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authorEvan Cheng <evan.cheng@apple.com>2010-03-17 23:58:35 +0000
committerEvan Cheng <evan.cheng@apple.com>2010-03-17 23:58:35 +0000
commitf3caa525cc887b696df8e8a8d9ddb03515d1695a (patch)
tree30c6e7404069593e30ca58c14d740db12bfd1cc1 /lib
parentc3188ce0f1ff2d1b830702a93134905b9719f410 (diff)
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X86 address mode matching code MatchAddressRecursively does some aggressive hack which require doing a RAUW. It may end up deleting some SDNode up stream. It should avoid referencing deleted nodes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98780 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
-rw-r--r--lib/Target/X86/X86ISelDAGToDAG.cpp74
1 files changed, 60 insertions, 14 deletions
diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp
index 4058885..1c0ed7e 100644
--- a/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -140,6 +140,21 @@ namespace {
}
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.
@@ -187,6 +202,7 @@ namespace {
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,
@@ -651,7 +667,8 @@ bool X86DAGToDAGISel::MatchWrapper(SDValue N, X86ISelAddressMode &AM) {
/// returning true if it cannot be done. This just pattern matches for the
/// addressing mode.
bool X86DAGToDAGISel::MatchAddress(SDValue N, X86ISelAddressMode &AM) {
- if (MatchAddressRecursively(N, AM, 0))
+ X86ISelListener DeadNodes;
+ if (MatchAddressRecursively(N, AM, DeadNodes, 0))
return true;
// Post-processing: Convert lea(,%reg,2) to lea(%reg,%reg), which has
@@ -680,6 +697,7 @@ bool X86DAGToDAGISel::MatchAddress(SDValue N, X86ISelAddressMode &AM) {
}
bool X86DAGToDAGISel::MatchAddressRecursively(SDValue N, X86ISelAddressMode &AM,
+ X86ISelListener &DeadNodes,
unsigned Depth) {
bool is64Bit = Subtarget->is64Bit();
DebugLoc dl = N.getDebugLoc();
@@ -845,7 +863,11 @@ bool X86DAGToDAGISel::MatchAddressRecursively(SDValue N, X86ISelAddressMode &AM,
// Test if the LHS of the sub can be folded.
X86ISelAddressMode Backup = AM;
- if (MatchAddressRecursively(N.getNode()->getOperand(0), AM, Depth+1)) {
+ 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())) {
AM = Backup;
break;
}
@@ -854,6 +876,7 @@ bool X86DAGToDAGISel::MatchAddressRecursively(SDValue N, X86ISelAddressMode &AM,
AM = Backup;
break;
}
+
int Cost = 0;
SDValue RHS = N.getNode()->getOperand(1);
// If the RHS involves a register with multiple uses, this
@@ -907,13 +930,33 @@ bool X86DAGToDAGISel::MatchAddressRecursively(SDValue N, X86ISelAddressMode &AM,
case ISD::ADD: {
X86ISelAddressMode Backup = AM;
- if (!MatchAddressRecursively(N.getNode()->getOperand(0), AM, Depth+1) &&
- !MatchAddressRecursively(N.getNode()->getOperand(1), AM, Depth+1))
- return false;
+ 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());
+ }
+
+ // Try again after commuting the operands.
AM = Backup;
- if (!MatchAddressRecursively(N.getNode()->getOperand(1), AM, Depth+1) &&
- !MatchAddressRecursively(N.getNode()->getOperand(0), AM, Depth+1))
- return false;
+ 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;
// If we couldn't fold both operands into the address at the same time,
@@ -935,16 +978,19 @@ bool X86DAGToDAGISel::MatchAddressRecursively(SDValue N, X86ISelAddressMode &AM,
if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N.getOperand(1))) {
X86ISelAddressMode Backup = AM;
uint64_t Offset = CN->getSExtValue();
+
+ // Check to see if the LHS & C is zero.
+ if (!CurDAG->MaskedValueIsZero(N.getOperand(0), CN->getAPIntValue()))
+ break;
+
// Start with the LHS as an addr mode.
- if (!MatchAddressRecursively(N.getOperand(0), AM, Depth+1) &&
+ if (!MatchAddressRecursively(N.getOperand(0), AM, DeadNodes, 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.
(!is64Bit ||
X86::isOffsetSuitableForCodeModel(AM.Disp + Offset, M,
- AM.hasSymbolicDisplacement())) &&
- // Check to see if the LHS & C is zero.
- CurDAG->MaskedValueIsZero(N.getOperand(0), CN->getAPIntValue())) {
+ AM.hasSymbolicDisplacement()))) {
AM.Disp += Offset;
return false;
}
@@ -1015,7 +1061,7 @@ bool X86DAGToDAGISel::MatchAddressRecursively(SDValue N, X86ISelAddressMode &AM,
CurDAG->RepositionNode(N.getNode(), Shl.getNode());
Shl.getNode()->setNodeId(N.getNode()->getNodeId());
}
- CurDAG->ReplaceAllUsesWith(N, Shl);
+ CurDAG->ReplaceAllUsesWith(N, Shl, &DeadNodes);
AM.IndexReg = And;
AM.Scale = (1 << ScaleLog);
return false;
@@ -1066,7 +1112,7 @@ bool X86DAGToDAGISel::MatchAddressRecursively(SDValue N, X86ISelAddressMode &AM,
NewSHIFT.getNode()->setNodeId(N.getNode()->getNodeId());
}
- CurDAG->ReplaceAllUsesWith(N, NewSHIFT);
+ CurDAG->ReplaceAllUsesWith(N, NewSHIFT, &DeadNodes);
AM.Scale = 1 << ShiftCst;
AM.IndexReg = NewAND;
generated by cgit v1.1 at 2025-03-14 21:25:32 +0000