Re: [PATCH RFC 1/3] rust: add useful ops for u64

[John Hubbard <jhubbard@nvidia.com>]

On 2/18/25 5:21 PM, Alexandre Courbot wrote:
> On Wed Feb 19, 2025 at 5:51 AM JST, Timur Tabi wrote:
>> On Tue, 2025-02-18 at 22:16 +0900, Alexandre Courbot wrote:
...
> More likely this would be something like:
> 
>    let SplitU64 { high: some_u32, .. } = some_u64;
> 
> Which is still a bit verbose, but a single-liner.
> 
> Actually. How about adding methods to this trait that return either
> component?
> 
>    let some_u32 = some_u64.high_half();
>    let another_u32 = some_u64.low_half();
> 
> These should be used most of the times, and using destructuring/tuple
> would only be useful for a few select cases.

I think I like this approach best so far, because that is actually how
drivers tend to use these values: one or the other 32 bits at a time.
Registers are often grouped into 32-bit named registers, and driver code
wants to refer to them one at a time (before breaking some of them down
into smaller named fields)>

The .high_half() and .low_half() approach matches that very closely.
And it's simpler to read than the SplitU64 API, without losing anything
we need, right?

  
thanks,
-- 
John Hubbard