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| author | Nirav Dave <niravd@google.com> | 2017-07-20 13:57:32 +0000 |
|---|---|---|
| committer | Nirav Dave <niravd@google.com> | 2017-07-20 13:57:32 +0000 |
| commit | df86d2d008b22f4e8cbed14f587acc611f687961 (patch) | |
| tree | ec037c3d9ba8118a835490bd8b84f053b55e58e0 /llvm/lib/CodeGen | |
| parent | 77cc6f23b99f7693f1552470ecc0081a712c7987 (diff) | |
| download | bcm5719-llvm-df86d2d008b22f4e8cbed14f587acc611f687961.tar.gz bcm5719-llvm-df86d2d008b22f4e8cbed14f587acc611f687961.zip | |
[DAG] Handle missing transform in fold of value extension case.
Summary:
When pushing an extension of a constant bitwise operator on a load
into the load, change other uses of the load value if they exist to
prevent the old load from persisting.
Reviewers: spatel, RKSimon, efriedma
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D35030
llvm-svn: 308618
Diffstat (limited to 'llvm/lib/CodeGen')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 50cad23a00a..3658544f085 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -7316,8 +7316,15 @@ SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) { SDLoc(N0.getOperand(0)), N0.getOperand(0).getValueType(), ExtLoad); ExtendSetCCUses(SetCCs, Trunc, ExtLoad, DL, ISD::SIGN_EXTEND); + bool NoReplaceTruncAnd = !N0.hasOneUse(); bool NoReplaceTrunc = SDValue(LN0, 0).hasOneUse(); CombineTo(N, And); + // If N0 has multiple uses, change other uses as well. + if (NoReplaceTruncAnd) { + SDValue TruncAnd = + DAG.getNode(ISD::TRUNCATE, DL, N0.getValueType(), And); + CombineTo(N0.getNode(), TruncAnd); + } if (NoReplaceTrunc) DAG.ReplaceAllUsesOfValueWith(SDValue(LN0, 1), ExtLoad.getValue(1)); else @@ -7620,8 +7627,15 @@ SDValue DAGCombiner::visitZERO_EXTEND(SDNode *N) { SDLoc(N0.getOperand(0)), N0.getOperand(0).getValueType(), ExtLoad); ExtendSetCCUses(SetCCs, Trunc, ExtLoad, DL, ISD::ZERO_EXTEND); + bool NoReplaceTruncAnd = !N0.hasOneUse(); bool NoReplaceTrunc = SDValue(LN0, 0).hasOneUse(); CombineTo(N, And); + // If N0 has multiple uses, change other uses as well. + if (NoReplaceTruncAnd) { + SDValue TruncAnd = + DAG.getNode(ISD::TRUNCATE, DL, N0.getValueType(), And); + CombineTo(N0.getNode(), TruncAnd); + } if (NoReplaceTrunc) DAG.ReplaceAllUsesOfValueWith(SDValue(LN0, 1), ExtLoad.getValue(1)); else |
