1//===-- MipsISelLowering.h - Mips 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 Mips uses to lower LLVM code into a
11// selection DAG.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_LIB_TARGET_MIPS_MIPSISELLOWERING_H
16#define LLVM_LIB_TARGET_MIPS_MIPSISELLOWERING_H
17
18#include "MCTargetDesc/MipsABIInfo.h"
19#include "MCTargetDesc/MipsBaseInfo.h"
20#include "Mips.h"
21#include "llvm/CodeGen/CallingConvLower.h"
22#include "llvm/CodeGen/SelectionDAG.h"
23#include "llvm/IR/Function.h"
24#include "llvm/Target/TargetLowering.h"
25#include <deque>
26#include <string>
27
28namespace llvm {
29  namespace MipsISD {
30    enum NodeType {
31      // Start the numbering from where ISD NodeType finishes.
32      FIRST_NUMBER = ISD::BUILTIN_OP_END,
33
34      // Jump and link (call)
35      JmpLink,
36
37      // Tail call
38      TailCall,
39
40      // Get the Higher 16 bits from a 32-bit immediate
41      // No relation with Mips Hi register
42      Hi,
43
44      // Get the Lower 16 bits from a 32-bit immediate
45      // No relation with Mips Lo register
46      Lo,
47
48      // Handle gp_rel (small data/bss sections) relocation.
49      GPRel,
50
51      // Thread Pointer
52      ThreadPointer,
53
54      // Floating Point Branch Conditional
55      FPBrcond,
56
57      // Floating Point Compare
58      FPCmp,
59
60      // Floating Point Conditional Moves
61      CMovFP_T,
62      CMovFP_F,
63
64      // FP-to-int truncation node.
65      TruncIntFP,
66
67      // Return
68      Ret,
69
70      EH_RETURN,
71
72      // Node used to extract integer from accumulator.
73      MFHI,
74      MFLO,
75
76      // Node used to insert integers to accumulator.
77      MTLOHI,
78
79      // Mult nodes.
80      Mult,
81      Multu,
82
83      // MAdd/Sub nodes
84      MAdd,
85      MAddu,
86      MSub,
87      MSubu,
88
89      // DivRem(u)
90      DivRem,
91      DivRemU,
92      DivRem16,
93      DivRemU16,
94
95      BuildPairF64,
96      ExtractElementF64,
97
98      Wrapper,
99
100      DynAlloc,
101
102      Sync,
103
104      Ext,
105      Ins,
106
107      // EXTR.W instrinsic nodes.
108      EXTP,
109      EXTPDP,
110      EXTR_S_H,
111      EXTR_W,
112      EXTR_R_W,
113      EXTR_RS_W,
114      SHILO,
115      MTHLIP,
116
117      // DPA.W intrinsic nodes.
118      MULSAQ_S_W_PH,
119      MAQ_S_W_PHL,
120      MAQ_S_W_PHR,
121      MAQ_SA_W_PHL,
122      MAQ_SA_W_PHR,
123      DPAU_H_QBL,
124      DPAU_H_QBR,
125      DPSU_H_QBL,
126      DPSU_H_QBR,
127      DPAQ_S_W_PH,
128      DPSQ_S_W_PH,
129      DPAQ_SA_L_W,
130      DPSQ_SA_L_W,
131      DPA_W_PH,
132      DPS_W_PH,
133      DPAQX_S_W_PH,
134      DPAQX_SA_W_PH,
135      DPAX_W_PH,
136      DPSX_W_PH,
137      DPSQX_S_W_PH,
138      DPSQX_SA_W_PH,
139      MULSA_W_PH,
140
141      MULT,
142      MULTU,
143      MADD_DSP,
144      MADDU_DSP,
145      MSUB_DSP,
146      MSUBU_DSP,
147
148      // DSP shift nodes.
149      SHLL_DSP,
150      SHRA_DSP,
151      SHRL_DSP,
152
153      // DSP setcc and select_cc nodes.
154      SETCC_DSP,
155      SELECT_CC_DSP,
156
157      // Vector comparisons.
