xref: /freebsd/contrib/llvm-project/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonAsmBackend.cpp (revision 2e3507c25e42292b45a5482e116d278f5515d04d)
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/MCAsmLayout.h"
18 #include "llvm/MC/MCAssembler.h"
19 #include "llvm/MC/MCContext.h"
20 #include "llvm/MC/MCELFObjectWriter.h"
21 #include "llvm/MC/MCFixupKindInfo.h"
22 #include "llvm/MC/MCInstrInfo.h"
23 #include "llvm/MC/MCObjectWriter.h"
24 #include "llvm/MC/MCSubtargetInfo.h"
25 #include "llvm/MC/TargetRegistry.h"
26 #include "llvm/Support/Debug.h"
27 #include "llvm/Support/EndianStream.h"
28 
29 #include <sstream>
30 
31 using namespace llvm;
32 using namespace Hexagon;
33 
34 #define DEBUG_TYPE "hexagon-asm-backend"
35 
36 static cl::opt<bool> DisableFixup
37   ("mno-fixup", cl::desc("Disable fixing up resolved relocations for Hexagon"));
38 
39 namespace {
40 
41 class HexagonAsmBackend : public MCAsmBackend {
42   uint8_t OSABI;
43   StringRef CPU;
44   mutable uint64_t relaxedCnt;
45   std::unique_ptr <MCInstrInfo> MCII;
46   std::unique_ptr <MCInst *> RelaxTarget;
47   MCInst * Extender;
48   unsigned MaxPacketSize;
49 
50   void ReplaceInstruction(MCCodeEmitter &E, MCRelaxableFragment &RF,
51                           MCInst &HMB) const {
52     SmallVector<MCFixup, 4> Fixups;
53     SmallString<256> Code;
54     E.encodeInstruction(HMB, Code, Fixups, *RF.getSubtargetInfo());
55 
56     // Update the fragment.
57     RF.setInst(HMB);
58     RF.getContents() = Code;
59     RF.getFixups() = Fixups;
60   }
61 
62 public:
63   HexagonAsmBackend(const Target &T, const Triple &TT, uint8_t OSABI,
64                     StringRef CPU)
65       : MCAsmBackend(support::little), OSABI(OSABI), CPU(CPU), relaxedCnt(0),
66         MCII(T.createMCInstrInfo()), RelaxTarget(new MCInst *),
67         Extender(nullptr), MaxPacketSize(HexagonMCInstrInfo::packetSize(CPU))
68         {}
69 
70   std::unique_ptr<MCObjectTargetWriter>
71   createObjectTargetWriter() const override {
72     return createHexagonELFObjectWriter(OSABI, CPU);
73   }
74 
75   void setExtender(MCContext &Context) const {
76     if (Extender == nullptr)
77       const_cast<HexagonAsmBackend *>(this)->Extender = Context.createMCInst();
78   }
79 
80   MCInst *takeExtender() const {
81     assert(Extender != nullptr);
82     MCInst * Result = Extender;
83     const_cast<HexagonAsmBackend *>(this)->Extender = nullptr;
84     return Result;
85   }
86 
87   unsigned getNumFixupKinds() const override {
88     return Hexagon::NumTargetFixupKinds;
89   }
90 
91   const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const override {
92     const static MCFixupKindInfo Infos[Hexagon::NumTargetFixupKinds] = {
93       // This table *must* be in same the order of fixup_* kinds in
94       // HexagonFixupKinds.h.
95       //
96       // namei                          offset  bits    flags
97       { "fixup_Hexagon_B22_PCREL",      0,      32,     MCFixupKindInfo::FKF_IsPCRel },
98       { "fixup_Hexagon_B15_PCREL",      0,      32,     MCFixupKindInfo::FKF_IsPCRel },
99       { "fixup_Hexagon_B7_PCREL",       0,      32,     MCFixupKindInfo::FKF_IsPCRel },
100       { "fixup_Hexagon_LO16",           0,      32,     0 },
101       { "fixup_Hexagon_HI16",           0,      32,     0 },
102       { "fixup_Hexagon_32",             0,      32,     0 },
103       { "fixup_Hexagon_16",             0,      32,     0 },
104       { "fixup_Hexagon_8",              0,      32,     0 },
105       { "fixup_Hexagon_GPREL16_0",      0,      32,     0 },
106       { "fixup_Hexagon_GPREL16_1",      0,      32,     0 },
107       { "fixup_Hexagon_GPREL16_2",      0,      32,     0 },
