diff options
Diffstat (limited to 'lib/Target/Blackfin/BlackfinISelDAGToDAG.cpp')
| -rw-r--r-- | lib/Target/Blackfin/BlackfinISelDAGToDAG.cpp | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/lib/Target/Blackfin/BlackfinISelDAGToDAG.cpp b/lib/Target/Blackfin/BlackfinISelDAGToDAG.cpp new file mode 100644 index 0000000000..062b22abe6 --- /dev/null +++ b/lib/Target/Blackfin/BlackfinISelDAGToDAG.cpp @@ -0,0 +1,191 @@ +//===- BlackfinISelDAGToDAG.cpp - A dag to dag inst selector for Blackfin -===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file defines an instruction selector for the Blackfin target. +// +//===----------------------------------------------------------------------===// + +#include "Blackfin.h" +#include "BlackfinISelLowering.h" +#include "BlackfinTargetMachine.h" +#include "BlackfinRegisterInfo.h" +#include "llvm/Intrinsics.h" +#include "llvm/CodeGen/SelectionDAGISel.h" +#include "llvm/CodeGen/MachineRegisterInfo.h" +#include "llvm/Support/Compiler.h" +#include "llvm/Support/Debug.h" +#include "llvm/Support/ErrorHandling.h" +#include "llvm/Support/raw_ostream.h" + +using namespace llvm; + +//===----------------------------------------------------------------------===// +// Instruction Selector Implementation +//===----------------------------------------------------------------------===// + +//===----------------------------------------------------------------------===// +/// BlackfinDAGToDAGISel - Blackfin specific code to select blackfin machine +/// instructions for SelectionDAG operations. +namespace { + class BlackfinDAGToDAGISel : public SelectionDAGISel { + /// Subtarget - Keep a pointer to the Blackfin Subtarget around so that we + /// can make the right decision when generating code for different targets. + //const BlackfinSubtarget &Subtarget; + public: + BlackfinDAGToDAGISel(BlackfinTargetMachine &TM, CodeGenOpt::Level OptLevel) + : SelectionDAGISel(TM, OptLevel) {} + + virtual void InstructionSelect(); + + virtual const char *getPassName() const { + return "Blackfin DAG->DAG Pattern Instruction Selection"; + } + + // Include the pieces autogenerated from the target description. +#include "BlackfinGenDAGISel.inc" + + private: + SDNode *Select(SDValue Op); + bool SelectADDRspii(SDValue Op, SDValue Addr, + SDValue &Base, SDValue &Offset); + + // Walk the DAG after instruction selection, fixing register class issues. + void FixRegisterClasses(SelectionDAG &DAG); + + const BlackfinInstrInfo &getInstrInfo() { + return *static_cast<const BlackfinTargetMachine&>(TM).getInstrInfo(); + } + const BlackfinRegisterInfo *getRegisterInfo() { + return static_cast<const BlackfinTargetMachine&>(TM).getRegisterInfo(); + } + }; +} // end anonymous namespace + +FunctionPass *llvm::createBlackfinISelDag(BlackfinTargetMachine &TM, + CodeGenOpt::Level OptLevel) { + return new BlackfinDAGToDAGISel(TM, OptLevel); +} + +/// InstructionSelect - This callback is invoked by +/// SelectionDAGISel when it has created a SelectionDAG for us to codegen. +void BlackfinDAGToDAGISel::InstructionSelect() { + // Select target instructions for the DAG. + SelectRoot(*CurDAG); + DOUT << "Selected selection DAG before regclass fixup:\n"; + DEBUG(CurDAG->dump()); + FixRegisterClasses(*CurDAG); +} + +SDNode *BlackfinDAGToDAGISel::Select(SDValue Op) { + SDNode *N = Op.getNode(); + DebugLoc dl = N->getDebugLoc(); + if (N->isMachineOpcode()) + return