wasm2js: Support arbitrary temp variable types #6661
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src/wasm2js.h
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| // Which are currently free to use | ||
| std::vector<std::vector<IString>> frees; // type => list of free names | ||
| std::unordered_map<Type, std::vector<IString>> | ||
| frees; // type => list of free names |
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If the comment is placed on its own line, we won't need this odd line break before the variable name.
| frees.resize(std::max(Type::i32, std::max(Type::f32, Type::f64)) + 1); | ||
| temps.clear(); | ||
| temps.resize(std::max(Type::i32, std::max(Type::f32, Type::f64)) + 1); | ||
| temps[Type::i32] = temps[Type::f32] = temps[Type::f64] = 0; |
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Was this resetting only necessary for the asserts below?
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Good catch, turns out it was not. I did not realize this class reused the instance for all the functions. What made me miss this in the outputs is that any excess temp vars that were added get removed by later optimizations... so it seemed like manually clearing was not needed, but it was. Fixed.
test/wasm2js/left-to-right.2asm.js
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| @@ -942,23 +942,23 @@ function asmFunc(imports) { | |||
| } | |||
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| function $53() { | |||
| var wasm2js_i32$0 = 0, wasm2js_i32$1 = 0; | |||
| var wasm2js_i32$0 = 0, wasm2js_i32$2 = 0; | |||
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Do you know why the names changed?
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This diff was because of the extra temp vars - unneeded ones get optimized out, but the optimizer happened to pick other ones here. Anyhow, this part of the diff goes away in the last commit.
Previously only basic types were allowed.
Generalizing this to arbitrary types means we use a map instead of a vector,
which is slower, but I can't measure any noticeable difference. Temp vars are
pretty rare, and there are just much slower parts of wasm2js, I think.