1 //===-- llvm/Support/APInt.h - For Arbitrary Precision Integer -*- C++ -*--===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Sheng Zhou and is distributed under the
6 // University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements a class to represent arbitrary precision integral
13 //===----------------------------------------------------------------------===//
18 #include "llvm/Support/DataTypes.h"
24 /// Forward declaration.
27 APInt udiv(const APInt& LHS, const APInt& RHS);
28 APInt urem(const APInt& LHS, const APInt& RHS);
31 //===----------------------------------------------------------------------===//
33 //===----------------------------------------------------------------------===//
35 /// APInt - This class represents arbitrary precision constant integral values.
36 /// It is a functional replacement for common case unsigned integer type like
37 /// "unsigned", "unsigned long" or "uint64_t", but also allows non-byte-width
38 /// integer sizes and large integer value types such as 3-bits, 15-bits, or more
39 /// than 64-bits of precision. APInt provides a variety of arithmetic operators
40 /// and methods to manipulate integer values of any bit-width. It supports both
41 /// the typical integer arithmetic and comparison operations as well as bitwise
44 /// The class has several invariants worth noting:
45 /// * All bit, byte, and word positions are zero-based.
46 /// * Once the bit width is set, it doesn't change except by the Truncate,
47 /// SignExtend, or ZeroExtend operations.
48 /// * All binary operators must be on APInt instances of the same bit width.
49 /// Attempting to use these operators on instances with different bit
50 /// widths will yield an assertion.
51 /// * The value is stored canonically as an unsigned value. For operations
52 /// where it makes a difference, there are both signed and unsigned variants
53 /// of the operation. For example, sdiv and udiv. However, because the bit
54 /// widths must be the same, operations such as Mul and Add produce the same
55 /// results regardless of whether the values are interpreted as signed or
57 /// * In general, the class tries to follow the style of computation that LLVM
58 /// uses in its IR. This simplifies its use for LLVM.
60 /// @brief Class for arbitrary precision integers.
64 uint32_t BitWidth; ///< The number of bits in this APInt.
66 /// This union is used to store the integer value. When the
67 /// integer bit-width <= 64, it uses VAL;
68 /// otherwise it uses the pVal.
70 uint64_t VAL; ///< Used to store the <= 64 bits integer value.
71 uint64_t *pVal; ///< Used to store the >64 bits integer value.
74 /// This enum is just used to hold a constant we needed for APInt.
76 APINT_BITS_PER_WORD = sizeof(uint64_t) * 8,
77 APINT_WORD_SIZE = sizeof(uint64_t)
80 // Fast internal constructor
81 APInt(uint64_t* val, uint32_t bits) : BitWidth(bits), pVal(val) { }
83 /// Here one word's bitwidth equals to that of uint64_t.
84 /// @returns the number of words to hold the integer value of this APInt.
85 /// @brief Get the number of words.
86 inline uint32_t getNumWords() const {
87 return (BitWidth + APINT_BITS_PER_WORD - 1) / APINT_BITS_PER_WORD;
90 /// @returns true if the number of bits <= 64, false otherwise.
91 /// @brief Determine if this APInt just has one word to store value.
92 inline bool isSingleWord() const {
93 return BitWidth <= APINT_BITS_PER_WORD;
96 /// @returns the word position for the specified bit position.
97 static inline uint32_t whichWord(uint32_t bitPosition) {
98 return bitPosition / APINT_BITS_PER_WORD;
101 /// @returns the bit position in a word for the specified bit position
103 static inline uint32_t whichBit(uint32_t bitPosition) {
104 return bitPosition % APINT_BITS_PER_WORD;
107 /// @returns a uint64_t type integer with just bit position at
108 /// "whichBit(bitPosition)" setting, others zero.
