1 //===-- SparcAsmBackend.cpp - Sparc 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 "MCTargetDesc/SparcFixupKinds.h"
10 #include "MCTargetDesc/SparcMCTargetDesc.h"
11 #include "llvm/MC/MCAsmBackend.h"
12 #include "llvm/MC/MCELFObjectWriter.h"
13 #include "llvm/MC/MCExpr.h"
14 #include "llvm/MC/MCFixupKindInfo.h"
15 #include "llvm/MC/MCObjectWriter.h"
16 #include "llvm/MC/MCSubtargetInfo.h"
17 #include "llvm/MC/MCValue.h"
18 #include "llvm/Support/TargetRegistry.h"
19 
20 using namespace llvm;
21 
adjustFixupValue(unsigned Kind,uint64_t Value)22 static unsigned adjustFixupValue(unsigned Kind, uint64_t Value) {
23   switch (Kind) {
24   default:
25     llvm_unreachable("Unknown fixup kind!");
26   case FK_Data_1:
27   case FK_Data_2:
28   case FK_Data_4:
29   case FK_Data_8:
30     return Value;
31 
32   case Sparc::fixup_sparc_wplt30:
33   case Sparc::fixup_sparc_call30:
34     return (Value >> 2) & 0x3fffffff;
35 
36   case Sparc::fixup_sparc_br22:
37     return (Value >> 2) & 0x3fffff;
38 
39   case Sparc::fixup_sparc_br19:
40     return (Value >> 2) & 0x7ffff;
41 
42   case Sparc::fixup_sparc_br16_2:
43     return (Value >> 2) & 0xc000;
44 
45   case Sparc::fixup_sparc_br16_14:
46     return (Value >> 2) & 0x3fff;
47 
48   case Sparc::fixup_sparc_pc22:
49   case Sparc::fixup_sparc_got22:
50   case Sparc::fixup_sparc_tls_gd_hi22:
51   case Sparc::fixup_sparc_tls_ldm_hi22:
52   case Sparc::fixup_sparc_tls_ie_hi22:
53   case Sparc::fixup_sparc_hi22:
54     return (Value >> 10) & 0x3fffff;
55 
56   case Sparc::fixup_sparc_got13:
57   case Sparc::fixup_sparc_13:
58     return Value & 0x1fff;
59 
60   case Sparc::fixup_sparc_pc10:
61   case Sparc::fixup_sparc_got10:
62   case Sparc::fixup_sparc_tls_gd_lo10:
63   case Sparc::fixup_sparc_tls_ldm_lo10:
64   case Sparc::fixup_sparc_tls_ie_lo10:
65   case Sparc::fixup_sparc_lo10:
66     return Value & 0x3ff;
67 
68   case Sparc::fixup_sparc_h44:
69     return (Value >> 22) & 0x3fffff;
70 
71   case Sparc::fixup_sparc_m44:
72     return (Value >> 12) & 0x3ff;
73 
74   case Sparc::fixup_sparc_l44:
75     return Value & 0xfff;
76 
77   case Sparc::fixup_sparc_hh:
78     return (Value >> 42) & 0x3fffff;
79 
80   case Sparc::fixup_sparc_hm:
81     return (Value >> 32) & 0x3ff;
82 
83   case Sparc::fixup_sparc_tls_ldo_hix22:
84   case Sparc::fixup_sparc_tls_le_hix22:
85   case Sparc::fixup_sparc_tls_ldo_lox10:
86   case Sparc::fixup_sparc_tls_le_lox10:
87     assert(Value == 0 && "Sparc TLS relocs expect zero Value");
88     return 0;
89 
90   case Sparc::fixup_sparc_tls_gd_add:
91   case Sparc::fixup_sparc_tls_gd_call:
92   case Sparc::fixup_sparc_tls_ldm_add:
93   case Sparc::fixup_sparc_tls_ldm_call:
94   case Sparc::fixup_sparc_tls_ldo_add:
95   case Sparc::fixup_sparc_tls_ie_ld:
96   case Sparc::fixup_sparc_tls_ie_ldx:
97   case Sparc::fixup_sparc_tls_ie_add:
98     return 0;
99   }
100 }
101 
102 /// getFixupKindNumBytes - The number of bytes the fixup may change.
