Function insert_atomic_rmw

cranelift/fuzzgen/src/function_generator.rs:333–361

(
    fgen: &mut FunctionGenerator,
    builder: &mut FunctionBuilder,
    _: Opcode,
    _: &[Type],
    rets: &[Type],
)

}

fn insert_atomic_rmw(
    fgen: &mut FunctionGenerator,
    builder: &mut FunctionBuilder,
    _: Opcode,
    _: &[Type],
    rets: &[Type],
) -> Result<()> {
    let ctrl_type = *rets.first().unwrap();
    let type_size = ctrl_type.bytes();

    let rmw_op = *fgen.u.choose(AtomicRmwOp::all())?;

    let (address, flags, offset) = fgen.generate_address_and_memflags(builder, type_size, true)?;

    // AtomicRMW does not directly support offsets, so add the offset to the address separately.
    let address = builder.ins().iadd_imm(address, i64::from(offset));

    // Load and store target variables
    let source_var = fgen.get_variable_of_type(ctrl_type)?;
    let target_var = fgen.get_variable_of_type(ctrl_type)?;

    let source_val = builder.use_var(source_var);
    let new_val = builder
        .ins()
        .atomic_rmw(ctrl_type, flags, rmw_op, address, source_val);

    builder.def_var(target_var, new_val);
    Ok(())
}

fn insert_atomic_cas(
    fgen: &mut FunctionGenerator,