Index: clang/docs/LanguageExtensions.rst
===================================================================
--- clang/docs/LanguageExtensions.rst
+++ clang/docs/LanguageExtensions.rst
@@ -1945,6 +1945,31 @@
 These builtins are intended for use in the implementation of ``std::allocator``
 and other similar allocation libraries, and are only available in C++.
 
+PowerPC cache builtins
+----------------------
+
+The PowerPC architecture specifies instructions implementing cache operations.
+Clang provides builtins that give direct programmer access to these cache
+instructions. 
+
+Currently the following builtins are implemented in clang:
+
+``__builtin_dcbf`` copies the contents of a modified block from the data cache
+to main memory and flushes the copy from the data cache.
+
+**Syntax**:
+
+.. code-block:: c
+
+  void __dcbf(const void* addr); /* Data Cache Block Flush */
+
+**Example of Use**:
+
+.. code-block:: c
+
+  int a = 1;
+  __builtin_dcbf (&a);
+
 Multiprecision Arithmetic Builtins
 ----------------------------------