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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 Damien P. George
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "py/smallint.h"
bool mp_small_int_mul_overflow(mp_int_t x, mp_int_t y) {
// Check for multiply overflow; see CERT INT32-C
if (x > 0) { // x is positive
if (y > 0) { // x and y are positive
if (x > (MP_SMALL_INT_MAX / y)) {
return true;
}
} else { // x positive, y nonpositive
if (y < (MP_SMALL_INT_MIN / x)) {
return true;
}
} // x positive, y nonpositive
} else { // x is nonpositive
if (y > 0) { // x is nonpositive, y is positive
if (x < (MP_SMALL_INT_MIN / y)) {
return true;
}
} else { // x and y are nonpositive
if (x != 0 && y < (MP_SMALL_INT_MAX / x)) {
return true;
}
} // End if x and y are nonpositive
} // End if x is nonpositive
return false;
}
mp_int_t mp_small_int_modulo(mp_int_t dividend, mp_int_t divisor) {
// Python specs require that mod has same sign as second operand
dividend %= divisor;
if ((dividend < 0 && divisor > 0) || (dividend > 0 && divisor < 0)) {
dividend += divisor;
}
return dividend;
}
mp_int_t mp_small_int_floor_divide(mp_int_t num, mp_int_t denom) {
if (num >= 0) {
if (denom < 0) {
num += -denom - 1;
}
} else {
if (denom >= 0) {
num += -denom + 1;
}
}
return num / denom;
}
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