1 /* Header file for range operator class. 2 Copyright (C) 2017-2022 Free Software Foundation, Inc. 3 Contributed by Andrew MacLeod <amacleod (at) redhat.com> 4 and Aldy Hernandez <aldyh (at) redhat.com>. 5 6 This file is part of GCC. 7 8 GCC is free software; you can redistribute it and/or modify it under 9 the terms of the GNU General Public License as published by the Free 10 Software Foundation; either version 3, or (at your option) any later 11 version. 12 13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14 WARRANTY; without even the implied warranty of MERCHANTABILITY or 15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16 for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with GCC; see the file COPYING3. If not see 20 <http://www.gnu.org/licenses/>. */ 21 22 #ifndef GCC_RANGE_OP_H 23 #define GCC_RANGE_OP_H 24 25 // This class is implemented for each kind of operator supported by 26 // the range generator. It serves various purposes. 27 // 28 // 1 - Generates range information for the specific operation between 29 // two ranges. This provides the ability to fold ranges for an 30 // expression. 31 // 32 // 2 - Performs range algebra on the expression such that a range can be 33 // adjusted in terms of one of the operands: 34 // 35 // def = op1 + op2 36 // 37 // Given a range for def, we can adjust the range so that it is in 38 // terms of either operand. 39 // 40 // op1_range (def_range, op2) will adjust the range in place so it 41 // is in terms of op1. Since op1 = def - op2, it will subtract 42 // op2 from each element of the range. 43 // 44 // 3 - Creates a range for an operand based on whether the result is 0 or 45 // non-zero. This is mostly for logical true false, but can serve other 46 // purposes. 47 // ie 0 = op1 - op2 implies op2 has the same range as op1. 48 49 class range_operator 50 { 51 public: 52 // Perform an operation between 2 ranges and return it. 53 virtual bool fold_range (irange &r, tree type, 54 const irange &lh, 55 const irange &rh, 56 relation_kind rel = VREL_NONE) const; 57 58 // Return the range for op[12] in the general case. LHS is the range for 59 // the LHS of the expression, OP[12]is the range for the other 60 // 61 // The operand and the result is returned in R. 62 // 63 // TYPE is the expected type of the range. 64 // 65 // Return TRUE if the operation is performed and a valid range is available. 66 // 67 // i.e. [LHS] = ??? + OP2 68 // is re-formed as R = [LHS] - OP2. 69 virtual bool op1_range (irange &r, tree type, 70 const irange &lhs, 71 const irange &op2, 72 relation_kind rel = VREL_NONE) const; 73 virtual bool op2_range (irange &r, tree type, 74 const irange &lhs, 75 const irange &op1, 76 relation_kind rel = VREL_NONE) const; 77 78 // The following routines are used to represent relations between the 79 // various operations. If the caller knows where the symbolics are, 80 // it can query for relationships between them given known ranges. 81 virtual enum tree_code lhs_op1_relation (const irange &lhs, 82 const irange &op1, 83 const irange &op2) const; 84 virtual enum tree_code lhs_op2_relation (const irange &lhs, 85 const irange &op1, 86 const irange &op2) const; 87 virtual enum tree_code op1_op2_relation (const irange &lhs) const; 88 protected: 89 // Perform an integral operation between 2 sub-ranges and return it. 90 virtual void wi_fold (irange &r, tree type, 91 const wide_int &lh_lb, 92 const wide_int &lh_ub, 93 const wide_int &rh_lb, 94 const wide_int &rh_ub) const; 95 // Side effect of relation for generic fold_range clients. 96 virtual bool op1_op2_relation_effect (irange &lhs_range, tree type, 97 const irange &op1_range, 98 const irange &op2_range, 99 relation_kind rel) const; 100 // Called by fold range to split small subranges into parts. 101 void wi_fold_in_parts (irange &r, tree type, 102 const wide_int &lh_lb, 103 const wide_int &lh_ub, 104 const wide_int &rh_lb, 105 const wide_int &rh_ub) const; 106 }; 107 108 extern range_operator *range_op_handler (enum tree_code code, tree type); 109 extern void range_cast (irange &, tree type); 110 extern void wi_set_zero_nonzero_bits (tree type, 111 const wide_int &, const wide_int &, 112 wide_int &maybe_nonzero, 113 wide_int &mustbe_nonzero); 114 115 #endif // GCC_RANGE_OP_H 116
Indexes created Wed Mar 04 15:26:31 UTC 2026