Index: include/clang/Basic/Builtins.def
===================================================================
--- include/clang/Basic/Builtins.def
+++ include/clang/Basic/Builtins.def
@@ -113,14 +113,17 @@
 BUILTIN(__builtin_abs  , "ii"  , "ncF")
 BUILTIN(__builtin_copysign, "ddd", "ncF")
 BUILTIN(__builtin_copysignf, "fff", "ncF")
+BUILTIN(__builtin_copysignf16, "hhh", "ncF")
 BUILTIN(__builtin_copysignl, "LdLdLd", "ncF")
 BUILTIN(__builtin_copysignf128, "LLdLLdLLd", "ncF")
 BUILTIN(__builtin_fabs , "dd"  , "ncF")
 BUILTIN(__builtin_fabsf, "ff"  , "ncF")
 BUILTIN(__builtin_fabsl, "LdLd", "ncF")
+BUILTIN(__builtin_fabsf16, "hh"  , "ncF")
 BUILTIN(__builtin_fabsf128, "LLdLLd", "ncF")
 BUILTIN(__builtin_fmod , "ddd"  , "Fne")
 BUILTIN(__builtin_fmodf, "fff"  , "Fne")
+BUILTIN(__builtin_fmodf16, "hhh"  , "Fne")
 BUILTIN(__builtin_fmodl, "LdLdLd", "Fne")
 BUILTIN(__builtin_frexp , "ddi*"  , "Fn")
 BUILTIN(__builtin_frexpf, "ffi*"  , "Fn")
@@ -154,6 +157,7 @@
 BUILTIN(__builtin_powil, "LdLdi", "Fnc")
 BUILTIN(__builtin_pow , "ddd"  , "Fne")
 BUILTIN(__builtin_powf, "fff"  , "Fne")
+BUILTIN(__builtin_powf16, "hhh"  , "Fne")
 BUILTIN(__builtin_powl, "LdLdLd", "Fne")
 
