Fix PR 7191. I have been unable to create a .ll file that fails, sorry.
(oye, a word which should be better known to people writing tree
traversals, means grandchild.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104619 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 6253839..df1a0a3 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -3431,8 +3431,12 @@
// fold (sext (truncate (srl (load x), c))) -> (sext (smaller load (x+c/n)))
SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
if (NarrowLoad.getNode()) {
- if (NarrowLoad.getNode() != N0.getNode())
+ SDNode* oye = N0.getNode()->getOperand(0).getNode();
+ if (NarrowLoad.getNode() != N0.getNode()) {
CombineTo(N0.getNode(), NarrowLoad);
+ // CombineTo deleted the truncate, if needed, but not what's under it.
+ AddToWorkList(oye);
+ }
return SDValue(N, 0); // Return N so it doesn't get rechecked!
}
@@ -3619,8 +3623,12 @@
if (N0.getOpcode() == ISD::TRUNCATE) {
SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
if (NarrowLoad.getNode()) {
- if (NarrowLoad.getNode() != N0.getNode())
+ SDNode* oye = N0.getNode()->getOperand(0).getNode();
+ if (NarrowLoad.getNode() != N0.getNode()) {
CombineTo(N0.getNode(), NarrowLoad);
+ // CombineTo deleted the truncate, if needed, but not what's under it.
+ AddToWorkList(oye);
+ }
return DAG.getNode(ISD::ZERO_EXTEND, N->getDebugLoc(), VT, NarrowLoad);
}
}