1 //===-- PPCSubtarget.h - Define Subtarget for the PPC ----------*- 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 PowerPC specific subclass of TargetSubtargetInfo.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_TARGET_POWERPC_PPCSUBTARGET_H
14 #define LLVM_LIB_TARGET_POWERPC_PPCSUBTARGET_H
15 
16 #include "PPCFrameLowering.h"
17 #include "PPCISelLowering.h"
18 #include "PPCInstrInfo.h"
19 #include "llvm/ADT/Triple.h"
20 #include "llvm/CodeGen/SelectionDAGTargetInfo.h"
21 #include "llvm/CodeGen/TargetSubtargetInfo.h"
22 #include "llvm/IR/DataLayout.h"
23 #include "llvm/MC/MCInstrItineraries.h"
24 #include <string>
25 
26 #define GET_SUBTARGETINFO_HEADER
27 #include "PPCGenSubtargetInfo.inc"
28 
29 // GCC #defines PPC on Linux but we use it as our namespace name
30 #undef PPC
31 
32 namespace llvm {
33 class StringRef;
34 
35 namespace PPC {
36   // -m directive values.
37   enum {
38     DIR_NONE,
39     DIR_32,
40     DIR_440,
41     DIR_601,
42     DIR_602,
43     DIR_603,
44     DIR_7400,
45     DIR_750,
46     DIR_970,
47     DIR_A2,
48     DIR_E500,
49     DIR_E500mc,
50     DIR_E5500,
51     DIR_PWR3,
52     DIR_PWR4,
53     DIR_PWR5,
54     DIR_PWR5X,
55     DIR_PWR6,
56     DIR_PWR6X,
57     DIR_PWR7,
58     DIR_PWR8,
59     DIR_PWR9,
60     DIR_64
61   };
62 }
63 
64 class GlobalValue;
65 class TargetMachine;
66 
67 class PPCSubtarget : public PPCGenSubtargetInfo {
68 public:
69   enum POPCNTDKind {
70     POPCNTD_Unavailable,
71     POPCNTD_Slow,
72     POPCNTD_Fast
73   };
74 
75 protected:
76   /// TargetTriple - What processor and OS we're targeting.
77   Triple TargetTriple;
78 
79   /// stackAlignment - The minimum alignment known to hold of the stack frame on
80   /// entry to the function and which must be maintained by every function.
81   unsigned StackAlignment;
82 
83   /// Selected instruction itineraries (one entry per itinerary class.)
84   InstrItineraryData InstrItins;
85 
86   /// Which cpu directive was used.
87   unsigned DarwinDirective;
88 
89   /// Used by the ISel to turn in optimizations for POWER4-derived architectures
90   bool HasMFOCRF;
91   bool Has64BitSupport;
92   bool Use64BitRegs;
93   bool UseCRBits;
94   bool HasHardFloat;
95   bool IsPPC64;
96   bool HasAltivec;
97   bool HasFPU;
98   bool HasSPE;
99   bool HasQPX;
100   bool HasVSX;
101   bool HasP8Vector;
102   bool HasP8Altivec;
103   bool HasP8Crypto;
104   bool HasP9Vector;
105   bool HasP9Altivec;
106   bool HasFCPSGN;
107   bool HasFSQRT;
108   bool HasFRE, HasFRES, HasFRSQRTE, HasFRSQRTES;
109   bool HasRecipPrec;
110   bool HasSTFIWX;
111   bool HasLFIWAX;
112   bool HasFPRND;
113   bool HasFPCVT;
114   bool HasISEL;
115   bool HasBPERMD;
116   bool HasExtDiv;
117   bool HasCMPB;
118   bool HasLDBRX;
119   bool IsBookE;
120   bool HasOnlyMSYNC;
121   bool IsE500;
122   bool IsPPC4xx;
123   bool IsPPC6xx;
124   bool FeatureMFTB;
125   bool DeprecatedDST;
126   bool HasLazyResolverStubs;
127   bool IsLittleEndian;
128   bool HasICBT;
129   bool HasInvariantFunctionDescriptors;
130   bool HasPartwordAtomics;
131   bool HasDirectMove;
132   bool HasHTM;
133   bool HasFusion;
134   bool HasFloat128;
135   bool IsISA3_0;
136   bool UseLongCalls;
137   bool SecurePlt;
138   bool VectorsUseTwoUnits;
139   bool UsePPCPreRASchedStrategy;
140   bool UsePPCPostRASchedStrategy;
141 
142   POPCNTDKind HasPOPCNTD;
143 
144   /// When targeting QPX running a stock PPC64 Linux kernel where the stack
145   /// alignment has not been changed, we need to keep the 16-byte alignment
146   /// of the stack.
