I don't think such changes should be made a few weeks before a freeze,
or if that change should be made at all. This is a discussion that
should be made during the freeze and then implemented at the start of
the next release cycle.
The current baseline is i686-linux-gnu, without access to any SSE
instructions. Apparently other toolchains are actively raising these
baselines, or are unaware about what is used as a baseline upstream (as
seen in here for LLVM and rustc).
Mixing fp87 and SSE instructions leads to a performance penalty (I don't
have references to that, so people might want to investigate).
fp87 instructions also show some excess precision, so test cases and
test suites of packages might be affected by this change as well.
When preparing for such a change (maybe during the freeze when the
archive is not active), please do at least a comparative test rebuild
with these changes, also checking that affected toolchains adhere to the
new baseline. A test rebuild still does not cover the use of the
rebuilt binaries as dependencies.
Is this really worth doing that change, alternatives could also include
to retire the i386 port, or to keep the status quo, and document that
packages built by toolchains with unknown baselines might not run on
some hardware.
Matthias
