_16bit.py

# --------------------------------------------------------------------
# SPDX-License-Identifier: AGPL-3.0-or-later
# © Copyright 2008-2024 José Manuel Rodríguez de la Rosa and contributors.
# See the file CONTRIBUTORS.md for copyright details.
# See https://www.gnu.org/licenses/agpl-3.0.html for details.
# --------------------------------------------------------------------

from src.api.tmp_labels import tmp_label
from src.arch.z80.backend._8bit import Bits8
from src.arch.z80.backend.common import _int_ops, is_2n, is_int, log2, runtime_call
from src.arch.z80.backend.quad import Quad
from src.arch.z80.backend.runtime import Labels as RuntimeLabel


class Bits16:
    """Implementation of 16bit operations."""

    @classmethod
    def int16(cls, op):
        """Returns a 16 bit operand converted to 16 bits unsigned int.
        Negative numbers are returned in 2 complement.
        """
        return int(op) & 0xFFFF

    @classmethod
    def get_oper(cls, op1, op2=None, *, reversed: bool = False):
        """Returns pop sequence for 16 bits operands
        1st operand in HL, 2nd operand in DE

        For subtraction, division, etc. you can swap operators extraction order
        by setting reversed to True
        """
        output = []

        if op1 is not None:
            op1 = str(op1)  # always to str

        if op2 is not None:
            op2 = str(op2)  # always to str

        if op2 is not None and reversed:
            op1, op2 = op2, op1

        op = op1
        indirect = op[0] == "*"
        if indirect:
            op = op[1:]

        immediate = op[0] == "#"
        if immediate:
            op = op[1:]

        if is_int(op):
            op = int(op)

            if indirect:
                output.append("ld hl, (%i)" % op)
            else:
                output.append("ld hl, %i" % cls.int16(op))
        else:
            if immediate:
                if indirect:
                    output.append("ld hl, (%s)" % op)
                else:
                    output.append("ld hl, %s" % op)
            else:
                if op[0] == "_":
                    output.append("ld hl, (%s)" % op)
                else:
                    output.append("pop hl")

                if indirect:
                    output.append("ld a, (hl)")
                    output.append("inc hl")
                    output.append("ld h, (hl)")
                    output.append("ld l, a")

        if op2 is None:
            return output

        if not reversed:
            tmp = output
            output = []

        op = op2
        indirect = op[0] == "*"
        if indirect:
            op = op[1:]

        immediate = op[0] == "#"
        if immediate:
            op = op[1:]

        if is_int(op):
            op = int(op)

            if indirect:
                output.append("ld de, (%i)" % op)
            else:
                output.append("ld de, %i" % cls.int16(op))
        else:
            if immediate:
                output.append("ld de, %s" % op)
            else:
                if op[0] == "_":
                    output.append("ld de, (%s)" % op)
                else:
                    output.append("pop de")

                if indirect:
                    output.append(runtime_call(RuntimeLabel.LOAD_DE_DE))  # DE = (DE)

        if not reversed:
            output.extend(tmp)

        return output

    # -----------------------------------------------------
    #               Arithmetic operations
    # -----------------------------------------------------

    @classmethod
    def add16(cls, ins: Quad) -> list[str]:
        """Pops last 2 bytes from the stack and adds them.
        Then push the result onto the stack.


        Optimizations:
          * If any of the operands is ZERO,
            then do NOTHING: A + 0 = 0 + A = A

          * If any of the operands is < 4, then
            INC is used

          * If any of the operands is > (65531) (-4), then
            DEC is used
        """
        op1, op2 = tuple(ins[2:])
        if _int_ops(op1, op2) is not None:
            op1, op2 = _int_ops(op1, op2)
            op2 = cls.int16(op2)
            output = cls.get_oper(op1)

            if op2 == 0:
                output.append("push hl")
                return output  # ADD HL, 0 => NOTHING

            if op2 < 4:
                output.extend(["inc hl"] * op2)  # ADD HL, 2 ==> inc hl; inc hl
                output.append("push hl")
                return output

            if op2 > 65531:  # (between -4 and 0)
                output.extend(["dec hl"] * (0x10000 - op2))
                output.append("push hl")
                return output

            output.append("ld de, %i" % op2)
            output.append("add hl, de")
            output.append("push hl")
            return output

        if op2[0] == "_":  # stack optimization
            op1, op2 = op2, op1

        output = cls.get_oper(op1, op2)
        output.append("add hl, de")
        output.append("push hl")
        return output

