//
// The LLVM Compiler Infrastructure
//
-// This file was developed by Sheng Zhou and Reid Spencer and is distributed
-// under the // University of Illinois Open Source License. See LICENSE.TXT
-// for details.
+// This file was developed by Sheng Zhou and is distributed under the
+// University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
-// This file implements a class to represent arbitrary precision integral
-// constant values.
+// This file implements a class to represent arbitrary precision integer
+// constant values and provide a variety of arithmetic operations on them.
//
//===----------------------------------------------------------------------===//
#include "llvm/DerivedTypes.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/MathExtras.h"
+#include <math.h>
+#include <limits>
#include <cstring>
#include <cstdlib>
#ifndef NDEBUG
using namespace llvm;
-// A utility function for allocating memory, checking for allocation failures,
-// and ensuring the contents are zeroed.
+/// A utility function for allocating memory, checking for allocation failures,
+/// and ensuring the contents are zeroed.
inline static uint64_t* getClearedMemory(uint32_t numWords) {
uint64_t * result = new uint64_t[numWords];
assert(result && "APInt memory allocation fails!");
return result;
}
-// A utility function for allocating memory and checking for allocation failure.
-// The content is not zero'd
+/// A utility function for allocating memory and checking for allocation
+/// failure. The content is not zeroed.
inline static uint64_t* getMemory(uint32_t numWords) {
uint64_t * result = new uint64_t[numWords];
assert(result && "APInt memory allocation fails!");
return result;
}
-APInt::APInt(uint32_t numBits, uint64_t val)
+APInt::APInt(uint32_t numBits, uint64_t val, bool isSigned)
: BitWidth(numBits), VAL(0) {
assert(BitWidth >= IntegerType::MIN_INT_BITS && "bitwidth too small");
assert(BitWidth <= IntegerType::MAX_INT_BITS && "bitwidth too large");
- if (isSingleWord())
- VAL = val & (~uint64_t(0ULL) >> (APINT_BITS_PER_WORD - BitWidth));
+ if (isSingleWord())
+ VAL = val;
else {
pVal = getClearedMemory(getNumWords());
pVal[0] = val;
+ if (isSigned && int64_t(val) < 0)
+ for (unsigned i = 1; i < getNumWords(); ++i)
+ pVal[i] = -1ULL;
}
+ clearUnusedBits();
}
APInt::APInt(uint32_t numBits, uint32_t numWords, uint64_t bigVal[])
APInt::~APInt() {
if (!isSingleWord() && pVal)
- delete[] pVal;
+ delete [] pVal;
}
APInt& APInt::operator=(const APInt& RHS) {
- assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
- if (isSingleWord())
+ // Don't do anything for X = X
+ if (this == &RHS)
+ return *this;
+
+ // If the bitwidths are the same, we can avoid mucking with memory
+ if (BitWidth == RHS.getBitWidth()) {
+ if (isSingleWord())
+ VAL = RHS.VAL;
+ else
+ memcpy(pVal, RHS.pVal, getNumWords() * APINT_WORD_SIZE);
+ return *this;
+ }
+
+ if (isSingleWord())
+ if (RHS.isSingleWord())
+ VAL = RHS.VAL;
+ else {
+ VAL = 0;
+ pVal = getMemory(RHS.getNumWords());
+ memcpy(pVal, RHS.pVal, RHS.getNumWords() * APINT_WORD_SIZE);
+ }
+ else if (getNumWords() == RHS.getNumWords())
+ memcpy(pVal, RHS.pVal, RHS.getNumWords() * APINT_WORD_SIZE);
+ else if (RHS.isSingleWord()) {
+ delete [] pVal;
VAL = RHS.VAL;
- else
- memcpy(pVal, RHS.pVal, getNumWords() * APINT_WORD_SIZE);
- return *this;
+ } else {
+ delete [] pVal;
+ pVal = getMemory(RHS.getNumWords());
+ memcpy(pVal, RHS.pVal, RHS.getNumWords() * APINT_WORD_SIZE);
+ }
+ BitWidth = RHS.BitWidth;
+ return clearUnusedBits();
}
APInt& APInt::operator=(uint64_t RHS) {
pVal[0] = RHS;
memset(pVal+1, 0, (getNumWords() - 1) * APINT_WORD_SIZE);
}
- return *this;
+ return clearUnusedBits();
}
/// add_1 - This function adds a single "digit" integer, y, to the multiple
/// "digit" integer array, x[]. x[] is modified to reflect the addition and
/// 1 is returned if there is a carry out, otherwise 0 is returned.
/// @returns the carry of the addition.
-static uint64_t add_1(uint64_t dest[], uint64_t x[], uint32_t len, uint64_t y) {
+static bool add_1(uint64_t dest[], uint64_t x[], uint32_t len, uint64_t y) {
for (uint32_t i = 0; i < len; ++i) {
dest[i] = y + x[i];
if (dest[i] < y)
++VAL;
else
add_1(pVal, pVal, getNumWords(), 1);
- clearUnusedBits();
- return *this;
+ return clearUnusedBits();
}
/// sub_1 - This function subtracts a single "digit" (64-bit word), y, from
/// no further borrowing is neeeded or it runs out of "digits" in x. The result
/// is 1 if "borrowing" exhausted the digits in x, or 0 if x was not exhausted.
/// In other words, if y > x then this function returns 1, otherwise 0.
-static uint64_t sub_1(uint64_t x[], uint32_t len,
- uint64_t y) {
+/// @returns the borrow out of the subtraction
+static bool sub_1(uint64_t x[], uint32_t len, uint64_t y) {
for (uint32_t i = 0; i < len; ++i) {
uint64_t X = x[i];
x[i] -= y;
break; // Remaining digits are unchanged so exit early
}
}
- return y;
+ return bool(y);
}
/// @brief Prefix decrement operator. Decrements the APInt by one.
--VAL;
else
sub_1(pVal, getNumWords(), 1);
- clearUnusedBits();
- return *this;
+ return clearUnusedBits();
}
-/// add - This function adds the integer array x[] by integer array
-/// y[] and returns the carry.
+/// add - This function adds the integer array x to the integer array Y and
+/// places the result in dest.
+/// @returns the carry out from the addition
+/// @brief General addition of 64-bit integer arrays
static bool add(uint64_t *dest, const uint64_t *x, const uint64_t *y,
uint32_t len) {
bool carry = false;
return carry;
}
-/// @brief Addition assignment operator. Adds this APInt by the given APInt&
-/// RHS and assigns the result to this APInt.
+/// Adds the RHS APint to this APInt.
+/// @returns this, after addition of RHS.
+/// @brief Addition assignment operator.
APInt& APInt::operator+=(const APInt& RHS) {
assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
if (isSingleWord())
else {
add(pVal, pVal, RHS.pVal, getNumWords());
}
- clearUnusedBits();
- return *this;
+ return clearUnusedBits();
}
-/// sub - This function subtracts the integer array x[] by
-/// integer array y[], and returns the borrow-out.
+/// Subtracts the integer array y from the integer array x
+/// @returns returns the borrow out.
+/// @brief Generalized subtraction of 64-bit integer arrays.
static bool sub(uint64_t *dest, const uint64_t *x, const uint64_t *y,
uint32_t len) {
bool borrow = false;
return borrow;
}
-/// @brief Subtraction assignment operator. Subtracts this APInt by the given
-/// APInt &RHS and assigns the result to this APInt.
