Zig did go on to apply the same style to their two later IRs, ZIR (https://github.com/ziglang/zig/pull/8266 https://github.com/ziglang/zig/pull/8266) and AIR (h

Zig did go on to apply the same style to their two later IRs, ZIR (https://github.com/ziglang/zig/pull/8266 https://github.com/ziglang/zig/pull/8266) and AIR (https://github.com/ziglang/zig/pull/9353 https://github.com/ziglang/zig/pull/9353). These don't look as thoroughly benchmarked (at least not on the PRs) but it looks like they got significant wins there as well. Of course Zig is a very different language and its compiler handles a rather different workload. It's totally possible that their approach makes more sense in younger codebases, or with a different source language design, or whatever else. But I also don't think node size tells the whole story- there's a synergy between memory usage, memory layout, and memory access patterns. For example Cranelift gets a lot of mileage from tweaking their algorithms in combination with their data structures, e.g. the "half-move" design mentioned in https://cfallin.org/blog/2022/06/09/cranelift-regalloc2/#performance https://cfallin.org/blog/2022/06/09/cranelift-regalloc2/#per...