    @classmethod
    def sub16(cls, ins: Quad) -> list[str]:
        """Pops last 2 words from the stack and subtract them.
        Then push the result onto the stack. Top of the stack is
        subtracted Top -1

        Optimizations:
          * If 2nd op is ZERO,
            then do NOTHING: A - 0 = A

          * If any of the operands is < 4, then
            DEC is used

          * If any of the operands is > 65531 (-4..-1), then
            INC is used
        """
        op1, op2 = tuple(ins[2:4])

        if is_int(op2):
            op = cls.int16(op2)
            output = cls.get_oper(op1)

            if op == 0:
                output.append("push hl")
                return output

            if op < 4:
                output.extend(["dec hl"] * op)
                output.append("push hl")
                return output

            if op > 65531:
                output.extend(["inc hl"] * (0x10000 - op))
                output.append("push hl")
                return output

            output.append("ld de, -%i" % op)
            output.append("add hl, de")
            output.append("push hl")
            return output

        if op2[0] == "_":  # Optimization when 2nd operand is an id
            rev = True
            op1, op2 = op2, op1
        else:
            rev = False

        output = cls.get_oper(op1, op2, reversed=rev)
        output.append("or a")
        output.append("sbc hl, de")
        output.append("push hl")
        return output

    @classmethod
    def mul16(cls, ins: Quad) -> list[str]:
        """Multiplies tow last 16bit values on top of the stack and
        and returns the value on top of the stack

        Optimizations:
          * If any of the ops is ZERO,
            then do A = 0 ==> XOR A, cause A * 0 = 0 * A = 0

          * If any ot the ops is ONE, do NOTHING
            A * 1 = 1 * A = A

          * If B is 2^n and B < 16 => Shift Right n
        """
        op1, op2 = tuple(ins[2:])
        if _int_ops(op1, op2) is not None:  # If any of the operands is constant
            op1, op2 = _int_ops(op1, op2)  # put the constant one the 2nd
            output = cls.get_oper(op1)

            if op2 == 0:  # A * 0 = 0 * A = 0
                if op1[0] in ("_", "$"):
                    output = []  # Optimization: Discard previous op if not from the stack
                output.append("ld hl, 0")
                output.append("push hl")
                return output

            if op2 == 1:  # A * 1 = 1 * A == A => Do nothing
                output.append("push hl")
                return output

            if op2 == 0xFFFF:  # This is the same as (-1)
                output.append(runtime_call(RuntimeLabel.NEGHL))
                output.append("push hl")
                return output

            if is_2n(op2) and log2(op2) < 4:
                output.extend(["add hl, hl"] * int(log2(op2)))
                output.append("push hl")
                return output

            output.append(f"ld de, {op2}")
        else:
            if op2[0] == "_":  # stack optimization
                op1, op2 = op2, op1

            output = cls.get_oper(op1, op2)

        output.append(runtime_call(RuntimeLabel.MUL16_FAST))  # Immediate
        output.append("push hl")
        return output

    @classmethod
    def divu16(cls, ins: Quad) -> list[str]:
        """Divides 2 16bit unsigned integers. The result is pushed onto the stack.

