CbC/CbC_gcc: gcc/vr-values.c comparison

comparison gcc/vr-values.c @ 132:d34655255c78

update gcc-8.2

author	mir3636
date	Thu, 25 Oct 2018 10:21:07 +0900
parents	84e7813d76e9
children	1830386684a0

comparison

equal deleted inserted replaced

-:e108057fa461
+:d34655255c78
+/* Support routines for Value Range Propagation (VRP).
+Copyright (C) 2005-2018 Free Software Foundation, Inc.
+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 "tree.h"
+#include "gimple.h"
+#include "ssa.h"
+#include "optabs-tree.h"
+#include "gimple-pretty-print.h"
+#include "diagnostic-core.h"
+#include "flags.h"
+#include "fold-const.h"
+#include "calls.h"
+#include "cfganal.h"
+#include "gimple-fold.h"
+#include "gimple-iterator.h"
+#include "tree-cfg.h"
+#include "tree-ssa-loop-niter.h"
+#include "tree-ssa-loop.h"
+#include "intl.h"
+#include "cfgloop.h"
+#include "tree-scalar-evolution.h"
+#include "tree-ssa-propagate.h"
+#include "tree-chrec.h"
+#include "omp-general.h"
+#include "case-cfn-macros.h"
+#include "alloc-pool.h"
+#include "attribs.h"
+#include "vr-values.h"
+#include "cfghooks.h"
+/* Set value range VR to a non-negative range of type TYPE.  */
+static inline void
+set_value_range_to_nonnegative (value_range *vr, tree type)
+{
+tree zero = build_int_cst (type, 0);
+vr->update (VR_RANGE, zero, vrp_val_max (type));
+}
+/* Set value range VR to a range of a truthvalue of type TYPE.  */
+static inline void
+set_value_range_to_truthvalue (value_range *vr, tree type)
+{
+if (TYPE_PRECISION (type) == 1)
+set_value_range_to_varying (vr);
+else
+vr->update (VR_RANGE, build_int_cst (type, 0), build_int_cst (type, 1));
+}
+/* Return value range information for VAR.
+If we have no values ranges recorded (ie, VRP is not running), then
+return NULL.  Otherwise create an empty range if none existed for VAR.  */
+value_range *
+vr_values::get_value_range (const_tree var)
+{
+static const value_range vr_const_varying (VR_VARYING, NULL, NULL);
+value_range *vr;
+tree sym;
+unsigned ver = SSA_NAME_VERSION (var);
+/* If we have no recorded ranges, then return NULL.  */
+if (! vr_value)
+return NULL;
+/* If we query the range for a new SSA name return an unmodifiable VARYING.
+We should get here at most from the substitute-and-fold stage which
+will never try to change values.  */
+if (ver >= num_vr_values)
+return CONST_CAST (value_range *, &vr_const_varying);
+vr = vr_value[ver];
+if (vr)
+return vr;
+/* After propagation finished do not allocate new value-ranges.  */
+if (values_propagated)
+return CONST_CAST (value_range *, &vr_const_varying);
+/* Create a default value range.  */
+vr_value[ver] = vr = vrp_value_range_pool.allocate ();
+vr->set_undefined ();
+/* If VAR is a default definition of a parameter, the variable can
+take any value in VAR's type.  */
+if (SSA_NAME_IS_DEFAULT_DEF (var))
+{
+sym = SSA_NAME_VAR (var);
+if (TREE_CODE (sym) == PARM_DECL)
+	{
+	  /* Try to use the "nonnull" attribute to create ~[0, 0]
+	     anti-ranges for pointers.  Note that this is only valid with
+	     default definitions of PARM_DECLs.  */
+	  if (POINTER_TYPE_P (TREE_TYPE (sym))
+	      && (nonnull_arg_p (sym)
+		  || get_ptr_nonnull (var)))
+	    set_value_range_to_nonnull (vr, TREE_TYPE (sym));
+	  else if (INTEGRAL_TYPE_P (TREE_TYPE (sym)))
+	    {
+	      wide_int min, max;
+	      value_range_kind rtype = get_range_info (var, &min, &max);
+	      if (rtype == VR_RANGE || rtype == VR_ANTI_RANGE)
+		set_value_range (vr, rtype,
+				 wide_int_to_tree (TREE_TYPE (var), min),
+				 wide_int_to_tree (TREE_TYPE (var), max),
+				 NULL);
+	      else
+		set_value_range_to_varying (vr);
+	    }
+	  else
+	    set_value_range_to_varying (vr);
+	}
+else if (TREE_CODE (sym) == RESULT_DECL
+	       && DECL_BY_REFERENCE (sym))
+	set_value_range_to_nonnull (vr, TREE_TYPE (sym));
+}
+return vr;
+}
+/* Set value-ranges of all SSA names defined by STMT to varying.  */
+void
+vr_values::set_defs_to_varying (gimple *stmt)
+{
+ssa_op_iter i;
+tree def;
+FOR_EACH_SSA_TREE_OPERAND (def, stmt, i, SSA_OP_DEF)
+{
+value_range *vr = get_value_range (def);
+/* Avoid writing to vr_const_varying get_value_range may return.  */
+if (!vr->varying_p ())
+	set_value_range_to_varying (vr);
+}
+}
+/* Update the value range and equivalence set for variable VAR to
+NEW_VR.  Return true if NEW_VR is different from VAR's previous
+value.
+NOTE: This function assumes that NEW_VR is a temporary value range
+object created for the sole purpose of updating VAR's range.  The
+storage used by the equivalence set from NEW_VR will be freed by
+this function.  Do not call update_value_range when NEW_VR
+is the range object associated with another SSA name.  */
+bool
+vr_values::update_value_range (const_tree var, value_range *new_vr)
+{
+value_range *old_vr;
+bool is_new;
+/* If there is a value-range on the SSA name from earlier analysis
+factor that in.  */
+if (INTEGRAL_TYPE_P (TREE_TYPE (var)))
+{
+wide_int min, max;
+value_range_kind rtype = get_range_info (var, &min, &max);
+if (rtype == VR_RANGE || rtype == VR_ANTI_RANGE)
+	{
+	  tree nr_min, nr_max;
+	  nr_min = wide_int_to_tree (TREE_TYPE (var), min);
+	  nr_max = wide_int_to_tree (TREE_TYPE (var), max);
+	  value_range nr;
+	  nr.set_and_canonicalize (rtype, nr_min, nr_max, NULL);
+	  new_vr->intersect (&nr);
+	}
+}
+/* Update the value range, if necessary.  */
+old_vr = get_value_range (var);
+is_new = *old_vr != *new_vr;
+if (is_new)
+{
+/* Do not allow transitions up the lattice.  The following
+	 is slightly more awkward than just new_vr->type < old_vr->type
+	 because VR_RANGE and VR_ANTI_RANGE need to be considered
+	 the same.  We may not have is_new when transitioning to
+	 UNDEFINED.  If old_vr->type is VARYING, we shouldn't be
+	 called.  */
+if (new_vr->undefined_p ())
+	{
+	  set_value_range_to_varying (old_vr);
+	  set_value_range_to_varying (new_vr);
+	  return true;
+	}
+else
+	set_value_range (old_vr, new_vr->kind (),
+			 new_vr->min (), new_vr->max (), new_vr->equiv ());
+}
+new_vr->equiv_clear ();
+return is_new;
+}
+/* Return true if value range VR involves exactly one symbol SYM.  */
+static bool
+symbolic_range_based_on_p (value_range *vr, const_tree sym)
+{
+bool neg, min_has_symbol, max_has_symbol;
+tree inv;
+if (is_gimple_min_invariant (vr->min ()))
+min_has_symbol = false;
+else if (get_single_symbol (vr->min (), &neg, &inv) == sym)
+min_has_symbol = true;
+else
+return false;
+if (is_gimple_min_invariant (vr->max ()))
+max_has_symbol = false;
+else if (get_single_symbol (vr->max (), &neg, &inv) == sym)
+max_has_symbol = true;
+else
+return false;
+return (min_has_symbol || max_has_symbol);
+}
+/* Return true if the result of assignment STMT is know to be non-zero.  */
+static bool
+gimple_assign_nonzero_p (gimple *stmt)
+{
+enum tree_code code = gimple_assign_rhs_code (stmt);
+bool strict_overflow_p;
+switch (get_gimple_rhs_class (code))
+{
+case GIMPLE_UNARY_RHS:
+return tree_unary_nonzero_warnv_p (gimple_assign_rhs_code (stmt),
+					 gimple_expr_type (stmt),
+					 gimple_assign_rhs1 (stmt),
+					 &strict_overflow_p);
+case GIMPLE_BINARY_RHS:
+return tree_binary_nonzero_warnv_p (gimple_assign_rhs_code (stmt),
+					  gimple_expr_type (stmt),
+					  gimple_assign_rhs1 (stmt),
+					  gimple_assign_rhs2 (stmt),
+					  &strict_overflow_p);
+case GIMPLE_TERNARY_RHS:
+return false;
+case GIMPLE_SINGLE_RHS:
+return tree_single_nonzero_warnv_p (gimple_assign_rhs1 (stmt),
+					  &strict_overflow_p);
+case GIMPLE_INVALID_RHS:
+gcc_unreachable ();
+default:
+gcc_unreachable ();
+}
+}
+/* Return true if STMT is known to compute a non-zero value.  */
+static bool
+gimple_stmt_nonzero_p (gimple *stmt)
+{
+switch (gimple_code (stmt))
+{
+case GIMPLE_ASSIGN:
+return gimple_assign_nonzero_p (stmt);
+case GIMPLE_CALL:
+{
+gcall *call_stmt = as_a<gcall *> (stmt);
+	return (gimple_call_nonnull_result_p (call_stmt)
+		|| gimple_call_nonnull_arg (call_stmt));
+}
+default:
+gcc_unreachable ();
+}
+}
+/* Like tree_expr_nonzero_p, but this function uses value ranges
+obtained so far.  */
+bool
+vr_values::vrp_stmt_computes_nonzero (gimple *stmt)
+{
+if (gimple_stmt_nonzero_p (stmt))
+return true;
+/* If we have an expression of the form &X->a, then the expression
+is nonnull if X is nonnull.  */
+if (is_gimple_assign (stmt)
+&& gimple_assign_rhs_code (stmt) == ADDR_EXPR)
+{
+tree expr = gimple_assign_rhs1 (stmt);
+tree base = get_base_address (TREE_OPERAND (expr, 0));
+if (base != NULL_TREE
+	  && TREE_CODE (base) == MEM_REF
+	  && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
+	{
+	  value_range *vr = get_value_range (TREE_OPERAND (base, 0));
+	  if (!range_includes_zero_p (vr))
+	    return true;
+	}
+}
+return false;
+}
+/* Returns true if EXPR is a valid value (as expected by compare_values) --
+a gimple invariant, or SSA_NAME +- CST.  */
+static bool
+valid_value_p (tree expr)
+{
+if (TREE_CODE (expr) == SSA_NAME)
+return true;
+if (TREE_CODE (expr) == PLUS_EXPR
+|| TREE_CODE (expr) == MINUS_EXPR)
+return (TREE_CODE (TREE_OPERAND (expr, 0)) == SSA_NAME
+	    && TREE_CODE (TREE_OPERAND (expr, 1)) == INTEGER_CST);
+return is_gimple_min_invariant (expr);
+}
+/* If OP has a value range with a single constant value return that,
+otherwise return NULL_TREE.  This returns OP itself if OP is a
+constant.  */
+tree
+vr_values::op_with_constant_singleton_value_range (tree op)
+{
+if (is_gimple_min_invariant (op))
+return op;
+if (TREE_CODE (op) != SSA_NAME)
+return NULL_TREE;
+return value_range_constant_singleton (get_value_range (op));
+}
+/* Return true if op is in a boolean [0, 1] value-range.  */
+bool
+vr_values::op_with_boolean_value_range_p (tree op)
+{
+value_range *vr;
+if (TYPE_PRECISION (TREE_TYPE (op)) == 1)
+return true;
+if (integer_zerop (op)
+|| integer_onep (op))
+return true;
+if (TREE_CODE (op) != SSA_NAME)
+return false;
+vr = get_value_range (op);
+return (vr->kind () == VR_RANGE
+	  && integer_zerop (vr->min ())
+	  && integer_onep (vr->max ()));
+}
+/* Extract value range information for VAR when (OP COND_CODE LIMIT) is
+true and store it in *VR_P.  */
+void
+vr_values::extract_range_for_var_from_comparison_expr (tree var,
+						       enum tree_code cond_code,
+						       tree op, tree limit,
+						       value_range *vr_p)
+{
+tree  min, max, type;
+value_range *limit_vr;
+type = TREE_TYPE (var);
+/* For pointer arithmetic, we only keep track of pointer equality
+and inequality.  If we arrive here with unfolded conditions like
+_1 > _1 do not derive anything.  */
+if ((POINTER_TYPE_P (type) && cond_code != NE_EXPR && cond_code != EQ_EXPR)
+|| limit == var)
+{
+set_value_range_to_varying (vr_p);
+return;
+}
+/* If LIMIT is another SSA name and LIMIT has a range of its own,
+try to use LIMIT's range to avoid creating symbolic ranges
+unnecessarily. */
+limit_vr = (TREE_CODE (limit) == SSA_NAME) ? get_value_range (limit) : NULL;
+/* LIMIT's range is only interesting if it has any useful information.  */
+if (! limit_vr
+|| limit_vr->undefined_p ()
+|| limit_vr->varying_p ()
+|| (limit_vr->symbolic_p ()
+	  && ! (limit_vr->kind () == VR_RANGE
+		&& (limit_vr->min () == limit_vr->max ()
+		    || operand_equal_p (limit_vr->min (),
+					limit_vr->max (), 0)))))
+limit_vr = NULL;
+/* Initially, the new range has the same set of equivalences of
+VAR's range.  This will be revised before returning the final
+value.  Since assertions may be chained via mutually exclusive
+predicates, we will need to trim the set of equivalences before
+we are done.  */
+gcc_assert (vr_p->equiv () == NULL);
+vr_p->equiv_add (var, get_value_range (var), &vrp_equiv_obstack);
+/* Extract a new range based on the asserted comparison for VAR and
+LIMIT's value range.  Notice that if LIMIT has an anti-range, we
+will only use it for equality comparisons (EQ_EXPR).  For any
+other kind of assertion, we cannot derive a range from LIMIT's
+anti-range that can be used to describe the new range.  For
+instance, ASSERT_EXPR <x_2, x_2 <= b_4>.  If b_4 is ~[2, 10],
+then b_4 takes on the ranges [-INF, 1] and [11, +INF].  There is
+no single range for x_2 that could describe LE_EXPR, so we might
+as well build the range [b_4, +INF] for it.
+One special case we handle is extracting a range from a
+range test encoded as (unsigned)var + CST <= limit.  */
+if (TREE_CODE (op) == NOP_EXPR
+|| TREE_CODE (op) == PLUS_EXPR)
+{
+if (TREE_CODE (op) == PLUS_EXPR)
+{
+	  min = fold_build1 (NEGATE_EXPR, TREE_TYPE (TREE_OPERAND (op, 1)),
+			     TREE_OPERAND (op, 1));
+max = int_const_binop (PLUS_EXPR, limit, min);
+	  op = TREE_OPERAND (op, 0);
+	}
+else
+	{
+	  min = build_int_cst (TREE_TYPE (var), 0);
+	  max = limit;
+	}
+/* Make sure to not set TREE_OVERFLOW on the final type
+	 conversion.  We are willingly interpreting large positive
+	 unsigned values as negative signed values here.  */
+min = force_fit_type (TREE_TYPE (var), wi::to_widest (min), 0, false);
+max = force_fit_type (TREE_TYPE (var), wi::to_widest (max), 0, false);
+/* We can transform a max, min range to an anti-range or
+vice-versa.  Use set_and_canonicalize which does this for
+us.  */
+if (cond_code == LE_EXPR)
+vr_p->set_and_canonicalize (VR_RANGE, min, max, vr_p->equiv ());
+else if (cond_code == GT_EXPR)
+vr_p->set_and_canonicalize (VR_ANTI_RANGE, min, max, vr_p->equiv ());
+else
+	gcc_unreachable ();
+}
+else if (cond_code == EQ_EXPR)
+{
+enum value_range_kind range_type;
+if (limit_vr)
+	{
+	  range_type = limit_vr->kind ();
+	  min = limit_vr->min ();
+	  max = limit_vr->max ();
+	}
+else
+	{
+	  range_type = VR_RANGE;
+	  min = limit;
+	  max = limit;
+	}
+vr_p->update (range_type, min, max);
+/* When asserting the equality VAR == LIMIT and LIMIT is another
+	 SSA name, the new range will also inherit the equivalence set
+	 from LIMIT.  */
+if (TREE_CODE (limit) == SSA_NAME)
+	vr_p->equiv_add (limit, get_value_range (limit), &vrp_equiv_obstack);
+}
+else if (cond_code == NE_EXPR)
+{
+/* As described above, when LIMIT's range is an anti-range and
+	 this assertion is an inequality (NE_EXPR), then we cannot
+	 derive anything from the anti-range.  For instance, if
+	 LIMIT's range was ~[0, 0], the assertion 'VAR != LIMIT' does
+	 not imply that VAR's range is [0, 0].  So, in the case of
+	 anti-ranges, we just assert the inequality using LIMIT and
+	 not its anti-range.
+	 If LIMIT_VR is a range, we can only use it to build a new
+	 anti-range if LIMIT_VR is a single-valued range.  For
+	 instance, if LIMIT_VR is [0, 1], the predicate
+	 VAR != [0, 1] does not mean that VAR's range is ~[0, 1].
+	 Rather, it means that for value 0 VAR should be ~[0, 0]
+	 and for value 1, VAR should be ~[1, 1].  We cannot
+	 represent these ranges.
+	 The only situation in which we can build a valid
+	 anti-range is when LIMIT_VR is a single-valued range
+	 (i.e., LIMIT_VR->MIN == LIMIT_VR->MAX).  In that case,
+	 build the anti-range ~[LIMIT_VR->MIN, LIMIT_VR->MAX].  */
+if (limit_vr
+	  && limit_vr->kind () == VR_RANGE
+	  && compare_values (limit_vr->min (), limit_vr->max ()) == 0)
+	{
+	  min = limit_vr->min ();
+	  max = limit_vr->max ();
+	}
+else
+	{
+	  /* In any other case, we cannot use LIMIT's range to build a
+	     valid anti-range.  */
+	  min = max = limit;
+	}
+/* If MIN and MAX cover the whole range for their type, then
+	 just use the original LIMIT.  */
+if (INTEGRAL_TYPE_P (type)
+	  && vrp_val_is_min (min)
+	  && vrp_val_is_max (max))
+	min = max = limit;
+vr_p->set_and_canonicalize (VR_ANTI_RANGE, min, max, vr_p->equiv ());
+}
+else if (cond_code == LE_EXPR || cond_code == LT_EXPR)
+{
+min = TYPE_MIN_VALUE (type);
+if (limit_vr == NULL || limit_vr->kind () == VR_ANTI_RANGE)
+	max = limit;
+else
+	{
+	  /* If LIMIT_VR is of the form [N1, N2], we need to build the
+	     range [MIN, N2] for LE_EXPR and [MIN, N2 - 1] for
+	     LT_EXPR.  */
+	  max = limit_vr->max ();
+	}
+/* If the maximum value forces us to be out of bounds, simply punt.
