diff mbox series

[5/6] gimple-range

Message ID 5c66f584-5940-6e52-b54d-784737cb9c3f@redhat.com
State New
Headers show
Series [1/6] Ranger patches. | expand

Commit Message

Andrew MacLeod Oct. 2, 2020, 5:04 p.m. UTC
This is the ranger component that pulls all the others bits together.

Its API is basically the range_query we've already pushed into the 
compiler. The main ones a client are likely to use are

bool range_of_stmt (irange &r, gimple *, tree name = NULL)
bool range_of_expr (irange &r, tree name, gimple * = NULL)
bool range_on_edge (irange &r, edge e, tree name)

These are for calculating ranges of ssa names as used ON a statement, ON 
and edge, or as the result of a statement.. respectively.

The ranger is responsible for calculating the range of any gimple 
statement, but before doing that, resolves any dependencies that 
statement has first.

given
a_2 = b_3 + c_4

The ranger will first use its own API to resolve a range_of_expr (b_3), 
then a range_of_expr (c_4), then finally calculate a range for a_2using 
the values it gets back.

A lot of the heavy lifting is done by the earlier components, the ranger 
is mostly responsible for actually calculating a global value for an 
ssa_name based on the stmt, as well as resolving dependencies as much as 
possible before asking for a cache fill. Cycles are handled by breaking 
the request cycle if we get back to the same definition, and then using 
a best guess up to that point.

Future enhancements will involve updating back edges with more accurate 
values when they become available.. but thats more of an issue for when 
we go to replace the ASSERT driven VRP pass.
diff mbox series

Patch


	* gimple-range.h: New File.
	(class gimple_ranger): New.  Ranger base class.
	(gimple_range_handler): New.  Get range-ops handler.
	(gimple_range_ssa_p): New.  Is this a range comptible ssa_name.
	(gimple_range_global): New.  Retreive legacy global value.
	(class trace_ranger): New.  Ranger with tracing capabilties.

	* gimple-range.cc: New File.
	(adjust_pointer_diff_expr): New.  Ptrdiff adjustements.
	(gimple_range_adjustment): New.  Multi-statement range adjustments.
	(get_tree_range): New.  What range is known about a tree node.
	(gimple_range_fold): New.  Gimple interface to range_op::fold.
	(gimple_range_base_of_assignment): New.  Base name of an assignment.
	(gimple_range_operand1): New.  Symbolic name of operand 1.
	(gimple_range_operand2): New.  Symbolic name of operand 2.
	(gimple_range_calc_op1): New.  Gimple interface to range-op::op1_range.
	(gimple_range_calc_op2): New.  Gimple interface to range-op::op2_range.
	(gimple_ranger::calc_stmt): New.  Calculate a range for a statement.
	(gimple_ranger::range_of_range_op): New.  Handle range_op statements.
	(gimple_ranger::range_of_non_trivial_assignment): New.  Handle pointer
	expressions on ssa_names.
	(gimple_ranger::range_of_phi): New.
	(gimple_ranger::range_of_call): New.
	(gimple_ranger::range_of_builtin_ubsan_call): New.
	(gimple_ranger::range_of_builtin_call): New.
	(gimple_ranger::range_of_cond_expr): New.  Handle x ? y : z.
	(gimple_ranger::range_of_expr): New.  Calculate range on stmt.
	(gimple_ranger::range_on_entry): New.  Calculate range at block entry.
	(gimple_ranger::range_on_exit): New.  Calculate range at block exit.
	(gimple_ranger::range_on_edge): New.  Calculate range on an edge.
	(gimple_ranger::range_of_stmt): New.  Calculate LHS of statement.
	(gimple_ranger::export_global_ranges): New.  Export known ranges to
	the legacy cache SSA_NAME_RANGE_INFO.
	(gimple_ranger::dump): New.
	(gimple_ranger::range_of_ssa_name_with_loop_info): New. SCEV hook.
	(trace_ranger::trace_ranger): New.
	(trace_ranger::dumping: New.  Tracing prefix handler.
	(trace_ranger::trailer): New.  Tracing suffix handler.
	(trace_ranger::range_on_edge): New.  Provide tracing.
	(trace_ranger::range_on_entry): New.  Provide tracing.
	(trace_ranger::range_on_exit): New.  Provide tracing.
	(trace_ranger::range_of_stmt): New.  Provide tracing.
	(trace_ranger::range_of_expr): New.  Provide tracing.

