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/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-crc" } */
#include <stdio.h>
#include <stdint.h>
#define CRC16 0x8005
uint16_t gen_crc16(const uint8_t *data, uint16_t size) {
uint16_t out = 0;
int bits_read = 0, bit_flag;
printf("buffer in function %s\n", data);
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;
}
/* { dg-final { scan-tree-dump "Found naive crc implementation in gen_crc16." "crc"} } */
/* { dg-final { scan-tree-dump "Return size is 16" "crc"} } */
/* { dg-final { scan-tree-dump "Loop iteration number is 15" "crc"} } */
/* { dg-final { scan-tree-dump "Bit forward" "crc"} } */
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