byte and short data types use cases

[Cecil Ward]

On Sunday, 11 June 2023 at 00:05:52 UTC, H. S. Teoh wrote:
> On Sat, Jun 10, 2023 at 09:58:12PM +0000, Cecil Ward via 
> Digitalmars-d-learn wrote:
>> On Friday, 9 June 2023 at 15:07:54 UTC,

> [...]
>
> On contemporary machines, the CPU is so fast that memory access 
> is a much bigger bottleneck than processing speed. So unless an 
> operation is being run hundreds of thousands of times, you're 
> not likely to notice the difference. OTOH, accessing memory is 
> slow (that's why the memory cache hierarchy exists). So utf8 is 
> actually advantageous here: it fits in a smaller space, so it's 
> faster to fetch from memory; more of it can fit in the CPU 
> cache, so less DRAM roundtrips are needed. Which is faster.  
> Yes you need extra processing because of the variable-width 
> encoding, but it happens mostly inside the CPU, which is fast 
> enough that it generally outstrips the memory roundtrip 
> overhead. So unless you're doing something *really* complex 
> with the utf8 data, it's an overall win in terms of 
> performance. The CPU gets to do what it's good at -- running 
> complex code -- and the memory cache gets to do what it's good 
> at: minimizing the amount of slow DRAM roundtrips.
>

I completely agree with H. S. Teoh. That is exactly what I was 
going to say. The point is that considerations like this have to 
be thought through carefully and width of types really does 
matter in the cases brought up.

But outside these cases, as I said earlier, stick to uint, size_t 
and ulong, or uint32_t and uint64_t if exact size is vital, but 
do also check out the other std.stdint types too as very 
occasionally they are needed.