Add initial bigint implementation for the fmt library

This commit is contained in:
2025-03-05 21:34:03 +03:00
parent 0683389d7b
commit fc3d4e22d5
3 changed files with 661 additions and 0 deletions

489
src/String/Int1120.c Normal file
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#include "String.h"
#include <stdio.h>
#include <string.h>
#include <assert.h>
static const uint8_t clzLookup[256] =
{
8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
static const uint16_t pow10Data[] =
{
0x0001, 0x000A, 0x0064, 0x2710, 0xE100, 0x05F5, 0x0000, 0x6FC1,
0x86F2, 0x0023, 0x0000, 0x0000, 0xEF81, 0x85AC, 0x415B, 0x2D6D,
0x04EE, 0x0000, 0x0000, 0x0000, 0x0000, 0x1F01, 0xBF6A, 0xED64,
0x6E38, 0x97ED, 0xDAA7, 0xF9F4, 0xE93F, 0x4F03, 0x0018, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x3E01,
0x2E95, 0x9909, 0x03DF, 0x38FD, 0x0F15, 0xE42F, 0x2374, 0xF5EC,
0xD3CF, 0xDC08, 0xC404, 0xB0DA, 0xBCCD, 0x7F19, 0xA633, 0x2603,
0xE91F, 0x024E, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
0x0000, 0x0000, 0x7C01, 0x982E, 0x875B, 0xBED3, 0x9F72, 0xD8D9,
0x2F87, 0x1215, 0x50C6, 0x6BDE, 0x6E70, 0xCF4A, 0xD80F, 0xD595,
0x716E, 0x26B2, 0x66B0, 0xADC6, 0x3624, 0x1D15, 0xD35A, 0x3C42,
0x540E, 0x63FF, 0x73C0, 0xCC55, 0xEF17, 0x65F9, 0x28F2, 0x55BC,
0xC7F7, 0x80DC, 0xEDDC, 0xF46E, 0xEFCE, 0x5FDC, 0x53F7, 0x0005,
};
static const int pow10Index[] =
{
0, 1, 2, 3, 4, 6, 10, 17, 31, 58,
};
static const int pow10Size[] =
{
1, 1, 1, 1, 2, 4, 7, 14, 27, 54,
};
static void pow10Set(int index,
BH_Int1120 *out)
{
out->size = pow10Size[index];
memcpy(out->digits, pow10Data + pow10Index[index], out->size);
}
int BH_Int1120Clz(const uint16_t value)
{
if (value & 0xFF00)
return clzLookup[(value >> 8) & 0xFF];
else
return 8 + clzLookup[value & 0xFF];
}
int BH_Int1120Compare(const BH_Int1120 *a,
const BH_Int1120 *b)
{
int i, result;
/* Compare by lengths */
result = a->size - b->size;
if (result)
return result;
/* Compare by blocks */
for (i = a->size; i; i--)
{
if (a->digits[i - 1] < b->digits[i - 1])
return -1;
else if (a->digits[i - 1] > b->digits[i - 1])
return 1;
}
return 0;
}
void BH_Int1120Add(const BH_Int1120 *a,
const BH_Int1120 *b,
BH_Int1120 *out)
{
const BH_Int1120 *small, *big;
uint32_t carry, tmp;
int i;
small = b;
big = a;
assert(a->size + 1 <= BH_INT1120_DIGITS);
assert(b->size + 1 <= BH_INT1120_DIGITS);
/* Find smaller interger */
if (a->size < b->size)
{
small = a;
big = b;
}
/* Main addition loop */
carry = 0;
for (i = 0; i < small->size; i++)
{
tmp = (uint32_t)small->digits[i] + (uint32_t)big->digits[i] + carry;
carry = (tmp >> 16) & 0xFFFF;
out->digits[i] = tmp & 0xFFFF;
}
/* Carry propogation */
for (; i < big->size; i++)
{
tmp = (uint32_t)big->digits[i] + carry;
carry = (tmp >> 16) & 0xFFFF;
out->digits[i] = tmp & 0xFFFF;
}
/* Handle carry */
if (carry)
out->digits[i++] = carry;
out->size = i;
}
void BH_Int1120Sub(const BH_Int1120 *a,
const BH_Int1120 *b,
BH_Int1120 *out)
{
uint32_t carry, tmp;
int i;
/* Main subtraction loop */
carry = 0;