+/// Subtracts the RHS APInt from this APInt
+/// @returns this, after subtraction
+/// @brief Subtraction assignment operator.
APInt& APInt::operator-=(const APInt& RHS) {
assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
if (isSingleWord())
VAL -= RHS.VAL;
else
sub(pVal, pVal, RHS.pVal, getNumWords());
- clearUnusedBits();
- return *this;
+ return clearUnusedBits();
}
-/// mul_1 - This function performs the multiplication operation on a
-/// large integer (represented as an integer array) and a uint64_t integer.
-/// @returns the carry of the multiplication.
+/// Multiplies an integer array, x by a a uint64_t integer and places the result
+/// into dest.
+/// @returns the carry out of the multiplication.
+/// @brief Multiply a multi-digit APInt by a single digit (64-bit) integer.
static uint64_t mul_1(uint64_t dest[], uint64_t x[], uint32_t len, uint64_t y) {
// Split y into high 32-bit part (hy) and low 32-bit part (ly)
uint64_t ly = y & 0xffffffffULL, hy = y >> 32;
- uint64_t carry = 0, lx, hx;
+ uint64_t carry = 0;
+
+ // For each digit of x.
for (uint32_t i = 0; i < len; ++i) {
- lx = x[i] & 0xffffffffULL;
- hx = x[i] >> 32;
- // hasCarry - A flag to indicate if has carry.
+ // Split x into high and low words
+ uint64_t lx = x[i] & 0xffffffffULL;
+ uint64_t hx = x[i] >> 32;
+ // hasCarry - A flag to indicate if there is a carry to the next digit.
// hasCarry == 0, no carry
// hasCarry == 1, has carry
// hasCarry == 2, no carry and the calculation result == 0.
carry = (((!carry && hasCarry != 2) || hasCarry == 1) ? (1ULL << 32) : 0) +
(carry >> 32) + ((lx * hy) >> 32) + hx * hy;
}
-
return carry;
}
-/// mul - This function multiplies integer array x[] by integer array y[] and
-/// stores the result into integer array dest[].
-/// Note the array dest[]'s size should no less than xlen + ylen.
+/// Multiplies integer array x by integer array y and stores the result into
+/// the integer array dest. Note that dest's size must be >= xlen + ylen.
+/// @brief Generalized multiplicate of integer arrays.
static void mul(uint64_t dest[], uint64_t x[], uint32_t xlen, uint64_t y[],
uint32_t ylen) {
dest[xlen] = mul_1(dest, x, xlen, y[0]);
}
}
-/// @brief Multiplication assignment operator. Multiplies this APInt by the
-/// given APInt& RHS and assigns the result to this APInt.
APInt& APInt::operator*=(const APInt& RHS) {
assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
if (isSingleWord()) {
return *this;
}
-/// @brief Bitwise AND assignment operator. Performs bitwise AND operation on
-/// this APInt and the given APInt& RHS, assigns the result to this APInt.
APInt& APInt::operator&=(const APInt& RHS) {
assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
if (isSingleWord()) {
return *this;
}
-/// @brief Bitwise OR assignment operator. Performs bitwise OR operation on
-/// this APInt and the given APInt& RHS, assigns the result to this APInt.
APInt& APInt::operator|=(const APInt& RHS) {
assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
if (isSingleWord()) {
return *this;
}
-/// @brief Bitwise XOR assignment operator. Performs bitwise XOR operation on
-/// this APInt and the given APInt& RHS, assigns the result to this APInt.
APInt& APInt::operator^=(const APInt& RHS) {
assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
if (isSingleWord()) {
uint32_t numWords = getNumWords();
for (uint32_t i = 0; i < numWords; ++i)
pVal[i] ^= RHS.pVal[i];
- this->clearUnusedBits();
- return *this;
+ return clearUnusedBits();
}
-/// @brief Bitwise AND operator. Performs bitwise AND operation on this APInt
-/// and the given APInt& RHS.
APInt APInt::operator&(const APInt& RHS) const {
assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
if (isSingleWord())
return APInt(getBitWidth(), VAL & RHS.VAL);
- APInt Result(*this);
uint32_t numWords = getNumWords();
+ uint64_t* val = getMemory(numWords);
for (uint32_t i = 0; i < numWords; ++i)
- Result.pVal[i] &= RHS.pVal[i];
- return Result;
+ val[i] = pVal[i] & RHS.pVal[i];
+ return APInt(val, getBitWidth());
}
-/// @brief Bitwise OR operator. Performs bitwise OR operation on this APInt
-/// and the given APInt& RHS.
APInt APInt::operator|(const APInt& RHS) const {
assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
if (isSingleWord())
return APInt(getBitWidth(), VAL | RHS.VAL);
- APInt Result(*this);
uint32_t numWords = getNumWords();
+ uint64_t *val = getMemory(numWords);
for (uint32_t i = 0; i < numWords; ++i)
- Result.pVal[i] |= RHS.pVal[i];
- return Result;
+ val[i] = pVal[i] | RHS.pVal[i];
+ return APInt(val, getBitWidth());
}
-/// @brief Bitwise XOR operator. Performs bitwise XOR operation on this APInt
-/// and the given APInt& RHS.
APInt APInt::operator^(const APInt& RHS) const {
assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
- if (isSingleWord()) {
- APInt Result(BitWidth, VAL ^ RHS.VAL);
- Result.clearUnusedBits();
- return Result;
- }
- APInt Result(*this);
+ if (isSingleWord())
+ return APInt(BitWidth, VAL ^ RHS.VAL);
+
uint32_t numWords = getNumWords();
+ uint64_t *val = getMemory(numWords);
for (uint32_t i = 0; i < numWords; ++i)
- Result.pVal[i] ^= RHS.pVal[i];
- return Result;
+ val[i] = pVal[i] ^ RHS.pVal[i];
+
+ // 0^0==1 so clear the high bits in case they got set.
+ return APInt(val, getBitWidth()).clearUnusedBits();
}
-/// @brief Logical negation operator. Performs logical negation operation on
-/// this APInt.
bool APInt::operator !() const {
if (isSingleWord())
return !VAL;
return true;
}
-/// @brief Multiplication operator. Multiplies this APInt by the given APInt&
-/// RHS.
APInt APInt::operator*(const APInt& RHS) const {
assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
- if (isSingleWord()) {
- APInt Result(BitWidth, VAL * RHS.VAL);
- Result.clearUnusedBits();
- return Result;
- }
+ if (isSingleWord())
+ return APInt(BitWidth, VAL * RHS.VAL);
APInt Result(*this);
Result *= RHS;
- Result.clearUnusedBits();
- return Result;
+ return Result.clearUnusedBits();
}
-/// @brief Addition operator. Adds this APInt by the given APInt& RHS.
