diff --git a/llvm/lib/Transforms/Scalar/SCCP.cpp b/llvm/lib/Transforms/Scalar/SCCP.cpp
index feeb23136eaa..90c3520c8323 100644
--- a/llvm/lib/Transforms/Scalar/SCCP.cpp
+++ b/llvm/lib/Transforms/Scalar/SCCP.cpp
@@ -494,7 +494,9 @@ private:
   void visitResumeInst    (TerminatorInst &I) { /*returns void*/ }
   void visitUnreachableInst(TerminatorInst &I) { /*returns void*/ }
   void visitFenceInst     (FenceInst &I) { /*returns void*/ }
-  void visitAtomicCmpXchgInst (AtomicCmpXchgInst &I) { markOverdefined(&I); }
+  void visitAtomicCmpXchgInst(AtomicCmpXchgInst &I) {
+    markAnythingOverdefined(&I);
+  }
   void visitAtomicRMWInst (AtomicRMWInst &I) { markOverdefined(&I); }
   void visitAllocaInst    (Instruction &I) { markOverdefined(&I); }
   void visitVAArgInst     (Instruction &I) { markAnythingOverdefined(&I); }
diff --git a/llvm/test/Transforms/SCCP/atomic.ll b/llvm/test/Transforms/SCCP/atomic.ll
new file mode 100644
index 000000000000..60d4896ec2b0
--- /dev/null
+++ b/llvm/test/Transforms/SCCP/atomic.ll
@@ -0,0 +1,9 @@
+; RUN: opt < %s -sccp -S | FileCheck %s
+
+define i1 @test_cmpxchg(i32* %addr, i32 %desired, i32 %new) {
+; CHECK-LABEL: @test_cmpxchg
+; CHECK: cmpxchg i32* %addr, i32 %desired, i32 %new seq_cst seq_cst
+  %val = cmpxchg i32* %addr, i32 %desired, i32 %new seq_cst seq_cst
+  %res = extractvalue { i32, i1 } %val, 1
+  ret i1 %res
+}