Simple repeat: Extend too short source scanlines into temporary buffer

Too short scanlines can cause repeat handling overhead and optimized
pixman composite functions usually process a bunch of pixels in a
single loop iteration it might be beneficial to pre-extend source
scanlines. The temporary buffers will usually reside in cache, so
accessing them should be quite efficient.

1 files changed, 92 insertions, 3 deletions

diff --git a/pixman/pixman-fast-path.c b/pixman/pixman-fast-path.c
index 89c973a..038dcf7 100644
--- a/pixman/pixman-fast-path.c
+++ b/pixman/pixman-fast-path.c
@@ -1191,6 +1191,8 @@ FAST_NEAREST (8888_565_none, 8888, 0565, uint32_t, uint16_t, OVER, NONE)
 FAST_NEAREST (8888_565_pad, 8888, 0565, uint32_t, uint16_t, OVER, PAD)
 FAST_NEAREST (8888_565_normal, 8888, 0565, uint32_t, uint16_t, OVER, NORMAL)
 
+#define REPEAT_MIN_WIDTH    32
+
 static void
 fast_composite_tiled_repeat (pixman_implementation_t *imp,
 			     pixman_composite_info_t *info)
@@ -1224,27 +1226,111 @@ fast_composite_tiled_repeat (pixman_implementation_t *imp,
 	int32_t sx, sy;
 	int32_t width_remain;
 	int32_t num_pixels;
+	int32_t src_width;
+	int32_t i, j;
+	pixman_image_t extended_src_image;
+	uint32_t extended_src[REPEAT_MIN_WIDTH * 2];
+	pixman_bool_t need_src_extension;
+	uint32_t *src_line;
+	int32_t src_stride;
+	int32_t src_bpp;
 	pixman_composite_info_t info2 = *info;
 
+	src_bpp = PIXMAN_FORMAT_BPP (src_image->bits.format);
+
+	if (src_image->bits.width < REPEAT_MIN_WIDTH &&
+	    (src_bpp == 32 || src_bpp == 16 || src_bpp == 8))
+	{
+	    sx = src_x;
+	    sx = MOD (sx, src_image->bits.width);
+	    sx += width;
+	    src_width = 0;
+
+	    while (src_width < REPEAT_MIN_WIDTH && src_width <= sx)
+		src_width += src_image->bits.width;
+
+	    src_stride = (src_width * (src_bpp >> 3) + 3) / (int) sizeof (uint32_t);
+
+	    /* Initialize/validate stack-allocated temporary image */
+	    _pixman_bits_image_init (&extended_src_image, src_image->bits.format,
+				     src_width, 1, &extended_src[0], src_stride);
+	    _pixman_image_validate (&extended_src_image);
+
+	    info2.src_image = &extended_src_image;
+	    need_src_extension = TRUE;
+	}
+	else
+	{
+	    src_width = src_image->bits.width;
+	    need_src_extension = FALSE;
+	}
+
 	sx = src_x;
 	sy = src_y;
 
 	while (--height >= 0)
 	{
-	    sx = MOD (sx, src_image->bits.width);
+	    sx = MOD (sx, src_width);
 	    sy = MOD (sy, src_image->bits.height);
 
+	    if (need_src_extension)
+	    {
+		if (src_bpp == 32)
+		{
+		    PIXMAN_IMAGE_GET_LINE (src_image, 0, sy, uint32_t, src_stride, src_line, 1);
+
+		    for (i = 0; i < src_width; )
+		    {
+			for (j = 0; j < src_image->bits.width; j++, i++)
+			    extended_src[i] = src_line[j];
+		    }
+		}
+		else if (src_bpp == 16)
+		{
+		    uint16_t *src_line_16;
+
+		    PIXMAN_IMAGE_GET_LINE (src_image, 0, sy, uint16_t, src_stride,
+					   src_line_16, 1);
+		    src_line = (uint32_t*)src_line_16;
+
+		    for (i = 0; i < src_width; )
+		    {
+			for (j = 0; j < src_image->bits.width; j++, i++)
+			    ((uint16_t*)extended_src)[i] = ((uint16_t*)src_line)[j];
+		    }
+		}
+		else if (src_bpp == 8)
+		{
+		    uint8_t *src_line_8;
+
+		    PIXMAN_IMAGE_GET_LINE (src_image, 0, sy, uint8_t, src_stride,
+					   src_line_8, 1);
+		    src_line = (uint32_t*)src_line_8;
+
+		    for (i = 0; i < src_width; )
+		    {
+			for (j = 0; j < src_image->bits.width; j++, i++)
+			    ((uint8_t*)extended_src)[i] = ((uint8_t*)src_line)[j];
+		    }
+		}
+
+		info2.src_y = 0;
+	    }
+	    else
+	    {
+		info2.src_y = sy;
+	    }
+
 	    width_remain = width;
 
 	    while (width_remain > 0)
 	    {
-		num_pixels = src_image->bits.width - sx;
+		num_pixels = src_width - sx;
 
 		if (num_pixels > width_remain)
 		    num_pixels = width_remain;
 
 		info2.src_x = sx;
-		info2.src_y = sy;
 		info2.width = num_pixels;
 		info2.height = 1;
 
@@ -1263,6 +1349,9 @@ fast_composite_tiled_repeat (pixman_implementation_t *imp,
 	    info2.dest_x = info->dest_x;
 	    info2.dest_y++;
 	}
+
+	if (need_src_extension)
+	    _pixman_image_fini (&extended_src_image);
     }
     else
     {