APInt APInt::operator+(const APInt& RHS) const {
assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
- if (isSingleWord()) {
- APInt Result(BitWidth, VAL + RHS.VAL);
- Result.clearUnusedBits();
- return Result;
- }
+ if (isSingleWord())
+ return APInt(BitWidth, VAL + RHS.VAL);
APInt Result(BitWidth, 0);
add(Result.pVal, this->pVal, RHS.pVal, getNumWords());
- Result.clearUnusedBits();
- return Result;
+ return Result.clearUnusedBits();
}
-/// @brief Subtraction operator. Subtracts this APInt by the given APInt& RHS
APInt APInt::operator-(const APInt& RHS) const {
assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
- if (isSingleWord()) {
- APInt Result(BitWidth, VAL - RHS.VAL);
- Result.clearUnusedBits();
- return Result;
- }
+ if (isSingleWord())
+ return APInt(BitWidth, VAL - RHS.VAL);
APInt Result(BitWidth, 0);
sub(Result.pVal, this->pVal, RHS.pVal, getNumWords());
- Result.clearUnusedBits();
- return Result;
+ return Result.clearUnusedBits();
}
-/// @brief Array-indexing support.
bool APInt::operator[](uint32_t bitPosition) const {
- return (maskBit(bitPosition) & (isSingleWord() ?
- VAL : pVal[whichWord(bitPosition)])) != 0;
+ return (maskBit(bitPosition) &
+ (isSingleWord() ? VAL : pVal[whichWord(bitPosition)])) != 0;
}
-/// @brief Equality operator. Compare this APInt with the given APInt& RHS
-/// for the validity of the equality relationship.
bool APInt::operator==(const APInt& RHS) const {
+ assert(BitWidth == RHS.BitWidth && "Comparison requires equal bit widths");
if (isSingleWord())
return VAL == RHS.VAL;
+ // Get some facts about the number of bits used in the two operands.
uint32_t n1 = getActiveBits();
uint32_t n2 = RHS.getActiveBits();
+
+ // If the number of bits isn't the same, they aren't equal
if (n1 != n2)
return false;
+ // If the number of bits fits in a word, we only need to compare the low word.
if (n1 <= APINT_BITS_PER_WORD)
return pVal[0] == RHS.pVal[0];
+ // Otherwise, compare everything
for (int i = whichWord(n1 - 1); i >= 0; --i)
if (pVal[i] != RHS.pVal[i])
return false;
return true;
}
-/// @brief Equality operator. Compare this APInt with the given uint64_t value
-/// for the validity of the equality relationship.
bool APInt::operator==(uint64_t Val) const {
if (isSingleWord())
return VAL == Val;
return false;
}
-/// @brief Unsigned less than comparison
bool APInt::ult(const APInt& RHS) const {
assert(BitWidth == RHS.BitWidth && "Bit widths must be same for comparison");
if (isSingleWord())
return VAL < RHS.VAL;
- else {
- uint32_t n1 = getActiveBits();
- uint32_t n2 = RHS.getActiveBits();
- if (n1 < n2)
- return true;
- else if (n2 < n1)
+
+ // Get active bit length of both operands
+ uint32_t n1 = getActiveBits();
+ uint32_t n2 = RHS.getActiveBits();
+
+ // If magnitude of LHS is less than RHS, return true.
+ if (n1 < n2)
+ return true;
+
+ // If magnitude of RHS is greather than LHS, return false.
+ if (n2 < n1)
+ return false;
+
+ // If they bot fit in a word, just compare the low order word
+ if (n1 <= APINT_BITS_PER_WORD && n2 <= APINT_BITS_PER_WORD)
+ return pVal[0] < RHS.pVal[0];
+
+ // Otherwise, compare all words
+ uint32_t topWord = whichWord(std::max(n1,n2)-1);
+ for (int i = topWord; i >= 0; --i) {
+ if (pVal[i] > RHS.pVal[i])
return false;
- else if (n1 <= APINT_BITS_PER_WORD && n2 <= APINT_BITS_PER_WORD)
- return pVal[0] < RHS.pVal[0];
- for (int i = whichWord(n1 - 1); i >= 0; --i) {
- if (pVal[i] > RHS.pVal[i]) return false;
- else if (pVal[i] < RHS.pVal[i]) return true;
- }
+ if (pVal[i] < RHS.pVal[i])
+ return true;
}
return false;
}
-/// @brief Signed less than comparison
bool APInt::slt(const APInt& RHS) const {
assert(BitWidth == RHS.BitWidth && "Bit widths must be same for comparison");
if (isSingleWord()) {
}
APInt lhs(*this);
- APInt rhs(*this);
- bool lhsNegative = false;
- bool rhsNegative = false;
- if (lhs[BitWidth-1]) {
- lhsNegative = true;
+ APInt rhs(RHS);
+ bool lhsNeg = isNegative();
+ bool rhsNeg = rhs.isNegative();
+ if (lhsNeg) {
+ // Sign bit is set so perform two's complement to make it positive
lhs.flip();
lhs++;
}
- if (rhs[BitWidth-1]) {
- rhsNegative = true;
+ if (rhsNeg) {
+ // Sign bit is set so perform two's complement to make it positive
rhs.flip();
rhs++;
}
- if (lhsNegative)
- if (rhsNegative)
- return !lhs.ult(rhs);
+
+ // Now we have unsigned values to compare so do the comparison if necessary
+ // based on the negativeness of the values.
+ if (lhsNeg)
+ if (rhsNeg)
+ return lhs.ugt(rhs);
else
return true;
- else if (rhsNegative)
+ else if (rhsNeg)
return false;
else
return lhs.ult(rhs);
}
-/// Set the given bit to 1 whose poition is given as "bitPosition".
-/// @brief Set a given bit to 1.
APInt& APInt::set(uint32_t bitPosition) {
- if (isSingleWord()) VAL |= maskBit(bitPosition);
- else pVal[whichWord(bitPosition)] |= maskBit(bitPosition);
+ if (isSingleWord())
+ VAL |= maskBit(bitPosition);
+ else
+ pVal[whichWord(bitPosition)] |= maskBit(bitPosition);
return *this;
}
-/// @brief Set every bit to 1.
APInt& APInt::set() {
- if (isSingleWord())
- VAL = ~0ULL >> (APINT_BITS_PER_WORD - BitWidth);
- else {
- for (uint32_t i = 0; i < getNumWords() - 1; ++i)
- pVal[i] = -1ULL;
- pVal[getNumWords() - 1] = ~0ULL >>
- (APINT_BITS_PER_WORD - BitWidth % APINT_BITS_PER_WORD);
+ if (isSingleWord()) {
+ VAL = -1ULL;
+ return clearUnusedBits();
}
- return *this;
+
+ // Set all the bits in all the words.
+ for (uint32_t i = 0; i < getNumWords(); ++i)
+ pVal[i] = -1ULL;
+ // Clear the unused ones
+ return clearUnusedBits();
}
/// Set the given bit to 0 whose position is given as "bitPosition".
/// @brief Bitwise NOT operator. Performs a bitwise logical NOT operation on
/// this APInt.
APInt APInt::operator~() const {
- APInt API(*this);
- API.flip();
- return API;
+ APInt Result(*this);
+ Result.flip();
+ return Result;
}
/// @brief Toggle every bit to its opposite value.
APInt& APInt::flip() {
- if (isSingleWord()) VAL = (~(VAL <<
- (APINT_BITS_PER_WORD - BitWidth))) >> (APINT_BITS_PER_WORD - BitWidth);
- else {
- uint32_t i = 0;
- for (; i < getNumWords() - 1; ++i)
- pVal[i] = ~pVal[i];
- uint32_t offset =
- APINT_BITS_PER_WORD - (BitWidth - APINT_BITS_PER_WORD * (i - 1));
- pVal[i] = (~(pVal[i] << offset)) >> offset;
+ if (isSingleWord()) {
+ VAL ^= -1ULL;
+ return clearUnusedBits();
}
- return *this;
+ for (uint32_t i = 0; i < getNumWords(); ++i)
+ pVal[i] ^= -1ULL;
+ return clearUnusedBits();
}
/// Toggle a given bit to its opposite value whose position is given
return *this;
}
-/// getMaxValue - This function returns the largest value
-/// for an APInt of the specified bit-width and if isSign == true,
-/// it should be largest signed value, otherwise unsigned value.
