llvm/lib/Support/APInt.cpp
Reid Spencer 9eec241347 1. Fix the flip() method to correctly flip all words of the APInt.
2. Implement the trunc, sext, and zext operations.
3. Improve fromString to accept negative values as input.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34616 91177308-0d34-0410-b5e6-96231b3b80d8
2007-02-25 23:44:53 +00:00

1622 lines
51 KiB
C++

//===-- APInt.cpp - Implement APInt class ---------------------------------===//
//
// 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 implements a class to represent arbitrary precision integer
// constant values and provide a variety of arithmetic operations on them.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "apint"
#include "llvm/ADT/APInt.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/MathExtras.h"
#include <cstring>
#include <cstdlib>
#ifndef NDEBUG
#include <iomanip>
#endif
using namespace llvm;
/// 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!");
memset(result, 0, numWords * sizeof(uint64_t));
return result;
}
/// 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)
: 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;
else {
pVal = getClearedMemory(getNumWords());
pVal[0] = val;
}
clearUnusedBits();
}
APInt::APInt(uint32_t numBits, uint32_t numWords, uint64_t bigVal[])
: BitWidth(numBits), VAL(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];
else {
// Get memory, cleared to 0
pVal = getClearedMemory(getNumWords());
// Calculate the number of words to copy
uint32_t words = std::min<uint32_t>(numWords, getNumWords());
// Copy the words from bigVal to pVal
memcpy(pVal, bigVal, words * APINT_WORD_SIZE);
}
// Make sure unused high bits are cleared
clearUnusedBits();
}
APInt::APInt(uint32_t numbits, const char StrStart[], uint32_t slen,
uint8_t radix)
: BitWidth(numbits), VAL(0) {
fromString(numbits, StrStart, slen, radix);
}
APInt::APInt(uint32_t numbits, const std::string& Val, uint8_t radix)
: BitWidth(numbits), VAL(0) {
assert(!Val.empty() && "String empty?");
fromString(numbits, Val.c_str(), Val.size(), radix);
}
APInt::APInt(const APInt& that)
: BitWidth(that.BitWidth), VAL(0) {
if (isSingleWord())
VAL = that.VAL;
else {
pVal = getMemory(getNumWords());
memcpy(pVal, that.pVal, getNumWords() * APINT_WORD_SIZE);
}
}
APInt::~APInt() {
if (!isSingleWord() && pVal)
delete[] pVal;
}
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;
}
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 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)
y = 1; // Carry one to next digit.
else {
y = 0; // No need to carry so exit early
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);
return clearUnusedBits();
}
/// 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.
/// @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;
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 bool(y);
}
/// @brief Prefix decrement operator. Decrements the APInt by one.
APInt& APInt::operator--() {
if (isSingleWord())
--VAL;
else
sub_1(pVal, getNumWords(), 1);
return clearUnusedBits();
}
/// 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;
for (uint32_t i = 0; i< len; ++i) {
uint64_t limit = std::min(x[i],y[i]); // must come first in case dest == x
dest[i] = x[i] + y[i] + carry;
carry = dest[i] < limit || (carry && dest[i] == limit);
}
return carry;
}
/// 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())
VAL += RHS.VAL;
else {
add(pVal, pVal, RHS.pVal, getNumWords());
}
return clearUnusedBits();
}
/// 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;
for (uint32_t i = 0; i < len; ++i) {
uint64_t x_tmp = borrow ? x[i] - 1 : x[i];
borrow = y[i] > x_tmp || (borrow && x[i] == 0);
dest[i] = x_tmp - y[i];
}
return borrow;
}
/// 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());
return clearUnusedBits();
}
/// 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;
// For each digit of x.
for (uint32_t i = 0; i < len; ++i) {
// 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.
