diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp index cf17c51b04fcc..7e3dae727c0fe 100644 --- a/llvm/lib/Target/X86/X86ISelLowering.cpp +++ b/llvm/lib/Target/X86/X86ISelLowering.cpp @@ -499,7 +499,7 @@ X86TargetLowering::X86TargetLowering(const X86TargetMachine &TM, } if (Subtarget.hasSSEPrefetch() || Subtarget.hasThreeDNow()) - setOperationAction(ISD::PREFETCH , MVT::Other, Legal); + setOperationAction(ISD::PREFETCH , MVT::Other, Custom); setOperationAction(ISD::ATOMIC_FENCE , MVT::Other, Custom); @@ -33093,6 +33093,18 @@ static SDValue LowerCVTPS2PH(SDValue Op, SelectionDAG &DAG) { return DAG.getNode(ISD::CONCAT_VECTORS, dl, VT, Lo, Hi); } +static SDValue LowerPREFETCH(SDValue Op, const X86Subtarget &Subtarget, + SelectionDAG &DAG) { + unsigned IsData = cast(Op.getOperand(4))->getZExtValue(); + + // We don't support non-data prefetch without PREFETCHI. + // Just preserve the chain. + if (!IsData && !Subtarget.hasPREFETCHI()) + return Op.getOperand(0); + + return Op; +} + static StringRef getInstrStrFromOpNo(const SmallVectorImpl &AsmStrs, unsigned OpNo) { const APInt Operand(32, OpNo); @@ -33294,6 +33306,7 @@ SDValue X86TargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const { case ISD::GC_TRANSITION_END: return LowerGC_TRANSITION(Op, DAG); case ISD::ADDRSPACECAST: return LowerADDRSPACECAST(Op, DAG); case X86ISD::CVTPS2PH: return LowerCVTPS2PH(Op, DAG); + case ISD::PREFETCH: return LowerPREFETCH(Op, Subtarget, DAG); } } diff --git a/llvm/test/CodeGen/X86/prefetchi.ll b/llvm/test/CodeGen/X86/prefetchi.ll index 8f97e077e535b..442819ea20d04 100644 --- a/llvm/test/CodeGen/X86/prefetchi.ll +++ b/llvm/test/CodeGen/X86/prefetchi.ll @@ -1,5 +1,6 @@ ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py ; RUN: llc < %s -mtriple=x86_64-- -mattr=+prefetchi | FileCheck %s +; RUN: llc < %s -mtriple=x86_64-- | FileCheck %s --check-prefix=NOPREFETCHI define dso_local void @t(ptr %ptr) nounwind { ; CHECK-LABEL: t: @@ -9,6 +10,10 @@ define dso_local void @t(ptr %ptr) nounwind { ; CHECK-NEXT: prefetchit1 t(%rip) ; CHECK-NEXT: prefetchit0 ext(%rip) ; CHECK-NEXT: retq +; +; NOPREFETCHI-LABEL: t: +; NOPREFETCHI: # %bb.0: # %entry +; NOPREFETCHI-NEXT: retq entry: tail call void @llvm.prefetch(ptr %ptr, i32 0, i32 2, i32 0) tail call void @llvm.prefetch(ptr %ptr, i32 0, i32 3, i32 0)