--- /dev/null
+/* Code for range operators.
+ Copyright (C) 2017-2019 Free Software Foundation, Inc.
+ Contributed by Andrew MacLeod <amacleod@redhat.com>
+ and Aldy Hernandez <aldyh@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "backend.h"
+#include "insn-codes.h"
+#include "rtl.h"
+#include "tree.h"
+#include "gimple.h"
+#include "cfghooks.h"
+#include "tree-pass.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 "stor-layout.h"
+#include "calls.h"
+#include "cfganal.h"
+#include "gimple-fold.h"
+#include "tree-eh.h"
+#include "gimple-iterator.h"
+#include "gimple-walk.h"
+#include "tree-cfg.h"
+#include "wide-int.h"
+#include "range-op.h"
+
+// Return the upper limit for a type.
+
+static inline wide_int
+max_limit (const_tree type)
+{
+ return wi::max_value (TYPE_PRECISION (type) , TYPE_SIGN (type));
+}
+
+// Return the lower limit for a type.
+
+static inline wide_int
+min_limit (const_tree type)
+{
+ return wi::min_value (TYPE_PRECISION (type) , TYPE_SIGN (type));
+}
+
+// If the range of either op1 or op2 is undefined, set the result to
+// undefined and return TRUE.
+
+inline bool
+empty_range_check (value_range_base &r,
+ const value_range_base &op1,
+ const value_range_base & op2)
+{
+ if (op1.undefined_p () || op2.undefined_p ())
+ {
+ r.set_undefined ();
+ return true;
+ }
+ else
+ return false;
+}
+
+// Return TRUE if shifting by OP is undefined behavior, and set R to
+// the appropriate range.
+
+static inline bool
+undefined_shift_range_check (value_range_base &r, tree type,
+ value_range_base op)
+{
+ if (op.undefined_p ())
+ {
+ r = value_range_base ();
+ return true;
+ }
+
+ // Shifting by any values outside [0..prec-1], gets undefined
+ // behavior from the shift operation. We cannot even trust
+ // SHIFT_COUNT_TRUNCATED at this stage, because that applies to rtl
+ // shifts, and the operation at the tree level may be widened.
+ if (wi::lt_p (op.lower_bound (), 0, TYPE_SIGN (op.type ()))
+ || wi::ge_p (op.upper_bound (),
+ TYPE_PRECISION (type), TYPE_SIGN (op.type ())))
+ {
+ r = value_range_base (type);
+ return true;
+ }
+ return false;
+}
+
+// Return TRUE if 0 is within [WMIN, WMAX].
+
+static inline bool
+wi_includes_zero_p (tree type, const wide_int &wmin, const wide_int &wmax)
+{
+ signop sign = TYPE_SIGN (type);
+ return wi::le_p (wmin, 0, sign) && wi::ge_p (wmax, 0, sign);
+}
+
+// Return TRUE if [WMIN, WMAX] is the singleton 0.
+
+static inline bool
+wi_zero_p (tree type, const wide_int &wmin, const wide_int &wmax)
+{
+ unsigned prec = TYPE_PRECISION (type);
+ return wmin == wmax && wi::eq_p (wmin, wi::zero (prec));
+}
+
+// Default wide_int fold operation returns [MIN, MAX].
+
+value_range_base
+range_operator::wi_fold (tree type,
+ const wide_int &lh_lb ATTRIBUTE_UNUSED,
+ const wide_int &lh_ub ATTRIBUTE_UNUSED,
+ const wide_int &rh_lb ATTRIBUTE_UNUSED,
+ const wide_int &rh_ub ATTRIBUTE_UNUSED) const
+{
+ return value_range_base (type);
+}
+
+// The default for fold is to break all ranges into sub-ranges and
+// invoke the wi_fold method on each sub-range pair.
+
+value_range_base
+range_operator::fold_range (tree type,
+ const value_range_base &lh,
+ const value_range_base &rh) const
+{
+ value_range_base r;
+ if (empty_range_check (r, lh, rh))
+ return r;
+
+ for (unsigned x = 0; x < lh.num_pairs (); ++x)
+ for (unsigned y = 0; y < rh.num_pairs (); ++y)
+ {
+ wide_int lh_lb = lh.lower_bound (x);
+ wide_int lh_ub = lh.upper_bound (x);
+ wide_int rh_lb = rh.lower_bound (y);
+ wide_int rh_ub = rh.upper_bound (y);
+ r.union_ (wi_fold (type, lh_lb, lh_ub, rh_lb, rh_ub));
+ if (r.varying_p ())
+ return r;
+ }
+ return r;
+}
+
+// The default for op1_range is to return false.
+
+bool
+range_operator::op1_range (value_range_base &r ATTRIBUTE_UNUSED,
+ tree type ATTRIBUTE_UNUSED,
+ const value_range_base &lhs ATTRIBUTE_UNUSED,
+ const value_range_base &op2 ATTRIBUTE_UNUSED) const
+{
+ return false;
+}
+
+// The default for op2_range is to return false.
+
+bool
+range_operator::op2_range (value_range_base &r ATTRIBUTE_UNUSED,
+ tree type ATTRIBUTE_UNUSED,
+ const value_range_base &lhs ATTRIBUTE_UNUSED,
+ const value_range_base &op1 ATTRIBUTE_UNUSED) const
+{
+ return false;
+}
+
+
+// Called when there is either an overflow OR an underflow... which
+// means an anti range must be created to compensate. This does not
+// cover the case where there are 2 possible overflows, or none.
+
+static value_range_base
+adjust_overflow_bound (tree type, const wide_int &wmin, const wide_int &wmax)
+{
+ const signop sgn = TYPE_SIGN (type);
+ const unsigned int prec = TYPE_PRECISION (type);
+
+ wide_int tmin = wide_int::from (wmin, prec, sgn);
+ wide_int tmax = wide_int::from (wmax, prec, sgn);
+
+ bool covers = false;
+ wide_int tem = tmin;
+ tmin = tmax + 1;
+ if (wi::cmp (tmin, tmax, sgn) < 0)
+ covers = true;
+ tmax = tem - 1;
+ if (wi::cmp (tmax, tem, sgn) > 0)
+ covers = true;
+
+ // If the anti-range would cover nothing, drop to varying.
+ // Likewise if the anti-range bounds are outside of the types
+ // values.
+ if (covers || wi::cmp (tmin, tmax, sgn) > 0)
+ return value_range_base (type);
+
+ return value_range_base (VR_ANTI_RANGE, type, tmin, tmax);
+}
+
+// Given a newly calculated lbound and ubound, examine their
+// respective overflow bits to determine how to create a range.
+// Return said range.
+
+static value_range_base
+create_range_with_overflow (tree type,
+ const wide_int &wmin, const wide_int &wmax,
+ wi::overflow_type min_ovf = wi::OVF_NONE,
+ wi::overflow_type max_ovf = wi::OVF_NONE)
+{
+ const signop sgn = TYPE_SIGN (type);
+ const unsigned int prec = TYPE_PRECISION (type);
+ const bool overflow_wraps = TYPE_OVERFLOW_WRAPS (type);
+
+ // For one bit precision if max != min, then the range covers all
+ // values.
+ if (prec == 1 && wi::ne_p (wmax, wmin))
+ return value_range_base (type);
+
+ if (overflow_wraps)
+ {
+ // If overflow wraps, truncate the values and adjust the range,
+ // kind, and bounds appropriately.
+ if ((min_ovf != wi::OVF_NONE) == (max_ovf != wi::OVF_NONE))
+ {
+ wide_int tmin = wide_int::from (wmin, prec, sgn);
+ wide_int tmax = wide_int::from (wmax, prec, sgn);
+ // If the limits are swapped, we wrapped around and cover
+ // the entire range.
+ if (wi::gt_p (tmin, tmax, sgn))
+ return value_range_base (type);
+
+ // No overflow or both overflow or underflow. The range
+ // kind stays normal.
+ return value_range_base (type, tmin, tmax);
+ }
+
+ if ((min_ovf == wi::OVF_UNDERFLOW && max_ovf == wi::OVF_NONE)
+ || (max_ovf == wi::OVF_OVERFLOW && min_ovf == wi::OVF_NONE))
+ return adjust_overflow_bound (type, wmin, wmax);
+
+ // Other underflow and/or overflow, drop to VR_VARYING.
+ return value_range_base (type);
+ }
+ else
+ {
+ // If overflow does not wrap, saturate to [MIN, MAX].
+ wide_int new_lb, new_ub;
+ if (min_ovf == wi::OVF_UNDERFLOW)
+ new_lb = wi::min_value (prec, sgn);
+ else if (min_ovf == wi::OVF_OVERFLOW)
+ new_lb = wi::max_value (prec, sgn);
+ else
+ new_lb = wmin;
+
+ if (max_ovf == wi::OVF_UNDERFLOW)
+ new_ub = wi::min_value (prec, sgn);
+ else if (max_ovf == wi::OVF_OVERFLOW)
+ new_ub = wi::max_value (prec, sgn);
+ else
+ new_ub = wmax;
+
+ return value_range_base (type, new_lb, new_ub);
+ }
+}
+
+// Like above, but canonicalize the case where the bounds are swapped
+// and overflow may wrap. In which case, we transform [10,5] into
+// [MIN,5][10,MAX].
+
+static inline value_range_base
+create_possibly_reversed_range (tree type,
+ const wide_int &new_lb, const wide_int &new_ub)
+{
+ signop s = TYPE_SIGN (type);
+ // If the bounds are swapped, treat the result as if an overflow occured.
+ if (wi::gt_p (new_lb, new_ub, s))
+ return adjust_overflow_bound (type, new_lb, new_ub);
+
+ // Otherwise its just a normal range.
+ return value_range_base (type, new_lb, new_ub);
+}
+
+// Return a value_range_base instance that is a boolean TRUE.
+
+static inline value_range_base
+range_true (tree type)
+{
+ unsigned prec = TYPE_PRECISION (type);
+ return value_range_base (type, wi::one (prec), wi::one (prec));
+}
+
+// Return a value_range_base instance that is a boolean FALSE.
+
+static inline value_range_base
+range_false (tree type)
+{
+ unsigned prec = TYPE_PRECISION (type);
+ return value_range_base (type, wi::zero (prec), wi::zero (prec));
+}
+
+// Return a value_range_base that covers both true and false.
+
+static inline value_range_base
+range_true_and_false (tree type)
+{
+ unsigned prec = TYPE_PRECISION (type);
+ return value_range_base (type, wi::zero (prec), wi::one (prec));
+}
+
+enum bool_range_state { BRS_FALSE, BRS_TRUE, BRS_EMPTY, BRS_FULL };
+
+// Return the summary information about boolean range LHS. Return an
+// "interesting" range in R. For EMPTY or FULL, return the equivalent
+// range for TYPE, for BRS_TRUE and BRS false, return the negation of
+// the bool range.
+
+static bool_range_state
+get_bool_state (value_range_base &r,
+ const value_range_base &lhs, tree val_type)
+{
+ // If there is no result, then this is unexecutable.
+ if (lhs.undefined_p ())
+ {
+ r.set_undefined ();
+ return BRS_EMPTY;
+ }
+
+ // If the bounds aren't the same, then it's not a constant.
+ if (!wi::eq_p (lhs.upper_bound (), lhs.lower_bound ()))
+ {
+ r.set_varying (val_type);
+ return BRS_FULL;
+ }
+
+ if (lhs.zero_p ())
+ return BRS_FALSE;
+
+ return BRS_TRUE;
+}
+
+
+class operator_equal : public range_operator
+{
+public:
+ virtual value_range_base fold_range (tree type,
+ const value_range_base &op1,
+ const value_range_base &op2) const;
+ virtual bool op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &val) const;
+ virtual bool op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &val) const;
+} op_equal;
+
+value_range_base
+operator_equal::fold_range (tree type,
+ const value_range_base &op1,
+ const value_range_base &op2) const
+{
+ value_range_base r;
+ if (empty_range_check (r, op1, op2))
+ return r;
+
+ // We can be sure the values are always equal or not if both ranges
+ // consist of a single value, and then compare them.
+ if (wi::eq_p (op1.lower_bound (), op1.upper_bound ())
+ && wi::eq_p (op2.lower_bound (), op2.upper_bound ()))
+ {
+ if (wi::eq_p (op1.lower_bound (), op2.upper_bound()))
+ r = range_true (type);
+ else
+ r = range_false (type);
+ }
+ else
+ {
+ // If ranges do not intersect, we know the range is not equal,
+ // otherwise we don't know anything for sure.
+ r = range_intersect (op1, op2);
+ if (r.undefined_p ())
+ r = range_false (type);
+ else
+ r = range_true_and_false (type);
+ }
+
+ return r;
+}
+
+bool
+operator_equal::op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const
+{
+ switch (get_bool_state (r, lhs, type))
+ {
+ case BRS_FALSE:
+ // If the result is false, the only time we know anything is
+ // if OP2 is a constant.
+ if (wi::eq_p (op2.lower_bound(), op2.upper_bound()))
+ r = range_invert (op2);
+ else
+ r.set_varying (type);
+ break;
+
+ case BRS_TRUE:
+ // If it's true, the result is the same as OP2.
+ r = op2;
+ break;
+
+ default:
+ break;
+ }
+ return true;
+}
+
+bool
+operator_equal::op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const
+{
+ return operator_equal::op1_range (r, type, lhs, op1);
+}
+
+
+class operator_not_equal : public range_operator
+{
+public:
+ virtual value_range_base fold_range (tree type,
+ const value_range_base &op1,
+ const value_range_base &op2) const;
+ virtual bool op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const;
+ virtual bool op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const;
+} op_not_equal;
+
+value_range_base
+operator_not_equal::fold_range (tree type,
+ const value_range_base &op1,
+ const value_range_base &op2) const
+{
+ value_range_base r;
+ if (empty_range_check (r, op1, op2))
+ return r;
+
+ // We can be sure the values are always equal or not if both ranges
+ // consist of a single value, and then compare them.
+ if (wi::eq_p (op1.lower_bound (), op1.upper_bound ())
+ && wi::eq_p (op2.lower_bound (), op2.upper_bound ()))
+ {
+ if (wi::ne_p (op1.lower_bound (), op2.upper_bound()))
+ r = range_true (type);
+ else
+ r = range_false (type);
+ }
+ else
+ {
+ // If ranges do not intersect, we know the range is not equal,
+ // otherwise we don't know anything for sure.
+ r = range_intersect (op1, op2);
+ if (r.undefined_p ())
+ r = range_true (type);
+ else
+ r = range_true_and_false (type);
+ }
+
+ return r;
+}
+
+bool
+operator_not_equal::op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const
+{
+ switch (get_bool_state (r, lhs, type))
+ {
+ case BRS_TRUE:
+ // If the result is true, the only time we know anything is if
+ // OP2 is a constant.
+ if (wi::eq_p (op2.lower_bound(), op2.upper_bound()))
+ r = range_invert (op2);
+ else
+ r.set_varying (type);
+ break;
+
+ case BRS_FALSE:
+ // If its true, the result is the same as OP2.
+ r = op2;
+ break;
+
+ default:
+ break;
+ }
+ return true;
+}
+
+
+bool
+operator_not_equal::op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const
+{
+ return operator_not_equal::op1_range (r, type, lhs, op1);
+}
+
+// (X < VAL) produces the range of [MIN, VAL - 1].
+
+static void
+build_lt (value_range_base &r, tree type, const wide_int &val)
+{
+ wi::overflow_type ov;
+ wide_int lim = wi::sub (val, 1, TYPE_SIGN (type), &ov);
+
+ // If val - 1 underflows, check if X < MIN, which is an empty range.
+ if (ov)
+ r.set_undefined ();
+ else
+ r = value_range_base (type, min_limit (type), lim);
+}
+
+// (X <= VAL) produces the range of [MIN, VAL].
+
+static void
+build_le (value_range_base &r, tree type, const wide_int &val)
+{
+ r = value_range_base (type, min_limit (type), val);
+}
+
+// (X > VAL) produces the range of [VAL + 1, MAX].
+
+static void
+build_gt (value_range_base &r, tree type, const wide_int &val)
+{
+ wi::overflow_type ov;
+ wide_int lim = wi::add (val, 1, TYPE_SIGN (type), &ov);
+ // If val + 1 overflows, check is for X > MAX, which is an empty range.
+ if (ov)
+ r.set_undefined ();
+ else
+ r = value_range_base (type, lim, max_limit (type));
+}
+
+// (X >= val) produces the range of [VAL, MAX].
+
+static void
+build_ge (value_range_base &r, tree type, const wide_int &val)
+{
+ r = value_range_base (type, val, max_limit (type));
+}
+
+
+class operator_lt : public range_operator
+{
+public:
+ virtual value_range_base fold_range (tree type,
+ const value_range_base &op1,
+ const value_range_base &op2) const;
+ virtual bool op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const;
+ virtual bool op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const;
+} op_lt;
+
+value_range_base
+operator_lt::fold_range (tree type,
+ const value_range_base &op1,
+ const value_range_base &op2) const
+{
+ value_range_base r;
+ if (empty_range_check (r, op1, op2))
+ return r;
+
+ signop sign = TYPE_SIGN (op1.type ());
+ gcc_checking_assert (sign == TYPE_SIGN (op2.type ()));
+
+ if (wi::lt_p (op1.upper_bound (), op2.lower_bound (), sign))
+ r = range_true (type);
+ else if (!wi::lt_p (op1.lower_bound (), op2.upper_bound (), sign))
+ r = range_false (type);
+ else
+ r = range_true_and_false (type);
+ return r;
+}
+
+bool
+operator_lt::op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const
+{
+ switch (get_bool_state (r, lhs, type))
+ {
+ case BRS_TRUE:
+ build_lt (r, type, op2.upper_bound ());
+ break;
+
+ case BRS_FALSE:
+ build_ge (r, type, op2.lower_bound ());
+ break;
+
+ default:
+ break;
+ }
+ return true;
+}
+
+bool
+operator_lt::op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const
+{
+ switch (get_bool_state (r, lhs, type))
+ {
+ case BRS_FALSE:
+ build_le (r, type, op1.upper_bound ());
+ break;
+
+ case BRS_TRUE:
+ build_gt (r, type, op1.lower_bound ());
+ break;
+
+ default:
+ break;
+ }
+ return true;
+}
+
+
+class operator_le : public range_operator
+{
+public:
+ virtual value_range_base fold_range (tree type,
+ const value_range_base &op1,
+ const value_range_base &op2) const;
+ virtual bool op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const;
+ virtual bool op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const;
+} op_le;
+
+value_range_base
+operator_le::fold_range (tree type,
+ const value_range_base &op1,
+ const value_range_base &op2) const
+{
+ value_range_base r;
+ if (empty_range_check (r, op1, op2))
+ return r;
+
+ signop sign = TYPE_SIGN (op1.type ());
+ gcc_checking_assert (sign == TYPE_SIGN (op2.type ()));
+
+ if (wi::le_p (op1.upper_bound (), op2.lower_bound (), sign))
+ r = range_true (type);
+ else if (!wi::le_p (op1.lower_bound (), op2.upper_bound (), sign))
+ r = range_false (type);
+ else
+ r = range_true_and_false (type);
+ return r;
+}
+
+bool
+operator_le::op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const
+{
+ switch (get_bool_state (r, lhs, type))
+ {
+ case BRS_TRUE:
+ build_le (r, type, op2.upper_bound ());
+ break;
+
+ case BRS_FALSE:
+ build_gt (r, type, op2.lower_bound ());
+ break;
+
+ default:
+ break;
+ }
+ return true;
+}
+
+bool
+operator_le::op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const
+{
+ switch (get_bool_state (r, lhs, type))
+ {
+ case BRS_FALSE:
+ build_lt (r, type, op1.upper_bound ());
+ break;
+
+ case BRS_TRUE:
+ build_ge (r, type, op1.lower_bound ());
+ break;
+
+ default:
+ break;
+ }
+ return true;
+}
+
+
+class operator_gt : public range_operator
+{
+public:
+ virtual value_range_base fold_range (tree type,
+ const value_range_base &op1,
+ const value_range_base &op2) const;
+ virtual bool op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const;
+ virtual bool op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const;
+} op_gt;
+
+value_range_base
+operator_gt::fold_range (tree type,
+ const value_range_base &op1,
+ const value_range_base &op2) const
+{
+ value_range_base r;
+ if (empty_range_check (r, op1, op2))
+ return r;
+
+ signop sign = TYPE_SIGN (op1.type ());
+ gcc_checking_assert (sign == TYPE_SIGN (op2.type ()));
+
+ if (wi::gt_p (op1.lower_bound (), op2.upper_bound (), sign))
+ r = range_true (type);
+ else if (!wi::gt_p (op1.upper_bound (), op2.lower_bound (), sign))
+ r = range_false (type);
+ else
+ r = range_true_and_false (type);
+ return r;
+}
+
+bool
+operator_gt::op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const
+{
+ switch (get_bool_state (r, lhs, type))
+ {
+ case BRS_TRUE:
+ build_gt (r, type, op2.lower_bound ());
+ break;
+
+ case BRS_FALSE:
+ build_le (r, type, op2.upper_bound ());
+ break;
+
+ default:
+ break;
+ }
+ return true;
+}
+
+bool
+operator_gt::op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const
+{
+ switch (get_bool_state (r, lhs, type))
+ {
+ case BRS_FALSE:
+ build_ge (r, type, op1.lower_bound ());
+ break;
+
+ case BRS_TRUE:
+ build_lt (r, type, op1.upper_bound ());
+ break;
+
+ default:
+ break;
+ }
+ return true;
+}
+
+
+class operator_ge : public range_operator
+{
+public:
+ virtual value_range_base fold_range (tree type,
+ const value_range_base &op1,
+ const value_range_base &op2) const;
+ virtual bool op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const;
+ virtual bool op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const;
+} op_ge;
+
+value_range_base
+operator_ge::fold_range (tree type,
+ const value_range_base &op1,
+ const value_range_base &op2) const
+{
+ value_range_base r;
+ if (empty_range_check (r, op1, op2))
+ return r;
+
+ signop sign = TYPE_SIGN (op1.type ());
+ gcc_checking_assert (sign == TYPE_SIGN (op2.type ()));
+
+ if (wi::ge_p (op1.lower_bound (), op2.upper_bound (), sign))
+ r = range_true (type);
+ else if (!wi::ge_p (op1.upper_bound (), op2.lower_bound (), sign))
+ r = range_false (type);
+ else
+ r = range_true_and_false (type);
+ return r;
+}
+
+bool
+operator_ge::op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const
+{
+ switch (get_bool_state (r, lhs, type))
+ {
+ case BRS_TRUE:
+ build_ge (r, type, op2.lower_bound ());
+ break;
+
+ case BRS_FALSE:
+ build_lt (r, type, op2.upper_bound ());
+ break;
+
+ default:
+ break;
+ }
+ return true;
+}
+
+bool
+operator_ge::op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const
+{
+ switch (get_bool_state (r, lhs, type))
+ {
+ case BRS_FALSE:
+ build_gt (r, type, op1.lower_bound ());
+ break;
+
+ case BRS_TRUE:
+ build_le (r, type, op1.upper_bound ());
+ break;
+
+ default:
+ break;
+ }
+ return true;
+}
+
+
+class operator_plus : public range_operator
+{
+public:
+ virtual bool op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const;
+ virtual bool op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const;
+ virtual value_range_base wi_fold (tree type,
+ const wide_int &lh_lb,
+ const wide_int &lh_ub,
+ const wide_int &rh_lb,
+ const wide_int &rh_ub) const;
+} op_plus;
+
+value_range_base
+operator_plus::wi_fold (tree type,
+ const wide_int &lh_lb, const wide_int &lh_ub,
+ const wide_int &rh_lb, const wide_int &rh_ub) const
+{
+ wi::overflow_type ov_lb, ov_ub;
+ signop s = TYPE_SIGN (type);
+ wide_int new_lb = wi::add (lh_lb, rh_lb, s, &ov_lb);
+ wide_int new_ub = wi::add (lh_ub, rh_ub, s, &ov_ub);
+ return create_range_with_overflow (type, new_lb, new_ub, ov_lb, ov_ub);
+}
+
+bool
+operator_plus::op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const
+{
+ r = range_op_handler (MINUS_EXPR, type)->fold_range (type, lhs, op2);
+ return true;
+}
+
+bool
+operator_plus::op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const
+{
+ r = range_op_handler (MINUS_EXPR, type)->fold_range (type, lhs, op1);
+ return true;
+}
+
+
+class operator_minus : public range_operator
+{
+public:
+ virtual bool op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const;
+ virtual bool op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const;
+ virtual value_range_base wi_fold (tree type,
+ const wide_int &lh_lb,
+ const wide_int &lh_ub,
+ const wide_int &rh_lb,
+ const wide_int &rh_ub) const;
+} op_minus;
+
+value_range_base
+operator_minus::wi_fold (tree type,
+ const wide_int &lh_lb, const wide_int &lh_ub,
+ const wide_int &rh_lb, const wide_int &rh_ub) const
+{
+ wi::overflow_type ov_lb, ov_ub;
+ signop s = TYPE_SIGN (type);
+ wide_int new_lb = wi::sub (lh_lb, rh_ub, s, &ov_lb);
+ wide_int new_ub = wi::sub (lh_ub, rh_lb, s, &ov_ub);
+ return create_range_with_overflow (type, new_lb, new_ub, ov_lb, ov_ub);
+}
+
+bool
+operator_minus::op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const
+{
+ r = range_op_handler (PLUS_EXPR, type)->fold_range (type, lhs, op2);
+ return true;
+}
+
+bool
+operator_minus::op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const
+{
+ r = fold_range (type, op1, lhs);
+ return true;
+}
+
+
+class operator_min : public range_operator
+{
+public:
+ virtual value_range_base wi_fold (tree type,
+ const wide_int &lh_lb,
+ const wide_int &lh_ub,
+ const wide_int &rh_lb,
+ const wide_int &rh_ub) const;
+} op_min;
+
+value_range_base
+operator_min::wi_fold (tree type,
+ const wide_int &lh_lb, const wide_int &lh_ub,
+ const wide_int &rh_lb, const wide_int &rh_ub) const
+{
+ signop s = TYPE_SIGN (type);
+ wide_int new_lb = wi::min (lh_lb, rh_lb, s);
+ wide_int new_ub = wi::min (lh_ub, rh_ub, s);
+ return create_range_with_overflow (type, new_lb, new_ub);
+}
+
+
+class operator_max : public range_operator
+{
+public:
+ virtual value_range_base wi_fold (tree type,
+ const wide_int &lh_lb,
+ const wide_int &lh_ub,
+ const wide_int &rh_lb,
+ const wide_int &rh_ub) const;
+} op_max;
+
+value_range_base
+operator_max::wi_fold (tree type,
+ const wide_int &lh_lb, const wide_int &lh_ub,
+ const wide_int &rh_lb, const wide_int &rh_ub) const
+{
+ signop s = TYPE_SIGN (type);
+ wide_int new_lb = wi::max (lh_lb, rh_lb, s);
+ wide_int new_ub = wi::max (lh_ub, rh_ub, s);
+ return create_range_with_overflow (type, new_lb, new_ub);
+}
+
+
+class cross_product_operator : public range_operator
+{
+public:
+ // Perform an operation between two wide-ints and place the result
+ // in R. Return true if the operation overflowed.
