1 //===-- RISCVISelLowering.h - RISCV DAG Lowering Interface ------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines the interfaces that RISCV uses to lower LLVM code into a
10 // selection DAG.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_LIB_TARGET_RISCV_RISCVISELLOWERING_H
15 #define LLVM_LIB_TARGET_RISCV_RISCVISELLOWERING_H
16 
17 #include "RISCV.h"
18 #include "llvm/CodeGen/SelectionDAG.h"
19 #include "llvm/CodeGen/TargetLowering.h"
20 
21 namespace llvm {
22 class RISCVSubtarget;
23 struct RISCVRegisterInfo;
24 namespace RISCVISD {
25 enum NodeType : unsigned {
26   FIRST_NUMBER = ISD::BUILTIN_OP_END,
27   RET_FLAG,
28   URET_FLAG,
29   SRET_FLAG,
30   MRET_FLAG,
31   CALL,
32   /// Select with condition operator - This selects between a true value and
33   /// a false value (ops #3 and #4) based on the boolean result of comparing
34   /// the lhs and rhs (ops #0 and #1) of a conditional expression with the
35   /// condition code in op #2, a XLenVT constant from the ISD::CondCode enum.
36   /// The lhs and rhs are XLenVT integers. The true and false values can be
37   /// integer or floating point.
38   SELECT_CC,
39   BR_CC,
40   BuildPairF64,
41   SplitF64,
42   TAIL,
43   // Multiply high for signedxunsigned.
44   MULHSU,
45   // RV64I shifts, directly matching the semantics of the named RISC-V
46   // instructions.
47   SLLW,
48   SRAW,
49   SRLW,
50   // 32-bit operations from RV64M that can't be simply matched with a pattern
51   // at instruction selection time. These have undefined behavior for division
52   // by 0 or overflow (divw) like their target independent counterparts.
53   DIVW,
54   DIVUW,
55   REMUW,
56   // RV64IB rotates, directly matching the semantics of the named RISC-V
57   // instructions.
58   ROLW,
59   RORW,
60   // RV64IZbb bit counting instructions directly matching the semantics of the
61   // named RISC-V instructions.
62   CLZW,
63   CTZW,
64   // RV64IB/RV32IB funnel shifts, with the semantics of the named RISC-V
65   // instructions, but the same operand order as fshl/fshr intrinsics.
66   FSR,
67   FSL,
68   // RV64IB funnel shifts, with the semantics of the named RISC-V instructions,
69   // but the same operand order as fshl/fshr intrinsics.
70   FSRW,
71   FSLW,
72   // FPR<->GPR transfer operations when the FPR is smaller than XLEN, needed as
73   // XLEN is the only legal integer width.
74   //
75   // FMV_H_X matches the semantics of the FMV.H.X.
76   // FMV_X_ANYEXTH is similar to FMV.X.H but has an any-extended result.
77   // FMV_W_X_RV64 matches the semantics of the FMV.W.X.
78   // FMV_X_ANYEXTW_RV64 is similar to FMV.X.W but has an any-extended result.
79   //
80   // This is a more convenient semantic for producing dagcombines that remove
81   // unnecessary GPR->FPR->GPR moves.
82   FMV_H_X,
83   FMV_X_ANYEXTH,
84   FMV_W_X_RV64,
85   FMV_X_ANYEXTW_RV64,
86   // READ_CYCLE_WIDE - A read of the 64-bit cycle CSR on a 32-bit target
87   // (returns (Lo, Hi)). It takes a chain operand.
88   READ_CYCLE_WIDE,
89   // Generalized Reverse and Generalized Or-Combine - directly matching the
90   // semantics of the named RISC-V instructions. Lowered as custom nodes as
91   // TableGen chokes when faced with commutative permutations in deeply-nested
92   // DAGs. Each node takes an input operand and a control operand and outputs a
93   // bit-manipulated version of input. All operands are i32 or XLenVT.
