diff options
Diffstat (limited to 'llvm/lib/CodeGen')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index 4fa438a2795..59180597130 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -2834,6 +2834,9 @@ KnownBits SelectionDAG::computeKnownBits(SDValue Op, const APInt &DemandedElts, Known.One <<= Shift; // Low bits are known zero. Known.Zero.setLowBits(Shift); + } else if (const APInt *ShMinAmt = getValidMinimumShiftAmountConstant(Op)) { + // Minimum shift low bits are known zero. + Known.Zero.setLowBits(ShMinAmt->getZExtValue()); } else { // No matter the shift amount, the trailing zeros will stay zero. Known = computeKnownBits(Op.getOperand(0), DemandedElts, Depth + 1); |
