xref: /freebsd/contrib/llvm-project/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonAsmBackend.cpp (revision 52418fc2be8efa5172b90a3a9e617017173612c4)
1 //===-- HexagonAsmBackend.cpp - Hexagon Assembler Backend -----------------===//
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 #include "HexagonFixupKinds.h"
10 #include "MCTargetDesc/HexagonBaseInfo.h"
11 #include "MCTargetDesc/HexagonMCChecker.h"
12 #include "MCTargetDesc/HexagonMCCodeEmitter.h"
13 #include "MCTargetDesc/HexagonMCInstrInfo.h"
14 #include "MCTargetDesc/HexagonMCShuffler.h"
15 #include "MCTargetDesc/HexagonMCTargetDesc.h"
16 #include "llvm/MC/MCAsmBackend.h"
17 #include "llvm/MC/MCAssembler.h"
18 #include "llvm/MC/MCContext.h"
19 #include "llvm/MC/MCELFObjectWriter.h"
20 #include "llvm/MC/MCFixupKindInfo.h"
21 #include "llvm/MC/MCInstrInfo.h"
22 #include "llvm/MC/MCObjectWriter.h"
23 #include "llvm/MC/MCSubtargetInfo.h"
24 #include "llvm/MC/TargetRegistry.h"
25 #include "llvm/Support/Debug.h"
26 #include "llvm/Support/EndianStream.h"
27 
28 #include <sstream>
29 
30 using namespace llvm;
31 using namespace Hexagon;
32 
33 #define DEBUG_TYPE "hexagon-asm-backend"
34 
35 static cl::opt<bool> DisableFixup
36   ("mno-fixup", cl::desc("Disable fixing up resolved relocations for Hexagon"));
37 
38 namespace {
39 
40 class HexagonAsmBackend : public MCAsmBackend {
41   uint8_t OSABI;
42   StringRef CPU;
43   mutable uint64_t relaxedCnt;
44   std::unique_ptr <MCInstrInfo> MCII;
45   std::unique_ptr <MCInst *> RelaxTarget;
46   MCInst * Extender;
47   unsigned MaxPacketSize;
48 
ReplaceInstruction(MCCodeEmitter & E,MCRelaxableFragment & RF,MCInst & HMB) const49   void ReplaceInstruction(MCCodeEmitter &E, MCRelaxableFragment &RF,
50                           MCInst &HMB) const {
51     SmallVector<MCFixup, 4> Fixups;
52     SmallString<256> Code;
53     E.encodeInstruction(HMB, Code, Fixups, *RF.getSubtargetInfo());
54 
55     // Update the fragment.
56     RF.setInst(HMB);
57     RF.getContents() = Code;
58     RF.getFixups() = Fixups;
59   }
60 
61 public:
HexagonAsmBackend(const Target & T,const Triple & TT,uint8_t OSABI,StringRef CPU)62   HexagonAsmBackend(const Target &T, const Triple &TT, uint8_t OSABI,
63                     StringRef CPU)
64       : MCAsmBackend(llvm::endianness::little), OSABI(OSABI), CPU(CPU),
65         relaxedCnt(0), MCII(T.createMCInstrInfo()), RelaxTarget(new MCInst *),
66         Extender(nullptr), MaxPacketSize(HexagonMCInstrInfo::packetSize(CPU)) {}
67 
68   std::unique_ptr<MCObjectTargetWriter>
createObjectTargetWriter() const69   createObjectTargetWriter() const override {
70     return createHexagonELFObjectWriter(OSABI, CPU);
71   }
72 
setExtender(MCContext & Context) const73   void setExtender(MCContext &Context) const {
74     if (Extender == nullptr)
75       const_cast<HexagonAsmBackend *>(this)->Extender = Context.createMCInst();
76   }
77 
takeExtender() const78   MCInst *takeExtender() const {
79     assert(Extender != nullptr);
80     MCInst * Result = Extender;
81     const_cast<HexagonAsmBackend *>(this)->Extender = nullptr;
82     return Result;
83   }
84 
getNumFixupKinds() const85   unsigned getNumFixupKinds() const override {
86     return Hexagon::NumTargetFixupKinds;
87   }
88 
getFixupKindInfo(MCFixupKind Kind) const89   const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const override {
90     const static MCFixupKindInfo Infos[Hexagon::NumTargetFixupKinds] = {
91       // This table *must* be in same the order of fixup_* kinds in
92       // HexagonFixupKinds.h.
