PATCH: Add pause intrinsic

[Andrew Pinski]

On Wed, May 25, 2011 at 10:19 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> --
> H.J.
> ---
> Index: doc/extend.texi
> ===================================================================
> --- doc/extend.texi     (revision 174216)
> +++ doc/extend.texi     (working copy)
> @@ -8699,7 +8699,8 @@ The following built-in function is alway
>
>  @table @code
>  @item void __builtin_ia32_pause (void)
> -Generates the @code{pause} machine instruction with full memory barrier.
> +Generates the @code{pause} machine instruction with a compiler memory
> +barrier.

What is the pause machine instruction do?  How is it different from a
normal nop?

Also pause to me means it waits for input or an interrupt.

Thanks,
Andrew Pinski