[Debian-lego-team] FYI: GCC 15 appears to generate faulty h8300-hitachi-coff cross-compiler binaries

[Matthew Sheets]

Update: Of the optimizations enabled by default with `-O2` when using GCC 15.2.0 [1],
it appears `-ftree-pre` (“Perform partial redundancy elimination (PRE) on trees”) is
responsible for the faulty executables GCC 15 has been creating when building the
source code for GCC 3.4.6 [2].

Thus, instead of having to fall all the way back from `-O2` to `-O1`,
`-O2 -fno-tree-pre` appears to also be an alternative workaround supporting more
optimizations.

This would not seem to be related to GCC bug 125019 [3], as version `15.2.0` is
listed among the "known to work" versions.


Thank you,
Matthew

[1] https://gcc.gnu.org/onlinedocs/gcc-15.2.0/gcc/Optimize-Options.html
[2] https://github.com/BrickBot/GNU-Legacy-Toolchain/actions/runs/42944752773/job/130274752693
[3] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125019