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;
}
/// 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]);
for (uint32_t i = 1; i < ylen; ++i) {
uint64_t ly = y[i] & 0xffffffffULL, hy = y[i] >> 32;
uint64_t carry = 0, lx = 0, hx = 0;
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;
}
}
APInt& APInt::operator*=(const APInt& RHS) {
assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
if (isSingleWord()) {
VAL *= RHS.VAL;
clearUnusedBits();
return *this;
}
// Get some bit facts about LHS and check for zero
uint32_t lhsBits = getActiveBits();
uint32_t lhsWords = !lhsBits ? 0 : whichWord(lhsBits - 1) + 1;
if (!lhsWords)
// 0 * X ===> 0
return *this;
// Get some bit facts about RHS and check for zero
uint32_t rhsBits = RHS.getActiveBits();
uint32_t rhsWords = !rhsBits ? 0 : whichWord(rhsBits - 1) + 1;
if (!rhsWords) {
// X * 0 ===> 0
clear();
return *this;
}
// Allocate space for the result
uint32_t destWords = rhsWords + lhsWords;
uint64_t *dest = getMemory(destWords);
// Perform the long multiply
mul(dest, pVal, lhsWords, RHS.pVal, rhsWords);
// Copy result back into *this
clear();
uint32_t wordsToCopy = destWords >= getNumWords() ? getNumWords() : destWords;
memcpy(pVal, dest, wordsToCopy * APINT_WORD_SIZE);
// delete dest array and return
delete[] dest;
return *this;
}
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;
}
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;
}
APInt& APInt::operator^=(const APInt& RHS) {
assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
if (isSingleWord()) {
VAL ^= RHS.VAL;
this->clearUnusedBits();
return *this;
}
uint32_t numWords = getNumWords();
for (uint32_t i = 0; i < numWords; ++i)
pVal[i] ^= RHS.pVal[i];
return clearUnusedBits();
}
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);
uint32_t numWords = getNumWords();
uint64_t* val = getMemory(numWords);
for (uint32_t i = 0; i < numWords; ++i)
val[i] = pVal[i] & RHS.pVal[i];
return APInt(val, getBitWidth());
}
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);
uint32_t numWords = getNumWords();
uint64_t *val = getMemory(numWords);
for (uint32_t i = 0; i < numWords; ++i)
val[i] = pVal[i] | RHS.pVal[i];
return APInt(val, getBitWidth());
}
APInt APInt::operator^(const APInt& RHS) const {
assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
if (isSingleWord())
return APInt(BitWidth, VAL ^ RHS.VAL).clearUnusedBits();
uint32_t numWords = getNumWords();
uint64_t *val = getMemory(numWords);
for (uint32_t i = 0; i < numWords; ++i)
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();
}
bool APInt::operator !() const {
if (isSingleWord())
return !VAL;
for (uint32_t i = 0; i < getNumWords(); ++i)
if (pVal[i])
return false;
return true;
}
APInt APInt::operator*(const APInt& RHS) const {
assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
if (isSingleWord())
return APInt(BitWidth, VAL * RHS.VAL).clearUnusedBits();
APInt Result(*this);
Result *= RHS;
return Result.clearUnusedBits();
}
APInt APInt::operator+(const APInt& RHS) const {
assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
if (isSingleWord())
return APInt(BitWidth, VAL + RHS.VAL).clearUnusedBits();
APInt Result(BitWidth, 0);
add(Result.pVal, this->pVal, RHS.pVal, getNumWords());
return Result.clearUnusedBits();
}
APInt APInt::operator-(const APInt& RHS) const {
assert(BitWidth == RHS.BitWidth && "Bit widths must be the same");
if (isSingleWord())
return APInt(BitWidth, VAL - RHS.VAL).clearUnusedBits();
APInt Result(BitWidth, 0);
sub(Result.pVal, this->pVal, RHS.pVal, getNumWords());
return Result.clearUnusedBits();
}
bool APInt::operator[](uint32_t bitPosition) const {
return (maskBit(bitPosition) &
(isSingleWord() ? VAL : pVal[whichWord(bitPosition)])) != 0;
}
bool APInt::operator==(const APInt& RHS) const {
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;
}
bool APInt::operator==(uint64_t Val) const {
if (isSingleWord())
return VAL == Val;
uint32_t n = getActiveBits();
if (n <= APINT_BITS_PER_WORD)
return pVal[0] == Val;
else
return false;
}
bool APInt::ult(const APInt& RHS) const {
assert(BitWidth == RHS.BitWidth && "Bit widths must be same for comparison");
if (isSingleWord())
return VAL < RHS.VAL;
// 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
for (int i = whichWord(n1 - 1); i >= 0; --i) {
if (pVal[i] > RHS.pVal[i])
return false;
if (pVal[i] < RHS.pVal[i])
return true;
}
return false;
}
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]) {
// Sign bit is set so make a note of it and perform two's complement
lhsNegative = true;
lhs.flip();
lhs++;
}
if (rhs[BitWidth-1]) {
// Sign bit is set so make a note of it and perform two's complement
rhsNegative = true;
rhs.flip();
rhs++;
}
// Now we have unsigned values to compare so do the comparison if necessary
// based on the negativeness of the values.
