1 //===-- MipsSubtarget.h - Define Subtarget for the Mips ---------*- 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 declares the Mips specific subclass of TargetSubtargetInfo.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_TARGET_MIPS_MIPSSUBTARGET_H
14 #define LLVM_LIB_TARGET_MIPS_MIPSSUBTARGET_H
15 
16 #include "MCTargetDesc/MipsABIInfo.h"
17 #include "MipsFrameLowering.h"
18 #include "MipsISelLowering.h"
19 #include "MipsInstrInfo.h"
20 #include "llvm/CodeGen/SelectionDAGTargetInfo.h"
21 #include "llvm/CodeGen/TargetSubtargetInfo.h"
22 #include "llvm/CodeGen/GlobalISel/CallLowering.h"
23 #include "llvm/CodeGen/GlobalISel/LegalizerInfo.h"
24 #include "llvm/CodeGen/GlobalISel/RegisterBankInfo.h"
25 #include "llvm/CodeGen/GlobalISel/InstructionSelector.h"
26 #include "llvm/IR/DataLayout.h"
27 #include "llvm/MC/MCInstrItineraries.h"
28 #include "llvm/Support/ErrorHandling.h"
29 #include <string>
30 
31 #define GET_SUBTARGETINFO_HEADER
32 #include "MipsGenSubtargetInfo.inc"
33 
34 namespace llvm {
35 class StringRef;
36 
37 class MipsTargetMachine;
38 
39 class MipsSubtarget : public MipsGenSubtargetInfo {
40   virtual void anchor();
41 
42   enum MipsArchEnum {
43     MipsDefault,
44     Mips1, Mips2, Mips32, Mips32r2, Mips32r3, Mips32r5, Mips32r6, Mips32Max,
45     Mips3, Mips4, Mips5, Mips64, Mips64r2, Mips64r3, Mips64r5, Mips64r6
46   };
47 
48   enum class CPU { P5600 };
49 
50   // Used to avoid printing dsp warnings multiple times.
51   static bool DspWarningPrinted;
52 
53   // Used to avoid printing msa warnings multiple times.
54   static bool MSAWarningPrinted;
55 
56   // Used to avoid printing crc warnings multiple times.
57   static bool CRCWarningPrinted;
58 
59   // Used to avoid printing ginv warnings multiple times.
60   static bool GINVWarningPrinted;
61 
62   // Used to avoid printing virt warnings multiple times.
63   static bool VirtWarningPrinted;
64 
65   // Mips architecture version
66   MipsArchEnum MipsArchVersion;
67 
68   // Processor implementation (unused but required to exist by
69   // tablegen-erated code).
70   CPU ProcImpl;
71 
72   // IsLittle - The target is Little Endian
73   bool IsLittle;
74 
75   // IsSoftFloat - The target does not support any floating point instructions.
76   bool IsSoftFloat;
77 
78   // IsSingleFloat - The target only supports single precision float
79   // point operations. This enable the target to use all 32 32-bit
80   // floating point registers instead of only using even ones.
81   bool IsSingleFloat;
82 
83   // IsFPXX - MIPS O32 modeless ABI.
84   bool IsFPXX;
85 
86   // NoABICalls - Disable SVR4-style position-independent code.
87   bool NoABICalls;
88 
89   // Abs2008 - Use IEEE 754-2008 abs.fmt instruction.
90   bool Abs2008;
91 
92   // IsFP64bit - The target processor has 64-bit floating point registers.
93   bool IsFP64bit;
94 
95   /// Are odd single-precision registers permitted?
96   /// This corresponds to -modd-spreg and -mno-odd-spreg
97   bool UseOddSPReg;
98 
99   // IsNan2008 - IEEE 754-2008 NaN encoding.
100   bool IsNaN2008bit;
101 
102   // IsGP64bit - General-purpose registers are 64 bits wide
103   bool IsGP64bit;
104 
105   // IsPTR64bit - Pointers are 64 bit wide
106   bool IsPTR64bit;
107 
108   // HasVFPU - Processor has a vector floating point unit.
109   bool HasVFPU;
110 
111   // CPU supports cnMIPS (Cavium Networks Octeon CPU).
112   bool HasCnMips;
113 
114   // CPU supports cnMIPSP (Cavium Networks Octeon+ CPU).
