Index: llvm/lib/Target/AArch64/AArch64CallingConvention.td
===================================================================
--- llvm/lib/Target/AArch64/AArch64CallingConvention.td
+++ llvm/lib/Target/AArch64/AArch64CallingConvention.td
@@ -75,10 +75,10 @@
   CCIfConsecutiveRegs<CCCustom<"CC_AArch64_Custom_Block">>,
 
   CCIfType<[nxv16i8, nxv8i16, nxv4i32, nxv2i64, nxv2f16, nxv4f16, nxv8f16,
-            nxv1f32, nxv2f32, nxv4f32, nxv1f64, nxv2f64],
+            nxv2f32, nxv4f32, nxv2f64],
            CCAssignToReg<[Z0, Z1, Z2, Z3, Z4, Z5, Z6, Z7]>>,
   CCIfType<[nxv16i8, nxv8i16, nxv4i32, nxv2i64, nxv2f16, nxv4f16, nxv8f16,
-            nxv1f32, nxv2f32, nxv4f32, nxv1f64, nxv2f64],
+            nxv2f32, nxv4f32, nxv2f64],
            CCPassIndirect<i64>>,
 
   CCIfType<[nxv2i1, nxv4i1, nxv8i1, nxv16i1],
@@ -155,7 +155,7 @@
       CCAssignToReg<[Q0, Q1, Q2, Q3, Q4, Q5, Q6, Q7]>>,
 
   CCIfType<[nxv16i8, nxv8i16, nxv4i32, nxv2i64, nxv2f16, nxv4f16, nxv8f16,
-            nxv1f32, nxv2f32, nxv4f32, nxv1f64, nxv2f64],
+            nxv2f32, nxv4f32, nxv2f64],
            CCAssignToReg<[Z0, Z1, Z2, Z3, Z4, Z5, Z6, Z7]>>,
 
   CCIfType<[nxv2i1, nxv4i1, nxv8i1, nxv16i1],
Index: llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
===================================================================
--- llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -178,10 +178,8 @@
     addRegisterClass(MVT::nxv2f16, &AArch64::ZPRRegClass);
     addRegisterClass(MVT::nxv4f16, &AArch64::ZPRRegClass);
     addRegisterClass(MVT::nxv8f16, &AArch64::ZPRRegClass);
-    addRegisterClass(MVT::nxv1f32, &AArch64::ZPRRegClass);
     addRegisterClass(MVT::nxv2f32, &AArch64::ZPRRegClass);
     addRegisterClass(MVT::nxv4f32, &AArch64::ZPRRegClass);
-    addRegisterClass(MVT::nxv1f64, &AArch64::ZPRRegClass);
     addRegisterClass(MVT::nxv2f64, &AArch64::ZPRRegClass);
 
     for (auto VT : { MVT::nxv16i8, MVT::nxv8i16, MVT::nxv4i32, MVT::nxv2i64 }) {
Index: llvm/lib/Target/AArch64/AArch64RegisterInfo.td
===================================================================
--- llvm/lib/Target/AArch64/AArch64RegisterInfo.td
+++ llvm/lib/Target/AArch64/AArch64RegisterInfo.td
@@ -858,35 +858,19 @@
 
 //******************************************************************************
 
-// SVE vector register class
-def ZPR : RegisterClass<"AArch64",
-                        [nxv16i8, nxv8i16, nxv4i32, nxv2i64,
-                         nxv2f16, nxv4f16, nxv8f16,
-                         nxv1f32, nxv2f32, nxv4f32,
-                         nxv1f64, nxv2f64],
-                        128, (sequence "Z%u", 0, 31)> {
+// SVE vector register classes
+class ZPRClass<int lastreg> : RegisterClass<"AArch64",
+                                            [nxv16i8, nxv8i16, nxv4i32, nxv2i64,
+                                             nxv2f16, nxv4f16, nxv8f16,
+                                             nxv2f32, nxv4f32,
+                                             nxv2f64],
+                                            128, (sequence "Z%u", 0, lastreg)> {
   let Size = 128;
 }
 
-// SVE restricted 4 bit scalable vector register class
-def ZPR_4b : RegisterClass<"AArch64",
-                         [nxv16i8, nxv8i16, nxv4i32, nxv2i64,
-                          nxv2f16, nxv4f16, nxv8f16,
-                          nxv1f32, nxv2f32, nxv4f32,
-                          nxv1f64, nxv2f64],
-                         128, (sequence "Z%u", 0, 15)> {
-  let Size = 128;
-}
-
-// SVE restricted 3 bit scalable vector register class
-def ZPR_3b : RegisterClass<"AArch64",
-                         [nxv16i8, nxv8i16, nxv4i32, nxv2i64,
-                          nxv2f16, nxv4f16, nxv8f16,
-                          nxv1f32, nxv2f32, nxv4f32,
-                          nxv1f64, nxv2f64],
-                         128, (sequence "Z%u", 0, 7)> {
-  let Size = 128;
-}
+def ZPR    : ZPRClass<31>;
+def ZPR_4b : ZPRClass<15>; // Restricted 4 bit SVE vector register class.
+def ZPR_3b : ZPRClass<7>;  // Restricted 3 bit SVE vector register class.
 
 class ZPRAsmOperand<string name, int Width, string RegClassSuffix = "">
     : AsmOperandClass {