158      // These take a vector and return a boolean.
159      VALL_ZERO,
160      VANY_ZERO,
161      VALL_NONZERO,
162      VANY_NONZERO,
163
164      // These take a vector and return a vector bitmask.
165      VCEQ,
166      VCLE_S,
167      VCLE_U,
168      VCLT_S,
169      VCLT_U,
170
171      // Element-wise vector max/min.
172      VSMAX,
173      VSMIN,
174      VUMAX,
175      VUMIN,
176
177      // Vector Shuffle with mask as an operand
178      VSHF,  // Generic shuffle
179      SHF,   // 4-element set shuffle.
180      ILVEV, // Interleave even elements
181      ILVOD, // Interleave odd elements
182      ILVL,  // Interleave left elements
183      ILVR,  // Interleave right elements
184      PCKEV, // Pack even elements
185      PCKOD, // Pack odd elements
186
187      // Vector Lane Copy
188      INSVE, // Copy element from one vector to another
189
190      // Combined (XOR (OR $a, $b), -1)
191      VNOR,
192
193      // Extended vector element extraction
194      VEXTRACT_SEXT_ELT,
195      VEXTRACT_ZEXT_ELT,
196
197      // Load/Store Left/Right nodes.
198      LWL = ISD::FIRST_TARGET_MEMORY_OPCODE,
199      LWR,
200      SWL,
201      SWR,
202      LDL,
203      LDR,
204      SDL,
205      SDR
206    };
207  }
208
209  //===--------------------------------------------------------------------===//
210  // TargetLowering Implementation
211  //===--------------------------------------------------------------------===//
212  class MipsFunctionInfo;
213  class MipsSubtarget;
214  class MipsCCState;
215
216  class MipsTargetLowering : public TargetLowering  {
217    bool isMicroMips;
218  public:
219    explicit MipsTargetLowering(const MipsTargetMachine &TM,
220                                const MipsSubtarget &STI);
221
222    static const MipsTargetLowering *create(const MipsTargetMachine &TM,
223                                            const MipsSubtarget &STI);
224
225    /// createFastISel - This method returns a target specific FastISel object,
226    /// or null if the target does not support "fast" ISel.
227    FastISel *createFastISel(FunctionLoweringInfo &funcInfo,
228                             const TargetLibraryInfo *libInfo) const override;
229
230    MVT getScalarShiftAmountTy(EVT LHSTy) const override { return MVT::i32; }
231
232    void LowerOperationWrapper(SDNode *N,
233                               SmallVectorImpl<SDValue> &Results,
234                               SelectionDAG &DAG) const override;
235
236    /// LowerOperation - Provide custom lowering hooks for some operations.
237    SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
238
239    /// ReplaceNodeResults - Replace the results of node with an illegal result
240    /// type with new values built out of custom code.
241    ///
242    void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue>&Results,
243                            SelectionDAG &DAG) const override;
244
245    /// getTargetNodeName - This method returns the name of a target specific
246    //  DAG node.