        Optimizations:
          * If 2nd op is 1 then
            do nothing

          * If 2nd op is 2 then
            Shift Right Logical
        """
        op1, op2 = tuple(ins[2:])
        if is_int(op1) and int(op1) == 0:  # 0 / A = 0
            if op2[0] in ("_", "$"):
                output = []  # Optimization: Discard previous op if not from the stack
            else:
                output = cls.get_oper(op2)  # Normalize stack

            output.append("ld hl, 0")
            output.append("push hl")
            return output

        if is_int(op2):
            op = cls.int16(op2)
            output = cls.get_oper(op1)

            if op2 == 0:  # A * 0 = 0 * A = 0
                if op1[0] in ("_", "$"):
                    output = []  # Optimization: Discard previous op if not from the stack
                output.append("ld hl, 0")
                output.append("push hl")
                return output

            if op == 1:
                output.append("push hl")
                return output

            if op == 2:
                output.append("srl h")
                output.append("rr l")
                output.append("push hl")
                return output

            output.append("ld de, %i" % op)
        else:
            if op2[0] == "_":  # Optimization when 2nd operand is an id
                rev = True
                op1, op2 = op2, op1
            else:
                rev = False
            output = cls.get_oper(op1, op2, reversed=rev)

        output.append(runtime_call(RuntimeLabel.DIVU16))
        output.append("push hl")
        return output

    @classmethod
    def divi16(cls, ins: Quad) -> list[str]:
        """Divides 2 16bit signed integers. The result is pushed onto the stack.

        Optimizations:
          * If 2nd op is 1 then
            do nothing

          * If 2nd op is -1 then
            do NEG

          * If 2nd op is 2 then
            Shift Right Arithmetic
        """
        op1, op2 = tuple(ins[2:])
        if is_int(op1) and int(op1) == 0:  # 0 / A = 0
            if op2[0] in ("_", "$"):
                output = []  # Optimization: Discard previous op if not from the stack
            else:
                output = cls.get_oper(op2)  # Normalize stack

            output.append("ld hl, 0")
            output.append("push hl")
            return output

        if is_int(op2):
            op = cls.int16(op2)
            output = cls.get_oper(op1)

            if op == 1:
                output.append("push hl")
                return output

            if op == -1:
                output.append(runtime_call(RuntimeLabel.NEGHL))  # TODO: Is this ever used?
                output.append("push hl")
                return output

            if op == 2:
                output.append("sra h")
                output.append("rr l")
                output.append("push hl")
                return output

            output.append("ld de, %i" % op)
        else:
            if op2[0] == "_":  # Optimization when 2nd operand is an id
                rev = True
                op1, op2 = op2, op1
            else:
                rev = False
            output = cls.get_oper(op1, op2, reversed=rev)

        output.append(runtime_call(RuntimeLabel.DIVI16))
        output.append("push hl")
        return output

    @classmethod
    def modu16(cls, ins: Quad) -> list[str]:
        """Reminder of div. 2 16bit unsigned integers. The result is pushed onto the stack.

        Optimizations:
         * If 2nd operand is 1 => Return 0
         * If 2nd operand = 2^n => do AND (2^n - 1)
        """
        op1, op2 = tuple(ins[2:])

        if is_int(op2):
            op2 = cls.int16(op2)
            output = cls.get_oper(op1)

            if op2 == 1:
                if op2[0] in ("_", "$"):
                    output = []  # Optimization: Discard previous op if not from the stack

                output.append("ld hl, 0")
                output.append("push hl")
                return output

            if is_2n(op2):
                k = op2 - 1
                if op2 > 255:  # only affects H
                    output.append("ld a, h")
                    output.append("and %i" % (k >> 8))
                    output.append("ld h, a")
                else:
                    output.append("ld h, 0")  # High part goes 0
                    output.append("ld a, l")
                    output.append("and %i" % (k % 0xFF))
                    output.append("ld l, a")

                output.append("push hl")
                return output

            output.append("ld de, %i" % op2)
        else:
            output = cls.get_oper(op1, op2)

        output.append(runtime_call(RuntimeLabel.MODU16))
        output.append("push hl")
        return output

    @classmethod
    def modi16(cls, ins: Quad) -> list[str]:
        """Reminder of div 2 16bit signed integers. The result is pushed onto the stack.

