1 //===-- SparcISelLowering.h - Sparc 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 Sparc uses to lower LLVM code into a
10 // selection DAG.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_LIB_TARGET_SPARC_SPARCISELLOWERING_H
15 #define LLVM_LIB_TARGET_SPARC_SPARCISELLOWERING_H
16 
17 #include "Sparc.h"
18 #include "llvm/CodeGen/TargetLowering.h"
19 
20 namespace llvm {
21   class SparcSubtarget;
22 
23   namespace SPISD {
24   enum NodeType : unsigned {
25     FIRST_NUMBER = ISD::BUILTIN_OP_END,
26     CMPICC,    // Compare two GPR operands, set icc+xcc.
27     CMPFCC,    // Compare two FP operands, set fcc.
28     CMPFCC_V9, // Compare two FP operands, set fcc (v9 variant).
29     BRICC,     // Branch to dest on icc condition
30     BPICC,    // Branch to dest on icc condition, with prediction (64-bit only).
31     BPXCC,    // Branch to dest on xcc condition, with prediction (64-bit only).
32     BRFCC,    // Branch to dest on fcc condition
33     BRFCC_V9, // Branch to dest on fcc condition (v9 variant).
34     BR_REG,   // Branch to dest using the comparison of a register with zero.
35     SELECT_ICC, // Select between two values using the current ICC flags.
36     SELECT_XCC, // Select between two values using the current XCC flags.
37     SELECT_FCC, // Select between two values using the current FCC flags.
38     SELECT_REG, // Select between two values using the comparison of a register
39                 // with zero.
40 
41     Hi,
42     Lo, // Hi/Lo operations, typically on a global address.
43 
44     FTOI, // FP to Int within a FP register.
45     ITOF, // Int to FP within a FP register.
46     FTOX, // FP to Int64 within a FP register.
47     XTOF, // Int64 to FP within a FP register.
48 
49     CALL,            // A call instruction.
50     RET_GLUE,        // Return with a glue operand.
51     GLOBAL_BASE_REG, // Global base reg for PIC.
52     FLUSHW,          // FLUSH register windows to stack.
53 
54     TAIL_CALL, // Tail call
55 
56     TLS_ADD, // For Thread Local Storage (TLS).
57     TLS_LD,
58     TLS_CALL,
59 
60     LOAD_GDOP, // Load operation w/ gdop relocation.
61   };
62   }
63 
64   class SparcTargetLowering : public TargetLowering {
65     const SparcSubtarget *Subtarget;
66   public:
67     SparcTargetLowering(const TargetMachine &TM, const SparcSubtarget &STI);
68     SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
69 
70     bool useSoftFloat() const override;
71 
72     /// computeKnownBitsForTargetNode - Determine which of the bits specified
73     /// in Mask are known to be either zero or one and return them in the
74     /// KnownZero/KnownOne bitsets.
75     void computeKnownBitsForTargetNode(const SDValue Op,
76                                        KnownBits &Known,
77                                        const APInt &DemandedElts,
78                                        const SelectionDAG &DAG,
79                                        unsigned Depth = 0) const override;
80 
81     MachineBasicBlock *
82     EmitInstrWithCustomInserter(MachineInstr &MI,
83                                 MachineBasicBlock *MBB) const override;
84 
85     const char *getTargetNodeName(unsigned Opcode) const override;
86 
87     ConstraintType getConstraintType(StringRef Constraint) const override;
88     ConstraintWeight
89     getSingleConstraintMatchWeight(AsmOperandInfo &info,
90                                    const char *constraint) const override;
91     void LowerAsmOperandForConstraint(SDValue Op,
92                                       std::string &Constraint,
93                                       std::vector<SDValue> &Ops,
94                                       SelectionDAG &DAG) const override;
95 
96     std::pair<unsigned, const TargetRegisterClass *>
97     getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
98                                  StringRef Constraint, MVT VT) const override;
99 
100     bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const override;
101     MVT getScalarShiftAmountTy(const DataLayout &, EVT) const override {
102       return MVT::i32;
103     }
104 
105     Register getRegisterByName(const char* RegName, LLT VT,
106                                const MachineFunction &MF) const override;
107 
108     /// If a physical register, this returns the register that receives the
109     /// exception address on entry to an EH pad.
110     Register
111     getExceptionPointerRegister(const Constant *PersonalityFn) const override {
112       return SP::I0;
113     }
114 
115     /// If a physical register, this returns the register that receives the
116     /// exception typeid on entry to a landing pad.
117     Register
118     getExceptionSelectorRegister(const Constant *PersonalityFn) const override {
119       return SP::I1;
120     }
121 
122     /// Override to support customized stack guard loading.