94   GREV,
95   GREVW,
96   GORC,
97   GORCW,
98   SHFL,
99   // Vector Extension
100   // VMV_V_X_VL matches the semantics of vmv.v.x but includes an extra operand
101   // for the VL value to be used for the operation.
102   VMV_V_X_VL,
103   // VFMV_V_F_VL matches the semantics of vfmv.v.f but includes an extra operand
104   // for the VL value to be used for the operation.
105   VFMV_V_F_VL,
106   // VMV_X_S matches the semantics of vmv.x.s. The result is always XLenVT sign
107   // extended from the vector element size.
108   VMV_X_S,
109   // VMV_S_X_VL matches the semantics of vmv.s.x. It carries a VL operand.
110   VMV_S_X_VL,
111   // VFMV_S_F_VL matches the semantics of vfmv.s.f. It carries a VL operand.
112   VFMV_S_F_VL,
113   // Splats an i64 scalar to a vector type (with element type i64) where the
114   // scalar is a sign-extended i32.
115   SPLAT_VECTOR_I64,
116   // Read VLENB CSR
117   READ_VLENB,
118   // Truncates a RVV integer vector by one power-of-two. Carries both an extra
119   // mask and VL operand.
120   TRUNCATE_VECTOR_VL,
121   // Unit-stride fault-only-first load
122   VLEFF,
123   VLEFF_MASK,
124   // Matches the semantics of vslideup/vslidedown. The first operand is the
125   // pass-thru operand, the second is the source vector, the third is the
126   // XLenVT index (either constant or non-constant), the fourth is the mask
127   // and the fifth the VL.
128   VSLIDEUP_VL,
129   VSLIDEDOWN_VL,
130   // Matches the semantics of vslide1up/slide1down. The first operand is the
131   // source vector, the second is the XLenVT scalar value. The third and fourth
132   // operands are the mask and VL operands.
133   VSLIDE1UP_VL,
134   VSLIDE1DOWN_VL,
135   // Matches the semantics of the vid.v instruction, with a mask and VL
136   // operand.
137   VID_VL,
138   // Matches the semantics of the vfcnvt.rod function (Convert double-width
139   // float to single-width float, rounding towards odd). Takes a double-width
140   // float vector and produces a single-width float vector. Also has a mask and
141   // VL operand.
142   VFNCVT_ROD_VL,
143   // These nodes match the semantics of the corresponding RVV vector reduction
144   // instructions. They produce a vector result which is the reduction
145   // performed over the first vector operand plus the first element of the
146   // second vector operand. The first operand is an unconstrained vector type,
147   // and the result and second operand's types are expected to be the
148   // corresponding full-width LMUL=1 type for the first operand:
149   //   nxv8i8 = vecreduce_add nxv32i8, nxv8i8
150   //   nxv2i32 = vecreduce_add nxv8i32, nxv2i32
151   // The different in types does introduce extra vsetvli instructions but
152   // similarly it reduces the number of registers consumed per reduction.
153   // Also has a mask and VL operand.
154   VECREDUCE_ADD_VL,
155   VECREDUCE_UMAX_VL,
156   VECREDUCE_SMAX_VL,
157   VECREDUCE_UMIN_VL,
158   VECREDUCE_SMIN_VL,
159   VECREDUCE_AND_VL,
160   VECREDUCE_OR_VL,
161   VECREDUCE_XOR_VL,
162   VECREDUCE_FADD_VL,
163   VECREDUCE_SEQ_FADD_VL,
164 
165   // Vector binary and unary ops with a mask as a third operand, and VL as a
166   // fourth operand.
167   // FIXME: Can we replace these with ISD::VP_*?
