mesa/st: Simplify st_choose_matching_format().

We now have a nice helper function for finding those memcpy formats,
without needing to go through each entry of the mesa format table to
see if it happens to match.

While looking at sysprof of a softpipe GLES2 CTS run, we were spending
~8% of the CPU on ChooseTextureFormat.  With this, roughly the same
region of the testsuite was .4%.

v2: Add Ken's fix for canonicalizing array formats.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

diff --git a/src/mesa/state_tracker/st_format.c b/src/mesa/state_tracker/st_format.c
index d2199d5af597d5eb8c3293ab05183d220bf8ee0f..396254afbeafc006bb7c138859e0694d647f0116 100644 (file)
--- a/src/mesa/state_tracker/st_format.c
+++ b/src/mesa/state_tracker/st_format.c
@@ -1277,36 +1277,20 @@ st_choose_matching_format(struct st_context *st, unsigned bind,
                           GLenum format, GLenum type, GLboolean swapBytes)
 {
    struct pipe_screen *screen = st->pipe->screen;
-   mesa_format mesa_format;
 
-   for (mesa_format = 1; mesa_format < MESA_FORMAT_COUNT; mesa_format++) {
-      if (!_mesa_get_format_name(mesa_format))
-         continue;
-
-      if (_mesa_is_format_srgb(mesa_format)) {
-         continue;
-      }
-      if (_mesa_get_format_bits(mesa_format, GL_TEXTURE_INTENSITY_SIZE) > 0) {
-         /* If `format` is GL_RED/GL_RED_INTEGER, then we might match some
-          * intensity formats, which we don't want.
-          */
-         continue;
-      }
-
-      if (_mesa_format_matches_format_and_type(mesa_format, format, type,
-                                               swapBytes, NULL)) {
-         enum pipe_format format =
-            st_mesa_format_to_pipe_format(st, mesa_format);
+   if (swapBytes && !_mesa_swap_bytes_in_type_enum(&type))
+      return PIPE_FORMAT_NONE;
 
-         if (format &&
-             screen->is_format_supported(screen, format, PIPE_TEXTURE_2D,
-                                         0, 0, bind)) {
-            return format;
-         }
-         /* It's unlikely to find 2 matching Mesa formats. */
-         break;
-      }
+   mesa_format mesa_format = _mesa_format_from_format_and_type(format, type);
+   if (_mesa_format_is_mesa_array_format(mesa_format))
+      mesa_format = _mesa_format_from_array_format(mesa_format);
+   if (mesa_format != MESA_FORMAT_NONE) {
+      enum pipe_format format = st_mesa_format_to_pipe_format(st, mesa_format);
+      if (format != PIPE_FORMAT_NONE &&
+          screen->is_format_supported(screen, format, PIPE_TEXTURE_2D, 0, 0, bind))
+         return format;
    }
+
    return PIPE_FORMAT_NONE;
 }