109 static inline uint64_t maskBit(uint32_t bitPosition) {
110 return (static_cast<uint64_t>(1)) << whichBit(bitPosition);
113 /// This method is used internally to clear the to "N" bits that are not used
114 /// by the APInt. This is needed after the most significant word is assigned
115 /// a value to ensure that those bits are zero'd out.
116 /// @brief Clear high order bits
117 inline void clearUnusedBits() {
119 VAL &= ~uint64_t(0ULL) >> (APINT_BITS_PER_WORD - BitWidth);
121 pVal[getNumWords() - 1] &= ~uint64_t(0ULL) >>
122 (APINT_BITS_PER_WORD - (whichBit(BitWidth - 1) + 1));
125 /// @returns the corresponding word for the specified bit position.
126 /// @brief Get the word corresponding to a bit position
127 inline uint64_t getWord(uint32_t bitPosition) const {
128 return isSingleWord() ? VAL : pVal[whichWord(bitPosition)];
131 /// This is used by the constructors that take string arguments.
132 /// @brief Converts a char array into an APInt
133 void fromString(uint32_t numBits, const char *StrStart, uint32_t slen,
136 /// This is used by the toString method to divide by the radix. It simply
137 /// provides a more convenient form of divide for internal use.
138 /// @brief An internal division function for dividing APInts.
139 static void divide(const APInt LHS, uint32_t lhsWords,
140 const APInt &RHS, uint32_t rhsWords,
141 APInt *Quotient, APInt *Remainder);
144 /// @brief debug method
149 /// @brief Create a new APInt of numBits width, initialized as val.
150 APInt(uint32_t numBits, uint64_t val);
152 /// Note that numWords can be smaller or larger than the corresponding bit
153 /// width but any extraneous bits will be dropped.
154 /// @brief Create a new APInt of numBits width, initialized as bigVal[].
155 APInt(uint32_t numBits, uint32_t numWords, uint64_t bigVal[]);
157 /// @brief Create a new APInt by translating the string represented
159 APInt(uint32_t numBits, const std::string& Val, uint8_t radix);
161 /// @brief Create a new APInt by translating the char array represented
163 APInt(uint32_t numBits, const char StrStart[], uint32_t slen, uint8_t radix);
165 /// @brief Copy Constructor.
166 APInt(const APInt& API);
168 /// @brief Destructor.
171 /// @brief Copy assignment operator.
172 APInt& operator=(const APInt& RHS);
174 /// Assigns an integer value to the APInt.
175 /// @brief Assignment operator.
176 APInt& operator=(uint64_t RHS);
178 /// Increments the APInt by one.
179 /// @brief Postfix increment operator.
180 inline const APInt operator++(int) {
186 /// Increments the APInt by one.
187 /// @brief Prefix increment operator.
190 /// Decrements the APInt by one.
191 /// @brief Postfix decrement operator.
192 inline const APInt operator--(int) {
198 /// Decrements the APInt by one.
199 /// @brief Prefix decrement operator.
202 /// Performs bitwise AND operation on this APInt and the given APInt& RHS,
203 /// assigns the result to this APInt.
204 /// @brief Bitwise AND assignment operator.
205 APInt& operator&=(const APInt& RHS);
207 /// Performs bitwise OR operation on this APInt and the given APInt& RHS,
208 /// assigns the result to this APInt.
209 /// @brief Bitwise OR assignment operator.
210 APInt& operator|=(const APInt& RHS);
212 /// Performs bitwise XOR operation on this APInt and the given APInt& RHS,
213 /// assigns the result to this APInt.
214 /// @brief Bitwise XOR assignment operator.
215 APInt& operator^=(const APInt& RHS);
217 /// Performs a bitwise complement operation on this APInt.
218 /// @brief Bitwise complement operator.
219 APInt operator~() const;
221 /// Multiplies this APInt by the given APInt& RHS and
222 /// assigns the result to this APInt.
223 /// @brief Multiplication assignment operator.