108       { "fixup_Hexagon_GPREL16_3",      0,      32,     0 },
109       { "fixup_Hexagon_HL16",           0,      32,     0 },
110       { "fixup_Hexagon_B13_PCREL",      0,      32,     MCFixupKindInfo::FKF_IsPCRel },
111       { "fixup_Hexagon_B9_PCREL",       0,      32,     MCFixupKindInfo::FKF_IsPCRel },
112       { "fixup_Hexagon_B32_PCREL_X",    0,      32,     MCFixupKindInfo::FKF_IsPCRel },
113       { "fixup_Hexagon_32_6_X",         0,      32,     0 },
114       { "fixup_Hexagon_B22_PCREL_X",    0,      32,     MCFixupKindInfo::FKF_IsPCRel },
115       { "fixup_Hexagon_B15_PCREL_X",    0,      32,     MCFixupKindInfo::FKF_IsPCRel },
116       { "fixup_Hexagon_B13_PCREL_X",    0,      32,     MCFixupKindInfo::FKF_IsPCRel },
117       { "fixup_Hexagon_B9_PCREL_X",     0,      32,     MCFixupKindInfo::FKF_IsPCRel },
118       { "fixup_Hexagon_B7_PCREL_X",     0,      32,     MCFixupKindInfo::FKF_IsPCRel },
119       { "fixup_Hexagon_16_X",           0,      32,     0 },
120       { "fixup_Hexagon_12_X",           0,      32,     0 },
121       { "fixup_Hexagon_11_X",           0,      32,     0 },
122       { "fixup_Hexagon_10_X",           0,      32,     0 },
123       { "fixup_Hexagon_9_X",            0,      32,     0 },
124       { "fixup_Hexagon_8_X",            0,      32,     0 },
125       { "fixup_Hexagon_7_X",            0,      32,     0 },
126       { "fixup_Hexagon_6_X",            0,      32,     0 },
127       { "fixup_Hexagon_32_PCREL",       0,      32,     MCFixupKindInfo::FKF_IsPCRel },
128       { "fixup_Hexagon_COPY",           0,      32,     0 },
129       { "fixup_Hexagon_GLOB_DAT",       0,      32,     0 },
130       { "fixup_Hexagon_JMP_SLOT",       0,      32,     0 },
131       { "fixup_Hexagon_RELATIVE",       0,      32,     0 },
132       { "fixup_Hexagon_PLT_B22_PCREL",  0,      32,     MCFixupKindInfo::FKF_IsPCRel },
133       { "fixup_Hexagon_GOTREL_LO16",    0,      32,     0 },
134       { "fixup_Hexagon_GOTREL_HI16",    0,      32,     0 },
135       { "fixup_Hexagon_GOTREL_32",      0,      32,     0 },
136       { "fixup_Hexagon_GOT_LO16",       0,      32,     0 },
137       { "fixup_Hexagon_GOT_HI16",       0,      32,     0 },
138       { "fixup_Hexagon_GOT_32",         0,      32,     0 },
139       { "fixup_Hexagon_GOT_16",         0,      32,     0 },
140       { "fixup_Hexagon_DTPMOD_32",      0,      32,     0 },
141       { "fixup_Hexagon_DTPREL_LO16",    0,      32,     0 },
142       { "fixup_Hexagon_DTPREL_HI16",    0,      32,     0 },
143       { "fixup_Hexagon_DTPREL_32",      0,      32,     0 },
144       { "fixup_Hexagon_DTPREL_16",      0,      32,     0 },
145       { "fixup_Hexagon_GD_PLT_B22_PCREL",0,     32,     MCFixupKindInfo::FKF_IsPCRel },
146       { "fixup_Hexagon_LD_PLT_B22_PCREL",0,     32,     MCFixupKindInfo::FKF_IsPCRel },
147       { "fixup_Hexagon_GD_GOT_LO16",    0,      32,     0 },
148       { "fixup_Hexagon_GD_GOT_HI16",    0,      32,     0 },
149       { "fixup_Hexagon_GD_GOT_32",      0,      32,     0 },
150       { "fixup_Hexagon_GD_GOT_16",      0,      32,     0 },
151       { "fixup_Hexagon_LD_GOT_LO16",    0,      32,     0 },
152       { "fixup_Hexagon_LD_GOT_HI16",    0,      32,     0 },
153       { "fixup_Hexagon_LD_GOT_32",      0,      32,     0 },
154       { "fixup_Hexagon_LD_GOT_16",      0,      32,     0 },
155       { "fixup_Hexagon_IE_LO16",        0,      32,     0 },
156       { "fixup_Hexagon_IE_HI16",        0,      32,     0 },
157       { "fixup_Hexagon_IE_32",          0,      32,     0 },
158       { "fixup_Hexagon_IE_16",          0,      32,     0 },
159       { "fixup_Hexagon_IE_GOT_LO16",    0,      32,     0 },
160       { "fixup_Hexagon_IE_GOT_HI16",    0,      32,     0 },