diff --git a/gcc/gimple-range.h b/gcc/gimple-range.h
new file mode 100644
index 00000000000..c45760af393
--- /dev/null
+++ b/gcc/gimple-range.h
@@ -0,0 +1,170 @@ 
+/* Header file for the GIMPLE range interface.
+   Copyright (C) 2019-2020 Free Software Foundation, Inc.
+   Contributed by Andrew MacLeod <amacleod@redhat.com>
+   and Aldy Hernandez <aldyh@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef GCC_GIMPLE_RANGE_STMT_H
+#define GCC_GIMPLE_RANGE_STMT_H
+
+
+#include "range.h"
+#include "range-op.h"
+#include "gimple-range-edge.h"
+#include "gimple-range-gori.h"
+#include "gimple-range-cache.h"
+#include "value-query.h"
+
+// This is the basic range generator interface.
+//
+// This base class provides all the API entry points, but only provides
+// functionality at the statement level.  Ie, it can calculate ranges on
+// statements, but does no additonal lookup.
+//
+// All the range_of_* methods will return a range if the types is
+// supported by the range engine.  It may be the full range for the
+// type, AKA varying_p or it may be a refined range.  If the range
+// type is not supported, then false is returned.  Non-statement
+// related methods return whatever the current global value is.
+
+
+class gimple_ranger : public range_query
+{
+public:
+  gimple_ranger () : m_cache (*this) { }
+  virtual bool range_of_stmt (irange &r, gimple *, tree name = NULL) OVERRIDE;
+  virtual bool range_of_expr (irange &r, tree name, gimple * = NULL) OVERRIDE;
+  virtual bool range_on_edge (irange &r, edge e, tree name) OVERRIDE;
+  virtual void range_on_entry (irange &r, basic_block bb, tree name);
+  virtual void range_on_exit (irange &r, basic_block bb, tree name);
+  void export_global_ranges ();
+  void dump (FILE *f);
+protected:
+  bool calc_stmt (irange &r, gimple *s, tree name = NULL_TREE);
+  bool range_of_range_op (irange &r, gimple *s);
+  bool range_of_call (irange &r, gcall *call);
+  bool range_of_cond_expr (irange &r, gassign* cond);
+  ranger_cache m_cache;
+private:
+  bool range_of_phi (irange &r, gphi *phi);
+  bool range_of_non_trivial_assignment (irange &r, gimple *s);
+  bool range_of_builtin_call (irange &r, gcall *call);
+  void range_of_builtin_ubsan_call (irange &r, gcall *call, tree_code code);
+  bool range_with_loop_info (irange &r, tree name);
+  void range_of_ssa_name_with_loop_info (irange &, tree, class loop *,
+					 gphi *);
+};
+
+// Calculate a basic range for a tree expression.
+extern bool get_tree_range (irange &r, tree expr);
+
+// These routines provide a GIMPLE interface to the range-ops code.
+extern tree gimple_range_operand1 (const gimple *s);
+extern tree gimple_range_operand2 (const gimple *s);
+extern tree gimple_range_base_of_assignment (const gimple *s);
+extern bool gimple_range_fold (irange &res, const gimple *s,
+			       const irange &r1);
+extern bool gimple_range_fold (irange &res, const gimple *s,
+			       const irange &r1,
+			       const irange &r2);
+extern bool gimple_range_calc_op1 (irange &r, const gimple *s,
+				   const irange &lhs_range);
+extern bool gimple_range_calc_op1 (irange &r, const gimple *s,
+				   const irange &lhs_range,
+				   const irange &op2_range);
+extern bool gimple_range_calc_op2 (irange &r, const gimple *s,
+				   const irange &lhs_range,
+				   const irange &op1_range);
+
+
+// Return the range_operator pointer for this statement.  This routine
+// can also be used to gate whether a routine is range-ops enabled.
+
+static inline range_operator *
+gimple_range_handler (const gimple *s)
+{
+  if ((gimple_code (s) == GIMPLE_ASSIGN) || (gimple_code (s) == GIMPLE_COND))
+    return range_op_handler (gimple_expr_code (s), gimple_expr_type (s));
+  return NULL;
+}
+
+// Return EXP if it is an SSA_NAME with a type supported by gimple ranges.
+
+static inline tree
+gimple_range_ssa_p (tree exp)
+{
+  if (exp && TREE_CODE (exp) == SSA_NAME &&
+      !SSA_NAME_IS_VIRTUAL_OPERAND (exp) &&
+      irange::supports_type_p (TREE_TYPE (exp)))
+    return exp;
+  return NULL_TREE;
+}
+
+// Return the legacy GCC global range for NAME if it has one, otherwise
+// return VARYING.
+
+static inline value_range
+gimple_range_global (tree name)
+{
+  gcc_checking_assert (gimple_range_ssa_p (name));
+  tree type = TREE_TYPE (name);
+#if 0
+  // Reenable picking up global ranges when we are OK failing tests that look
+  // for builtin_unreachable in the code, like
+  // RUNTESTFLAGS=dg.exp=pr61034.C check-g++
+  // pre-optimizations (inlining) set a global range which causes the ranger
+  // to remove the condition which leads to builtin_unreachable.
+  if (!POINTER_TYPE_P (type) && SSA_NAME_RANGE_INFO (name))
+    {
+      // Return a range from an SSA_NAME's available range.
+      wide_int min, max;
+      enum value_range_kind kind = get_range_info (name, &min, &max);
+      return value_range (type, min, max, kind);
+    }
+#endif
+ // Otherwise return range for the type.
+ return value_range (type);
+}
+
+
+// This class overloads the ranger routines to provide tracing facilties
+// Entry and exit values to each of the APIs is placed in the dumpfile.
+
+class trace_ranger : public gimple_ranger
+{
+public:
+  trace_ranger ();
+  virtual bool range_of_stmt (irange &r, gimple *s, tree name = NULL_TREE);
+  virtual bool range_of_expr (irange &r, tree name, gimple *s = NULL);
+  virtual bool range_on_edge (irange &r, edge e, tree name);
+  virtual void range_on_entry (irange &r, basic_block bb, tree name);
+  virtual void range_on_exit (irange &r, basic_block bb, tree name);
+private:
+  static const unsigned bump = 2;
+  unsigned indent;
+  unsigned trace_count;		// Current trace index count.
+
+  bool dumping (unsigned counter, bool trailing = false);
+  bool trailer (unsigned counter, const char *caller, bool result, tree name,
+		const irange &r);
+};
+
+// Flag to enable debugging the various internal Caches.
+#define DEBUG_RANGE_CACHE (0 && dump_file)
+
+#endif // GCC_GIMPLE_RANGE_STMT_H
diff --git a/gcc/gimple-range.cc b/gcc/gimple-range.cc
new file mode 100644
index 00000000000..75c03d6610b
--- /dev/null
+++ b/gcc/gimple-range.cc