115   bool HasCnMipsP;
116 
117   // isLinux - Target system is Linux. Is false we consider ELFOS for now.
118   bool IsLinux;
119 
120   // UseSmallSection - Small section is used.
121   bool UseSmallSection;
122 
123   /// Features related to the presence of specific instructions.
124 
125   // HasMips3_32 - The subset of MIPS-III instructions added to MIPS32
126   bool HasMips3_32;
127 
128   // HasMips3_32r2 - The subset of MIPS-III instructions added to MIPS32r2
129   bool HasMips3_32r2;
130 
131   // HasMips4_32 - Has the subset of MIPS-IV present in MIPS32
132   bool HasMips4_32;
133 
134   // HasMips4_32r2 - Has the subset of MIPS-IV present in MIPS32r2
135   bool HasMips4_32r2;
136 
137   // HasMips5_32r2 - Has the subset of MIPS-V present in MIPS32r2
138   bool HasMips5_32r2;
139 
140   // InMips16 -- can process Mips16 instructions
141   bool InMips16Mode;
142 
143   // Mips16 hard float
144   bool InMips16HardFloat;
145 
146   // InMicroMips -- can process MicroMips instructions
147   bool InMicroMipsMode;
148 
149   // HasDSP, HasDSPR2, HasDSPR3 -- supports DSP ASE.
150   bool HasDSP, HasDSPR2, HasDSPR3;
151 
152   // Allow mixed Mips16 and Mips32 in one source file
153   bool AllowMixed16_32;
154 
155   // Optimize for space by compiling all functions as Mips 16 unless
156   // it needs floating point. Functions needing floating point are
157   // compiled as Mips32
158   bool Os16;
159 
160   // HasMSA -- supports MSA ASE.
161   bool HasMSA;
162 
163   // UseTCCInDIV -- Enables the use of trapping in the assembler.
164   bool UseTCCInDIV;
165 
166   // Sym32 -- On Mips64 symbols are 32 bits.
167   bool HasSym32;
168 
169   // HasEVA -- supports EVA ASE.
170   bool HasEVA;
171 
172   // nomadd4 - disables generation of 4-operand madd.s, madd.d and
173   // related instructions.
174   bool DisableMadd4;
175 
176   // HasMT -- support MT ASE.
177   bool HasMT;
178 
179   // HasCRC -- supports R6 CRC ASE
180   bool HasCRC;
181 
182   // HasVirt -- supports Virtualization ASE
183   bool HasVirt;
184 
185   // HasGINV -- supports R6 Global INValidate ASE
186   bool HasGINV;
187 
188   // Use hazard variants of the jump register instructions for indirect
189   // function calls and jump tables.
190   bool UseIndirectJumpsHazard;
191 
192   // Disable use of the `jal` instruction.
193   bool UseLongCalls = false;
194 
195   // Assume 32-bit GOT.
196   bool UseXGOT = false;
197 
198   /// The minimum alignment known to hold of the stack frame on
199   /// entry to the function and which must be maintained by every function.
200   Align stackAlignment;
201 
202   /// The overridden stack alignment.
203   MaybeAlign StackAlignOverride;
204 
205   InstrItineraryData InstrItins;
206 
207   // We can override the determination of whether we are in mips16 mode
208   // as from the command line
209   enum {NoOverride, Mips16Override, NoMips16Override} OverrideMode;
210 
211   const MipsTargetMachine &TM;
212 
213   Triple TargetTriple;
214 
215   const SelectionDAGTargetInfo TSInfo;
216   std::unique_ptr<const MipsInstrInfo> InstrInfo;
217   std::unique_ptr<const MipsFrameLowering> FrameLowering;
218   std::unique_ptr<const MipsTargetLowering> TLInfo;
219 
220 public:
221   bool isPositionIndependent() const;
222   /// This overrides the PostRAScheduler bit in the SchedModel for each CPU.
223   bool enablePostRAScheduler() const override;
224   void getCriticalPathRCs(RegClassVector &CriticalPathRCs) const override;
225   CodeGenOpt::Level getOptLevelToEnablePostRAScheduler() const override;
226 
227   bool isABI_N64() const;
228   bool isABI_N32() const;
229   bool isABI_O32() const;
230   const MipsABIInfo &getABI() const;
231   bool isABI_FPXX() const { return isABI_O32() && IsFPXX; }
232 
233   /// This constructor initializes the data members to match that
234   /// of the specified triple.
