Re-apply 97040 with fix. This survives a ppc self-host llvm-gcc bootstrap.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97310 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 7da7848..0447e3b 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -4655,7 +4655,8 @@
DAG.DeleteNode(Trunc);
}
// Replace the uses of SRL with SETCC
- DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
+ WorkListRemover DeadNodes(*this);
+ DAG.ReplaceAllUsesOfValueWith(N1, SetCC, &DeadNodes);
removeFromWorkList(N1.getNode());
DAG.DeleteNode(N1.getNode());
return SDValue(N, 0); // Return N so it doesn't get rechecked!
@@ -4663,6 +4664,56 @@
}
}
}
+
+ // 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();
}
@@ -5012,7 +5063,7 @@
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.6 ";
+ DEBUG(dbgs() << "\nReplacing.7 ";
N->dump(&DAG);
dbgs() << "\nWith: ";
Undef.getNode()->dump(&DAG);