--- /dev/null
+Index: xserver/miext/shadow/shrotate.c
+===================================================================
+RCS file: /scratch/openbsd/cvs/XF4/xc/programs/Xserver/miext/shadow/shrotate.c,v
+retrieving revision 1.2
+diff -u -r1.2 shrotate.c
+--- xserver/miext/shadow/shrotate.c 3 Nov 2004 00:09:54 -0000 1.2
++++ xserver/miext/shadow/shrotate.c 20 Sep 2005 23:07:58 -0000
+@@ -45,6 +45,106 @@
+ #define TOP_TO_BOTTOM 2
+ #define BOTTOM_TO_TOP -2
+
++
++static void
++shadowUpdateRotatePackedSubRectangle(shadowBufPtr pBuf,
++ FbBits *shaLine, int shaFirstShift,
++ int shaStepOverX, int shaStepOverY,
++ int shaStepDownX, int shaStepDownY,
++ int shaBpp, FbBits shaMask,
++ ScreenPtr pScreen,
++ int scr_x1, int scr_y,
++ int scr_h, int scr_w,
++ int pixelsPerBits)
++{
++ FbBits *sha;
++ int shaShift;
++ int scr_x;
++ int w;
++
++ /*
++ * Copy the bits, always write across the physical frame buffer
++ * to take advantage of write combining.
++ */
++ while (scr_h--)
++ {
++ int p;
++ FbBits bits;
++ FbBits *win;
++ int i;
++ CARD32 winSize;
++
++ sha = shaLine;
++ shaShift = shaFirstShift;
++ w = scr_w;
++ scr_x = scr_x1 * shaBpp >> FB_SHIFT;
++
++ while (w)
++ {
++ /*
++ * Map some of this line
++ */
++ win = (FbBits *) (*pBuf->window) (pScreen,
++ scr_y,
++ scr_x << 2,
++ SHADOW_WINDOW_WRITE,
++ &winSize,
++ pBuf->closure);
++ i = (winSize >> 2);
++ if (i > w)
++ i = w;
++ w -= i;
++ scr_x += i;
++ /*
++ * Copy the portion of the line mapped
++ */
++ while (i--)
++ {
++ bits = 0;
++ p = pixelsPerBits;
++ /*
++ * Build one word of output from multiple inputs
++ */
++ while (p--)
++ {
++ bits = FbScrLeft(bits, shaBpp);
++ bits |= FbScrRight (*sha, shaShift) & shaMask;
++
++ shaShift -= shaStepOverX;
++ if (shaShift >= FB_UNIT)
++ {
++ shaShift -= FB_UNIT;
++ sha--;
++ }
++ else if (shaShift < 0)
++ {
++ shaShift += FB_UNIT;
++ sha++;
++ }
++ sha += shaStepOverY;
++ }
++ *win++ = bits;
++ }
++ }
++ scr_y++;
++ shaFirstShift -= shaStepDownX;
++ if (shaFirstShift >= FB_UNIT)
++ {
++ shaFirstShift -= FB_UNIT;
++ shaLine--;
++ }
++ else if (shaFirstShift < 0)
++ {
++ shaFirstShift += FB_UNIT;
++ shaLine++;
++ }
++ shaLine += shaStepDownY;
++ }
++}
++
++#define BLOCKSIZE_HEIGHT 32
++#define BLOCKSIZE_WIDTH 32
++
+ void
+ shadowUpdateRotatePacked (ScreenPtr pScreen,
+ shadowBufPtr pBuf)
+@@ -61,7 +161,6 @@
+ int sha_x1 = 0, sha_y1 = 0;
+ int scr_x1 = 0, scr_x2 = 0, scr_y1 = 0, scr_y2 = 0, scr_w, scr_h;
+ int scr_x, scr_y;
+- int w;
+ int pixelsPerBits;
+ int pixelsMask;
+ FbStride shaStepOverY = 0, shaStepDownY = 0;
+@@ -221,86 +320,46 @@
+ ((sha_x1 * shaBpp) >> FB_SHIFT));
+
+ /*
+- * Copy the bits, always write across the physical frame buffer
+- * to take advantage of write combining.