93       //
94       // namei                          offset  bits    flags
95       { "fixup_Hexagon_B22_PCREL",      0,      32,     MCFixupKindInfo::FKF_IsPCRel },
96       { "fixup_Hexagon_B15_PCREL",      0,      32,     MCFixupKindInfo::FKF_IsPCRel },
97       { "fixup_Hexagon_B7_PCREL",       0,      32,     MCFixupKindInfo::FKF_IsPCRel },
98       { "fixup_Hexagon_LO16",           0,      32,     0 },
99       { "fixup_Hexagon_HI16",           0,      32,     0 },
100       { "fixup_Hexagon_32",             0,      32,     0 },
101       { "fixup_Hexagon_16",             0,      32,     0 },
102       { "fixup_Hexagon_8",              0,      32,     0 },
103       { "fixup_Hexagon_GPREL16_0",      0,      32,     0 },
104       { "fixup_Hexagon_GPREL16_1",      0,      32,     0 },
105       { "fixup_Hexagon_GPREL16_2",      0,      32,     0 },
106       { "fixup_Hexagon_GPREL16_3",      0,      32,     0 },
107       { "fixup_Hexagon_HL16",           0,      32,     0 },
108       { "fixup_Hexagon_B13_PCREL",      0,      32,     MCFixupKindInfo::FKF_IsPCRel },
109       { "fixup_Hexagon_B9_PCREL",       0,      32,     MCFixupKindInfo::FKF_IsPCRel },
110       { "fixup_Hexagon_B32_PCREL_X",    0,      32,     MCFixupKindInfo::FKF_IsPCRel },
111       { "fixup_Hexagon_32_6_X",         0,      32,     0 },
112       { "fixup_Hexagon_B22_PCREL_X",    0,      32,     MCFixupKindInfo::FKF_IsPCRel },
113       { "fixup_Hexagon_B15_PCREL_X",    0,      32,     MCFixupKindInfo::FKF_IsPCRel },
114       { "fixup_Hexagon_B13_PCREL_X",    0,      32,     MCFixupKindInfo::FKF_IsPCRel },
115       { "fixup_Hexagon_B9_PCREL_X",     0,      32,     MCFixupKindInfo::FKF_IsPCRel },
116       { "fixup_Hexagon_B7_PCREL_X",     0,      32,     MCFixupKindInfo::FKF_IsPCRel },
117       { "fixup_Hexagon_16_X",           0,      32,     0 },
118       { "fixup_Hexagon_12_X",           0,      32,     0 },
119       { "fixup_Hexagon_11_X",           0,      32,     0 },
120       { "fixup_Hexagon_10_X",           0,      32,     0 },
121       { "fixup_Hexagon_9_X",            0,      32,     0 },
122       { "fixup_Hexagon_8_X",            0,      32,     0 },
123       { "fixup_Hexagon_7_X",            0,      32,     0 },
124       { "fixup_Hexagon_6_X",            0,      32,     0 },
125       { "fixup_Hexagon_32_PCREL",       0,      32,     MCFixupKindInfo::FKF_IsPCRel },
126       { "fixup_Hexagon_COPY",           0,      32,     0 },
127       { "fixup_Hexagon_GLOB_DAT",       0,      32,     0 },
128       { "fixup_Hexagon_JMP_SLOT",       0,      32,     0 },
129       { "fixup_Hexagon_RELATIVE",       0,      32,     0 },
130       { "fixup_Hexagon_PLT_B22_PCREL",  0,      32,     MCFixupKindInfo::FKF_IsPCRel },
131       { "fixup_Hexagon_GOTREL_LO16",    0,      32,     0 },
132       { "fixup_Hexagon_GOTREL_HI16",    0,      32,     0 },
133       { "fixup_Hexagon_GOTREL_32",      0,      32,     0 },
134       { "fixup_Hexagon_GOT_LO16",       0,      32,     0 },
135       { "fixup_Hexagon_GOT_HI16",       0,      32,     0 },
136       { "fixup_Hexagon_GOT_32",         0,      32,     0 },
137       { "fixup_Hexagon_GOT_16",         0,      32,     0 },
138       { "fixup_Hexagon_DTPMOD_32",      0,      32,     0 },
139       { "fixup_Hexagon_DTPREL_LO16",    0,      32,     0 },
140       { "fixup_Hexagon_DTPREL_HI16",    0,      32,     0 },
141       { "fixup_Hexagon_DTPREL_32",      0,      32,     0 },
142       { "fixup_Hexagon_DTPREL_16",      0,      32,     0 },
143       { "fixup_Hexagon_GD_PLT_B22_PCREL",0,     32,     MCFixupKindInfo::FKF_IsPCRel },
144       { "fixup_Hexagon_LD_PLT_B22_PCREL",0,     32,     MCFixupKindInfo::FKF_IsPCRel },
145       { "fixup_Hexagon_GD_GOT_LO16",    0,      32,     0 },
146       { "fixup_Hexagon_GD_GOT_HI16",    0,      32,     0 },
147       { "fixup_Hexagon_GD_GOT_32",      0,      32,     0 },
148       { "fixup_Hexagon_GD_GOT_16",      0,      32,     0 },
149       { "fixup_Hexagon_LD_GOT_LO16",    0,      32,     0 },
