[Mesa-dev] [PATCH 1/6] util: Add big-endian layout for depth/stencil formats

[Richard Sandiford]

This patch builds on 6c8f547f66e68b495c708f8ffcb67370caa5ffe8 and
previous patches by allowing u_format.csv to specify separate big-endian
and little-endian layouts.  It then uses this to specify the correct layouts
for various depth/stencil formats.  Later patches handle other formats.

To recap, the idea is that u_format.csv lists the channels for an N-byte
value as though it were an N-byte integer.  For little-endian targets
the channels are listed starting at the least-significant bit of the
integer while for big-endian targets the channels are listed starting
at the most-significant bit.  This means that for something like
PIPE_FORMAT_B8G8R8A8_UNORM (blue in first byte of memory, alpha in last
byte of memory) the orders are the same for both endiannesses.  But for
something like PIPE_FORMAT_S8_UINT_Z24_UNORM, where the stencil is in
the least significant byte of a 32-bit integer, there need to be separate
channel definitions for each endianness.

The effect of this patch is to make the affected PIPE_FORMAT_*s have
the same layout as the associated MESA_FORMAT_*s for big-endian.
The MESA_FORMAT_*s are already handled correctly.

Fixes various piglit tests on z.  No regressions on x86_64.
---
 src/gallium/auxiliary/util/u_format.csv      | 18 ++++++++++--------
 src/gallium/auxiliary/util/u_format_parse.py |  9 +++++++--
 2 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/src/gallium/auxiliary/util/u_format.csv b/src/gallium/auxiliary/util/u_format.csv
index 8aa5c36..c596de9 100644
--- a/src/gallium/auxiliary/util/u_format.csv
+++ b/src/gallium/auxiliary/util/u_format.csv
@@ -46,6 +46,8 @@
 #   - number of bits
 # - channel swizzle 
 # - color space: rgb, yub, sz
+# - (optional) channel encoding for big-endian targets
+# - (optional) channel swizzle for big-endian targets
 #
 # See also:
 # - http://msdn.microsoft.com/en-us/library/bb172558.aspx (D3D9)
@@ -128,14 +130,14 @@ PIPE_FORMAT_S8_UINT                 , plain, 1, 1, up8 ,     ,     ,     , _x__,
 PIPE_FORMAT_Z16_UNORM               , plain, 1, 1, un16,     ,     ,     , x___, zs
 PIPE_FORMAT_Z32_UNORM               , plain, 1, 1, un32,     ,     ,     , x___, zs
 PIPE_FORMAT_Z32_FLOAT               , plain, 1, 1, f32 ,     ,     ,     , x___, zs
-PIPE_FORMAT_Z24_UNORM_S8_UINT       , plain, 1, 1, un24, up8 ,     ,     , xy__, zs
-PIPE_FORMAT_S8_UINT_Z24_UNORM       , plain, 1, 1, up8 , un24,     ,     , yx__, zs
-PIPE_FORMAT_X24S8_UINT              , plain, 1, 1, x24 , up8 ,     ,     , _y__, zs
-PIPE_FORMAT_S8X24_UINT              , plain, 1, 1, up8 , x24 ,     ,     , _x__, zs
-PIPE_FORMAT_Z24X8_UNORM             , plain, 1, 1, un24, x8  ,     ,     , x___, zs
-PIPE_FORMAT_X8Z24_UNORM             , plain, 1, 1, x8  , un24,     ,     , y___, zs
-PIPE_FORMAT_Z32_FLOAT_S8X24_UINT    , plain, 1, 1, f32 , up8 ,  x24,     , xy__, zs
-PIPE_FORMAT_X32_S8X24_UINT          , plain, 1, 1, x32 , up8 ,  x24,     , _y__, zs
+PIPE_FORMAT_Z24_UNORM_S8_UINT       , plain, 1, 1, un24, up8 ,     ,     , xy__, zs,    up8 , un24,     ,     , yx__
+PIPE_FORMAT_S8_UINT_Z24_UNORM       , plain, 1, 1, up8 , un24,     ,     , yx__, zs,    un24, up8 ,     ,     , xy__
+PIPE_FORMAT_X24S8_UINT              , plain, 1, 1, x24 , up8 ,     ,     , _y__, zs,    up8 , x24 ,     ,     , _x__
+PIPE_FORMAT_S8X24_UINT              , plain, 1, 1, up8 , x24 ,     ,     , _x__, zs,    x24 , up8 ,     ,     , _y__
+PIPE_FORMAT_Z24X8_UNORM             , plain, 1, 1, un24, x8  ,     ,     , x___, zs,    x8  , un24,     ,     , y___
+PIPE_FORMAT_X8Z24_UNORM             , plain, 1, 1, x8  , un24,     ,     , y___, zs,    un24, x8  ,     ,     , x___
+PIPE_FORMAT_Z32_FLOAT_S8X24_UINT    , plain, 1, 1, f32 , up8 ,  x24,     , xy__, zs,    f32 , x24 ,  up8,     , xz__
+PIPE_FORMAT_X32_S8X24_UINT          , plain, 1, 1, x32 , up8 ,  x24,     , _y__, zs,    x32 , x24 ,  up8,     , _z__
 
 # YUV formats
 # http://www.fourcc.org/yuv.php#UYVY
diff --git a/src/gallium/auxiliary/util/u_format_parse.py b/src/gallium/auxiliary/util/u_format_parse.py
index 15cc6d4..929017a 100755
--- a/src/gallium/auxiliary/util/u_format_parse.py
+++ b/src/gallium/auxiliary/util/u_format_parse.py
@@ -330,6 +330,9 @@ def parse(filename):
             continue
 
         fields = [field.strip() for field in line.split(',')]
+        if len (fields) == 10:
+           fields += fields[4:9]
+        assert len (fields) == 15
         
         name = fields[0]
         layout = fields[1]
@@ -339,8 +342,8 @@ def parse(filename):
         le_swizzles = [_swizzle_parse_map[swizzle] for swizzle in fields[8]]
         le_channels = _parse_channels(fields[4:8], layout, colorspace, le_swizzles)
 
-        be_swizzles = [_swizzle_parse_map[swizzle] for swizzle in fields[8]]
-        be_channels = _parse_channels(fields[4:8], layout, colorspace, be_swizzles)
+        be_swizzles = [_swizzle_parse_map[swizzle] for swizzle in fields[14]]
+        be_channels = _parse_channels(fields[10:14], layout, colorspace, be_swizzles)
 
         le_shift = 0
         for channel in le_channels:
@@ -353,6 +356,8 @@ def parse(filename):
             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, le_channels, le_swizzles, be_channels, be_swizzles, colorspace)
         formats.append(format)
-- 
1.8.3.1