On (Mon) 24 Nov 2014 [19:55:50], arei.gong...@huawei.com wrote: > From: ChenLiang <chenlian...@huawei.com> > > The logic of old code is correct. But Checking byte by byte will > consume time after an concurrency scene. > > Signed-off-by: ChenLiang <chenlian...@huawei.com> > Signed-off-by: Gonglei <arei.gong...@huawei.com> > --- > xbzrle.c | 28 ++++++++++++++++++---------- > 1 file changed, 18 insertions(+), 10 deletions(-) > > diff --git a/xbzrle.c b/xbzrle.c > index d27a140..0477367 100644 > --- a/xbzrle.c > +++ b/xbzrle.c > @@ -50,16 +50,24 @@ int xbzrle_encode_buffer(uint8_t *old_buf, uint8_t > *new_buf, int slen, > > /* word at a time for speed */ > if (!res) { > - while (i < slen && > - (*(long *)(old_buf + i)) == (*(long *)(new_buf + i))) { > - i += sizeof(long); > - zrun_len += sizeof(long); > - } > - > - /* go over the rest */ > - while (i < slen && old_buf[i] == new_buf[i]) { > - zrun_len++; > - i++; > + while (i < slen) { > + if ((*(long *)(old_buf + i)) == (*(long *)(new_buf + i))) { > + i += sizeof(long); > + zrun_len += sizeof(long); > + } else { > + /* go over the rest */ > + for (j = 0; j < sizeof(long); j++) { > + if (old_buf[i] == new_buf[i]) { > + i++; > + zrun_len++;
I don't see how this is different from the code it's replacing. The check and increments are all the same. Difficult to see why there'll be a speed benefit. Can you please explain? Do you have any performance numbers for before/after? Thanks, Amit