diff options
Diffstat (limited to 'llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp | 44 |
1 files changed, 26 insertions, 18 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp index 8bb9541bfe10..409d66adfd67 100644 --- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp @@ -742,6 +742,13 @@ SDValue TargetLowering::SimplifyMultipleUseDemandedBits( break; } + case ISD::FREEZE: { + SDValue N0 = Op.getOperand(0); + if (DAG.isGuaranteedNotToBeUndefOrPoison(N0, DemandedElts, + /*PoisonOnly=*/false)) + return N0; + break; + } case ISD::AND: { LHSKnown = DAG.computeKnownBits(Op.getOperand(0), DemandedElts, Depth + 1); RHSKnown = DAG.computeKnownBits(Op.getOperand(1), DemandedElts, Depth + 1); @@ -3184,6 +3191,20 @@ bool TargetLowering::SimplifyDemandedVectorElts( } break; } + case ISD::FREEZE: { + SDValue N0 = Op.getOperand(0); + if (TLO.DAG.isGuaranteedNotToBeUndefOrPoison(N0, DemandedElts, + /*PoisonOnly=*/false)) + return TLO.CombineTo(Op, N0); + + // TODO: Replace this with the general fold from DAGCombiner::visitFREEZE + // freeze(op(x, ...)) -> op(freeze(x), ...). + if (N0.getOpcode() == ISD::SCALAR_TO_VECTOR && DemandedElts == 1) + return TLO.CombineTo( + Op, TLO.DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, VT, + TLO.DAG.getFreeze(N0.getOperand(0)))); + break; + } case ISD::BUILD_VECTOR: { // Check all elements and simplify any unused elements with UNDEF. if (!DemandedElts.isAllOnes()) { @@ -6050,11 +6071,7 @@ static SDValue BuildExactSDIV(const TargetLowering &TLI, SDNode *N, Divisor.ashrInPlace(Shift); UseSRA = true; } - // Calculate the multiplicative inverse, using Newton's method. - APInt t; - APInt Factor = Divisor; - while ((t = Divisor * Factor) != 1) - Factor *= APInt(Divisor.getBitWidth(), 2) - t; + APInt Factor = Divisor.multiplicativeInverse(); Shifts.push_back(DAG.getConstant(Shift, dl, ShSVT)); Factors.push_back(DAG.getConstant(Factor, dl, SVT)); return true; @@ -6643,10 +6660,7 @@ TargetLowering::prepareUREMEqFold(EVT SETCCVT, SDValue REMNode, // P = inv(D0, 2^W) // 2^W requires W + 1 bits, so we have to extend and then truncate. unsigned W = D.getBitWidth(); - APInt P = D0.zext(W + 1) - .multiplicativeInverse(APInt::getSignedMinValue(W + 1)) - .trunc(W); - assert(!P.isZero() && "No multiplicative inverse!"); // unreachable + APInt P = D0.multiplicativeInverse(); assert((D0 * P).isOne() && "Multiplicative inverse basic check failed."); // Q = floor((2^W - 1) u/ D) @@ -6901,10 +6915,7 @@ TargetLowering::prepareSREMEqFold(EVT SETCCVT, SDValue REMNode, // P = inv(D0, 2^W) // 2^W requires W + 1 bits, so we have to extend and then truncate. unsigned W = D.getBitWidth(); - APInt P = D0.zext(W + 1) - .multiplicativeInverse(APInt::getSignedMinValue(W + 1)) - .trunc(W); - assert(!P.isZero() && "No multiplicative inverse!"); // unreachable + APInt P = D0.multiplicativeInverse(); assert((D0 * P).isOne() && "Multiplicative inverse basic check failed."); // A = floor((2^(W - 1) - 1) / D0) & -2^K @@ -7630,7 +7641,7 @@ bool TargetLowering::expandMUL(SDNode *N, SDValue &Lo, SDValue &Hi, EVT HiLoVT, // // For division, we can compute the remainder using the algorithm described // above, subtract it from the dividend to get an exact multiple of Constant. -// Then multiply that extact multiply by the multiplicative inverse modulo +// Then multiply that exact multiply by the multiplicative inverse modulo // (1 << (BitWidth / 2)) to get the quotient. // If Constant is even, we can shift right the dividend and the divisor by the @@ -7765,10 +7776,7 @@ bool TargetLowering::expandDIVREMByConstant(SDNode *N, // Multiply by the multiplicative inverse of the divisor modulo // (1 << BitWidth). - APInt Mod = APInt::getSignedMinValue(BitWidth + 1); - APInt MulFactor = Divisor.zext(BitWidth + 1); - MulFactor = MulFactor.multiplicativeInverse(Mod); - MulFactor = MulFactor.trunc(BitWidth); + APInt MulFactor = Divisor.multiplicativeInverse(); SDValue Quotient = DAG.getNode(ISD::MUL, dl, VT, Dividend, DAG.getConstant(MulFactor, dl, VT)); |