-APInt APInt::getMaxValue(uint32_t numBits, bool isSign) {
- APInt Result(numBits, 0);
- Result.set();
- if (isSign)
- Result.clear(numBits - 1);
- return Result;
-}
+uint32_t APInt::getBitsNeeded(const char* str, uint32_t slen, uint8_t radix) {
+ assert(str != 0 && "Invalid value string");
+ assert(slen > 0 && "Invalid string length");
-/// getMinValue - This function returns the smallest value for
-/// an APInt of the given bit-width and if isSign == true,
-/// it should be smallest signed value, otherwise zero.
-APInt APInt::getMinValue(uint32_t numBits, bool isSign) {
- APInt Result(numBits, 0);
- if (isSign)
- Result.set(numBits - 1);
- return Result;
-}
+ // Each computation below needs to know if its negative
+ uint32_t isNegative = str[0] == '-';
+ if (isNegative) {
+ slen--;
+ str++;
+ }
+ // For radixes of power-of-two values, the bits required is accurately and
+ // easily computed
+ if (radix == 2)
+ return slen + isNegative;
+ if (radix == 8)
+ return slen * 3 + isNegative;
+ if (radix == 16)
+ return slen * 4 + isNegative;
-/// getAllOnesValue - This function returns an all-ones value for
-/// an APInt of the specified bit-width.
-APInt APInt::getAllOnesValue(uint32_t numBits) {
- return getMaxValue(numBits, false);
+ // Otherwise it must be radix == 10, the hard case
+ assert(radix == 10 && "Invalid radix");
+
+ // This is grossly inefficient but accurate. We could probably do something
+ // with a computation of roughly slen*64/20 and then adjust by the value of
+ // the first few digits. But, I'm not sure how accurate that could be.
+
+ // Compute a sufficient number of bits that is always large enough but might
+ // be too large. This avoids the assertion in the constructor.
+ uint32_t sufficient = slen*64/18;
+
+ // Convert to the actual binary value.
+ APInt tmp(sufficient, str, slen, radix);
+
+ // Compute how many bits are required.
+ return isNegative + tmp.logBase2() + 1;
}
-/// getNullValue - This function creates an '0' value for an
-/// APInt of the specified bit-width.
-APInt APInt::getNullValue(uint32_t numBits) {
- return getMinValue(numBits, false);
+uint64_t APInt::getHashValue() const {
+ // Put the bit width into the low order bits.
+ uint64_t hash = BitWidth;
+
+ // Add the sum of the words to the hash.
+ if (isSingleWord())
+ hash += VAL << 6; // clear separation of up to 64 bits
+ else
+ for (uint32_t i = 0; i < getNumWords(); ++i)
+ hash += pVal[i] << 6; // clear sepration of up to 64 bits
+ return hash;
}
/// HiBits - This function returns the high "numBits" bits of this APInt.
return (!!*this) && !(*this & (*this - APInt(BitWidth,1)));
}
-/// countLeadingZeros - This function is a APInt version corresponding to
-/// llvm/include/llvm/Support/MathExtras.h's function
-/// countLeadingZeros_{32, 64}. It performs platform optimal form of counting
-/// the number of zeros from the most significant bit to the first one bit.
-/// @returns numWord() * 64 if the value is zero.
uint32_t APInt::countLeadingZeros() const {
uint32_t Count = 0;
if (isSingleWord())
return Count;
}
-/// countTrailingZeros - This function is a APInt version corresponding to
-/// llvm/include/llvm/Support/MathExtras.h's function
-/// countTrailingZeros_{32, 64}. It performs platform optimal form of counting
-/// the number of zeros from the least significant bit to the first one bit.
-/// @returns numWord() * 64 if the value is zero.
+static uint32_t countLeadingOnes_64(uint64_t V, uint32_t skip) {
+ uint32_t Count = 0;
+ if (skip)
+ V <<= skip;
+ while (V && (V & (1ULL << 63))) {
+ Count++;
+ V <<= 1;
+ }
+ return Count;
+}
+
+uint32_t APInt::countLeadingOnes() const {
+ if (isSingleWord())
+ return countLeadingOnes_64(VAL, APINT_BITS_PER_WORD - BitWidth);
+
+ uint32_t highWordBits = BitWidth % APINT_BITS_PER_WORD;
+ uint32_t shift = (highWordBits == 0 ? 0 : APINT_BITS_PER_WORD - highWordBits);
+ int i = getNumWords() - 1;
+ uint32_t Count = countLeadingOnes_64(pVal[i], shift);
+ if (Count == highWordBits) {
+ for (i--; i >= 0; --i) {
+ if (pVal[i] == -1ULL)
+ Count += APINT_BITS_PER_WORD;
+ else {
+ Count += countLeadingOnes_64(pVal[i], 0);
+ break;
+ }
+ }
+ }
+ return Count;
+}
+
uint32_t APInt::countTrailingZeros() const {
if (isSingleWord())
return CountTrailingZeros_64(VAL);
- APInt Tmp( ~(*this) & ((*this) - APInt(BitWidth,1)) );
- return getNumWords() * APINT_BITS_PER_WORD - Tmp.countLeadingZeros();
+ uint32_t Count = 0;
+ uint32_t i = 0;
+ for (; i < getNumWords() && pVal[i] == 0; ++i)
+ Count += APINT_BITS_PER_WORD;
+ if (i < getNumWords())
+ Count += CountTrailingZeros_64(pVal[i]);
+ return Count;
}
-/// countPopulation - This function is a APInt version corresponding to
-/// llvm/include/llvm/Support/MathExtras.h's function
-/// countPopulation_{32, 64}. It counts the number of set bits in a value.
-/// @returns 0 if the value is zero.
uint32_t APInt::countPopulation() const {
if (isSingleWord())
return CountPopulation_64(VAL);
return Count;
}
-
-/// byteSwap - This function returns a byte-swapped representation of the
-/// this APInt.
APInt APInt::byteSwap() const {
assert(BitWidth >= 16 && BitWidth % 16 == 0 && "Cannot byteswap!");
if (BitWidth == 16)
- return APInt(BitWidth, ByteSwap_16(VAL));
+ return APInt(BitWidth, ByteSwap_16(uint16_t(VAL)));
else if (BitWidth == 32)
- return APInt(BitWidth, ByteSwap_32(VAL));
+ return APInt(BitWidth, ByteSwap_32(uint32_t(VAL)));
else if (BitWidth == 48) {
- uint64_t Tmp1 = ((VAL >> 32) << 16) | (VAL & 0xFFFF);
+ uint32_t Tmp1 = uint32_t(VAL >> 16);
Tmp1 = ByteSwap_32(Tmp1);
- uint64_t Tmp2 = (VAL >> 16) & 0xFFFF;
+ uint16_t Tmp2 = uint16_t(VAL);
Tmp2 = ByteSwap_16(Tmp2);
- return
- APInt(BitWidth,
- (Tmp1 & 0xff) | ((Tmp1<<16) & 0xffff00000000ULL) | (Tmp2 << 16));
+ return APInt(BitWidth, (uint64_t(Tmp2) << 32) | Tmp1);
} else if (BitWidth == 64)
return APInt(BitWidth, ByteSwap_64(VAL));
else {
}
}
-/// GreatestCommonDivisor - This function returns the greatest common
-/// divisor of the two APInt values using Enclid's algorithm.
