* bitmap.c (bitmap_head::dump): New.

	* bitmap.h (bitmap_head): Add dump().
	* gimple-ssa-evrp-analyze.c
	(evrp_range_analyzer::try_find_new_range): Adjust for value_range API.
	(evrp_range_analyzer::set_ssa_range_info): Same.
	(evrp_range_analyzer::record_ranges_from_phis): Same.
	(evrp_range_analyzer::record_ranges_from_stmt): Same.
	* gimple-ssa-evrp.c (evrp_dom_walker::before_dom_children): Same.
	* gimple-ssa-sprintf.c (get_int_range): Same.
	(format_integer): Same.
	(sprintf_dom_walker::handle_gimple_call): Same.
	* ipa-cp.c (ipcp_vr_lattice::meet_with_1): Same.
	(ipcp_vr_lattice::top_p): Same.
	(ipcp_vr_lattice::bottom_p): Same.
	(ipcp_vr_lattice::set_to_bottom): Same.
	(ipa_vr_operation_and_type_effects): Same.
	(propagate_vr_across_jump_function): Same.
	(ipcp_store_vr_results): Same.
	* ipa-prop.c (struct ipa_vr_ggc_hash_traits): Same.
	(ipa_print_node_jump_functions_for_edge): Same.
	(ipa_get_value_range): Same.
	(ipa_compute_jump_functions_for_edge): Same.
	(ipa_write_jump_function): Same.
	* tree-ssa-dom.c (simplify_stmt_for_jump_threading): Same.
	* tree-ssa-threadedge.c (record_temporary_equivalences_from_phis):
	Same.
	* vr-values.c (set_value_range_to_nonnegative): Same.
	(set_value_range_to_truthvalue): Same.
	(vr_values::get_value_range): Same.
	(vr_values::set_defs_to_varying): Same.
	(vr_values::update_value_range): Same.
	(symbolic_range_based_on_p): Same.
	(vr_values::op_with_boolean_value_range_p): Same.
	(vr_values::extract_range_for_var_from_comparison_expr): Same.
	(vr_values::extract_range_from_ssa_name): Same.
	(vr_values::extract_range_from_binary_expr): Same.
	(vr_values::extract_range_from_unary_expr): Same.
	(vr_values::extract_range_from_cond_expr): Same.
	(vr_values::extract_range_from_comparison): Same.
	(vr_values::check_for_binary_op_overflow): Same.
	(vr_values::extract_range_basic): Same.
	(vr_values::extract_range_from_assignment): Same.
	(compare_ranges): Same.
	(compare_range_with_value): Same.
	(vr_values::adjust_range_with_scev): Same.
	(vrp_valueize): Same.
	(vrp_valueize_1): Same.
	(vr_values::get_vr_for_comparison): Same.
	(vr_values::compare_name_with_value): Same.
	(vr_values::compare_names): Same.
	(vr_values::vrp_evaluate_conditional): Same.
	(find_case_label_ranges): Same.
	(vr_values::vrp_visit_switch_stmt): Same.
	(vr_values::extract_range_from_phi_node): Same.
	(vr_values::simplify_div_or_mod_using_ranges): Same.
	(vr_values::simplify_bit_ops_using_ranges): Same.
	(test_for_singularity): Same.
	(range_fits_type_p): Same.
	(vr_values::simplify_cond_using_ranges_1): Same.
	(vr_values::simplify_switch_using_ranges): Same.
	(vr_values::simplify_float_conversion_using_ranges): Same.
	(vr_values::two_valued_val_range_p): Same.
	(vr_values::add_equivalence): Move to value_range::equiv_add.
	* vr-values.h (vr_values::add_equivalence): Remove.
	(VR_INITIALIZER): Remove.
	* tree-vrp.c (value_range::set): New.
	(value_range::equiv_add): New.
	(value_range::value_range): New.
	(value_range::deep_copy): New.
	(value_range::check): New.
	(value_range::equal_p): New.
	(value_range::ignore_equivs_equal_p): New.
	(value_range::operator==): New.
	(value_range::operator!=): New.
	(value_range::symbolic_p): New.
	(value_range::numeric_p): New.
	(value_range::set_undefined): New.
	(value_range::set_varying): New.
	(value_range::may_contain_p): New.
	(value_range::equiv_clear): New.
	(value_range::singleton_p): New.
	(value_range::intersect): New.
	(value_range::dump): New.
	(value_range::set_and_canonicalize): New.
	(set_value_range): Adjust for value_range API.
	(set_value_range_to_undefined): Same.
	(set_value_range_to_varying): Same.
	(set_and_canonicalize_value_range): Same.
	(set_value_range_to_nonnull): Same.
	(set_value_range_to_null): Same.
	(range_is_null): Same.
	(range_is_nonnull): Same.
	(range_int_cst_p): Same.
	(range_int_cst_singleton_p): Same.
	(symbolic_range_p): Same.
	(range_includes_zero_p): Same.
	(value_range_constant_singleton): Same.
	(vrp_set_zero_nonzero_bits): Same.
	(ranges_from_anti_range): Same.
	(extract_range_into_wide_ints): Same.
	(extract_range_from_multiplicative_op): Same.
	(set_value_range_with_overflow): Same.
	(extract_range_from_binary_expr_1): Same.
	(extract_range_from_unary_expr): Same.
	(dump_value_range): Same.
	(debug_value_range): Same.
	(vrp_prop::check_array_ref): Same.
	(vrp_prop::check_mem_ref): Same.
	(vrp_prop::vrp_initialize): Same.
	(vrp_prop::visit_stmt): Same.
	(intersect_ranges): Same.
	(vrp_prop::visit_phi): Same.
	(vrp_prop::vrp_finalize): Same.
	(determine_value_range_1): Same.
	(determine_value_range): Same.
	(vrp_intersect_ranges_1): Rename to...
	(vrp_intersect_1): this.
	(vrp_intersect_ranges): Rename to...
	(value_range::intersect_helper): ...this.
	(vrp_meet_1): Rename to...
	(value_range::union_helper): ...this.
	(vrp_meet): Rename to...
	(value_range::union_): ...this.
	(copy_value_range): Remove.
	* tree-vrp.h (struct value_range): Rewrite into a proper class.
	(value_range::vrtype): New.
	(value_range::type): New.
	(value_range::equiv): New.
	(value_range::min): New.
	(value_range::max): New.
	(value_range::varying_p): New.
	(value_range::undefined_p): New.
	(value_range::null_p): New.
	(value_range::equiv_add): New.
	(copy_value_range): Remove.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@265241 138bc75d-0d04-0410-961f-82ee72b054a4

