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/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index c40a783..3d01bb2 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -652,8 +652,7 @@
Result = DAG.getNode(ISD::FP_EXTEND, VT, Result);
SDOperand Ops[] = { Result, Chain };
- return DAG.getNode(ISD::MERGE_VALUES, DAG.getVTList(VT, MVT::Other),
- Ops, 2);
+ return DAG.getMergeValues(DAG.getVTList(VT, MVT::Other), Ops, 2);
}
assert(LoadedVT.isInteger() && !LoadedVT.isVector() &&
"Unaligned load of unsupported type.");
@@ -702,7 +701,7 @@
Hi.getValue(1));
SDOperand Ops[] = { Result, TF };
- return DAG.getNode(ISD::MERGE_VALUES, DAG.getVTList(VT, MVT::Other), Ops, 2);
+ return DAG.getMergeValues(DAG.getVTList(VT, MVT::Other), Ops, 2);
}
/// UnrollVectorOp - We know that the given vector has a legal type, however
@@ -933,8 +932,7 @@
// Fall Thru
case TargetLowering::Legal: {
SDOperand Ops[] = { DAG.getConstant(0, VT), Tmp1 };
- Result = DAG.getNode(ISD::MERGE_VALUES, DAG.getVTList(VT, MVT::Other),
- Ops, 2);
+ Result = DAG.getMergeValues(DAG.getVTList(VT, MVT::Other), Ops, 2);
break;
}
}
@@ -968,8 +966,7 @@
// Fall Thru
case TargetLowering::Legal: {
SDOperand Ops[] = { DAG.getConstant(0, VT), Tmp2 };
- Result = DAG.getNode(ISD::MERGE_VALUES, DAG.getVTList(VT, MVT::Other),
- Ops, 2);
+ Result = DAG.getMergeValues(DAG.getVTList(VT, MVT::Other), Ops, 2);
break;
}
}
@@ -4737,10 +4734,10 @@
default: assert(0 && "Unsupported FP setcc!");
}
}
-
+
SDOperand Dummy;
Tmp1 = ExpandLibCall(LC1,
- DAG.getNode(ISD::MERGE_VALUES, VT, LHS, RHS).Val,
+ DAG.getNode(ISD::MERGE_VALUES, VT, LHS, RHS).Val,
false /*sign irrelevant*/, Dummy);
Tmp2 = DAG.getConstant(0, MVT::i32);
CC = DAG.getCondCode(TLI.getCmpLibcallCC(LC1));