+	 It would be pointless to try and do anything more since this
+	 all should be optimized away above us.  */
+if (cond_code == LT_EXPR
+	  && compare_values (max, min) == 0)
+	set_value_range_to_varying (vr_p);
+else
+	{
+	  /* For LT_EXPR, we create the range [MIN, MAX - 1].  */
+	  if (cond_code == LT_EXPR)
+	    {
+	      if (TYPE_PRECISION (TREE_TYPE (max)) == 1
+		  && !TYPE_UNSIGNED (TREE_TYPE (max)))
+		max = fold_build2 (PLUS_EXPR, TREE_TYPE (max), max,
+				   build_int_cst (TREE_TYPE (max), -1));
+	      else
+		max = fold_build2 (MINUS_EXPR, TREE_TYPE (max), max,
+				   build_int_cst (TREE_TYPE (max), 1));
+	      /* Signal to compare_values_warnv this expr doesn't overflow.  */
+	      if (EXPR_P (max))
+		TREE_NO_WARNING (max) = 1;
+	    }
+	  vr_p->update (VR_RANGE, min, max);
+	}
+}
+else if (cond_code == GE_EXPR || cond_code == GT_EXPR)
+{
+max = TYPE_MAX_VALUE (type);
+if (limit_vr == NULL || limit_vr->kind () == VR_ANTI_RANGE)
+	min = limit;
+else
+	{
+	  /* If LIMIT_VR is of the form [N1, N2], we need to build the
+	     range [N1, MAX] for GE_EXPR and [N1 + 1, MAX] for
+	     GT_EXPR.  */
+	  min = limit_vr->min ();
+	}
+/* If the minimum value forces us to be out of bounds, simply punt.
+	 It would be pointless to try and do anything more since this
+	 all should be optimized away above us.  */
+if (cond_code == GT_EXPR
+	  && compare_values (min, max) == 0)
+	set_value_range_to_varying (vr_p);
+else
+	{
+	  /* For GT_EXPR, we create the range [MIN + 1, MAX].  */
+	  if (cond_code == GT_EXPR)
+	    {
+	      if (TYPE_PRECISION (TREE_TYPE (min)) == 1
+		  && !TYPE_UNSIGNED (TREE_TYPE (min)))
+		min = fold_build2 (MINUS_EXPR, TREE_TYPE (min), min,
+				   build_int_cst (TREE_TYPE (min), -1));
+	      else
+		min = fold_build2 (PLUS_EXPR, TREE_TYPE (min), min,
+				   build_int_cst (TREE_TYPE (min), 1));
+	      /* Signal to compare_values_warnv this expr doesn't overflow.  */
+	      if (EXPR_P (min))
+		TREE_NO_WARNING (min) = 1;
+	    }
+	  vr_p->update (VR_RANGE, min, max);
+	}
+}
+else
+gcc_unreachable ();
+/* Finally intersect the new range with what we already know about var.  */
+vr_p->intersect (get_value_range (var));
+}
+/* Extract value range information from an ASSERT_EXPR EXPR and store
+it in *VR_P.  */
+void
+vr_values::extract_range_from_assert (value_range *vr_p, tree expr)
+{
+tree var = ASSERT_EXPR_VAR (expr);
+tree cond = ASSERT_EXPR_COND (expr);
+tree limit, op;
+enum tree_code cond_code;
+gcc_assert (COMPARISON_CLASS_P (cond));
+/* Find VAR in the ASSERT_EXPR conditional.  */
+if (var == TREE_OPERAND (cond, 0)
+|| TREE_CODE (TREE_OPERAND (cond, 0)) == PLUS_EXPR
+|| TREE_CODE (TREE_OPERAND (cond, 0)) == NOP_EXPR)
+{
+/* If the predicate is of the form VAR COMP LIMIT, then we just
+	 take LIMIT from the RHS and use the same comparison code.  */
+cond_code = TREE_CODE (cond);
+limit = TREE_OPERAND (cond, 1);
+op = TREE_OPERAND (cond, 0);
+}
+else
+{
+/* If the predicate is of the form LIMIT COMP VAR, then we need
+	 to flip around the comparison code to create the proper range
+	 for VAR.  */
+cond_code = swap_tree_comparison (TREE_CODE (cond));
+limit = TREE_OPERAND (cond, 0);
+op = TREE_OPERAND (cond, 1);
+}
+extract_range_for_var_from_comparison_expr (var, cond_code, op,
+					      limit, vr_p);
+}
+/* Extract range information from SSA name VAR and store it in VR.  If
+VAR has an interesting range, use it.  Otherwise, create the
+range [VAR, VAR] and return it.  This is useful in situations where
+we may have conditionals testing values of VARYING names.  For
+instance,
+	x_3 = y_5;
+	if (x_3 > y_5)
+	  ...
+Even if y_5 is deemed VARYING, we can determine that x_3 > y_5 is
+always false.  */
+void
+vr_values::extract_range_from_ssa_name (value_range *vr, tree var)
+{
+value_range *var_vr = get_value_range (var);
+if (!var_vr->varying_p ())
+vr->deep_copy (var_vr);
+else
+set_value_range (vr, VR_RANGE, var, var, NULL);
+vr->equiv_add (var, get_value_range (var), &vrp_equiv_obstack);
+}
+/* Extract range information from a binary expression OP0 CODE OP1 based on
+the ranges of each of its operands with resulting type EXPR_TYPE.
+The resulting range is stored in *VR.  */
+void
+vr_values::extract_range_from_binary_expr (value_range *vr,
+					   enum tree_code code,
+					   tree expr_type, tree op0, tree op1)
+{
+/* Get value ranges for each operand.  For constant operands, create
+a new value range with the operand to simplify processing.  */
+value_range vr0, vr1;
+if (TREE_CODE (op0) == SSA_NAME)
+vr0 = *(get_value_range (op0));
+else if (is_gimple_min_invariant (op0))
+set_value_range_to_value (&vr0, op0, NULL);
+else
+set_value_range_to_varying (&vr0);
+if (TREE_CODE (op1) == SSA_NAME)
+vr1 = *(get_value_range (op1));
+else if (is_gimple_min_invariant (op1))
+set_value_range_to_value (&vr1, op1, NULL);
+else
+set_value_range_to_varying (&vr1);
+/* If one argument is varying, we can sometimes still deduce a
+range for the output: any + [3, +INF] is in [MIN+3, +INF].  */
+if (INTEGRAL_TYPE_P (TREE_TYPE (op0))
+&& TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (op0)))
+{
+if (vr0.varying_p () && !vr1.varying_p ())
+	vr0 = value_range (VR_RANGE,
+			   vrp_val_min (expr_type),
+			   vrp_val_max (expr_type));
+else if (vr1.varying_p () && !vr0.varying_p ())
+	vr1 = value_range (VR_RANGE,
+			   vrp_val_min (expr_type),
+			   vrp_val_max (expr_type));
+}
+extract_range_from_binary_expr_1 (vr, code, expr_type, &vr0, &vr1);
+/* Set value_range for n in following sequence:
+def = __builtin_memchr (arg, 0, sz)
+n = def - arg
+Here the range for n can be set to [0, PTRDIFF_MAX - 1]. */
+if (vr->varying_p ()
+&& code == POINTER_DIFF_EXPR
+&& TREE_CODE (op0) == SSA_NAME
+&& TREE_CODE (op1) == SSA_NAME)
+{
+tree op0_ptype = TREE_TYPE (TREE_TYPE (op0));
+tree op1_ptype = TREE_TYPE (TREE_TYPE (op1));
+gcall *call_stmt = NULL;
+if (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)
+	  && (call_stmt = dyn_cast<gcall *>(SSA_NAME_DEF_STMT (op0)))
+	  && gimple_call_builtin_p (call_stmt, BUILT_IN_MEMCHR)
+	  && operand_equal_p (op0, gimple_call_lhs (call_stmt), 0)
+	  && operand_equal_p (op1, gimple_call_arg (call_stmt, 0), 0)
+	  && integer_zerop (gimple_call_arg (call_stmt, 1)))
+	    {
+	      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 (expr_type);
+	      tree range_max = wide_int_to_tree (expr_type, wmax - 1);
+	      set_value_range (vr, VR_RANGE, range_min, range_max, NULL);
+	      return;
+	    }
+}
+/* Try harder for PLUS and MINUS if the range of one operand is symbolic
+and based on the other operand, for example if it was deduced from a
+symbolic comparison.  When a bound of the range of the first operand
+is invariant, we set the corresponding bound of the new range to INF
+in order to avoid recursing on the range of the second operand.  */
+if (vr->varying_p ()
+&& (code == PLUS_EXPR || code == MINUS_EXPR)
+&& TREE_CODE (op1) == SSA_NAME
+&& vr0.kind () == VR_RANGE
+&& symbolic_range_based_on_p (&vr0, op1))
+{
+const bool minus_p = (code == MINUS_EXPR);
+value_range n_vr1;
+/* Try with VR0 and [-INF, OP1].  */
+if (is_gimple_min_invariant (minus_p ? vr0.max () : vr0.min ()))
+	set_value_range (&n_vr1, VR_RANGE, vrp_val_min (expr_type), op1, NULL);
+/* Try with VR0 and [OP1, +INF].  */
+else if (is_gimple_min_invariant (minus_p ? vr0.min () : vr0.max ()))
+	set_value_range (&n_vr1, VR_RANGE, op1, vrp_val_max (expr_type), NULL);
+/* Try with VR0 and [OP1, OP1].  */
+else
+	set_value_range (&n_vr1, VR_RANGE, op1, op1, NULL);
+extract_range_from_binary_expr_1 (vr, code, expr_type, &vr0, &n_vr1);
+}
+if (vr->varying_p ()
+&& (code == PLUS_EXPR || code == MINUS_EXPR)
+&& TREE_CODE (op0) == SSA_NAME
+&& vr1.kind () == VR_RANGE
+&& symbolic_range_based_on_p (&vr1, op0))
+{
+const bool minus_p = (code == MINUS_EXPR);
+value_range n_vr0;
+/* Try with [-INF, OP0] and VR1.  */
+if (is_gimple_min_invariant (minus_p ? vr1.max () : vr1.min ()))
+	set_value_range (&n_vr0, VR_RANGE, vrp_val_min (expr_type), op0, NULL);
+/* Try with [OP0, +INF] and VR1.  */
+else if (is_gimple_min_invariant (minus_p ? vr1.min (): vr1.max ()))
+	set_value_range (&n_vr0, VR_RANGE, op0, vrp_val_max (expr_type), NULL);
+/* Try with [OP0, OP0] and VR1.  */
+else
+	set_value_range (&n_vr0, VR_RANGE, op0, op0, NULL);
+extract_range_from_binary_expr_1 (vr, code, expr_type, &n_vr0, &vr1);
+}
+/* If we didn't derive a range for MINUS_EXPR, and
+op1's range is ~[op0,op0] or vice-versa, then we
+can derive a non-null range.  This happens often for
+pointer subtraction.  */
+if (vr->varying_p ()
+&& (code == MINUS_EXPR || code == POINTER_DIFF_EXPR)
+&& TREE_CODE (op0) == SSA_NAME
+&& ((vr0.kind () == VR_ANTI_RANGE
+	   && vr0.min () == op1
+	   && vr0.min () == vr0.max ())
+	  || (vr1.kind () == VR_ANTI_RANGE
+	      && vr1.min () == op0
+	      && vr1.min () == vr1.max ())))
+set_value_range_to_nonnull (vr, expr_type);
+}
+/* Extract range information from a unary expression CODE OP0 based on
+the range of its operand with resulting type TYPE.
+The resulting range is stored in *VR.  */
+void
+vr_values::extract_range_from_unary_expr (value_range *vr, enum tree_code code,
+					  tree type, tree op0)
+{
+value_range vr0;
+/* Get value ranges for the operand.  For constant operands, create
+a new value range with the operand to simplify processing.  */
+if (TREE_CODE (op0) == SSA_NAME)
+vr0 = *(get_value_range (op0));
+else if (is_gimple_min_invariant (op0))
+set_value_range_to_value (&vr0, op0, NULL);
+else
+set_value_range_to_varying (&vr0);
+::extract_range_from_unary_expr (vr, code, type, &vr0, TREE_TYPE (op0));
+}
+/* Extract range information from a conditional expression STMT based on
+the ranges of each of its operands and the expression code.  */
+void
+vr_values::extract_range_from_cond_expr (value_range *vr, gassign *stmt)
+{
+/* Get value ranges for each operand.  For constant operands, create
+a new value range with the operand to simplify processing.  */
+tree op0 = gimple_assign_rhs2 (stmt);
+value_range vr0;
+if (TREE_CODE (op0) == SSA_NAME)
+vr0 = *(get_value_range (op0));
+else if (is_gimple_min_invariant (op0))
+set_value_range_to_value (&vr0, op0, NULL);
+else
+set_value_range_to_varying (&vr0);
+tree op1 = gimple_assign_rhs3 (stmt);
+value_range vr1;
+if (TREE_CODE (op1) == SSA_NAME)
+vr1 = *(get_value_range (op1));
+else if (is_gimple_min_invariant (op1))
+set_value_range_to_value (&vr1, op1, NULL);
+else
+set_value_range_to_varying (&vr1);
+/* The resulting value range is the union of the operand ranges */
+vr->deep_copy (&vr0);
+vr->union_ (&vr1);
+}
+/* Extract range information from a comparison expression EXPR based
+on the range of its operand and the expression code.  */
+void
+vr_values::extract_range_from_comparison (value_range *vr, enum tree_code code,
+					  tree type, tree op0, tree op1)
+{
+bool sop;
+tree val;
+val = vrp_evaluate_conditional_warnv_with_ops (code, op0, op1, false, &sop,
+						 NULL);
+if (val)
+{
+/* Since this expression was found on the RHS of an assignment,
+	 its type may be different from _Bool.  Convert VAL to EXPR's
+	 type.  */
+val = fold_convert (type, val);
+if (is_gimple_min_invariant (val))
+	set_value_range_to_value (vr, val, vr->equiv ());
+else
+	vr->update (VR_RANGE, val, val);
+}
+else
+/* The result of a comparison is always true or false.  */
+set_value_range_to_truthvalue (vr, type);
+}
+/* Helper function for simplify_internal_call_using_ranges and
+extract_range_basic.  Return true if OP0 SUBCODE OP1 for
+SUBCODE {PLUS,MINUS,MULT}_EXPR is known to never overflow or
+always overflow.  Set *OVF to true if it is known to always
+overflow.  */
+bool
+vr_values::check_for_binary_op_overflow (enum tree_code subcode, tree type,
+					 tree op0, tree op1, bool *ovf)
+{
+value_range vr0, vr1;
+if (TREE_CODE (op0) == SSA_NAME)
+vr0 = *get_value_range (op0);
+else if (TREE_CODE (op0) == INTEGER_CST)
+set_value_range_to_value (&vr0, op0, NULL);
+else
+set_value_range_to_varying (&vr0);
+if (TREE_CODE (op1) == SSA_NAME)
+vr1 = *get_value_range (op1);
+else if (TREE_CODE (op1) == INTEGER_CST)
+set_value_range_to_value (&vr1, op1, NULL);
+else
+set_value_range_to_varying (&vr1);
+tree vr0min = vr0.min (), vr0max = vr0.max ();
+tree vr1min = vr1.min (), vr1max = vr1.max ();
+if (!range_int_cst_p (&vr0)
+|| TREE_OVERFLOW (vr0min)
+|| TREE_OVERFLOW (vr0max))
+{
+vr0min = vrp_val_min (TREE_TYPE (op0));
+vr0max = vrp_val_max (TREE_TYPE (op0));
+}
+if (!range_int_cst_p (&vr1)
+|| TREE_OVERFLOW (vr1min)
+|| TREE_OVERFLOW (vr1max))
+{
+vr1min = vrp_val_min (TREE_TYPE (op1));
+vr1max = vrp_val_max (TREE_TYPE (op1));
+}
+*ovf = arith_overflowed_p (subcode, type, vr0min,
+			     subcode == MINUS_EXPR ? vr1max : vr1min);
+if (arith_overflowed_p (subcode, type, vr0max,
+			  subcode == MINUS_EXPR ? vr1min : vr1max) != *ovf)
+return false;
+if (subcode == MULT_EXPR)
+{
+if (arith_overflowed_p (subcode, type, vr0min, vr1max) != *ovf
+	  || arith_overflowed_p (subcode, type, vr0max, vr1min) != *ovf)
+	return false;
+}
+if (*ovf)
+{
+/* So far we found that there is an overflow on the boundaries.
+	 That doesn't prove that there is an overflow even for all values
+	 in between the boundaries.  For that compute widest_int range
+	 of the result and see if it doesn't overlap the range of
+	 type.  */
+widest_int wmin, wmax;
+widest_int w[4];
+int i;
+w[0] = wi::to_widest (vr0min);
+w[1] = wi::to_widest (vr0max);
+w[2] = wi::to_widest (vr1min);
+w[3] = wi::to_widest (vr1max);
+for (i = 0; i < 4; i++)
+	{
+	  widest_int wt;
+	  switch (subcode)
+	    {
+	    case PLUS_EXPR:
+	      wt = wi::add (w[i & 1], w[2 + (i & 2) / 2]);
+	      break;
+	    case MINUS_EXPR:
+	      wt = wi::sub (w[i & 1], w[2 + (i & 2) / 2]);
+	      break;
+	    case MULT_EXPR:
+	      wt = wi::mul (w[i & 1], w[2 + (i & 2) / 2]);
+	      break;
+	    default:
+	      gcc_unreachable ();
+	    }
+	  if (i == 0)
+	    {
+	      wmin = wt;
+	      wmax = wt;
+	    }
+	  else
+	    {
+	      wmin = wi::smin (wmin, wt);
+	      wmax = wi::smax (wmax, wt);
+	    }
+	}
+/* The result of op0 CODE op1 is known to be in range
+	 [wmin, wmax].  */
+widest_int wtmin = wi::to_widest (vrp_val_min (type));
+widest_int wtmax = wi::to_widest (vrp_val_max (type));
+/* If all values in [wmin, wmax] are smaller than
+	 [wtmin, wtmax] or all are larger than [wtmin, wtmax],
+	 the arithmetic operation will always overflow.  */
+if (wmax < wtmin || wmin > wtmax)
+	return true;
+return false;
+}
+return true;
+}
+/* Try to derive a nonnegative or nonzero range out of STMT relying
+primarily on generic routines in fold in conjunction with range data.
+Store the result in *VR */
+void
+vr_values::extract_range_basic (value_range *vr, gimple *stmt)
+{
+bool sop;
+tree type = gimple_expr_type (stmt);
+if (is_gimple_call (stmt))
+{
+tree arg;
+int mini, maxi, zerov = 0, prec;
+enum tree_code subcode = ERROR_MARK;
+combined_fn cfn = gimple_call_combined_fn (stmt);
+scalar_int_mode mode;
+switch (cfn)
+	{
+	case CFN_BUILT_IN_CONSTANT_P:
+	  /* If the call is __builtin_constant_p and the argument is a
+	     function parameter resolve it to false.  This avoids bogus
+	     array bound warnings.
