1274955Ssvnmir//===- ConstantRange.h - Represent a range ----------------------*- C++ -*-===// 2274955Ssvnmir// 3274955Ssvnmir// The LLVM Compiler Infrastructure 4274955Ssvnmir// 5274955Ssvnmir// This file is distributed under the University of Illinois Open Source 6274955Ssvnmir// License. See LICENSE.TXT for details. 7274955Ssvnmir// 8274955Ssvnmir//===----------------------------------------------------------------------===// 9274955Ssvnmir// 10274955Ssvnmir// Represent a range of possible values that may occur when the program is run 11274955Ssvnmir// for an integral value. This keeps track of a lower and upper bound for the 12274955Ssvnmir// constant, which MAY wrap around the end of the numeric range. To do this, it 13274955Ssvnmir// keeps track of a [lower, upper) bound, which specifies an interval just like 14274955Ssvnmir// STL iterators. When used with boolean values, the following are important 15274955Ssvnmir// ranges: : 16274955Ssvnmir// 17274955Ssvnmir// [F, F) = {} = Empty set 18274955Ssvnmir// [T, F) = {T} 19274955Ssvnmir// [F, T) = {F} 20274955Ssvnmir// [T, T) = {F, T} = Full set 21274955Ssvnmir// 22274955Ssvnmir// The other integral ranges use min/max values for special range values. For 23274955Ssvnmir// example, for 8-bit types, it uses: 24274955Ssvnmir// [0, 0) = {} = Empty set 25274955Ssvnmir// [255, 255) = {0..255} = Full Set 26274955Ssvnmir// 27274955Ssvnmir// Note that ConstantRange can be used to represent either signed or 28274955Ssvnmir// unsigned ranges. 29274955Ssvnmir// 30274955Ssvnmir//===----------------------------------------------------------------------===// 31274955Ssvnmir 32280031Sdim#ifndef LLVM_IR_CONSTANTRANGE_H 33280031Sdim#define LLVM_IR_CONSTANTRANGE_H 34274955Ssvnmir 35274955Ssvnmir#include "llvm/ADT/APInt.h" 36288943Sdim#include "llvm/IR/InstrTypes.h" 37274955Ssvnmir#include "llvm/Support/DataTypes.h" 38274955Ssvnmir 39274955Ssvnmirnamespace llvm { 40274955Ssvnmir 41280031Sdim/// This class represents a range of values. 42274955Ssvnmir/// 43274955Ssvnmirclass ConstantRange { 44274955Ssvnmir APInt Lower, Upper; 45274955Ssvnmir 46274955Ssvnmir // If we have move semantics, pass APInts by value and move them into place. 47274955Ssvnmir typedef APInt APIntMoveTy; 48274955Ssvnmir 49274955Ssvnmirpublic: 50274955Ssvnmir /// Initialize a full (the default) or empty set for the specified bit width. 51274955Ssvnmir /// 52274955Ssvnmir explicit ConstantRange(uint32_t BitWidth, bool isFullSet = true); 53274955Ssvnmir 54274955Ssvnmir /// Initialize a range to hold the single specified value. 55274955Ssvnmir /// 56274955Ssvnmir ConstantRange(APIntMoveTy Value); 57274955Ssvnmir 58274955Ssvnmir /// @brief Initialize a range of values explicitly. This will assert out if 59274955Ssvnmir /// Lower==Upper and Lower != Min or Max value for its type. It will also 60274955Ssvnmir /// assert out if the two APInt's are not the same bit width. 61274955Ssvnmir ConstantRange(APIntMoveTy Lower, APIntMoveTy Upper); 62274955Ssvnmir 63288943Sdim /// Produce the smallest range such that all values that may satisfy the given 64288943Sdim /// predicate with any value contained within Other is contained in the 65288943Sdim /// returned range. Formally, this returns a superset of 66288943Sdim /// 'union over all y in Other . { x : icmp op x y is true }'. If the exact 67288943Sdim /// answer is not representable as a ConstantRange, the return value will be a 68288943Sdim /// proper superset of the above. 69274955Ssvnmir /// 70288943Sdim /// Example: Pred = ult and Other = i8 [2, 5) returns Result = [0, 4) 71288943Sdim static ConstantRange makeAllowedICmpRegion(CmpInst::Predicate Pred, 72288943Sdim const ConstantRange &Other); 73274955Ssvnmir 74288943Sdim /// Produce the largest range such that all values in the returned range 75288943Sdim /// satisfy the given predicate with all values contained within Other. 