if (lhsNegative)
if (rhsNegative)
return !lhs.ult(rhs);
else
return true;
else if (rhsNegative)
return false;
else
return lhs.ult(rhs);
}
APInt& APInt::set(uint32_t bitPosition) {
if (isSingleWord())
VAL |= maskBit(bitPosition);
else
pVal[whichWord(bitPosition)] |= maskBit(bitPosition);
return *this;
}
APInt& APInt::set() {
if (isSingleWord()) {
VAL = -1ULL;
return clearUnusedBits();
}
// Set all the bits in all the words.
for (uint32_t i = 0; i < getNumWords() - 1; ++i)
pVal[i] = -1ULL;
// Clear the unused ones
return clearUnusedBits();
}
/// 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;
return clearUnusedBits();
}
for (uint32_t i = 0; i < getNumWords(); ++i)
pVal[i] = ~pVal[i];
return clearUnusedBits();
}
/// 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)));
}
uint32_t APInt::countLeadingZeros() const {
uint32_t Count = 0;
if (isSingleWord())
Count = CountLeadingZeros_64(VAL);
else {
for (uint32_t i = getNumWords(); i > 0u; --i) {
if (pVal[i-1] == 0)
Count += APINT_BITS_PER_WORD;
else {
Count += CountLeadingZeros_64(pVal[i-1]);
break;
}
}
}
uint32_t remainder = BitWidth % APINT_BITS_PER_WORD;
if (remainder)
Count -= APINT_BITS_PER_WORD - remainder;
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 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;
}
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;
}
}
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;
}
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");
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;
}
}
clearUnusedBits();
}
// Sign extend to a new width.
void APInt::sext(uint32_t width) {
assert(width > BitWidth && "Invalid APInt SignExtend request");
assert(width <= IntegerType::MAX_INT_BITS && "Too many bits");
bool isNegative = (*this)[BitWidth-1];
// If the sign bit isn't set, this is the same as zext.
if (!isNegative) {
zext(width);
return;
}
// 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 >> (APINT_BITS_PER_WORD - newWordBits)) << wordBits;
if (wordsBefore == 1)
VAL |= mask;
else
pVal[wordsBefore-1] |= mask;
clearUnusedBits();
return;
}
uint64_t mask = ~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;
clearUnusedBits();
}
// Zero extend to a new width.
void 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;
}
}
/// Arithmetic right-shift this APInt by shiftAmt.
/// @brief Arithmetic right-shift function.
APInt APInt::ashr(uint32_t shiftAmt) const {
if (isSingleWord()) {
if (shiftAmt == BitWidth)
return APInt(BitWidth, -1ULL);
else
return APInt(BitWidth,
(((int64_t(VAL) << (APINT_BITS_PER_WORD - BitWidth)) >>
(APINT_BITS_PER_WORD - BitWidth)) >> shiftAmt)).clearUnusedBits();
}
APInt Result(*this);
if (shiftAmt >= BitWidth) {
memset(Result.pVal, Result[BitWidth-1] ? 1 : 0,
(getNumWords()-1) * APINT_WORD_SIZE);
return Result.clearUnusedBits();
}
// FIXME: bit-at-a-time shift is really slow.
uint32_t i = 0;
for (; i < BitWidth - shiftAmt; ++i)
if (Result[i+shiftAmt])
Result.set(i);
else
Result.clear(i);
for (; i < BitWidth; ++i)
if (Result[BitWidth-1])
Result.set(i);
else
Result.clear(i);
return Result;
}
/// Logical right-shift this APInt by shiftAmt.
/// @brief Logical right-shift function.
APInt APInt::lshr(uint32_t shiftAmt) const {
if (isSingleWord())
if (shiftAmt == BitWidth)
return APInt(BitWidth, 0);
else
return APInt(BitWidth, this->VAL >> shiftAmt);
APInt Result(*this);
if (shiftAmt >= BitWidth) {
Result.clear();
return Result;
}
// FIXME: bit at a time shift is really slow
uint32_t i = 0;
for (i = 0; i < Result.BitWidth - shiftAmt; ++i)
if (Result[i+shiftAmt])
Result.set(i);
else
Result.clear(i);
for (; i < Result.BitWidth; ++i)
Result.clear(i);
return Result;
}
/// Left-shift this APInt by shiftAmt.
/// @brief Left-shift function.
