本文整理汇总了C++中APInt::setSignBit方法的典型用法代码示例。如果您正苦于以下问题：C++ APInt::setSignBit方法的具体用法？C++ APInt::setSignBit怎么用？C++ APInt::setSignBit使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类APInt的用法示例。
在下文中一共展示了APInt::setSignBit方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: determineLiveOperandBits
//.........这里部分代码省略.........
uint64_t ShiftAmt = ShiftAmtC->getLimitedValue(BitWidth - 1);
AB = AOut.lshr(ShiftAmt);
// If the shift is nuw/nsw, then the high bits are not dead
// (because we've promised that they *must* be zero).
const ShlOperator *S = cast<ShlOperator>(UserI);
if (S->hasNoSignedWrap())
AB |= APInt::getHighBitsSet(BitWidth, ShiftAmt+1);
else if (S->hasNoUnsignedWrap())
AB |= APInt::getHighBitsSet(BitWidth, ShiftAmt);
}
break;
case Instruction::LShr:
if (OperandNo == 0)
if (auto *ShiftAmtC = dyn_cast<ConstantInt>(UserI->getOperand(1))) {
uint64_t ShiftAmt = ShiftAmtC->getLimitedValue(BitWidth - 1);
AB = AOut.shl(ShiftAmt);
// If the shift is exact, then the low bits are not dead
// (they must be zero).
if (cast<LShrOperator>(UserI)->isExact())
AB |= APInt::getLowBitsSet(BitWidth, ShiftAmt);
}
break;
case Instruction::AShr:
if (OperandNo == 0)
if (auto *ShiftAmtC = dyn_cast<ConstantInt>(UserI->getOperand(1))) {
uint64_t ShiftAmt = ShiftAmtC->getLimitedValue(BitWidth - 1);
AB = AOut.shl(ShiftAmt);
// Because the high input bit is replicated into the
// high-order bits of the result, if we need any of those
// bits, then we must keep the highest input bit.
if ((AOut & APInt::getHighBitsSet(BitWidth, ShiftAmt))
.getBoolValue())
AB.setSignBit();
// If the shift is exact, then the low bits are not dead
// (they must be zero).
if (cast<AShrOperator>(UserI)->isExact())
AB |= APInt::getLowBitsSet(BitWidth, ShiftAmt);
}
break;
case Instruction::And:
AB = AOut;
// For bits that are known zero, the corresponding bits in the
// other operand are dead (unless they're both zero, in which
// case they can't both be dead, so just mark the LHS bits as
// dead).
if (OperandNo == 0) {
ComputeKnownBits(BitWidth, I, UserI->getOperand(1));
AB &= ~Known2.Zero;
} else {
if (!isa<Instruction>(UserI->getOperand(0)))
ComputeKnownBits(BitWidth, UserI->getOperand(0), I);
AB &= ~(Known.Zero & ~Known2.Zero);
}
break;
case Instruction::Or:
AB = AOut;
// For bits that are known one, the corresponding bits in the
// other operand are dead (unless they're both one, in which
// case they can't both be dead, so just mark the LHS bits as
// dead).
if (OperandNo == 0) {
ComputeKnownBits(BitWidth, I, UserI->getOperand(1));
AB &= ~Known2.One;
} else {
if (!isa<Instruction>(UserI->getOperand(0)))
ComputeKnownBits(BitWidth, UserI->getOperand(0), I);
AB &= ~(Known.One & ~Known2.One);
}
break;
case Instruction::Xor:
case Instruction::PHI:
AB = AOut;
break;
case Instruction::Trunc:
AB = AOut.zext(BitWidth);
break;
case Instruction::ZExt:
AB = AOut.trunc(BitWidth);
break;
case Instruction::SExt:
AB = AOut.trunc(BitWidth);
// Because the high input bit is replicated into the
// high-order bits of the result, if we need any of those
// bits, then we must keep the highest input bit.
if ((AOut & APInt::getHighBitsSet(AOut.getBitWidth(),
AOut.getBitWidth() - BitWidth))
.getBoolValue())
AB.setSignBit();
break;
case Instruction::Select:
if (OperandNo != 0)
AB = AOut;
break;
}
}