xz/src/liblzma/rangecoder/price_tablegen.c

88 lines
1.7 KiB
C

///////////////////////////////////////////////////////////////////////////////
//
/// \file price_tablegen.c
/// \brief Probability price table generator
///
/// Compiling: gcc -std=c99 -o price_tablegen price_tablegen.c
///
// Authors: Igor Pavlov
// Lasse Collin
//
// This file has been put into the public domain.
// You can do whatever you want with this file.
//
///////////////////////////////////////////////////////////////////////////////
#include <inttypes.h>
#include <stdio.h>
#include "range_common.h"
#include "price.h"
static uint32_t rc_prices[RC_PRICE_TABLE_SIZE];
static void
init_price_table(void)
{
for (uint32_t i = (UINT32_C(1) << RC_MOVE_REDUCING_BITS) / 2;
i < RC_BIT_MODEL_TOTAL;
i += (UINT32_C(1) << RC_MOVE_REDUCING_BITS)) {
const uint32_t cycles_bits = RC_BIT_PRICE_SHIFT_BITS;
uint32_t w = i;
uint32_t bit_count = 0;
for (uint32_t j = 0; j < cycles_bits; ++j) {
w *= w;
bit_count <<= 1;
while (w >= (UINT32_C(1) << 16)) {
w >>= 1;
++bit_count;
}
}
rc_prices[i >> RC_MOVE_REDUCING_BITS]
= (RC_BIT_MODEL_TOTAL_BITS << cycles_bits)
- 15 - bit_count;
}
return;
}
static void
print_price_table(void)
{
printf("/* This file has been automatically generated by "
"price_tablegen.c. */\n\n"
"#include \"range_encoder.h\"\n\n"
"const uint8_t lzma_rc_prices["
"RC_PRICE_TABLE_SIZE] = {");
const size_t array_size = sizeof(lzma_rc_prices)
/ sizeof(lzma_rc_prices[0]);
for (size_t i = 0; i < array_size; ++i) {
if (i % 8 == 0)
printf("\n\t");
printf("%4" PRIu32, rc_prices[i]);
if (i != array_size - 1)
printf(",");
}
printf("\n};\n");
return;
}
int
main(void)
{
init_price_table();
print_price_table();
return 0;
}