xref: /freebsd/contrib/llvm-project/llvm/lib/Target/Mips/MipsISelDAGToDAG.h (revision 1db9f3b21e39176dd5b67cf8ac378633b172463e)
1 //===---- MipsISelDAGToDAG.h - A Dag to Dag Inst Selector for Mips --------===//
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 an instruction selector for the MIPS target.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_TARGET_MIPS_MIPSISELDAGTODAG_H
14 #define LLVM_LIB_TARGET_MIPS_MIPSISELDAGTODAG_H
15 
16 #include "Mips.h"
17 #include "MipsSubtarget.h"
18 #include "MipsTargetMachine.h"
19 #include "llvm/CodeGen/SelectionDAGISel.h"
20 
21 //===----------------------------------------------------------------------===//
22 // Instruction Selector Implementation
23 //===----------------------------------------------------------------------===//
24 
25 //===----------------------------------------------------------------------===//
26 // MipsDAGToDAGISel - MIPS specific code to select MIPS machine
27 // instructions for SelectionDAG operations.
28 //===----------------------------------------------------------------------===//
29 namespace llvm {
30 
31 class MipsDAGToDAGISel : public SelectionDAGISel {
32 public:
33   static char ID;
34 
35   MipsDAGToDAGISel() = delete;
36 
37   explicit MipsDAGToDAGISel(MipsTargetMachine &TM, CodeGenOptLevel OL)
38       : SelectionDAGISel(ID, TM, OL), Subtarget(nullptr) {}
39 
40   bool runOnMachineFunction(MachineFunction &MF) override;
41 
42   void getAnalysisUsage(AnalysisUsage &AU) const override;
43 
44 protected:
45   SDNode *getGlobalBaseReg();
46 
47   /// Keep a pointer to the MipsSubtarget around so that we can make the right
48   /// decision when generating code for different targets.
49   const MipsSubtarget *Subtarget;
50 
51 private:
52   // Include the pieces autogenerated from the target description.
53   #include "MipsGenDAGISel.inc"
54 
55   // Complex Pattern.
56   /// (reg + imm).
57   virtual bool selectAddrRegImm(SDValue Addr, SDValue &Base,
58                                 SDValue &Offset) const;
59 
60   /// Fall back on this function if all else fails.
61   virtual bool selectAddrDefault(SDValue Addr, SDValue &Base,
62                                  SDValue &Offset) const;
63 
64   /// Match integer address pattern.
65   virtual bool selectIntAddr(SDValue Addr, SDValue &Base,
66                              SDValue &Offset) const;
67 
68   virtual bool selectIntAddr11MM(SDValue Addr, SDValue &Base,
69                                  SDValue &Offset) const;
70 
71   virtual bool selectIntAddr12MM(SDValue Addr, SDValue &Base,
72                                SDValue &Offset) const;
73 
74   virtual bool selectIntAddr16MM(SDValue Addr, SDValue &Base,
75                                  SDValue &Offset) const;
76 
77   virtual bool selectIntAddrLSL2MM(SDValue Addr, SDValue &Base,
78                                    SDValue &Offset) const;
79 
80   /// Match addr+simm10 and addr
81   virtual bool selectIntAddrSImm10(SDValue Addr, SDValue &Base,
82                                    SDValue &Offset) const;
83 
84   virtual bool selectIntAddrSImm10Lsl1(SDValue Addr, SDValue &Base,
85                                        SDValue &Offset) const;
86 
87   virtual bool selectIntAddrSImm10Lsl2(SDValue Addr, SDValue &Base,
88                                        SDValue &Offset) const;
89 
90   virtual bool selectIntAddrSImm10Lsl3(SDValue Addr, SDValue &Base,
91                                        SDValue &Offset) const;
92 
93   virtual bool selectAddr16(SDValue Addr, SDValue &Base, SDValue &Offset);
94   virtual bool selectAddr16SP(SDValue Addr, SDValue &Base, SDValue &Offset);
95 
96   /// Select constant vector splats.
97   virtual bool selectVSplat(SDNode *N, APInt &Imm,
98                             unsigned MinSizeInBits) const;
99   /// Select constant vector splats whose value fits in a uimm1.
100   virtual bool selectVSplatUimm1(SDValue N, SDValue &Imm) const;
101   /// Select constant vector splats whose value fits in a uimm2.
102   virtual bool selectVSplatUimm2(SDValue N, SDValue &Imm) const;
103   /// Select constant vector splats whose value fits in a uimm3.
104   virtual bool selectVSplatUimm3(SDValue N, SDValue &Imm) const;
105   /// Select constant vector splats whose value fits in a uimm4.
106   virtual bool selectVSplatUimm4(SDValue N, SDValue &Imm) const;
107   /// Select constant vector splats whose value fits in a uimm5.
108   virtual bool selectVSplatUimm5(SDValue N, SDValue &Imm) const;
109   /// Select constant vector splats whose value fits in a uimm6.
110   virtual bool selectVSplatUimm6(SDValue N, SDValue &Imm) const;
111   /// Select constant vector splats whose value fits in a uimm8.
112   virtual bool selectVSplatUimm8(SDValue N, SDValue &Imm) const;
113   /// Select constant vector splats whose value fits in a simm5.
114   virtual bool selectVSplatSimm5(SDValue N, SDValue &Imm) const;
115   /// Select constant vector splats whose value is a power of 2.
116   virtual bool selectVSplatUimmPow2(SDValue N, SDValue &Imm) const;
117   /// Select constant vector splats whose value is the inverse of a
118   /// power of 2.
119   virtual bool selectVSplatUimmInvPow2(SDValue N, SDValue &Imm) const;
120   /// Select constant vector splats whose value is a run of set bits
121   /// ending at the most significant bit
122   virtual bool selectVSplatMaskL(SDValue N, SDValue &Imm) const;
123   /// Select constant vector splats whose value is a run of set bits
124   /// starting at bit zero.
125   virtual bool selectVSplatMaskR(SDValue N, SDValue &Imm) const;
126 
127   /// Convert vector addition with vector subtraction if that allows to encode
128   /// constant as an immediate and thus avoid extra 'ldi' instruction.
129   /// add X, <-1, -1...> --> sub X, <1, 1...>
130   bool selectVecAddAsVecSubIfProfitable(SDNode *Node);
131 
132   void Select(SDNode *N) override;
133 
134   virtual bool trySelect(SDNode *Node) = 0;
135 
136   // getImm - Return a target constant with the specified value.
137   inline SDValue getImm(const SDNode *Node, uint64_t Imm) {
138     return CurDAG->getTargetConstant(Imm, SDLoc(Node), Node->getValueType(0));
139   }
140 
141   virtual void processFunctionAfterISel(MachineFunction &MF) = 0;
142 
143   bool SelectInlineAsmMemoryOperand(const SDValue &Op,
144                                     InlineAsm::ConstraintCode ConstraintID,
145                                     std::vector<SDValue> &OutOps) override;
146   bool isUnneededShiftMask(SDNode *N, unsigned ShAmtBits) const;
147 };
148 }
149 
150 #endif
151