247    const char *getTargetNodeName(unsigned Opcode) const override;
248
249    /// getSetCCResultType - get the ISD::SETCC result ValueType
250    EVT getSetCCResultType(LLVMContext &Context, EVT VT) const override;
251
252    SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const override;
253
254    MachineBasicBlock *
255    EmitInstrWithCustomInserter(MachineInstr *MI,
256                                MachineBasicBlock *MBB) const override;
257
258    struct LTStr {
259      bool operator()(const char *S1, const char *S2) const {
260        return strcmp(S1, S2) < 0;
261      }
262    };
263
264    void HandleByVal(CCState *, unsigned &, unsigned) const override;
265
266    unsigned getRegisterByName(const char* RegName, EVT VT) const override;
267
268  protected:
269    SDValue getGlobalReg(SelectionDAG &DAG, EVT Ty) const;
270
271    // This method creates the following nodes, which are necessary for
272    // computing a local symbol's address:
273    //
274    // (add (load (wrapper $gp, %got(sym)), %lo(sym))
275    template <class NodeTy>
276    SDValue getAddrLocal(NodeTy *N, SDLoc DL, EVT Ty, SelectionDAG &DAG,
277                         bool IsN32OrN64) const {
278      unsigned GOTFlag = IsN32OrN64 ? MipsII::MO_GOT_PAGE : MipsII::MO_GOT;
279      SDValue GOT = DAG.getNode(MipsISD::Wrapper, DL, Ty, getGlobalReg(DAG, Ty),
280                                getTargetNode(N, Ty, DAG, GOTFlag));
281      SDValue Load = DAG.getLoad(Ty, DL, DAG.getEntryNode(), GOT,
282                                 MachinePointerInfo::getGOT(), false, false,
283                                 false, 0);
284      unsigned LoFlag = IsN32OrN64 ? MipsII::MO_GOT_OFST : MipsII::MO_ABS_LO;
285      SDValue Lo = DAG.getNode(MipsISD::Lo, DL, Ty,
286                               getTargetNode(N, Ty, DAG, LoFlag));
287      return DAG.getNode(ISD::ADD, DL, Ty, Load, Lo);
288    }
289
290    // This method creates the following nodes, which are necessary for
291    // computing a global symbol's address:
292    //
293    // (load (wrapper $gp, %got(sym)))
294    template <class NodeTy>
295    SDValue getAddrGlobal(NodeTy *N, SDLoc DL, EVT Ty, SelectionDAG &DAG,
296                          unsigned Flag, SDValue Chain,
297                          const MachinePointerInfo &PtrInfo) const {
298      SDValue Tgt = DAG.getNode(MipsISD::Wrapper, DL, Ty, getGlobalReg(DAG, Ty),
299                                getTargetNode(N, Ty, DAG, Flag));
300      return DAG.getLoad(Ty, DL, Chain, Tgt, PtrInfo, false, false, false, 0);
301    }
302
303    // This method creates the following nodes, which are necessary for
304    // computing a global symbol's address in large-GOT mode:
305    //
306    // (load (wrapper (add %hi(sym), $gp), %lo(sym)))
307    template <class NodeTy>
308    SDValue getAddrGlobalLargeGOT(NodeTy *N, SDLoc DL, EVT Ty,
309                                  SelectionDAG &DAG, unsigned HiFlag,
310                                  unsigned LoFlag, SDValue Chain,
311                                  const MachinePointerInfo &PtrInfo) const {
312      SDValue Hi =
313          DAG.getNode(MipsISD::Hi, DL, Ty, getTargetNode(N, Ty, DAG, HiFlag));
314      Hi = DAG.getNode(ISD::ADD, DL, Ty, Hi, getGlobalReg(DAG, Ty));
315      SDValue Wrapper = DAG.getNode(MipsISD::Wrapper, DL, Ty, Hi,
316                                    getTargetNode(N, Ty, DAG, LoFlag));
317      return DAG.getLoad(Ty, DL, Chain, Wrapper, PtrInfo, false, false, false,
318                         0);
319    }
320
321    // This method creates the following nodes, which are necessary for
322    // computing a symbol's address in non-PIC mode:
323    //
324    // (add %hi(sym), %lo(sym))
325    template <class NodeTy>
326    SDValue getAddrNonPIC(NodeTy *N, SDLoc DL, EVT Ty,
327                          SelectionDAG &DAG) const {
328      SDValue Hi = getTargetNode(N, Ty, DAG, MipsII::MO_ABS_HI);
329      SDValue Lo = getTargetNode(N, Ty, DAG, MipsII::MO_ABS_LO);
330      return DAG.getNode(ISD::ADD, DL, Ty,
331                         DAG.getNode(MipsISD::Hi, DL, Ty, Hi),
332                         DAG.getNode(MipsISD::Lo, DL, Ty, Lo));
333    }
334
335    // This method creates the following nodes, which are necessary for
336    // computing a symbol's address using gp-relative addressing:
337    //
338    // (add $gp, %gp_rel(sym))
339    template <class NodeTy>
340    SDValue getAddrGPRel(NodeTy *N, SDLoc DL, EVT Ty, SelectionDAG &DAG) const {
341      assert(Ty == MVT::i32);
342      SDValue GPRel = getTargetNode(N, Ty, DAG, MipsII::MO_GPREL);
343      return DAG.getNode(ISD::ADD, DL, Ty,
344                         DAG.getRegister(Mips::GP, Ty),
345                         DAG.getNode(MipsISD::GPRel, DL, DAG.getVTList(Ty),
346                                     GPRel));
347    }
348
349    /// This function fills Ops, which is the list of operands that will later
350    /// be used when a function call node is created. It also generates
351    /// copyToReg nodes to set up argument registers.
