diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 0543c211c4971f..bfc2273c9425cf 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -2050,8 +2050,15 @@ SDValue SelectionDAGLegalize::ExpandSPLAT_VECTOR(SDNode *Node) {
 std::pair<SDValue, SDValue> SelectionDAGLegalize::ExpandLibCall(RTLIB::Libcall LC, SDNode *Node,
                                             TargetLowering::ArgListTy &&Args,
                                             bool isSigned) {
-  SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC),
-                                         TLI.getPointerTy(DAG.getDataLayout()));
+  EVT CodePtrTy = TLI.getPointerTy(DAG.getDataLayout());
+  SDValue Callee;
+  if (const char *LibcallName = TLI.getLibcallName(LC))
+    Callee = DAG.getExternalSymbol(LibcallName, CodePtrTy);
+  else {
+    Callee = DAG.getUNDEF(CodePtrTy);
+    DAG.getContext()->emitError(Twine("no libcall available for ") +
+                                Node->getOperationName(&DAG));
+  }
 
   EVT RetVT = Node->getValueType(0);
   Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext());
diff --git a/llvm/lib/CodeGen/TargetLoweringBase.cpp b/llvm/lib/CodeGen/TargetLoweringBase.cpp
index 09b70cfb72278f..82a59918b085b3 100644
--- a/llvm/lib/CodeGen/TargetLoweringBase.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringBase.cpp
@@ -227,6 +227,34 @@ void TargetLoweringBase::InitLibcalls(const Triple &TT) {
                               CallingConv::ARM_AAPCS_VFP);
       }
     }
+
+    switch (TT.getOS()) {
+    case Triple::MacOSX:
+      if (TT.isMacOSXVersionLT(10, 9)) {
+        setLibcallName(RTLIB::EXP10_F32, nullptr);
+        setLibcallName(RTLIB::EXP10_F64, nullptr);
+      } else {
+        setLibcallName(RTLIB::EXP10_F32, "__exp10f");
+        setLibcallName(RTLIB::EXP10_F64, "__exp10");
+      }
+      break;
+    case Triple::IOS:
+    case Triple::TvOS:
+    case Triple::WatchOS:
+    case Triple::XROS:
+      if (!TT.isWatchOS() &&
+          (TT.isOSVersionLT(7, 0) || (TT.isOSVersionLT(9, 0) && TT.isX86()))) {
+        setLibcallName(RTLIB::EXP10_F32, nullptr);
+        setLibcallName(RTLIB::EXP10_F64, nullptr);
+      } else {
+        setLibcallName(RTLIB::EXP10_F32, "__exp10f");
+        setLibcallName(RTLIB::EXP10_F64, "__exp10");
+      }
+
+      break;
+    default:
+      break;
+    }
   } else {
     setLibcallName(RTLIB::FPEXT_F16_F32, "__gnu_h2f_ieee");
     setLibcallName(RTLIB::FPROUND_F32_F16, "__gnu_f2h_ieee");
diff --git a/llvm/test/CodeGen/AArch64/exp10-libcall-names.ll b/llvm/test/CodeGen/AArch64/exp10-libcall-names.ll
new file mode 100644
index 00000000000000..1220aec447abda
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/exp10-libcall-names.ll
@@ -0,0 +1,39 @@
+; RUN: llc -mtriple=aarch64-linux-gnu < %s | FileCheck -check-prefix=LINUX %s
+; RUN: llc -mtriple=aarch64-apple-macos10.9 < %s | FileCheck -check-prefix=APPLE %s
+; RUN: llc -mtriple=aarch64-apple-ios7.0 < %s | FileCheck -check-prefix=APPLE %s
+; RUN: llc -mtriple=aarch64-apple-tvos7.0 < %s | FileCheck -check-prefix=APPLE %s
+; RUN: llc -mtriple=aarch64-apple-watchos7.0 < %s | FileCheck -check-prefix=APPLE %s
+; RUN: llc -mtriple=aarch64-apple-xros7.0 < %s | FileCheck -check-prefix=APPLE %s
+
+; RUN: not llc -mtriple=aarch64-apple-macos10.8 -filetype=null %s 2>&1 | FileCheck -check-prefix=ERR %s
+; RUN: not llc -mtriple=aarch64-apple-ios6.0 -filetype=null %s 2>&1 | FileCheck -check-prefix=ERR %s
+; RUN: not llc -mtriple=aarch64-apple-tvos6.0 -filetype=null %s 2>&1 | FileCheck -check-prefix=ERR %s
+; RUN: not llc -mtriple=aarch64-apple-xros6.0 -filetype=null %s 2>&1 | FileCheck -check-prefix=ERR %s
+
+; Check exp10/exp10f is emitted as __exp10/__exp10f on assorted systems.
