2 files changed, 21 insertions, 0 deletions
diff --git a/src/ir/bits.h b/src/ir/bits.h
index 950864a23..dc02bd8f8 100644
--- a/src/ir/bits.h
+++ b/src/ir/bits.h
@@ -413,6 +413,8 @@ Index getMaxBits(Expression* curr,
     // a tee passes through the value
     return getMaxBits(set->value, localInfoProvider);
   } else if (auto* get = curr->dynCast<LocalGet>()) {
+    // TODO: Should this be optional?
+    assert(localInfoProvider);
     return localInfoProvider->getMaxBitsForLocal(get);
   } else if (auto* load = curr->dynCast<Load>()) {
     // if signed, then the sign-extension might fill all the bits
diff --git a/src/passes/OptimizeInstructions.cpp b/src/passes/OptimizeInstructions.cpp
index 357f172d9..768ea5702 100644
--- a/src/passes/OptimizeInstructions.cpp
+++ b/src/passes/OptimizeInstructions.cpp
@@ -1819,6 +1819,25 @@ private:
         }
       }
     }
+    if (curr->type == Type::i32 &&
+        Bits::getMaxBits(curr->condition, this) <= 1 &&
+        Bits::getMaxBits(curr->ifTrue, this) <= 1 &&
+        Bits::getMaxBits(curr->ifFalse, this) <= 1) {
+      // The condition and both arms are i32 booleans, which allows us to do
+      // boolean optimizations.
+      Expression* x;
+      Expression* y;
+
+      // x ? y : 0   ==>   x & y
+      if (matches(curr, select(any(&y), ival(0), any(&x)))) {
+        return builder.makeBinary(AndInt32, y, x);
+      }
+
+      // x ? 1 : y   ==>   x | y
+      if (matches(curr, select(ival(1), any(&y), any(&x)))) {
+        return builder.makeBinary(OrInt32, y, x);
+      }
+    }
     {
       // Sides are identical, fold
       Expression *ifTrue, *ifFalse, *c;