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author | Eric Christopher <echristo@apple.com> | 2011-02-16 04:50:12 +0000 |
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committer | Eric Christopher <echristo@apple.com> | 2011-02-16 04:50:12 +0000 |
commit | 7bccf6abdc5de989cdb3872369480825ebc9c3a9 (patch) | |
tree | 08f15b39881ef94dc474c631ea0c6f6b07c0b935 /lib/CodeGen/SelectionDAG/DAGCombiner.cpp | |
parent | 908159b46ae118d36fccbc1d5145dcedfc3d4185 (diff) | |
download | external_llvm-7bccf6abdc5de989cdb3872369480825ebc9c3a9.zip external_llvm-7bccf6abdc5de989cdb3872369480825ebc9c3a9.tar.gz external_llvm-7bccf6abdc5de989cdb3872369480825ebc9c3a9.tar.bz2 |
Refactor zero folding slightly. Clean up todo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125651 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/SelectionDAG/DAGCombiner.cpp')
-rw-r--r-- | lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 42 |
1 files changed, 20 insertions, 22 deletions
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index e213d72..a3f3ee9 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -1518,6 +1518,22 @@ SDValue DAGCombiner::visitADDE(SDNode *N) { return SDValue(); } +// Since it may not be valid to emit a fold to zero for vector initializers +// check if we can before folding. +static SDValue tryFoldToZero(DebugLoc DL, const TargetLowering &TLI, EVT VT, + SelectionDAG &DAG, bool LegalOperations) { + if (!VT.isVector()) { + return DAG.getConstant(0, VT); + } else if (!LegalOperations || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT)) { + // Produce a vector of zeros. + SDValue El = DAG.getConstant(0, VT.getVectorElementType()); + std::vector<SDValue> Ops(VT.getVectorNumElements(), El); + return DAG.getNode(ISD::BUILD_VECTOR, DL, VT, + &Ops[0], Ops.size()); + } + return SDValue(); +} + SDValue DAGCombiner::visitSUB(SDNode *N) { SDValue N0 = N->getOperand(0); SDValue N1 = N->getOperand(1); @@ -1533,17 +1549,8 @@ SDValue DAGCombiner::visitSUB(SDNode *N) { // fold (sub x, x) -> 0 // FIXME: Refactor this and xor and other similar operations together. - if (N0 == N1) { - if (!VT.isVector()) { - return DAG.getConstant(0, VT); - } else if (!LegalOperations || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT)){ - // Produce a vector of zeros. - SDValue El = DAG.getConstant(0, VT.getVectorElementType()); - std::vector<SDValue> Ops(VT.getVectorNumElements(), El); - return DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(), VT, - &Ops[0], Ops.size()); - } - } + if (N0 == N1) + return tryFoldToZero(N->getDebugLoc(), TLI, VT, DAG, LegalOperations); // fold (sub c1, c2) -> c1-c2 if (N0C && N1C) return DAG.FoldConstantArithmetic(ISD::SUB, VT, N0C, N1C); @@ -2843,17 +2850,8 @@ SDValue DAGCombiner::visitXOR(SDNode *N) { N01C->getAPIntValue(), VT)); } // fold (xor x, x) -> 0 - if (N0 == N1) { - if (!VT.isVector()) { - return DAG.getConstant(0, VT); - } else if (!LegalOperations || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT)){ - // Produce a vector of zeros. - SDValue El = DAG.getConstant(0, VT.getVectorElementType()); - std::vector<SDValue> Ops(VT.getVectorNumElements(), El); - return DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(), VT, - &Ops[0], Ops.size()); - } - } + if (N0 == N1) + return tryFoldToZero(N->getDebugLoc(), TLI, VT, DAG, LegalOperations); // Simplify: xor (op x...), (op y...) -> (op (xor x, y)) if (N0.getOpcode() == N1.getOpcode()) { |