 // Standard unary libc/libm functions with double/float/long double variants:
@@ -180,9 +184,11 @@
 BUILTIN(__builtin_cbrtl, "LdLd", "Fnc")
 BUILTIN(__builtin_ceil , "dd"  , "Fnc")
 BUILTIN(__builtin_ceilf, "ff"  , "Fnc")
+BUILTIN(__builtin_ceilf16, "hh"  , "Fnc")
 BUILTIN(__builtin_ceill, "LdLd", "Fnc")
 BUILTIN(__builtin_cos , "dd"  , "Fne")
 BUILTIN(__builtin_cosf, "ff"  , "Fne")
+BUILTIN(__builtin_cosf16, "hh"  , "Fne")
 BUILTIN(__builtin_cosh , "dd"  , "Fne")
 BUILTIN(__builtin_coshf, "ff"  , "Fne")
 BUILTIN(__builtin_coshl, "LdLd", "Fne")
@@ -195,9 +201,11 @@
 BUILTIN(__builtin_erfcl, "LdLd", "Fne")
 BUILTIN(__builtin_exp , "dd"  , "Fne")
 BUILTIN(__builtin_expf, "ff"  , "Fne")
+BUILTIN(__builtin_expf16, "hh"  , "Fne")
 BUILTIN(__builtin_expl, "LdLd", "Fne")
 BUILTIN(__builtin_exp2 , "dd"  , "Fne")
 BUILTIN(__builtin_exp2f, "ff"  , "Fne")
+BUILTIN(__builtin_exp2f16, "hh"  , "Fne")
 BUILTIN(__builtin_exp2l, "LdLd", "Fne")
 BUILTIN(__builtin_expm1 , "dd", "Fne")
 BUILTIN(__builtin_expm1f, "ff", "Fne")
@@ -207,15 +215,19 @@
 BUILTIN(__builtin_fdiml, "LdLdLd", "Fne")
 BUILTIN(__builtin_floor , "dd"  , "Fnc")
 BUILTIN(__builtin_floorf, "ff"  , "Fnc")
+BUILTIN(__builtin_floorf16, "hh"  , "Fnc")
 BUILTIN(__builtin_floorl, "LdLd", "Fnc")
 BUILTIN(__builtin_fma, "dddd", "Fne")
 BUILTIN(__builtin_fmaf, "ffff", "Fne")
+BUILTIN(__builtin_fmaf16, "hhhh", "Fne")
 BUILTIN(__builtin_fmal, "LdLdLdLd", "Fne")
 BUILTIN(__builtin_fmax, "ddd", "Fnc")
 BUILTIN(__builtin_fmaxf, "fff", "Fnc")
+BUILTIN(__builtin_fmaxf16, "hhh", "Fnc")
 BUILTIN(__builtin_fmaxl, "LdLdLd", "Fnc")
 BUILTIN(__builtin_fmin, "ddd", "Fnc")
 BUILTIN(__builtin_fminf, "fff", "Fnc")
+BUILTIN(__builtin_fminf16, "hhh", "Fnc")
 BUILTIN(__builtin_fminl, "LdLdLd", "Fnc")
 BUILTIN(__builtin_hypot , "ddd"  , "Fne")
 BUILTIN(__builtin_hypotf, "fff"  , "Fne")
@@ -235,17 +247,20 @@
 BUILTIN(__builtin_log , "dd"  , "Fne")
 BUILTIN(__builtin_log10 , "dd"  , "Fne")
 BUILTIN(__builtin_log10f, "ff"  , "Fne")
+BUILTIN(__builtin_log10f16, "hh"  , "Fne")
 BUILTIN(__builtin_log10l, "LdLd", "Fne")
 BUILTIN(__builtin_log1p , "dd"  , "Fne")
 BUILTIN(__builtin_log1pf, "ff"  , "Fne")
 BUILTIN(__builtin_log1pl, "LdLd", "Fne")
 BUILTIN(__builtin_log2, "dd"  , "Fne")
 BUILTIN(__builtin_log2f, "ff"  , "Fne")
+BUILTIN(__builtin_log2f16, "hh"  , "Fne")
 BUILTIN(__builtin_log2l, "LdLd"  , "Fne")
 BUILTIN(__builtin_logb , "dd", "Fne")
 BUILTIN(__builtin_logbf, "ff", "Fne")
 BUILTIN(__builtin_logbl, "LdLd", "Fne")
 BUILTIN(__builtin_logf, "ff"  , "Fne")
+BUILTIN(__builtin_logf16, "hh"  , "Fne")
 BUILTIN(__builtin_logl, "LdLd", "Fne")
 BUILTIN(__builtin_lrint , "Lid", "Fne")
 BUILTIN(__builtin_lrintf, "Lif", "Fne")
@@ -270,9 +285,11 @@
 BUILTIN(__builtin_remquol, "LdLdLdi*", "Fn")
 BUILTIN(__builtin_rint , "dd", "Fnc")
 BUILTIN(__builtin_rintf, "ff", "Fnc")
+BUILTIN(__builtin_rintf16, "hh", "Fnc")
 BUILTIN(__builtin_rintl, "LdLd", "Fnc")
 BUILTIN(__builtin_round, "dd"  , "Fnc")
 BUILTIN(__builtin_roundf, "ff"  , "Fnc")
+BUILTIN(__builtin_roundf16, "hh"  , "Fnc")
 BUILTIN(__builtin_roundl, "LdLd"  , "Fnc")
 BUILTIN(__builtin_scalbln , "ddLi", "Fne")
 BUILTIN(__builtin_scalblnf, "ffLi", "Fne")
@@ -282,12 +299,14 @@
 BUILTIN(__builtin_scalbnl, "LdLdi", "Fne")
 BUILTIN(__builtin_sin , "dd"  , "Fne")
 BUILTIN(__builtin_sinf, "ff"  , "Fne")
+BUILTIN(__builtin_sinf16, "hh"  , "Fne")
 BUILTIN(__builtin_sinh , "dd"  , "Fne")
 BUILTIN(__builtin_sinhf, "ff"  , "Fne")
 BUILTIN(__builtin_sinhl, "LdLd", "Fne")
 BUILTIN(__builtin_sinl, "LdLd", "Fne")
 BUILTIN(__builtin_sqrt , "dd"  , "Fne")
 BUILTIN(__builtin_sqrtf, "ff"  , "Fne")
+BUILTIN(__builtin_sqrtf16, "hh"  , "Fne")
 BUILTIN(__builtin_sqrtl, "LdLd", "Fne")
 BUILTIN(__builtin_tan , "dd"  , "Fne")
 BUILTIN(__builtin_tanf, "ff"  , "Fne")
@@ -301,6 +320,7 @@
 BUILTIN(__builtin_trunc , "dd", "Fnc")
 BUILTIN(__builtin_truncf, "ff", "Fnc")
 BUILTIN(__builtin_truncl, "LdLd", "Fnc")
+BUILTIN(__builtin_truncf16, "hh", "Fnc")
 