147   bool IsQPXStackUnaligned;
148 
149   const PPCTargetMachine &TM;
150   PPCFrameLowering FrameLowering;
151   PPCInstrInfo InstrInfo;
152   PPCTargetLowering TLInfo;
153   SelectionDAGTargetInfo TSInfo;
154 
155 public:
156   /// This constructor initializes the data members to match that
157   /// of the specified triple.
158   ///
159   PPCSubtarget(const Triple &TT, const std::string &CPU, const std::string &FS,
160                const PPCTargetMachine &TM);
161 
162   /// ParseSubtargetFeatures - Parses features string setting specified
163   /// subtarget options.  Definition of function is auto generated by tblgen.
164   void ParseSubtargetFeatures(StringRef CPU, StringRef FS);
165 
166   /// getStackAlignment - Returns the minimum alignment known to hold of the
167   /// stack frame on entry to the function and which must be maintained by every
168   /// function for this subtarget.
169   unsigned getStackAlignment() const { return StackAlignment; }
170 
171   /// getDarwinDirective - Returns the -m directive specified for the cpu.
172   ///
173   unsigned getDarwinDirective() const { return DarwinDirective; }
174 
175   /// getInstrItins - Return the instruction itineraries based on subtarget
176   /// selection.
177   const InstrItineraryData *getInstrItineraryData() const override {
178     return &InstrItins;
179   }
180 
181   const PPCFrameLowering *getFrameLowering() const override {
182     return &FrameLowering;
183   }
184   const PPCInstrInfo *getInstrInfo() const override { return &InstrInfo; }
185   const PPCTargetLowering *getTargetLowering() const override {
186     return &TLInfo;
187   }
188   const SelectionDAGTargetInfo *getSelectionDAGInfo() const override {
189     return &TSInfo;
190   }
191   const PPCRegisterInfo *getRegisterInfo() const override {
192     return &getInstrInfo()->getRegisterInfo();
193   }
194   const PPCTargetMachine &getTargetMachine() const { return TM; }
195 
196   /// initializeSubtargetDependencies - Initializes using a CPU and feature string
197   /// so that we can use initializer lists for subtarget initialization.
198   PPCSubtarget &initializeSubtargetDependencies(StringRef CPU, StringRef FS);
199 
200 private:
201   void initializeEnvironment();
202   void initSubtargetFeatures(StringRef CPU, StringRef FS);
203 
204 public:
205   /// isPPC64 - Return true if we are generating code for 64-bit pointer mode.
206   ///
207   bool isPPC64() const;
208 
209   /// has64BitSupport - Return true if the selected CPU supports 64-bit
210   /// instructions, regardless of whether we are in 32-bit or 64-bit mode.
211   bool has64BitSupport() const { return Has64BitSupport; }
212   // useSoftFloat - Return true if soft-float option is turned on.
213   bool useSoftFloat() const { return !HasHardFloat; }
214 
215   /// use64BitRegs - Return true if in 64-bit mode or if we should use 64-bit
216   /// registers in 32-bit mode when possible.  This can only true if
217   /// has64BitSupport() returns true.
218   bool use64BitRegs() const { return Use64BitRegs; }
219 
220   /// useCRBits - Return true if we should store and manipulate i1 values in
221   /// the individual condition register bits.
222   bool useCRBits() const { return UseCRBits; }
223 
224   /// hasLazyResolverStub - Return true if accesses to the specified global have
225   /// to go through a dyld lazy resolution stub.  This means that an extra load
226   /// is required to get the address of the global.
227   bool hasLazyResolverStub(const GlobalValue *GV) const;
228 
229   // isLittleEndian - True if generating little-endian code
230   bool isLittleEndian() const { return IsLittleEndian; }
231 
232   // Specific obvious features.
