__fetch_and_and, __builtin_ppc_fetch_and_and, __fetch_and_andlp, __builtin_ppc_fetch_and_andlp

Purpose

Clears bits in the word or doubleword specified by addr by AND-ing that value with the value specified by val, in a single atomic operation, and returns the original value of addr.

Prototype

unsigned int __builtin_ppc_fetch_and_and (volatile unsigned int* addr, unsigned int val);

unsigned long __builtin_ppc_fetch_and_andlp (volatile unsigned long* addr, unsigned long val);

unsigned int __fetch_and_and (volatile unsigned int* addr, unsigned int val);

unsigned long __fetch_and_andlp (volatile unsigned long* addr, unsigned long val);

Note:

The built-in function in the form of __name is a synonym of the built-in function in the form of __builtin_ppc_name.
The built-in function in the form of __name is provided for compatibility with IBM® XL C/C++ for AIX® 16.1.0 or earlier releases. This built-in function form might be deprecated in the future.

Parameters

addr: The address of the variable to be ANDed. Must be aligned on a 4-byte boundary for a single word and on an 8-byte boundary for a doubleword.
value: The value by which the value in addr is to be ANDed.

Usage

This operation is useful when a variable containing bit flags is shared between several threads or processes.

__fetch_and_andlp is valid only in 64-bit mode.

Note:

This function generates the hardware instruction but does not act as an instruction movement barrier within the compiler. If that is needed, you must also use the __fence function.