{#     Copyright 2022, Kay Hayen, mailto:kay.hayen@gmail.com                    #}
{#                                                                              #}
{#     Part of "Nuitka", an optimizing Python compiler that is compatible and   #}
{#     integrates with CPython, but also works on its own.                      #}
{#                                                                              #}
{#     Licensed under the Apache License, Version 2.0 (the "License");          #}
{#     you may not use this file except in compliance with the License.         #}
{#     You may obtain a copy of the License at                                  #}
{#                                                                              #}
{#        http://www.apache.org/licenses/LICENSE-2.0                            #}
{#                                                                              #}
{#     Unless required by applicable law or agreed to in writing, software      #}
{#     distributed under the License is distributed on an "AS IS" BASIS,        #}
{#     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. #}
{#     See the License for the specific language governing permissions and      #}
{#     limitations under the License.                                           #}
{#                                                                              #}
{% from 'HelperSlotsCommon.c.j2' import goto_exit, constant_int_exit_target, constant_float_exit_target %}

{% macro int_core(props, operator, nb_slot, bool_mode, left, right, result, operand1, operand2, exit_result_ok, exit_result_exception, exit_result_ok_cbool, exit_result_ok_clong, exit_result_ok_cfloat, exit_result_object, exit_result_ok_left, exit_result_ok_const_int_0, exit_result_ok_const_int_neg_1, exit_result_ok_const_float_0_0, exit_result_ok_const_float_minus_0_0) %}
    {% set fall_through_needed = 1 %}

    {{ left.getCheckValueCode(operand1) }}
    {{ right.getCheckValueCode(operand2) }}

    {# This is supposed to be Python2 only code with types no bigger than int, therefore this works always #}
    const long a = {{ left.getAsLongValueExpression(operand1) }};
    const long b = {{ right.getAsLongValueExpression(operand2) }};

{% if operator in "+-" %}
    const long x = (long)((unsigned long)a {{operator}} b);
    bool no_overflow = ((x^a) >= 0 || (x^{{"~" if operator == "-" else ""}}b) >= 0);
{% if bool_mode %}
    bool t = !no_overflow || x != 0;

    {{ goto_exit(props, exit_result_ok_cbool, "t") }}
    {% set fall_through_needed = 0 %}
{% else %}
    if (likely(no_overflow)) {
        {{ goto_exit(props, exit_result_ok_clong, "x") }}
    }
{% endif %}
{% elif operator == "*" %}
    const long longprod = (long)((unsigned long)a * b);
    const double doubleprod = (double)a * (double)b;
    const double doubled_longprod = (double)longprod;

    if (likely(doubled_longprod == doubleprod)) {
        {{ goto_exit(props, exit_result_ok_clong, "longprod") }}
    } else {
        const double diff = doubled_longprod - doubleprod;
        const double absdiff = diff >= 0.0 ? diff : -diff;
        const double absprod = doubleprod >= 0.0 ? doubleprod : -doubleprod;

        if (likely(32.0 * absdiff <= absprod)) {
            {{ goto_exit(props, exit_result_ok_clong, "longprod") }}
        }
    }
{% elif operator == "//" or nb_slot == "nb_divide" %}
    if (unlikely(b == 0)) {
        SET_CURRENT_EXCEPTION_TYPE0_STR(PyExc_ZeroDivisionError, "integer division or modulo by zero");
        {{ goto_exit(props, exit_result_exception) }}
    }

    /* TODO: Isn't this a very specific value only, of which we could
     * hardcode the constant result. Not sure how well the C compiler
     * optimizes UNARY_NEG_WOULD_OVERFLOW to this, but dividing by
     * -1 has to be rare anyway.
     */

    if (likely(b != -1 || !UNARY_NEG_WOULD_OVERFLOW(a))) {
        long a_div_b = a / b;
        long a_mod_b = (long)(a - (unsigned long)a_div_b * b);

        if (a_mod_b && (b ^ a_mod_b) < 0) {
            a_mod_b += b;
            a_div_b -= 1;
        }

        {{ goto_exit(props, exit_result_ok_clong, "a_div_b") }}
    }
{% elif operator=="/" and "true_div" in nb_slot %}
    if (unlikely(b == 0)) {
        SET_CURRENT_EXCEPTION_TYPE0_STR(PyExc_ZeroDivisionError, "division by zero");
        {{ goto_exit(props, exit_result_exception) }}
    }

