Don't maintain a set of deleted nodes; instead, use a HandleSDNode
to track a node over CSE events. This fixes PR7368.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106266 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp
index 492a522..8bdd123 100644
--- a/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -137,21 +137,6 @@
}
namespace {
- class X86ISelListener : public SelectionDAG::DAGUpdateListener {
- SmallSet<SDNode*, 4> Deletes;
- public:
- explicit X86ISelListener() {}
- virtual void NodeDeleted(SDNode *N, SDNode *E) {
- Deletes.insert(N);
- }
- virtual void NodeUpdated(SDNode *N) {
- // Ignore updates.
- }
- bool IsDeleted(SDNode *N) {
- return Deletes.count(N);
- }
- };
-
//===--------------------------------------------------------------------===//
/// ISel - X86 specific code to select X86 machine instructions for
/// SelectionDAG operations.
@@ -199,7 +184,6 @@
bool MatchWrapper(SDValue N, X86ISelAddressMode &AM);
bool MatchAddress(SDValue N, X86ISelAddressMode &AM);
bool MatchAddressRecursively(SDValue N, X86ISelAddressMode &AM,
- X86ISelListener &DeadNodes,
unsigned Depth);
bool MatchAddressBase(SDValue N, X86ISelAddressMode &AM);
bool SelectAddr(SDNode *Op, SDValue N, SDValue &Base,
@@ -664,8 +648,7 @@
/// returning true if it cannot be done. This just pattern matches for the
/// addressing mode.
bool X86DAGToDAGISel::MatchAddress(SDValue N, X86ISelAddressMode &AM) {
- X86ISelListener DeadNodes;
- if (MatchAddressRecursively(N, AM, DeadNodes, 0))
+ if (MatchAddressRecursively(N, AM, 0))
return true;
// Post-processing: Convert lea(,%reg,2) to lea(%reg,%reg), which has
@@ -713,7 +696,6 @@
}
bool X86DAGToDAGISel::MatchAddressRecursively(SDValue N, X86ISelAddressMode &AM,
- X86ISelListener &DeadNodes,
unsigned Depth) {
bool is64Bit = Subtarget->is64Bit();
DebugLoc dl = N.getDebugLoc();
@@ -876,13 +858,13 @@
// other uses, since it avoids a two-address sub instruction, however
// it costs an additional mov if the index register has other uses.
+ // Add an artificial use to this node so that we can keep track of
+ // it if it gets CSE'd with a different node.
+ HandleSDNode Handle(N);
+
// Test if the LHS of the sub can be folded.
X86ISelAddressMode Backup = AM;
- if (MatchAddressRecursively(N.getNode()->getOperand(0), AM,
- DeadNodes, Depth+1) ||
- // If it is successful but the recursive update causes N to be deleted,
- // then it's not safe to continue.
- DeadNodes.IsDeleted(N.getNode())) {
+ if (MatchAddressRecursively(N.getNode()->getOperand(0), AM, Depth+1)) {
AM = Backup;
break;
}
@@ -893,7 +875,7 @@
}
int Cost = 0;
- SDValue RHS = N.getNode()->getOperand(1);
+ SDValue RHS = Handle.getValue().getNode()->getOperand(1);
// If the RHS involves a register with multiple uses, this
// transformation incurs an extra mov, due to the neg instruction
// clobbering its operand.
@@ -944,35 +926,27 @@
}
case ISD::ADD: {
+ // Add an artificial use to this node so that we can keep track of
+ // it if it gets CSE'd with a different node.
+ HandleSDNode Handle(N);
+ SDValue LHS = Handle.getValue().getNode()->getOperand(0);
+ SDValue RHS = Handle.getValue().getNode()->getOperand(1);
+
X86ISelAddressMode Backup = AM;
- if (!MatchAddressRecursively(N.getNode()->getOperand(0), AM,
- DeadNodes, Depth+1)) {
- if (DeadNodes.IsDeleted(N.getNode()))
- // If it is successful but the recursive update causes N to be deleted,
- // then it's not safe to continue.
- return true;
- if (!MatchAddressRecursively(N.getNode()->getOperand(1), AM,
- DeadNodes, Depth+1))
- // If it is successful but the recursive update causes N to be deleted,
- // then it's not safe to continue.
- return DeadNodes.IsDeleted(N.getNode());
- }
+ if (!MatchAddressRecursively(LHS, AM, Depth+1) &&
+ !MatchAddressRecursively(RHS, AM, Depth+1))
+ return false;
+ AM = Backup;
+ LHS = Handle.getValue().getNode()->getOperand(0);
+ RHS = Handle.getValue().getNode()->getOperand(1);
// Try again after commuting the operands.
+ if (!MatchAddressRecursively(RHS, AM, Depth+1) &&
+ !MatchAddressRecursively(LHS, AM, Depth+1))
+ return false;
AM = Backup;
- if (!MatchAddressRecursively(N.getNode()->getOperand(1), AM,
- DeadNodes, Depth+1)) {
- if (DeadNodes.IsDeleted(N.getNode()))
- // If it is successful but the recursive update causes N to be deleted,
- // then it's not safe to continue.
- return true;
- if (!MatchAddressRecursively(N.getNode()->getOperand(0), AM,
- DeadNodes, Depth+1))
- // If it is successful but the recursive update causes N to be deleted,
- // then it's not safe to continue.
- return DeadNodes.IsDeleted(N.getNode());
- }
- AM = Backup;
+ LHS = Handle.getValue().getNode()->getOperand(0);
+ RHS = Handle.getValue().getNode()->getOperand(1);
// If we couldn't fold both operands into the address at the same time,
// see if we can just put each operand into a register and fold at least
@@ -980,8 +954,8 @@
if (AM.BaseType == X86ISelAddressMode::RegBase &&
!AM.Base_Reg.getNode() &&
!AM.IndexReg.getNode()) {
- AM.Base_Reg = N.getNode()->getOperand(0);
- AM.IndexReg = N.getNode()->getOperand(1);
+ AM.Base_Reg = LHS;
+ AM.IndexReg = RHS;
AM.Scale = 1;
return false;
}
@@ -996,7 +970,7 @@
uint64_t Offset = CN->getSExtValue();
// Start with the LHS as an addr mode.
- if (!MatchAddressRecursively(N.getOperand(0), AM, DeadNodes, Depth+1) &&
+ if (!MatchAddressRecursively(N.getOperand(0), AM, Depth+1) &&
// Address could not have picked a GV address for the displacement.
AM.GV == NULL &&
// On x86-64, the resultant disp must fit in 32-bits.
@@ -1073,7 +1047,7 @@
CurDAG->RepositionNode(N.getNode(), Shl.getNode());
Shl.getNode()->setNodeId(N.getNode()->getNodeId());
}
- CurDAG->ReplaceAllUsesWith(N, Shl, &DeadNodes);
+ CurDAG->ReplaceAllUsesWith(N, Shl);
AM.IndexReg = And;
AM.Scale = (1 << ScaleLog);
return false;
@@ -1124,7 +1098,7 @@
NewSHIFT.getNode()->setNodeId(N.getNode()->getNodeId());
}
- CurDAG->ReplaceAllUsesWith(N, NewSHIFT, &DeadNodes);
+ CurDAG->ReplaceAllUsesWith(N, NewSHIFT);
AM.Scale = 1 << ShiftCst;
AM.IndexReg = NewAND;