I used this as some testing ground for investigating some compiler
bits initially (e.g. lrint calls etc.), figured I could do much better
in the end just for fun...
This is mathematically equivalent, but uses some tricks to avoid
doubles and also replaces some float math with ints. Good for another
performance doubling or so. As a side note, some quick tests show that
llvm's loop vectorizer would be able to properly vectorize this version
(which it failed to do earlier due to doubles, producing a mess), giving
another 3 times performance increase with sse2 (more with sse4.1), but this
may not apply to mesa.
No piglit change.
Acked-by: Marek Olšák <marek.olsak@amd.com>
This code (lifted straight from the extension) was doing things the most
inefficient way you could think of.
This drops some of the more expensive float operations, in particular
- int-cast floors (pointless, values always positive)
- 2 raised to (signed) integers (replace with simple exponent manipulation),
getting rid of a misguided comment in the process (implement with table...)
- float division (replace with mul of reverse of those exponents)
This is like 3 times faster (measured for float3_to_rgb9e5), though it depends
(e.g. llvm is clever enough to replace exp2 with ldexp whereas gcc is not,
division is not too bad on cpus with early-exit divs).
Note that keeping the double math for now (float x + 0.5), as the results may
otherwise differ.
Acked-by: Marek Olšák <marek.olsak@amd.com>
Generated by running:
git grep -l INLINE src/gallium/ | xargs sed -i 's/\bINLINE\b/inline/g'
git grep -l INLINE src/mesa/state_tracker/ | xargs sed -i 's/\bINLINE\b/inline/g'
git checkout src/gallium/state_trackers/clover/Doxyfile
and manual edits to
src/gallium/include/pipe/p_compiler.h
src/gallium/README.portability
to remove mentions of the inline define.
Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Acked-by: Marek Olšák <marek.olsak@amd.com>
Also use MAX3 and incorporate Ian's suggestion in texformat.c.
I don't think wrapping u_format_rgb9e5.h in another header and thus making it
more complicated is worth it.
Jason Ekstrand
Roland Scheidegger
Jose Fonseca
Matt Turner
Ilia Mirkin
Marek Olšák