150       { "fixup_Hexagon_LD_GOT_HI16",    0,      32,     0 },
151       { "fixup_Hexagon_LD_GOT_32",      0,      32,     0 },
152       { "fixup_Hexagon_LD_GOT_16",      0,      32,     0 },
153       { "fixup_Hexagon_IE_LO16",        0,      32,     0 },
154       { "fixup_Hexagon_IE_HI16",        0,      32,     0 },
155       { "fixup_Hexagon_IE_32",          0,      32,     0 },
156       { "fixup_Hexagon_IE_16",          0,      32,     0 },
157       { "fixup_Hexagon_IE_GOT_LO16",    0,      32,     0 },
158       { "fixup_Hexagon_IE_GOT_HI16",    0,      32,     0 },
159       { "fixup_Hexagon_IE_GOT_32",      0,      32,     0 },
160       { "fixup_Hexagon_IE_GOT_16",      0,      32,     0 },
161       { "fixup_Hexagon_TPREL_LO16",     0,      32,     0 },
162       { "fixup_Hexagon_TPREL_HI16",     0,      32,     0 },
163       { "fixup_Hexagon_TPREL_32",       0,      32,     0 },
164       { "fixup_Hexagon_TPREL_16",       0,      32,     0 },
165       { "fixup_Hexagon_6_PCREL_X",      0,      32,     MCFixupKindInfo::FKF_IsPCRel },
166       { "fixup_Hexagon_GOTREL_32_6_X",  0,      32,     0 },
167       { "fixup_Hexagon_GOTREL_16_X",    0,      32,     0 },
168       { "fixup_Hexagon_GOTREL_11_X",    0,      32,     0 },
169       { "fixup_Hexagon_GOT_32_6_X",     0,      32,     0 },
170       { "fixup_Hexagon_GOT_16_X",       0,      32,     0 },
171       { "fixup_Hexagon_GOT_11_X",       0,      32,     0 },
172       { "fixup_Hexagon_DTPREL_32_6_X",  0,      32,     0 },
173       { "fixup_Hexagon_DTPREL_16_X",    0,      32,     0 },
174       { "fixup_Hexagon_DTPREL_11_X",    0,      32,     0 },
175       { "fixup_Hexagon_GD_GOT_32_6_X",  0,      32,     0 },
176       { "fixup_Hexagon_GD_GOT_16_X",    0,      32,     0 },
177       { "fixup_Hexagon_GD_GOT_11_X",    0,      32,     0 },
178       { "fixup_Hexagon_LD_GOT_32_6_X",  0,      32,     0 },
179       { "fixup_Hexagon_LD_GOT_16_X",    0,      32,     0 },
180       { "fixup_Hexagon_LD_GOT_11_X",    0,      32,     0 },
181       { "fixup_Hexagon_IE_32_6_X",      0,      32,     0 },
182       { "fixup_Hexagon_IE_16_X",        0,      32,     0 },
183       { "fixup_Hexagon_IE_GOT_32_6_X",  0,      32,     0 },
184       { "fixup_Hexagon_IE_GOT_16_X",    0,      32,     0 },
185       { "fixup_Hexagon_IE_GOT_11_X",    0,      32,     0 },
186       { "fixup_Hexagon_TPREL_32_6_X",   0,      32,     0 },
187       { "fixup_Hexagon_TPREL_16_X",     0,      32,     0 },
188       { "fixup_Hexagon_TPREL_11_X",     0,      32,     0 },
189       { "fixup_Hexagon_GD_PLT_B22_PCREL_X",0,     32,     MCFixupKindInfo::FKF_IsPCRel },
190       { "fixup_Hexagon_GD_PLT_B32_PCREL_X",0,     32,     MCFixupKindInfo::FKF_IsPCRel },
191       { "fixup_Hexagon_LD_PLT_B22_PCREL_X",0,     32,     MCFixupKindInfo::FKF_IsPCRel },
192       { "fixup_Hexagon_LD_PLT_B32_PCREL_X",0,     32,     MCFixupKindInfo::FKF_IsPCRel }
193     };
194 
195     if (Kind < FirstTargetFixupKind)
196       return MCAsmBackend::getFixupKindInfo(Kind);
197 
198     assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
199            "Invalid kind!");
200     return Infos[Kind - FirstTargetFixupKind];
201   }
202 
shouldForceRelocation(const MCAssembler & Asm,const MCFixup & Fixup,const MCValue & Target,const MCSubtargetInfo * STI)203   bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup,
204                              const MCValue &Target,
205                              const MCSubtargetInfo *STI) override {
206     switch(Fixup.getTargetKind()) {
207       default:
208         llvm_unreachable("Unknown Fixup Kind!");
209 
210       case fixup_Hexagon_LO16:
211       case fixup_Hexagon_HI16:
212       case fixup_Hexagon_16:
213       case fixup_Hexagon_8:
214       case fixup_Hexagon_GPREL16_0:
215       case fixup_Hexagon_GPREL16_1:
216       case fixup_Hexagon_GPREL16_2:
217       case fixup_Hexagon_GPREL16_3:
218       case fixup_Hexagon_HL16:
219       case fixup_Hexagon_32_6_X:
