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af0e956cef
llvm-6502/lib/Support/APInt.cpp
Reid Spencer af0e956cef 1. Remove dead code (lshift function). 
2. Consolidate memory allocation into just two inline functions.
3. Convert "unsigned" to uint32_t to gaurantee its size.
4. Eliminate magic constants and replace with symbolic equivalent.
5. Improve code documentation slightly.
6. Simplify the logical operator code because bitwidths must be the same.
7. Fix indentation per coding standards.
8. Use exit-early style to reduce indentation in several functions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34389 91177308-0d34-0410-b5e6-96231b3b80d8
2007-02-18 18:38:44 +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) {
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) {
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) * sizeof(uint64_t));
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) * sizeof(uint64_t));
}
}
/// @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) {
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) {
assert(!Val.empty() && "String empty?");
fromString(numbits, Val.c_str(), Val.size(), radix);
}
APInt::APInt(const APInt& APIVal)
: BitWidth(APIVal.BitWidth) {
if (isSingleWord())
VAL = APIVal.VAL;
else {
pVal = getMemory(getNumWords());
memcpy(pVal, APIVal.pVal, getNumWords() * sizeof(uint64_t));
}
}
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() * sizeof(uint64_t));
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) * sizeof(uint64_t));
}
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.isSingleWord() ? RHS.VAL : RHS.pVal[0];
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() * sizeof(uint64_t));
return *this;
}
uint64_t *dest = getMemory(xlen+ylen);
mul(dest, pVal, xlen, RHS.pVal, ylen);
memcpy(pVal, dest, ((xlen + ylen >= getNumWords()) ?
getNumWords() : xlen + ylen) * sizeof(uint64_t));
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 API(RHS);
API *= *this;
API.clearUnusedBits();
return API;
}
/// @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())
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;
}
/// 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() * sizeof(uint64_t));
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;
}
/// 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;
}
APInt tmp(*this);
APInt divisor(tmp.getBitWidth(), 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 = APIntOps::urem(tmp,divisor);
uint32_t digit = APdigit.getValue();
assert(digit < radix && "urem failed");
result.insert(insert_at,digits[digit]);
tmp = APIntOps::udiv(tmp, divisor);
}
return result;
}
/// 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 APIVal(numBits, 0);
APIVal.set();
if (isSign) APIVal.clear(numBits - 1);
return APIVal;
}
/// 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 APIVal(numBits, 0);
if (isSign) APIVal.set(numBits - 1);
return APIVal;
}
/// 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 / sizeof(uint64_t) / 2; ++i) {
char Tmp = pByte[i];
pByte[i] = pByte[BitWidth / sizeof(uint64_t) - 1 - i];
pByte[BitWidth / sizeof(uint64_t) - 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 {
bool isNeg = isSigned ? (*this)[BitWidth-1] : false;
APInt Tmp(isNeg ? -(*this) : (*this));
if (Tmp.isSingleWord())
return isSigned ? double(int64_t(Tmp.VAL)) : double(Tmp.VAL);
uint32_t n = Tmp.getActiveBits();
if (n <= APINT_BITS_PER_WORD)
return isSigned ? double(int64_t(Tmp.pVal[0])) : double(Tmp.pVal[0]);
// Exponent when normalized to have decimal point directly after
// leading one. This is stored excess 1023 in the exponent bit field.
uint64_t exp = n - 1;
// Gross overflow.
assert(exp <= 1023 && "Infinity value!");
// Number of bits in mantissa including the leading one
// equals to 53.
uint64_t mantissa;
if (n % APINT_BITS_PER_WORD >= 53)
mantissa = Tmp.pVal[whichWord(n - 1)] >> (n % APINT_BITS_PER_WORD - 53);
else
mantissa = (Tmp.pVal[whichWord(n - 1)] << (53 - n % APINT_BITS_PER_WORD)) |
(Tmp.pVal[whichWord(n - 1) - 1] >>
(11 + n % APINT_BITS_PER_WORD));
// The leading bit of mantissa is implicit, so get rid of it.
mantissa &= ~(1ULL << 52);
uint64_t sign = isNeg ? (1ULL << (APINT_BITS_PER_WORD - 1)) : 0;
exp += 1023;
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) * sizeof(uint64_t));
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() * sizeof(uint64_t));
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() * sizeof(uint64_t));
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 * sizeof(uint64_t));
}
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;
}
/// 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);
}
/// 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).
static void div(uint32_t zds[], uint32_t nx, uint32_t y[], uint32_t ny) {
uint32_t j = nx;
do { // loop over digits of quotient
// Knuth's j == our nx-j.
