https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78437
--- Comment #7 from Eric Botcazou <ebotcazou at gcc dot gnu.org> --- Author: ebotcazou Date: Thu Nov 24 15:01:32 2016 New Revision: 242839 URL: https://gcc.gnu.org/viewcvs?rev=242839&root=gcc&view=rev Log: PR rtl-optimization/78437 * ree.c (get_uses): New function. (combine_reaching_defs): When a copy is needed, return false if any reaching use of the source register reads it in a mode larger than the mode it is set in and WORD_REGISTER_OPERATIONS is true. Modified: trunk/gcc/ChangeLog trunk/gcc/ree.c