@@ -0,0 +1,1284 @@ 
+/* Code for GIMPLE range related routines.
+   Copyright (C) 2019-2020 Free Software Foundation, Inc.
+   Contributed by Andrew MacLeod <amacleod@redhat.com>
+   and Aldy Hernandez <aldyh@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "backend.h"
+#include "insn-codes.h"
+#include "rtl.h"
+#include "tree.h"
+#include "gimple.h"
+#include "ssa.h"
+#include "gimple-pretty-print.h"
+#include "gimple-iterator.h"
+#include "optabs-tree.h"
+#include "gimple-fold.h"
+#include "tree-cfg.h"
+#include "fold-const.h"
+#include "tree-cfg.h"
+#include "wide-int.h"
+#include "fold-const.h"
+#include "case-cfn-macros.h"
+#include "omp-general.h"
+#include "cfgloop.h"
+#include "tree-ssa-loop.h"
+#include "tree-scalar-evolution.h"
+#include "dbgcnt.h"
+#include "alloc-pool.h"
+#include "vr-values.h"
+#include "gimple-range.h"
+
+
+// Adjust the range for a pointer difference where the operands came
+// from a memchr.
+//
+// This notices the following sequence:
+//
+//	def = __builtin_memchr (arg, 0, sz)
+//	n = def - arg
+//
+// The range for N can be narrowed to [0, PTRDIFF_MAX - 1].
+
+static void
+adjust_pointer_diff_expr (irange &res, const gimple *diff_stmt)
+{
+  tree op0 = gimple_assign_rhs1 (diff_stmt);
+  tree op1 = gimple_assign_rhs2 (diff_stmt);
+  tree op0_ptype = TREE_TYPE (TREE_TYPE (op0));
+  tree op1_ptype = TREE_TYPE (TREE_TYPE (op1));
+  gimple *call;
+
+  if (TREE_CODE (op0) == SSA_NAME
+      && TREE_CODE (op1) == SSA_NAME
+      && (call = SSA_NAME_DEF_STMT (op0))
+      && is_gimple_call (call)
+      && gimple_call_builtin_p (call, BUILT_IN_MEMCHR)
+      && TYPE_MODE (op0_ptype) == TYPE_MODE (char_type_node)
+      && TYPE_PRECISION (op0_ptype) == TYPE_PRECISION (char_type_node)
+      && TYPE_MODE (op1_ptype) == TYPE_MODE (char_type_node)
+      && TYPE_PRECISION (op1_ptype) == TYPE_PRECISION (char_type_node)
+      && gimple_call_builtin_p (call, BUILT_IN_MEMCHR)
+      && vrp_operand_equal_p (op1, gimple_call_arg (call, 0))
+      && integer_zerop (gimple_call_arg (call, 1)))
+    {
+      tree max = vrp_val_max (ptrdiff_type_node);
+      wide_int wmax = wi::to_wide (max, TYPE_PRECISION (TREE_TYPE (max)));
+      tree expr_type = gimple_expr_type (diff_stmt);
+      tree range_min = build_zero_cst (expr_type);
+      tree range_max = wide_int_to_tree (expr_type, wmax - 1);
+      int_range<2> r (range_min, range_max);
+      res.intersect (r);
+    }
+}
+
+// This function looks for situations when walking the use/def chains
+// may provide additonal contextual range information not exposed on
+// this statement.  Like knowing the IMAGPART return value from a
+// builtin function is a boolean result.
+
+// We should rework how we're called, as we have an op_unknown entry
+// for IMAGPART_EXPR and POINTER_DIFF_EXPR in range-ops just so this
+// function gets called.
+
+static void
+gimple_range_adjustment (irange &res, const gimple *stmt)
+{
+  switch (gimple_expr_code (stmt))
+    {
+    case POINTER_DIFF_EXPR:
+      adjust_pointer_diff_expr (res, stmt);
+      return;
+
+    case IMAGPART_EXPR:
+      {
+	tree name = TREE_OPERAND (gimple_assign_rhs1 (stmt), 0);
+	if (TREE_CODE (name) == SSA_NAME)
+	  {
+	    gimple *def_stmt = SSA_NAME_DEF_STMT (name);
+	    if (def_stmt && is_gimple_call (def_stmt)
+		&& gimple_call_internal_p (def_stmt))
+	      {
+		switch (gimple_call_internal_fn (def_stmt))
+		  {
+		  case IFN_ADD_OVERFLOW:
+		  case IFN_SUB_OVERFLOW:
+		  case IFN_MUL_OVERFLOW:
+		  case IFN_ATOMIC_COMPARE_EXCHANGE:
+		    {
+		      int_range<2> r;
+		      r.set_varying (boolean_type_node);
+		      tree type = TREE_TYPE (gimple_assign_lhs (stmt));
+		      range_cast (r, type);
+		      res.intersect (r);
+		    }
+		  default:
+		    break;
+		  }
+	      }
+	  }
+	break;
+      }
+
+    default:
+      break;
+    }
+}
+
+// Return a range in R for the tree EXPR.  Return true if a range is
+// representable.
+
+bool
+get_tree_range (irange &r, tree expr)
+{
+  tree type;
+  if (TYPE_P (expr))
+    type = expr;
+  else
+    type = TREE_TYPE (expr);
+
+  // Return false if the type isn't suported.
+  if (!irange::supports_type_p (type))
+    return false;
+
+  switch (TREE_CODE (expr))
+    {
+      case INTEGER_CST:
+	r.set (expr, expr);
+	return true;
+
+      case SSA_NAME:
+	r = gimple_range_global (expr);
+	return true;
+
+      case ADDR_EXPR:
+        {
+	  // Handle &var which can show up in phi arguments.
+	  bool ov;
+	  if (tree_single_nonzero_warnv_p (expr, &ov))
+	    {
+	      r = range_nonzero (type);
+	      return true;
+	    }
+	  break;
+	}
+
+      default:
+        break;
+    }
+  r.set_varying (type);
+  return true;
+}
+
+// Fold this unary statement using R1 as operand1's range, returning
+// the result in RES.  Return false if the operation fails.
+
+bool
+gimple_range_fold (irange &res, const gimple *stmt, const irange &r1)
+{
+  gcc_checking_assert (gimple_range_handler (stmt));
+
+  tree type = gimple_expr_type (stmt);
+  // Unary SSA operations require the LHS type as the second range.
+  int_range<2> r2 (type);
+
+  return gimple_range_fold (res, stmt, r1, r2);
+}
+
+// Fold this binary statement using R1 and R2 as the operands ranges,
+// returning the result in RES.  Return false if the operation fails.
+
+bool
+gimple_range_fold (irange &res, const gimple *stmt,
+		   const irange &r1, const irange &r2)
+{
+  gcc_checking_assert (gimple_range_handler (stmt));
+
+  gimple_range_handler (stmt)->fold_range (res, gimple_expr_type (stmt),
+					   r1, r2);
+
+  // If there are any gimple lookups, do those now.
+  gimple_range_adjustment (res, stmt);
+  return true;
+}
+
+// Return the base of the RHS of an assignment.
+
+tree
+gimple_range_base_of_assignment (const gimple *stmt)
+{
+  gcc_checking_assert (gimple_code (stmt) == GIMPLE_ASSIGN);
+  tree op1 = gimple_assign_rhs1 (stmt);
+  if (gimple_assign_rhs_code (stmt) == ADDR_EXPR)
+    return get_base_address (TREE_OPERAND (op1, 0));
+  return op1;
+}
+
+// Return the first operand of this statement if it is a valid operand
+// supported by ranges, otherwise return NULL_TREE.  Special case is
