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
This commit is contained in:
Reid Spencer 2007-02-25 23:44:53 +00:00
parent c30654cc96
commit 9eec241347

View File

@ -609,17 +609,13 @@ APInt APInt::operator~() const {
/// @brief Toggle every bit to its opposite value.
APInt& APInt::flip() {
if (isSingleWord()) VAL = (~(VAL <<
(APINT_BITS_PER_WORD - BitWidth))) >> (APINT_BITS_PER_WORD - BitWidth);
else {
uint32_t i = 0;
for (; i < getNumWords() - 1; ++i)
pVal[i] = ~pVal[i];
uint32_t offset =
APINT_BITS_PER_WORD - (BitWidth - APINT_BITS_PER_WORD * (i - 1));
pVal[i] = (~(pVal[i] << offset)) >> offset;
if (isSingleWord()) {
VAL = ~VAL;
return clearUnusedBits();
}
return *this;
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
@ -843,19 +839,91 @@ double APInt::roundToDouble(bool isSigned) const {
// Truncate to new width.
void APInt::trunc(uint32_t width) {
assert(width < BitWidth && "Invalid APInt Truncate request");
// FIXME: implement
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");
// FIXME: implement
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");
// FIXME: implement
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.
@ -1406,6 +1474,9 @@ void APInt::fromString(uint32_t numbits, const char *str, uint32_t slen,
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");
@ -1453,6 +1524,11 @@ void APInt::fromString(uint32_t numbits, const char *str, uint32_t slen,
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 {