+ virtual bool wi_op_overflows (wide_int &r,
+ tree type,
+ const wide_int &,
+ const wide_int &) const = 0;
+
+ // Calculate the cross product of two sets of sub-ranges and return it.
+ value_range_base wi_cross_product (tree type,
+ const wide_int &lh_lb,
+ const wide_int &lh_ub,
+ const wide_int &rh_lb,
+ const wide_int &rh_ub) const;
+};
+
+// Calculate the cross product of two sets of ranges and return it.
+//
+// Multiplications, divisions and shifts are a bit tricky to handle,
+// depending on the mix of signs we have in the two ranges, we need to
+// operate on different values to get the minimum and maximum values
+// for the new range. One approach is to figure out all the
+// variations of range combinations and do the operations.
+//
+// However, this involves several calls to compare_values and it is
+// pretty convoluted. It's simpler to do the 4 operations (MIN0 OP
+// MIN1, MIN0 OP MAX1, MAX0 OP MIN1 and MAX0 OP MAX0 OP MAX1) and then
+// figure the smallest and largest values to form the new range.
+
+value_range_base
+cross_product_operator::wi_cross_product (tree type,
+ const wide_int &lh_lb,
+ const wide_int &lh_ub,
+ const wide_int &rh_lb,
+ const wide_int &rh_ub) const
+{
+ wide_int cp1, cp2, cp3, cp4;
+
+ // Compute the 4 cross operations, bailing if we get an overflow we
+ // can't handle.
+ if (wi_op_overflows (cp1, type, lh_lb, rh_lb))
+ return value_range_base (type);
+ if (wi::eq_p (lh_lb, lh_ub))
+ cp3 = cp1;
+ else if (wi_op_overflows (cp3, type, lh_ub, rh_lb))
+ return value_range_base (type);
+ if (wi::eq_p (rh_lb, rh_ub))
+ cp2 = cp1;
+ else if (wi_op_overflows (cp2, type, lh_lb, rh_ub))
+ return value_range_base (type);
+ if (wi::eq_p (lh_lb, lh_ub))
+ cp4 = cp2;
+ else if (wi_op_overflows (cp4, type, lh_ub, rh_ub))
+ return value_range_base (type);
+
+ // Order pairs.
+ signop sign = TYPE_SIGN (type);
+ if (wi::gt_p (cp1, cp2, sign))
+ std::swap (cp1, cp2);
+ if (wi::gt_p (cp3, cp4, sign))
+ std::swap (cp3, cp4);
+
+ // Choose min and max from the ordered pairs.
+ wide_int res_lb = wi::min (cp1, cp3, sign);
+ wide_int res_ub = wi::max (cp2, cp4, sign);
+ return create_range_with_overflow (type, res_lb, res_ub);
+}
+
+
+class operator_mult : public cross_product_operator
+{
+public:
+ virtual value_range_base wi_fold (tree type,
+ const wide_int &lh_lb,
+ const wide_int &lh_ub,
+ const wide_int &rh_lb,
+ const wide_int &rh_ub) const;
+ virtual bool wi_op_overflows (wide_int &res,
+ tree type,
+ const wide_int &w0,
+ const wide_int &w1) const;
+} op_mult;
+
+bool
+operator_mult::wi_op_overflows (wide_int &res,
+ tree type,
+ const wide_int &w0,
+ const wide_int &w1) const
+{
+ wi::overflow_type overflow = wi::OVF_NONE;
+ signop sign = TYPE_SIGN (type);
+ res = wi::mul (w0, w1, sign, &overflow);
+ if (overflow && TYPE_OVERFLOW_UNDEFINED (type))
+ {
+ // For multiplication, the sign of the overflow is given
+ // by the comparison of the signs of the operands.
+ if (sign == UNSIGNED || w0.sign_mask () == w1.sign_mask ())
+ res = wi::max_value (w0.get_precision (), sign);
+ else
+ res = wi::min_value (w0.get_precision (), sign);
+ return false;
+ }
+ return overflow;
+}
+
+value_range_base
+operator_mult::wi_fold (tree type,
+ const wide_int &lh_lb, const wide_int &lh_ub,
+ const wide_int &rh_lb, const wide_int &rh_ub) const
+{
+ if (TYPE_OVERFLOW_UNDEFINED (type))
+ return wi_cross_product (type, lh_lb, lh_ub, rh_lb, rh_ub);
+
+ // Multiply the ranges when overflow wraps. This is basically fancy
+ // code so we don't drop to varying with an unsigned
+ // [-3,-1]*[-3,-1].
+ //
+ // This test requires 2*prec bits if both operands are signed and
+ // 2*prec + 2 bits if either is not. Therefore, extend the values
+ // using the sign of the result to PREC2. From here on out,
+ // everthing is just signed math no matter what the input types
+ // were.
+
+ signop sign = TYPE_SIGN (type);
+ unsigned prec = TYPE_PRECISION (type);
+ widest2_int min0 = widest2_int::from (lh_lb, sign);
+ widest2_int max0 = widest2_int::from (lh_ub, sign);
+ widest2_int min1 = widest2_int::from (rh_lb, sign);
+ widest2_int max1 = widest2_int::from (rh_ub, sign);
+ widest2_int sizem1 = wi::mask <widest2_int> (prec, false);
+ widest2_int size = sizem1 + 1;
+
+ // Canonicalize the intervals.
+ if (sign == UNSIGNED)
+ {
+ if (wi::ltu_p (size, min0 + max0))
+ {
+ min0 -= size;
+ max0 -= size;
+ }
+ if (wi::ltu_p (size, min1 + max1))
+ {
+ min1 -= size;
+ max1 -= size;
+ }
+ }
+
+ // Sort the 4 products so that min is in prod0 and max is in
+ // prod3.
+ widest2_int prod0 = min0 * min1;
+ widest2_int prod1 = min0 * max1;
+ widest2_int prod2 = max0 * min1;
+ widest2_int prod3 = max0 * max1;
+
+ // min0min1 > max0max1
+ if (prod0 > prod3)
+ std::swap (prod0, prod3);
+
+ // min0max1 > max0min1
+ if (prod1 > prod2)
+ std::swap (prod1, prod2);
+
+ if (prod0 > prod1)
+ std::swap (prod0, prod1);
+
+ if (prod2 > prod3)
+ std::swap (prod2, prod3);
+
+ // diff = max - min
+ prod2 = prod3 - prod0;
+ if (wi::geu_p (prod2, sizem1))
+ // The range covers all values.
+ return value_range_base (type);
+
+ wide_int new_lb = wide_int::from (prod0, prec, sign);
+ wide_int new_ub = wide_int::from (prod3, prec, sign);
+ return create_possibly_reversed_range (type, new_lb, new_ub);
+}
+
+
+class operator_div : public cross_product_operator
+{
+public:
+ operator_div (enum tree_code c) { code = c; }
+ virtual value_range_base wi_fold (tree type,
+ const wide_int &lh_lb,
+ const wide_int &lh_ub,
+ const wide_int &rh_lb,
+ const wide_int &rh_ub) const;
+ virtual bool wi_op_overflows (wide_int &res,
+ tree type,
+ const wide_int &,
+ const wide_int &) const;
+private:
+ enum tree_code code;
+};
+
+bool
+operator_div::wi_op_overflows (wide_int &res,
+ tree type,
+ const wide_int &w0,
+ const wide_int &w1) const
+{
+ if (w1 == 0)
+ return true;
+
+ wi::overflow_type overflow = wi::OVF_NONE;
+ signop sign = TYPE_SIGN (type);
+
+ switch (code)
+ {
+ case EXACT_DIV_EXPR:
+ // EXACT_DIV_EXPR is implemented as TRUNC_DIV_EXPR in
+ // operator_exact_divide. No need to handle it here.
+ gcc_unreachable ();
+ break;
+ case TRUNC_DIV_EXPR:
+ res = wi::div_trunc (w0, w1, sign, &overflow);
+ break;
+ case FLOOR_DIV_EXPR:
+ res = wi::div_floor (w0, w1, sign, &overflow);
+ break;
+ case ROUND_DIV_EXPR:
+ res = wi::div_round (w0, w1, sign, &overflow);
+ break;
+ case CEIL_DIV_EXPR:
+ res = wi::div_ceil (w0, w1, sign, &overflow);
+ break;
+ default:
+ gcc_unreachable ();
+ }
+
+ if (overflow && TYPE_OVERFLOW_UNDEFINED (type))
+ {
+ // For division, the only case is -INF / -1 = +INF.
+ res = wi::max_value (w0.get_precision (), sign);
+ return false;
+ }
+ return overflow;
+}
+
+value_range_base
+operator_div::wi_fold (tree type,
+ const wide_int &lh_lb, const wide_int &lh_ub,
+ const wide_int &rh_lb, const wide_int &rh_ub) const
+{
+ // If we know we will divide by zero, return undefined.
+ if (rh_lb == 0 && rh_ub == 0)
+ return value_range_base ();
+
+ const wide_int dividend_min = lh_lb;
+ const wide_int dividend_max = lh_ub;
+ const wide_int divisor_min = rh_lb;
+ const wide_int divisor_max = rh_ub;
+ signop sign = TYPE_SIGN (type);
+ unsigned prec = TYPE_PRECISION (type);
+ wide_int extra_min, extra_max;
+
+ // If we know we won't divide by zero, just do the division.
+ if (!wi_includes_zero_p (type, divisor_min, divisor_max))
+ return wi_cross_product (type, dividend_min, dividend_max,
+ divisor_min, divisor_max);
+
+ // If flag_non_call_exceptions, we must not eliminate a division by zero.
+ if (cfun->can_throw_non_call_exceptions)
+ return value_range_base (type);
+
+ // If we're definitely dividing by zero, there's nothing to do.
+ if (wi_zero_p (type, divisor_min, divisor_max))
+ return value_range_base ();
+
+ // Perform the division in 2 parts, [LB, -1] and [1, UB], which will
+ // skip any division by zero.
+
+ // First divide by the negative numbers, if any.
+ value_range_base r;
+ if (wi::neg_p (divisor_min, sign))
+ r = wi_cross_product (type, dividend_min, dividend_max,
+ divisor_min, wi::minus_one (prec));
+ // Then divide by the non-zero positive numbers, if any.
+ if (wi::gt_p (divisor_max, wi::zero (prec), sign))
+ {
+ value_range_base tmp;
+ tmp = wi_cross_product (type, dividend_min, dividend_max,
+ wi::one (prec), divisor_max);
+ r.union_ (tmp);
+ }
+ return r;
+}
+
+operator_div op_trunc_div (TRUNC_DIV_EXPR);
+operator_div op_floor_div(FLOOR_DIV_EXPR);
+operator_div op_round_div (ROUND_DIV_EXPR);
+operator_div op_ceil_div (CEIL_DIV_EXPR);
+
+
+class operator_exact_divide : public operator_div
+{
+public:
+ operator_exact_divide () : operator_div (TRUNC_DIV_EXPR) { }
+ virtual bool op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const;
+
+} op_exact_div;
+
+bool
+operator_exact_divide::op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const
+{
+ tree offset;
+ // [2, 4] = op1 / [3,3] since its exact divide, no need to worry about
+ // remainders in the endpoints, so op1 = [2,4] * [3,3] = [6,12].
+ // We wont bother trying to enumerate all the in between stuff :-P
+ // TRUE accuraacy is [6,6][9,9][12,12]. This is unlikely to matter most of
+ // the time however.
+ // If op2 is a multiple of 2, we would be able to set some non-zero bits.
+ if (op2.singleton_p (&offset)
+ && !integer_zerop (offset))
+ {
+ r = range_op_handler (MULT_EXPR, type)->fold_range (type, lhs, op2);
+ return true;
+ }
+ return false;
+}
+
+
+class operator_lshift : public cross_product_operator
+{
+public:
+ virtual value_range_base fold_range (tree type,
+ const value_range_base &op1,
+ const value_range_base &op2) const;
+
+ virtual value_range_base wi_fold (tree type,
+ const wide_int &lh_lb, const wide_int &lh_ub,
+ const wide_int &rh_lb, const wide_int &rh_ub) const;
+ virtual bool wi_op_overflows (wide_int &res,
+ tree type,
+ const wide_int &,
+ const wide_int &) const;
+} op_lshift;
+
+value_range_base
+operator_lshift::fold_range (tree type,
+ const value_range_base &op1,
+ const value_range_base &op2) const
+{
+ value_range_base r;
+ if (undefined_shift_range_check (r, type, op2))
+ return r;
+
+ // Transform left shifts by constants into multiplies.
+ if (op2.singleton_p ())
+ {
+ unsigned shift = op2.lower_bound ().to_uhwi ();
+ wide_int tmp = wi::set_bit_in_zero (shift, TYPE_PRECISION (type));
+ value_range_base mult (type, tmp, tmp);
+
+ // Force wrapping multiplication.
+ bool saved_flag_wrapv = flag_wrapv;
+ bool saved_flag_wrapv_pointer = flag_wrapv_pointer;
+ flag_wrapv = 1;
+ flag_wrapv_pointer = 1;
+ r = range_op_handler (MULT_EXPR, type)->fold_range (type, op1, mult);
+ flag_wrapv = saved_flag_wrapv;
+ flag_wrapv_pointer = saved_flag_wrapv_pointer;
+ return r;
+ }
+
+ // Otherwise, invoke the generic fold routine.
+ return range_operator::fold_range (type, op1, op2);
+}
+
+value_range_base
+operator_lshift::wi_fold (tree type,
+ const wide_int &lh_lb, const wide_int &lh_ub,
+ const wide_int &rh_lb, const wide_int &rh_ub) const
+{
+ signop sign = TYPE_SIGN (type);
+ unsigned prec = TYPE_PRECISION (type);
+ int overflow_pos = sign == SIGNED ? prec - 1 : prec;
+ int bound_shift = overflow_pos - rh_ub.to_shwi ();
+ // If bound_shift == HOST_BITS_PER_WIDE_INT, the llshift can
+ // overflow. However, for that to happen, rh.max needs to be zero,
+ // which means rh is a singleton range of zero, which means it
+ // should be handled by the lshift fold_range above.
+ wide_int bound = wi::set_bit_in_zero (bound_shift, prec);
+ wide_int complement = ~(bound - 1);
+ wide_int low_bound, high_bound;
+ bool in_bounds = false;
+
+ if (sign == UNSIGNED)
+ {
+ low_bound = bound;
+ high_bound = complement;
+ if (wi::ltu_p (lh_ub, low_bound))
+ {
+ // [5, 6] << [1, 2] == [10, 24].
+ // We're shifting out only zeroes, the value increases
+ // monotonically.
+ in_bounds = true;
+ }
+ else if (wi::ltu_p (high_bound, lh_lb))
+ {
+ // [0xffffff00, 0xffffffff] << [1, 2]
+ // == [0xfffffc00, 0xfffffffe].
+ // We're shifting out only ones, the value decreases
+ // monotonically.
+ in_bounds = true;
+ }
+ }
+ else
+ {
+ // [-1, 1] << [1, 2] == [-4, 4]
+ low_bound = complement;
+ high_bound = bound;
+ if (wi::lts_p (lh_ub, high_bound)
+ && wi::lts_p (low_bound, lh_lb))
+ {
+ // For non-negative numbers, we're shifting out only zeroes,
+ // the value increases monotonically. For negative numbers,
+ // we're shifting out only ones, the value decreases
+ // monotonically.
+ in_bounds = true;
+ }
+ }
+
+ if (in_bounds)
+ return wi_cross_product (type, lh_lb, lh_ub, rh_lb, rh_ub);
+
+ return value_range_base (type);
+}
+
+bool
+operator_lshift::wi_op_overflows (wide_int &res,
+ tree type,
+ const wide_int &w0,
+ const wide_int &w1) const
+{
+ signop sign = TYPE_SIGN (type);
+ if (wi::neg_p (w1))
+ {
+ // It's unclear from the C standard whether shifts can overflow.
+ // The following code ignores overflow; perhaps a C standard
+ // interpretation ruling is needed.
+ res = wi::rshift (w0, -w1, sign);
+ }
+ else
+ res = wi::lshift (w0, w1);
+ return false;
+}
+
+
+class operator_rshift : public cross_product_operator
+{
+public:
+ virtual value_range_base fold_range (tree type,
+ const value_range_base &op1,
+ const value_range_base &op2) const;
+ virtual value_range_base wi_fold (tree type,
+ const wide_int &lh_lb, const wide_int &lh_ub,
+ const wide_int &rh_lb, const wide_int &rh_ub) const;
+ virtual bool wi_op_overflows (wide_int &res,
+ tree type,
+ const wide_int &w0,
+ const wide_int &w1) const;
+} op_rshift;
+
+bool
+operator_rshift::wi_op_overflows (wide_int &res,
+ tree type,
+ const wide_int &w0,
+ const wide_int &w1) const
+{
+ signop sign = TYPE_SIGN (type);
+ if (wi::neg_p (w1))
+ res = wi::lshift (w0, -w1);
+ else
+ {
+ // It's unclear from the C standard whether shifts can overflow.
+ // The following code ignores overflow; perhaps a C standard
+ // interpretation ruling is needed.
+ res = wi::rshift (w0, w1, sign);
+ }
+ return false;
+}
+
+value_range_base
+operator_rshift::fold_range (tree type,
+ const value_range_base &op1,
+ const value_range_base &op2) const
+{
+ value_range_base r;
+ if (undefined_shift_range_check (r, type, op2))
+ return r;
+
+ // Otherwise, invoke the generic fold routine.
+ return range_operator::fold_range (type, op1, op2);
+}
+
+value_range_base
+operator_rshift::wi_fold (tree type,
+ const wide_int &lh_lb, const wide_int &lh_ub,
+ const wide_int &rh_lb, const wide_int &rh_ub) const
+{
+ return wi_cross_product (type, lh_lb, lh_ub, rh_lb, rh_ub);
+}
+
+
+class operator_cast: public range_operator
+{
+public:
+ virtual value_range_base fold_range (tree type,
+ const value_range_base &op1,
+ const value_range_base &op2) const;
+ virtual bool op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const;
+
+} op_convert;
+
+value_range_base
+operator_cast::fold_range (tree type ATTRIBUTE_UNUSED,
+ const value_range_base &lh,
+ const value_range_base &rh) const
+{
+ value_range_base r;
+ if (empty_range_check (r, lh, rh))
+ return r;
+
+ tree inner = lh.type ();
+ tree outer = rh.type ();
+ gcc_checking_assert (rh.varying_p ());
+ gcc_checking_assert (types_compatible_p (outer, type));
+ signop inner_sign = TYPE_SIGN (inner);
+ signop outer_sign = TYPE_SIGN (outer);
+ unsigned inner_prec = TYPE_PRECISION (inner);
+ unsigned outer_prec = TYPE_PRECISION (outer);
+
+ for (unsigned x = 0; x < lh.num_pairs (); ++x)
+ {
+ wide_int lh_lb = lh.lower_bound (x);
+ wide_int lh_ub = lh.upper_bound (x);
+
+ // If the conversion is not truncating we can convert the min
+ // and max values and canonicalize the resulting range.
+ // Otherwise, we can do the conversion if the size of the range
+ // is less than what the precision of the target type can
+ // represent.
+ if (outer_prec >= inner_prec
+ || wi::rshift (wi::sub (lh_ub, lh_lb),
+ wi::uhwi (outer_prec, inner_prec),
+ inner_sign) == 0)
+ {
+ wide_int min = wide_int::from (lh_lb, outer_prec, inner_sign);
+ wide_int max = wide_int::from (lh_ub, outer_prec, inner_sign);
+ if (!wi::eq_p (min, wi::min_value (outer_prec, outer_sign))
+ || !wi::eq_p (max, wi::max_value (outer_prec, outer_sign)))
+ {
+ value_range_base tmp;
+ tmp = create_possibly_reversed_range (type, min, max);
+ r.union_ (tmp);
+ continue;
+ }
+ }
+ return value_range_base (type);
+ }
+ return r;
+}
+
+bool
+operator_cast::op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const
+{
+ tree lhs_type = lhs.type ();
+ gcc_checking_assert (types_compatible_p (op2.type(), type));
+
+ // If the precision of the LHS is smaller than the precision of the
+ // RHS, then there would be truncation of the value on the RHS, and
+ // so we can tell nothing about it.
+ if (TYPE_PRECISION (lhs_type) < TYPE_PRECISION (type))
+ {
+ // If we've been passed an actual value for the RHS rather than
+ // the type, see if it fits the LHS, and if so, then we can allow
+ // it.
+ r = op2;
+ r = fold_range (lhs_type, r, value_range_base (lhs_type));
+ r = fold_range (type, r, value_range_base (type));
+ if (r == op2)
+ {
+ // We know the value of the RHS fits in the LHS type, so
+ // convert the LHS and remove any values that arent in OP2.
+ r = lhs;
+ r = fold_range (type, r, value_range_base (type));
+ r.intersect (op2);
+ return true;
+ }
+ // Special case if the LHS is a boolean. A 0 means the RHS is
+ // zero, and a 1 means the RHS is non-zero.
