Re: question about "x86 Built-in Functions" to detect cpu type

[Dennis Clarke <dclarke at blastwave dot org>]

On 07/08/2018 12:36 PM, U.Mutlu wrote:
> Dennis Clarke wrote on 07/08/2018 03:44 PM:
> > As seen at :
> >
> >      https://gcc.gnu.org/onlinedocs/gcc/x86-Built-in-Functions.html
> >
> >
> > The example there seems to suggest that I could do this :
> >
> >
> >      __builtin_cpu_init ();
> >      if ( __builtin_cpu_is ("corei7") ){
> >          fprintf ( stdout, "Intel Core i7 CPU.       \n" );
> >      } else {
> >          fprintf ( stdout, " NOT Intel Core i7 CPU.       \n" );
> >      }
> >
> >
> > However I get an odd result from my Debian machine here when I try to
> > check for every possible option :
>
> Just guessing: are you maybe calling __builtin_cpu_init() multiple times?
> Though it shouldn't make a difference, IMO.

Tried that once before calling "__builtin_cpu_is" and also tried it
 every time and it makes no difference.


Dennis