        Optimizations:
         * If 2nd operand is 1 => Return 0
         * If 2nd operand = 2^n => do AND (2^n - 1)
        """
        op1, op2 = tuple(ins[2:])

        if is_int(op2):
            op2 = cls.int16(op2)
            output = cls.get_oper(op1)

            if op2 == 1:
                if op1 in ("_", "$"):
                    output = []  # Optimization: Discard previous op if not from the stack

                output.append("ld hl, 0")
                output.append("push hl")
                return output

            if is_2n(op2):
                k = op2 - 1
                if op2 > 255:  # only affects H
                    output.append("ld a, h")
                    output.append("and %i" % (k >> 8))
                    output.append("ld h, a")
                else:
                    output.append("ld h, 0")  # High part goes 0
                    output.append("ld a, l")
                    output.append("and %i" % (k % 0xFF))
                    output.append("ld l, a")

                output.append("push hl")
                return output

            output.append("ld de, %i" % op2)
        else:
            output = cls.get_oper(op1, op2)

        output.append(runtime_call(RuntimeLabel.MODI16))
        output.append("push hl")
        return output

    @classmethod
    def ltu16(cls, ins: Quad) -> list[str]:
        """Compares & pops top 2 operands out of the stack, and checks
        if the 1st operand < 2nd operand (top of the stack).
        Pushes 0 if False, 1 if True.

        16 bit unsigned version
        """
        output = cls.get_oper(ins[2], ins[3])
        output.append("or a")
        output.append("sbc hl, de")
        output.append("sbc a, a")
        output.append("push af")
        return output

    @classmethod
    def lti16(cls, ins: Quad) -> list[str]:
        """Compares & pops top 2 operands out of the stack, and checks
        if the 1st operand < 2nd operand (top of the stack).
        Pushes 0 if False, 1 if True.

        16 bit signed version
        """
        output = cls.get_oper(ins[2], ins[3])
        output.append(runtime_call(RuntimeLabel.LTI16))
        output.append("push af")
        return output

    @classmethod
    def gtu16(cls, ins: Quad) -> list[str]:
        """Compares & pops top 2 operands out of the stack, and checks
        if the 1st operand > 2nd operand (top of the stack).
        Pushes 0 if False, 1 if True.

        16 bit unsigned version
        """
        output = cls.get_oper(ins[2], ins[3], reversed=True)
        output.append("or a")
        output.append("sbc hl, de")
        output.append("sbc a, a")
        output.append("push af")
        return output

    @classmethod
    def gti16(cls, ins: Quad) -> list[str]:
        """Compares & pops top 2 operands out of the stack, and checks
        if the 1st operand > 2nd operand (top of the stack).
        Pushes 0 if False, 1 if True.

        16 bit signed version
        """
        output = cls.get_oper(ins[2], ins[3], reversed=True)
        output.append(runtime_call(RuntimeLabel.LTI16))
        output.append("push af")
        return output

    @classmethod
    def leu16(cls, ins: Quad) -> list[str]:
        """Compares & pops top 2 operands out of the stack, and checks
        if the 1st operand <= 2nd operand (top of the stack).
        Pushes 0 if False, 1 if True.

        16 bit unsigned version
        """
        output = cls.get_oper(ins[2], ins[3], reversed=True)
        output.append("or a")
        output.append("sbc hl, de")  # Carry if A > B
        output.append("ccf")  # Negates the result => Carry if A <= B
        output.append("sbc a, a")
        output.append("push af")
        return output

    @classmethod
    def lei16(cls, ins: Quad) -> list[str]:
        """Compares & pops top 2 operands out of the stack, and checks
        if the 1st operand <= 2nd operand (top of the stack).
        Pushes 0 if False, 1 if True.

        16 bit signed version
        """
        output = cls.get_oper(ins[2], ins[3])
        output.append(runtime_call(RuntimeLabel.LEI16))
        output.append("push af")
        return output

    @classmethod
    def geu16(cls, ins: Quad) -> list[str]:
        """Compares & pops top 2 operands out of the stack, and checks
        if the 1st operand >= 2nd operand (top of the stack).
        Pushes 0 if False, 1 if True.

