lib/Target/PIC16/PIC16ISelLowering.h

   1 //===-- PIC16ISelLowering.h - PIC16 DAG Lowering Interface ------*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file defines the interfaces that PIC16 uses to lower LLVM code into a
  11 // selection DAG.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #ifndef PIC16ISELLOWERING_H
  16 #define PIC16ISELLOWERING_H
  17
  18 #include "PIC16.h"
  19 #include "PIC16Subtarget.h"
  20 #include "llvm/CodeGen/SelectionDAG.h"
  21 #include "llvm/Target/TargetLowering.h"
  22 #include <map>
  23
  24 namespace llvm {
  25   namespace PIC16ISD {
  26     enum NodeType {
  27       // Start the numbering from where ISD NodeType finishes.
  28       FIRST_NUMBER = ISD::BUILTIN_OP_END,
  29
  30       Lo,            // Low 8-bits of GlobalAddress.
  31       Hi,            // High 8-bits of GlobalAddress.
  32       PIC16Load,
  33       PIC16LdArg,   // This is replica of PIC16Load but used to load function
  34                     // arguments and is being used for facilitating for some
  35                     // store removal optimizations.
  36
  37       PIC16LdWF,
  38       PIC16Store,
  39       PIC16StWF,
  40       Banksel,
  41       MTLO,          // Move to low part of FSR
  42       MTHI,          // Move to high part of FSR
  43       MTPCLATH,      // Move to PCLATCH
  44       PIC16Connect,  // General connector for PIC16 nodes
  45       BCF,
  46       LSLF,          // PIC16 Logical shift left
  47       LRLF,          // PIC16 Logical shift right
  48       RLF,           // Rotate left through carry
  49       RRF,           // Rotate right through carry
  50       CALL,          // PIC16 Call instruction
  51       CALLW,         // PIC16 CALLW instruction
  52       SUBCC,         // Compare for equality or inequality.
  53       SELECT_ICC,    // Psuedo to be caught in schedular and expanded to brcond.
  54       BRCOND,        // Conditional branch.
  55       Dummy
  56     };
  57
  58     // Keep track of different address spaces.
  59     enum AddressSpace {
  60       RAM_SPACE = 0,   // RAM address space
  61       ROM_SPACE = 1    // ROM address space number is 1
  62     };
  63     enum PIC16Libcall {
  64       MUL_I8,
  65       SRA_I8,
  66       SLL_I8,
  67       SRL_I8,
  68       PIC16UnknownCall
  69     };
  70   }
  71
  72
  73   //===--------------------------------------------------------------------===//
  74   // TargetLowering Implementation
  75   //===--------------------------------------------------------------------===//
  76   class PIC16TargetLowering : public TargetLowering {
  77   public:
  78     explicit PIC16TargetLowering(PIC16TargetMachine &TM);
  79
  80     /// getTargetNodeName - This method returns the name of a target specific
  81     /// DAG node.
  82     virtual const char *getTargetNodeName(unsigned Opcode) const;
  83     /// getSetCCResultType - Return the ISD::SETCC ValueType
  84     virtual MVT getSetCCResultType(MVT ValType) const;
  85     SDValue LowerFORMAL_ARGUMENTS(SDValue Op, SelectionDAG &DAG);
  86     SDValue LowerShift(SDValue Op, SelectionDAG &DAG);
  87     SDValue LowerADD(SDValue Op, SelectionDAG &DAG);
  88     SDValue LowerSUB(SDValue Op, SelectionDAG &DAG);
  89     SDValue LowerBinOp(SDValue Op, SelectionDAG &DAG);
  90     SDValue LowerCALL(SDValue Op, SelectionDAG &DAG);
  91     SDValue LowerRET(SDValue Op, SelectionDAG &DAG);
  92     // Call returns
  93     SDValue
  94     LowerDirectCallReturn(SDValue Op, SDValue Chain, SDValue FrameAddress,
  95                           SDValue InFlag, SelectionDAG &DAG);
  96     SDValue
  97     LowerIndirectCallReturn(SDValue Op, SDValue Chain, SDValue InFlag,
  98                             SDValue DataAddr_Lo, SDValue DataAddr_Hi,
  99                             SelectionDAG &DAG);
 100
 101     // Call arguments
 102     SDValue
 103     LowerDirectCallArguments(SDValue Op, SDValue Chain, SDValue FrameAddress,
 104                              SDValue InFlag, SelectionDAG &DAG);
 105
 106     SDValue
 107     LowerIndirectCallArguments(SDValue Op, SDValue Chain, SDValue InFlag,
 108                                SDValue DataAddr_Lo, SDValue DataAddr_Hi,
 109                                SelectionDAG &DAG);
 110
 111     SDValue LowerBR_CC(SDValue Op, SelectionDAG &DAG);
 112     SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG);
 113     SDValue getPIC16Cmp(SDValue LHS, SDValue RHS, unsigned OrigCC, SDValue &CC,
 114                         SelectionDAG &DAG, DebugLoc dl);
 115     virtual MachineBasicBlock *EmitInstrWithCustomInserter(MachineInstr *MI,
 116                                                   MachineBasicBlock *MBB) const;
 117
 118
 119     virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG);
 120     virtual void ReplaceNodeResults(SDNode *N,
 121                                     SmallVectorImpl<SDValue> &Results,
 122                                     SelectionDAG &DAG);
 123     virtual void LowerOperationWrapper(SDNode *N,
 124                                        SmallVectorImpl<SDValue> &Results,
 125                                        SelectionDAG &DAG);
 126
 127     SDValue ExpandStore(SDNode *N, SelectionDAG &DAG);
 128     SDValue ExpandLoad(SDNode *N, SelectionDAG &DAG);
 129     SDValue ExpandGlobalAddress(SDNode *N, SelectionDAG &DAG);
 130     SDValue ExpandExternalSymbol(SDNode *N, SelectionDAG &DAG);
 131     SDValue ExpandFrameIndex(SDNode *N, SelectionDAG &DAG);
 132
 133     SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const;
 134     SDValue PerformPIC16LoadCombine(SDNode *N, DAGCombinerInfo &DCI) const;
 135     SDValue PerformStoreCombine(SDNode *N, DAGCombinerInfo &DCI) const;
 136
 137     // This function returns the Tmp Offset for FrameIndex. If any TmpOffset
 138     // already exists for the FI then it returns the same else it creates the
 139     // new offset and returns.
