diff --git a/llvm/include/llvm/IR/RuntimeLibcalls.def b/llvm/include/llvm/IR/RuntimeLibcalls.def
index 5e17ed6418461..fe2c32e3c975e 100644
--- a/llvm/include/llvm/IR/RuntimeLibcalls.def
+++ b/llvm/include/llvm/IR/RuntimeLibcalls.def
@@ -386,10 +386,6 @@ HANDLE_LIBCALL(UO_F32, "__unordsf2")
 HANDLE_LIBCALL(UO_F64, "__unorddf2")
 HANDLE_LIBCALL(UO_F128, "__unordtf2")
 HANDLE_LIBCALL(UO_PPCF128, "__gcc_qunord")
-HANDLE_LIBCALL(O_F32, "__unordsf2")
-HANDLE_LIBCALL(O_F64, "__unorddf2")
-HANDLE_LIBCALL(O_F128, "__unordtf2")
-HANDLE_LIBCALL(O_PPCF128, "__gcc_qunord")
 
 // Memory
 HANDLE_LIBCALL(MEMCPY, "memcpy")
diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 329d101476f35..d37a733d242ec 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -344,16 +344,14 @@ void TargetLowering::softenSetCCOperands(SelectionDAG &DAG, EVT VT,
           (VT == MVT::f64) ? RTLIB::OGT_F64 :
           (VT == MVT::f128) ? RTLIB::OGT_F128 : RTLIB::OGT_PPCF128;
     break;
+  case ISD::SETO:
+    ShouldInvertCC = true;
+    LLVM_FALLTHROUGH;
   case ISD::SETUO:
     LC1 = (VT == MVT::f32) ? RTLIB::UO_F32 :
           (VT == MVT::f64) ? RTLIB::UO_F64 :
           (VT == MVT::f128) ? RTLIB::UO_F128 : RTLIB::UO_PPCF128;
     break;
-  case ISD::SETO:
-    LC1 = (VT == MVT::f32) ? RTLIB::O_F32 :
-          (VT == MVT::f64) ? RTLIB::O_F64 :
-          (VT == MVT::f128) ? RTLIB::O_F128 : RTLIB::O_PPCF128;
-    break;
   case ISD::SETONE:
     // SETONE = O && UNE
     ShouldInvertCC = true;
diff --git a/llvm/lib/CodeGen/TargetLoweringBase.cpp b/llvm/lib/CodeGen/TargetLoweringBase.cpp
index 0fa10c113750f..e5a7b70d82c85 100644
--- a/llvm/lib/CodeGen/TargetLoweringBase.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringBase.cpp
@@ -156,7 +156,6 @@ void TargetLoweringBase::InitLibcalls(const Triple &TT) {
     setLibcallName(RTLIB::OLE_F128, "__lekf2");
     setLibcallName(RTLIB::OGT_F128, "__gtkf2");
     setLibcallName(RTLIB::UO_F128, "__unordkf2");
-    setLibcallName(RTLIB::O_F128, "__unordkf2");
   }
 
   // A few names are different on particular architectures or environments.
@@ -564,10 +563,6 @@ static void InitCmpLibcallCCs(ISD::CondCode *CCs) {
   CCs[RTLIB::UO_F64] = ISD::SETNE;
   CCs[RTLIB::UO_F128] = ISD::SETNE;
   CCs[RTLIB::UO_PPCF128] = ISD::SETNE;
-  CCs[RTLIB::O_F32] = ISD::SETEQ;
-  CCs[RTLIB::O_F64] = ISD::SETEQ;
-  CCs[RTLIB::O_F128] = ISD::SETEQ;
-  CCs[RTLIB::O_PPCF128] = ISD::SETEQ;
 }
 
 /// NOTE: The TargetMachine owns TLOF.
diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index 00a1a45b4ef3c..cf738cd664346 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -466,7 +466,6 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
         { RTLIB::OGE_F32, "__gesf2vfp",    ISD::SETNE },
         { RTLIB::OGT_F32, "__gtsf2vfp",    ISD::SETNE },
         { RTLIB::UO_F32,  "__unordsf2vfp", ISD::SETNE },
-        { RTLIB::O_F32,   "__unordsf2vfp", ISD::SETEQ },
 
