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/* { dg-do run } */
/* { dg-options "-fdump-tree-crc-details -fdisable-tree-phiopt2 -fdisable-tree-phiopt3" } */
/* { dg-skip-if "" { *-*-* } { "-O0" "-O1" "-Os" "-flto" } } */
/* { dg-require-effective-target int32plus } */
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#define CRC16 0x8005
__attribute__ ((noinline,optimize(0)))
uint16_t gen_crc16_O0 (const uint8_t *data, uint16_t size) {
uint16_t out = 0;
int bits_read = 0, bit_flag;
if (data == NULL)
return 0;
while (size > 0) {
bit_flag = out >> 15;
out <<= 1;
out |= (*data >> bits_read) & 1;
bits_read++;
if (bits_read > 7) {
bits_read = 0;
data++;
size--;
}
if (bit_flag)
out ^= CRC16;
}
int i;
for (i = 0; i < 16; ++i) {
bit_flag = out >> 15;
out <<= 1;
if (bit_flag)
out ^= CRC16;
}
uint16_t crc = 0;
i = 0x8000;
int j = 0x0001;
for (; i != 0; i >>= 1, j <<= 1) {
if (i & out) crc |= j;
}
return crc;
}
uint16_t gen_crc16 (const uint8_t *data, uint16_t size) {
uint16_t out = 0;
int bits_read = 0, bit_flag;
if (data == NULL)
return 0;
while (size > 0) {
bit_flag = out >> 15;
out <<= 1;
out |= (*data >> bits_read) & 1;
bits_read++;
if (bits_read > 7) {
bits_read = 0;
data++;
size--;
}
if (bit_flag)
out ^= CRC16;
}
int i;
for (i = 0; i < 16; ++i) {
bit_flag = out >> 15;
out <<= 1;
if (bit_flag)
out ^= CRC16;
}
uint16_t crc = 0;
i = 0x8000;
int j = 0x0001;
for (; i != 0; i >>= 1, j <<= 1) {
if (i & out) crc |= j;
}
return crc;
}
int main ()
{
if (gen_crc16 ("hello", 5) != 13522)
__builtin_abort ();
for (uint8_t i = 0; i < 255; i++)
{
uint16_t res1 = gen_crc16_O0 (&i, 1);
uint16_t res2 = gen_crc16 (&i, 1);
if (res1 != res2)
__builtin_abort ();
}
__builtin_exit (0);
}
/* { dg-final { scan-tree-dump "function maybe contains CRC calculation." "crc" } } */
/* { dg-final { scan-tree-dump "Loop iteration number is 15" "crc" } } */
/* { dg-final { scan-tree-dump "Bit forward" "crc" } } */
/* { dg-final { scan-tree-dump "Polynomial's value is \\\{\[0, \]*1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1\\\}" "crc" } } */
/* { dg-final { scan-tree-dump "calculates CRC!" "crc" } } */
/* { dg-final { scan-tree-dump-times "Couldn't generate faster CRC code." 0 "crc" } } */
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