+ if (TREE_CODE (lhs_type) == BOOLEAN_TYPE)
+ {
+ // If the LHS is unknown, the result is whatever op2 already is.
+ if (!lhs.singleton_p ())
+ {
+ r = op2;
+ return true;
+ }
+ // Boolean casts are weird in GCC. It's actually an implied
+ // mask with 0x01, so all that is known is whether the
+ // rightmost bit is 0 or 1, which implies the only value
+ // *not* in the RHS is 0 or -1.
+ unsigned prec = TYPE_PRECISION (type);
+ if (lhs.zero_p ())
+ r = value_range_base (VR_ANTI_RANGE, type,
+ wi::minus_one (prec), wi::minus_one (prec));
+ else
+ r = value_range_base (VR_ANTI_RANGE, type,
+ wi::zero (prec), wi::zero (prec));
+ // And intersect it with what we know about op2.
+ r.intersect (op2);
+ }
+ else
+ // Otherwise we'll have to assume it's whatever we know about op2.
+ r = op2;
+ return true;
+ }
+
+ // If the LHS precision is greater than the rhs precision, the LHS
+ // range is restricted to the range of the RHS by this
+ // assignment.
+ if (TYPE_PRECISION (lhs_type) > TYPE_PRECISION (type))
+ {
+ // Cast the range of the RHS to the type of the LHS.
+ value_range_base op_type (type);
+ op_type = fold_range (lhs_type, op_type, value_range_base (lhs_type));
+
+ // Intersect this with the LHS range will produce the RHS range.
+ r = range_intersect (lhs, op_type);
+ }
+ else
+ r = lhs;
+
+ // Cast the calculated range to the type of the RHS.
+ r = fold_range (type, r, value_range_base (type));
+ return true;
+}
+
+
+class operator_logical_and : public range_operator
+{
+public:
+ virtual value_range_base fold_range (tree type,
+ const value_range_base &lh,
+ const value_range_base &rh) const;
+ virtual bool op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const;
+ virtual bool op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const;
+} op_logical_and;
+
+
+value_range_base
+operator_logical_and::fold_range (tree type,
+ const value_range_base &lh,
+ const value_range_base &rh) const
+{
+ value_range_base r;
+ if (empty_range_check (r, lh, rh))
+ return r;
+
+ // 0 && anything is 0.
+ if ((wi::eq_p (lh.lower_bound (), 0) && wi::eq_p (lh.upper_bound (), 0))
+ || (wi::eq_p (lh.lower_bound (), 0) && wi::eq_p (rh.upper_bound (), 0)))
+ return range_false (type);
+
+ // To reach this point, there must be a logical 1 on each side, and
+ // the only remaining question is whether there is a zero or not.
+ if (lh.contains_p (build_zero_cst (lh.type ()))
+ || rh.contains_p (build_zero_cst (rh.type ())))
+ return range_true_and_false (type);
+
+ return range_true (type);
+}
+
+bool
+operator_logical_and::op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2 ATTRIBUTE_UNUSED) const
+{
+ switch (get_bool_state (r, lhs, type))
+ {
+ case BRS_TRUE:
+ // A true result means both sides of the AND must be true.
+ r = range_true (type);
+ break;
+ default:
+ // Any other result means only one side has to be false, the
+ // other side can be anything. So we cannott be sure of any
+ // result here.
+ r = range_true_and_false (type);
+ break;
+ }
+ return true;
+}
+
+bool
+operator_logical_and::op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const
+{
+ return operator_logical_and::op1_range (r, type, lhs, op1);
+}
+
+
+class operator_bitwise_and : public range_operator
+{
+public:
+ virtual bool op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const;
+ virtual bool op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const;
+ virtual value_range_base wi_fold (tree type,
+ const wide_int &lh_lb,
+ const wide_int &lh_ub,
+ const wide_int &rh_lb,
+ const wide_int &rh_ub) const;
+} op_bitwise_and;
+
+// Optimize BIT_AND_EXPR and BIT_IOR_EXPR in terms of a mask if
+// possible. Basically, see if we can optimize:
+//
+// [LB, UB] op Z
+// into:
+// [LB op Z, UB op Z]
+//
+// If the optimization was successful, accumulate the range in R and
+// return TRUE.
+
+static bool
+wi_optimize_and_or (value_range_base &r,
+ enum tree_code code,
+ tree type,
+ const wide_int &lh_lb, const wide_int &lh_ub,
+ const wide_int &rh_lb, const wide_int &rh_ub)
+{
+ // Calculate the singleton mask among the ranges, if any.
+ wide_int lower_bound, upper_bound, mask;
+ if (wi::eq_p (rh_lb, rh_ub))
+ {
+ mask = rh_lb;
+ lower_bound = lh_lb;
+ upper_bound = lh_ub;
+ }
+ else if (wi::eq_p (lh_lb, lh_ub))
+ {
+ mask = lh_lb;
+ lower_bound = rh_lb;
+ upper_bound = rh_ub;
+ }
+ else
+ return false;
+
+ // If Z is a constant which (for op | its bitwise not) has n
+ // consecutive least significant bits cleared followed by m 1
+ // consecutive bits set immediately above it and either
+ // m + n == precision, or (x >> (m + n)) == (y >> (m + n)).
+ //
+ // The least significant n bits of all the values in the range are
+ // cleared or set, the m bits above it are preserved and any bits
+ // above these are required to be the same for all values in the
+ // range.
+ wide_int w = mask;
+ int m = 0, n = 0;
+ if (code == BIT_IOR_EXPR)
+ w = ~w;
+ if (wi::eq_p (w, 0))
+ n = w.get_precision ();
+ else
+ {
+ n = wi::ctz (w);
+ w = ~(w | wi::mask (n, false, w.get_precision ()));
+ if (wi::eq_p (w, 0))
+ m = w.get_precision () - n;
+ else
+ m = wi::ctz (w) - n;
+ }
+ wide_int new_mask = wi::mask (m + n, true, w.get_precision ());
+ if ((new_mask & lower_bound) != (new_mask & upper_bound))
+ return false;
+
+ wide_int res_lb, res_ub;
+ if (code == BIT_AND_EXPR)
+ {
+ res_lb = wi::bit_and (lower_bound, mask);
+ res_ub = wi::bit_and (upper_bound, mask);
+ }
+ else if (code == BIT_IOR_EXPR)
+ {
+ res_lb = wi::bit_or (lower_bound, mask);
+ res_ub = wi::bit_or (upper_bound, mask);
+ }
+ else
+ gcc_unreachable ();
+ r = create_range_with_overflow (type, res_lb, res_ub);
+ return true;
+}
+
+// For range [LB, UB] compute two wide_int bit masks.
+//
+// In the MAYBE_NONZERO bit mask, if some bit is unset, it means that
+// for all numbers in the range the bit is 0, otherwise it might be 0
+// or 1.
+//
+// In the MUSTBE_NONZERO bit mask, if some bit is set, it means that
+// for all numbers in the range the bit is 1, otherwise it might be 0
+// or 1.
+
+static void
+wi_set_zero_nonzero_bits (tree type,
+ const wide_int &lb, const wide_int &ub,
+ wide_int &maybe_nonzero,
+ wide_int &mustbe_nonzero)
+{
+ signop sign = TYPE_SIGN (type);
+
+ if (wi::eq_p (lb, ub))
+ maybe_nonzero = mustbe_nonzero = lb;
+ else if (wi::ge_p (lb, 0, sign) || wi::lt_p (ub, 0, sign))
+ {
+ wide_int xor_mask = lb ^ ub;
+ maybe_nonzero = lb | ub;
+ mustbe_nonzero = lb & ub;
+ if (xor_mask != 0)
+ {
+ wide_int mask = wi::mask (wi::floor_log2 (xor_mask), false,
+ maybe_nonzero.get_precision ());
+ maybe_nonzero = maybe_nonzero | mask;
+ mustbe_nonzero = wi::bit_and_not (mustbe_nonzero, mask);
+ }
+ }
+ else
+ {
+ maybe_nonzero = wi::minus_one (lb.get_precision ());
+ mustbe_nonzero = wi::zero (lb.get_precision ());
+ }
+}
+
+value_range_base
+operator_bitwise_and::wi_fold (tree type,
+ const wide_int &lh_lb,
+ const wide_int &lh_ub,
+ const wide_int &rh_lb,
+ const wide_int &rh_ub) const
+{
+ value_range_base r;
+ if (wi_optimize_and_or (r, BIT_AND_EXPR, type, lh_lb, lh_ub, rh_lb, rh_ub))
+ return r;
+
+ wide_int maybe_nonzero_lh, mustbe_nonzero_lh;
+ wide_int maybe_nonzero_rh, mustbe_nonzero_rh;
+ wi_set_zero_nonzero_bits (type, lh_lb, lh_ub,
+ maybe_nonzero_lh, mustbe_nonzero_lh);
+ wi_set_zero_nonzero_bits (type, rh_lb, rh_ub,
+ maybe_nonzero_rh, mustbe_nonzero_rh);
+
+ wide_int new_lb = mustbe_nonzero_lh & mustbe_nonzero_rh;
+ wide_int new_ub = maybe_nonzero_lh & maybe_nonzero_rh;
+ signop sign = TYPE_SIGN (type);
+ unsigned prec = TYPE_PRECISION (type);
+ // If both input ranges contain only negative values, we can
+ // truncate the result range maximum to the minimum of the
+ // input range maxima.
+ if (wi::lt_p (lh_ub, 0, sign) && wi::lt_p (rh_ub, 0, sign))
+ {
+ new_ub = wi::min (new_ub, lh_ub, sign);
+ new_ub = wi::min (new_ub, rh_ub, sign);
+ }
+ // If either input range contains only non-negative values
+ // we can truncate the result range maximum to the respective
+ // maximum of the input range.
+ if (wi::ge_p (lh_lb, 0, sign))
+ new_ub = wi::min (new_ub, lh_ub, sign);
+ if (wi::ge_p (rh_lb, 0, sign))
+ new_ub = wi::min (new_ub, rh_ub, sign);
+ // PR68217: In case of signed & sign-bit-CST should
+ // result in [-INF, 0] instead of [-INF, INF].
+ if (wi::gt_p (new_lb, new_ub, sign))
+ {
+ wide_int sign_bit = wi::set_bit_in_zero (prec - 1, prec);
+ if (sign == SIGNED
+ && ((wi::eq_p (lh_lb, lh_ub)
+ && !wi::cmps (lh_lb, sign_bit))
+ || (wi::eq_p (rh_lb, rh_ub)
+ && !wi::cmps (rh_lb, sign_bit))))
+ {
+ new_lb = wi::min_value (prec, sign);
+ new_ub = wi::zero (prec);
+ }
+ }
+ // If the limits got swapped around, return varying.
+ if (wi::gt_p (new_lb, new_ub,sign))
+ return value_range_base (type);
+
+ return create_range_with_overflow (type, new_lb, new_ub);
+}
+
+bool
+operator_bitwise_and::op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const
+{
+ // If this is really a logical wi_fold, call that.
+ if (types_compatible_p (type, boolean_type_node))
+ return op_logical_and.op1_range (r, type, lhs, op2);
+
+ // For now do nothing with bitwise AND of value_range's.
+ r.set_varying (type);
+ return true;
+}
+
+bool
+operator_bitwise_and::op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const
+{
+ return operator_bitwise_and::op1_range (r, type, lhs, op1);
+}
+
+
+class operator_logical_or : public range_operator
+{
+public:
+ virtual value_range_base fold_range (tree type,
+ const value_range_base &lh,
+ const value_range_base &rh) const;
+ virtual bool op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const;
+ virtual bool op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const;
+} op_logical_or;
+
+value_range_base
+operator_logical_or::fold_range (tree type ATTRIBUTE_UNUSED,
+ const value_range_base &lh,
+ const value_range_base &rh) const
+{
+ value_range_base r;
+ if (empty_range_check (r, lh, rh))
+ return r;
+
+ return range_union (lh, rh);
+}
+
+bool
+operator_logical_or::op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2 ATTRIBUTE_UNUSED) const
+{
+ switch (get_bool_state (r, lhs, type))
+ {
+ case BRS_FALSE:
+ // A false result means both sides of the OR must be false.
+ r = range_false (type);
+ break;
+ default:
+ // Any other result means only one side has to be true, the
+ // other side can be anything. so we can't be sure of any result
+ // here.
+ r = range_true_and_false (type);
+ break;
+ }
+ return true;
+}
+
+bool
+operator_logical_or::op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const
+{
+ return operator_logical_or::op1_range (r, type, lhs, op1);
+}
+
+
+class operator_bitwise_or : public range_operator
+{
+public:
+ virtual bool op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const;
+ virtual bool op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const;
+ virtual value_range_base wi_fold (tree type,
+ const wide_int &lh_lb,
+ const wide_int &lh_ub,
+ const wide_int &rh_lb,
+ const wide_int &rh_ub) const;
+} op_bitwise_or;
+
+value_range_base
+operator_bitwise_or::wi_fold (tree type,
+ const wide_int &lh_lb,
+ const wide_int &lh_ub,
+ const wide_int &rh_lb,
+ const wide_int &rh_ub) const
+{
+ value_range_base r;
+ if (wi_optimize_and_or (r, BIT_IOR_EXPR, type, lh_lb, lh_ub, rh_lb, rh_ub))
+ return r;
+
+ wide_int maybe_nonzero_lh, mustbe_nonzero_lh;
+ wide_int maybe_nonzero_rh, mustbe_nonzero_rh;
+ wi_set_zero_nonzero_bits (type, lh_lb, lh_ub,
+ maybe_nonzero_lh, mustbe_nonzero_lh);
+ wi_set_zero_nonzero_bits (type, rh_lb, rh_ub,
+ maybe_nonzero_rh, mustbe_nonzero_rh);
+ wide_int new_lb = mustbe_nonzero_lh | mustbe_nonzero_rh;
+ wide_int new_ub = maybe_nonzero_lh | maybe_nonzero_rh;
+ signop sign = TYPE_SIGN (type);
+ // If the input ranges contain only positive values we can
+ // truncate the minimum of the result range to the maximum
+ // of the input range minima.
+ if (wi::ge_p (lh_lb, 0, sign)
+ && wi::ge_p (rh_lb, 0, sign))
+ {
+ new_lb = wi::max (new_lb, lh_lb, sign);
+ new_lb = wi::max (new_lb, rh_lb, sign);
+ }
+ // If either input range contains only negative values
+ // we can truncate the minimum of the result range to the
+ // respective minimum range.
+ if (wi::lt_p (lh_ub, 0, sign))
+ new_lb = wi::max (new_lb, lh_lb, sign);
+ if (wi::lt_p (rh_ub, 0, sign))
+ new_lb = wi::max (new_lb, rh_lb, sign);
+ // If the limits got swapped around, return varying.
+ if (wi::gt_p (new_lb, new_ub,sign))
+ return value_range_base (type);
+
+ return create_range_with_overflow (type, new_lb, new_ub);
+}
+
+bool
+operator_bitwise_or::op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const
+{
+ // If this is really a logical wi_fold, call that.
+ if (types_compatible_p (type, boolean_type_node))
+ return op_logical_or.op1_range (r, type, lhs, op2);
+
+ // For now do nothing with bitwise OR of value_range's.
+ r.set_varying (type);
+ return true;
+}
+
+bool
+operator_bitwise_or::op2_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op1) const
+{
+ return operator_bitwise_or::op1_range (r, type, lhs, op1);
+}
+
+
+class operator_bitwise_xor : public range_operator
+{
+public:
+ virtual value_range_base wi_fold (tree type,
+ const wide_int &lh_lb,
+ const wide_int &lh_ub,
+ const wide_int &rh_lb,
+ const wide_int &rh_ub) const;
+} op_bitwise_xor;
+
+value_range_base
+operator_bitwise_xor::wi_fold (tree type,
+ const wide_int &lh_lb,
+ const wide_int &lh_ub,
+ const wide_int &rh_lb,
+ const wide_int &rh_ub) const
+{
+ signop sign = TYPE_SIGN (type);
+ wide_int maybe_nonzero_lh, mustbe_nonzero_lh;
+ wide_int maybe_nonzero_rh, mustbe_nonzero_rh;
+ wi_set_zero_nonzero_bits (type, lh_lb, lh_ub,
+ maybe_nonzero_lh, mustbe_nonzero_lh);
+ wi_set_zero_nonzero_bits (type, rh_lb, rh_ub,
+ maybe_nonzero_rh, mustbe_nonzero_rh);
+
+ wide_int result_zero_bits = ((mustbe_nonzero_lh & mustbe_nonzero_rh)
+ | ~(maybe_nonzero_lh | maybe_nonzero_rh));
+ wide_int result_one_bits
+ = (wi::bit_and_not (mustbe_nonzero_lh, maybe_nonzero_rh)
+ | wi::bit_and_not (mustbe_nonzero_rh, maybe_nonzero_lh));
+ wide_int new_ub = ~result_zero_bits;
+ wide_int new_lb = result_one_bits;
+
+ // If the range has all positive or all negative values, the result
+ // is better than VARYING.
+ if (wi::lt_p (new_lb, 0, sign) || wi::ge_p (new_ub, 0, sign))
+ return create_range_with_overflow (type, new_lb, new_ub);
+
+ return value_range_base (type);
+}
+
+
+class operator_trunc_mod : public range_operator
+{
+public:
+ virtual value_range_base wi_fold (tree type,
+ const wide_int &lh_lb,
+ const wide_int &lh_ub,
+ const wide_int &rh_lb,
+ const wide_int &rh_ub) const;
+} op_trunc_mod;
+
+value_range_base
+operator_trunc_mod::wi_fold (tree type,
+ const wide_int &lh_lb,
+ const wide_int &lh_ub,
+ const wide_int &rh_lb,
+ const wide_int &rh_ub) const
+{
+ wide_int new_lb, new_ub, tmp;
+ signop sign = TYPE_SIGN (type);
+ unsigned prec = TYPE_PRECISION (type);
+
+ // Mod 0 is undefined. Return undefined.
+ if (wi_zero_p (type, rh_lb, rh_ub))
+ return value_range_base ();
+
+ // ABS (A % B) < ABS (B) and either 0 <= A % B <= A or A <= A % B <= 0.
+ new_ub = rh_ub - 1;
+ if (sign == SIGNED)
+ {
+ tmp = -1 - rh_lb;
+ new_ub = wi::smax (new_ub, tmp);
+ }
+
+ if (sign == UNSIGNED)
+ new_lb = wi::zero (prec);
+ else
+ {
+ new_lb = -new_ub;
+ tmp = lh_lb;
+ if (wi::gts_p (tmp, 0))
+ tmp = wi::zero (prec);
+ new_lb = wi::smax (new_lb, tmp);
+ }
+ tmp = lh_ub;
+ if (sign == SIGNED && wi::neg_p (tmp))
+ tmp = wi::zero (prec);
+ new_ub = wi::min (new_ub, tmp, sign);
+
+ return create_range_with_overflow (type, new_lb, new_ub);
+}
+
+
+class operator_logical_not : public range_operator
+{
+public:
+ virtual value_range_base fold_range (tree type,
+ const value_range_base &lh,
+ const value_range_base &rh) const;
+ virtual bool op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const;
+} op_logical_not;
+
+// Folding a logical NOT, oddly enough, involves doing nothing on the
+// forward pass through. During the initial walk backwards, the
+// logical NOT reversed the desired outcome on the way back, so on the
+// way forward all we do is pass the range forward.
+//
+// b_2 = x_1 < 20
+// b_3 = !b_2
+// if (b_3)
+// to determine the TRUE branch, walking backward
+// if (b_3) if ([1,1])
+// b_3 = !b_2 [1,1] = ![0,0]
+// b_2 = x_1 < 20 [0,0] = x_1 < 20, false, so x_1 == [20, 255]
+// which is the result we are looking for.. so.. pass it through.
+
+value_range_base
+operator_logical_not::fold_range (tree type,
+ const value_range_base &lh,
+ const value_range_base &rh ATTRIBUTE_UNUSED) const
+{
+ value_range_base r;
+ if (empty_range_check (r, lh, rh))
+ return r;
+
+ if (lh.varying_p () || lh.undefined_p ())
+ r = lh;
+ else
+ r = range_invert (lh);
+ gcc_checking_assert (lh.type() == type);
+ return r;
+}
+
+bool
+operator_logical_not::op1_range (value_range_base &r,
+ tree type ATTRIBUTE_UNUSED,
+ const value_range_base &lhs,
+ const value_range_base &op2 ATTRIBUTE_UNUSED) const
+{
+ if (lhs.varying_p () || lhs.undefined_p ())
+ r = lhs;
+ else
+ r = range_invert (lhs);
+ return true;
+}
+
+
+class operator_bitwise_not : public range_operator
+{
+public:
+ virtual value_range_base fold_range (tree type,
+ const value_range_base &lh,
+ const value_range_base &rh) const;
+ virtual bool op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const;
+} op_bitwise_not;
+
+value_range_base
+operator_bitwise_not::fold_range (tree type,
+ const value_range_base &lh,
+ const value_range_base &rh) const
+{
+ value_range_base r;
+ if (empty_range_check (r, lh, rh))
+ return r;
+
+ // ~X is simply -1 - X.
+ value_range_base minusone (type,
+ wi::minus_one (TYPE_PRECISION (type)),
+ wi::minus_one (TYPE_PRECISION (type)));
+ r = range_op_handler (MINUS_EXPR, type)->fold_range (type, minusone, lh);
+ return r;
+}
+
+bool
+operator_bitwise_not::op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const
+{
+ // ~X is -1 - X and since bitwise NOT is involutary...do it again.
+ r = fold_range (type, lhs, op2);
+ return true;
+}
+
+
+class operator_cst : public range_operator
+{
+public:
+ virtual value_range_base fold_range (tree type,
+ const value_range_base &op1,
+ const value_range_base &op2) const;
+} op_integer_cst;
+
+value_range_base
+operator_cst::fold_range (tree type ATTRIBUTE_UNUSED,
+ const value_range_base &lh,
+ const value_range_base &rh ATTRIBUTE_UNUSED) const
+{
+ return lh;
+}
+
+
+class operator_identity : public range_operator
+{
+public:
+ virtual value_range_base fold_range (tree type,
+ const value_range_base &op1,
+ const value_range_base &op2) const;
+ virtual bool op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const;
+} op_identity;
+
+value_range_base
+operator_identity::fold_range (tree type ATTRIBUTE_UNUSED,
+ const value_range_base &lh,
+ const value_range_base &rh ATTRIBUTE_UNUSED) const
+{
+ return lh;
+}
+
+bool
+operator_identity::op1_range (value_range_base &r, tree type ATTRIBUTE_UNUSED,
+ const value_range_base &lhs,
+ const value_range_base &op2 ATTRIBUTE_UNUSED) const
+{
+ r = lhs;
+ return true;
+}
+
+
+class operator_abs : public range_operator
+{
+ public:
+ virtual value_range_base wi_fold (tree type,
+ const wide_int &lh_lb,
+ const wide_int &lh_ub,
+ const wide_int &rh_lb,
+ const wide_int &rh_ub) const;
+ virtual bool op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const;
+} op_abs;
+
+value_range_base
+operator_abs::wi_fold (tree type,
+ const wide_int &lh_lb, const wide_int &lh_ub,
+ const wide_int &rh_lb ATTRIBUTE_UNUSED,
+ const wide_int &rh_ub ATTRIBUTE_UNUSED) const
+{
+ wide_int min, max;
+ signop sign = TYPE_SIGN (type);
+ unsigned prec = TYPE_PRECISION (type);
+
+ // Pass through LH for the easy cases.
+ if (sign == UNSIGNED || wi::ge_p (lh_lb, 0, sign))
+ return value_range_base (type, lh_lb, lh_ub);
+
+ // -TYPE_MIN_VALUE = TYPE_MIN_VALUE with flag_wrapv so we can't get
+ // a useful range.
