Message ID | 1363956370-23681-4-git-send-email-pl@kamp.de |
---|---|
State | New |
Headers | show |
On 03/22/2013 02:46 PM, Peter Lieven wrote: > performance gain on SSE2 is approx. 20-25%. altivec > is not tested. performance for unsigned long arithmetic > is unchanged. > > Signed-off-by: Peter Lieven <pl@kamp.de> > Reviewed-by: Eric Blake <eblake@redhat.com> > --- > util/cutils.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/util/cutils.c b/util/cutils.c > index 41c627e..0f43c22 100644 > --- a/util/cutils.c > +++ b/util/cutils.c > @@ -205,6 +205,11 @@ bool buffer_is_zero(const void *buf, size_t len) > long d0, d1, d2, d3; > const long * const data = buf; > > + /* use vector optimized zero check if possible */ > + if (can_use_buffer_find_nonzero_offset(buf, len)) { > + return buffer_find_nonzero_offset(buf, len) == len; > + } > + > assert(len % (4 * sizeof(long)) == 0); > len /= sizeof(long); > > Reviewed-by: Orit Wasserman <owasserm@redhat.com>
diff --git a/util/cutils.c b/util/cutils.c index 41c627e..0f43c22 100644 --- a/util/cutils.c +++ b/util/cutils.c @@ -205,6 +205,11 @@ bool buffer_is_zero(const void *buf, size_t len) long d0, d1, d2, d3; const long * const data = buf; + /* use vector optimized zero check if possible */ + if (can_use_buffer_find_nonzero_offset(buf, len)) { + return buffer_find_nonzero_offset(buf, len) == len; + } + assert(len % (4 * sizeof(long)) == 0); len /= sizeof(long);