diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp index ab31898e262e7..d8f3095ed7fb6 100644 --- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp +++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp @@ -200,6 +200,11 @@ PPCTargetLowering::PPCTargetLowering(const PPCTargetMachine &TM, setOperationAction(ISD::UADDO, isPPC64 ? MVT::i64 : MVT::i32, Custom); + // On P10, the default lowering generates better code using the + // setbc instruction. + if (!Subtarget.hasP10Vector() && isPPC64) + setOperationAction(ISD::SSUBO, MVT::i32, Custom); + // Match BITREVERSE to customized fast code sequence in the td file. setOperationAction(ISD::BITREVERSE, MVT::i32, Legal); setOperationAction(ISD::BITREVERSE, MVT::i64, Legal); @@ -12016,6 +12021,36 @@ SDValue PPCTargetLowering::LowerUaddo(SDValue Op, SelectionDAG &DAG) const { return Res; } +SDValue PPCTargetLowering::LowerSSUBO(SDValue Op, SelectionDAG &DAG) const { + + SDLoc dl(Op); + + SDValue LHS64 = DAG.getNode(ISD::ANY_EXTEND, dl, MVT::i64, Op.getOperand(0)); + SDValue RHS64 = DAG.getNode(ISD::ANY_EXTEND, dl, MVT::i64, Op.getOperand(1)); + + SDValue Sub = DAG.getNode(ISD::SUB, dl, MVT::i64, LHS64, RHS64); + + SDValue Extsw = DAG.getNode(ISD::SIGN_EXTEND_INREG, dl, MVT::i64, Sub, + DAG.getValueType(MVT::i32)); + + SDValue Xor = DAG.getNode(ISD::XOR, dl, MVT::i64, Extsw, Sub); + + SDValue Addic = DAG.getNode(ISD::ADDC, dl, DAG.getVTList(MVT::i64, MVT::Glue), + Xor, DAG.getConstant(-1, dl, MVT::i64)); + + SDValue Overflow = + DAG.getNode(ISD::SUBE, dl, DAG.getVTList(MVT::i64, MVT::Glue), Xor, Addic, + Addic.getValue(1)); + + SDValue OverflowTrunc = + DAG.getNode(ISD::TRUNCATE, dl, Op.getNode()->getValueType(1), Overflow); + SDValue SubTrunc = + (Sub->getValueType(0) != Op.getNode()->getValueType(0)) + ? DAG.getNode(ISD::TRUNCATE, dl, Op.getNode()->getValueType(0), Sub) + : Sub; + return DAG.getMergeValues({SubTrunc, OverflowTrunc}, dl); +} + /// LowerOperation - Provide custom lowering hooks for some operations. /// SDValue PPCTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const { @@ -12038,6 +12073,8 @@ SDValue PPCTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const { case ISD::SETCC: return LowerSETCC(Op, DAG); case ISD::INIT_TRAMPOLINE: return LowerINIT_TRAMPOLINE(Op, DAG); case ISD::ADJUST_TRAMPOLINE: return LowerADJUST_TRAMPOLINE(Op, DAG); + case ISD::SSUBO: + return LowerSSUBO(Op, DAG); case ISD::INLINEASM: case ISD::INLINEASM_BR: return LowerINLINEASM(Op, DAG); diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.h b/llvm/lib/Target/PowerPC/PPCISelLowering.h index 0adbad8684597..dde45e4cf6f4a 100644 --- a/llvm/lib/Target/PowerPC/PPCISelLowering.h +++ b/llvm/lib/Target/PowerPC/PPCISelLowering.h @@ -1279,6 +1279,7 @@ namespace llvm { SDValue LowerJumpTable(SDValue Op, SelectionDAG &DAG) const; SDValue LowerUaddo(SDValue Op, SelectionDAG &DAG) const; SDValue LowerSETCC(SDValue Op, SelectionDAG &DAG) const; + SDValue LowerSSUBO(SDValue Op, SelectionDAG &DAG) const; SDValue LowerINIT_TRAMPOLINE(SDValue Op, SelectionDAG &DAG) const; SDValue LowerADJUST_TRAMPOLINE(SDValue Op, SelectionDAG &DAG) const; SDValue LowerINLINEASM(SDValue Op, SelectionDAG &DAG) const; diff --git a/llvm/test/CodeGen/PowerPC/saddo-ssubo.ll b/llvm/test/CodeGen/PowerPC/saddo-ssubo.ll index fd5f26ba35742..7147257d27c4b 100644 --- a/llvm/test/CodeGen/PowerPC/saddo-ssubo.ll +++ b/llvm/test/CodeGen/PowerPC/saddo-ssubo.ll @@ -129,12 +129,11 @@ entry: define i1 @test_ssubo_i32(i32 %a, i32 %b) nounwind { ; CHECK-LABEL: test_ssubo_i32: ; CHECK: # %bb.0: # %entry -; CHECK-NEXT: sub 5, 3, 4 -; CHECK-NEXT: cmpwi 1, 4, 0 -; CHECK-NEXT: cmpw 5, 3 -; CHECK-NEXT: li 3, 1 -; CHECK-NEXT: creqv 20, 5, 0 -; CHECK-NEXT: isel 3, 0, 3, 20 +; CHECK-NEXT: sub 3, 3, 4 +; CHECK-NEXT: extsw 4, 3 +; CHECK-NEXT: xor 3, 4, 3 +; CHECK-NEXT: addic 4, 3, -1 +; CHECK-NEXT: subfe 3, 4, 3 ; CHECK-NEXT: blr entry: %res = call { i32, i1 } @llvm.ssub.with.overflow.i32(i32 %a, i32 %b) nounwind