        16 bit unsigned version
        """
        output = cls.get_oper(ins[2], ins[3])
        output.append("or a")
        output.append("sbc hl, de")
        output.append("ccf")
        output.append("sbc a, a")
        output.append("push af")
        return output

    @classmethod
    def gei16(cls, ins: Quad) -> list[str]:
        """Compares & pops top 2 operands out of the stack, and checks
        if the 1st operand >= 2nd operand (top of the stack).
        Pushes 0 if False, 1 if True.

        16 bit signed version
        """
        output = cls.get_oper(ins[2], ins[3], reversed=True)
        output.append(runtime_call(RuntimeLabel.LEI16))
        output.append("push af")
        return output

    @classmethod
    def eq16(cls, ins: Quad) -> list[str]:
        """Compares & pops top 2 operands out of the stack, and checks
        if the 1st operand == 2nd operand (top of the stack).
        Pushes 0 if False, 1 if True.

        16 bit un/signed version
        """
        output = cls.get_oper(ins[2], ins[3])
        output.append(runtime_call(RuntimeLabel.EQ16))
        output.append("push af")

        return output

    @classmethod
    def ne16(cls, ins: Quad) -> list[str]:
        """Compares & pops top 2 operands out of the stack, and checks
        if the 1st operand != 2nd operand (top of the stack).
        Pushes 0 if False, 1 if True.

        16 bit un/signed version
        """
        output = cls.get_oper(ins[2], ins[3])
        output.append("or a")  # Resets carry flag
        output.append("sbc hl, de")
        output.append("ld a, h")
        output.append("or l")
        output.append("push af")

        return output

    @classmethod
    def or16(cls, ins: Quad) -> list[str]:
        """Compares & pops top 2 operands out of the stack, and checks
        if the 1st operand OR (logical) 2nd operand (top of the stack),
        pushes 0 if False, 1 if True.

        16 bit un/signed version

        Optimizations:

        If any of the operators are constants: Returns either 0 or
        the other operand
        """
        op1, op2 = tuple(ins[2:])

        if _int_ops(op1, op2) is not None:
            op1, op2 = _int_ops(op1, op2)

            if op2 == 0:
                output = cls.get_oper(op1)
                output.append("ld a, h")
                output.append("or l")  # Convert x to Boolean
                output.append("push af")
                return output  # X or False = X

            output = cls.get_oper(op1)
            output.append("ld a, 0FFh")  # X or True = True
            output.append("push af")
            return output

        output = cls.get_oper(ins[2], ins[3])
        output.append("ld a, h")
        output.append("or l")
        output.append("or d")
        output.append("or e")
        output.append("push af")
        return output

    @classmethod
    def bor16(cls, ins: Quad) -> list[str]:
        """Pops top 2 operands out of the stack, and performs
        1st operand OR (bitwise) 2nd operand (top of the stack),
        pushes result (16 bit in HL).

        16 bit un/signed version

        Optimizations:

        If any of the operators are constants: Returns either 0 or
        the other operand
        """
        op1, op2 = tuple(ins[2:])

        if _int_ops(op1, op2) is not None:
            op1, op2 = _int_ops(op1, op2)

            output = cls.get_oper(op1)
            if op2 == 0:  # X | 0 = X
                output.append("push hl")
                return output

            if op2 == 0xFFFF:  # X & 0xFFFF = 0xFFFF
                output.append("ld hl, 0FFFFh")
                output.append("push hl")
                return output

        output = cls.get_oper(op1, op2)
        output.append(runtime_call(RuntimeLabel.BOR16))
        output.append("push hl")
        return output

    @classmethod
    def xor16(cls, ins: Quad) -> list[str]:
        """Compares & pops top 2 operands out of the stack, and checks
        if the 1st operand XOR (logical) 2nd operand (top of the stack),
        pushes 0 if False, 1 if True.