168   ADD_VL,
169   AND_VL,
170   MUL_VL,
171   OR_VL,
172   SDIV_VL,
173   SHL_VL,
174   SREM_VL,
175   SRA_VL,
176   SRL_VL,
177   SUB_VL,
178   UDIV_VL,
179   UREM_VL,
180   XOR_VL,
181   FADD_VL,
182   FSUB_VL,
183   FMUL_VL,
184   FDIV_VL,
185   FNEG_VL,
186   FABS_VL,
187   FSQRT_VL,
188   FMA_VL,
189   FCOPYSIGN_VL,
190   SMIN_VL,
191   SMAX_VL,
192   UMIN_VL,
193   UMAX_VL,
194   MULHS_VL,
195   MULHU_VL,
196   FP_TO_SINT_VL,
197   FP_TO_UINT_VL,
198   SINT_TO_FP_VL,
199   UINT_TO_FP_VL,
200   FP_ROUND_VL,
201   FP_EXTEND_VL,
202 
203   // Vector compare producing a mask. Fourth operand is input mask. Fifth
204   // operand is VL.
205   SETCC_VL,
206 
207   // Vector select with an additional VL operand. This operation is unmasked.
208   VSELECT_VL,
209 
210   // Mask binary operators.
211   VMAND_VL,
212   VMOR_VL,
213   VMXOR_VL,
214 
215   // Set mask vector to all zeros or ones.
216   VMCLR_VL,
217   VMSET_VL,
218 
219   // Matches the semantics of vrgather.vx and vrgather.vv with an extra operand
220   // for VL.
221   VRGATHER_VX_VL,
222   VRGATHER_VV_VL,
223   VRGATHEREI16_VV_VL,
224 
225   // Vector sign/zero extend with additional mask & VL operands.
226   VSEXT_VL,
227   VZEXT_VL,
228   //  vpopc.m with additional mask and VL operands.
229   VPOPC_VL,
230 
231   // Reads value of CSR.
232   // The first operand is a chain pointer. The second specifies address of the
233   // required CSR. Two results are produced, the read value and the new chain
234   // pointer.
235   READ_CSR,
236   // Write value to CSR.
237   // The first operand is a chain pointer, the second specifies address of the
238   // required CSR and the third is the value to write. The result is the new
239   // chain pointer.
240   WRITE_CSR,
241   // Read and write value of CSR.
242   // The first operand is a chain pointer, the second specifies address of the
243   // required CSR and the third is the value to write. Two results are produced,
244   // the value read before the modification and the new chain pointer.
245   SWAP_CSR,
246 
247   // Memory opcodes start here.
248   VLE_VL = ISD::FIRST_TARGET_MEMORY_OPCODE,
249   VSE_VL,
250 
251   // WARNING: Do not add anything in the end unless you want the node to
252   // have memop! In fact, starting from FIRST_TARGET_MEMORY_OPCODE all
253   // opcodes will be thought as target memory ops!
254 };
255 } // namespace RISCVISD
256 
257 class RISCVTargetLowering : public TargetLowering {
258   const RISCVSubtarget &Subtarget;
259 
260 public:
261   explicit RISCVTargetLowering(const TargetMachine &TM,
262                                const RISCVSubtarget &STI);
263 
264   const RISCVSubtarget &getSubtarget() const { return Subtarget; }
265 
266   bool getTgtMemIntrinsic(IntrinsicInfo &Info, const CallInst &I,
267                           MachineFunction &MF,
268                           unsigned Intrinsic) const override;
269   bool isLegalAddressingMode(const DataLayout &DL, const AddrMode &AM, Type *Ty,
270                              unsigned AS,
271                              Instruction *I = nullptr) const override;
272   bool isLegalICmpImmediate(int64_t Imm) const override;
273   bool isLegalAddImmediate(int64_t Imm) const override;
274   bool isTruncateFree(Type *SrcTy, Type *DstTy) const override;
275   bool isTruncateFree(EVT SrcVT, EVT DstVT) const override;
276   bool isZExtFree(SDValue Val, EVT VT2) const override;
277   bool isSExtCheaperThanZExt(EVT SrcVT, EVT DstVT) const override;
278   bool isCheapToSpeculateCttz() const override;
279   bool isCheapToSpeculateCtlz() const override;
280   bool isFPImmLegal(const APFloat &Imm, EVT VT,
281                     bool ForCodeSize) const override;
282 
283   bool softPromoteHalfType() const override { return true; }
284 
285   /// Return the register type for a given MVT, ensuring vectors are treated
286   /// as a series of gpr sized integers.
