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/Support/Debug.h"
25#include "llvm/Support/EndianStream.h"
26#include "llvm/Support/TargetRegistry.h"
27
28#include <sstream>
29
30using namespace llvm;
31using namespace Hexagon;
32
33#define DEBUG_TYPE "hexagon-asm-backend"
34
35static cl::opt<bool> DisableFixup
36  ("mno-fixup", cl::desc("Disable fixing up resolved relocations for Hexagon"));
37
38namespace {
39
40class 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
49  void ReplaceInstruction(MCCodeEmitter &E, MCRelaxableFragment &RF,
50                          MCInst &HMB) const {
51    SmallVector<MCFixup, 4> Fixups;
52    SmallString<256> Code;
53    raw_svector_ostream VecOS(Code);
54    E.encodeInstruction(HMB, VecOS, Fixups, *RF.getSubtargetInfo());
55
56    // Update the fragment.
57    RF.setInst(HMB);
58    RF.getContents() = Code;
59    RF.getFixups() = Fixups;
60  }
61
62public:
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        LLVM_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        LLVM_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        LLVM_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        LLVM_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        LLVM_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        LLVM_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) const override {
690    static const uint32_t Nopcode  = 0x7f000000, // Hard-coded NOP.
691                          ParseIn  = 0x00004000, // In packet parse-bits.
692                          ParseEnd = 0x0000c000; // End of packet parse-bits.
693
694    while (Count % HEXAGON_INSTR_SIZE) {
695      LLVM_DEBUG(dbgs() << "Alignment not a multiple of the instruction size:"
696                        << Count % HEXAGON_INSTR_SIZE << "/"
697                        << HEXAGON_INSTR_SIZE << "\n");
698      --Count;
699      OS << '\0';
700    }
701
702    while (Count) {
703      Count -= HEXAGON_INSTR_SIZE;
704      // Close the packet whenever a multiple of the maximum packet size remains
705      uint32_t ParseBits = (Count % (MaxPacketSize * HEXAGON_INSTR_SIZE)) ?
706                           ParseIn : ParseEnd;
707      support::endian::write<uint32_t>(OS, Nopcode | ParseBits, Endian);
708    }
709    return true;
710  }
711
712  void finishLayout(MCAssembler const &Asm,
713                    MCAsmLayout &Layout) const override {
714    for (auto I : Layout.getSectionOrder()) {
715      auto &Fragments = I->getFragmentList();
716      for (auto &J : Fragments) {
717        switch (J.getKind()) {
718        default:
719          break;
720        case MCFragment::FT_Align: {
721          auto Size = Asm.computeFragmentSize(Layout, J);
722          for (auto K = J.getIterator();
723               K != Fragments.begin() && Size >= HEXAGON_PACKET_SIZE;) {
724            --K;
725            switch (K->getKind()) {
726            default:
727              break;
728            case MCFragment::FT_Align: {
729              // Don't pad before other alignments
730              Size = 0;
731              break;
732            }
733            case MCFragment::FT_Relaxable: {
734              MCContext &Context = Asm.getContext();
735              auto &RF = cast<MCRelaxableFragment>(*K);
736              auto &Inst = const_cast<MCInst &>(RF.getInst());
737              while (Size > 0 &&
738                     HexagonMCInstrInfo::bundleSize(Inst) < MaxPacketSize) {
739                MCInst *Nop = Context.createMCInst();
740                Nop->setOpcode(Hexagon::A2_nop);
741                Inst.addOperand(MCOperand::createInst(Nop));
742                Size -= 4;
743                if (!HexagonMCChecker(
744                         Context, *MCII, *RF.getSubtargetInfo(), Inst,
745                         *Context.getRegisterInfo(), false)
746                         .check()) {
747                  Inst.erase(Inst.end() - 1);
748                  Size = 0;
749                }
750              }
751              bool Error = HexagonMCShuffle(Context, true, *MCII,
752                                            *RF.getSubtargetInfo(), Inst);
753              //assert(!Error);
754              (void)Error;
755              ReplaceInstruction(Asm.getEmitter(), RF, Inst);
756              Layout.invalidateFragmentsFrom(&RF);
757              Size = 0; // Only look back one instruction
758              break;
759            }
760            }
761          }
762        }
763        }
764      }
765    }
766  }
767}; // class HexagonAsmBackend
768
769} // namespace
770
771// MCAsmBackend
772MCAsmBackend *llvm::createHexagonAsmBackend(Target const &T,
773                                            const MCSubtargetInfo &STI,
774                                            MCRegisterInfo const & /*MRI*/,
775                                            const MCTargetOptions &Options) {
776  const Triple &TT = STI.getTargetTriple();
777  uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(TT.getOS());
778
779  StringRef CPUString = Hexagon_MC::selectHexagonCPU(STI.getCPU());
780  return new HexagonAsmBackend(T, TT, OSABI, CPUString);
781}
782