[Mesa-dev] [PATCH 2/2] gallium: avoid generating loop overhead in case of a non cubemap texture.

[Vincent Lejeune]

---
 src/mesa/state_tracker/st_cb_texture.c |   82 ++++++++++++++++++++++++--------
 1 files changed, 62 insertions(+), 20 deletions(-)

diff --git a/src/mesa/state_tracker/st_cb_texture.c b/src/mesa/state_tracker/st_cb_texture.c
index 3cd1b2b..eeb6e3a 100644
--- a/src/mesa/state_tracker/st_cb_texture.c
+++ b/src/mesa/state_tracker/st_cb_texture.c
@@ -1197,6 +1197,60 @@ copy_image_data_to_texture(struct st_context *st,
    pipe_resource_reference(&stImage->pt, stObj->pt);
 }
 
+
+static void inline
+import_texture_given_level(struct st_context *st, struct st_texture_object *stObj,const struct pipe_resource *stObjpt,struct gl_texture_image **img, const GLuint level)
+{
+      struct st_texture_image *stImage =
+         st_texture_image(img[level]);
+
+       /* Need to import images in main memory or held in other textures.
+       */
+      if (stImage && stObjpt != stImage->pt) {
+         if (level == 0 ||
+             (stImage->base.Width == u_minify(stObj->width0, level) &&
+              stImage->base.Height == u_minify(stObj->height0, level) &&
+              stImage->base.Depth == u_minify(stObj->depth0, level))) {
+            /* src image fits expected dest mipmap level size */
+            copy_image_data_to_texture(st, stObj, level, stImage);
+         }
+      }
+}
+
+
+static void inline
+import_texture(struct st_context *st, struct st_texture_object *stObj, const GLuint face)
+{
+   const GLuint baselevel = stObj->base.BaseLevel;
+   const GLuint levelcount = stObj->lastLevel - baselevel;
+   const struct pipe_resource* stObjpt = stObj->pt;
+
+   struct gl_texture_image **img = &(stObj->base.Image[face][baselevel]);
+
+   for (unsigned n = (levelcount + 7) / 8;n>0;n--) {
+      import_texture_given_level(st,stObj,stObjpt,img,0);
+      import_texture_given_level(st,stObj,stObjpt,img,1);
+      import_texture_given_level(st,stObj,stObjpt,img,2);
+      import_texture_given_level(st,stObj,stObjpt,img,3);
+      import_texture_given_level(st,stObj,stObjpt,img,4);
+      import_texture_given_level(st,stObj,stObjpt,img,5);
+      import_texture_given_level(st,stObj,stObjpt,img,6);
+      import_texture_given_level(st,stObj,stObjpt,img,7);
+      img += 8;
+   }
+
+   switch (levelcount % 8) {
+      case 7: import_texture_given_level(st,stObj,stObjpt,img,6);
+      case 6: import_texture_given_level(st,stObj,stObjpt,img,5);
+      case 5: import_texture_given_level(st,stObj,stObjpt,img,4);
+      case 4: import_texture_given_level(st,stObj,stObjpt,img,3);
+      case 3: import_texture_given_level(st,stObj,stObjpt,img,2);
+      case 2: import_texture_given_level(st,stObj,stObjpt,img,1);
+      case 1: import_texture_given_level(st,stObj,stObjpt,img,0);
+      case 0: break;
+   }
+}
+
 static void inline
 set_mipmap_level(struct st_texture_object *stObj)
 {
@@ -1219,8 +1273,6 @@ st_finalize_texture_body(struct gl_context *ctx,
                struct st_texture_object *stObj)
 {
    struct st_context *st = st_context(ctx);
-   const GLuint nr_faces = (stObj->base.Target == GL_TEXTURE_CUBE_MAP) ? 6 : 1;
-   GLuint face;
    struct st_texture_image *firstImage;
    enum pipe_format firstImageFormat;
    GLuint ptWidth, ptHeight, ptDepth, ptLayers;
@@ -1305,25 +1357,15 @@ st_finalize_texture_body(struct gl_context *ctx,
 
    /* Pull in any images not in the object's texture:
     */
-   for (face = 0; face < nr_faces; face++) {
-      GLuint level;
-      for (level = stObj->base.BaseLevel; level <= stObj->lastLevel; level++) {
-         struct st_texture_image *stImage =
-            st_texture_image(stObj->base.Image[face][level]);
+   import_texture(st, stObj, 0);
+   if (stObj->base.Target != GL_TEXTURE_CUBE_MAP)
+      return GL_TRUE;
 
-         /* Need to import images in main memory or held in other textures.
-          */
-         if (stImage && stObj->pt != stImage->pt) {
-            if (level == 0 ||
-                (stImage->base.Width == u_minify(stObj->width0, level) &&
-                 stImage->base.Height == u_minify(stObj->height0, level) &&
-                 stImage->base.Depth == u_minify(stObj->depth0, level))) {
-               /* src image fits expected dest mipmap level size */
-               copy_image_data_to_texture(st, stObj, level, stImage);
-            }
-         }
-      }
-   }
+   import_texture(st, stObj, 1);
+   import_texture(st, stObj, 2);
+   import_texture(st, stObj, 3);
+   import_texture(st, stObj, 4);
+   import_texture(st, stObj, 5);
 
    return GL_TRUE;
 }
-- 
1.7.7