[FFmpeg-devel] [PATCH] VP8 luma(16) inner-MB H/V loopfilter MMX/SSE2

[Eli Friedman]

On Sun, Jul 11, 2010 at 8:53 AM, Ronald S. Bultje <rsbultje at gmail.com> wrote:
> Hi,
>
> as per $subj. All tested to be identical to C reference. If wanted, I
> can try to share parts of the filter code with the simple loopfilter,
> but I'm a little scared that it'll turn into massive spaghetti so I
> didn't do it yet.

+    mova             m4, m1
+    SWAP              4, 1

This pattern seems to be repeated a lot... I fail to see the point.
Swapping two registers with the same contents doesn't do anything
significant.

For the following:
+    mova             m4, [rsp+mmsize]
+    pxor             m3, m3
+    psubusb          m0, m4
+    psubusb          m1, m4
+    psubusb          m7, m4
+    psubusb          m6, m4
+    pcmpeqb          m0, m3        ; abs(p3-p2) <= I
+    pcmpeqb          m1, m3        ; abs(p2-p1) <= I
+    pcmpeqb          m7, m3        ; abs(q3-q2) <= I
+    pcmpeqb          m6, m3        ; abs(q2-q1) <= I
+    pand             m0, m1
+    pand             m7, m6
+    pand             m0, m7

The following should be faster with mmxext/sse2:

    mova             m4, [rsp+mmsize]
    pxor             m3, m3
    pmaxub          m0, m1
    pmaxub          m6, m7
    pmaxub          m0, m6
    psubusb          m0, m4
    pcmpeqb          m0, m3

+    mova             m6, [rsp+mmsize*3]
+    pxor             m7, m7
+    pand             m0, m6
+    pand             m1, m6
+    pavgb            m0, m7        ; a
+    psubusb          m1, [pb_1]
+    pavgb            m1, m7        ; -a
+    psubusb          m5, m0
+    paddusb          m5, m1        ; q1-a
+    psubusb          m2, m1
+    paddusb          m2, m0        ; p1+a

pavgb is mmxext/sse2 only.

-Eli