getFixupKindNumBytes(unsigned Kind)103 static unsigned getFixupKindNumBytes(unsigned Kind) {
104     switch (Kind) {
105   default:
106     return 4;
107   case FK_Data_1:
108     return 1;
109   case FK_Data_2:
110     return 2;
111   case FK_Data_8:
112     return 8;
113   }
114 }
115 
116 namespace {
117   class SparcAsmBackend : public MCAsmBackend {
118   protected:
119     const Target &TheTarget;
120     bool Is64Bit;
121 
122   public:
SparcAsmBackend(const Target & T)123     SparcAsmBackend(const Target &T)
124         : MCAsmBackend(StringRef(T.getName()) == "sparcel" ? support::little
125                                                            : support::big),
126           TheTarget(T), Is64Bit(StringRef(TheTarget.getName()) == "sparcv9") {}
127 
getNumFixupKinds() const128     unsigned getNumFixupKinds() const override {
129       return Sparc::NumTargetFixupKinds;
130     }
131 
getFixupKindInfo(MCFixupKind Kind) const132     const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const override {
133       const static MCFixupKindInfo InfosBE[Sparc::NumTargetFixupKinds] = {
134         // name                    offset bits  flags
135         { "fixup_sparc_call30",     2,     30,  MCFixupKindInfo::FKF_IsPCRel },
136         { "fixup_sparc_br22",      10,     22,  MCFixupKindInfo::FKF_IsPCRel },
137         { "fixup_sparc_br19",      13,     19,  MCFixupKindInfo::FKF_IsPCRel },
138         { "fixup_sparc_br16_2",    10,      2,  MCFixupKindInfo::FKF_IsPCRel },
139         { "fixup_sparc_br16_14",   18,     14,  MCFixupKindInfo::FKF_IsPCRel },
140         { "fixup_sparc_13",        19,     13,  0 },
141         { "fixup_sparc_hi22",      10,     22,  0 },
142         { "fixup_sparc_lo10",      22,     10,  0 },
143         { "fixup_sparc_h44",       10,     22,  0 },
144         { "fixup_sparc_m44",       22,     10,  0 },
145         { "fixup_sparc_l44",       20,     12,  0 },
146         { "fixup_sparc_hh",        10,     22,  0 },
147         { "fixup_sparc_hm",        22,     10,  0 },
148         { "fixup_sparc_pc22",      10,     22,  MCFixupKindInfo::FKF_IsPCRel },
149         { "fixup_sparc_pc10",      22,     10,  MCFixupKindInfo::FKF_IsPCRel },
150         { "fixup_sparc_got22",     10,     22,  0 },
151         { "fixup_sparc_got10",     22,     10,  0 },
152         { "fixup_sparc_got13",     19,     13,  0 },
153         { "fixup_sparc_wplt30",     2,     30,  MCFixupKindInfo::FKF_IsPCRel },
154         { "fixup_sparc_tls_gd_hi22",   10, 22,  0 },
155         { "fixup_sparc_tls_gd_lo10",   22, 10,  0 },
156         { "fixup_sparc_tls_gd_add",     0,  0,  0 },
157         { "fixup_sparc_tls_gd_call",    0,  0,  0 },
158         { "fixup_sparc_tls_ldm_hi22",  10, 22,  0 },
159         { "fixup_sparc_tls_ldm_lo10",  22, 10,  0 },
160         { "fixup_sparc_tls_ldm_add",    0,  0,  0 },
161         { "fixup_sparc_tls_ldm_call",   0,  0,  0 },
162         { "fixup_sparc_tls_ldo_hix22", 10, 22,  0 },
163         { "fixup_sparc_tls_ldo_lox10", 22, 10,  0 },
164         { "fixup_sparc_tls_ldo_add",    0,  0,  0 },
165         { "fixup_sparc_tls_ie_hi22",   10, 22,  0 },
166         { "fixup_sparc_tls_ie_lo10",   22, 10,  0 },
167         { "fixup_sparc_tls_ie_ld",      0,  0,  0 },
168         { "fixup_sparc_tls_ie_ldx",     0,  0,  0 },
169         { "fixup_sparc_tls_ie_add",     0,  0,  0 },
170         { "fixup_sparc_tls_le_hix22",   0,  0,  0 },
171         { "fixup_sparc_tls_le_lox10",   0,  0,  0 }
172       };
173 
174       const static MCFixupKindInfo InfosLE[Sparc::NumTargetFixupKinds] = {
175         // name                    offset bits  flags
176         { "fixup_sparc_call30",     0,     30,  MCFixupKindInfo::FKF_IsPCRel },
177         { "fixup_sparc_br22",       0,     22,  MCFixupKindInfo::FKF_IsPCRel },
178         { "fixup_sparc_br19",       0,     19,  MCFixupKindInfo::FKF_IsPCRel },
179         { "fixup_sparc_br16_2",    20,      2,  MCFixupKindInfo::FKF_IsPCRel },
