Make it simplier to dump DAGs while in DAGCombiner. Remove a nasty optimization.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31009 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jim Laskey 2006-10-17 19:33:52 +00:00
parent 3f3a6f6c3b
commit 26f7fa7bba
3 changed files with 7 additions and 10 deletions

View File

@ -49,7 +49,7 @@ namespace {
static cl::opt<bool>
CombinerAA("combiner-alias-analysis", cl::Hidden,
cl::desc("Turn on alias analysis turning testing"));
cl::desc("Turn on alias analysis during testing"));
//------------------------------ DAGCombiner ---------------------------------//
@ -388,6 +388,9 @@ void DAGCombiner::Run(bool RunningAfterLegalize) {
// 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(SDOperand());
/// DagCombineInfo - Expose the DAG combiner to the target combiner impls.
TargetLowering::DAGCombinerInfo
@ -2759,13 +2762,6 @@ SDOperand DAGCombiner::visitSTORE(SDNode *N) {
}
if (CombinerAA) {
// If the store ptr is a frame index and the frame index has a use of one
// and this is a return block, then the store is redundant.
if (Ptr.hasOneUse() && isa<FrameIndexSDNode>(Ptr) &&
DAG.getRoot().getOpcode() == ISD::RET) {
return Chain;
}
// Walk up chain skipping non-aliasing memory nodes.
SDOperand BetterChain = FindBetterChain(N, Chain);

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@ -2684,7 +2684,7 @@ void SelectionDAG::dump() const {
DumpNodes(Nodes[i], 2, this);
}
DumpNodes(getRoot().Val, 2, this);
if (getRoot().Val) DumpNodes(getRoot().Val, 2, this);
std::cerr << "\n\n";
}

View File

@ -61,7 +61,8 @@ namespace llvm {
static void addCustomGraphFeatures(SelectionDAG *G,
GraphWriter<SelectionDAG*> &GW) {
GW.emitSimpleNode(0, "plaintext=circle", "GraphRoot");
GW.emitEdge(0, -1, G->getRoot().Val, -1, "");
if (G->getRoot().Val)
GW.emitEdge(0, -1, G->getRoot().Val, -1, "");
}
};
}