+	     ???  We could do this as early as inlining is finished.  */
+	  arg = gimple_call_arg (stmt, 0);
+	  if (TREE_CODE (arg) == SSA_NAME
+	      && SSA_NAME_IS_DEFAULT_DEF (arg)
+	      && TREE_CODE (SSA_NAME_VAR (arg)) == PARM_DECL
+	      && cfun->after_inlining)
+	    {
+	      set_value_range_to_null (vr, type);
+	      return;
+	    }
+	  break;
+	  /* Both __builtin_ffs* and __builtin_popcount return
+	     [0, prec].  */
+	CASE_CFN_FFS:
+	CASE_CFN_POPCOUNT:
+	  arg = gimple_call_arg (stmt, 0);
+	  prec = TYPE_PRECISION (TREE_TYPE (arg));
+	  mini = 0;
+	  maxi = prec;
+	  if (TREE_CODE (arg) == SSA_NAME)
+	    {
+	      value_range *vr0 = get_value_range (arg);
+	      /* If arg is non-zero, then ffs or popcount are non-zero.  */
+	      if (range_includes_zero_p (vr0) == 0)
+		mini = 1;
+	      /* If some high bits are known to be zero,
+		 we can decrease the maximum.  */
+	      if (vr0->kind () == VR_RANGE
+		  && TREE_CODE (vr0->max ()) == INTEGER_CST
+		  && !operand_less_p (vr0->min (),
+				      build_zero_cst (TREE_TYPE (vr0->min ()))))
+		maxi = tree_floor_log2 (vr0->max ()) + 1;
+	    }
+	  goto bitop_builtin;
+	  /* __builtin_parity* returns [0, 1].  */
+	CASE_CFN_PARITY:
+	  mini = 0;
+	  maxi = 1;
+	  goto bitop_builtin;
+	  /* __builtin_c[lt]z* return [0, prec-1], except for
+	     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.  */
+	CASE_CFN_CLZ:
+	  arg = gimple_call_arg (stmt, 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)
+	      /* Handle only the single common value.  */
+	      && zerov != prec)
+	    /* Magic value to give up, unless vr0 proves
+	       arg is non-zero.  */
+	    mini = -2;
+	  if (TREE_CODE (arg) == SSA_NAME)
+	    {
+	      value_range *vr0 = get_value_range (arg);
+	      /* From clz of VR_RANGE minimum we can compute
+		 result maximum.  */
+	      if (vr0->kind () == VR_RANGE
+		  && TREE_CODE (vr0->min ()) == INTEGER_CST)
+		{
+		  maxi = prec - 1 - tree_floor_log2 (vr0->min ());
+		  if (maxi != prec)
+		    mini = 0;
+		}
+	      else if (vr0->kind () == VR_ANTI_RANGE
+		       && integer_zerop (vr0->min ()))
+		{
+		  maxi = prec - 1;
+		  mini = 0;
+		}
+	      if (mini == -2)
+		break;
+	      /* From clz of VR_RANGE maximum we can compute
+		 result minimum.  */
+	      if (vr0->kind () == VR_RANGE
+		  && TREE_CODE (vr0->max ()) == INTEGER_CST)
+		{
+		  mini = prec - 1 - tree_floor_log2 (vr0->max ());
+		  if (mini == prec)
+		    break;
+		}
+	    }
+	  if (mini == -2)
+	    break;
+	  goto bitop_builtin;
+	  /* __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.  */
+	CASE_CFN_CTZ:
+	  arg = gimple_call_arg (stmt, 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 vr0 proves
+		   arg is non-zero.  */
+		mini = -2;
+	    }
+	  if (TREE_CODE (arg) == SSA_NAME)
+	    {
+	      value_range *vr0 = get_value_range (arg);
+	      /* If arg is non-zero, then use [0, prec - 1].  */
+	      if ((vr0->kind () == VR_RANGE
+		   && integer_nonzerop (vr0->min ()))
+		  || (vr0->kind () == VR_ANTI_RANGE
+		      && integer_zerop (vr0->min ())))
+		{
+		  mini = 0;
+		  maxi = prec - 1;
+		}
+	      /* If some high bits are known to be zero,
+		 we can decrease the result maximum.  */
+	      if (vr0->kind () == VR_RANGE
+		  && TREE_CODE (vr0->max ()) == INTEGER_CST)
+		{
+		  maxi = tree_floor_log2 (vr0->max ());
+		  /* For vr0 [0, 0] give up.  */
+		  if (maxi == -1)
+		    break;
+		}
+	    }
+	  if (mini == -2)
+	    break;
+	  goto bitop_builtin;
+	  /* __builtin_clrsb* returns [0, prec-1].  */
+	CASE_CFN_CLRSB:
+	  arg = gimple_call_arg (stmt, 0);
+	  prec = TYPE_PRECISION (TREE_TYPE (arg));
+	  mini = 0;
+	  maxi = prec - 1;
+	  goto bitop_builtin;
+	bitop_builtin:
+	  set_value_range (vr, VR_RANGE, build_int_cst (type, mini),
+			   build_int_cst (type, maxi), NULL);
+	  return;
+	case CFN_UBSAN_CHECK_ADD:
+	  subcode = PLUS_EXPR;
+	  break;
+	case CFN_UBSAN_CHECK_SUB:
+	  subcode = MINUS_EXPR;
+	  break;
+	case CFN_UBSAN_CHECK_MUL:
+	  subcode = MULT_EXPR;
+	  break;
+	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 = cfn == CFN_GOACC_DIM_POS;
+	    int axis = oacc_get_ifn_dim_arg (stmt);
+	    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);
+	    tree type = TREE_TYPE (gimple_call_lhs (stmt));
+	    set_value_range (vr, VR_RANGE,
+			     build_int_cst (type, is_pos ? 0 : 1),
+			     size ? build_int_cst (type, size - is_pos)
+			          : vrp_val_max (type), NULL);
+	  }
+	  return;
+	case CFN_BUILT_IN_STRLEN:
+	  if (tree lhs = gimple_call_lhs (stmt))
+	    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);
+		tree range_max = wide_int_to_tree (type, wmax - 1);
+		set_value_range (vr, VR_RANGE, range_min, range_max, NULL);
+		return;
+	      }
+	  break;
+	default:
+	  break;
+	}
+if (subcode != ERROR_MARK)
+	{
+	  bool saved_flag_wrapv = flag_wrapv;
+	  /* Pretend the arithmetics is wrapping.  If there is
+	     any overflow, we'll complain, but will actually do
+	     wrapping operation.  */
+	  flag_wrapv = 1;
+	  extract_range_from_binary_expr (vr, subcode, type,
+					  gimple_call_arg (stmt, 0),
+					  gimple_call_arg (stmt, 1));
+	  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 (vr->kind () == VR_RANGE
+	      && (vr->min () == vr->max ()
+		  || operand_equal_p (vr->min (), vr->max (), 0)))
+	    set_value_range_to_varying (vr);
+	  return;
+	}
+}
+/* Handle extraction of the two results (result of arithmetics and
+a flag whether arithmetics overflowed) from {ADD,SUB,MUL}_OVERFLOW
+internal function.  Similarly from ATOMIC_COMPARE_EXCHANGE.  */
+else if (is_gimple_assign (stmt)
+	   && (gimple_assign_rhs_code (stmt) == REALPART_EXPR
+	       || gimple_assign_rhs_code (stmt) == IMAGPART_EXPR)
+	   && INTEGRAL_TYPE_P (type))
+{
+enum tree_code code = gimple_assign_rhs_code (stmt);
+tree op = gimple_assign_rhs1 (stmt);
+if (TREE_CODE (op) == code && TREE_CODE (TREE_OPERAND (op, 0)) == SSA_NAME)
+	{
+	  gimple *g = SSA_NAME_DEF_STMT (TREE_OPERAND (op, 0));
+	  if (is_gimple_call (g) && gimple_call_internal_p (g))
+	    {
+	      enum tree_code subcode = ERROR_MARK;
+	      switch (gimple_call_internal_fn (g))
+		{
+		case IFN_ADD_OVERFLOW:
+		  subcode = PLUS_EXPR;
+		  break;
+		case IFN_SUB_OVERFLOW:
+		  subcode = MINUS_EXPR;
+		  break;
+		case IFN_MUL_OVERFLOW:
+		  subcode = MULT_EXPR;
+		  break;
+		case IFN_ATOMIC_COMPARE_EXCHANGE:
+		  if (code == IMAGPART_EXPR)
+		    {
+		      /* This is the boolean return value whether compare and
+			 exchange changed anything or not.  */
+		      set_value_range (vr, VR_RANGE, build_int_cst (type, 0),
+				       build_int_cst (type, 1), NULL);
+		      return;
+		    }
+		  break;
+		default:
+		  break;
+		}
+	      if (subcode != ERROR_MARK)
+		{
+		  tree op0 = gimple_call_arg (g, 0);
+		  tree op1 = gimple_call_arg (g, 1);
+		  if (code == IMAGPART_EXPR)
+		    {
+		      bool ovf = false;
+		      if (check_for_binary_op_overflow (subcode, type,
+							op0, op1, &ovf))
+			set_value_range_to_value (vr,
+						  build_int_cst (type, ovf),
+						  NULL);
+		      else if (TYPE_PRECISION (type) == 1
+			       && !TYPE_UNSIGNED (type))
+			set_value_range_to_varying (vr);
+		      else
+			set_value_range (vr, VR_RANGE, build_int_cst (type, 0),
+					 build_int_cst (type, 1), NULL);
+		    }
+		  else if (types_compatible_p (type, TREE_TYPE (op0))
+			   && types_compatible_p (type, TREE_TYPE (op1)))
+		    {
+		      bool saved_flag_wrapv = flag_wrapv;
+		      /* Pretend the arithmetics is wrapping.  If there is
+			 any overflow, IMAGPART_EXPR will be set.  */
+		      flag_wrapv = 1;
+		      extract_range_from_binary_expr (vr, subcode, type,
+						      op0, op1);
+		      flag_wrapv = saved_flag_wrapv;
+		    }
+		  else
+		    {
+		      value_range vr0, vr1;
+		      bool saved_flag_wrapv = flag_wrapv;
+		      /* Pretend the arithmetics is wrapping.  If there is
+			 any overflow, IMAGPART_EXPR will be set.  */
+		      flag_wrapv = 1;
+		      extract_range_from_unary_expr (&vr0, NOP_EXPR,
+						     type, op0);
+		      extract_range_from_unary_expr (&vr1, NOP_EXPR,
+						     type, op1);
+		      extract_range_from_binary_expr_1 (vr, subcode, type,
+							&vr0, &vr1);
+		      flag_wrapv = saved_flag_wrapv;
+		    }
+		  return;
+		}
+	    }
+	}
+}
+if (INTEGRAL_TYPE_P (type)
+&& gimple_stmt_nonnegative_warnv_p (stmt, &sop))
+set_value_range_to_nonnegative (vr, type);
+else if (vrp_stmt_computes_nonzero (stmt))
+set_value_range_to_nonnull (vr, type);
+else
+set_value_range_to_varying (vr);
+}
+/* Try to compute a useful range out of assignment STMT and store it
+in *VR.  */
+void
+vr_values::extract_range_from_assignment (value_range *vr, gassign *stmt)
+{
+enum tree_code code = gimple_assign_rhs_code (stmt);
+if (code == ASSERT_EXPR)
+extract_range_from_assert (vr, gimple_assign_rhs1 (stmt));
+else if (code == SSA_NAME)
+extract_range_from_ssa_name (vr, gimple_assign_rhs1 (stmt));
+else if (TREE_CODE_CLASS (code) == tcc_binary)
+extract_range_from_binary_expr (vr, gimple_assign_rhs_code (stmt),
+				    gimple_expr_type (stmt),
+				    gimple_assign_rhs1 (stmt),
+				    gimple_assign_rhs2 (stmt));
+else if (TREE_CODE_CLASS (code) == tcc_unary)
+extract_range_from_unary_expr (vr, gimple_assign_rhs_code (stmt),
+				   gimple_expr_type (stmt),
+				   gimple_assign_rhs1 (stmt));
+else if (code == COND_EXPR)
+extract_range_from_cond_expr (vr, stmt);
+else if (TREE_CODE_CLASS (code) == tcc_comparison)
+extract_range_from_comparison (vr, gimple_assign_rhs_code (stmt),
+				   gimple_expr_type (stmt),
+				   gimple_assign_rhs1 (stmt),
+				   gimple_assign_rhs2 (stmt));
+else if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS
+	   && is_gimple_min_invariant (gimple_assign_rhs1 (stmt)))
+set_value_range_to_value (vr, gimple_assign_rhs1 (stmt), NULL);
+else
+set_value_range_to_varying (vr);
+if (vr->varying_p ())
+extract_range_basic (vr, stmt);
+}
+/* Given two numeric value ranges VR0, VR1 and a comparison code COMP:
+- Return BOOLEAN_TRUE_NODE if VR0 COMP VR1 always returns true for
+all the values in the ranges.
+- Return BOOLEAN_FALSE_NODE if the comparison always returns false.
+- Return NULL_TREE if it is not always possible to determine the
+value of the comparison.
+Also set *STRICT_OVERFLOW_P to indicate whether comparision evaluation
+assumed signed overflow is undefined.  */
+static tree
+compare_ranges (enum tree_code comp, value_range *vr0, value_range *vr1,
+		bool *strict_overflow_p)
+{
+/* VARYING or UNDEFINED ranges cannot be compared.  */
+if (vr0->varying_p ()
+|| vr0->undefined_p ()
+|| vr1->varying_p ()
+|| vr1->undefined_p ())
+return NULL_TREE;
+/* Anti-ranges need to be handled separately.  */
+if (vr0->kind () == VR_ANTI_RANGE || vr1->kind () == VR_ANTI_RANGE)
+{
+/* If both are anti-ranges, then we cannot compute any
+	 comparison.  */
+if (vr0->kind () == VR_ANTI_RANGE && vr1->kind () == VR_ANTI_RANGE)
+	return NULL_TREE;
+/* These comparisons are never statically computable.  */
+if (comp == GT_EXPR
+	  || comp == GE_EXPR
+	  || comp == LT_EXPR
+	  || comp == LE_EXPR)
+	return NULL_TREE;
+/* Equality can be computed only between a range and an
+	 anti-range.  ~[VAL1, VAL2] == [VAL1, VAL2] is always false.  */
+if (vr0->kind () == VR_RANGE)
+	{
+	  /* To simplify processing, make VR0 the anti-range.  */
+	  value_range *tmp = vr0;
+	  vr0 = vr1;
+	  vr1 = tmp;
+	}
+gcc_assert (comp == NE_EXPR || comp == EQ_EXPR);
+if (compare_values_warnv (vr0->min (), vr1->min (), strict_overflow_p) == 0
+	  && compare_values_warnv (vr0->max (), vr1->max (), strict_overflow_p) == 0)
+	return (comp == NE_EXPR) ? boolean_true_node : boolean_false_node;
+return NULL_TREE;
+}
+/* Simplify processing.  If COMP is GT_EXPR or GE_EXPR, switch the
+operands around and change the comparison code.  */
+if (comp == GT_EXPR || comp == GE_EXPR)
+{
+comp = (comp == GT_EXPR) ? LT_EXPR : LE_EXPR;
+std::swap (vr0, vr1);
+}
+if (comp == EQ_EXPR)
+{
+/* Equality may only be computed if both ranges represent
+	 exactly one value.  */
+if (compare_values_warnv (vr0->min (), vr0->max (), strict_overflow_p) == 0
+	  && compare_values_warnv (vr1->min (), vr1->max (), strict_overflow_p) == 0)
+	{
+	  int cmp_min = compare_values_warnv (vr0->min (), vr1->min (),
+					      strict_overflow_p);
+	  int cmp_max = compare_values_warnv (vr0->max (), vr1->max (),
+					      strict_overflow_p);
+	  if (cmp_min == 0 && cmp_max == 0)
+	    return boolean_true_node;
+	  else if (cmp_min != -2 && cmp_max != -2)
+	    return boolean_false_node;
+	}
+/* If [V0_MIN, V1_MAX] < [V1_MIN, V1_MAX] then V0 != V1.  */
+else if (compare_values_warnv (vr0->min (), vr1->max (),
+				     strict_overflow_p) == 1
+	       || compare_values_warnv (vr1->min (), vr0->max (),
+					strict_overflow_p) == 1)
+	return boolean_false_node;
+return NULL_TREE;
+}
+else if (comp == NE_EXPR)
+{
+int cmp1, cmp2;
+/* If VR0 is completely to the left or completely to the right
+	 of VR1, they are always different.  Notice that we need to
+	 make sure that both comparisons yield similar results to
+	 avoid comparing values that cannot be compared at
+	 compile-time.  */
+cmp1 = compare_values_warnv (vr0->max (), vr1->min (), strict_overflow_p);
+cmp2 = compare_values_warnv (vr0->min (), vr1->max (), strict_overflow_p);
+if ((cmp1 == -1 && cmp2 == -1) || (cmp1 == 1 && cmp2 == 1))
+	return boolean_true_node;
+/* If VR0 and VR1 represent a single value and are identical,
+	 return false.  */
+else if (compare_values_warnv (vr0->min (), vr0->max (),
+				     strict_overflow_p) == 0
+	       && compare_values_warnv (vr1->min (), vr1->max (),
+					strict_overflow_p) == 0
+	       && compare_values_warnv (vr0->min (), vr1->min (),
+					strict_overflow_p) == 0
+	       && compare_values_warnv (vr0->max (), vr1->max (),
+					strict_overflow_p) == 0)
+	return boolean_false_node;
+/* Otherwise, they may or may not be different.  */
+else
+	return NULL_TREE;
+}
+else if (comp == LT_EXPR || comp == LE_EXPR)
+{
+int tst;
+/* If VR0 is to the left of VR1, return true.  */
+tst = compare_values_warnv (vr0->max (), vr1->min (), strict_overflow_p);
+if ((comp == LT_EXPR && tst == -1)
+	  || (comp == LE_EXPR && (tst == -1 || tst == 0)))
+	return boolean_true_node;
+/* If VR0 is to the right of VR1, return false.  */
+tst = compare_values_warnv (vr0->min (), vr1->max (), strict_overflow_p);
+if ((comp == LT_EXPR && (tst == 0 || tst == 1))
+	  || (comp == LE_EXPR && tst == 1))
+	return boolean_false_node;
+/* Otherwise, we don't know.  */
+return NULL_TREE;
+}
+gcc_unreachable ();
+}
+/* Given a value range VR, a value VAL and a comparison code COMP, return
+BOOLEAN_TRUE_NODE if VR COMP VAL always returns true for all the
+values in VR.  Return BOOLEAN_FALSE_NODE if the comparison
+always returns false.  Return NULL_TREE if it is not always
+possible to determine the value of the comparison.  Also set
+*STRICT_OVERFLOW_P to indicate whether comparision evaluation
+assumed signed overflow is undefined.  */
+static tree
+compare_range_with_value (enum tree_code comp, value_range *vr, tree val,
+			  bool *strict_overflow_p)
+{
+if (vr->varying_p () || vr->undefined_p ())
+return NULL_TREE;
+/* Anti-ranges need to be handled separately.  */
+if (vr->kind () == VR_ANTI_RANGE)
+{
+/* For anti-ranges, the only predicates that we can compute at
+	 compile time are equality and inequality.  */
+if (comp == GT_EXPR
+	  || comp == GE_EXPR
+	  || comp == LT_EXPR
+	  || comp == LE_EXPR)
+	return NULL_TREE;
+/* ~[VAL_1, VAL_2] OP VAL is known if VAL_1 <= VAL <= VAL_2.  */
+if (value_inside_range (val, vr->min (), vr->max ()) == 1)
+	return (comp == NE_EXPR) ? boolean_true_node : boolean_false_node;
+return NULL_TREE;
+}
+if (comp == EQ_EXPR)
+{
+/* EQ_EXPR may only be computed if VR represents exactly
+	 one value.  */
+if (compare_values_warnv (vr->min (), vr->max (), strict_overflow_p) == 0)
+	{
+	  int cmp = compare_values_warnv (vr->min (), val, strict_overflow_p);
+	  if (cmp == 0)
+	    return boolean_true_node;
+	  else if (cmp == -1 || cmp == 1 || cmp == 2)
+	    return boolean_false_node;
+	}
+else if (compare_values_warnv (val, vr->min (), strict_overflow_p) == -1
+	       || compare_values_warnv (vr->max (), val, strict_overflow_p) == -1)
+	return boolean_false_node;
+return NULL_TREE;
+}
+else if (comp == NE_EXPR)
+{
+/* If VAL is not inside VR, then they are always different.  */
+if (compare_values_warnv (vr->max (), val, strict_overflow_p) == -1
+	  || compare_values_warnv (vr->min (), val, strict_overflow_p) == 1)
+	return boolean_true_node;
+/* If VR represents exactly one value equal to VAL, then return
+	 false.  */
+if (compare_values_warnv (vr->min (), vr->max (), strict_overflow_p) == 0
+	  && compare_values_warnv (vr->min (), val, strict_overflow_p) == 0)
+	return boolean_false_node;
+/* Otherwise, they may or may not be different.  */
+return NULL_TREE;
+}
+else if (comp == LT_EXPR || comp == LE_EXPR)
+{
+int tst;
+/* If VR is to the left of VAL, return true.  */
+tst = compare_values_warnv (vr->max (), val, strict_overflow_p);
+if ((comp == LT_EXPR && tst == -1)
+	  || (comp == LE_EXPR && (tst == -1 || tst == 0)))
+	return boolean_true_node;
+/* If VR is to the right of VAL, return false.  */
+tst = compare_values_warnv (vr->min (), val, strict_overflow_p);
+if ((comp == LT_EXPR && (tst == 0 || tst == 1))
+	  || (comp == LE_EXPR && tst == 1))
+	return boolean_false_node;
+/* Otherwise, we don't know.  */
+return NULL_TREE;
+}
+else if (comp == GT_EXPR || comp == GE_EXPR)
+{
+int tst;
+/* If VR is to the right of VAL, return true.  */
+tst = compare_values_warnv (vr->min (), val, strict_overflow_p);
+if ((comp == GT_EXPR && tst == 1)
