Speculatively revert r97011, "Re-apply 96540 and 96556 with fixes.", again in

the hopes of fixing PPC bootstrap.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97040 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 9 insertions, 86 deletions

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 0447e3b828..7da7848930 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -4655,8 +4655,7 @@ SDValue DAGCombiner::visitBRCOND(SDNode *N) {
             DAG.DeleteNode(Trunc);
           }
           // Replace the uses of SRL with SETCC
-          WorkListRemover DeadNodes(*this);
-          DAG.ReplaceAllUsesOfValueWith(N1, SetCC, &DeadNodes);
+          DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
           removeFromWorkList(N1.getNode());
           DAG.DeleteNode(N1.getNode());
           return SDValue(N, 0);   // Return N so it doesn't get rechecked!
@@ -4664,56 +4663,6 @@ SDValue DAGCombiner::visitBRCOND(SDNode *N) {
       }
     }
   }
-  
-  // Transform br(xor(x, y)) -> br(x != y)
-  // Transform br(xor(xor(x,y), 1)) -> br (x == y)
-  if (N1.hasOneUse() && N1.getOpcode() == ISD::XOR) {
-    SDNode *TheXor = N1.getNode();
-    SDValue Op0 = TheXor->getOperand(0);
-    SDValue Op1 = TheXor->getOperand(1);
-    if (Op0.getOpcode() == Op1.getOpcode()) {
-      // Avoid missing important xor optimizations.
-      SDValue Tmp = visitXOR(TheXor);
-      if (Tmp.getNode()) {
-        DEBUG(dbgs() << "\nReplacing.8 ";
-              TheXor->dump(&DAG);
-              dbgs() << "\nWith: ";
-              Tmp.getNode()->dump(&DAG);
-              dbgs() << '\n');
-        WorkListRemover DeadNodes(*this);
-        DAG.ReplaceAllUsesOfValueWith(N1, Tmp, &DeadNodes);
-        removeFromWorkList(TheXor);
-        DAG.DeleteNode(TheXor);
-        return DAG.getNode(ISD::BRCOND, N->getDebugLoc(),
-                           MVT::Other, Chain, Tmp, N2);
-      }
-    }
-
-    if (Op0.getOpcode() != ISD::SETCC && Op1.getOpcode() != ISD::SETCC) {
-      bool Equal = false;
-      if (ConstantSDNode *RHSCI = dyn_cast<ConstantSDNode>(Op0))
-        if (RHSCI->getAPIntValue() == 1 && Op0.hasOneUse() &&
-            Op0.getOpcode() == ISD::XOR) {
-          TheXor = Op0.getNode();
-          Equal = true;
-        }
-
-      EVT SetCCVT = N1.getValueType();
-      if (LegalTypes)
-        SetCCVT = TLI.getSetCCResultType(SetCCVT);
-      SDValue SetCC = DAG.getSetCC(TheXor->getDebugLoc(),
-                                   SetCCVT,
-                                   Op0, Op1,
-                                   Equal ? ISD::SETEQ : ISD::SETNE);
-      // Replace the uses of XOR with SETCC
-      WorkListRemover DeadNodes(*this);
-      DAG.ReplaceAllUsesOfValueWith(N1, SetCC, &DeadNodes);
-      removeFromWorkList(N1.getNode());
-      DAG.DeleteNode(N1.getNode());
-      return DAG.getNode(ISD::BRCOND, N->getDebugLoc(),
-                         MVT::Other, Chain, SetCC, N2);
-    }
-  }
 
