K 10 svn:author V 7 sobomax K 8 svn:date V 27 2018-11-29T19:28:01.265070Z K 7 svn:log V 361 Replace hand-crafted naive byte-by-byte zero block detection routine with macro based around memcmp(). The latter is expected to be some 8 times faster on a modern 64-bit architectures. In practice, throughput of doing conv=sparse from /dev/zero to /dev/null went up some 5-fold here from 1.9GB/sec to 9.7GB/sec with this change (bs=128k). MFC after: 2 weeks END