diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp index 9a81ec51dda..6b366cc4af6 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp @@ -2282,7 +2282,11 @@ void SelectionDAGBuilder::visitSelect(const User &I) { 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(&I)->getCondition()->hasOneUse()) { OpCode = Opc; LHSVal = getValue(LHS); RHSVal = getValue(RHS); diff --git a/test/CodeGen/AArch64/minmax.ll b/test/CodeGen/AArch64/minmax.ll index a6b5adebe10..df4912ca1f7 100644 --- a/test/CodeGen/AArch64/minmax.ll +++ b/test/CodeGen/AArch64/minmax.ll @@ -94,3 +94,14 @@ define <16 x i32> @t11(<16 x i32> %a, <16 x i32> %b) { %t2 = select <16 x i1> %t1, <16 x i32> %a, <16 x i32> %b ret <16 x i32> %t2 } + +; CHECK-LABEL: t12 +; CHECK-NOT: umin +; The icmp is used by two instructions, so don't produce a umin node. +define <16 x i8> @t12(<16 x i8> %a, <16 x i8> %b) { + %t1 = icmp ugt <16 x i8> %b, %a + %t2 = select <16 x i1> %t1, <16 x i8> %a, <16 x i8> %b + %t3 = zext <16 x i1> %t1 to <16 x i8> + %t4 = add <16 x i8> %t3, %t2 + ret <16 x i8> %t4 +}