diff options
author | Dimitry Andric <dim@FreeBSD.org> | 2021-04-26 11:23:24 +0000 |
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committer | Dimitry Andric <dim@FreeBSD.org> | 2021-06-13 20:01:15 +0000 |
commit | d409305fa3838fb39b38c26fc085fb729b8766d5 (patch) | |
tree | fd234b27775fb59a57266cf36a05ec916e79a85f /contrib/llvm-project/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | |
parent | e8d8bef961a50d4dc22501cde4fb9fb0be1b2532 (diff) | |
parent | b4125f7d51da2bb55d3b850dba9a69c201c3422c (diff) |
Diffstat (limited to 'contrib/llvm-project/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp')
-rw-r--r-- | contrib/llvm-project/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/contrib/llvm-project/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/contrib/llvm-project/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 615bea2a4905..6a6f83827f72 100644 --- a/contrib/llvm-project/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/contrib/llvm-project/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -6517,8 +6517,11 @@ static SDValue extractShiftForRotate(SelectionDAG &DAG, SDValue OppShift, // reduces to a rotate in direction shift2 by Pos or (equivalently) a rotate // in direction shift1 by Neg. The range [0, EltSize) means that we only need // to consider shift amounts with defined behavior. +// +// The IsRotate flag should be set when the LHS of both shifts is the same. +// Otherwise if matching a general funnel shift, it should be clear. static bool matchRotateSub(SDValue Pos, SDValue Neg, unsigned EltSize, - SelectionDAG &DAG) { + SelectionDAG &DAG, bool IsRotate) { // If EltSize is a power of 2 then: // // (a) (Pos == 0 ? 0 : EltSize - Pos) == (EltSize - Pos) & (EltSize - 1) @@ -6550,8 +6553,11 @@ static bool matchRotateSub(SDValue Pos, SDValue Neg, unsigned EltSize, // always invokes undefined behavior for 32-bit X. // // Below, Mask == EltSize - 1 when using [A] and is all-ones otherwise. + // + // NOTE: We can only do this when matching an AND and not a general + // funnel shift. unsigned MaskLoBits = 0; - if (Neg.getOpcode() == ISD::AND && isPowerOf2_64(EltSize)) { + if (IsRotate && Neg.getOpcode() == ISD::AND && isPowerOf2_64(EltSize)) { if (ConstantSDNode *NegC = isConstOrConstSplat(Neg.getOperand(1))) { KnownBits Known = DAG.computeKnownBits(Neg.getOperand(0)); unsigned Bits = Log2_64(EltSize); @@ -6641,7 +6647,8 @@ SDValue DAGCombiner::MatchRotatePosNeg(SDValue Shifted, SDValue Pos, // (srl x, (*ext y))) -> // (rotr x, y) or (rotl x, (sub 32, y)) EVT VT = Shifted.getValueType(); - if (matchRotateSub(InnerPos, InnerNeg, VT.getScalarSizeInBits(), DAG)) { + if (matchRotateSub(InnerPos, InnerNeg, VT.getScalarSizeInBits(), DAG, + /*IsRotate*/ true)) { bool HasPos = TLI.isOperationLegalOrCustom(PosOpcode, VT); return DAG.getNode(HasPos ? PosOpcode : NegOpcode, DL, VT, Shifted, HasPos ? Pos : Neg); @@ -6670,7 +6677,7 @@ SDValue DAGCombiner::MatchFunnelPosNeg(SDValue N0, SDValue N1, SDValue Pos, // fold (or (shl x0, (*ext (sub 32, y))), // (srl x1, (*ext y))) -> // (fshr x0, x1, y) or (fshl x0, x1, (sub 32, y)) - if (matchRotateSub(InnerPos, InnerNeg, EltBits, DAG)) { + if (matchRotateSub(InnerPos, InnerNeg, EltBits, DAG, /*IsRotate*/ N0 == N1)) { bool HasPos = TLI.isOperationLegalOrCustom(PosOpcode, VT); return DAG.getNode(HasPos ? PosOpcode : NegOpcode, DL, VT, N0, N1, HasPos ? Pos : Neg); @@ -21174,7 +21181,7 @@ SDValue DAGCombiner::visitFP16_TO_FP(SDNode *N) { SDValue N0 = N->getOperand(0); // fold fp16_to_fp(op & 0xffff) -> fp16_to_fp(op) - if (N0->getOpcode() == ISD::AND) { + if (!TLI.shouldKeepZExtForFP16Conv() && N0->getOpcode() == ISD::AND) { ConstantSDNode *AndConst = getAsNonOpaqueConstant(N0.getOperand(1)); if (AndConst && AndConst->getAPIntValue() == 0xffff) { return DAG.getNode(ISD::FP16_TO_FP, SDLoc(N), N->getValueType(0), |