Mercurial > hg > CbC > CbC_gcc
view gcc/range-op.cc @ 145:1830386684a0
gcc-9.2.0
| author | anatofuz |
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| date | Thu, 13 Feb 2020 11:34:05 +0900 |
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/* Code for range operators. Copyright (C) 2017-2020 Free Software Foundation, Inc. Contributed by Andrew MacLeod <amacleod@redhat.com> and Aldy Hernandez <aldyh@redhat.com>. This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GCC; see the file COPYING3. If not see <http://www.gnu.org/licenses/>. */ #include "config.h" #include "system.h" #include "coretypes.h" #include "backend.h" #include "insn-codes.h" #include "rtl.h" #include "tree.h" #include "gimple.h" #include "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 &r, const value_range &op1, const value_range & 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 &r, tree type, const value_range op) { if (op.undefined_p ()) { r = value_range (); 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 (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]. void range_operator::wi_fold (value_range &r, 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 { gcc_checking_assert (value_range::supports_type_p (type)); r = value_range (type); } // The default for fold is to break all ranges into sub-ranges and // invoke the wi_fold method on each sub-range pair. bool range_operator::fold_range (value_range &r, tree type, const value_range &lh, const value_range &rh) const { gcc_checking_assert (value_range::supports_type_p (type)); if (empty_range_check (r, lh, rh)) return true; value_range tmp; r.set_undefined (); 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); wi_fold (tmp, type, lh_lb, lh_ub, rh_lb, rh_ub); r.union_ (tmp); if (r.varying_p ()) return true; } return true; } // The default for op1_range is to return false. bool range_operator::op1_range (value_range &r ATTRIBUTE_UNUSED, tree type ATTRIBUTE_UNUSED, const value_range &lhs ATTRIBUTE_UNUSED, const value_range &op2 ATTRIBUTE_UNUSED) const { return false; } // The default for op2_range is to return false. bool range_operator::op2_range (value_range &r ATTRIBUTE_UNUSED, tree type ATTRIBUTE_UNUSED, const value_range &lhs ATTRIBUTE_UNUSED, const value_range &op1 ATTRIBUTE_UNUSED) const { return false; } // Create and return a range from a pair of wide-ints that are known // to have overflowed (or underflowed). static void value_range_from_overflowed_bounds (value_range &r, 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) r = value_range (type); else r = value_range (type, tmin, tmax, VR_ANTI_RANGE); } // Create and return a range from a pair of wide-ints. MIN_OVF and // MAX_OVF describe any overflow that might have occurred while // calculating WMIN and WMAX respectively. static void value_range_with_overflow (value_range &r, 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)) { r = value_range (type); return; } 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)) r = value_range (type); else // No overflow or both overflow or underflow. The range // kind stays normal. r = value_range (type, tmin, tmax); return; } if ((min_ovf == wi::OVF_UNDERFLOW && max_ovf == wi::OVF_NONE) || (max_ovf == wi::OVF_OVERFLOW && min_ovf == wi::OVF_NONE)) value_range_from_overflowed_bounds (r, type, wmin, wmax); else // Other underflow and/or overflow, drop to VR_VARYING. r = value_range (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; r = value_range (type, new_lb, new_ub); } } // Create and return a range from a pair of wide-ints. Canonicalize // the case where the bounds are swapped. In which case, we transform // [10,5] into [MIN,5][10,MAX]. static inline void create_possibly_reversed_range (value_range &r, 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)) value_range_from_overflowed_bounds (r, type, new_lb, new_ub); else // Otherwise its just a normal range. r = value_range (type, new_lb, new_ub); } // Return a value_range instance that is a boolean TRUE. static inline value_range range_true (tree type) { unsigned prec = TYPE_PRECISION (type); return value_range (type, wi::one (prec), wi::one (prec)); } // Return a value_range instance that is a boolean FALSE. static inline value_range range_false (tree type) { unsigned prec = TYPE_PRECISION (type); return value_range (type, wi::zero (prec), wi::zero (prec)); } // Return a value_range that covers both true and false. static inline value_range range_true_and_false (tree type) { unsigned prec = TYPE_PRECISION (type); return value_range (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 &r, const value_range &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 bool fold_range (value_range &r, tree type, const value_range &op1, const value_range &op2) const; virtual bool op1_range (value_range &r, tree type, const value_range &lhs, const value_range &val) const; virtual bool op2_range (value_range &r, tree type, const value_range &lhs, const value_range &val) const; } op_equal; bool operator_equal::fold_range (value_range &r, tree type, const value_range &op1, const value_range &op2) const { if (empty_range_check (r, op1, op2)) return true; // 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 = op1; r.intersect (op2); if (r.undefined_p ()) r = range_false (type); else r = range_true_and_false (type); } return true; } bool operator_equal::op1_range (value_range &r, tree type, const value_range &lhs, const value_range &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 = op2; r.invert (); } 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 &r, tree type, const value_range &lhs, const value_range &op1) const { return operator_equal::op1_range (r, type, lhs, op1); } class operator_not_equal : public range_operator { public: virtual bool fold_range (value_range &r, tree type, const value_range &op1, const value_range &op2) const; virtual bool op1_range (value_range &r, tree type, const value_range &lhs, const value_range &op2) const; virtual bool op2_range (value_range &r, tree type, const value_range &lhs, const value_range &op1) const; } op_not_equal; bool operator_not_equal::fold_range (value_range &r, tree type, const value_range &op1, const value_range &op2) const { if (empty_range_check (r, op1, op2)) return true; // 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 = op1; r.intersect (op2); if (r.undefined_p ()) r = range_true (type); else r = range_true_and_false (type); } return true; } bool operator_not_equal::op1_range (value_range &r, tree type, const value_range &lhs, const value_range &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 = op2; r.invert (); } 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 &r, tree type, const value_range &lhs, const value_range &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 &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 (type, min_limit (type), lim); } // (X <= VAL) produces the range of [MIN, VAL]. static void build_le (value_range &r, tree type, const wide_int &val) { r = value_range (type, min_limit (type), val); } // (X > VAL) produces the range of [VAL + 1, MAX]. static void build_gt (value_range &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 (type, lim, max_limit (type)); } // (X >= val) produces the range of [VAL, MAX]. static void build_ge (value_range &r, tree type, const wide_int &val) { r = value_range (type, val, max_limit (type)); } class operator_lt : public range_operator { public: virtual bool fold_range (value_range &r, tree type, const value_range &op1, const value_range &op2) const; virtual bool op1_range (value_range &r, tree type, const value_range &lhs, const value_range &op2) const; virtual bool op2_range (value_range &r, tree type, const value_range &lhs, const value_range &op1) const; } op_lt; bool operator_lt::fold_range (value_range &r, tree type, const value_range &op1, const value_range &op2) const { if (empty_range_check (r, op1, op2)) return true; 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 true; } bool operator_lt::op1_range (value_range &r, tree type, const value_range &lhs, const value_range &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 &r, tree type, const value_range &lhs, const value_range &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 bool fold_range (value_range &r, tree type, const value_range &op1, const value_range &op2) const; virtual bool op1_range (value_range &r, tree type, const value_range &lhs, const value_range &op2) const; virtual bool op2_range (value_range &r, tree type, const value_range &lhs, const value_range &op1) const; } op_le; bool operator_le::fold_range (value_range &r, tree type, const value_range &op1, const value_range &op2) const { if (empty_range_check (r, op1, op2)) return true; 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 true; } bool operator_le::op1_range (value_range &r, tree type, const value_range &lhs, const value_range &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 &r, tree type, const value_range &lhs, const value_range &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 bool fold_range (value_range &r, tree type, const value_range &op1, const value_range &op2) const; virtual bool op1_range (value_range &r, tree type, const value_range &lhs, const value_range &op2) const; virtual bool op2_range (value_range &r, tree type, const value_range &lhs, const value_range &op1) const; } op_gt; bool