| /* Duff's device is legal C; test to make sure the compiler |
| doesn't complain about it. |
| |
| Roger Sayle <roger@eyesopen.com> |
| Derived from duff-2.c. */ |
| |
| /* { dg-do run } */ |
| /* { dg-options "-O2" } */ |
| |
| extern void abort (void); |
| extern void exit (int); |
| |
| #if __INT_MAX__ >= 2147483647 |
| /* At least 32-bit integers. */ |
| typedef int type32; |
| #else |
| typedef long type32; |
| #endif |
| |
| type32 |
| cksum (const unsigned char *src, unsigned long size) |
| { |
| type32 ck = 0; |
| |
| switch (size & 3) |
| { |
| do |
| { |
| case 0: |
| ck ^= (type32)*src++ << 24; |
| --size; |
| case 3: |
| ck ^= (type32)*src++ << 16; |
| --size; |
| case 2: |
| ck ^= (type32)*src++ << 8; |
| --size; |
| case 1: |
| ck ^= (type32)*src++; |
| --size; |
| } |
| while (size > 0); |
| } |
| |
| return ck; |
| } |
| |
| const char testpat[] = "The quick brown fox jumped over the lazy dog."; |
| |
| int |
| main() |
| { |
| type32 ck; |
| |
| ck = cksum ((const unsigned char *) testpat, sizeof (testpat)); |
| if (ck != 925902908) |
| abort (); |
| |
| exit (0); |
| } |