// Knuth's u[j:j+n] == our zds[j:j-ny].
uint32_t qhat; // treated as unsigned
if (zds[j] == y[ny-1])
qhat = -1U; // 0xffffffff
else {
uint64_t w = (((uint64_t)(zds[j])) << 32) +
((uint64_t)zds[j-1] & 0xffffffffL);
qhat = (uint32_t) unitDiv(w, y[ny-1]);
}
if (qhat) {
uint32_t borrow = subMul(zds, j - ny, y, ny, qhat);
uint32_t save = zds[j];
uint64_t num = ((uint64_t)save&0xffffffffL) -
((uint64_t)borrow&0xffffffffL);
while (num) {
qhat--;
uint64_t carry = 0;
for (uint32_t i = 0; i < ny; i++) {
carry += ((uint64_t) zds[j-ny+i] & 0xffffffffL)
+ ((uint64_t) y[i] & 0xffffffffL);
zds[j-ny+i] = (uint32_t) carry;
carry >>= 32;
}
zds[j] += carry;
num = carry - 1;
}
}
zds[j] = qhat;
} while (--j >= ny);
}
/// 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);
}
// Make a temporary to hold the result
APInt Result(*this);
// 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 = Result.getActiveBits();
uint32_t lhsWords = !lhsBits ? 0 : (APInt::whichWord(lhsBits - 1) + 1);
// 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() * sizeof(uint64_t));
else if (Result == RHS) {
// X / X == 1
memset(Result.pVal, 0, Result.getNumWords() * sizeof(uint64_t));
Result.pVal[0] = 1;
} else if (lhsWords == 1)
// All high words are zero, just use native divide
Result.pVal[0] /= RHS.pVal[0];
else {
// Compute it the hard way ..
APInt X(BitWidth, 0);
APInt Y(BitWidth, 0);
uint32_t nshift =
(APINT_BITS_PER_WORD - 1) - ((rhsBits - 1) % APINT_BITS_PER_WORD );
if (nshift) {
Y = APIntOps::shl(RHS, nshift);
X = APIntOps::shl(Result, nshift);
++lhsWords;
}
div((uint32_t*)X.pVal, lhsWords * 2 - 1,
(uint32_t*)(Y.isSingleWord()? &Y.VAL : Y.pVal), rhsWords*2);
memset(Result.pVal, 0, Result.getNumWords() * sizeof(uint64_t));
memcpy(Result.pVal, X.pVal + rhsWords,
(lhsWords - rhsWords) * sizeof(uint64_t));
}
return Result;
}
/// 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() * sizeof(uint64_t));
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() * sizeof(uint64_t));
else if (lhsWords == 1)
// All high words are zero, just use native remainder
Result.pVal[0] %= RHS.pVal[0];
else {
// Do it the hard way
APInt X((lhsWords+1)*APINT_BITS_PER_WORD, 0);
APInt Y(rhsWords*APINT_BITS_PER_WORD, 0);
uint32_t nshift =
(APINT_BITS_PER_WORD - 1) - (rhsBits - 1) % APINT_BITS_PER_WORD;
if (nshift) {
APIntOps::shl(Y, nshift);
APIntOps::shl(X, nshift);
}
div((uint32_t*)X.pVal, rhsWords*2-1,
(uint32_t*)(Y.isSingleWord()? &Y.VAL : Y.pVal), rhsWords*2);
memset(Result.pVal, 0, Result.getNumWords() * sizeof(uint64_t));
for (uint32_t i = 0; i < rhsWords-1; ++i)
Result.pVal[i] = (X.pVal[i] >> nshift) |
(X.pVal[i+1] << (APINT_BITS_PER_WORD - nshift));
Result.pVal[rhsWords-1] = X.pVal[rhsWords-1] >> nshift;
}
return Result;
}
/// @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;
}
}
}
}
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