287   MVT getRegisterTypeForCallingConv(LLVMContext &Context, CallingConv::ID CC,
288                                     EVT VT) const override;
289 
290   /// Return the number of registers for a given MVT, ensuring vectors are
291   /// treated as a series of gpr sized integers.
292   unsigned getNumRegistersForCallingConv(LLVMContext &Context,
293                                          CallingConv::ID CC,
294                                          EVT VT) const override;
295 
296   /// Return true if the given shuffle mask can be codegen'd directly, or if it
297   /// should be stack expanded.
298   bool isShuffleMaskLegal(ArrayRef<int> M, EVT VT) const override;
299 
300   bool hasBitPreservingFPLogic(EVT VT) const override;
301   bool
302   shouldExpandBuildVectorWithShuffles(EVT VT,
303                                       unsigned DefinedValues) const override;
304 
305   // Provide custom lowering hooks for some operations.
306   SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
307   void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue> &Results,
308                           SelectionDAG &DAG) const override;
309 
310   SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const override;
311 
312   bool targetShrinkDemandedConstant(SDValue Op, const APInt &DemandedBits,
313                                     const APInt &DemandedElts,
314                                     TargetLoweringOpt &TLO) const override;
315 
316   void computeKnownBitsForTargetNode(const SDValue Op,
317                                      KnownBits &Known,
318                                      const APInt &DemandedElts,
319                                      const SelectionDAG &DAG,
320                                      unsigned Depth) const override;
321   unsigned ComputeNumSignBitsForTargetNode(SDValue Op,
322                                            const APInt &DemandedElts,
323                                            const SelectionDAG &DAG,
324                                            unsigned Depth) const override;
325 
326   // This method returns the name of a target specific DAG node.
327   const char *getTargetNodeName(unsigned Opcode) const override;
328 
329   ConstraintType getConstraintType(StringRef Constraint) const override;
330 
331   unsigned getInlineAsmMemConstraint(StringRef ConstraintCode) const override;
332 
333   std::pair<unsigned, const TargetRegisterClass *>
334   getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
335                                StringRef Constraint, MVT VT) const override;
336 
337   void LowerAsmOperandForConstraint(SDValue Op, std::string &Constraint,
338                                     std::vector<SDValue> &Ops,
339                                     SelectionDAG &DAG) const override;
340 
341   MachineBasicBlock *
342   EmitInstrWithCustomInserter(MachineInstr &MI,
343                               MachineBasicBlock *BB) const override;
344 
345   EVT getSetCCResultType(const DataLayout &DL, LLVMContext &Context,
346                          EVT VT) const override;
347 
348   bool convertSetCCLogicToBitwiseLogic(EVT VT) const override {
349     return VT.isScalarInteger();
350   }
351   bool convertSelectOfConstantsToMath(EVT VT) const override { return true; }
352 
353   bool shouldInsertFencesForAtomic(const Instruction *I) const override {
354     return isa<LoadInst>(I) || isa<StoreInst>(I);
355   }
356   Instruction *emitLeadingFence(IRBuilder<> &Builder, Instruction *Inst,
357                                 AtomicOrdering Ord) const override;
358   Instruction *emitTrailingFence(IRBuilder<> &Builder, Instruction *Inst,
359                                  AtomicOrdering Ord) const override;
360 
361   bool isFMAFasterThanFMulAndFAdd(const MachineFunction &MF,
362                                   EVT VT) const override;
363 
364   ISD::NodeType getExtendForAtomicOps() const override {
365     return ISD::SIGN_EXTEND;
366   }
367 
368   ISD::NodeType getExtendForAtomicCmpSwapArg() const override {
369     return ISD::SIGN_EXTEND;
370   }
371 
372   bool shouldExpandShift(SelectionDAG &DAG, SDNode *N) const override {
373     if (DAG.getMachineFunction().getFunction().hasMinSize())
374       return false;
375     return true;
376   }
377   bool isDesirableToCommuteWithShift(const SDNode *N,
378                                      CombineLevel Level) const override;
379 
380   /// If a physical register, this returns the register that receives the
381   /// exception address on entry to an EH pad.
