vr-values.c (vr_values::extract_range_from_ssa_name): Do not put equivalences on UNDEFINED ranges.

2019-06-06  Richard Biener  <rguenther@suse.de>

	* vr-values.c (vr_values::extract_range_from_ssa_name): Do not
	put equivalences on UNDEFINED ranges.
	* gimple-ssa-evrp.c (evrp_dom_walker::before_dom_children):
	Make sure to drop defs of stmts added during simplification
	to VARYING.

From-SVN: r271990

gcc/ChangeLog

 2019-06-06  Richard Biener  <rguenther@suse.de>
 
+	* vr-values.c (vr_values::extract_range_from_ssa_name): Do not
+	put equivalences on UNDEFINED ranges.
+	* gimple-ssa-evrp.c (evrp_dom_walker::before_dom_children):
+	Make sure to drop defs of stmts added during simplification
+	to VARYING.
+
+2019-06-06  Richard Biener  <rguenther@suse.de>
+
 	* tree-ssa-structalias.c: Include tree-cfg.h.
 	(make_heapvar): Do not make heap vars artificial.
 	(find_func_aliases_for_builtin_call): Handle stack allocation

gcc/gimple-ssa-evrp.c

@@ -175,6 +175,8 @@ evrp_dom_walker::before_dom_children (basic_block bb)
 
       /* Try folding stmts with the VR discovered.  */
       bool did_replace = evrp_folder.replace_uses_in (stmt);
+      gimple_stmt_iterator prev_gsi = gsi;
+      gsi_prev (&prev_gsi);
       if (fold_stmt (&gsi, follow_single_use_edges)
 	  || did_replace)
 	{
@@ -191,6 +193,21 @@ evrp_dom_walker::before_dom_children (basic_block bb)
 
       if (did_replace)
 	{
+	  /* If we wound up generating new stmts during folding
+	     drop all their defs to VARYING.  We can't easily
+	     process them because we've already instantiated
+	     ranges on uses on STMT that only hold after it.  */
+	  if (gsi_end_p (prev_gsi))
+	    prev_gsi = gsi_start_bb (bb);
+	  else
+	    gsi_next (&prev_gsi);
+	  while (gsi_stmt (prev_gsi) != gsi_stmt (gsi))
+	    {
+	      evrp_range_analyzer.get_vr_values ()
+		->set_defs_to_varying (gsi_stmt (prev_gsi));
+	      gsi_next (&prev_gsi);
+	    }
+
 	  /* If we cleaned up EH information from the statement,
 	     remove EH edges.  */
 	  if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt))

gcc/vr-values.c

@@ -719,7 +719,8 @@ vr_values::extract_range_from_ssa_name (value_range *vr, tree var)
   else
     vr->set (var);
 
-  vr->equiv_add (var, get_value_range (var), &vrp_equiv_obstack);
+  if (!vr->undefined_p ())
+    vr->equiv_add (var, get_value_range (var), &vrp_equiv_obstack);
 }
 
 /* Extract range information from a binary expression OP0 CODE OP1 based on