220       case fixup_Hexagon_16_X:
221       case fixup_Hexagon_12_X:
222       case fixup_Hexagon_11_X:
223       case fixup_Hexagon_10_X:
224       case fixup_Hexagon_9_X:
225       case fixup_Hexagon_8_X:
226       case fixup_Hexagon_7_X:
227       case fixup_Hexagon_6_X:
228       case fixup_Hexagon_COPY:
229       case fixup_Hexagon_GLOB_DAT:
230       case fixup_Hexagon_JMP_SLOT:
231       case fixup_Hexagon_RELATIVE:
232       case fixup_Hexagon_PLT_B22_PCREL:
233       case fixup_Hexagon_GOTREL_LO16:
234       case fixup_Hexagon_GOTREL_HI16:
235       case fixup_Hexagon_GOTREL_32:
236       case fixup_Hexagon_GOT_LO16:
237       case fixup_Hexagon_GOT_HI16:
238       case fixup_Hexagon_GOT_32:
239       case fixup_Hexagon_GOT_16:
240       case fixup_Hexagon_DTPMOD_32:
241       case fixup_Hexagon_DTPREL_LO16:
242       case fixup_Hexagon_DTPREL_HI16:
243       case fixup_Hexagon_DTPREL_32:
244       case fixup_Hexagon_DTPREL_16:
245       case fixup_Hexagon_GD_PLT_B22_PCREL:
246       case fixup_Hexagon_LD_PLT_B22_PCREL:
247       case fixup_Hexagon_GD_GOT_LO16:
248       case fixup_Hexagon_GD_GOT_HI16:
249       case fixup_Hexagon_GD_GOT_32:
250       case fixup_Hexagon_GD_GOT_16:
251       case fixup_Hexagon_LD_GOT_LO16:
252       case fixup_Hexagon_LD_GOT_HI16:
253       case fixup_Hexagon_LD_GOT_32:
254       case fixup_Hexagon_LD_GOT_16:
255       case fixup_Hexagon_IE_LO16:
256       case fixup_Hexagon_IE_HI16:
257       case fixup_Hexagon_IE_32:
258       case fixup_Hexagon_IE_16:
259       case fixup_Hexagon_IE_GOT_LO16:
260       case fixup_Hexagon_IE_GOT_HI16:
261       case fixup_Hexagon_IE_GOT_32:
262       case fixup_Hexagon_IE_GOT_16:
263       case fixup_Hexagon_TPREL_LO16:
264       case fixup_Hexagon_TPREL_HI16:
265       case fixup_Hexagon_TPREL_32:
266       case fixup_Hexagon_TPREL_16:
267       case fixup_Hexagon_GOTREL_32_6_X:
268       case fixup_Hexagon_GOTREL_16_X:
269       case fixup_Hexagon_GOTREL_11_X:
270       case fixup_Hexagon_GOT_32_6_X:
271       case fixup_Hexagon_GOT_16_X:
272       case fixup_Hexagon_GOT_11_X:
273       case fixup_Hexagon_DTPREL_32_6_X:
274       case fixup_Hexagon_DTPREL_16_X:
275       case fixup_Hexagon_DTPREL_11_X:
276       case fixup_Hexagon_GD_GOT_32_6_X:
277       case fixup_Hexagon_GD_GOT_16_X:
278       case fixup_Hexagon_GD_GOT_11_X:
279       case fixup_Hexagon_LD_GOT_32_6_X:
280       case fixup_Hexagon_LD_GOT_16_X:
281       case fixup_Hexagon_LD_GOT_11_X:
282       case fixup_Hexagon_IE_32_6_X:
283       case fixup_Hexagon_IE_16_X:
284       case fixup_Hexagon_IE_GOT_32_6_X:
285       case fixup_Hexagon_IE_GOT_16_X:
286       case fixup_Hexagon_IE_GOT_11_X:
287       case fixup_Hexagon_TPREL_32_6_X:
288       case fixup_Hexagon_TPREL_16_X:
289       case fixup_Hexagon_TPREL_11_X:
290       case fixup_Hexagon_32_PCREL:
291       case fixup_Hexagon_6_PCREL_X:
292       case fixup_Hexagon_23_REG:
293       case fixup_Hexagon_27_REG:
294       case fixup_Hexagon_GD_PLT_B22_PCREL_X:
295       case fixup_Hexagon_GD_PLT_B32_PCREL_X:
296       case fixup_Hexagon_LD_PLT_B22_PCREL_X:
297       case fixup_Hexagon_LD_PLT_B32_PCREL_X:
298         // These relocations should always have a relocation recorded
299         return true;
300 
301       case fixup_Hexagon_B22_PCREL:
302         //IsResolved = false;
303         break;
304 
305       case fixup_Hexagon_B13_PCREL:
306       case fixup_Hexagon_B13_PCREL_X:
307       case fixup_Hexagon_B32_PCREL_X:
308       case fixup_Hexagon_B22_PCREL_X:
309       case fixup_Hexagon_B15_PCREL:
310       case fixup_Hexagon_B15_PCREL_X:
311       case fixup_Hexagon_B9_PCREL:
312       case fixup_Hexagon_B9_PCREL_X:
313       case fixup_Hexagon_B7_PCREL:
314       case fixup_Hexagon_B7_PCREL_X:
315         if (DisableFixup)
316           return true;
317         break;
318 
319       case FK_Data_1:
320       case FK_Data_2:
321       case FK_Data_4:
322       case FK_PCRel_4:
323       case fixup_Hexagon_32:
324         // Leave these relocations alone as they are used for EH.