+ wide_int min_value = wi::min_value (prec, sign);
+ wide_int max_value = wi::max_value (prec, sign);
+ if (!TYPE_OVERFLOW_UNDEFINED (type) && wi::eq_p (lh_lb, min_value))
+ return value_range_base (type);
+
+ // ABS_EXPR may flip the range around, if the original range
+ // included negative values.
+ if (wi::eq_p (lh_lb, min_value))
+ min = max_value;
+ else
+ min = wi::abs (lh_lb);
+ if (wi::eq_p (lh_ub, min_value))
+ max = max_value;
+ else
+ max = wi::abs (lh_ub);
+
+ // If the range contains zero then we know that the minimum value in the
+ // range will be zero.
+ if (wi::le_p (lh_lb, 0, sign) && wi::ge_p (lh_ub, 0, sign))
+ {
+ if (wi::gt_p (min, max, sign))
+ max = min;
+ min = wi::zero (prec);
+ }
+ else
+ {
+ // If the range was reversed, swap MIN and MAX.
+ if (wi::gt_p (min, max, sign))
+ std::swap (min, max);
+ }
+
+ // If the new range has its limits swapped around (MIN > MAX), then
+ // the operation caused one of them to wrap around. The only thing
+ // we know is that the result is positive.
+ if (wi::gt_p (min, max, sign))
+ {
+ min = wi::zero (prec);
+ max = max_value;
+ }
+ return value_range_base (type, min, max);
+}
+
+bool
+operator_abs::op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const
+{
+ if (empty_range_check (r, lhs, op2))
+ return true;
+ if (TYPE_UNSIGNED (type))
+ {
+ r = lhs;
+ return true;
+ }
+ // Start with the positives because negatives are an impossible result.
+ value_range_base positives = range_positives (type);
+ positives.intersect (lhs);
+ r = positives;
+ // Then add the negative of each pair:
+ // ABS(op1) = [5,20] would yield op1 => [-20,-5][5,20].
+ for (unsigned i = 0; i < positives.num_pairs (); ++i)
+ r.union_ (value_range_base (type,
+ -positives.upper_bound (i),
+ -positives.lower_bound (i)));
+ return true;
+}
+
+
+class operator_absu : public range_operator
+{
+ public:
+ virtual value_range_base wi_fold (tree type,
+ const wide_int &lh_lb, const wide_int &lh_ub,
+ const wide_int &rh_lb, const wide_int &rh_ub) const;
+} op_absu;
+
+value_range_base
+operator_absu::wi_fold (tree type,
+ const wide_int &lh_lb, const wide_int &lh_ub,
+ const wide_int &rh_lb ATTRIBUTE_UNUSED,
+ const wide_int &rh_ub ATTRIBUTE_UNUSED) const
+{
+ wide_int new_lb, new_ub;
+
+ // Pass through VR0 the easy cases.
+ if (wi::ges_p (lh_lb, 0))
+ {
+ new_lb = lh_lb;
+ new_ub = lh_ub;
+ }
+ else
+ {
+ new_lb = wi::abs (lh_lb);
+ new_ub = wi::abs (lh_ub);
+
+ // If the range contains zero then we know that the minimum
+ // value in the range will be zero.
+ if (wi::ges_p (lh_ub, 0))
+ {
+ if (wi::gtu_p (new_lb, new_ub))
+ new_ub = new_lb;
+ new_lb = wi::zero (TYPE_PRECISION (type));
+ }
+ else
+ std::swap (new_lb, new_ub);
+ }
+
+ gcc_checking_assert (TYPE_UNSIGNED (type));
+ return value_range_base (type, new_lb, new_ub);
+}
+
+
+class operator_negate : public range_operator
+{
+ public:
+ virtual value_range_base fold_range (tree type,
+ const value_range_base &op1,
+ const value_range_base &op2) const;
+ virtual bool op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const;
+} op_negate;
+
+value_range_base
+operator_negate::fold_range (tree type,
+ const value_range_base &lh,
+ const value_range_base &rh) const
+{
+ value_range_base r;
+ if (empty_range_check (r, lh, rh))
+ return r;
+ // -X is simply 0 - X.
+ return
+ range_op_handler (MINUS_EXPR, type)->fold_range (type,
+ range_zero (type), lh);
+}
+
+bool
+operator_negate::op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const
+{
+ // NEGATE is involutory.
+ r = fold_range (type, lhs, op2);
+ return true;
+}
+
+
+class operator_addr_expr : public range_operator
+{
+public:
+ virtual value_range_base fold_range (tree type,
+ const value_range_base &op1,
+ const value_range_base &op2) const;
+ virtual bool op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const;
+} op_addr;
+
+value_range_base
+operator_addr_expr::fold_range (tree type,
+ const value_range_base &lh,
+ const value_range_base &rh) const
+{
+ value_range_base r;
+ if (empty_range_check (r, lh, rh))
+ return r;
+
+ // Return a non-null pointer of the LHS type (passed in op2).
+ if (lh.zero_p ())
+ return range_zero (type);
+ if (!lh.contains_p (build_zero_cst (lh.type ())))
+ return range_nonzero (type);
+ return value_range_base (type);
+}
+
+bool
+operator_addr_expr::op1_range (value_range_base &r, tree type,
+ const value_range_base &lhs,
+ const value_range_base &op2) const
+{
+ r = operator_addr_expr::fold_range (type, lhs, op2);
+ return true;
+}
+
+
+class pointer_plus_operator : public range_operator
+{
+public:
+ virtual value_range_base wi_fold (tree type,
+ const wide_int &lh_lb, const wide_int &lh_ub,
+ const wide_int &rh_lb, const wide_int &rh_ub) const;
+} op_pointer_plus;
+
+value_range_base
+pointer_plus_operator::wi_fold (tree type,
+ const wide_int &lh_lb,
+ const wide_int &lh_ub,
+ const wide_int &rh_lb,
+ const wide_int &rh_ub) const
+{
+ // For pointer types, we are really only interested in asserting
+ // whether the expression evaluates to non-NULL.
+ //
+ // With -fno-delete-null-pointer-checks we need to be more
+ // conservative. As some object might reside at address 0,
+ // then some offset could be added to it and the same offset
+ // subtracted again and the result would be NULL.
+ // E.g.
+ // static int a[12]; where &a[0] is NULL and
+ // ptr = &a[6];
+ // ptr -= 6;
+ // ptr will be NULL here, even when there is POINTER_PLUS_EXPR
+ // where the first range doesn't include zero and the second one
+ // doesn't either. As the second operand is sizetype (unsigned),
+ // consider all ranges where the MSB could be set as possible
+ // subtractions where the result might be NULL.
+ if ((!wi_includes_zero_p (type, lh_lb, lh_ub)
+ || !wi_includes_zero_p (type, rh_lb, rh_ub))
+ && !TYPE_OVERFLOW_WRAPS (type)
+ && (flag_delete_null_pointer_checks
+ || !wi::sign_mask (rh_ub)))
+ return range_nonzero (type);
+ if (lh_lb == lh_ub && lh_lb == 0
+ && rh_lb == rh_ub && rh_lb == 0)
+ return range_zero (type);
+ return value_range_base (type);
+}
+
+
+class pointer_min_max_operator : public range_operator
+{
+public:
+ virtual value_range_base wi_fold (tree type,
+ const wide_int &lh_lb, const wide_int &lh_ub,
+ const wide_int &rh_lb, const wide_int &rh_ub) const;
+} op_ptr_min_max;
+
+value_range_base
+pointer_min_max_operator::wi_fold (tree type,
+ const wide_int &lh_lb,
+ const wide_int &lh_ub,
+ const wide_int &rh_lb,
+ const wide_int &rh_ub) const
+{
+ // For MIN/MAX expressions with pointers, we only care about
+ // nullness. If both are non null, then the result is nonnull.
+ // If both are null, then the result is null. Otherwise they
+ // are varying.
+ if (!wi_includes_zero_p (type, lh_lb, lh_ub)
+ && !wi_includes_zero_p (type, rh_lb, rh_ub))
+ return range_nonzero (type);
+ if (wi_zero_p (type, lh_lb, lh_ub) && wi_zero_p (type, rh_lb, rh_ub))
+ return range_zero (type);
+ return value_range_base (type);
+}
+
+
+class pointer_and_operator : public range_operator
+{
+public:
+ virtual value_range_base wi_fold (tree type,
+ const wide_int &lh_lb, const wide_int &lh_ub,
+ const wide_int &rh_lb, const wide_int &rh_ub) const;
+} op_pointer_and;
+
+value_range_base
+pointer_and_operator::wi_fold (tree type,
+ const wide_int &lh_lb,
+ const wide_int &lh_ub,
+ const wide_int &rh_lb ATTRIBUTE_UNUSED,
+ const wide_int &rh_ub ATTRIBUTE_UNUSED) const
+{
+ // For pointer types, we are really only interested in asserting
+ // whether the expression evaluates to non-NULL.
+ if (wi_zero_p (type, lh_lb, lh_ub) || wi_zero_p (type, lh_lb, lh_ub))
+ return range_zero (type);
+
+ return value_range_base (type);
+}
+
+
+class pointer_or_operator : public range_operator
+{
+public:
+ virtual value_range_base wi_fold (tree type,
+ const wide_int &lh_lb, const wide_int &lh_ub,
+ const wide_int &rh_lb, const wide_int &rh_ub) const;
+} op_pointer_or;
+
+value_range_base
+pointer_or_operator::wi_fold (tree type,
+ const wide_int &lh_lb,
+ const wide_int &lh_ub,
+ const wide_int &rh_lb,
+ const wide_int &rh_ub) const
+{
+ // For pointer types, we are really only interested in asserting
+ // whether the expression evaluates to non-NULL.
+ if (!wi_includes_zero_p (type, lh_lb, lh_ub)
+ && !wi_includes_zero_p (type, rh_lb, rh_ub))
+ return range_nonzero (type);
+ if (wi_zero_p (type, lh_lb, lh_ub) && wi_zero_p (type, rh_lb, rh_ub))
+ return range_zero (type);
+ return value_range_base (type);
+}
+\f
+// This implements the range operator tables as local objects in this file.
+
+class range_op_table
+{
+public:
+ inline range_operator *operator[] (enum tree_code code);
+protected:
+ void set (enum tree_code code, range_operator &op);
+private:
+ range_operator *m_range_tree[MAX_TREE_CODES];
+};
+
+// Return a pointer to the range_operator instance, if there is one
+// associated with tree_code CODE.
+
+range_operator *
+range_op_table::operator[] (enum tree_code code)
+{
+ gcc_checking_assert (code > 0 && code < MAX_TREE_CODES);
+ return m_range_tree[code];
+}
+
+// Add OP to the handler table for CODE.
+
+void
+range_op_table::set (enum tree_code code, range_operator &op)
+{
+ gcc_checking_assert (m_range_tree[code] == NULL);
+ m_range_tree[code] = &op;
+}
+
+// Instantiate a range op table for integral operations.
+
+class integral_table : public range_op_table
+{
+public:
+ integral_table ();
+} integral_tree_table;
+
+integral_table::integral_table ()
+{
+ set (EQ_EXPR, op_equal);
+ set (NE_EXPR, op_not_equal);
+ set (LT_EXPR, op_lt);
+ set (LE_EXPR, op_le);
+ set (GT_EXPR, op_gt);
+ set (GE_EXPR, op_ge);
+ set (PLUS_EXPR, op_plus);
+ set (MINUS_EXPR, op_minus);
+ set (MIN_EXPR, op_min);
+ set (MAX_EXPR, op_max);
+ set (MULT_EXPR, op_mult);
+ set (TRUNC_DIV_EXPR, op_trunc_div);
+ set (FLOOR_DIV_EXPR, op_floor_div);
+ set (ROUND_DIV_EXPR, op_round_div);
+ set (CEIL_DIV_EXPR, op_ceil_div);
+ set (EXACT_DIV_EXPR, op_exact_div);
+ set (LSHIFT_EXPR, op_lshift);
+ set (RSHIFT_EXPR, op_rshift);
+ set (NOP_EXPR, op_convert);
+ set (CONVERT_EXPR, op_convert);
+ set (TRUTH_AND_EXPR, op_logical_and);
+ set (BIT_AND_EXPR, op_bitwise_and);
+ set (TRUTH_OR_EXPR, op_logical_or);
+ set (BIT_IOR_EXPR, op_bitwise_or);
+ set (BIT_XOR_EXPR, op_bitwise_xor);
+ set (TRUNC_MOD_EXPR, op_trunc_mod);
+ set (TRUTH_NOT_EXPR, op_logical_not);
+ set (BIT_NOT_EXPR, op_bitwise_not);
+ set (INTEGER_CST, op_integer_cst);
+ set (SSA_NAME, op_identity);
+ set (PAREN_EXPR, op_identity);
+ set (OBJ_TYPE_REF, op_identity);
+ set (ABS_EXPR, op_abs);
+ set (ABSU_EXPR, op_absu);
+ set (NEGATE_EXPR, op_negate);
+ set (ADDR_EXPR, op_addr);
+}
+
+// Instantiate a range op table for pointer operations.
+
+class pointer_table : public range_op_table
+{
+public:
+ pointer_table ();
+} pointer_tree_table;
+
+pointer_table::pointer_table ()
+{
+ set (BIT_AND_EXPR, op_pointer_and);
+ set (BIT_IOR_EXPR, op_pointer_or);
+ set (MIN_EXPR, op_ptr_min_max);
+ set (MAX_EXPR, op_ptr_min_max);
+ set (POINTER_PLUS_EXPR, op_pointer_plus);
+
+ set (EQ_EXPR, op_equal);
+ set (NE_EXPR, op_not_equal);
+ set (LT_EXPR, op_lt);
+ set (LE_EXPR, op_le);
+ set (GT_EXPR, op_gt);
+ set (GE_EXPR, op_ge);
+ set (SSA_NAME, op_identity);
+ set (ADDR_EXPR, op_addr);
+ set (NOP_EXPR, op_convert);
+ set (CONVERT_EXPR, op_convert);
+
+ set (BIT_NOT_EXPR, op_bitwise_not);
+ set (BIT_XOR_EXPR, op_bitwise_xor);
+}
+
+// The tables are hidden and accessed via a simple extern function.
+
+range_operator *
+range_op_handler (enum tree_code code, tree type)
+{
+ // First check if there is apointer specialization.
+ if (POINTER_TYPE_P (type))
+ return pointer_tree_table[code];
+ return integral_tree_table[code];
+}
+
+// Cast the range in R to TYPE.
+
+void
+range_cast (value_range_base &r, tree type)
+{
+ range_operator *op = range_op_handler (CONVERT_EXPR, type);
+ r = op->fold_range (type, r, value_range_base (type));
+}
+
+#if CHECKING_P
+#include "selftest.h"
+#include "stor-layout.h"
+
+// Ideally this should go in namespace selftest, but range_tests
+// needs to be a friend of class value_range_base so it can access
+// value_range_base::m_max_pairs.
+
+#define INT(N) build_int_cst (integer_type_node, (N))
+#define UINT(N) build_int_cstu (unsigned_type_node, (N))
+#define INT16(N) build_int_cst (short_integer_type_node, (N))
+#define UINT16(N) build_int_cstu (short_unsigned_type_node, (N))
+#define INT64(N) build_int_cstu (long_long_integer_type_node, (N))
+#define UINT64(N) build_int_cstu (long_long_unsigned_type_node, (N))
+#define UINT128(N) build_int_cstu (u128_type, (N))
+#define UCHAR(N) build_int_cstu (unsigned_char_type_node, (N))
+#define SCHAR(N) build_int_cst (signed_char_type_node, (N))
+
+#define RANGE3(A,B,C,D,E,F) \
+( i1 = value_range_base (INT (A), INT (B)), \
+ i2 = value_range_base (INT (C), INT (D)), \
+ i3 = value_range_base (INT (E), INT (F)), \
+ i1.union_ (i2), \
+ i1.union_ (i3), \
+ i1 )
+
+// Run all of the selftests within this file.
+
+void
+range_tests ()
+{
+ tree u128_type = build_nonstandard_integer_type (128, /*unsigned=*/1);
+ value_range_base i1, i2, i3;
+ value_range_base r0, r1, rold;
+
+ // Test that NOT(255) is [0..254] in 8-bit land.
+ value_range_base not_255 (VR_ANTI_RANGE, UCHAR (255), UCHAR (255));
+ ASSERT_TRUE (not_255 == value_range_base (UCHAR (0), UCHAR (254)));
+
+ // Test that NOT(0) is [1..255] in 8-bit land.
+ value_range_base not_zero = range_nonzero (unsigned_char_type_node);
+ ASSERT_TRUE (not_zero == value_range_base (UCHAR (1), UCHAR (255)));
+
+ // Check that [0,127][0x..ffffff80,0x..ffffff]
+ // => ~[128, 0x..ffffff7f].
+ r0 = value_range_base (UINT128 (0), UINT128 (127));
+ tree high = build_minus_one_cst (u128_type);
+ // low = -1 - 127 => 0x..ffffff80.
+ tree low = fold_build2 (MINUS_EXPR, u128_type, high, UINT128(127));
+ r1 = value_range_base (low, high); // [0x..ffffff80, 0x..ffffffff]
+ // r0 = [0,127][0x..ffffff80,0x..fffffff].
+ r0.union_ (r1);
+ // r1 = [128, 0x..ffffff7f].
+ r1 = value_range_base (UINT128(128),
+ fold_build2 (MINUS_EXPR, u128_type,
+ build_minus_one_cst (u128_type),
+ UINT128(128)));
+ r0.invert ();
+ ASSERT_TRUE (r0 == r1);
+
+ r0.set_varying (integer_type_node);
+ tree minint = wide_int_to_tree (integer_type_node, r0.lower_bound ());
+ tree maxint = wide_int_to_tree (integer_type_node, r0.upper_bound ());
+
+ r0.set_varying (short_integer_type_node);
+ tree minshort = wide_int_to_tree (short_integer_type_node, r0.lower_bound ());
+ tree maxshort = wide_int_to_tree (short_integer_type_node, r0.upper_bound ());
+
+ r0.set_varying (unsigned_type_node);
+ tree maxuint = wide_int_to_tree (unsigned_type_node, r0.upper_bound ());
+
+ // Check that ~[0,5] => [6,MAX] for unsigned int.
+ r0 = value_range_base (UINT (0), UINT (5));
+ r0.invert ();
+ ASSERT_TRUE (r0 == value_range_base (UINT(6), maxuint));
+
+ // Check that ~[10,MAX] => [0,9] for unsigned int.
+ r0 = value_range_base (VR_RANGE, UINT(10), maxuint);
+ r0.invert ();
+ ASSERT_TRUE (r0 == value_range_base (UINT (0), UINT (9)));
+
+ // Check that ~[0,5] => [6,MAX] for unsigned 128-bit numbers.
+ r0 = value_range_base (VR_ANTI_RANGE, UINT128 (0), UINT128 (5));
+ r1 = value_range_base (UINT128(6), build_minus_one_cst (u128_type));
+ ASSERT_TRUE (r0 == r1);
+
+ // Check that [~5] is really [-MIN,4][6,MAX].
+ r0 = value_range_base (VR_ANTI_RANGE, INT (5), INT (5));
+ r1 = value_range_base (minint, INT (4));
+ r1.union_ (value_range_base (INT (6), maxint));
+ ASSERT_FALSE (r1.undefined_p ());
+ ASSERT_TRUE (r0 == r1);
+
+ r1 = value_range_base (INT (5), INT (5));
+ r1.check ();
+ value_range_base r2 (r1);
+ ASSERT_TRUE (r1 == r2);
+
+ r1 = value_range_base (INT (5), INT (10));
+ r1.check ();
+
+ r1 = value_range_base (integer_type_node,
+ wi::to_wide (INT (5)), wi::to_wide (INT (10)));
+ r1.check ();
+ ASSERT_TRUE (r1.contains_p (INT (7)));
+
+ r1 = value_range_base (SCHAR (0), SCHAR (20));
+ ASSERT_TRUE (r1.contains_p (SCHAR(15)));
+ ASSERT_FALSE (r1.contains_p (SCHAR(300)));
+
+ // If a range is in any way outside of the range for the converted
+ // to range, default to the range for the new type.
+ r1 = value_range_base (integer_zero_node, maxint);
+ range_cast (r1, short_integer_type_node);
+ ASSERT_TRUE (r1.lower_bound () == wi::to_wide (minshort)
+ && r1.upper_bound() == wi::to_wide (maxshort));
+
+ // (unsigned char)[-5,-1] => [251,255].
+ r0 = rold = value_range_base (SCHAR (-5), SCHAR (-1));
+ range_cast (r0, unsigned_char_type_node);
+ ASSERT_TRUE (r0 == value_range_base (UCHAR (251), UCHAR (255)));
+ range_cast (r0, signed_char_type_node);
+ ASSERT_TRUE (r0 == rold);
+
+ // (signed char)[15, 150] => [-128,-106][15,127].
+ r0 = rold = value_range_base (UCHAR (15), UCHAR (150));
+ range_cast (r0, signed_char_type_node);
+ r1 = value_range_base (SCHAR (15), SCHAR (127));
+ r2 = value_range_base (SCHAR (-128), SCHAR (-106));
+ r1.union_ (r2);
+ ASSERT_TRUE (r1 == r0);
+ range_cast (r0, unsigned_char_type_node);
+ ASSERT_TRUE (r0 == rold);
+
+ // (unsigned char)[-5, 5] => [0,5][251,255].
+ r0 = rold = value_range_base (SCHAR (-5), SCHAR (5));
+ range_cast (r0, unsigned_char_type_node);
+ r1 = value_range_base (UCHAR (251), UCHAR (255));
+ r2 = value_range_base (UCHAR (0), UCHAR (5));
+ r1.union_ (r2);
+ ASSERT_TRUE (r0 == r1);
+ range_cast (r0, signed_char_type_node);
+ ASSERT_TRUE (r0 == rold);
+
+ // (unsigned char)[-5,5] => [0,5][251,255].
+ r0 = value_range_base (INT (-5), INT (5));
+ range_cast (r0, unsigned_char_type_node);
+ r1 = value_range_base (UCHAR (0), UCHAR (5));
+ r1.union_ (value_range_base (UCHAR (251), UCHAR (255)));
+ ASSERT_TRUE (r0 == r1);
+
+ // (unsigned char)[5U,1974U] => [0,255].
+ r0 = value_range_base (UINT (5), UINT (1974));
+ range_cast (r0, unsigned_char_type_node);
+ ASSERT_TRUE (r0 == value_range_base (UCHAR (0), UCHAR (255)));
+ range_cast (r0, integer_type_node);
+ // Going to a wider range should not sign extend.
+ ASSERT_TRUE (r0 == value_range_base (INT (0), INT (255)));
+
+ // (unsigned char)[-350,15] => [0,255].
+ r0 = value_range_base (INT (-350), INT (15));
+ range_cast (r0, unsigned_char_type_node);
+ ASSERT_TRUE (r0 == (value_range_base
+ (TYPE_MIN_VALUE (unsigned_char_type_node),
+ TYPE_MAX_VALUE (unsigned_char_type_node))));
+
+ // Casting [-120,20] from signed char to unsigned short.
+ // => [0, 20][0xff88, 0xffff].
+ r0 = value_range_base (SCHAR (-120), SCHAR (20));
+ range_cast (r0, short_unsigned_type_node);
+ r1 = value_range_base (UINT16 (0), UINT16 (20));
+ r2 = value_range_base (UINT16 (0xff88), UINT16 (0xffff));
+ r1.union_ (r2);
+ ASSERT_TRUE (r0 == r1);
+ // A truncating cast back to signed char will work because [-120, 20]
+ // is representable in signed char.
+ range_cast (r0, signed_char_type_node);
+ ASSERT_TRUE (r0 == value_range_base (SCHAR (-120), SCHAR (20)));
+
+ // unsigned char -> signed short
+ // (signed short)[(unsigned char)25, (unsigned char)250]
+ // => [(signed short)25, (signed short)250]
+ r0 = rold = value_range_base (UCHAR (25), UCHAR (250));
+ range_cast (r0, short_integer_type_node);
+ r1 = value_range_base (INT16 (25), INT16 (250));
+ ASSERT_TRUE (r0 == r1);
+ range_cast (r0, unsigned_char_type_node);
+ ASSERT_TRUE (r0 == rold);
+
+ // Test casting a wider signed [-MIN,MAX] to a nar`rower unsigned.
