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llvm/lib/Support/APInt.cpp
Reid Spencer 61eb180a53 Clean up variable names in operator*. 
Attempt #3 for getting a portable INFINITY value.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34454 91177308-0d34-0410-b5e6-96231b3b80d8
2007-02-20 20:42:10 +00:00

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//===-- APInt.cpp - Implement APInt class ---------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// 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.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/APInt.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Support/MathExtras.h"
#include <cstring>
#include <cstdlib>
using namespace llvm;
// A utility function for allocating memory, checking for allocation failures,
// and ensuring the contents is zeroed.
inline static uint64_t* getClearedMemory(uint32_t numWords) {
uint64_t * result = new uint64_t[numWords];
assert(result && "APInt memory allocation fails!");
memset(result, 0, numWords * sizeof(uint64_t));
return result;
}
// A utility function for allocating memory and checking for allocation failure.
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)
: BitWidth(numBits), pVal(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));
else {
pVal = getClearedMemory(getNumWords());
pVal[0] = val;
}
}
APInt::APInt(uint32_t numBits, uint32_t numWords, uint64_t bigVal[])
: BitWidth(numBits), pVal(0) {
assert(BitWidth >= IntegerType::MIN_INT_BITS && "bitwidth too small");
assert(BitWidth <= IntegerType::MAX_INT_BITS && "bitwidth too large");
assert(bigVal && "Null pointer detected!");
if (isSingleWord())
VAL = bigVal[0] & (~uint64_t(0ULL) >> (APINT_BITS_PER_WORD - BitWidth));
else {
pVal = getMemory(getNumWords());
// Calculate the actual length of bigVal[].
uint32_t maxN = std::max<uint32_t>(numWords, getNumWords());
uint32_t minN = std::min<uint32_t>(numWords, getNumWords());
memcpy(pVal, bigVal, (minN - 1) * APINT_WORD_SIZE);
pVal[minN-1] = bigVal[minN-1] &
(~uint64_t(0ULL) >>
(APINT_BITS_PER_WORD - BitWidth % APINT_BITS_PER_WORD));
if (maxN == getNumWords())
memset(pVal+numWords, 0, (getNumWords() - numWords) * APINT_WORD_SIZE);
}
}
/// @brief Create a new APInt by translating the char array represented
/// integer value.
APInt::APInt(uint32_t numbits, const char StrStart[], uint32_t slen,
uint8_t radix)
: BitWidth(numbits), pVal(0) {
fromString(numbits, StrStart, slen, radix);
}
/// @brief Create a new APInt by translating the string represented
/// integer value.
APInt::APInt(uint32_t numbits, const std::string& Val, uint8_t radix)
: BitWidth(numbits), pVal(0) {
assert(!Val.empty() && "String empty?");
fromString(numbits, Val.c_str(), Val.size(), radix);
}
/// @brief Copy constructor
APInt::APInt(const APInt& APIVal)
: BitWidth(APIVal.BitWidth), pVal(0) {
if (isSingleWord())
VAL = APIVal.VAL;
else {
pVal = getMemory(getNumWords());
memcpy(pVal, APIVal.pVal, getNumWords() * APINT_WORD_SIZE);
}
}
APInt::~APInt() {
if (!isSingleWord() && pVal)
delete[] pVal;
}
/// @brief Copy assignment operator. Create a new object from the given
/// APInt one by initialization.
APInt& APInt::operator=(const APInt& RHS) {
assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
if (isSingleWord())
VAL = RHS.VAL;
else
memcpy(pVal, RHS.pVal, getNumWords() * APINT_WORD_SIZE);
return *this;
}
/// @brief Assignment operator. Assigns a common case integer value to
/// the APInt.
APInt& APInt::operator=(uint64_t RHS) {
if (isSingleWord())
VAL = RHS;
else {
pVal[0] = RHS;
memset(pVal+1, 0, (getNumWords() - 1) * APINT_WORD_SIZE);
}
return *this;
}
/// 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) {
for (uint32_t i = 0; i < len; ++i) {
dest[i] = y + x[i];
if (dest[i] < y)
y = 1;
else {
y = 0;
break;
}
}
return y;
}
/// @brief Prefix increment operator. Increments the APInt by one.
APInt& APInt::operator++() {
if (isSingleWord())
++VAL;
else
add_1(pVal, pVal, getNumWords(), 1);
clearUnusedBits();
return *this;
}
/// sub_1 - This function subtracts a single "digit" (64-bit word), y, from
/// the multi-digit integer array, x[], propagating the borrowed 1 value until
/// 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) {
for (uint32_t i = 0; i < len; ++i) {
uint64_t X = x[i];
x[i] -= y;
if (y > X)
y = 1; // We have to "borrow 1" from next "digit"
else {
y = 0; // No need to borrow
break; // Remaining digits are unchanged so exit early
}
}
return y;
}
/// @brief Prefix decrement operator. Decrements the APInt by one.
