[Bug 261977] lang/gcc12-devel: enable LTO
- In reply to: bugzilla-noreply_a_freebsd.org: "[Bug 261977] lang/gcc12-devel: enable LTO"
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Date: Tue, 19 Apr 2022 21:22:58 UTC
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=261977 --- Comment #30 from Piotr Kubaj <pkubaj@FreeBSD.org> --- This issue is quickly getting out of hand, I'll do the last fix to default to LTO, but allow non LTO. However, some remarks: - LTO is NOT used only for stage 1. In fact, if it were used only for only stage (like mat@ implied), then powerpc64 builds would be broken (because LTO with LLVM is known to be broken on powerpc64). That is not the case, LTOized GCC works fine on powerpc64, because -flto is only passed AFTER stage 1. - comparison of bulk -a builds is just idiotic. How can you compare bulk -a with LTOized GCC when nothing else depends on it? It just doesn't make sense at all. Those -devel ports are only to serve as CI-like safety measure to make sure the newest GCC snapshots build. They use LTO, because the current release (lang/gcc11) also does, and I hope lang/gcc12 will as well. - if you compare bulk -a builds with LTO for gcc*-devel ports, then we might as well just drop -devel ports completely - build times will be lower. In fact, they will be even lower if we drop all the gcc ports completely (along with the required reverse dependencies). - Regarding performance benchmarks for LTO - has anyone done that when -O2 was introduced? This is one of the reasons why I hear things like "it's hard introduce anything in FreeBSD, because many devs oppose it" and "I gave up fighting it" (from one former portmgr@ people, who also did some ppc work). - How is it that e.g. Ubuntu or OpenSUSE can afford to enforce LTO for their own repo and we can't? -- You are receiving this mail because: You are on the CC list for the bug.