diff --git a/llvm/include/llvm/CodeGen/RuntimeLibcalls.def b/llvm/include/llvm/CodeGen/RuntimeLibcalls.def
index 4facc90635f7..7ed90d959f01 100644
--- a/llvm/include/llvm/CodeGen/RuntimeLibcalls.def
+++ b/llvm/include/llvm/CodeGen/RuntimeLibcalls.def
@@ -251,6 +251,7 @@ HANDLE_LIBCALL(FMAX_PPCF128, "fmaxl")
 // Conversion
 HANDLE_LIBCALL(FPEXT_F32_PPCF128, "__gcc_stoq")
 HANDLE_LIBCALL(FPEXT_F64_PPCF128, "__gcc_dtoq")
+HANDLE_LIBCALL(FPEXT_F80_F128, "__extendxftf2")
 HANDLE_LIBCALL(FPEXT_F64_F128, "__extenddftf2")
 HANDLE_LIBCALL(FPEXT_F32_F128, "__extendsftf2")
 HANDLE_LIBCALL(FPEXT_F32_F64, "__extendsfdf2")
@@ -267,6 +268,7 @@ HANDLE_LIBCALL(FPROUND_PPCF128_F32, "__gcc_qtos")
 HANDLE_LIBCALL(FPROUND_F80_F64, "__truncxfdf2")
 HANDLE_LIBCALL(FPROUND_F128_F64, "__trunctfdf2")
 HANDLE_LIBCALL(FPROUND_PPCF128_F64, "__gcc_qtod")
+HANDLE_LIBCALL(FPROUND_F128_F80, "__trunctfxf2")
 HANDLE_LIBCALL(FPTOSINT_F32_I32, "__fixsfsi")
 HANDLE_LIBCALL(FPTOSINT_F32_I64, "__fixsfdi")
 HANDLE_LIBCALL(FPTOSINT_F32_I128, "__fixsfti")
diff --git a/llvm/lib/CodeGen/TargetLoweringBase.cpp b/llvm/lib/CodeGen/TargetLoweringBase.cpp
index b29a33ac1c14..4dcb705934c5 100644
--- a/llvm/lib/CodeGen/TargetLoweringBase.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringBase.cpp
@@ -192,6 +192,9 @@ RTLIB::Libcall RTLIB::getFPEXT(EVT OpVT, EVT RetVT) {
       return FPEXT_F64_F128;
     else if (RetVT == MVT::ppcf128)
       return FPEXT_F64_PPCF128;
+  } else if (OpVT == MVT::f80) {
+    if (RetVT == MVT::f128)
+      return FPEXT_F80_F128;
   }
 
   return UNKNOWN_LIBCALL;
@@ -227,6 +230,9 @@ RTLIB::Libcall RTLIB::getFPROUND(EVT OpVT, EVT RetVT) {
       return FPROUND_F128_F64;
     if (OpVT == MVT::ppcf128)
       return FPROUND_PPCF128_F64;
+  } else if (RetVT == MVT::f80) {
+    if (OpVT == MVT::f128)
+      return FPROUND_F128_F80;
   }
 