+// &(SSA_NAME expr), return the SSA_NAME instead of the ADDR expr.
+
+tree
+gimple_range_operand1 (const gimple *stmt)
+{
+  gcc_checking_assert (gimple_range_handler (stmt));
+
+  switch (gimple_code (stmt))
+    {
+      case GIMPLE_COND:
+	return gimple_cond_lhs (stmt);
+      case GIMPLE_ASSIGN:
+	{
+	  tree base = gimple_range_base_of_assignment (stmt);
+	  if (base && TREE_CODE (base) == MEM_REF)
+	    {
+	      // If the base address is an SSA_NAME, we return it
+	      // here.  This allows processing of the range of that
+	      // name, while the rest of the expression is simply
+	      // ignored.  The code in range_ops will see the
+	      // ADDR_EXPR and do the right thing.
+	      tree ssa = TREE_OPERAND (base, 0);
+	      if (TREE_CODE (ssa) == SSA_NAME)
+		return ssa;
+	    }
+	  return base;
+	}
+      default:
+	break;
+    }
+  return NULL;
+}
+
+// Return the second operand of statement STMT, otherwise return NULL_TREE.
+
+tree
+gimple_range_operand2 (const gimple *stmt)
+{
+  gcc_checking_assert (gimple_range_handler (stmt));
+
+  switch (gimple_code (stmt))
+    {
+    case GIMPLE_COND:
+      return gimple_cond_rhs (stmt);
+    case GIMPLE_ASSIGN:
+      if (gimple_num_ops (stmt) >= 3)
+	return gimple_assign_rhs2 (stmt);
+    default:
+      break;
+    }
+  return NULL_TREE;
+}
+
+// Calculate what we can determine of the range of this unary
+// statement's operand if the lhs of the expression has the range
+// LHS_RANGE.  Return false if nothing can be determined.
+
+bool
+gimple_range_calc_op1 (irange &r, const gimple *stmt, const irange &lhs_range)
+{
+  gcc_checking_assert (gimple_num_ops (stmt) < 3);
+
+  // An empty range is viral.
+  tree type = TREE_TYPE (gimple_range_operand1 (stmt));
+  if (lhs_range.undefined_p ())
+    {
+      r.set_undefined ();
+      return true;
+    }
+  // Unary operations require the type of the first operand in the
+  // second range position.
+  int_range<2> type_range (type);
+  return gimple_range_handler (stmt)->op1_range (r, type, lhs_range,
+						 type_range);
+}
+
+// Calculate what we can determine of the range of this statement's
+// first operand if the lhs of the expression has the range LHS_RANGE
+// and the second operand has the range OP2_RANGE.  Return false if
+// nothing can be determined.
+
+bool
+gimple_range_calc_op1 (irange &r, const gimple *stmt,
+		       const irange &lhs_range, const irange &op2_range)
+{
+  // Unary operation are allowed to pass a range in for second operand
+  // as there are often additional restrictions beyond the type which
+  // can be imposed.  See operator_cast::op1_range().
+  tree type = TREE_TYPE (gimple_range_operand1 (stmt));
+  // An empty range is viral.
+  if (op2_range.undefined_p () || lhs_range.undefined_p ())
+    {
+      r.set_undefined ();
+      return true;
+    }
+  return gimple_range_handler (stmt)->op1_range (r, type, lhs_range,
+						 op2_range);
+}
+
+// Calculate what we can determine of the range of this statement's
+// second operand if the lhs of the expression has the range LHS_RANGE
+// and the first operand has the range OP1_RANGE.  Return false if
+// nothing can be determined.
+
+bool
+gimple_range_calc_op2 (irange &r, const gimple *stmt,
+		       const irange &lhs_range, const irange &op1_range)
+{
+  tree type = TREE_TYPE (gimple_range_operand2 (stmt));
+  // An empty range is viral.
+  if (op1_range.undefined_p () || lhs_range.undefined_p ())
+    {
+      r.set_undefined ();
+      return true;
+    }
+  return gimple_range_handler (stmt)->op2_range (r, type, lhs_range,
+						 op1_range);
+}
+
+// Calculate a range for statement S and return it in R. If NAME is provided it
+// represents the SSA_NAME on the LHS of the statement. It is only required
+// if there is more than one lhs/output.  If a range cannot
+// be calculated, return false.
+
+bool
+gimple_ranger::calc_stmt (irange &r, gimple *s, tree name)
+{
+  bool res = false;
+  // If name is specified, make sure it is an LHS of S.
+  gcc_checking_assert (name ? SSA_NAME_DEF_STMT (name) == s : true);
+
+  if (gimple_range_handler (s))
+    res = range_of_range_op (r, s);
+  else if (is_a<gphi *>(s))
+    res = range_of_phi (r, as_a<gphi *> (s));
+  else if (is_a<gcall *>(s))
+    res = range_of_call (r, as_a<gcall *> (s));
+  else if (is_a<gassign *> (s) && gimple_assign_rhs_code (s) == COND_EXPR)
+    res = range_of_cond_expr (r, as_a<gassign *> (s));
+  else
+    {
+      // If no name is specified, try the expression kind.
+      if (!name)
+	{
+	  tree t = gimple_expr_type (s);
+	  if (!irange::supports_type_p (t))
+	    return false;
+	  r.set_varying (t);
+	  return true;
+	}
+      // We don't understand the stmt, so return the global range.
+      r = gimple_range_global (name);
+      return true;
+    }
+  if (res)
+    {
+      if (r.undefined_p ())
+	return true;
+      if (name && TREE_TYPE (name) != r.type ())
+	range_cast (r, TREE_TYPE (name));
+      return true;
+    }
+  return false;
+}
+
+// Calculate a range for range_op statement S and return it in R.  If any
+// If a range cannot be calculated, return false.
+
+bool
+gimple_ranger::range_of_range_op (irange &r, gimple *s)
+{
+  int_range_max range1, range2;
+  tree type = gimple_expr_type (s);
+  gcc_checking_assert (irange::supports_type_p (type));
+
+  tree op1 = gimple_range_operand1 (s);
+  tree op2 = gimple_range_operand2 (s);
+
+  if (range_of_non_trivial_assignment (r, s))
+    return true;
+
+  if (range_of_expr (range1, op1, s))
+    {
+      if (!op2)
+	return gimple_range_fold (r, s, range1);
+
+      if (range_of_expr (range2, op2, s))
+	return gimple_range_fold (r, s, range1, range2);
+    }
+  r.set_varying (type);
+  return true;
+}
+
+// Calculate the range of a non-trivial assignment.  That is, is one
+// inolving arithmetic on an SSA name (for example, an ADDR_EXPR).
+// Return the range in R.
+//
+// If a range cannot be calculated, return false.
+
+bool
+gimple_ranger::range_of_non_trivial_assignment (irange &r, gimple *stmt)
+{
+  if (gimple_code (stmt) != GIMPLE_ASSIGN)
+    return false;
+
