Change #270198

Comments

swscale/x86/uops: generate NASM macros using uops_macros.h
Rather than hard-coding a separate set of NASM macros, or generating them
with a separate function, we can just leverage the C preprocessor to generate
a NASM source file *from* the existing ops macros.

This is maybe a bit unorthodox, but it avoids unnecessary overhead from
re-generating the macros twice, avoids manual updating of the NASM macros,
and generally does not come with any real downside except being a bit ugly.

The main source of ugliness is the fact that the C preprocessor expands
everything into a single line, whereas NASM expects separate statements to
be on separate lines. Very fortunately, we can work around this by writing a
another NASM macro to take its arguments and dump them onto multiple lines.

It may seem premature, but I went ahead and defined all the macros, since
it was easy enough to do.

I added the %include in this commit to trigger build errors that occur only
as a result of introducing this file in the same commit that introduces it.

Signed-off-by: Niklas Haas <git@haasn.dev>

Changed files

• .gitignore
• ffbuild/common.mak
• libswscale/x86/Makefile
• libswscale/x86/ops_include.asm
• libswscale/x86/uops_macros.asm.h
• tests/ref/fate/source