Index: lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
+++ lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
@@ -343,8 +343,8 @@
   Op = DAG.getNode(N->getOpcode(), dl, NVT, Op);
   // Subtract off the extra leading bits in the bigger type.
   return DAG.getNode(ISD::SUB, dl, NVT, Op,
-                     DAG.getConstant(NVT.getSizeInBits() -
-                                     OVT.getSizeInBits(), NVT));
+                     DAG.getConstant(NVT.getScalarSizeInBits() -
+                                     OVT.getScalarSizeInBits(), NVT));
 }
 
 SDValue DAGTypeLegalizer::PromoteIntRes_CTPOP(SDNode *N) {
Index: test/CodeGen/X86/pr20917.ll
===================================================================
--- /dev/null
+++ test/CodeGen/X86/pr20917.ll
@@ -0,0 +1,17 @@
+; RUN: llc < %s -mtriple=i686-none-linux-gnueabi -mattr=+sse2 | FileCheck %s
+
+; CHECK: .LCPI0_1:
+; CHECK-NEXT: .long   32                      # 0x20
+; CHECK-NEXT: .long   0                       # 0x0
+; CHECK-NEXT: .long   32                      # 0x20
+; CHECK-NEXT: .long   0                       # 0x0
+; CHECK: psubq   .LCPI0_1
+
+define <2 x i32> @test(<2 x i32> %x) {
+  %1 = call <2 x i32> @llvm.ctlz.v2i32(<2 x i32> %x, i1 false)
+  ret <2 x i32> %1
+}
+
+declare <2 x i32> @llvm.ctlz.v2i32(<2 x i32>, i1)
+
+