224 APInt& operator*=(const APInt& RHS);
226 /// Adds this APInt by the given APInt& RHS and
227 /// assigns the result to this APInt.
228 /// @brief Addition assignment operator.
229 APInt& operator+=(const APInt& RHS);
231 /// Subtracts this APInt by the given APInt &RHS and
232 /// assigns the result to this APInt.
233 /// @brief Subtraction assignment operator.
234 APInt& operator-=(const APInt& RHS);
236 /// Performs bitwise AND operation on this APInt and
237 /// the given APInt& RHS.
238 /// @brief Bitwise AND operator.
239 APInt operator&(const APInt& RHS) const;
241 /// Performs bitwise OR operation on this APInt and the given APInt& RHS.
242 /// @brief Bitwise OR operator.
243 APInt operator|(const APInt& RHS) const;
245 /// Performs bitwise XOR operation on this APInt and the given APInt& RHS.
246 /// @brief Bitwise XOR operator.
247 APInt operator^(const APInt& RHS) const;
249 /// Performs logical negation operation on this APInt.
250 /// @brief Logical negation operator.
251 bool operator !() const;
253 /// Multiplies this APInt by the given APInt& RHS.
254 /// @brief Multiplication operator.
255 APInt operator*(const APInt& RHS) const;
257 /// Adds this APInt by the given APInt& RHS.
258 /// @brief Addition operator.
259 APInt operator+(const APInt& RHS) const;
261 /// Subtracts this APInt by the given APInt& RHS
262 /// @brief Subtraction operator.
263 APInt operator-(const APInt& RHS) const;
265 /// @brief Unary negation operator
266 inline APInt operator-() const {
267 return APInt(BitWidth, 0) - (*this);
270 /// @brief Array-indexing support.
271 bool operator[](uint32_t bitPosition) const;
273 /// Compare this APInt with the given APInt& RHS
274 /// for the validity of the equality relationship.
275 /// @brief Equality operator.
276 bool operator==(const APInt& RHS) const;
278 /// Compare this APInt with the given uint64_t value
279 /// for the validity of the equality relationship.
280 /// @brief Equality operator.
281 bool operator==(uint64_t Val) const;
283 /// Compare this APInt with the given APInt& RHS
284 /// for the validity of the inequality relationship.
285 /// @brief Inequality operator.
286 inline bool operator!=(const APInt& RHS) const {
287 return !((*this) == RHS);
290 /// Compare this APInt with the given uint64_t value
291 /// for the validity of the inequality relationship.
292 /// @brief Inequality operator.
293 inline bool operator!=(uint64_t Val) const {
294 return !((*this) == Val);
297 /// @brief Equality comparison
298 bool eq(const APInt &RHS) const {
299 return (*this) == RHS;
302 /// @brief Inequality comparison
303 bool ne(const APInt &RHS) const {
304 return !((*this) == RHS);
307 /// @brief Unsigned less than comparison
308 bool ult(const APInt& RHS) const;
310 /// @brief Signed less than comparison
311 bool slt(const APInt& RHS) const;
313 /// @brief Unsigned less or equal comparison
314 bool ule(const APInt& RHS) const {
315 return ult(RHS) || eq(RHS);
318 /// @brief Signed less or equal comparison
319 bool sle(const APInt& RHS) const {
320 return slt(RHS) || eq(RHS);
323 /// @brief Unsigned greather than comparison
324 bool ugt(const APInt& RHS) const {
325 return !ult(RHS) && !eq(RHS);
328 /// @brief Signed greather than comparison
329 bool sgt(const APInt& RHS) const {
330 return !slt(RHS) && !eq(RHS);
333 /// @brief Unsigned greater or equal comparison
334 bool uge(const APInt& RHS) const {
338 /// @brief Signed greather or equal comparison
339 bool sge(const APInt& RHS) const {
343 /// Arithmetic right-shift this APInt by shiftAmt.
344 /// @brief Arithmetic right-shift function.