76288943Sdim /// Formally, this returns a subset of 77288943Sdim /// 'intersection over all y in Other . { x : icmp op x y is true }'. If the 78288943Sdim /// exact answer is not representable as a ConstantRange, the return value 79288943Sdim /// will be a proper subset of the above. 80288943Sdim /// 81288943Sdim /// Example: Pred = ult and Other = i8 [2, 5) returns [0, 2) 82288943Sdim static ConstantRange makeSatisfyingICmpRegion(CmpInst::Predicate Pred, 83288943Sdim const ConstantRange &Other); 84288943Sdim 85296417Sdim /// Return the largest range containing all X such that "X BinOpC C" does not 86296417Sdim /// wrap (overflow). 87296417Sdim /// 88296417Sdim /// Example: 89296417Sdim /// typedef OverflowingBinaryOperator OBO; 90296417Sdim /// makeNoWrapRegion(Add, i8 1, OBO::NoSignedWrap) == [-128, 127) 91296417Sdim /// makeNoWrapRegion(Add, i8 1, OBO::NoUnsignedWrap) == [0, -1) 92296417Sdim /// makeNoWrapRegion(Add, i8 0, OBO::NoUnsignedWrap) == Full Set 93296417Sdim static ConstantRange makeNoWrapRegion(Instruction::BinaryOps BinOp, 94296417Sdim const APInt &C, unsigned NoWrapKind); 95296417Sdim 96280031Sdim /// Return the lower value for this range. 97274955Ssvnmir /// 98274955Ssvnmir const APInt &getLower() const { return Lower; } 99274955Ssvnmir 100280031Sdim /// Return the upper value for this range. 101274955Ssvnmir /// 102274955Ssvnmir const APInt &getUpper() const { return Upper; } 103274955Ssvnmir 104280031Sdim /// Get the bit width of this ConstantRange. 105274955Ssvnmir /// 106274955Ssvnmir uint32_t getBitWidth() const { return Lower.getBitWidth(); } 107274955Ssvnmir 108280031Sdim /// Return true if this set contains all of the elements possible 109280031Sdim /// for this data-type. 110274955Ssvnmir /// 111274955Ssvnmir bool isFullSet() const; 112274955Ssvnmir 113280031Sdim /// Return true if this set contains no members. 114274955Ssvnmir /// 115274955Ssvnmir bool isEmptySet() const; 116274955Ssvnmir 117280031Sdim /// Return true if this set wraps around the top of the range. 118280031Sdim /// For example: [100, 8). 119274955Ssvnmir /// 120274955Ssvnmir bool isWrappedSet() const; 121274955Ssvnmir 122280031Sdim /// Return true if this set wraps around the INT_MIN of 123280031Sdim /// its bitwidth. For example: i8 [120, 140). 124274955Ssvnmir /// 125274955Ssvnmir bool isSignWrappedSet() const; 126274955Ssvnmir 127280031Sdim /// Return true if the specified value is in the set. 128274955Ssvnmir /// 129274955Ssvnmir bool contains(const APInt &Val) const; 130274955Ssvnmir 131280031Sdim /// Return true if the other range is a subset of this one. 132274955Ssvnmir /// 133274955Ssvnmir bool contains(const ConstantRange &CR) const; 134274955Ssvnmir 135280031Sdim /// If this set contains a single element, return it, otherwise return null. 136274955Ssvnmir /// 137274955Ssvnmir const APInt *getSingleElement() const { 138274955Ssvnmir if (Upper == Lower + 1) 139274955Ssvnmir return &Lower; 140274955Ssvnmir return nullptr; 141274955Ssvnmir } 142274955Ssvnmir 143280031Sdim /// Return true if this set contains exactly one member. 144274955Ssvnmir /// 145274955Ssvnmir bool isSingleElement() const { return getSingleElement() != nullptr; } 146274955Ssvnmir 147280031Sdim /// Return the number of elements in this set. 148274955Ssvnmir /// 149274955Ssvnmir APInt getSetSize() const; 150274955Ssvnmir 151280031Sdim /// Return the largest unsigned value contained in the ConstantRange. 152274955Ssvnmir /// 153274955Ssvnmir APInt getUnsignedMax() const; 154274955Ssvnmir 155280031Sdim /// Return the smallest unsigned value contained in the ConstantRange. 