XMM register preserving SIGILL probe for AES-NI instructions on x86 and AMD64. Should work on Linux, BSD, OSX, Windows

aesnidetect.c

#include<stdio.h>
#include<setjmp.h>
#include<signal.h>

jmp_buf state;

void sigill_handler( int i ) {
  signal( SIGILL, SIG_DFL );
  longjmp( state, 1 );
}

//register preserving aesenc/aesdec sequence
#if(unix)
const
#else //windows
#pragma section("foo", execute)
__declspec(allocate("foo"))
#endif
char aesni[]="\x66\x0F\x38\xDD\xC1\x66\x0F\x38\xDF\xC1\xc3";

int aesnidetect( ) {
  signal( SIGILL, sigill_handler );
  int r = setjmp( state );
  if( !r ) ((void(*)())(char*)aesni)();
  return !r;
}

int main(){
  puts( aesnidetect()?"YES":"NO" );
}