2 files changed, 59 insertions, 2 deletions
diff --git a/src/ir/effects.h b/src/ir/effects.h
index 7c64beafd..b7c420100 100644
--- a/src/ir/effects.h
+++ b/src/ir/effects.h
@@ -27,7 +27,7 @@ namespace wasm {
 
 struct EffectAnalyzer
   : public PostWalker<EffectAnalyzer, OverriddenVisitor<EffectAnalyzer>> {
-  EffectAnalyzer(PassOptions& passOptions, Expression* ast = nullptr) {
+  EffectAnalyzer(const PassOptions& passOptions, Expression* ast = nullptr) {
     ignoreImplicitTraps = passOptions.ignoreImplicitTraps;
     debugInfo = passOptions.debugInfo;
     if (ast) {
@@ -372,7 +372,7 @@ struct EffectAnalyzer
   // Helpers
 
   static bool
-  canReorder(PassOptions& passOptions, Expression* a, Expression* b) {
+  canReorder(const PassOptions& passOptions, Expression* a, Expression* b) {
     EffectAnalyzer aEffects(passOptions, a);
     EffectAnalyzer bEffects(passOptions, b);
     return !aEffects.invalidates(bEffects);
diff --git a/src/ir/module-utils.h b/src/ir/module-utils.h
index c13e9f1ca..88298fd43 100644
--- a/src/ir/module-utils.h
+++ b/src/ir/module-utils.h
@@ -19,6 +19,7 @@
 
 #include "ir/find_all.h"
 #include "ir/manipulation.h"
+#include "pass.h"
 #include "wasm.h"
 
 namespace wasm {
@@ -287,6 +288,62 @@ template<typename T> inline void iterDefinedEvents(Module& wasm, T visitor) {
   }
 }
 
+// Performs a parallel map on function in the module, emitting a map object
+// of function => result.
+// TODO: use in inlining and elsewhere
+template<typename T> struct ParallelFunctionMap {
+
+  typedef std::map<Function*, T> Map;
+  Map map;
+
+  typedef std::function<void(Function*, T&)> Func;
+
+  struct Info {
+    Map* map;
+    Func work;
+  };
+
+  ParallelFunctionMap(Module& wasm, Func work) {
+    // Fill in map, as we operate on it in parallel (each function to its own
+    // entry).
+    for (auto& func : wasm.functions) {
+      map[func.get()];
+    }
+
+    // Run on the imports first. TODO: parallelize this too
+    for (auto& func : wasm.functions) {
+      if (func->imported()) {
+        work(func.get(), map[func.get()]);
+      }
+    }
+
+    // Run on the implemented functions.
+    struct Mapper : public WalkerPass<PostWalker<Mapper>> {
+
+      bool isFunctionParallel() override { return true; }
+
+      Mapper(Info* info) : info(info) {}
+
+      Mapper* create() override { return new Mapper(info); }
+
+      void doWalkFunction(Function* curr) {
+        assert((*info->map).count(curr));
+        info->work(curr, (*info->map)[curr]);
+      }
+
+    private:
+      Info* info;
+    };
+
+    Info info = {&map, work};
+
+    PassRunner runner(&wasm);
+    runner.setIsNested(true);
+    runner.add<Mapper>(&info);
+    runner.run();
+  }
+};
+
 } // namespace ModuleUtils
 
 } // namespace wasm