An iwmmxt optimised shadowUpdateRotate16_270YX, with problems.
Marko Katić
dromede at gmail.com
Fri Aug 26 04:21:10 PDT 2011
Hi there!
I'm trying to optimise shadow copies from landscape oriented 16bit shadowfb
to portrait 16bit fb proper. This is done in shadowUpdateRotate16_270YX
which is located in miext/shadow/shrotpackYX.h. My optimisation is aimed at
pxa27x and xscale3 arm processors only since it uses iwmmxt asm code. I
guess it could easily be ported to x86 mmx code too.
As I understand, the current implementation copies a single pixel at a time,
like this:
*win = *sha++;
win += WINSTEPX(winStride);
This also means that we're stepping over entire cachelines since every pixel
of a single shadowfb line has to be copied to a new line of fb proper.
My patch tries to copy 4x4 pixel blocks prerotated to portrait orientation.
Basically, it takes 4 lines of shadowfb and divides it into 4x4 blocks.
Then it rotates them and copies them to fb proper. This way, instead of
copying a single pixel per fb proper line, it copies four. The rotation code
is
done in iwmmxt asm and takes about 0.9 instructions per pixel (assuming the
4x4 block is already in iwmmxt registers). 4x4 blocks imply that the
rectangle
to be copied is width and height aligned to 4 pixels. If not, the patch
reduces the rectangle to proper alignment with single pixel copies for width
and height.
It doesn't really work and i can't find a reason why. The inital Xfbdev
screen is looking fine, but when i start moving the pointer or windows, all
i get is garbage.
The patch was tested on kdrive 1.3.0.0 running in qemu and on a Zaurus
C-1000.
If anyone has any suggestions, please do tell.
diff --git a/miext/shadow/Makefile.am b/miext/shadow/Makefile.am
index a73d0ec..bab1045 100644
--- a/miext/shadow/Makefile.am
+++ b/miext/shadow/Makefile.am
@@ -1,5 +1,7 @@
noinst_LTLIBRARIES = libshadow.la
+
+
AM_CFLAGS = $(DIX_CFLAGS)
INCLUDES = -I$(top_srcdir)/hw/xfree86/os-support
@@ -31,4 +33,5 @@ libshadow_la_SOURCES = \
shrot8pack.c \
shrotate.c \
shrotpack.h \
- shrotpackYX.h
+ shrotpackYX.h \
+ iwmmxt_rotate_copy.s
diff --git a/miext/shadow/iwmmxt_rotate_copy.s
b/miext/shadow/iwmmxt_rotate_copy.s
new file mode 100644
index 0000000..f6dac05
--- /dev/null
+++ b/miext/shadow/iwmmxt_rotate_copy.s
@@ -0,0 +1,60 @@
+@ r0 - shadowfb line
+@ r1 - fb proper line
+@ r2 - shadowfb stride
+@ r3 - width
+ .code 32
+ .arch iwmmxt
+ .cpu iwmmxt
+ .text
+ .global iwmmxt_rotate_copy
+iwmmxt_rotate_copy:
+ mov r4, r0 @ save shaBase
+ mov r6, #16 @ used for 2 pixel bitwise rotation
+ mov r7, #32 @ used for 4 pixel bitwise rotation
+ tmcr wcgr0, r6
+ tmcr wcgr1, r7
+iwmmxt_rotate_copy_main_loop:
+ wldrd wr0,[r0]
+ add r0, r0, r2
+ wldrd wr1,[r0]
+ add r0, r0, r2
+ wldrd wr2,[r0]
+ add r0, r0, r2
+ wldrd wr3,[r0]
+ @ Block transpose
+ wunpckihh wr4, wr0, wr1
+ wunpckihh wr5, wr2, wr3
+ wunpckilh wr6, wr0, wr1
+ wunpckilh wr7, wr2, wr3
+ wunpckihw wr0, wr4, wr5
+ wunpckilw wr1, wr4, wr5
+ wunpckihw wr2, wr6, wr7
+ wunpckilw wr3, wr6, wr7
+ @Block rotate to portrait and write to fb proper
+ wrorwg wr3, wr3, wcgr0
+ wrordg wr3, wr3, wcgr1
+ wstrd wr3,[r1]
+ wrorwg wr2, wr2, wcgr0
+ wrordg wr2, wr2, wcgr1
+ add r1, #960
+ wstrd wr2,[r1]
+ wrorwg wr1, wr1, wcgr0
+ wrordg wr1, wr1, wcgr1
+ add r1, #960
+ wstrd wr1,[r1]
+ wrorwg wr0, wr0, wcgr0
+ wrordg wr0, wr0, wcgr1
+ add r1, #960
+ wstrd wr0,[r1]
+ add r1, #960
+ subs r3, r3, #4 @ decrement width
+ beq exit
+ bmi exit
+ add r4, r4, #8 @ update shaBase
+ mov r0, r4
+ b iwmmxt_rotate_copy_main_loop
+
+exit:
+ mov pc, lr
+ .end
+
diff --git a/miext/shadow/shrotpackYX.h b/miext/shadow/shrotpackYX.h
index f51da2f..5613233 100644
--- a/miext/shadow/shrotpackYX.h
+++ b/miext/shadow/shrotpackYX.h
@@ -33,6 +33,7 @@
#include "shadow.h"
#include "fb.h"
+#define PIXELS_PER_BLOCK 4
#if ROTATE == 270
#define WINSTEPX(stride) (stride)
@@ -58,6 +59,9 @@
void
FUNC (ScreenPtr pScreen,
shadowBufPtr pBuf);
+
+extern inline void iwmmxt_rotate_copy (Data *shadowfb, Data *fb,
+ FbStride stride, signed int nr_lines);
void
FUNC (ScreenPtr pScreen,
@@ -73,6 +77,7 @@ FUNC (ScreenPtr pScreen,
int shaBpp;
int shaXoff, shaYoff; /* XXX assumed to be zero */
int x, y, w, h;
+ int h_temp, w_prologue, h_prologue;
Data *winBase, *win, *winLine;
CARD32 winSize;
@@ -87,76 +92,79 @@ FUNC (ScreenPtr pScreen,
SHADOW_WINDOW_WRITE,
&winSize, pBuf->closure) - winBase;
- while (nbox--)
- {
- x = pbox->x1;
- y = pbox->y1;
- w = (pbox->x2 - pbox->x1);
- h = pbox->y2 - pbox->y1;
+/*the width and height of the rectangle
+ * should be modulo 4 = 0 aligned for the
+ * iwmmxt_rotate_copy. If not, reduce the
+ * rectangle with per pixel copy for width
+ * and height.