APInt& APInt::operator--() {
if (isSingleWord())
--VAL;
else
sub_1(pVal, getNumWords(), 1);
clearUnusedBits();
return *this;
}
/// add - This function adds the integer array x[] by integer array
/// y[] and returns the carry.
static uint64_t add(uint64_t dest[], uint64_t x[],
uint64_t y[], uint32_t len) {
uint32_t carry = 0;
for (uint32_t i = 0; i< len; ++i) {
carry += x[i];
dest[i] = carry + y[i];
carry = carry < x[i] ? 1 : (dest[i] < carry ? 1 : 0);
}
return carry;
}
/// @brief Addition assignment operator. Adds 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()) VAL += RHS.isSingleWord() ? RHS.VAL : RHS.pVal[0];
else {
if (RHS.isSingleWord()) add_1(pVal, pVal, getNumWords(), RHS.VAL);
else {
if (getNumWords() <= RHS.getNumWords())
add(pVal, pVal, RHS.pVal, getNumWords());
else {
uint64_t carry = add(pVal, pVal, RHS.pVal, RHS.getNumWords());
add_1(pVal + RHS.getNumWords(), pVal + RHS.getNumWords(),
getNumWords() - RHS.getNumWords(), carry);
}
}
}
clearUnusedBits();
return *this;
}
/// sub - This function subtracts the integer array x[] by
/// integer array y[], and returns the borrow-out carry.
static uint64_t sub(uint64_t dest[], uint64_t x[],
uint64_t y[], uint32_t len) {
// Carry indicator.
uint64_t cy = 0;
for (uint32_t i = 0; i < len; ++i) {
uint64_t Y = y[i], X = x[i];
Y += cy;
cy = Y < cy ? 1 : 0;
Y = X - Y;
cy += Y > X ? 1 : 0;
dest[i] = Y;
}
return cy;
}
/// @brief Subtraction assignment operator. Subtracts 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())
VAL -= RHS.isSingleWord() ? RHS.VAL : RHS.pVal[0];
else {
if (RHS.isSingleWord())
sub_1(pVal, getNumWords(), RHS.VAL);
else {
if (RHS.getNumWords() < getNumWords()) {
uint64_t carry = sub(pVal, pVal, RHS.pVal, RHS.getNumWords());
sub_1(pVal + RHS.getNumWords(), getNumWords() - RHS.getNumWords(),
carry);
}
else
sub(pVal, pVal, RHS.pVal, getNumWords());
}
}
clearUnusedBits();
return *this;
}
/// 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.
static uint64_t mul_1(uint64_t dest[],
uint64_t x[], uint32_t len,
uint64_t y) {
// Split y into high 32-bit part and low 32-bit part.
uint64_t ly = y & 0xffffffffULL, hy = y >> 32;
uint64_t carry = 0, lx, hx;
for (uint32_t i = 0; i < len; ++i) {
lx = x[i] & 0xffffffffULL;
hx = x[i] >> 32;
// hasCarry - A flag to indicate if has carry.
// hasCarry == 0, no carry
// hasCarry == 1, has carry
// hasCarry == 2, no carry and the calculation result == 0.
uint8_t hasCarry = 0;
dest[i] = carry + lx * ly;
// Determine if the add above introduces carry.
hasCarry = (dest[i] < carry) ? 1 : 0;
carry = hx * ly + (dest[i] >> 32) + (hasCarry ? (1ULL << 32) : 0);
// The upper limit of carry can be (2^32 - 1)(2^32 - 1) +
// (2^32 - 1) + 2^32 = 2^64.
hasCarry = (!carry && hasCarry) ? 1 : (!carry ? 2 : 0);
carry += (lx * hy) & 0xffffffffULL;
dest[i] = (carry << 32) | (dest[i] & 0xffffffffULL);
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.
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]);
for (uint32_t i = 1; i < ylen; ++i) {
uint64_t ly = y[i] & 0xffffffffULL, hy = y[i] >> 32;
uint64_t carry = 0, lx, hx;
for (uint32_t j = 0; j < xlen; ++j) {
lx = x[j] & 0xffffffffULL;
hx = x[j] >> 32;
// hasCarry - A flag to indicate if has carry.
// hasCarry == 0, no carry
// hasCarry == 1, has carry
// hasCarry == 2, no carry and the calculation result == 0.
uint8_t hasCarry = 0;
uint64_t resul = carry + lx * ly;
hasCarry = (resul < carry) ? 1 : 0;
carry = (hasCarry ? (1ULL << 32) : 0) + hx * ly + (resul >> 32);
hasCarry = (!carry && hasCarry) ? 1 : (!carry ? 2 : 0);
carry += (lx * hy) & 0xffffffffULL;
resul = (carry << 32) | (resul & 0xffffffffULL);
dest[i+j] += resul;
carry = (((!carry && hasCarry != 2) || hasCarry == 1) ? (1ULL << 32) : 0)+
(carry >> 32) + (dest[i+j] < resul ? 1 : 0) +
((lx * hy) >> 32) + hx * hy;
}
dest[i+xlen] = carry;
}
}
/// @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())
VAL *= RHS.VAL;
else {
// one-based first non-zero bit position.
uint32_t first = getActiveBits();
uint32_t xlen = !first ? 0 : whichWord(first - 1) + 1;
if (!xlen)
return *this;
else if (RHS.isSingleWord())
mul_1(pVal, pVal, xlen, RHS.VAL);
else {
first = RHS.getActiveBits();
uint32_t ylen = !first ? 0 : whichWord(first - 1) + 1;
if (!ylen) {
memset(pVal, 0, getNumWords() * APINT_WORD_SIZE);
return *this;
}
uint64_t *dest = getMemory(xlen+ylen);
mul(dest, pVal, xlen, RHS.pVal, ylen);
memcpy(pVal, dest, ((xlen + ylen >= getNumWords()) ?
