1 //===- ConstantRange.h - Represent a range ----------------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // Represent a range of possible values that may occur when the program is run 11 // for an integral value. This keeps track of a lower and upper bound for the 12 // constant, which MAY wrap around the end of the numeric range. To do this, it 13 // keeps track of a [lower, upper) bound, which specifies an interval just like 14 // STL iterators. When used with boolean values, the following are important 15 // ranges: : 16 // 17 // [F, F) = {} = Empty set 18 // [T, F) = {T} 19 // [F, T) = {F} 20 // [T, T) = {F, T} = Full set 21 // 22 // The other integral ranges use min/max values for special range values. For 23 // example, for 8-bit types, it uses: 24 // [0, 0) = {} = Empty set 25 // [255, 255) = {0..255} = Full Set 26 // 27 // Note that ConstantRange can be used to represent either signed or 28 // unsigned ranges. 29 // 30 //===----------------------------------------------------------------------===// 31 32 #ifndef LLVM_SUPPORT_CONSTANTRANGE_H 33 #define LLVM_SUPPORT_CONSTANTRANGE_H 34 35 #include "llvm/ADT/APInt.h" 36 #include "llvm/Support/DataTypes.h" 37 38 namespace llvm { 39 40 /// ConstantRange - This class represents an range of values. 41 /// 42 class ConstantRange { 43 APInt Lower, Upper; 44 45 // If we have move semantics, pass APInts by value and move them into place. 46 typedef APInt APIntMoveTy; 47 48 public: 49 /// Initialize a full (the default) or empty set for the specified bit width. 50 /// 51 explicit ConstantRange(uint32_t BitWidth, bool isFullSet = true); 52 53 /// Initialize a range to hold the single specified value. 54 /// 55 ConstantRange(APIntMoveTy Value); 56 57 /// @brief Initialize a range of values explicitly. This will assert out if 58 /// Lower==Upper and Lower != Min or Max value for its type. It will also 59 /// assert out if the two APInt's are not the same bit width. 60 ConstantRange(APIntMoveTy Lower, APIntMoveTy Upper); 61 62 /// makeICmpRegion - Produce the smallest range that contains all values that 63 /// might satisfy the comparison specified by Pred when compared to any value 64 /// contained within Other. 65 /// 66 /// Solves for range X in 'for all x in X, there exists a y in Y such that 67 /// icmp op x, y is true'. Every value that might make the comparison true 68 /// is included in the resulting range. 69 static ConstantRange makeICmpRegion(unsigned Pred, 70 const ConstantRange &Other); 71 72 /// getLower - Return the lower value for this range... 73 /// 74 const APInt &getLower() const { return Lower; } 75 76 /// getUpper - Return the upper value for this range... 77 /// 78 const APInt &getUpper() const { return Upper; } 79 80 /// getBitWidth - get the bit width of this ConstantRange 81 /// 82 uint32_t getBitWidth() const { return Lower.getBitWidth(); } 83 84 /// isFullSet - Return true if this set contains all of the elements possible 85 /// for this data-type 86 /// 87 bool isFullSet() const; 88 89 /// isEmptySet - Return true if this set contains no members. 90 /// 91 bool isEmptySet() const; 92 93 /// isWrappedSet - Return true if this set wraps around the top of the range, 94 /// for example: [100, 8) 95 /// 96 bool isWrappedSet() const; 97 98 /// isSignWrappedSet - Return true if this set wraps around the INT_MIN of 99 /// its bitwidth, for example: i8 [120, 140). 100 /// 101 bool isSignWrappedSet() const; 102 103 /// contains - Return true if the specified value is in the set. 104 /// 105 bool contains(const APInt &Val) const; 106 107 /// contains - Return true if the other range is a subset of this one. 108 /// 109 bool contains(const ConstantRange &CR) const; 110 111 /// getSingleElement - If this set contains a single element, return it, 112 /// otherwise return null. 113 /// 114 const APInt *getSingleElement() const { 115 if (Upper == Lower + 1) 116 return &Lower; 117 return nullptr; 118 } 119 120 /// isSingleElement - Return true if this set contains exactly one member. 121 /// 122 bool isSingleElement() const { return getSingleElement() != nullptr; } 123 124 /// getSetSize - Return the number of elements in this set. 125 /// 126 APInt getSetSize() const; 127 128 /// getUnsignedMax - Return the largest unsigned value contained in the 129 /// ConstantRange. 130 /// 131 APInt getUnsignedMax() const; 132 133 /// getUnsignedMin - Return the smallest unsigned value contained in the 134 /// ConstantRange. 135 /// 136 APInt getUnsignedMin() const; 137 138 /// getSignedMax - Return the largest signed value contained in the 139 /// ConstantRange. 140 /// 141 APInt getSignedMax() const; 142 143 /// getSignedMin - Return the smallest signed value contained in the 144 /// ConstantRange. 145 /// 146 APInt getSignedMin() const; 147 148 /// operator== - Return true if this range is equal to another range. 149 /// 150 bool operator==(const ConstantRange &CR) const { 151 return Lower == CR.Lower && Upper == CR.Upper; 152 } 153 bool operator!=(const ConstantRange &CR) const { 154 return !operator==(CR); 155 } 156 157 /// subtract - Subtract the specified constant from the endpoints of this 158 /// constant range. 159 ConstantRange subtract(const APInt &CI) const; 160 161 /// \brief Subtract the specified range from this range (aka relative 162 /// complement of the sets). 