Revert the SelectionDAG optimization that makes
it impossible to create a MERGE_VALUES node with
only one result: sometimes it is useful to be able
to create a node with only one result out of one of
the results of a node with more than one result, for
example because the new node will eventually be used
to replace a one-result node using ReplaceAllUsesWith,
cf X86TargetLowering::ExpandFP_TO_SINT. On the other
hand, most users of MERGE_VALUES don't need this and
for them the optimization was valuable. So add a new
utility method getMergeValues for creating MERGE_VALUES
nodes which by default performs the optimization.
Change almost everywhere to use getMergeValues (and
tidy some stuff up at the same time).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52893 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 0ab5b62..e8537d2 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -1165,9 +1165,8 @@
ValueVTs.push_back(Val->getValueType(i));
}
}
- return DAG.getNode(ISD::MERGE_VALUES,
- DAG.getVTList(&ValueVTs[0], ValueVTs.size()),
- &Constants[0], Constants.size());
+ return DAG.getMergeValues(DAG.getVTList(&ValueVTs[0], ValueVTs.size()),
+ &Constants[0], Constants.size());
}
if (const ArrayType *ATy = dyn_cast<ArrayType>(C->getType())) {
@@ -1187,9 +1186,8 @@
else
Constants[i] = DAG.getConstant(0, EltVT);
}
- return DAG.getNode(ISD::MERGE_VALUES,
- DAG.getVTList(&ValueVTs[0], ValueVTs.size()),
- &Constants[0], Constants.size());
+ return DAG.getMergeValues(DAG.getVTList(&ValueVTs[0], ValueVTs.size()),
+ &Constants[0], Constants.size());
}
if (const StructType *STy = dyn_cast<StructType>(C->getType())) {
@@ -1210,9 +1208,8 @@
else
Constants[i] = DAG.getConstant(0, EltVT);
}
- return DAG.getNode(ISD::MERGE_VALUES,
- DAG.getVTList(&ValueVTs[0], ValueVTs.size()),
- &Constants[0], Constants.size());
+ return DAG.getMergeValues(DAG.getVTList(&ValueVTs[0], ValueVTs.size()),
+ &Constants[0], Constants.size());
}
const VectorType *VecTy = cast<VectorType>(V->getType());
@@ -2722,9 +2719,8 @@
Values[i] = IntoUndef ? DAG.getNode(ISD::UNDEF, AggValueVTs[i]) :
SDOperand(Agg.Val, Agg.ResNo + i);
- setValue(&I, DAG.getNode(ISD::MERGE_VALUES,
- DAG.getVTList(&AggValueVTs[0], NumAggValues),
- &Values[0], NumAggValues));
+ setValue(&I, DAG.getMergeValues(DAG.getVTList(&AggValueVTs[0], NumAggValues),
+ &Values[0], NumAggValues));
}
void SelectionDAGLowering::visitExtractValue(ExtractValueInst &I) {
@@ -2749,9 +2745,8 @@
OutOfUndef ? DAG.getNode(ISD::UNDEF, Agg.Val->getValueType(Agg.ResNo + i)) :
SDOperand(Agg.Val, Agg.ResNo + i);
- setValue(&I, DAG.getNode(ISD::MERGE_VALUES,
- DAG.getVTList(&ValValueVTs[0], NumValValues),
- &Values[0], NumValValues));
+ setValue(&I, DAG.getMergeValues(DAG.getVTList(&ValValueVTs[0], NumValValues),
+ &Values[0], NumValValues));
}
@@ -2906,9 +2901,8 @@
else
PendingLoads.push_back(Chain);
- setValue(&I, DAG.getNode(ISD::MERGE_VALUES,
- DAG.getVTList(&ValueVTs[0], NumValues),
- &Values[0], NumValues));
+ setValue(&I, DAG.getMergeValues(DAG.getVTList(&ValueVTs[0], NumValues),
+ &Values[0], NumValues));
}
@@ -3796,9 +3790,8 @@
if (ValueVTs.size() == 1)
return Values[0];
- return DAG.getNode(ISD::MERGE_VALUES,
- DAG.getVTList(&ValueVTs[0], ValueVTs.size()),
- &Values[0], ValueVTs.size());
+ return DAG.getMergeValues(DAG.getVTList(&ValueVTs[0], ValueVTs.size()),
+ &Values[0], ValueVTs.size());
}
/// getCopyToRegs - Emit a series of CopyToReg nodes that copies the
@@ -4867,10 +4860,8 @@
AssertOp);
ReturnValues.push_back(ReturnValue);
}
- Res = ReturnValues.size() == 1 ? ReturnValues.front() :
- DAG.getNode(ISD::MERGE_VALUES,
- DAG.getVTList(&RetTys[0], RetTys.size()),
- &ReturnValues[0], ReturnValues.size());
+ Res = DAG.getMergeValues(DAG.getVTList(&RetTys[0], RetTys.size()),
+ &ReturnValues[0], ReturnValues.size());
}
return std::make_pair(Res, Chain);
@@ -4972,10 +4963,10 @@
SmallVector<MVT, 4> LegalValueVTs(NumValues);
for (unsigned VI = 0; VI != NumValues; ++VI)
LegalValueVTs[VI] = Args[a + VI].getValueType();
- SDL.setValue(AI, SDL.DAG.getNode(ISD::MERGE_VALUES,
- SDL.DAG.getVTList(&LegalValueVTs[0],
- NumValues),
- &Args[a], NumValues));
+ SDL.setValue(AI,
+ SDL.DAG.getMergeValues(SDL.DAG.getVTList(&LegalValueVTs[0],
+ NumValues),
+ &Args[a], NumValues));
// If this argument is live outside of the entry block, insert a copy from
// whereever we got it to the vreg that other BB's will reference it as.
DenseMap<const Value*, unsigned>::iterator VMI=FuncInfo.ValueMap.find(AI);