+  tree base = gimple_range_base_of_assignment (stmt);
+  if (base && TREE_CODE (base) == MEM_REF
+      && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
+    {
+      int_range_max range1;
+      tree ssa = TREE_OPERAND (base, 0);
+      if (range_of_expr (range1, ssa, stmt))
+	{
+	  tree type = TREE_TYPE (ssa);
+	  range_operator *op = range_op_handler (POINTER_PLUS_EXPR, type);
+	  int_range<2> offset (TREE_OPERAND (base, 1), TREE_OPERAND (base, 1));
+	  op->fold_range (r, type, range1, offset);
+	  return true;
+	}
+    }
+  return false;
+}
+
+// Calculate a range for phi statement S and return it in R.
+// If a range cannot be calculated, return false.
+
+bool
+gimple_ranger::range_of_phi (irange &r, gphi *phi)
+{
+  tree phi_def = gimple_phi_result (phi);
+  tree type = TREE_TYPE (phi_def);
+  int_range_max arg_range;
+  unsigned x;
+
+  if (!irange::supports_type_p (type))
+    return false;
+
+  // Start with an empty range, unioning in each argument's range.
+  r.set_undefined ();
+  for (x = 0; x < gimple_phi_num_args (phi); x++)
+    {
+      tree arg = gimple_phi_arg_def (phi, x);
+      edge e = gimple_phi_arg_edge (phi, x);
+
+      range_on_edge (arg_range, e, arg);
+      r.union_ (arg_range);
+      // Once the value reaches varying, stop looking.
+      if (r.varying_p ())
+	break;
+    }
+
+  // If SCEV is available, query if this PHI has any knonwn values.
+  if (scev_initialized_p () && !POINTER_TYPE_P (TREE_TYPE (phi_def)))
+    {
+      value_range loop_range;
+      class loop *l = loop_containing_stmt (phi);
+      if (l)
+        {
+	  range_of_ssa_name_with_loop_info (loop_range, phi_def, l, phi);
+	  if (!loop_range.varying_p ())
+	    {
+	      if (dump_file && (dump_flags & TDF_DETAILS))
+		{
+		  fprintf (dump_file, "   Loops range found for ");
+		  print_generic_expr (dump_file, phi_def, TDF_SLIM);
+		  fprintf (dump_file, ": ");
+		  loop_range.dump (dump_file);
+		  fprintf (dump_file, " and calculated range :");
+		  r.dump (dump_file);
+		  fprintf (dump_file, "\n");
+		}
+	      r.intersect (loop_range);
+	    }
+	}
+    }
+
+  return true;
+}
+
+// Calculate a range for call statement S and return it in R.
+// If a range cannot be calculated, return false.
+
+bool
+gimple_ranger::range_of_call (irange &r, gcall *call)
+{
+  tree type = gimple_call_return_type (call);
+  tree lhs = gimple_call_lhs (call);
+  bool strict_overflow_p;
+
+  if (!irange::supports_type_p (type))
+    return false;
+
+  if (range_of_builtin_call (r, call))
+    ;
+  else if (gimple_stmt_nonnegative_warnv_p (call, &strict_overflow_p))
+    r.set (build_int_cst (type, 0), TYPE_MAX_VALUE (type));
+  else if (gimple_call_nonnull_result_p (call)
+	   || gimple_call_nonnull_arg (call))
+    r = range_nonzero (type);
+  else
+    r.set_varying (type);
+
+  // If there is an LHS, intersect that with what is known.
+  if (lhs)
+    {
+      value_range def;
+      def = gimple_range_global (lhs);
+      r.intersect (def);
+    }
+  return true;
+}
+
+
+void
+gimple_ranger::range_of_builtin_ubsan_call (irange &r, gcall *call,
+					    tree_code code)
+{
+  gcc_checking_assert (code == PLUS_EXPR || code == MINUS_EXPR
+		       || code == MULT_EXPR);
+  tree type = gimple_call_return_type (call);
+  range_operator *op = range_op_handler (code, type);
+  gcc_checking_assert (op);
+  int_range_max ir0, ir1;
+  tree arg0 = gimple_call_arg (call, 0);
+  tree arg1 = gimple_call_arg (call, 1);
+  gcc_assert (range_of_expr (ir0, arg0, call));
+  gcc_assert (range_of_expr (ir1, arg1, call));
+
+  bool saved_flag_wrapv = flag_wrapv;
+  // Pretend the arithmetic is wrapping.  If there is any overflow,
+  // we'll complain, but will actually do wrapping operation.
+  flag_wrapv = 1;
+  op->fold_range (r, type, ir0, ir1);
+  flag_wrapv = saved_flag_wrapv;
+
+  // If for both arguments vrp_valueize returned non-NULL, this should
+  // have been already folded and if not, it wasn't folded because of
+  // overflow.  Avoid removing the UBSAN_CHECK_* calls in that case.
+  if (r.singleton_p ())
+    r.set_varying (type);
+}
+
+
+bool
+gimple_ranger::range_of_builtin_call (irange &r, gcall *call)
+{
+  combined_fn func = gimple_call_combined_fn (call);
+  if (func == CFN_LAST)
+    return false;
+
+  tree type = gimple_call_return_type (call);
+  tree arg;
+  int mini, maxi, zerov, prec;
+  scalar_int_mode mode;
+
+  switch (func)
+    {
+    case CFN_BUILT_IN_CONSTANT_P:
+      if (cfun->after_inlining)
+	{
+	  r.set_zero (type);
+	  // r.equiv_clear ();
+	  return true;
+	}
+      arg = gimple_call_arg (call, 0);
+      if (range_of_expr (r, arg, call) && r.singleton_p ())
+	{
+	  r.set (build_one_cst (type), build_one_cst (type));
+	  return true;
+	}
+      break;
+
+    CASE_CFN_FFS:
+    CASE_CFN_POPCOUNT:
+      // __builtin_ffs* and __builtin_popcount* return [0, prec].
+      arg = gimple_call_arg (call, 0);
+      prec = TYPE_PRECISION (TREE_TYPE (arg));
+      mini = 0;
+      maxi = prec;
+      gcc_assert (range_of_expr (r, arg, call));
+      // If arg is non-zero, then ffs or popcount are non-zero.
+      if (!range_includes_zero_p (&r))
+	mini = 1;
+      // If some high bits are known to be zero, decrease the maximum.
+      if (!r.undefined_p ())
+	{
+	  wide_int max = r.upper_bound ();
+	  maxi = wi::floor_log2 (max) + 1;
+	}
+      r.set (build_int_cst (type, mini), build_int_cst (type, maxi));
+      return true;
+
+    CASE_CFN_PARITY:
+      r.set (build_zero_cst (type), build_one_cst (type));
+      return true;
+
+    CASE_CFN_CLZ:
+      // __builtin_c[lt]z* return [0, prec-1], except when the
+      // argument is 0, but that is undefined behavior.
+      //
+      // On many targets where the CLZ RTL or optab value is defined
+      // for 0, the value is prec, so include that in the range by
+      // default.
+      arg = gimple_call_arg (call, 0);
+      prec = TYPE_PRECISION (TREE_TYPE (arg));
+      mini = 0;
+      maxi = prec;
+      mode = SCALAR_INT_TYPE_MODE (TREE_TYPE (arg));
+      if (optab_handler (clz_optab, mode) != CODE_FOR_nothing
+	  && CLZ_DEFINED_VALUE_AT_ZERO (mode, zerov)
