2 files changed, 25 insertions, 6 deletions
diff --git a/src/ast/LocalGraph.cpp b/src/ast/LocalGraph.cpp
index c997eff1b..0d36fec84 100644
--- a/src/ast/LocalGraph.cpp
+++ b/src/ast/LocalGraph.cpp
@@ -17,6 +17,7 @@
 #include <iterator>
 
 #include <wasm-builder.h>
+#include <wasm-printing.h>
 #include <ast/find_all.h>
 #include <ast/local-graph.h>
 
@@ -24,6 +25,18 @@ namespace wasm {
 
 LocalGraph::LocalGraph(Function* func, Module* module) {
   walkFunctionInModule(func, module);
+
+#ifdef LOCAL_GRAPH_DEBUG
+  std::cout << "LocalGraph::dump\n";
+  for (auto& pair : getSetses) {
+    auto* get = pair.first;
+    auto& sets = pair.second;
+    std::cout << "GET\n" << get << " is influenced by\n";
+    for (auto* set : sets) {
+      std::cout << set << '\n';
+    }
+  }
+#endif
 }
 
 void LocalGraph::computeInfluences() {
diff --git a/src/passes/SSAify.cpp b/src/passes/SSAify.cpp
index a71a75308..aafea8a97 100644
--- a/src/passes/SSAify.cpp
+++ b/src/passes/SSAify.cpp
@@ -60,7 +60,7 @@ struct SSAify : public Pass {
     LocalGraph graph(func, module);
     // create new local indexes, one for each set
     createNewIndexes(graph);
-    // we now know the sets for each get
+    // we now know the sets for each get, and can compute get indexes and handle phis
     computeGetsAndPhis(graph);
     // add prepends to function
     addPrepends();
@@ -75,7 +75,6 @@ struct SSAify : public Pass {
     }
   }
 
-  // After we traversed it all, we can compute gets and phis
   void computeGetsAndPhis(LocalGraph& graph) {
     for (auto& iter : graph.getSetses) {
       auto* get = iter.first;
@@ -84,8 +83,7 @@ struct SSAify : public Pass {
         continue; // unreachable, ignore
       }
       if (sets.size() == 1) {
-        // TODO: add tests for this case
-        // easy, just one set, use it's index
+        // easy, just one set, use its index
         auto* set = *sets.begin();
         if (set) {
           get->index = set->index;
@@ -138,10 +136,18 @@ struct SSAify : public Pass {
         for (auto* set : sets) {
           if (set) {
             // a set exists, just add a tee of its value
-            set->value = builder.makeTeeLocal(
+            auto* value = set->value;
+            auto* tee = builder.makeTeeLocal(
               new_,
-              set->value
+              value
             );
+            set->value = tee;
+            // the value may have been something we tracked the location
+            // of. if so, update that, since we moved it into the tee
+            if (graph.locations.count(value) > 0) {
+              assert(graph.locations[value] == &set->value);
+              graph.locations[value] = &tee->value;
+            }
           } else {
             // this is a param or the zero init value.
             if (func->isParam(old)) {