diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -101,8 +101,42 @@
   // that prefix labels.
   if (FD->hasAttr<AsmLabelAttr>())
     Name = getMangledName(D);
-  else
-    Name = Context.BuiltinInfo.getName(BuiltinID) + 10;
+  else {
+    // TODO: This mutation should also be applied to other targets other than
+    // PPC, after backend supports IEEE 128-bit style libcalls.
+    bool UseF128Name =
+        getTriple().isPPC64() &&
+        &getTarget().getLongDoubleFormat() == &llvm::APFloat::IEEEquad();
+    switch (BuiltinID) {
+    case Builtin::BIprintf:
+    case Builtin::BI__builtin_printf:
+      Name = UseF128Name ? "__printfieee128" : "printf";
+      break;
+    case Builtin::BIvsnprintf:
+    case Builtin::BI__builtin_vsnprintf:
+      Name = UseF128Name ? "__vsnprintfieee128" : "vsnprintf";
+      break;
+    case Builtin::BIvsprintf:
+    case Builtin::BI__builtin_vsprintf:
+      Name = UseF128Name ? "__vsprintfieee128" : "vsprintf";
+      break;
+    case Builtin::BIsprintf:
+    case Builtin::BI__builtin_sprintf:
+      Name = UseF128Name ? "__sprintfieee128" : "sprintf";
+      break;
+    case Builtin::BIsnprintf:
+    case Builtin::BI__builtin_snprintf:
+      Name = UseF128Name ? "__snprintfieee128" : "snprintf";
+      break;
+    case Builtin::BIfprintf:
+    case Builtin::BI__builtin_fprintf:
+      Name = UseF128Name ? "__fprintfieee128" : "fprintf";
+      break;
+    default:
+      Name = Context.BuiltinInfo.getName(BuiltinID) + 10;
+      break;
+    }
+  }
 
   llvm::FunctionType *Ty =
     cast<llvm::FunctionType>(getTypes().ConvertType(FD->getType()));
diff --git a/clang/test/CodeGen/ppc64-f128-builtins.c b/clang/test/CodeGen/ppc64-f128-builtins.c
new file mode 100644
--- /dev/null
+++ b/clang/test/CodeGen/ppc64-f128-builtins.c
@@ -0,0 +1,37 @@
+// RUN: %clang_cc1 -triple powerpc64le-linux-gnu -emit-llvm -o - %s \
+// RUN:   -mabi=ieeelongdouble | FileCheck --check-prefix=IEEE128 %s
+// RUN: %clang_cc1 -triple powerpc64le-linux-gnu -emit-llvm -o - %s \
+// RUN:   -mabi=ibmlongdouble | FileCheck --check-prefix=PPC128 %s
+
+long double x;
+
+void test_printf() {
+  __builtin_printf("%.Lf", x);
+}
+
+void test_vsnprintf() {
+  char buf[20];
+  __builtin_va_list va;
+  __builtin_vsnprintf(buf, 20, "%.Lf", va);
+}
+
+void test_vsprintf() {
+  char buf[20];
+  __builtin_va_list va;
+  __builtin_vsprintf(buf, "%.Lf", va);
+}
+
+void test_sprintf() {
+  char buf[20];
+  __builtin_sprintf(buf, "%.Lf", x);
+}
+
+void test_snprintf() {
+  char buf[20];
+  __builtin_snprintf(buf, 20, "%.Lf", x);
+}
+
+void test_fprintf() {
+  FILE *fp;
+  __builtin_fprintf(fp, "%.Lf", x):
+}