operator_gt::fold_range (value_range &r, tree type, const value_range &op1, const value_range &op2) const { if (empty_range_check (r, op1, op2)) return true; 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 true; } bool operator_gt::op1_range (value_range &r, tree type, const value_range &lhs, const value_range &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 &r, tree type, const value_range &lhs, const value_range &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 bool fold_range (value_range &r, tree type, const value_range &op1, const value_range &op2) const; virtual bool op1_range (value_range &r, tree type, const value_range &lhs, const value_range &op2) const; virtual bool op2_range (value_range &r, tree type, const value_range &lhs, const value_range &op1) const; } op_ge; bool operator_ge::fold_range (value_range &r, tree type, const value_range &op1, const value_range &op2) const { if (empty_range_check (r, op1, op2)) return true; 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 true; } bool operator_ge::op1_range (value_range &r, tree type, const value_range &lhs, const value_range &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 &r, tree type, const value_range &lhs, const value_range &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 &r, tree type, const value_range &lhs, const value_range &op2) const; virtual bool op2_range (value_range &r, tree type, const value_range &lhs, const value_range &op1) const; virtual void wi_fold (value_range &r, 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; void operator_plus::wi_fold (value_range &r, 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); value_range_with_overflow (r, type, new_lb, new_ub, ov_lb, ov_ub); } bool operator_plus::op1_range (value_range &r, tree type, const value_range &lhs, const value_range &op2) const { return range_op_handler (MINUS_EXPR, type)->fold_range (r, type, lhs, op2); } bool operator_plus::op2_range (value_range &r, tree type, const value_range &lhs, const value_range &op1) const { return range_op_handler (MINUS_EXPR, type)->fold_range (r, type, lhs, op1); } class operator_minus : public range_operator { public: virtual bool op1_range (value_range &r, tree type, const value_range &lhs, const value_range &op2) const; virtual bool op2_range (value_range &r, tree type, const value_range &lhs, const value_range &op1) const; virtual void wi_fold (value_range &r, 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; void operator_minus::wi_fold (value_range &r, 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); value_range_with_overflow (r, type, new_lb, new_ub, ov_lb, ov_ub); } bool operator_minus::op1_range (value_range &r, tree type, const value_range &lhs, const value_range &op2) const { return range_op_handler (PLUS_EXPR, type)->fold_range (r, type, lhs, op2); } bool operator_minus::op2_range (value_range &r, tree type, const value_range &lhs, const value_range &op1) const { return fold_range (r, type, op1, lhs); } class operator_min : public range_operator { public: virtual void wi_fold (value_range &r, 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; void operator_min::wi_fold (value_range &r, 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); value_range_with_overflow (r, type, new_lb, new_ub); } class operator_max : public range_operator { public: virtual void wi_fold (value_range &r, 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; void operator_max::wi_fold (value_range &r, 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); value_range_with_overflow (r, 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. void wi_cross_product (value_range &r, 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. void cross_product_operator::wi_cross_product (value_range &r, 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; // Default to varying. r = value_range (type); // 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; if (wi::eq_p (lh_lb, lh_ub)) cp3 = cp1; else if (wi_op_overflows (cp3, type, lh_ub, rh_lb)) return; if (wi::eq_p (rh_lb, rh_ub)) cp2 = cp1; else if (wi_op_overflows (cp2, type, lh_lb, rh_ub)) return; if (wi::eq_p (lh_lb, lh_ub)) cp4 = cp2; else if (wi_op_overflows (cp4, type, lh_ub, rh_ub)) return; // 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); value_range_with_overflow (r, type, res_lb, res_ub); } class operator_mult : public cross_product_operator { public: virtual void wi_fold (value_range &r, 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; } void operator_mult::wi_fold (value_range &r, 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)) { wi_cross_product (r, type, lh_lb, lh_ub, rh_lb, rh_ub); return; } // 