++ * Copy in blocks of size BLOCKSIZE_WIDTH x BLOCKSIZE_HEIGHT
++ * to reduce the number of cache misses when rotating 90 or
++ * 270 degrees.
+ */
+- while (scr_h--)
++ for (scr_y = scr_y1; scr_y < scr_y2; scr_y += BLOCKSIZE_HEIGHT)
+ {
+- int p;
+- FbBits bits;
+- FbBits *win;
+- int i;
+- CARD32 winSize;
+-
+ sha = shaLine;
+ shaShift = shaFirstShift;
+- w = scr_w;
+- scr_x = scr_x1 * shaBpp >> FB_SHIFT;
+
+- while (w)
++ for (scr_x = scr_x1; scr_x < scr_x2; scr_x += BLOCKSIZE_WIDTH)
+ {
+- /*
+- * Map some of this line
+- */
+- win = (FbBits *) (*pBuf->window) (pScreen,
+- scr_y,
+- scr_x << 2,
+- SHADOW_WINDOW_WRITE,
+- &winSize,
+- pBuf->closure);
+- i = (winSize >> 2);
+- if (i > w)
+- i = w;
+- w -= i;
+- scr_x += i;
+- /*
+- * Copy the portion of the line mapped
+- */
+- while (i--)
+- {
+- bits = 0;
+- p = pixelsPerBits;
+- /*
+- * Build one word of output from multiple inputs
+- *
+- * Note that for 90/270 rotations, this will walk
+- * down the shadow hitting each scanline once.
+- * This is probably not very efficient.
+- */
+- while (p--)
+- {
+- bits = FbScrLeft(bits, shaBpp);
+- bits |= FbScrRight (*sha, shaShift) & shaMask;
++ int h = BLOCKSIZE_HEIGHT;
++ int w = BLOCKSIZE_WIDTH;
+
+- shaShift -= shaStepOverX;
+- if (shaShift >= FB_UNIT)
+- {
+- shaShift -= FB_UNIT;
+- sha--;
+- }
+- else if (shaShift < 0)
+- {
+- shaShift += FB_UNIT;
+- sha++;
+- }
+- sha += shaStepOverY;
+- }
+- *win++ = bits;
+- }
+- }
+- scr_y++;
+- shaFirstShift -= shaStepDownX;
+- if (shaFirstShift >= FB_UNIT)
+- {
+- shaFirstShift -= FB_UNIT;
+- shaLine--;
+- }
+- else if (shaFirstShift < 0)
+- {
+- shaFirstShift += FB_UNIT;
+- shaLine++;
++ if (scr_y + h > scr_y2)
++ h = scr_y2 - scr_y;
++ if (scr_x + w > scr_x2)
++ w = scr_x2 - scr_x;
++ w = (w * shaBpp) >> FB_SHIFT;
++
++ shadowUpdateRotatePackedSubRectangle
++ (pBuf,
++ sha, shaShift,
++ shaStepOverX, shaStepOverY,
++ shaStepDownX, shaStepDownY,
++ shaBpp, shaMask,
++ pScreen,
++ scr_x, scr_y,
++ h, w,
++ pixelsPerBits);
++
++ shaShift -= BLOCKSIZE_WIDTH * shaStepOverX;
++ sha += BLOCKSIZE_WIDTH * shaStepOverY;
++ sha -= (shaShift >> FB_SHIFT);
++ shaShift &= FB_MASK;
+ }
+- shaLine += shaStepDownY;
++ shaFirstShift -= BLOCKSIZE_HEIGHT * shaStepDownX;
++ shaLine += BLOCKSIZE_HEIGHT * shaStepDownY;
++ shaLine -= (shaFirstShift >> FB_SHIFT);
++ shaFirstShift &= FB_MASK;
+ }
+ }
+ }
