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author | Michael Liao <michael.liao@intel.com> | 2012-10-19 17:15:18 +0000 |
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committer | Michael Liao <michael.liao@intel.com> | 2012-10-19 17:15:18 +0000 |
commit | facace808cc5f83067a05c4c319f98fd75336f47 (patch) | |
tree | 5a93a1a3afb28ec1bb2ac672b867740c96509abb /lib/Target/X86/X86ISelLowering.cpp | |
parent | 239fd44f7a68aae4b2e8b6f1738ef9e8fd4ddc01 (diff) | |
download | llvm-facace808cc5f83067a05c4c319f98fd75336f47.tar.gz llvm-facace808cc5f83067a05c4c319f98fd75336f47.tar.bz2 llvm-facace808cc5f83067a05c4c319f98fd75336f47.tar.xz |
Lower BUILD_VECTOR to SHUFFLE + INSERT_VECTOR_ELT for X86
- If INSERT_VECTOR_ELT is supported (above SSE2, either by custom
sequence of legal insn), transform BUILD_VECTOR into SHUFFLE +
INSERT_VECTOR_ELT if most of elements could be built from SHUFFLE with few
(so far 1) elements being inserted.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166288 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/X86/X86ISelLowering.cpp')
-rw-r--r-- | lib/Target/X86/X86ISelLowering.cpp | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp index a205aef742..2e77e64f2f 100644 --- a/lib/Target/X86/X86ISelLowering.cpp +++ b/lib/Target/X86/X86ISelLowering.cpp @@ -5176,6 +5176,80 @@ X86TargetLowering::LowerVectorBroadcast(SDValue Op, SelectionDAG &DAG) const { } SDValue +X86TargetLowering::buildFromShuffleMostly(SDValue Op, SelectionDAG &DAG) const { + EVT VT = Op.getValueType(); + + // Skip if insert_vec_elt is not supported. + if (!isOperationLegalOrCustom(ISD::INSERT_VECTOR_ELT, VT)) + return SDValue(); + + DebugLoc DL = Op.getDebugLoc(); + unsigned NumElems = Op.getNumOperands(); + + SDValue VecIn1; + SDValue VecIn2; + SmallVector<unsigned, 4> InsertIndices; + SmallVector<int, 8> Mask(NumElems, -1); + + for (unsigned i = 0; i != NumElems; ++i) { + unsigned Opc = Op.getOperand(i).getOpcode(); + + if (Opc == ISD::UNDEF) + continue; + + if (Opc != ISD::EXTRACT_VECTOR_ELT) { + // Quit if more than 1 elements need inserting. + if (InsertIndices.size() > 1) + return SDValue(); + + InsertIndices.push_back(i); + continue; + } + + SDValue ExtractedFromVec = Op.getOperand(i).getOperand(0); + SDValue ExtIdx = Op.getOperand(i).getOperand(1); + + // Quit if extracted from vector of different type. + if (ExtractedFromVec.getValueType() != VT) + return SDValue(); + + // Quit if non-constant index. + if (!isa<ConstantSDNode>(ExtIdx)) + return SDValue(); + + if (VecIn1.getNode() == 0) + VecIn1 = ExtractedFromVec; + else if (VecIn1 != ExtractedFromVec) { + if (VecIn2.getNode() == 0) + VecIn2 = ExtractedFromVec; + else if (VecIn2 != ExtractedFromVec) + // Quit if more than 2 vectors to shuffle + return SDValue(); + } + + unsigned Idx = cast<ConstantSDNode>(ExtIdx)->getZExtValue(); + + if (ExtractedFromVec == VecIn1) + Mask[i] = Idx; + else if (ExtractedFromVec == VecIn2) + Mask[i] = Idx + NumElems; + } + + if (VecIn1.getNode() == 0) + return SDValue(); + + VecIn2 = VecIn2.getNode() ? VecIn2 : DAG.getUNDEF(VT); + SDValue NV = DAG.getVectorShuffle(VT, DL, VecIn1, VecIn2, &Mask[0]); + for (unsigned i = 0, e = InsertIndices.size(); i != e; ++i) { + unsigned Idx = InsertIndices[i]; + NV = DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, VT, NV, Op.getOperand(Idx), + DAG.getIntPtrConstant(Idx)); + } + + return NV; +} + +SDValue X86TargetLowering::LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG) const { DebugLoc dl = Op.getDebugLoc(); @@ -5451,6 +5525,11 @@ X86TargetLowering::LowerBUILD_VECTOR(SDValue Op, SelectionDAG &DAG) const { if (LD.getNode()) return LD; + // Check for a build vector from mostly shuffle plus few inserting. + SDValue Sh = buildFromShuffleMostly(Op, DAG); + if (Sh.getNode()) + return Sh; + // For SSE 4.1, use insertps to put the high elements into the low element. if (getSubtarget()->hasSSE41()) { SDValue Result; |