enable thinlto for packages will increase the first time compile time

Question

enable thinlto for packages will increase the first time compile time

Closed this issue 8 months ago · 8 comments

Enable thinlto for packages will increase the x86_64(not x86_64-v3) compile time.
The comparison is very obvious, especially when compiling ffmpeg and mpv.

enable thinlto for all packages, took about 44min(https://github.com/eko5624/mpv-winbuild/actions/runs/7676626171)
disable thinlto for all packages, took about 24min(https://github.com/eko5624/mpv-winbuild/actions/runs/7677718754)

Answer 1 · 2024-01-27T11:10:38.000Z

Yes, it's normal.

Answer 2 · 2024-01-27T14:36:49.000Z

Then the CI should switch to default CLANG_PACKAGES_LTO="OFF" for x86_64 compilation.

Answer 3 · 2024-01-27T22:11:55.000Z

Thanks. I will try to add ThinLTO cache to see if the problem can be resolved.

Answer 4 · 2024-01-29T07:11:26.000Z

I try to add ThinLTO and ccache，but I get this errors. https://github.com/eko5624/mpv-winbuild/actions

My x86_64-w64-mingw32-clang:
https://github.com/eko5624/toolchain/blob/11b33325636538e92e24899d2f8b7edb112a57e1/llvm-wrapper-x86_64_v3/x86_64-w64-mingw32-clang#L12

My x86_64-w64-mingw32-ld :
https://github.com/eko5624/toolchain/blob/11b33325636538e92e24899d2f8b7edb112a57e1/llvm-wrapper-x86_64_v3/x86_64-w64-mingw32-ld#L7

And my makepkg_cross.conf:
https://github.com/eko5624/mpv-winbuild/blob/52dd2212e1a59eda859ac036bdba6789df3f5a66/pacman-config/makepkg_cross.conf#L47

And ccache.conf:
https://github.com/eko5624/mpv-winbuild/blob/52dd2212e1a59eda859ac036bdba6789df3f5a66/ccache.conf#L1

Any suggestions?

Answer 5 · 2024-01-29T13:30:18.000Z

So I consider to drop ccache, just only packages thinlto.

Fortunately, only shaderc and ffmpeg link dll/exe, so you can consider merge shaderc/libplacebo/ffmpeg into the same runner.

what confuse me is where is the thinlto directory when shaderc compiled done. Do you mean only ffmpeg has thinlto things? If so, I only need to cache thinlto dir when ffmpeg compiled done.

Answer 6 · 2024-01-29T14:31:55.000Z

So I should set --thinlto-cache-dir to where?
By the way, in archlinux docker, when input cd ~, the output is /github/home

Answer 7 · 2024-01-29T15:19:40.000Z

Thanks for your tip, I will try it.

Answer 8 · 2024-01-31T16:52:25.000Z

It works now since https://github.com/eko5624/mpv-winbuild/tree/e3ff1d33014ac0379ad17b792a243d576ce1bd9c
But It seems the compilation speed is no difference between enable thinlto and disable thinlto. And I find when enable thinlto, the size of mpv.exe is slightly larger than disable thinlto.