1 files changed, 15 insertions, 2 deletions
diff --git a/libyul/optimiser/Semantics.cpp b/libyul/optimiser/Semantics.cpp
index 91bb2709..7edf97d7 100644
--- a/libyul/optimiser/Semantics.cpp
+++ b/libyul/optimiser/Semantics.cpp
@@ -22,6 +22,7 @@
 
 #include <libyul/Exceptions.h>
 #include <libyul/AsmData.h>
+#include <libyul/Dialect.h>
 
 #include <libevmasm/SemanticInformation.h>
 
@@ -31,7 +32,13 @@ using namespace std;
 using namespace dev;
 using namespace yul;
 
-MovableChecker::MovableChecker(Expression const& _expression)
+MovableChecker::MovableChecker(Dialect const& _dialect):
+	m_dialect(_dialect)
+{
+}
+
+MovableChecker::MovableChecker(Dialect const& _dialect, Expression const& _expression):
+	MovableChecker(_dialect)
 {
 	visit(_expression);
 }
@@ -50,8 +57,14 @@ void MovableChecker::operator()(FunctionalInstruction const& _instr)
 		ASTWalker::operator()(_instr);
 }
 
-void MovableChecker::operator()(FunctionCall const&)
+void MovableChecker::operator()(FunctionCall const& _functionCall)
 {
+	if (BuiltinFunction const* f = m_dialect.builtin(_functionCall.functionName.name))
+		if (f->movable)
+		{
+			ASTWalker::operator()(_functionCall);
+			return;
+		}
 	m_movable = false;
 }