        16 bit un/signed version

        Optimizations:

        If any of the operators are constants: Returns either 0 or
        the other operand
        """
        op1, op2 = tuple(ins[2:])

        if _int_ops(op1, op2) is not None:
            op1, op2 = _int_ops(op1, op2)
            output = cls.get_oper(op1)

            if op2 == 0:  # X xor False = X
                output.append("ld a, h")
                output.append("or l")
                output.append("push af")
                return output

            # X xor True = NOT X
            output.append("ld a, h")
            output.append("or l")
            output.append("sub 1")
            output.append("sbc a, a")
            output.append("push af")
            return output

        output = cls.get_oper(ins[2], ins[3])
        output.append(runtime_call(RuntimeLabel.XOR16))
        output.append("push af")
        return output

    @classmethod
    def bxor16(cls, ins: Quad) -> list[str]:
        """Pops top 2 operands out of the stack, and performs
        1st operand XOR (bitwise) 2nd operand (top of the stack),
        pushes result (16 bit in HL).

        16 bit un/signed version

        Optimizations:

        If any of the operators are constants: Returns either 0 or
        the other operand
        """
        op1, op2 = tuple(ins[2:])

        if _int_ops(op1, op2) is not None:
            op1, op2 = _int_ops(op1, op2)

            output = cls.get_oper(op1)
            if op2 == 0:  # X ^ 0 = X
                output.append("push hl")
                return output

        output = cls.get_oper(op1, op2)
        output.append(runtime_call(RuntimeLabel.BXOR16))
        output.append("push hl")
        return output

    @classmethod
    def and16(cls, ins: Quad) -> list[str]:
        """Compares & pops top 2 operands out of the stack, and checks
        if the 1st operand AND (logical) 2nd operand (top of the stack),
        pushes 0 if False, 1 if True.

        16 bit un/signed version

        Optimizations:

        If any of the operators are constants: Returns either 0 or
        the other operand
        """
        op1, op2 = tuple(ins[2:])

        if _int_ops(op1, op2) is not None:
            op1, op2 = _int_ops(op1, op2)

            output = cls.get_oper(op1)
            if op2 != 0:
                output.append("ld a, h")
                output.append("or l")
                output.append("push af")
                return output  # X and True = X

            output = cls.get_oper(op1)
            output.append("xor a")  # X and False = False
            output.append("push af")
            return output

        output = cls.get_oper(op1, op2)
        output.append(runtime_call(RuntimeLabel.AND16))
        output.append("push af")
        return output

    @classmethod
    def band16(cls, ins: Quad) -> list[str]:
        """Pops top 2 operands out of the stack, and performs
        1st operand AND (bitwise) 2nd operand (top of the stack),
        pushes result (16 bit in HL).

        16 bit un/signed version

        Optimizations:

        If any of the operators are constants: Returns either 0 or
        the other operand
        """
        op1, op2 = tuple(ins[2:])

        if _int_ops(op1, op2) is not None:
            op1, op2 = _int_ops(op1, op2)

            if op2 == 0xFFFF:  # X & 0xFFFF = X
                return []

            if op2 == 0:  # X & 0 = 0
                output = cls.get_oper(op1)
                output.append("ld hl, 0")
                output.append("push hl")
                return output

        output = cls.get_oper(op1, op2)
        output.append(runtime_call(RuntimeLabel.BAND16))
        output.append("push hl")
        return output

    @classmethod
    def not16(cls, ins: Quad) -> list[str]:
        """Negates top (Logical NOT) of the stack (16 bits in HL)"""
        output = cls.get_oper(ins[2])
        output.append("ld a, h")
        output.append("or l")
        output.append("sub 1")
        output.append("sbc a, a")
        output.append("push af")
        return output

    @classmethod
    def bnot16(cls, ins: Quad) -> list[str]:
        """Negates top (Bitwise NOT) of the stack (16 bits in HL)"""
        output = cls.get_oper(ins[2])
        output.append(runtime_call(RuntimeLabel.BNOT16))
        output.append("push hl")
        return output

    @classmethod
    def neg16(cls, ins: Quad) -> list[str]:
        """Negates top of the stack (16 bits in HL)"""
        output = cls.get_oper(ins[2])
        output.append(runtime_call(RuntimeLabel.NEGHL))
        output.append("push hl")
        return output

    @classmethod
    def abs16(cls, ins: Quad) -> list[str]:
        """Absolute value of top of the stack (16 bits in HL)"""
        output = cls.get_oper(ins[2])
        output.append(runtime_call(RuntimeLabel.ABS16))
        output.append("push hl")
        return output

    @classmethod
    def shru16(cls, ins: Quad) -> list[str]:
        """Logical right shift 16bit unsigned integer.
        The result is pushed onto the stack.