+	  || (comp == GE_EXPR && (tst == 0 || tst == 1)))
+	return boolean_true_node;
+/* If VR is to the left of VAL, return false.  */
+tst = compare_values_warnv (vr->max (), val, strict_overflow_p);
+if ((comp == GT_EXPR && (tst == -1 || tst == 0))
+	  || (comp == GE_EXPR && tst == -1))
+	return boolean_false_node;
+/* Otherwise, we don't know.  */
+return NULL_TREE;
+}
+gcc_unreachable ();
+}
+/* Given a range VR, a LOOP and a variable VAR, determine whether it
+would be profitable to adjust VR using scalar evolution information
+for VAR.  If so, update VR with the new limits.  */
+void
+vr_values::adjust_range_with_scev (value_range *vr, struct loop *loop,
+				   gimple *stmt, tree var)
+{
+tree init, step, chrec, tmin, tmax, min, max, type, tem;
+enum ev_direction dir;
+/* TODO.  Don't adjust anti-ranges.  An anti-range may provide
+better opportunities than a regular range, but I'm not sure.  */
+if (vr->kind () == VR_ANTI_RANGE)
+return;
+chrec = instantiate_parameters (loop, analyze_scalar_evolution (loop, var));
+/* Like in PR19590, scev can return a constant function.  */
+if (is_gimple_min_invariant (chrec))
+{
+set_value_range_to_value (vr, chrec, vr->equiv ());
+return;
+}
+if (TREE_CODE (chrec) != POLYNOMIAL_CHREC)
+return;
+init = initial_condition_in_loop_num (chrec, loop->num);
+tem = op_with_constant_singleton_value_range (init);
+if (tem)
+init = tem;
+step = evolution_part_in_loop_num (chrec, loop->num);
+tem = op_with_constant_singleton_value_range (step);
+if (tem)
+step = tem;
+/* If STEP is symbolic, we can't know whether INIT will be the
+minimum or maximum value in the range.  Also, unless INIT is
+a simple expression, compare_values and possibly other functions
+in tree-vrp won't be able to handle it.  */
+if (step == NULL_TREE
+|| !is_gimple_min_invariant (step)
+|| !valid_value_p (init))
+return;
+dir = scev_direction (chrec);
+if (/* Do not adjust ranges if we do not know whether the iv increases
+	 or decreases,  ... */
+dir == EV_DIR_UNKNOWN
+/* ... or if it may wrap.  */
+|| scev_probably_wraps_p (NULL_TREE, init, step, stmt,
+				get_chrec_loop (chrec), true))
+return;
+type = TREE_TYPE (var);
+if (POINTER_TYPE_P (type) || !TYPE_MIN_VALUE (type))
+tmin = lower_bound_in_type (type, type);
+else
+tmin = TYPE_MIN_VALUE (type);
+if (POINTER_TYPE_P (type) || !TYPE_MAX_VALUE (type))
+tmax = upper_bound_in_type (type, type);
+else
+tmax = TYPE_MAX_VALUE (type);
+/* Try to use estimated number of iterations for the loop to constrain the
+final value in the evolution.  */
+if (TREE_CODE (step) == INTEGER_CST
+&& is_gimple_val (init)
+&& (TREE_CODE (init) != SSA_NAME
+	  || get_value_range (init)->kind () == VR_RANGE))
+{
+widest_int nit;
+/* We are only entering here for loop header PHI nodes, so using
+	 the number of latch executions is the correct thing to use.  */
+if (max_loop_iterations (loop, &nit))
+	{
+	  value_range maxvr;
+	  signop sgn = TYPE_SIGN (TREE_TYPE (step));
+	  wi::overflow_type overflow;
+	  widest_int wtmp = wi::mul (wi::to_widest (step), nit, sgn,
+				     &overflow);
+	  /* If the multiplication overflowed we can't do a meaningful
+	     adjustment.  Likewise if the result doesn't fit in the type
+	     of the induction variable.  For a signed type we have to
+	     check whether the result has the expected signedness which
+	     is that of the step as number of iterations is unsigned.  */
+	  if (!overflow
+	      && wi::fits_to_tree_p (wtmp, TREE_TYPE (init))
+	      && (sgn == UNSIGNED
+		  || wi::gts_p (wtmp, 0) == wi::gts_p (wi::to_wide (step), 0)))
+	    {
+	      tem = wide_int_to_tree (TREE_TYPE (init), wtmp);
+	      extract_range_from_binary_expr (&maxvr, PLUS_EXPR,
+					      TREE_TYPE (init), init, tem);
+	      /* Likewise if the addition did.  */
+	      if (maxvr.kind () == VR_RANGE)
+		{
+		  value_range initvr;
+		  if (TREE_CODE (init) == SSA_NAME)
+		    initvr = *(get_value_range (init));
+		  else if (is_gimple_min_invariant (init))
+		    set_value_range_to_value (&initvr, init, NULL);
+		  else
+		    return;
+		  /* Check if init + nit * step overflows.  Though we checked
+		     scev {init, step}_loop doesn't wrap, it is not enough
+		     because the loop may exit immediately.  Overflow could
+		     happen in the plus expression in this case.  */
+		  if ((dir == EV_DIR_DECREASES
+		       && compare_values (maxvr.min (), initvr.min ()) != -1)
+		      || (dir == EV_DIR_GROWS
+			  && compare_values (maxvr.max (), initvr.max ()) != 1))
+		    return;
+		  tmin = maxvr.min ();
+		  tmax = maxvr.max ();
+		}
+	    }
+	}
+}
+if (vr->varying_p () || vr->undefined_p ())
+{
+min = tmin;
+max = tmax;
+/* For VARYING or UNDEFINED ranges, just about anything we get
+	 from scalar evolutions should be better.  */
+if (dir == EV_DIR_DECREASES)
+	max = init;
+else
+	min = init;
+}
+else if (vr->kind () == VR_RANGE)
+{
+min = vr->min ();
+max = vr->max ();
+if (dir == EV_DIR_DECREASES)
+	{
+	  /* INIT is the maximum value.  If INIT is lower than VR->MAX ()
+	     but no smaller than VR->MIN (), set VR->MAX () to INIT.  */
+	  if (compare_values (init, max) == -1)
+	    max = init;
+	  /* According to the loop information, the variable does not
+	     overflow.  */
+	  if (compare_values (min, tmin) == -1)
+	    min = tmin;
+	}
+else
+	{
+	  /* If INIT is bigger than VR->MIN (), set VR->MIN () to INIT.  */
+	  if (compare_values (init, min) == 1)
+	    min = init;
+	  if (compare_values (tmax, max) == -1)
+	    max = tmax;
+	}
+}
+else
+return;
+/* If we just created an invalid range with the minimum
+greater than the maximum, we fail conservatively.
+This should happen only in unreachable
+parts of code, or for invalid programs.  */
+if (compare_values (min, max) == 1)
+return;
+/* Even for valid range info, sometimes overflow flag will leak in.
+As GIMPLE IL should have no constants with TREE_OVERFLOW set, we
+drop them.  */
+if (TREE_OVERFLOW_P (min))
+min = drop_tree_overflow (min);
+if (TREE_OVERFLOW_P (max))
+max = drop_tree_overflow (max);
+vr->update (VR_RANGE, min, max);
+}
+/* Dump value ranges of all SSA_NAMEs to FILE.  */
+void
+vr_values::dump_all_value_ranges (FILE *file)
+{
+size_t i;
+for (i = 0; i < num_vr_values; i++)
+{
+if (vr_value[i])
+	{
+	  print_generic_expr (file, ssa_name (i));
+	  fprintf (file, ": ");
+	  dump_value_range (file, vr_value[i]);
+	  fprintf (file, "\n");
+	}
+}
+fprintf (file, "\n");
+}
+/* Initialize VRP lattice.  */
+vr_values::vr_values () : vrp_value_range_pool ("Tree VRP value ranges")
+{
+values_propagated = false;
+num_vr_values = num_ssa_names;
+vr_value = XCNEWVEC (value_range *, num_vr_values);
+vr_phi_edge_counts = XCNEWVEC (int, num_ssa_names);
+bitmap_obstack_initialize (&vrp_equiv_obstack);
+to_remove_edges = vNULL;
+to_update_switch_stmts = vNULL;
+}
+/* Free VRP lattice.  */
+vr_values::~vr_values ()
+{
+/* Free allocated memory.  */
+free (vr_value);
+free (vr_phi_edge_counts);
+bitmap_obstack_release (&vrp_equiv_obstack);
+vrp_value_range_pool.release ();
+/* So that we can distinguish between VRP data being available
+and not available.  */
+vr_value = NULL;
+vr_phi_edge_counts = NULL;
+/* If there are entries left in TO_REMOVE_EDGES or TO_UPDATE_SWITCH_STMTS
+then an EVRP client did not clean up properly.  Catch it now rather
+than seeing something more obscure later.  */
+gcc_assert (to_remove_edges.is_empty ()
+	      && to_update_switch_stmts.is_empty ());
+}
+/* A hack.  */
+static class vr_values *x_vr_values;
+/* Return the singleton value-range for NAME or NAME.  */
+static inline tree
+vrp_valueize (tree name)
+{
+if (TREE_CODE (name) == SSA_NAME)
+{
+value_range *vr = x_vr_values->get_value_range (name);
+if (vr->kind () == VR_RANGE
+	  && (TREE_CODE (vr->min ()) == SSA_NAME
+	      || is_gimple_min_invariant (vr->min ()))
+	  && vrp_operand_equal_p (vr->min (), vr->max ()))
+	return vr->min ();
+}
+return name;
+}
+/* Return the singleton value-range for NAME if that is a constant
+but signal to not follow SSA edges.  */
+static inline tree
+vrp_valueize_1 (tree name)
+{
+if (TREE_CODE (name) == SSA_NAME)
+{
+/* If the definition may be simulated again we cannot follow
+this SSA edge as the SSA propagator does not necessarily
+	 re-visit the use.  */
+gimple *def_stmt = SSA_NAME_DEF_STMT (name);
+if (!gimple_nop_p (def_stmt)
+	  && prop_simulate_again_p (def_stmt))
+	return NULL_TREE;
+value_range *vr = x_vr_values->get_value_range (name);
+tree singleton;
+if (vr->singleton_p (&singleton))
+	return singleton;
+}
+return name;
+}
+/* Given STMT, an assignment or call, return its LHS if the type
+of the LHS is suitable for VRP analysis, else return NULL_TREE.  */
+tree
+get_output_for_vrp (gimple *stmt)
+{
+if (!is_gimple_assign (stmt) && !is_gimple_call (stmt))
+return NULL_TREE;
+/* We only keep track of ranges in integral and pointer types.  */
+tree lhs = gimple_get_lhs (stmt);
+if (TREE_CODE (lhs) == SSA_NAME
+&& ((INTEGRAL_TYPE_P (TREE_TYPE (lhs))
+	   /* It is valid to have NULL MIN/MAX values on a type.  See
+	      build_range_type.  */
+	   && TYPE_MIN_VALUE (TREE_TYPE (lhs))
+	   && TYPE_MAX_VALUE (TREE_TYPE (lhs)))
+	  || POINTER_TYPE_P (TREE_TYPE (lhs))))
+return lhs;
+return NULL_TREE;
+}
+/* Visit assignment STMT.  If it produces an interesting range, record
+the range in VR and set LHS to OUTPUT_P.  */
+void
+vr_values::vrp_visit_assignment_or_call (gimple *stmt, tree *output_p,
+					 value_range *vr)
+{
+tree lhs = get_output_for_vrp (stmt);
+*output_p = lhs;
+/* We only keep track of ranges in integral and pointer types.  */
+if (lhs)
+{
+enum gimple_code code = gimple_code (stmt);
+/* Try folding the statement to a constant first.  */
+x_vr_values = this;
+tree tem = gimple_fold_stmt_to_constant_1 (stmt, vrp_valueize,
+						 vrp_valueize_1);
+x_vr_values = NULL;
+if (tem)
+	{
+	  if (TREE_CODE (tem) == SSA_NAME
+	      && (SSA_NAME_IS_DEFAULT_DEF (tem)
+		  || ! prop_simulate_again_p (SSA_NAME_DEF_STMT (tem))))
+	    {
+	      extract_range_from_ssa_name (vr, tem);
+	      return;
+	    }
+	  else if (is_gimple_min_invariant (tem))
+	    {
+	      set_value_range_to_value (vr, tem, NULL);
+	      return;
+	    }
+	}
+/* Then dispatch to value-range extracting functions.  */
+if (code == GIMPLE_CALL)
+	extract_range_basic (vr, stmt);
+else
+	extract_range_from_assignment (vr, as_a <gassign *> (stmt));
+}
+}
+/* Helper that gets the value range of the SSA_NAME with version I
+or a symbolic range containing the SSA_NAME only if the value range
+is varying or undefined.  */
+value_range
+vr_values::get_vr_for_comparison (int i)
+{
+value_range vr = *get_value_range (ssa_name (i));
+/* If name N_i does not have a valid range, use N_i as its own
+range.  This allows us to compare against names that may
+have N_i in their ranges.  */
+if (vr.varying_p () || vr.undefined_p ())
+vr = value_range (VR_RANGE, ssa_name (i), ssa_name (i), NULL);
+return vr;
+}
+/* Compare all the value ranges for names equivalent to VAR with VAL
+using comparison code COMP.  Return the same value returned by
+compare_range_with_value, including the setting of
+*STRICT_OVERFLOW_P.  */
+tree
+vr_values::compare_name_with_value (enum tree_code comp, tree var, tree val,
+				    bool *strict_overflow_p, bool use_equiv_p)
+{
+bitmap_iterator bi;
+unsigned i;
+bitmap e;
+tree retval, t;
+int used_strict_overflow;
+bool sop;
+value_range equiv_vr;
+/* Get the set of equivalences for VAR.  */
+e = get_value_range (var)->equiv ();
+/* Start at -1.  Set it to 0 if we do a comparison without relying
+on overflow, or 1 if all comparisons rely on overflow.  */
+used_strict_overflow = -1;
+/* Compare vars' value range with val.  */
+equiv_vr = get_vr_for_comparison (SSA_NAME_VERSION (var));
+sop = false;
+retval = compare_range_with_value (comp, &equiv_vr, val, &sop);
+if (retval)
+used_strict_overflow = sop ? 1 : 0;
+/* If the equiv set is empty we have done all work we need to do.  */
+if (e == NULL)
+{
+if (retval
+	  && used_strict_overflow > 0)
+	*strict_overflow_p = true;
+return retval;
+}
+EXECUTE_IF_SET_IN_BITMAP (e, 0, i, bi)
+{
+tree name = ssa_name (i);
+if (! name)
+	continue;
+if (! use_equiv_p
+	  && ! SSA_NAME_IS_DEFAULT_DEF (name)
+	  && prop_simulate_again_p (SSA_NAME_DEF_STMT (name)))
+	continue;
+equiv_vr = get_vr_for_comparison (i);
+sop = false;
+t = compare_range_with_value (comp, &equiv_vr, val, &sop);
+if (t)
+	{
+	  /* If we get different answers from different members
+	     of the equivalence set this check must be in a dead
+	     code region.  Folding it to a trap representation
+	     would be correct here.  For now just return don't-know.  */
+	  if (retval != NULL
+	      && t != retval)
+	    {
+	      retval = NULL_TREE;
+	      break;
+	    }
+	  retval = t;
+	  if (!sop)
+	    used_strict_overflow = 0;
+	  else if (used_strict_overflow < 0)
+	    used_strict_overflow = 1;
+	}
+}
+if (retval
+&& used_strict_overflow > 0)
+*strict_overflow_p = true;
+return retval;
+}
+/* Given a comparison code COMP and names N1 and N2, compare all the
+ranges equivalent to N1 against all the ranges equivalent to N2
+to determine the value of N1 COMP N2.  Return the same value
+returned by compare_ranges.  Set *STRICT_OVERFLOW_P to indicate
+whether we relied on undefined signed overflow in the comparison.  */
+tree
+vr_values::compare_names (enum tree_code comp, tree n1, tree n2,
+			  bool *strict_overflow_p)
+{
+tree t, retval;
+bitmap e1, e2;
+bitmap_iterator bi1, bi2;
+unsigned i1, i2;
+int used_strict_overflow;
+static bitmap_obstack *s_obstack = NULL;
+static bitmap s_e1 = NULL, s_e2 = NULL;
+/* Compare the ranges of every name equivalent to N1 against the
+ranges of every name equivalent to N2.  */
+e1 = get_value_range (n1)->equiv ();
+e2 = get_value_range (n2)->equiv ();
+/* Use the fake bitmaps if e1 or e2 are not available.  */
+if (s_obstack == NULL)
+{
+s_obstack = XNEW (bitmap_obstack);
+bitmap_obstack_initialize (s_obstack);
+s_e1 = BITMAP_ALLOC (s_obstack);
+s_e2 = BITMAP_ALLOC (s_obstack);
+}
+if (e1 == NULL)
+e1 = s_e1;
+if (e2 == NULL)
+e2 = s_e2;
+/* Add N1 and N2 to their own set of equivalences to avoid
+duplicating the body of the loop just to check N1 and N2
+ranges.  */
+bitmap_set_bit (e1, SSA_NAME_VERSION (n1));
+bitmap_set_bit (e2, SSA_NAME_VERSION (n2));
+/* If the equivalence sets have a common intersection, then the two
+names can be compared without checking their ranges.  */
+if (bitmap_intersect_p (e1, e2))
+{
+bitmap_clear_bit (e1, SSA_NAME_VERSION (n1));
+bitmap_clear_bit (e2, SSA_NAME_VERSION (n2));
+return (comp == EQ_EXPR || comp == GE_EXPR || comp == LE_EXPR)
+	     ? boolean_true_node
+	     : boolean_false_node;
+}
+/* Start at -1.  Set it to 0 if we do a comparison without relying
+on overflow, or 1 if all comparisons rely on overflow.  */
+used_strict_overflow = -1;
+/* Otherwise, compare all the equivalent ranges.  First, add N1 and
+N2 to their own set of equivalences to avoid duplicating the body
+of the loop just to check N1 and N2 ranges.  */
+EXECUTE_IF_SET_IN_BITMAP (e1, 0, i1, bi1)
+{
+if (! ssa_name (i1))
+	continue;
+value_range vr1 = get_vr_for_comparison (i1);
+t = retval = NULL_TREE;
+EXECUTE_IF_SET_IN_BITMAP (e2, 0, i2, bi2)
+	{
+	  if (! ssa_name (i2))
+	    continue;
+	  bool sop = false;
+	  value_range vr2 = get_vr_for_comparison (i2);
+	  t = compare_ranges (comp, &vr1, &vr2, &sop);
+	  if (t)
+	    {
+	      /* If we get different answers from different members
+		 of the equivalence set this check must be in a dead
+		 code region.  Folding it to a trap representation
+		 would be correct here.  For now just return don't-know.  */
+	      if (retval != NULL
+		  && t != retval)
+		{
+		  bitmap_clear_bit (e1, SSA_NAME_VERSION (n1));
+		  bitmap_clear_bit (e2, SSA_NAME_VERSION (n2));
+		  return NULL_TREE;
+		}
+	      retval = t;
+	      if (!sop)
+		used_strict_overflow = 0;
+	      else if (used_strict_overflow < 0)
+		used_strict_overflow = 1;
+	    }
+	}
+if (retval)
+	{
+	  bitmap_clear_bit (e1, SSA_NAME_VERSION (n1));
+	  bitmap_clear_bit (e2, SSA_NAME_VERSION (n2));
+	  if (used_strict_overflow > 0)
+	    *strict_overflow_p = true;
+	  return retval;
+	}
+}
+/* None of the equivalent ranges are useful in computing this
+comparison.  */
+bitmap_clear_bit (e1, SSA_NAME_VERSION (n1));
+bitmap_clear_bit (e2, SSA_NAME_VERSION (n2));
+return NULL_TREE;
+}
+/* Helper function for vrp_evaluate_conditional_warnv & other
+optimizers.  */
+tree
+vr_values::vrp_evaluate_conditional_warnv_with_ops_using_ranges
+(enum tree_code code, tree op0, tree op1, bool * strict_overflow_p)
+{
+value_range *vr0, *vr1;
+vr0 = (TREE_CODE (op0) == SSA_NAME) ? get_value_range (op0) : NULL;
+vr1 = (TREE_CODE (op1) == SSA_NAME) ? get_value_range (op1) : NULL;
+tree res = NULL_TREE;
+if (vr0 && vr1)
+res = compare_ranges (code, vr0, vr1, strict_overflow_p);
+if (!res && vr0)
+res = compare_range_with_value (code, vr0, op1, strict_overflow_p);
+if (!res && vr1)
+res = (compare_range_with_value
+	    (swap_tree_comparison (code), vr1, op0, strict_overflow_p));
+return res;
+}
+/* Helper function for vrp_evaluate_conditional_warnv. */
+tree
+vr_values::vrp_evaluate_conditional_warnv_with_ops (enum tree_code code,
+						    tree op0, tree op1,
+						    bool use_equiv_p,
+						    bool *strict_overflow_p,
+						    bool *only_ranges)
+{
+tree ret;
+if (only_ranges)
+*only_ranges = true;
+/* We only deal with integral and pointer types.  */
+if (!INTEGRAL_TYPE_P (TREE_TYPE (op0))
+&& !POINTER_TYPE_P (TREE_TYPE (op0)))
+return NULL_TREE;
+/* If OP0 CODE OP1 is an overflow comparison, if it can be expressed
+as a simple equality test, then prefer that over its current form
+for evaluation.
