stage2-wasm: implement AIR handling for labeled switch/continue #21450
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Old code could not handle > 32 bits case + there were no test case for this so I added one. By mostly purging previous logic, I deleted special handling of non-sparse switch case branching, which were emitting .br_table for wasm VM level optimisation. I think we do not need this complexity for debug wasm backend.
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this is luuk's area, i know next to nothing about this backend lol |
The self-hosted backends are not just for debug builds; that's the initial focus, but our goal is to eventually provide optimization passes to make them useful for release builds too. It's currently unclear what this will look like implementation-wise, but I don't like the idea of eliminating existing optimized lowerings for (AFAICT) no real gain. |
I thought you did implement airRepeat handling because of this commit cb68c09? |
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No, Luuk wrote most of that commit, the authorship information unfortunately was unintentionally lost through some cherry-picks and squashes I did. |
I am myself a proponent of even having some simple optimization in debug build for performance. But in the WASM backend context, because any reasonable VM implementation does advanced control-flow analysis during lowering to native code, the benefit is miniscule. |
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It doesn't matter. Zig's task is to output the best wasm code given the constraints (optimization mode, cpu features, etc). |
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