### 6.56 Cilk Plus C/C++ Language Extension Built-in Functions

GCC provides support for the following built-in reduction functions if Cilk Plus is enabled. Cilk Plus can be enabled using the `-fcilkplus` flag.

- `__sec_implicit_index`
- `__sec_reduce`
- `__sec_reduce_add`
- `__sec_reduce_all_nonzero`
- `__sec_reduce_all_zero`
- `__sec_reduce_any_nonzero`
- `__sec_reduce_any_zero`
- `__sec_reduce_max`
- `__sec_reduce_min`
- `__sec_reduce_max_ind`
- `__sec_reduce_min_ind`
- `__sec_reduce_mul`
- `__sec_reduce_mutating`

Further details and examples about these built-in functions are described in the Cilk Plus language manual which can be found at http://www.cilkplus.org.