+ r0 = value_range_base (TYPE_MIN_VALUE (long_long_integer_type_node),
+ TYPE_MAX_VALUE (long_long_integer_type_node));
+ range_cast (r0, short_unsigned_type_node);
+ r1 = value_range_base (TYPE_MIN_VALUE (short_unsigned_type_node),
+ TYPE_MAX_VALUE (short_unsigned_type_node));
+ ASSERT_TRUE (r0 == r1);
+
+ // NOT([10,20]) ==> [-MIN,9][21,MAX].
+ r0 = r1 = value_range_base (INT (10), INT (20));
+ r2 = value_range_base (minint, INT(9));
+ r2.union_ (value_range_base (INT(21), maxint));
+ ASSERT_FALSE (r2.undefined_p ());
+ r1.invert ();
+ ASSERT_TRUE (r1 == r2);
+ // Test that NOT(NOT(x)) == x.
+ r2.invert ();
+ ASSERT_TRUE (r0 == r2);
+
+ // Test that booleans and their inverse work as expected.
+ r0 = range_zero (boolean_type_node);
+ ASSERT_TRUE (r0 == value_range_base (build_zero_cst (boolean_type_node),
+ build_zero_cst (boolean_type_node)));
+ r0.invert ();
+ ASSERT_TRUE (r0 == value_range_base (build_one_cst (boolean_type_node),
+ build_one_cst (boolean_type_node)));
+
+ // Casting NONZERO to a narrower type will wrap/overflow so
+ // it's just the entire range for the narrower type.
+ //
+ // "NOT 0 at signed 32-bits" ==> [-MIN_32,-1][1, +MAX_32]. This is
+ // is outside of the range of a smaller range, return the full
+ // smaller range.
+ r0 = range_nonzero (integer_type_node);
+ range_cast (r0, short_integer_type_node);
+ r1 = value_range_base (TYPE_MIN_VALUE (short_integer_type_node),
+ TYPE_MAX_VALUE (short_integer_type_node));
+ ASSERT_TRUE (r0 == r1);
+
+ // Casting NONZERO from a narrower signed to a wider signed.
+ //
+ // NONZERO signed 16-bits is [-MIN_16,-1][1, +MAX_16].
+ // Converting this to 32-bits signed is [-MIN_16,-1][1, +MAX_16].
+ r0 = range_nonzero (short_integer_type_node);
+ range_cast (r0, integer_type_node);
+ r1 = value_range_base (INT (-32768), INT (-1));
+ r2 = value_range_base (INT (1), INT (32767));
+ r1.union_ (r2);
+ ASSERT_TRUE (r0 == r1);
+
+ if (value_range_base::m_max_pairs > 2)
+ {
+ // ([10,20] U [5,8]) U [1,3] ==> [1,3][5,8][10,20].
+ r0 = value_range_base (INT (10), INT (20));
+ r1 = value_range_base (INT (5), INT (8));
+ r0.union_ (r1);
+ r1 = value_range_base (INT (1), INT (3));
+ r0.union_ (r1);
+ ASSERT_TRUE (r0 == RANGE3 (1, 3, 5, 8, 10, 20));
+
+ // [1,3][5,8][10,20] U [-5,0] => [-5,3][5,8][10,20].
+ r1 = value_range_base (INT (-5), INT (0));
+ r0.union_ (r1);
+ ASSERT_TRUE (r0 == RANGE3 (-5, 3, 5, 8, 10, 20));
+ }
+
+ // [10,20] U [30,40] ==> [10,20][30,40].
+ r0 = value_range_base (INT (10), INT (20));
+ r1 = value_range_base (INT (30), INT (40));
+ r0.union_ (r1);
+ ASSERT_TRUE (r0 == range_union (value_range_base (INT (10), INT (20)),
+ value_range_base (INT (30), INT (40))));
+ if (value_range_base::m_max_pairs > 2)
+ {
+ // [10,20][30,40] U [50,60] ==> [10,20][30,40][50,60].
+ r1 = value_range_base (INT (50), INT (60));
+ r0.union_ (r1);
+ ASSERT_TRUE (r0 == RANGE3 (10, 20, 30, 40, 50, 60));
+ // [10,20][30,40][50,60] U [70, 80] ==> [10,20][30,40][50,60][70,80].
+ r1 = value_range_base (INT (70), INT (80));
+ r0.union_ (r1);
+
+ r2 = RANGE3 (10, 20, 30, 40, 50, 60);
+ r2.union_ (value_range_base (INT (70), INT (80)));
+ ASSERT_TRUE (r0 == r2);
+ }
+
+ // Make sure NULL and non-NULL of pointer types work, and that
+ // inverses of them are consistent.
+ tree voidp = build_pointer_type (void_type_node);
+ r0 = range_zero (voidp);
+ r1 = r0;
+ r0.invert ();
+ r0.invert ();
+ ASSERT_TRUE (r0 == r1);
+
+ if (value_range_base::m_max_pairs > 2)
+ {
+ // [10,20][30,40][50,60] U [6,35] => [6,40][50,60].
+ r0 = RANGE3 (10, 20, 30, 40, 50, 60);
+ r1 = value_range_base (INT (6), INT (35));
+ r0.union_ (r1);
+ ASSERT_TRUE (r0 == range_union (value_range_base (INT (6), INT (40)),
+ value_range_base (INT (50), INT (60))));
+
+ // [10,20][30,40][50,60] U [6,60] => [6,60].
+ r0 = RANGE3 (10, 20, 30, 40, 50, 60);
+ r1 = value_range_base (INT (6), INT (60));
+ r0.union_ (r1);
+ ASSERT_TRUE (r0 == value_range_base (INT (6), INT (60)));
+
+ // [10,20][30,40][50,60] U [6,70] => [6,70].
+ r0 = RANGE3 (10, 20, 30, 40, 50, 60);
+ r1 = value_range_base (INT (6), INT (70));
+ r0.union_ (r1);
+ ASSERT_TRUE (r0 == value_range_base (INT (6), INT (70)));
+
+ // [10,20][30,40][50,60] U [35,70] => [10,20][30,70].
+ r0 = RANGE3 (10, 20, 30, 40, 50, 60);
+ r1 = value_range_base (INT (35), INT (70));
+ r0.union_ (r1);
+ ASSERT_TRUE (r0 == range_union (value_range_base (INT (10), INT (20)),
+ value_range_base (INT (30), INT (70))));
+ }
+
+ // [10,20][30,40] U [25,70] => [10,70].
+ r0 = range_union (value_range_base (INT (10), INT (20)),
+ value_range_base (INT (30), INT (40)));
+ r1 = value_range_base (INT (25), INT (70));
+ r0.union_ (r1);
+ ASSERT_TRUE (r0 == range_union (value_range_base (INT (10), INT (20)),
+ value_range_base (INT (25), INT (70))));
+
+ if (value_range_base::m_max_pairs > 2)
+ {
+ // [10,20][30,40][50,60] U [15,35] => [10,40][50,60].
+ r0 = RANGE3 (10, 20, 30, 40, 50, 60);
+ r1 = value_range_base (INT (15), INT (35));
+ r0.union_ (r1);
+ ASSERT_TRUE (r0 == range_union (value_range_base (INT (10), INT (40)),
+ value_range_base (INT (50), INT (60))));
+ }
+
+ // [10,20] U [15, 30] => [10, 30].
+ r0 = value_range_base (INT (10), INT (20));
+ r1 = value_range_base (INT (15), INT (30));
+ r0.union_ (r1);
+ ASSERT_TRUE (r0 == value_range_base (INT (10), INT (30)));
+
+ // [10,20] U [25,25] => [10,20][25,25].
+ r0 = value_range_base (INT (10), INT (20));
+ r1 = value_range_base (INT (25), INT (25));
+ r0.union_ (r1);
+ ASSERT_TRUE (r0 == range_union (value_range_base (INT (10), INT (20)),
+ value_range_base (INT (25), INT (25))));
+
+ if (value_range_base::m_max_pairs > 2)
+ {
+ // [10,20][30,40][50,60] U [35,35] => [10,20][30,40][50,60].
+ r0 = RANGE3 (10, 20, 30, 40, 50, 60);
+ r1 = value_range_base (INT (35), INT (35));
+ r0.union_ (r1);
+ ASSERT_TRUE (r0 == RANGE3 (10, 20, 30, 40, 50, 60));
+ }
+
+ // [15,40] U [] => [15,40].
+ r0 = value_range_base (INT (15), INT (40));
+ r1.set_undefined ();
+ r0.union_ (r1);
+ ASSERT_TRUE (r0 == value_range_base (INT (15), INT (40)));
+
+ // [10,20] U [10,10] => [10,20].
+ r0 = value_range_base (INT (10), INT (20));
+ r1 = value_range_base (INT (10), INT (10));
+ r0.union_ (r1);
+ ASSERT_TRUE (r0 == value_range_base (INT (10), INT (20)));
+
+ // [10,20] U [9,9] => [9,20].
+ r0 = value_range_base (INT (10), INT (20));
+ r1 = value_range_base (INT (9), INT (9));
+ r0.union_ (r1);
+ ASSERT_TRUE (r0 == value_range_base (INT (9), INT (20)));
+
+ if (value_range_base::m_max_pairs > 2)
+ {
+ // [10,10][12,12][20,100] ^ [15,200].
+ r0 = RANGE3 (10, 10, 12, 12, 20, 100);
+ r1 = value_range_base (INT (15), INT (200));
+ r0.intersect (r1);
+ ASSERT_TRUE (r0 == value_range_base (INT (20), INT (100)));
+
+ // [10,20][30,40][50,60] ^ [15,25][38,51][55,70]
+ // => [15,20][38,40][50,51][55,60]
+ r0 = RANGE3 (10, 20, 30, 40, 50, 60);
+ r1 = RANGE3 (15, 25, 38, 51, 55, 70);
+ r0.intersect (r1);
+ if (value_range_base::m_max_pairs == 3)
+ {
+ // When pairs==3, we don't have enough space, so
+ // conservatively handle things. Thus, the ...[50,60].
+ ASSERT_TRUE (r0 == RANGE3 (15, 20, 38, 40, 50, 60));
+ }
+ else
+ {
+ r2 = RANGE3 (15, 20, 38, 40, 50, 51);
+ r2.union_ (value_range_base (INT (55), INT (60)));
+ ASSERT_TRUE (r0 == r2);
+ }
+
+ // [15,20][30,40][50,60] ^ [15,35][40,90][100,200]
+ // => [15,20][30,35][40,60]
+ r0 = RANGE3 (15, 20, 30, 40, 50, 60);
+ r1 = RANGE3 (15, 35, 40, 90, 100, 200);
+ r0.intersect (r1);
+ if (value_range_base::m_max_pairs == 3)
+ {
+ // When pairs==3, we don't have enough space, so
+ // conservatively handle things.
+ ASSERT_TRUE (r0 == RANGE3 (15, 20, 30, 35, 40, 60));
+ }
+ else
+ {
+ r2 = RANGE3 (15, 20, 30, 35, 40, 40);
+ r2.union_ (value_range_base (INT (50), INT (60)));
+ ASSERT_TRUE (r0 == r2);
+ }
+
+ // Test cases where a union inserts a sub-range inside a larger
+ // range.
+ //
+ // [8,10][135,255] U [14,14] => [8,10][14,14][135,255]
+ r0 = range_union (value_range_base (INT (8), INT (10)),
+ value_range_base (INT (135), INT (255)));
+ r1 = value_range_base (INT (14), INT (14));
+ r0.union_ (r1);
+ ASSERT_TRUE (r0 == RANGE3 (8, 10, 14, 14, 135, 255));
+ }
+
+ // [10,20] ^ [15,30] => [15,20].
+ r0 = value_range_base (INT (10), INT (20));
+ r1 = value_range_base (INT (15), INT (30));
+ r0.intersect (r1);
+ ASSERT_TRUE (r0 == value_range_base (INT (15), INT (20)));
+
+ // [10,20][30,40] ^ [40,50] => [40,40].
+ r0 = range_union (value_range_base (INT (10), INT (20)),
+ value_range_base (INT (30), INT (40)));
+ r1 = value_range_base (INT (40), INT (50));
+ r0.intersect (r1);
+ ASSERT_TRUE (r0 == value_range_base (INT (40), INT (40)));
+
+ // Test non-destructive intersection.
+ r0 = rold = value_range_base (INT (10), INT (20));
+ ASSERT_FALSE (range_intersect (r0, value_range_base (INT (15),
+ INT (30))).undefined_p ());
+ ASSERT_TRUE (r0 == rold);
+
+ // Test the internal sanity of wide_int's wrt HWIs.
+ ASSERT_TRUE (wi::max_value (TYPE_PRECISION (boolean_type_node),
+ TYPE_SIGN (boolean_type_node))
+ == wi::uhwi (1, TYPE_PRECISION (boolean_type_node)));
+
+ // Test zero_p().
+ r0 = value_range_base (INT (0), INT (0));
+ ASSERT_TRUE (r0.zero_p ());
+
+ // Test nonzero_p().
+ r0 = value_range_base (INT (0), INT (0));
+ r0.invert ();
+ ASSERT_TRUE (r0.nonzero_p ());
+}
+#endif // CHECKING_P
#include "attribs.h"
#include "vr-values.h"
#include "builtins.h"
-#include "wide-int-range.h"
+#include "range-op.h"
static bool
ranges_from_anti_range (const value_range_base *ar,
set (other.kind (), other.min(), other.max (), NULL);
}
+value_range_base::value_range_base (tree type)
+{
+ set_varying (type);
+}
+
+value_range_base::value_range_base (enum value_range_kind kind,
+ tree type,
+ const wide_int &wmin,
+ const wide_int &wmax)
+{
+ tree min = wide_int_to_tree (type, wmin);
+ tree max = wide_int_to_tree (type, wmax);
+ gcc_checking_assert (kind == VR_RANGE || kind == VR_ANTI_RANGE);
+ set (kind, min, max);
+}
+
+value_range_base::value_range_base (tree type,
+ const wide_int &wmin,
+ const wide_int &wmax)
+{
+ tree min = wide_int_to_tree (type, wmin);
+ tree max = wide_int_to_tree (type, wmax);
+ set (VR_RANGE, min, max);
+}
+
+value_range_base::value_range_base (tree min, tree max)
+{
+ set (VR_RANGE, min, max);
+}
+
/* Like set, but keep the equivalences in place. */
void
return false;
}
- value_range_base vr0, vr1;
- return (ranges_from_anti_range (this, &vr0, &vr1, true)
- && vr1.undefined_p ()
- && vr0.singleton_p (result));
+ /* An anti-range that includes an extreme, is just a range with
+ one sub-range. Use the one sub-range. */
+ if (vrp_val_is_min (m_min, true) || vrp_val_is_max (m_max, true))
+ {
+ value_range_base vr0, vr1;
+ ranges_from_anti_range (this, &vr0, &vr1, true);
+ return vr0.singleton_p (result);
+ }
}
if (m_kind == VR_RANGE
&& vrp_operand_equal_p (min (), max ())
tree
value_range_base::type () const
{
- gcc_assert (m_min);
+ gcc_checking_assert (m_min);
return TREE_TYPE (min ());
}
is not == to the integer constant with the same value in the type. */
bool
-vrp_val_is_max (const_tree val)
+vrp_val_is_max (const_tree val, bool handle_pointers)
{
- tree type_max = vrp_val_max (TREE_TYPE (val));
+ tree type_max = vrp_val_max (TREE_TYPE (val), handle_pointers);
return (val == type_max
|| (type_max != NULL_TREE
&& operand_equal_p (val, type_max, 0)));
/* Return whether VAL is equal to the minimum value of its type. */
bool
-vrp_val_is_min (const_tree val)
+vrp_val_is_min (const_tree val, bool handle_pointers)
{
- tree type_min = vrp_val_min (TREE_TYPE (val));
+ tree type_min = vrp_val_min (TREE_TYPE (val), handle_pointers);
return (val == type_min
|| (type_min != NULL_TREE
&& operand_equal_p (val, type_min, 0)));
return !!cmp2;
}
-/* Value range wrapper for wide_int_range_set_zero_nonzero_bits.
+/* For range [LB, UB] compute two wide_int bit masks.
+
+ In the MAY_BE_NONZERO bit mask, if some bit is unset, it means that
+ for all numbers in the range the bit is 0, otherwise it might be 0
+ or 1.
+
+ In the MUST_BE_NONZERO bit mask, if some bit is set, it means that
+ for all numbers in the range the bit is 1, otherwise it might be 0
+ or 1. */
+
+static inline void
+wide_int_range_set_zero_nonzero_bits (signop sign,
+ const wide_int &lb, const wide_int &ub,
+ wide_int &may_be_nonzero,
+ wide_int &must_be_nonzero)
+{
+ may_be_nonzero = wi::minus_one (lb.get_precision ());
+ must_be_nonzero = wi::zero (lb.get_precision ());
+
+ if (wi::eq_p (lb, ub))
+ {
+ may_be_nonzero = lb;
+ must_be_nonzero = may_be_nonzero;
+ }
+ else if (wi::ge_p (lb, 0, sign) || wi::lt_p (ub, 0, sign))
+ {
+ wide_int xor_mask = lb ^ ub;
+ may_be_nonzero = lb | ub;
+ must_be_nonzero = lb & ub;
+ if (xor_mask != 0)
+ {
+ wide_int mask = wi::mask (wi::floor_log2 (xor_mask), false,
+ may_be_nonzero.get_precision ());
+ may_be_nonzero = may_be_nonzero | mask;
+ must_be_nonzero = wi::bit_and_not (must_be_nonzero, mask);
+ }
+ }
+}
- Compute MAY_BE_NONZERO and MUST_BE_NONZERO bit masks for range in VR.
+/* value_range wrapper for wide_int_range_set_zero_nonzero_bits above.
Return TRUE if VR was a constant range and we were able to compute
the bit masks. */
return !vr0->undefined_p ();
}
-/* Extract the components of a value range into a pair of wide ints in
- [WMIN, WMAX], after having normalized any symbolics from the input. */
-
-static void inline
-extract_range_into_wide_ints (const value_range_base *vr_,
- tree type, wide_int &wmin, wide_int &wmax)
-{
- signop sign = TYPE_SIGN (type);
- unsigned int prec = TYPE_PRECISION (type);
- gcc_assert (vr_->kind () != VR_ANTI_RANGE || vr_->symbolic_p ());
- value_range vr = vr_->normalize_symbolics ();
- if (range_int_cst_p (&vr))
- {
- wmin = wi::to_wide (vr.min ());
- wmax = wi::to_wide (vr.max ());
- }
- else
- {
- wmin = wi::min_value (prec, sign);
- wmax = wi::max_value (prec, sign);
- }
-}
-
-/* Value range wrapper for wide_int_range_multiplicative_op:
-
- *VR = *VR0 .CODE. *VR1. */
-
-static void
-extract_range_from_multiplicative_op (value_range_base *vr,
- enum tree_code code, tree type,
- const value_range_base *vr0,
- const value_range_base *vr1)
-{
- gcc_assert (code == MULT_EXPR
- || code == TRUNC_DIV_EXPR
- || code == FLOOR_DIV_EXPR
- || code == CEIL_DIV_EXPR
- || code == EXACT_DIV_EXPR
- || code == ROUND_DIV_EXPR
- || code == RSHIFT_EXPR
- || code == LSHIFT_EXPR);
- if (!range_int_cst_p (vr1))
- {
- vr->set_varying (type);
- return;
- }
-
- /* Even if vr0 is VARYING or otherwise not usable, we can derive
- useful ranges just from the shift count. E.g.
- x >> 63 for signed 64-bit x is always [-1, 0]. */
- value_range_base tem = vr0->normalize_symbolics ();
- tree vr0_min, vr0_max;
- if (tem.kind () == VR_RANGE)
- {
- vr0_min = tem.min ();
- vr0_max = tem.max ();
- }
- else
- {
- vr0_min = vrp_val_min (type);
- vr0_max = vrp_val_max (type);
- }
-
- wide_int res_lb, res_ub;
- wide_int vr0_lb = wi::to_wide (vr0_min);
- wide_int vr0_ub = wi::to_wide (vr0_max);
- wide_int vr1_lb = wi::to_wide (vr1->min ());
- wide_int vr1_ub = wi::to_wide (vr1->max ());
- bool overflow_undefined = TYPE_OVERFLOW_UNDEFINED (type);
- unsigned prec = TYPE_PRECISION (type);
-
- if (wide_int_range_multiplicative_op (res_lb, res_ub,
- code, TYPE_SIGN (type), prec,
- vr0_lb, vr0_ub, vr1_lb, vr1_ub,
- overflow_undefined))
- vr->set (VR_RANGE, wide_int_to_tree (type, res_lb),
- wide_int_to_tree (type, res_ub));
- else
- vr->set_varying (type);
-}
-
/* If BOUND will include a symbolic bound, adjust it accordingly,
otherwise leave it as is.
if ((min_ovf != wi::OVF_NONE) == (max_ovf != wi::OVF_NONE))
{
/* If the limits are swapped, we wrapped around and cover
- the entire range. We have a similar check at the end of
- extract_range_from_binary_expr. */
+ the entire range. */
if (wi::gt_p (tmin, tmax, sgn))
kind = VR_VARYING;
else
}
}
-/* Extract range information from a binary operation CODE based on
- the ranges of each of its operands *VR0 and *VR1 with resulting
- type EXPR_TYPE. The resulting range is stored in *VR. */
+/* Fold two value range's of a POINTER_PLUS_EXPR into VR. */
-void
-extract_range_from_binary_expr (value_range_base *vr,
- enum tree_code code, tree expr_type,
- const value_range_base *vr0_,
- const value_range_base *vr1_)
+static void
+extract_range_from_pointer_plus_expr (value_range_base *vr,
+ enum tree_code code,
+ tree expr_type,
+ const value_range_base *vr0,
+ const value_range_base *vr1)
{
- signop sign = TYPE_SIGN (expr_type);
- unsigned int prec = TYPE_PRECISION (expr_type);
- value_range_base vr0 = *vr0_, vr1 = *vr1_;
- value_range_base vrtem0, vrtem1;
- enum value_range_kind type;
- tree min = NULL_TREE, max = NULL_TREE;
- int cmp;
-
- if (!INTEGRAL_TYPE_P (expr_type)
- && !POINTER_TYPE_P (expr_type))
- {
- vr->set_varying (expr_type);
- return;
- }
+ gcc_checking_assert (POINTER_TYPE_P (expr_type)
+ && code == POINTER_PLUS_EXPR);
+ /* For pointer types, we are really only interested in asserting
+ whether the expression evaluates to non-NULL.
+ With -fno-delete-null-pointer-checks we need to be more
+ conservative. As some object might reside at address 0,
+ then some offset could be added to it and the same offset
+ subtracted again and the result would be NULL.
+ E.g.