382   Register
383   getExceptionPointerRegister(const Constant *PersonalityFn) const override;
384 
385   /// If a physical register, this returns the register that receives the
386   /// exception typeid on entry to a landing pad.
387   Register
388   getExceptionSelectorRegister(const Constant *PersonalityFn) const override;
389 
390   bool shouldExtendTypeInLibCall(EVT Type) const override;
391   bool shouldSignExtendTypeInLibCall(EVT Type, bool IsSigned) const override;
392 
393   /// Returns the register with the specified architectural or ABI name. This
394   /// method is necessary to lower the llvm.read_register.* and
395   /// llvm.write_register.* intrinsics. Allocatable registers must be reserved
396   /// with the clang -ffixed-xX flag for access to be allowed.
397   Register getRegisterByName(const char *RegName, LLT VT,
398                              const MachineFunction &MF) const override;
399 
400   // Lower incoming arguments, copy physregs into vregs
401   SDValue LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv,
402                                bool IsVarArg,
403                                const SmallVectorImpl<ISD::InputArg> &Ins,
404                                const SDLoc &DL, SelectionDAG &DAG,
405                                SmallVectorImpl<SDValue> &InVals) const override;
406   bool CanLowerReturn(CallingConv::ID CallConv, MachineFunction &MF,
407                       bool IsVarArg,
408                       const SmallVectorImpl<ISD::OutputArg> &Outs,
409                       LLVMContext &Context) const override;
410   SDValue LowerReturn(SDValue Chain, CallingConv::ID CallConv, bool IsVarArg,
411                       const SmallVectorImpl<ISD::OutputArg> &Outs,
412                       const SmallVectorImpl<SDValue> &OutVals, const SDLoc &DL,
413                       SelectionDAG &DAG) const override;
414   SDValue LowerCall(TargetLowering::CallLoweringInfo &CLI,
415                     SmallVectorImpl<SDValue> &InVals) const override;
416 
417   bool shouldConvertConstantLoadToIntImm(const APInt &Imm,
418                                          Type *Ty) const override {
419     return true;
420   }
421   bool mayBeEmittedAsTailCall(const CallInst *CI) const override;
422   bool shouldConsiderGEPOffsetSplit() const override { return true; }
423 
424   bool decomposeMulByConstant(LLVMContext &Context, EVT VT,
425                               SDValue C) const override;
426 
427   TargetLowering::AtomicExpansionKind
428   shouldExpandAtomicRMWInIR(AtomicRMWInst *AI) const override;
429   Value *emitMaskedAtomicRMWIntrinsic(IRBuilder<> &Builder, AtomicRMWInst *AI,
430                                       Value *AlignedAddr, Value *Incr,
431                                       Value *Mask, Value *ShiftAmt,
432                                       AtomicOrdering Ord) const override;
433   TargetLowering::AtomicExpansionKind
434   shouldExpandAtomicCmpXchgInIR(AtomicCmpXchgInst *CI) const override;
435   Value *emitMaskedAtomicCmpXchgIntrinsic(IRBuilder<> &Builder,
436                                           AtomicCmpXchgInst *CI,
437                                           Value *AlignedAddr, Value *CmpVal,
438                                           Value *NewVal, Value *Mask,
439                                           AtomicOrdering Ord) const override;
440 
441   /// Returns true if the target allows unaligned memory accesses of the
442   /// specified type.
