[DAG, X86] Fix ISel-time node insertion ids
As in SystemZ backend, correctly propagate node ids when inserting new
unselected nodes into the DAG during instruction Seleciton for X86
target.
Fixes PR36865.
Reviewers: jyknight, craig.topper
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D44797
llvm-svn: 328233
diff --git a/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp b/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
index 375f965..1edeb85 100644
--- a/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -1070,10 +1070,16 @@
// IDs! The selection DAG must no longer depend on their uniqueness when this
// is used.
static void insertDAGNode(SelectionDAG &DAG, SDValue Pos, SDValue N) {
- if (N.getNode()->getNodeId() == -1 ||
- N.getNode()->getNodeId() > Pos.getNode()->getNodeId()) {
- DAG.RepositionNode(Pos.getNode()->getIterator(), N.getNode());
- N.getNode()->setNodeId(Pos.getNode()->getNodeId());
+ if (N->getNodeId() == -1 ||
+ (SelectionDAGISel::getUninvalidatedNodeId(N.getNode()) >
+ SelectionDAGISel::getUninvalidatedNodeId(Pos.getNode()))) {
+ DAG.RepositionNode(Pos->getIterator(), N.getNode());
+ // Mark Node as invalid for pruning as after this it may be a successor to a
+ // selected node but otherwise be in the same position of Pos.
+ // Conservatively mark it with the same -abs(Id) to assure node id
+ // invariant is preserved.
+ N->setNodeId(Pos->getNodeId());
+ SelectionDAGISel::InvalidateNodeId(N.getNode());
}
}