diff options
| -rw-r--r-- | lib/CodeGen/SelectionDAG/LegalizeDAG.cpp | 37 | ||||
| -rw-r--r-- | test/CodeGen/PowerPC/vsx.ll | 6 |
2 files changed, 39 insertions, 4 deletions
diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp index 74c01cae43..608de82265 100644 --- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp +++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp @@ -1394,10 +1394,39 @@ SDValue SelectionDAGLegalize::ExpandExtractFromVectorThroughStack(SDValue Op) { SDValue Vec = Op.getOperand(0); SDValue Idx = Op.getOperand(1); SDLoc dl(Op); - // Store the value to a temporary stack slot, then LOAD the returned part. - SDValue StackPtr = DAG.CreateStackTemporary(Vec.getValueType()); - SDValue Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr, - MachinePointerInfo(), false, false, 0); + + // Before we generate a new store to a temporary stack slot, see if there is + // already one that we can use. There often is because when we scalarize + // vector operations (using SelectionDAG::UnrollVectorOp for example) a whole + // series of EXTRACT_VECTOR_ELT nodes are generated, one for each element in + // the vector. If all are expanded here, we don't want one store per vector + // element. + SDValue StackPtr, Ch; + for (SDNode::use_iterator UI = Vec.getNode()->use_begin(), + UE = Vec.getNode()->use_end(); UI != UE; ++UI) { + SDNode *User = *UI; + if (StoreSDNode *ST = dyn_cast<StoreSDNode>(User)) { + if (ST->isIndexed() || ST->isTruncatingStore() || + ST->getValue() != Vec) + continue; + + // Make sure that nothing else could have stored into the destination of + // this store. + if (!ST->getChain().reachesChainWithoutSideEffects(DAG.getEntryNode())) + continue; + + StackPtr = ST->getBasePtr(); + Ch = SDValue(ST, 0); + break; + } + } + + if (!Ch.getNode()) { + // Store the value to a temporary stack slot, then LOAD the returned part. + StackPtr = DAG.CreateStackTemporary(Vec.getValueType()); + Ch = DAG.getStore(DAG.getEntryNode(), dl, Vec, StackPtr, + MachinePointerInfo(), false, false, 0); + } // Add the offset to the index. unsigned EltSize = diff --git a/test/CodeGen/PowerPC/vsx.ll b/test/CodeGen/PowerPC/vsx.ll index 99796a9cd7..d0ff0f2829 100644 --- a/test/CodeGen/PowerPC/vsx.ll +++ b/test/CodeGen/PowerPC/vsx.ll @@ -281,6 +281,12 @@ define <2 x i64> @test26(<2 x i64> %a, <2 x i64> %b) { ret <2 x i64> %v ; CHECK-LABEL: @test26 + +; Make sure we use only two stores (one for each operand). +; CHECK: stxvd2x 35, +; CHECK: stxvd2x 34, +; CHECK-NOT: stxvd2x + ; FIXME: The code quality here is not good; just make sure we do something for now. ; CHECK: add ; CHECK: add |