161       { "fixup_Hexagon_IE_GOT_32",      0,      32,     0 },
162       { "fixup_Hexagon_IE_GOT_16",      0,      32,     0 },
163       { "fixup_Hexagon_TPREL_LO16",     0,      32,     0 },
164       { "fixup_Hexagon_TPREL_HI16",     0,      32,     0 },
165       { "fixup_Hexagon_TPREL_32",       0,      32,     0 },
166       { "fixup_Hexagon_TPREL_16",       0,      32,     0 },
167       { "fixup_Hexagon_6_PCREL_X",      0,      32,     MCFixupKindInfo::FKF_IsPCRel },
168       { "fixup_Hexagon_GOTREL_32_6_X",  0,      32,     0 },
169       { "fixup_Hexagon_GOTREL_16_X",    0,      32,     0 },
170       { "fixup_Hexagon_GOTREL_11_X",    0,      32,     0 },
171       { "fixup_Hexagon_GOT_32_6_X",     0,      32,     0 },
172       { "fixup_Hexagon_GOT_16_X",       0,      32,     0 },
173       { "fixup_Hexagon_GOT_11_X",       0,      32,     0 },
174       { "fixup_Hexagon_DTPREL_32_6_X",  0,      32,     0 },
175       { "fixup_Hexagon_DTPREL_16_X",    0,      32,     0 },
176       { "fixup_Hexagon_DTPREL_11_X",    0,      32,     0 },
177       { "fixup_Hexagon_GD_GOT_32_6_X",  0,      32,     0 },
178       { "fixup_Hexagon_GD_GOT_16_X",    0,      32,     0 },
179       { "fixup_Hexagon_GD_GOT_11_X",    0,      32,     0 },
180       { "fixup_Hexagon_LD_GOT_32_6_X",  0,      32,     0 },
181       { "fixup_Hexagon_LD_GOT_16_X",    0,      32,     0 },
182       { "fixup_Hexagon_LD_GOT_11_X",    0,      32,     0 },
183       { "fixup_Hexagon_IE_32_6_X",      0,      32,     0 },
184       { "fixup_Hexagon_IE_16_X",        0,      32,     0 },
185       { "fixup_Hexagon_IE_GOT_32_6_X",  0,      32,     0 },
186       { "fixup_Hexagon_IE_GOT_16_X",    0,      32,     0 },
187       { "fixup_Hexagon_IE_GOT_11_X",    0,      32,     0 },
188       { "fixup_Hexagon_TPREL_32_6_X",   0,      32,     0 },
189       { "fixup_Hexagon_TPREL_16_X",     0,      32,     0 },
190       { "fixup_Hexagon_TPREL_11_X",     0,      32,     0 },
191       { "fixup_Hexagon_GD_PLT_B22_PCREL_X",0,     32,     MCFixupKindInfo::FKF_IsPCRel },
192       { "fixup_Hexagon_GD_PLT_B32_PCREL_X",0,     32,     MCFixupKindInfo::FKF_IsPCRel },
193       { "fixup_Hexagon_LD_PLT_B22_PCREL_X",0,     32,     MCFixupKindInfo::FKF_IsPCRel },
194       { "fixup_Hexagon_LD_PLT_B32_PCREL_X",0,     32,     MCFixupKindInfo::FKF_IsPCRel }
195     };
196 
197     if (Kind < FirstTargetFixupKind)
198       return MCAsmBackend::getFixupKindInfo(Kind);
199 
200     assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
201            "Invalid kind!");
202     return Infos[Kind - FirstTargetFixupKind];
203   }
204 
205   bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup,
206                              const MCValue &Target) override {
207     switch(Fixup.getTargetKind()) {
208       default:
209         llvm_unreachable("Unknown Fixup Kind!");
210 
211       case fixup_Hexagon_LO16:
212       case fixup_Hexagon_HI16:
213       case fixup_Hexagon_16:
214       case fixup_Hexagon_8:
215       case fixup_Hexagon_GPREL16_0:
216       case fixup_Hexagon_GPREL16_1:
217       case fixup_Hexagon_GPREL16_2:
218       case fixup_Hexagon_GPREL16_3:
219       case fixup_Hexagon_HL16:
220       case fixup_Hexagon_32_6_X:
221       case fixup_Hexagon_16_X:
222       case fixup_Hexagon_12_X:
223       case fixup_Hexagon_11_X:
224       case fixup_Hexagon_10_X:
225       case fixup_Hexagon_9_X:
226       case fixup_Hexagon_8_X:
227       case fixup_Hexagon_7_X:
228       case fixup_Hexagon_6_X:
229       case fixup_Hexagon_COPY:
230       case fixup_Hexagon_GLOB_DAT:
231       case fixup_Hexagon_JMP_SLOT:
232       case fixup_Hexagon_RELATIVE:
233       case fixup_Hexagon_PLT_B22_PCREL:
234       case fixup_Hexagon_GOTREL_LO16:
235       case fixup_Hexagon_GOTREL_HI16:
236       case fixup_Hexagon_GOTREL_32:
237       case fixup_Hexagon_GOT_LO16:
238       case fixup_Hexagon_GOT_HI16:
239       case fixup_Hexagon_GOT_32:
240       case fixup_Hexagon_GOT_16:
241       case fixup_Hexagon_DTPMOD_32:
242       case fixup_Hexagon_DTPREL_LO16:
243       case fixup_Hexagon_DTPREL_HI16:
244       case fixup_Hexagon_DTPREL_32:
245       case fixup_Hexagon_DTPREL_16:
246       case fixup_Hexagon_GD_PLT_B22_PCREL:
247       case fixup_Hexagon_LD_PLT_B22_PCREL:
248       case fixup_Hexagon_GD_GOT_LO16:
249       case fixup_Hexagon_GD_GOT_HI16:
250       case fixup_Hexagon_GD_GOT_32:
251       case fixup_Hexagon_GD_GOT_16:
252       case fixup_Hexagon_LD_GOT_LO16:
253       case fixup_Hexagon_LD_GOT_HI16:
254       case fixup_Hexagon_LD_GOT_32:
255       case fixup_Hexagon_LD_GOT_16:
256       case fixup_Hexagon_IE_LO16:
257       case fixup_Hexagon_IE_HI16:
258       case fixup_Hexagon_IE_32:
259       case fixup_Hexagon_IE_16:
260       case fixup_Hexagon_IE_GOT_LO16:
261       case fixup_Hexagon_IE_GOT_HI16:
262       case fixup_Hexagon_IE_GOT_32:
263       case fixup_Hexagon_IE_GOT_16:
264       case fixup_Hexagon_TPREL_LO16:
265       case fixup_Hexagon_TPREL_HI16:
266       case fixup_Hexagon_TPREL_32:
267       case fixup_Hexagon_TPREL_16:
268       case fixup_Hexagon_GOTREL_32_6_X:
269       case fixup_Hexagon_GOTREL_16_X:
270       case fixup_Hexagon_GOTREL_11_X:
271       case fixup_Hexagon_GOT_32_6_X:
272       case fixup_Hexagon_GOT_16_X:
273       case fixup_Hexagon_GOT_11_X:
274       case fixup_Hexagon_DTPREL_32_6_X:
275       case fixup_Hexagon_DTPREL_16_X:
276       case fixup_Hexagon_DTPREL_11_X:
277       case fixup_Hexagon_GD_GOT_32_6_X:
278       case fixup_Hexagon_GD_GOT_16_X:
279       case fixup_Hexagon_GD_GOT_11_X:
280       case fixup_Hexagon_LD_GOT_32_6_X:
281       case fixup_Hexagon_LD_GOT_16_X:
282       case fixup_Hexagon_LD_GOT_11_X:
283       case fixup_Hexagon_IE_32_6_X:
284       case fixup_Hexagon_IE_16_X:
285       case fixup_Hexagon_IE_GOT_32_6_X:
286       case fixup_Hexagon_IE_GOT_16_X:
287       case fixup_Hexagon_IE_GOT_11_X:
288       case fixup_Hexagon_TPREL_32_6_X:
289       case fixup_Hexagon_TPREL_16_X:
290       case fixup_Hexagon_TPREL_11_X:
291       case fixup_Hexagon_32_PCREL:
292       case fixup_Hexagon_6_PCREL_X:
293       case fixup_Hexagon_23_REG:
294       case fixup_Hexagon_27_REG:
295       case fixup_Hexagon_GD_PLT_B22_PCREL_X:
296       case fixup_Hexagon_GD_PLT_B32_PCREL_X:
297       case fixup_Hexagon_LD_PLT_B22_PCREL_X:
298       case fixup_Hexagon_LD_PLT_B32_PCREL_X:
299         // These relocations should always have a relocation recorded
300         return true;
301 
302       case fixup_Hexagon_B22_PCREL:
303         //IsResolved = false;
304         break;
305 
306       case fixup_Hexagon_B13_PCREL:
307       case fixup_Hexagon_B13_PCREL_X:
308       case fixup_Hexagon_B32_PCREL_X:
309       case fixup_Hexagon_B22_PCREL_X:
310       case fixup_Hexagon_B15_PCREL:
311       case fixup_Hexagon_B15_PCREL_X:
312       case fixup_Hexagon_B9_PCREL:
313       case fixup_Hexagon_B9_PCREL_X:
314       case fixup_Hexagon_B7_PCREL:
315       case fixup_Hexagon_B7_PCREL_X:
316         if (DisableFixup)
317           return true;
318         break;
319 
320       case FK_Data_1:
321       case FK_Data_2:
322       case FK_Data_4:
323       case FK_PCRel_4:
324       case fixup_Hexagon_32:
325         // Leave these relocations alone as they are used for EH.
326         return false;
327     }
328     return false;
329   }
330 
331   /// getFixupKindNumBytes - The number of bytes the fixup may change.
