diff options
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 34 |
1 files changed, 26 insertions, 8 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index c80509caf05..b970dc0e5f5 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -2087,7 +2087,10 @@ void SelectionDAG::computeKnownBits(SDValue Op, APInt &KnownZero, if (M < 0) { // For UNDEF elements, we don't know anything about the common state of // the shuffle result. - KnownZero = KnownOne = APInt(BitWidth, 0); + KnownOne.clearAllBits(); + KnownZero.clearAllBits(); + DemandedLHS.clearAllBits(); + DemandedRHS.clearAllBits(); break; } @@ -2103,6 +2106,9 @@ void SelectionDAG::computeKnownBits(SDValue Op, APInt &KnownZero, KnownOne &= KnownOne2; KnownZero &= KnownZero2; } + // If we don't know any bits, early out. + if (!KnownOne && !KnownZero) + break; if (!!DemandedRHS) { SDValue RHS = Op.getOperand(1); computeKnownBits(RHS, KnownZero2, KnownOne2, DemandedRHS, Depth + 1); @@ -2126,6 +2132,9 @@ void SelectionDAG::computeKnownBits(SDValue Op, APInt &KnownZero, KnownOne &= KnownOne2; KnownZero &= KnownZero2; } + // If we don't know any bits, early out. + if (!KnownOne && !KnownZero) + break; } break; } @@ -2207,6 +2216,9 @@ void SelectionDAG::computeKnownBits(SDValue Op, APInt &KnownZero, unsigned Offset = (i % SubScale) * BitWidth; KnownOne &= KnownOne2.lshr(Offset).trunc(BitWidth); KnownZero &= KnownZero2.lshr(Offset).trunc(BitWidth); + // If we don't know any bits, early out. + if (!KnownOne && !KnownZero) + break; } } break; @@ -2290,6 +2302,9 @@ void SelectionDAG::computeKnownBits(SDValue Op, APInt &KnownZero, } case ISD::SELECT: computeKnownBits(Op.getOperand(2), KnownZero, KnownOne, Depth+1); + // If we don't know any bits, early out. + if (!KnownOne && !KnownZero) + break; computeKnownBits(Op.getOperand(1), KnownZero2, KnownOne2, Depth+1); // Only known if known in both the LHS and RHS. @@ -2298,6 +2313,9 @@ void SelectionDAG::computeKnownBits(SDValue Op, APInt &KnownZero, break; case ISD::SELECT_CC: computeKnownBits(Op.getOperand(3), KnownZero, KnownOne, Depth+1); + // If we don't know any bits, early out. + if (!KnownOne && !KnownZero) + break; computeKnownBits(Op.getOperand(2), KnownZero2, KnownOne2, Depth+1); // Only known if known in both the LHS and RHS. @@ -2691,15 +2709,15 @@ void SelectionDAG::computeKnownBits(SDValue Op, APInt &KnownZero, case ISD::SMAX: case ISD::UMIN: case ISD::UMAX: { - APInt Op0Zero, Op0One; - APInt Op1Zero, Op1One; - computeKnownBits(Op.getOperand(0), Op0Zero, Op0One, DemandedElts, + computeKnownBits(Op.getOperand(0), KnownZero, KnownOne, DemandedElts, Depth + 1); - computeKnownBits(Op.getOperand(1), Op1Zero, Op1One, DemandedElts, + // If we don't know any bits, early out. + if (!KnownOne && !KnownZero) + break; + computeKnownBits(Op.getOperand(1), KnownZero2, KnownOne2, DemandedElts, Depth + 1); - - KnownZero = Op0Zero & Op1Zero; - KnownOne = Op0One & Op1One; + KnownZero &= KnownZero2; + KnownOne &= KnownOne2; break; } case ISD::FrameIndex: |
