On Thu, Oct 26, 2017 at 03:39:57AM +1100, Matt Oliver wrote:
> On 25 October 2017 at 07:15, Dale Curtis wrote:
>
> > Technically _tzcnt* intrinsics are only available when the BMI
> > instruction set is present. However the instruction encoding
> > degrades to "rep bsf"
On 25 October 2017 at 07:15, Dale Curtis wrote:
> Technically _tzcnt* intrinsics are only available when the BMI
> instruction set is present. However the instruction encoding
> degrades to "rep bsf" on older processors.
>
> Clang for Windows debatably restricts the
Technically _tzcnt* intrinsics are only available when the BMI
instruction set is present. However the instruction encoding
degrades to "rep bsf" on older processors.
Clang for Windows debatably restricts the _tzcnt* instrinics behind
the __BMI__ architecture define, so check for its presence or