180         { "fixup_sparc_br16_14",    0,     14,  MCFixupKindInfo::FKF_IsPCRel },
181         { "fixup_sparc_13",         0,     13,  0 },
182         { "fixup_sparc_hi22",       0,     22,  0 },
183         { "fixup_sparc_lo10",       0,     10,  0 },
184         { "fixup_sparc_h44",        0,     22,  0 },
185         { "fixup_sparc_m44",        0,     10,  0 },
186         { "fixup_sparc_l44",        0,     12,  0 },
187         { "fixup_sparc_hh",         0,     22,  0 },
188         { "fixup_sparc_hm",         0,     10,  0 },
189         { "fixup_sparc_pc22",       0,     22,  MCFixupKindInfo::FKF_IsPCRel },
190         { "fixup_sparc_pc10",       0,     10,  MCFixupKindInfo::FKF_IsPCRel },
191         { "fixup_sparc_got22",      0,     22,  0 },
192         { "fixup_sparc_got10",      0,     10,  0 },
193         { "fixup_sparc_got13",      0,     13,  0 },
194         { "fixup_sparc_wplt30",      0,     30,  MCFixupKindInfo::FKF_IsPCRel },
195         { "fixup_sparc_tls_gd_hi22",    0, 22,  0 },
196         { "fixup_sparc_tls_gd_lo10",    0, 10,  0 },
197         { "fixup_sparc_tls_gd_add",     0,  0,  0 },
198         { "fixup_sparc_tls_gd_call",    0,  0,  0 },
199         { "fixup_sparc_tls_ldm_hi22",   0, 22,  0 },
200         { "fixup_sparc_tls_ldm_lo10",   0, 10,  0 },
201         { "fixup_sparc_tls_ldm_add",    0,  0,  0 },
202         { "fixup_sparc_tls_ldm_call",   0,  0,  0 },
203         { "fixup_sparc_tls_ldo_hix22",  0, 22,  0 },
204         { "fixup_sparc_tls_ldo_lox10",  0, 10,  0 },
205         { "fixup_sparc_tls_ldo_add",    0,  0,  0 },
206         { "fixup_sparc_tls_ie_hi22",    0, 22,  0 },
207         { "fixup_sparc_tls_ie_lo10",    0, 10,  0 },
208         { "fixup_sparc_tls_ie_ld",      0,  0,  0 },
209         { "fixup_sparc_tls_ie_ldx",     0,  0,  0 },
210         { "fixup_sparc_tls_ie_add",     0,  0,  0 },
211         { "fixup_sparc_tls_le_hix22",   0,  0,  0 },
212         { "fixup_sparc_tls_le_lox10",   0,  0,  0 }
213       };
214 
215       if (Kind < FirstTargetFixupKind)
216         return MCAsmBackend::getFixupKindInfo(Kind);
217 
218       assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
219              "Invalid kind!");
220       if (Endian == support::little)
221         return InfosLE[Kind - FirstTargetFixupKind];
222 
223       return InfosBE[Kind - FirstTargetFixupKind];
224     }
225 
shouldForceRelocation(const MCAssembler & Asm,const MCFixup & Fixup,const MCValue & Target)226     bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup,
227                                const MCValue &Target) override {
228       switch ((Sparc::Fixups)Fixup.getKind()) {
229       default:
230         return false;
231       case Sparc::fixup_sparc_wplt30:
232         if (Target.getSymA()->getSymbol().isTemporary())
233           return false;
234         LLVM_FALLTHROUGH;
235       case Sparc::fixup_sparc_tls_gd_hi22:
236       case Sparc::fixup_sparc_tls_gd_lo10:
237       case Sparc::fixup_sparc_tls_gd_add:
238       case Sparc::fixup_sparc_tls_gd_call:
239       case Sparc::fixup_sparc_tls_ldm_hi22:
240       case Sparc::fixup_sparc_tls_ldm_lo10:
241       case Sparc::fixup_sparc_tls_ldm_add:
242       case Sparc::fixup_sparc_tls_ldm_call:
243       case Sparc::fixup_sparc_tls_ldo_hix22:
244       case Sparc::fixup_sparc_tls_ldo_lox10:
245       case Sparc::fixup_sparc_tls_ldo_add:
246       case Sparc::fixup_sparc_tls_ie_hi22:
247       case Sparc::fixup_sparc_tls_ie_lo10:
248       case Sparc::fixup_sparc_tls_ie_ld:
249       case Sparc::fixup_sparc_tls_ie_ldx:
250       case Sparc::fixup_sparc_tls_ie_add:
251       case Sparc::fixup_sparc_tls_le_hix22:
252       case Sparc::fixup_sparc_tls_le_lox10:
253         return true;
254       }
255     }
256 
mayNeedRelaxation(const MCInst & Inst,const MCSubtargetInfo & STI) const257     bool mayNeedRelaxation(const MCInst &Inst,
258                            const MCSubtargetInfo &STI) const override {
259       // FIXME.