352    virtual void
353    getOpndList(SmallVectorImpl<SDValue> &Ops,
354                std::deque< std::pair<unsigned, SDValue> > &RegsToPass,
355                bool IsPICCall, bool GlobalOrExternal, bool InternalLinkage,
356                bool IsCallReloc, CallLoweringInfo &CLI, SDValue Callee,
357                SDValue Chain) const;
358
359  protected:
360    SDValue lowerLOAD(SDValue Op, SelectionDAG &DAG) const;
361    SDValue lowerSTORE(SDValue Op, SelectionDAG &DAG) const;
362
363    // Subtarget Info
364    const MipsSubtarget &Subtarget;
365    // Cache the ABI from the TargetMachine, we use it everywhere.
366    const MipsABIInfo &ABI;
367
368  private:
369    // Create a TargetGlobalAddress node.
370    SDValue getTargetNode(GlobalAddressSDNode *N, EVT Ty, SelectionDAG &DAG,
371                          unsigned Flag) const;
372
373    // Create a TargetExternalSymbol node.
374    SDValue getTargetNode(ExternalSymbolSDNode *N, EVT Ty, SelectionDAG &DAG,
375                          unsigned Flag) const;
376
377    // Create a TargetBlockAddress node.
378    SDValue getTargetNode(BlockAddressSDNode *N, EVT Ty, SelectionDAG &DAG,
379                          unsigned Flag) const;
380
381    // Create a TargetJumpTable node.
382    SDValue getTargetNode(JumpTableSDNode *N, EVT Ty, SelectionDAG &DAG,
383                          unsigned Flag) const;
384
385    // Create a TargetConstantPool node.
386    SDValue getTargetNode(ConstantPoolSDNode *N, EVT Ty, SelectionDAG &DAG,
387                          unsigned Flag) const;
388
389    // Lower Operand helpers
390    SDValue LowerCallResult(SDValue Chain, SDValue InFlag,
391                            CallingConv::ID CallConv, bool isVarArg,
392                            const SmallVectorImpl<ISD::InputArg> &Ins, SDLoc dl,
393                            SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals,
394                            TargetLowering::CallLoweringInfo &CLI) const;
395
396    // Lower Operand specifics
397    SDValue lowerBR_JT(SDValue Op, SelectionDAG &DAG) const;
398    SDValue lowerBRCOND(SDValue Op, SelectionDAG &DAG) const;
399    SDValue lowerConstantPool(SDValue Op, SelectionDAG &DAG) const;
400    SDValue lowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
401    SDValue lowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
402    SDValue lowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
403    SDValue lowerJumpTable(SDValue Op, SelectionDAG &DAG) const;
404    SDValue lowerSELECT(SDValue Op, SelectionDAG &DAG) const;
405    SDValue lowerSELECT_CC(SDValue Op, SelectionDAG &DAG) const;
406    SDValue lowerSETCC(SDValue Op, SelectionDAG &DAG) const;
407    SDValue lowerVASTART(SDValue Op, SelectionDAG &DAG) const;
408    SDValue lowerVAARG(SDValue Op, SelectionDAG &DAG) const;
409    SDValue lowerFCOPYSIGN(SDValue Op, SelectionDAG &DAG) const;
410    SDValue lowerFABS(SDValue Op, SelectionDAG &DAG) const;
411    SDValue lowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
412    SDValue lowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
413    SDValue lowerEH_RETURN(SDValue Op, SelectionDAG &DAG) const;
414    SDValue lowerATOMIC_FENCE(SDValue Op, SelectionDAG& DAG) const;
415    SDValue lowerShiftLeftParts(SDValue Op, SelectionDAG& DAG) const;
416    SDValue lowerShiftRightParts(SDValue Op, SelectionDAG& DAG,
417                                 bool IsSRA) const;
418    SDValue lowerADD(SDValue Op, SelectionDAG &DAG) const;
419    SDValue lowerFP_TO_SINT(SDValue Op, SelectionDAG &DAG) const;
420
421    /// isEligibleForTailCallOptimization - Check whether the call is eligible
422    /// for tail call optimization.
