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| author | Alon Zakai <azakai@google.com> | 2022-03-28 14:57:48 -0700 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2022-03-28 21:57:48 +0000 |
| commit | dbb7047289d5bc7d12a4c7fb1982f153f5e0127a (patch) | |
| tree | 0e66f6282bb80d8d2c911b00c0f9ccde0d9337a0 /src/passes/SignaturePruning.cpp | |
| parent | 4643f26e113476ebb273ee4f69e89c61801c7c2f (diff) | |
| download | binaryen-dbb7047289d5bc7d12a4c7fb1982f153f5e0127a.tar.gz binaryen-dbb7047289d5bc7d12a4c7fb1982f153f5e0127a.tar.bz2 binaryen-dbb7047289d5bc7d12a4c7fb1982f153f5e0127a.zip | |
[Wasm GC] Signature Pruning: Remove params passed constant values (#4551)
This basically just adds a call to ParamUtils::applyConstantValues, however,
we also need to be careful to not optimize in the presence of imports or
exports, so this adds a boolean that indicates unoptimizability.
Diffstat (limited to 'src/passes/SignaturePruning.cpp')
| -rw-r--r-- | src/passes/SignaturePruning.cpp | 47 |
1 files changed, 34 insertions, 13 deletions
diff --git a/src/passes/SignaturePruning.cpp b/src/passes/SignaturePruning.cpp index d41c04d57..033333758 100644 --- a/src/passes/SignaturePruning.cpp +++ b/src/passes/SignaturePruning.cpp @@ -22,6 +22,10 @@ // looks at each heap type at a time, and if all functions with a heap type do // not use a particular param, will remove the param. // +// Like in DAE, as part of pruning parameters this will find parameters that are +// always sent the same constant value. We can then apply that value in the +// function, making the parameter's value unused, which means we can prune it. +// #include "ir/find_all.h" #include "ir/lubs.h" @@ -65,20 +69,16 @@ struct SignaturePruning : public Pass { std::unordered_set<Index> usedParams; - void markUnoptimizable(Function* func) { - // To prevent any optimization, mark all the params as if there were - // used. - for (Index i = 0; i < func->getNumParams(); i++) { - usedParams.insert(i); - } - } + // If we set this to false, we may not attempt to perform any optimization + // whatsoever on this data. + bool optimizable = true; }; ModuleUtils::ParallelFunctionAnalysis<Info> analysis( *module, [&](Function* func, Info& info) { if (func->imported()) { // Imports cannot be modified. - info.markUnoptimizable(func); + info.optimizable = false; return; } @@ -116,6 +116,11 @@ struct SignaturePruning : public Pass { for (auto index : info.usedParams) { allUsedParams.insert(index); } + + if (!info.optimizable) { + allInfo[func->type].optimizable = false; + } + sigFuncs[func->type].push_back(func); } @@ -123,7 +128,7 @@ struct SignaturePruning : public Pass { for (auto& exp : module->exports) { if (exp->kind == ExternalKind::Function) { auto* func = module->getFunction(exp->value); - allInfo[func->type].markUnoptimizable(func); + allInfo[func->type].optimizable = false; } } @@ -131,17 +136,33 @@ struct SignaturePruning : public Pass { for (auto& [type, funcs] : sigFuncs) { auto sig = type.getSignature(); auto& info = allInfo[type]; + auto& usedParams = info.usedParams; auto numParams = sig.params.size(); - if (info.usedParams.size() == numParams) { + + if (!info.optimizable) { + continue; + } + + // Apply constant indexes: find the parameters that are always sent a + // constant value, and apply that value in the function. That then makes + // the parameter unused (since the applied value makes us ignore the value + // arriving in the parameter). + auto optimizedIndexes = ParamUtils::applyConstantValues( + funcs, info.calls, info.callRefs, module); + for (auto i : optimizedIndexes) { + usedParams.erase(i); + } + + if (usedParams.size() == numParams) { // All parameters are used, give up on this one. continue; } - // We found possible work! Find the specific params that are unused try to - // prune them. + // We found possible work! Find the specific params that are unused & try + // to prune them. SortedVector unusedParams; for (Index i = 0; i < numParams; i++) { - if (info.usedParams.count(i) == 0) { + if (usedParams.count(i) == 0) { unusedParams.insert(i); } } |