diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Analysis/BranchProbabilityInfo.cpp | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/llvm/lib/Analysis/BranchProbabilityInfo.cpp b/llvm/lib/Analysis/BranchProbabilityInfo.cpp index 14800f4a28b..d7cee3afaf5 100644 --- a/llvm/lib/Analysis/BranchProbabilityInfo.cpp +++ b/llvm/lib/Analysis/BranchProbabilityInfo.cpp @@ -379,6 +379,14 @@ bool BranchProbabilityInfo::calcZeroHeuristics(BasicBlock *BB) { if (!CV) return false; + // If the LHS is the result of AND'ing a value with a single bit bitmask, + // we don't have information about probabilities. + if (Instruction *LHS = dyn_cast<Instruction>(CI->getOperand(0))) + if (LHS->getOpcode() == Instruction::And) + if (ConstantInt *AndRHS = dyn_cast<ConstantInt>(LHS->getOperand(1))) + if (AndRHS->getUniqueInteger().isPowerOf2()) + return false; + bool isProb; if (CV->isZero()) { switch (CI->getPredicate()) { |
