Add a bunch of calls to RemoveDeadNode in LegalizeDAG, so legalization doesn't get confused by CSE later on. Fixes PR11318.
Re-commit of r144034, with an extra fix so that RemoveDeadNode doesn't blow up.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144055 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 7425669..9cce6fe 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -285,6 +285,7 @@
Result = DAG.getStore(Chain, dl, Result, Ptr, ST->getPointerInfo(),
ST->isVolatile(), ST->isNonTemporal(), Alignment);
DAG.ReplaceAllUsesWith(SDValue(ST, 0), Result, DUL);
+ DAG.RemoveDeadNode(ST, DUL);
return;
}
// Do a (aligned) store to a stack slot, then copy from the stack slot
@@ -349,6 +350,7 @@
DAG.getNode(ISD::TokenFactor, dl, MVT::Other, &Stores[0],
Stores.size());
DAG.ReplaceAllUsesWith(SDValue(ST, 0), Result, DUL);
+ DAG.RemoveDeadNode(ST, DUL);
return;
}
assert(ST->getMemoryVT().isInteger() &&
@@ -381,6 +383,7 @@
SDValue Result =
DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Store1, Store2);
DAG.ReplaceAllUsesWith(SDValue(ST, 0), Result, DUL);
+ DAG.RemoveDeadNode(ST, DUL);
}
/// ExpandUnalignedLoad - Expands an unaligned load to 2 half-size loads.
@@ -1144,6 +1147,7 @@
if (!ST->isTruncatingStore()) {
if (SDNode *OptStore = OptimizeFloatStore(ST).getNode()) {
DAG.ReplaceAllUsesWith(ST, OptStore, this);
+ DAG.RemoveDeadNode(ST, this);
break;
}
@@ -1169,8 +1173,10 @@
break;
case TargetLowering::Custom:
Tmp1 = TLI.LowerOperation(SDValue(Node, 0), DAG);
- if (Tmp1.getNode())
+ if (Tmp1.getNode()) {
DAG.ReplaceAllUsesWith(SDValue(Node, 0), Tmp1, this);
+ DAG.RemoveDeadNode(Node, this);
+ }
break;
case TargetLowering::Promote: {
assert(VT.isVector() && "Unknown legal promote case!");
@@ -1181,6 +1187,7 @@
ST->getPointerInfo(), isVolatile,
isNonTemporal, Alignment);
DAG.ReplaceAllUsesWith(SDValue(Node, 0), Result, this);
+ DAG.RemoveDeadNode(Node, this);
break;
}
}
@@ -1203,6 +1210,7 @@
DAG.getTruncStore(Tmp1, dl, Tmp3, Tmp2, ST->getPointerInfo(),
NVT, isVolatile, isNonTemporal, Alignment);
DAG.ReplaceAllUsesWith(SDValue(Node, 0), Result, this);
+ DAG.RemoveDeadNode(Node, this);
} else if (StWidth & (StWidth - 1)) {
// If not storing a power-of-2 number of bits, expand as two stores.
assert(!StVT.isVector() && "Unsupported truncstore!");
@@ -1258,6 +1266,7 @@
// The order of the stores doesn't matter.
SDValue Result = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
DAG.ReplaceAllUsesWith(SDValue(Node, 0), Result, this);
+ DAG.RemoveDeadNode(Node, this);
} else {
if (Tmp1 != ST->getChain() || Tmp3 != ST->getValue() ||
Tmp2 != ST->getBasePtr())
@@ -1280,6 +1289,7 @@
DAG.ReplaceAllUsesWith(SDValue(Node, 0),
TLI.LowerOperation(SDValue(Node, 0), DAG),
this);
+ DAG.RemoveDeadNode(Node, this);
break;
case TargetLowering::Expand:
assert(!StVT.isVector() &&
@@ -1292,6 +1302,7 @@
DAG.getStore(Tmp1, dl, Tmp3, Tmp2, ST->getPointerInfo(),
isVolatile, isNonTemporal, Alignment);
DAG.ReplaceAllUsesWith(SDValue(Node, 0), Result, this);
+ DAG.RemoveDeadNode(Node, this);
break;
}
}
@@ -3361,6 +3372,7 @@
DAG.getNode(ISD::BUILD_VECTOR, dl, Node->getValueType(0),
&Scalars[0], Scalars.size());
DAG.ReplaceAllUsesWith(SDValue(Node, 0), Result, this);
+ DAG.RemoveDeadNode(Node, this);
break;
}
case ISD::GLOBAL_OFFSET_TABLE:
@@ -3377,8 +3389,10 @@
}
// Replace the original node with the legalized result.
- if (!Results.empty())
+ if (!Results.empty()) {
DAG.ReplaceAllUsesWith(Node, Results.data(), this);
+ DAG.RemoveDeadNode(Node, this);
+ }
}
void SelectionDAGLegalize::PromoteNode(SDNode *Node) {
@@ -3512,8 +3526,10 @@
}
// Replace the original node with the legalized result.
- if (!Results.empty())
+ if (!Results.empty()) {
DAG.ReplaceAllUsesWith(Node, Results.data(), this);
+ DAG.RemoveDeadNode(Node, this);
+ }
}
// SelectionDAG::Legalize - This is the entry point for the file.
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 010a740..b3f94a4 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -564,6 +564,12 @@
void SelectionDAG::RemoveDeadNode(SDNode *N, DAGUpdateListener *UpdateListener){
SmallVector<SDNode*, 16> DeadNodes(1, N);
+
+ // Create a dummy node that adds a reference to the root node, preventing
+ // it from being deleted. (This matters if the root is an operand of the
+ // dead node.)
+ HandleSDNode Dummy(getRoot());
+
RemoveDeadNodes(DeadNodes, UpdateListener);
}