https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115060
--- Comment #3 from Feng Xue <fxue at os dot amperecomputing.com> --- Linaro reported a regression: https://linaro.atlassian.net/browse/GNU-1226 Actually, this is not, but exposes a new bug in vect_look_through_possible_promotion. The function fails to figure out root definition if casts involves more than two promotions with sign change as: long a = (long)b; // promotion cast -> int b = (int)c; // promotion cast, sign change -> unsigned short c = ...; For this case, the function thinks the 2nd cast has different sign as the 1st, so stop looking through, while "unsigned short -> integer" is a nature sign extension.
