util/format: expose generated format packing functions through a header

Some of the generated functions can be useful without going through the
format table (filling border color struct in turnip). By not calling these
functions through the format table, we should eventually be able to garbage
collect the unused packing functions, and also allows LTOs to happen.

Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Reviewed-by: Eric Anholt <eric@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6093>

src/util/Makefile.sources

@@ -130,7 +130,8 @@ MESA_UTIL_FILES := \
 
 MESA_UTIL_GENERATED_FILES = \
 	format_srgb.c \
-	format/u_format_table.c
+	format/u_format_table.c \
+	format/u_format_pack.h
 
 XMLCONFIG_FILES := \
 	xmlconfig.c \

src/util/SConscript

@@ -26,6 +26,18 @@ env.CodeGenerate(
     command = python_cmd + ' $SCRIPT > $TARGET'
 )
 
+env.CodeGenerate(
+    target = 'format/u_format_pack.h',
+    script = 'format/u_format_table.py',
+    source = ['format/u_format.csv'],
+    command = python_cmd + ' $SCRIPT $SOURCE --header > $TARGET'
+)
+
+env.Depends('format/u_format_pack.h', [
+    'format/u_format_parse.py',
+    'format/u_format_pack.py',
+])
+
 env.CodeGenerate(
     target = 'format/u_format_table.c',
     script = 'format/u_format_table.py',

src/util/format/meson.build

@@ -31,6 +31,15 @@ files_mesa_format = [
   'u_format_zs.c',
 ]
 
+u_format_pack_h = custom_target(
+  'u_format_pack.h',
+  input : ['u_format_table.py', 'u_format.csv'],
+  output : 'u_format_pack.h',
+  command : [prog_python, '@INPUT@', '--header'],
+  depend_files : files('u_format_pack.py', 'u_format_parse.py'),
+  capture : true,
+)
+
 u_format_table_c = custom_target(
   'u_format_table.c',
   input : ['u_format_table.py', 'u_format.csv'],
@@ -42,7 +51,7 @@ u_format_table_c = custom_target(
 
 libmesa_format = static_library(
   'mesa_format',
-  [files_mesa_format, u_format_table_c],
+  [files_mesa_format, u_format_table_c, u_format_pack_h],
   include_directories : [inc_include, inc_src, inc_mapi, inc_mesa, inc_gallium, inc_gallium_aux],
   dependencies : dep_m,
   c_args : [c_msvc_compat_args],

src/util/format/u_format_pack.py

@@ -49,7 +49,6 @@ if sys.version_info < (3, 0):
 else:
     integer_types = (int, )
 
-
 def inv_swizzles(swizzles):
     '''Return an array[4] of inverse swizzle terms'''
     '''Only pick the first matching value to avoid l8 getting blue and i8 getting alpha'''
@@ -658,10 +657,12 @@ def generate_format_pack(format, src_channel, src_native_type, src_suffix):
 
     name = format.short_name()
 
-    print('static inline void')
+    print('void')
     print('util_format_%s_pack_%s(uint8_t *dst_row, unsigned dst_stride, const %s *src_row, unsigned src_stride, unsigned width, unsigned height)' % (name, src_suffix, src_native_type))
     print('{')
 
+    print('void util_format_%s_pack_%s(uint8_t *dst_row, unsigned dst_stride, const %s *src_row, unsigned src_stride, unsigned width, unsigned height);' % (name, src_suffix, src_native_type), file=sys.stdout2)
+    
     if is_format_supported(format):
         print('   unsigned x, y;')
         print('   for(y = 0; y < height; y += %u) {' % (format.block_height,))
@@ -712,6 +713,7 @@ def generate(formats):
     print('#include "util/format_srgb.h"')
     print('#include "u_format_yuv.h"')
     print('#include "u_format_zs.h"')
+    print('#include "u_format_pack.h"')
     print()
 
     for format in formats:
@@ -761,4 +763,3 @@ def generate(formats):
 
                 generate_format_unpack(format, channel, native_type, suffix)
                 generate_format_pack(format, channel, native_type, suffix)
-

src/util/format/u_format_table.py

@@ -30,7 +30,7 @@ CopyRight = '''
 '''
 
 
-import sys
+import sys, os
 
 from u_format_parse import *
 import u_format_pack
@@ -112,13 +112,16 @@ def has_access(format):
         return False
     return True
 
-def write_format_table(formats):
-    print('/* This file is autogenerated by u_format_table.py from u_format.csv. Do not edit directly. */')
-    print()
+def write_format_table_header(file):
+    print('/* This file is autogenerated by u_format_table.py from u_format.csv. Do not edit directly. */', file=file)
+    print(file=file)
     # This will print the copyright message on the top of this file
-    print(CopyRight.strip())
-    print()
-    print('#include "u_format.h"')
+    print(CopyRight.strip(), file=file)
+    print(file=file)
+    print('#include "util/format/u_format.h"', file=file)
+
+def write_format_table(formats):
+    write_format_table_header(sys.stdout)
     print('#include "u_format_bptc.h"')
     print('#include "u_format_s3tc.h"')
     print('#include "u_format_rgtc.h"')
@@ -126,6 +129,8 @@ def write_format_table(formats):
     print('#include "u_format_etc.h"')
     print()
 
+    write_format_table_header(sys.stdout2)
+    
     u_format_pack.generate(formats)
     
     def do_channel_array(channels, swizzles):
@@ -261,12 +266,19 @@ def write_format_table(formats):
     generate_table_getter("unpack_")
 
 def main():
-
     formats = []
-    for arg in sys.argv[1:]:
-        formats.extend(parse(arg))
-    write_format_table(formats)
 
+    sys.stdout2 = open(os.devnull, "w")
+
+    for arg in sys.argv[1:]:
+        if arg == '--header':
+            sys.stdout2 = sys.stdout
+            sys.stdout = open(os.devnull, "w")
+            continue
+
+        formats.extend(parse(arg))
+
+    write_format_table(formats)
 
 if __name__ == '__main__':
     main()