325         return false;
326     }
327     return false;
328   }
329 
330   /// getFixupKindNumBytes - The number of bytes the fixup may change.
getFixupKindNumBytes(unsigned Kind)331   static unsigned getFixupKindNumBytes(unsigned Kind) {
332     switch (Kind) {
333     default:
334         return 0;
335 
336       case FK_Data_1:
337         return 1;
338       case FK_Data_2:
339         return 2;
340       case FK_Data_4:         // this later gets mapped to R_HEX_32
341       case FK_PCRel_4:        // this later gets mapped to R_HEX_32_PCREL
342       case fixup_Hexagon_32:
343       case fixup_Hexagon_B32_PCREL_X:
344       case fixup_Hexagon_B22_PCREL:
345       case fixup_Hexagon_B22_PCREL_X:
346       case fixup_Hexagon_B15_PCREL:
347       case fixup_Hexagon_B15_PCREL_X:
348       case fixup_Hexagon_B13_PCREL:
349       case fixup_Hexagon_B13_PCREL_X:
350       case fixup_Hexagon_B9_PCREL:
351       case fixup_Hexagon_B9_PCREL_X:
352       case fixup_Hexagon_B7_PCREL:
353       case fixup_Hexagon_B7_PCREL_X:
354       case fixup_Hexagon_GD_PLT_B32_PCREL_X:
355       case fixup_Hexagon_LD_PLT_B32_PCREL_X:
356         return 4;
357     }
358   }
359 
360   // Make up for left shift when encoding the operand.
adjustFixupValue(MCFixupKind Kind,uint64_t Value)361   static uint64_t adjustFixupValue(MCFixupKind Kind, uint64_t Value) {
362     switch((unsigned)Kind) {
363       default:
364         break;
365 
366       case fixup_Hexagon_B7_PCREL:
367       case fixup_Hexagon_B9_PCREL:
368       case fixup_Hexagon_B13_PCREL:
369       case fixup_Hexagon_B15_PCREL:
370       case fixup_Hexagon_B22_PCREL:
371         Value >>= 2;
372         break;
373 
374       case fixup_Hexagon_B7_PCREL_X:
375       case fixup_Hexagon_B9_PCREL_X:
376       case fixup_Hexagon_B13_PCREL_X:
377       case fixup_Hexagon_B15_PCREL_X:
378       case fixup_Hexagon_B22_PCREL_X:
379         Value &= 0x3f;
380         break;
381 
382       case fixup_Hexagon_B32_PCREL_X:
383       case fixup_Hexagon_GD_PLT_B32_PCREL_X:
384       case fixup_Hexagon_LD_PLT_B32_PCREL_X:
385         Value >>= 6;
386         break;
387     }
388     return (Value);
389   }
390 
HandleFixupError(const int bits,const int align_bits,const int64_t FixupValue,const char * fixupStr) const391   void HandleFixupError(const int bits, const int align_bits,
392     const int64_t FixupValue, const char *fixupStr) const {
393     // Error: value 1124 out of range: -1024-1023 when resolving
394     // symbol in file xprtsock.S
395     const APInt IntMin = APInt::getSignedMinValue(bits+align_bits);
396     const APInt IntMax = APInt::getSignedMaxValue(bits+align_bits);
397     std::stringstream errStr;
398     errStr << "\nError: value " <<
399       FixupValue <<
400       " out of range: " <<
401       IntMin.getSExtValue() <<
402       "-" <<
403       IntMax.getSExtValue() <<
404       " when resolving " <<
405       fixupStr <<
406       " fixup\n";
407     llvm_unreachable(errStr.str().c_str());
408   }
409 
410   /// ApplyFixup - Apply the \arg Value for given \arg Fixup into the provided
411   /// data fragment, at the offset specified by the fixup and following the
412   /// fixup kind as appropriate.
applyFixup(const MCAssembler & Asm,const MCFixup & Fixup,const MCValue & Target,MutableArrayRef<char> Data,uint64_t FixupValue,bool IsResolved,const MCSubtargetInfo * STI) const413   void applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
414                   const MCValue &Target, MutableArrayRef<char> Data,
415                   uint64_t FixupValue, bool IsResolved,
416                   const MCSubtargetInfo *STI) const override {
417 
418     // When FixupValue is 0 the relocation is external and there
419     // is nothing for us to do.
420     if (!FixupValue) return;
421 
422     MCFixupKind Kind = Fixup.getKind();
423     uint64_t Value;
424     uint32_t InstMask;
425     uint32_t Reloc;
426 
427     // LLVM gives us an encoded value, we have to convert it back
428     // to a real offset before we can use it.
429     uint32_t Offset = Fixup.getOffset();
430     unsigned NumBytes = getFixupKindNumBytes(Kind);
431     assert(Offset + NumBytes <= Data.size() && "Invalid fixup offset!");
432     char *InstAddr = Data.data() + Offset;
433 
434     Value = adjustFixupValue(Kind, FixupValue);
435     if(!Value)
436       return;
437     int sValue = (int)Value;
438 
439     switch((unsigned)Kind) {
440       default:
441         return;
442 
443       case fixup_Hexagon_B7_PCREL:
444         if (!(isIntN(7, sValue)))
445           HandleFixupError(7, 2, (int64_t)FixupValue, "B7_PCREL");
446         [[fallthrough]];
447       case fixup_Hexagon_B7_PCREL_X:
448         InstMask = 0x00001f18;  // Word32_B7
449         Reloc = (((Value >> 2) & 0x1f) << 8) |    // Value 6-2 = Target 12-8
450                 ((Value & 0x3) << 3);             // Value 1-0 = Target 4-3
451         break;
452 
453       case fixup_Hexagon_B9_PCREL:
454         if (!(isIntN(9, sValue)))
455           HandleFixupError(9, 2, (int64_t)FixupValue, "B9_PCREL");
456         [[fallthrough]];
457       case fixup_Hexagon_B9_PCREL_X:
458         InstMask = 0x003000fe;  // Word32_B9
459         Reloc = (((Value >> 7) & 0x3) << 20) |    // Value 8-7 = Target 21-20
460                 ((Value & 0x7f) << 1);            // Value 6-0 = Target 7-1
461         break;
462 
463         // Since the existing branches that use this relocation cannot be
464         // extended, they should only be fixed up if the target is within range.