+ static int a[12]; where &a[0] is NULL and
+ ptr = &a[6];
+ ptr -= 6;
+ ptr will be NULL here, even when there is POINTER_PLUS_EXPR
+ where the first range doesn't include zero and the second one
+ doesn't either. As the second operand is sizetype (unsigned),
+ consider all ranges where the MSB could be set as possible
+ subtractions where the result might be NULL. */
+ if ((!range_includes_zero_p (vr0)
+ || !range_includes_zero_p (vr1))
+ && !TYPE_OVERFLOW_WRAPS (expr_type)
+ && (flag_delete_null_pointer_checks
+ || (range_int_cst_p (vr1)
+ && !tree_int_cst_sign_bit (vr1->max ()))))
+ vr->set_nonzero (expr_type);
+ else if (vr0->zero_p () && vr1->zero_p ())
+ vr->set_zero (expr_type);
+ else
+ vr->set_varying (expr_type);
+}
- /* Not all binary expressions can be applied to ranges in a
- meaningful way. Handle only arithmetic operations. */
- if (code != PLUS_EXPR
- && code != MINUS_EXPR
- && code != POINTER_PLUS_EXPR
- && code != MULT_EXPR
- && code != TRUNC_DIV_EXPR
- && code != FLOOR_DIV_EXPR
- && code != CEIL_DIV_EXPR
- && code != EXACT_DIV_EXPR
- && code != ROUND_DIV_EXPR
- && code != TRUNC_MOD_EXPR
- && code != RSHIFT_EXPR
- && code != LSHIFT_EXPR
- && code != MIN_EXPR
- && code != MAX_EXPR
- && code != BIT_AND_EXPR
- && code != BIT_IOR_EXPR
- && code != BIT_XOR_EXPR)
- {
- vr->set_varying (expr_type);
- return;
- }
+/* Extract range information from a PLUS/MINUS_EXPR and store the
+ result in *VR. */
- /* If both ranges are UNDEFINED, so is the result. */
- if (vr0.undefined_p () && vr1.undefined_p ())
- {
- vr->set_undefined ();
- return;
- }
- /* If one of the ranges is UNDEFINED drop it to VARYING for the following
- code. At some point we may want to special-case operations that
- have UNDEFINED result for all or some value-ranges of the not UNDEFINED
- operand. */
- else if (vr0.undefined_p ())
- vr0.set_varying (expr_type);
- else if (vr1.undefined_p ())
- vr1.set_varying (expr_type);
+static void
+extract_range_from_plus_minus_expr (value_range_base *vr,
+ enum tree_code code,
+ tree expr_type,
+ const value_range_base *vr0_,
+ const value_range_base *vr1_)
+{
+ gcc_checking_assert (code == PLUS_EXPR || code == MINUS_EXPR);
- /* We get imprecise results from ranges_from_anti_range when
- code is EXACT_DIV_EXPR. We could mask out bits in the resulting
- range, but then we also need to hack up vrp_union. It's just
- easier to special case when vr0 is ~[0,0] for EXACT_DIV_EXPR. */
- if (code == EXACT_DIV_EXPR && vr0.nonzero_p ())
- {
- vr->set_nonzero (expr_type);
- return;
- }
+ value_range_base vr0 = *vr0_, vr1 = *vr1_;
+ value_range_base vrtem0, vrtem1;
/* Now canonicalize anti-ranges to ranges when they are not symbolic
and express ~[] op X as ([]' op X) U ([]'' op X). */
if (vr0.kind () == VR_ANTI_RANGE
&& ranges_from_anti_range (&vr0, &vrtem0, &vrtem1))
{
- extract_range_from_binary_expr (vr, code, expr_type, &vrtem0, vr1_);
+ extract_range_from_plus_minus_expr (vr, code, expr_type, &vrtem0, vr1_);
if (!vrtem1.undefined_p ())
{
value_range_base vrres;
- extract_range_from_binary_expr (&vrres, code, expr_type,
- &vrtem1, vr1_);
+ extract_range_from_plus_minus_expr (&vrres, code, expr_type,
+ &vrtem1, vr1_);
vr->union_ (&vrres);
}
return;
if (vr1.kind () == VR_ANTI_RANGE
&& ranges_from_anti_range (&vr1, &vrtem0, &vrtem1))
{
- extract_range_from_binary_expr (vr, code, expr_type, vr0_, &vrtem0);
+ extract_range_from_plus_minus_expr (vr, code, expr_type, vr0_, &vrtem0);
if (!vrtem1.undefined_p ())
{
value_range_base vrres;
- extract_range_from_binary_expr (&vrres, code, expr_type,
- vr0_, &vrtem1);
+ extract_range_from_plus_minus_expr (&vrres, code, expr_type,
+ vr0_, &vrtem1);
vr->union_ (&vrres);
}
return;
}
- /* The type of the resulting value range defaults to VR0.TYPE. */
- type = vr0.kind ();
-
- /* Refuse to operate on VARYING ranges, ranges of different kinds
- and symbolic ranges. As an exception, we allow BIT_{AND,IOR}
- because we may be able to derive a useful range even if one of
- the operands is VR_VARYING or symbolic range. Similarly for
- divisions, MIN/MAX and PLUS/MINUS.
-
- TODO, we may be able to derive anti-ranges in some cases. */
- if (code != BIT_AND_EXPR
- && code != BIT_IOR_EXPR
- && code != TRUNC_DIV_EXPR
- && code != FLOOR_DIV_EXPR
- && code != CEIL_DIV_EXPR
- && code != EXACT_DIV_EXPR
- && code != ROUND_DIV_EXPR
- && code != TRUNC_MOD_EXPR
- && code != MIN_EXPR
- && code != MAX_EXPR
- && code != PLUS_EXPR
- && code != MINUS_EXPR
- && code != RSHIFT_EXPR
- && code != POINTER_PLUS_EXPR
- && (vr0.varying_p ()
- || vr1.varying_p ()
- || vr0.kind () != vr1.kind ()
- || vr0.symbolic_p ()
- || vr1.symbolic_p ()))
- {
- vr->set_varying (expr_type);
- return;
- }
-
- /* Now evaluate the expression to determine the new range. */
- if (POINTER_TYPE_P (expr_type))
+ value_range_kind kind;
+ value_range_kind vr0_kind = vr0.kind (), vr1_kind = vr1.kind ();
+ tree vr0_min = vr0.min (), vr0_max = vr0.max ();
+ tree vr1_min = vr1.min (), vr1_max = vr1.max ();
+ tree min = NULL, max = NULL;
+
+ /* This will normalize things such that calculating
+ [0,0] - VR_VARYING is not dropped to varying, but is
+ calculated as [MIN+1, MAX]. */
+ if (vr0.varying_p ())
+ {
+ vr0_kind = VR_RANGE;
+ vr0_min = vrp_val_min (expr_type);
+ vr0_max = vrp_val_max (expr_type);
+ }
+ if (vr1.varying_p ())
+ {
+ vr1_kind = VR_RANGE;
+ vr1_min = vrp_val_min (expr_type);
+ vr1_max = vrp_val_max (expr_type);
+ }
+
+ const bool minus_p = (code == MINUS_EXPR);
+ tree min_op0 = vr0_min;
+ tree min_op1 = minus_p ? vr1_max : vr1_min;
+ tree max_op0 = vr0_max;
+ tree max_op1 = minus_p ? vr1_min : vr1_max;
+ tree sym_min_op0 = NULL_TREE;
+ tree sym_min_op1 = NULL_TREE;
+ tree sym_max_op0 = NULL_TREE;
+ tree sym_max_op1 = NULL_TREE;
+ bool neg_min_op0, neg_min_op1, neg_max_op0, neg_max_op1;
+
+ neg_min_op0 = neg_min_op1 = neg_max_op0 = neg_max_op1 = false;
+
+ /* If we have a PLUS or MINUS with two VR_RANGEs, either constant or
+ single-symbolic ranges, try to compute the precise resulting range,
+ but only if we know that this resulting range will also be constant
+ or single-symbolic. */
+ if (vr0_kind == VR_RANGE && vr1_kind == VR_RANGE
+ && (TREE_CODE (min_op0) == INTEGER_CST
+ || (sym_min_op0
+ = get_single_symbol (min_op0, &neg_min_op0, &min_op0)))
+ && (TREE_CODE (min_op1) == INTEGER_CST
+ || (sym_min_op1
+ = get_single_symbol (min_op1, &neg_min_op1, &min_op1)))
+ && (!(sym_min_op0 && sym_min_op1)
+ || (sym_min_op0 == sym_min_op1
+ && neg_min_op0 == (minus_p ? neg_min_op1 : !neg_min_op1)))
+ && (TREE_CODE (max_op0) == INTEGER_CST
+ || (sym_max_op0
+ = get_single_symbol (max_op0, &neg_max_op0, &max_op0)))
+ && (TREE_CODE (max_op1) == INTEGER_CST
+ || (sym_max_op1
+ = get_single_symbol (max_op1, &neg_max_op1, &max_op1)))
+ && (!(sym_max_op0 && sym_max_op1)
+ || (sym_max_op0 == sym_max_op1
+ && neg_max_op0 == (minus_p ? neg_max_op1 : !neg_max_op1))))
{
- if (code == MIN_EXPR || code == MAX_EXPR)
- {
- /* For MIN/MAX expressions with pointers, we only care about
- nullness, if both are non null, then the result is nonnull.
- If both are null, then the result is null. Otherwise they
- are varying. */
- if (!range_includes_zero_p (&vr0) && !range_includes_zero_p (&vr1))
- vr->set_nonzero (expr_type);
- else if (vr0.zero_p () && vr1.zero_p ())
- vr->set_zero (expr_type);
- else
- vr->set_varying (expr_type);
- }
- else if (code == POINTER_PLUS_EXPR)
- {
- /* For pointer types, we are really only interested in asserting
- whether the expression evaluates to non-NULL.
- With -fno-delete-null-pointer-checks we need to be more
- conservative. As some object might reside at address 0,
- then some offset could be added to it and the same offset
- subtracted again and the result would be NULL.
- E.g.
- static int a[12]; where &a[0] is NULL and
- ptr = &a[6];
- ptr -= 6;
- ptr will be NULL here, even when there is POINTER_PLUS_EXPR
- where the first range doesn't include zero and the second one
- doesn't either. As the second operand is sizetype (unsigned),
- consider all ranges where the MSB could be set as possible
- subtractions where the result might be NULL. */
- if ((!range_includes_zero_p (&vr0)
- || !range_includes_zero_p (&vr1))
- && !TYPE_OVERFLOW_WRAPS (expr_type)
- && (flag_delete_null_pointer_checks
- || (range_int_cst_p (&vr1)
- && !tree_int_cst_sign_bit (vr1.max ()))))
- vr->set_nonzero (expr_type);
- else if (vr0.zero_p () && vr1.zero_p ())
- vr->set_zero (expr_type);
- else
- vr->set_varying (expr_type);
- }
- else if (code == BIT_AND_EXPR)
- {
- /* For pointer types, we are really only interested in asserting
- whether the expression evaluates to non-NULL. */
- if (vr0.zero_p () || vr1.zero_p ())
- vr->set_zero (expr_type);
- else
- vr->set_varying (expr_type);
- }
- else
- vr->set_varying (expr_type);
-
- return;
- }
-
- /* For integer ranges, apply the operation to each end of the
- range and see what we end up with. */
- if (code == PLUS_EXPR || code == MINUS_EXPR)
- {
- value_range_kind vr0_kind = vr0.kind (), vr1_kind = vr1.kind ();
- tree vr0_min = vr0.min (), vr0_max = vr0.max ();
- tree vr1_min = vr1.min (), vr1_max = vr1.max ();
- /* This will normalize things such that calculating
- [0,0] - VR_VARYING is not dropped to varying, but is
- calculated as [MIN+1, MAX]. */
- if (vr0.varying_p ())
- {
- vr0_kind = VR_RANGE;
- vr0_min = vrp_val_min (expr_type);
- vr0_max = vrp_val_max (expr_type);
- }
- if (vr1.varying_p ())
- {
- vr1_kind = VR_RANGE;
- vr1_min = vrp_val_min (expr_type);
- vr1_max = vrp_val_max (expr_type);
- }
-
- const bool minus_p = (code == MINUS_EXPR);
- tree min_op0 = vr0_min;
- tree min_op1 = minus_p ? vr1_max : vr1_min;
- tree max_op0 = vr0_max;
- tree max_op1 = minus_p ? vr1_min : vr1_max;
- tree sym_min_op0 = NULL_TREE;
- tree sym_min_op1 = NULL_TREE;
- tree sym_max_op0 = NULL_TREE;
- tree sym_max_op1 = NULL_TREE;
- bool neg_min_op0, neg_min_op1, neg_max_op0, neg_max_op1;
-
- neg_min_op0 = neg_min_op1 = neg_max_op0 = neg_max_op1 = false;
-
- /* If we have a PLUS or MINUS with two VR_RANGEs, either constant or
- single-symbolic ranges, try to compute the precise resulting range,
- but only if we know that this resulting range will also be constant
- or single-symbolic. */
- if (vr0_kind == VR_RANGE && vr1_kind == VR_RANGE
- && (TREE_CODE (min_op0) == INTEGER_CST
- || (sym_min_op0
- = get_single_symbol (min_op0, &neg_min_op0, &min_op0)))
- && (TREE_CODE (min_op1) == INTEGER_CST
- || (sym_min_op1
- = get_single_symbol (min_op1, &neg_min_op1, &min_op1)))
- && (!(sym_min_op0 && sym_min_op1)
- || (sym_min_op0 == sym_min_op1
- && neg_min_op0 == (minus_p ? neg_min_op1 : !neg_min_op1)))
- && (TREE_CODE (max_op0) == INTEGER_CST
- || (sym_max_op0
- = get_single_symbol (max_op0, &neg_max_op0, &max_op0)))
- && (TREE_CODE (max_op1) == INTEGER_CST
- || (sym_max_op1
- = get_single_symbol (max_op1, &neg_max_op1, &max_op1)))
- && (!(sym_max_op0 && sym_max_op1)
- || (sym_max_op0 == sym_max_op1
- && neg_max_op0 == (minus_p ? neg_max_op1 : !neg_max_op1))))
- {
- wide_int wmin, wmax;
- wi::overflow_type min_ovf = wi::OVF_NONE;
- wi::overflow_type max_ovf = wi::OVF_NONE;
-
- /* Build the bounds. */
- combine_bound (code, wmin, min_ovf, expr_type, min_op0, min_op1);
- combine_bound (code, wmax, max_ovf, expr_type, max_op0, max_op1);
-
- /* If we have overflow for the constant part and the resulting
- range will be symbolic, drop to VR_VARYING. */
- if (((bool)min_ovf && sym_min_op0 != sym_min_op1)
- || ((bool)max_ovf && sym_max_op0 != sym_max_op1))
- {
- vr->set_varying (expr_type);
- return;
- }
+ wide_int wmin, wmax;
+ wi::overflow_type min_ovf = wi::OVF_NONE;
+ wi::overflow_type max_ovf = wi::OVF_NONE;
- /* Adjust the range for possible overflow. */
- min = NULL_TREE;
- max = NULL_TREE;
- set_value_range_with_overflow (type, min, max, expr_type,
- wmin, wmax, min_ovf, max_ovf);
- if (type == VR_VARYING)
- {
- vr->set_varying (expr_type);
- return;
- }
+ /* Build the bounds. */
+ combine_bound (code, wmin, min_ovf, expr_type, min_op0, min_op1);
+ combine_bound (code, wmax, max_ovf, expr_type, max_op0, max_op1);
- /* Build the symbolic bounds if needed. */
- adjust_symbolic_bound (min, code, expr_type,
- sym_min_op0, sym_min_op1,
- neg_min_op0, neg_min_op1);
- adjust_symbolic_bound (max, code, expr_type,
- sym_max_op0, sym_max_op1,
- neg_max_op0, neg_max_op1);
- }
- else
+ /* If we have overflow for the constant part and the resulting
+ range will be symbolic, drop to VR_VARYING. */
+ if (((bool)min_ovf && sym_min_op0 != sym_min_op1)
+ || ((bool)max_ovf && sym_max_op0 != sym_max_op1))
{
- /* For other cases, for example if we have a PLUS_EXPR with two
- VR_ANTI_RANGEs, drop to VR_VARYING. It would take more effort
- to compute a precise range for such a case.
- ??? General even mixed range kind operations can be expressed
- by for example transforming ~[3, 5] + [1, 2] to range-only
- operations and a union primitive:
- [-INF, 2] + [1, 2] U [5, +INF] + [1, 2]
- [-INF+1, 4] U [6, +INF(OVF)]
- though usually the union is not exactly representable with
- a single range or anti-range as the above is
- [-INF+1, +INF(OVF)] intersected with ~[5, 5]
- but one could use a scheme similar to equivalences for this. */
vr->set_varying (expr_type);
return;
}
- }
- else if (code == MIN_EXPR
- || code == MAX_EXPR)
- {
- wide_int wmin, wmax;
- wide_int vr0_min, vr0_max;
- wide_int vr1_min, vr1_max;
- extract_range_into_wide_ints (&vr0, expr_type, vr0_min, vr0_max);
- extract_range_into_wide_ints (&vr1, expr_type, vr1_min, vr1_max);
- if (wide_int_range_min_max (wmin, wmax, code, sign, prec,
- vr0_min, vr0_max, vr1_min, vr1_max))
- vr->set (VR_RANGE, wide_int_to_tree (expr_type, wmin),
- wide_int_to_tree (expr_type, wmax));
- else
- vr->set_varying (expr_type);
- return;
- }
- else if (code == MULT_EXPR)
- {
- if (!range_int_cst_p (&vr0)
- || !range_int_cst_p (&vr1))
- {
- vr->set_varying (expr_type);
- return;
- }
- extract_range_from_multiplicative_op (vr, code, expr_type, &vr0, &vr1);
- return;
- }
- else if (code == RSHIFT_EXPR
- || code == LSHIFT_EXPR)
- {
- if (range_int_cst_p (&vr1)
- && !wide_int_range_shift_undefined_p
- (TYPE_SIGN (TREE_TYPE (vr1.min ())),
- prec,
- wi::to_wide (vr1.min ()),
- wi::to_wide (vr1.max ())))
- {
- if (code == RSHIFT_EXPR)
- {
- extract_range_from_multiplicative_op (vr, code, expr_type,
- &vr0, &vr1);
- return;
- }
- else if (code == LSHIFT_EXPR
- && range_int_cst_p (&vr0))
- {
- wide_int res_lb, res_ub;
- if (wide_int_range_lshift (res_lb, res_ub, sign, prec,
- wi::to_wide (vr0.min ()),
- wi::to_wide (vr0.max ()),
- wi::to_wide (vr1.min ()),
- wi::to_wide (vr1.max ()),
- TYPE_OVERFLOW_UNDEFINED (expr_type)))
- {
- min = wide_int_to_tree (expr_type, res_lb);
- max = wide_int_to_tree (expr_type, res_ub);
- vr->set (VR_RANGE, min, max);
- return;
- }
- }
- }
- vr->set_varying (expr_type);
- return;
- }
- else if (code == TRUNC_DIV_EXPR
- || code == FLOOR_DIV_EXPR
- || code == CEIL_DIV_EXPR
- || code == EXACT_DIV_EXPR
- || code == ROUND_DIV_EXPR)
- {
- wide_int dividend_min, dividend_max, divisor_min, divisor_max;
- wide_int wmin, wmax, extra_min, extra_max;
- bool extra_range_p;
-
- /* Special case explicit division by zero as undefined. */
- if (vr1.zero_p ())
- {
- vr->set_undefined ();
- return;
- }
- /* First, normalize ranges into constants we can handle. Note
- that VR_ANTI_RANGE's of constants were already normalized
- before arriving here.
-
- NOTE: As a future improvement, we may be able to do better
- with mixed symbolic (anti-)ranges like [0, A]. See note in
- ranges_from_anti_range. */
- extract_range_into_wide_ints (&vr0, expr_type,
- dividend_min, dividend_max);
- extract_range_into_wide_ints (&vr1, expr_type,
- divisor_min, divisor_max);
- if (!wide_int_range_div (wmin, wmax, code, sign, prec,
- dividend_min, dividend_max,
- divisor_min, divisor_max,
- TYPE_OVERFLOW_UNDEFINED (expr_type),
- extra_range_p, extra_min, extra_max))
+ /* Adjust the range for possible overflow. */
+ min = NULL_TREE;
+ max = NULL_TREE;
+ set_value_range_with_overflow (kind, min, max, expr_type,
+ wmin, wmax, min_ovf, max_ovf);
+ if (kind == VR_VARYING)
{
vr->set_varying (expr_type);
return;
}
- vr->set (VR_RANGE, wide_int_to_tree (expr_type, wmin),
- wide_int_to_tree (expr_type, wmax));
- if (extra_range_p)
- {
- value_range_base
- extra_range (VR_RANGE, wide_int_to_tree (expr_type, extra_min),
- wide_int_to_tree (expr_type, extra_max));
- vr->union_ (&extra_range);
- }
- return;
+
+ /* Build the symbolic bounds if needed. */
+ adjust_symbolic_bound (min, code, expr_type,
+ sym_min_op0, sym_min_op1,
+ neg_min_op0, neg_min_op1);
+ adjust_symbolic_bound (max, code, expr_type,
+ sym_max_op0, sym_max_op1,
+ neg_max_op0, neg_max_op1);
}
- else if (code == TRUNC_MOD_EXPR)
+ else
{
- if (vr1.zero_p ())
- {
- vr->set_undefined ();
- return;
- }
- wide_int wmin, wmax, tmp;
- wide_int vr0_min, vr0_max, vr1_min, vr1_max;
- extract_range_into_wide_ints (&vr0, expr_type, vr0_min, vr0_max);
- extract_range_into_wide_ints (&vr1, expr_type, vr1_min, vr1_max);
- wide_int_range_trunc_mod (wmin, wmax, sign, prec,
- vr0_min, vr0_max, vr1_min, vr1_max);
- min = wide_int_to_tree (expr_type, wmin);
- max = wide_int_to_tree (expr_type, wmax);
- vr->set (VR_RANGE, min, max);
+ /* For other cases, for example if we have a PLUS_EXPR with two
+ VR_ANTI_RANGEs, drop to VR_VARYING. It would take more effort
+ to compute a precise range for such a case.
+ ??? General even mixed range kind operations can be expressed
+ by for example transforming ~[3, 5] + [1, 2] to range-only
+ operations and a union primitive:
+ [-INF, 2] + [1, 2] U [5, +INF] + [1, 2]
+ [-INF+1, 4] U [6, +INF(OVF)]
+ though usually the union is not exactly representable with
+ a single range or anti-range as the above is
+ [-INF+1, +INF(OVF)] intersected with ~[5, 5]
+ but one could use a scheme similar to equivalences for this. */
+ vr->set_varying (expr_type);
return;
}
- else if (code == BIT_AND_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR)
- {
- wide_int may_be_nonzero0, may_be_nonzero1;
- wide_int must_be_nonzero0, must_be_nonzero1;
- wide_int wmin, wmax;
- wide_int vr0_min, vr0_max, vr1_min, vr1_max;
- vrp_set_zero_nonzero_bits (expr_type, &vr0,
- &may_be_nonzero0, &must_be_nonzero0);
- vrp_set_zero_nonzero_bits (expr_type, &vr1,
- &may_be_nonzero1, &must_be_nonzero1);
- extract_range_into_wide_ints (&vr0, expr_type, vr0_min, vr0_max);
- extract_range_into_wide_ints (&vr1, expr_type, vr1_min, vr1_max);
- if (code == BIT_AND_EXPR)
- {
- if (wide_int_range_bit_and (wmin, wmax, sign, prec,
- vr0_min, vr0_max,
- vr1_min, vr1_max,
- must_be_nonzero0,
- may_be_nonzero0,
- must_be_nonzero1,
- may_be_nonzero1))
- {
- min = wide_int_to_tree (expr_type, wmin);
- max = wide_int_to_tree (expr_type, wmax);
- vr->set (VR_RANGE, min, max);
- }
- else
- vr->set_varying (expr_type);
- return;
- }
- else if (code == BIT_IOR_EXPR)
- {
- if (wide_int_range_bit_ior (wmin, wmax, sign,
- vr0_min, vr0_max,
- vr1_min, vr1_max,
- must_be_nonzero0,
- may_be_nonzero0,
- must_be_nonzero1,
- may_be_nonzero1))
- {
- min = wide_int_to_tree (expr_type, wmin);
- max = wide_int_to_tree (expr_type, wmax);
- vr->set (VR_RANGE, min, max);
- }
- else
- vr->set_varying (expr_type);
- return;
- }
- else if (code == BIT_XOR_EXPR)
- {
- if (wide_int_range_bit_xor (wmin, wmax, sign, prec,
- must_be_nonzero0,
- may_be_nonzero0,
- must_be_nonzero1,
- may_be_nonzero1))
- {
- min = wide_int_to_tree (expr_type, wmin);
- max = wide_int_to_tree (expr_type, wmax);
- vr->set (VR_RANGE, min, max);
- }
- else
- vr->set_varying (expr_type);
- return;
- }
- }
- else
- gcc_unreachable ();
/* If either MIN or MAX overflowed, then set the resulting range to
VARYING. */
return;
}
- /* We punt for [-INF, +INF].
