1 files changed, 13 insertions, 0 deletions
diff --git a/src/passes/SignaturePruning.cpp b/src/passes/SignaturePruning.cpp
index ecf6d7e21..ca7bd0548 100644
--- a/src/passes/SignaturePruning.cpp
+++ b/src/passes/SignaturePruning.cpp
@@ -28,6 +28,7 @@
 //
 
 #include "ir/find_all.h"
+#include "ir/intrinsics.h"
 #include "ir/lubs.h"
 #include "ir/module-utils.h"
 #include "ir/type-updating.h"
@@ -103,6 +104,18 @@ struct SignaturePruning : public Pass {
       // called.
       for (auto* call : info.calls) {
         allInfo[module->getFunction(call->target)->type].calls.push_back(call);
+
+        // Intrinsics limit our ability to optimize in some cases. We will avoid
+        // modifying any type that is used by call.without.effects, to avoid
+        // the complexity of handling that. After intrinsics are lowered,
+        // this optimization will be able to run at full power anyhow.
+        if (Intrinsics(*module).isCallWithoutEffects(call)) {
+          // The last operand is the actual call target.
+          auto* target = call->operands.back();
+          if (target->type != Type::unreachable) {
+            allInfo[target->type.getHeapType()].optimizable = false;
+          }
+        }
       }
 
       // For indirect calls, add each call_ref to the type the call_ref uses.