[llvm-commits] [llvm] r55549 - /llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
Evan Cheng
evan.cheng at apple.com
Fri Aug 29 15:21:44 PDT 2008
Author: evancheng
Date: Fri Aug 29 17:21:44 2008
New Revision: 55549
URL: http://llvm.org/viewvc/llvm-project?rev=55549&view=rev
Log:
Back out 55498. It broken Apple style bootstrapping.
Modified:
llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=55549&r1=55548&r2=55549&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Fri Aug 29 17:21:44 2008
@@ -53,31 +53,12 @@
bool AfterLegalize;
bool Fast;
- // Create a dummy node (which is not added to allnodes), that adds a reference
- // to the root node, preventing it from being deleted, and tracking any
- // changes of the root.
- HandleSDNode Dummy;
-
// Worklist of all of the nodes that need to be simplified.
- SmallVector<SDNode*, 8> WorkList;
-
- // The current position of our iteration through the allnodes list.
- SelectionDAG::allnodes_iterator CurNode;
+ std::vector<SDNode*> WorkList;
// AA - Used for DAG load/store alias analysis.
AliasAnalysis &AA;
- /// AdvanceCurNode - Update CurNode to point to the next node to process.
- ///
- void AdvanceCurNode() {
- // We start at the end of the list and work towards the front. Setting
- // CurNode to DAG.allnodes_end() indicates that we're done.
- if (CurNode == DAG.allnodes_begin())
- CurNode = DAG.allnodes_end();
- else
- --CurNode;
- }
-
/// AddUsersToWorkList - When an instruction is simplified, add all users of
/// the instruction to the work lists because they might get more simplified
/// now.
@@ -105,10 +86,6 @@
void removeFromWorkList(SDNode *N) {
WorkList.erase(std::remove(WorkList.begin(), WorkList.end(), N),
WorkList.end());
- // If the next node we were planning to process is deleted,
- // skip past it.
- if (N == CurNode)
- AdvanceCurNode();
}
SDValue CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
@@ -148,9 +125,9 @@
// Visitation implementation - Implement dag node combining for different
// node types. The semantics are as follows:
// Return Value:
- // SDValue.getNode() == 0 - No change was made
- // SDValue.getNode() == N - N was replaced, is dead, and is already handled.
- // otherwise - N should be replaced by the returned Operand.
+ // SDValue.getNode() == 0 - No change was made
+ // SDValue.getNode() == N - N was replaced, is dead and has been handled.
+ // otherwise - N should be replaced by the returned Operand.
//
SDValue visitTokenFactor(SDNode *N);
SDValue visitMERGE_VALUES(SDNode *N);
@@ -266,14 +243,10 @@
TLI(D.getTargetLoweringInfo()),
AfterLegalize(false),
Fast(fast),
- Dummy(D.getRoot()),
AA(A) {}
/// Run - runs the dag combiner on all nodes in the work list
void Run(bool RunningAfterLegalize);
-
- /// ProcessNode - runs the dag combiner on a node
- void ProcessNode(SDNode *N);
};
}
@@ -602,89 +575,91 @@
// Main DAG Combiner implementation
//===----------------------------------------------------------------------===//
-void DAGCombiner::ProcessNode(SDNode *N) {
- // If N has no uses, it is dead. Make sure to revisit all N's operands once
- // N is deleted from the DAG, since they too may now be dead or may have a
- // reduced number of uses, allowing other xforms.
- if (N->use_empty() && N != &Dummy) {
- for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
- AddToWorkList(N->getOperand(i).getNode());
-
- DAG.DeleteNode(N);
- return;
- }
-
- SDValue RV = combine(N);
-
- if (RV.getNode() == 0)
- return;
-
- ++NodesCombined;
-
- // If we get back the same node we passed in, rather than a new node or
- // zero, we know that the node must have defined multiple values and
- // CombineTo was used. Since CombineTo takes care of the worklist
- // mechanics for us, we have no work to do in this case.
- if (RV.getNode() == N)
- return;
-
- assert(N->getOpcode() != ISD::DELETED_NODE &&
- RV.getNode()->getOpcode() != ISD::DELETED_NODE &&
- "Node was deleted but visit returned new node!");
-
- DOUT << "\nReplacing.3 "; DEBUG(N->dump(&DAG));
- DOUT << "\nWith: "; DEBUG(RV.getNode()->dump(&DAG));
- DOUT << '\n';
-
- if (N->getNumValues() == RV.getNode()->getNumValues())
- DAG.ReplaceAllUsesWith(N, RV.getNode());
- else {
- assert(N->getValueType(0) == RV.getValueType() &&
- N->getNumValues() == 1 && "Type mismatch");
- SDValue OpV = RV;
- DAG.ReplaceAllUsesWith(N, &OpV);
- }
-
- // Delete the old node.
