refactor get_local counting out of simplify-locals (#812)

1 files changed, 50 insertions, 0 deletions

diff --git a/src/ast/count.h b/src/ast/count.h
new file mode 100644
index 000000000..56f281ce6
--- /dev/null
+++ b/src/ast/count.h
@@ -0,0 +1,50 @@
+/*
+ * 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.
+ */
+
+#ifndef wasm_ast_count_h
+#define wasm_ast_count_h
+
+namespace wasm {
+
+struct GetLocalCounter : public PostWalker<GetLocalCounter, Visitor<GetLocalCounter>> {
+  std::vector<Index> num;
+
+  GetLocalCounter() {}
+  GetLocalCounter(Function* func) {
+    analyze(func, func->body);
+  }
+  GetLocalCounter(Function* func, Expression* ast) {
+    analyze(func, ast);
+  }
+
+  void analyze(Function* func) {
+    analyze(func, func->body);
+  }
+  void analyze(Function* func, Expression* ast) {
+    num.resize(func->getNumLocals());
+    std::fill(num.begin(), num.end(), 0);
+    walk(ast);
+  }
+
+  void visitGetLocal(GetLocal *curr) {
+    num[curr->index]++;
+  }
+};
+
+} // namespace wasm
+
+#endif // wasm_ast_count_h
+