diff --git a/CodeGen/CGBuiltin.cpp b/CodeGen/CGBuiltin.cpp
index 27c82e8..8f9b7b3 100644
--- a/CodeGen/CGBuiltin.cpp
+++ b/CodeGen/CGBuiltin.cpp
@@ -112,6 +112,22 @@
       
     return RValue::get(V);      
   }
+  case Builtin::BI__builtin_inff: {
+    llvm::APFloat f(llvm::APFloat::IEEEsingle,
+                    llvm::APFloat::fcInfinity, false);
+    
+    llvm::Value *V = llvm::ConstantFP::get(llvm::Type::FloatTy, f);
+    return RValue::get(V);
+  }
+  case Builtin::BI__builtin_inf:
+  // FIXME: mapping long double onto double.      
+  case Builtin::BI__builtin_infl: {
+    llvm::APFloat f(llvm::APFloat::IEEEdouble,
+                    llvm::APFloat::fcInfinity, false);
+    
+    llvm::Value *V = llvm::ConstantFP::get(llvm::Type::DoubleTy, f);
+    return RValue::get(V);
+  }
   }
   
   return RValue::get(0);
diff --git a/include/clang/AST/Builtins.def b/include/clang/AST/Builtins.def
index d95dbd4..c0e978f 100644
--- a/include/clang/AST/Builtins.def
+++ b/include/clang/AST/Builtins.def
@@ -54,9 +54,9 @@
 //  F -> this is a libc/libm function with a '__builtin_' prefix added.
 
 // Standard libc/libm functions:
-BUILTIN(__builtin_inf  , "d"   , "ncF")
-BUILTIN(__builtin_inff , "f"   , "ncF")
-BUILTIN(__builtin_infl , "Ld"  , "ncF")
+BUILTIN(__builtin_inf  , "d"   , "nc")
+BUILTIN(__builtin_inff , "f"   , "nc")
+BUILTIN(__builtin_infl , "Ld"  , "nc")
 BUILTIN(__builtin_abs  , "ii"  , "ncF")
 BUILTIN(__builtin_fabs , "dd"  , "ncF")
 BUILTIN(__builtin_fabsf, "ff"  , "ncF")