1 //===-- SparcAsmBackend.cpp - Sparc Assembler Backend ---------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "llvm/MC/MCAsmBackend.h"
11 #include "MCTargetDesc/SparcMCTargetDesc.h"
12 #include "MCTargetDesc/SparcFixupKinds.h"
13 #include "llvm/MC/MCELFObjectWriter.h"
14 #include "llvm/MC/MCFixupKindInfo.h"
15 #include "llvm/MC/MCObjectWriter.h"
16 #include "llvm/Support/TargetRegistry.h"
17 
18 using namespace llvm;
19 
adjustFixupValue(unsigned Kind,uint64_t Value)20 static unsigned adjustFixupValue(unsigned Kind, uint64_t Value) {
21   switch (Kind) {
22   default:
23     llvm_unreachable("Unknown fixup kind!");
24   case FK_Data_1:
25   case FK_Data_2:
26   case FK_Data_4:
27   case FK_Data_8:
28     return Value;
29 
30   case Sparc::fixup_sparc_wplt30:
31   case Sparc::fixup_sparc_call30:
32     return (Value >> 2) & 0x3fffffff;
33 
34   case Sparc::fixup_sparc_br22:
35     return (Value >> 2) & 0x3fffff;
36 
37   case Sparc::fixup_sparc_br19:
38     return (Value >> 2) & 0x7ffff;
39 
40   case Sparc::fixup_sparc_pc22:
41   case Sparc::fixup_sparc_got22:
42   case Sparc::fixup_sparc_tls_gd_hi22:
43   case Sparc::fixup_sparc_tls_ldm_hi22:
44   case Sparc::fixup_sparc_tls_ie_hi22:
45   case Sparc::fixup_sparc_hi22:
46     return (Value >> 10) & 0x3fffff;
47 
48   case Sparc::fixup_sparc_pc10:
49   case Sparc::fixup_sparc_got10:
50   case Sparc::fixup_sparc_tls_gd_lo10:
51   case Sparc::fixup_sparc_tls_ldm_lo10:
52   case Sparc::fixup_sparc_tls_ie_lo10:
53   case Sparc::fixup_sparc_lo10:
54     return Value & 0x3ff;
55 
56   case Sparc::fixup_sparc_tls_ldo_hix22:
57   case Sparc::fixup_sparc_tls_le_hix22:
58     return (~Value >> 10) & 0x3fffff;
59 
60   case Sparc::fixup_sparc_tls_ldo_lox10:
61   case Sparc::fixup_sparc_tls_le_lox10:
62     return (~(~Value & 0x3ff)) & 0x1fff;
63 
64   case Sparc::fixup_sparc_h44:
65     return (Value >> 22) & 0x3fffff;
66 
67   case Sparc::fixup_sparc_m44:
68     return (Value >> 12) & 0x3ff;
69 
70   case Sparc::fixup_sparc_l44:
71     return Value & 0xfff;
72 
73   case Sparc::fixup_sparc_hh:
74     return (Value >> 42) & 0x3fffff;
75 
76   case Sparc::fixup_sparc_hm:
77     return (Value >> 32) & 0x3ff;
78 
79   case Sparc::fixup_sparc_tls_gd_add:
80   case Sparc::fixup_sparc_tls_gd_call:
81   case Sparc::fixup_sparc_tls_ldm_add:
82   case Sparc::fixup_sparc_tls_ldm_call:
83   case Sparc::fixup_sparc_tls_ldo_add:
84   case Sparc::fixup_sparc_tls_ie_ld:
85   case Sparc::fixup_sparc_tls_ie_ldx:
86   case Sparc::fixup_sparc_tls_ie_add:
87     return 0;
88   }
89 }
90 
91 namespace {
92   class SparcAsmBackend : public MCAsmBackend {
93     const Target &TheTarget;
94   public:
SparcAsmBackend(const Target & T)95     SparcAsmBackend(const Target &T) : MCAsmBackend(), TheTarget(T) {}
96 
getNumFixupKinds() const97     unsigned getNumFixupKinds() const {
98       return Sparc::NumTargetFixupKinds;
99     }
100 
getFixupKindInfo(MCFixupKind Kind) const101     const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const {
102       const static MCFixupKindInfo Infos[Sparc::NumTargetFixupKinds] = {
103         // name                    offset bits  flags
104         { "fixup_sparc_call30",     2,     30,  MCFixupKindInfo::FKF_IsPCRel },
105         { "fixup_sparc_br22",      10,     22,  MCFixupKindInfo::FKF_IsPCRel },
106         { "fixup_sparc_br19",      13,     19,  MCFixupKindInfo::FKF_IsPCRel },
107         { "fixup_sparc_hi22",      10,     22,  0 },
108         { "fixup_sparc_lo10",      22,     10,  0 },
109         { "fixup_sparc_h44",       10,     22,  0 },
