Merge branch 'uli42-pr/fb_fastpath' into 3.6.x

nx-X11/programs/Xserver/fb/fbblt.c

@@ -67,38 +67,50 @@ fbBlt (FbBits   *srcLine,
     int	    n, nmiddle;
     Bool    destInvarient;
     int	    startbyte, endbyte;
+
     FbDeclareMergeRop ();
 
-#ifdef FB_24BIT
-    if (bpp == 24 && !FbCheck24Pix (pm))
+    if (alu == GXcopy && pm == FB_ALLONES &&
+        !(srcX & 7) && !(dstX & 7) && !(width & 7))
     {
-	fbBlt24 (srcLine, srcStride, srcX, dstLine, dstStride, dstX,
-		 width, height, alu, pm, reverse, upsidedown);
-	return;
-    }
-#endif
+        CARD8           *src_byte = (CARD8 *) srcLine + (srcX >> 3);
+        CARD8           *dst_byte = (CARD8 *) dstLine + (dstX >> 3);
+        FbStride        src_byte_stride = srcStride << (FB_SHIFT - 3);
+        FbStride        dst_byte_stride = dstStride << (FB_SHIFT - 3);
+        int             width_byte = (width >> 3);
 
-    if (alu == GXcopy && pm == FB_ALLONES && !reverse &&
-            !(srcX & 7) && !(dstX & 7) && !(width & 7)) {
+        /* Make sure there's no overlap; we can't use memcpy in that
+         * case as it's not well defined, so fall through to the
+         * general code
+         */
+        if (src_byte + width_byte <= dst_byte ||
+            dst_byte + width_byte <= src_byte)
+        {
             int i;
-        CARD8 *src = (CARD8 *) srcLine;
-        CARD8 *dst = (CARD8 *) dstLine;
-
-        srcStride *= sizeof(FbBits);
-        dstStride *= sizeof(FbBits);
-        width >>= 3;
-        src += (srcX >> 3);
-        dst += (dstX >> 3);
 
             if (!upsidedown)
                 for (i = 0; i < height; i++)
-                memcpy(dst + i * dstStride, src + i * srcStride, width);
+                    memcpy(dst_byte + i * dst_byte_stride,
+                           src_byte + i * src_byte_stride,
+                           width_byte);
             else
                 for (i = height - 1; i >= 0; i--)
-                memcpy(dst + i * dstStride, src + i * srcStride, width);
+                    memcpy(dst_byte + i * dst_byte_stride,
+                           src_byte + i * src_byte_stride,
+                           width_byte);
 
             return;
         }
+    }
+
+#ifdef FB_24BIT
+    if (bpp == 24 && !FbCheck24Pix (pm))
+    {
+	fbBlt24 (srcLine, srcStride, srcX, dstLine, dstStride, dstX,
+		 width, height, alu, pm, reverse, upsidedown);
+	return;
+    }
+#endif
 
     FbInitializeMergeRop(alu, pm);
     destInvarient = FbDestInvarientMergeRop();