diff options
Diffstat (limited to 'llvm/lib/Target/X86')
| -rw-r--r-- | llvm/lib/Target/X86/X86ISelLowering.cpp | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp index 75d8f35ee80..7d840cedeb8 100644 --- a/llvm/lib/Target/X86/X86ISelLowering.cpp +++ b/llvm/lib/Target/X86/X86ISelLowering.cpp @@ -31234,6 +31234,23 @@ static SDValue combineSIntToFP(SDNode *N, SelectionDAG &DAG, return DAG.getNode(ISD::SINT_TO_FP, dl, VT, P); } + // Without AVX512DQ we only support i64 to float scalar conversion. For both + // vectors and scalars, see if we know that the upper bits are all the sign + // bit, in which case we can truncate the input to i32 and convert from that. + if (InVT.getScalarSizeInBits() > 32 && !Subtarget.hasDQI()) { + unsigned BitWidth = InVT.getScalarSizeInBits(); + unsigned NumSignBits = DAG.ComputeNumSignBits(Op0); + if (NumSignBits >= (BitWidth - 31)) { + EVT TruncVT = EVT::getIntegerVT(*DAG.getContext(), 32); + if (InVT.isVector()) + TruncVT = EVT::getVectorVT(*DAG.getContext(), TruncVT, + InVT.getVectorNumElements()); + SDLoc dl(N); + SDValue Trunc = DAG.getNode(ISD::TRUNCATE, dl, TruncVT, Op0); + return DAG.getNode(ISD::SINT_TO_FP, dl, VT, Trunc); + } + } + // Transform (SINT_TO_FP (i64 ...)) into an x87 operation if we have // a 32-bit target where SSE doesn't support i64->FP operations. if (!Subtarget.useSoftFloat() && Op0.getOpcode() == ISD::LOAD) { |