110         { "fixup_sparc_m44",       22,     10,  0 },
111         { "fixup_sparc_l44",       20,     12,  0 },
112         { "fixup_sparc_hh",        10,     22,  0 },
113         { "fixup_sparc_hm",        22,     10,  0 },
114         { "fixup_sparc_pc22",      10,     22,  MCFixupKindInfo::FKF_IsPCRel },
115         { "fixup_sparc_pc10",      22,     10,  MCFixupKindInfo::FKF_IsPCRel },
116         { "fixup_sparc_got22",     10,     22,  0 },
117         { "fixup_sparc_got10",     22,     10,  0 },
118         { "fixup_sparc_wplt30",     2,     30,  MCFixupKindInfo::FKF_IsPCRel },
119         { "fixup_sparc_tls_gd_hi22",   10, 22,  0 },
120         { "fixup_sparc_tls_gd_lo10",   22, 10,  0 },
121         { "fixup_sparc_tls_gd_add",     0,  0,  0 },
122         { "fixup_sparc_tls_gd_call",    0,  0,  0 },
123         { "fixup_sparc_tls_ldm_hi22",  10, 22,  0 },
124         { "fixup_sparc_tls_ldm_lo10",  22, 10,  0 },
125         { "fixup_sparc_tls_ldm_add",    0,  0,  0 },
126         { "fixup_sparc_tls_ldm_call",   0,  0,  0 },
127         { "fixup_sparc_tls_ldo_hix22", 10, 22,  0 },
128         { "fixup_sparc_tls_ldo_lox10", 22, 10,  0 },
129         { "fixup_sparc_tls_ldo_add",    0,  0,  0 },
130         { "fixup_sparc_tls_ie_hi22",   10, 22,  0 },
131         { "fixup_sparc_tls_ie_lo10",   22, 10,  0 },
132         { "fixup_sparc_tls_ie_ld",      0,  0,  0 },
133         { "fixup_sparc_tls_ie_ldx",     0,  0,  0 },
134         { "fixup_sparc_tls_ie_add",     0,  0,  0 },
135         { "fixup_sparc_tls_le_hix22",   0,  0,  0 },
136         { "fixup_sparc_tls_le_lox10",   0,  0,  0 }
137       };
138 
139       if (Kind < FirstTargetFixupKind)
140         return MCAsmBackend::getFixupKindInfo(Kind);
141 
142       assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
143              "Invalid kind!");
144       return Infos[Kind - FirstTargetFixupKind];
145     }
146 
processFixupValue(const MCAssembler & Asm,const MCAsmLayout & Layout,const MCFixup & Fixup,const MCFragment * DF,MCValue & Target,uint64_t & Value,bool & IsResolved)147     void processFixupValue(const MCAssembler &Asm,
148                            const MCAsmLayout &Layout,
149                            const MCFixup &Fixup,
150                            const MCFragment *DF,
151                            MCValue &  Target,
152                            uint64_t &Value,
153                            bool &IsResolved) {
154       switch ((Sparc::Fixups)Fixup.getKind()) {
155       default: break;
156       case Sparc::fixup_sparc_wplt30:
157       case Sparc::fixup_sparc_tls_gd_hi22:
158       case Sparc::fixup_sparc_tls_gd_lo10:
159       case Sparc::fixup_sparc_tls_gd_add:
160       case Sparc::fixup_sparc_tls_gd_call:
161       case Sparc::fixup_sparc_tls_ldm_hi22:
162       case Sparc::fixup_sparc_tls_ldm_lo10:
163       case Sparc::fixup_sparc_tls_ldm_add:
164       case Sparc::fixup_sparc_tls_ldm_call:
165       case Sparc::fixup_sparc_tls_ldo_hix22:
166       case Sparc::fixup_sparc_tls_ldo_lox10:
167       case Sparc::fixup_sparc_tls_ldo_add:
168       case Sparc::fixup_sparc_tls_ie_hi22:
169       case Sparc::fixup_sparc_tls_ie_lo10:
170       case Sparc::fixup_sparc_tls_ie_ld:
171       case Sparc::fixup_sparc_tls_ie_ldx:
172       case Sparc::fixup_sparc_tls_ie_add:
173       case Sparc::fixup_sparc_tls_le_hix22:
174       case Sparc::fixup_sparc_tls_le_lox10:  IsResolved = false; break;
175       }
176     }
177 
mayNeedRelaxation(const MCInst & Inst) const178     bool mayNeedRelaxation(const MCInst &Inst) const {
179       // FIXME.
