//! ISLE integration glue code for s390x lowering.

// Pull in the ISLE generated code.
pub mod generated_code;

// Types that the generated ISLE code uses via `use super::*`.
use super::{
    BranchTarget, CallIndInfo, CallInfo, Cond, Inst as MInst, JTSequenceInfo, MachLabel, MemArg,
    MemFlags, Opcode, Reg, UImm16Shifted, UImm32Shifted,
};
use crate::isa::s390x::settings::Flags as IsaFlags;
use crate::machinst::isle::*;
use crate::settings::Flags;
use crate::{
    ir::{
        condcodes::*, immediates::*, types::*, AtomicRmwOp, Endianness, ExternalName, Inst,
        InstructionData, StackSlot, TrapCode, Value, ValueLabel, ValueList,
    },
    isa::s390x::inst::s390x_map_regs,
    isa::unwind::UnwindInst,
    machinst::{InsnOutput, LowerCtx, RelocDistance},
};
use std::boxed::Box;
use std::convert::TryFrom;
use std::vec::Vec;

type BoxCallInfo = Box<CallInfo>;
type BoxCallIndInfo = Box<CallIndInfo>;
type VecMachLabel = Vec<MachLabel>;
type BoxJTSequenceInfo = Box<JTSequenceInfo>;
type BoxExternalName = Box<ExternalName>;

/// The main entry point for lowering with ISLE.
pub(crate) fn lower<C>(
    lower_ctx: &mut C,
    flags: &Flags,
    isa_flags: &IsaFlags,
    outputs: &[InsnOutput],
    inst: Inst,
) -> Result<(), ()>
where
    C: LowerCtx<I = MInst>,
{
    lower_common(
        lower_ctx,
        flags,
        isa_flags,
        outputs,
        inst,
        |cx, insn| generated_code::constructor_lower(cx, insn),
        s390x_map_regs,
    )
}

impl<C> generated_code::Context for IsleContext<'_, C, Flags, IsaFlags, 6>
where
    C: LowerCtx<I = MInst>,
{
    isle_prelude_methods!();

    #[inline]
    fn allow_div_traps(&mut self, _: Type) -> Option<()> {
        if !self.flags.avoid_div_traps() {
            Some(())
        } else {
            None
        }
    }

    #[inline]
    fn mie2_enabled(&mut self, _: Type) -> Option<()> {
        if self.isa_flags.has_mie2() {
            Some(())
        } else {
            None
        }
    }

    #[inline]
    fn mie2_disabled(&mut self, _: Type) -> Option<()> {
        if !self.isa_flags.has_mie2() {
            Some(())
        } else {
            None
        }
    }

    #[inline]
    fn vxrs_ext2_enabled(&mut self, _: Type) -> Option<()> {
        if self.isa_flags.has_vxrs_ext2() {
            Some(())
        } else {
            None
        }
    }

    #[inline]
    fn vxrs_ext2_disabled(&mut self, _: Type) -> Option<()> {
        if !self.isa_flags.has_vxrs_ext2() {
            Some(())
        } else {
            None
        }
    }

    #[inline]
    fn symbol_value_data(&mut self, inst: Inst) -> Option<(BoxExternalName, RelocDistance, i64)> {
        let (name, dist, offset) = self.lower_ctx.symbol_value(inst)?;
        Some((Box::new(name.clone()), dist, offset))
    }

    #[inline]
    fn call_target_data(&mut self, inst: Inst) -> Option<(BoxExternalName, RelocDistance)> {
        let (name, dist) = self.lower_ctx.call_target(inst)?;
        Some((Box::new(name.clone()), dist))
    }

    #[inline]
    fn writable_gpr(&mut self, regno: u8) -> WritableReg {
        super::writable_gpr(regno)
    }

    #[inline]
    fn zero_reg(&mut self) -> Reg {
        super::zero_reg()
    }

    #[inline]
    fn gpr32_ty(&mut self, ty: Type) -> Option<Type> {
        match ty {
            I8 | I16 | I32 | B1 | B8 | B16 | B32 => Some(ty),
            _ => None,
        }
    }

    #[inline]
    fn gpr64_ty(&mut self, ty: Type) -> Option<Type> {
        match ty {
            I64 | B64 | R64 => Some(ty),
            _ => None,
        }
    }

    #[inline]
    fn uimm32shifted(&mut self, n: u32, shift: u8) -> UImm32Shifted {
        UImm32Shifted::maybe_with_shift(n, shift).unwrap()
    }

    #[inline]
    fn uimm16shifted(&mut self, n: u16, shift: u8) -> UImm16Shifted {
        UImm16Shifted::maybe_with_shift(n, shift).unwrap()
    }

