diff --git a/lib/Target/R600/SIISelLowering.cpp b/lib/Target/R600/SIISelLowering.cpp
index 175709cad6d..235665ab89e 100644
--- a/lib/Target/R600/SIISelLowering.cpp
+++ b/lib/Target/R600/SIISelLowering.cpp
@@ -972,8 +972,12 @@ SDValue SITargetLowering::LowerZERO_EXTEND(SDValue Op,
     return SDValue();
   }
 
-  return DAG.getNode(ISD::BUILD_PAIR, DL, VT, Op.getOperand(0),
-                                              DAG.getConstant(0, MVT::i32));
+  SDValue Src = Op.getOperand(0);
+  if (Src.getValueType() != MVT::i32)
+    Src = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, Src);
+
+  SDValue Zero = DAG.getConstant(0, MVT::i32);
+  return DAG.getNode(ISD::BUILD_PAIR, DL, VT, Src, Zero);
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/test/CodeGen/R600/uaddo.ll b/test/CodeGen/R600/uaddo.ll
new file mode 100644
index 00000000000..4f24c85f1a0
--- /dev/null
+++ b/test/CodeGen/R600/uaddo.ll
@@ -0,0 +1,17 @@
+; RUN: llc -march=r600 -mcpu=SI < %s | FileCheck -check-prefix=SI %s
+
+declare { i64, i1 } @llvm.uadd.with.overflow.i64(i64, i64) nounwind readnone
+
+; SI-LABEL: @uaddo_i64_zext
+; SI: ADD
+; SI: ADDC
+; SI: ADDC
+define void @uaddo_i64_zext(i64 addrspace(1)* %out, i64 %a, i64 %b) nounwind {
+  %uadd = call { i64, i1 } @llvm.uadd.with.overflow.i64(i64 %a, i64 %b) nounwind
+  %val = extractvalue { i64, i1 } %uadd, 0
+  %carry = extractvalue { i64, i1 } %uadd, 1
+  %ext = zext i1 %carry to i64
+  %add2 = add i64 %val, %ext
+  store i64 %add2, i64 addrspace(1)* %out, align 8
+  ret void
+}
diff --git a/test/CodeGen/R600/zero_extend.ll b/test/CodeGen/R600/zero_extend.ll
index a114bfc4a02..c561ff7428e 100644
--- a/test/CodeGen/R600/zero_extend.ll
+++ b/test/CodeGen/R600/zero_extend.ll
@@ -26,3 +26,14 @@ entry:
   store i32 %1, i32 addrspace(1)* %out
   ret void
 }
+
+; SI-CHECK-LABEL: @zext_i1_to_i64
+; SI-CHECK: V_CMP_EQ_I32
+; SI-CHECK: V_CNDMASK_B32
+; SI-CHECK: V_MOV_B32_e32 v{{[0-9]+}}, 0
+define void @zext_i1_to_i64(i64 addrspace(1)* %out, i32 %a, i32 %b) nounwind {
+  %cmp = icmp eq i32 %a, %b
+  %ext = zext i1 %cmp to i64
+  store i64 %ext, i64 addrspace(1)* %out, align 8
+  ret void
+}