use crate::cdsl::isa::{TargetIsa, TargetIsaBuilder};
use crate::cdsl::regs::{RegBankBuilder, RegClassBuilder};
use crate::cdsl::settings::{SettingGroup, SettingGroupBuilder};

fn define_settings(_shared: &SettingGroup) -> SettingGroup {
    let setting = SettingGroupBuilder::new("arm64");
    setting.finish()
}

pub fn define(shared_settings: &SettingGroup) -> TargetIsa {
    let mut isa = TargetIsaBuilder::new("arm64", define_settings(shared_settings));

    // The `x31` regunit serves as the stack pointer / zero register depending on context. We
    // reserve it and don't model the difference.
    let builder = RegBankBuilder::new("IntRegs", "x")
        .units(32)
        .track_pressure(true);
    let int_regs = isa.add_reg_bank(builder);

    let builder = RegBankBuilder::new("FloatRegs", "v")
        .units(32)
        .track_pressure(true);
    let float_regs = isa.add_reg_bank(builder);

    let builder = RegBankBuilder::new("FlagRegs", "")
        .units(1)
        .names(vec!["nzcv"])
        .track_pressure(false);
    let flag_reg = isa.add_reg_bank(builder);

    let builder = RegClassBuilder::new_toplevel("GPR", int_regs);
    isa.add_reg_class(builder);

    let builder = RegClassBuilder::new_toplevel("FPR", float_regs);
    isa.add_reg_class(builder);

    let builder = RegClassBuilder::new_toplevel("FLAG", flag_reg);
    isa.add_reg_class(builder);

    isa.finish()
}