// isHighOnes - Return true if the constant is of the form 1+0+.
// This is the same as lowones(~X).
static bool isHighOnes(const ConstantInt *CI) {
- if (CI->getValue() == 0) return false; // 0's does not match "1+"
-
- APInt V(~CI->getValue());
-
- // There won't be bits set in parts that the type doesn't contain.
- V &= APInt::getAllOnesValue(CI->getType()->getBitWidth());
-
- APInt U(V+1); // If it is low ones, this should be a power of two.
- return (U!=0) && (V!=0) && (U & V) == 0;
+ return (~CI->getValue() + 1).isPowerOf2();
}
/// getICmpCode - Encode a icmp predicate into a three bit mask. These bits