332   static unsigned getFixupKindNumBytes(unsigned Kind) {
333     switch (Kind) {
334     default:
335         return 0;
336 
337       case FK_Data_1:
338         return 1;
339       case FK_Data_2:
340         return 2;
341       case FK_Data_4:         // this later gets mapped to R_HEX_32
342       case FK_PCRel_4:        // this later gets mapped to R_HEX_32_PCREL
343       case fixup_Hexagon_32:
344       case fixup_Hexagon_B32_PCREL_X:
345       case fixup_Hexagon_B22_PCREL:
346       case fixup_Hexagon_B22_PCREL_X:
347       case fixup_Hexagon_B15_PCREL:
348       case fixup_Hexagon_B15_PCREL_X:
349       case fixup_Hexagon_B13_PCREL:
350       case fixup_Hexagon_B13_PCREL_X:
351       case fixup_Hexagon_B9_PCREL:
352       case fixup_Hexagon_B9_PCREL_X:
353       case fixup_Hexagon_B7_PCREL:
354       case fixup_Hexagon_B7_PCREL_X:
355       case fixup_Hexagon_GD_PLT_B32_PCREL_X:
356       case fixup_Hexagon_LD_PLT_B32_PCREL_X:
357         return 4;
358     }
359   }
360 
361   // Make up for left shift when encoding the operand.
362   static uint64_t adjustFixupValue(MCFixupKind Kind, uint64_t Value) {
363     switch((unsigned)Kind) {
364       default:
365         break;
366 
367       case fixup_Hexagon_B7_PCREL:
368       case fixup_Hexagon_B9_PCREL:
369       case fixup_Hexagon_B13_PCREL:
370       case fixup_Hexagon_B15_PCREL:
371       case fixup_Hexagon_B22_PCREL:
372         Value >>= 2;
373         break;
374 
375       case fixup_Hexagon_B7_PCREL_X:
376       case fixup_Hexagon_B9_PCREL_X:
377       case fixup_Hexagon_B13_PCREL_X:
378       case fixup_Hexagon_B15_PCREL_X:
379       case fixup_Hexagon_B22_PCREL_X:
380         Value &= 0x3f;
381         break;
382 
383       case fixup_Hexagon_B32_PCREL_X:
384       case fixup_Hexagon_GD_PLT_B32_PCREL_X:
385       case fixup_Hexagon_LD_PLT_B32_PCREL_X:
386         Value >>= 6;
387         break;
388     }
389     return (Value);
390   }
391 
392   void HandleFixupError(const int bits, const int align_bits,
393     const int64_t FixupValue, const char *fixupStr) const {
394     // Error: value 1124 out of range: -1024-1023 when resolving
395     // symbol in file xprtsock.S
396     const APInt IntMin = APInt::getSignedMinValue(bits+align_bits);
397     const APInt IntMax = APInt::getSignedMaxValue(bits+align_bits);
398     std::stringstream errStr;
399     errStr << "\nError: value " <<
400       FixupValue <<
401       " out of range: " <<
402       IntMin.getSExtValue() <<
403       "-" <<
404       IntMax.getSExtValue() <<
405       " when resolving " <<
406       fixupStr <<
407       " fixup\n";
408     llvm_unreachable(errStr.str().c_str());
409   }
410 
411   /// ApplyFixup - Apply the \arg Value for given \arg Fixup into the provided
412   /// data fragment, at the offset specified by the fixup and following the
413   /// fixup kind as appropriate.
414   void applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
415                   const MCValue &Target, MutableArrayRef<char> Data,
416                   uint64_t FixupValue, bool IsResolved,
417                   const MCSubtargetInfo *STI) const override {
418 
419     // When FixupValue is 0 the relocation is external and there
420     // is nothing for us to do.
421     if (!FixupValue) return;
422 
423     MCFixupKind Kind = Fixup.getKind();
424     uint64_t Value;
425     uint32_t InstMask;
426     uint32_t Reloc;
427 
428     // LLVM gives us an encoded value, we have to convert it back
429     // to a real offset before we can use it.
430     uint32_t Offset = Fixup.getOffset();
431     unsigned NumBytes = getFixupKindNumBytes(Kind);
432     assert(Offset + NumBytes <= Data.size() && "Invalid fixup offset!");
433     char *InstAddr = Data.data() + Offset;
434 
435     Value = adjustFixupValue(Kind, FixupValue);
436     if(!Value)
437       return;
438     int sValue = (int)Value;
439 
440     switch((unsigned)Kind) {
441       default:
442         return;
443 
444       case fixup_Hexagon_B7_PCREL:
445         if (!(isIntN(7, sValue)))
446           HandleFixupError(7, 2, (int64_t)FixupValue, "B7_PCREL");
447         [[fallthrough]];
448       case fixup_Hexagon_B7_PCREL_X:
449         InstMask = 0x00001f18;  // Word32_B7
450         Reloc = (((Value >> 2) & 0x1f) << 8) |    // Value 6-2 = Target 12-8
451                 ((Value & 0x3) << 3);             // Value 1-0 = Target 4-3
452         break;
453 
454       case fixup_Hexagon_B9_PCREL:
455         if (!(isIntN(9, sValue)))
456           HandleFixupError(9, 2, (int64_t)FixupValue, "B9_PCREL");
457         [[fallthrough]];
458       case fixup_Hexagon_B9_PCREL_X:
459         InstMask = 0x003000fe;  // Word32_B9
460         Reloc = (((Value >> 7) & 0x3) << 20) |    // Value 8-7 = Target 21-20
461                 ((Value & 0x7f) << 1);            // Value 6-0 = Target 7-1
462         break;
463 
464         // Since the existing branches that use this relocation cannot be
465         // extended, they should only be fixed up if the target is within range.
