def METHOD_NAME(ctx):
    if ctx.build_setting_value == "all":
        isa_extensions = _ISA_EXTENSIONS
    elif ctx.build_setting_value == "modern":
        isa_extensions = _ISA_EXTENSIONS_MODERN
    elif ctx.build_setting_value == "auto":
        isa_extensions = [ ctx.attr.auto_cpu ]
    else:
        isa_extensions = ctx.build_setting_value.split(" ")
        isa_extensions = [x.strip() for x in isa_extensions]
    isa_extensions = utils.unique(["sse2"] + isa_extensions)
    _check_cpu_extensions(isa_extensions)
    return CpuInfo(
        enabled = isa_extensions,
        allowed = _ISA_EXTENSIONS,
    )