How do I do a 64 bits mulhi in D?

[Walter Bright]

On 11/26/2022 5:53 PM, Vladimir Panteleev wrote:
> On Sunday, 27 November 2022 at 01:26:36 UTC, deadalnix wrote:
>> Mulhi is an instruction that is effectively available on any 64 bits CPU that 
>> multiply that effectively does the following:
> 
> For x86 I made this: 
> https://github.com/cybershadow/ae/blob/master/utils/math/longmul.d


Should work that into:

https://github.com/dlang/dmd/blob/master/druntime/src/core/int128.d#L407