diff options
Diffstat (limited to 'src/passes/ReorderFunctions.cpp')
-rw-r--r-- | src/passes/ReorderFunctions.cpp | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/src/passes/ReorderFunctions.cpp b/src/passes/ReorderFunctions.cpp new file mode 100644 index 000000000..0991155e0 --- /dev/null +++ b/src/passes/ReorderFunctions.cpp @@ -0,0 +1,62 @@ +/* + * Copyright 2016 WebAssembly Community Group participants + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +// +// Sorts functions by their static use count. This helps reduce the size of wasm +// binaries because fewer bytes are needed to encode references to frequently +// used functions. +// + + +#include <memory> + +#include <wasm.h> +#include <pass.h> + +namespace wasm { + +struct ReorderFunctions : public WalkerPass<PostWalker<ReorderFunctions, Visitor<ReorderFunctions>>> { + std::map<Name, uint32_t> counts; + + void visitModule(Module *module) { + if (module->start.is()) { + counts[module->start]++; + } + for (auto& curr : module->exports) { + counts[curr->value]++; + } + for (auto& curr : module->table.names) { + counts[curr]++; + } + sort(module->functions.begin(), module->functions.end(), [this]( + std::unique_ptr<Function>& a, + std::unique_ptr<Function>& b) -> bool { + if (this->counts[a->name] == this->counts[b->name]) { + return strcmp(a->name.str, b->name.str) > 0; + } + return this->counts[a->name] > this->counts[b->name]; + }); + counts.clear(); + } + + void visitCall(Call *curr) { + counts[curr->target]++; + } +}; + +static RegisterPass<ReorderFunctions> registerPass("reorder-functions", "sorts functions by access frequency"); + +} // namespace wasm |