1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
|
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-crc-details -fdisable-tree-phiopt2 -fdisable-tree-phiopt3" } */
#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;
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 "gen_crc16 function maybe calculates CRC." "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"} } */
/* { dg-final { scan-tree-dump "Executing \[a-zA-Z_\]\[a-zA-Z0-9_\]* = \[a-zA-Z_\]\[a-zA-Z0-9_\]* \\\^ \[a-zA-Z0-9_\]+(\(\[a-zA-Z\]\))?;" "crc" } } */
/* { dg-final { scan-tree-dump "Executing \[a-zA-Z_\]\[a-zA-Z0-9_\]* = \[a-zA-Z_\]\[a-zA-Z0-9_\]* \(<<|>>\) \[0-9]+;" "crc" } } */
/* { dg-final { scan-tree-dump-times "Return value is \\\{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0\\\}" 3 "crc" } } */
/* { dg-final { scan-tree-dump "Polynomial's value is \\\{1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1\\\}" "crc" } } */
|
