https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67483
--- Comment #3 from Segher Boessenkool <segher at gcc dot gnu.org> --- Author: segher Date: Fri May 13 23:01:40 2016 New Revision: 236232 URL: https://gcc.gnu.org/viewcvs?rev=236232&root=gcc&view=rev Log: combine: Don't call extract_left_shift with count < 0 (PR67483) If the compiled program does a shift by a negative amount, combine will happily work with that, but it shouldn't then do an undefined operation in GCC itself. This patch fixes the first case mentioned in the bug report (I haven't been able to reproduce the second case, on trunk at least). PR rtl-optimization/67483 * combine.c (make_compound_operation): Don't call extract_left_shift with negative shift amounts. Modified: trunk/gcc/ChangeLog trunk/gcc/combine.c
