Walter's talk on D backend

[Bruce Carneal]

On Monday, 23 September 2024 at 08:44:04 UTC, Walter Bright wrote:
> On 9/23/2024 1:23 AM, claptrap wrote:
>> Thats why OP asked about phi instructions, you need them to 
>> merge the versions of a variable that reach the start of a 
>> basic block. Or at least you need to have some mechanism for 
>> it.
>
> Seems to me it's the same thing from a different angle.

Here are some musings from Grok given this prompt:

What are the pros and cons of employing an SSA architecture in a 
compiler back end?  What does SSA enable that alternative 
approaches do not?

https://x.com/i/grok/share/cQC4v0ZFIHoRbSAV4D9Gz98eV

In answering the question: "What, if anything, has superseded 
SSA?" Grok has:

https://x.com/i/grok/share/FTF6QzKzqF0nxQ3wrPo48oEoE

I've not detected any hallucinations in these but I've been out 
of the compiler biz a long time and didn't dig into the responses.

FWIW, my opinion is that SSA provides a lot stronger framework to 
build upon going forward.  Better optimization possibilities 
certainly but also a better ecosystem.

Corrections, additions, opinions all welcome of course.