gcc/ChangeLog

@@ -1,3 +1,141 @@
+2018-10-09  Aldy Hernandez  <aldyh@redhat.com>
+
+	* bitmap.c (bitmap_head::dump): New.
+	* bitmap.h (bitmap_head): Add dump().
+	* gimple-ssa-evrp-analyze.c
+	(evrp_range_analyzer::try_find_new_range): Adjust for value_range API.
+	(evrp_range_analyzer::set_ssa_range_info): Same.
+	(evrp_range_analyzer::record_ranges_from_phis): Same.
+	(evrp_range_analyzer::record_ranges_from_stmt): Same.
+	* gimple-ssa-evrp.c (evrp_dom_walker::before_dom_children): Same.
+	* gimple-ssa-sprintf.c (get_int_range): Same.
+	(format_integer): Same.
+	(sprintf_dom_walker::handle_gimple_call): Same.
+	* ipa-cp.c (ipcp_vr_lattice::meet_with_1): Same.
+	(ipcp_vr_lattice::top_p): Same.
+	(ipcp_vr_lattice::bottom_p): Same.
+	(ipcp_vr_lattice::set_to_bottom): Same.
+	(ipa_vr_operation_and_type_effects): Same.
+	(propagate_vr_across_jump_function): Same.
+	(ipcp_store_vr_results): Same.
+	* ipa-prop.c (struct ipa_vr_ggc_hash_traits): Same.
+	(ipa_print_node_jump_functions_for_edge): Same.
+	(ipa_get_value_range): Same.
+	(ipa_compute_jump_functions_for_edge): Same.
+	(ipa_write_jump_function): Same.
+	* tree-ssa-dom.c (simplify_stmt_for_jump_threading): Same.
+	* tree-ssa-threadedge.c (record_temporary_equivalences_from_phis):
+	Same.
+	* vr-values.c (set_value_range_to_nonnegative): Same.
+	(set_value_range_to_truthvalue): Same.
+	(vr_values::get_value_range): Same.
+	(vr_values::set_defs_to_varying): Same.
+	(vr_values::update_value_range): Same.
+	(symbolic_range_based_on_p): Same.
+	(vr_values::op_with_boolean_value_range_p): Same.
+	(vr_values::extract_range_for_var_from_comparison_expr): Same.
+	(vr_values::extract_range_from_ssa_name): Same.
+	(vr_values::extract_range_from_binary_expr): Same.
+	(vr_values::extract_range_from_unary_expr): Same.
+	(vr_values::extract_range_from_cond_expr): Same.
+	(vr_values::extract_range_from_comparison): Same.
+	(vr_values::check_for_binary_op_overflow): Same.
+	(vr_values::extract_range_basic): Same.
+	(vr_values::extract_range_from_assignment): Same.
+	(compare_ranges): Same.
+	(compare_range_with_value): Same.
+	(vr_values::adjust_range_with_scev): Same.
+	(vrp_valueize): Same.
+	(vrp_valueize_1): Same.
+	(vr_values::get_vr_for_comparison): Same.
+	(vr_values::compare_name_with_value): Same.
+	(vr_values::compare_names): Same.
+	(vr_values::vrp_evaluate_conditional): Same.
+	(find_case_label_ranges): Same.
+	(vr_values::vrp_visit_switch_stmt): Same.
+	(vr_values::extract_range_from_phi_node): Same.
+	(vr_values::simplify_div_or_mod_using_ranges): Same.
+	(vr_values::simplify_bit_ops_using_ranges): Same.
+	(test_for_singularity): Same.
+	(range_fits_type_p): Same.
+	(vr_values::simplify_cond_using_ranges_1): Same.
+	(vr_values::simplify_switch_using_ranges): Same.