465       case fixup_Hexagon_B13_PCREL:
466         if (!(isIntN(13, sValue)))
467           HandleFixupError(13, 2, (int64_t)FixupValue, "B13_PCREL");
468         [[fallthrough]];
469       case fixup_Hexagon_B13_PCREL_X:
470         InstMask = 0x00202ffe;  // Word32_B13
471         Reloc = (((Value >> 12) & 0x1) << 21) |    // Value 12   = Target 21
472                 (((Value >> 11) & 0x1) << 13) |    // Value 11   = Target 13
473                 ((Value & 0x7ff) << 1);            // Value 10-0 = Target 11-1
474         break;
475 
476       case fixup_Hexagon_B15_PCREL:
477         if (!(isIntN(15, sValue)))
478           HandleFixupError(15, 2, (int64_t)FixupValue, "B15_PCREL");
479         [[fallthrough]];
480       case fixup_Hexagon_B15_PCREL_X:
481         InstMask = 0x00df20fe;  // Word32_B15
482         Reloc = (((Value >> 13) & 0x3) << 22) |    // Value 14-13 = Target 23-22
483                 (((Value >> 8) & 0x1f) << 16) |    // Value 12-8  = Target 20-16
484                 (((Value >> 7) & 0x1)  << 13) |    // Value 7     = Target 13
485                 ((Value & 0x7f) << 1);             // Value 6-0   = Target 7-1
486         break;
487 
488       case fixup_Hexagon_B22_PCREL:
489         if (!(isIntN(22, sValue)))
490           HandleFixupError(22, 2, (int64_t)FixupValue, "B22_PCREL");
491         [[fallthrough]];
492       case fixup_Hexagon_B22_PCREL_X:
493         InstMask = 0x01ff3ffe;  // Word32_B22
494         Reloc = (((Value >> 13) & 0x1ff) << 16) |  // Value 21-13 = Target 24-16
495                 ((Value & 0x1fff) << 1);           // Value 12-0  = Target 13-1
496         break;
497 
498       case fixup_Hexagon_B32_PCREL_X:
499         InstMask = 0x0fff3fff;  // Word32_X26
500         Reloc = (((Value >> 14) & 0xfff) << 16) |  // Value 25-14 = Target 27-16
501                 (Value & 0x3fff);                  // Value 13-0  = Target 13-0
502         break;
503 
504       case FK_Data_1:
505       case FK_Data_2:
506       case FK_Data_4:
507       case fixup_Hexagon_32:
508         InstMask = 0xffffffff;  // Word32
509         Reloc = Value;
510         break;
511     }
512 
513     LLVM_DEBUG(dbgs() << "Name=" << getFixupKindInfo(Kind).Name << "("
514                       << (unsigned)Kind << ")\n");
515     LLVM_DEBUG(
516         uint32_t OldData = 0; for (unsigned i = 0; i < NumBytes; i++) OldData |=
517                               (InstAddr[i] << (i * 8)) & (0xff << (i * 8));
518         dbgs() << "\tBValue=0x"; dbgs().write_hex(Value) << ": AValue=0x";
519         dbgs().write_hex(FixupValue)
520         << ": Offset=" << Offset << ": Size=" << Data.size() << ": OInst=0x";
521         dbgs().write_hex(OldData) << ": Reloc=0x"; dbgs().write_hex(Reloc););
522 
523     // For each byte of the fragment that the fixup touches, mask in the
524     // bits from the fixup value. The Value has been "split up" into the
525     // appropriate bitfields above.
526     for (unsigned i = 0; i < NumBytes; i++){
527       InstAddr[i] &= uint8_t(~InstMask >> (i * 8)) & 0xff; // Clear reloc bits
528       InstAddr[i] |= uint8_t(Reloc >> (i * 8)) & 0xff;     // Apply new reloc
529     }
530 
531     LLVM_DEBUG(uint32_t NewData = 0;
532                for (unsigned i = 0; i < NumBytes; i++) NewData |=
533                (InstAddr[i] << (i * 8)) & (0xff << (i * 8));
534                dbgs() << ": NInst=0x"; dbgs().write_hex(NewData) << "\n";);
535   }
536 
isInstRelaxable(MCInst const & HMI) const537   bool isInstRelaxable(MCInst const &HMI) const {
538     const MCInstrDesc &MCID = HexagonMCInstrInfo::getDesc(*MCII, HMI);
539     bool Relaxable = false;
540     // Branches and loop-setup insns are handled as necessary by relaxation.
