• Debarshi Ray's avatar
    perf: Test gegl:translate fast paths · 171e1b9d
    Debarshi Ray authored
    A "R'G'B' u8" buffer nicely demonstrates all the aspects of the fast
    paths - the buffer shifting trick and avoiding Babl format conversions.
    eg., on a Intel Core i7 it gives a throughput of more than 8000 MB/s,
    and if (needless) Babl conversions are introduced it drops to 1300 to
    1400 MB/s.
    
    On the other hand, a "RGBA float" buffer always performs at 1200 to
    1300 MB/s, whether we avoid the Babl conversions or not. Presumably,
    this is because converting "RGBA float" pixels to "RaGaBaA float" is
    as fast as a NOP.
    
    (The general fall in performance of "RGBA float" buffers is simply
    because they have more bytes than their "R'G'B' u8" counterparts.)
    
    https://bugzilla.gnome.org/show_bug.cgi?id=759616
    171e1b9d
test-translate.c 1.74 KB