getNumWords() : xlen + ylen) * APINT_WORD_SIZE);
delete[] dest;
}
}
clearUnusedBits();
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()) {
VAL &= RHS.VAL;
return *this;
}
uint32_t numWords = getNumWords();
for (uint32_t i = 0; i < numWords; ++i)
pVal[i] &= RHS.pVal[i];
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()) {
VAL |= RHS.VAL;
return *this;
}
uint32_t numWords = getNumWords();
for (uint32_t i = 0; i < numWords; ++i)
pVal[i] |= RHS.pVal[i];
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()) {
VAL ^= RHS.VAL;
return *this;
}
uint32_t numWords = getNumWords();
for (uint32_t i = 0; i < numWords; ++i)
pVal[i] ^= RHS.pVal[i];
return *this;
}
/// @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();
for (uint32_t i = 0; i < numWords; ++i)
Result.pVal[i] &= RHS.pVal[i];
return Result;
}
/// @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();
for (uint32_t i = 0; i < numWords; ++i)
Result.pVal[i] |= RHS.pVal[i];
return Result;
}
/// @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())
return APInt(getBitWidth(), VAL ^ RHS.VAL);
APInt Result(*this);
uint32_t numWords = getNumWords();
for (uint32_t i = 0; i < numWords; ++i)
Result.pVal[i] ^= RHS.pVal[i];
return Result;
}
/// @brief Logical negation operator. Performs logical negation operation on
/// this APInt.
bool APInt::operator !() const {
if (isSingleWord())
return !VAL;
for (uint32_t i = 0; i < getNumWords(); ++i)
if (pVal[i])
return false;
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");
APInt Result(*this);
Result *= RHS;
Result.clearUnusedBits();
return Result;
}
/// @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");
APInt API(*this);
API += RHS;
API.clearUnusedBits();
return API;
}
/// @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");
APInt API(*this);
API -= RHS;
return API;
}
/// @brief Array-indexing support.
bool APInt::operator[](uint32_t bitPosition) const {
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 {
uint32_t n1 = getActiveBits();
uint32_t n2 = RHS.getActiveBits();
if (n1 != n2) return false;
else if (isSingleWord())
return VAL == (RHS.isSingleWord() ? RHS.VAL : RHS.pVal[0]);
else {
if (n1 <= APINT_BITS_PER_WORD)
return pVal[0] == (RHS.isSingleWord() ? RHS.VAL : RHS.pVal[0]);
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;
else {
uint32_t n = getActiveBits();
if (n <= APINT_BITS_PER_WORD)
return pVal[0] == Val;
else
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)
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;
}
}
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()) {
int64_t lhsSext = (int64_t(VAL) << (64-BitWidth)) >> (64-BitWidth);
int64_t rhsSext = (int64_t(RHS.VAL) << (64-BitWidth)) >> (64-BitWidth);
return lhsSext < rhsSext;
}
APInt lhs(*this);
APInt rhs(*this);
bool lhsNegative = false;
bool rhsNegative = false;
if (lhs[BitWidth-1]) {
lhsNegative = true;
lhs.flip();
lhs++;
}
if (rhs[BitWidth-1]) {
rhsNegative = true;
rhs.flip();
rhs++;
}
if (lhsNegative)
if (rhsNegative)
return !lhs.ult(rhs);
else
return true;
else if (rhsNegative)
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);
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);
}
return *this;
}
/// Set the given bit to 0 whose position is given as "bitPosition".
/// @brief Set a given bit to 0.
APInt& APInt::clear(uint32_t bitPosition) {
if (isSingleWord())
VAL &= ~maskBit(bitPosition);
else
pVal[whichWord(bitPosition)] &= ~maskBit(bitPosition);
return *this;
}
/// @brief Set every bit to 0.
APInt& APInt::clear() {
if (isSingleWord())
VAL = 0;
else
memset(pVal, 0, getNumWords() * APINT_WORD_SIZE);
return *this;
}
/// @brief Bitwise NOT operator. Performs a bitwise logical NOT operation on
/// this APInt.
APInt APInt::operator~() const {
APInt API(*this);
API.flip();
return API;
}
/// @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;
}
return *this;
}
/// Toggle a given bit to its opposite value whose position is given
/// as "bitPosition".
/// @brief Toggles a given bit to its opposite value.
APInt& APInt::flip(uint32_t bitPosition) {
assert(bitPosition < BitWidth && "Out of the bit-width range!");
if ((*this)[bitPosition]) clear(bitPosition);
else set(bitPosition);
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;
}
/// 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;
}
/// 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);
}
/// 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);
}
/// HiBits - This function returns the high "numBits" bits of this APInt.
APInt APInt::getHiBits(uint32_t numBits) const {
return APIntOps::lshr(*this, BitWidth - numBits);
}
/// LoBits - This function returns the low "numBits" bits of this APInt.
