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Diffstat (limited to 'src/passes/RemoveUnusedBrs.cpp')
-rw-r--r-- | src/passes/RemoveUnusedBrs.cpp | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/src/passes/RemoveUnusedBrs.cpp b/src/passes/RemoveUnusedBrs.cpp new file mode 100644 index 000000000..ff50847de --- /dev/null +++ b/src/passes/RemoveUnusedBrs.cpp @@ -0,0 +1,41 @@ +/* + * Copyright 2015 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. + */ + +// +// Removes branches that go to where they go anyhow +// + +#include <wasm.h> +#include <pass.h> + +namespace wasm { + +struct RemoveUnusedBrs : public Pass { + void visitBlock(Block *curr) override { + if (curr->name.isNull()) return; + if (curr->list.size() == 0) return; + Break* last = curr->list.back()->dyn_cast<Break>(); + if (!last) return; + if (last->value) return; + if (last->name == curr->name) { + curr->list.pop_back(); + } + } +}; + +static RegisterPass<RemoveUnusedBrs> registerPass("remove-unused-brs", "removes breaks from locations that are never branched to"); + +} // namespace wasm |