    #[inline]
    fn i64_nonequal(&mut self, val: i64, cmp: i64) -> Option<i64> {
        if val != cmp {
            Some(val)
        } else {
            None
        }
    }

    #[inline]
    fn u8_as_u16(&mut self, n: u8) -> u16 {
        n as u16
    }

    #[inline]
    fn u64_as_u32(&mut self, n: u64) -> u32 {
        n as u32
    }

    #[inline]
    fn u64_as_i16(&mut self, n: u64) -> i16 {
        n as i16
    }

    #[inline]
    fn u64_nonzero_hipart(&mut self, n: u64) -> Option<u64> {
        let part = n & 0xffff_ffff_0000_0000;
        if part != 0 {
            Some(part)
        } else {
            None
        }
    }

    #[inline]
    fn u64_nonzero_lopart(&mut self, n: u64) -> Option<u64> {
        let part = n & 0x0000_0000_ffff_ffff;
        if part != 0 {
            Some(part)
        } else {
            None
        }
    }

    #[inline]
    fn i32_from_u64(&mut self, n: u64) -> Option<i32> {
        if let Ok(imm) = i32::try_from(n as i64) {
            Some(imm)
        } else {
            None
        }
    }

    #[inline]
    fn i16_from_u64(&mut self, n: u64) -> Option<i16> {
        if let Ok(imm) = i16::try_from(n as i64) {
            Some(imm)
        } else {
            None
        }
    }

    #[inline]
    fn uimm32shifted_from_u64(&mut self, n: u64) -> Option<UImm32Shifted> {
        UImm32Shifted::maybe_from_u64(n)
    }

    #[inline]
    fn uimm16shifted_from_u64(&mut self, n: u64) -> Option<UImm16Shifted> {
        UImm16Shifted::maybe_from_u64(n)
    }

    #[inline]
    fn u64_from_value(&mut self, val: Value) -> Option<u64> {
        let inst = self.lower_ctx.dfg().value_def(val).inst()?;
        let constant = self.lower_ctx.get_constant(inst)?;
        Some(constant)
    }

    #[inline]
    fn u32_from_value(&mut self, val: Value) -> Option<u32> {
        let constant = self.u64_from_value(val)?;
        let imm = u32::try_from(constant).ok()?;
        Some(imm)
    }

    #[inline]
    fn u8_from_value(&mut self, val: Value) -> Option<u8> {
        let constant = self.u64_from_value(val)?;
        let imm = u8::try_from(constant).ok()?;
        Some(imm)
    }

    #[inline]
    fn u64_from_signed_value(&mut self, val: Value) -> Option<u64> {
        let inst = self.lower_ctx.dfg().value_def(val).inst()?;
        let constant = self.lower_ctx.get_constant(inst)?;
        let ty = self.lower_ctx.output_ty(inst, 0);
        Some(super::sign_extend_to_u64(constant, self.ty_bits(ty)))
    }

    #[inline]
    fn i64_from_value(&mut self, val: Value) -> Option<i64> {
        let constant = self.u64_from_signed_value(val)? as i64;
        Some(constant)
    }

    #[inline]
    fn i32_from_value(&mut self, val: Value) -> Option<i32> {
        let constant = self.u64_from_signed_value(val)? as i64;
        let imm = i32::try_from(constant).ok()?;
        Some(imm)
    }

    #[inline]
    fn i16_from_value(&mut self, val: Value) -> Option<i16> {
        let constant = self.u64_from_signed_value(val)? as i64;
        let imm = i16::try_from(constant).ok()?;
        Some(imm)
    }

    #[inline]
    fn i16_from_swapped_value(&mut self, val: Value) -> Option<i16> {
        let constant = self.u64_from_signed_value(val)? as i64;
        let imm = i16::try_from(constant).ok()?;
        Some(imm.swap_bytes())
    }

    #[inline]
    fn i64_from_negated_value(&mut self, val: Value) -> Option<i64> {
        let constant = self.u64_from_signed_value(val)? as i64;
        let imm = -constant;
        Some(imm)
    }

    #[inline]
    fn i32_from_negated_value(&mut self, val: Value) -> Option<i32> {
        let constant = self.u64_from_signed_value(val)? as i64;
        let imm = i32::try_from(-constant).ok()?;
        Some(imm)
    }

    #[inline]
    fn i16_from_negated_value(&mut self, val: Value) -> Option<i16> {
        let constant = self.u64_from_signed_value(val)? as i64;
        let imm = i16::try_from(-constant).ok()?;
        Some(imm)
    }

    #[inline]
    fn uimm16shifted_from_value(&mut self, val: Value) -> Option<UImm16Shifted> {
        let constant = self.u64_from_value(val)?;
        UImm16Shifted::maybe_from_u64(constant)
    }

