diff --git a/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp b/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
index c0f54b223877cf..dbea42d55b5fce 100644
--- a/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ b/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -2318,7 +2318,7 @@ bool X86AsmParser::parseCFlagsOp(OperandVector &Operands) {
     return Error(Tok.getLoc(), "Expected { at this point");
   Parser.Lex(); // Eat "{"
   Tok = Parser.getTok();
-  if (Tok.getIdentifier() != "dfv")
+  if (Tok.getIdentifier().lower() != "dfv")
     return Error(Tok.getLoc(), "Expected dfv at this point");
   Parser.Lex(); // Eat "dfv"
   Tok = Parser.getTok();
@@ -2338,7 +2338,7 @@ bool X86AsmParser::parseCFlagsOp(OperandVector &Operands) {
   unsigned CFlags = 0;
   for (unsigned I = 0; I < 4; ++I) {
     Tok = Parser.getTok();
-    unsigned CFlag = StringSwitch<unsigned>(Tok.getIdentifier())
+    unsigned CFlag = StringSwitch<unsigned>(Tok.getIdentifier().lower())
                          .Case("of", 0x8)
                          .Case("sf", 0x4)
                          .Case("zf", 0x2)
diff --git a/llvm/test/MC/X86/apx/ccmp-att.s b/llvm/test/MC/X86/apx/ccmp-att.s
index 0b78562f32e18e..405071b0f4310f 100644
--- a/llvm/test/MC/X86/apx/ccmp-att.s
+++ b/llvm/test/MC/X86/apx/ccmp-att.s
@@ -1,7 +1,7 @@
 # RUN: llvm-mc -triple x86_64 -show-encoding %s | FileCheck %s
 # RUN: not llvm-mc -triple i386 -show-encoding %s 2>&1 | FileCheck %s --check-prefix=ERROR
 
-# ERROR-COUNT-401: error:
+# ERROR-COUNT-402: error:
 # ERROR-NOT: error:
 ## Condition flags
 
@@ -1211,3 +1211,9 @@
 # CHECK: ccmpeq {dfv=of} %r9, %r15
 # CHECK: encoding: [0x62,0x54,0xc4,0x04,0x39,0xcf]
          ccmpeq {dfv=of} %r9, %r15
+
+## Case sensitive
+
+# CHECK: ccmpoq {dfv=of,sf,zf,cf} %rax, %rbx
+# CHECK: encoding: [0x62,0xf4,0xfc,0x00,0x39,0xc3]
+         ccmpoq {dFV=Cf,zF,SF,of} %rax, %rbx
diff --git a/llvm/test/MC/X86/apx/ccmp-intel.s b/llvm/test/MC/X86/apx/ccmp-intel.s
index 095f7fb71b7c84..2d446b053d94e0 100644
--- a/llvm/test/MC/X86/apx/ccmp-intel.s
+++ b/llvm/test/MC/X86/apx/ccmp-intel.s
@@ -1208,3 +1208,9 @@
 # CHECK: ccmpe {dfv=of} r15, r9
 # CHECK: encoding: [0x62,0x54,0xc4,0x04,0x39,0xcf]
          ccmpe {dfv=of} r15, r9
+
+## Case sensitive
+
+# CHECK: ccmpo {dfv=of,sf,zf,cf} rbx, rax
+# CHECK: encoding: [0x62,0xf4,0xfc,0x00,0x39,0xc3]
+         ccmpo {DFv=Cf,zF,SF,of} rbx, rax