LLVM asm with constraints, and 2 operands

[Guillaume Piolat]

On Monday, 19 July 2021 at 10:49:56 UTC, kinke wrote:
> This workaround is actually missing the clobber constraint for 
> `%2`, which might be problematic after inlining.
>

An unrelated other issue with asm/__asm is that it doesn't follow 
consistent VEX encoding compared to normal compiler output.

     sometimes you might want: paddq x, y
               at other times: vpaddq x, y, z

but rarely both in the same program.
So this can easily nullify any gain obtained with VEX transition 
costs (if they are still a thing).