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   SHFLW,
100   UNSHFL,
101   UNSHFLW,
102   // Bit Compress/Decompress implement the generic bit extract and bit deposit
103   // functions. This operation is also referred to as bit gather/scatter, bit
104   // pack/unpack, parallel extract/deposit, compress/expand, or right
105   // compress/right expand.
106   BCOMPRESS,
107   BCOMPRESSW,
108   BDECOMPRESS,
109   BDECOMPRESSW,
110   // Vector Extension
111   // VMV_V_X_VL matches the semantics of vmv.v.x but includes an extra operand
112   // for the VL value to be used for the operation.
113   VMV_V_X_VL,
114   // VFMV_V_F_VL matches the semantics of vfmv.v.f but includes an extra operand
115   // for the VL value to be used for the operation.
116   VFMV_V_F_VL,
117   // VMV_X_S matches the semantics of vmv.x.s. The result is always XLenVT sign
118   // extended from the vector element size.
119   VMV_X_S,
120   // VMV_S_X_VL matches the semantics of vmv.s.x. It carries a VL operand.
121   VMV_S_X_VL,
122   // VFMV_S_F_VL matches the semantics of vfmv.s.f. It carries a VL operand.
123   VFMV_S_F_VL,
124   // Splats an i64 scalar to a vector type (with element type i64) where the
125   // scalar is a sign-extended i32.
126   SPLAT_VECTOR_I64,
127   // Read VLENB CSR
128   READ_VLENB,
129   // Truncates a RVV integer vector by one power-of-two. Carries both an extra
130   // mask and VL operand.
131   TRUNCATE_VECTOR_VL,
132   // Unit-stride fault-only-first load
133   VLEFF,
134   VLEFF_MASK,
135   // Matches the semantics of vslideup/vslidedown. The first operand is the
136   // pass-thru operand, the second is the source vector, the third is the
137   // XLenVT index (either constant or non-constant), the fourth is the mask
138   // and the fifth the VL.
139   VSLIDEUP_VL,
140   VSLIDEDOWN_VL,
141   // Matches the semantics of vslide1up/slide1down. The first operand is the
142   // source vector, the second is the XLenVT scalar value. The third and fourth
143   // operands are the mask and VL operands.
144   VSLIDE1UP_VL,
145   VSLIDE1DOWN_VL,
146   // Matches the semantics of the vid.v instruction, with a mask and VL
147   // operand.
148   VID_VL,
149   // Matches the semantics of the vfcnvt.rod function (Convert double-width
150   // float to single-width float, rounding towards odd). Takes a double-width
151   // float vector and produces a single-width float vector. Also has a mask and
152   // VL operand.
153   VFNCVT_ROD_VL,
154   // These nodes match the semantics of the corresponding RVV vector reduction
155   // instructions. They produce a vector result which is the reduction
156   // performed over the first vector operand plus the first element of the
157   // second vector operand. The first operand is an unconstrained vector type,
158   // and the result and second operand's types are expected to be the
159   // corresponding full-width LMUL=1 type for the first operand:
160   //   nxv8i8 = vecreduce_add nxv32i8, nxv8i8
161   //   nxv2i32 = vecreduce_add nxv8i32, nxv2i32
162   // The different in types does introduce extra vsetvli instructions but
163   // similarly it reduces the number of registers consumed per reduction.
164   // Also has a mask and VL operand.
165   VECREDUCE_ADD_VL,
166   VECREDUCE_UMAX_VL,
167   VECREDUCE_SMAX_VL,
168   VECREDUCE_UMIN_VL,
169   VECREDUCE_SMIN_VL,
170   VECREDUCE_AND_VL,
171   VECREDUCE_OR_VL,
172   VECREDUCE_XOR_VL,
173   VECREDUCE_FADD_VL,
174   VECREDUCE_SEQ_FADD_VL,
175 
176   // Vector binary and unary ops with a mask as a third operand, and VL as a
177   // fourth operand.
178   // FIXME: Can we replace these with ISD::VP_*?