466       case fixup_Hexagon_B13_PCREL:
467         if (!(isIntN(13, sValue)))
468           HandleFixupError(13, 2, (int64_t)FixupValue, "B13_PCREL");
469         [[fallthrough]];
470       case fixup_Hexagon_B13_PCREL_X:
471         InstMask = 0x00202ffe;  // Word32_B13
472         Reloc = (((Value >> 12) & 0x1) << 21) |    // Value 12   = Target 21
473                 (((Value >> 11) & 0x1) << 13) |    // Value 11   = Target 13
474                 ((Value & 0x7ff) << 1);            // Value 10-0 = Target 11-1
475         break;
476 
477       case fixup_Hexagon_B15_PCREL:
478         if (!(isIntN(15, sValue)))
479           HandleFixupError(15, 2, (int64_t)FixupValue, "B15_PCREL");
480         [[fallthrough]];
481       case fixup_Hexagon_B15_PCREL_X:
482         InstMask = 0x00df20fe;  // Word32_B15
483         Reloc = (((Value >> 13) & 0x3) << 22) |    // Value 14-13 = Target 23-22
484                 (((Value >> 8) & 0x1f) << 16) |    // Value 12-8  = Target 20-16
485                 (((Value >> 7) & 0x1)  << 13) |    // Value 7     = Target 13
486                 ((Value & 0x7f) << 1);             // Value 6-0   = Target 7-1
487         break;
488 
489       case fixup_Hexagon_B22_PCREL:
490         if (!(isIntN(22, sValue)))
491           HandleFixupError(22, 2, (int64_t)FixupValue, "B22_PCREL");
492         [[fallthrough]];
493       case fixup_Hexagon_B22_PCREL_X:
494         InstMask = 0x01ff3ffe;  // Word32_B22
495         Reloc = (((Value >> 13) & 0x1ff) << 16) |  // Value 21-13 = Target 24-16
496                 ((Value & 0x1fff) << 1);           // Value 12-0  = Target 13-1
497         break;
498 
499       case fixup_Hexagon_B32_PCREL_X:
500         InstMask = 0x0fff3fff;  // Word32_X26
501         Reloc = (((Value >> 14) & 0xfff) << 16) |  // Value 25-14 = Target 27-16
502                 (Value & 0x3fff);                  // Value 13-0  = Target 13-0
503         break;
504 
505       case FK_Data_1:
506       case FK_Data_2:
507       case FK_Data_4:
508       case fixup_Hexagon_32:
509         InstMask = 0xffffffff;  // Word32
510         Reloc = Value;
511         break;
512     }
513 
514     LLVM_DEBUG(dbgs() << "Name=" << getFixupKindInfo(Kind).Name << "("
515                       << (unsigned)Kind << ")\n");
516     LLVM_DEBUG(
517         uint32_t OldData = 0; for (unsigned i = 0; i < NumBytes; i++) OldData |=
518                               (InstAddr[i] << (i * 8)) & (0xff << (i * 8));
519         dbgs() << "\tBValue=0x"; dbgs().write_hex(Value) << ": AValue=0x";
520         dbgs().write_hex(FixupValue)
521         << ": Offset=" << Offset << ": Size=" << Data.size() << ": OInst=0x";
522         dbgs().write_hex(OldData) << ": Reloc=0x"; dbgs().write_hex(Reloc););
523 
524     // For each byte of the fragment that the fixup touches, mask in the
525     // bits from the fixup value. The Value has been "split up" into the
526     // appropriate bitfields above.
527     for (unsigned i = 0; i < NumBytes; i++){
528       InstAddr[i] &= uint8_t(~InstMask >> (i * 8)) & 0xff; // Clear reloc bits
529       InstAddr[i] |= uint8_t(Reloc >> (i * 8)) & 0xff;     // Apply new reloc
530     }
531 
532     LLVM_DEBUG(uint32_t NewData = 0;
533                for (unsigned i = 0; i < NumBytes; i++) NewData |=
534                (InstAddr[i] << (i * 8)) & (0xff << (i * 8));
535                dbgs() << ": NInst=0x"; dbgs().write_hex(NewData) << "\n";);
536   }
537 
538   bool isInstRelaxable(MCInst const &HMI) const {
539     const MCInstrDesc &MCID = HexagonMCInstrInfo::getDesc(*MCII, HMI);
540     bool Relaxable = false;
541     // Branches and loop-setup insns are handled as necessary by relaxation.
