[avr-gcc-list] Miscompilation with GCC 4.5.1 / diagnosis and possible patch

[Owen Taylor]

[ Not subscribed, please Cc: me on replies ]

Ran into some miscompilation of 16-bit arithmetic with the AVR backend
in stock GCC 4.5.1. A diagnosis and minimally tested patch can be
found at:

 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45291

Debugging into the GCC internals was more entertaining than digging
through collections of patches for GCC, so it may be that this is
fixed somewhere and just not in upstream GCC. But if not, hopefully
the above is useful.

- Owen