From 9472b4fbf96fb840eb416acd00bbee173c62e8da Mon Sep 17 00:00:00 2001 From: Craig Topper Date: Sat, 8 Dec 2012 22:49:19 +0000 Subject: Teach DAG combine to handle vector logical operations with vectors of all 1s or all 0s. These cases can show up when vectors are split for legalizing. Fix some tests that were dependent on these cases not being combined. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169684 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'lib/CodeGen') diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 6cd07c2c72..4a17dc0d2c 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -2427,6 +2427,18 @@ SDValue DAGCombiner::visitAND(SDNode *N) { if (VT.isVector()) { SDValue FoldedVOp = SimplifyVBinOp(N); if (FoldedVOp.getNode()) return FoldedVOp; + + // fold (and x, 0) -> 0, vector edition + if (ISD::isBuildVectorAllZeros(N0.getNode())) + return N0; + if (ISD::isBuildVectorAllZeros(N1.getNode())) + return N1; + + // fold (and x, -1) -> x, vector edition + if (ISD::isBuildVectorAllOnes(N0.getNode())) + return N1; + if (ISD::isBuildVectorAllOnes(N1.getNode())) + return N0; } // fold (and x, undef) -> 0 @@ -3025,6 +3037,18 @@ SDValue DAGCombiner::visitOR(SDNode *N) { if (VT.isVector()) { SDValue FoldedVOp = SimplifyVBinOp(N); if (FoldedVOp.getNode()) return FoldedVOp; + + // fold (or x, 0) -> x, vector edition + if (ISD::isBuildVectorAllZeros(N0.getNode())) + return N1; + if (ISD::isBuildVectorAllZeros(N1.getNode())) + return N0; + + // fold (or x, -1) -> -1, vector edition + if (ISD::isBuildVectorAllOnes(N0.getNode())) + return N0; + if (ISD::isBuildVectorAllOnes(N1.getNode())) + return N1; } // fold (or x, undef) -> -1 @@ -3334,6 +3358,12 @@ SDValue DAGCombiner::visitXOR(SDNode *N) { if (VT.isVector()) { SDValue FoldedVOp = SimplifyVBinOp(N); if (FoldedVOp.getNode()) return FoldedVOp; + + // fold (xor x, 0) -> x, vector edition + if (ISD::isBuildVectorAllZeros(N0.getNode())) + return N1; + if (ISD::isBuildVectorAllZeros(N1.getNode())) + return N0; } // fold (xor undef, undef) -> 0. This is a common idiom (misuse). -- cgit v1.2.3-70-g09d2