   return UNKNOWN_LIBCALL;
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyRuntimeLibcallSignatures.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyRuntimeLibcallSignatures.cpp
index 18d914f01339..46a937561ce1 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyRuntimeLibcallSignatures.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyRuntimeLibcallSignatures.cpp
@@ -309,6 +309,7 @@ RuntimeLibcallSignatures[RTLIB::UNKNOWN_LIBCALL] = {
 // CONVERSION
 /* FPEXT_F32_PPCF128 */ unsupported,
 /* FPEXT_F64_PPCF128 */ unsupported,
+/* FPEXT_F80_F128 */ unsupported,
 /* FPEXT_F64_F128 */ func_iPTR_f64,
 /* FPEXT_F32_F128 */ func_iPTR_f32,
 /* FPEXT_F32_F64 */ f64_func_f32,
@@ -325,6 +326,7 @@ RuntimeLibcallSignatures[RTLIB::UNKNOWN_LIBCALL] = {
 /* FPROUND_F80_F64 */ unsupported,
 /* FPROUND_F128_F64 */ f64_func_i64_i64,
 /* FPROUND_PPCF128_F64 */ unsupported,
+/* FPROUND_F128_F80 */ unsupported,
 /* FPTOSINT_F32_I32 */ i32_func_f32,
 /* FPTOSINT_F32_I64 */ i64_func_f32,
 /* FPTOSINT_F32_I128 */ i64_i64_func_f32,
@@ -804,6 +806,7 @@ RuntimeLibcallNames[RTLIB::UNKNOWN_LIBCALL] = {
 /* FMAX_PPCF128 */ nullptr,
 /* FPEXT_F32_PPCF128 */ nullptr,
 /* FPEXT_F64_PPCF128 */ nullptr,
+/* FPEXT_F80_F128 */ nullptr,
 /* FPEXT_F64_F128 */ "__extenddftf2",
 /* FPEXT_F32_F128 */ "__extendsftf2",
 /* FPEXT_F32_F64 */ "__extendsfdf2",
@@ -820,6 +823,7 @@ RuntimeLibcallNames[RTLIB::UNKNOWN_LIBCALL] = {
 /* FPROUND_F80_F64 */ "__truncxfdf2",
 /* FPROUND_F128_F64 */ "__trunctfdf2",
 /* FPROUND_PPCF128_F64 */ nullptr,
+/* FPROUND_F128_F80 */ nullptr,
 /* FPTOSINT_F32_I32 */ "__fixsfsi",
 /* FPTOSINT_F32_I64 */ "__fixsfdi",
 /* FPTOSINT_F32_I128 */ "__fixsfti",
diff --git a/llvm/test/CodeGen/X86/fp128-cast.ll b/llvm/test/CodeGen/X86/fp128-cast.ll
index 3e49f6715081..bfcc18d54a17 100644
--- a/llvm/test/CodeGen/X86/fp128-cast.ll
+++ b/llvm/test/CodeGen/X86/fp128-cast.ll
@@ -12,6 +12,7 @@
 @vu64 = common global i64 0, align 8
 @vf32 = common global float 0.000000e+00, align 4
 @vf64 = common global double 0.000000e+00, align 8
+@vf80 = common global x86_fp80 0xK00000000000000000000, align 8
 @vf128 = common global fp128 0xL00000000000000000000000000000000, align 16
 
 define void @TestFPExtF32_F128() {
@@ -52,6 +53,19 @@ entry:
 ; X64:       ret
 }
 
+define void @TestFPExtF80_F128() {
+entry:
+  %0 = load x86_fp80, x86_fp80* @vf80, align 8
+  %conv = fpext x86_fp80 %0 to fp128
+  store fp128 %conv, fp128* @vf128, align 16
+  ret void
+; X32-LABEL: TestFPExtF80_F128:
+; X32:       calll __extendxftf2
+;
+; X64-LABEL: TestFPExtF80_F128:
+; X64:       callq __extendxftf2
+}
+
 define void @TestFPToSIF128_I32() {
 entry:
   %0 = load fp128, fp128* @vf128, align 16
@@ -160,6 +174,19 @@ entry:
 ; X64:       retq
 }
 
+define void @TestFPTruncF128_F80() {
+entry:
+  %0 = load fp128, fp128* @vf128, align 16
+  %conv = fptrunc fp128 %0 to x86_fp80
+  store x86_fp80 %conv, x86_fp80* @vf80, align 8
+  ret void
+; X32-LABEL: TestFPTruncF128_F80:
+; X32:       calll      __trunctfxf2
+;
+; X64-LABEL: TestFPTruncF128_F80:
+; X64:       callq      __trunctfxf2
+}
+
 define void @TestSIToFPI32_F128() {
 entry:
   %0 = load i32, i32* @vi32, align 4