On Fri, Oct 9, 2015 at 11:09 PM, Tom de Vries <tom_devr...@mentor.com> wrote: > Hi, > > In tree-parloops.c:gather_scalar_reductions, we find the comment: > ... > /* As gimple_uid is used by the vectorizer in between > vect_analyze_loop_form and destroy_loop_vec_info, we can set > gimple_uid of reduc_phi stmts only now. */ > reduction_list->traverse <void *, set_reduc_phi_uids> (NULL); > ... > > However, the usage of gimple_uid seems to extend until the > free_stmt_vec_info_vec call at the end of parallelize_loops (the pass > top-level function). During free_stmt_vec_info_vec we test for gimple_uid == > 0 in vinfo_for_stmt. > > By initializing all the phis in the function with -1 before using them in > the reduct_phi stmts: > ... > destroy_loop_vec_info (simple_loop_info, true); > destroy_loop_vec_info (simple_inner_loop_info, true); > > > > /* As gimple_uid is used by the vectorizer in between > vect_analyze_loop_form and destroy_loop_vec_info, we can set > gimple_uid of reduc_phi stmts only now. */ > + basic_block bb; > + FOR_EACH_BB_FN (bb, cfun) > + for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) > + gimple_set_uid (gsi_stmt (gsi), (unsigned int)-1); > reduction_list->traverse <void *, set_reduc_phi_uids> (NULL); > ... > we trigger a sigsegv in vinfo_for_stmt while trying to access > stmt_vec_info_vec[4294967295 - 1]. > > This patch fixes that by moving the calls to init_stmt_vec_info_vec and > free_stmt_vec_info_vec from parallelize_loops and gather_scalar_reductions. > > Furthermore, now that the gimple_uids are properly initialized, we can in > reduction_phi: > - handle 0 (new phi) and -1 (initialized) values, both meaning the > phi's not in the table, and > - assert that returned entries in fact match the phi argument. > > OK for trunk if bootstrap and reg-test passes?
Ok. Richard. > Thanks, > - Tom >