         // Double-precision comparisons.
         { RTLIB::OEQ_F64, "__eqdf2vfp",    ISD::SETNE },
@@ -476,7 +475,6 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
         { RTLIB::OGE_F64, "__gedf2vfp",    ISD::SETNE },
         { RTLIB::OGT_F64, "__gtdf2vfp",    ISD::SETNE },
         { RTLIB::UO_F64,  "__unorddf2vfp", ISD::SETNE },
-        { RTLIB::O_F64,   "__unorddf2vfp", ISD::SETEQ },
 
         // Floating-point to integer conversions.
         // i64 conversions are done via library routines even when generating VFP
@@ -540,7 +538,6 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
       { RTLIB::OGE_F64, "__aeabi_dcmpge", CallingConv::ARM_AAPCS, ISD::SETNE },
       { RTLIB::OGT_F64, "__aeabi_dcmpgt", CallingConv::ARM_AAPCS, ISD::SETNE },
       { RTLIB::UO_F64,  "__aeabi_dcmpun", CallingConv::ARM_AAPCS, ISD::SETNE },
-      { RTLIB::O_F64,   "__aeabi_dcmpun", CallingConv::ARM_AAPCS, ISD::SETEQ },
 
       // Single-precision floating-point arithmetic helper functions
       // RTABI chapter 4.1.2, Table 4
@@ -558,7 +555,6 @@ ARMTargetLowering::ARMTargetLowering(const TargetMachine &TM,
       { RTLIB::OGE_F32, "__aeabi_fcmpge", CallingConv::ARM_AAPCS, ISD::SETNE },
       { RTLIB::OGT_F32, "__aeabi_fcmpgt", CallingConv::ARM_AAPCS, ISD::SETNE },
       { RTLIB::UO_F32,  "__aeabi_fcmpun", CallingConv::ARM_AAPCS, ISD::SETNE },
-      { RTLIB::O_F32,   "__aeabi_fcmpun", CallingConv::ARM_AAPCS, ISD::SETEQ },
 
