diff options
Diffstat (limited to 'llvm/lib/CodeGen')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index bd11c5aa1b3..5a5a81e8f6e 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -2631,12 +2631,16 @@ SDValue DAGCombiner::visitMUL(SDNode *N) { DAG.getConstant(0, DL, VT), N0); } // fold (mul x, (1 << c)) -> x << c - if (N1IsConst && !N1IsOpaqueConst && ConstValue1.isPowerOf2() && - IsFullSplat) { + if (isConstantOrConstantVector(N1, /*NoOpaques*/ true) && + DAG.isKnownToBeAPowerOfTwo(N1)) { SDLoc DL(N); - return DAG.getNode(ISD::SHL, DL, VT, N0, - DAG.getConstant(ConstValue1.logBase2(), DL, - getShiftAmountTy(N0.getValueType()))); + SDValue LogBase2 = BuildLogBase2(N1, DL); + AddToWorklist(LogBase2.getNode()); + + EVT ShiftVT = getShiftAmountTy(N0.getValueType()); + SDValue Trunc = DAG.getZExtOrTrunc(LogBase2, DL, ShiftVT); + AddToWorklist(Trunc.getNode()); + return DAG.getNode(ISD::SHL, DL, VT, N0, Trunc); } // fold (mul x, -(1 << c)) -> -(x << c) or (-x) << c if (N1IsConst && !N1IsOpaqueConst && (-ConstValue1).isPowerOf2() && |