179   ADD_VL,
180   AND_VL,
181   MUL_VL,
182   OR_VL,
183   SDIV_VL,
184   SHL_VL,
185   SREM_VL,
186   SRA_VL,
187   SRL_VL,
188   SUB_VL,
189   UDIV_VL,
190   UREM_VL,
191   XOR_VL,
192   FADD_VL,
193   FSUB_VL,
194   FMUL_VL,
195   FDIV_VL,
196   FNEG_VL,
197   FABS_VL,
198   FSQRT_VL,
199   FMA_VL,
200   FCOPYSIGN_VL,
201   SMIN_VL,
202   SMAX_VL,
203   UMIN_VL,
204   UMAX_VL,
205   FMINNUM_VL,
206   FMAXNUM_VL,
207   MULHS_VL,
208   MULHU_VL,
209   FP_TO_SINT_VL,
210   FP_TO_UINT_VL,
211   SINT_TO_FP_VL,
212   UINT_TO_FP_VL,
213   FP_ROUND_VL,
214   FP_EXTEND_VL,
215 
216   // Vector compare producing a mask. Fourth operand is input mask. Fifth
217   // operand is VL.
218   SETCC_VL,
219 
220   // Vector select with an additional VL operand. This operation is unmasked.
221   VSELECT_VL,
222 
223   // Mask binary operators.
224   VMAND_VL,
225   VMOR_VL,
226   VMXOR_VL,
227 
228   // Set mask vector to all zeros or ones.
229   VMCLR_VL,
230   VMSET_VL,
231 
232   // Matches the semantics of vrgather.vx and vrgather.vv with an extra operand
233   // for VL.
234   VRGATHER_VX_VL,
235   VRGATHER_VV_VL,
236   VRGATHEREI16_VV_VL,
237 
238   // Vector sign/zero extend with additional mask & VL operands.
239   VSEXT_VL,
240   VZEXT_VL,
241   //  vpopc.m with additional mask and VL operands.
242   VPOPC_VL,
243 
244   // Reads value of CSR.
245   // The first operand is a chain pointer. The second specifies address of the
246   // required CSR. Two results are produced, the read value and the new chain
247   // pointer.
248   READ_CSR,
249   // Write value to CSR.
250   // The first operand is a chain pointer, the second specifies address of the
251   // required CSR and the third is the value to write. The result is the new
252   // chain pointer.
253   WRITE_CSR,
254   // Read and write value of CSR.
255   // The first operand is a chain pointer, the second specifies address of the
256   // required CSR and the third is the value to write. Two results are produced,
257   // the value read before the modification and the new chain pointer.
258   SWAP_CSR,
259 
260   // Memory opcodes start here.
261   VLE_VL = ISD::FIRST_TARGET_MEMORY_OPCODE,
262   VSE_VL,
263 
264   // WARNING: Do not add anything in the end unless you want the node to
265   // have memop! In fact, starting from FIRST_TARGET_MEMORY_OPCODE all
266   // opcodes will be thought as target memory ops!
267 };
268 } // namespace RISCVISD
269 
270 class RISCVTargetLowering : public TargetLowering {
271   const RISCVSubtarget &Subtarget;
272 
273 public:
274   explicit RISCVTargetLowering(const TargetMachine &TM,
275                                const RISCVSubtarget &STI);
276 
277   const RISCVSubtarget &getSubtarget() const { return Subtarget; }
278 
279   bool getTgtMemIntrinsic(IntrinsicInfo &Info, const CallInst &I,
280                           MachineFunction &MF,
281                           unsigned Intrinsic) const override;
282   bool isLegalAddressingMode(const DataLayout &DL, const AddrMode &AM, Type *Ty,
283                              unsigned AS,
284                              Instruction *I = nullptr) const override;
285   bool isLegalICmpImmediate(int64_t Imm) const override;
286   bool isLegalAddImmediate(int64_t Imm) const override;
287   bool isTruncateFree(Type *SrcTy, Type *DstTy) const override;
288   bool isTruncateFree(EVT SrcVT, EVT DstVT) const override;
289   bool isZExtFree(SDValue Val, EVT VT2) const override;
290   bool isSExtCheaperThanZExt(EVT SrcVT, EVT DstVT) const override;
291   bool isCheapToSpeculateCttz() const override;
292   bool isCheapToSpeculateCtlz() const override;
293   bool isFPImmLegal(const APFloat &Imm, EVT VT,
294                     bool ForCodeSize) const override;
295 
296   bool softPromoteHalfType() const override { return true; }
297 
298   /// Return the register type for a given MVT, ensuring vectors are treated
299   /// as a series of gpr sized integers.
