/* { dg-do run } */
/* { dg-options "-fdump-tree-crc-details" } */
/* { dg-skip-if "" { *-*-* } { "-O0" "-O1" "-Os" "-O3" "-flto"} } */

#include <stdlib.h>

typedef unsigned char uint8_t;

__attribute__ ((noinline,optimize(0)))
uint8_t gencrc_O0 (uint8_t *data, size_t len) {
    uint8_t crc = 0xff;
    size_t i, j;
    for (i = 0; i < len; i++) {
        crc ^= data[i];
        for (j = 0; j < 8; j++) {
            if ((crc & 0x80) != 0)
                crc = (uint8_t) ((crc << 1) ^ 0x31);
            else
                crc <<= 1;
        }
    }
    return crc;
}

uint8_t gencrc (uint8_t *data, size_t len) {
    uint8_t crc = 0xff;
    size_t i, j;
    for (i = 0; i < len; i++) {
        crc ^= data[i];
        for (j = 0; j < 8; j++) {
            if ((crc & 0x80) != 0)
                crc = (uint8_t) ((crc << 1) ^ 0x31);
            else
                crc <<= 1;
        }
    }
    return crc;
}

int main ()
{
  for (uint8_t i = 0; i < 255; i++)
    {
      uint8_t res1 = gencrc_O0 (&i, 1);
      uint8_t res2 = gencrc (&i, 1);
      if (res1 != res2)
	__builtin_abort ();
    }
  __builtin_exit (0);
}

/* { dg-final { scan-tree-dump "gencrc function maybe contains CRC calculation." "crc"} } */
/* { dg-final { scan-tree-dump "Loop iteration number is 7" "crc"} } */
/* { dg-final { scan-tree-dump "Bit forward" "crc"} } */
/* { dg-final { scan-tree-dump "Polynomial's value is \\\{\[0, \]*0, 0, 1, 1, 0, 0, 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"} } */