156274955Ssvnmir /// 157274955Ssvnmir APInt getUnsignedMin() const; 158274955Ssvnmir 159280031Sdim /// Return the largest signed value contained in the ConstantRange. 160274955Ssvnmir /// 161274955Ssvnmir APInt getSignedMax() const; 162274955Ssvnmir 163280031Sdim /// Return the smallest signed value contained in the ConstantRange. 164274955Ssvnmir /// 165274955Ssvnmir APInt getSignedMin() const; 166274955Ssvnmir 167280031Sdim /// Return true if this range is equal to another range. 168274955Ssvnmir /// 169274955Ssvnmir bool operator==(const ConstantRange &CR) const { 170274955Ssvnmir return Lower == CR.Lower && Upper == CR.Upper; 171274955Ssvnmir } 172274955Ssvnmir bool operator!=(const ConstantRange &CR) const { 173274955Ssvnmir return !operator==(CR); 174274955Ssvnmir } 175274955Ssvnmir 176280031Sdim /// Subtract the specified constant from the endpoints of this constant range. 177274955Ssvnmir ConstantRange subtract(const APInt &CI) const; 178274955Ssvnmir 179274955Ssvnmir /// \brief Subtract the specified range from this range (aka relative 180274955Ssvnmir /// complement of the sets). 181274955Ssvnmir ConstantRange difference(const ConstantRange &CR) const; 182274955Ssvnmir 183280031Sdim /// Return the range that results from the intersection of 184274955Ssvnmir /// this range with another range. The resultant range is guaranteed to 185274955Ssvnmir /// include all elements contained in both input ranges, and to have the 186274955Ssvnmir /// smallest possible set size that does so. Because there may be two 187274955Ssvnmir /// intersections with the same set size, A.intersectWith(B) might not 188274955Ssvnmir /// be equal to B.intersectWith(A). 189274955Ssvnmir /// 190274955Ssvnmir ConstantRange intersectWith(const ConstantRange &CR) const; 191274955Ssvnmir 192280031Sdim /// Return the range that results from the union of this range 193274955Ssvnmir /// with another range. The resultant range is guaranteed to include the 194274955Ssvnmir /// elements of both sets, but may contain more. For example, [3, 9) union 195274955Ssvnmir /// [12,15) is [3, 15), which includes 9, 10, and 11, which were not included 196274955Ssvnmir /// in either set before. 197274955Ssvnmir /// 198274955Ssvnmir ConstantRange unionWith(const ConstantRange &CR) const; 199274955Ssvnmir 200280031Sdim /// Return a new range in the specified integer type, which must 201274955Ssvnmir /// be strictly larger than the current type. The returned range will 202274955Ssvnmir /// correspond to the possible range of values if the source range had been 203274955Ssvnmir /// zero extended to BitWidth. 204274955Ssvnmir ConstantRange zeroExtend(uint32_t BitWidth) const; 205274955Ssvnmir 206280031Sdim /// Return a new range in the specified integer type, which must 207274955Ssvnmir /// be strictly larger than the current type. The returned range will 208274955Ssvnmir /// correspond to the possible range of values if the source range had been 209274955Ssvnmir /// sign extended to BitWidth. 210274955Ssvnmir ConstantRange signExtend(uint32_t BitWidth) const; 211274955Ssvnmir 212280031Sdim /// Return a new range in the specified integer type, which must be 213274955Ssvnmir /// strictly smaller than the current type. The returned range will 214274955Ssvnmir /// correspond to the possible range of values if the source range had been 215274955Ssvnmir /// truncated to the specified type. 216274955Ssvnmir ConstantRange truncate(uint32_t BitWidth) const; 217274955Ssvnmir 218280031Sdim /// Make this range have the bit width given by \p BitWidth. The 219274955Ssvnmir /// value is zero extended, truncated, or left alone to make it that width. 