{% if bool_mode %}
    {{ goto_exit(props, exit_result_ok_cbool, "a == 0") }}
    {% set fall_through_needed = 0 %}
{% else %}
    if (a == 0) {
        if (b < 0) {
            {{ goto_exit(props, exit_result_ok_const_float_minus_0_0) }}
        } else {
            {{ goto_exit(props, exit_result_ok_const_float_0_0) }}
        }
    }

/* May need to resort to LONG code, which we currently do not
 * specialize yet. TODO: Once we do that, call it here instead.
 */
#if DBL_MANT_DIG < WIDTH_OF_ULONG
    if ((a >= 0 ? 0UL + a : 0UL - a) >> DBL_MANT_DIG || (b >= 0 ? 0UL + b : 0UL - b) >> DBL_MANT_DIG) {
    } else
#endif
    {
        double r = (double)a / (double)b;

        {{ goto_exit(props, exit_result_ok_cfloat, "r") }}
    }
{% endif %}
{% elif operator=="%" %}
    /* TODO: Isn't this a very specific value only, of which we could
     * hardcode the constant result. Not sure how well the C compiler
     * optimizes UNARY_NEG_WOULD_OVERFLOW to this, but dividing by
     * -1 has to be rare anyway.
     */

    if (likely(b != -1 || !UNARY_NEG_WOULD_OVERFLOW(a))) {
        long r = a % b;

        // Sign handling.
        if (r != 0 && ((b ^ r) < 0) ) {
            r += b;
        }

        {{ goto_exit(props, exit_result_ok_clong, "r") }}
    }
{% elif operator in "|^&" %}
    const long r = a {{operator}} b;

    {{ goto_exit(props, exit_result_ok_clong, "r") }}
    {% set fall_through_needed = 0 %}
{% elif operator == "<<" %}
    if (unlikely(b < 0)) {
        SET_CURRENT_EXCEPTION_TYPE0_STR(PyExc_ValueError, "negative shift count");
        {{ goto_exit(props, exit_result_exception) }}
    }
    /* Short cut for zero shift or shifting zero. */
    if (a == 0 || b == 0) {
        {{ goto_exit(props, exit_result_ok_left) }}
    } else if (b >= LONG_BIT) {
        PyObject *operand1_long = PyLong_FromLong(a);
        PyObject *operand2_long = PyLong_FromLong(b);

        // TODO: Change this to using CLONG once we specialize that too.
        PyObject *r = _BINARY_OPERATION_LSHIFT_OBJECT_LONG_LONG(operand1_long, operand2_long);

        Py_DECREF(operand1_long);
        Py_DECREF(operand2_long);

        {{ goto_exit(props, exit_result_object, "r") }}
    } else {
        long c = a << b;

        if (a != Py_ARITHMETIC_RIGHT_SHIFT(long, c, b)) {
            PyObject *operand1_long = PyLong_FromLong(a);
            PyObject *operand2_long = PyLong_FromLong(b);

            // TODO: Change this to using CLONG once we specialize that too.
            PyObject *r = _BINARY_OPERATION_LSHIFT_OBJECT_LONG_LONG(operand1_long, operand2_long);

            Py_DECREF(operand1_long);
            Py_DECREF(operand2_long);

            {{ goto_exit(props, exit_result_object, "r") }}
        } else {
            {{ goto_exit(props, exit_result_ok_clong, "c") }}
        }
    }
    {% set fall_through_needed = 0 %}
{% elif operator == ">>" %}
    if (unlikely(b < 0)) {
        SET_CURRENT_EXCEPTION_TYPE0_STR(PyExc_ValueError, "negative shift count");
        {{ goto_exit(props, exit_result_exception) }}
    }

    /* Short cut for zero shift or shifting zero. */
    if (a == 0 || b == 0) {
        {{ goto_exit(props, exit_result_ok_left) }}
    } else if (b >= LONG_BIT) {
        if (a < 0) {
            {{ goto_exit(props, exit_result_ok_const_int_neg_1) }}
        } else {
            {{ goto_exit(props, exit_result_ok_const_int_0) }}
        }
    } else {
        long r = Py_ARITHMETIC_RIGHT_SHIFT(long, a, b);