APInt APInt::getLoBits(uint32_t numBits) const {
return APIntOps::lshr(APIntOps::shl(*this, BitWidth - numBits),
BitWidth - numBits);
}
bool APInt::isPowerOf2() const {
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 {
if (isSingleWord())
return CountLeadingZeros_64(VAL) - (APINT_BITS_PER_WORD - BitWidth);
uint32_t Count = 0;
for (uint32_t i = getNumWords(); i > 0u; --i) {
uint32_t tmp = CountLeadingZeros_64(pVal[i-1]);
Count += tmp;
if (tmp != APINT_BITS_PER_WORD)
if (i == getNumWords())
Count -= (APINT_BITS_PER_WORD - whichBit(BitWidth));
break;
}
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.
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();
}
/// 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);
uint32_t Count = 0;
for (uint32_t i = 0; i < getNumWords(); ++i)
Count += CountPopulation_64(pVal[i]);
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));
else if (BitWidth == 32)
return APInt(BitWidth, ByteSwap_32(VAL));
else if (BitWidth == 48) {
uint64_t Tmp1 = ((VAL >> 32) << 16) | (VAL & 0xFFFF);
Tmp1 = ByteSwap_32(Tmp1);
uint64_t Tmp2 = (VAL >> 16) & 0xFFFF;
Tmp2 = ByteSwap_16(Tmp2);
return
APInt(BitWidth,
(Tmp1 & 0xff) | ((Tmp1<<16) & 0xffff00000000ULL) | (Tmp2 << 16));
} else if (BitWidth == 64)
return APInt(BitWidth, ByteSwap_64(VAL));
else {
APInt Result(BitWidth, 0);
char *pByte = (char*)Result.pVal;
for (uint32_t i = 0; i < BitWidth / APINT_WORD_SIZE / 2; ++i) {
char Tmp = pByte[i];
pByte[i] = pByte[BitWidth / APINT_WORD_SIZE - 1 - i];
pByte[BitWidth / APINT_WORD_SIZE - i - 1] = Tmp;
}
return Result;
}
}
/// 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;
while (!!B) {
APInt T = B;
B = APIntOps::urem(A, B);
A = T;
}
return A;
}
/// DoubleRoundToAPInt - This function convert a double value to
/// a APInt value.
APInt llvm::APIntOps::RoundDoubleToAPInt(double Double) {
union {
double D;
uint64_t I;
} T;
T.D = Double;
bool isNeg = T.I >> 63;
int64_t exp = ((T.I >> 52) & 0x7ff) - 1023;
if (exp < 0)
return APInt(64ull, 0u);
uint64_t mantissa = ((T.I << 12) >> 12) | (1ULL << 52);
if (exp < 52)
return isNeg ? -APInt(64u, mantissa >> (52 - exp)) :
APInt(64u, mantissa >> (52 - exp));
APInt Tmp(exp + 1, mantissa);
Tmp = Tmp.shl(exp - 52);
return isNeg ? -Tmp : Tmp;
}
/// RoundToDouble - This function convert this APInt to a double.
/// The layout for double is as following (IEEE Standard 754):
/// --------------------------------------
/// | Sign Exponent Fraction Bias |
/// |-------------------------------------- |
/// | 1[63] 11[62-52] 52[51-00] 1023 |
/// --------------------------------------
double APInt::roundToDouble(bool isSigned) const {
// Handle the simple case where the value is contained in one uint64_t.
if (isSingleWord() || getActiveBits() <= APINT_BITS_PER_WORD) {
if (isSigned) {
int64_t sext = (int64_t(VAL) << (64-BitWidth)) >> (64-BitWidth);
return double(sext);
} else
return double(VAL);
}
// Determine if the value is negative.
bool isNeg = isSigned ? (*this)[BitWidth-1] : false;
// Construct the absolute value if we're negative.
APInt Tmp(isNeg ? -(*this) : (*this));
// Figure out how many bits we're using.
uint32_t n = Tmp.getActiveBits();
// The exponent (without bias normalization) is just the number of bits
// we are using. Note that the sign bit is gone since we constructed the
// absolute value.
uint64_t exp = n;
// Return infinity for exponent overflow
if (exp > 1023) {
if (!isSigned || !isNeg)
return double(1.0E300 * 1.0E300); // positive infinity
else
return double(-1.0E300 * 1.0E300); // negative infinity
}
exp += 1023; // Increment for 1023 bias
// Number of bits in mantissa is 52. To obtain the mantissa value, we must
// extract the high 52 bits from the correct words in pVal.
uint64_t mantissa;
unsigned hiWord = whichWord(n-1);
if (hiWord == 0) {
mantissa = Tmp.pVal[0];
if (n > 52)
mantissa >>= n - 52; // shift down, we want the top 52 bits.
} else {
assert(hiWord > 0 && "huh?");
uint64_t hibits = Tmp.pVal[hiWord] << (52 - n % APINT_BITS_PER_WORD);
uint64_t lobits = Tmp.pVal[hiWord-1] >> (11 + n % APINT_BITS_PER_WORD);
mantissa = hibits | lobits;
}
// The leading bit of mantissa is implicit, so get rid of it.
uint64_t sign = isNeg ? (1ULL << (APINT_BITS_PER_WORD - 1)) : 0;
union {
double D;
uint64_t I;
} T;
T.I = sign | (exp << 52) | mantissa;
return T.D;
}
// Truncate to new width.
void APInt::trunc(uint32_t width) {
assert(width < BitWidth && "Invalid APInt Truncate request");
}
// Sign extend to a new width.
void APInt::sext(uint32_t width) {
assert(width > BitWidth && "Invalid APInt SignExtend request");
}
// Zero extend to a new width.
void APInt::zext(uint32_t width) {
assert(width > BitWidth && "Invalid APInt ZeroExtend request");
}
/// 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);
}
}
return API;
}
/// 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);
}
return API;
}
/// Left-shift this APInt by shiftAmt.
