Index: lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
===================================================================
--- lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
+++ lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
@@ -1764,7 +1764,7 @@
 /// }
 
 static unsigned matchVectorRegName(StringRef Name) {
-  return StringSwitch<unsigned>(Name)
+  return StringSwitch<unsigned>(Name.lower())
       .Case("v0", AArch64::Q0)
       .Case("v1", AArch64::Q1)
       .Case("v2", AArch64::Q2)
Index: test/MC/AArch64/case-insen-reg-names.s
===================================================================
--- test/MC/AArch64/case-insen-reg-names.s
+++ test/MC/AArch64/case-insen-reg-names.s
@@ -0,0 +1,8 @@
+// RUN: llvm-mc -triple aarch64-none-linux-gnu -show-encoding < %s | FileCheck %s
+
+fadd v0.2d, v5.2d, v6.2d
+fadd V0.2d, V5.2d, V6.2d
+fadd v0.2d, V5.2d, v6.2d
+// CHECK: fadd v0.2d, v5.2d, v6.2d          // encoding: [0xa0,0xd4,0x66,0x4e]
+// CHECK: fadd v0.2d, v5.2d, v6.2d          // encoding: [0xa0,0xd4,0x66,0x4e]
+// CHECK: fadd v0.2d, v5.2d, v6.2d          // encoding: [0xa0,0xd4,0x66,0x4e]