423    virtual bool
424    isEligibleForTailCallOptimization(const CCState &CCInfo,
425                                      unsigned NextStackOffset,
426                                      const MipsFunctionInfo &FI) const = 0;
427
428    /// copyByValArg - Copy argument registers which were used to pass a byval
429    /// argument to the stack. Create a stack frame object for the byval
430    /// argument.
431    void copyByValRegs(SDValue Chain, SDLoc DL, std::vector<SDValue> &OutChains,
432                       SelectionDAG &DAG, const ISD::ArgFlagsTy &Flags,
433                       SmallVectorImpl<SDValue> &InVals,
434                       const Argument *FuncArg, unsigned FirstReg,
435                       unsigned LastReg, const CCValAssign &VA,
436                       MipsCCState &State) const;
437
438    /// passByValArg - Pass a byval argument in registers or on stack.
439    void passByValArg(SDValue Chain, SDLoc DL,
440                      std::deque<std::pair<unsigned, SDValue>> &RegsToPass,
441                      SmallVectorImpl<SDValue> &MemOpChains, SDValue StackPtr,
442                      MachineFrameInfo *MFI, SelectionDAG &DAG, SDValue Arg,
443                      unsigned FirstReg, unsigned LastReg,
444                      const ISD::ArgFlagsTy &Flags, bool isLittle,
445                      const CCValAssign &VA) const;
446
447    /// writeVarArgRegs - Write variable function arguments passed in registers
448    /// to the stack. Also create a stack frame object for the first variable
449    /// argument.
450    void writeVarArgRegs(std::vector<SDValue> &OutChains, SDValue Chain,
451                         SDLoc DL, SelectionDAG &DAG, CCState &State) const;
452
453    SDValue
454      LowerFormalArguments(SDValue Chain,
455                           CallingConv::ID CallConv, bool isVarArg,
456                           const SmallVectorImpl<ISD::InputArg> &Ins,
457                           SDLoc dl, SelectionDAG &DAG,
458                           SmallVectorImpl<SDValue> &InVals) const override;
459
460    SDValue passArgOnStack(SDValue StackPtr, unsigned Offset, SDValue Chain,
461                           SDValue Arg, SDLoc DL, bool IsTailCall,
462                           SelectionDAG &DAG) const;
463
464    SDValue LowerCall(TargetLowering::CallLoweringInfo &CLI,
465                      SmallVectorImpl<SDValue> &InVals) const override;
466
467    bool CanLowerReturn(CallingConv::ID CallConv, MachineFunction &MF,
468                        bool isVarArg,
469                        const SmallVectorImpl<ISD::OutputArg> &Outs,
470                        LLVMContext &Context) const override;
471
472    SDValue LowerReturn(SDValue Chain,
473                        CallingConv::ID CallConv, bool isVarArg,
474                        const SmallVectorImpl<ISD::OutputArg> &Outs,
475                        const SmallVectorImpl<SDValue> &OutVals,
476                        SDLoc dl, SelectionDAG &DAG) const override;
477
478    bool shouldSignExtendTypeInLibCall(EVT Type, bool IsSigned) const override;
479
480    // Inline asm support
481    ConstraintType
482      getConstraintType(const std::string &Constraint) const override;
483
484    /// Examine constraint string and operand type and determine a weight value.
