H300, X5: Faster lcd_yuv_blit() using EMAC. Speedup of the function itself at 124MHz: 10.5% on X5, 16.5% on H300. mpegplayer speedup 3..4%

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@11429 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 7 insertions, 5 deletions

diff --git a/firmware/drivers/lcd-h300.c b/firmware/drivers/lcd-h300.c
index b7865fa7c5..3e5642e35d 100644
--- a/firmware/drivers/lcd-h300.c
+++ b/firmware/drivers/lcd-h300.c
@@ -304,10 +304,11 @@ void lcd_blit(const fb_data* data, int x, int by, int width,
 /* Line write helper function for lcd_yuv_blit. Write two lines of yuv420.
  * y should have two lines of Y back to back.
  * bu and rv should contain the Cb and Cr data for the two lines of Y.
- * Stores bu, guv and rv in repective buffers for use in second line.
+ * Needs EMAC set to saturated, signed integer mode.
  */
 extern void lcd_write_yuv420_lines(const unsigned char *y,
-    unsigned char *bu, unsigned char *guv, unsigned char *rv, int width);
+                                   const unsigned char *bu,
+                                   const unsigned char *rv, int width);
 
 /* Performance function to blit a YUV bitmap directly to the LCD
  * src_x, src_y, width and height should be even
@@ -317,10 +318,9 @@ void lcd_yuv_blit(unsigned char * const src[3],
                   int src_x, int src_y, int stride,
                   int x, int y, int width, int height)
 {
-    /* IRAM Y, Cb/bu, guv and Cb/rv buffers. */
+    /* IRAM Y, Cb and Cb buffers. */
     unsigned char y_ibuf[LCD_WIDTH*2];
     unsigned char bu_ibuf[LCD_WIDTH/2];
-    unsigned char guv_ibuf[LCD_WIDTH/2];
     unsigned char rv_ibuf[LCD_WIDTH/2];
     const unsigned char *ysrc, *usrc, *vsrc;
     const unsigned char *ysrc_max;
@@ -342,13 +342,14 @@ void lcd_yuv_blit(unsigned char * const src[3],
     vsrc = src[2] + (src_y * stride >> 2) + (src_x >> 1);
     ysrc_max = ysrc + height * stride;
 
+    coldfire_set_macsr(EMAC_SATURATE);
     do
     {
         memcpy(y_ibuf, ysrc, width);
         memcpy(y_ibuf + width, ysrc + stride, width);
         memcpy(bu_ibuf, usrc, width >> 1);
         memcpy(rv_ibuf, vsrc, width >> 1);
-        lcd_write_yuv420_lines(y_ibuf, bu_ibuf, guv_ibuf, rv_ibuf, width);
+        lcd_write_yuv420_lines(y_ibuf, bu_ibuf, rv_ibuf, width);
         ysrc += 2 * stride;
         usrc += stride >> 1;
         vsrc += stride >> 1;
@@ -381,6 +382,7 @@ void lcd_update(void)
     }
 }
 
+
 /* Update a fraction of the display. */
 void lcd_update_rect(int, int, int, int) ICODE_ATTR;
 void lcd_update_rect(int x, int y, int width, int height)