start + i)->linux_id, &cpu_set);
}
pthread_setaffinity_np(pthread_self(), sizeof(cpu_set_t), &cpu_set);

Upvotes: 0

Thorbj&#248;rn Ravn Andersen
Thorbj&#248;rn Ravn Andersen

Reputation: 75416

Under linux peek in /proc/cpuinfo

Upvotes: 1

Gregory Pakosz
Gregory Pakosz

Reputation: 70234

EDIT: At first, I googled for "libcpuid" remembering a conversation with peer programmers, and the google search pointed me to this sourceforge page which looks quite outdated. Then I noticed it was the project page of "libcpu".

Actually, there really is a libcpuid that might suit your needs.

Last time I looked for such a library, I found crisscross. It's C++ though.

There is also geekinfo.

But I don't know a cross-platform library that just does cpuid.

Upvotes: 4

Dirk is no longer here
Dirk is no longer here

Reputation: 368499

This so hardware-dependent --- which is an aspect the OS usually shields you from --- that requiring it to be cross-platform is a tad hard.

It would be useful to have, but I fear you may just have to enumerate the cross-product of CPU s and features you would like to support, times the number of OSs (here two) and write tests for all. I do not think it has been done -- and someone will surely correct me if I overlooked something.

That would be a useful library to have, so good luck with the endeavor!

Upvotes: 0

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