+	(vr_values::simplify_float_conversion_using_ranges): Same.
+	(vr_values::two_valued_val_range_p): Same.
+	(vr_values::add_equivalence): Move to value_range::equiv_add.
+	* vr-values.h (vr_values::add_equivalence): Remove.
+	(VR_INITIALIZER): Remove.
+	* tree-vrp.c (value_range::set): New.
+	(value_range::equiv_add): New.
+	(value_range::value_range): New.
+	(value_range::deep_copy): New.
+	(value_range::check): New.
+	(value_range::equal_p): New.
+	(value_range::ignore_equivs_equal_p): New.
+	(value_range::operator==): New.
+	(value_range::operator!=): New.
+	(value_range::symbolic_p): New.
+	(value_range::numeric_p): New.
+	(value_range::set_undefined): New.
+	(value_range::set_varying): New.
+	(value_range::may_contain_p): New.
+	(value_range::equiv_clear): New.
+	(value_range::singleton_p): New.
+	(value_range::intersect): New.
+	(value_range::dump): New.
+	(value_range::set_and_canonicalize): New.
+	(set_value_range): Adjust for value_range API.
+	(set_value_range_to_undefined): Same.
+	(set_value_range_to_varying): Same.
+	(set_and_canonicalize_value_range): Same.
+	(set_value_range_to_nonnull): Same.
+	(set_value_range_to_null): Same.
+	(range_is_null): Same.
+	(range_is_nonnull): Same.
+	(range_int_cst_p): Same.
+	(range_int_cst_singleton_p): Same.
+	(symbolic_range_p): Same.
+	(range_includes_zero_p): Same.
+	(value_range_constant_singleton): Same.
+	(vrp_set_zero_nonzero_bits): Same.
+	(ranges_from_anti_range): Same.
+	(extract_range_into_wide_ints): Same.
+	(extract_range_from_multiplicative_op): Same.
+	(set_value_range_with_overflow): Same.
+	(extract_range_from_binary_expr_1): Same.
+	(extract_range_from_unary_expr): Same.
+	(dump_value_range): Same.
+	(debug_value_range): Same.
+	(vrp_prop::check_array_ref): Same.
+	(vrp_prop::check_mem_ref): Same.
+	(vrp_prop::vrp_initialize): Same.
+	(vrp_prop::visit_stmt): Same.
+	(intersect_ranges): Same.
+	(vrp_prop::visit_phi): Same.
+	(vrp_prop::vrp_finalize): Same.
+	(determine_value_range_1): Same.
+	(determine_value_range): Same.
+	(vrp_intersect_ranges_1): Rename to...
+	(vrp_intersect_1): this.
+	(vrp_intersect_ranges): Rename to...
+	(value_range::intersect_helper): ...this.
+	(vrp_meet_1): Rename to...
+	(value_range::union_helper): ...this.
+	(vrp_meet): Rename to...
+	(value_range::union_): ...this.
+	(copy_value_range): Remove.
+	* tree-vrp.h (struct value_range): Rewrite into a proper class.
+	(value_range::vrtype): New.
+	(value_range::type): New.
+	(value_range::equiv): New.
+	(value_range::min): New.
+	(value_range::max): New.
+	(value_range::varying_p): New.
+	(value_range::undefined_p): New.
+	(value_range::null_p): New.
+	(value_range::equiv_add): New.
+	(copy_value_range): Remove.
+
 2018-10-17  David Malcolm  <dmalcolm@redhat.com>
 