542     if (llvm::HexagonMCInstrInfo::getType(*MCII, HMI) == HexagonII::TypeJ ||
543         (llvm::HexagonMCInstrInfo::getType(*MCII, HMI) == HexagonII::TypeCJ &&
544          MCID.isBranch()) ||
545         (llvm::HexagonMCInstrInfo::getType(*MCII, HMI) == HexagonII::TypeNCJ &&
546          MCID.isBranch()) ||
547         (llvm::HexagonMCInstrInfo::getType(*MCII, HMI) == HexagonII::TypeCR &&
548          HMI.getOpcode() != Hexagon::C4_addipc))
549       if (HexagonMCInstrInfo::isExtendable(*MCII, HMI)) {
550         Relaxable = true;
551         MCOperand const &Operand =
552             HMI.getOperand(HexagonMCInstrInfo::getExtendableOp(*MCII, HMI));
553         if (HexagonMCInstrInfo::mustNotExtend(*Operand.getExpr()))
554           Relaxable = false;
555       }
556 
557     return Relaxable;
558   }
559 
560   /// MayNeedRelaxation - Check whether the given instruction may need
561   /// relaxation.
562   ///
563   /// \param Inst - The instruction to test.
564   bool mayNeedRelaxation(MCInst const &Inst,
565                          const MCSubtargetInfo &STI) const override {
566     return true;
567   }
568 
569   /// fixupNeedsRelaxation - Target specific predicate for whether a given
570   /// fixup requires the associated instruction to be relaxed.
571   bool fixupNeedsRelaxationAdvanced(const MCFixup &Fixup, bool Resolved,
572                                     uint64_t Value,
573                                     const MCRelaxableFragment *DF,
574                                     const MCAsmLayout &Layout,
575                                     const bool WasForced) const override {
576     MCInst const &MCB = DF->getInst();
577     assert(HexagonMCInstrInfo::isBundle(MCB));
578 
579     *RelaxTarget = nullptr;
580     MCInst &MCI = const_cast<MCInst &>(HexagonMCInstrInfo::instruction(
581         MCB, Fixup.getOffset() / HEXAGON_INSTR_SIZE));
582     bool Relaxable = isInstRelaxable(MCI);
583     if (Relaxable == false)
584       return false;
585     // If we cannot resolve the fixup value, it requires relaxation.
586     if (!Resolved) {
587       switch (Fixup.getTargetKind()) {
588       case fixup_Hexagon_B22_PCREL:
589         // GetFixupCount assumes B22 won't relax
590         [[fallthrough]];
591       default:
592         return false;
593         break;
594       case fixup_Hexagon_B13_PCREL:
595       case fixup_Hexagon_B15_PCREL:
596       case fixup_Hexagon_B9_PCREL:
597       case fixup_Hexagon_B7_PCREL: {
598         if (HexagonMCInstrInfo::bundleSize(MCB) < HEXAGON_PACKET_SIZE) {
599           ++relaxedCnt;
600           *RelaxTarget = &MCI;
601           setExtender(Layout.getAssembler().getContext());
602           return true;
603         } else {
604           return false;
605         }
606         break;
607       }
608       }
609     }
610 
611     MCFixupKind Kind = Fixup.getKind();
612     int64_t sValue = Value;
613     int64_t maxValue;
614 
615     switch ((unsigned)Kind) {
616     case fixup_Hexagon_B7_PCREL:
617       maxValue = 1 << 8;
618       break;
619     case fixup_Hexagon_B9_PCREL:
620       maxValue = 1 << 10;
621       break;
622     case fixup_Hexagon_B15_PCREL:
623       maxValue = 1 << 16;
624       break;
625     case fixup_Hexagon_B22_PCREL:
626       maxValue = 1 << 23;
627       break;
628     default:
629       maxValue = INT64_MAX;
630       break;
631     }
632 
633     bool isFarAway = -maxValue > sValue || sValue > maxValue - 1;
634 
635     if (isFarAway) {
636       if (HexagonMCInstrInfo::bundleSize(MCB) < HEXAGON_PACKET_SIZE) {
637         ++relaxedCnt;
638         *RelaxTarget = &MCI;
639         setExtender(Layout.getAssembler().getContext());
640         return true;
641       }
642     }
643 
644     return false;
645   }
646 
647   /// Simple predicate for targets where !Resolved implies requiring relaxation
648   bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
649                             const MCRelaxableFragment *DF,
650                             const MCAsmLayout &Layout) const override {
651     llvm_unreachable("Handled by fixupNeedsRelaxationAdvanced");
652   }
653 
654   void relaxInstruction(MCInst &Inst,
655                         const MCSubtargetInfo &STI) const override {
656     assert(HexagonMCInstrInfo::isBundle(Inst) &&
657            "Hexagon relaxInstruction only works on bundles");
658 
659     MCInst Res;
660     Res.setOpcode(Hexagon::BUNDLE);
661     Res.addOperand(MCOperand::createImm(Inst.getOperand(0).getImm()));
662     // Copy the results into the bundle.
