Index: lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -771,9 +771,16 @@
         // Promote to a byte-sized store with upper bits zero if not
         // storing an integral number of bytes.  For example, promote
         // TRUNCSTORE:i1 X -> TRUNCSTORE:i8 (and X, 1)
+
+        EVT ScalarStVT = StVT.getScalarType();
         EVT NVT = EVT::getIntegerVT(*DAG.getContext(),
-                                    StVT.getStoreSizeInBits());
-        Value = DAG.getZeroExtendInReg(Value, dl, StVT);
+                                    ScalarStVT.getStoreSizeInBits());
+        if (StVT.isVector()) {
+          NVT = EVT::getVectorVT(*DAG.getContext(), NVT,
+                                 StVT.getVectorNumElements());
+        }
+
+        Value = DAG.getZeroExtendInReg(Value, dl, ScalarStVT);
         SDValue Result =
           DAG.getTruncStore(Chain, dl, Value, Ptr, ST->getPointerInfo(),
                             NVT, isVolatile, isNonTemporal, Alignment,
Index: lib/CodeGen/SelectionDAG/TargetLowering.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -340,8 +340,14 @@
   unsigned SmallVTBits = DemandedSize;
   if (!isPowerOf2_32(SmallVTBits))
     SmallVTBits = NextPowerOf2(SmallVTBits);
+
+  EVT VT = Op.getValueType();
+  unsigned NElts = VT.isVector() ? VT.getVectorNumElements() : 0;
   for (; SmallVTBits < BitWidth; SmallVTBits = NextPowerOf2(SmallVTBits)) {
     EVT SmallVT = EVT::getIntegerVT(*DAG.getContext(), SmallVTBits);
+    if (NElts != 0)
+      SmallVT = EVT::getVectorVT(*DAG.getContext(), SmallVT, NElts);
+
     if (TLI.isTruncateFree(Op.getValueType(), SmallVT) &&
         TLI.isZExtFree(SmallVT, Op.getValueType())) {
       // We found a type with free casts.
Index: test/CodeGen/R600/trunc-store-i1-vector.ll
===================================================================
--- /dev/null
+++ test/CodeGen/R600/trunc-store-i1-vector.ll
@@ -0,0 +1,9 @@
+; XFAIL: *
+; RUN: llc -march=r600 -mcpu=SI < %s | FileCheck -check-prefix=SI %s
+
+; SI-LABEL: @global_truncstore_v4i32_to_v4i1
+define void @global_truncstore_v4i32_to_v4i1(<4 x i1> addrspace(1)* %out, <4 x i32> %val) nounwind {
+  %trunc = trunc <4 x i32> %val to <4 x i1>
+  store <4 x i1> %trunc, <4 x i1> addrspace(1)* %out
+  ret void
+}