+
+; ERR: no libcall available for fexp10
+
+define float @test_exp10_f32(float %x) {
+; LINUX-LABEL: test_exp10_f32:
+; LINUX:       // %bb.0:
+; LINUX-NEXT:    b exp10f
+;
+; APPLE-LABEL: test_exp10_f32:
+; APPLE:       ; %bb.0:
+; APPLE-NEXT:    b ___exp10f
+  %ret = call float @llvm.exp10.f32(float %x)
+  ret float %ret
+}
+
+define double @test_exp10_f64(double %x) {
+; LINUX-LABEL: test_exp10_f64:
+; LINUX:       // %bb.0:
+; LINUX-NEXT:    b exp10
+;
+; APPLE-LABEL: test_exp10_f64:
+; APPLE:       ; %bb.0:
+; APPLE-NEXT:    b ___exp10
+  %ret = call double @llvm.exp10.f64(double %x)
+  ret double %ret
+}
diff --git a/llvm/test/CodeGen/ARM/exp10-libcall-names.ll b/llvm/test/CodeGen/ARM/exp10-libcall-names.ll
new file mode 100644
index 00000000000000..0ac68b3e8c4662
--- /dev/null
+++ b/llvm/test/CodeGen/ARM/exp10-libcall-names.ll
@@ -0,0 +1,39 @@
+; RUN: llc -mtriple=armv7-linux-gnu < %s | FileCheck -check-prefix=LINUX %s
+; RUN: llc -mtriple=armv7-apple-macos10.9 < %s | FileCheck -check-prefix=APPLE %s
+; RUN: llc -mtriple=armv7-apple-ios7.0 < %s | FileCheck -check-prefix=APPLE %s
+; RUN: llc -mtriple=armv7-apple-tvos7.0 < %s | FileCheck -check-prefix=APPLE %s
+; RUN: llc -mtriple=armv7-apple-watchos7.0 < %s | FileCheck -check-prefix=APPLE %s
+; RUN: llc -mtriple=armv7-apple-xros7.0 < %s | FileCheck -check-prefix=APPLE %s
+
+; RUN: not llc -mtriple=armv7-apple-macos10.8 -filetype=null %s 2>&1 | FileCheck -check-prefix=ERR %s
+; RUN: not llc -mtriple=armv7-apple-ios6.0 -filetype=null %s 2>&1 | FileCheck -check-prefix=ERR %s
+; RUN: not llc -mtriple=armv7-apple-tvos6.0 -filetype=null %s 2>&1 | FileCheck -check-prefix=ERR %s
+; RUN: not llc -mtriple=armv7-apple-xros6.0 -filetype=null %s 2>&1 | FileCheck -check-prefix=ERR %s
+
+; Check exp10/exp10f is emitted as __exp10/__exp10f on assorted systems.
+
+; ERR: no libcall available for fexp10
+
+define float @test_exp10_f32(float %x) {
+; LINUX-LABEL: test_exp10_f32:
+; LINUX:       @ %bb.0:
+; LINUX-NEXT:    b exp10f
+;
+; APPLE-LABEL: test_exp10_f32:
+; APPLE:       @ %bb.0:
+; APPLE-NEXT:    b ___exp10f
+  %ret = call float @llvm.exp10.f32(float %x)
+  ret float %ret
+}
+
+define double @test_exp10_f64(double %x) {
+; LINUX-LABEL: test_exp10_f64:
+; LINUX:       @ %bb.0:
+; LINUX-NEXT:    b exp10
+;
+; APPLE-LABEL: test_exp10_f64:
+; APPLE:       @ %bb.0:
+; APPLE-NEXT:    b ___exp10
+  %ret = call double @llvm.exp10.f64(double %x)
+  ret double %ret
+}
diff --git a/llvm/test/CodeGen/X86/exp10-libcall-names.ll b/llvm/test/CodeGen/X86/exp10-libcall-names.ll
new file mode 100644
index 00000000000000..ce26a0e738e90a
--- /dev/null
+++ b/llvm/test/CodeGen/X86/exp10-libcall-names.ll
@@ -0,0 +1,40 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 4
+; RUN: llc -mtriple=x86_64-linux-gnu < %s | FileCheck -check-prefix=LINUX %s
+; RUN: llc -mtriple=x86_64-apple-macos10.9 < %s | FileCheck -check-prefix=APPLE %s
+; RUN: llc -mtriple=x86_64-apple-ios9.0 < %s | FileCheck -check-prefix=APPLE %s
+; RUN: llc -mtriple=x86_64-apple-tvos9.0 < %s | FileCheck -check-prefix=APPLE %s
+; RUN: llc -mtriple=x86_64-apple-watchos9.0 < %s | FileCheck -check-prefix=APPLE %s
+; RUN: llc -mtriple=x86_64-apple-xros9.0 < %s | FileCheck -check-prefix=APPLE %s
+
+; RUN: not llc -mtriple=x86_64-apple-macos10.8 -filetype=null %s 2>&1 | FileCheck -check-prefix=ERR %s
+; RUN: not llc -mtriple=x86_64-apple-ios8.0 -filetype=null %s 2>&1 | FileCheck -check-prefix=ERR %s
+; RUN: not llc -mtriple=x86_64-apple-tvos8.0 -filetype=null %s 2>&1 | FileCheck -check-prefix=ERR %s
+; RUN: not llc -mtriple=x86_64-apple-xros8.0 -filetype=null %s 2>&1 | FileCheck -check-prefix=ERR %s
+
+; Check exp10/exp10f is emitted as __exp10/__exp10f on assorted systems.
+
+; ERR: no libcall available for fexp10
+
+define float @test_exp10_f32(float %x) {
+; LINUX-LABEL: test_exp10_f32:
+; LINUX:       # %bb.0:
+; LINUX-NEXT:    jmp exp10f@PLT # TAILCALL
+;
+; APPLE-LABEL: test_exp10_f32:
+; APPLE:       ## %bb.0:
+; APPLE-NEXT:    jmp ___exp10f ## TAILCALL
+  %ret = call float @llvm.exp10.f32(float %x)
+  ret float %ret
+}
+
+define double @test_exp10_f64(double %x) {
+; LINUX-LABEL: test_exp10_f64:
+; LINUX:       # %bb.0:
+; LINUX-NEXT:    jmp exp10@PLT # TAILCALL
+;
+; APPLE-LABEL: test_exp10_f64:
+; APPLE:       ## %bb.0:
+; APPLE-NEXT:    jmp ___exp10 ## TAILCALL
+  %ret = call double @llvm.exp10.f64(double %x)
+  ret double %ret
+}