180       return false;
181     }
182 
183     /// fixupNeedsRelaxation - Target specific predicate for whether a given
184     /// fixup requires the associated instruction to be relaxed.
fixupNeedsRelaxation(const MCFixup & Fixup,uint64_t Value,const MCRelaxableFragment * DF,const MCAsmLayout & Layout) const185     bool fixupNeedsRelaxation(const MCFixup &Fixup,
186                               uint64_t Value,
187                               const MCRelaxableFragment *DF,
188                               const MCAsmLayout &Layout) const {
189       // FIXME.
190       assert(0 && "fixupNeedsRelaxation() unimplemented");
191       return false;
192     }
relaxInstruction(const MCInst & Inst,MCInst & Res) const193     void relaxInstruction(const MCInst &Inst, MCInst &Res) const {
194       // FIXME.
195       assert(0 && "relaxInstruction() unimplemented");
196     }
197 
writeNopData(uint64_t Count,MCObjectWriter * OW) const198     bool writeNopData(uint64_t Count, MCObjectWriter *OW) const {
199       // FIXME: Zero fill for now.
200       for (uint64_t i = 0; i != Count; ++i)
201         OW->Write8(0);
202       return true;
203     }
204 
is64Bit() const205     bool is64Bit() const {
206       StringRef name = TheTarget.getName();
207       return name == "sparcv9";
208     }
209   };
210 
211   class ELFSparcAsmBackend : public SparcAsmBackend {
212     Triple::OSType OSType;
213   public:
ELFSparcAsmBackend(const Target & T,Triple::OSType OSType)214     ELFSparcAsmBackend(const Target &T, Triple::OSType OSType) :
215       SparcAsmBackend(T), OSType(OSType) { }
216 
applyFixup(const MCFixup & Fixup,char * Data,unsigned DataSize,uint64_t Value) const217     void applyFixup(const MCFixup &Fixup, char *Data, unsigned DataSize,
218                     uint64_t Value) const {
219 
220       Value = adjustFixupValue(Fixup.getKind(), Value);
221       if (!Value) return;           // Doesn't change encoding.
222 
223       unsigned Offset = Fixup.getOffset();
224 
225       // For each byte of the fragment that the fixup touches, mask in the bits
226       // from the fixup value. The Value has been "split up" into the
227       // appropriate bitfields above.
228       for (unsigned i = 0; i != 4; ++i)
229         Data[Offset + i] |= uint8_t((Value >> ((4 - i - 1)*8)) & 0xff);
230 
231     }
232 
createObjectWriter(raw_ostream & OS) const233     MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
234       uint8_t OSABI = MCELFObjectTargetWriter::getOSABI(OSType);
235       return createSparcELFObjectWriter(OS, is64Bit(), OSABI);
236     }
237 
doesSectionRequireSymbols(const MCSection & Section) const238     virtual bool doesSectionRequireSymbols(const MCSection &Section) const {
239       return false;
240     }
241   };
242 
243 } // end anonymous namespace
244 
245 
createSparcAsmBackend(const Target & T,const MCRegisterInfo & MRI,StringRef TT,StringRef CPU)246 MCAsmBackend *llvm::createSparcAsmBackend(const Target &T,
247                                           const MCRegisterInfo &MRI,
248                                           StringRef TT,
249                                           StringRef CPU) {
250   return new ELFSparcAsmBackend(T, Triple(TT).getOS());
251 }
252