diff options
Diffstat (limited to 'llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index aea7613ceb6..4cfcbcd07a9 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -4275,7 +4275,10 @@ SDValue DAGCombiner::MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1, if (!N0.getNode()->hasOneUse()) return SDValue(); ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1)); - if (!N01C || N01C->getZExtValue() != 0xFF00) + // Also handle 0xffff since the LHS is guaranteed to have zeros there. + // This is needed for X86. + if (!N01C || (N01C->getZExtValue() != 0xFF00 && + N01C->getZExtValue() != 0xFFFF)) return SDValue(); N0 = N0.getOperand(0); LookPassAnd0 = true; @@ -4322,7 +4325,10 @@ SDValue DAGCombiner::MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1, if (!N10.getNode()->hasOneUse()) return SDValue(); ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N10.getOperand(1)); - if (!N101C || N101C->getZExtValue() != 0xFF00) + // Also allow 0xFFFF since the bits will be shifted out. This is needed + // for X86. + if (!N101C || (N101C->getZExtValue() != 0xFF00 && + N101C->getZExtValue() != 0xFFFF)) return SDValue(); N10 = N10.getOperand(0); LookPassAnd1 = true; @@ -4393,6 +4399,14 @@ static bool isBSwapHWordElement(SDValue N, MutableArrayRef<SDNode *> Parts) { return false; case 0xFF: MaskByteOffset = 0; break; case 0xFF00: MaskByteOffset = 1; break; + case 0xFFFF: + // In case demanded bits didn't clear the bits that will be shifted out. + // This is needed for X86. + if (Opc == ISD::SRL || (Opc == ISD::AND && Opc0 == ISD::SHL)) { + MaskByteOffset = 1; + break; + } + return false; case 0xFF0000: MaskByteOffset = 2; break; case 0xFF000000: MaskByteOffset = 3; break; } |