220274955Ssvnmir ConstantRange zextOrTrunc(uint32_t BitWidth) const; 221296417Sdim 222280031Sdim /// Make this range have the bit width given by \p BitWidth. The 223274955Ssvnmir /// value is sign extended, truncated, or left alone to make it that width. 224274955Ssvnmir ConstantRange sextOrTrunc(uint32_t BitWidth) const; 225274955Ssvnmir 226280031Sdim /// Return a new range representing the possible values resulting 227274955Ssvnmir /// from an addition of a value in this range and a value in \p Other. 228274955Ssvnmir ConstantRange add(const ConstantRange &Other) const; 229274955Ssvnmir 230280031Sdim /// Return a new range representing the possible values resulting 231274955Ssvnmir /// from a subtraction of a value in this range and a value in \p Other. 232274955Ssvnmir ConstantRange sub(const ConstantRange &Other) const; 233274955Ssvnmir 234280031Sdim /// Return a new range representing the possible values resulting 235288943Sdim /// from a multiplication of a value in this range and a value in \p Other, 236288943Sdim /// treating both this and \p Other as unsigned ranges. 237274955Ssvnmir ConstantRange multiply(const ConstantRange &Other) const; 238274955Ssvnmir 239280031Sdim /// Return a new range representing the possible values resulting 240274955Ssvnmir /// from a signed maximum of a value in this range and a value in \p Other. 241274955Ssvnmir ConstantRange smax(const ConstantRange &Other) const; 242274955Ssvnmir 243280031Sdim /// Return a new range representing the possible values resulting 244274955Ssvnmir /// from an unsigned maximum of a value in this range and a value in \p Other. 245274955Ssvnmir ConstantRange umax(const ConstantRange &Other) const; 246274955Ssvnmir 247280031Sdim /// Return a new range representing the possible values resulting 248274955Ssvnmir /// from an unsigned division of a value in this range and a value in 249274955Ssvnmir /// \p Other. 250274955Ssvnmir ConstantRange udiv(const ConstantRange &Other) const; 251274955Ssvnmir 252280031Sdim /// Return a new range representing the possible values resulting 253274955Ssvnmir /// from a binary-and of a value in this range by a value in \p Other. 254274955Ssvnmir ConstantRange binaryAnd(const ConstantRange &Other) const; 255274955Ssvnmir 256280031Sdim /// Return a new range representing the possible values resulting 257274955Ssvnmir /// from a binary-or of a value in this range by a value in \p Other. 258274955Ssvnmir ConstantRange binaryOr(const ConstantRange &Other) const; 259274955Ssvnmir 260280031Sdim /// Return a new range representing the possible values resulting 261274955Ssvnmir /// from a left shift of a value in this range by a value in \p Other. 262274955Ssvnmir /// TODO: This isn't fully implemented yet. 263274955Ssvnmir ConstantRange shl(const ConstantRange &Other) const; 264274955Ssvnmir 265280031Sdim /// Return a new range representing the possible values resulting from a 266280031Sdim /// logical right shift of a value in this range and a value in \p Other. 267274955Ssvnmir ConstantRange lshr(const ConstantRange &Other) const; 268274955Ssvnmir 269280031Sdim /// Return a new range that is the logical not of the current set. 270274955Ssvnmir /// 271274955Ssvnmir ConstantRange inverse() const; 272296417Sdim 273280031Sdim /// Print out the bounds to a stream. 274274955Ssvnmir /// 275274955Ssvnmir void print(raw_ostream &OS) const; 276274955Ssvnmir 277280031Sdim /// Allow printing from a debugger easily. 278274955Ssvnmir /// 279274955Ssvnmir void dump() const; 280274955Ssvnmir}; 281274955Ssvnmir 282274955Ssvnmirinline raw_ostream &operator<<(raw_ostream &OS, const ConstantRange &CR) { 283274955Ssvnmir CR.print(OS); 284274955Ssvnmir return OS; 285274955Ssvnmir} 286274955Ssvnmir 287274955Ssvnmir} // End llvm namespace 288274955Ssvnmir 289274955Ssvnmir#endif 290