123     bool useLoadStackGuardNode() const override;
124     void insertSSPDeclarations(Module &M) const override;
125 
126     /// getSetCCResultType - Return the ISD::SETCC ValueType
127     EVT getSetCCResultType(const DataLayout &DL, LLVMContext &Context,
128                            EVT VT) const override;
129 
130     SDValue
131     LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
132                          const SmallVectorImpl<ISD::InputArg> &Ins,
133                          const SDLoc &dl, SelectionDAG &DAG,
134                          SmallVectorImpl<SDValue> &InVals) const override;
135     SDValue LowerFormalArguments_32(SDValue Chain, CallingConv::ID CallConv,
136                                     bool isVarArg,
137                                     const SmallVectorImpl<ISD::InputArg> &Ins,
138                                     const SDLoc &dl, SelectionDAG &DAG,
139                                     SmallVectorImpl<SDValue> &InVals) const;
140     SDValue LowerFormalArguments_64(SDValue Chain, CallingConv::ID CallConv,
141                                     bool isVarArg,
142                                     const SmallVectorImpl<ISD::InputArg> &Ins,
143                                     const SDLoc &dl, SelectionDAG &DAG,
144                                     SmallVectorImpl<SDValue> &InVals) const;
145 
146     SDValue
147       LowerCall(TargetLowering::CallLoweringInfo &CLI,
148                 SmallVectorImpl<SDValue> &InVals) const override;
149     SDValue LowerCall_32(TargetLowering::CallLoweringInfo &CLI,
150                          SmallVectorImpl<SDValue> &InVals) const;
151     SDValue LowerCall_64(TargetLowering::CallLoweringInfo &CLI,
152                          SmallVectorImpl<SDValue> &InVals) const;
153 
154     bool CanLowerReturn(CallingConv::ID CallConv, MachineFunction &MF,
155                         bool isVarArg,
156                         const SmallVectorImpl<ISD::OutputArg> &Outs,
157                         LLVMContext &Context) const override;
158 
159     SDValue LowerReturn(SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
160                         const SmallVectorImpl<ISD::OutputArg> &Outs,
161                         const SmallVectorImpl<SDValue> &OutVals,
162                         const SDLoc &dl, SelectionDAG &DAG) const override;
163     SDValue LowerReturn_32(SDValue Chain, CallingConv::ID CallConv,
164                            bool IsVarArg,
165                            const SmallVectorImpl<ISD::OutputArg> &Outs,
166                            const SmallVectorImpl<SDValue> &OutVals,
167                            const SDLoc &DL, SelectionDAG &DAG) const;
168     SDValue LowerReturn_64(SDValue Chain, CallingConv::ID CallConv,
169                            bool IsVarArg,
170                            const SmallVectorImpl<ISD::OutputArg> &Outs,
171                            const SmallVectorImpl<SDValue> &OutVals,
172                            const SDLoc &DL, SelectionDAG &DAG) const;
173 
174     SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
175     SDValue LowerGlobalTLSAddress(SDValue Op, SelectionDAG &DAG) const;
176     SDValue LowerConstantPool(SDValue Op, SelectionDAG &DAG) const;
177     SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
178 
179     SDValue withTargetFlags(SDValue Op, unsigned TF, SelectionDAG &DAG) const;
180     SDValue makeHiLoPair(SDValue Op, unsigned HiTF, unsigned LoTF,
181                          SelectionDAG &DAG) const;
182     SDValue makeAddress(SDValue Op, SelectionDAG &DAG) const;
183 
184     SDValue LowerF128_LibCallArg(SDValue Chain, ArgListTy &Args, SDValue Arg,
185                                  const SDLoc &DL, SelectionDAG &DAG) const;
186     SDValue LowerF128Op(SDValue Op, SelectionDAG &DAG,
187                         const char *LibFuncName,
188                         unsigned numArgs) const;
189     SDValue LowerF128Compare(SDValue LHS, SDValue RHS, unsigned &SPCC,
190                              const SDLoc &DL, SelectionDAG &DAG) const;
191 
192     SDValue LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG) const;
193 
194     SDValue PerformBITCASTCombine(SDNode *N, DAGCombinerInfo &DCI) const;
195 
196     SDValue bitcastConstantFPToInt(ConstantFPSDNode *C, const SDLoc &DL,
197                                    SelectionDAG &DAG) const;
198 
199     SDValue PerformDAGCombine(SDNode *N, DAGCombinerInfo &DCI) const override;
200 
201     bool IsEligibleForTailCallOptimization(CCState &CCInfo,
202                                            CallLoweringInfo &CLI,
203                                            MachineFunction &MF) const;
204 
205     bool ShouldShrinkFPConstant(EVT VT) const override {
206       // Do not shrink FP constpool if VT == MVT::f128.
207       // (ldd, call _Q_fdtoq) is more expensive than two ldds.
208       return VT != MVT::f128;
209     }
210 
211     bool shouldInsertFencesForAtomic(const Instruction *I) const override {
212       // FIXME: We insert fences for each atomics and generate
213       // sub-optimal code for PSO/TSO. (Approximately nobody uses any
214       // mode but TSO, which makes this even more silly)
215       return true;
216     }
217 
218     AtomicExpansionKind shouldExpandAtomicRMWInIR(AtomicRMWInst *AI) const override;
219 
220     void ReplaceNodeResults(SDNode *N,
221                             SmallVectorImpl<SDValue>& Results,
222                             SelectionDAG &DAG) const override;
223 
224     MachineBasicBlock *expandSelectCC(MachineInstr &MI, MachineBasicBlock *BB,
225                                       unsigned BROpcode) const;
226   };
227 } // end namespace llvm
228 
229 #endif    // SPARC_ISELLOWERING_H
230