On 2025-03-30 at 05:41, Thiago Macieira via Std-Proposals wrote:
> On Saturday, 29 March 2025 17:04:46 Eastern Daylight Time Jonathan Wakely via
> Std-Proposals wrote:
>> On what platform in existence today does a type that's at least 32 bits
>> promote?
>
> None. It would need to be a platform with an int probably of 64 bits, which
> doesn't exist. A 36-bit int platform *probably* uses the 36-bit integer as the
> "fast 32-bit" - if it has an exact 32-bit type, it's probably slower than the
> native 36-bit.
>
> However, maybe Frederick is being fooled by the fact that the uint_fast32_t on
> x86-64 Linux is "unsigned long" - that is, the same type as uint64_t and
> uint_fast64_t. Someone decided that 64-bit on x86-64 was "faster" than 32-bit
> and now we're stuck with that ABI.

The standard fails to say what should be faster for a "fast" type. If a
certain type uses more data cache, but less i-cache (because of a
compact instruction encoding), does that make it "fast"?

And "obviously" a 64-bit type must be the best on a 64-bit CPU. That's
in the name. :-)