541     if (llvm::HexagonMCInstrInfo::getType(*MCII, HMI) == HexagonII::TypeJ ||
542         (llvm::HexagonMCInstrInfo::getType(*MCII, HMI) == HexagonII::TypeCJ &&
543          MCID.isBranch()) ||
544         (llvm::HexagonMCInstrInfo::getType(*MCII, HMI) == HexagonII::TypeNCJ &&
545          MCID.isBranch()) ||
546         (llvm::HexagonMCInstrInfo::getType(*MCII, HMI) == HexagonII::TypeCR &&
547          HMI.getOpcode() != Hexagon::C4_addipc))
548       if (HexagonMCInstrInfo::isExtendable(*MCII, HMI)) {
549         Relaxable = true;
550         MCOperand const &Operand =
551             HMI.getOperand(HexagonMCInstrInfo::getExtendableOp(*MCII, HMI));
552         if (HexagonMCInstrInfo::mustNotExtend(*Operand.getExpr()))
553           Relaxable = false;
554       }
555 
556     return Relaxable;
557   }
558 
559   /// MayNeedRelaxation - Check whether the given instruction may need
560   /// relaxation.
561   ///
562   /// \param Inst - The instruction to test.
mayNeedRelaxation(MCInst const & Inst,const MCSubtargetInfo & STI) const563   bool mayNeedRelaxation(MCInst const &Inst,
564                          const MCSubtargetInfo &STI) const override {
565     return true;
566   }
567 
568   /// fixupNeedsRelaxation - Target specific predicate for whether a given
569   /// fixup requires the associated instruction to be relaxed.
fixupNeedsRelaxationAdvanced(const MCAssembler & Asm,const MCFixup & Fixup,bool Resolved,uint64_t Value,const MCRelaxableFragment * DF,const bool WasForced) const570   bool fixupNeedsRelaxationAdvanced(const MCAssembler &Asm,
571                                     const MCFixup &Fixup, bool Resolved,
572                                     uint64_t Value,
573                                     const MCRelaxableFragment *DF,
574                                     const bool WasForced) const override {
575     MCInst const &MCB = DF->getInst();
576     assert(HexagonMCInstrInfo::isBundle(MCB));
577 
578     *RelaxTarget = nullptr;
579     MCInst &MCI = const_cast<MCInst &>(HexagonMCInstrInfo::instruction(
580         MCB, Fixup.getOffset() / HEXAGON_INSTR_SIZE));
581     bool Relaxable = isInstRelaxable(MCI);
582     if (Relaxable == false)
583       return false;
584     // If we cannot resolve the fixup value, it requires relaxation.
585     if (!Resolved) {
586       switch (Fixup.getTargetKind()) {
587       case fixup_Hexagon_B22_PCREL:
588         // GetFixupCount assumes B22 won't relax
589         [[fallthrough]];
590       default:
591         return false;
592         break;
593       case fixup_Hexagon_B13_PCREL:
594       case fixup_Hexagon_B15_PCREL:
595       case fixup_Hexagon_B9_PCREL:
596       case fixup_Hexagon_B7_PCREL: {
597         if (HexagonMCInstrInfo::bundleSize(MCB) < HEXAGON_PACKET_SIZE) {
598           ++relaxedCnt;
599           *RelaxTarget = &MCI;
600           setExtender(Asm.getContext());
601           return true;
602         } else {
603           return false;
604         }
605         break;
606       }
607       }
608     }
609 
610     MCFixupKind Kind = Fixup.getKind();
611     int64_t sValue = Value;
612     int64_t maxValue;
613 
614     switch ((unsigned)Kind) {
615     case fixup_Hexagon_B7_PCREL:
616       maxValue = 1 << 8;
617       break;
618     case fixup_Hexagon_B9_PCREL:
619       maxValue = 1 << 10;
620       break;
621     case fixup_Hexagon_B15_PCREL:
622       maxValue = 1 << 16;
623       break;
624     case fixup_Hexagon_B22_PCREL:
625       maxValue = 1 << 23;
626       break;
627     default:
628       maxValue = INT64_MAX;
629       break;
630     }
631 
632     bool isFarAway = -maxValue > sValue || sValue > maxValue - 1;
633 
634     if (isFarAway) {
635       if (HexagonMCInstrInfo::bundleSize(MCB) < HEXAGON_PACKET_SIZE) {
636         ++relaxedCnt;
637         *RelaxTarget = &MCI;
638         setExtender(Asm.getContext());
639         return true;
640       }
641     }
642 
643     return false;
644   }
645 
relaxInstruction(MCInst & Inst,const MCSubtargetInfo & STI) const646   void relaxInstruction(MCInst &Inst,
647                         const MCSubtargetInfo &STI) const override {
648     assert(HexagonMCInstrInfo::isBundle(Inst) &&
649            "Hexagon relaxInstruction only works on bundles");
650 
651     MCInst Res;
652     Res.setOpcode(Hexagon::BUNDLE);
653     Res.addOperand(MCOperand::createImm(Inst.getOperand(0).getImm()));
654     // Copy the results into the bundle.
