https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92704
prathamesh3492 at gcc dot gnu.org changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |prathamesh3492 at gcc dot gnu.org --- Comment #1 from prathamesh3492 at gcc dot gnu.org --- This seems, to happen because we end up with following phi defining .MEM_113 in ifcvt dump: <bb 40> [local count: 3667364]: # q7_91 = PHI <q7_15(5), q7_108(50)> # zr_lsm.55_92 = PHI <iftmp.5_13(5), iftmp.5_105(50)> # .MEM_113 = PHI <(5), .MEM_106(50)> .MEM_113 phi seems to have NULL (!) arg, which then causes segfault in following hunk in tree-ssa-sccvn.c:process_bb() gphi *phi = gsi.phi (); use_operand_p use_p = PHI_ARG_DEF_PTR_FROM_EDGE (phi, e); tree arg = USE_FROM_PTR (use_p); if (TREE_CODE (arg) != SSA_NAME || virtual_operand_p (arg)) continue; Passing -fno-tree-loop-ifconvert in addition to other options, doesn't cause the segfault. I assume phi args cannot be NULL ? Thanks, Prathamesh