gallium: Fix big-endian addressing of non-bitmask array formats.

The formats affected are:

- LA x (16_FLOAT, 32_FLOAT, 32_UINT, 32_SINT)
- R8G8B8 x (UNORM, SNORM, SRGB, USCALED, SSCALED, UINT, SINT)
- RG/RGB/RGBA x (64_FLOAT, 32_FLOAT, 16_FLOAT, 32_UNORM, 32_SNORM,
                 32_USCALED, 32_SSCALED, 32_FIXED, 32_UINT, 32_SINT)
- RGB/RGBA x (16_UNORM, 16_SNORM, 16_USCALED, 16_SSCALED,
              16_UINT, 16_SINT)
- RGBx16 x (UNORM, SNORM, FLOAT, UINT, SINT)
- RGBx32 x (FLOAT, UINT, SINT)
- RA x (16_FLOAT, 32_FLOAT, 32_UINT, 32_SINT)

The updated st_formats.c unit test checks that the formats affected by
this change are all array formats in the equivalent Mesa format (if
any).  Mesa's array format definition is clear: the value stored is an
array (increasing memory address) of values of the channel's type.
It's also the only thing that makes sense for the RGB types, or very
large types like RGBA64_FLOAT (A should not move to the low address
because the cpu is BE).

Acked-by: Roland Scheidegger <sroland@vmware.com>
Acked-by: Adam Jackson <ajax@redhat.com>
Tested-by: Matt Turner <mattst88@gmail.com> (unit tests on BE)
Reviewed-by: Marek Olšák <marek.olsak@amd.com>

src/gallium/auxiliary/util/u_format_parse.py

@@ -379,16 +379,27 @@ def parse(filename):
             channel.shift = le_shift
             le_shift += channel.size
 
-        be_shift = 0
-        for channel in be_channels[3::-1]:
-            channel.shift = be_shift
-            be_shift += channel.size
-
-        assert le_shift == be_shift
         for i in range(4):
             assert (le_swizzles[i] != SWIZZLE_NONE) == (be_swizzles[i] != SWIZZLE_NONE)
 
         format = Format(name, layout, block_width, block_height, block_depth, le_channels, le_swizzles, be_channels, be_swizzles, colorspace)
+
+        if format.is_array() and not format.is_bitmask():
+            # Formats accessed as arrays by the pack functions (R32G32_FLOAT or
+            # R8G8B8_UNORM, for example) should not be channel-ordering-reversed
+            # for BE.
+            # Note that __eq__ on channels ignores .shift!
+            assert(format.be_channels == format.le_channels)
+            assert(format.be_swizzles == format.le_swizzles)
+            format.be_channels = format.le_channels
+        else:
+            be_shift = 0
+            for channel in format.be_channels[3::-1]:
+                channel.shift = be_shift
+                be_shift += channel.size
+
+            assert le_shift == be_shift
+
         formats.append(format)
     return formats
 

src/mesa/state_tracker/tests/st_format.c

@@ -87,6 +87,29 @@ int main(int argc, char **argv)
          continue;
 
       if (mf != MESA_FORMAT_NONE) {
+         const struct util_format_description *desc = util_format_description(i);
+
+         /* Make sure that gallium and Mesa agree on whether the format is an
+          * array format.
+          */
+         if (desc->nr_channels > 1) {
+            bool mesa_array = (_mesa_get_format_layout(mf) ==
+                               MESA_FORMAT_LAYOUT_ARRAY);
+            bool gallium_array = desc->is_array && !desc->is_bitmask;
+            /* We should probably be checking equality here, but we have some
+             * UINT and SINT types that are array formats in Mesa but not in
+             * gallium.
+             */
+            if (gallium_array && !mesa_array) {
+               fprintf(stderr, "%s is %sarray, %s is %sarray\n",
+                       util_format_short_name(i),
+                       gallium_array ? "" : "not ",
+                       _mesa_get_format_name(mf),
+                       mesa_array ? "" : "not ");
+               return 1;
+            }
+         }
+
          enum pipe_format pf =
             st_mesa_format_to_pipe_format(st, mf);
          if (pf != i) {