235   MipsSubtarget(const Triple &TT, StringRef CPU, StringRef FS, bool little,
236                 const MipsTargetMachine &TM, MaybeAlign StackAlignOverride);
237 
238   /// ParseSubtargetFeatures - Parses features string setting specified
239   /// subtarget options.  Definition of function is auto generated by tblgen.
240   void ParseSubtargetFeatures(StringRef CPU, StringRef FS);
241 
242   bool hasMips1() const { return MipsArchVersion >= Mips1; }
243   bool hasMips2() const { return MipsArchVersion >= Mips2; }
244   bool hasMips3() const { return MipsArchVersion >= Mips3; }
245   bool hasMips4() const { return MipsArchVersion >= Mips4; }
246   bool hasMips5() const { return MipsArchVersion >= Mips5; }
247   bool hasMips4_32() const { return HasMips4_32; }
248   bool hasMips4_32r2() const { return HasMips4_32r2; }
249   bool hasMips32() const {
250     return (MipsArchVersion >= Mips32 && MipsArchVersion < Mips32Max) ||
251            hasMips64();
252   }
253   bool hasMips32r2() const {
254     return (MipsArchVersion >= Mips32r2 && MipsArchVersion < Mips32Max) ||
255            hasMips64r2();
256   }
257   bool hasMips32r3() const {
258     return (MipsArchVersion >= Mips32r3 && MipsArchVersion < Mips32Max) ||
259            hasMips64r2();
260   }
261   bool hasMips32r5() const {
262     return (MipsArchVersion >= Mips32r5 && MipsArchVersion < Mips32Max) ||
263            hasMips64r5();
264   }
265   bool hasMips32r6() const {
266     return (MipsArchVersion >= Mips32r6 && MipsArchVersion < Mips32Max) ||
267            hasMips64r6();
268   }
269   bool hasMips64() const { return MipsArchVersion >= Mips64; }
270   bool hasMips64r2() const { return MipsArchVersion >= Mips64r2; }
271   bool hasMips64r3() const { return MipsArchVersion >= Mips64r3; }
272   bool hasMips64r5() const { return MipsArchVersion >= Mips64r5; }
273   bool hasMips64r6() const { return MipsArchVersion >= Mips64r6; }
274 
275   bool hasCnMips() const { return HasCnMips; }
276   bool hasCnMipsP() const { return HasCnMipsP; }
277 
278   bool isLittle() const { return IsLittle; }
279   bool isABICalls() const { return !NoABICalls; }
280   bool isFPXX() const { return IsFPXX; }
281   bool isFP64bit() const { return IsFP64bit; }
282   bool useOddSPReg() const { return UseOddSPReg; }
283   bool noOddSPReg() const { return !UseOddSPReg; }
284   bool isNaN2008() const { return IsNaN2008bit; }
285   bool inAbs2008Mode() const { return Abs2008; }
286   bool isGP64bit() const { return IsGP64bit; }
287   bool isGP32bit() const { return !IsGP64bit; }
288   unsigned getGPRSizeInBytes() const { return isGP64bit() ? 8 : 4; }
289   bool isPTR64bit() const { return IsPTR64bit; }
290   bool isPTR32bit() const { return !IsPTR64bit; }
291   bool hasSym32() const {
292     return (HasSym32 && isABI_N64()) || isABI_N32() || isABI_O32();
293   }
294   bool isSingleFloat() const { return IsSingleFloat; }
295   bool isTargetELF() const { return TargetTriple.isOSBinFormatELF(); }
296   bool hasVFPU() const { return HasVFPU; }
297   bool inMips16Mode() const { return InMips16Mode; }
298   bool inMips16ModeDefault() const {
299     return InMips16Mode;
300   }
301   // Hard float for mips16 means essentially to compile as soft float
302   // but to use a runtime library for soft float that is written with
303   // native mips32 floating point instructions (those runtime routines
304   // run in mips32 hard float mode).