+	  // Only handle the single common value.
+	  && zerov != prec)
+	// Magic value to give up, unless we can prove arg is non-zero.
+	mini = -2;
+
+      gcc_assert (range_of_expr (r, arg, call));
+      // From clz of minimum we can compute result maximum.
+      if (r.constant_p ())
+	{
+	  maxi = prec - 1 - wi::floor_log2 (r.lower_bound ());
+	  if (maxi != prec)
+	    mini = 0;
+	}
+      else if (!range_includes_zero_p (&r))
+	{
+	  maxi = prec - 1;
+	  mini = 0;
+	}
+      if (mini == -2)
+	break;
+      // From clz of maximum we can compute result minimum.
+      if (r.constant_p ())
+	{
+	  mini = prec - 1 - wi::floor_log2 (r.upper_bound ());
+	  if (mini == prec)
+	    break;
+	}
+      if (mini == -2)
+	break;
+      r.set (build_int_cst (type, mini), build_int_cst (type, maxi));
+      return true;
+
+    CASE_CFN_CTZ:
+      // __builtin_ctz* return [0, prec-1], except for when the
+      // argument is 0, but that is undefined behavior.
+      //
+      // If there is a ctz optab for this mode and
+      // CTZ_DEFINED_VALUE_AT_ZERO, include that in the range,
+      // otherwise just assume 0 won't be seen.
+      arg = gimple_call_arg (call, 0);
+      prec = TYPE_PRECISION (TREE_TYPE (arg));
+      mini = 0;
+      maxi = prec - 1;
+      mode = SCALAR_INT_TYPE_MODE (TREE_TYPE (arg));
+      if (optab_handler (ctz_optab, mode) != CODE_FOR_nothing
+	  && CTZ_DEFINED_VALUE_AT_ZERO (mode, zerov))
+	{
+	  // Handle only the two common values.
+	  if (zerov == -1)
+	    mini = -1;
+	  else if (zerov == prec)
+	    maxi = prec;
+	  else
+	    // Magic value to give up, unless we can prove arg is non-zero.
+	    mini = -2;
+	}
+      gcc_assert (range_of_expr (r, arg, call));
+      if (!r.undefined_p ())
+	{
+	  if (r.lower_bound () != 0)
+	    {
+	      mini = 0;
+	      maxi = prec - 1;
+	    }
+	  // If some high bits are known to be zero, we can decrease
+	  // the maximum.
+	  wide_int max = r.upper_bound ();
+	  if (max == 0)
+	    break;
+	  maxi = wi::floor_log2 (max);
+	}
+      if (mini == -2)
+	break;
+      r.set (build_int_cst (type, mini), build_int_cst (type, maxi));
+      return true;
+
+    CASE_CFN_CLRSB:
+      arg = gimple_call_arg (call, 0);
+      prec = TYPE_PRECISION (TREE_TYPE (arg));
+      r.set (build_int_cst (type, 0), build_int_cst (type, prec - 1));
+      return true;
+    case CFN_UBSAN_CHECK_ADD:
+      range_of_builtin_ubsan_call (r, call, PLUS_EXPR);
+      return true;
+    case CFN_UBSAN_CHECK_SUB:
+      range_of_builtin_ubsan_call (r, call, MINUS_EXPR);
+      return true;
+    case CFN_UBSAN_CHECK_MUL:
+      range_of_builtin_ubsan_call (r, call, MULT_EXPR);
+      return true;
+
+    case CFN_GOACC_DIM_SIZE:
+    case CFN_GOACC_DIM_POS:
+      // Optimizing these two internal functions helps the loop
+      // optimizer eliminate outer comparisons.  Size is [1,N]
+      // and pos is [0,N-1].
+      {
+	bool is_pos = func == CFN_GOACC_DIM_POS;
+	int axis = oacc_get_ifn_dim_arg (call);
+	int size = oacc_get_fn_dim_size (current_function_decl, axis);
+	if (!size)
+	  // If it's dynamic, the backend might know a hardware limitation.
+	  size = targetm.goacc.dim_limit (axis);
+
+	r.set (build_int_cst (type, is_pos ? 0 : 1),
+	       size
+	       ? build_int_cst (type, size - is_pos) : vrp_val_max (type));
+	return true;
+      }
+
+    case CFN_BUILT_IN_STRLEN:
+      if (tree lhs = gimple_call_lhs (call))
+	if (ptrdiff_type_node
+	    && (TYPE_PRECISION (ptrdiff_type_node)
+		== TYPE_PRECISION (TREE_TYPE (lhs))))
+	  {
+	    tree type = TREE_TYPE (lhs);
+	    tree max = vrp_val_max (ptrdiff_type_node);
+	    wide_int wmax
+	      = wi::to_wide (max, TYPE_PRECISION (TREE_TYPE (max)));
+	    tree range_min = build_zero_cst (type);
+	    // To account for the terminating NULL, the maximum length
+	    // is one less than the maximum array size, which in turn
+	    // is one less than PTRDIFF_MAX (or SIZE_MAX where it's
+	    // smaller than the former type).
+	    // FIXME: Use max_object_size() - 1 here.
+	    tree range_max = wide_int_to_tree (type, wmax - 2);
+	    r.set (range_min, range_max);
+	    return true;
+	  }
+      break;
+    default:
+      break;
+    }
+  return false;
+}
+
+
+
+// Calculate a range for COND_EXPR statement S and return it in R.
+// If a range cannot be calculated, return false.
+
+bool
+gimple_ranger::range_of_cond_expr  (irange &r, gassign *s)
+{
+  int_range_max cond_range, range1, range2;
+  tree cond = gimple_assign_rhs1 (s);
+  tree op1 = gimple_assign_rhs2 (s);
+  tree op2 = gimple_assign_rhs3 (s);
+
+  gcc_checking_assert (gimple_assign_rhs_code (s) == COND_EXPR);
+  gcc_checking_assert (useless_type_conversion_p  (TREE_TYPE (op1),
+						   TREE_TYPE (op2)));
+  if (!irange::supports_type_p (TREE_TYPE (op1)))
+    return false;
+
+  gcc_assert (range_of_expr (cond_range, cond, s));
+  gcc_assert (range_of_expr (range1, op1, s));
+  gcc_assert (range_of_expr (range2, op2, s));
+
+  // If the condition is known, choose the appropriate expression.
+  if (cond_range.singleton_p ())
+    {
+      // False, pick second operand.
+      if (cond_range.zero_p ())
+	r = range2;
+      else
+	r = range1;
+    }
+  else
+    {
+      r = range1;
+      r.union_ (range2);
+    }
+  return true;
+}
+
+bool
+gimple_ranger::range_of_expr (irange &r, tree expr, gimple *stmt)
+{
+  if (!gimple_range_ssa_p (expr))
+    return get_tree_range (r, expr);
+
+  // If there is no statement, just get the global value.
+  if (!stmt)
+    {
+      if (!m_cache.m_globals.get_global_range (r, expr))
+        r = gimple_range_global (expr);
+      return true;
+    }
+
+  basic_block bb = gimple_bb (stmt);
+  gimple *def_stmt = SSA_NAME_DEF_STMT (expr);
+
+  // If name is defined in this block, try to get an range from S.
+  if (def_stmt && gimple_bb (def_stmt) == bb)
+    gcc_assert (range_of_stmt (r, def_stmt, expr));
+  else
+    // Otherwise OP comes from outside this block, use range on entry.
+    range_on_entry (r, bb, expr);
+
+  // No range yet, see if there is a dereference in the block.
+  // We don't care if it's between the def and a use within a block