300   MVT getRegisterTypeForCallingConv(LLVMContext &Context, CallingConv::ID CC,
301                                     EVT VT) const override;
302 
303   /// Return the number of registers for a given MVT, ensuring vectors are
304   /// treated as a series of gpr sized integers.
305   unsigned getNumRegistersForCallingConv(LLVMContext &Context,
306                                          CallingConv::ID CC,
307                                          EVT VT) const override;
308 
309   /// Return true if the given shuffle mask can be codegen'd directly, or if it
310   /// should be stack expanded.
311   bool isShuffleMaskLegal(ArrayRef<int> M, EVT VT) const override;
312 
313   bool hasBitPreservingFPLogic(EVT VT) const override;
314   bool
315   shouldExpandBuildVectorWithShuffles(EVT VT,
316                                       unsigned DefinedValues) const override;
317 
318   // Provide custom lowering hooks for some operations.
319   SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
320   void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue> &Results,
321                           SelectionDAG &DAG) const override;
322 
323   SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const override;
324 
325   bool targetShrinkDemandedConstant(SDValue Op, const APInt &DemandedBits,
326                                     const APInt &DemandedElts,
327                                     TargetLoweringOpt &TLO) const override;
328 
329   void computeKnownBitsForTargetNode(const SDValue Op,
330                                      KnownBits &Known,
331                                      const APInt &DemandedElts,
332                                      const SelectionDAG &DAG,
333                                      unsigned Depth) const override;
334   unsigned ComputeNumSignBitsForTargetNode(SDValue Op,
335                                            const APInt &DemandedElts,
336                                            const SelectionDAG &DAG,
337                                            unsigned Depth) const override;
338 
339   // This method returns the name of a target specific DAG node.
340   const char *getTargetNodeName(unsigned Opcode) const override;
341 
342   ConstraintType getConstraintType(StringRef Constraint) const override;
343 
344   unsigned getInlineAsmMemConstraint(StringRef ConstraintCode) const override;
345 
346   std::pair<unsigned, const TargetRegisterClass *>
347   getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
348                                StringRef Constraint, MVT VT) const override;
349 
350   void LowerAsmOperandForConstraint(SDValue Op, std::string &Constraint,
351                                     std::vector<SDValue> &Ops,
352                                     SelectionDAG &DAG) const override;
353 
354   MachineBasicBlock *
355   EmitInstrWithCustomInserter(MachineInstr &MI,
356                               MachineBasicBlock *BB) const override;
357 
358   EVT getSetCCResultType(const DataLayout &DL, LLVMContext &Context,
359                          EVT VT) const override;
360 
361   bool convertSetCCLogicToBitwiseLogic(EVT VT) const override {
362     return VT.isScalarInteger();
363   }
364   bool convertSelectOfConstantsToMath(EVT VT) const override { return true; }
365 
366   bool shouldInsertFencesForAtomic(const Instruction *I) const override {
367     return isa<LoadInst>(I) || isa<StoreInst>(I);
368   }
369   Instruction *emitLeadingFence(IRBuilder<> &Builder, Instruction *Inst,
370                                 AtomicOrdering Ord) const override;
371   Instruction *emitTrailingFence(IRBuilder<> &Builder, Instruction *Inst,
372                                  AtomicOrdering Ord) const override;
373 
374   bool isFMAFasterThanFMulAndFAdd(const MachineFunction &MF,
375                                   EVT VT) const override;
376 
377   ISD::NodeType getExtendForAtomicOps() const override {
378     return ISD::SIGN_EXTEND;
379   }
380 
381   ISD::NodeType getExtendForAtomicCmpSwapArg() const override {
382     return ISD::SIGN_EXTEND;
383   }
384 
385   bool shouldExpandShift(SelectionDAG &DAG, SDNode *N) const override {
386     if (DAG.getMachineFunction().getFunction().hasMinSize())
387       return false;
388     return true;
389   }
390   bool isDesirableToCommuteWithShift(const SDNode *N,
391                                      CombineLevel Level) const override;
392 
393   /// If a physical register, this returns the register that receives the
394   /// exception address on entry to an EH pad.
