| /* Header file for range operator class. |
| Copyright (C) 2017-2021 Free Software Foundation, Inc. |
| Contributed by Andrew MacLeod <amacleod@redhat.com> |
| and Aldy Hernandez <aldyh@redhat.com>. |
| |
| This file is part of GCC. |
| |
| GCC is free software; you can redistribute it and/or modify it under |
| the terms of the GNU General Public License as published by the Free |
| Software Foundation; either version 3, or (at your option) any later |
| version. |
| |
| GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
| WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GCC; see the file COPYING3. If not see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #ifndef GCC_RANGE_OP_H |
| #define GCC_RANGE_OP_H |
| |
| // This class is implemented for each kind of operator supported by |
| // the range generator. It serves various purposes. |
| // |
| // 1 - Generates range information for the specific operation between |
| // two ranges. This provides the ability to fold ranges for an |
| // expression. |
| // |
| // 2 - Performs range algebra on the expression such that a range can be |
| // adjusted in terms of one of the operands: |
| // |
| // def = op1 + op2 |
| // |
| // Given a range for def, we can adjust the range so that it is in |
| // terms of either operand. |
| // |
| // op1_range (def_range, op2) will adjust the range in place so it |
| // is in terms of op1. Since op1 = def - op2, it will subtract |
| // op2 from each element of the range. |
| // |
| // 3 - Creates a range for an operand based on whether the result is 0 or |
| // non-zero. This is mostly for logical true false, but can serve other |
| // purposes. |
| // ie 0 = op1 - op2 implies op2 has the same range as op1. |
| |
| class range_operator |
| { |
| public: |
| // Perform an operation between 2 ranges and return it. |
| virtual bool fold_range (irange &r, tree type, |
| const irange &lh, |
| const irange &rh) const; |
| |
| // Return the range for op[12] in the general case. LHS is the range for |
| // the LHS of the expression, OP[12]is the range for the other |
| // |
| // The operand and the result is returned in R. |
| // |
| // TYPE is the expected type of the range. |
| // |
| // Return TRUE if the operation is performed and a valid range is available. |
| // |
| // i.e. [LHS] = ??? + OP2 |
| // is re-formed as R = [LHS] - OP2. |
| virtual bool op1_range (irange &r, tree type, |
| const irange &lhs, |
| const irange &op2) const; |
| virtual bool op2_range (irange &r, tree type, |
| const irange &lhs, |
| const irange &op1) const; |
| |
| protected: |
| // Perform an integral operation between 2 sub-ranges and return it. |
| virtual void wi_fold (irange &r, tree type, |
| const wide_int &lh_lb, |
| const wide_int &lh_ub, |
| const wide_int &rh_lb, |
| const wide_int &rh_ub) const; |
| }; |
| |
| extern range_operator *range_op_handler (enum tree_code code, tree type); |
| extern void range_cast (irange &, tree type); |
| extern void wi_set_zero_nonzero_bits (tree type, |
| const wide_int &, const wide_int &, |
| wide_int &maybe_nonzero, |
| wide_int &mustbe_nonzero); |
| |
| #endif // GCC_RANGE_OP_H |