https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118360
--- Comment #7 from Georg-Johann Lay <gjl at gcc dot gnu.org> --- (In reply to Jeffrey A. Law from comment #6) > For AVR a sequence using shifts is bad and the variant with MUL is even worse. It's so bad that I added stuff in the avr backend that try to hack around PR118360 / PR118012. So to see whether any changes will improve the situation for avr and have any effect, you'll have to compile with -mno-pr118012 in order to turn off these hacks. It's still beyond me why the root cause isn't fixed, that is: Transformations in match.pd that is not optimizations, not a canonicalization, that cannot be rolled back due to its structure, and that cannot be turned off by some target means.
