diff --git a/llvm/include/llvm/CodeGen/TargetLowering.h b/llvm/include/llvm/CodeGen/TargetLowering.h
--- a/llvm/include/llvm/CodeGen/TargetLowering.h
+++ b/llvm/include/llvm/CodeGen/TargetLowering.h
@@ -4202,6 +4202,10 @@
   virtual unsigned getInlineAsmMemConstraint(StringRef ConstraintCode) const {
     if (ConstraintCode == "m")
       return InlineAsm::Constraint_m;
+    if (ConstraintCode == "o")
+      return InlineAsm::Constraint_o;
+    if (ConstraintCode == "X")
+      return InlineAsm::Constraint_X;
     return InlineAsm::Constraint_Unknown;
   }
 
diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.h b/llvm/lib/Target/AArch64/AArch64ISelLowering.h
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.h
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.h
@@ -1027,8 +1027,6 @@
   unsigned getInlineAsmMemConstraint(StringRef ConstraintCode) const override {
     if (ConstraintCode == "Q")
       return InlineAsm::Constraint_Q;
-    if (ConstraintCode == "o")
-      return InlineAsm::Constraint_o;
     // FIXME: clang has code for 'Ump', 'Utf', 'Usa', and 'Ush' but these are
     //        followed by llvm_unreachable so we'll leave them unimplemented in
     //        the backend for now.
diff --git a/llvm/lib/Target/ARM/ARMISelLowering.h b/llvm/lib/Target/ARM/ARMISelLowering.h
--- a/llvm/lib/Target/ARM/ARMISelLowering.h
+++ b/llvm/lib/Target/ARM/ARMISelLowering.h
@@ -514,8 +514,6 @@
     getInlineAsmMemConstraint(StringRef ConstraintCode) const override {
       if (ConstraintCode == "Q")
         return InlineAsm::Constraint_Q;
-      else if (ConstraintCode == "o")
-        return InlineAsm::Constraint_o;
       else if (ConstraintCode.size() == 2) {
         if (ConstraintCode[0] == 'U') {
           switch(ConstraintCode[1]) {
diff --git a/llvm/lib/Target/Hexagon/HexagonISelLowering.h b/llvm/lib/Target/Hexagon/HexagonISelLowering.h
--- a/llvm/lib/Target/Hexagon/HexagonISelLowering.h
+++ b/llvm/lib/Target/Hexagon/HexagonISelLowering.h
@@ -278,13 +278,6 @@
   getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
                                StringRef Constraint, MVT VT) const override;
 
-  unsigned
-  getInlineAsmMemConstraint(StringRef ConstraintCode) const override {
-    if (ConstraintCode == "o")
-      return InlineAsm::Constraint_o;
-    return TargetLowering::getInlineAsmMemConstraint(ConstraintCode);
-  }
-
   // Intrinsics
   SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG) const;
   SDValue LowerINTRINSIC_VOID(SDValue Op, SelectionDAG &DAG) const;
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.h b/llvm/lib/Target/PowerPC/PPCISelLowering.h
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.h
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.h
@@ -889,8 +889,6 @@
     getInlineAsmMemConstraint(StringRef ConstraintCode) const override {
       if (ConstraintCode == "es")
         return InlineAsm::Constraint_es;
-      else if (ConstraintCode == "o")
-        return InlineAsm::Constraint_o;
       else if (ConstraintCode == "Q")
         return InlineAsm::Constraint_Q;
       else if (ConstraintCode == "Z")
diff --git a/llvm/lib/Target/Sparc/SparcISelLowering.h b/llvm/lib/Target/Sparc/SparcISelLowering.h
--- a/llvm/lib/Target/Sparc/SparcISelLowering.h
+++ b/llvm/lib/Target/Sparc/SparcISelLowering.h
@@ -82,13 +82,6 @@
                                       std::vector<SDValue> &Ops,
                                       SelectionDAG &DAG) const override;
 
-    unsigned
-    getInlineAsmMemConstraint(StringRef ConstraintCode) const override {
-      if (ConstraintCode == "o")
-        return InlineAsm::Constraint_o;
-      return TargetLowering::getInlineAsmMemConstraint(ConstraintCode);
-    }
-
     std::pair<unsigned, const TargetRegisterClass *>
     getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
                                  StringRef Constraint, MVT VT) const override;
diff --git a/llvm/lib/Target/X86/X86ISelLowering.h b/llvm/lib/Target/X86/X86ISelLowering.h
--- a/llvm/lib/Target/X86/X86ISelLowering.h
+++ b/llvm/lib/Target/X86/X86ISelLowering.h
@@ -1118,12 +1118,8 @@
 
     unsigned
     getInlineAsmMemConstraint(StringRef ConstraintCode) const override {
-      if (ConstraintCode == "o")
-        return InlineAsm::Constraint_o;
-      else if (ConstraintCode == "v")
+      if (ConstraintCode == "v")
         return InlineAsm::Constraint_v;
-      else if (ConstraintCode == "X")
-        return InlineAsm::Constraint_X;
       return TargetLowering::getInlineAsmMemConstraint(ConstraintCode);
     }