diff options
Diffstat (limited to 'lib/Target/X86/X86ISelLowering.cpp')
| -rw-r--r-- | lib/Target/X86/X86ISelLowering.cpp | 43 |
1 files changed, 42 insertions, 1 deletions
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp index 3657ac0696..081ac00693 100644 --- a/lib/Target/X86/X86ISelLowering.cpp +++ b/lib/Target/X86/X86ISelLowering.cpp @@ -449,8 +449,8 @@ X86TargetLowering::X86TargetLowering(X86TargetMachine &TM) if (Subtarget->hasXMM()) setOperationAction(ISD::PREFETCH , MVT::Other, Legal); - // We may not have a libcall for MEMBARRIER so we should lower this. setOperationAction(ISD::MEMBARRIER , MVT::Other, Custom); + setOperationAction(ISD::ATOMIC_FENCE , MVT::Other, Custom); // On X86 and X86-64, atomic operations are lowered to locked instructions. // Locked instructions, in turn, have implicit fence semantics (all memory @@ -9407,6 +9407,45 @@ SDValue X86TargetLowering::LowerMEMBARRIER(SDValue Op, SelectionDAG &DAG) const{ return DAG.getNode(X86ISD::MFENCE, dl, MVT::Other, Op.getOperand(0)); } +SDValue X86TargetLowering::LowerATOMIC_FENCE(SDValue Op, + SelectionDAG &DAG) const { + DebugLoc dl = Op.getDebugLoc(); + AtomicOrdering FenceOrdering = static_cast<AtomicOrdering>( + cast<ConstantSDNode>(Op.getOperand(1))->getZExtValue()); + SynchronizationScope FenceScope = static_cast<SynchronizationScope>( + cast<ConstantSDNode>(Op.getOperand(2))->getZExtValue()); + + // The only fence that needs an instruction is a sequentially-consistent + // cross-thread fence. + if (FenceOrdering == SequentiallyConsistent && FenceScope == CrossThread) { + // Use mfence if we have SSE2 or we're on x86-64 (even if we asked for + // no-sse2). There isn't any reason to disable it if the target processor + // supports it. + if (Subtarget->hasSSE2() || Subtarget->is64Bit()) + return DAG.getNode(X86ISD::MFENCE, dl, MVT::Other, Op.getOperand(0)); + + SDValue Chain = Op.getOperand(0); + SDValue Zero = DAG.getConstant(0, MVT::i32); + SDValue Ops[] = { + DAG.getRegister(X86::ESP, MVT::i32), // Base + DAG.getTargetConstant(1, MVT::i8), // Scale + DAG.getRegister(0, MVT::i32), // Index + DAG.getTargetConstant(0, MVT::i32), // Disp + DAG.getRegister(0, MVT::i32), // Segment. + Zero, + Chain + }; + SDNode *Res = + DAG.getMachineNode(X86::OR32mrLocked, dl, MVT::Other, Ops, + array_lengthof(Ops)); + return SDValue(Res, 0); + } + + // MEMBARRIER is a compiler barrier; it codegens to a no-op. + return DAG.getNode(X86ISD::MEMBARRIER, dl, MVT::Other, Op.getOperand(0)); +} + + SDValue X86TargetLowering::LowerCMP_SWAP(SDValue Op, SelectionDAG &DAG) const { EVT T = Op.getValueType(); DebugLoc DL = Op.getDebugLoc(); @@ -9526,6 +9565,7 @@ SDValue X86TargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const { default: llvm_unreachable("Should not custom lower this!"); case ISD::SIGN_EXTEND_INREG: return LowerSIGN_EXTEND_INREG(Op,DAG); case ISD::MEMBARRIER: return LowerMEMBARRIER(Op,DAG); + case ISD::ATOMIC_FENCE: return LowerATOMIC_FENCE(Op,DAG); case ISD::ATOMIC_CMP_SWAP: return LowerCMP_SWAP(Op,DAG); case ISD::ATOMIC_LOAD_SUB: return LowerLOAD_SUB(Op,DAG); case ISD::BUILD_VECTOR: return LowerBUILD_VECTOR(Op, DAG); @@ -9849,6 +9889,7 @@ const char *X86TargetLowering::getTargetNodeName(unsigned Opcode) const { case X86ISD::VASTART_SAVE_XMM_REGS: return "X86ISD::VASTART_SAVE_XMM_REGS"; case X86ISD::VAARG_64: return "X86ISD::VAARG_64"; case X86ISD::WIN_ALLOCA: return "X86ISD::WIN_ALLOCA"; + case X86ISD::MEMBARRIER: return "X86ISD::MEMBARRIER"; } } |