345 APInt ashr(uint32_t shiftAmt) const;
347 /// Logical right-shift this APInt by shiftAmt.
348 /// @brief Logical right-shift function.
349 APInt lshr(uint32_t shiftAmt) const;
351 /// Left-shift this APInt by shiftAmt.
352 /// @brief Left-shift function.
353 APInt shl(uint32_t shiftAmt) const;
355 /// Signed divide this APInt by APInt RHS.
356 /// @brief Signed division function for APInt.
357 inline APInt sdiv(const APInt& RHS) const {
358 bool isNegativeLHS = (*this)[BitWidth - 1];
359 bool isNegativeRHS = RHS[RHS.BitWidth - 1];
360 APInt Result = APIntOps::udiv(
361 isNegativeLHS ? -(*this) : (*this), isNegativeRHS ? -RHS : RHS);
362 return isNegativeLHS != isNegativeRHS ? -Result : Result;
365 /// Unsigned divide this APInt by APInt RHS.
366 /// @brief Unsigned division function for APInt.
367 APInt udiv(const APInt& RHS) const;
369 /// Signed remainder operation on APInt.
370 /// @brief Function for signed remainder operation.
371 inline APInt srem(const APInt& RHS) const {
372 bool isNegativeLHS = (*this)[BitWidth - 1];
373 bool isNegativeRHS = RHS[RHS.BitWidth - 1];
374 APInt Result = APIntOps::urem(
375 isNegativeLHS ? -(*this) : (*this), isNegativeRHS ? -RHS : RHS);
376 return isNegativeLHS ? -Result : Result;
379 /// Unsigned remainder operation on APInt.
380 /// @brief Function for unsigned remainder operation.
381 APInt urem(const APInt& RHS) const;
383 /// Truncate the APInt to a specified width. It is an error to specify a width
384 /// that is greater than or equal to the current width.
385 /// @brief Truncate to new width.
386 void trunc(uint32_t width);
388 /// This operation sign extends the APInt to a new width. If the high order
389 /// bit is set, the fill on the left will be done with 1 bits, otherwise zero.
390 /// It is an error to specify a width that is less than or equal to the
392 /// @brief Sign extend to a new width.
393 void sext(uint32_t width);
395 /// This operation zero extends the APInt to a new width. Thie high order bits
396 /// are filled with 0 bits. It is an error to specify a width that is less
397 /// than or equal to the current width.
398 /// @brief Zero extend to a new width.
399 void zext(uint32_t width);
401 /// @brief Set every bit to 1.
404 /// Set the given bit to 1 whose position is given as "bitPosition".
405 /// @brief Set a given bit to 1.
406 APInt& set(uint32_t bitPosition);
408 /// @brief Set every bit to 0.
411 /// Set the given bit to 0 whose position is given as "bitPosition".
412 /// @brief Set a given bit to 0.
413 APInt& clear(uint32_t bitPosition);
415 /// @brief Toggle every bit to its opposite value.
418 /// Toggle a given bit to its opposite value whose position is given
419 /// as "bitPosition".
420 /// @brief Toggles a given bit to its opposite value.
421 APInt& flip(uint32_t bitPosition);
423 /// This function returns the number of active bits which is defined as the
424 /// bit width minus the number of leading zeros. This is used in several
425 /// computations to see how "wide" the value is.
426 /// @brief Compute the number of active bits in the value
427 inline uint32_t getActiveBits() const {
428 return BitWidth - countLeadingZeros();
431 /// @returns a uint64_t value from this APInt. If this APInt contains a single
432 /// word, just returns VAL, otherwise pVal[0].
433 inline uint64_t getValue(bool isSigned = false) const {
435 return isSigned ? int64_t(VAL << (64 - BitWidth)) >>
436 (64 - BitWidth) : VAL;
437 uint32_t n = getActiveBits();
440 assert(0 && "This APInt's bitwidth > 64");
443 /// @returns the largest value for an APInt of the specified bit-width and
444 /// if isSign == true, it should be largest signed value, otherwise largest
446 /// @brief Gets max value of the APInt with bitwidth <= 64.
