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/*#include <stdint.h>*/
typedef char int8_t;
typedef unsigned char uint8_t;
typedef short int16_t;
typedef unsigned short uint16_t;
typedef long int32_t;
typedef unsigned long uint32_t;
/*#include <stdbool.h>*/
typedef uint8_t bool;
#ifndef true
#define true 1
#endif
#ifndef false
#define false 0
#endif
/*Defines*/
#define PREFIX_BITS_PER_BYTE 8
/*Neither can be greater than 128*/
#define PREFIX_intsize 4
#define PREFIX_INTSIZE 8
/*Typedefs*/
typedef uint8_t PREFIX_INT[PREFIX_INTSIZE];
typedef int32_t PREFIX_int;
/*Globals*/
bool PREFIX_math_overflow;
/*==============================================================CODE=============================================================*/
void PREFIX_zero_int(PREFIX_INT *ptr)
{
uint8_t i;
for (i = 0; i < PREFIX_INTSIZE; i++)
*ptr[i] = 0;
}
bool PREFIX_isneg(PREFIX_INT *in)
{
return (*in[PREFIX_INTSIZE-1] & 0x80) >> 7;
}
void PREFIX_int_to_buf(PREFIX_INT *dest, PREFIX_int *src)
{
PREFIX_int tmp;
uint8_t i;
tmp = *src;
for (i = 0; i < PREFIX_intsize; i++)
*dest[i] = (tmp >> (i*PREFIX_BITS_PER_BYTE)) & 0xFF;
}
void PREFIX_buf_to_int(PREFIX_int *dest, PREFIX_INT *src)
{
PREFIX_int ret;
uint8_t i;
ret = 0;
for (i = 0; i < PREFIX_INTSIZE; i++) {
ret += dest[i];
ret <<= PREFIX_BITS_PER_BYTE;
}
*src[0] = ret;
}
void PREFIX_buf_to_buf(PREFIX_INT *dest, PREFIX_INT *src)
{
uint8_t i;
for (i = 0; i < PREFIX_INTSIZE; i++)
*dest[i] = *src[i];
}
/*True to*/
bool PREFIX_equal(PREFIX_INT *left, PREFIX_INT *right)
{
uint8_t i;
for (i = 0; i < PREFIX_INTSIZE; i++)
if (*left[i] != *right[i])
return false;
return true;
}
/*greater than*/
bool PREFIX_greater(PREFIX_INT *left, PREFIX_INT *right)
{
uint8_t i;
bool left_neg, right_neg;
left_neg = PREFIX_isneg(left);
right_neg = PREFIX_isneg(right);
if (left_neg || right_neg) {
if (left_neg && !right_neg)
return false;
else if (!left_neg && right_neg)
return true;
}
for (i = 0; i < PREFIX_INTSIZE; i++) {
if (*left[i] > *right[i])
return true;
else if (*left[i] < *right[i])
return false;
}
return false;
}
/*less than*/
bool PREFIX_less(PREFIX_INT *left, PREFIX_INT *right)
{
return !PREFIX_greater(left, right);
}
/*greater than or equal to*/
bool PREFIX_greater_or_equal(PREFIX_INT *left, PREFIX_INT *right)
{
return PREFIX_greater(left, right) || PREFIX_equal(left, right);
}
/*less than or equal to*/
bool PREFIX_less_or_equal(PREFIX_INT *left, PREFIX_INT *right)
{
return PREFIX_less(left, right) || PREFIX_equal(left, right);
}
/*Negatives not currently supported*/
void PREFIX_add(PREFIX_INT *dest, PREFIX_INT *src)
{
/*operator*/
uint16_t op;
uint8_t i;
bool dest_neg, src_neg;
src_neg = PREFIX_isneg(src);
dest_neg = PREFIX_isneg(dest);
if (src_neg || dest_neg) {
PREFIX_math_overflow = true;
return;
}
for (i = 0; i < PREFIX_INTSIZE; i++) {
op = *src[i];
op += *dest[i];
*dest[i] = op & 0xFF;
op >>= PREFIX_BITS_PER_BYTE;
}
if (i == PREFIX_INTSIZE && op != 0)
PREFIX_math_overflow = true;
if (!(src_neg || dest_neg) && PREFIX_isneg(dest))
PREFIX_math_overflow = true;
}
/*Negatives not currently supported*/
void PREFIX_sub(PREFIX_INT *dest, PREFIX_INT *src)
{
uint16_t op;
uint8_t i, j;
bool dest_neg, src_neg;
uint16_t tmp_op = 0;
bool got_borrow = false;
PREFIX_INT tmp_dest, tmp_src;
src_neg = PREFIX_isneg(src);
dest_neg = PREFIX_isneg(dest);
if (src_neg || dest_neg)
PREFIX_math_overflow = true;
PREFIX_buf_to_buf(&tmp_src, src);
PREFIX_buf_to_buf(&tmp_dest, dest);
for (i = 0; i < PREFIX_INTSIZE; i++) {
op = tmp_dest[i];
if (tmp_src[i] > tmp_dest[i]) {
if (i == (PREFIX_INTSIZE-1))
PREFIX_math_overflow = true;
for (j = (i+1); j < PREFIX_INTSIZE; j++ )
if (tmp_dest[j]) {
tmp_dest[j] -= 1;
tmp_op = 0xFF;
got_borrow = true;
break;
}
if (!got_borrow)
PREFIX_math_overflow = true;
for (j--; j > i; j--)
tmp_src[j] = 0xFF;
op += tmp_op;
}
op -= tmp_src[i];
*dest[i] = op & 0xFF;
}
}
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