+An overflow test which collapses to an equality test can always be
+expressed as a comparison of one argument against zero.  Overflow
+occurs when the chosen argument is zero and does not occur if the
+chosen argument is not zero.  */
+tree x;
+if (overflow_comparison_p (code, op0, op1, use_equiv_p, &x))
+{
+wide_int max = wi::max_value (TYPE_PRECISION (TREE_TYPE (op0)), UNSIGNED);
+/* B = A - 1; if (A < B) -> B = A - 1; if (A == 0)
+B = A - 1; if (A > B) -> B = A - 1; if (A != 0)
+B = A + 1; if (B < A) -> B = A + 1; if (B == 0)
+B = A + 1; if (B > A) -> B = A + 1; if (B != 0) */
+if (integer_zerop (x))
+	{
+	  op1 = x;
+	  code = (code == LT_EXPR || code == LE_EXPR) ? EQ_EXPR : NE_EXPR;
+	}
+/* B = A + 1; if (A > B) -> B = A + 1; if (B == 0)
+B = A + 1; if (A < B) -> B = A + 1; if (B != 0)
+B = A - 1; if (B > A) -> B = A - 1; if (A == 0)
+B = A - 1; if (B < A) -> B = A - 1; if (A != 0) */
+else if (wi::to_wide (x) == max - 1)
+	{
+	  op0 = op1;
+	  op1 = wide_int_to_tree (TREE_TYPE (op0), 0);
+	  code = (code == GT_EXPR || code == GE_EXPR) ? EQ_EXPR : NE_EXPR;
+	}
+}
+if ((ret = vrp_evaluate_conditional_warnv_with_ops_using_ranges
+	       (code, op0, op1, strict_overflow_p)))
+return ret;
+if (only_ranges)
+*only_ranges = false;
+/* Do not use compare_names during propagation, it's quadratic.  */
+if (TREE_CODE (op0) == SSA_NAME && TREE_CODE (op1) == SSA_NAME
+&& use_equiv_p)
+return compare_names (code, op0, op1, strict_overflow_p);
+else if (TREE_CODE (op0) == SSA_NAME)
+return compare_name_with_value (code, op0, op1,
+				    strict_overflow_p, use_equiv_p);
+else if (TREE_CODE (op1) == SSA_NAME)
+return compare_name_with_value (swap_tree_comparison (code), op1, op0,
+				    strict_overflow_p, use_equiv_p);
+return NULL_TREE;
+}
+/* Given (CODE OP0 OP1) within STMT, try to simplify it based on value range
+information.  Return NULL if the conditional can not be evaluated.
+The ranges of all the names equivalent with the operands in COND
+will be used when trying to compute the value.  If the result is
+based on undefined signed overflow, issue a warning if
+appropriate.  */
+tree
+vr_values::vrp_evaluate_conditional (tree_code code, tree op0,
+				     tree op1, gimple *stmt)
+{
+bool sop;
+tree ret;
+bool only_ranges;
+/* Some passes and foldings leak constants with overflow flag set
+into the IL.  Avoid doing wrong things with these and bail out.  */
+if ((TREE_CODE (op0) == INTEGER_CST
+&& TREE_OVERFLOW (op0))
+|| (TREE_CODE (op1) == INTEGER_CST
+	  && TREE_OVERFLOW (op1)))
+return NULL_TREE;
+sop = false;
+ret = vrp_evaluate_conditional_warnv_with_ops (code, op0, op1, true, &sop,
+						 &only_ranges);
+if (ret && sop)
+{
+enum warn_strict_overflow_code wc;
+const char* warnmsg;
+if (is_gimple_min_invariant (ret))
+	{
+	  wc = WARN_STRICT_OVERFLOW_CONDITIONAL;
+	  warnmsg = G_("assuming signed overflow does not occur when "
+		       "simplifying conditional to constant");
+	}
+else
+	{
+	  wc = WARN_STRICT_OVERFLOW_COMPARISON;
+	  warnmsg = G_("assuming signed overflow does not occur when "
+		       "simplifying conditional");
+	}
+if (issue_strict_overflow_warning (wc))
+	{
+	  location_t location;
+	  if (!gimple_has_location (stmt))
+	    location = input_location;
+	  else
+	    location = gimple_location (stmt);
+	  warning_at (location, OPT_Wstrict_overflow, "%s", warnmsg);
+	}
+}
+if (warn_type_limits
+&& ret && only_ranges
+&& TREE_CODE_CLASS (code) == tcc_comparison
+&& TREE_CODE (op0) == SSA_NAME)
+{
+/* If the comparison is being folded and the operand on the LHS
+	 is being compared against a constant value that is outside of
+	 the natural range of OP0's type, then the predicate will
+	 always fold regardless of the value of OP0.  If -Wtype-limits
+	 was specified, emit a warning.  */
+tree type = TREE_TYPE (op0);
+value_range *vr0 = get_value_range (op0);
+if (vr0->kind () == VR_RANGE
+	  && INTEGRAL_TYPE_P (type)
+	  && vrp_val_is_min (vr0->min ())
+	  && vrp_val_is_max (vr0->max ())
+	  && is_gimple_min_invariant (op1))
+	{
+	  location_t location;
+	  if (!gimple_has_location (stmt))
+	    location = input_location;
+	  else
+	    location = gimple_location (stmt);
+	  warning_at (location, OPT_Wtype_limits,
+		      integer_zerop (ret)
+		      ? G_("comparison always false "
+"due to limited range of data type")
+		      : G_("comparison always true "
+"due to limited range of data type"));
+	}
+}
+return ret;
+}
+/* Visit conditional statement STMT.  If we can determine which edge
+will be taken out of STMT's basic block, record it in
+*TAKEN_EDGE_P.  Otherwise, set *TAKEN_EDGE_P to NULL.  */
+void
+vr_values::vrp_visit_cond_stmt (gcond *stmt, edge *taken_edge_p)
+{
+tree val;
+*taken_edge_p = NULL;
+if (dump_file && (dump_flags & TDF_DETAILS))
+{
+tree use;
+ssa_op_iter i;
+fprintf (dump_file, "\nVisiting conditional with predicate: ");
+print_gimple_stmt (dump_file, stmt, 0);
+fprintf (dump_file, "\nWith known ranges\n");
+FOR_EACH_SSA_TREE_OPERAND (use, stmt, i, SSA_OP_USE)
+	{
+	  fprintf (dump_file, "\t");
+	  print_generic_expr (dump_file, use);
+	  fprintf (dump_file, ": ");
+	  dump_value_range (dump_file, vr_value[SSA_NAME_VERSION (use)]);
+	}
+fprintf (dump_file, "\n");
+}
+/* Compute the value of the predicate COND by checking the known
+ranges of each of its operands.
+Note that we cannot evaluate all the equivalent ranges here
+because those ranges may not yet be final and with the current
+propagation strategy, we cannot determine when the value ranges
+of the names in the equivalence set have changed.
+For instance, given the following code fragment
+i_5 = PHI <8, i_13>
+	...
+	i_14 = ASSERT_EXPR <i_5, i_5 != 0>
+	if (i_14 == 1)
+	  ...
+Assume that on the first visit to i_14, i_5 has the temporary
+range [8, 8] because the second argument to the PHI function is
+not yet executable.  We derive the range ~[0, 0] for i_14 and the
+equivalence set { i_5 }.  So, when we visit 'if (i_14 == 1)' for
+the first time, since i_14 is equivalent to the range [8, 8], we
+determine that the predicate is always false.
+On the next round of propagation, i_13 is determined to be
+VARYING, which causes i_5 to drop down to VARYING.  So, another
+visit to i_14 is scheduled.  In this second visit, we compute the
+exact same range and equivalence set for i_14, namely ~[0, 0] and
+{ i_5 }.  But we did not have the previous range for i_5
+registered, so vrp_visit_assignment thinks that the range for
+i_14 has not changed.  Therefore, the predicate 'if (i_14 == 1)'
+is not visited again, which stops propagation from visiting
+statements in the THEN clause of that if().
+To properly fix this we would need to keep the previous range
+value for the names in the equivalence set.  This way we would've
+discovered that from one visit to the other i_5 changed from
+range [8, 8] to VR_VARYING.
+However, fixing this apparent limitation may not be worth the
+additional checking.  Testing on several code bases (GCC, DLV,
+MICO, TRAMP3D and SPEC2000) showed that doing this results in
+4 more predicates folded in SPEC.  */
+bool sop;
+val = vrp_evaluate_conditional_warnv_with_ops (gimple_cond_code (stmt),
+						 gimple_cond_lhs (stmt),
+						 gimple_cond_rhs (stmt),
+						 false, &sop, NULL);
+if (val)
+*taken_edge_p = find_taken_edge (gimple_bb (stmt), val);
+if (dump_file && (dump_flags & TDF_DETAILS))
+{
+fprintf (dump_file, "\nPredicate evaluates to: ");
+if (val == NULL_TREE)
+	fprintf (dump_file, "DON'T KNOW\n");
+else
+	print_generic_stmt (dump_file, val);
+}
+}
+/* Searches the case label vector VEC for the ranges of CASE_LABELs that are
+used in range VR.  The indices are placed in MIN_IDX1, MAX_IDX, MIN_IDX2 and
+MAX_IDX2.  If the ranges of CASE_LABELs are empty then MAX_IDX1 < MIN_IDX1.
+Returns true if the default label is not needed.  */
+static bool
+find_case_label_ranges (gswitch *stmt, value_range *vr, size_t *min_idx1,
+			size_t *max_idx1, size_t *min_idx2,
+			size_t *max_idx2)
+{
+size_t i, j, k, l;
+unsigned int n = gimple_switch_num_labels (stmt);
+bool take_default;
+tree case_low, case_high;
+tree min = vr->min (), max = vr->max ();
+gcc_checking_assert (!vr->varying_p () && !vr->undefined_p ());
+take_default = !find_case_label_range (stmt, min, max, &i, &j);
+/* Set second range to emtpy.  */
+*min_idx2 = 1;
+*max_idx2 = 0;
+if (vr->kind () == VR_RANGE)
+{
+*min_idx1 = i;
+*max_idx1 = j;
+return !take_default;
+}
+/* Set first range to all case labels.  */
+*min_idx1 = 1;
+*max_idx1 = n - 1;
+if (i > j)
+return false;
+/* Make sure all the values of case labels [i , j] are contained in
+range [MIN, MAX].  */
+case_low = CASE_LOW (gimple_switch_label (stmt, i));
+case_high = CASE_HIGH (gimple_switch_label (stmt, j));
+if (tree_int_cst_compare (case_low, min) < 0)
+i += 1;
+if (case_high != NULL_TREE
+&& tree_int_cst_compare (max, case_high) < 0)
+j -= 1;
+if (i > j)
+return false;
+/* If the range spans case labels [i, j], the corresponding anti-range spans
+the labels [1, i - 1] and [j + 1, n -  1].  */
+k = j + 1;
+l = n - 1;
+if (k > l)
+{
+k = 1;
+l = 0;
+}
+j = i - 1;
+i = 1;
+if (i > j)
+{
+i = k;
+j = l;
+k = 1;
+l = 0;
+}
+*min_idx1 = i;
+*max_idx1 = j;
+*min_idx2 = k;
+*max_idx2 = l;
+return false;
+}
+/* Visit switch statement STMT.  If we can determine which edge
+will be taken out of STMT's basic block, record it in
+*TAKEN_EDGE_P.  Otherwise, *TAKEN_EDGE_P set to NULL.  */
+void
+vr_values::vrp_visit_switch_stmt (gswitch *stmt, edge *taken_edge_p)
+{
+tree op, val;
+value_range *vr;
+size_t i = 0, j = 0, k, l;
+bool take_default;
+*taken_edge_p = NULL;
+op = gimple_switch_index (stmt);
+if (TREE_CODE (op) != SSA_NAME)
+return;
+vr = get_value_range (op);
+if (dump_file && (dump_flags & TDF_DETAILS))
+{
+fprintf (dump_file, "\nVisiting switch expression with operand ");
+print_generic_expr (dump_file, op);
+fprintf (dump_file, " with known range ");
+dump_value_range (dump_file, vr);
+fprintf (dump_file, "\n");
+}
+if (vr->undefined_p ()
+|| vr->varying_p ()
+|| vr->symbolic_p ())
+return;
+/* Find the single edge that is taken from the switch expression.  */
+take_default = !find_case_label_ranges (stmt, vr, &i, &j, &k, &l);
+/* Check if the range spans no CASE_LABEL. If so, we only reach the default
+label */
+if (j < i)
+{
+gcc_assert (take_default);
+val = gimple_switch_default_label (stmt);
+}
+else
+{
+/* Check if labels with index i to j and maybe the default label
+	 are all reaching the same label.  */
+val = gimple_switch_label (stmt, i);
+if (take_default
+	  && CASE_LABEL (gimple_switch_default_label (stmt))
+	  != CASE_LABEL (val))
+	{
+	  if (dump_file && (dump_flags & TDF_DETAILS))
+	    fprintf (dump_file, "  not a single destination for this "
+		     "range\n");
+	  return;
+	}
+for (++i; i <= j; ++i)
+{
+if (CASE_LABEL (gimple_switch_label (stmt, i)) != CASE_LABEL (val))
+	    {
+	      if (dump_file && (dump_flags & TDF_DETAILS))
+		fprintf (dump_file, "  not a single destination for this "
+			 "range\n");
+	      return;
+	    }
+}
+for (; k <= l; ++k)
+{
+if (CASE_LABEL (gimple_switch_label (stmt, k)) != CASE_LABEL (val))
+	    {
+	      if (dump_file && (dump_flags & TDF_DETAILS))
+		fprintf (dump_file, "  not a single destination for this "
+			 "range\n");
+	      return;
+	    }
+}
+}
+*taken_edge_p = find_edge (gimple_bb (stmt),
+			     label_to_block (cfun, CASE_LABEL (val)));
+if (dump_file && (dump_flags & TDF_DETAILS))
+{
+fprintf (dump_file, "  will take edge to ");
+print_generic_stmt (dump_file, CASE_LABEL (val));
+}
+}
+/* Evaluate statement STMT.  If the statement produces a useful range,
+set VR and corepsponding OUTPUT_P.