/// @brief Left-shift function.
APInt APInt::shl(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);
else {
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);
}
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;
}
#if 0
/// subMul - This function substracts x[len-1:0] * y from
/// dest[offset+len-1:offset], and returns the most significant
/// word of the product, minus the borrow-out from the subtraction.
static uint32_t subMul(uint32_t dest[], uint32_t offset,
uint32_t x[], uint32_t len, uint32_t y) {
uint64_t yl = (uint64_t) y & 0xffffffffL;
uint32_t carry = 0;
uint32_t j = 0;
do {
uint64_t prod = ((uint64_t) x[j] & 0xffffffffUL) * yl;
uint32_t prod_low = (uint32_t) prod;
uint32_t prod_high = (uint32_t) (prod >> 32);
prod_low += carry;
carry = (prod_low < carry ? 1 : 0) + prod_high;
uint32_t x_j = dest[offset+j];
prod_low = x_j - prod_low;
if (prod_low > x_j) ++carry;
dest[offset+j] = prod_low;
} while (++j < len);
return carry;
}
/// unitDiv - This function divides N by D,
/// and returns (remainder << 32) | quotient.
/// Assumes (N >> 32) < D.
static uint64_t unitDiv(uint64_t N, uint32_t D) {
uint64_t q, r; // q: quotient, r: remainder.
uint64_t a1 = N >> 32; // a1: high 32-bit part of N.
uint64_t a0 = N & 0xffffffffL; // a0: low 32-bit part of N
if (a1 < ((D - a1 - (a0 >> 31)) & 0xffffffffL)) {
q = N / D;
r = N % D;
}
else {
// Compute c1*2^32 + c0 = a1*2^32 + a0 - 2^31*d
uint64_t c = N - ((uint64_t) D << 31);
// Divide (c1*2^32 + c0) by d
q = c / D;
r = c % D;
// Add 2^31 to quotient
q += 1 << 31;
}
return (r << 32) | (q & 0xFFFFFFFFl);
}
#endif
/// div - This is basically Knuth's formulation of the classical algorithm.
/// Correspondance with Knuth's notation:
/// Knuth's u[0:m+n] == zds[nx:0].
/// Knuth's v[1:n] == y[ny-1:0]
/// Knuth's n == ny.
/// Knuth's m == nx-ny.
/// Our nx == Knuth's m+n.
/// Could be re-implemented using gmp's mpn_divrem:
/// zds[nx] = mpn_divrem (&zds[ny], 0, zds, nx, y, ny).
/// Implementation of Knuth's Algorithm D (Division of nonnegative integers)
/// from "Art of Computer Programming, Volume 2", section 4.3.1, p. 272. The
/// variables here have the same names as in the algorithm. Comments explain
/// the algorithm and any deviation from it.
static void KnuthDiv(uint32_t *u, uint32_t *v, uint32_t *q, uint32_t* r,
uint32_t m, uint32_t n) {
assert(u && "Must provide dividend");
assert(v && "Must provide divisor");
assert(q && "Must provide quotient");
assert(n>1 && "n must be > 1");
// Knuth uses the value b as the base of the number system. In our case b
// is 2^31 so we just set it to -1u.
uint64_t b = uint64_t(1) << 32;
// D1. [Normalize.] Set d = b / (v[n-1] + 1) and multiply all the digits of
// u and v by d. Note that we have taken Knuth's advice here to use a power
// of 2 value for d such that d * v[n-1] >= b/2 (b is the base). A power of
// 2 allows us to shift instead of multiply and it is easy to determine the
// shift amount from the leading zeros. We are basically normalizing the u
// and v so that its high bits are shifted to the top of v's range without
// overflow. Note that this can require an extra word in u so that u must
// be of length m+n+1.
uint32_t shift = CountLeadingZeros_32(v[n-1]);
uint32_t v_carry = 0;
uint32_t u_carry = 0;
if (shift) {
for (uint32_t i = 0; i < m+n; ++i) {
uint32_t u_tmp = u[i] >> (32 - shift);
u[i] = (u[i] << shift) | u_carry;
u_carry = u_tmp;
}
for (uint32_t i = 0; i < n; ++i) {
uint32_t v_tmp = v[i] >> (32 - shift);
v[i] = (v[i] << shift) | v_carry;
v_carry = v_tmp;
}
}
u[m+n] = u_carry;
// D2. [Initialize j.] Set j to m. This is the loop counter over the places.
int j = m;
do {
// D3. [Calculate q'.].
