Should we finally ditch the 32-bit build of dmd?

[max haughton]

On Thursday, 17 June 2021 at 05:48:57 UTC, Walter Bright wrote:
> On 6/16/2021 2:38 PM, max haughton wrote:
>> Perhaps we can start by ditching the schedulers for Pentium 
>> chips from the 90s - even charitably (i.e. The P6 architecture 
>> did live for a while) it's obsolete (and more importantly not 
>> needed for supporting those targets). That way we gain 
>> experience pressing delete rather than making the code dead 
>> and leaving it, and we reduce the surface area of old/dead 
>> code which could be silently broken if other things change 
>> around it.
>
> At one point, Intel did release a low power 32 bit chip for 
> embedded systems that benefited quite a bit from the Pentium 
> scheduler, as that chip had sacrificed its own internal 
> scheduler.
>
> Besides, the bugs have been sorted out from that scheduler long 
> ago. It's not impairing anyone.

Compile times?

OT: I've been reading chunks of the GCC instruction schedulers 
recently, and I can report that they'd be much more readable (and 
safer, obviously) in D. The actual approach taken for the OoO 
monster-cpus we have now (New Apple chips have *16* execution 
units) isn't totally dissimilar to the code in dmd, just more 
general (It's effectively an in-order scheduler specifically 
aimed at the decoder, but the state machine can be generated from 
the machine description files rather than ad-hoc in code)