        Optimizations:
          * If 2nd op is 0 then
            do nothing

          * If 2nd op is 1
            Shift Right Arithmetic
        """
        op1, op2 = tuple(ins[2:])
        label = tmp_label()
        label2 = tmp_label()

        if is_int(op2):
            op = cls.int16(op2)
            if op == 0:
                return []

            output = cls.get_oper(op1)
            if op == 1:
                output.append("srl h")
                output.append("rr l")
                output.append("push hl")
                return output

            output.append("ld b, %i" % op)
        else:
            output = Bits8.get_oper(op2)
            output.append("ld b, a")
            output.extend(cls.get_oper(op1))
            output.append("or a")
            output.append("jr z, %s" % label2)

        output.append("%s:" % label)
        output.append("srl h")
        output.append("rr l")
        output.append("djnz %s" % label)
        output.append("%s:" % label2)
        output.append("push hl")
        return output

    @classmethod
    def shri16(cls, ins: Quad) -> list[str]:
        """Arithmetical right shift 16bit signed integer.
        The result is pushed onto the stack.

        Optimizations:
          * If 2nd op is 0 then
            do nothing

          * If 2nd op is 1
            Shift Right Arithmetic
        """
        op1, op2 = tuple(ins[2:])
        label = tmp_label()
        label2 = tmp_label()

        if is_int(op2):
            op = cls.int16(op2)
            if op == 0:
                return []

            output = cls.get_oper(op1)
            if op == 1:
                output.append("srl h")
                output.append("rr l")
                output.append("push hl")
                return output

            output.append("ld b, %i" % op)
        else:
            output = Bits8.get_oper(op2)
            output.append("ld b, a")
            output.extend(cls.get_oper(op1))
            output.append("or a")
            output.append("jr z, %s" % label2)

        output.append("%s:" % label)
        output.append("sra h")
        output.append("rr l")
        output.append("djnz %s" % label)
        output.append("%s:" % label2)
        output.append("push hl")
        return output

    @classmethod
    def shl16(cls, ins: Quad) -> list[str]:
        """Logical/aritmetical left shift 16bit (un)signed integer.
        The result is pushed onto the stack.

        Optimizations:
          * If 2nd op is 0 then
            do nothing

          * If 2nd op is lower than 6
            unroll lop
        """
        op1, op2 = tuple(ins[2:])
        label = tmp_label()
        label2 = tmp_label()

        if is_int(op2):
            op = cls.int16(op2)
            if op == 0:
                return []

            output = cls.get_oper(op1)
            if op < 6:
                output.extend(["add hl, hl"] * op)
                output.append("push hl")
                return output

            output.append("ld b, %i" % op)
        else:
            output = Bits8.get_oper(op2)
            output.append("ld b, a")
            output.extend(cls.get_oper(op1))
            output.append("or a")
            output.append("jr z, %s" % label2)

        output.append("%s:" % label)
        output.append("add hl, hl")
        output.append("djnz %s" % label)
        output.append("%s:" % label2)
        output.append("push hl")
        return output

    @classmethod
    def load16(cls, ins: Quad) -> list[str]:
        """Loads a 16 bit value from a memory address
        If 2nd arg. start with '*', it is always treated as
        an indirect value.
        """
        output = cls.get_oper(ins[2])
        output.append("push hl")
        return output

