KnownZero = ZeroBits[BitWidth - 1];
}
-/// isPowerOfTwo - Return true if the given value is known to have exactly one
+/// isKnownToBeAPowerOfTwo - Return true if the given value is known to have exactly one
/// bit set when defined. For vectors return true if every element is known to
/// be a power of two when defined. Supports values with integer or pointer
/// types and vectors of integers.
-bool llvm::isPowerOfTwo(Value *V, bool OrZero, unsigned Depth) {
+bool llvm::isKnownToBeAPowerOfTwo(Value *V, bool OrZero, unsigned Depth) {
if (Constant *C = dyn_cast<Constant>(V)) {
if (C->isNullValue())
return OrZero;
// A shift of a power of two is a power of two or zero.
if (OrZero && (match(V, m_Shl(m_Value(X), m_Value())) ||
match(V, m_Shr(m_Value(X), m_Value()))))
- return isPowerOfTwo(X, /*OrZero*/true, Depth);
+ return isKnownToBeAPowerOfTwo(X, /*OrZero*/true, Depth);
if (ZExtInst *ZI = dyn_cast<ZExtInst>(V))
- return isPowerOfTwo(ZI->getOperand(0), OrZero, Depth);
+ return isKnownToBeAPowerOfTwo(ZI->getOperand(0), OrZero, Depth);
if (SelectInst *SI = dyn_cast<SelectInst>(V))
- return isPowerOfTwo(SI->getTrueValue(), OrZero, Depth) &&
- isPowerOfTwo(SI->getFalseValue(), OrZero, Depth);
+ return isKnownToBeAPowerOfTwo(SI->getTrueValue(), OrZero, Depth) &&
+ isKnownToBeAPowerOfTwo(SI->getFalseValue(), OrZero, Depth);
if (OrZero && match(V, m_And(m_Value(X), m_Value(Y)))) {
// A power of two and'd with anything is a power of two or zero.
- if (isPowerOfTwo(X, /*OrZero*/true, Depth) ||
- isPowerOfTwo(Y, /*OrZero*/true, Depth))
+ if (isKnownToBeAPowerOfTwo(X, /*OrZero*/true, Depth) ||
+ isKnownToBeAPowerOfTwo(Y, /*OrZero*/true, Depth))
return true;
// X & (-X) is always a power of two or zero.
if (match(X, m_Neg(m_Specific(Y))) || match(Y, m_Neg(m_Specific(X))))
// copying a sign bit (sdiv int_min, 2).
if (match(V, m_Exact(m_LShr(m_Value(), m_Value()))) ||
match(V, m_Exact(m_UDiv(m_Value(), m_Value())))) {
- return isPowerOfTwo(cast<Operator>(V)->getOperand(0), OrZero, Depth);
+ return isKnownToBeAPowerOfTwo(cast<Operator>(V)->getOperand(0), OrZero, Depth);
}
return false;
}
// The sum of a non-negative number and a power of two is not zero.
- if (XKnownNonNegative && isPowerOfTwo(Y, /*OrZero*/false, Depth))
+ if (XKnownNonNegative && isKnownToBeAPowerOfTwo(Y, /*OrZero*/false, Depth))
return true;
- if (YKnownNonNegative && isPowerOfTwo(X, /*OrZero*/false, Depth))
+ if (YKnownNonNegative && isKnownToBeAPowerOfTwo(X, /*OrZero*/false, Depth))
return true;
}
// X * Y.