for (i = 0; i < b->size; i++)
{
tmp = (uint32_t)a->digits[i] - (uint32_t)b->digits[i] - carry;
carry = (tmp >> 31) & 0x1;
out->digits[i] = tmp & 0xFFFF;
}
/* Carry propogation */
for (; i < a->size; i++)
{
tmp = (uint32_t)a->digits[i] - carry;
carry = (tmp >> 31) & 0x1;
out->digits[i] = tmp & 0xFFFF;
}
/* Truncate length on empty blocks */
out->size = a->size;
while(out->size && !out->digits[out->size - 1])
out->size--;
}
void BH_Int1120Mul(const BH_Int1120 *a,
const BH_Int1120 *b,
BH_Int1120 *out)
{
int i, j;
uint32_t tmp, carry;
assert(a->size + b->size <= BH_INT1120_DIGITS);
for (i = 0; i < BH_INT1120_DIGITS; i++)
out->digits[i] = 0;
for (i = 0; i < a->size; i++)
{
carry = 0;
/* Multiplication loop */
for (j = 0; j < b->size; j++)
{
carry += (uint32_t)out->digits[i + j];
tmp = (uint32_t)a->digits[i] * (uint32_t)b->digits[j] + carry;
carry = (tmp >> 16) & 0xFFFF;
out->digits[i + j] = tmp & 0xFFFF;
}
/* Carry propagation */
if (carry)
{
tmp = (uint32_t)out->digits[i + j] + carry;
out->digits[i + j] = tmp & 0xFFFF;
}
}
out->size = a->size + b->size;
if (!out->digits[out->size - 1])
out->size--;
}
void BH_Int1120MulDigit(const BH_Int1120 *in,
uint16_t digit,
BH_Int1120 *out)
{
int i;
uint32_t tmp, carry;
assert(in->size + 1 <= BH_INT1120_DIGITS);
for (i = 0; i < BH_INT1120_DIGITS; i++)
out->digits[i] = 0;
/* Multiplication loop */
carry = 0;
for (i = 0; i < in->size; i++)
{
carry += (uint32_t)out->digits[i];
tmp = (uint32_t)in->digits[i] * digit + carry;
carry = (tmp >> 16) & 0xFFFF;
out->digits[i] = tmp & 0xFFFF;
}
/* Carry propagation */
if (carry)
{
tmp = (uint32_t)out->digits[i] + carry;
out->digits[i] = tmp & 0xFFFF;
}
out->size = in->size + 1;
if (!out->digits[out->size - 1])
out->size--;
}
static uint16_t BH_Int1120DivGuess(const BH_Int1120 *a,
const BH_Int1120 *b)
{
uint32_t tmp;
/* Compare two values */
if (BH_Int1120Compare(a, b) < 0)
return 0;
/* Make a guess */
tmp = a->digits[a->size - 1];
if (a->size != b->size)
tmp = tmp << 16 | a->digits[a->size - 2];
return tmp / b->digits[b->size - 1];
}
void BH_Int1120Div(const BH_Int1120 *a,
const BH_Int1120 *b,
BH_Int1120 *q,
BH_Int1120 *r)
{
BH_Int1120 left, right, tmp;
uint16_t guess;
int shift;
assert(a->size >= b->size);
assert(b->size > 0);
/* Normilize input to reduce tries */
shift = BH_Int1120Clz(b->digits[b->size - 1]);
BH_Int1120Lsh(a, shift, &left);
BH_Int1120Lsh(b, shift, &right);
/* Prepare first step of the division */
q->size = 0;
r->size = 0;
while (BH_Int1120Compare(r, &right) < 0)
{
BH_Int1120Lsh(r, 16, r);
r->digits[0] = left.digits[--left.size];
if (!r->size)
r->size = 1;
}
while (1)
{
/* Make a guess and check */
guess = BH_Int1120DivGuess(r, &right);
BH_Int1120MulDigit(&right, guess, &tmp);
/* If the guess was wrong - decrement guess and try again */
while (BH_Int1120Compare(r, &tmp) < 0)
BH_Int1120MulDigit(&right, --guess, &tmp);
/* Store digit in quotient */
BH_Int1120Lsh(q, 16, q);
q->digits[0] = guess;
if (!q->size)
q->size = 1;
/* Adjust remainder */
BH_Int1120Sub(r, &tmp, r);