       // Floating-point to integer conversions.
       // RTABI chapter 4.1.2, Table 6
diff --git a/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp b/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp
index b758046e0f3a9..e2dff51ea61c0 100644
--- a/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMLegalizerInfo.cpp
@@ -264,7 +264,7 @@ void ARMLegalizerInfo::setFCmpLibcallsAEABI() {
       {RTLIB::OLE_F32, CmpInst::BAD_ICMP_PREDICATE}};
   FCmp32Libcalls[CmpInst::FCMP_OLT] = {
       {RTLIB::OLT_F32, CmpInst::BAD_ICMP_PREDICATE}};
-  FCmp32Libcalls[CmpInst::FCMP_ORD] = {{RTLIB::O_F32, CmpInst::ICMP_EQ}};
+  FCmp32Libcalls[CmpInst::FCMP_ORD] = {{RTLIB::UO_F32, CmpInst::ICMP_EQ}};
   FCmp32Libcalls[CmpInst::FCMP_UGE] = {{RTLIB::OLT_F32, CmpInst::ICMP_EQ}};
   FCmp32Libcalls[CmpInst::FCMP_UGT] = {{RTLIB::OLE_F32, CmpInst::ICMP_EQ}};
   FCmp32Libcalls[CmpInst::FCMP_ULE] = {{RTLIB::OGT_F32, CmpInst::ICMP_EQ}};
@@ -290,7 +290,7 @@ void ARMLegalizerInfo::setFCmpLibcallsAEABI() {
       {RTLIB::OLE_F64, CmpInst::BAD_ICMP_PREDICATE}};
   FCmp64Libcalls[CmpInst::FCMP_OLT] = {
       {RTLIB::OLT_F64, CmpInst::BAD_ICMP_PREDICATE}};
-  FCmp64Libcalls[CmpInst::FCMP_ORD] = {{RTLIB::O_F64, CmpInst::ICMP_EQ}};
+  FCmp64Libcalls[CmpInst::FCMP_ORD] = {{RTLIB::UO_F64, CmpInst::ICMP_EQ}};
   FCmp64Libcalls[CmpInst::FCMP_UGE] = {{RTLIB::OLT_F64, CmpInst::ICMP_EQ}};
   FCmp64Libcalls[CmpInst::FCMP_UGT] = {{RTLIB::OLE_F64, CmpInst::ICMP_EQ}};
   FCmp64Libcalls[CmpInst::FCMP_ULE] = {{RTLIB::OGT_F64, CmpInst::ICMP_EQ}};
@@ -315,7 +315,7 @@ void ARMLegalizerInfo::setFCmpLibcallsGNU() {
   FCmp32Libcalls[CmpInst::FCMP_OGT] = {{RTLIB::OGT_F32, CmpInst::ICMP_SGT}};
   FCmp32Libcalls[CmpInst::FCMP_OLE] = {{RTLIB::OLE_F32, CmpInst::ICMP_SLE}};
   FCmp32Libcalls[CmpInst::FCMP_OLT] = {{RTLIB::OLT_F32, CmpInst::ICMP_SLT}};
-  FCmp32Libcalls[CmpInst::FCMP_ORD] = {{RTLIB::O_F32, CmpInst::ICMP_EQ}};
+  FCmp32Libcalls[CmpInst::FCMP_ORD] = {{RTLIB::UO_F32, CmpInst::ICMP_EQ}};
   FCmp32Libcalls[CmpInst::FCMP_UGE] = {{RTLIB::OLT_F32, CmpInst::ICMP_SGE}};
   FCmp32Libcalls[CmpInst::FCMP_UGT] = {{RTLIB::OLE_F32, CmpInst::ICMP_SGT}};
   FCmp32Libcalls[CmpInst::FCMP_ULE] = {{RTLIB::OGT_F32, CmpInst::ICMP_SLE}};
@@ -333,7 +333,7 @@ void ARMLegalizerInfo::setFCmpLibcallsGNU() {
   FCmp64Libcalls[CmpInst::FCMP_OGT] = {{RTLIB::OGT_F64, CmpInst::ICMP_SGT}};
   FCmp64Libcalls[CmpInst::FCMP_OLE] = {{RTLIB::OLE_F64, CmpInst::ICMP_SLE}};
   FCmp64Libcalls[CmpInst::FCMP_OLT] = {{RTLIB::OLT_F64, CmpInst::ICMP_SLT}};
-  FCmp64Libcalls[CmpInst::FCMP_ORD] = {{RTLIB::O_F64, CmpInst::ICMP_EQ}};
+  FCmp64Libcalls[CmpInst::FCMP_ORD] = {{RTLIB::UO_F64, CmpInst::ICMP_EQ}};
   FCmp64Libcalls[CmpInst::FCMP_UGE] = {{RTLIB::OLT_F64, CmpInst::ICMP_SGE}};
   FCmp64Libcalls[CmpInst::FCMP_UGT] = {{RTLIB::OLE_F64, CmpInst::ICMP_SGT}};
   FCmp64Libcalls[CmpInst::FCMP_ULE] = {{RTLIB::OGT_F64, CmpInst::ICMP_SLE}};
diff --git a/llvm/lib/Target/Mips/Mips16ISelLowering.cpp b/llvm/lib/Target/Mips/Mips16ISelLowering.cpp
index 5a5b78c9d5f97..5425df77d9b8f 100644
--- a/llvm/lib/Target/Mips/Mips16ISelLowering.cpp
+++ b/llvm/lib/Target/Mips/Mips16ISelLowering.cpp
@@ -252,9 +252,6 @@ void Mips16TargetLowering::setMips16HardFloatLibCalls() {
     if (HardFloatLibCalls[I].Libcall != RTLIB::UNKNOWN_LIBCALL)
       setLibcallName(HardFloatLibCalls[I].Libcall, HardFloatLibCalls[I].Name);
   }
-
-  setLibcallName(RTLIB::O_F64, "__mips16_unorddf2");
-  setLibcallName(RTLIB::O_F32, "__mips16_unordsf2");
 }
 
 //
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyRuntimeLibcallSignatures.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyRuntimeLibcallSignatures.cpp
index 7b9ae90326f0f..c6cf7b6bc551a 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyRuntimeLibcallSignatures.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyRuntimeLibcallSignatures.cpp
@@ -316,12 +316,6 @@ struct RuntimeLibcallSignatureTable {
     Table[RTLIB::UO_F32] = i32_func_f32_f32;
     Table[RTLIB::UO_F64] = i32_func_f64_f64;
     Table[RTLIB::UO_F128] = i32_func_i64_i64_i64_i64;
-    // O_FXX has the weird property that it uses the same libcall name as UO_FXX
-    // This breaks our name-based lookup. Fortunately only the UO family of
-    // libcalls appears to be actually used.
-    Table[RTLIB::O_F32] = unsupported;
-    Table[RTLIB::O_F64] = unsupported;
-    Table[RTLIB::O_F128] = unsupported;
 
     // Memory
     Table[RTLIB::MEMCPY] = iPTR_func_iPTR_iPTR_iPTR;