// Set qp = (u[j+n]*b + u[j+n-1]) / v[n-1]. (qp=qprime=q')
// Set rp = (u[j+n]*b + u[j+n-1]) % v[n-1]. (rp=rprime=r')
// Now test if qp == b or qp*v[n-2] > b*rp + u[j+n-2]; if so, decrease
// qp by 1, inrease rp by v[n-1], and repeat this test if rp < b. The test
// on v[n-2] determines at high speed most of the cases in which the trial
// value qp is one too large, and it eliminates all cases where qp is two
// too large.
uint64_t qp = ((uint64_t(u[j+n]) << 32) | uint64_t(u[j+n-1])) / v[n-1];
uint64_t rp = ((uint64_t(u[j+n]) << 32) | uint64_t(u[j+n-1])) % v[n-1];
if (qp == b || qp*v[n-2] > b*rp + u[j+n-2]) {
qp--;
rp += v[n-1];
}
if (rp < b)
if (qp == b || qp*v[n-2] > b*rp + u[j+n-2]) {
qp--;
rp += v[n-1];
}
// D4. [Multiply and subtract.] Replace u with u - q*v (for each word).
uint32_t borrow = 0;
for (uint32_t i = 0; i < n; i++) {
uint32_t save = u[j+i];
u[j+i] = uint64_t(u[j+i]) - (qp * v[i]) - borrow;
if (u[j+i] > save) {
borrow = 1;
u[j+i+1] += b;
} else {
borrow = 0;
}
}
if (borrow)
u[j+n] += 1;
// 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 (borrow) {
// 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. Decreate qj by 1 and add v[...] to u[...]. A carry
// will occur to the left of u[j+n], and it should be ignored since it
// cancels with the borrow that occurred in D4.
uint32_t carry = 0;
for (uint32_t i = 0; i < n; i++) {
uint32_t save = u[j+i];
u[j+i] += v[i] + carry;
carry = u[j+i] < save;
}
}
// D7. [Loop on j.] Decreate j by one. Now if j >= 0, go back to D3.
j--;
} while (j >= 0);
// D8. [Unnormalize]. Now q[...] is the desired quotient, and the desired
// remainder may be obtained by dividing u[...] by d. If r is non-null we
// compute the remainder (urem uses this).
if (r) {
// The value d is expressed by the "shift" value above since we avoided
// multiplication by d by using a shift left. So, all we have to do is
// shift right here. In order to mak
uint32_t mask = ~0u >> (32 - shift);
uint32_t carry = 0;
for (int i = n-1; i >= 0; i--) {
uint32_t save = u[i] & mask;
r[i] = (u[i] >> shift) | carry;
carry = save;
}
}
}
// 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)
{
assert(lhsWords >= rhsWords && "Fractional result");
// First, compose the values into an array of 32-bit words instead of
// 64-bit words. This is a necessity of both the "short division" algorithm
// and the the Knuth "classical algorithm" which requires there to be native
// operations for +, -, and * on an m bit value with an m*2 bit result. We
// can't use 64-bit operands here because we don't have native results of
// 128-bits. Furthremore, casting the 64-bit values to 32-bit values won't
// work on large-endian machines.
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];
memset(U, 0, (m+n+1)*sizeof(uint32_t));
for (unsigned i = 0; i < lhsWords; ++i) {
uint64_t tmp = (lhsWords == 1 ? LHS.VAL : LHS.pVal[i]);
U[i * 2] = tmp & mask;
U[i * 2 + 1] = tmp >> (sizeof(uint32_t)*8);
}
U[m+n] = 0; // this extra word is for "spill" in the Knuth algorithm.
uint32_t *V = new uint32_t[n];
memset(V, 0, (n)*sizeof(uint32_t));
for (unsigned i = 0; i < rhsWords; ++i) {
uint64_t tmp = (rhsWords == 1 ? RHS.VAL : RHS.pVal[i]);
V[i * 2] = tmp & mask;
V[i * 2 + 1] = tmp >> (sizeof(uint32_t)*8);
}
// Set up the quotient and remainder
uint32_t *Q = new uint32_t[m+n];
memset(Q, 0, (m+n) * sizeof(uint32_t));
uint32_t *R = 0;
if (Remainder) {
R = new uint32_t[n];
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
// divisor (i.e. m+n is the length of the dividend). These sizes must not
// contain any zero words or the Knuth algorithm fails.
for (unsigned i = n; i > 0 && V[i-1] == 0; i--) {
n--;
m++;
}
for (unsigned i = m+n; i > 0 && U[i-1] == 0; i--)
m--;
// If we're left with only a single word for the divisor, Knuth doesn't work
// so we implement the short division algorithm here. This is much simpler
// and faster because we are certain that we can divide a 64-bit quantity
// by a 32-bit quantity at hardware speed and short division is simply a
// series of such operations. This is just like doing short division but we
// are using base 2^32 instead of base 10.
assert(n != 0 && "Divide by zero?");
if (n == 1) {
uint32_t divisor = V[0];
uint32_t remainder = 0;
for (int i = m+n-1; i >= 0; i--) {
uint64_t partial_dividend = uint64_t(remainder) << 32 | U[i];
if (partial_dividend == 0) {
Q[i] = 0;
remainder = 0;
} else if (partial_dividend < divisor) {
Q[i] = 0;
remainder = partial_dividend;
} else if (partial_dividend == divisor) {
Q[i] = 1;
remainder = 0;
} else {
Q[i] = partial_dividend / divisor;
remainder = partial_dividend - (Q[i] * divisor);
}
}
if (R)
R[0] = remainder;
} else {
// Now we're ready to invoke the Knuth classical divide algorithm. In this
// case n > 1.
