On 06/21/2016 03:08 AM, Nicolai Hähnle wrote:
From: Nicolai Hähnle <[email protected]>

This avoids costly address recomputations, function overhead, and may trigger
large copy optimizations.
---
  src/mesa/state_tracker/st_cb_readpixels.c | 23 +++++++++++++++--------
  1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/src/mesa/state_tracker/st_cb_readpixels.c 
b/src/mesa/state_tracker/st_cb_readpixels.c
index 39d2274..77c6332 100644
--- a/src/mesa/state_tracker/st_cb_readpixels.c
+++ b/src/mesa/state_tracker/st_cb_readpixels.c
@@ -520,14 +520,21 @@ st_ReadPixels(struct gl_context *ctx, GLint x, GLint y,
     /* memcpy data into a user buffer */
     {
        const uint bytesPerRow = width * util_format_get_blocksize(dst_format);
-      GLuint row;
-
-      for (row = 0; row < (unsigned) height; row++) {
-         void *dest = _mesa_image_address2d(pack, pixels,
-                                              width, height, format,
-                                              type, row, 0);
-         memcpy(dest, map, bytesPerRow);
-         map += tex_xfer->stride;
+      const uint destStride = _mesa_image_row_stride(pack, width, format, 
type);
+      char *dest = _mesa_image_address2d(pack, pixels,
+                                         width, height, format,
+                                         type, 0, 0);
+
+      if (tex_xfer->stride == bytesPerRow && destStride == bytesPerRow) {
+         memcpy(dest, map, bytesPerRow * height);
+      } else {
+         GLuint row;
+
+         for (row = 0; row < (unsigned) height; row++) {
+            memcpy(dest, map, bytesPerRow);
+            map += tex_xfer->stride;
+            dest += destStride;
+         }
        }
     }



Reviewed-by: Brian Paul <[email protected]>

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