    @classmethod
    def store16(cls, ins: Quad) -> list[str]:
        """Stores 2nd operand content into address of 1st operand.
        store16 a, x =>  *(&a) = x
        Use '*' for indirect store on 1st operand.
        """
        output = cls.get_oper(ins[2])

        value = ins[1]
        indirect = False

        try:
            if value[0] == "*":
                indirect = True
                value = value[1:]

            value = int(value) & 0xFFFF
            if indirect:
                output.append("ex de, hl")
                output.append("ld hl, (%s)" % str(value))
                output.append("ld (hl), e")
                output.append("inc hl")
                output.append("ld (hl), d")
            else:
                output.append("ld (%s), hl" % str(value))
        except ValueError:
            if value[0] in "_.":
                if indirect:
                    output.append("ex de, hl")
                    output.append("ld hl, (%s)" % str(value))
                    output.append("ld (hl), e")
                    output.append("inc hl")
                    output.append("ld (hl), d")
                else:
                    output.append("ld (%s), hl" % str(value))
            elif value[0] == "#":
                value = value[1:]
                if indirect:
                    output.append("ex de, hl")
                    output.append("ld hl, (%s)" % str(value))
                    output.append("ld (hl), e")
                    output.append("inc hl")
                    output.append("ld (hl), d")
                else:
                    output.append("ld (%s), hl" % str(value))
            else:
                output.append("ex de, hl")
                if indirect:
                    output.append("pop hl")
                    output.append("ld a, (hl)")
                    output.append("inc hl")
                    output.append("ld h, (hl)")
                    output.append("ld l, a")
                else:
                    output.append("pop hl")

                output.append("ld (hl), e")
                output.append("inc hl")
                output.append("ld (hl), d")

        return output

    @classmethod
    def jzero16(cls, ins: Quad) -> list[str]:
        """Jumps if top of the stack (16bit) is 0 to arg(1)"""
        value = ins[1]
        if is_int(value):
            if int(value) == 0:
                return ["jp %s" % str(ins[2])]  # Always true
            return []

        output = cls.get_oper(value)
        output.append("ld a, h")
        output.append("or l")
        output.append("jp z, %s" % str(ins[2]))
        return output

    @classmethod
    def jgezerou16(cls, ins: Quad) -> list[str]:
        """Jumps if top of the stack (16bit) is >= 0 to arg(1)
        Always TRUE for unsigned
        """
        output = []
        value = ins[1]
        if not is_int(value):
            output = cls.get_oper(value)

        output.append("jp %s" % str(ins[2]))
        return output

    @classmethod
    def jgezeroi16(cls, ins: Quad) -> list[str]:
        """Jumps if top of the stack (16bit) is >= 0 to arg(1)"""
        value = ins[1]
        if is_int(value):
            if int(value) >= 0:
                return ["jp %s" % str(ins[2])]  # Always true
            return []

        output = cls.get_oper(value)
        output.append("add hl, hl")  # Puts sign into carry
        output.append("jp nc, %s" % str(ins[2]))
        return output

    @classmethod
    def ret16(cls, ins: Quad) -> list[str]:
        """Returns from a procedure / function a 16bits value"""
        output = cls.get_oper(ins[1])
        output.append("#pragma opt require hl")
        output.append("jp %s" % str(ins[2]))
        return output

    @classmethod
    def param16(cls, ins: Quad) -> list[str]:
        """Pushes 16bit param into the stack"""
        output = cls.get_oper(ins[1])
        output.append("push hl")
        return output

    @classmethod
    def fparam16(cls, ins: Quad) -> list[str]:
        """Passes a word as a __FASTCALL__ parameter.
        This is done by popping out of the stack for a
        value, or by loading it from memory (indirect)
        or directly (immediate)
        """
        return cls.get_oper(ins[1])

    @classmethod
    def jnzero16(cls, ins: Quad) -> list[str]:
        """Jumps if top of the stack (16bit) is != 0 to arg(1)"""
        value = ins[1]
        if is_int(value):
            if int(value) != 0:
                return ["jp %s" % str(ins[2])]  # Always true
            return []

        output = cls.get_oper(value)
        output.append("ld a, h")
        output.append("or l")
        output.append("jp nz, %s" % str(ins[2]))
        return output