- removeFromWorkList(N);
- DAG.DeleteNode(N);
-
- // Push the new node and any users onto the worklist
- AddToWorkList(RV.getNode());
- AddUsersToWorkList(RV.getNode());
-}
-
void DAGCombiner::Run(bool RunningAfterLegalize) {
// set the instance variable, so that the various visit routines may use it.
AfterLegalize = RunningAfterLegalize;
+ // Add all the dag nodes to the worklist.
+ WorkList.reserve(DAG.allnodes_size());
+ for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(),
+ E = DAG.allnodes_end(); I != E; ++I)
+ WorkList.push_back(I);
+
+ // Create a dummy node (which is not added to allnodes), that adds a reference
+ // to the root node, preventing it from being deleted, and tracking any
+ // changes of the root.
+ HandleSDNode Dummy(DAG.getRoot());
+
// The root of the dag may dangle to deleted nodes until the dag combiner is
// done. Set it to null to avoid confusion.
DAG.setRoot(SDValue());
- // Process all the original dag nodes. We process starting from the
- // end of the list and working forward, which is in roughly topological
- // order. Starting at the end and working forward means we won't
- // accidentally revisit nodes created during the dagcombine process.
- CurNode = prior(DAG.allnodes_end());
- do {
- SDNode *N = &*CurNode;
- AdvanceCurNode();
- ProcessNode(N);
- // Processing the node may have resulted in nodes being added to the
- // worklist, because the were newly created or because one of their
- // operands changed or some other reason they should be revisited.
- // While the worklist isn't empty, inspect the node on the end of it
- // and try and combine it.
- while (!WorkList.empty()) {
- SDNode *N = WorkList.back();
- WorkList.pop_back();
- if (N == CurNode)
- AdvanceCurNode();
- ProcessNode(N);
+ // while the worklist isn't empty, inspect the node on the end of it and
+ // try and combine it.
+ while (!WorkList.empty()) {
+ SDNode *N = WorkList.back();
+ WorkList.pop_back();
+
+ // If N has no uses, it is dead. Make sure to revisit all N's operands once
+ // N is deleted from the DAG, since they too may now be dead or may have a
+ // reduced number of uses, allowing other xforms.
+ if (N->use_empty() && N != &Dummy) {
+ for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
+ AddToWorkList(N->getOperand(i).getNode());
+
+ DAG.DeleteNode(N);
+ continue;
}
- } while (CurNode != DAG.allnodes_end());
+
+ SDValue RV = combine(N);
+
+ if (RV.getNode() == 0)
+ continue;
+
+ ++NodesCombined;
+
+ // If we get back the same node we passed in, rather than a new node or
+ // zero, we know that the node must have defined multiple values and
+ // CombineTo was used. Since CombineTo takes care of the worklist
+ // mechanics for us, we have no work to do in this case.
+ if (RV.getNode() == N)
+ continue;
+
+ assert(N->getOpcode() != ISD::DELETED_NODE &&
+ RV.getNode()->getOpcode() != ISD::DELETED_NODE &&
+ "Node was deleted but visit returned new node!");
+ DOUT << "\nReplacing.3 "; DEBUG(N->dump(&DAG));
+ DOUT << "\nWith: "; DEBUG(RV.getNode()->dump(&DAG));
+ DOUT << '\n';
+ WorkListRemover DeadNodes(*this);
+ if (N->getNumValues() == RV.getNode()->getNumValues())
+ DAG.ReplaceAllUsesWith(N, RV.getNode(), &DeadNodes);
+ else {
+ assert(N->getValueType(0) == RV.getValueType() &&
+ N->getNumValues() == 1 && "Type mismatch");
+ SDValue OpV = RV;
+ DAG.ReplaceAllUsesWith(N, &OpV, &DeadNodes);
+ }
+
+ // Push the new node and any users onto the worklist
+ AddToWorkList(RV.getNode());
+ AddUsersToWorkList(RV.getNode());
+
+ // Add any uses of the old node to the worklist in case this node is the
+ // last one that uses them. They may become dead after this node is
+ // deleted.
+ for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
+ AddToWorkList(N->getOperand(i).getNode());
+
+ // Nodes can be reintroduced into the worklist. Make sure we do not
+ // process a node that has been replaced.
+ removeFromWorkList(N);
+
+ // Finally, since the node is now dead, remove it from the graph.
+ DAG.DeleteNode(N);
+ }
+
// If the root changed (e.g. it was a dead load, update the root).
DAG.setRoot(Dummy.getValue());
}
@@ -3453,7 +3428,7 @@
}
}
- // If the input is a constant, let getNode() fold it.
+ // If the input is a constant, let Val fold it.
if (isa<ConstantSDNode>(N0) || isa<ConstantFPSDNode>(N0)) {
SDValue Res = DAG.getNode(ISD::BIT_CONVERT, VT, N0);
if (Res.getNode() != N) return Res;
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