Fix the new ARMv8 CRC code for short and unaligned input.

The code before the main loop, to handle the possible 1-7 unaligned bytes
at the beginning of the input, was broken, and read past the input, if the
the input was very short.
This commit is contained in:
Heikki Linnakangas 2018-04-04 14:40:20 +03:00
parent ee9e145531
commit 3a5e0a91bb

View File

@ -29,17 +29,17 @@ pg_comp_crc32c_armv8(pg_crc32c crc, const void *data, size_t len)
* significantly faster. Process leading bytes so that the loop below
* starts with a pointer aligned to eight bytes.
*/
if (!PointerIsAligned(p, uint16) && p < pend)
if (!PointerIsAligned(p, uint16) && p + 1 <= pend)
{
crc = __crc32cb(crc, *p);
p += 1;
}
if (!PointerIsAligned(p, uint32) && p < pend)
if (!PointerIsAligned(p, uint32) && p + 2 <= pend)
{
crc = __crc32ch(crc, *(uint16 *) p);
p += 2;
}
if (!PointerIsAligned(p, uint64) && p < pend)
if (!PointerIsAligned(p, uint64) && p + 4 <= pend)
{
crc = __crc32cw(crc, *(uint32 *) p);
p += 4;