https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78598
--- Comment #1 from Markus Trippelsdorf <trippels at gcc dot gnu.org> --- Author: trippels Date: Thu Dec 1 14:59:03 2016 New Revision: 243113 URL: https://gcc.gnu.org/viewcvs?rev=243113&root=gcc&view=rev Log: Fix PR tree-optimization/78598 - tree-ssa-loop-prefetch.c:835:16: runtime error: signed integer overflow Using bootstrap-ubsan gcc to build mplayer shows: tree-ssa-loop-prefetch.c:835:16: runtime error: signed integer overflow: 288230376151711743 * 64 cannot be represented in type 'long int' Here signed und unsigned integers are mixed in a division resulting in bogus values: (-83 + 64ULL -1) / 64ULL) == 288230376151711743 Fixed by casting the unsigned parameter to signed. PR tree-optimization/78598 * tree-ssa-loop-prefetch.c (ddown): Cast to signed to avoid overflows. Modified: trunk/gcc/ChangeLog trunk/gcc/tree-ssa-loop-prefetch.c