233   bool hasFCPSGN() const { return HasFCPSGN; }
234   bool hasFSQRT() const { return HasFSQRT; }
235   bool hasFRE() const { return HasFRE; }
236   bool hasFRES() const { return HasFRES; }
237   bool hasFRSQRTE() const { return HasFRSQRTE; }
238   bool hasFRSQRTES() const { return HasFRSQRTES; }
239   bool hasRecipPrec() const { return HasRecipPrec; }
240   bool hasSTFIWX() const { return HasSTFIWX; }
241   bool hasLFIWAX() const { return HasLFIWAX; }
242   bool hasFPRND() const { return HasFPRND; }
243   bool hasFPCVT() const { return HasFPCVT; }
244   bool hasAltivec() const { return HasAltivec; }
245   bool hasSPE() const { return HasSPE; }
246   bool hasFPU() const { return HasFPU; }
247   bool hasQPX() const { return HasQPX; }
248   bool hasVSX() const { return HasVSX; }
249   bool hasP8Vector() const { return HasP8Vector; }
250   bool hasP8Altivec() const { return HasP8Altivec; }
251   bool hasP8Crypto() const { return HasP8Crypto; }
252   bool hasP9Vector() const { return HasP9Vector; }
253   bool hasP9Altivec() const { return HasP9Altivec; }
254   bool hasMFOCRF() const { return HasMFOCRF; }
255   bool hasISEL() const { return HasISEL; }
256   bool hasBPERMD() const { return HasBPERMD; }
257   bool hasExtDiv() const { return HasExtDiv; }
258   bool hasCMPB() const { return HasCMPB; }
259   bool hasLDBRX() const { return HasLDBRX; }
260   bool isBookE() const { return IsBookE; }
261   bool hasOnlyMSYNC() const { return HasOnlyMSYNC; }
262   bool isPPC4xx() const { return IsPPC4xx; }
263   bool isPPC6xx() const { return IsPPC6xx; }
264   bool isSecurePlt() const {return SecurePlt; }
265   bool vectorsUseTwoUnits() const {return VectorsUseTwoUnits; }
266   bool isE500() const { return IsE500; }
267   bool isFeatureMFTB() const { return FeatureMFTB; }
268   bool isDeprecatedDST() const { return DeprecatedDST; }
269   bool hasICBT() const { return HasICBT; }
270   bool hasInvariantFunctionDescriptors() const {
271     return HasInvariantFunctionDescriptors;
272   }
273   bool usePPCPreRASchedStrategy() const { return UsePPCPreRASchedStrategy; }
274   bool usePPCPostRASchedStrategy() const { return UsePPCPostRASchedStrategy; }
275   bool hasPartwordAtomics() const { return HasPartwordAtomics; }
276   bool hasDirectMove() const { return HasDirectMove; }
277 
278   bool isQPXStackUnaligned() const { return IsQPXStackUnaligned; }
279   unsigned getPlatformStackAlignment() const {
280     if ((hasQPX() || isBGQ()) && !isQPXStackUnaligned())
281       return 32;
282 
283     return 16;
284   }
285 
286   // DarwinABI has a 224-byte red zone. PPC32 SVR4ABI(Non-DarwinABI) has no
287   // red zone and PPC64 SVR4ABI has a 288-byte red zone.
288   unsigned  getRedZoneSize() const {
289     return isDarwinABI() ? 224 : (isPPC64() ? 288 : 0);
290   }
291 
292   bool hasHTM() const { return HasHTM; }
293   bool hasFusion() const { return HasFusion; }
294   bool hasFloat128() const { return HasFloat128; }
295   bool isISA3_0() const { return IsISA3_0; }
296   bool useLongCalls() const { return UseLongCalls; }
297   bool needsSwapsForVSXMemOps() const {
298     return hasVSX() && isLittleEndian() && !hasP9Vector();
299   }
300 
301   POPCNTDKind hasPOPCNTD() const { return HasPOPCNTD; }
302 
303   const Triple &getTargetTriple() const { return TargetTriple; }
304 
305   /// isDarwin - True if this is any darwin platform.
306   bool isDarwin() const { return TargetTriple.isMacOSX(); }
307   /// isBGQ - True if this is a BG/Q platform.
308   bool isBGQ() const { return TargetTriple.getVendor() == Triple::BGQ; }
309 
310   bool isTargetELF() const { return TargetTriple.isOSBinFormatELF(); }
311   bool isTargetMachO() const { return TargetTriple.isOSBinFormatMachO(); }
312   bool isTargetLinux() const { return TargetTriple.isOSLinux(); }
313 
314   bool isDarwinABI() const { return isTargetMachO() || isDarwin(); }
315   bool isSVR4ABI() const { return !isDarwinABI(); }
316   bool isELFv2ABI() const;
317 
318   /// Originally, this function return hasISEL(). Now we always enable it,
319   /// but may expand the ISEL instruction later.
320   bool enableEarlyIfConversion() const override { return true; }
321 
322   // Scheduling customization.
323   bool enableMachineScheduler() const override;
324   // This overrides the PostRAScheduler bit in the SchedModel for each CPU.
325   bool enablePostRAScheduler() const override;
326   AntiDepBreakMode getAntiDepBreakMode() const override;
327   void getCriticalPathRCs(RegClassVector &CriticalPathRCs) const override;
328 
329   void overrideSchedPolicy(MachineSchedPolicy &Policy,
330                            unsigned NumRegionInstrs) const override;
331   bool useAA() const override;
332 
333   bool enableSubRegLiveness() const override;
334 
335   /// classifyGlobalReference - Classify a global variable reference for the
336   /// current subtarget accourding to how we should reference it.
337   unsigned char classifyGlobalReference(const GlobalValue *GV) const;
338 
339   bool isXRaySupported() const override { return IsPPC64 && IsLittleEndian; }
340 };
341 } // End llvm namespace
342 
343 #endif
344