-def VK8 : RegisterClass<"X86", [v8i1], 8, (sequence "K%u", 0, 7)>;
-def VK16 : RegisterClass<"X86", [v16i1], 16, (add VK8)>;
-
-def VK8WM : RegisterClass<"X86", [v8i1], 8, (sub VK8, K0)>;
-def VK16WM : RegisterClass<"X86", [v16i1], 16, (add VK8WM)>;
-
+// Mask registers
+def VK1 : RegisterClass<"X86", [i1], 16, (sequence "K%u", 0, 7)> {let Size = 16;}
+def VK2 : RegisterClass<"X86", [v2i1], 16, (add VK1)> {let Size = 16;}
+def VK4 : RegisterClass<"X86", [v4i1], 16, (add VK2)> {let Size = 16;}
+def VK8 : RegisterClass<"X86", [v8i1], 16, (add VK4)> {let Size = 16;}
+def VK16 : RegisterClass<"X86", [v16i1], 16, (add VK8)> {let Size = 16;}
+def VK32 : RegisterClass<"X86", [v32i1], 32, (add VK16)> {let Size = 32;}
+def VK64 : RegisterClass<"X86", [v64i1], 64, (add VK32)> {let Size = 64;}
+
+def VK1WM : RegisterClass<"X86", [i1], 16, (sub VK1, K0)> {let Size = 16;}
+def VK2WM : RegisterClass<"X86", [v2i1], 16, (sub VK2, K0)> {let Size = 16;}
+def VK4WM : RegisterClass<"X86", [v4i1], 16, (sub VK4, K0)> {let Size = 16;}
+def VK8WM : RegisterClass<"X86", [v8i1], 16, (sub VK8, K0)> {let Size = 16;}
+def VK16WM : RegisterClass<"X86", [v16i1], 16, (add VK8WM)> {let Size = 16;}
+def VK32WM : RegisterClass<"X86", [v32i1], 32, (add VK16WM)> {let Size = 32;}
+def VK64WM : RegisterClass<"X86", [v64i1], 64, (add VK32WM)> {let Size = 64;}