 	* Makefile.in (SELFTEST_TARGETS): New.

gcc/bitmap.c

@@ -2164,6 +2164,12 @@ debug (const bitmap_head *ptr)
     fprintf (stderr, "<nil>\n");
 }
 
+void
+bitmap_head::dump ()
+{
+  debug (this);
+}
+
 #if CHECKING_P
 
 namespace selftest {

gcc/bitmap.h

@@ -243,6 +243,7 @@ struct GTY(()) bitmap_head {
   bitmap_element * GTY((skip(""))) current; /* Last element looked at.  */
   bitmap_obstack *obstack;		/* Obstack to allocate elements from.
 					   If NULL, then use GGC allocation.  */
+  void dump ();
 };
 
 /* Global data */

gcc/builtins.c

@@ -3139,7 +3139,7 @@ expand_builtin_strnlen (tree exp, rtx target, machine_mode target_mode)
     return NULL_RTX;
 
   wide_int min, max;
-  enum value_range_type rng = get_range_info (bound, &min, &max);
+  enum value_range_kind rng = get_range_info (bound, &min, &max);
   if (rng != VR_RANGE)
     return NULL_RTX;
 
@@ -3227,7 +3227,7 @@ determine_block_size (tree len, rtx len_rtx,
   else
     {
       wide_int min, max;
-      enum value_range_type range_type = VR_UNDEFINED;
+      enum value_range_kind range_type = VR_UNDEFINED;
 
       /* Determine bounds from the type.  */
       if (tree_fits_uhwi_p (TYPE_MIN_VALUE (TREE_TYPE (len))))
@@ -3629,7 +3629,7 @@ compute_objsize (tree dest, int ostype)
 	      && INTEGRAL_TYPE_P (TREE_TYPE (off)))
 	    {
 	      wide_int min, max;
-	      enum value_range_type rng = get_range_info (off, &min, &max);
+	      enum value_range_kind rng = get_range_info (off, &min, &max);
 
 	      if (rng == VR_RANGE)
 		{

gcc/calls.c

@@ -1255,7 +1255,7 @@ get_size_range (tree exp, tree range[2], bool allow_zero /* = false */)
   bool integral = INTEGRAL_TYPE_P (exptype);
 
   wide_int min, max;
-  enum value_range_type range_type;
+  enum value_range_kind range_type;
 
   if (integral)
     range_type = determine_value_range (exp, &min, &max);

gcc/coretypes.h

@@ -46,6 +46,7 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 typedef int64_t gcov_type;
 typedef uint64_t gcov_type_unsigned;
 
+struct bitmap_obstack;
 struct bitmap_head;
 typedef struct bitmap_head *bitmap;
 typedef const struct bitmap_head *const_bitmap;

gcc/fold-const.c

@@ -9255,7 +9255,7 @@ bool
 expr_not_equal_to (tree t, const wide_int &w)
 {
   wide_int min, max, nz;
-  value_range_type rtype;
+  value_range_kind rtype;
   switch (TREE_CODE (t))
     {
     case INTEGER_CST:

gcc/gimple-fold.c

@@ -649,7 +649,7 @@ size_must_be_zero_p (tree size)
     return false;
 
