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[DAG] Immediately cleanup unused nodes from extend-based combines. 

llvm-svn: 353338
This commit is contained in:
Nirav Dave 2019-02-06 20:12:03 +00:00
parent dcb9e08fae
commit b3506bf985
1 changed files with 7 additions and 2 deletions
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9
llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
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@ -8543,19 +8543,21 @@ static SDValue tryToFoldExtOfExtload(SelectionDAG &DAG, DAGCombiner &Combiner,
: ISD::isZEXTLoad(N0Node);
if ((!isAExtLoad && !ISD::isEXTLoad(N0Node)) ||
!ISD::isUNINDEXEDLoad(N0Node) || !N0.hasOneUse())
return {};
return SDValue();
LoadSDNode *LN0 = cast<LoadSDNode>(N0);
EVT MemVT = LN0->getMemoryVT();
if ((LegalOperations || LN0->isVolatile() || VT.isVector()) &&
!TLI.isLoadExtLegal(ExtLoadType, VT, MemVT))
return {};
return SDValue();
SDValue ExtLoad =
DAG.getExtLoad(ExtLoadType, SDLoc(LN0), VT, LN0->getChain(),
LN0->getBasePtr(), MemVT, LN0->getMemOperand());
Combiner.CombineTo(N, ExtLoad);
DAG.ReplaceAllUsesOfValueWith(SDValue(LN0, 1), ExtLoad.getValue(1));
if (LN0->use_empty())
Combiner.recursivelyDeleteUnusedNodes(LN0);
return SDValue(N, 0); // Return N so it doesn't get rechecked!
}
@ -8593,6 +8595,7 @@ static SDValue tryToFoldExtOfLoad(SelectionDAG &DAG, DAGCombiner &Combiner,
Combiner.CombineTo(N, ExtLoad);
if (NoReplaceTrunc) {
DAG.ReplaceAllUsesOfValueWith(SDValue(LN0, 1), ExtLoad.getValue(1));
Combiner.recursivelyDeleteUnusedNodes(LN0);
} else {
SDValue Trunc =
DAG.getNode(ISD::TRUNCATE, SDLoc(N0), N0.getValueType(), ExtLoad);
@ -9196,6 +9199,7 @@ SDValue DAGCombiner::visitANY_EXTEND(SDNode *N) {
CombineTo(N, ExtLoad);
if (NoReplaceTrunc) {
DAG.ReplaceAllUsesOfValueWith(SDValue(LN0, 1), ExtLoad.getValue(1));
recursivelyDeleteUnusedNodes(LN0);
} else {
SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
N0.getValueType(), ExtLoad);
@ -9219,6 +9223,7 @@ SDValue DAGCombiner::visitANY_EXTEND(SDNode *N) {
MemVT, LN0->getMemOperand());
CombineTo(N, ExtLoad);
DAG.ReplaceAllUsesOfValueWith(SDValue(LN0, 1), ExtLoad.getValue(1));
recursivelyDeleteUnusedNodes(LN0);
return SDValue(N, 0); // Return N so it doesn't get rechecked!
}
}