- We learn nothing when we have INF on both sides.
- Note that we do accept [-INF, -INF] and [+INF, +INF]. */
- if (vrp_val_is_min (min) && vrp_val_is_max (max))
- {
- vr->set_varying (expr_type);
- return;
- }
-
- cmp = compare_values (min, max);
+ int cmp = compare_values (min, max);
if (cmp == -2 || cmp == 1)
{
/* If the new range has its limits swapped around (MIN > MAX),
vr->set_varying (expr_type);
}
else
- vr->set (type, min, max);
+ vr->set (kind, min, max);
}
-/* Extract range information from a unary operation CODE based on
- the range of its operand *VR0 with type OP0_TYPE with resulting type TYPE.
- The resulting range is stored in *VR. */
+/* Normalize a value_range for use in range_ops and return it. */
-void
-extract_range_from_unary_expr (value_range_base *vr,
- enum tree_code code, tree type,
- const value_range_base *vr0_, tree op0_type)
+static value_range_base
+normalize_for_range_ops (const value_range_base &vr)
{
- signop sign = TYPE_SIGN (type);
- unsigned int prec = TYPE_PRECISION (type);
- value_range_base vr0 = *vr0_;
- value_range_base vrtem0, vrtem1;
+ tree type = vr.type ();
- /* VRP only operates on integral and pointer types. */
- if (!(INTEGRAL_TYPE_P (op0_type)
- || POINTER_TYPE_P (op0_type))
- || !(INTEGRAL_TYPE_P (type)
- || POINTER_TYPE_P (type)))
+ /* This will return ~[0,0] for [&var, &var]. */
+ if (POINTER_TYPE_P (type) && !range_includes_zero_p (&vr))
{
- vr->set_varying (type);
- return;
+ value_range_base temp;
+ temp.set_nonzero (type);
+ return temp;
}
+ if (vr.symbolic_p ())
+ return normalize_for_range_ops (vr.normalize_symbolics ());
+ if (TREE_CODE (vr.min ()) == INTEGER_CST
+ && TREE_CODE (vr.max ()) == INTEGER_CST)
+ return vr;
+ /* Anything not strictly numeric at this point becomes varying. */
+ return value_range_base (vr.type ());
+}
- /* If VR0 is UNDEFINED, so is the result. */
- if (vr0.undefined_p ())
- {
- vr->set_undefined ();
- return;
- }
+/* Fold a binary expression of two value_range's with range-ops. */
- /* Handle operations that we express in terms of others. */
- if (code == PAREN_EXPR)
+void
+range_fold_binary_expr (value_range_base *vr,
+ enum tree_code code,
+ tree expr_type,
+ const value_range_base *vr0_,
+ const value_range_base *vr1_)
+{
+ if (!value_range_base::supports_type_p (expr_type)
+ || (!vr0_->undefined_p ()
+ && !value_range_base::supports_type_p (vr0_->type ()))
+ || (!vr1_->undefined_p ()
+ && !value_range_base::supports_type_p (vr1_->type ())))
{
- /* PAREN_EXPR and OBJ_TYPE_REF are simple copies. */
- *vr = vr0;
+ vr->set_varying (expr_type);
return;
}
- else if (code == NEGATE_EXPR)
+ if (vr0_->undefined_p () && vr1_->undefined_p ())
{
- /* -X is simply 0 - X, so re-use existing code that also handles
- anti-ranges fine. */
- value_range_base zero;
- zero.set (build_int_cst (type, 0));
- extract_range_from_binary_expr (vr, MINUS_EXPR, type, &zero, &vr0);
+ vr->set_undefined ();
return;
}
- else if (code == BIT_NOT_EXPR)
+ range_operator *op = range_op_handler (code, expr_type);
+ if (!op)
{
- /* ~X is simply -1 - X, so re-use existing code that also handles
- anti-ranges fine. */
- value_range_base minusone;
- minusone.set (build_int_cst (type, -1));
- extract_range_from_binary_expr (vr, MINUS_EXPR, type, &minusone, &vr0);
+ vr->set_varying (expr_type);
return;
}
- /* Now canonicalize anti-ranges to ranges when they are not symbolic
- and express op ~[] as (op []') U (op []''). */
- if (vr0.kind () == VR_ANTI_RANGE
- && ranges_from_anti_range (&vr0, &vrtem0, &vrtem1))
+ /* Mimic any behavior users of extract_range_from_binary_expr may
+ expect. */
+ value_range_base vr0 = *vr0_, vr1 = *vr1_;
+ if (vr0.undefined_p ())
+ vr0.set_varying (expr_type);
+ else if (vr1.undefined_p ())
+ vr1.set_varying (expr_type);
+
+ /* Handle symbolics. */
+ if (vr0.symbolic_p () || vr1.symbolic_p ())
{
- extract_range_from_unary_expr (vr, code, type, &vrtem0, op0_type);
- if (!vrtem1.undefined_p ())
+ if ((code == PLUS_EXPR || code == MINUS_EXPR))
{
- value_range_base vrres;
- extract_range_from_unary_expr (&vrres, code, type,
- &vrtem1, op0_type);
- vr->union_ (&vrres);
+ extract_range_from_plus_minus_expr (vr, code, expr_type,
+ &vr0, &vr1);
+ return;
+ }
+ if (POINTER_TYPE_P (expr_type) && code == POINTER_PLUS_EXPR)
+ {
+ extract_range_from_pointer_plus_expr (vr, code, expr_type,
+ &vr0, &vr1);
+ return;
}
- return;
}
- if (CONVERT_EXPR_CODE_P (code))
- {
- tree inner_type = op0_type;
- tree outer_type = type;
+ /* Do the range-ops dance. */
+ value_range_base n0 = normalize_for_range_ops (vr0);
+ value_range_base n1 = normalize_for_range_ops (vr1);
+ *vr = op->fold_range (expr_type, n0, n1);
+}
- /* If the expression involves a pointer, we are only interested in
- determining if it evaluates to NULL [0, 0] or non-NULL (~[0, 0]).
+/* Fold a unary expression of a value_range with range-ops. */
- This may lose precision when converting (char *)~[0,2] to
- int, because we'll forget that the pointer can also not be 1
- or 2. In practice we don't care, as this is some idiot
- storing a magic constant to a pointer. */
- if (POINTER_TYPE_P (type) || POINTER_TYPE_P (op0_type))
+void
+range_fold_unary_expr (value_range_base *vr,
+ enum tree_code code, tree expr_type,
+ const value_range_base *vr0,
+ tree vr0_type)
+{
+ /* Mimic any behavior users of extract_range_from_unary_expr may
+ expect. */
+ if (!value_range_base::supports_type_p (expr_type)
+ || !value_range_base::supports_type_p (vr0_type))
+ {
+ vr->set_varying (expr_type);
+ return;
+ }
+ if (vr0->undefined_p ())
+ {
+ vr->set_undefined ();
+ return;
+ }
+ range_operator *op = range_op_handler (code, expr_type);
+ if (!op)
+ {
+ vr->set_varying (expr_type);
+ return;
+ }
+
+ /* Handle symbolics. */
+ if (vr0->symbolic_p ())
+ {
+ if (code == NEGATE_EXPR)
{
- if (!range_includes_zero_p (&vr0))
- vr->set_nonzero (type);
- else if (vr0.zero_p ())
- vr->set_zero (type);
- else
- vr->set_varying (type);
+ /* -X is simply 0 - X. */
+ value_range_base zero;
+ zero.set_zero (vr0->type ());
+ range_fold_binary_expr (vr, MINUS_EXPR, expr_type, &zero, vr0);
return;
}
-
- /* The POINTER_TYPE_P code above will have dealt with all
- pointer anti-ranges. Any remaining anti-ranges at this point
- will be integer conversions from SSA names that will be
- normalized into VARYING. For instance: ~[x_55, x_55]. */
- gcc_assert (vr0.kind () != VR_ANTI_RANGE
- || TREE_CODE (vr0.min ()) != INTEGER_CST);
-
- /* NOTES: Previously we were returning VARYING for all symbolics, but
- we can do better by treating them as [-MIN, +MAX]. For
- example, converting [SYM, SYM] from INT to LONG UNSIGNED,
- we can return: ~[0x8000000, 0xffffffff7fffffff].
-
- We were also failing to convert ~[0,0] from char* to unsigned,
- instead choosing to return VR_VARYING. Now we return ~[0,0]. */
- wide_int vr0_min, vr0_max, wmin, wmax;
- signop inner_sign = TYPE_SIGN (inner_type);
- signop outer_sign = TYPE_SIGN (outer_type);
- unsigned inner_prec = TYPE_PRECISION (inner_type);
- unsigned outer_prec = TYPE_PRECISION (outer_type);
- extract_range_into_wide_ints (&vr0, inner_type, vr0_min, vr0_max);
- if (wide_int_range_convert (wmin, wmax,
- inner_sign, inner_prec,
- outer_sign, outer_prec,
- vr0_min, vr0_max))
+ if (code == BIT_NOT_EXPR)
{
- tree min = wide_int_to_tree (outer_type, wmin);
- tree max = wide_int_to_tree (outer_type, wmax);
- vr->set (VR_RANGE, min, max);
+ /* ~X is simply -1 - X. */
+ value_range_base minusone;
+ minusone.set (build_int_cst (vr0->type (), -1));
+ range_fold_binary_expr (vr, MINUS_EXPR, expr_type, &minusone, vr0);
+ return;
}
- else
- vr->set_varying (outer_type);
+ *vr = op->fold_range (expr_type,
+ normalize_for_range_ops (*vr0),
+ value_range_base (expr_type));
return;
}
- else if (code == ABS_EXPR)
+ if (CONVERT_EXPR_CODE_P (code) && (POINTER_TYPE_P (expr_type)
+ || POINTER_TYPE_P (vr0->type ())))
{
- wide_int wmin, wmax;
- wide_int vr0_min, vr0_max;
- extract_range_into_wide_ints (&vr0, type, vr0_min, vr0_max);
- if (wide_int_range_abs (wmin, wmax, sign, prec, vr0_min, vr0_max,
- TYPE_OVERFLOW_UNDEFINED (type)))
- vr->set (VR_RANGE, wide_int_to_tree (type, wmin),
- wide_int_to_tree (type, wmax));
+ /* This handles symbolic conversions such such as [25, x_4]. */
+ if (!range_includes_zero_p (vr0))
+ vr->set_nonzero (expr_type);
+ else if (vr0->zero_p ())
+ vr->set_zero (expr_type);
else
- vr->set_varying (type);
- return;
- }
- else if (code == ABSU_EXPR)
- {
- wide_int wmin, wmax;
- wide_int vr0_min, vr0_max;
- tree signed_type = make_signed_type (TYPE_PRECISION (type));
- extract_range_into_wide_ints (&vr0, signed_type, vr0_min, vr0_max);
- wide_int_range_absu (wmin, wmax, prec, vr0_min, vr0_max);
- vr->set (VR_RANGE, wide_int_to_tree (type, wmin),
- wide_int_to_tree (type, wmax));
+ vr->set_varying (expr_type);
return;
}
- /* For unhandled operations fall back to varying. */
- vr->set_varying (type);
- return;
+ /* Do the range-ops dance. */
+ value_range_base n0 = normalize_for_range_ops (*vr0);
+ value_range_base n1 (expr_type);
+ *vr = op->fold_range (expr_type, n0, n1);
}
/* Given a COND_EXPR COND of the form 'V OP W', and an SSA name V,
{
// [SYM, NUM] -> [-MIN, NUM]
if (min_symbolic)
- return value_range_base (VR_RANGE, vrp_val_min (ttype), max ());
+ return value_range_base (VR_RANGE, vrp_val_min (ttype, true), max ());
// [NUM, SYM] -> [NUM, +MAX]
- return value_range_base (VR_RANGE, min (), vrp_val_max (ttype));
+ return value_range_base (VR_RANGE, min (), vrp_val_max (ttype, true));
}
- gcc_assert (kind () == VR_ANTI_RANGE);
+ gcc_checking_assert (kind () == VR_ANTI_RANGE);
// ~[SYM, NUM] -> [NUM + 1, +MAX]
if (min_symbolic)
{
if (!vrp_val_is_max (max ()))
{
tree n = wide_int_to_tree (ttype, wi::to_wide (max ()) + 1);
- return value_range_base (VR_RANGE, n, vrp_val_max (ttype));
+ return value_range_base (VR_RANGE, n, vrp_val_max (ttype, true));
}
value_range_base var;
var.set_varying (ttype);
if (!vrp_val_is_min (min ()))
{
tree n = wide_int_to_tree (ttype, wi::to_wide (min ()) - 1);
- return value_range_base (VR_RANGE, vrp_val_min (ttype), n);
+ return value_range_base (VR_RANGE, vrp_val_min (ttype, true), n);
}
value_range_base var;
var.set_varying (ttype);
return var;
}
+/* Return the number of sub-ranges in a range. */
+
+unsigned
+value_range_base::num_pairs () const
+{
+ if (undefined_p ())
+ return 0;
+ if (varying_p ())
+ return 1;
+ if (symbolic_p ())
+ return normalize_symbolics ().num_pairs ();
+ if (m_kind == VR_ANTI_RANGE)
+ {
+ // ~[MIN, X] has one sub-range of [X+1, MAX], and
+ // ~[X, MAX] has one sub-range of [MIN, X-1].
+ if (vrp_val_is_min (m_min, true) || vrp_val_is_max (m_max, true))
+ return 1;
+ return 2;
+ }
+ return 1;
+}
+
+/* Return the lower bound for a sub-range. PAIR is the sub-range in
+ question. */
+
+wide_int
+value_range_base::lower_bound (unsigned pair) const
+{
+ if (symbolic_p ())
+ return normalize_symbolics ().lower_bound (pair);
+
+ gcc_checking_assert (!undefined_p ());
+ gcc_checking_assert (pair + 1 <= num_pairs ());
+ tree t = NULL;
+ if (m_kind == VR_ANTI_RANGE)
+ {
+ tree typ = type ();
+ if (pair == 1 || vrp_val_is_min (m_min, true))
+ t = wide_int_to_tree (typ, wi::to_wide (m_max) + 1);
+ else
+ t = vrp_val_min (typ, true);
+ }
+ else
+ t = m_min;
+ return wi::to_wide (t);
+}
+
+/* Return the upper bound for a sub-range. PAIR is the sub-range in
+ question. */
+
+wide_int
+value_range_base::upper_bound (unsigned pair) const
+{
+ if (symbolic_p ())
+ return normalize_symbolics ().upper_bound (pair);
+
+ gcc_checking_assert (!undefined_p ());
+ gcc_checking_assert (pair + 1 <= num_pairs ());
+ tree t = NULL;
+ if (m_kind == VR_ANTI_RANGE)
+ {
+ tree typ = type ();
+ if (pair == 1 || vrp_val_is_min (m_min, true))
+ t = vrp_val_max (typ, true);
+ else
+ t = wide_int_to_tree (typ, wi::to_wide (m_min) - 1);
+ }
+ else
+ t = m_max;
+ return wi::to_wide (t);
+}
+
+/* Return the highest bound in a range. */
+
+wide_int
+value_range_base::upper_bound () const
+{
+ unsigned pairs = num_pairs ();
+ gcc_checking_assert (pairs > 0);
+ return upper_bound (pairs - 1);
+}
+
+/* Return TRUE if range contains INTEGER_CST. */
+
+bool
+value_range_base::contains_p (tree cst) const
+{
+ gcc_checking_assert (TREE_CODE (cst) == INTEGER_CST);
+ if (symbolic_p ())
+ return normalize_symbolics ().contains_p (cst);
+ return value_inside_range (cst) == 1;
+}
+
+/* Return the inverse of a range. */
+
+void
+value_range_base::invert ()
+{
+ if (m_kind == VR_RANGE)
+ m_kind = VR_ANTI_RANGE;
+ else if (m_kind == VR_ANTI_RANGE)
+ m_kind = VR_RANGE;
+ else
+ gcc_unreachable ();
+}
+
+/* Range union, but for references. */
+
+void
+value_range_base::union_ (const value_range_base &r)
+{
+ /* Disable details for now, because it makes the ranger dump
+ unnecessarily verbose. */
+ bool details = dump_flags & TDF_DETAILS;
+ if (details)
+ dump_flags &= ~TDF_DETAILS;
+ union_ (&r);
+ if (details)
+ dump_flags |= TDF_DETAILS;
+}
+
+/* Range intersect, but for references. */
+
+void
+value_range_base::intersect (const value_range_base &r)
+{
+ /* Disable details for now, because it makes the ranger dump
+ unnecessarily verbose. */
+ bool details = dump_flags & TDF_DETAILS;
+ if (details)
+ dump_flags &= ~TDF_DETAILS;
+ intersect (&r);
+ if (details)
+ dump_flags |= TDF_DETAILS;
+}
+
+/* Return TRUE if two types are compatible for range operations. */
+
+static bool
+range_compatible_p (tree t1, tree t2)
+{
+ if (POINTER_TYPE_P (t1) && POINTER_TYPE_P (t2))
+ return true;
+
+ return types_compatible_p (t1, t2);
+}
+
+bool
+value_range_base::operator== (const value_range_base &r) const
+{
+ if (undefined_p ())
+ return r.undefined_p ();
+
+ if (num_pairs () != r.num_pairs ()
+ || !range_compatible_p (type (), r.type ()))
+ return false;
+
+ for (unsigned p = 0; p < num_pairs (); p++)
+ if (wi::ne_p (lower_bound (p), r.lower_bound (p))
+ || wi::ne_p (upper_bound (p), r.upper_bound (p)))
+ return false;
+
+ return true;
+}
+
/* 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 for the LHS of PHI. */
value_range_base vr0, vr1;
determine_value_range_1 (&vr0, TREE_OPERAND (expr, 0));
determine_value_range_1 (&vr1, TREE_OPERAND (expr, 1));
- extract_range_from_binary_expr (vr, TREE_CODE (expr), TREE_TYPE (expr),
- &vr0, &vr1);
+ range_fold_binary_expr (vr, TREE_CODE (expr), TREE_TYPE (expr),
+ &vr0, &vr1);
}
else if (UNARY_CLASS_P (expr))
{
value_range_base vr0;
determine_value_range_1 (&vr0, TREE_OPERAND (expr, 0));
- extract_range_from_unary_expr (vr, TREE_CODE (expr), TREE_TYPE (expr),
- &vr0, TREE_TYPE (TREE_OPERAND (expr, 0)));
+ range_fold_unary_expr (vr, TREE_CODE (expr), TREE_TYPE (expr),
+ &vr0, TREE_TYPE (TREE_OPERAND (expr, 0)));
}
else if (TREE_CODE (expr) == INTEGER_CST)
vr->set (expr);
+++ /dev/null
-/* Support routines for range operations on wide ints.
- Copyright (C) 2018-2019 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 "tree.h"
-#include "function.h"
-#include "fold-const.h"
-#include "wide-int-range.h"
-
-/* Wrapper around wide_int_binop that adjusts for overflow.
-
- Return true if we can compute the result; i.e. if the operation
- doesn't overflow or if the overflow is undefined. In the latter
- case (if the operation overflows and overflow is undefined), then
- adjust the result to be -INF or +INF depending on CODE, VAL1 and
- VAL2. Return the value in *RES.
-
- Return false for division by zero, for which the result is
- indeterminate. */
-
-static bool
-wide_int_binop_overflow (wide_int &res,
- enum tree_code code,
- const wide_int &w0, const wide_int &w1,
- signop sign, bool overflow_undefined)
-{
- wi::overflow_type overflow;
- if (!wide_int_binop (res, code, w0, w1, sign, &overflow))
- return false;
-
- /* If the operation overflowed return -INF or +INF depending on the
- operation and the combination of signs of the operands. */
- if (overflow && overflow_undefined)
- {
- switch (code)
- {
- case MULT_EXPR:
- /* For multiplication, the sign of the overflow is given
- by the comparison of the signs of the operands. */
- if (sign == UNSIGNED || w0.sign_mask () == w1.sign_mask ())
- res = wi::max_value (w0.get_precision (), sign);
- else
- res = wi::min_value (w0.get_precision (), sign);
- return true;
-
- case TRUNC_DIV_EXPR:
- case FLOOR_DIV_EXPR:
- case CEIL_DIV_EXPR:
- case EXACT_DIV_EXPR:
- case ROUND_DIV_EXPR:
- /* For division, the only case is -INF / -1 = +INF. */
- res = wi::max_value (w0.get_precision (), sign);
- return true;
-
- default:
- gcc_unreachable ();
- }
- }
- return !overflow;
-}
-
-/* For range [LB, UB] compute two wide_int bit masks.
-
- In the MAY_BE_NONZERO bit mask, if some bit is unset, it means that
- for all numbers in the range the bit is 0, otherwise it might be 0
- or 1.
-
- In the MUST_BE_NONZERO bit mask, if some bit is set, it means that
- for all numbers in the range the bit is 1, otherwise it might be 0
- or 1. */
-
-void
-wide_int_range_set_zero_nonzero_bits (signop sign,
- const wide_int &lb, const wide_int &ub,
- wide_int &may_be_nonzero,
- wide_int &must_be_nonzero)
-{
- may_be_nonzero = wi::minus_one (lb.get_precision ());
- must_be_nonzero = wi::zero (lb.get_precision ());
-
- if (wi::eq_p (lb, ub))
- {
- may_be_nonzero = lb;
- must_be_nonzero = may_be_nonzero;
- }
- else if (wi::ge_p (lb, 0, sign) || wi::lt_p (ub, 0, sign))
- {
- wide_int xor_mask = lb ^ ub;
- may_be_nonzero = lb | ub;
- must_be_nonzero = lb & ub;
- if (xor_mask != 0)
- {
- wide_int mask = wi::mask (wi::floor_log2 (xor_mask), false,
- may_be_nonzero.get_precision ());
- may_be_nonzero = may_be_nonzero | mask;
- must_be_nonzero = wi::bit_and_not (must_be_nonzero, mask);
- }
- }
-}
-
-/* Order 2 sets of wide int ranges (w0/w1, w2/w3) and set MIN/MAX
- accordingly. */
-
-static void
-wide_int_range_order_set (wide_int &min, wide_int &max,
- wide_int &w0, wide_int &w1,
- wide_int &w2, wide_int &w3,
- signop sign)
-{
- /* Order pairs w0,w1 and w2,w3. */
- if (wi::gt_p (w0, w1, sign))
- std::swap (w0, w1);
- if (wi::gt_p (w2, w3, sign))
- std::swap (w2, w3);
-
- /* Choose min and max from the ordered pairs. */
- min = wi::min (w0, w2, sign);
- max = wi::max (w1, w3, sign);
-}
-
-/* Calculate the cross product of two sets of ranges (VR0 and VR1) and
- store the result in [RES_LB, RES_UB].
-
- CODE is the operation to perform with sign SIGN.
-
- OVERFLOW_UNDEFINED is set if overflow is undefined for the operation type.
-
- Return TRUE if we were able to calculate the cross product. */
-
-bool
-wide_int_range_cross_product (wide_int &res_lb, wide_int &res_ub,
- enum tree_code code, signop sign,
- const wide_int &vr0_lb, const wide_int &vr0_ub,
- const wide_int &vr1_lb, const wide_int &vr1_ub,
- bool overflow_undefined)
-{
- wide_int cp1, cp2, cp3, cp4;
-
- /* Compute the 4 cross operations, bailing if we get an overflow we
- can't handle. */
-
- if (!wide_int_binop_overflow (cp1, code, vr0_lb, vr1_lb, sign,
- overflow_undefined))
- return false;
-
- if (wi::eq_p (vr0_lb, vr0_ub))
- cp3 = cp1;
- else if (!wide_int_binop_overflow (cp3, code, vr0_ub, vr1_lb, sign,
- overflow_undefined))
- return false;
-
- if (wi::eq_p (vr1_lb, vr1_ub))
- cp2 = cp1;
- else if (!wide_int_binop_overflow (cp2, code, vr0_lb, vr1_ub, sign,
- overflow_undefined))
- return false;
-
- if (wi::eq_p (vr0_lb, vr0_ub))
- cp4 = cp2;
- else if (!wide_int_binop_overflow (cp4, code, vr0_ub, vr1_ub, sign,
- overflow_undefined))
- return false;
-
- wide_int_range_order_set (res_lb, res_ub, cp1, cp2, cp3, cp4, sign);
- return true;
-}
-
-/* Multiply two ranges when TYPE_OVERFLOW_WRAPS:
-
- [RES_LB, RES_UB] = [MIN0, MAX0] * [MIN1, MAX1]
-
- This is basically fancy code so we don't drop to varying with an
- unsigned [-3,-1]*[-3,-1].