443   bool allowsMisalignedMemoryAccesses(
444       EVT VT, unsigned AddrSpace = 0, Align Alignment = Align(1),
445       MachineMemOperand::Flags Flags = MachineMemOperand::MONone,
446       bool *Fast = nullptr) const override;
447 
448   bool splitValueIntoRegisterParts(SelectionDAG &DAG, const SDLoc &DL,
449                                    SDValue Val, SDValue *Parts,
450                                    unsigned NumParts, MVT PartVT,
451                                    Optional<CallingConv::ID> CC) const override;
452 
453   SDValue
454   joinRegisterPartsIntoValue(SelectionDAG &DAG, const SDLoc &DL,
455                              const SDValue *Parts, unsigned NumParts,
456                              MVT PartVT, EVT ValueVT,
457                              Optional<CallingConv::ID> CC) const override;
458 
459   static RISCVVLMUL getLMUL(MVT VT);
460   static unsigned getRegClassIDForLMUL(RISCVVLMUL LMul);
461   static unsigned getSubregIndexByMVT(MVT VT, unsigned Index);
462   static unsigned getRegClassIDForVecVT(MVT VT);
463   static std::pair<unsigned, unsigned>
464   decomposeSubvectorInsertExtractToSubRegs(MVT VecVT, MVT SubVecVT,
465                                            unsigned InsertExtractIdx,
466                                            const RISCVRegisterInfo *TRI);
467   MVT getContainerForFixedLengthVector(MVT VT) const;
468   static MVT getContainerForFixedLengthVector(const TargetLowering &TLI, MVT VT,
469                                               const RISCVSubtarget &Subtarget);
470   static MVT getContainerForFixedLengthVector(SelectionDAG &DAG, MVT VT,
471                                               const RISCVSubtarget &Subtarget);
472 
473   bool shouldRemoveExtendFromGSIndex(EVT VT) const override;
474 
475 private:
476   void analyzeInputArgs(MachineFunction &MF, CCState &CCInfo,
477                         const SmallVectorImpl<ISD::InputArg> &Ins,
478                         bool IsRet) const;
479   void analyzeOutputArgs(MachineFunction &MF, CCState &CCInfo,
480                          const SmallVectorImpl<ISD::OutputArg> &Outs,
481                          bool IsRet, CallLoweringInfo *CLI) const;
482 
483   template <class NodeTy>
484   SDValue getAddr(NodeTy *N, SelectionDAG &DAG, bool IsLocal = true) const;
485 
486   SDValue getStaticTLSAddr(GlobalAddressSDNode *N, SelectionDAG &DAG,
487                            bool UseGOT) const;
488   SDValue getDynamicTLSAddr(GlobalAddressSDNode *N, SelectionDAG &DAG) const;
489 
490   SDValue lowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
491   SDValue lowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
492   SDValue lowerConstantPool(SDValue Op, SelectionDAG &DAG) const;
493   SDValue lowerJumpTable(SDValue Op, SelectionDAG &DAG) const;
494   SDValue lowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
495   SDValue lowerSELECT(SDValue Op, SelectionDAG &DAG) const;
496   SDValue lowerBRCOND(SDValue Op, SelectionDAG &DAG) const;
497   SDValue lowerVASTART(SDValue Op, SelectionDAG &DAG) const;
498   SDValue lowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
499   SDValue lowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
500   SDValue lowerShiftLeftParts(SDValue Op, SelectionDAG &DAG) const;
501   SDValue lowerShiftRightParts(SDValue Op, SelectionDAG &DAG, bool IsSRA) const;
502   SDValue lowerSPLAT_VECTOR_PARTS(SDValue Op, SelectionDAG &DAG) const;
