5.17.5 Built-In Functions

The following built-in functions are supported:

• __builtin_abs()
• __builtin_constant_p()
• __builtin_expect()
• __builtin_fabs()
• __builtin_fabsf()
• __builtin_frame_address()
• __builtin_labs()
• __builtin_memcpy()
• __builtin_return_address()

The __builtin_frame_address() function always returns zero.

The __builtin_return_address() function always returns zero.