   return SDValue();
 }
@@ -5063,7 +5012,7 @@ SDValue DAGCombiner::visitLOAD(SDNode *N) {
       assert(N->getValueType(2) == MVT::Other && "Malformed indexed loads?");
       if (N->hasNUsesOfValue(0, 0) && N->hasNUsesOfValue(0, 1)) {
         SDValue Undef = DAG.getUNDEF(N->getValueType(0));
-        DEBUG(dbgs() << "\nReplacing.7 ";
+        DEBUG(dbgs() << "\nReplacing.6 ";
               N->dump(&DAG);
               dbgs() << "\nWith: ";
               Undef.getNode()->dump(&DAG);
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 96d4e20ee2..e88af4f3e0 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -1775,7 +1775,7 @@ TargetLowering::SimplifySetCC(EVT VT, SDValue N0, SDValue N1,
         break;   // todo, be more careful with signed comparisons
       }
     } else if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
-               (Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
+                (Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
       EVT ExtSrcTy = cast<VTSDNode>(N0.getOperand(1))->getVT();
       unsigned ExtSrcTyBits = ExtSrcTy.getSizeInBits();
       EVT ExtDstTy = N0.getValueType();
@@ -1809,21 +1809,22 @@ TargetLowering::SimplifySetCC(EVT VT, SDValue N0, SDValue N1,
                           Cond);
     } else if ((N1C->isNullValue() || N1C->getAPIntValue() == 1) &&
                 (Cond == ISD::SETEQ || Cond == ISD::SETNE)) {
+      
       // SETCC (SETCC), [0|1], [EQ|NE]  -> SETCC
-      if (N0.getOpcode() == ISD::SETCC &&
-          isTypeLegal(VT) && VT.bitsLE(N0.getValueType())) {
+      if (N0.getOpcode() == ISD::SETCC) {
         bool TrueWhenTrue = (Cond == ISD::SETEQ) ^ (N1C->getAPIntValue() != 1);
         if (TrueWhenTrue)
-          return DAG.getNode(ISD::TRUNCATE, dl, VT, N0);        
+          return N0;
+        
         // Invert the condition.
         ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
         CC = ISD::getSetCCInverse(CC, 
                                   N0.getOperand(0).getValueType().isInteger());
         return DAG.getSetCC(dl, VT, N0.getOperand(0), N0.getOperand(1), CC);
       }
-
+      
       if ((N0.getOpcode() == ISD::XOR ||
-           (N0.getOpcode() == ISD::AND && 
+            (N0.getOpcode() == ISD::AND && 
             N0.getOperand(0).getOpcode() == ISD::XOR &&
             N0.getOperand(1) == N0.getOperand(0).getOperand(1))) &&
           isa<ConstantSDNode>(N0.getOperand(1)) &&
@@ -1846,36 +1847,9 @@ TargetLowering::SimplifySetCC(EVT VT, SDValue N0, SDValue N1,
                               N0.getOperand(0).getOperand(0),
                               N0.getOperand(1));
           }
-
           return DAG.getSetCC(dl, VT, Val, N1,
                               Cond == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ);
         }
-      } else if (N1C->getAPIntValue() == 1) {
-        SDValue Op0 = N0;
-        if (Op0.getOpcode() == ISD::TRUNCATE)
-          Op0 = Op0.getOperand(0);
-
-        if ((Op0.getOpcode() == ISD::XOR || Op0.getOpcode() == ISD::AND) &&
-            Op0.getOperand(0).getOpcode() == ISD::SETCC &&
-            Op0.getOperand(1).getOpcode() == ISD::SETCC) {
-          // (and (setcc), (setcc)) == / != 1 -> (setcc) == / != (setcc)
-          // (xor (setcc), (setcc)) == / != 1 -> (setcc) != / == (setcc)
-          if (Op0.getOpcode() == ISD::XOR)
-            Cond = (Cond == ISD::SETEQ) ? ISD::SETNE : ISD::SETEQ;
-          return DAG.getSetCC(dl, VT, Op0.getOperand(0), Op0.getOperand(1),
-                              Cond);
-        } else if (Op0.getOpcode() == ISD::AND &&
-                isa<ConstantSDNode>(Op0.getOperand(1)) &&
-                cast<ConstantSDNode>(Op0.getOperand(1))->getAPIntValue() == 1) {
-          // If this is (X&1) == / != 1, normalize it to (X&1) != / == 0.
-          if (Op0.getValueType() != VT)
-            Op0 = DAG.getNode(ISD::AND, dl, VT,
-                          DAG.getNode(ISD::TRUNCATE, dl, VT, Op0.getOperand(0)),
-                          DAG.getConstant(1, VT));
-          return DAG.getSetCC(dl, VT, Op0,
-                              DAG.getConstant(0, Op0.getValueType()),
-                              Cond == ISD::SETEQ ? ISD::SETNE : ISD::SETEQ);
-        }
       }
     }