start work on LowerInt64 pass

1 files changed, 110 insertions, 0 deletions

diff --git a/src/passes/LowerInt64.cpp b/src/passes/LowerInt64.cpp
new file mode 100644
index 000000000..79b053d44
--- /dev/null
+++ b/src/passes/LowerInt64.cpp
@@ -0,0 +1,110 @@
+/*
+ * 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.
+ */
+
+//
+// Lowers 64-bit ints to pairs of 32-bit ints, plus some library routines
+//
+// This is useful for wasm2asm, as JS has no native 64-bit integer support.
+//
+
+#include <wasm.h>
+#include <pass.h>
+
+namespace wasm {
+
+cashew::IString GET_HIGH("getHigh");
+
+struct LowerInt64 : public Pass {
+  MixedArena* allocator;
+
+  std::map<Expression*, Expression*> fixes; // fixed nodes, outputs of lowering, mapped to their high bits
+
+  void prepare(PassRunner* runner, Module *module) override {
+    allocator = runner->allocator;
+  }
+
+  void makeGetHigh() {
+    auto ret = allocator->alloc<CallImport>();
+    ret->target = GET_HIGH;
+    ret->type = i32;
+    return ret;
+  }
+
+  void fixCall(CallBase *call) {
+    auto& operands = call->operands;
+    for (size_t i = 0; i < operands.size(); i++) {
+      auto fix = fixes.find(operands[i]);
+      if (fix != fixes.end()) {
+        operands.insert(operands.begin() + i + 1, *fix);
+      }
+    }
+    if (curr->type == i64) {
+      curr->type = i32;
+      fixes[curr] = makeGetHigh();
+    }
+  }
+
+  void visitCall(Call *curr) override {
+    fixCall(curr);
+  }
+  void visitCallImport(CallImport *curr) override {
+    fixCall(curr);
+  }
+  void visitCallIndirect(CallIndirect *curr) override {
+    fixCall(curr);
+  }
+  void visitGetLocal(GetLocal *curr) override {
+  }
+  void visitSetLocal(SetLocal *curr) override {
+  }
+  void visitLoad(Load *curr) override {
+  }
+  void visitStore(Store *curr) override {
+  }
+  void visitConst(Const *curr) override {
+  }
+  void visitUnary(Unary *curr) override {
+  }
+  void visitBinary(Binary *curr) override {
+  }
+  void visitSelect(Select *curr) override {
+  }
+  void visitHost(Host *curr) override {
+  }
+  void visitNop(Nop *curr) override {
+  }
+  void visitUnreachable(Unreachable *curr) override {
+  }
+
+  void visitFunctionType(FunctionType *curr) override {
+  }
+  void visitImport(Import *curr) override {
+  }
+  void visitExport(Export *curr) override {
+  }
+  void visitFunction(Function *curr) override {
+  }
+  void visitTable(Table *curr) override {
+  }
+  void visitMemory(Memory *curr) override {
+  }
+  void visitModule(Module *curr) override {
+  }
+};
+
+static RegisterPass<LowerInt64> registerPass("lower-i64", "lowers i64 into pairs of i32s");
+
+} // namespace wasm