DEFINITION MODULE ATOMIC;

(* Pseudo-module for Atomic Intrinsics *)

TYPE INTRINSIC = ( SWAP, CAS, INC, DEC, BWAND, BWNAND, BWOR, BWXOR );

PROCEDURE AVAIL( intrinsic : INTRINSIC; bitwidth : CARDINAL ) : BOOLEAN;
(* Returns TRUE if the given intrinsic is available for the given bitwidth,
   otherwise FALSE. The value of bitwidth must be a compile time expression.*)

PROCEDURE SWAP( VAR x, y : <Type> );
(* Atomically swaps x and y. Type must be an 8, 16, 32 or 64 bit type. *)

PROCEDURE CAS( VAR expectedValue, y : <Type> ) : Type;
(* Atomically compares x and expectedValue, if they are equal, swaps x and y.
   Returns original value of x. Type must be an 8, 16, 32 or 64 bit type. *)

PROCEDURE INC( VAR x : <Type>; y : <Type> );
(* Atomically increments x by y. Type must be an 8, 16, 32 or 64 bit type. *)

PROCEDURE DEC( VAR x : <Type>; y : <Type> );
(* Atomically decrements x by y. Type must be an 8, 16, 32 or 64 bit type. *)

PROCEDURE BWAND( VAR x : <Type>; y : <Type> );
(* Atomically performs bitwise AND of x and y, and passes the result in x.
   Type must be an 8, 16, 32 or 64 bit type. *)

PROCEDURE BWNAND( VAR x : <Type>; y : <Type> );
(* Atomically performs bitwise NAND of x and y, and passes the result in x.
   Type must be an 8, 16, 32 or 64 bit type. *)

PROCEDURE BWOR( VAR x : <Type>; y : <Type> );
(* Atomically performs bitwise OR of x and y, and passes the result in x.
   Type must be an 8, 16, 32 or 64 bit type. *)

PROCEDURE BWXOR( VAR x : <Type>; y : <Type> );
(* Atomically performs bitwise XOR of x and y, and passes the result in x.
   Type must be an 8, 16, 32 or 64 bit type. *)

END ATOMIC.