260       return false;
261     }
262 
263     /// fixupNeedsRelaxation - Target specific predicate for whether a given
264     /// fixup requires the associated instruction to be relaxed.
fixupNeedsRelaxation(const MCFixup & Fixup,uint64_t Value,const MCRelaxableFragment * DF,const MCAsmLayout & Layout) const265     bool fixupNeedsRelaxation(const MCFixup &Fixup,
266                               uint64_t Value,
267                               const MCRelaxableFragment *DF,
268                               const MCAsmLayout &Layout) const override {
269       // FIXME.
270       llvm_unreachable("fixupNeedsRelaxation() unimplemented");
271       return false;
272     }
relaxInstruction(const MCInst & Inst,const MCSubtargetInfo & STI,MCInst & Res) const273     void relaxInstruction(const MCInst &Inst, const MCSubtargetInfo &STI,
274                           MCInst &Res) const override {
275       // FIXME.
276       llvm_unreachable("relaxInstruction() unimplemented");
277     }
278 
writeNopData(raw_ostream & OS,uint64_t Count) const279     bool writeNopData(raw_ostream &OS, uint64_t Count) const override {
280       // Cannot emit NOP with size not multiple of 32 bits.
281       if (Count % 4 != 0)
282         return false;
283 
284       uint64_t NumNops = Count / 4;
285       for (uint64_t i = 0; i != NumNops; ++i)
286         support::endian::write<uint32_t>(OS, 0x01000000, Endian);
287 
288       return true;
289     }
290   };
291 
292   class ELFSparcAsmBackend : public SparcAsmBackend {
293     Triple::OSType OSType;
294   public:
ELFSparcAsmBackend(const Target & T,Triple::OSType OSType)295     ELFSparcAsmBackend(const Target &T, Triple::OSType OSType) :
296       SparcAsmBackend(T), OSType(OSType) { }
297 
applyFixup(const MCAssembler & Asm,const MCFixup & Fixup,const MCValue & Target,MutableArrayRef<char> Data,uint64_t Value,bool IsResolved,const MCSubtargetInfo * STI) const298     void applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
299                     const MCValue &Target, MutableArrayRef<char> Data,
300                     uint64_t Value, bool IsResolved,
301                     const MCSubtargetInfo *STI) const override {
302 
303       Value = adjustFixupValue(Fixup.getKind(), Value);
304       if (!Value) return;           // Doesn't change encoding.
305 
306       unsigned NumBytes = getFixupKindNumBytes(Fixup.getKind());
307       unsigned Offset = Fixup.getOffset();
308       // For each byte of the fragment that the fixup touches, mask in the bits
309       // from the fixup value. The Value has been "split up" into the
310       // appropriate bitfields above.
311       for (unsigned i = 0; i != NumBytes; ++i) {
312         unsigned Idx = Endian == support::little ? i : (NumBytes - 1) - i;
313         Data[Offset + Idx] |= uint8_t((Value >> (i * 8)) & 0xff);
314       }
315     }
316 
317     std::unique_ptr<MCObjectTargetWriter>
createObjectTargetWriter() const318     createObjectTargetWriter() const override {
319       uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(OSType);
320       return createSparcELFObjectWriter(Is64Bit, OSABI);
321     }
322   };
323 
324 } // end anonymous namespace
325 
createSparcAsmBackend(const Target & T,const MCSubtargetInfo & STI,const MCRegisterInfo & MRI,const MCTargetOptions & Options)326 MCAsmBackend *llvm::createSparcAsmBackend(const Target &T,
327                                           const MCSubtargetInfo &STI,
328                                           const MCRegisterInfo &MRI,
329                                           const MCTargetOptions &Options) {
330   return new ELFSparcAsmBackend(T, STI.getTargetTriple().getOS());
331 }
332