APInt llvm::APIntOps::GreatestCommonDivisor(const APInt& API1,
const APInt& API2) {
APInt A = API1, B = API2;
return A;
}
-/// DoubleRoundToAPInt - This function convert a double value to
-/// a APInt value.
-APInt llvm::APIntOps::RoundDoubleToAPInt(double Double) {
+APInt llvm::APIntOps::RoundDoubleToAPInt(double Double, uint32_t width) {
union {
double D;
uint64_t I;
} T;
T.D = Double;
+
+ // Get the sign bit from the highest order bit
bool isNeg = T.I >> 63;
+
+ // Get the 11-bit exponent and adjust for the 1023 bit bias
int64_t exp = ((T.I >> 52) & 0x7ff) - 1023;
+
+ // If the exponent is negative, the value is < 0 so just return 0.
if (exp < 0)
- return APInt(64ull, 0u);
- uint64_t mantissa = ((T.I << 12) >> 12) | (1ULL << 52);
+ return APInt(width, 0u);
+
+ // Extract the mantissa by clearing the top 12 bits (sign + exponent).
+ uint64_t mantissa = (T.I & (~0ULL >> 12)) | 1ULL << 52;
+
+ // If the exponent doesn't shift all bits out of the mantissa
if (exp < 52)
- return isNeg ? -APInt(64u, mantissa >> (52 - exp)) :
- APInt(64u, mantissa >> (52 - exp));
- APInt Tmp(exp + 1, mantissa);
+ return isNeg ? -APInt(width, mantissa >> (52 - exp)) :
+ APInt(width, mantissa >> (52 - exp));
+
+ // If the client didn't provide enough bits for us to shift the mantissa into
+ // then the result is undefined, just return 0
+ if (width <= exp - 52)
+ return APInt(width, 0);
+
+ // Otherwise, we have to shift the mantissa bits up to the right location
+ APInt Tmp(width, mantissa);
Tmp = Tmp.shl(exp - 52);
return isNeg ? -Tmp : Tmp;
}
// Return infinity for exponent overflow
if (exp > 1023) {
if (!isSigned || !isNeg)
- return double(1.0E300 * 1.0E300); // positive infinity
+ return std::numeric_limits<double>::infinity();
else
- return double(-1.0E300 * 1.0E300); // negative infinity
+ return -std::numeric_limits<double>::infinity();
}
exp += 1023; // Increment for 1023 bias
}
// Truncate to new width.
-void APInt::trunc(uint32_t width) {
+APInt &APInt::trunc(uint32_t width) {
assert(width < BitWidth && "Invalid APInt Truncate request");
+ assert(width >= IntegerType::MIN_INT_BITS && "Can't truncate to 0 bits");
+ uint32_t wordsBefore = getNumWords();
+ BitWidth = width;
+ uint32_t wordsAfter = getNumWords();
+ if (wordsBefore != wordsAfter) {
+ if (wordsAfter == 1) {
+ uint64_t *tmp = pVal;
+ VAL = pVal[0];
+ delete [] tmp;
+ } else {
+ uint64_t *newVal = getClearedMemory(wordsAfter);
+ for (uint32_t i = 0; i < wordsAfter; ++i)
+ newVal[i] = pVal[i];
+ delete [] pVal;
+ pVal = newVal;
+ }
+ }
+ return clearUnusedBits();
}
// Sign extend to a new width.
-void APInt::sext(uint32_t width) {
+APInt &APInt::sext(uint32_t width) {
assert(width > BitWidth && "Invalid APInt SignExtend request");
+ assert(width <= IntegerType::MAX_INT_BITS && "Too many bits");
+ // If the sign bit isn't set, this is the same as zext.
+ if (!isNegative()) {
+ zext(width);
+ return *this;
+ }
+
+ // The sign bit is set. First, get some facts
+ uint32_t wordsBefore = getNumWords();
+ uint32_t wordBits = BitWidth % APINT_BITS_PER_WORD;
+ BitWidth = width;
+ uint32_t wordsAfter = getNumWords();
+
+ // Mask the high order word appropriately
+ if (wordsBefore == wordsAfter) {
+ uint32_t newWordBits = width % APINT_BITS_PER_WORD;
+ // The extension is contained to the wordsBefore-1th word.
+ uint64_t mask = ~0ULL;
+ if (newWordBits)
+ mask >>= APINT_BITS_PER_WORD - newWordBits;
+ mask <<= wordBits;
+ if (wordsBefore == 1)
+ VAL |= mask;
+ else
+ pVal[wordsBefore-1] |= mask;
+ return clearUnusedBits();
+ }
+
+ uint64_t mask = wordBits == 0 ? 0 : ~0ULL << wordBits;
+ uint64_t *newVal = getMemory(wordsAfter);
+ if (wordsBefore == 1)
+ newVal[0] = VAL | mask;
+ else {
+ for (uint32_t i = 0; i < wordsBefore; ++i)
+ newVal[i] = pVal[i];
+ newVal[wordsBefore-1] |= mask;
+ }
+ for (uint32_t i = wordsBefore; i < wordsAfter; i++)
+ newVal[i] = -1ULL;
+ if (wordsBefore != 1)
+ delete [] pVal;
+ pVal = newVal;
+ return clearUnusedBits();
}
// Zero extend to a new width.
-void APInt::zext(uint32_t width) {
+APInt &APInt::zext(uint32_t width) {
assert(width > BitWidth && "Invalid APInt ZeroExtend request");
+ assert(width <= IntegerType::MAX_INT_BITS && "Too many bits");
+ uint32_t wordsBefore = getNumWords();
+ BitWidth = width;
+ uint32_t wordsAfter = getNumWords();
+ if (wordsBefore != wordsAfter) {
+ uint64_t *newVal = getClearedMemory(wordsAfter);
+ if (wordsBefore == 1)
+ newVal[0] = VAL;
+ else
+ for (uint32_t i = 0; i < wordsBefore; ++i)
+ newVal[i] = pVal[i];
+ if (wordsBefore != 1)
+ delete [] pVal;
+ pVal = newVal;
+ }
+ return *this;
+}
+
+APInt &APInt::zextOrTrunc(uint32_t width) {
+ if (BitWidth < width)
+ return zext(width);
+ if (BitWidth > width)
+ return trunc(width);
+ return *this;
+}
+
+APInt &APInt::sextOrTrunc(uint32_t width) {
+ if (BitWidth < width)
+ return sext(width);
+ if (BitWidth > width)
+ return trunc(width);
+ return *this;
}
/// Arithmetic right-shift this APInt by shiftAmt.
/// @brief Arithmetic right-shift function.
