Index: llvm/trunk/lib/Target/ARM/ARMInstrNEON.td
===================================================================
--- llvm/trunk/lib/Target/ARM/ARMInstrNEON.td
+++ llvm/trunk/lib/Target/ARM/ARMInstrNEON.td
@@ -4710,7 +4710,7 @@
 // Indexed dot product instructions:
 class DOTI<string opc, string dt, bit Q, bit U, RegisterClass Ty> :
   N3Vnp<0b11100, 0b10, 0b1101, Q, U,
-       (outs Ty:$Vd), (ins Ty:$Vn, DPR:$Vm, VectorIndex32:$lane),
+       (outs Ty:$Vd), (ins Ty:$Vn, DPR_VFP2:$Vm, VectorIndex32:$lane),
        N3RegFrm, IIC_VDOTPROD, opc, dt, []> {
   bit lane;
   let Inst{5} = lane;
Index: llvm/trunk/test/MC/ARM/armv8.2a-dotprod-error.s
===================================================================
--- llvm/trunk/test/MC/ARM/armv8.2a-dotprod-error.s
+++ llvm/trunk/test/MC/ARM/armv8.2a-dotprod-error.s
@@ -3,12 +3,34 @@
 // RUN: not llvm-mc -triple thumb -mattr=+dotprod -show-encoding < %s 2> %t
 // RUN: FileCheck --check-prefix=CHECK-ERROR < %t %s
 
+// Only indices 0 an 1 should be accepted:
+
 vudot.u8 d0, d1, d2[2]
 vsdot.s8 d0, d1, d2[2]
 vudot.u8 q0, q1, d4[2]
 vsdot.s8 q0, q1, d4[2]
 
 // CHECK-ERROR: error: invalid operand for instruction
+// CHECK-ERROR: vudot.u8 d0, d1, d2[2]
+// CHECK-ERROR:                    ^
+// CHECK-ERROR: error: invalid operand for instruction
+// CHECK-ERROR: vsdot.s8 d0, d1, d2[2]
+// CHECK-ERROR:                    ^
+// CHECK-ERROR: error: invalid operand for instruction
+// CHECK-ERROR: vudot.u8 q0, q1, d4[2]
+// CHECK-ERROR:                    ^
 // CHECK-ERROR: error: invalid operand for instruction
+// CHECK-ERROR: vsdot.s8 q0, q1, d4[2]
+// CHECK-ERROR:                    ^
+
+// Only the lower 16 D-registers should be accepted:
+
+vudot.u8 q0, q1, d16[0]
+vsdot.s8 q0, q1, d16[0]
+
 // CHECK-ERROR: error: invalid operand for instruction
+// CHECK-ERROR: vudot.u8 q0, q1, d16[0]
+// CHECK-ERROR:                     ^
 // CHECK-ERROR: error: invalid operand for instruction
+// CHECK-ERROR: vsdot.s8 q0, q1, d16[0]
+// CHECK-ERROR:                     ^