KnuthDiv(U, V, Q, R, m, n);
}
// If the caller wants the quotient
if (Quotient) {
// Set up the Quotient value's memory.
if (Quotient->BitWidth != LHS.BitWidth) {
if (Quotient->isSingleWord())
Quotient->VAL = 0;
else
delete Quotient->pVal;
Quotient->BitWidth = LHS.BitWidth;
if (!Quotient->isSingleWord())
Quotient->pVal = getClearedMemory(lhsWords);
} else
Quotient->clear();
// The quotient is in Q. Reconstitute the quotient into Quotient's low
// order words.
if (lhsWords == 1) {
uint64_t tmp =
uint64_t(Q[0]) | (uint64_t(Q[1]) << (APINT_BITS_PER_WORD / 2));
if (Quotient->isSingleWord())
Quotient->VAL = tmp;
else
Quotient->pVal[0] = tmp;
} else {
assert(!Quotient->isSingleWord() && "Quotient APInt not large enough");
for (unsigned i = 0; i < lhsWords; ++i)
Quotient->pVal[i] =
uint64_t(Q[i*2]) | (uint64_t(Q[i*2+1]) << (APINT_BITS_PER_WORD / 2));
}
}
// If the caller wants the remainder
if (Remainder) {
// Set up the Remainder value's memory.
if (Remainder->BitWidth != RHS.BitWidth) {
if (Remainder->isSingleWord())
Remainder->VAL = 0;
else
delete Remainder->pVal;
Remainder->BitWidth = RHS.BitWidth;
if (!Remainder->isSingleWord())
Remainder->pVal = getClearedMemory(rhsWords);
} else
Remainder->clear();
// The remainder is in R. Reconstitute the remainder into Remainder's low
// order words.
if (rhsWords == 1) {
uint64_t tmp =
uint64_t(R[0]) | (uint64_t(R[1]) << (APINT_BITS_PER_WORD / 2));
if (Remainder->isSingleWord())
Remainder->VAL = tmp;
else
Remainder->pVal[0] = tmp;
} else {
assert(!Remainder->isSingleWord() && "Remainder APInt not large enough");
for (unsigned i = 0; i < rhsWords; ++i)
Remainder->pVal[i] =
uint64_t(R[i*2]) | (uint64_t(R[i*2+1]) << (APINT_BITS_PER_WORD / 2));
}
}
// Clean up the memory we allocated.
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");
// First, deal with the easy case
if (isSingleWord()) {
assert(RHS.VAL != 0 && "Divide by zero?");
return APInt(BitWidth, VAL / RHS.VAL);
}
// Get some facts about the LHS and RHS number of bits and words
uint32_t rhsBits = RHS.getActiveBits();
uint32_t rhsWords = !rhsBits ? 0 : (APInt::whichWord(rhsBits - 1) + 1);
assert(rhsWords && "Divided by zero???");
uint32_t lhsBits = this->getActiveBits();
uint32_t lhsWords = !lhsBits ? 0 : (APInt::whichWord(lhsBits - 1) + 1);
// Make a temporary to hold the result
APInt Result(*this);
// Deal with some degenerate cases
if (!lhsWords)
return Result; // 0 / X == 0
else if (lhsWords < rhsWords || Result.ult(RHS)) {
// X / Y with X < Y == 0
memset(Result.pVal, 0, Result.getNumWords() * APINT_WORD_SIZE);
return Result;
} else if (Result == RHS) {
// X / X == 1
memset(Result.pVal, 0, Result.getNumWords() * APINT_WORD_SIZE);
Result.pVal[0] = 1;
return Result;
} else if (lhsWords == 1 && rhsWords == 1) {
// All high words are zero, just use native divide
Result.pVal[0] /= RHS.pVal[0];
return Result;
}
// We have to compute it the hard way. Invoke the Knuth divide algorithm.
APInt Quotient(1,0); // to hold result.
divide(*this, lhsWords, RHS, rhsWords, &Quotient, 0);
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()) {
assert(RHS.VAL != 0 && "Remainder by zero?");
return APInt(BitWidth, VAL % RHS.VAL);
}
// Make a temporary to hold the result
APInt Result(*this);
// Get some facts about the RHS
uint32_t rhsBits = RHS.getActiveBits();
uint32_t rhsWords = !rhsBits ? 0 : (APInt::whichWord(rhsBits - 1) + 1);
assert(rhsWords && "Performing remainder operation by zero ???");
// Get some facts about the LHS
uint32_t lhsBits = Result.getActiveBits();
uint32_t lhsWords = !lhsBits ? 0 : (Result.whichWord(lhsBits - 1) + 1);
// Check the degenerate cases
if (lhsWords == 0) {
// 0 % Y == 0
memset(Result.pVal, 0, Result.getNumWords() * APINT_WORD_SIZE);
return Result;
} else if (lhsWords < rhsWords || Result.ult(RHS)) {
// X % Y == X iff X < Y
return Result;
} else if (Result == RHS) {
// X % X == 0;
memset(Result.pVal, 0, Result.getNumWords() * APINT_WORD_SIZE);
return Result;
} else if (lhsWords == 1) {
// All high words are zero, just use native remainder
Result.pVal[0] %= RHS.pVal[0];
return Result;
}
// We have to compute it the hard way. Invoke the Knute divide algorithm.