305   bool inMips16HardFloat() const {
306     return inMips16Mode() && InMips16HardFloat;
307   }
308   bool inMicroMipsMode() const { return InMicroMipsMode && !InMips16Mode; }
309   bool inMicroMips32r6Mode() const {
310     return inMicroMipsMode() && hasMips32r6();
311   }
312   bool hasDSP() const { return HasDSP; }
313   bool hasDSPR2() const { return HasDSPR2; }
314   bool hasDSPR3() const { return HasDSPR3; }
315   bool hasMSA() const { return HasMSA; }
316   bool disableMadd4() const { return DisableMadd4; }
317   bool hasEVA() const { return HasEVA; }
318   bool hasMT() const { return HasMT; }
319   bool hasCRC() const { return HasCRC; }
320   bool hasVirt() const { return HasVirt; }
321   bool hasGINV() const { return HasGINV; }
322   bool useIndirectJumpsHazard() const {
323     return UseIndirectJumpsHazard && hasMips32r2();
324   }
325   bool useSmallSection() const { return UseSmallSection; }
326 
327   bool hasStandardEncoding() const { return !InMips16Mode && !InMicroMipsMode; }
328 
329   bool useSoftFloat() const { return IsSoftFloat; }
330 
331   bool useLongCalls() const { return UseLongCalls; }
332 
333   bool useXGOT() const { return UseXGOT; }
334 
335   bool enableLongBranchPass() const {
336     return hasStandardEncoding() || inMicroMipsMode() || allowMixed16_32();
337   }
338 
339   /// Features related to the presence of specific instructions.
340   bool hasExtractInsert() const { return !inMips16Mode() && hasMips32r2(); }
341   bool hasMTHC1() const { return hasMips32r2(); }
342 
343   bool allowMixed16_32() const { return inMips16ModeDefault() |
344                                         AllowMixed16_32; }
345 
346   bool os16() const { return Os16; }
347 
348   bool isTargetNaCl() const { return TargetTriple.isOSNaCl(); }
349 
350   bool isXRaySupported() const override { return true; }
351 
352   // for now constant islands are on for the whole compilation unit but we only
353   // really use them if in addition we are in mips16 mode
354   static bool useConstantIslands();
355 
356   Align getStackAlignment() const { return stackAlignment; }
357 
358   // Grab relocation model
359   Reloc::Model getRelocationModel() const;
360 
361   MipsSubtarget &initializeSubtargetDependencies(StringRef CPU, StringRef FS,
362                                                  const TargetMachine &TM);
363 
364   /// Does the system support unaligned memory access.
365   ///
366   /// MIPS32r6/MIPS64r6 require full unaligned access support but does not
367   /// specify which component of the system provides it. Hardware, software, and
368   /// hybrid implementations are all valid.
369   bool systemSupportsUnalignedAccess() const { return hasMips32r6(); }
370 
371   // Set helper classes
372   void setHelperClassesMips16();
373   void setHelperClassesMipsSE();
374 
375   const SelectionDAGTargetInfo *getSelectionDAGInfo() const override {
376     return &TSInfo;
377   }
378   const MipsInstrInfo *getInstrInfo() const override { return InstrInfo.get(); }
379   const TargetFrameLowering *getFrameLowering() const override {
380     return FrameLowering.get();
381   }
382   const MipsRegisterInfo *getRegisterInfo() const override {
383     return &InstrInfo->getRegisterInfo();
384   }
385   const MipsTargetLowering *getTargetLowering() const override {
386     return TLInfo.get();
387   }
388   const InstrItineraryData *getInstrItineraryData() const override {
389     return &InstrItins;
390   }
391 
392 protected:
393   // GlobalISel related APIs.
394   std::unique_ptr<CallLowering> CallLoweringInfo;
395   std::unique_ptr<LegalizerInfo> Legalizer;
396   std::unique_ptr<RegisterBankInfo> RegBankInfo;
397   std::unique_ptr<InstructionSelector> InstSelector;
398 
399 public:
400   const CallLowering *getCallLowering() const override;
401   const LegalizerInfo *getLegalizerInfo() const override;
402   const RegisterBankInfo *getRegBankInfo() const override;
403   InstructionSelector *getInstructionSelector() const override;
404 };
405 } // End llvm namespace
406 
407 #endif
408