+If STMT is a conditional branch and we can determine its truth
+value, the taken edge is recorded in *TAKEN_EDGE_P.  */
+void
+vr_values::extract_range_from_stmt (gimple *stmt, edge *taken_edge_p,
+				    tree *output_p, value_range *vr)
+{
+if (dump_file && (dump_flags & TDF_DETAILS))
+{
+fprintf (dump_file, "\nVisiting statement:\n");
+print_gimple_stmt (dump_file, stmt, 0, dump_flags);
+}
+if (!stmt_interesting_for_vrp (stmt))
+gcc_assert (stmt_ends_bb_p (stmt));
+else if (is_gimple_assign (stmt) || is_gimple_call (stmt))
+vrp_visit_assignment_or_call (stmt, output_p, vr);
+else if (gimple_code (stmt) == GIMPLE_COND)
+vrp_visit_cond_stmt (as_a <gcond *> (stmt), taken_edge_p);
+else if (gimple_code (stmt) == GIMPLE_SWITCH)
+vrp_visit_switch_stmt (as_a <gswitch *> (stmt), taken_edge_p);
+}
+/* Visit all arguments for PHI node PHI that flow through executable
+edges.  If a valid value range can be derived from all the incoming
+value ranges, set a new range in VR_RESULT.  */
+void
+vr_values::extract_range_from_phi_node (gphi *phi, value_range *vr_result)
+{
+size_t i;
+tree lhs = PHI_RESULT (phi);
+value_range *lhs_vr = get_value_range (lhs);
+bool first = true;
+int edges, old_edges;
+struct loop *l;
+if (dump_file && (dump_flags & TDF_DETAILS))
+{
+fprintf (dump_file, "\nVisiting PHI node: ");
+print_gimple_stmt (dump_file, phi, 0, dump_flags);
+}
+bool may_simulate_backedge_again = false;
+edges = 0;
+for (i = 0; i < gimple_phi_num_args (phi); i++)
+{
+edge e = gimple_phi_arg_edge (phi, i);
+if (dump_file && (dump_flags & TDF_DETAILS))
+	{
+	  fprintf (dump_file,
+	      "    Argument #%d (%d -> %d %sexecutable)\n",
+	      (int) i, e->src->index, e->dest->index,
+	      (e->flags & EDGE_EXECUTABLE) ? "" : "not ");
+	}
+if (e->flags & EDGE_EXECUTABLE)
+	{
+	  tree arg = PHI_ARG_DEF (phi, i);
+	  value_range vr_arg;
+	  ++edges;
+	  if (TREE_CODE (arg) == SSA_NAME)
+	    {
+	      /* See if we are eventually going to change one of the args.  */
+	      gimple *def_stmt = SSA_NAME_DEF_STMT (arg);
+	      if (! gimple_nop_p (def_stmt)
+		  && prop_simulate_again_p (def_stmt)
+		  && e->flags & EDGE_DFS_BACK)
+		may_simulate_backedge_again = true;
+	      vr_arg = *(get_value_range (arg));
+	      /* Do not allow equivalences or symbolic ranges to leak in from
+		 backedges.  That creates invalid equivalencies.
+		 See PR53465 and PR54767.  */
+	      if (e->flags & EDGE_DFS_BACK)
+		{
+		  if (!vr_arg.varying_p () && !vr_arg.undefined_p ())
+		    {
+		      vr_arg.equiv_clear ();
+		      if (vr_arg.symbolic_p ())
+			vr_arg.set_varying ();
+		    }
+		}
+	      /* If the non-backedge arguments range is VR_VARYING then
+		 we can still try recording a simple equivalence.  */
+	      else if (vr_arg.varying_p ())
+		vr_arg = value_range (VR_RANGE, arg, arg, NULL);
+	    }
+	  else
+	    {
+	      if (TREE_OVERFLOW_P (arg))
+		arg = drop_tree_overflow (arg);
+	      vr_arg = value_range (VR_RANGE, arg, arg);
+	    }
+	  if (dump_file && (dump_flags & TDF_DETAILS))
+	    {
+	      fprintf (dump_file, "\t");
+	      print_generic_expr (dump_file, arg, dump_flags);
+	      fprintf (dump_file, ": ");
+	      dump_value_range (dump_file, &vr_arg);
+	      fprintf (dump_file, "\n");
+	    }
+	  if (first)
+	    vr_result->deep_copy (&vr_arg);
+	  else
+	    vr_result->union_ (&vr_arg);
+	  first = false;
+	  if (vr_result->varying_p ())
+	    break;
+	}
+}
+if (vr_result->varying_p ())
+goto varying;
+else if (vr_result->undefined_p ())
+goto update_range;
+old_edges = vr_phi_edge_counts[SSA_NAME_VERSION (lhs)];
+vr_phi_edge_counts[SSA_NAME_VERSION (lhs)] = edges;
+/* To prevent infinite iterations in the algorithm, derive ranges
+when the new value is slightly bigger or smaller than the
+previous one.  We don't do this if we have seen a new executable
+edge; this helps us avoid an infinity for conditionals
+which are not in a loop.  If the old value-range was VR_UNDEFINED
+use the updated range and iterate one more time.  If we will not
+simulate this PHI again via the backedge allow us to iterate.  */
+if (edges > 0
+&& gimple_phi_num_args (phi) > 1
+&& edges == old_edges
+&& !lhs_vr->undefined_p ()
+&& may_simulate_backedge_again)
+{
+/* Compare old and new ranges, fall back to varying if the
+values are not comparable.  */
+int cmp_min = compare_values (lhs_vr->min (), vr_result->min ());
+if (cmp_min == -2)
+	goto varying;
+int cmp_max = compare_values (lhs_vr->max (), vr_result->max ());
+if (cmp_max == -2)
+	goto varying;
+/* For non VR_RANGE or for pointers fall back to varying if
+	 the range changed.  */
+if ((lhs_vr->kind () != VR_RANGE || vr_result->kind () != VR_RANGE
+	   || POINTER_TYPE_P (TREE_TYPE (lhs)))
+	  && (cmp_min != 0 || cmp_max != 0))
+	goto varying;
+/* If the new minimum is larger than the previous one
+	 retain the old value.  If the new minimum value is smaller
+	 than the previous one and not -INF go all the way to -INF + 1.
+	 In the first case, to avoid infinite bouncing between different
+	 minimums, and in the other case to avoid iterating millions of
+	 times to reach -INF.  Going to -INF + 1 also lets the following
+	 iteration compute whether there will be any overflow, at the
+	 expense of one additional iteration.  */
+tree new_min = vr_result->min ();
+tree new_max = vr_result->max ();
+if (cmp_min < 0)
+	new_min = lhs_vr->min ();
+else if (cmp_min > 0
+	       && !vrp_val_is_min (vr_result->min ()))
+	new_min = int_const_binop (PLUS_EXPR,
+				   vrp_val_min (vr_result->type ()),
+				   build_int_cst (vr_result->type (), 1));
+/* Similarly for the maximum value.  */
+if (cmp_max > 0)
+	new_max = lhs_vr->max ();
+else if (cmp_max < 0
+	       && !vrp_val_is_max (vr_result->max ()))
+	new_max = int_const_binop (MINUS_EXPR,
+				   vrp_val_max (vr_result->type ()),
+				   build_int_cst (vr_result->type (), 1));
+*vr_result = value_range (vr_result->kind (), new_min, new_max,
+				vr_result->equiv ());
+/* If we dropped either bound to +-INF then if this is a loop
+	 PHI node SCEV may known more about its value-range.  */
+if (cmp_min > 0 || cmp_min < 0
+	   || cmp_max < 0 || cmp_max > 0)
+	goto scev_check;
+goto infinite_check;
+}
+goto update_range;
+varying:
+set_value_range_to_varying (vr_result);
+scev_check:
+/* If this is a loop PHI node SCEV may known more about its value-range.
+scev_check can be reached from two paths, one is a fall through from above
+"varying" label, the other is direct goto from code block which tries to
+avoid infinite simulation.  */
+if (scev_initialized_p ()
+&& (l = loop_containing_stmt (phi))
+&& l->header == gimple_bb (phi))
+adjust_range_with_scev (vr_result, l, phi, lhs);
+infinite_check:
+/* If we will end up with a (-INF, +INF) range, set it to
+VARYING.  Same if the previous max value was invalid for
+the type and we end up with vr_result.min > vr_result.max.  */
+if ((!vr_result->varying_p () && !vr_result->undefined_p ())
+&& !((vrp_val_is_max (vr_result->max ()) && vrp_val_is_min (vr_result->min ()))
+	   || compare_values (vr_result->min (), vr_result->max ()) > 0))
+;
+else
+set_value_range_to_varying (vr_result);
+/* If the new range is different than the previous value, keep
+iterating.  */
+update_range:
+return;
+}
+/* Simplify boolean operations if the source is known
+to be already a boolean.  */
+bool
+vr_values::simplify_truth_ops_using_ranges (gimple_stmt_iterator *gsi,
+					    gimple *stmt)
+{
+enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
+tree lhs, op0, op1;
+bool need_conversion;
+/* We handle only !=/== case here.  */
+gcc_assert (rhs_code == EQ_EXPR || rhs_code == NE_EXPR);
+op0 = gimple_assign_rhs1 (stmt);
+if (!op_with_boolean_value_range_p (op0))
+return false;
+op1 = gimple_assign_rhs2 (stmt);
+if (!op_with_boolean_value_range_p (op1))
+return false;
+/* Reduce number of cases to handle to NE_EXPR.  As there is no
+BIT_XNOR_EXPR we cannot replace A == B with a single statement.  */
+if (rhs_code == EQ_EXPR)
+{
+if (TREE_CODE (op1) == INTEGER_CST)
+	op1 = int_const_binop (BIT_XOR_EXPR, op1,
+			       build_int_cst (TREE_TYPE (op1), 1));
+else
+	return false;
+}
+lhs = gimple_assign_lhs (stmt);
+need_conversion
+= !useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (op0));
+/* Make sure to not sign-extend a 1-bit 1 when converting the result.  */
+if (need_conversion
+&& !TYPE_UNSIGNED (TREE_TYPE (op0))
+&& TYPE_PRECISION (TREE_TYPE (op0)) == 1
+&& TYPE_PRECISION (TREE_TYPE (lhs)) > 1)
+return false;
+/* For A != 0 we can substitute A itself.  */
+if (integer_zerop (op1))
+gimple_assign_set_rhs_with_ops (gsi,
+				    need_conversion
+				    ? NOP_EXPR : TREE_CODE (op0), op0);
+/* For A != B we substitute A ^ B.  Either with conversion.  */
+else if (need_conversion)
+{
+tree tem = make_ssa_name (TREE_TYPE (op0));
+gassign *newop
+	= gimple_build_assign (tem, BIT_XOR_EXPR, op0, op1);
+gsi_insert_before (gsi, newop, GSI_SAME_STMT);
+if (INTEGRAL_TYPE_P (TREE_TYPE (tem))
+	  && TYPE_PRECISION (TREE_TYPE (tem)) > 1)
+	set_range_info (tem, VR_RANGE,
+			wi::zero (TYPE_PRECISION (TREE_TYPE (tem))),
+			wi::one (TYPE_PRECISION (TREE_TYPE (tem))));
+gimple_assign_set_rhs_with_ops (gsi, NOP_EXPR, tem);
+}
+/* Or without.  */
+else
+gimple_assign_set_rhs_with_ops (gsi, BIT_XOR_EXPR, op0, op1);
+update_stmt (gsi_stmt (*gsi));
+fold_stmt (gsi, follow_single_use_edges);
+return true;
+}
+/* Simplify a division or modulo operator to a right shift or bitwise and
+if the first operand is unsigned or is greater than zero and the second
+operand is an exact power of two.  For TRUNC_MOD_EXPR op0 % op1 with
+constant op1 (op1min = op1) or with op1 in [op1min, op1max] range,
+optimize it into just op0 if op0's range is known to be a subset of
+[-op1min + 1, op1min - 1] for signed and [0, op1min - 1] for unsigned
+modulo.  */
+bool
+vr_values::simplify_div_or_mod_using_ranges (gimple_stmt_iterator *gsi,
+					     gimple *stmt)
+{
+enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
+tree val = NULL;
+tree op0 = gimple_assign_rhs1 (stmt);
+tree op1 = gimple_assign_rhs2 (stmt);
+tree op0min = NULL_TREE, op0max = NULL_TREE;
+tree op1min = op1;
+value_range *vr = NULL;
+if (TREE_CODE (op0) == INTEGER_CST)
+{
+op0min = op0;
+op0max = op0;
+}
+else
+{
+vr = get_value_range (op0);
+if (range_int_cst_p (vr))
+	{
+	  op0min = vr->min ();
+	  op0max = vr->max ();
+	}
+}
+if (rhs_code == TRUNC_MOD_EXPR
+&& TREE_CODE (op1) == SSA_NAME)
+{
+value_range *vr1 = get_value_range (op1);
+if (range_int_cst_p (vr1))
+	op1min = vr1->min ();
+}
+if (rhs_code == TRUNC_MOD_EXPR
+&& TREE_CODE (op1min) == INTEGER_CST
+&& tree_int_cst_sgn (op1min) == 1
+&& op0max
+&& tree_int_cst_lt (op0max, op1min))
+{
+if (TYPE_UNSIGNED (TREE_TYPE (op0))
+	  || tree_int_cst_sgn (op0min) >= 0
+	  || tree_int_cst_lt (fold_unary (NEGATE_EXPR, TREE_TYPE (op1min), op1min),
+			      op0min))
+	{
+	  /* If op0 already has the range op0 % op1 has,
+	     then TRUNC_MOD_EXPR won't change anything.  */
+	  gimple_assign_set_rhs_from_tree (gsi, op0);
+	  return true;
+	}
+}
+if (TREE_CODE (op0) != SSA_NAME)
+return false;
+if (!integer_pow2p (op1))
+{
+/* X % -Y can be only optimized into X % Y either if
+	 X is not INT_MIN, or Y is not -1.  Fold it now, as after
+	 remove_range_assertions the range info might be not available
+	 anymore.  */
+if (rhs_code == TRUNC_MOD_EXPR
+	  && fold_stmt (gsi, follow_single_use_edges))
+	return true;
+return false;
+}
+if (TYPE_UNSIGNED (TREE_TYPE (op0)))
+val = integer_one_node;
+else
+{
+bool sop = false;
+val = compare_range_with_value (GE_EXPR, vr, integer_zero_node, &sop);
+if (val
+	  && sop
+	  && integer_onep (val)
+	  && issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC))
+	{
+	  location_t location;
+	  if (!gimple_has_location (stmt))
+	    location = input_location;
+	  else
+	    location = gimple_location (stmt);
+	  warning_at (location, OPT_Wstrict_overflow,
+		      "assuming signed overflow does not occur when "
+		      "simplifying %</%> or %<%%%> to %<>>%> or %<&%>");
+	}
+}
+if (val && integer_onep (val))
+{
+tree t;
+if (rhs_code == TRUNC_DIV_EXPR)
+	{
+	  t = build_int_cst (integer_type_node, tree_log2 (op1));
+	  gimple_assign_set_rhs_code (stmt, RSHIFT_EXPR);
+	  gimple_assign_set_rhs1 (stmt, op0);
+	  gimple_assign_set_rhs2 (stmt, t);
+	}
+else
+	{
+	  t = build_int_cst (TREE_TYPE (op1), 1);
+	  t = int_const_binop (MINUS_EXPR, op1, t);
+	  t = fold_convert (TREE_TYPE (op0), t);
+	  gimple_assign_set_rhs_code (stmt, BIT_AND_EXPR);
+	  gimple_assign_set_rhs1 (stmt, op0);
+	  gimple_assign_set_rhs2 (stmt, t);
+	}
+update_stmt (stmt);
+fold_stmt (gsi, follow_single_use_edges);
+return true;
+}
+return false;
+}
+/* Simplify a min or max if the ranges of the two operands are
+disjoint.   Return true if we do simplify.  */
+bool
+vr_values::simplify_min_or_max_using_ranges (gimple_stmt_iterator *gsi,
+					     gimple *stmt)
+{
+tree op0 = gimple_assign_rhs1 (stmt);
+tree op1 = gimple_assign_rhs2 (stmt);
+bool sop = false;
+tree val;
+val = (vrp_evaluate_conditional_warnv_with_ops_using_ranges
+	 (LE_EXPR, op0, op1, &sop));
+if (!val)
+{
+sop = false;
+val = (vrp_evaluate_conditional_warnv_with_ops_using_ranges
+	     (LT_EXPR, op0, op1, &sop));
+}
+if (val)
+{
+if (sop && issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC))
+	{
+	  location_t location;
+	  if (!gimple_has_location (stmt))
+	    location = input_location;
+	  else
+	    location = gimple_location (stmt);
+	  warning_at (location, OPT_Wstrict_overflow,
+		      "assuming signed overflow does not occur when "
+		      "simplifying %<min/max (X,Y)%> to %<X%> or %<Y%>");
+	}
+/* VAL == TRUE -> OP0 < or <= op1
+	 VAL == FALSE -> OP0 > or >= op1.  */
+tree res = ((gimple_assign_rhs_code (stmt) == MAX_EXPR)
+		  == integer_zerop (val)) ? op0 : op1;
+gimple_assign_set_rhs_from_tree (gsi, res);
+return true;
+}
+return false;
+}
+/* If the operand to an ABS_EXPR is >= 0, then eliminate the
+ABS_EXPR.  If the operand is <= 0, then simplify the
+ABS_EXPR into a NEGATE_EXPR.  */
+bool
+vr_values::simplify_abs_using_ranges (gimple_stmt_iterator *gsi, gimple *stmt)
+{
+tree op = gimple_assign_rhs1 (stmt);
+value_range *vr = get_value_range (op);
+if (vr)
+{
+tree val = NULL;
+bool sop = false;
+val = compare_range_with_value (LE_EXPR, vr, integer_zero_node, &sop);
+if (!val)
+	{
+	  /* The range is neither <= 0 nor > 0.  Now see if it is
+	     either < 0 or >= 0.  */
+	  sop = false;
+	  val = compare_range_with_value (LT_EXPR, vr, integer_zero_node,
+					  &sop);
+	}
+if (val)
+	{
+	  if (sop && issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC))
+	    {
+	      location_t location;
+	      if (!gimple_has_location (stmt))
+		location = input_location;
+	      else
+		location = gimple_location (stmt);
+	      warning_at (location, OPT_Wstrict_overflow,
+			  "assuming signed overflow does not occur when "
+			  "simplifying %<abs (X)%> to %<X%> or %<-X%>");
+	    }
+	  gimple_assign_set_rhs1 (stmt, op);
+	  if (integer_zerop (val))
+	    gimple_assign_set_rhs_code (stmt, SSA_NAME);
+	  else
+	    gimple_assign_set_rhs_code (stmt, NEGATE_EXPR);
+	  update_stmt (stmt);
+	  fold_stmt (gsi, follow_single_use_edges);
+	  return true;
+	}
+}
+return false;
+}
+/* Optimize away redundant BIT_AND_EXPR and BIT_IOR_EXPR.