/* Fetch next digit or exit */
if (!left.size)
break;
BH_Int1120Lsh(r, 16, r);
r->digits[0] = left.digits[--left.size];
if (!r->size)
r->size = 1;
}
/* Normilize remainder */
BH_Int1120Rsh(r, shift, r);
}
void BH_Int1120Pow10(int exponent,
BH_Int1120 *out)
{
BH_Int1120 one;
one.digits[0] = 1;
one.size = 1;
BH_Int1120MulPow10(&one, exponent, out);
}
void BH_Int1120MulPow10(const BH_Int1120 *in,
int exponent,
BH_Int1120 *out)
{
BH_Int1120 *current, *next, *swap;
BH_Int1120 tmp[2], factor;
int index;
/* Make sure exponent is low, otherwise we get an overflow */
assert(exponent < 512);
/* Prepare variables and temporaries */
current = tmp;
next = tmp + 1;
index = 0;
*current = *in;
/* Main multiply loop */
while (exponent)
{
if (exponent & 0x1)
{
pow10Set(index, &factor);
BH_Int1120Mul(current, &factor, next);
swap = current;
current = next;
next = swap;
}
index++;
exponent >>= 1;
}
*out = *current;
}
void BH_Int1120Pow2(int exponent,
BH_Int1120 *out)
{
int blocks, bits, i;
assert(exponent < 1120);
blocks = exponent / 16;
bits = exponent % 16;
/* Zero out blocks and set one bit */
for (i = 0; i < blocks; i++)
out->digits[i] = 0;
out->digits[blocks] = (1 << bits);
out->size = blocks;
}
void BH_Int1120Lsh(const BH_Int1120 *in,
int amount,
BH_Int1120 *out)
{
int blocks, bits, i;
uint16_t low, high;
/* No input - no output */
if (in->size == 0)
return;
blocks = amount / 16;
bits = amount % 16;
assert(in->size + blocks + (bits > 0) <= BH_INT1120_DIGITS);
if (bits)
{
/* Shift and copy parts of two blocks */
low = 0;
high = in->digits[in->size - 1] >> (16 - bits);
for (i = in->size; i > 1; i--)
{
out->digits[i + blocks] = high | low;
low = in->digits[i - 1] << bits;
high = in->digits[i - 2] >> (16 - bits);
}
out->digits[blocks + 1] = high | low;
out->digits[blocks] = in->digits[0] << bits;
out->size = in->size + blocks + 1;
}
else
{
/* Copy whole blocks */
for (i = in->size; i; i--)
out->digits[i - 1 + blocks] = in->digits[i - 1];
out->size = in->size + blocks;
}
/* Check upper block */
if (!out->digits[out->size - 1])
out->size--;
/* Zero out lower blocks */
for (i = blocks; i; i--)
out->digits[i - 1] = 0;
}
void BH_Int1120Rsh(const BH_Int1120 *in,
int amount,
BH_Int1120 *out)
{
int blocks, bits, i;
uint16_t low, high;
/* No input - no output */
if (in->size == 0)
return;
blocks = amount / 16;
bits = amount % 16;
if (bits)
{
/* Shift and copy parts of two blocks */
low = in->digits[blocks] >> bits;
high = in->digits[blocks + 1] << (16 - bits);
for (i = 0; i < in->size - blocks - 2; i++)
{
out->digits[i] = low | high;
low = in->digits[i + blocks + 1] >> bits;
high = in->digits[i + blocks + 2] << (16 - bits);
}
out->digits[in->size - blocks - 2] = low | high;
out->digits[in->size - blocks - 1] = in->digits[in->size - 1] >> bits;
}
else
{
/* Copy whole blocks */
for (i = 0; i < in->size - blocks; i++)
out->digits[i] = in->digits[i + blocks];
}
/* Check upper block */
out->size = in->size - blocks;
if (!out->digits[out->size - 1])
out->size--;
}