[llvm] r344132 - [TargetLowering] Add root node back to work list after successful SimplifyDemandedBits/SimplifyDemandedVectorElts

[Simon Pilgrim via llvm-commits]

Author: rksimon
Date: Wed Oct 10 03:44:15 2018
New Revision: 344132

URL: http://llvm.org/viewvc/llvm-project?rev=344132&view=rev
Log:
[TargetLowering] Add root node back to work list after successful SimplifyDemandedBits/SimplifyDemandedVectorElts

Similar to what already happens in the DAGCombiner wrappers, this patch adds the root nodes back onto the worklist if the DCI wrappers' SimplifyDemandedBits/SimplifyDemandedVectorElts were successful.

Differential Revision: https://reviews.llvm.org/D53026

Modified:
    llvm/trunk/include/llvm/CodeGen/TargetLowering.h
    llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp

Modified: llvm/trunk/include/llvm/CodeGen/TargetLowering.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/TargetLowering.h?rev=344132&r1=344131&r2=344132&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/TargetLowering.h (original)
+++ llvm/trunk/include/llvm/CodeGen/TargetLowering.h Wed Oct 10 03:44:15 2018
@@ -2846,7 +2846,8 @@ public:
                             unsigned Depth = 0,
                             bool AssumeSingleUse = false) const;
 
-  /// Helper wrapper around SimplifyDemandedBits
+  /// Helper wrapper around SimplifyDemandedBits.
+  /// Adds Op back to the worklist upon success.
   bool SimplifyDemandedBits(SDValue Op, const APInt &DemandedMask,
                             DAGCombinerInfo &DCI) const;
 
@@ -2869,7 +2870,8 @@ public:
                                   TargetLoweringOpt &TLO, unsigned Depth = 0,
                                   bool AssumeSingleUse = false) const;
 
-  /// Helper wrapper around SimplifyDemandedVectorElts
+  /// Helper wrapper around SimplifyDemandedVectorElts.
+  /// Adds Op back to the worklist upon success.
   bool SimplifyDemandedVectorElts(SDValue Op, const APInt &DemandedElts,
                                   APInt &KnownUndef, APInt &KnownZero,
                                   DAGCombinerInfo &DCI) const;

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp?rev=344132&r1=344131&r2=344132&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp Wed Oct 10 03:44:15 2018
@@ -490,8 +490,10 @@ bool TargetLowering::SimplifyDemandedBit
   KnownBits Known;
 
   bool Simplified = SimplifyDemandedBits(Op, DemandedMask, Known, TLO);
-  if (Simplified)
+  if (Simplified) {
+    DCI.AddToWorklist(Op.getNode());
     DCI.CommitTargetLoweringOpt(TLO);
+  }
   return Simplified;
 }
 
@@ -1359,8 +1361,10 @@ bool TargetLowering::SimplifyDemandedVec
 
   bool Simplified =
       SimplifyDemandedVectorElts(Op, DemandedElts, KnownUndef, KnownZero, TLO);
-  if (Simplified)
+  if (Simplified) {
+    DCI.AddToWorklist(Op.getNode());
     DCI.CommitTargetLoweringOpt(TLO);
+  }
   return Simplified;
 }
 

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=344132&r1=344131&r2=344132&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Wed Oct 10 03:44:15 2018
@@ -36534,16 +36534,10 @@ static SDValue combineMaskedStore(SDNode
     // simplify ops leading up to it. We only demand the MSB of each lane.
     SDValue Mask = Mst->getMask();
     if (Mask.getScalarValueSizeInBits() != 1) {
-      TargetLowering::TargetLoweringOpt TLO(DAG, !DCI.isBeforeLegalize(),
-                                            !DCI.isBeforeLegalizeOps());
       const TargetLowering &TLI = DAG.getTargetLoweringInfo();
       APInt DemandedMask(APInt::getSignMask(VT.getScalarSizeInBits()));
-      KnownBits Known;
-      if (TLI.SimplifyDemandedBits(Mask, DemandedMask, Known, TLO)) {
-        DCI.AddToWorklist(Mask.getNode());
-        DCI.CommitTargetLoweringOpt(TLO);
+      if (TLI.SimplifyDemandedBits(Mask, DemandedMask, DCI))
         return SDValue(N, 0);
-      }
     }
 
     // TODO: AVX512 targets should also be able to simplify something like the
@@ -38962,16 +38956,10 @@ static SDValue combineGatherScatter(SDNo
   // With AVX2 we only demand the upper bit of the mask.
   if (!Subtarget.hasAVX512()) {
     const TargetLowering &TLI = DAG.getTargetLoweringInfo();
-    TargetLowering::TargetLoweringOpt TLO(DAG, !DCI.isBeforeLegalize(),
-                                          !DCI.isBeforeLegalizeOps());
     SDValue Mask = N->getOperand(2);
-    KnownBits Known;
     APInt DemandedMask(APInt::getSignMask(Mask.getScalarValueSizeInBits()));
-    if (TLI.SimplifyDemandedBits(Mask, DemandedMask, Known, TLO)) {
-      DCI.AddToWorklist(Mask.getNode());
-      DCI.CommitTargetLoweringOpt(TLO);
+    if (TLI.SimplifyDemandedBits(Mask, DemandedMask, DCI))
       return SDValue(N, 0);
-    }
   }
 
   return SDValue();