__vector equality compare: LDC vs {GDC, DMD}

[Iain Buclaw]

On Wednesday, 27 July 2022 at 08:04:03 UTC, kinke wrote:
> On Wednesday, 27 July 2022 at 03:50:50 UTC, Bruce Carneal wrote:
>> That said, I am curious: is this behavior intentional or 
>> accidental?
>
> Intentional (based on the front-end type of (in)equality and 
> identity expressions being a scalar bool, no special case for 
> vectors): 
> https://github.com/ldc-developers/ldc/commit/db8797e1ced40d555baa3007e6a5f6d05e29b58d

Just a random observation, why `(1 << sizeInBits) - 1` and not 
just `-1`? I'd have thought the former would suffer from overflow 
issues (sizeInBits == 64).