fetch_op_N

inline fn fetch_op_N(comptime T: type, comptime op: std.builtin.AtomicRmwOp, ptr: *T, val: T, model: i32) T

File

Code

inline fn fetch_op_N(comptime T: type, comptime op: std.builtin.AtomicRmwOp, ptr: *T, val: T, model: i32) T {
    _ = model;
    const Updater = struct {
        fn update(new: T, old: T) T {
            return switch (op) {
                .Add => old +% new,
                .Sub => old -% new,
                .And => old & new,
                .Nand => ~(old & new),
                .Or => old | new,
                .Xor => old ^ new,
                .Max => @max(old, new),
                .Min => @min(old, new),
                else => @compileError("unsupported atomic op"),
            };
        }
    };

    if (@sizeOf(T) > largest_atomic_size) {
        var sl = spinlocks.get(@intFromPtr(ptr));
        defer sl.release();

        const value = ptr.*;
        ptr.* = Updater.update(val, value);
        return value;
    } else if (@sizeOf(T) < smallest_atomic_fetch_exch_size) {
        // Machine does not support this type, but it does support a larger type.
        return wideUpdate(T, ptr, val, Updater.update);
    }

    return @atomicRmw(T, ptr, op, val, .seq_cst);
}