diff options
Diffstat (limited to 'llvm/lib/Target/X86/X86ISelLowering.cpp')
| -rw-r--r-- | llvm/lib/Target/X86/X86ISelLowering.cpp | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp index 4b6ab745828..ce9b0a89c0e 100644 --- a/llvm/lib/Target/X86/X86ISelLowering.cpp +++ b/llvm/lib/Target/X86/X86ISelLowering.cpp @@ -14399,6 +14399,14 @@ static SDValue PerformEXTRACT_VECTOR_ELTCombine(SDNode *N, SelectionDAG &DAG, return NewOp; SDValue InputVector = N->getOperand(0); + // Detect whether we are trying to convert from mmx to i32 and the bitcast + // from mmx to v2i32 has a single usage. + if (InputVector.getNode()->getOpcode() == llvm::ISD::BITCAST && + InputVector.getNode()->getOperand(0).getValueType() == MVT::x86mmx && + InputVector.hasOneUse() && N->getValueType(0) == MVT::i32) + return DAG.getNode(X86ISD::MMX_MOVD2W, InputVector.getDebugLoc(), + N->getValueType(0), + InputVector.getNode()->getOperand(0)); // Only operate on vectors of 4 elements, where the alternative shuffling // gets to be more expensive. |