655     bool Update = false;
656     for (auto &I : HexagonMCInstrInfo::bundleInstructions(Inst)) {
657       MCInst &CrntHMI = const_cast<MCInst &>(*I.getInst());
658 
659       // if immediate extender needed, add it in
660       if (*RelaxTarget == &CrntHMI) {
661         Update = true;
662         assert((HexagonMCInstrInfo::bundleSize(Res) < HEXAGON_PACKET_SIZE) &&
663                "No room to insert extender for relaxation");
664 
665         MCInst *HMIx = takeExtender();
666         *HMIx = HexagonMCInstrInfo::deriveExtender(
667                 *MCII, CrntHMI,
668                 HexagonMCInstrInfo::getExtendableOperand(*MCII, CrntHMI));
669         Res.addOperand(MCOperand::createInst(HMIx));
670         *RelaxTarget = nullptr;
671       }
672       // now copy over the original instruction(the one we may have extended)
673       Res.addOperand(MCOperand::createInst(I.getInst()));
674     }
675 
676     Inst = std::move(Res);
677     (void)Update;
678     assert(Update && "Didn't find relaxation target");
679   }
680 
writeNopData(raw_ostream & OS,uint64_t Count,const MCSubtargetInfo * STI) const681   bool writeNopData(raw_ostream &OS, uint64_t Count,
682                     const MCSubtargetInfo *STI) const override {
683     static const uint32_t Nopcode = 0x7f000000, // Hard-coded NOP.
684         ParseIn = 0x00004000,                   // In packet parse-bits.
685         ParseEnd = 0x0000c000;                  // End of packet parse-bits.
686 
687     while (Count % HEXAGON_INSTR_SIZE) {
688       LLVM_DEBUG(dbgs() << "Alignment not a multiple of the instruction size:"
689                         << Count % HEXAGON_INSTR_SIZE << "/"
690                         << HEXAGON_INSTR_SIZE << "\n");
691       --Count;
692       OS << '\0';
693     }
694 
695     while (Count) {
696       Count -= HEXAGON_INSTR_SIZE;
697       // Close the packet whenever a multiple of the maximum packet size remains
698       uint32_t ParseBits = (Count % (MaxPacketSize * HEXAGON_INSTR_SIZE)) ?
699                            ParseIn : ParseEnd;
700       support::endian::write<uint32_t>(OS, Nopcode | ParseBits, Endian);
701     }
702     return true;
703   }
704 
finishLayout(MCAssembler const & Asm) const705   void finishLayout(MCAssembler const &Asm) const override {
706     SmallVector<MCFragment *> Frags;
707     for (MCSection &Sec : Asm) {
708       Frags.clear();
709       for (MCFragment &F : Sec)
710         Frags.push_back(&F);
711       for (size_t J = 0, E = Frags.size(); J != E; ++J) {
712         switch (Frags[J]->getKind()) {
713         default:
714           break;
715         case MCFragment::FT_Align: {
716           auto Size = Asm.computeFragmentSize(*Frags[J]);
717           for (auto K = J; K != 0 && Size >= HEXAGON_PACKET_SIZE;) {
718             --K;
719             switch (Frags[K]->getKind()) {
720             default:
721               break;
722             case MCFragment::FT_Align: {
723               // Don't pad before other alignments
724               Size = 0;
725               break;
726             }
727             case MCFragment::FT_Relaxable: {
728               MCContext &Context = Asm.getContext();
729               auto &RF = cast<MCRelaxableFragment>(*Frags[K]);
730               auto &Inst = const_cast<MCInst &>(RF.getInst());
731               while (Size > 0 &&
732                      HexagonMCInstrInfo::bundleSize(Inst) < MaxPacketSize) {
733                 MCInst *Nop = Context.createMCInst();
734                 Nop->setOpcode(Hexagon::A2_nop);
735                 Inst.addOperand(MCOperand::createInst(Nop));
736                 Size -= 4;
737                 if (!HexagonMCChecker(
738                          Context, *MCII, *RF.getSubtargetInfo(), Inst,
739                          *Context.getRegisterInfo(), false)
740                          .check()) {
741                   Inst.erase(Inst.end() - 1);
742                   Size = 0;
743                 }
744               }
745               bool Error = HexagonMCShuffle(Context, true, *MCII,
746                                             *RF.getSubtargetInfo(), Inst);
747               //assert(!Error);
748               (void)Error;
749               ReplaceInstruction(Asm.getEmitter(), RF, Inst);
750               Sec.setHasLayout(false);
751               Size = 0; // Only look back one instruction
752               break;
753             }
754             }
755           }
756         }
757         }
758       }
759     }
760   }
761 }; // class HexagonAsmBackend
762 
763 } // namespace
764 
765 // MCAsmBackend
createHexagonAsmBackend(Target const & T,const MCSubtargetInfo & STI,MCRegisterInfo const &,const MCTargetOptions & Options)766 MCAsmBackend *llvm::createHexagonAsmBackend(Target const &T,
767                                             const MCSubtargetInfo &STI,
768                                             MCRegisterInfo const & /*MRI*/,
769                                             const MCTargetOptions &Options) {
770   const Triple &TT = STI.getTargetTriple();
771   uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(TT.getOS());
772 
773   StringRef CPUString = Hexagon_MC::selectHexagonCPU(STI.getCPU());
774   return new HexagonAsmBackend(T, TT, OSABI, CPUString);
775 }
776