diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 5384713d04b33..efd5ea51b7e47 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -13924,6 +13924,34 @@ SDValue DAGCombiner::visitSETCC(SDNode *N) { } } } + + // (setcc (zext a), (zext b), setu??) -> (setcc a, b, setu??) + // (setcc (sext a), (sext b), sets??) -> (setcc a, b, sets??) + if ((ISD::isUnsignedIntSetCC(Cond) && N0.getOpcode() == ISD::ZERO_EXTEND && + N1.getOpcode() == ISD::ZERO_EXTEND) || + (ISD::isSignedIntSetCC(Cond) && N0.getOpcode() == ISD::SIGN_EXTEND && + N1.getOpcode() == ISD::SIGN_EXTEND)) { + SDValue LHS = N0.getOperand(0), RHS = N1.getOperand(0); + EVT SmallVT = + LHS.getScalarValueSizeInBits() > RHS.getScalarValueSizeInBits() + ? LHS.getValueType() + : RHS.getValueType(); + if (!LegalOperations || + (SmallVT.isSimple() && + TLI.isCondCodeLegal(Cond, SmallVT.getSimpleVT()))) { + LHS = DAG.getExtOrTrunc(ISD::isSignedIntSetCC(Cond), LHS, SDLoc(LHS), + SmallVT); + RHS = DAG.getExtOrTrunc(ISD::isSignedIntSetCC(Cond), RHS, SDLoc(RHS), + SmallVT); + SDValue NewSetCC = + DAG.getSetCC(DL, getSetCCResultType(SmallVT), LHS, RHS, Cond); + // Promote to a legal type for setcc, then adjust back to VT (if before + // LegalOperations) + return DAG.getZExtOrTrunc( + TLI.promoteTargetBoolean(DAG, NewSetCC, N0.getValueType()), DL, VT); + } + } + return SDValue(); } diff --git a/llvm/test/CodeGen/AArch64/arm64-vcmp.ll b/llvm/test/CodeGen/AArch64/arm64-vcmp.ll index 1e05b452de300..b88df3028fc3c 100644 --- a/llvm/test/CodeGen/AArch64/arm64-vcmp.ll +++ b/llvm/test/CodeGen/AArch64/arm64-vcmp.ll @@ -234,3 +234,31 @@ define <1 x i64> @cmnez_d(<1 x i64> %A) nounwind { %mask = sext <1 x i1> %tst to <1 x i64> ret <1 x i64> %mask } + +; Check for the elimination of spurious type extensions +define <16 x i1> @abdu_cmp(<16 x i8> %a, <16 x i8> %b, <16 x i8> %g) { +; CHECK-LABEL: abdu_cmp: +; CHECK: // %bb.0: +; CHECK-NEXT: uabd.16b v0, v0, v1 +; CHECK-NEXT: cmhi.16b v0, v2, v0 +; CHECK-NEXT: ret + %za = zext <16 x i8> %a to <16 x i32> + %zb = zext <16 x i8> %b to <16 x i32> + %zg = zext <16 x i8> %g to <16 x i32> + %mx = call <16 x i32> @llvm.umax.v16i32(<16 x i32> %za, <16 x i32> %zb) + %mn = call <16 x i32> @llvm.umin.v16i32(<16 x i32> %za, <16 x i32> %zb) + %abdu = sub <16 x i32> %mx, %mn + %cond = icmp ult <16 x i32> %abdu, %zg + ret <16 x i1> %cond +} + +define <16 x i1> @sext_cmp(<16 x i8> %a, <16 x i8> %b) { +; CHECK-LABEL: sext_cmp: +; CHECK: // %bb.0: +; CHECK-NEXT: cmgt.16b v0, v1, v0 +; CHECK-NEXT: ret + %za = sext <16 x i8> %a to <16 x i32> + %zb = sext <16 x i8> %b to <16 x i32> + %cond = icmp slt <16 x i32> %za, %zb + ret <16 x i1> %cond +}