   wide_int min, max;
-  enum value_range_type rtype = get_range_info (size, &min, &max);
+  enum value_range_kind rtype = get_range_info (size, &min, &max);
   if (rtype != VR_ANTI_RANGE)
     return false;
 

gcc/gimple-pretty-print.c

@@ -2123,7 +2123,7 @@ dump_ssaname_info (pretty_printer *buffer, tree node, int spc)
       && SSA_NAME_RANGE_INFO (node))
     {
       wide_int min, max, nonzero_bits;
-      value_range_type range_type = get_range_info (node, &min, &max);
+      value_range_kind range_type = get_range_info (node, &min, &max);
 
       if (range_type == VR_VARYING)
 	pp_printf (buffer, "# RANGE VR_VARYING");

gcc/gimple-ssa-evrp-analyze.c

@@ -82,19 +82,19 @@ value_range *
 evrp_range_analyzer::try_find_new_range (tree name,
 				    tree op, tree_code code, tree limit)
 {
-  value_range vr = VR_INITIALIZER;
+  value_range vr;
   value_range *old_vr = get_value_range (name);
 
   /* Discover VR when condition is true.  */
   vr_values->extract_range_for_var_from_comparison_expr (name, code, op,
 							 limit, &vr);
   /* If we found any usable VR, set the VR to ssa_name and create a
      PUSH old value in the stack with the old VR.  */
-  if (vr.type == VR_RANGE || vr.type == VR_ANTI_RANGE)
+  if (!vr.undefined_p () && !vr.varying_p ())
     {
-      if (old_vr->type == vr.type
-	  && vrp_operand_equal_p (old_vr->min, vr.min)
-	  && vrp_operand_equal_p (old_vr->max, vr.max))
+      if (old_vr->kind () == vr.kind ()
+	  && vrp_operand_equal_p (old_vr->min (), vr.min ())
+	  && vrp_operand_equal_p (old_vr->max (), vr.max ()))
 	return NULL;
       value_range *new_vr = vr_values->allocate_value_range ();
       *new_vr = vr;
@@ -110,13 +110,10 @@ evrp_range_analyzer::set_ssa_range_info (tree lhs, value_range *vr)
   /* Set the SSA with the value range.  */
   if (INTEGRAL_TYPE_P (TREE_TYPE (lhs)))
     {
-      if ((vr->type == VR_RANGE
-	   || vr->type == VR_ANTI_RANGE)
-	  && (TREE_CODE (vr->min) == INTEGER_CST)
-	  && (TREE_CODE (vr->max) == INTEGER_CST))
-	set_range_info (lhs, vr->type,
-			wi::to_wide (vr->min),
-			wi::to_wide (vr->max));
+      if (vr->constant_p ())
+	set_range_info (lhs, vr->kind (),
+			wi::to_wide (vr->min ()),
+			wi::to_wide (vr->max ()));
     }
   else if (POINTER_TYPE_P (TREE_TYPE (lhs))
 	   && range_includes_zero_p (vr) == 0)
@@ -241,7 +238,7 @@ evrp_range_analyzer::record_ranges_from_phis (basic_block bb)
       if (virtual_operand_p (lhs))
 	continue;
 
-      value_range vr_result = VR_INITIALIZER;
+      value_range vr_result;
       bool interesting = stmt_interesting_for_vrp (phi);
       if (!has_unvisited_preds && interesting)
 	vr_values->extract_range_from_phi_node (phi, &vr_result);
@@ -284,7 +281,7 @@ evrp_range_analyzer::record_ranges_from_stmt (gimple *stmt, bool temporary)
   else if (stmt_interesting_for_vrp (stmt))
     {
       edge taken_edge;
-      value_range vr = VR_INITIALIZER;
+      value_range vr;
       vr_values->extract_range_from_stmt (stmt, &taken_edge, &output, &vr);
       if (output)
 	{
@@ -315,7 +312,7 @@ evrp_range_analyzer::record_ranges_from_stmt (gimple *stmt, bool temporary)
 		 bitmaps.  Ugh.  */
 	      value_range *new_vr = vr_values->allocate_value_range ();
 	      *new_vr = vr;
-	      new_vr->equiv = NULL;
+	      new_vr->equiv_clear ();
 	      push_value_range (output, new_vr);
 	    }
 	}

gcc/gimple-ssa-evrp.c

@@ -161,8 +161,7 @@ evrp_dom_walker::before_dom_children (basic_block bb)
 	      value_range *vr = evrp_range_analyzer.get_value_range (output);
 
