[SelectionDAG] Optimize VSELECT->SETCC of incompatible or illegal types.

Don't scalarize VSELECT->SETCC when operands/results needs to be widened,
or when the type of the SETCC operands are different from those of the VSELECT.

(VSELECT SETCC) and (VSELECT (AND/OR/XOR (SETCC,SETCC))) are handled.

The previous splitting of VSELECT->SETCC in DAGCombiner::visitVSELECT() is
no longer needed and has been removed.

Updated tests:

test/CodeGen/ARM/vuzp.ll
test/CodeGen/NVPTX/f16x2-instructions.ll
test/CodeGen/X86/2011-10-19-widen_vselect.ll
test/CodeGen/X86/2011-10-21-widen-cmp.ll
test/CodeGen/X86/psubus.ll
test/CodeGen/X86/vselect-pcmp.ll

Review: Eli Friedman, Simon Pilgrim
https://reviews.llvm.org/D29489

llvm-svn: 297930

1 files changed, 0 insertions, 28 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 2d6739ce085..40ce46a0d79 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -6557,34 +6557,6 @@ SDValue DAGCombiner::visitVSELECT(SDNode *N) {
   if (SimplifySelectOps(N, N1, N2))
     return SDValue(N, 0);  // Don't revisit N.
 
-  // If the VSELECT result requires splitting and the mask is provided by a
-  // SETCC, then split both nodes and its operands before legalization. This
-  // prevents the type legalizer from unrolling SETCC into scalar comparisons
-  // and enables future optimizations (e.g. min/max pattern matching on X86).
-  if (N0.getOpcode() == ISD::SETCC) {
-    EVT VT = N->getValueType(0);
-
-    // Check if any splitting is required.
-    if (TLI.getTypeAction(*DAG.getContext(), VT) !=
-        TargetLowering::TypeSplitVector)
-      return SDValue();
-
-    SDValue Lo, Hi, CCLo, CCHi, LL, LH, RL, RH;
-    std::tie(CCLo, CCHi) = SplitVSETCC(N0.getNode(), DAG);
-    std::tie(LL, LH) = DAG.SplitVectorOperand(N, 1);
-    std::tie(RL, RH) = DAG.SplitVectorOperand(N, 2);
-
-    Lo = DAG.getNode(N->getOpcode(), DL, LL.getValueType(), CCLo, LL, RL);
-    Hi = DAG.getNode(N->getOpcode(), DL, LH.getValueType(), CCHi, LH, RH);
-
-    // Add the new VSELECT nodes to the work list in case they need to be split
-    // again.
-    AddToWorklist(Lo.getNode());
-    AddToWorklist(Hi.getNode());
-
-    return DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, Lo, Hi);
-  }
-
   // Fold (vselect (build_vector all_ones), N1, N2) -> N1
   if (ISD::isBuildVectorAllOnes(N0.getNode()))
     return N1;