Index: include/clang/Basic/Builtins.def
===================================================================
--- include/clang/Basic/Builtins.def
+++ include/clang/Basic/Builtins.def
@@ -916,6 +916,14 @@
 LIBBUILTIN(fabsf, "ff", "fnc", "math.h", ALL_LANGUAGES)
 LIBBUILTIN(fabsl, "LdLd", "fnc", "math.h", ALL_LANGUAGES)
 
+LIBBUILTIN(finite, "id", "fnc", "math.h", GNU_LANG)
+LIBBUILTIN(finitef, "if", "fnc", "math.h", GNU_LANG)
+LIBBUILTIN(finitel, "iLd", "fnc", "math.h", GNU_LANG)
+// glibc's math.h generates calls to __finite
+LIBBUILTIN(__finite, "id", "fnc", "math.h", ALL_LANGUAGES)
+LIBBUILTIN(__finitef, "if", "fnc", "math.h", ALL_LANGUAGES)
+LIBBUILTIN(__finitel, "iLd", "fnc", "math.h", ALL_LANGUAGES)
+
 LIBBUILTIN(fmod, "ddd", "fne", "math.h", ALL_LANGUAGES)
 LIBBUILTIN(fmodf, "fff", "fne", "math.h", ALL_LANGUAGES)
 LIBBUILTIN(fmodl, "LdLdLd", "fne", "math.h", ALL_LANGUAGES)
Index: lib/CodeGen/CGBuiltin.cpp
===================================================================
--- lib/CodeGen/CGBuiltin.cpp
+++ lib/CodeGen/CGBuiltin.cpp
@@ -903,6 +903,12 @@
     return RValue::get(Builder.CreateZExt(V, ConvertType(E->getType())));
   }
 
+  case Builtin::BIfinite:
+  case Builtin::BI__finite:
+  case Builtin::BIfinitef:
+  case Builtin::BI__finitef:
+  case Builtin::BIfinitel:
+  case Builtin::BI__finitel:
   case Builtin::BI__builtin_isinf:
   case Builtin::BI__builtin_isfinite: {
     // isinf(x)    --> fabs(x) == infinity
Index: test/CodeGen/builtins.c
===================================================================
--- test/CodeGen/builtins.c
+++ test/CodeGen/builtins.c
@@ -220,6 +220,10 @@
   // CHECK: call float @llvm.fabs.f32(float
   // CHECK: fcmp one float {{.*}}, 0x7FF0000000000000
 
+  res = finite(D);
+  // CHECK: call double @llvm.fabs.f64(double
+  // CHECK: fcmp one double {{.*}}, 0x7FF0000000000000
+
   res = __builtin_isnormal(F);
   // CHECK: fcmp oeq float
   // CHECK: call float @llvm.fabs.f32(float