-
- Return TRUE if we were able to perform the operation. */
-
-bool
-wide_int_range_mult_wrapping (wide_int &res_lb,
- wide_int &res_ub,
- signop sign,
- unsigned prec,
- const wide_int &min0_,
- const wide_int &max0_,
- const wide_int &min1_,
- const wide_int &max1_)
-{
- /* This test requires 2*prec bits if both operands are signed and
- 2*prec + 2 bits if either is not. Therefore, extend the values
- using the sign of the result to PREC2. From here on out,
- everthing is just signed math no matter what the input types
- were. */
- widest2_int min0 = widest2_int::from (min0_, sign);
- widest2_int max0 = widest2_int::from (max0_, sign);
- widest2_int min1 = widest2_int::from (min1_, sign);
- widest2_int max1 = widest2_int::from (max1_, sign);
- widest2_int sizem1 = wi::mask <widest2_int> (prec, false);
- widest2_int size = sizem1 + 1;
-
- /* Canonicalize the intervals. */
- if (sign == UNSIGNED)
- {
- if (wi::ltu_p (size, min0 + max0))
- {
- min0 -= size;
- max0 -= size;
- }
-
- if (wi::ltu_p (size, min1 + max1))
- {
- min1 -= size;
- max1 -= size;
- }
- }
-
- widest2_int prod0 = min0 * min1;
- widest2_int prod1 = min0 * max1;
- widest2_int prod2 = max0 * min1;
- widest2_int prod3 = max0 * max1;
-
- /* Sort the 4 products so that min is in prod0 and max is in
- prod3. */
- /* min0min1 > max0max1 */
- if (prod0 > prod3)
- std::swap (prod0, prod3);
-
- /* min0max1 > max0min1 */
- if (prod1 > prod2)
- std::swap (prod1, prod2);
-
- if (prod0 > prod1)
- std::swap (prod0, prod1);
-
- if (prod2 > prod3)
- std::swap (prod2, prod3);
-
- /* diff = max - min. */
- prod2 = prod3 - prod0;
- if (wi::geu_p (prod2, sizem1))
- /* The range covers all values. */
- return false;
-
- res_lb = wide_int::from (prod0, prec, sign);
- res_ub = wide_int::from (prod3, prec, sign);
- return true;
-}
-
-/* Perform multiplicative operation CODE on two ranges:
-
- [RES_LB, RES_UB] = [VR0_LB, VR0_UB] .CODE. [VR1_LB, VR1_LB]
-
- Return TRUE if we were able to perform the operation.
-
- NOTE: If code is MULT_EXPR and !TYPE_OVERFLOW_UNDEFINED, the resulting
- range must be canonicalized by the caller because its components
- may be swapped. */
-
-bool
-wide_int_range_multiplicative_op (wide_int &res_lb, wide_int &res_ub,
- enum tree_code code,
- signop sign,
- unsigned prec,
- const wide_int &vr0_lb,
- const wide_int &vr0_ub,
- const wide_int &vr1_lb,
- const wide_int &vr1_ub,
- bool overflow_undefined)
-{
- /* Multiplications, divisions and shifts are a bit tricky to handle,
- depending on the mix of signs we have in the two ranges, we
- need to operate on different values to get the minimum and
- maximum values for the new range. One approach is to figure
- out all the variations of range combinations and do the
- operations.
-
- However, this involves several calls to compare_values and it
- is pretty convoluted. It's simpler to do the 4 operations
- (MIN0 OP MIN1, MIN0 OP MAX1, MAX0 OP MIN1 and MAX0 OP MAX0 OP
- MAX1) and then figure the smallest and largest values to form
- the new range. */
- if (code == MULT_EXPR && !overflow_undefined)
- return wide_int_range_mult_wrapping (res_lb, res_ub,
- sign, prec,
- vr0_lb, vr0_ub, vr1_lb, vr1_ub);
- return wide_int_range_cross_product (res_lb, res_ub,
- code, sign,
- vr0_lb, vr0_ub, vr1_lb, vr1_ub,
- overflow_undefined);
-}
-
-/* Perform a left shift operation on two ranges:
-
- [RES_LB, RES_UB] = [VR0_LB, VR0_UB] << [VR1_LB, VR1_LB]
-
- Return TRUE if we were able to perform the operation.
-
- NOTE: The resulting range must be canonicalized by the caller
- because its contents components may be swapped. */
-
-bool
-wide_int_range_lshift (wide_int &res_lb, wide_int &res_ub,
- signop sign, unsigned prec,
- const wide_int &vr0_lb, const wide_int &vr0_ub,
- const wide_int &vr1_lb, const wide_int &vr1_ub,
- bool overflow_undefined)
-{
- /* Transform left shifts by constants into multiplies. */
- if (wi::eq_p (vr1_lb, vr1_ub))
- {
- unsigned shift = vr1_ub.to_uhwi ();
- wide_int tmp = wi::set_bit_in_zero (shift, prec);
- return wide_int_range_multiplicative_op (res_lb, res_ub,
- MULT_EXPR, sign, prec,
- vr0_lb, vr0_ub, tmp, tmp,
- /*overflow_undefined=*/false);
- }
-
- int overflow_pos = prec;
- if (sign == SIGNED)
- overflow_pos -= 1;
- int bound_shift = overflow_pos - vr1_ub.to_shwi ();
- /* If bound_shift == HOST_BITS_PER_WIDE_INT, the llshift can
- overflow. However, for that to happen, vr1.max needs to be
- zero, which means vr1 is a singleton range of zero, which
- means it should be handled by the previous LSHIFT_EXPR
- if-clause. */
- wide_int bound = wi::set_bit_in_zero (bound_shift, prec);
- wide_int complement = ~(bound - 1);
- wide_int low_bound, high_bound;
- bool in_bounds = false;
- if (sign == UNSIGNED)
- {
- low_bound = bound;
- high_bound = complement;
- if (wi::ltu_p (vr0_ub, low_bound))
- {
- /* [5, 6] << [1, 2] == [10, 24]. */
- /* We're shifting out only zeroes, the value increases
- monotonically. */
- in_bounds = true;
- }
- else if (wi::ltu_p (high_bound, vr0_lb))
- {
- /* [0xffffff00, 0xffffffff] << [1, 2]
- == [0xfffffc00, 0xfffffffe]. */
- /* We're shifting out only ones, the value decreases
- monotonically. */
- in_bounds = true;
- }
- }
- else
- {
- /* [-1, 1] << [1, 2] == [-4, 4]. */
- low_bound = complement;
- high_bound = bound;
- if (wi::lts_p (vr0_ub, high_bound)
- && wi::lts_p (low_bound, vr0_lb))
- {
- /* For non-negative numbers, we're shifting out only
- zeroes, the value increases monotonically.
- For negative numbers, we're shifting out only ones, the
- value decreases monotomically. */
- in_bounds = true;
- }
- }
- if (in_bounds)
- return wide_int_range_multiplicative_op (res_lb, res_ub,
- LSHIFT_EXPR, sign, prec,
- vr0_lb, vr0_ub,
- vr1_lb, vr1_ub,
- overflow_undefined);
- return false;
-}
-
-/* Return TRUE if a bit operation on two ranges can be easily
- optimized in terms of a mask.
-
- Basically, for BIT_AND_EXPR or BIT_IOR_EXPR see if we can optimize:
-
- [LB, UB] op Z
- into:
- [LB op Z, UB op Z]
-
- It is up to the caller to perform the actual folding above. */
-
-static bool
-wide_int_range_can_optimize_bit_op (tree_code code,
- const wide_int &lb, const wide_int &ub,
- const wide_int &mask)
-
-{
- if (code != BIT_AND_EXPR && code != BIT_IOR_EXPR)
- return false;
- /* If Z is a constant which (for op | its bitwise not) has n
- consecutive least significant bits cleared followed by m 1
- consecutive bits set immediately above it and either
- m + n == precision, or (x >> (m + n)) == (y >> (m + n)).
-
- The least significant n bits of all the values in the range are
- cleared or set, the m bits above it are preserved and any bits
- above these are required to be the same for all values in the
- range. */
-
- wide_int w = mask;
- int m = 0, n = 0;
- if (code == BIT_IOR_EXPR)
- w = ~w;
- if (wi::eq_p (w, 0))
- n = w.get_precision ();
- else
- {
- n = wi::ctz (w);
- w = ~(w | wi::mask (n, false, w.get_precision ()));
- if (wi::eq_p (w, 0))
- m = w.get_precision () - n;
- else
- m = wi::ctz (w) - n;
- }
- wide_int new_mask = wi::mask (m + n, true, w.get_precision ());
- if ((new_mask & lb) == (new_mask & ub))
- return true;
-
- return false;
-}
-
-/* Helper function for wide_int_range_optimize_bit_op.
-
- Calculates bounds and mask for a pair of ranges. The mask is the
- singleton range among the ranges, if any. The bounds are the
- bounds for the remaining range. */
-
-bool
-wide_int_range_get_mask_and_bounds (wide_int &mask,
- wide_int &lower_bound,
- wide_int &upper_bound,
- const wide_int &vr0_min,
- const wide_int &vr0_max,
- const wide_int &vr1_min,
- const wide_int &vr1_max)
-{
- if (wi::eq_p (vr1_min, vr1_max))
- {
- mask = vr1_min;
- lower_bound = vr0_min;
- upper_bound = vr0_max;
- return true;
- }
- else if (wi::eq_p (vr0_min, vr0_max))
- {
- mask = vr0_min;
- lower_bound = vr1_min;
- upper_bound = vr1_max;
- return true;
- }
- return false;
-}
-
-/* Optimize a bit operation (BIT_AND_EXPR or BIT_IOR_EXPR) if
- possible. If so, return TRUE and store the result in
- [RES_LB, RES_UB]. */
-
-bool
-wide_int_range_optimize_bit_op (wide_int &res_lb, wide_int &res_ub,
- enum tree_code code,
- signop sign,
- const wide_int &vr0_min,
- const wide_int &vr0_max,
- const wide_int &vr1_min,
- const wide_int &vr1_max)
-{
- gcc_assert (code == BIT_AND_EXPR || code == BIT_IOR_EXPR);
-
- wide_int lower_bound, upper_bound, mask;
- if (!wide_int_range_get_mask_and_bounds (mask, lower_bound, upper_bound,
- vr0_min, vr0_max, vr1_min, vr1_max))
- return false;
- if (wide_int_range_can_optimize_bit_op (code,
- lower_bound, upper_bound, mask))
- {
- wi::overflow_type ovf;
- wide_int_binop (res_lb, code, lower_bound, mask, sign, &ovf);
- wide_int_binop (res_ub, code, upper_bound, mask, sign, &ovf);
- return true;
- }
- return false;
-}
-
-/* Calculate the XOR of two ranges and store the result in [WMIN,WMAX].
- The two input ranges are described by their MUST_BE_NONZERO and
- MAY_BE_NONZERO bit masks.
-
- Return TRUE if we were able to successfully calculate the new range. */
-
-bool
-wide_int_range_bit_xor (wide_int &wmin, wide_int &wmax,
- signop sign,
- unsigned prec,
- const wide_int &must_be_nonzero0,
- const wide_int &may_be_nonzero0,
- const wide_int &must_be_nonzero1,
- const wide_int &may_be_nonzero1)
-{
- wide_int result_zero_bits = ((must_be_nonzero0 & must_be_nonzero1)
- | ~(may_be_nonzero0 | may_be_nonzero1));
- wide_int result_one_bits
- = (wi::bit_and_not (must_be_nonzero0, may_be_nonzero1)
- | wi::bit_and_not (must_be_nonzero1, may_be_nonzero0));
- wmax = ~result_zero_bits;
- wmin = result_one_bits;
- /* If the range has all positive or all negative values, the result
- is better than VARYING. */
- if (wi::lt_p (wmin, 0, sign) || wi::ge_p (wmax, 0, sign))
- return true;
- wmin = wi::min_value (prec, sign);
- wmax = wi::max_value (prec, sign);
- return false;
-}
-
-/* Calculate the IOR of two ranges and store the result in [WMIN,WMAX].
- Return TRUE if we were able to successfully calculate the new range. */
-
-bool
-wide_int_range_bit_ior (wide_int &wmin, wide_int &wmax,
- signop sign,
- const wide_int &vr0_min,
- const wide_int &vr0_max,
- const wide_int &vr1_min,
- const wide_int &vr1_max,
- const wide_int &must_be_nonzero0,
- const wide_int &may_be_nonzero0,
- const wide_int &must_be_nonzero1,
- const wide_int &may_be_nonzero1)
-{
- if (wide_int_range_optimize_bit_op (wmin, wmax, BIT_IOR_EXPR, sign,
- vr0_min, vr0_max,
- vr1_min, vr1_max))
- return true;
- wmin = must_be_nonzero0 | must_be_nonzero1;
- wmax = may_be_nonzero0 | may_be_nonzero1;
- /* If the input ranges contain only positive values we can
- truncate the minimum of the result range to the maximum
- of the input range minima. */
- if (wi::ge_p (vr0_min, 0, sign)
- && wi::ge_p (vr1_min, 0, sign))
- {
- wmin = wi::max (wmin, vr0_min, sign);
- wmin = wi::max (wmin, vr1_min, sign);
- }
- /* If either input range contains only negative values
- we can truncate the minimum of the result range to the
- respective minimum range. */
- if (wi::lt_p (vr0_max, 0, sign))
- wmin = wi::max (wmin, vr0_min, sign);
- if (wi::lt_p (vr1_max, 0, sign))
- wmin = wi::max (wmin, vr1_min, sign);
- /* If the limits got swapped around, indicate error so we can adjust
- the range to VARYING. */
- if (wi::gt_p (wmin, wmax,sign))
- return false;
- return true;
-}
-
-/* Calculate the bitwise AND of two ranges and store the result in [WMIN,WMAX].
- Return TRUE if we were able to successfully calculate the new range. */
-
-bool
-wide_int_range_bit_and (wide_int &wmin, wide_int &wmax,
- signop sign,
- unsigned prec,
- const wide_int &vr0_min,
- const wide_int &vr0_max,
- const wide_int &vr1_min,
- const wide_int &vr1_max,
- const wide_int &must_be_nonzero0,
- const wide_int &may_be_nonzero0,
- const wide_int &must_be_nonzero1,
- const wide_int &may_be_nonzero1)
-{
- if (wide_int_range_optimize_bit_op (wmin, wmax, BIT_AND_EXPR, sign,
- vr0_min, vr0_max,
- vr1_min, vr1_max))
- return true;
- wmin = must_be_nonzero0 & must_be_nonzero1;
- wmax = may_be_nonzero0 & may_be_nonzero1;
- /* If both input ranges contain only negative values we can
- truncate the result range maximum to the minimum of the
- input range maxima. */
- if (wi::lt_p (vr0_max, 0, sign) && wi::lt_p (vr1_max, 0, sign))
- {
- wmax = wi::min (wmax, vr0_max, sign);
- wmax = wi::min (wmax, vr1_max, sign);
- }
- /* If either input range contains only non-negative values
- we can truncate the result range maximum to the respective
- maximum of the input range. */
- if (wi::ge_p (vr0_min, 0, sign))
- wmax = wi::min (wmax, vr0_max, sign);
- if (wi::ge_p (vr1_min, 0, sign))
- wmax = wi::min (wmax, vr1_max, sign);
- /* PR68217: In case of signed & sign-bit-CST should
- result in [-INF, 0] instead of [-INF, INF]. */
- if (wi::gt_p (wmin, wmax, sign))
- {
- wide_int sign_bit = wi::set_bit_in_zero (prec - 1, prec);
- if (sign == SIGNED
- && ((wi::eq_p (vr0_min, vr0_max)
- && !wi::cmps (vr0_min, sign_bit))
- || (wi::eq_p (vr1_min, vr1_max)
- && !wi::cmps (vr1_min, sign_bit))))
- {
- wmin = wi::min_value (prec, sign);
- wmax = wi::zero (prec);
- }
- }
- /* If the limits got swapped around, indicate error so we can adjust
- the range to VARYING. */
- if (wi::gt_p (wmin, wmax,sign))
- return false;
- return true;
-}
-
-/* Calculate TRUNC_MOD_EXPR on two ranges and store the result in
- [WMIN,WMAX]. */
-
-void
-wide_int_range_trunc_mod (wide_int &wmin, wide_int &wmax,
- signop sign,
- unsigned prec,
- const wide_int &vr0_min,
- const wide_int &vr0_max,
- const wide_int &vr1_min,
- const wide_int &vr1_max)
-{
- wide_int tmp;
-
- /* ABS (A % B) < ABS (B) and either
- 0 <= A % B <= A or A <= A % B <= 0. */
- wmax = vr1_max - 1;
- if (sign == SIGNED)
- {
- tmp = -1 - vr1_min;
- wmax = wi::smax (wmax, tmp);
- }
-
- if (sign == UNSIGNED)
- wmin = wi::zero (prec);
- else
- {
- wmin = -wmax;
- tmp = vr0_min;
- if (wi::gts_p (tmp, 0))
- tmp = wi::zero (prec);
- wmin = wi::smax (wmin, tmp);
- }
- tmp = vr0_max;
- if (sign == SIGNED && wi::neg_p (tmp))
- tmp = wi::zero (prec);
- wmax = wi::min (wmax, tmp, sign);
-}
-
-/* Calculate ABS_EXPR on a range and store the result in [MIN, MAX]. */
-
-bool
-wide_int_range_abs (wide_int &min, wide_int &max,
- signop sign, unsigned prec,
- const wide_int &vr0_min, const wide_int &vr0_max,
- bool overflow_undefined)
-{
- /* Pass through VR0 the easy cases. */
- if (sign == UNSIGNED || wi::ge_p (vr0_min, 0, sign))
- {
- min = vr0_min;
- max = vr0_max;
- return true;
- }
-
- /* -TYPE_MIN_VALUE = TYPE_MIN_VALUE with flag_wrapv so we can't get a
- useful range. */
- wide_int min_value = wi::min_value (prec, sign);
- wide_int max_value = wi::max_value (prec, sign);
- if (!overflow_undefined && wi::eq_p (vr0_min, min_value))
- return false;
-
- /* ABS_EXPR may flip the range around, if the original range
- included negative values. */
- if (wi::eq_p (vr0_min, min_value))
- min = max_value;
- else
- min = wi::abs (vr0_min);
- if (wi::eq_p (vr0_max, min_value))
- max = max_value;
- else
- max = wi::abs (vr0_max);
-
- /* If the range contains zero then we know that the minimum value in the
- range will be zero. */
- if (wi::le_p (vr0_min, 0, sign) && wi::ge_p (vr0_max, 0, sign))
- {
- if (wi::gt_p (min, max, sign))
- max = min;
- min = wi::zero (prec);
- }
- else
- {
- /* If the range was reversed, swap MIN and MAX. */
- if (wi::gt_p (min, max, sign))
- std::swap (min, max);
- }
-
- /* If the new range has its limits swapped around (MIN > MAX), then
- the operation caused one of them to wrap around. The only thing
- we know is that the result is positive. */
- if (wi::gt_p (min, max, sign))
- {
- min = wi::zero (prec);
- max = max_value;
- }
- return true;
-}
-
-/* Calculate ABSU_EXPR on a range and store the result in [MIN, MAX]. */
-
-void
-wide_int_range_absu (wide_int &min, wide_int &max,
- unsigned prec, const wide_int &vr0_min,
- const wide_int &vr0_max)
-{
- /* Pass through VR0 the easy cases. */
- if (wi::ges_p (vr0_min, 0))
- {
- min = vr0_min;
- max = vr0_max;
- return;
- }
-
- min = wi::abs (vr0_min);
- max = wi::abs (vr0_max);
-
- /* If the range contains zero then we know that the minimum value in the
- range will be zero. */
- if (wi::ges_p (vr0_max, 0))
- {
- if (wi::gtu_p (min, max))
- max = min;
- min = wi::zero (prec);
- }
- else
- /* Otherwise, swap MIN and MAX. */
- std::swap (min, max);
-}
-
-/* Convert range in [VR0_MIN, VR0_MAX] with INNER_SIGN and INNER_PREC,
- to a range in [MIN, MAX] with OUTER_SIGN and OUTER_PREC.
-
- Return TRUE if we were able to successfully calculate the new range.
-
- Caller is responsible for canonicalizing the resulting range. */
-
-bool
-wide_int_range_convert (wide_int &min, wide_int &max,
- signop inner_sign,
- unsigned inner_prec,
- signop outer_sign,
- unsigned outer_prec,
- const wide_int &vr0_min,
- const wide_int &vr0_max)
-{
- /* If the conversion is not truncating we can convert the min and
- max values and canonicalize the resulting range. Otherwise we
- can do the conversion if the size of the range is less than what
- the precision of the target type can represent. */
- if (outer_prec >= inner_prec
- || wi::rshift (wi::sub (vr0_max, vr0_min),
- wi::uhwi (outer_prec, inner_prec),
- inner_sign) == 0)
- {
- min = wide_int::from (vr0_min, outer_prec, inner_sign);
- max = wide_int::from (vr0_max, outer_prec, inner_sign);
- return (!wi::eq_p (min, wi::min_value (outer_prec, outer_sign))
- || !wi::eq_p (max, wi::max_value (outer_prec, outer_sign)));
- }
- return false;
-}
-
-/* Calculate a division operation on two ranges and store the result in
- [WMIN, WMAX] U [EXTRA_MIN, EXTRA_MAX].
-
- If EXTRA_RANGE_P is set upon return, EXTRA_MIN/EXTRA_MAX hold
- meaningful information, otherwise they should be ignored.
-
- Return TRUE if we were able to successfully calculate the new range. */
-
-bool
-wide_int_range_div (wide_int &wmin, wide_int &wmax,
- tree_code code, signop sign, unsigned prec,
- const wide_int ÷nd_min, const wide_int ÷nd_max,
- const wide_int &divisor_min, const wide_int &divisor_max,
- bool overflow_undefined,
- bool &extra_range_p,
- wide_int &extra_min, wide_int &extra_max)
-{
- extra_range_p = false;
-
- /* If we know we won't divide by zero, just do the division. */
- if (!wide_int_range_includes_zero_p (divisor_min, divisor_max, sign))
- return wide_int_range_multiplicative_op (wmin, wmax, code, sign, prec,
- dividend_min, dividend_max,
- divisor_min, divisor_max,
- overflow_undefined);
-
- /* If flag_non_call_exceptions, we must not eliminate a division
- by zero. */
- if (cfun->can_throw_non_call_exceptions)
- return false;
-
- /* If we're definitely dividing by zero, there's nothing to do. */
- if (wide_int_range_zero_p (divisor_min, divisor_max, prec))
- return false;
-
- /* Perform the division in 2 parts, [LB, -1] and [1, UB],
- which will skip any division by zero.
-
- First divide by the negative numbers, if any. */
- if (wi::neg_p (divisor_min, sign))
- {
- if (!wide_int_range_multiplicative_op (wmin, wmax,
- code, sign, prec,
- dividend_min, dividend_max,
- divisor_min, wi::minus_one (prec),
- overflow_undefined))
- return false;
- extra_range_p = true;
- }
- /* Then divide by the non-zero positive numbers, if any. */
- if (wi::gt_p (divisor_max, wi::zero (prec), sign))
- {
- if (!wide_int_range_multiplicative_op (extra_range_p ? extra_min : wmin,
- extra_range_p ? extra_max : wmax,
- code, sign, prec,
- dividend_min, dividend_max,
- wi::one (prec), divisor_max,
- overflow_undefined))
- return false;
- }
- else
- extra_range_p = false;
- return true;
-}
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