APInt APInt::ashr(uint32_t shiftAmt) const {
- APInt API(*this);
- if (API.isSingleWord())
- API.VAL =
- (((int64_t(API.VAL) << (APINT_BITS_PER_WORD - API.BitWidth)) >>
- (APINT_BITS_PER_WORD - API.BitWidth)) >> shiftAmt) &
- (~uint64_t(0UL) >> (APINT_BITS_PER_WORD - API.BitWidth));
- else {
- if (shiftAmt >= API.BitWidth) {
- memset(API.pVal, API[API.BitWidth-1] ? 1 : 0,
- (API.getNumWords()-1) * APINT_WORD_SIZE);
- API.pVal[API.getNumWords() - 1] =
- ~uint64_t(0UL) >>
- (APINT_BITS_PER_WORD - API.BitWidth % APINT_BITS_PER_WORD);
- } else {
- uint32_t i = 0;
- for (; i < API.BitWidth - shiftAmt; ++i)
- if (API[i+shiftAmt])
- API.set(i);
- else
- API.clear(i);
- for (; i < API.BitWidth; ++i)
- if (API[API.BitWidth-1])
- API.set(i);
- else API.clear(i);
+ assert(shiftAmt <= BitWidth && "Invalid shift amount");
+ // Handle a degenerate case
+ if (shiftAmt == 0)
+ return *this;
+
+ // Handle single word shifts with built-in ashr
+ if (isSingleWord()) {
+ if (shiftAmt == BitWidth)
+ return APInt(BitWidth, 0); // undefined
+ else {
+ uint32_t SignBit = APINT_BITS_PER_WORD - BitWidth;
+ return APInt(BitWidth,
+ (((int64_t(VAL) << SignBit) >> SignBit) >> shiftAmt));
+ }
+ }
+
+ // If all the bits were shifted out, the result is, technically, undefined.
+ // We return -1 if it was negative, 0 otherwise. We check this early to avoid
+ // issues in the algorithm below.
+ if (shiftAmt == BitWidth) {
+ if (isNegative())
+ return APInt(BitWidth, -1ULL);
+ else
+ return APInt(BitWidth, 0);
+ }
+
+ // Create some space for the result.
+ uint64_t * val = new uint64_t[getNumWords()];
+
+ // Compute some values needed by the following shift algorithms
+ uint32_t wordShift = shiftAmt % APINT_BITS_PER_WORD; // bits to shift per word
+ uint32_t offset = shiftAmt / APINT_BITS_PER_WORD; // word offset for shift
+ uint32_t breakWord = getNumWords() - 1 - offset; // last word affected
+ uint32_t bitsInWord = whichBit(BitWidth); // how many bits in last word?
+ if (bitsInWord == 0)
+ bitsInWord = APINT_BITS_PER_WORD;
+
+ // If we are shifting whole words, just move whole words
+ if (wordShift == 0) {
+ // Move the words containing significant bits
+ for (uint32_t i = 0; i <= breakWord; ++i)
+ val[i] = pVal[i+offset]; // move whole word
+
+ // Adjust the top significant word for sign bit fill, if negative
+ if (isNegative())
+ if (bitsInWord < APINT_BITS_PER_WORD)
+ val[breakWord] |= ~0ULL << bitsInWord; // set high bits
+ } else {
+ // Shift the low order words
+ for (uint32_t i = 0; i < breakWord; ++i) {
+ // This combines the shifted corresponding word with the low bits from
+ // the next word (shifted into this word's high bits).
+ val[i] = (pVal[i+offset] >> wordShift) |
+ (pVal[i+offset+1] << (APINT_BITS_PER_WORD - wordShift));
+ }
+
+ // Shift the break word. In this case there are no bits from the next word
+ // to include in this word.
+ val[breakWord] = pVal[breakWord+offset] >> wordShift;
+
+ // Deal with sign extenstion in the break word, and possibly the word before
+ // it.
+ if (isNegative()) {
+ if (wordShift > bitsInWord) {
+ if (breakWord > 0)
+ val[breakWord-1] |=
+ ~0ULL << (APINT_BITS_PER_WORD - (wordShift - bitsInWord));
+ val[breakWord] |= ~0ULL;
+ } else
+ val[breakWord] |= (~0ULL << (bitsInWord - wordShift));
}
}
- return API;
+
+ // Remaining words are 0 or -1, just assign them.
+ uint64_t fillValue = (isNegative() ? -1ULL : 0);
+ for (uint32_t i = breakWord+1; i < getNumWords(); ++i)
+ val[i] = fillValue;
+ return APInt(val, BitWidth).clearUnusedBits();
}
/// Logical right-shift this APInt by shiftAmt.
/// @brief Logical right-shift function.
APInt APInt::lshr(uint32_t shiftAmt) const {
- APInt API(*this);
- if (API.isSingleWord())
- API.VAL >>= shiftAmt;
- else {
- if (shiftAmt >= API.BitWidth)
- memset(API.pVal, 0, API.getNumWords() * APINT_WORD_SIZE);
- uint32_t i = 0;
- for (i = 0; i < API.BitWidth - shiftAmt; ++i)
- if (API[i+shiftAmt]) API.set(i);
- else API.clear(i);
- for (; i < API.BitWidth; ++i)
- API.clear(i);
+ if (isSingleWord()) {
+ if (shiftAmt == BitWidth)
+ return APInt(BitWidth, 0);
+ else
+ return APInt(BitWidth, this->VAL >> shiftAmt);
+ }
+
+ // If all the bits were shifted out, the result is 0. This avoids issues
+ // with shifting by the size of the integer type, which produces undefined
+ // results. We define these "undefined results" to always be 0.
+ if (shiftAmt == BitWidth)
+ return APInt(BitWidth, 0);
+
+ // Create some space for the result.
+ uint64_t * val = new uint64_t[getNumWords()];
+
+ // If we are shifting less than a word, compute the shift with a simple carry
+ if (shiftAmt < APINT_BITS_PER_WORD) {
+ uint64_t carry = 0;
+ for (int i = getNumWords()-1; i >= 0; --i) {
+ val[i] = (pVal[i] >> shiftAmt) | carry;
+ carry = pVal[i] << (APINT_BITS_PER_WORD - shiftAmt);
+ }
+ return APInt(val, BitWidth).clearUnusedBits();
+ }
+
+ // Compute some values needed by the remaining shift algorithms
+ uint32_t wordShift = shiftAmt % APINT_BITS_PER_WORD;
+ uint32_t offset = shiftAmt / APINT_BITS_PER_WORD;
+
+ // If we are shifting whole words, just move whole words
+ if (wordShift == 0) {
+ for (uint32_t i = 0; i < getNumWords() - offset; ++i)
+ val[i] = pVal[i+offset];
+ for (uint32_t i = getNumWords()-offset; i < getNumWords(); i++)
+ val[i] = 0;
+ return APInt(val,BitWidth).clearUnusedBits();
}
- return API;
+
+ // Shift the low order words
+ uint32_t breakWord = getNumWords() - offset -1;
+ for (uint32_t i = 0; i < breakWord; ++i)
+ val[i] = (pVal[i+offset] >> wordShift) |
+ (pVal[i+offset+1] << (APINT_BITS_PER_WORD - wordShift));
+ // Shift the break word.
+ val[breakWord] = pVal[breakWord+offset] >> wordShift;
+
+ // Remaining words are 0
+ for (uint32_t i = breakWord+1; i < getNumWords(); ++i)
+ val[i] = 0;
+ return APInt(val, BitWidth).clearUnusedBits();
}
/// Left-shift this APInt by shiftAmt.
/// @brief Left-shift function.
