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APIntify the isHighOnes utility function.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35190 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Reid Spencer 2007-03-19 21:29:50 +00:00
parent adf2a206ec
commit 05227d88af
1 changed files with 6 additions and 5 deletions
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11
lib/Transforms/Scalar/InstructionCombining.cpp
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@ -3491,14 +3491,15 @@ static bool isLowOnes(const ConstantInt *CI) {
// 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) {
uint64_t V = ~CI->getZExtValue();
if (~V == 0) return false; // 0's does not match "1+"
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 &= ConstantInt::getAllOnesValue(CI->getType())->getZExtValue();
V &= APInt::getAllOnesValue(CI->getType()->getBitWidth());
uint64_t U = V+1; // If it is low ones, this should be a power of two.
return U && V && (U & V) == 0;
APInt U(V+1); // If it is low ones, this should be a power of two.
return (U!=0) && (V!=0) && (U & V) == 0;
}
/// getICmpCode - Encode a icmp predicate into a three bit mask. These bits