APInt APInt::shl(uint32_t shiftAmt) const {
assert(shiftAmt <= BitWidth && "Invalid shift amount");
if (isSingleWord()) {
if (shiftAmt == BitWidth)
return APInt(BitWidth, 0); // avoid undefined shift results
return APInt(BitWidth, VAL << shiftAmt).clearUnusedBits();
}
// 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;
shiftAmt %= APINT_BITS_PER_WORD;
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();
}
/// 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(u != v && u != q && v != q && "Must us different memory");
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;
DEBUG(cerr << "KnuthDiv: m=" << m << " n=" << n << '\n');
DEBUG(cerr << "KnuthDiv: original:");
DEBUG(for (int i = m+n; i >=0; i--) cerr << " " << std::setbase(16) << u[i]);
DEBUG(cerr << " by");
DEBUG(for (int i = n; i >0; i--) cerr << " " << std::setbase(16) << v[i-1]);
DEBUG(cerr << '\n');
// 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;
DEBUG(cerr << "KnuthDiv: normal:");
DEBUG(for (int i = m+n; i >=0; i--) cerr << " " << std::setbase(16) << u[i]);
DEBUG(cerr << " by");
DEBUG(for (int i = n; i >0; i--) cerr << " " << std::setbase(16) << v[i-1]);
DEBUG(cerr << '\n');
// D2. [Initialize j.] Set j to m. This is the loop counter over the places.
int j = m;
do {
DEBUG(cerr << "KnuthDiv: quotient digit #" << j << '\n');
// 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 dividend = ((uint64_t(u[j+n]) << 32) + u[j+n-1]);
DEBUG(cerr << "KnuthDiv: dividend == " << dividend << '\n');
uint64_t qp = dividend / v[n-1];
uint64_t rp = dividend % v[n-1];
if (qp == b || qp*v[n-2] > b*rp + u[j+n-2]) {
qp--;
rp += v[n-1];
if (rp < b && (qp == b || qp*v[n-2] > b*rp + u[j+n-2]))
qp--;
}
DEBUG(cerr << "KnuthDiv: qp == " << qp << ", rp == " << rp << '\n');
// D4. [Multiply and subtract.] Replace (u[j+n]u[j+n-1]...u[j]) with
// (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;
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]);
bool borrow = subtrahend > u_tmp;
DEBUG(cerr << "KnuthDiv: u_tmp == " << u_tmp
<< ", subtrahend == " << subtrahend
<< ", borrow = " << borrow << '\n');
uint64_t result = u_tmp - subtrahend;
uint32_t k = j + i;
u[k++] = result & (b-1); // subtract low word
u[k++] = result >> 32; // subtract high word
while (borrow && k <= m+n) { // deal with borrow to the left
borrow = u[k] == 0;
u[k]--;
k++;
}
isNegative |= borrow;
DEBUG(cerr << "KnuthDiv: u[j+i] == " << u[j+i] << ", u[j+i+1] == " <<
u[j+i+1] << '\n');
}
DEBUG(cerr << "KnuthDiv: after subtraction:");
DEBUG(for (int i = m+n; i >=0; i--) cerr << " " << u[i]);
DEBUG(cerr << '\n');
// The digits (u[j+n]...u[j]) should be kept positive; if the result of
// this step is actually negative, (u[j+n]...u[j]) should be left as the
// 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) {
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
carry = carry && u[i] == 0;
}
}
DEBUG(cerr << "KnuthDiv: after complement:");
DEBUG(for (int i = m+n; i >=0; i--) cerr << " " << u[i]);
DEBUG(cerr << '\n');
// 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) {
// 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
q[j]--;
// and add (0v[n-1]...v[1]v[0]) to (u[j+n]u[j+n-1]...u[j+1]u[j]).
// 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.
bool carry = false;
for (uint32_t i = 0; i < n; i++) {
uint32_t limit = std::min(u[j+i],v[i]);
u[j+i] += v[i] + carry;
carry = u[j+i] < limit || (carry && u[j+i] == limit);
}
u[j+n] += carry;
}
DEBUG(cerr << "KnuthDiv: after correction:");
DEBUG(for (int i = m+n; i >=0; i--) cerr <<" " << u[i]);
DEBUG(cerr << "\nKnuthDiv: digit result = " << q[j] << '\n');
// D7. [Loop on j.] Decrease j by one. Now if j >= 0, go back to D3.
} while (--j >= 0);
DEBUG(cerr << "KnuthDiv: quotient:");
DEBUG(for (int i = m; i >=0; i--) cerr <<" " << q[i]);
DEBUG(cerr << '\n');
// 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
if (shift) {
uint32_t carry = 0;
DEBUG(cerr << "KnuthDiv: remainder:");
for (int i = n-1; i >= 0; i--) {
r[i] = (u[i] >> shift) | carry;
carry = u[i] << (32 - shift);
DEBUG(cerr << " " << r[i]);
}
} else {
for (int i = n-1; i >= 0; i--) {
r[i] = u[i];
DEBUG(cerr << " " << r[i]);
}
}
DEBUG(cerr << '\n');
}
DEBUG(cerr << std::setbase(10) << '\n');
}
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;
// 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[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.