 // C99 complex builtins
 BUILTIN(__builtin_cabs, "dXd", "Fne")
@@ -394,6 +414,7 @@
 // Special FP builtins.
 BUILTIN(__builtin_canonicalize, "dd", "nc")
 BUILTIN(__builtin_canonicalizef, "ff", "nc")
+BUILTIN(__builtin_canonicalizef16, "hh", "nc")
 BUILTIN(__builtin_canonicalizel, "LdLd", "nc")
 
 // Builtins for arithmetic.
Index: lib/CodeGen/CGBuiltin.cpp
===================================================================
--- lib/CodeGen/CGBuiltin.cpp
+++ lib/CodeGen/CGBuiltin.cpp
@@ -1557,6 +1557,7 @@
     case Builtin::BIceill:
     case Builtin::BI__builtin_ceil:
     case Builtin::BI__builtin_ceilf:
+    case Builtin::BI__builtin_ceilf16:
     case Builtin::BI__builtin_ceill:
       return RValue::get(emitUnaryBuiltin(*this, E, Intrinsic::ceil));
 
@@ -1565,6 +1566,7 @@
     case Builtin::BIcopysignl:
     case Builtin::BI__builtin_copysign:
     case Builtin::BI__builtin_copysignf:
+    case Builtin::BI__builtin_copysignf16:
     case Builtin::BI__builtin_copysignl:
     case Builtin::BI__builtin_copysignf128:
       return RValue::get(emitBinaryBuiltin(*this, E, Intrinsic::copysign));
@@ -1574,6 +1576,7 @@
     case Builtin::BIcosl:
     case Builtin::BI__builtin_cos:
     case Builtin::BI__builtin_cosf:
+    case Builtin::BI__builtin_cosf16:
     case Builtin::BI__builtin_cosl:
       return RValue::get(emitUnaryBuiltin(*this, E, Intrinsic::cos));
 
@@ -1582,6 +1585,7 @@
     case Builtin::BIexpl:
     case Builtin::BI__builtin_exp:
     case Builtin::BI__builtin_expf:
+    case Builtin::BI__builtin_expf16:
     case Builtin::BI__builtin_expl:
       return RValue::get(emitUnaryBuiltin(*this, E, Intrinsic::exp));
 
@@ -1590,6 +1594,7 @@
     case Builtin::BIexp2l:
     case Builtin::BI__builtin_exp2:
     case Builtin::BI__builtin_exp2f:
+    case Builtin::BI__builtin_exp2f16:
     case Builtin::BI__builtin_exp2l:
       return RValue::get(emitUnaryBuiltin(*this, E, Intrinsic::exp2));
 
@@ -1598,6 +1603,7 @@
     case Builtin::BIfabsl:
     case Builtin::BI__builtin_fabs:
     case Builtin::BI__builtin_fabsf:
+    case Builtin::BI__builtin_fabsf16:
     case Builtin::BI__builtin_fabsl:
     case Builtin::BI__builtin_fabsf128:
       return RValue::get(emitUnaryBuiltin(*this, E, Intrinsic::fabs));
@@ -1607,6 +1613,7 @@
     case Builtin::BIfloorl:
     case Builtin::BI__builtin_floor:
     case Builtin::BI__builtin_floorf:
+    case Builtin::BI__builtin_floorf16:
     case Builtin::BI__builtin_floorl:
       return RValue::get(emitUnaryBuiltin(*this, E, Intrinsic::floor));
 