447 static APInt getMaxValue(uint32_t numBits, bool isSign);
449 /// @returns the smallest value for an APInt of the given bit-width and
450 /// if isSign == true, it should be smallest signed value, otherwise zero.
451 /// @brief Gets min value of the APInt with bitwidth <= 64.
452 static APInt getMinValue(uint32_t numBits, bool isSign);
454 /// @returns the all-ones value for an APInt of the specified bit-width.
455 /// @brief Get the all-ones value.
456 static APInt getAllOnesValue(uint32_t numBits);
458 /// @returns the '0' value for an APInt of the specified bit-width.
459 /// @brief Get the '0' value.
460 static APInt getNullValue(uint32_t numBits);
462 /// This converts the APInt to a boolean valy as a test against zero.
463 /// @brief Boolean conversion function.
464 inline bool getBoolValue() const {
465 return countLeadingZeros() != BitWidth;
468 /// @returns a character interpretation of the APInt.
469 std::string toString(uint8_t radix = 10, bool wantSigned = true) const;
471 /// Get an APInt with the same BitWidth as this APInt, just zero mask
472 /// the low bits and right shift to the least significant bit.
473 /// @returns the high "numBits" bits of this APInt.
474 APInt getHiBits(uint32_t numBits) const;
476 /// Get an APInt with the same BitWidth as this APInt, just zero mask
478 /// @returns the low "numBits" bits of this APInt.
479 APInt getLoBits(uint32_t numBits) const;
481 /// @returns true if the argument APInt value is a power of two > 0.
482 bool isPowerOf2() const;
484 /// @returns the number of zeros from the most significant bit to the first
486 uint32_t countLeadingZeros() const;
488 /// @returns the number of zeros from the least significant bit to the first
490 uint32_t countTrailingZeros() const;
492 /// @returns the number of set bits.
493 uint32_t countPopulation() const;
495 /// @returns the total number of bits.
496 inline uint32_t getBitWidth() const {
500 /// @brief Check if this APInt has a N-bits integer value.
501 inline bool isIntN(uint32_t N) const {
502 assert(N && "N == 0 ???");
503 if (isSingleWord()) {
504 return VAL == (VAL & (~0ULL >> (64 - N)));
506 APInt Tmp(N, getNumWords(), pVal);
507 return Tmp == (*this);
511 /// @returns a byte-swapped representation of this APInt Value.
512 APInt byteSwap() const;
514 /// @returns the floor log base 2 of this APInt.
515 inline uint32_t logBase2() const {
516 return getNumWords() * APINT_BITS_PER_WORD - 1 - countLeadingZeros();
519 /// @brief Converts this APInt to a double value.
520 double roundToDouble(bool isSigned = false) const;
526 /// @brief Check if the specified APInt has a N-bits integer value.
527 inline bool isIntN(uint32_t N, const APInt& APIVal) {
528 return APIVal.isIntN(N);
531 /// @returns true if the argument APInt value is a sequence of ones
532 /// starting at the least significant bit with the remainder zero.
533 inline const bool isMask(uint32_t numBits, const APInt& APIVal) {
534 return APIVal.getBoolValue() && ((APIVal + APInt(numBits,1)) & APIVal) == 0;
537 /// @returns true if the argument APInt value contains a sequence of ones
538 /// with the remainder zero.
539 inline const bool isShiftedMask(uint32_t numBits, const APInt& APIVal) {
540 return isMask(numBits, (APIVal - APInt(numBits,1)) | APIVal);
543 /// @returns a byte-swapped representation of the specified APInt Value.
544 inline APInt byteSwap(const APInt& APIVal) {
545 return APIVal.byteSwap();
548 /// @returns the floor log base 2 of the specified APInt value.