// 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] = tmp & mask;
V[i * 2 + 1] = tmp >> (sizeof(uint32_t)*8);
}
// initialize the quotient and remainder
memset(Q, 0, (m+n) * sizeof(uint32_t));
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
// 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(Quotient->getNumWords());
} 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(Remainder->getNumWords());
} 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.
if (U != &SPACE[0]) {
delete [] U;
delete [] V;
delete [] Q;
delete [] R;
}
}
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);
// Deal with some degenerate cases
if (!lhsWords)
// 0 / X ===> 0
return APInt(BitWidth, 0);
else if (lhsWords < rhsWords || this->ult(RHS)) {
// X / Y ===> 0, iff X < Y
return APInt(BitWidth, 0);
} else if (*this == RHS) {
// X / X ===> 1
return APInt(BitWidth, 1);
} else if (lhsWords == 1 && rhsWords == 1) {
// All high words are zero, just use native divide
return APInt(BitWidth, this->pVal[0] / RHS.pVal[0]);
}
// 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;
}
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);
}
// Get some facts about the LHS
uint32_t lhsBits = getActiveBits();
uint32_t lhsWords = !lhsBits ? 0 : (whichWord(lhsBits - 1) + 1);
// 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 ???");
// Check the degenerate cases
if (lhsWords == 0) {
// 0 % Y ===> 0
return APInt(BitWidth, 0);
} else if (lhsWords < rhsWords || this->ult(RHS)) {
// X % Y ===> X, iff X < Y
return *this;
} else if (*this == RHS) {
// X % X == 0;
return APInt(BitWidth, 0);
} else if (lhsWords == 1) {
// All high words are zero, just use native remainder
return APInt(BitWidth, pVal[0] % RHS.pVal[0]);
}
// 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;
}
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?");
bool isNegative = str[0] == '-';
if (isNegative)
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)/20 <= numbits || radix != 10 && "Insufficient bit width");
// Allocate memory
if (!isSingleWord())
pVal = getClearedMemory(getNumWords());
// Figure out if we can shift instead of multiply
uint32_t shift = (radix == 16 ? 4 : radix == 8 ? 3 : radix == 2 ? 1 : 0);
// Set up an APInt for the digit to add outside the loop so we don't
// constantly construct/destruct it.
APInt apdigit(getBitWidth(), 0);
APInt apradix(getBitWidth(), radix);
// Enter digit traversal loop
for (unsigned i = 0; i < slen; i++) {
// Get a digit
uint32_t digit = 0;
char cdigit = str[i];
if (isdigit(cdigit))
digit = cdigit - '0';
else if (isxdigit(cdigit))
if (cdigit >= 'a')
digit = cdigit - 'a' + 10;
else if (cdigit >= 'A')
digit = cdigit - 'A' + 10;
else
assert(0 && "huh?");
else
assert(0 && "Invalid character in digit string");
// Shift or multiple the value by the radix
if (shift)
this->shl(shift);
else
*this *= apradix;
// Add in the digit we just interpreted
if (apdigit.isSingleWord())
apdigit.VAL = digit;
else
apdigit.pVal[0] = digit;
*this += apdigit;
}
// If its negative, put it in two's complement form
if (isNegative) {
this->flip();
(*this)++;
}
}
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 == APInt(tmp.getBitWidth(), 0))
result = "0";
else while (tmp.ne(zero)) {
APInt APdigit(1,0);
APInt tmp2(tmp.getBitWidth(), 0);
divide(tmp, tmp.getNumWords(), divisor, divisor.getNumWords(), &tmp2,
&APdigit);
uint32_t digit = APdigit.getValue();
assert(digit < radix && "divide failed");
result.insert(insert_at,digits[digit]);
tmp = tmp2;
}
return result;
}
#ifndef NDEBUG
void APInt::dump() const
{
cerr << "APInt(" << BitWidth << ")=" << std::setbase(16);
if (isSingleWord())
cerr << VAL;
else for (unsigned i = getNumWords(); i > 0; i--) {
cerr << pVal[i-1] << " ";
}
cerr << " (" << this->toString(10, false) << ")\n" << std::setbase(10);
}
#endif