3 files changed, 23 insertions, 0 deletions
diff --git a/src/passes/RemoveUnusedBrs.cpp b/src/passes/RemoveUnusedBrs.cpp
index 8994c7fe2..f0db1eee6 100644
--- a/src/passes/RemoveUnusedBrs.cpp
+++ b/src/passes/RemoveUnusedBrs.cpp
@@ -31,6 +31,8 @@ namespace wasm {
 // condition and possible value, and the possible value must
 // not have side effects (as they would run unconditionally)
 static bool canTurnIfIntoBrIf(Expression* ifCondition, Expression* brValue, PassOptions& options) {
+  // if the if isn't even taken, this is all dead code anyhow
+  if (ifCondition->type == unreachable) return false;
   if (!brValue) return true;
   EffectAnalyzer value(options, brValue);
   if (value.hasSideEffects()) return false;
diff --git a/test/passes/remove-unused-brs.txt b/test/passes/remove-unused-brs.txt
index fe0c59fca..5cc900abd 100644
--- a/test/passes/remove-unused-brs.txt
+++ b/test/passes/remove-unused-brs.txt
@@ -6,6 +6,7 @@
  (type $4 (func (param i32 i32)))
  (type $5 (func (param f32 i32 f32 i32 i32 f64 f32) (result i32)))
  (type $6 (func (param i32) (result i64)))
+ (type $7 (func (result i64)))
  (memory $0 256 256)
  (func $b0-yes (type $0) (param $i1 i32)
   (block $topmost
@@ -1059,4 +1060,14 @@
    )
   )
  )
+ (func $unreachable-if-that-could-be-a-br_if (type $7) (result i64)
+  (loop $label$3
+   (if
+    (unreachable)
+    (f64.const 1)
+    (br $label$3)
+   )
+   (i64.const 1)
+  )
+ )
 )
diff --git a/test/passes/remove-unused-brs.wast b/test/passes/remove-unused-brs.wast
index 996b05264..ecf70b758 100644
--- a/test/passes/remove-unused-brs.wast
+++ b/test/passes/remove-unused-brs.wast
@@ -943,5 +943,15 @@
     )
    )
   )
+  (func $unreachable-if-that-could-be-a-br_if (result i64)
+   (loop $label$3
+    (if
+     (unreachable)
+     (f64.const 1)
+     (br $label$3)
+    )
+    (i64.const 1)
+   )
+  )
 )