        {{ goto_exit(props, exit_result_ok_clong, "r") }}
    }
    {% set fall_through_needed = 0 %}
{% elif operator == "**" %}
    if (b < 0) {
        // TODO: Use CFLOAT once available.
        PyObject *operand1_float = MAKE_FLOAT_FROM_DOUBLE(a);
        PyObject *operand2_float = MAKE_FLOAT_FROM_DOUBLE(b);

        PyObject *r = _BINARY_OPERATION_POW_OBJECT_FLOAT_FLOAT(operand1_float, operand2_float);

        Py_DECREF(operand1_float);
        Py_DECREF(operand2_float);

        {{ goto_exit(props, exit_result_object, "r") }}
    } else {
        long temp = a;
        long ix = 1;
        long bb = b;

        while (bb > 0) {
            long prev = ix;
            if (bb & 1) {
                ix = (unsigned long)ix * temp;
                if (temp == 0) {
                    break;
                }
                if (ix / temp != prev) {
                    PyObject *operand1_long = PyLong_FromLong(a);
                    PyObject *operand2_long = PyLong_FromLong(b);

                    PyObject *r = _BINARY_OPERATION_POW_OBJECT_LONG_LONG(operand1_long, operand2_long);

                    Py_DECREF(operand1_long);
                    Py_DECREF(operand2_long);

                    {{ goto_exit(props, exit_result_object, "r") }}
                }
            }
            bb >>= 1;
            if (bb==0) {
                break;
            }
            prev = temp;
            temp = (unsigned long)temp * temp;

            if (prev != 0 && temp / prev != prev) {
                PyObject *operand1_long = PyLong_FromLong(a);
                PyObject *operand2_long = PyLong_FromLong(b);

                PyObject *r = _BINARY_OPERATION_POW_OBJECT_LONG_LONG(operand1_long, operand2_long);

                Py_DECREF(operand1_long);
                Py_DECREF(operand2_long);

                {{ goto_exit(props, exit_result_object, "r") }}
            }
        }

        {{ goto_exit(props, exit_result_ok_clong, "ix") }}
    }
    {% set fall_through_needed = 0 %}
{% elif operator == "divmod" %}
    if (unlikely(b == 0)) {
        SET_CURRENT_EXCEPTION_TYPE0_STR(PyExc_ZeroDivisionError, "integer division or modulo by zero");
        {{ goto_exit(props, exit_result_exception) }}
    }

    if (likely(b != -1 || !UNARY_NEG_WOULD_OVERFLOW(a))) {
        long a_div_b = a / b;
        long a_mod_b = (long)(a - (unsigned long)a_div_b * b);

        if (a_mod_b && (b ^ a_mod_b) < 0) {
            a_mod_b += b;
            a_div_b -= 1;
        }

        PyObject *r = Py_BuildValue("(ll)", a_div_b, a_mod_b);
        {{ goto_exit(props, exit_result_object, "r") }}
    }
{% else %}
#error Operator {{operator}} not implemented
{% endif %}
{% if fall_through_needed %}
    {
        PyObject *operand1_object = {{ left.getAsObjectValueExpression(operand1) }};
        PyObject *operand2_object = {{ right.getAsObjectValueExpression(operand2) }};

        PyObject *r = {{ left.getSlotCallExpression(nb_slot, "PyLong_Type.tp_as_number->"+nb_slot, "operand1_object", "operand2_object") }};
        assert(r != Py_NotImplemented);

        {{ left.releaseAsObjectValueStatement("operand1_object") }}
        {{ right.releaseAsObjectValueStatement("operand2_object") }}

        {{ goto_exit(props, exit_result_object, "r") }}
    }
{% endif %}
{% endmacro %}

{% macro int_slot(props, operator, nb_slot, target, left, right, result, operand1, operand2, exit_result_ok, exit_result_exception) %}
    {% set bool_mode = target and target.type_name in ("nuitka_bool", "nbool") %}

    // Not every code path will make use of all possible results.
#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable : 4101)
#endif
    NUITKA_MAY_BE_UNUSED bool cbool_result;
    NUITKA_MAY_BE_UNUSED PyObject *obj_result;
    NUITKA_MAY_BE_UNUSED long clong_result;
    NUITKA_MAY_BE_UNUSED double cfloat_result;
#ifdef _MSC_VER
#pragma warning(pop)
#endif