485    /// The operand object must already have been set up with the operand type.
486    ConstraintWeight getSingleConstraintMatchWeight(
487      AsmOperandInfo &info, const char *constraint) const override;
488
489    /// This function parses registers that appear in inline-asm constraints.
490    /// It returns pair (0, 0) on failure.
491    std::pair<unsigned, const TargetRegisterClass *>
492    parseRegForInlineAsmConstraint(StringRef C, MVT VT) const;
493
494    std::pair<unsigned, const TargetRegisterClass *>
495    getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
496                                 const std::string &Constraint,
497                                 MVT VT) const override;
498
499    /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
500    /// vector.  If it is invalid, don't add anything to Ops. If hasMemory is
501    /// true it means one of the asm constraint of the inline asm instruction
502    /// being processed is 'm'.
503    void LowerAsmOperandForConstraint(SDValue Op,
504                                      std::string &Constraint,
505                                      std::vector<SDValue> &Ops,
506                                      SelectionDAG &DAG) const override;
507
508    unsigned getInlineAsmMemConstraint(
509        const std::string &ConstraintCode) const override {
510      if (ConstraintCode == "R")
511        return InlineAsm::Constraint_R;
512      else if (ConstraintCode == "ZC")
513        return InlineAsm::Constraint_ZC;
514      return TargetLowering::getInlineAsmMemConstraint(ConstraintCode);
515    }
516
517    bool isLegalAddressingMode(const AddrMode &AM, Type *Ty) const override;
518
519    bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const override;
520
521    EVT getOptimalMemOpType(uint64_t Size, unsigned DstAlign,
522                            unsigned SrcAlign,
523                            bool IsMemset, bool ZeroMemset,
524                            bool MemcpyStrSrc,
525                            MachineFunction &MF) const override;
526
527    /// isFPImmLegal - Returns true if the target can instruction select the
528    /// specified FP immediate natively. If false, the legalizer will
529    /// materialize the FP immediate as a load from a constant pool.
530    bool isFPImmLegal(const APFloat &Imm, EVT VT) const override;
531
532    unsigned getJumpTableEncoding() const override;
533
534    /// Emit a sign-extension using sll/sra, seb, or seh appropriately.
535    MachineBasicBlock *emitSignExtendToI32InReg(MachineInstr *MI,
536                                                MachineBasicBlock *BB,
537                                                unsigned Size, unsigned DstReg,
538                                                unsigned SrcRec) const;
539
540    MachineBasicBlock *emitAtomicBinary(MachineInstr *MI, MachineBasicBlock *BB,
541                    unsigned Size, unsigned BinOpcode, bool Nand = false) const;
542    MachineBasicBlock *emitAtomicBinaryPartword(MachineInstr *MI,
543                    MachineBasicBlock *BB, unsigned Size, unsigned BinOpcode,
544                    bool Nand = false) const;
545    MachineBasicBlock *emitAtomicCmpSwap(MachineInstr *MI,
546                                  MachineBasicBlock *BB, unsigned Size) const;
547    MachineBasicBlock *emitAtomicCmpSwapPartword(MachineInstr *MI,
548                                  MachineBasicBlock *BB, unsigned Size) const;
549    MachineBasicBlock *emitSEL_D(MachineInstr *MI, MachineBasicBlock *BB) const;
550    MachineBasicBlock *emitPseudoSELECT(MachineInstr *MI,
551                                        MachineBasicBlock *BB, bool isFPCmp,
552                                        unsigned Opc) const;
553  };
554
555  /// Create MipsTargetLowering objects.
556  const MipsTargetLowering *
557  createMips16TargetLowering(const MipsTargetMachine &TM,
558                             const MipsSubtarget &STI);
559  const MipsTargetLowering *
560  createMipsSETargetLowering(const MipsTargetMachine &TM,
561                             const MipsSubtarget &STI);
562
563  namespace Mips {
564    FastISel *createFastISel(FunctionLoweringInfo &funcInfo,
565                             const TargetLibraryInfo *libInfo);
566  }
567}
568
569#endif
570