549 inline uint32_t logBase2(const APInt& APIVal) {
550 return APIVal.logBase2();
553 /// @returns the greatest common divisor of the two values
554 /// using Euclid's algorithm.
555 APInt GreatestCommonDivisor(const APInt& API1, const APInt& API2);
557 /// @brief Converts the given APInt to a double value.
558 inline double RoundAPIntToDouble(const APInt& APIVal, bool isSigned = false) {
559 return APIVal.roundToDouble(isSigned);
562 /// @brief Converts the given APInt to a float vlalue.
563 inline float RoundAPIntToFloat(const APInt& APIVal) {
564 return float(RoundAPIntToDouble(APIVal));
567 /// @brief Converts the given double value into a APInt.
568 APInt RoundDoubleToAPInt(double Double);
570 /// @brief Converts the given float value into a APInt.
571 inline APInt RoundFloatToAPInt(float Float) {
572 return RoundDoubleToAPInt(double(Float));
575 /// Arithmetic right-shift the APInt by shiftAmt.
576 /// @brief Arithmetic right-shift function.
577 inline APInt ashr(const APInt& LHS, uint32_t shiftAmt) {
578 return LHS.ashr(shiftAmt);
581 /// Logical right-shift the APInt by shiftAmt.
582 /// @brief Logical right-shift function.
583 inline APInt lshr(const APInt& LHS, uint32_t shiftAmt) {
584 return LHS.lshr(shiftAmt);
587 /// Left-shift the APInt by shiftAmt.
588 /// @brief Left-shift function.
589 inline APInt shl(const APInt& LHS, uint32_t shiftAmt) {
590 return LHS.shl(shiftAmt);
593 /// Signed divide APInt LHS by APInt RHS.
594 /// @brief Signed division function for APInt.
595 inline APInt sdiv(const APInt& LHS, const APInt& RHS) {
596 return LHS.sdiv(RHS);
599 /// Unsigned divide APInt LHS by APInt RHS.
600 /// @brief Unsigned division function for APInt.
601 inline APInt udiv(const APInt& LHS, const APInt& RHS) {
602 return LHS.udiv(RHS);
605 /// Signed remainder operation on APInt.
606 /// @brief Function for signed remainder operation.
607 inline APInt srem(const APInt& LHS, const APInt& RHS) {
608 return LHS.srem(RHS);
611 /// Unsigned remainder operation on APInt.
612 /// @brief Function for unsigned remainder operation.
613 inline APInt urem(const APInt& LHS, const APInt& RHS) {
614 return LHS.urem(RHS);
617 /// Performs multiplication on APInt values.
618 /// @brief Function for multiplication operation.
619 inline APInt mul(const APInt& LHS, const APInt& RHS) {
623 /// Performs addition on APInt values.
624 /// @brief Function for addition operation.
625 inline APInt add(const APInt& LHS, const APInt& RHS) {
629 /// Performs subtraction on APInt values.
630 /// @brief Function for subtraction operation.
631 inline APInt sub(const APInt& LHS, const APInt& RHS) {
635 /// Performs bitwise AND operation on APInt LHS and
637 /// @brief Bitwise AND function for APInt.
638 inline APInt And(const APInt& LHS, const APInt& RHS) {
642 /// Performs bitwise OR operation on APInt LHS and APInt RHS.
643 /// @brief Bitwise OR function for APInt.
644 inline APInt Or(const APInt& LHS, const APInt& RHS) {
648 /// Performs bitwise XOR operation on APInt.
649 /// @brief Bitwise XOR function for APInt.
650 inline APInt Xor(const APInt& LHS, const APInt& RHS) {
654 /// Performs a bitwise complement operation on APInt.
655 /// @brief Bitwise complement function.
656 inline APInt Not(const APInt& APIVal) {
660 } // End of APIntOps namespace
662 } // End of llvm namespace