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. r = value_range (type); else { wide_int new_lb = wide_int::from (prod0, prec, sign); wide_int new_ub = wide_int::from (prod3, prec, sign); create_possibly_reversed_range (r, type, new_lb, new_ub); } } class operator_div : public cross_product_operator { public: operator_div (enum tree_code c) { code = c; } virtual void wi_fold (value_range &r, 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; } void operator_div::wi_fold (value_range &r, 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) { r = value_range (); return; } 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)) { wi_cross_product (r, type, dividend_min, dividend_max, divisor_min, divisor_max); return; } // If flag_non_call_exceptions, we must not eliminate a division by zero. if (cfun->can_throw_non_call_exceptions) { r = value_range (type); return; } // If we're definitely dividing by zero, there's nothing to do. if (wi_zero_p (type, divisor_min, divisor_max)) { r = value_range (); return; } // 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)) wi_cross_product (r, type, dividend_min, dividend_max, divisor_min, wi::minus_one (prec)); else r = value_range (); // Then divide by the non-zero positive numbers, if any. if (wi::gt_p (divisor_max, wi::zero (prec), sign)) { value_range tmp; wi_cross_product (tmp, type, dividend_min, dividend_max, wi::one (prec), divisor_max); r.union_ (tmp); } // We shouldn't still have undefined here. gcc_checking_assert (!r.undefined_p ()); } 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 &r, tree type, const value_range &lhs, const value_range &op2) const; } op_exact_div; bool operator_exact_divide::op1_range (value_range &r, tree type, const value_range &lhs, const value_range &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)) return range_op_handler (MULT_EXPR, type)->fold_range (r, type, lhs, op2); return false; } class operator_lshift : public cross_product_operator { public: virtual bool fold_range (value_range &r, tree type, const value_range &op1, const value_range &op2) const; virtual void wi_fold (value_range &r, 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; bool operator_lshift::fold_range (value_range &r, tree type, const value_range &op1, const value_range &op2) const { if (undefined_shift_range_check (r, type, op2)) return true; // 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 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; bool b = range_op_handler (MULT_EXPR, type)->fold_range (r, type, op1, mult); flag_wrapv = saved_flag_wrapv; flag_wrapv_pointer = saved_flag_wrapv_pointer; return b; } else // Otherwise, invoke the generic fold routine. return range_operator::fold_range (r, type, op1, op2); } void operator_lshift::wi_fold (value_range &r, 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) wi_cross_product (r, type, lh_lb, lh_ub, rh_lb, rh_ub); else r = value_range (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 bool fold_range (value_range &r, tree type, const value_range &op1, const value_range &op2) const; virtual void wi_fold (value_range &r, 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; } bool operator_rshift::fold_range (value_range &r, tree type, const value_range &op1, const value_range &op2) const { // Invoke the generic fold routine if not undefined.. if (undefined_shift_range_check (r, type, op2)) return true; return range_operator::fold_range (r, type, op1, op2); } void operator_rshift::wi_fold (value_range &r, tree type, const wide_int &lh_lb, const wide_int &lh_ub, const wide_int &rh_lb, const wide_int &rh_ub) const { wi_cross_product (r, type, lh_lb, lh_ub, rh_lb, rh_ub); } class operator_cast: public range_operator { public: virtual bool fold_range (value_range &r, tree type, const value_range &op1, const value_range &op2) const; virtual bool op1_range (value_range &r, tree type, const value_range &lhs, const value_range &op2) const; } op_convert; bool operator_cast::fold_range (value_range &r, tree type ATTRIBUTE_UNUSED, const value_range &lh, const value_range &rh) const { if (empty_range_check (r, lh, rh)) return true; 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); // Start with an empty range and add subranges. r = value_range (); 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 tmp; create_possibly_reversed_range (tmp, type, min, max); r.union_ (tmp); continue; } } r = value_range (type); break; } return true; } bool operator_cast::op1_range (value_range &r, tree type, const value_range &lhs, const value_range &op2) const { tree lhs_type = lhs.type (); value_range tmp; 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. fold_range (r, lhs_type, op2, value_range (lhs_type)); fold_range (tmp, type, r, value_range (type)); if (tmp == 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. fold_range (r, type, lhs, value_range (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 (type, wi::minus_one (prec), wi::minus_one (prec), VR_ANTI_RANGE); else r = value_range (type, wi::zero (prec), wi::zero (prec), VR_ANTI_RANGE); // 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. fold_range (tmp, lhs_type, value_range (type), value_range (lhs_type)); // Intersect this with the LHS range will produce the range, which // will be cast to the RHS type before returning. tmp.intersect (lhs); } else tmp = lhs; // Cast the calculated range to the type of the RHS. fold_range (r, type, tmp, value_range (type)); return true; } class operator_logical_and : public range_operator { public: virtual bool fold_range (value_range &r, tree type, const value_range &lh, const value_range &rh) const; virtual bool op1_range (value_range &r, tree type, const value_range &lhs, const value_range &op2) const; virtual bool op2_range (value_range &r, tree type, const value_range &lhs, const value_range &op1) const; } op_logical_and; bool operator_logical_and::fold_range (value_range &r, tree type, const value_range &lh, const value_range &rh) const { if (empty_range_check (r, lh, rh)) return true; // 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))) r = range_false (type); else if (lh.contains_p (build_zero_cst (lh.type ())) || rh.contains_p (build_zero_cst (rh.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. r = range_true_and_false (type); else r = range_true (type); return true; } bool operator_logical_and::op1_range (value_range &r, tree type, const value_range &lhs, const value_range &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 &r, tree type, const value_range &lhs, const value_range &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 &r, tree type, const value_range &lhs, const value_range &op2) const; virtual bool op2_range (value_range &r, tree type, const value_range &lhs, const value_range &op1) const; virtual void wi_fold (value_range &r, 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 &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 (); value_range_with_overflow (r, 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. 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 ()); } } void operator_bitwise_and::wi_fold (value_range &r, tree type, const wide_int &lh_lb, const wide_int &lh_ub, const wide_int &rh_lb, const wide_int &rh_ub) const { if (wi_optimize_and_or (r, BIT_AND_EXPR, type, lh_lb, lh_ub, rh_lb, rh_ub)) return; 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)) r = value_range (type); else value_range_with_overflow (r, type, new_lb, new_ub); } bool operator_bitwise_and::op1_range (value_range &r, tree type, const value_range &lhs, const value_range &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 &r, tree type, const value_range &lhs, const value_range &op1) const { return operator_bitwise_and::op1_range (r, type, lhs, op1); } class operator_logical_or : public range_operator { public: virtual bool fold_range (value_range &r, tree type, const value_range &lh, const value_range &rh) const; virtual bool op1_range (value_range &r, tree type, const value_range &lhs, const value_range &op2) const; virtual bool op2_range (value_range &r, tree type, const value_range &lhs, const value_range &op1) const; } op_logical_or; bool operator_logical_or::fold_range (value_range &r, tree type ATTRIBUTE_UNUSED, const value_range &lh, const value_range &rh) const { if (empty_range_check (r, lh, rh)) return true; r = lh; r.union_ (rh); return true; } bool operator_logical_or::op1_range (value_range &r, tree type, const value_range &lhs, const value_range &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 &r, tree type, const value_range &lhs, const value_range &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 &r, tree type, const value_range &lhs, const value_range &op2) const; virtual bool op2_range (value_range &r, tree type, const value_range &lhs, const value_range &op1) const; virtual void wi_fold (value_range &r, 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; void operator_bitwise_or::wi_fold (value_range &r, tree type, const wide_int &lh_lb, const wide_int &lh_ub, const wide_int &rh_lb, const wide_int &rh_ub) const { if (wi_optimize_and_or (r, BIT_IOR_EXPR, type, lh_lb, lh_ub, rh_lb, rh_ub)) return; 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)) r = value_range (type); else value_range_with_overflow (r, type, new_lb, new_ub); } bool operator_bitwise_or::op1_range (value_range &r, tree type, const value_range &lhs, const value_range &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 &r, tree type, const value_range &lhs, const value_range &op1) const { return operator_bitwise_or::op1_range (r, type, lhs, op1); } class operator_bitwise_xor : public range_operator { public: virtual void wi_fold (value_range &r, 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; void operator_bitwise_xor::wi_fold (value_range &r, 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)) value_range_with_overflow (r, type, new_lb, new_ub); else r = value_range (type); } class operator_trunc_mod : public range_operator { public: virtual void wi_fold (value_range &r, 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; void operator_trunc_mod::wi_fold (value_range &r, 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)) { r = value_range (); return; } // 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); value_range_with_overflow (r, type, new_lb, new_ub); } class operator_logical_not : public range_operator { public: virtual bool fold_range (value_range &r, tree type, const value_range &lh, const value_range &rh) const; virtual bool op1_range (value_range &r, tree type, const value_range &lhs, const value_range &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. bool operator_logical_not::fold_range (value_range &r, tree type, const value_range &lh, const value_range &rh ATTRIBUTE_UNUSED) const { if (empty_range_check (r, lh, rh)) return true; if (lh.varying_p () || lh.undefined_p ()) r = lh; else { r = lh; r.invert (); } gcc_checking_assert (lh.type() == type); return true; } bool operator_logical_not::op1_range (value_range &r, tree type ATTRIBUTE_UNUSED, const value_range &lhs, const value_range &op2 ATTRIBUTE_UNUSED) const { r = lhs; if (!lhs.varying_p () && !lhs.undefined_p ()) r.invert (); return true; } class operator_bitwise_not : public range_operator { public: virtual bool fold_range (value_range &r, tree type, const value_range &lh, const value_range &rh) const; virtual bool op1_range (value_range &r, tree type, const value_range &lhs, const value_range &op2) const; } op_bitwise_not; bool operator_bitwise_not::fold_range (value_range &r, tree type, const value_range &lh, const value_range &rh) const { if (empty_range_check (r, lh, rh)) return true; // ~X is simply -1 - X. value_range minusone (type, wi::minus_one (TYPE_PRECISION (type)), wi::minus_one (TYPE_PRECISION (type))); return range_op_handler (MINUS_EXPR, type)->fold_range (r, type, minusone, lh); } bool operator_bitwise_not::op1_range (value_range &r, tree type, const value_range &lhs, const value_range &op2) const { // ~X is -1 - X and since bitwise NOT is involutary...do it again. return fold_range (r, type, lhs, op2); } class operator_cst : public range_operator { public: virtual bool fold_range (value_range &r, tree type, const value_range &op1, const value_range &op2) const; } op_integer_cst; bool operator_cst::fold_range (value_range &r, tree type ATTRIBUTE_UNUSED, const value_range &lh, const value_range &rh ATTRIBUTE_UNUSED) const { r = lh; return true; } class operator_identity : public range_operator { public: virtual bool fold_range (value_range &r, tree type, const value_range &op1, const value_range &op2) const; virtual bool op1_range (value_range &r, tree type, const value_range &lhs, const value_range &op2) const; } op_identity; bool operator_identity::fold_range (value_range &r, tree type ATTRIBUTE_UNUSED, const value_range &lh, const value_range &rh ATTRIBUTE_UNUSED) const { r = lh; return true; } bool operator_identity::op1_range (value_range &r, tree type ATTRIBUTE_UNUSED, const value_range &lhs, const value_range &op2 ATTRIBUTE_UNUSED) const { r = lhs; return true; } class operator_abs : public range_operator { public: virtual void wi_fold (value_range &r, 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 &r, tree type, const value_range &lhs, const value_range &op2) const; } op_abs; void operator_abs::wi_fold (value_range &r, 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)) { r = value_range (type, lh_lb, lh_ub); return; } // -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)) { r = value_range (type); return; } // 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; } r = value_range (type, min, max); } bool operator_abs::op1_range (value_range &r, tree type, const value_range &lhs, const value_range &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 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 (type, -positives.upper_bound (i), -positives.lower_bound (i))); return true; } class operator_absu : public range_operator { public: virtual void wi_fold (value_range &r, 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; void