+ */
+while (nbox--) {
+ x = pbox->x1;
+ y = pbox->y1;
+ w = (pbox->x2 - pbox->x1);
+ h = pbox->y2 - pbox->y1;
+
+ w_prologue = w % PIXELS_PER_BLOCK;
+
+ if (w_prologue) {
+ shaLine = shaBase + (y * shaStride) + x;
+ winLine = winBase + WINSTART(x, y);
+ h_temp = h;
+ while (h_temp--)
+ {
+ sha = shaLine;
+ win = winLine;
+ while (sha < (shaLine + w_prologue))
+ {
+ *win = *sha++;
+ win += WINSTEPX(winStride);
+
+ }
+ shaLine += shaStride;
+ winLine += WINSTEPY();
+ }
+ w -= w_prologue;
+ x += w_prologue;
+ }
+ h_prologue = h % PIXELS_PER_BLOCK;
+
+ if (h_prologue) {
+ shaLine = shaBase + (y * shaStride) + x;
+ winLine = winBase + WINSTART(x, y);
+ h_temp = h_prologue;
+ while (h_temp--)
+ {
+ sha = shaLine;
+ win = winLine;
+ while (sha < (shaLine + w))
+ {
+ *win = *sha++;
+ win += WINSTEPX(winStride);
+ }
+ shaLine += shaStride;
+ winLine += WINSTEPY();
+ }
+ h -= h_prologue;
+ y += h_prologue;
+ }
shaLine = shaBase + (y * shaStride) + x;
-#ifdef PREFETCH
- __builtin_prefetch (shaLine);
-#endif
- winLine = winBase + WINSTART(x, y);
+ winLine = winBase + (((pScreen->height - PIXELS_PER_BLOCK) - y) + (x *
winStride));
- while (h--)
- {
- sha = shaLine;
- win = winLine;
+ while (h > 0)
+ {
- while (sha < (shaLine + w - 16))
- {
-#ifdef PREFETCH
- __builtin_prefetch (sha + shaStride);
-#endif
- *win = *sha++;
- win += WINSTEPX(winStride);
- *win = *sha++;
- win += WINSTEPX(winStride);
- *win = *sha++;
- win += WINSTEPX(winStride);
- *win = *sha++;
- win += WINSTEPX(winStride);
-
- *win = *sha++;
- win += WINSTEPX(winStride);
- *win = *sha++;
- win += WINSTEPX(winStride);
- *win = *sha++;
- win += WINSTEPX(winStride);
- *win = *sha++;
- win += WINSTEPX(winStride);
-
- *win = *sha++;
- win += WINSTEPX(winStride);
- *win = *sha++;
- win += WINSTEPX(winStride);
- *win = *sha++;
- win += WINSTEPX(winStride);
- *win = *sha++;
- win += WINSTEPX(winStride);
-
- *win = *sha++;
- win += WINSTEPX(winStride);
- *win = *sha++;
- win += WINSTEPX(winStride);
- *win = *sha++;
- win += WINSTEPX(winStride);
- *win = *sha++;
- win += WINSTEPX(winStride);
- }
-
- while (sha < (shaLine + w))
- {
- *win = *sha++;
- win += WINSTEPX(winStride);
- }
-
- y++;
- shaLine += shaStride;
- winLine += WINSTEPY();
- }
- pbox++;
- } /* nbox */
+ sha = shaLine;
+ win = winLine;
+ /*rotate and copy 4x4 pixel blocks. */
+ iwmmxt_rotate_copy(sha, win, (shaStride * 2), w);
+
+ shaLine += (shaStride * PIXELS_PER_BLOCK);
+ winLine -= PIXELS_PER_BLOCK;
+ h-= PIXELS_PER_BLOCK;
+
+ }
+ }
+pbox++;
}
+
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.x.org/archives/xorg-devel/attachments/20110826/dd194bfc/attachment-0001.htm>
More information about the xorg-devel
mailing list