 	      /* Mark stmts whose output we fully propagate for removal.  */
-	      if ((vr->type == VR_RANGE || vr->type == VR_ANTI_RANGE)
-		  && (val = value_range_constant_singleton (vr))
+	      if ((val = value_range_constant_singleton (vr))
 		  && may_propagate_copy (output, val)
 		  && !stmt_could_throw_p (stmt)
 		  && !gimple_has_side_effects (stmt))

gcc/gimple-ssa-sprintf.c

@@ -1052,9 +1052,7 @@ get_int_range (tree arg, HOST_WIDE_INT *pmin, HOST_WIDE_INT *pmax,
 	{
 	  /* Try to determine the range of values of the integer argument.  */
 	  value_range *vr = vr_values->get_value_range (arg);
-	  if (vr->type == VR_RANGE
-	      && TREE_CODE (vr->min) == INTEGER_CST
-	      && TREE_CODE (vr->max) == INTEGER_CST)
+	  if (range_int_cst_p (vr))
 	    {
 	      HOST_WIDE_INT type_min
 		= (TYPE_UNSIGNED (argtype)
@@ -1063,8 +1061,8 @@ get_int_range (tree arg, HOST_WIDE_INT *pmin, HOST_WIDE_INT *pmax,
 
 	      HOST_WIDE_INT type_max = tree_to_uhwi (TYPE_MAX_VALUE (argtype));
 
-	      *pmin = TREE_INT_CST_LOW (vr->min);
-	      *pmax = TREE_INT_CST_LOW (vr->max);
+	      *pmin = TREE_INT_CST_LOW (vr->min ());
+	      *pmax = TREE_INT_CST_LOW (vr->max ());
 
 	      if (*pmin < *pmax)
 		{
@@ -1354,12 +1352,10 @@ format_integer (const directive &dir, tree arg, vr_values *vr_values)
       /* Try to determine the range of values of the integer argument
 	 (range information is not available for pointers).  */
       value_range *vr = vr_values->get_value_range (arg);
-      if (vr->type == VR_RANGE
-	  && TREE_CODE (vr->min) == INTEGER_CST
-	  && TREE_CODE (vr->max) == INTEGER_CST)
+      if (range_int_cst_p (vr))
 	{
-	  argmin = vr->min;
-	  argmax = vr->max;
+	  argmin = vr->min ();
+	  argmax = vr->max ();
 
 	  /* Set KNOWNRANGE if the argument is in a known subrange
 	     of the directive's type and neither width nor precision
@@ -1372,12 +1368,11 @@ format_integer (const directive &dir, tree arg, vr_values *vr_values)
 	  res.argmin = argmin;
 	  res.argmax = argmax;
 	}
-      else if (vr->type == VR_ANTI_RANGE)
+      else if (vr->kind () == VR_ANTI_RANGE)
 	{
 	  /* Handle anti-ranges if/when bug 71690 is resolved.  */
 	}
-      else if (vr->type == VR_VARYING
-	       || vr->type == VR_UNDEFINED)
+      else if (vr->varying_p () || vr->undefined_p ())
 	{
 	  /* The argument here may be the result of promoting the actual
 	     argument to int.  Try to determine the type of the actual
@@ -3903,12 +3898,10 @@ sprintf_dom_walker::handle_gimple_call (gimple_stmt_iterator *gsi)
 	     and use the greater of the two at level 1 and the smaller
 	     of them at level 2.  */
 	  value_range *vr = evrp_range_analyzer.get_value_range (size);
-	  if (vr->type == VR_RANGE
-	      && TREE_CODE (vr->min) == INTEGER_CST
-	      && TREE_CODE (vr->max) == INTEGER_CST)
+	  if (range_int_cst_p (vr))
 	    dstsize = (warn_level < 2
-		       ? TREE_INT_CST_LOW (vr->max)
-		       : TREE_INT_CST_LOW (vr->min));
+		       ? TREE_INT_CST_LOW (vr->max ())
+		       : TREE_INT_CST_LOW (vr->min ()));
 
 	  /* The destination size is not constant.  If the function is
 	     bounded (e.g., snprintf) a lower bound of zero doesn't