iasm, lzcnt and tznct are not recognized

[Basile B.]

On Wednesday, 26 February 2020 at 03:07:22 UTC, kinke wrote:
> On Tuesday, 25 February 2020 at 21:18:48 UTC, Basile B. wrote:
>> lzcnt and tznct are not recognized.
>> DMD accept them.
>
> I guess you mean in DMD-style inline asm; that part doesn't see 
> much love. LDC-style __asm provides all of them, at least as 
> long as using appropriate -mcpu/-mattr switches.
>
> Looks like you're trying to manually optimize bsf/bsr; I'd 
> advise against that, standard core.bitop generates exactly 
> these 2 instructions: https://d.godbolt.org/z/PG8GiU

indeed -mcpu solves the problem.