NULL; // Already selected. + + switch (N->getOpcode()) { + default: break; + case ISD::FrameIndex: { + // Selects to ADDpp FI, 0 which in turn will become ADDimm7 SP, imm or ADDpp + // SP, Px + int FI = cast<FrameIndexSDNode>(N)->getIndex(); + SDValue TFI = CurDAG->getTargetFrameIndex(FI, MVT::i32); + return CurDAG->SelectNodeTo(N, BF::ADDpp, MVT::i32, TFI, + CurDAG->getTargetConstant(0, MVT::i32)); + } + } + + return SelectCode(Op); +} + +bool BlackfinDAGToDAGISel::SelectADDRspii(SDValue Op, + SDValue Addr, + SDValue &Base, + SDValue &Offset) { + FrameIndexSDNode *FIN = 0; + if ((FIN = dyn_cast<FrameIndexSDNode>(Addr))) { + Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i32); + Offset = CurDAG->getTargetConstant(0, MVT::i32); + return true; + } + if (Addr.getOpcode() == ISD::ADD) { + ConstantSDNode *CN = 0; + if ((FIN = dyn_cast<FrameIndexSDNode>(Addr.getOperand(0))) && + (CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1))) && + (CN->getSExtValue() % 4 == 0 && CN->getSExtValue() >= 0)) { + // Constant positive word offset from frame index + Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i32); + Offset = CurDAG->getTargetConstant(CN->getSExtValue(), MVT::i32); + return true; + } + } + return false; +} + +static inline bool isCC(const TargetRegisterClass *RC) { + return RC == &BF::AnyCCRegClass || BF::AnyCCRegClass.hasSubClass(RC); +} + +static inline bool isDCC(const TargetRegisterClass *RC) { + return RC == &BF::DRegClass || BF::DRegClass.hasSubClass(RC) || isCC(RC); +} + +static void UpdateNodeOperand(SelectionDAG &DAG, + SDNode *N, + unsigned Num, + SDValue Val) { + SmallVector<SDValue, 8> ops(N->op_begin(), N->op_end()); + ops[Num] = Val; + SDValue New = DAG.UpdateNodeOperands(SDValue(N, 0), ops.data(), ops.size()); + DAG.ReplaceAllUsesWith(N, New.getNode()); +} + +// After instruction selection, insert COPY_TO_REGCLASS nodes to help in +// choosing the proper register classes. +void BlackfinDAGToDAGISel::FixRegisterClasses(SelectionDAG &DAG) { + const BlackfinInstrInfo &TII = getInstrInfo(); + const BlackfinRegisterInfo *TRI = getRegisterInfo(); + DAG.AssignTopologicalOrder(); + HandleSDNode Dummy(DAG.getRoot()); + + for (SelectionDAG::allnodes_iterator NI = DAG.allnodes_begin(); + NI != DAG.allnodes_end(); ++NI) { + if (NI->use_empty() || !NI->isMachineOpcode()) + continue; + const TargetInstrDesc &DefTID = TII.get(NI->getMachineOpcode()); + for (SDNode::use_iterator UI = NI->use_begin(); !UI.atEnd(); ++UI) { + if (!UI->isMachineOpcode()) + continue; + + if (UI.getUse().getResNo() >= DefTID.getNumDefs()) + continue; + const TargetRegisterClass *DefRC = + DefTID.OpInfo[UI.getUse().getResNo()].getRegClass(TRI); + + const TargetInstrDesc &UseTID = TII.get(UI->getMachineOpcode()); + if (UseTID.getNumDefs()+UI.getOperandNo() >= UseTID.getNumOperands()) + continue; + const TargetRegisterClass *UseRC = + UseTID.OpInfo[UseTID.getNumDefs()+UI.getOperandNo()].getRegClass(TRI); + if (!DefRC || !UseRC) + continue; + // We cannot copy CC <-> !(CC/D) + if ((isCC(DefRC) && !isDCC(UseRC)) || (isCC(UseRC) && !isDCC(DefRC))) { + SDNode *Copy = + DAG.getTargetNode(TargetInstrInfo::COPY_TO_REGCLASS, + NI->getDebugLoc(), + MVT::i32, + UI.getUse().get(), + DAG.getTargetConstant(BF::DRegClassID, MVT::i32)); + UpdateNodeOperand(DAG, *UI, UI.getOperandNo(), SDValue(Copy, 0)); + } + } + } + DAG.setRoot(Dummy.getValue()); +} + |