+If all the bits that are being cleared by & are already
+known to be zero from VR, or all the bits that are being
+set by | are already known to be one from VR, the bit
+operation is redundant.  */
+bool
+vr_values::simplify_bit_ops_using_ranges (gimple_stmt_iterator *gsi,
+					  gimple *stmt)
+{
+tree op0 = gimple_assign_rhs1 (stmt);
+tree op1 = gimple_assign_rhs2 (stmt);
+tree op = NULL_TREE;
+value_range vr0, vr1;
+wide_int may_be_nonzero0, may_be_nonzero1;
+wide_int must_be_nonzero0, must_be_nonzero1;
+wide_int mask;
+if (TREE_CODE (op0) == SSA_NAME)
+vr0 = *(get_value_range (op0));
+else if (is_gimple_min_invariant (op0))
+set_value_range_to_value (&vr0, op0, NULL);
+else
+return false;
+if (TREE_CODE (op1) == SSA_NAME)
+vr1 = *(get_value_range (op1));
+else if (is_gimple_min_invariant (op1))
+set_value_range_to_value (&vr1, op1, NULL);
+else
+return false;
+if (!vrp_set_zero_nonzero_bits (TREE_TYPE (op0), &vr0, &may_be_nonzero0,
+				  &must_be_nonzero0))
+return false;
+if (!vrp_set_zero_nonzero_bits (TREE_TYPE (op1), &vr1, &may_be_nonzero1,
+				  &must_be_nonzero1))
+return false;
+switch (gimple_assign_rhs_code (stmt))
+{
+case BIT_AND_EXPR:
+mask = wi::bit_and_not (may_be_nonzero0, must_be_nonzero1);
+if (mask == 0)
+	{
+	  op = op0;
+	  break;
+	}
+mask = wi::bit_and_not (may_be_nonzero1, must_be_nonzero0);
+if (mask == 0)
+	{
+	  op = op1;
+	  break;
+	}
+break;
+case BIT_IOR_EXPR:
+mask = wi::bit_and_not (may_be_nonzero0, must_be_nonzero1);
+if (mask == 0)
+	{
+	  op = op1;
+	  break;
+	}
+mask = wi::bit_and_not (may_be_nonzero1, must_be_nonzero0);
+if (mask == 0)
+	{
+	  op = op0;
+	  break;
+	}
+break;
+default:
+gcc_unreachable ();
+}
+if (op == NULL_TREE)
+return false;
+gimple_assign_set_rhs_with_ops (gsi, TREE_CODE (op), op);
+update_stmt (gsi_stmt (*gsi));
+return true;
+}
+/* We are comparing trees OP0 and OP1 using COND_CODE.  OP0 has
+a known value range VR.
+If there is one and only one value which will satisfy the
+conditional, then return that value.  Else return NULL.
+If signed overflow must be undefined for the value to satisfy
+the conditional, then set *STRICT_OVERFLOW_P to true.  */
+static tree
+test_for_singularity (enum tree_code cond_code, tree op0,
+		      tree op1, value_range *vr)
+{
+tree min = NULL;
+tree max = NULL;
+/* Extract minimum/maximum values which satisfy the conditional as it was
+written.  */
+if (cond_code == LE_EXPR || cond_code == LT_EXPR)
+{
+min = TYPE_MIN_VALUE (TREE_TYPE (op0));
+max = op1;
+if (cond_code == LT_EXPR)
+	{
+	  tree one = build_int_cst (TREE_TYPE (op0), 1);
+	  max = fold_build2 (MINUS_EXPR, TREE_TYPE (op0), max, one);
+	  /* Signal to compare_values_warnv this expr doesn't overflow.  */
+	  if (EXPR_P (max))
+	    TREE_NO_WARNING (max) = 1;
+	}
+}
+else if (cond_code == GE_EXPR || cond_code == GT_EXPR)
+{
+max = TYPE_MAX_VALUE (TREE_TYPE (op0));
+min = op1;
+if (cond_code == GT_EXPR)
+	{
+	  tree one = build_int_cst (TREE_TYPE (op0), 1);
+	  min = fold_build2 (PLUS_EXPR, TREE_TYPE (op0), min, one);
+	  /* Signal to compare_values_warnv this expr doesn't overflow.  */
+	  if (EXPR_P (min))
+	    TREE_NO_WARNING (min) = 1;
+	}
+}
+/* Now refine the minimum and maximum values using any
+value range information we have for op0.  */
+if (min && max)
+{
+if (compare_values (vr->min (), min) == 1)
+	min = vr->min ();
+if (compare_values (vr->max (), max) == -1)
+	max = vr->max ();
+/* If the new min/max values have converged to a single value,
+	 then there is only one value which can satisfy the condition,
+	 return that value.  */
+if (operand_equal_p (min, max, 0) && is_gimple_min_invariant (min))
+	return min;
+}
+return NULL;
+}
+/* Return whether the value range *VR fits in an integer type specified
+by PRECISION and UNSIGNED_P.  */
+static bool
+range_fits_type_p (value_range *vr, unsigned dest_precision, signop dest_sgn)
+{
+tree src_type;
+unsigned src_precision;
+widest_int tem;
+signop src_sgn;
+/* We can only handle integral and pointer types.  */
+src_type = vr->type ();
+if (!INTEGRAL_TYPE_P (src_type)
+&& !POINTER_TYPE_P (src_type))
+return false;
+/* An extension is fine unless VR is SIGNED and dest_sgn is UNSIGNED,
+and so is an identity transform.  */
+src_precision = TYPE_PRECISION (vr->type ());
+src_sgn = TYPE_SIGN (src_type);
+if ((src_precision < dest_precision
+&& !(dest_sgn == UNSIGNED && src_sgn == SIGNED))
+|| (src_precision == dest_precision && src_sgn == dest_sgn))
+return true;
+/* Now we can only handle ranges with constant bounds.  */
+if (!range_int_cst_p (vr))
+return false;
+/* For sign changes, the MSB of the wide_int has to be clear.
+An unsigned value with its MSB set cannot be represented by
+a signed wide_int, while a negative value cannot be represented
+by an unsigned wide_int.  */
+if (src_sgn != dest_sgn
+&& (wi::lts_p (wi::to_wide (vr->min ()), 0)
+	  || wi::lts_p (wi::to_wide (vr->max ()), 0)))
+return false;
+/* Then we can perform the conversion on both ends and compare
+the result for equality.  */
+tem = wi::ext (wi::to_widest (vr->min ()), dest_precision, dest_sgn);
+if (tem != wi::to_widest (vr->min ()))
+return false;
+tem = wi::ext (wi::to_widest (vr->max ()), dest_precision, dest_sgn);
+if (tem != wi::to_widest (vr->max ()))
+return false;
+return true;
+}
+/* Simplify a conditional using a relational operator to an equality
+test if the range information indicates only one value can satisfy
+the original conditional.  */
+bool
+vr_values::simplify_cond_using_ranges_1 (gcond *stmt)
+{
+tree op0 = gimple_cond_lhs (stmt);
+tree op1 = gimple_cond_rhs (stmt);
+enum tree_code cond_code = gimple_cond_code (stmt);
+if (cond_code != NE_EXPR
+&& cond_code != EQ_EXPR
+&& TREE_CODE (op0) == SSA_NAME
+&& INTEGRAL_TYPE_P (TREE_TYPE (op0))
+&& is_gimple_min_invariant (op1))
+{
+value_range *vr = get_value_range (op0);
+/* If we have range information for OP0, then we might be
+	 able to simplify this conditional. */
+if (vr->kind () == VR_RANGE)
+	{
+	  tree new_tree = test_for_singularity (cond_code, op0, op1, vr);
+	  if (new_tree)
+	    {
+	      if (dump_file)
+		{
+		  fprintf (dump_file, "Simplified relational ");
+		  print_gimple_stmt (dump_file, stmt, 0);
+		  fprintf (dump_file, " into ");
+		}
+	      gimple_cond_set_code (stmt, EQ_EXPR);
+	      gimple_cond_set_lhs (stmt, op0);
+	      gimple_cond_set_rhs (stmt, new_tree);
+	      update_stmt (stmt);
+	      if (dump_file)
+		{
+		  print_gimple_stmt (dump_file, stmt, 0);
+		  fprintf (dump_file, "\n");
+		}
+	      return true;
+	    }
+	  /* Try again after inverting the condition.  We only deal
+	     with integral types here, so no need to worry about
+	     issues with inverting FP comparisons.  */
+	  new_tree = test_for_singularity
+		       (invert_tree_comparison (cond_code, false),
+			op0, op1, vr);
+	  if (new_tree)
+	    {
+	      if (dump_file)
+		{
+		  fprintf (dump_file, "Simplified relational ");
+		  print_gimple_stmt (dump_file, stmt, 0);
+		  fprintf (dump_file, " into ");
+		}
+	      gimple_cond_set_code (stmt, NE_EXPR);
+	      gimple_cond_set_lhs (stmt, op0);
+	      gimple_cond_set_rhs (stmt, new_tree);
+	      update_stmt (stmt);
+	      if (dump_file)
+		{
+		  print_gimple_stmt (dump_file, stmt, 0);
+		  fprintf (dump_file, "\n");
+		}
+	      return true;
+	    }
+	}
+}
+return false;
+}
+/* STMT is a conditional at the end of a basic block.
+If the conditional is of the form SSA_NAME op constant and the SSA_NAME
+was set via a type conversion, try to replace the SSA_NAME with the RHS
+of the type conversion.  Doing so makes the conversion dead which helps
+subsequent passes.  */
+void
+vr_values::simplify_cond_using_ranges_2 (gcond *stmt)
+{
+tree op0 = gimple_cond_lhs (stmt);
+tree op1 = gimple_cond_rhs (stmt);
+/* If we have a comparison of an SSA_NAME (OP0) against a constant,
+see if OP0 was set by a type conversion where the source of
+the conversion is another SSA_NAME with a range that fits
+into the range of OP0's type.
+If so, the conversion is redundant as the earlier SSA_NAME can be
+used for the comparison directly if we just massage the constant in the
+comparison.  */
+if (TREE_CODE (op0) == SSA_NAME
+&& TREE_CODE (op1) == INTEGER_CST)
+{
+gimple *def_stmt = SSA_NAME_DEF_STMT (op0);
+tree innerop;
+if (!is_gimple_assign (def_stmt)
+	  || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt)))
+	return;
+innerop = gimple_assign_rhs1 (def_stmt);
+if (TREE_CODE (innerop) == SSA_NAME
+	  && !POINTER_TYPE_P (TREE_TYPE (innerop))
+	  && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (innerop)
+	  && desired_pro_or_demotion_p (TREE_TYPE (innerop), TREE_TYPE (op0)))
+	{
+	  value_range *vr = get_value_range (innerop);
+	  if (range_int_cst_p (vr)
+	      && range_fits_type_p (vr,
+				    TYPE_PRECISION (TREE_TYPE (op0)),
+				    TYPE_SIGN (TREE_TYPE (op0)))
+	      && int_fits_type_p (op1, TREE_TYPE (innerop)))
+	    {
+	      tree newconst = fold_convert (TREE_TYPE (innerop), op1);
+	      gimple_cond_set_lhs (stmt, innerop);
+	      gimple_cond_set_rhs (stmt, newconst);
+	      update_stmt (stmt);
+	      if (dump_file && (dump_flags & TDF_DETAILS))
+		{
+		  fprintf (dump_file, "Folded into: ");
+		  print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
+		  fprintf (dump_file, "\n");
+		}
+	    }
+	}
+}
+}
+/* Simplify a switch statement using the value range of the switch
+argument.  */
+bool
+vr_values::simplify_switch_using_ranges (gswitch *stmt)
+{
+tree op = gimple_switch_index (stmt);
+value_range *vr = NULL;
+bool take_default;
+edge e;
+edge_iterator ei;
+size_t i = 0, j = 0, n, n2;
+tree vec2;
+switch_update su;
+size_t k = 1, l = 0;
+if (TREE_CODE (op) == SSA_NAME)
+{
+vr = get_value_range (op);
+/* We can only handle integer ranges.  */
+if (vr->varying_p ()
+	  || vr->undefined_p ()
+	  || vr->symbolic_p ())
+	return false;
+/* Find case label for min/max of the value range.  */
+take_default = !find_case_label_ranges (stmt, vr, &i, &j, &k, &l);
+}
+else if (TREE_CODE (op) == INTEGER_CST)
+{
+take_default = !find_case_label_index (stmt, 1, op, &i);
+if (take_default)
+	{
+	  i = 1;
+	  j = 0;
+	}
+else
+	{
+	  j = i;
+	}
+}
+else
+return false;
+n = gimple_switch_num_labels (stmt);
+/* We can truncate the case label ranges that partially overlap with OP's
+value range.  */
+size_t min_idx = 1, max_idx = 0;
+if (vr != NULL)
+find_case_label_range (stmt, vr->min (), vr->max (), &min_idx, &max_idx);
+if (min_idx <= max_idx)
+{
+tree min_label = gimple_switch_label (stmt, min_idx);
+tree max_label = gimple_switch_label (stmt, max_idx);
+/* Avoid changing the type of the case labels when truncating.  */
+tree case_label_type = TREE_TYPE (CASE_LOW (min_label));
+tree vr_min = fold_convert (case_label_type, vr->min ());
+tree vr_max = fold_convert (case_label_type, vr->max ());
+if (vr->kind () == VR_RANGE)
+	{
+	  /* If OP's value range is [2,8] and the low label range is
+	     0 ... 3, truncate the label's range to 2 .. 3.  */
+	  if (tree_int_cst_compare (CASE_LOW (min_label), vr_min) < 0
+	      && CASE_HIGH (min_label) != NULL_TREE
+	      && tree_int_cst_compare (CASE_HIGH (min_label), vr_min) >= 0)
+	    CASE_LOW (min_label) = vr_min;
+	  /* If OP's value range is [2,8] and the high label range is
+	     7 ... 10, truncate the label's range to 7 .. 8.  */
+	  if (tree_int_cst_compare (CASE_LOW (max_label), vr_max) <= 0
+	      && CASE_HIGH (max_label) != NULL_TREE
+	      && tree_int_cst_compare (CASE_HIGH (max_label), vr_max) > 0)
+	    CASE_HIGH (max_label) = vr_max;
+	}
+else if (vr->kind () == VR_ANTI_RANGE)
+	{
+	  tree one_cst = build_one_cst (case_label_type);
+	  if (min_label == max_label)
+	    {
+	      /* If OP's value range is ~[7,8] and the label's range is
+		 7 ... 10, truncate the label's range to 9 ... 10.  */
+	      if (tree_int_cst_compare (CASE_LOW (min_label), vr_min) == 0
+		  && CASE_HIGH (min_label) != NULL_TREE
+		  && tree_int_cst_compare (CASE_HIGH (min_label), vr_max) > 0)
+		CASE_LOW (min_label)
+		  = int_const_binop (PLUS_EXPR, vr_max, one_cst);
+	      /* If OP's value range is ~[7,8] and the label's range is
+		 5 ... 8, truncate the label's range to 5 ... 6.  */
+	      if (tree_int_cst_compare (CASE_LOW (min_label), vr_min) < 0
+		  && CASE_HIGH (min_label) != NULL_TREE
+		  && tree_int_cst_compare (CASE_HIGH (min_label), vr_max) == 0)
+		CASE_HIGH (min_label)
+		  = int_const_binop (MINUS_EXPR, vr_min, one_cst);
+	    }
+	  else
+	    {
+	      /* If OP's value range is ~[2,8] and the low label range is
+		 0 ... 3, truncate the label's range to 0 ... 1.  */
+	      if (tree_int_cst_compare (CASE_LOW (min_label), vr_min) < 0
+		  && CASE_HIGH (min_label) != NULL_TREE
+		  && tree_int_cst_compare (CASE_HIGH (min_label), vr_min) >= 0)
+		CASE_HIGH (min_label)
+		  = int_const_binop (MINUS_EXPR, vr_min, one_cst);
+	      /* If OP's value range is ~[2,8] and the high label range is
+		 7 ... 10, truncate the label's range to 9 ... 10.  */
+	      if (tree_int_cst_compare (CASE_LOW (max_label), vr_max) <= 0
+		  && CASE_HIGH (max_label) != NULL_TREE
+		  && tree_int_cst_compare (CASE_HIGH (max_label), vr_max) > 0)
+		CASE_LOW (max_label)
+		  = int_const_binop (PLUS_EXPR, vr_max, one_cst);
+	    }
+	}
+/* Canonicalize singleton case ranges.  */
+if (tree_int_cst_equal (CASE_LOW (min_label), CASE_HIGH (min_label)))
+	CASE_HIGH (min_label) = NULL_TREE;
+if (tree_int_cst_equal (CASE_LOW (max_label), CASE_HIGH (max_label)))
+	CASE_HIGH (max_label) = NULL_TREE;
+}
+/* We can also eliminate case labels that lie completely outside OP's value
+range.  */
+/* Bail out if this is just all edges taken.  */
+if (i == 1
+&& j == n - 1
+&& take_default)
+return false;
+/* Build a new vector of taken case labels.  */
+vec2 = make_tree_vec (j - i + 1 + l - k + 1 + (int)take_default);
+n2 = 0;
+/* Add the default edge, if necessary.  */
+if (take_default)
+TREE_VEC_ELT (vec2, n2++) = gimple_switch_default_label (stmt);
+for (; i <= j; ++i, ++n2)
+TREE_VEC_ELT (vec2, n2) = gimple_switch_label (stmt, i);
+for (; k <= l; ++k, ++n2)
+TREE_VEC_ELT (vec2, n2) = gimple_switch_label (stmt, k);
+/* Mark needed edges.  */
+for (i = 0; i < n2; ++i)
+{
+e = find_edge (gimple_bb (stmt),
+		     label_to_block (cfun,
+				     CASE_LABEL (TREE_VEC_ELT (vec2, i))));
+e->aux = (void *)-1;
+}
+/* Queue not needed edges for later removal.  */
+FOR_EACH_EDGE (e, ei, gimple_bb (stmt)->succs)
+{
+if (e->aux == (void *)-1)
+	{
+	  e->aux = NULL;
+	  continue;
+	}
+if (dump_file && (dump_flags & TDF_DETAILS))
+	{
+	  fprintf (dump_file, "removing unreachable case label\n");
+	}
+to_remove_edges.safe_push (e);
+e->flags &= ~EDGE_EXECUTABLE;