395   Register
396   getExceptionPointerRegister(const Constant *PersonalityFn) const override;
397 
398   /// If a physical register, this returns the register that receives the
399   /// exception typeid on entry to a landing pad.
400   Register
401   getExceptionSelectorRegister(const Constant *PersonalityFn) const override;
402 
403   bool shouldExtendTypeInLibCall(EVT Type) const override;
404   bool shouldSignExtendTypeInLibCall(EVT Type, bool IsSigned) const override;
405 
406   /// Returns the register with the specified architectural or ABI name. This
407   /// method is necessary to lower the llvm.read_register.* and
408   /// llvm.write_register.* intrinsics. Allocatable registers must be reserved
409   /// with the clang -ffixed-xX flag for access to be allowed.
410   Register getRegisterByName(const char *RegName, LLT VT,
411                              const MachineFunction &MF) const override;
412 
413   // Lower incoming arguments, copy physregs into vregs
414   SDValue LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv,
415                                bool IsVarArg,
416                                const SmallVectorImpl<ISD::InputArg> &Ins,
417                                const SDLoc &DL, SelectionDAG &DAG,
418                                SmallVectorImpl<SDValue> &InVals) const override;
419   bool CanLowerReturn(CallingConv::ID CallConv, MachineFunction &MF,
420                       bool IsVarArg,
421                       const SmallVectorImpl<ISD::OutputArg> &Outs,
422                       LLVMContext &Context) const override;
423   SDValue LowerReturn(SDValue Chain, CallingConv::ID CallConv, bool IsVarArg,
424                       const SmallVectorImpl<ISD::OutputArg> &Outs,
425                       const SmallVectorImpl<SDValue> &OutVals, const SDLoc &DL,
426                       SelectionDAG &DAG) const override;
427   SDValue LowerCall(TargetLowering::CallLoweringInfo &CLI,
428                     SmallVectorImpl<SDValue> &InVals) const override;
429 
430   bool shouldConvertConstantLoadToIntImm(const APInt &Imm,
431                                          Type *Ty) const override {
432     return true;
433   }
434   bool mayBeEmittedAsTailCall(const CallInst *CI) const override;
435   bool shouldConsiderGEPOffsetSplit() const override { return true; }
436 
437   bool decomposeMulByConstant(LLVMContext &Context, EVT VT,
438                               SDValue C) const override;
439 
440   TargetLowering::AtomicExpansionKind
441   shouldExpandAtomicRMWInIR(AtomicRMWInst *AI) const override;
442   Value *emitMaskedAtomicRMWIntrinsic(IRBuilder<> &Builder, AtomicRMWInst *AI,
443                                       Value *AlignedAddr, Value *Incr,
444                                       Value *Mask, Value *ShiftAmt,
445                                       AtomicOrdering Ord) const override;
446   TargetLowering::AtomicExpansionKind
447   shouldExpandAtomicCmpXchgInIR(AtomicCmpXchgInst *CI) const override;
448   Value *emitMaskedAtomicCmpXchgIntrinsic(IRBuilder<> &Builder,
449                                           AtomicCmpXchgInst *CI,
450                                           Value *AlignedAddr, Value *CmpVal,
451                                           Value *NewVal, Value *Mask,
452                                           AtomicOrdering Ord) const override;
453 
454   /// Returns true if the target allows unaligned memory accesses of the
455   /// specified type.