APInt APInt::shl(uint32_t shiftAmt) const {
assert(shiftAmt <= BitWidth && "Invalid shift amount");
- APInt API(*this);
- if (API.isSingleWord()) {
+ if (isSingleWord()) {
if (shiftAmt == BitWidth)
- API.VAL = 0;
- else
- API.VAL <<= shiftAmt;
- API.clearUnusedBits();
- return API;
+ return APInt(BitWidth, 0); // avoid undefined shift results
+ return APInt(BitWidth, VAL << shiftAmt);
}
- if (shiftAmt == BitWidth) {
- memset(API.pVal, 0, getNumWords() * APINT_WORD_SIZE);
- return API;
+ // If all the bits were shifted out, the result is 0. This avoids issues
+ // with shifting by the size of the integer type, which produces undefined
+ // results. We define these "undefined results" to always be 0.
+ if (shiftAmt == BitWidth)
+ return APInt(BitWidth, 0);
+
+ // Create some space for the result.
+ uint64_t * val = new uint64_t[getNumWords()];
+
+ // If we are shifting less than a word, do it the easy way
+ if (shiftAmt < APINT_BITS_PER_WORD) {
+ uint64_t carry = 0;
+ for (uint32_t i = 0; i < getNumWords(); i++) {
+ val[i] = pVal[i] << shiftAmt | carry;
+ carry = pVal[i] >> (APINT_BITS_PER_WORD - shiftAmt);
+ }
+ return APInt(val, BitWidth).clearUnusedBits();
+ }
+
+ // Compute some values needed by the remaining shift algorithms
+ uint32_t wordShift = shiftAmt % APINT_BITS_PER_WORD;
+ uint32_t offset = shiftAmt / APINT_BITS_PER_WORD;
+
+ // If we are shifting whole words, just move whole words
+ if (wordShift == 0) {
+ for (uint32_t i = 0; i < offset; i++)
+ val[i] = 0;
+ for (uint32_t i = offset; i < getNumWords(); i++)
+ val[i] = pVal[i-offset];
+ return APInt(val,BitWidth).clearUnusedBits();
+ }
+
+ // Copy whole words from this to Result.
+ uint32_t i = getNumWords() - 1;
+ for (; i > offset; --i)
+ val[i] = pVal[i-offset] << wordShift |
+ pVal[i-offset-1] >> (APINT_BITS_PER_WORD - wordShift);
+ val[offset] = pVal[0] << wordShift;
+ for (i = 0; i < offset; ++i)
+ val[i] = 0;
+ return APInt(val, BitWidth).clearUnusedBits();
+}
+
+
+// Square Root - this method computes and returns the square root of "this".
+// Three mechanisms are used for computation. For small values (<= 5 bits),
+// a table lookup is done. This gets some performance for common cases. For
+// values using less than 52 bits, the value is converted to double and then
+// the libc sqrt function is called. The result is rounded and then converted
+// back to a uint64_t which is then used to construct the result. Finally,
+// the Babylonian method for computing square roots is used.
+APInt APInt::sqrt() const {
+
+ // Determine the magnitude of the value.
+ uint32_t magnitude = getActiveBits();
+
+ // Use a fast table for some small values. This also gets rid of some
+ // rounding errors in libc sqrt for small values.
+ if (magnitude <= 5) {
+ static const uint8_t results[32] = {
+ /* 0 */ 0,
+ /* 1- 2 */ 1, 1,
+ /* 3- 6 */ 2, 2, 2, 2,
+ /* 7-12 */ 3, 3, 3, 3, 3, 3,
+ /* 13-20 */ 4, 4, 4, 4, 4, 4, 4, 4,
+ /* 21-30 */ 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
+ /* 31 */ 6
+ };
+ return APInt(BitWidth, results[ (isSingleWord() ? VAL : pVal[0]) ]);
}
- if (uint32_t offset = shiftAmt / APINT_BITS_PER_WORD) {
- for (uint32_t i = API.getNumWords() - 1; i > offset - 1; --i)
- API.pVal[i] = API.pVal[i-offset];
- memset(API.pVal, 0, offset * APINT_WORD_SIZE);
+ // If the magnitude of the value fits in less than 52 bits (the precision of
+ // an IEEE double precision floating point value), then we can use the
+ // libc sqrt function which will probably use a hardware sqrt computation.
+ // This should be faster than the algorithm below.
+ if (magnitude < 52) {
+#ifdef _MSC_VER
+ // Amazingly, VC++ doesn't have round().
+ return APInt(BitWidth,
+ uint64_t(::sqrt(double(isSingleWord()?VAL:pVal[0]))) + 0.5);
+#else
+ return APInt(BitWidth,
+ uint64_t(::round(::sqrt(double(isSingleWord()?VAL:pVal[0])))));
+#endif
+ }
+
+ // Okay, all the short cuts are exhausted. We must compute it. The following
+ // is a classical Babylonian method for computing the square root. This code
+ // was adapted to APINt from a wikipedia article on such computations.
+ // See http://www.wikipedia.org/ and go to the page named
+ // Calculate_an_integer_square_root.
+ uint32_t nbits = BitWidth, i = 4;
+ APInt testy(BitWidth, 16);
+ APInt x_old(BitWidth, 1);
+ APInt x_new(BitWidth, 0);
+ APInt two(BitWidth, 2);
+
+ // Select a good starting value using binary logarithms.
+ for (;; i += 2, testy = testy.shl(2))
+ if (i >= nbits || this->ule(testy)) {
+ x_old = x_old.shl(i / 2);
+ break;
+ }
+
+ // Use the Babylonian method to arrive at the integer square root:
+ for (;;) {
+ x_new = (this->udiv(x_old) + x_old).udiv(two);
+ if (x_old.ule(x_new))
+ break;
+ x_old = x_new;
}
- shiftAmt %= APINT_BITS_PER_WORD;
- uint32_t i;
- for (i = API.getNumWords() - 1; i > 0; --i)
- API.pVal[i] = (API.pVal[i] << shiftAmt) |
- (API.pVal[i-1] >> (APINT_BITS_PER_WORD - shiftAmt));
- API.pVal[i] <<= shiftAmt;
- API.clearUnusedBits();
- return API;
+
+ // Make sure we return the closest approximation
+ // NOTE: The rounding calculation below is correct. It will produce an
+ // off-by-one discrepancy with results from pari/gp. That discrepancy has been
+ // determined to be a rounding issue with pari/gp as it begins to use a
+ // floating point representation after 192 bits. There are no discrepancies
+ // between this algorithm and pari/gp for bit widths < 192 bits.
+ APInt square(x_old * x_old);
+ APInt nextSquare((x_old + 1) * (x_old +1));
+ if (this->ult(square))
+ return x_old;
+ else if (this->ule(nextSquare)) {
+ APInt midpoint((nextSquare - square).udiv(two));
+ APInt offset(*this - square);
+ if (offset.ult(midpoint))
+ return x_old;
+ else
+ return x_old + 1;
+ } else
+ assert(0 && "Error in APInt::sqrt computation");
+ return x_old + 1;
}
/// Implementation of Knuth's Algorithm D (Division of nonnegative integers)
// (u[j+n]u[j+n-1]..u[j]) - qp * (v[n-1]...v[1]v[0]). This computation
// consists of a simple multiplication by a one-place number, combined with
// a subtraction.
