https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85989
--- Comment #6 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> --- Author: rsandifo Date: Sat Jun 23 08:07:31 2018 New Revision: 261983 URL: https://gcc.gnu.org/viewcvs?rev=261983&root=gcc&view=rev Log: Fix phi backedge detection in backprop (PR85989) Backport trunk r261064. 2018-06-23 Richard Sandiford <richard.sandif...@linaro.org> gcc/ PR tree-optimization/85989 * gimple-ssa-backprop.c (backprop::m_visited_phis): New member variable. (backprop::intersect_uses): Check it when deciding whether this is a backedge reference. (backprop::process_block): Add each phi to m_visited_phis after visiting it, then clear it at the end. gcc/testsuite/ PR tree-optimization/85989 * gcc.dg/torture/pr85989.c: New test. Added: branches/gcc-8-branch/gcc/testsuite/gcc.dg/torture/pr85989.c Modified: branches/gcc-8-branch/gcc/ChangeLog branches/gcc-8-branch/gcc/gimple-ssa-backprop.c branches/gcc-8-branch/gcc/testsuite/ChangeLog
