Hi guys,
For some time now, we've been shipping broken i486 stage3s that do not
run on pre-i686 hardware [1]. Due to a change in catalyst [2], we no
longer set CXXFLAGS in the default make.conf, so the x86 profiles' (imho
wrong/broken) defaults [3] kick in.
I'd like to get this fixed, and I see 3 possible solutions, listed in
order of my own preference:
1) Adjust x86 profile defaults to drop the problematic -march=i686.
This would be more in line with amd64 profiles (et al), which set no
-march value so it can run on any hardware for this arch.
2) Patch catalyst to start setting CXXFLAGS again. Rather than roll
back to exactly CXXFLAGS="${CFLAGS}" again, it's been suggested that we
start setting COMMON_FLAGS, and CFLAGS="${COMMON_FLAGS}"
CXXFLAGS=${COMMON_FLAGS}" etc. I prepared such a patch a while back
[4], which seems to work but may need a bit of updating.
3) Drop i486 support. We're only pretending to have support now, we
could officially stop building these broken stages completely.
Personally I think #1 is the most technically correct and least amount
of work. The only result will be slightly less optimized builds for
people who choose not to customize *FLAGS at all in make.conf. But this
is correct behavior. What we have now is akin to setting -march=core2
on amd64 stage3 and saying "oops it doesn't work on early 64bit AMD
cpus, but oh well most people have newer and will appreciate the
optimization".
Thoughts?
-Ben
[1] https://bugs.gentoo.org/654080
[2]
https://gitweb.gentoo.org/proj/catalyst.git/commit/?id=b409bd9bb4b50f69a555e4e148057ade86a7ed16
[3]
https://gitweb.gentoo.org/repo/gentoo.git/tree/profiles/arch/x86/make.defaults
[4] https://bugs.gentoo.org/575446#c4
