static funct_state analyze_function (struct cgraph_node *fn, bool ipa) { tree decl = fn->decl; funct_state l; basic_block this_block; l = XCNEW (struct funct_state_d); l->pure_const_state = IPA_CONST; l->state_previously_known = IPA_NEITHER; l->looping_previously_known = true; l->looping = false; l->can_throw = false; state_from_flags (&l->state_previously_known, &l->looping_previously_known, flags_from_decl_or_type (fn->decl), cgraph_node_cannot_return (fn)); if (fn->thunk.thunk_p || fn->alias) { /* Thunk gets propagated through, so nothing interesting happens. */ gcc_assert (ipa); return l; } if (dump_file) { fprintf (dump_file, "\n\n local analysis of %s\n ", fn->name ()); } push_cfun (DECL_STRUCT_FUNCTION (decl)); FOR_EACH_BB_FN (this_block, cfun) { gimple_stmt_iterator gsi; struct walk_stmt_info wi; memset (&wi, 0, sizeof (wi)); for (gsi = gsi_start_bb (this_block); !gsi_end_p (gsi); gsi_next (&gsi)) { check_stmt (&gsi, l, ipa); if (l->pure_const_state == IPA_NEITHER && l->looping && l->can_throw) goto end; } }
static funct_state analyze_function (struct cgraph_node *fn, bool ipa) { tree decl = fn->symbol.decl; funct_state l; basic_block this_block; l = XCNEW (struct funct_state_d); l->pure_const_state = IPA_CONST; l->state_previously_known = IPA_NEITHER; l->looping_previously_known = true; l->looping = false; l->can_throw = false; state_from_flags (&l->state_previously_known, &l->looping_previously_known, flags_from_decl_or_type (fn->symbol.decl), cgraph_node_cannot_return (fn)); if (fn->thunk.thunk_p || fn->symbol.alias) { /* Thunk gets propagated through, so nothing interesting happens. */ gcc_assert (ipa); return l; } if (dump_file) { fprintf (dump_file, "\n\n local analysis of %s\n ", cgraph_node_name (fn)); } push_cfun (DECL_STRUCT_FUNCTION (decl)); FOR_EACH_BB (this_block) { gimple_stmt_iterator gsi; struct walk_stmt_info wi; memset (&wi, 0, sizeof(wi)); for (gsi = gsi_start_bb (this_block); !gsi_end_p (gsi); gsi_next (&gsi)) { check_stmt (&gsi, l, ipa); if (l->pure_const_state == IPA_NEITHER && l->looping && l->can_throw) goto end; } } end: if (l->pure_const_state != IPA_NEITHER) { /* Const functions cannot have back edges (an indication of possible infinite loop side effect. */ if (mark_dfs_back_edges ()) { /* Preheaders are needed for SCEV to work. Simple latches and recorded exits improve chances that loop will proved to be finite in testcases such as in loop-15.c and loop-24.c */ loop_optimizer_init (LOOPS_HAVE_PREHEADERS | LOOPS_HAVE_SIMPLE_LATCHES | LOOPS_HAVE_RECORDED_EXITS); if (dump_file && (dump_flags & TDF_DETAILS)) flow_loops_dump (dump_file, NULL, 0); if (mark_irreducible_loops ()) { if (dump_file) fprintf (dump_file, " has irreducible loops\n"); l->looping = true; } else { loop_iterator li; struct loop *loop; scev_initialize (); FOR_EACH_LOOP (li, loop, 0) if (!finite_loop_p (loop)) { if (dump_file) fprintf (dump_file, " can not prove finiteness of " "loop %i\n", loop->num); l->looping =true; FOR_EACH_LOOP_BREAK (li); } scev_finalize (); } loop_optimizer_finalize (); } } if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, " checking previously known:"); better_state (&l->pure_const_state, &l->looping, l->state_previously_known, l->looping_previously_known); if (TREE_NOTHROW (decl)) l->can_throw = false; pop_cfun (); if (dump_file) { if (l->looping) fprintf (dump_file, "Function is locally looping.\n"); if (l->can_throw) fprintf (dump_file, "Function is locally throwing.\n"); if (l->pure_const_state == IPA_CONST) fprintf (dump_file, "Function is locally const.\n"); if (l->pure_const_state == IPA_PURE) fprintf (dump_file, "Function is locally pure.\n"); } return l; }
/* Return true when execution of REF can lead to return from function. */ bool ipa_ref_cannot_lead_to_return (struct ipa_ref *ref) { return cgraph_node_cannot_return (ipa_ref_referring_node (ref)); }