+  // because the entire block must be executed anyway.
+  // FIXME:?? For non-call exceptions we could have a statement throw
+  // which causes an early block exit.
+  // in which case we may need to walk from S back to the def/top of block
+  // to make sure the deref happens between S and there before claiming
+  // there is a deref.   Punt for now.
+  if (!cfun->can_throw_non_call_exceptions && r.varying_p () &&
+      m_cache.m_non_null.non_null_deref_p (expr, bb))
+    r = range_nonzero (TREE_TYPE (expr));
+
+  return true;
+}
+
+// Return the range of NAME on entry to block BB in R.
+
+void
+gimple_ranger::range_on_entry (irange &r, basic_block bb, tree name)
+{
+  int_range_max entry_range;
+  gcc_checking_assert (gimple_range_ssa_p (name));
+
+  // Start with any known range
+  gcc_assert (range_of_stmt (r, SSA_NAME_DEF_STMT (name), name));
+
+  // Now see if there is any on_entry value which may refine it.
+  if (m_cache.block_range (entry_range, bb, name))
+    r.intersect (entry_range);
+}
+
+// Calculate the range for NAME at the end of block BB and return it in R.
+// Return false if no range can be calculated.
+
+void
+gimple_ranger::range_on_exit (irange &r, basic_block bb, tree name)
+{
+  // on-exit from the exit block?
+  gcc_checking_assert (bb != EXIT_BLOCK_PTR_FOR_FN (cfun));
+
+  gimple *s = last_stmt (bb);
+  // If there is no statement in the block and this isn't the entry
+  // block, go get the range_on_entry for this block.  For the entry
+  // block, a NULL stmt will return the global value for NAME.
+  if (!s && bb != ENTRY_BLOCK_PTR_FOR_FN (cfun))
+    range_on_entry (r, bb, name);
+  else
+    gcc_assert (range_of_expr (r, name, s));
+  gcc_checking_assert (r.undefined_p ()
+		       || types_compatible_p (r.type(), TREE_TYPE (name)));
+}
+
+// Calculate a range for NAME on edge E and return it in R.
+
+bool
+gimple_ranger::range_on_edge (irange &r, edge e, tree name)
+{
+  int_range_max edge_range;
+  gcc_checking_assert (irange::supports_type_p (TREE_TYPE (name)));
+
+  // PHI arguments can be constants, catch these here.
+  if (!gimple_range_ssa_p (name))
+    {
+      gcc_assert (range_of_expr (r, name));
+      return true;
+    }
+
+  range_on_exit (r, e->src, name);
+  gcc_checking_assert  (r.undefined_p ()
+			|| types_compatible_p (r.type(), TREE_TYPE (name)));
+
+  // Check to see if NAME is defined on edge e.
+  if (m_cache.outgoing_edge_range_p (edge_range, e, name))
+    r.intersect (edge_range);
+
+  return true;
+}
+
+// Calculate a range for statement S and return it in R.  If NAME is
+// provided it represents the SSA_NAME on the LHS of the statement.
+// It is only required if there is more than one lhs/output.  Check
+// the global cache for NAME first to see if the evaluation can be
+// avoided.  If a range cannot be calculated, return false.
+
+bool
+gimple_ranger::range_of_stmt (irange &r, gimple *s, tree name)
+{
+  // If no name, simply call the base routine.
+  if (!name)
+    name = gimple_get_lhs (s);
+
+  if (!name)
+    return calc_stmt (r, s, NULL_TREE);
+
+  gcc_checking_assert (TREE_CODE (name) == SSA_NAME &&
+		       irange::supports_type_p (TREE_TYPE (name)));
+
+  // If this STMT has already been processed, return that value.
+  if (m_cache.m_globals.get_global_range (r, name))
+    return true;
+  // Avoid infinite recursion by initializing global cache
+  int_range_max tmp = gimple_range_global (name);
+  m_cache.m_globals.set_global_range (name, tmp);
+
+  gcc_assert (calc_stmt (r, s, name));
+
+  if (is_a<gphi *> (s))
+    r.intersect (tmp);
+  m_cache.m_globals.set_global_range (name, r);
+  return true;
+}
+
+// This routine will export whatever global ranges are known to GCC
+// SSA_RANGE_NAME_INFO fields.
+
+void
+gimple_ranger::export_global_ranges ()
+{
+  unsigned x;
+  int_range_max r;
+  if (dump_file)
+    {
+      fprintf (dump_file, "Exported global range table\n");
+      fprintf (dump_file, "===========================\n");
+    }
+
+  for ( x = 1; x < num_ssa_names; x++)
+    {
+      tree name = ssa_name (x);
+      if (name && !SSA_NAME_IN_FREE_LIST (name)
+	  && gimple_range_ssa_p (name)
+	  && m_cache.m_globals.get_global_range (r, name)
+	  && !r.varying_p())
+	{
+	  // Make sure the new range is a subset of the old range.
+	  int_range_max old_range;
+	  old_range = gimple_range_global (name);
+	  old_range.intersect (r);
+	  /* Disable this while we fix tree-ssa/pr61743-2.c.  */
+	  //gcc_checking_assert (old_range == r);
+
+	  // WTF? Can't write non-null pointer ranges?? stupid set_range_info!
+	  if (!POINTER_TYPE_P (TREE_TYPE (name)) && !r.undefined_p ())
+	    {
+	      value_range vr = r;
+	      set_range_info (name, vr);
+	      if (dump_file)
+		{
+		  print_generic_expr (dump_file, name , TDF_SLIM);
+		  fprintf (dump_file, " --> ");
+		  vr.dump (dump_file);
+		  fprintf (dump_file, "\n");
+		  fprintf (dump_file, "         irange : ");
+		  r.dump (dump_file);
+		  fprintf (dump_file, "\n");
+		}
+	    }
+	}
+    }
+}
+
+// Print the known table values to file F.
+
+void
+gimple_ranger::dump (FILE *f)
+{
+  basic_block bb;
+
+  FOR_EACH_BB_FN (bb, cfun)
+    {
+      unsigned x;
+      edge_iterator ei;
+      edge e;
+      int_range_max range;
+      fprintf (f, "\n=========== BB %d ============\n", bb->index);
+      m_cache.m_on_entry.dump (f, bb);
+
+      dump_bb (f, bb, 4, TDF_NONE);
+
+      // Now find any globals defined in this block.
+      for (x = 1; x < num_ssa_names; x++)
+	{
+	  tree name = ssa_name (x);
+	  if (gimple_range_ssa_p (name) && SSA_NAME_DEF_STMT (name) &&
+	      gimple_bb (SSA_NAME_DEF_STMT (name)) == bb &&
+	      m_cache.m_globals.get_global_range (range, name))
+	    {
+	      if (!range.varying_p ())
+	       {
+		 print_generic_expr (f, name, TDF_SLIM);
+		 fprintf (f, " : ");
+		 range.dump (f);
+		 fprintf (f, "\n");
+	       }
+
+	    }
+	}
+
+      // And now outgoing edges, if they define anything.
+      FOR_EACH_EDGE (e, ei, bb->succs)
+	{
+	  for (x = 1; x < num_ssa_names; x++)
+	    {
+	      tree name = gimple_range_ssa_p (ssa_name (x));
+	      if (name && m_cache.outgoing_edge_range_p (range, e, name))
