[feisty2]

r5:
new parameter "opt"
opt: call the fastest possible functions if opt=True, else call the C++ functions.

Originally Posted by Myrsloik

Just copy those files into your own project. Done.

Originally Posted by TheFluff

You need to write asm to identify the CPU, but it's trivial. Just steal from the VS source tree:

cpu.asm
cpufeatures.c
cpufeatures.h

Tried to use them but got stuck at "cpu.asm", apparently it requires nasm or yasm and these 2 are real pain in the ass, I wasted hours trying to make them work on VS2017 and all I got was millions of errors popping out relentlessly...

I even thought about translating "cpu.asm" to masm, and obviously I would have to translate "x86inc.asm" along with it, and that's a big NO.

so I merged those 3 into one file, "cpufeatures.hpp", and wrote my own version of CPUFeatures, with absolutely no trace of (literal) asm.

these 2 functions:

vs_cpu_cpuid()
vs_cpu_xgetbv()

have been integrated into the compiler,

Visual Studio 2017:
vs_cpu_cpuid() -> __cpuid()
GCC:
vs_cpu_cpuid() -> __get_cpuid()

vs_cpu_xgetbv() -> _xgetbv() //defined in immintrin.h

so I think there's no need to write literal asm for them.
and I canceled the "getCPUFeatures()" function, it could be simply integrated into the constructor since I'm using a C++ header.

so instead of

CPUFeatures CPU;
getCPUFeatures(&CPU);
if (CPU.fma3)
	xxx

it's now cleaner like

auto CPU = CPUFeatures();
if (CPU.fma3)
	xxx