 140     unsigned GetTmpOffsetForFI(unsigned FI, unsigned slot_size);
 141     void ResetTmpOffsetMap() { FiTmpOffsetMap.clear(); SetTmpSize(0); }
 142     void InitReservedFrameCount(const Function *F);
 143
 144     // Return the size of Tmp variable
 145     unsigned GetTmpSize() { return TmpSize; }
 146     void SetTmpSize(unsigned Size) { TmpSize = Size; }
 147
 148   private:
 149     // If the Node is a BUILD_PAIR representing a direct Address,
 150     // then this function will return true.
 151     bool isDirectAddress(const SDValue &Op);
 152
 153     // If the Node is a DirectAddress in ROM_SPACE then this
 154     // function will return true
 155     bool isRomAddress(const SDValue &Op);
 156
 157     // Extract the Lo and Hi component of Op.
 158     void GetExpandedParts(SDValue Op, SelectionDAG &DAG, SDValue &Lo,
 159                           SDValue &Hi);
 160
 161
 162     // Load pointer can be a direct or indirect address. In PIC16 direct
 163     // addresses need Banksel and Indirect addresses need to be loaded to
 164     // FSR first. Handle address specific cases here.
 165     void LegalizeAddress(SDValue Ptr, SelectionDAG &DAG, SDValue &Chain,
 166                          SDValue &NewPtr, unsigned &Offset, DebugLoc dl);
 167
 168     // FrameIndex should be broken down into ExternalSymbol and FrameOffset.
 169     void LegalizeFrameIndex(SDValue Op, SelectionDAG &DAG, SDValue &ES,
 170                             int &Offset);
 171
 172
 173     // CALL node should have all legal operands only. Legalize all non-legal
 174     // operands of CALL node and then return the new call will all operands
 175     // legal.
 176     SDValue LegalizeCALL(SDValue Op, SelectionDAG &DAG);
 177
 178     // For indirect calls data address of the callee frame need to be
 179     // extracted. This function fills the arguments DataAddr_Lo and
 180     // DataAddr_Hi with the address of the callee frame.
 181     void GetDataAddress(DebugLoc dl, SDValue Callee, SDValue &Chain,
 182                         SDValue &DataAddr_Lo, SDValue &DataAddr_Hi,
 183                         SelectionDAG &DAG);
 184
 185     // We can not have both operands of a binary operation in W.
 186     // This function is used to put one operand on stack and generate a load.
 187     SDValue ConvertToMemOperand(SDValue Op, SelectionDAG &DAG, DebugLoc dl);
 188
 189     // This function checks if we need to put an operand of an operation on
 190     // stack and generate a load or not.
 191     bool NeedToConvertToMemOp(SDValue Op, unsigned &MemOp);
 192
 193     /// Subtarget - Keep a pointer to the PIC16Subtarget around so that we can
 194     /// make the right decision when generating code for different targets.
 195     const PIC16Subtarget *Subtarget;
 196
 197
 198     // Extending the LIB Call framework of LLVM
 199     // to hold the names of PIC16Libcalls.
 200     const char *PIC16LibcallNames[PIC16ISD::PIC16UnknownCall];
 201
 202     // To set and retrieve the lib call names.
 203     void setPIC16LibcallName(PIC16ISD::PIC16Libcall Call, const char *Name);
 204     const char *getPIC16LibcallName(PIC16ISD::PIC16Libcall Call);
 205
 206     // Make PIC16 Libcall.
 207     SDValue MakePIC16Libcall(PIC16ISD::PIC16Libcall Call, MVT RetVT,
 208                              const SDValue *Ops, unsigned NumOps, bool isSigned,
 209                              SelectionDAG &DAG, DebugLoc dl);
 210
 211     // Check if operation has a direct load operand.
 212     inline bool isDirectLoad(const SDValue Op);
 213
 214   private:
 215     // The frameindexes generated for spill/reload are stack based.
 216     // This maps maintain zero based indexes for these FIs.
 217     std::map<unsigned, unsigned> FiTmpOffsetMap;
 218     unsigned TmpSize;
 219
 220     // These are the frames for return value and argument passing
 221     // These FrameIndices will be expanded to foo.frame external symbol
 222     // and all others will be expanded to foo.tmp external symbol.
 223     unsigned ReservedFrameCount;
 224   };
 225 } // namespace llvm
 226
 227 #endif // PIC16ISELLOWERING_H