+		{
+		  gimple *s = SSA_NAME_DEF_STMT (name);
+		  // Only print the range if this is the def block, or
+		  // the on entry cache for either end of the edge is
+		  // set.
+		  if ((s && bb == gimple_bb (s)) ||
+		      m_cache.block_range (range, bb, name, false) ||
+		      m_cache.block_range (range, e->dest, name, false))
+		    {
+		      range_on_edge (range, e, name);
+		      if (!range.varying_p ())
+			{
+			  fprintf (f, "%d->%d ", e->src->index,
+				   e->dest->index);
+			  char c = ' ';
+			  if (e->flags & EDGE_TRUE_VALUE)
+			    fprintf (f, " (T)%c", c);
+			  else if (e->flags & EDGE_FALSE_VALUE)
+			    fprintf (f, " (F)%c", c);
+			  else
+			    fprintf (f, "     ");
+			  print_generic_expr (f, name, TDF_SLIM);
+			  fprintf(f, " : \t");
+			  range.dump(f);
+			  fprintf (f, "\n");
+			}
+		    }
+		}
+	    }
+	}
+    }
+
+  m_cache.m_globals.dump (dump_file);
+  fprintf (f, "\n");
+
+  if (dump_flags & TDF_DETAILS)
+    {
+      fprintf (f, "\nDUMPING GORI MAP\n");
+      m_cache.dump (f);
+      fprintf (f, "\n");
+    }
+}
+
+// If SCEV has any information about phi node NAME, return it as a range in R.
+
+void
+gimple_ranger::range_of_ssa_name_with_loop_info (irange &r, tree name,
+						 class loop *l, gphi *phi)
+{
+  gcc_checking_assert (TREE_CODE (name) == SSA_NAME);
+  tree min, max, type = TREE_TYPE (name);
+  if (bounds_of_var_in_loop (&min, &max, this, l, phi, name))
+    {
+      // ?? We could do better here.  Since MIN/MAX can only be an
+      // SSA, SSA +- INTEGER_CST, or INTEGER_CST, we could easily call
+      // the ranger and solve anything not an integer.
+      if (TREE_CODE (min) != INTEGER_CST)
+	min = vrp_val_min (type);
+      if (TREE_CODE (max) != INTEGER_CST)
+	max = vrp_val_max (type);
+      r.set (min, max);
+    }
+  else
+    r.set_varying (type);
+}
+
+// --------------------------------------------------------------------------
+// trace_ranger implementation.
+
+
+trace_ranger::trace_ranger ()
+{
+  indent = 0;
+  trace_count = 0;
+}
+
+// If dumping, return true and print the prefix for the next output line.
+
+bool
+trace_ranger::dumping (unsigned counter, bool trailing)
+{
+  if (dump_file && (dump_flags & TDF_DETAILS))
+    {
+      // Print counter index as well as INDENT spaces.
+      if (!trailing)
+	fprintf (dump_file, " %-7u ", counter);
+      else
+	fprintf (dump_file, "         ");
+      unsigned x;
+      for (x = 0; x< indent; x++)
+	fputc (' ', dump_file);
+      return true;
+    }
+  return false;
+}
+
+// After calling a routine, if dumping, print the CALLER, NAME, and RESULT,
+// returning RESULT.
+
+bool
+trace_ranger::trailer (unsigned counter, const char *caller, bool result,
+		       tree name, const irange &r)
+{
+  if (dumping (counter, true))
+    {
+      indent -= bump;
+      fputs(result ? "TRUE : " : "FALSE : ", dump_file);
+      fprintf (dump_file, "(%u) ", counter);
+      fputs (caller, dump_file);
+      fputs (" (",dump_file);
+      if (name)
+	print_generic_expr (dump_file, name, TDF_SLIM);
+      fputs (") ",dump_file);
+      if (result)
+	{
+	  r.dump (dump_file);
+	  fputc('\n', dump_file);
+	}
+      else
+	fputc('\n', dump_file);
+      // Marks the end of a request.
+      if (indent == 0)
+	fputc('\n', dump_file);
+    }
+  return result;
+}
+
+// Tracing version of range_on_edge.  Call it with printing wrappers.
+
+bool
+trace_ranger::range_on_edge (irange &r, edge e, tree name)
+{
+  unsigned idx = ++trace_count;
+  if (dumping (idx))
+    {
+      fprintf (dump_file, "range_on_edge (");
+      print_generic_expr (dump_file, name, TDF_SLIM);
+      fprintf (dump_file, ") on edge %d->%d\n", e->src->index, e->dest->index);
+      indent += bump;
+    }
+
+  bool res = gimple_ranger::range_on_edge (r, e, name);
+  trailer (idx, "range_on_edge", true, name, r);
+  return res;
+}
+
+// Tracing version of range_on_entry.  Call it with printing wrappers.
+
+void
+trace_ranger::range_on_entry (irange &r, basic_block bb, tree name)
+{
+  unsigned idx = ++trace_count;
+  if (dumping (idx))
+    {
+      fprintf (dump_file, "range_on_entry (");
+      print_generic_expr (dump_file, name, TDF_SLIM);
+      fprintf (dump_file, ") to BB %d\n", bb->index);
+      indent += bump;
+    }
+
+  gimple_ranger::range_on_entry (r, bb, name);
+
+  trailer (idx, "range_on_entry", true, name, r);
+}
+
+// Tracing version of range_on_exit.  Call it with printing wrappers.
+
+void
+trace_ranger::range_on_exit (irange &r, basic_block bb, tree name)
+{
+  unsigned idx = ++trace_count;
+  if (dumping (idx))
+    {
+      fprintf (dump_file, "range_on_exit (");
+      print_generic_expr (dump_file, name, TDF_SLIM);
+      fprintf (dump_file, ") from BB %d\n", bb->index);
+      indent += bump;
+    }
+
+  gimple_ranger::range_on_exit (r, bb, name);
+
+  trailer (idx, "range_on_exit", true, name, r);
+}
+
+// Tracing version of range_of_stmt.  Call it with printing wrappers.
+
+bool
+trace_ranger::range_of_stmt (irange &r, gimple *s, tree name)
+{
+  bool res;
+  unsigned idx = ++trace_count;
+  if (dumping (idx))
+    {
+      fprintf (dump_file, "range_of_stmt (");
+      if (name)
+	print_generic_expr (dump_file, name, TDF_SLIM);
+      fputs (") at stmt ", dump_file);
+      print_gimple_stmt (dump_file, s, 0, TDF_SLIM);
+      indent += bump;
+    }
+
+  res = gimple_ranger::range_of_stmt (r, s, name);
+
+  return trailer (idx, "range_of_stmt", res, name, r);
+}
+
+// Tracing version of range_of_expr.  Call it with printing wrappers.
+
+bool
+trace_ranger::range_of_expr (irange &r, tree name, gimple *s)
+{
+  bool res;
+  unsigned idx = ++trace_count;
+  if (dumping (idx))
+    {
+      fprintf (dump_file, "range_of_expr(");
+      print_generic_expr (dump_file, name, TDF_SLIM);
+      fputs (")", dump_file);
+      if (s)
+	{
+	  fputs (" at stmt ", dump_file);
+	  print_gimple_stmt (dump_file, s, 0, TDF_SLIM);
+	}
+      else
+	fputs ("\n", dump_file);
+      indent += bump;
+    }
+
+  res = gimple_ranger::range_of_expr (r, name, s);
+
+  return trailer (idx, "range_of_expr", res, name, r);
+}