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// SPDX-License-Identifier: BSD-2-Clause
/*
* Copyright (c) 2014, STMicroelectronics International N.V.
*/
#include "mpa.h"
/*************************************************************
*
* HELPERS
*
*************************************************************/
/* --------------------------------------------------------------------
* Function: __mpa_abs_cmp
*
* Returns 0 if |op1| == |op2|
* >0 if |op1| > |op2|
* <0 if |op1| < |op2|
*/
int __mpa_abs_cmp(const mpanum op1, const mpanum op2)
{
int wpos;
char same;
/* if they're really the same, return 0 */
if (op1 == op2)
return 0;
/* check the sizes */
if (__mpanum_size(op1) != __mpanum_size(op2))
return __mpanum_size(op1) - __mpanum_size(op2);
if (__mpanum_is_zero(op1) && __mpanum_is_zero(op2))
return 0;
/* Ok, so we have the same size and they're not zero. Check words */
wpos = __mpanum_size(op1) - 1;
same = 1;
while (same && (wpos >= 0)) {
same = (op1->d[wpos] == op2->d[wpos]);
wpos--;
}
if (same)
return 0;
wpos++;
return (op1->d[wpos] > op2->d[wpos] ? 1 : -1);
}
/* --------------------------------------------------------------------
* Function: __mpa_abs_greater_than
*
* Returns 1 if |op1| > |op2| and otherwise returns 0.
*/
int __mpa_abs_greater_than(const mpanum op1, const mpanum op2)
{
return (__mpa_abs_cmp(op1, op2) > 0 ? 1 : 0);
}
/* --------------------------------------------------------------------
* Function: __mpa_abs_less_than
*
* Returns 1 if |op1| < |op2| and otherwise returns 0.
*/
int __mpa_abs_less_than(const mpanum op1, const mpanum op2)
{
return (__mpa_abs_cmp(op1, op2) < 0 ? 1 : 0);
}
/*************************************************************
*
* LIB FUNCTIONS
*
*************************************************************/
/* --------------------------------------------------------------------
* Function: mpa_cmp
*
* Returns 0 if op1 == op2
* >0 if op1 > op2
* <0 if op1 < op2
*/
int32_t mpa_cmp(const mpanum op1, const mpanum op2)
{
int sign_1;
int abscmp;
/* if they have different signs, it's straight forward */
sign_1 = __mpanum_sign(op1);
if (sign_1 != __mpanum_sign(op2))
return sign_1;
/* handle the special case where op1->size = 0 */
if (__mpanum_size(op1) == 0)
return __mpanum_size(op2) == 0 ? 0 : -__mpanum_sign(op2);
/* so they have the same sign. compare the abs values and decide
* based on sign_1.
*/
abscmp = __mpa_abs_cmp(op1, op2);
if (sign_1 != MPA_POS_SIGN)
return -abscmp;
return abscmp;
}
/* --------------------------------------------------------------------
* Function: mpa_cmp_short
*
* Compares op1 to the word_t op2 and returns:
* >0 if op1 > op2,
* 0 if op1 == op2
* <0 if op1 < op2
*/
int32_t mpa_cmp_short(const mpanum op1, int32_t op2)
{
#if (MPA_WORD_SIZE == 32)
int sign_1;
int sign_2;
mpa_word_t op2abs;
sign_1 = __mpanum_sign(op1);
sign_2 = (op2 < 0) ? MPA_NEG_SIGN : MPA_POS_SIGN;
/* handle the special case where op1->size = 0 */
if (op1->size == 0)
return op2 == 0 ? 0 : -sign_2;
/* check if op1 is larger than an int32_t */
if (__mpanum_size(op1) > 1)
return sign_1;
/* check if they have different signs */
if (sign_1 != sign_2)
return sign_1;
/* here they have the same sign and we can compare absolute values */
op2abs = ((op2 < 0) ? (mpa_word_t) -op2 : (mpa_word_t) op2);
if (__mpanum_lsw(op1) == op2abs)
return 0;
return (__mpanum_lsw(op1) > op2abs) ? sign_1 : -sign_1;
#else
#error "Write code for digit size != 32"
#endif
}
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