    #[inline]
    fn uimm32shifted_from_value(&mut self, val: Value) -> Option<UImm32Shifted> {
        let constant = self.u64_from_value(val)?;
        UImm32Shifted::maybe_from_u64(constant)
    }

    #[inline]
    fn uimm16shifted_from_inverted_value(&mut self, val: Value) -> Option<UImm16Shifted> {
        let constant = self.u64_from_value(val)?;
        let imm = UImm16Shifted::maybe_from_u64(!constant)?;
        Some(imm.negate_bits())
    }

    #[inline]
    fn uimm32shifted_from_inverted_value(&mut self, val: Value) -> Option<UImm32Shifted> {
        let constant = self.u64_from_value(val)?;
        let imm = UImm32Shifted::maybe_from_u64(!constant)?;
        Some(imm.negate_bits())
    }

    #[inline]
    fn mask_amt_imm(&mut self, ty: Type, amt: i64) -> u8 {
        let mask = self.ty_bits(ty) - 1;
        (amt as u8) & mask
    }

    #[inline]
    fn mask_as_cond(&mut self, mask: u8) -> Cond {
        Cond::from_mask(mask)
    }

    #[inline]
    fn intcc_as_cond(&mut self, cc: &IntCC) -> Cond {
        Cond::from_intcc(*cc)
    }

    #[inline]
    fn floatcc_as_cond(&mut self, cc: &FloatCC) -> Cond {
        Cond::from_floatcc(*cc)
    }

    #[inline]
    fn invert_cond(&mut self, cond: &Cond) -> Cond {
        Cond::invert(*cond)
    }

    #[inline]
    fn signed(&mut self, cc: &IntCC) -> Option<()> {
        if super::condcode_is_signed(*cc) {
            Some(())
        } else {
            None
        }
    }

    #[inline]
    fn unsigned(&mut self, cc: &IntCC) -> Option<()> {
        if !super::condcode_is_signed(*cc) {
            Some(())
        } else {
            None
        }
    }

    #[inline]
    fn reloc_distance_near(&mut self, dist: &RelocDistance) -> Option<()> {
        if *dist == RelocDistance::Near {
            Some(())
        } else {
            None
        }
    }

    #[inline]
    fn zero_offset(&mut self) -> Offset32 {
        Offset32::new(0)
    }

    #[inline]
    fn i64_from_offset(&mut self, off: Offset32) -> i64 {
        i64::from(off)
    }

    #[inline]
    fn littleendian(&mut self, flags: MemFlags) -> Option<()> {
        let endianness = flags.endianness(Endianness::Big);
        if endianness == Endianness::Little {
            Some(())
        } else {
            None
        }
    }

    #[inline]
    fn bigendian(&mut self, flags: MemFlags) -> Option<()> {
        let endianness = flags.endianness(Endianness::Big);
        if endianness == Endianness::Big {
            Some(())
        } else {
            None
        }
    }

    #[inline]
    fn memflags_trusted(&mut self) -> MemFlags {
        MemFlags::trusted()
    }

    #[inline]
    fn memarg_reg_plus_reg(&mut self, x: Reg, y: Reg, flags: MemFlags) -> MemArg {
        MemArg::reg_plus_reg(x, y, flags)
    }

    #[inline]
    fn memarg_reg_plus_off(&mut self, reg: Reg, off: i64, flags: MemFlags) -> MemArg {
        MemArg::reg_plus_off(reg, off, flags)
    }

    #[inline]
    fn memarg_symbol(&mut self, name: BoxExternalName, offset: i32, flags: MemFlags) -> MemArg {
        MemArg::Symbol {
            name,
            offset,
            flags,
        }
    }

    #[inline]
    fn memarg_symbol_offset_sum(&mut self, off1: i64, off2: i64) -> Option<i32> {
        let off = i32::try_from(off1 + off2).ok()?;
        if off & 1 == 0 {
            Some(off)
        } else {
            None
        }
    }

    #[inline]
    fn abi_stackslot_addr(
        &mut self,
        dst: WritableReg,
        stack_slot: StackSlot,
        offset: Offset32,
    ) -> MInst {
        let offset = u32::try_from(i32::from(offset)).unwrap();
        self.lower_ctx.abi().stackslot_addr(stack_slot, offset, dst)
    }

    #[inline]
    fn sinkable_inst(&mut self, val: Value) -> Option<Inst> {
        let input = self.lower_ctx.get_value_as_source_or_const(val);
        if let Some((inst, 0)) = input.inst {
            return Some(inst);
        }
        None
    }

    #[inline]
    fn sink_inst(&mut self, inst: Inst) -> Unit {
        self.lower_ctx.sink_inst(inst);
    }

    #[inline]
    fn emit(&mut self, inst: &MInst) -> Unit {
        self.emitted_insts.push(inst.clone());
    }
}