diff --git a/lib/Target/ARM/ARMBaseInstrInfo.cpp b/lib/Target/ARM/ARMBaseInstrInfo.cpp
index b4266693c1a..251171daad1 100644
--- a/lib/Target/ARM/ARMBaseInstrInfo.cpp
+++ b/lib/Target/ARM/ARMBaseInstrInfo.cpp
@@ -1706,7 +1706,7 @@ MachineInstr *ARMBaseInstrInfo::optimizeSelect(MachineInstr *MI,
                                                bool PreferFalse) const {
   assert((MI->getOpcode() == ARM::MOVCCr || MI->getOpcode() == ARM::t2MOVCCr) &&
          "Unknown select instruction");
-  const MachineRegisterInfo &MRI = MI->getParent()->getParent()->getRegInfo();
+  MachineRegisterInfo &MRI = MI->getParent()->getParent()->getRegInfo();
   MachineInstr *DefMI = canFoldIntoMOVCC(MI->getOperand(2).getReg(), MRI, this);
   bool Invert = !DefMI;
   if (!DefMI)
@@ -1714,11 +1714,17 @@ MachineInstr *ARMBaseInstrInfo::optimizeSelect(MachineInstr *MI,
   if (!DefMI)
     return 0;
 
+  // Find new register class to use.
+  MachineOperand FalseReg = MI->getOperand(Invert ? 2 : 1);
+  unsigned       DestReg  = MI->getOperand(0).getReg();
+  const TargetRegisterClass *PreviousClass = MRI.getRegClass(FalseReg.getReg());
+  if (!MRI.constrainRegClass(DestReg, PreviousClass))
+    return 0;
+
   // Create a new predicated version of DefMI.
   // Rfalse is the first use.
   MachineInstrBuilder NewMI = BuildMI(*MI->getParent(), MI, MI->getDebugLoc(),
-                                      DefMI->getDesc(),
-                                      MI->getOperand(0).getReg());
+                                      DefMI->getDesc(), DestReg);
 
   // Copy all the DefMI operands, excluding its (null) predicate.
   const MCInstrDesc &DefDesc = DefMI->getDesc();
@@ -1741,7 +1747,6 @@ MachineInstr *ARMBaseInstrInfo::optimizeSelect(MachineInstr *MI,
   // register operand tied to the first def.
   // The tie makes the register allocator ensure the FalseReg is allocated the
   // same register as operand 0.
-  MachineOperand FalseReg = MI->getOperand(Invert ? 2 : 1);
   FalseReg.setImplicit();
   NewMI.addOperand(FalseReg);
   NewMI->tieOperands(0, NewMI->getNumOperands() - 1);
diff --git a/test/CodeGen/ARM/optselect-regclass.ll b/test/CodeGen/ARM/optselect-regclass.ll
new file mode 100644
index 00000000000..1aa45208964
--- /dev/null
+++ b/test/CodeGen/ARM/optselect-regclass.ll
@@ -0,0 +1,23 @@
+; RUN: llc < %s -march=arm -mcpu=swift -verify-machineinstrs
+%union.opcode.0.2.5.8.15.28 = type { i32 }
+
+@opcode = external global %union.opcode.0.2.5.8.15.28, align 4
+@operands = external hidden global [50 x i8], align 4
+@.str86 = external hidden unnamed_addr constant [13 x i8], align 1
+
+; Function Attrs: nounwind ssp
+define void @xfr() {
+entry:
+  %bf.load4 = load i32* getelementptr inbounds (%union.opcode.0.2.5.8.15.28* @opcode, i32 0, i32 0), align 4
+  %bf.clear10 = and i32 %bf.load4, 65535
+  %and11 = and i32 %bf.load4, 32768
+  %tobool12 = icmp ne i32 %and11, 0
+  %cond13 = select i1 %tobool12, i32 1073676288, i32 0
+  %or = or i32 %cond13, %bf.clear10
+  %shl = shl nuw i32 %or, 2
+  %add = add i32 0, %shl
+  tail call void (i8*, i32, i32, i8*, ...)* @__sprintf_chk(i8* getelementptr inbounds ([50 x i8]* @operands, i32 0, i32 0), i32 0, i32 50, i8* getelementptr inbounds ([13 x i8]* @.str86, i32 0, i32 0), i32 undef, i32 undef, i32 %add)
+  ret void
+}
+
+declare void @__sprintf_chk(i8*, i32, i32, i8*, ...)