1 files changed, 18 insertions, 0 deletions
diff --git a/js/src/jit/CodeGenerator.cpp b/js/src/jit/CodeGenerator.cpp
index ec3d35ff0..66e8e25dd 100644
--- a/js/src/jit/CodeGenerator.cpp
+++ b/js/src/jit/CodeGenerator.cpp
@@ -11518,6 +11518,24 @@ CodeGenerator::visitIsObjectAndBranch(LIsObjectAndBranch* ins)
 }
 
 void
+CodeGenerator::visitIsNullOrUndefined(LIsNullOrUndefined* ins)
+{
+    Register output = ToRegister(ins->output());
+    ValueOperand value = ToValue(ins, LIsNullOrUndefined::Input);
+
+    Label isNotNull, done;
+    masm.branchTestNull(Assembler::NotEqual, value, &isNotNull);
+
+    masm.move32(Imm32(1), output);
+    masm.jump(&done);
+
+    masm.bind(&isNotNull);
+    masm.testUndefinedSet(Assembler::Equal, value, output);
+
+    masm.bind(&done);
+}
+
+void
 CodeGenerator::loadOutermostJSScript(Register reg)
 {
     // The "outermost" JSScript means the script that we are compiling