503   SDValue lowerVectorMaskExt(SDValue Op, SelectionDAG &DAG,
504                              int64_t ExtTrueVal) const;
505   SDValue lowerVectorMaskTrunc(SDValue Op, SelectionDAG &DAG) const;
506   SDValue lowerINSERT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG) const;
507   SDValue lowerEXTRACT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG) const;
508   SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG) const;
509   SDValue LowerINTRINSIC_W_CHAIN(SDValue Op, SelectionDAG &DAG) const;
510   SDValue lowerVECREDUCE(SDValue Op, SelectionDAG &DAG) const;
511   SDValue lowerVectorMaskVECREDUCE(SDValue Op, SelectionDAG &DAG) const;
512   SDValue lowerFPVECREDUCE(SDValue Op, SelectionDAG &DAG) const;
513   SDValue lowerINSERT_SUBVECTOR(SDValue Op, SelectionDAG &DAG) const;
514   SDValue lowerEXTRACT_SUBVECTOR(SDValue Op, SelectionDAG &DAG) const;
515   SDValue lowerSTEP_VECTOR(SDValue Op, SelectionDAG &DAG) const;
516   SDValue lowerVECTOR_REVERSE(SDValue Op, SelectionDAG &DAG) const;
517   SDValue lowerABS(SDValue Op, SelectionDAG &DAG) const;
518   SDValue lowerMLOAD(SDValue Op, SelectionDAG &DAG) const;
519   SDValue lowerMSTORE(SDValue Op, SelectionDAG &DAG) const;
520   SDValue lowerFixedLengthVectorFCOPYSIGNToRVV(SDValue Op,
521                                                SelectionDAG &DAG) const;
522   SDValue lowerMGATHER(SDValue Op, SelectionDAG &DAG) const;
523   SDValue lowerMSCATTER(SDValue Op, SelectionDAG &DAG) const;
524   SDValue lowerFixedLengthVectorLoadToRVV(SDValue Op, SelectionDAG &DAG) const;
525   SDValue lowerFixedLengthVectorStoreToRVV(SDValue Op, SelectionDAG &DAG) const;
526   SDValue lowerFixedLengthVectorSetccToRVV(SDValue Op, SelectionDAG &DAG) const;
527   SDValue lowerFixedLengthVectorLogicOpToRVV(SDValue Op, SelectionDAG &DAG,
528                                              unsigned MaskOpc,
529                                              unsigned VecOpc) const;
530   SDValue lowerFixedLengthVectorSelectToRVV(SDValue Op,
531                                             SelectionDAG &DAG) const;
532   SDValue lowerToScalableOp(SDValue Op, SelectionDAG &DAG, unsigned NewOpc,
533                             bool HasMask = true) const;
534   SDValue lowerFixedLengthVectorExtendToRVV(SDValue Op, SelectionDAG &DAG,
535                                             unsigned ExtendOpc) const;
536 
537   bool isEligibleForTailCallOptimization(
538       CCState &CCInfo, CallLoweringInfo &CLI, MachineFunction &MF,
539       const SmallVector<CCValAssign, 16> &ArgLocs) const;
540 
541   /// Generate error diagnostics if any register used by CC has been marked
542   /// reserved.
543   void validateCCReservedRegs(
544       const SmallVectorImpl<std::pair<llvm::Register, llvm::SDValue>> &Regs,
545       MachineFunction &MF) const;
546 
547   bool useRVVForFixedLengthVectorVT(MVT VT) const;
548 };
549 
550 namespace RISCV {
551 // We use 64 bits as the known part in the scalable vector types.
552 static constexpr unsigned RVVBitsPerBlock = 64;
553 } // namespace RISCV
554 
555 namespace RISCVVIntrinsicsTable {
556 
557 struct RISCVVIntrinsicInfo {
558   unsigned IntrinsicID;
559   uint8_t SplatOperand;
560 };
561 
562 using namespace RISCV;
563 
564 #define GET_RISCVVIntrinsicsTable_DECL
565 #include "RISCVGenSearchableTables.inc"
566 
567 } // end namespace RISCVVIntrinsicsTable
568 
569 } // end namespace llvm
570 
571 #endif
572