456   bool allowsMisalignedMemoryAccesses(
457       EVT VT, unsigned AddrSpace = 0, Align Alignment = Align(1),
458       MachineMemOperand::Flags Flags = MachineMemOperand::MONone,
459       bool *Fast = nullptr) const override;
460 
461   bool splitValueIntoRegisterParts(SelectionDAG &DAG, const SDLoc &DL,
462                                    SDValue Val, SDValue *Parts,
463                                    unsigned NumParts, MVT PartVT,
464                                    Optional<CallingConv::ID> CC) const override;
465 
466   SDValue
467   joinRegisterPartsIntoValue(SelectionDAG &DAG, const SDLoc &DL,
468                              const SDValue *Parts, unsigned NumParts,
469                              MVT PartVT, EVT ValueVT,
470                              Optional<CallingConv::ID> CC) const override;
471 
472   static RISCVVLMUL getLMUL(MVT VT);
473   static unsigned getRegClassIDForLMUL(RISCVVLMUL LMul);
474   static unsigned getSubregIndexByMVT(MVT VT, unsigned Index);
475   static unsigned getRegClassIDForVecVT(MVT VT);
476   static std::pair<unsigned, unsigned>
477   decomposeSubvectorInsertExtractToSubRegs(MVT VecVT, MVT SubVecVT,
478                                            unsigned InsertExtractIdx,
479                                            const RISCVRegisterInfo *TRI);
480   MVT getContainerForFixedLengthVector(MVT VT) const;
481 
482   bool shouldRemoveExtendFromGSIndex(EVT VT) const override;
483 
484 private:
485   void analyzeInputArgs(MachineFunction &MF, CCState &CCInfo,
486                         const SmallVectorImpl<ISD::InputArg> &Ins,
487                         bool IsRet) const;
488   void analyzeOutputArgs(MachineFunction &MF, CCState &CCInfo,
489                          const SmallVectorImpl<ISD::OutputArg> &Outs,
490                          bool IsRet, CallLoweringInfo *CLI) const;
491 
492   template <class NodeTy>
493   SDValue getAddr(NodeTy *N, SelectionDAG &DAG, bool IsLocal = true) const;
494 
495   SDValue getStaticTLSAddr(GlobalAddressSDNode *N, SelectionDAG &DAG,
496                            bool UseGOT) const;
497   SDValue getDynamicTLSAddr(GlobalAddressSDNode *N, SelectionDAG &DAG) const;
498 
499   SDValue lowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
500   SDValue lowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
501   SDValue lowerConstantPool(SDValue Op, SelectionDAG &DAG) const;
502   SDValue lowerJumpTable(SDValue Op, SelectionDAG &DAG) const;
503   SDValue lowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
504   SDValue lowerSELECT(SDValue Op, SelectionDAG &DAG) const;
505   SDValue lowerBRCOND(SDValue Op, SelectionDAG &DAG) const;
506   SDValue lowerVASTART(SDValue Op, SelectionDAG &DAG) const;
507   SDValue lowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
508   SDValue lowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
509   SDValue lowerShiftLeftParts(SDValue Op, SelectionDAG &DAG) const;
510   SDValue lowerShiftRightParts(SDValue Op, SelectionDAG &DAG, bool IsSRA) const;
511   SDValue lowerSPLAT_VECTOR_PARTS(SDValue Op, SelectionDAG &DAG) const;
512   SDValue lowerVectorMaskExt(SDValue Op, SelectionDAG &DAG,
513                              int64_t ExtTrueVal) const;
514   SDValue lowerVectorMaskTrunc(SDValue Op, SelectionDAG &DAG) const;