@@ -1615,6 +1622,7 @@
     case Builtin::BIfmal:
     case Builtin::BI__builtin_fma:
     case Builtin::BI__builtin_fmaf:
+    case Builtin::BI__builtin_fmaf16:
     case Builtin::BI__builtin_fmal:
       return RValue::get(emitTernaryBuiltin(*this, E, Intrinsic::fma));
 
@@ -1623,6 +1631,7 @@
     case Builtin::BIfmaxl:
     case Builtin::BI__builtin_fmax:
     case Builtin::BI__builtin_fmaxf:
+    case Builtin::BI__builtin_fmaxf16:
     case Builtin::BI__builtin_fmaxl:
       return RValue::get(emitBinaryBuiltin(*this, E, Intrinsic::maxnum));
 
@@ -1631,6 +1640,7 @@
     case Builtin::BIfminl:
     case Builtin::BI__builtin_fmin:
     case Builtin::BI__builtin_fminf:
+    case Builtin::BI__builtin_fminf16:
     case Builtin::BI__builtin_fminl:
       return RValue::get(emitBinaryBuiltin(*this, E, Intrinsic::minnum));
 
@@ -1641,6 +1651,7 @@
     case Builtin::BIfmodl:
     case Builtin::BI__builtin_fmod:
     case Builtin::BI__builtin_fmodf:
+    case Builtin::BI__builtin_fmodf16:
     case Builtin::BI__builtin_fmodl: {
       Value *Arg1 = EmitScalarExpr(E->getArg(0));
       Value *Arg2 = EmitScalarExpr(E->getArg(1));
@@ -1652,6 +1663,7 @@
     case Builtin::BIlogl:
     case Builtin::BI__builtin_log:
     case Builtin::BI__builtin_logf:
+    case Builtin::BI__builtin_logf16:
     case Builtin::BI__builtin_logl:
       return RValue::get(emitUnaryBuiltin(*this, E, Intrinsic::log));
 
@@ -1660,6 +1672,7 @@
     case Builtin::BIlog10l:
     case Builtin::BI__builtin_log10:
     case Builtin::BI__builtin_log10f:
+    case Builtin::BI__builtin_log10f16:
     case Builtin::BI__builtin_log10l:
       return RValue::get(emitUnaryBuiltin(*this, E, Intrinsic::log10));
 
@@ -1668,6 +1681,7 @@
     case Builtin::BIlog2l:
     case Builtin::BI__builtin_log2:
     case Builtin::BI__builtin_log2f:
+    case Builtin::BI__builtin_log2f16:
     case Builtin::BI__builtin_log2l:
       return RValue::get(emitUnaryBuiltin(*this, E, Intrinsic::log2));
 
@@ -1684,6 +1698,7 @@
     case Builtin::BIpowl:
     case Builtin::BI__builtin_pow:
     case Builtin::BI__builtin_powf:
+    case Builtin::BI__builtin_powf16:
     case Builtin::BI__builtin_powl:
       return RValue::get(emitBinaryBuiltin(*this, E, Intrinsic::pow));
 
@@ -1692,6 +1707,7 @@
     case Builtin::BIrintl:
     case Builtin::BI__builtin_rint:
     case Builtin::BI__builtin_rintf:
+    case Builtin::BI__builtin_rintf16:
     case Builtin::BI__builtin_rintl:
       return RValue::get(emitUnaryBuiltin(*this, E, Intrinsic::rint));
 
@@ -1700,6 +1716,7 @@
     case Builtin::BIroundl:
     case Builtin::BI__builtin_round:
     case Builtin::BI__builtin_roundf:
+    case Builtin::BI__builtin_roundf16:
     case Builtin::BI__builtin_roundl:
       return RValue::get(emitUnaryBuiltin(*this, E, Intrinsic::round));
 
@@ -1708,6 +1725,7 @@
     case Builtin::BIsinl:
     case Builtin::BI__builtin_sin:
     case Builtin::BI__builtin_sinf:
+    case Builtin::BI__builtin_sinf16:
     case Builtin::BI__builtin_sinl:
       return RValue::get(emitUnaryBuiltin(*this, E, Intrinsic::sin));
 
