diff options
Diffstat (limited to 'src/H5checksum.c')
| -rw-r--r-- | src/H5checksum.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/src/H5checksum.c b/src/H5checksum.c index 3aafd3d..9ad575d 100644 --- a/src/H5checksum.c +++ b/src/H5checksum.c @@ -80,6 +80,11 @@ * http://en.wikipedia.org/wiki/Fletcher%27s_checksum * for more details, etc. * + * Note #2: The algorithm below differs from that given in the Wikipedia + * page by copying the data into 'sum1' in a more portable way + * and also by initializing 'sum1' and 'sum2' to 0 instead of + * 0xffff (for backward compatibility reasons, mostly). + * * Return: 32-bit fletcher checksum of input buffer (can't fail) * * Programmer: Quincey Koziol @@ -92,7 +97,7 @@ H5_fletcher32(const void *_data, size_t _len) { const uint8_t *data = (const uint8_t *)_data; /* Pointer to the data to be summed */ size_t len = _len / 2; /* Length in 16-bit words */ - uint32_t sum1 = 0xffff, sum2 = 0xffff; + uint32_t sum1 = 0, sum2 = 0; FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5_fletcher32) @@ -128,6 +133,6 @@ H5_fletcher32(const void *_data, size_t _len) sum1 = (sum1 & 0xffff) + (sum1 >> 16); sum2 = (sum2 & 0xffff) + (sum2 >> 16); - FUNC_LEAVE_NOAPI(sum2 << 16 | sum1) + FUNC_LEAVE_NOAPI((sum2 << 16) | sum1) } /* end H5_fletcher32() */ |