- bool isNegative = false;
+ bool isNeg = false;
for (uint32_t i = 0; i < n; ++i) {
uint64_t u_tmp = uint64_t(u[j+i]) | (uint64_t(u[j+i+1]) << 32);
uint64_t subtrahend = uint64_t(qp) * uint64_t(v[i]);
u[k]--;
k++;
}
- isNegative |= borrow;
+ isNeg |= borrow;
DEBUG(cerr << "KnuthDiv: u[j+i] == " << u[j+i] << ", u[j+i+1] == " <<
u[j+i+1] << '\n');
}
// true value plus b**(n+1), namely as the b's complement of
// the true value, and a "borrow" to the left should be remembered.
//
- if (isNegative) {
+ if (isNeg) {
bool carry = true; // true because b's complement is "complement + 1"
for (uint32_t i = 0; i <= m+n; ++i) {
u[i] = ~u[i] + carry; // b's complement
// D5. [Test remainder.] Set q[j] = qp. If the result of step D4 was
// negative, go to step D6; otherwise go on to step D7.
q[j] = qp;
- if (isNegative) {
+ if (isNeg) {
// D6. [Add back]. The probability that this step is necessary is very
// small, on the order of only 2/b. Make sure that test data accounts for
// this possibility. Decrease q[j] by 1
DEBUG(cerr << std::setbase(10) << '\n');
}
-// This function makes calling KnuthDiv a little more convenient. It uses
-// APInt parameters instead of uint32_t* parameters. It can also divide APInt
-// values of different widths.
void APInt::divide(const APInt LHS, uint32_t lhsWords,
const APInt &RHS, uint32_t rhsWords,
APInt *Quotient, APInt *Remainder)
uint64_t mask = ~0ull >> (sizeof(uint32_t)*8);
uint32_t n = rhsWords * 2;
uint32_t m = (lhsWords * 2) - n;
- // FIXME: allocate space on stack if m and n are sufficiently small.
- uint32_t *U = new uint32_t[m + n + 1];
+
+ // Allocate space for the temporary values we need either on the stack, if
+ // it will fit, or on the heap if it won't.
+ uint32_t SPACE[128];
+ uint32_t *U = 0;
+ uint32_t *V = 0;
+ uint32_t *Q = 0;
+ uint32_t *R = 0;
+ if ((Remainder?4:3)*n+2*m+1 <= 128) {
+ U = &SPACE[0];
+ V = &SPACE[m+n+1];
+ Q = &SPACE[(m+n+1) + n];
+ if (Remainder)
+ R = &SPACE[(m+n+1) + n + (m+n)];
+ } else {
+ U = new uint32_t[m + n + 1];
+ V = new uint32_t[n];
+ Q = new uint32_t[m+n];
+ if (Remainder)
+ R = new uint32_t[n];
+ }
+
+ // Initialize the dividend
memset(U, 0, (m+n+1)*sizeof(uint32_t));
for (unsigned i = 0; i < lhsWords; ++i) {
uint64_t tmp = (LHS.getNumWords() == 1 ? LHS.VAL : LHS.pVal[i]);
}
U[m+n] = 0; // this extra word is for "spill" in the Knuth algorithm.
- uint32_t *V = new uint32_t[n];
+ // Initialize the divisor
memset(V, 0, (n)*sizeof(uint32_t));
for (unsigned i = 0; i < rhsWords; ++i) {
uint64_t tmp = (RHS.getNumWords() == 1 ? RHS.VAL : RHS.pVal[i]);
V[i * 2 + 1] = tmp >> (sizeof(uint32_t)*8);
}
- // Set up the quotient and remainder
- uint32_t *Q = new uint32_t[m+n];
+ // initialize the quotient and remainder
memset(Q, 0, (m+n) * sizeof(uint32_t));
- uint32_t *R = 0;
- if (Remainder) {
- R = new uint32_t[n];
+ if (Remainder)
memset(R, 0, n * sizeof(uint32_t));
- }
// Now, adjust m and n for the Knuth division. n is the number of words in
// the divisor. m is the number of words by which the dividend exceeds the
if (Quotient->isSingleWord())
Quotient->VAL = 0;
else
- delete Quotient->pVal;
+ delete [] Quotient->pVal;
Quotient->BitWidth = LHS.BitWidth;
if (!Quotient->isSingleWord())
Quotient->pVal = getClearedMemory(Quotient->getNumWords());
if (Remainder->isSingleWord())
Remainder->VAL = 0;
else
- delete Remainder->pVal;
+ delete [] Remainder->pVal;
Remainder->BitWidth = RHS.BitWidth;
if (!Remainder->isSingleWord())
Remainder->pVal = getClearedMemory(Remainder->getNumWords());
}
// Clean up the memory we allocated.
- delete [] U;
- delete [] V;
- delete [] Q;
- delete [] R;
+ if (U != &SPACE[0]) {
+ delete [] U;
+ delete [] V;
+ delete [] Q;
+ delete [] R;
+ }
}
-/// Unsigned divide this APInt by APInt RHS.
-/// @brief Unsigned division function for APInt.
APInt APInt::udiv(const APInt& RHS) const {
assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
return Quotient;
}
-/// Unsigned remainder operation on APInt.
-/// @brief Function for unsigned remainder operation.
APInt APInt::urem(const APInt& RHS) const {
assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
if (isSingleWord()) {
return Remainder;
}
-/// @brief Converts a char array into an integer.
void APInt::fromString(uint32_t numbits, const char *str, uint32_t slen,
uint8_t radix) {
// Check our assumptions here
assert((radix == 10 || radix == 8 || radix == 16 || radix == 2) &&
"Radix should be 2, 8, 10, or 16!");
assert(str && "String is null?");
- assert(slen <= numbits || radix != 2 && "Insufficient bit width");
- assert(slen*3 <= numbits || radix != 8 && "Insufficient bit width");
- assert(slen*4 <= numbits || radix != 16 && "Insufficient bit width");
- assert((slen*64)/20 <= numbits || radix != 10 && "Insufficient bit width");
+ bool isNeg = str[0] == '-';
+ if (isNeg)
+ str++, slen--;
+ assert((slen <= numbits || radix != 2) && "Insufficient bit width");
+ assert((slen*3 <= numbits || radix != 8) && "Insufficient bit width");
+ assert((slen*4 <= numbits || radix != 16) && "Insufficient bit width");
+ assert(((slen*64)/22 <= numbits || radix != 10) && "Insufficient bit width");
// Allocate memory
if (!isSingleWord())
apdigit.pVal[0] = digit;
*this += apdigit;
}
+ // If its negative, put it in two's complement form
+ if (isNeg) {
+ (*this)--;
+ this->flip();
+ }
}
-/// to_string - This function translates the APInt into a string.
std::string APInt::toString(uint8_t radix, bool wantSigned) const {
assert((radix == 10 || radix == 8 || radix == 16 || radix == 2) &&
"Radix should be 2, 8, 10, or 16!");
APInt tmp2(tmp.getBitWidth(), 0);
divide(tmp, tmp.getNumWords(), divisor, divisor.getNumWords(), &tmp2,
&APdigit);
- uint32_t digit = APdigit.getValue();
+ uint32_t digit = APdigit.getZExtValue();
assert(digit < radix && "divide failed");
result.insert(insert_at,digits[digit]);
tmp = tmp2;
else for (unsigned i = getNumWords(); i > 0; i--) {
cerr << pVal[i-1] << " ";
}
- cerr << " (" << this->toString(10, false) << ")\n" << std::setbase(10);
+ cerr << " U(" << this->toString(10) << ") S(" << this->toStringSigned(10)
+ << ")\n" << std::setbase(10);
}
#endif
projects / oota-llvm.git / blobdiff