663     bool Update = false;
664     for (auto &I : HexagonMCInstrInfo::bundleInstructions(Inst)) {
665       MCInst &CrntHMI = const_cast<MCInst &>(*I.getInst());
666 
667       // if immediate extender needed, add it in
668       if (*RelaxTarget == &CrntHMI) {
669         Update = true;
670         assert((HexagonMCInstrInfo::bundleSize(Res) < HEXAGON_PACKET_SIZE) &&
671                "No room to insert extender for relaxation");
672 
673         MCInst *HMIx = takeExtender();
674         *HMIx = HexagonMCInstrInfo::deriveExtender(
675                 *MCII, CrntHMI,
676                 HexagonMCInstrInfo::getExtendableOperand(*MCII, CrntHMI));
677         Res.addOperand(MCOperand::createInst(HMIx));
678         *RelaxTarget = nullptr;
679       }
680       // now copy over the original instruction(the one we may have extended)
681       Res.addOperand(MCOperand::createInst(I.getInst()));
682     }
683 
684     Inst = std::move(Res);
685     (void)Update;
686     assert(Update && "Didn't find relaxation target");
687   }
688 
689   bool writeNopData(raw_ostream &OS, uint64_t Count,
690                     const MCSubtargetInfo *STI) const override {
691     static const uint32_t Nopcode = 0x7f000000, // Hard-coded NOP.
692         ParseIn = 0x00004000,                   // In packet parse-bits.
693         ParseEnd = 0x0000c000;                  // End of packet parse-bits.
694 
695     while (Count % HEXAGON_INSTR_SIZE) {
696       LLVM_DEBUG(dbgs() << "Alignment not a multiple of the instruction size:"
697                         << Count % HEXAGON_INSTR_SIZE << "/"
698                         << HEXAGON_INSTR_SIZE << "\n");
699       --Count;
700       OS << '\0';
701     }
702 
703     while (Count) {
704       Count -= HEXAGON_INSTR_SIZE;
705       // Close the packet whenever a multiple of the maximum packet size remains
706       uint32_t ParseBits = (Count % (MaxPacketSize * HEXAGON_INSTR_SIZE)) ?
707                            ParseIn : ParseEnd;
708       support::endian::write<uint32_t>(OS, Nopcode | ParseBits, Endian);
709     }
710     return true;
711   }
712 
713   void finishLayout(MCAssembler const &Asm,
714                     MCAsmLayout &Layout) const override {
715     for (auto *I : Layout.getSectionOrder()) {
716       auto &Fragments = I->getFragmentList();
717       for (auto &J : Fragments) {
718         switch (J.getKind()) {
719         default:
720           break;
721         case MCFragment::FT_Align: {
722           auto Size = Asm.computeFragmentSize(Layout, J);
723           for (auto K = J.getIterator();
724                K != Fragments.begin() && Size >= HEXAGON_PACKET_SIZE;) {
725             --K;
726             switch (K->getKind()) {
727             default:
728               break;
729             case MCFragment::FT_Align: {
730               // Don't pad before other alignments
731               Size = 0;
732               break;
733             }
734             case MCFragment::FT_Relaxable: {
735               MCContext &Context = Asm.getContext();
736               auto &RF = cast<MCRelaxableFragment>(*K);
737               auto &Inst = const_cast<MCInst &>(RF.getInst());
738               while (Size > 0 &&
739                      HexagonMCInstrInfo::bundleSize(Inst) < MaxPacketSize) {
740                 MCInst *Nop = Context.createMCInst();
741                 Nop->setOpcode(Hexagon::A2_nop);
742                 Inst.addOperand(MCOperand::createInst(Nop));
743                 Size -= 4;
744                 if (!HexagonMCChecker(
745                          Context, *MCII, *RF.getSubtargetInfo(), Inst,
746                          *Context.getRegisterInfo(), false)
747                          .check()) {
748                   Inst.erase(Inst.end() - 1);
749                   Size = 0;
750                 }
751               }
752               bool Error = HexagonMCShuffle(Context, true, *MCII,
753                                             *RF.getSubtargetInfo(), Inst);
754               //assert(!Error);
755               (void)Error;
756               ReplaceInstruction(Asm.getEmitter(), RF, Inst);
757               Layout.invalidateFragmentsFrom(&RF);
758               Size = 0; // Only look back one instruction
759               break;
760             }
761             }
762           }
763         }
764         }
765       }
766     }
767   }
768 }; // class HexagonAsmBackend
769 
770 } // namespace
771 
772 // MCAsmBackend
773 MCAsmBackend *llvm::createHexagonAsmBackend(Target const &T,
774                                             const MCSubtargetInfo &STI,
775                                             MCRegisterInfo const & /*MRI*/,
776                                             const MCTargetOptions &Options) {
777   const Triple &TT = STI.getTargetTriple();
778   uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(TT.getOS());
779 
780   StringRef CPUString = Hexagon_MC::selectHexagonCPU(STI.getCPU());
781   return new HexagonAsmBackend(T, TT, OSABI, CPUString);
782 }
783