alt Hacker NewsMy perspective using Nix is that it's hardly worth standardizing ISAs. Recompiling software is easy and we should have a Cambrian explosion of different designs.
This is especially good if one scopes out a family of ISAs that are ABI compatible such that one can compile down to a semi-pre-optimized portable IR, and just do the last bit per ISA.
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What exactly does a bespoke ISA buy you? What will justify hundreds of engineers writing a new good one & working through the compiler support?
I bet it would be pretty easy for a user to interoperate between 67 different drafts of the HTTP spec once they were all written, validated, and library implementations coded. But what would that Cambrian explosion of API revs actually get you?
An explosion of ISAs means the available talent for writing optimizing compilers will be stretched much more thinly. Unpopular ISAs will have slow, buggy codegen, and the popular ones will suffer somewhat, too.
I disagree, compiler optimization and software ecosystem in general already take a really really really long time to build, and I think it'll take longer without a standardized low-level binary interface i.e. ISA to enable rapid distribution.
And the approach you mentioned here:
> a family of ISAs that are ABI compatible such that one can compile down to a semi-pre-optimized portable IR, and just do the last bit per ISA
I think this is basically WebAssembly and PTX, and one may argue, Java bytecode. Yet look at how much efforts and time it took for WASM runtimes and JVMs to actually produce performant machine code (the "last bit per ISA" you mentioned) for just a couple of architectures! (e.g. X86 and ARM). And I wouldn't surprised if NVIDIA pour even more money on building optimization pipeline from PTX to each of their different uArchs.