APInt Remainder(1,0);
divide(*this, lhsWords, RHS, rhsWords, 0, &Remainder);
return Remainder;
}
/// @brief Converts a char array into an integer.
void APInt::fromString(uint32_t numbits, const char *StrStart, uint32_t slen,
uint8_t radix) {
assert((radix == 10 || radix == 8 || radix == 16 || radix == 2) &&
"Radix should be 2, 8, 10, or 16!");
assert(StrStart && "String is null?");
uint32_t size = 0;
// If the radix is a power of 2, read the input
// from most significant to least significant.
if ((radix & (radix - 1)) == 0) {
uint32_t nextBitPos = 0;
uint32_t bits_per_digit = radix / 8 + 2;
uint64_t resDigit = 0;
BitWidth = slen * bits_per_digit;
if (getNumWords() > 1)
pVal = getMemory(getNumWords());
for (int i = slen - 1; i >= 0; --i) {
uint64_t digit = StrStart[i] - '0';
resDigit |= digit << nextBitPos;
nextBitPos += bits_per_digit;
if (nextBitPos >= APINT_BITS_PER_WORD) {
if (isSingleWord()) {
VAL = resDigit;
break;
}
pVal[size++] = resDigit;
nextBitPos -= APINT_BITS_PER_WORD;
resDigit = digit >> (bits_per_digit - nextBitPos);
}
}
if (!isSingleWord() && size <= getNumWords())
pVal[size] = resDigit;
} else { // General case. The radix is not a power of 2.
// For 10-radix, the max value of 64-bit integer is 18446744073709551615,
// and its digits number is 20.
const uint32_t chars_per_word = 20;
if (slen < chars_per_word ||
(slen == chars_per_word && // In case the value <= 2^64 - 1
strcmp(StrStart, "18446744073709551615") <= 0)) {
BitWidth = APINT_BITS_PER_WORD;
VAL = strtoull(StrStart, 0, 10);
} else { // In case the value > 2^64 - 1
BitWidth = (slen / chars_per_word + 1) * APINT_BITS_PER_WORD;
pVal = getClearedMemory(getNumWords());
uint32_t str_pos = 0;
while (str_pos < slen) {
uint32_t chunk = slen - str_pos;
if (chunk > chars_per_word - 1)
chunk = chars_per_word - 1;
uint64_t resDigit = StrStart[str_pos++] - '0';
uint64_t big_base = radix;
while (--chunk > 0) {
resDigit = resDigit * radix + StrStart[str_pos++] - '0';
big_base *= radix;
}
uint64_t carry;
if (!size)
carry = resDigit;
else {
carry = mul_1(pVal, pVal, size, big_base);
carry += add_1(pVal, pVal, size, resDigit);
}
if (carry) pVal[size++] = carry;
}
}
}
}
/// 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!");
static const char *digits[] = {
"0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F"
};
std::string result;
uint32_t bits_used = getActiveBits();
if (isSingleWord()) {
char buf[65];
const char *format = (radix == 10 ? (wantSigned ? "%lld" : "%llu") :
(radix == 16 ? "%llX" : (radix == 8 ? "%llo" : 0)));
if (format) {
if (wantSigned) {
int64_t sextVal = (int64_t(VAL) << (APINT_BITS_PER_WORD-BitWidth)) >>
(APINT_BITS_PER_WORD-BitWidth);
sprintf(buf, format, sextVal);
} else
sprintf(buf, format, VAL);
} else {
memset(buf, 0, 65);
uint64_t v = VAL;
while (bits_used) {
uint32_t bit = v & 1;
bits_used--;
buf[bits_used] = digits[bit][0];
v >>=1;
}
}
result = buf;
return result;
}
if (radix != 10) {
uint64_t mask = radix - 1;
uint32_t shift = (radix == 16 ? 4 : radix == 8 ? 3 : 1);
uint32_t nibbles = APINT_BITS_PER_WORD / shift;
for (uint32_t i = 0; i < getNumWords(); ++i) {
uint64_t value = pVal[i];
for (uint32_t j = 0; j < nibbles; ++j) {
result.insert(0, digits[ value & mask ]);
value >>= shift;
}
}
return result;
}
APInt tmp(*this);
APInt divisor(4, radix);
APInt zero(tmp.getBitWidth(), 0);
size_t insert_at = 0;
if (wantSigned && tmp[BitWidth-1]) {
// They want to print the signed version and it is a negative value
// Flip the bits and add one to turn it into the equivalent positive
// value and put a '-' in the result.
tmp.flip();
tmp++;
result = "-";
insert_at = 1;
}
if (tmp == 0)
result = "0";
else while (tmp.ne(zero)) {
APInt APdigit(1,0);
divide(tmp, tmp.getNumWords(), divisor, divisor.getNumWords(), 0, &APdigit);
uint32_t digit = APdigit.getValue();
assert(digit < radix && "urem failed");
result.insert(insert_at,digits[digit]);
APInt tmp2(tmp.getBitWidth(), 0);
divide(tmp, tmp.getNumWords(), divisor, divisor.getNumWords(), &tmp2, 0);
tmp = tmp2;
}
return result;
}
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