Viewing file:  pr69714.c (4.2 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/* { dg-do run } */
/* { dg-options "-fno-strict-aliasing" } */
/* { dg-require-effective-target int32plus } */
#include <stdint.h>
#include <stdio.h>
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
#define av_le2ne32(x) (x)
#else
#define av_le2ne32(x) av_bswap32(x)
#endif
static __attribute__((always_inline)) inline __attribute__((const)) uint32_t av_bswap32(uint32_t x)
{
return ((((x) << 8 & 0xff00) | ((x) >> 8 & 0x00ff)) << 16 | ((((x) >> 16) << 8 & 0xff00) | (((x) >> 16) >> 8 & 0x00ff)));
}
typedef uint32_t AVCRC;
typedef enum {
AV_CRC_8_ATM,
AV_CRC_16_ANSI,
AV_CRC_16_CCITT,
AV_CRC_32_IEEE,
AV_CRC_32_IEEE_LE,
AV_CRC_16_ANSI_LE,
AV_CRC_24_IEEE = 12,
AV_CRC_MAX,
} AVCRCId;
int av_crc_init(AVCRC *ctx, int le, int bits, uint32_t poly, int ctx_size);
uint32_t av_crc(const AVCRC *ctx, uint32_t crc,
const uint8_t *buffer, size_t length) __attribute__((pure));
static struct {
uint8_t le;
uint8_t bits;
uint32_t poly;
} av_crc_table_params[AV_CRC_MAX] = {
[AV_CRC_8_ATM] = { 0, 8, 0x07 },
[AV_CRC_16_ANSI] = { 0, 16, 0x8005 },
[AV_CRC_16_CCITT] = { 0, 16, 0x1021 },
[AV_CRC_24_IEEE] = { 0, 24, 0x864CFB },
[AV_CRC_32_IEEE] = { 0, 32, 0x04C11DB7 },
[AV_CRC_32_IEEE_LE] = { 1, 32, 0xEDB88320 },
[AV_CRC_16_ANSI_LE] = { 1, 16, 0xA001 },
};
static AVCRC av_crc_table[AV_CRC_MAX][1024];
int av_crc_init(AVCRC *ctx, int le, int bits, uint32_t poly, int ctx_size)
{
unsigned i, j;
uint32_t c;
if (bits < 8 || bits > 32 || poly >= (1LL << bits))
return -1;
if (ctx_size != sizeof(AVCRC) * 257 && ctx_size != sizeof(AVCRC) * 1024)
return -1;
for (i = 0; i < 256; i++) {
if (le) {
for (c = i, j = 0; j < 8; j++)
c = (c >> 1) ^ (poly & (-(c & 1)));
ctx[i] = c;
} else {
for (c = i << 24, j = 0; j < 8; j++)
c = (c << 1) ^ ((poly << (32 - bits)) & (((int32_t) c) >> 31));
ctx[i] = av_bswap32(c);
}
}
ctx[256] = 1;
if (ctx_size >= sizeof(AVCRC) * 1024)
for (i = 0; i < 256; i++)
for (j = 0; j < 3; j++)
ctx[256 *(j + 1) + i] =
(ctx[256 * j + i] >> 8) ^ ctx[ctx[256 * j + i] & 0xFF];
return 0;
}
const AVCRC *av_crc_get_table(AVCRCId crc_id)
{
if (!av_crc_table[crc_id][(sizeof(av_crc_table[crc_id]) / sizeof((av_crc_table[crc_id])[0])) - 1])
if (av_crc_init(av_crc_table[crc_id],
av_crc_table_params[crc_id].le,
av_crc_table_params[crc_id].bits,
av_crc_table_params[crc_id].poly,
sizeof(av_crc_table[crc_id])) < 0)
return ((void *)0);
return av_crc_table[crc_id];
}
uint32_t av_crc(const AVCRC *ctx, uint32_t crc,
const uint8_t *buffer, size_t length)
{
const uint8_t *end = buffer + length;
if (!ctx[256]) {
while (((intptr_t) buffer & 3) && buffer < end)
crc = ctx[((uint8_t) crc) ^ *buffer++] ^ (crc >> 8);
while (buffer < end - 3) {
crc ^= av_le2ne32(*(const uint32_t *) buffer); buffer += 4;
crc = ctx[3 * 256 + ( crc & 0xFF)] ^
ctx[2 * 256 + ((crc >> 8 ) & 0xFF)] ^
ctx[1 * 256 + ((crc >> 16) & 0xFF)] ^
ctx[0 * 256 + ((crc >> 24) )];
}
}
while (buffer < end)
crc = ctx[((uint8_t) crc) ^ *buffer++] ^ (crc >> 8);
return crc;
}
int main(void)
{
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ || __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
uint8_t buf[1999];
int i;
unsigned
p[6][3] = { { AV_CRC_32_IEEE_LE, 0xEDB88320, 0x3D5CDD04 },
{ AV_CRC_32_IEEE , 0x04C11DB7, 0xE0BAF5C0 },
{ AV_CRC_24_IEEE , 0x864CFB , 0x326039 },
{ AV_CRC_16_ANSI_LE, 0xA001 , 0xBFD8 },
{ AV_CRC_16_ANSI , 0x8005 , 0xBB1F },
{ AV_CRC_8_ATM , 0x07 , 0xE3 }
};
const AVCRC *ctx;
for (i = 0; i < sizeof(buf); i++)
buf[i] = i + i * i;
for (i = 0; i < 6; i++) {
int id = p[i][0];
uint32_t result;
ctx = av_crc_get_table (id);
result = av_crc(ctx, 0, buf, sizeof(buf));
if (result != p[i][2])
__builtin_abort ();
}
#endif
return 0;
}
|
