diff options
Diffstat (limited to 'llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index 1a73a01cc49..d98c609ab3a 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -5078,6 +5078,7 @@ SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT, break; } case ISD::SELECT: + case ISD::VSELECT: if (SDValue V = simplifySelect(N1, N2, N3)) return V; break; @@ -6790,11 +6791,18 @@ SDValue SelectionDAG::simplifySelect(SDValue Cond, SDValue T, SDValue F) { if (F.isUndef()) return T; - // fold (select true, T, F) -> T - // fold (select false, T, F) -> F + // select true, T, F --> T + // select false, T, F --> F if (auto *CondC = dyn_cast<ConstantSDNode>(Cond)) return CondC->isNullValue() ? F : T; + // TODO: This should simplify VSELECT with constant condition using something + // like this (but check boolean contents to be complete?): + // if (ISD::isBuildVectorAllOnes(Cond.getNode())) + // return T; + // if (ISD::isBuildVectorAllZeros(Cond.getNode())) + // return F; + // select ?, T, T --> T if (T == F) return T; |
