xref: /llvm-project/llvm/include/llvm/IR/ConstantRangeList.h (revision 4028bb10c3a396023b877d025c5776d207f29f91)
1 //===- ConstantRangeList.h - A list of constant ranges ----------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // Represent a list of signed ConstantRange and do NOT support wrap around the
10 // end of the numeric range. Ranges in the list are ordered and not overlapping.
11 // Ranges should have the same bitwidth. Each range's lower should be less than
12 // its upper.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #ifndef LLVM_IR_CONSTANTRANGELIST_H
17 #define LLVM_IR_CONSTANTRANGELIST_H
18 
19 #include "llvm/ADT/APInt.h"
20 #include "llvm/IR/ConstantRange.h"
21 #include "llvm/Support/Debug.h"
22 #include <cstddef>
23 #include <cstdint>
24 
25 namespace llvm {
26 
27 class raw_ostream;
28 
29 /// This class represents a list of constant ranges.
30 class [[nodiscard]] ConstantRangeList {
31   SmallVector<ConstantRange, 2> Ranges;
32 
33 public:
34   ConstantRangeList() = default;
35   ConstantRangeList(ArrayRef<ConstantRange> RangesRef) {
36     assert(isOrderedRanges(RangesRef));
37     for (const ConstantRange &R : RangesRef) {
38       assert(empty() || R.getBitWidth() == getBitWidth());
39       Ranges.push_back(R);
40     }
41   }
42 
43   // Return true if the ranges are non-overlapping and increasing.
44   static bool isOrderedRanges(ArrayRef<ConstantRange> RangesRef);
45   static std::optional<ConstantRangeList>
46   getConstantRangeList(ArrayRef<ConstantRange> RangesRef);
47 
48   ArrayRef<ConstantRange> rangesRef() const { return Ranges; }
49   SmallVectorImpl<ConstantRange>::iterator begin() { return Ranges.begin(); }
50   SmallVectorImpl<ConstantRange>::iterator end() { return Ranges.end(); }
51   SmallVectorImpl<ConstantRange>::const_iterator begin() const {
52     return Ranges.begin();
53   }
54   SmallVectorImpl<ConstantRange>::const_iterator end() const {
55     return Ranges.end();
56   }
57   ConstantRange getRange(unsigned i) const { return Ranges[i]; }
58 
59   /// Return true if this list contains no members.
60   bool empty() const { return Ranges.empty(); }
61 
62   /// Get the bit width of this ConstantRangeList. It is invalid to call this
63   /// with an empty range.
64   uint32_t getBitWidth() const { return Ranges.front().getBitWidth(); }
65 
66   /// Return the number of ranges in this ConstantRangeList.
67   size_t size() const { return Ranges.size(); }
68 
69   /// Insert a new range to Ranges and keep the list ordered.
70   void insert(const ConstantRange &NewRange);
71   void insert(int64_t Lower, int64_t Upper) {
72     insert(ConstantRange(APInt(64, Lower, /*isSigned=*/true),
73                          APInt(64, Upper, /*isSigned=*/true)));
74   }
75 
76   void subtract(const ConstantRange &SubRange);
77 
78   /// Return the range list that results from the union of this
79   /// ConstantRangeList with another ConstantRangeList, "CRL".
80   ConstantRangeList unionWith(const ConstantRangeList &CRL) const;
81 
82   /// Return the range list that results from the intersection of this
83   /// ConstantRangeList with another ConstantRangeList, "CRL".
84   ConstantRangeList intersectWith(const ConstantRangeList &CRL) const;
85 
86   /// Return true if this range list is equal to another range list.
87   bool operator==(const ConstantRangeList &CRL) const {
88     return Ranges == CRL.Ranges;
89   }
90   bool operator!=(const ConstantRangeList &CRL) const {
91     return !operator==(CRL);
92   }
93 
94   /// Print out the ranges to a stream.
95   void print(raw_ostream &OS) const;
96 
97 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
98   void dump() const;
99 #endif
100 };
101 
102 } // end namespace llvm
103 
104 #endif // LLVM_IR_CONSTANTRANGELIST_H
105