    {{ int_core(props, operator, nb_slot, bool_mode, left, right, result, operand1, operand2, exit_result_ok, exit_result_exception, "exit_result_ok_cbool", "exit_result_ok_clong", "exit_result_ok_cfloat", "exit_result_object", "exit_result_ok_left", "exit_result_ok_const_int_0", "exit_result_ok_const_int_neg_1", "exit_result_ok_const_float_0_0", "exit_result_ok_const_float_minus_0_0") }}

{# // {{ props }} #}

{% if "exit_result_ok_cbool" in props["exits"] %}
exit_result_ok_cbool:
{% if target %}
    {{ target.getAssignFromBoolExpressionCode(result, "cbool_result", give_ref=1) }}
{% else %}
    {# TODO: Check the reference we were handed down. #}

    // We got an object handed, that we have to release.
    Py_DECREF({{ operand1 }});

    // That's our return value then. As we use a dedicated variable, it's
    // OK that way.
    {{ operand1 }} = PyInt_FromLong(cbool_result);
{% endif %}
    {{ goto_exit(props, exit_result_ok) }}
{% endif %}

{% if "exit_result_ok_clong" in props["exits"] %}
exit_result_ok_clong:
{% if target %}
    {{ (target if target != object_desc else int_desc).getAssignFromLongExpressionCode(result, "clong_result") }}
{% else %}
    {# TODO: Check the reference we were handed down. #}

    // We got an object handed, that we have to release.
    Py_DECREF({{ operand1 }});

    // That's our return value then. As we use a dedicated variable, it's
    // OK that way.
    {{ operand1 }} = PyInt_FromLong(clong_result);
{% endif %}
    {{ goto_exit(props, exit_result_ok) }}
{% endif %}

{% if "exit_result_ok_cfloat" in props["exits"] %}
exit_result_ok_cfloat:
{% if target %}
    {{ target.getAssignFromFloatExpressionCode(result, "cfloat_result") }}
{% else %}
    {# TODO: Check the reference we were handed down. #}

    // We got an object handed, that we have to release.
    Py_DECREF({{ operand1 }});

    {{ left.getAssignFromFloatExpressionCode(operand1, "cfloat_result") }}
{% endif %}
    {{ goto_exit(props, exit_result_ok) }}
{% endif %}

{% if "exit_result_ok_left" in props["exits"] %}
exit_result_ok_left:
{% if target %}
    {{ target.getAssignConversionCode(result, left, operand1) }}
{% endif %}
    {# Nothing to do in case of in-place. #}
    {{ goto_exit(props, exit_result_ok) }}
{% endif %}

{% if "exit_result_object" in props["exits"] %}
exit_result_object:
    if (unlikely(obj_result == NULL)) {
        {{ goto_exit(props, exit_result_exception) }}
    }
{% if target %}
    {{ target.getAssignFromObjectExpressionCode(result, "obj_result") }}
{% else %}
    {# TODO: Check the reference we were handed down and do it in-place really. #}
    // We got an object handed, that we have to release.
    Py_DECREF({{ operand1 }});

    {{ operand1 }} = obj_result;
{% endif %}
    {{ goto_exit(props, exit_result_ok) }}
{% endif %}

{% if "exit_result_ok_const_int_0" in props["exits"] %}
{{ constant_int_exit_target(props, target, result, left, operand1, "exit_result_ok_const_int_0", 0, exit_result_ok) }}
{% endif %}

{% if "exit_result_ok_const_int_neg_1" in props["exits"] %}
{{ constant_int_exit_target(props, target, result, left, operand1, "exit_result_ok_const_int_neg_1", -1, exit_result_ok) }}
{% endif %}

{% if "exit_result_ok_const_float_0_0" in props["exits"] %}
{{ constant_float_exit_target(props, target, result, left, operand1, "exit_result_ok_const_float_0_0", 0.0, exit_result_ok) }}
{% endif %}

{% if "exit_result_ok_const_float_minus_0_0" in props["exits"] %}
{{ constant_float_exit_target(props, target, result, left, operand1, "exit_result_ok_const_float_minus_0_0", -0.0, exit_result_ok) }}
{% endif %}

{% endmacro %}
