Don't create a MIN/MAX node if the underlying compare has more than one use.
If the compare in a select pattern has another use then it can't be removed, so we'd just
be creating repeated code if we created a min/max node.
Spotted by Matt Arsenault!
llvm-svn: 239037
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 9a81ec5..6b366cc 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -2282,7 +2282,11 @@
while (TLI.getTypeAction(Ctx, VT) == TargetLoweringBase::TypeSplitVector)
VT = TLI.getTypeToTransformTo(Ctx, VT);
- if (Opc != ISD::DELETED_NODE && TLI.isOperationLegalOrCustom(Opc, VT)) {
+ if (Opc != ISD::DELETED_NODE && TLI.isOperationLegalOrCustom(Opc, VT) &&
+ // If the underlying comparison instruction is used by any other instruction,
+ // the consumed instructions won't be destroyed, so it is not profitable
+ // to convert to a min/max.
+ cast<SelectInst>(&I)->getCondition()->hasOneUse()) {
OpCode = Opc;
LHSVal = getValue(LHS);
RHSVal = getValue(RHS);