operator_absu::wi_fold (value_range &r, 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)); r = value_range (type, new_lb, new_ub); } class operator_negate : public range_operator { public: virtual bool fold_range (value_range &r, tree type, const value_range &op1, const value_range &op2) const; virtual bool op1_range (value_range &r, tree type, const value_range &lhs, const value_range &op2) const; } op_negate; bool operator_negate::fold_range (value_range &r, tree type, const value_range &lh, const value_range &rh) const { if (empty_range_check (r, lh, rh)) return true; // -X is simply 0 - X. return range_op_handler (MINUS_EXPR, type)->fold_range (r, type, range_zero (type), lh); } bool operator_negate::op1_range (value_range &r, tree type, const value_range &lhs, const value_range &op2) const { // NEGATE is involutory. return fold_range (r, type, lhs, op2); } class operator_addr_expr : public range_operator { public: virtual bool fold_range (value_range &r, tree type, const value_range &op1, const value_range &op2) const; virtual bool op1_range (value_range &r, tree type, const value_range &lhs, const value_range &op2) const; } op_addr; bool operator_addr_expr::fold_range (value_range &r, tree type, const value_range &lh, const value_range &rh) const { if (empty_range_check (r, lh, rh)) return true; // Return a non-null pointer of the LHS type (passed in op2). if (lh.zero_p ()) r = range_zero (type); else if (!lh.contains_p (build_zero_cst (lh.type ()))) r = range_nonzero (type); else r = value_range (type); return true; } bool operator_addr_expr::op1_range (value_range &r, tree type, const value_range &lhs, const value_range &op2) const { return operator_addr_expr::fold_range (r, type, lhs, op2); } class pointer_plus_operator : public range_operator { public: virtual void wi_fold (value_range &r, 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; void pointer_plus_operator::wi_fold (value_range &r, 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))) r = range_nonzero (type); else if (lh_lb == lh_ub && lh_lb == 0 && rh_lb == rh_ub && rh_lb == 0) r = range_zero (type); else r = value_range (type); } class pointer_min_max_operator : public range_operator { public: virtual void wi_fold (value_range & r, 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; void pointer_min_max_operator::wi_fold (value_range &r, 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)) r = range_nonzero (type); else if (wi_zero_p (type, lh_lb, lh_ub) && wi_zero_p (type, rh_lb, rh_ub)) r = range_zero (type); else r = value_range (type); } class pointer_and_operator : public range_operator { public: virtual void wi_fold (value_range &r, 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; void pointer_and_operator::wi_fold (value_range &r, 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)) r = range_zero (type); else r = value_range (type); } class pointer_or_operator : public range_operator { public: virtual void wi_fold (value_range &r, 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; void pointer_or_operator::wi_fold (value_range &r, 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)) r = range_nonzero (type); else if (wi_zero_p (type, lh_lb, lh_ub) && wi_zero_p (type, rh_lb, rh_ub)) r = range_zero (type); else r = value_range (type); } // 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 &r, tree type) { value_range tmp = r; range_operator *op = range_op_handler (CONVERT_EXPR, type); // Call op_convert, if it fails, the result is varying. if (!op->fold_range (r, type, tmp, value_range (type))) r = value_range (type); } #if CHECKING_P #include "selftest.h" #include "stor-layout.h" namespace selftest { #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)) // Run all of the selftests within this file. void range_tests () { tree u128_type = build_nonstandard_integer_type (128, /*unsigned=*/1); value_range i1, i2, i3; value_range r0, r1, rold; // Test that NOT(255) is [0..254] in 8-bit land. value_range not_255 (UCHAR (255), UCHAR (255), VR_ANTI_RANGE); ASSERT_TRUE (not_255 == value_range (UCHAR (0), UCHAR (254))); // Test that NOT(0) is [1..255] in 8-bit land. value_range not_zero = range_nonzero (unsigned_char_type_node); ASSERT_TRUE (not_zero == value_range (UCHAR (1), UCHAR (255))); // Check that [0,127][0x..ffffff80,0x..ffffff] // => ~[128, 0x..ffffff7f]. r0 = value_range (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 (low, high); // [0x..ffffff80, 0x..ffffffff] // r0 = [0,127][0x..ffffff80,0x..fffffff]. r0.union_ (r1); // r1 = [128, 0x..ffffff7f]. r1 = value_range (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 (UINT (0), UINT (5)); r0.invert (); ASSERT_TRUE (r0 == value_range (UINT(6), maxuint)); // Check that ~[10,MAX] => [0,9] for unsigned int. r0 = value_range (UINT(10), maxuint); r0.invert (); ASSERT_TRUE (r0 == value_range (UINT (0), UINT (9))); // Check that ~[0,5] => [6,MAX] for unsigned 128-bit numbers. r0 = value_range (UINT128 (0), UINT128 (5), VR_ANTI_RANGE); r1 = value_range (UINT128(6), build_minus_one_cst (u128_type)); ASSERT_TRUE (r0 == r1); // Check that [~5] is really [-MIN,4][6,MAX]. r0 = value_range (INT (5), INT (5), VR_ANTI_RANGE); r1 = value_range (minint, INT (4)); r1.union_ (value_range (INT (6), maxint)); ASSERT_FALSE (r1.undefined_p ()); ASSERT_TRUE (r0 == r1); r1 = value_range (INT (5), INT (5)); value_range r2 (r1); ASSERT_TRUE (r1 == r2); r1 = value_range (INT (5), INT (10)); r1 = value_range (integer_type_node, wi::to_wide (INT (5)), wi::to_wide (INT (10))); ASSERT_TRUE (r1.contains_p (INT (7))); r1 = value_range (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. if (TYPE_PRECISION (TREE_TYPE (maxint)) > TYPE_PRECISION (short_integer_type_node)) { r1 = value_range (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 (SCHAR (-5), SCHAR (-1)); range_cast (r0, unsigned_char_type_node); ASSERT_TRUE (r0 == value_range (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 (UCHAR (15), UCHAR (150)); range_cast (r0, signed_char_type_node); r1 = value_range (SCHAR (15), SCHAR (127)); r2 = value_range (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 (SCHAR (-5), SCHAR (5)); range_cast (r0, unsigned_char_type_node); r1 = value_range (UCHAR (251), UCHAR (255)); r2 = value_range (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 (INT (-5), INT (5)); range_cast (r0, unsigned_char_type_node); r1 = value_range (UCHAR (0), UCHAR (5)); r1.union_ (value_range (UCHAR (251), UCHAR (255))); ASSERT_TRUE (r0 == r1); // (unsigned char)[5U,1974U] => [0,255]. r0 = value_range (UINT (5), UINT (1974)); range_cast (r0, unsigned_char_type_node); ASSERT_TRUE (r0 == value_range (UCHAR (0), UCHAR (255))); range_cast (r0, integer_type_node); // Going to a wider range should not sign extend. ASSERT_TRUE (r0 == value_range (INT (0), INT (255))); // (unsigned char)[-350,15] => [0,255]. r0 = value_range (INT (-350), INT (15)); range_cast (r0, unsigned_char_type_node); ASSERT_TRUE (r0 == (value_range (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 (SCHAR (-120), SCHAR (20)); range_cast (r0, short_unsigned_type_node); r1 = value_range (UINT16 (0), UINT16 (20)); r2 = value_range (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 (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 (UCHAR (25), UCHAR (250)); range_cast (r0, short_integer_type_node); r1 = value_range (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 (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 (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 (INT (10), INT (20)); r2 = value_range (minint, INT(9)); r2.union_ (value_range (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 (build_zero_cst (boolean_type_node), build_zero_cst (boolean_type_node))); r0.invert (); ASSERT_TRUE (r0 == value_range (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. if (TYPE_PRECISION (integer_type_node) > TYPE_PRECISION (short_integer_type_node)) { r0 = range_nonzero (integer_type_node); range_cast (r0, short_integer_type_node); r1 = value_range (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 (INT (-32768), INT (-1)); r2 = value_range (INT (1), INT (32767)); r1.union_ (r2); ASSERT_TRUE (r0 == r1); // 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); // [10,20] U [15, 30] => [10, 30]. r0 = value_range (INT (10), INT (20)); r1 = value_range (INT (15), INT (30)); r0.union_ (r1); ASSERT_TRUE (r0 == value_range (INT (10), INT (30))); // [15,40] U [] => [15,40]. r0 = value_range (INT (15), INT (40)); r1.set_undefined (); r0.union_ (r1); ASSERT_TRUE (r0 == value_range (INT (15), INT (40))); // [10,20] U [10,10] => [10,20]. r0 = value_range (INT (10), INT (20)); r1 = value_range (INT (10), INT (10)); r0.union_ (r1); ASSERT_TRUE (r0 == value_range (INT (10), INT (20))); // [10,20] U [9,9] => [9,20]. r0 = value_range (INT (10), INT (20)); r1 = value_range (INT (9), INT (9)); r0.union_ (r1); ASSERT_TRUE (r0 == value_range (INT (9), INT (20))); // [10,20] ^ [15,30] => [15,20]. r0 = value_range (INT (10), INT (20)); r1 = value_range (INT (15), INT (30)); r0.intersect (r1); ASSERT_TRUE (r0 == value_range (INT (15), INT (20))); // 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 (INT (0), INT (0)); ASSERT_TRUE (r0.zero_p ()); // Test nonzero_p(). r0 = value_range (INT (0), INT (0)); r0.invert (); ASSERT_TRUE (r0.nonzero_p ()); } } // namespace selftest #endif // CHECKING_P