163 ConstantRange difference(const ConstantRange &CR) const; 164 165 /// intersectWith - Return the range that results from the intersection of 166 /// this range with another range. The resultant range is guaranteed to 167 /// include all elements contained in both input ranges, and to have the 168 /// smallest possible set size that does so. Because there may be two 169 /// intersections with the same set size, A.intersectWith(B) might not 170 /// be equal to B.intersectWith(A). 171 /// 172 ConstantRange intersectWith(const ConstantRange &CR) const; 173 174 /// unionWith - Return the range that results from the union of this range 175 /// with another range. The resultant range is guaranteed to include the 176 /// elements of both sets, but may contain more. For example, [3, 9) union 177 /// [12,15) is [3, 15), which includes 9, 10, and 11, which were not included 178 /// in either set before. 179 /// 180 ConstantRange unionWith(const ConstantRange &CR) const; 181 182 /// zeroExtend - Return a new range in the specified integer type, which must 183 /// be strictly larger than the current type. The returned range will 184 /// correspond to the possible range of values if the source range had been 185 /// zero extended to BitWidth. 186 ConstantRange zeroExtend(uint32_t BitWidth) const; 187 188 /// signExtend - Return a new range in the specified integer type, which must 189 /// be strictly larger than the current type. The returned range will 190 /// correspond to the possible range of values if the source range had been 191 /// sign extended to BitWidth. 192 ConstantRange signExtend(uint32_t BitWidth) const; 193 194 /// truncate - Return a new range in the specified integer type, which must be 195 /// strictly smaller than the current type. The returned range will 196 /// correspond to the possible range of values if the source range had been 197 /// truncated to the specified type. 198 ConstantRange truncate(uint32_t BitWidth) const; 199 200 /// zextOrTrunc - make this range have the bit width given by \p BitWidth. The 201 /// value is zero extended, truncated, or left alone to make it that width. 202 ConstantRange zextOrTrunc(uint32_t BitWidth) const; 203 204 /// sextOrTrunc - make this range have the bit width given by \p BitWidth. The 205 /// value is sign extended, truncated, or left alone to make it that width. 206 ConstantRange sextOrTrunc(uint32_t BitWidth) const; 207 208 /// add - Return a new range representing the possible values resulting 209 /// from an addition of a value in this range and a value in \p Other. 210 ConstantRange add(const ConstantRange &Other) const; 211 212 /// sub - Return a new range representing the possible values resulting 213 /// from a subtraction of a value in this range and a value in \p Other. 214 ConstantRange sub(const ConstantRange &Other) const; 215 216 /// multiply - Return a new range representing the possible values resulting 217 /// from a multiplication of a value in this range and a value in \p Other. 218 /// TODO: This isn't fully implemented yet. 219 ConstantRange multiply(const ConstantRange &Other) const; 220 221 /// smax - Return a new range representing the possible values resulting 222 /// from a signed maximum of a value in this range and a value in \p Other. 223 ConstantRange smax(const ConstantRange &Other) const; 224 225 /// umax - Return a new range representing the possible values resulting 226 /// from an unsigned maximum of a value in this range and a value in \p Other. 227 ConstantRange umax(const ConstantRange &Other) const; 228 229 /// udiv - Return a new range representing the possible values resulting 230 /// from an unsigned division of a value in this range and a value in 231 /// \p Other. 232 ConstantRange udiv(const ConstantRange &Other) const; 233 234 /// binaryAnd - return a new range representing the possible values resulting 235 /// from a binary-and of a value in this range by a value in \p Other. 236 ConstantRange binaryAnd(const ConstantRange &Other) const; 237 238 /// binaryOr - return a new range representing the possible values resulting 239 /// from a binary-or of a value in this range by a value in \p Other. 240 ConstantRange binaryOr(const ConstantRange &Other) const; 241 242 /// shl - Return a new range representing the possible values resulting 243 /// from a left shift of a value in this range by a value in \p Other. 244 /// TODO: This isn't fully implemented yet. 245 ConstantRange shl(const ConstantRange &Other) const; 246 247 /// lshr - Return a new range representing the possible values resulting 248 /// from a logical right shift of a value in this range and a value in 249 /// \p Other. 250 ConstantRange lshr(const ConstantRange &Other) const; 251 252 /// inverse - Return a new range that is the logical not of the current set. 253 /// 254 ConstantRange inverse() const; 255 256 /// print - Print out the bounds to a stream... 257 /// 258 void print(raw_ostream &OS) const; 259 260 /// dump - Allow printing from a debugger easily... 261 /// 262 void dump() const; 263 }; 264 265 inline raw_ostream &operator<<(raw_ostream &OS, const ConstantRange &CR) { 266 CR.print(OS); 267 return OS; 268 } 269 270 } // End llvm namespace 271 272 #endif 273