@@ -1716,6 +1734,7 @@
     case Builtin::BIsqrtl:
     case Builtin::BI__builtin_sqrt:
     case Builtin::BI__builtin_sqrtf:
+    case Builtin::BI__builtin_sqrtf16:
     case Builtin::BI__builtin_sqrtl:
       return RValue::get(emitUnaryBuiltin(*this, E, Intrinsic::sqrt));
 
@@ -1724,6 +1743,7 @@
     case Builtin::BItruncl:
     case Builtin::BI__builtin_trunc:
     case Builtin::BI__builtin_truncf:
+    case Builtin::BI__builtin_truncf16:
     case Builtin::BI__builtin_truncl:
       return RValue::get(emitUnaryBuiltin(*this, E, Intrinsic::trunc));
 
@@ -3979,6 +3999,7 @@
     break;
   case Builtin::BI__builtin_canonicalize:
   case Builtin::BI__builtin_canonicalizef:
+  case Builtin::BI__builtin_canonicalizef16:
   case Builtin::BI__builtin_canonicalizel:
     return RValue::get(emitUnaryBuiltin(*this, E, Intrinsic::canonicalize));
 
Index: test/CodeGenOpenCL/builtins-f16.cl
===================================================================
--- /dev/null
+++ test/CodeGenOpenCL/builtins-f16.cl
@@ -0,0 +1,71 @@
+// RUN: %clang_cc1 -emit-llvm -o - -triple x86_64-darwin-apple %s | FileCheck %s
+
+#pragma OPENCL EXTENSION cl_khr_fp16 : enable
+
+// CHECK-LABEL: define void @test_half_builtins
+void test_half_builtins(half h0, half h1, half h2) {
+  volatile half res;
+
+  // CHECK: call half @llvm.copysign.f16(half %h0, half %h1)
+  res = __builtin_copysignf16(h0, h1);
+
+  // CHECK: call half @llvm.fabs.f16(half %h0)
+  res = __builtin_fabsf16(h0);
+
+  // CHECK: call half @llvm.ceil.f16(half %h0)
+  res = __builtin_ceilf16(h0);
+
+  // CHECK: call half @llvm.cos.f16(half %h0)
+  res = __builtin_cosf16(h0);
+
+  // CHECK: call half @llvm.exp.f16(half %h0)
+  res = __builtin_expf16(h0);
+
+  // CHECK: call half @llvm.exp2.f16(half %h0)
+  res = __builtin_exp2f16(h0);
+
+  // CHECK: call half @llvm.floor.f16(half %h0)
+  res = __builtin_floorf16(h0);
+
+  // CHECK: call half @llvm.fma.f16(half %h0, half %h1, half %h2)
+  res = __builtin_fmaf16(h0, h1 ,h2);
+
+  // CHECK: call half @llvm.maxnum.f16(half %h0, half %h1)
+  res = __builtin_fmaxf16(h0, h1);
+
+  // CHECK: call half @llvm.minnum.f16(half %h0, half %h1)
+  res = __builtin_fminf16(h0, h1);
+
+  // CHECK: frem half %h0, %h1
+  res = __builtin_fmodf16(h0, h1);
+
+  // CHECK: call half @llvm.pow.f16(half %h0, half %h1)
+  res = __builtin_powf16(h0, h1);
+
+  // CHECK: call half @llvm.log10.f16(half %h0)
+  res = __builtin_log10f16(h0);
+
+  // CHECK: call half @llvm.log2.f16(half %h0)
+  res = __builtin_log2f16(h0);
+
+  // CHECK: call half @llvm.log.f16(half %h0)
+  res = __builtin_logf16(h0);
+
+  // CHECK: call half @llvm.rint.f16(half %h0)
+  res = __builtin_rintf16(h0);
+
+  // CHECK: call half @llvm.round.f16(half %h0)
+  res = __builtin_roundf16(h0);
+
+  // CHECK: call half @llvm.sin.f16(half %h0)
+  res = __builtin_sinf16(h0);
+
+  // CHECK: call half @llvm.sqrt.f16(half %h0)
+  res = __builtin_sqrtf16(h0);
+
+  // CHECK: call half @llvm.trunc.f16(half %h0)
+  res = __builtin_truncf16(h0);
+
+  // CHECK: call half @llvm.canonicalize.f16(half %h0)
+  res = __builtin_canonicalizef16(h0);
+}