Revert "[DAGCombiner] Split up an indexed load if only the base pointer value is live"
This reverts r208640 (I've just XFAILed the test) because it broke ppc64/Linux
self-hosting. Because nearly every regression test triggers a segfault, I hope
this will be easy to fix.
llvm-svn: 209747
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 2d2fd53..c408944 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -167,7 +167,6 @@
bool CombineToPreIndexedLoadStore(SDNode *N);
bool CombineToPostIndexedLoadStore(SDNode *N);
- SDValue SplitIndexingFromLoad(LoadSDNode *LD);
bool SliceUpLoad(SDNode *N);
void ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad);
@@ -762,14 +761,10 @@
// If the operands of this node are only used by the node, they will now
// be dead. Make sure to visit them first to delete dead nodes early.
- for (unsigned i = 0, e = TLO.Old.getNode()->getNumOperands(); i != e; ++i) {
- SDNode *Op = TLO.Old.getNode()->getOperand(i).getNode();
- // For an operand generating multiple values, one of the values may
- // become dead allowing further simplification (e.g. split index
- // arithmetic from an indexed load).
- if (Op->hasOneUse() || Op->getNumValues() > 1)
- AddToWorkList(Op);
- }
+ for (unsigned i = 0, e = TLO.Old.getNode()->getNumOperands(); i != e; ++i)
+ if (TLO.Old.getNode()->getOperand(i).getNode()->hasOneUse())
+ AddToWorkList(TLO.Old.getNode()->getOperand(i).getNode());
+
DAG.DeleteNode(TLO.Old.getNode());
}
}
@@ -7849,17 +7844,6 @@
return false;
}
-/// \brief Return the base-pointer arithmetic from an indexed \p LD.
-SDValue DAGCombiner::SplitIndexingFromLoad(LoadSDNode *LD) {
- ISD::MemIndexedMode AM = LD->getAddressingMode();
- assert(AM != ISD::UNINDEXED);
- SDValue BP = LD->getOperand(1);
- SDValue Inc = LD->getOperand(2);
- unsigned Opc =
- (AM == ISD::PRE_INC || AM == ISD::POST_INC ? ISD::ADD : ISD::SUB);
- return DAG.getNode(Opc, SDLoc(LD), BP.getSimpleValueType(), BP, Inc);
-}
-
SDValue DAGCombiner::visitLOAD(SDNode *N) {
LoadSDNode *LD = cast<LoadSDNode>(N);
SDValue Chain = LD->getChain();
@@ -7896,16 +7880,8 @@
} else {
// Indexed loads.
assert(N->getValueType(2) == MVT::Other && "Malformed indexed loads?");
- if (!N->hasAnyUseOfValue(0)) {
+ if (!N->hasAnyUseOfValue(0) && !N->hasAnyUseOfValue(1)) {
SDValue Undef = DAG.getUNDEF(N->getValueType(0));
- SDValue Index;
- if (N->hasAnyUseOfValue(1)) {
- Index = SplitIndexingFromLoad(LD);
- // Try to fold the base pointer arithmetic into subsequent loads and
- // stores.
- AddUsersToWorkList(N);
- } else
- Index = DAG.getUNDEF(N->getValueType(1));
DEBUG(dbgs() << "\nReplacing.7 ";
N->dump(&DAG);
dbgs() << "\nWith: ";
@@ -7913,7 +7889,8 @@
dbgs() << " and 2 other values\n");
WorkListRemover DeadNodes(*this);
DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Undef);
- DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Index);
+ DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1),
+ DAG.getUNDEF(N->getValueType(1)));
DAG.ReplaceAllUsesOfValueWith(SDValue(N, 2), Chain);
removeFromWorkList(N);
DAG.DeleteNode(N);