515   SDValue lowerINSERT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG) const;
516   SDValue lowerEXTRACT_VECTOR_ELT(SDValue Op, SelectionDAG &DAG) const;
517   SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG) const;
518   SDValue LowerINTRINSIC_W_CHAIN(SDValue Op, SelectionDAG &DAG) const;
519   SDValue lowerVECREDUCE(SDValue Op, SelectionDAG &DAG) const;
520   SDValue lowerVectorMaskVECREDUCE(SDValue Op, SelectionDAG &DAG) const;
521   SDValue lowerFPVECREDUCE(SDValue Op, SelectionDAG &DAG) const;
522   SDValue lowerINSERT_SUBVECTOR(SDValue Op, SelectionDAG &DAG) const;
523   SDValue lowerEXTRACT_SUBVECTOR(SDValue Op, SelectionDAG &DAG) const;
524   SDValue lowerSTEP_VECTOR(SDValue Op, SelectionDAG &DAG) const;
525   SDValue lowerVECTOR_REVERSE(SDValue Op, SelectionDAG &DAG) const;
526   SDValue lowerABS(SDValue Op, SelectionDAG &DAG) const;
527   SDValue lowerMLOAD(SDValue Op, SelectionDAG &DAG) const;
528   SDValue lowerMSTORE(SDValue Op, SelectionDAG &DAG) const;
529   SDValue lowerFixedLengthVectorFCOPYSIGNToRVV(SDValue Op,
530                                                SelectionDAG &DAG) const;
531   SDValue lowerMGATHER(SDValue Op, SelectionDAG &DAG) const;
532   SDValue lowerMSCATTER(SDValue Op, SelectionDAG &DAG) const;
533   SDValue lowerFixedLengthVectorLoadToRVV(SDValue Op, SelectionDAG &DAG) const;
534   SDValue lowerFixedLengthVectorStoreToRVV(SDValue Op, SelectionDAG &DAG) const;
535   SDValue lowerFixedLengthVectorSetccToRVV(SDValue Op, SelectionDAG &DAG) const;
536   SDValue lowerFixedLengthVectorLogicOpToRVV(SDValue Op, SelectionDAG &DAG,
537                                              unsigned MaskOpc,
538                                              unsigned VecOpc) const;
539   SDValue lowerFixedLengthVectorSelectToRVV(SDValue Op,
540                                             SelectionDAG &DAG) const;
541   SDValue lowerToScalableOp(SDValue Op, SelectionDAG &DAG, unsigned NewOpc,
542                             bool HasMask = true) const;
543   SDValue lowerFixedLengthVectorExtendToRVV(SDValue Op, SelectionDAG &DAG,
544                                             unsigned ExtendOpc) const;
545   SDValue lowerGET_ROUNDING(SDValue Op, SelectionDAG &DAG) const;
546   SDValue lowerSET_ROUNDING(SDValue Op, SelectionDAG &DAG) const;
547 
548   bool isEligibleForTailCallOptimization(
549       CCState &CCInfo, CallLoweringInfo &CLI, MachineFunction &MF,
550       const SmallVector<CCValAssign, 16> &ArgLocs) const;
551 
552   /// Generate error diagnostics if any register used by CC has been marked
553   /// reserved.
554   void validateCCReservedRegs(
555       const SmallVectorImpl<std::pair<llvm::Register, llvm::SDValue>> &Regs,
556       MachineFunction &MF) const;
557 
558   bool useRVVForFixedLengthVectorVT(MVT VT) const;
559 };
560 
561 namespace RISCV {
562 // We use 64 bits as the known part in the scalable vector types.
563 static constexpr unsigned RVVBitsPerBlock = 64;
564 } // namespace RISCV
565 
566 namespace RISCVVIntrinsicsTable {
567 
568 struct RISCVVIntrinsicInfo {
569   unsigned IntrinsicID;
570   uint8_t SplatOperand;
571 };
572 
573 using namespace RISCV;
574 
575 #define GET_RISCVVIntrinsicsTable_DECL
576 #include "RISCVGenSearchableTables.inc"
577 
578 } // end namespace RISCVVIntrinsicsTable
579 
580 } // end namespace llvm
581 
582 #endif
583