when removing an if-copy in coalesce-locals, if it's a tee, we do still need the get in that arm. only when it is not a tee can we remove that arm and make the if-else into an if

1 files changed, 3 insertions, 1 deletions

diff --git a/src/passes/CoalesceLocals.cpp b/src/passes/CoalesceLocals.cpp
index 87eefb85c..5ab68da23 100644
--- a/src/passes/CoalesceLocals.cpp
+++ b/src/passes/CoalesceLocals.cpp
@@ -597,11 +597,13 @@ void CoalesceLocals::pickIndices(std::vector<Index>& indices) {
 // Remove a copy from a set of an if, where one if arm is a get of the same set
 static void removeIfCopy(Expression** origin, SetLocal* set, If* iff, Expression*& copy, Expression*& other, Module* module) {
   // replace the origin with the if, and sink the set into the other non-copying arm
+  bool tee = set->isTee();
   *origin = iff;
   set->value = other;
   set->finalize();
   other = set;
-  if (!isConcreteWasmType(set->type)) {
+  // if this is not a tee, then we can get rid of the copy in that arm
+  if (!tee) {
     // we don't need the copy at all
     copy = nullptr;
     if (!iff->ifTrue) {