+e->flags |= EDGE_IGNORE;
+}
+/* And queue an update for the stmt.  */
+su.stmt = stmt;
+su.vec = vec2;
+to_update_switch_stmts.safe_push (su);
+return false;
+}
+void
+vr_values::cleanup_edges_and_switches (void)
+{
+int i;
+edge e;
+switch_update *su;
+/* Remove dead edges from SWITCH_EXPR optimization.  This leaves the
+CFG in a broken state and requires a cfg_cleanup run.  */
+FOR_EACH_VEC_ELT (to_remove_edges, i, e)
+remove_edge (e);
+/* Update SWITCH_EXPR case label vector.  */
+FOR_EACH_VEC_ELT (to_update_switch_stmts, i, su)
+{
+size_t j;
+size_t n = TREE_VEC_LENGTH (su->vec);
+tree label;
+gimple_switch_set_num_labels (su->stmt, n);
+for (j = 0; j < n; j++)
+	gimple_switch_set_label (su->stmt, j, TREE_VEC_ELT (su->vec, j));
+/* As we may have replaced the default label with a regular one
+	 make sure to make it a real default label again.  This ensures
+	 optimal expansion.  */
+label = gimple_switch_label (su->stmt, 0);
+CASE_LOW (label) = NULL_TREE;
+CASE_HIGH (label) = NULL_TREE;
+}
+if (!to_remove_edges.is_empty ())
+{
+free_dominance_info (CDI_DOMINATORS);
+loops_state_set (LOOPS_NEED_FIXUP);
+}
+to_remove_edges.release ();
+to_update_switch_stmts.release ();
+}
+/* Simplify an integral conversion from an SSA name in STMT.  */
+static bool
+simplify_conversion_using_ranges (gimple_stmt_iterator *gsi, gimple *stmt)
+{
+tree innerop, middleop, finaltype;
+gimple *def_stmt;
+signop inner_sgn, middle_sgn, final_sgn;
+unsigned inner_prec, middle_prec, final_prec;
+widest_int innermin, innermed, innermax, middlemin, middlemed, middlemax;
+finaltype = TREE_TYPE (gimple_assign_lhs (stmt));
+if (!INTEGRAL_TYPE_P (finaltype))
+return false;
+middleop = gimple_assign_rhs1 (stmt);
+def_stmt = SSA_NAME_DEF_STMT (middleop);
+if (!is_gimple_assign (def_stmt)
+|| !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt)))
+return false;
+innerop = gimple_assign_rhs1 (def_stmt);
+if (TREE_CODE (innerop) != SSA_NAME
+|| SSA_NAME_OCCURS_IN_ABNORMAL_PHI (innerop))
+return false;
+/* Get the value-range of the inner operand.  Use get_range_info in
+case innerop was created during substitute-and-fold.  */
+wide_int imin, imax;
+if (!INTEGRAL_TYPE_P (TREE_TYPE (innerop))
+|| get_range_info (innerop, &imin, &imax) != VR_RANGE)
+return false;
+innermin = widest_int::from (imin, TYPE_SIGN (TREE_TYPE (innerop)));
+innermax = widest_int::from (imax, TYPE_SIGN (TREE_TYPE (innerop)));
+/* Simulate the conversion chain to check if the result is equal if
+the middle conversion is removed.  */
+inner_prec = TYPE_PRECISION (TREE_TYPE (innerop));
+middle_prec = TYPE_PRECISION (TREE_TYPE (middleop));
+final_prec = TYPE_PRECISION (finaltype);
+/* If the first conversion is not injective, the second must not
+be widening.  */
+if (wi::gtu_p (innermax - innermin,
+		 wi::mask <widest_int> (middle_prec, false))
+&& middle_prec < final_prec)
+return false;
+/* We also want a medium value so that we can track the effect that
+narrowing conversions with sign change have.  */
+inner_sgn = TYPE_SIGN (TREE_TYPE (innerop));
+if (inner_sgn == UNSIGNED)
+innermed = wi::shifted_mask <widest_int> (1, inner_prec - 1, false);
+else
+innermed = 0;
+if (wi::cmp (innermin, innermed, inner_sgn) >= 0
+|| wi::cmp (innermed, innermax, inner_sgn) >= 0)
+innermed = innermin;
+middle_sgn = TYPE_SIGN (TREE_TYPE (middleop));
+middlemin = wi::ext (innermin, middle_prec, middle_sgn);
+middlemed = wi::ext (innermed, middle_prec, middle_sgn);
+middlemax = wi::ext (innermax, middle_prec, middle_sgn);
+/* Require that the final conversion applied to both the original
+and the intermediate range produces the same result.  */
+final_sgn = TYPE_SIGN (finaltype);
+if (wi::ext (middlemin, final_prec, final_sgn)
+	 != wi::ext (innermin, final_prec, final_sgn)
+|| wi::ext (middlemed, final_prec, final_sgn)
+	 != wi::ext (innermed, final_prec, final_sgn)
+|| wi::ext (middlemax, final_prec, final_sgn)
+	 != wi::ext (innermax, final_prec, final_sgn))
+return false;
+gimple_assign_set_rhs1 (stmt, innerop);
+fold_stmt (gsi, follow_single_use_edges);
+return true;
+}
+/* Simplify a conversion from integral SSA name to float in STMT.  */
+bool
+vr_values::simplify_float_conversion_using_ranges (gimple_stmt_iterator *gsi,
+						   gimple *stmt)
+{
+tree rhs1 = gimple_assign_rhs1 (stmt);
+value_range *vr = get_value_range (rhs1);
+scalar_float_mode fltmode
+= SCALAR_FLOAT_TYPE_MODE (TREE_TYPE (gimple_assign_lhs (stmt)));
+scalar_int_mode mode;
+tree tem;
+gassign *conv;
+/* We can only handle constant ranges.  */
+if (!range_int_cst_p (vr))
+return false;
+/* First check if we can use a signed type in place of an unsigned.  */
+scalar_int_mode rhs_mode = SCALAR_INT_TYPE_MODE (TREE_TYPE (rhs1));
+if (TYPE_UNSIGNED (TREE_TYPE (rhs1))
+&& can_float_p (fltmode, rhs_mode, 0) != CODE_FOR_nothing
+&& range_fits_type_p (vr, TYPE_PRECISION (TREE_TYPE (rhs1)), SIGNED))
+mode = rhs_mode;
+/* If we can do the conversion in the current input mode do nothing.  */
+else if (can_float_p (fltmode, rhs_mode,
+			TYPE_UNSIGNED (TREE_TYPE (rhs1))) != CODE_FOR_nothing)
+return false;
+/* Otherwise search for a mode we can use, starting from the narrowest
+integer mode available.  */
+else
+{
+mode = NARROWEST_INT_MODE;
+for (;;)
+	{
+	  /* If we cannot do a signed conversion to float from mode
+	     or if the value-range does not fit in the signed type
+	     try with a wider mode.  */
+	  if (can_float_p (fltmode, mode, 0) != CODE_FOR_nothing
+	      && range_fits_type_p (vr, GET_MODE_PRECISION (mode), SIGNED))
+	    break;
+	  /* But do not widen the input.  Instead leave that to the
+	     optabs expansion code.  */
+	  if (!GET_MODE_WIDER_MODE (mode).exists (&mode)
+	      || GET_MODE_PRECISION (mode) > TYPE_PRECISION (TREE_TYPE (rhs1)))
+	    return false;
+	}
+}
+/* It works, insert a truncation or sign-change before the
+float conversion.  */
+tem = make_ssa_name (build_nonstandard_integer_type
+			  (GET_MODE_PRECISION (mode), 0));
+conv = gimple_build_assign (tem, NOP_EXPR, rhs1);
+gsi_insert_before (gsi, conv, GSI_SAME_STMT);
+gimple_assign_set_rhs1 (stmt, tem);
+fold_stmt (gsi, follow_single_use_edges);
+return true;
+}
+/* Simplify an internal fn call using ranges if possible.  */
+bool
+vr_values::simplify_internal_call_using_ranges (gimple_stmt_iterator *gsi,
+						gimple *stmt)
+{
+enum tree_code subcode;
+bool is_ubsan = false;
+bool ovf = false;
+switch (gimple_call_internal_fn (stmt))
+{
+case IFN_UBSAN_CHECK_ADD:
+subcode = PLUS_EXPR;
+is_ubsan = true;
+break;
+case IFN_UBSAN_CHECK_SUB:
+subcode = MINUS_EXPR;
+is_ubsan = true;
+break;
+case IFN_UBSAN_CHECK_MUL:
+subcode = MULT_EXPR;
+is_ubsan = true;
+break;
+case IFN_ADD_OVERFLOW:
+subcode = PLUS_EXPR;
+break;
+case IFN_SUB_OVERFLOW:
+subcode = MINUS_EXPR;
+break;
+case IFN_MUL_OVERFLOW:
+subcode = MULT_EXPR;
+break;
+default:
+return false;
+}
+tree op0 = gimple_call_arg (stmt, 0);
+tree op1 = gimple_call_arg (stmt, 1);
+tree type;
+if (is_ubsan)
+{
+type = TREE_TYPE (op0);
+if (VECTOR_TYPE_P (type))
+	return false;
+}
+else if (gimple_call_lhs (stmt) == NULL_TREE)
+return false;
+else
+type = TREE_TYPE (TREE_TYPE (gimple_call_lhs (stmt)));
+if (!check_for_binary_op_overflow (subcode, type, op0, op1, &ovf)
+|| (is_ubsan && ovf))
+return false;
+gimple *g;
+location_t loc = gimple_location (stmt);
+if (is_ubsan)
+g = gimple_build_assign (gimple_call_lhs (stmt), subcode, op0, op1);
+else
+{
+int prec = TYPE_PRECISION (type);
+tree utype = type;
+if (ovf
+	  || !useless_type_conversion_p (type, TREE_TYPE (op0))
+	  || !useless_type_conversion_p (type, TREE_TYPE (op1)))
+	utype = build_nonstandard_integer_type (prec, 1);
+if (TREE_CODE (op0) == INTEGER_CST)
+	op0 = fold_convert (utype, op0);
+else if (!useless_type_conversion_p (utype, TREE_TYPE (op0)))
+	{
+	  g = gimple_build_assign (make_ssa_name (utype), NOP_EXPR, op0);
+	  gimple_set_location (g, loc);
+	  gsi_insert_before (gsi, g, GSI_SAME_STMT);
+	  op0 = gimple_assign_lhs (g);
+	}
+if (TREE_CODE (op1) == INTEGER_CST)
+	op1 = fold_convert (utype, op1);
+else if (!useless_type_conversion_p (utype, TREE_TYPE (op1)))
+	{
+	  g = gimple_build_assign (make_ssa_name (utype), NOP_EXPR, op1);
+	  gimple_set_location (g, loc);
+	  gsi_insert_before (gsi, g, GSI_SAME_STMT);
+	  op1 = gimple_assign_lhs (g);
+	}
+g = gimple_build_assign (make_ssa_name (utype), subcode, op0, op1);
+gimple_set_location (g, loc);
+gsi_insert_before (gsi, g, GSI_SAME_STMT);
+if (utype != type)
+	{
+	  g = gimple_build_assign (make_ssa_name (type), NOP_EXPR,
+				   gimple_assign_lhs (g));
+	  gimple_set_location (g, loc);
+	  gsi_insert_before (gsi, g, GSI_SAME_STMT);
+	}
+g = gimple_build_assign (gimple_call_lhs (stmt), COMPLEX_EXPR,
+			       gimple_assign_lhs (g),
+			       build_int_cst (type, ovf));
+}
+gimple_set_location (g, loc);
+gsi_replace (gsi, g, false);
+return true;
+}
+/* Return true if VAR is a two-valued variable.  Set a and b with the
+two-values when it is true.  Return false otherwise.  */
+bool
+vr_values::two_valued_val_range_p (tree var, tree *a, tree *b)
+{
+value_range *vr = get_value_range (var);
+if (vr->varying_p ()
+|| vr->undefined_p ()
+|| TREE_CODE (vr->min ()) != INTEGER_CST
+|| TREE_CODE (vr->max ()) != INTEGER_CST)
+return false;
+if (vr->kind () == VR_RANGE
+&& wi::to_wide (vr->max ()) - wi::to_wide (vr->min ()) == 1)
+{
+*a = vr->min ();
+*b = vr->max ();
+return true;
+}
+/* ~[TYPE_MIN + 1, TYPE_MAX - 1] */
+if (vr->kind () == VR_ANTI_RANGE
+&& (wi::to_wide (vr->min ())
+	  - wi::to_wide (vrp_val_min (TREE_TYPE (var)))) == 1
+&& (wi::to_wide (vrp_val_max (TREE_TYPE (var)))
+	  - wi::to_wide (vr->max ())) == 1)
+{
+*a = vrp_val_min (TREE_TYPE (var));
+*b = vrp_val_max (TREE_TYPE (var));
+return true;
+}
+return false;
+}
+/* Simplify STMT using ranges if possible.  */
+bool
+vr_values::simplify_stmt_using_ranges (gimple_stmt_iterator *gsi)
+{
+gimple *stmt = gsi_stmt (*gsi);
+if (is_gimple_assign (stmt))
+{
+enum tree_code rhs_code = gimple_assign_rhs_code (stmt);
+tree rhs1 = gimple_assign_rhs1 (stmt);
+tree rhs2 = gimple_assign_rhs2 (stmt);
+tree lhs = gimple_assign_lhs (stmt);
+tree val1 = NULL_TREE, val2 = NULL_TREE;
+use_operand_p use_p;
+gimple *use_stmt;
+/* Convert:
+	 LHS = CST BINOP VAR
+	 Where VAR is two-valued and LHS is used in GIMPLE_COND only
+	 To:
+	 LHS = VAR == VAL1 ? (CST BINOP VAL1) : (CST BINOP VAL2)
+	 Also handles:
+	 LHS = VAR BINOP CST
+	 Where VAR is two-valued and LHS is used in GIMPLE_COND only
+	 To:
+	 LHS = VAR == VAL1 ? (VAL1 BINOP CST) : (VAL2 BINOP CST) */
+if (TREE_CODE_CLASS (rhs_code) == tcc_binary
+	  && INTEGRAL_TYPE_P (TREE_TYPE (rhs1))
+	  && ((TREE_CODE (rhs1) == INTEGER_CST
+	       && TREE_CODE (rhs2) == SSA_NAME)
+	      || (TREE_CODE (rhs2) == INTEGER_CST
+		  && TREE_CODE (rhs1) == SSA_NAME))
+	  && single_imm_use (lhs, &use_p, &use_stmt)
+	  && gimple_code (use_stmt) == GIMPLE_COND)
+	{
+	  tree new_rhs1 = NULL_TREE;
+	  tree new_rhs2 = NULL_TREE;
+	  tree cmp_var = NULL_TREE;
+	  if (TREE_CODE (rhs2) == SSA_NAME
+	      && two_valued_val_range_p (rhs2, &val1, &val2))
+	    {
+	      /* Optimize RHS1 OP [VAL1, VAL2].  */
+	      new_rhs1 = int_const_binop (rhs_code, rhs1, val1);
+	      new_rhs2 = int_const_binop (rhs_code, rhs1, val2);
+	      cmp_var = rhs2;
+	    }
+	  else if (TREE_CODE (rhs1) == SSA_NAME
+		   && two_valued_val_range_p (rhs1, &val1, &val2))
+	    {
+	      /* Optimize [VAL1, VAL2] OP RHS2.  */
+	      new_rhs1 = int_const_binop (rhs_code, val1, rhs2);
+	      new_rhs2 = int_const_binop (rhs_code, val2, rhs2);
+	      cmp_var = rhs1;
+	    }
+	  /* If we could not find two-vals or the optimzation is invalid as
+	     in divide by zero, new_rhs1 / new_rhs will be NULL_TREE.  */
+	  if (new_rhs1 && new_rhs2)
+	    {
+	      tree cond = build2 (EQ_EXPR, boolean_type_node, cmp_var, val1);
+	      gimple_assign_set_rhs_with_ops (gsi,
+					      COND_EXPR, cond,
+					      new_rhs1,
+					      new_rhs2);
+	      update_stmt (gsi_stmt (*gsi));
+	      fold_stmt (gsi, follow_single_use_edges);
+	      return true;
+	    }
+	}
+switch (rhs_code)
+	{
+	case EQ_EXPR:
+	case NE_EXPR:
+/* Transform EQ_EXPR, NE_EXPR into BIT_XOR_EXPR or identity
+	     if the RHS is zero or one, and the LHS are known to be boolean
+	     values.  */
+	  if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
+	    return simplify_truth_ops_using_ranges (gsi, stmt);
+	  break;
+/* Transform TRUNC_DIV_EXPR and TRUNC_MOD_EXPR into RSHIFT_EXPR
+	 and BIT_AND_EXPR respectively if the first operand is greater
+	 than zero and the second operand is an exact power of two.
+	 Also optimize TRUNC_MOD_EXPR away if the second operand is
+	 constant and the first operand already has the right value
+	 range.  */
+	case TRUNC_DIV_EXPR:
+	case TRUNC_MOD_EXPR:
+	  if ((TREE_CODE (rhs1) == SSA_NAME
+	       || TREE_CODE (rhs1) == INTEGER_CST)
+	      && INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
+	    return simplify_div_or_mod_using_ranges (gsi, stmt);
+	  break;
+/* Transform ABS (X) into X or -X as appropriate.  */
+	case ABS_EXPR:
+	  if (TREE_CODE (rhs1) == SSA_NAME
+	      && INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
+	    return simplify_abs_using_ranges (gsi, stmt);
+	  break;
+	case BIT_AND_EXPR:
+	case BIT_IOR_EXPR:
+	  /* Optimize away BIT_AND_EXPR and BIT_IOR_EXPR
+	     if all the bits being cleared are already cleared or
+	     all the bits being set are already set.  */
+	  if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
+	    return simplify_bit_ops_using_ranges (gsi, stmt);
+	  break;
+	CASE_CONVERT:
+	  if (TREE_CODE (rhs1) == SSA_NAME
+	      && INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
+	    return simplify_conversion_using_ranges (gsi, stmt);
+	  break;
+	case FLOAT_EXPR:
+	  if (TREE_CODE (rhs1) == SSA_NAME
+	      && INTEGRAL_TYPE_P (TREE_TYPE (rhs1)))
+	    return simplify_float_conversion_using_ranges (gsi, stmt);
+	  break;
+	case MIN_EXPR:
+	case MAX_EXPR:
+	  return simplify_min_or_max_using_ranges (gsi, stmt);
+	default:
+	  break;
+	}
+}
+else if (gimple_code (stmt) == GIMPLE_COND)
+return simplify_cond_using_ranges_1 (as_a <gcond *> (stmt));
+else if (gimple_code (stmt) == GIMPLE_SWITCH)
+return simplify_switch_using_ranges (as_a <gswitch *> (stmt));
+else if (is_gimple_call (stmt)
+	   && gimple_call_internal_p (stmt))
+return simplify_internal_call_using_ranges (gsi, stmt);
+return false;
+}
+void
+vr_values::set_vr_value (tree var, value_range *vr)
+{
+if (SSA_NAME_VERSION (var) >= num_vr_values)
+return;
+vr_value[SSA_NAME_VERSION (var)] = vr;
+}

Mercurial > hg > CbC > CbC_gcc

comparison gcc/vr-values.c @ 132:d34655255c78