blob: 6b9820565b5f02000a1216468661807533d44fb7 [file] [log] [blame]
Tim Northover5cc3dc82012-12-07 16:50:23 +00001//===- lib/MC/ARMELFStreamer.cpp - ELF Object Output for ARM --------------===//
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// This file assembles .s files and emits ARM ELF .o object files. Different
11// from generic ELF streamer in emitting mapping symbols ($a, $t and $d) to
12// delimit regions of data and code.
13//
14//===----------------------------------------------------------------------===//
15
Logan Chiend8bb4b72013-04-16 12:02:21 +000016#include "ARMRegisterInfo.h"
Logan Chien2bcc42c2013-01-30 15:39:04 +000017#include "ARMUnwindOp.h"
Logan Chiend8bb4b72013-04-16 12:02:21 +000018#include "ARMUnwindOpAsm.h"
Tim Northover5cc3dc82012-12-07 16:50:23 +000019#include "llvm/ADT/SmallPtrSet.h"
Benjamin Kramerf242d8c2012-12-08 10:45:24 +000020#include "llvm/ADT/Twine.h"
21#include "llvm/MC/MCAsmBackend.h"
Tim Northover5cc3dc82012-12-07 16:50:23 +000022#include "llvm/MC/MCAssembler.h"
23#include "llvm/MC/MCCodeEmitter.h"
24#include "llvm/MC/MCContext.h"
Tim Northover5cc3dc82012-12-07 16:50:23 +000025#include "llvm/MC/MCELF.h"
26#include "llvm/MC/MCELFStreamer.h"
27#include "llvm/MC/MCELFSymbolFlags.h"
28#include "llvm/MC/MCExpr.h"
29#include "llvm/MC/MCInst.h"
30#include "llvm/MC/MCObjectStreamer.h"
Logan Chiend8bb4b72013-04-16 12:02:21 +000031#include "llvm/MC/MCRegisterInfo.h"
Tim Northover5cc3dc82012-12-07 16:50:23 +000032#include "llvm/MC/MCSection.h"
Benjamin Kramerf242d8c2012-12-08 10:45:24 +000033#include "llvm/MC/MCSectionELF.h"
34#include "llvm/MC/MCStreamer.h"
Tim Northover5cc3dc82012-12-07 16:50:23 +000035#include "llvm/MC/MCSymbol.h"
36#include "llvm/MC/MCValue.h"
Tim Northover5cc3dc82012-12-07 16:50:23 +000037#include "llvm/Support/Debug.h"
38#include "llvm/Support/ELF.h"
Tim Northover5cc3dc82012-12-07 16:50:23 +000039#include "llvm/Support/raw_ostream.h"
40
41using namespace llvm;
42
Logan Chiend8bb4b72013-04-16 12:02:21 +000043static std::string GetAEABIUnwindPersonalityName(unsigned Index) {
44 assert(Index < NUM_PERSONALITY_INDEX && "Invalid personality index");
45 return (Twine("__aeabi_unwind_cpp_pr") + Twine(Index)).str();
46}
47
Tim Northover5cc3dc82012-12-07 16:50:23 +000048namespace {
49
50/// Extend the generic ELFStreamer class so that it can emit mapping symbols at
51/// the appropriate points in the object files. These symbols are defined in the
52/// ARM ELF ABI: infocenter.arm.com/help/topic/com.arm.../IHI0044D_aaelf.pdf.
53///
54/// In brief: $a, $t or $d should be emitted at the start of each contiguous
55/// region of ARM code, Thumb code or data in a section. In practice, this
56/// emission does not rely on explicit assembler directives but on inherent
57/// properties of the directives doing the emission (e.g. ".byte" is data, "add
58/// r0, r0, r0" an instruction).
59///
60/// As a result this system is orthogonal to the DataRegion infrastructure used
61/// by MachO. Beware!
62class ARMELFStreamer : public MCELFStreamer {
63public:
Chandler Carruthde093ef2013-01-31 23:29:57 +000064 ARMELFStreamer(MCContext &Context, MCAsmBackend &TAB, raw_ostream &OS,
65 MCCodeEmitter *Emitter, bool IsThumb)
66 : MCELFStreamer(SK_ARMELFStreamer, Context, TAB, OS, Emitter),
Logan Chiend8bb4b72013-04-16 12:02:21 +000067 IsThumb(IsThumb), MappingSymbolCounter(0), LastEMS(EMS_None) {
68 Reset();
69 }
Tim Northover5cc3dc82012-12-07 16:50:23 +000070
71 ~ARMELFStreamer() {}
72
Logan Chien2bcc42c2013-01-30 15:39:04 +000073 // ARM exception handling directives
74 virtual void EmitFnStart();
75 virtual void EmitFnEnd();
76 virtual void EmitCantUnwind();
77 virtual void EmitPersonality(const MCSymbol *Per);
78 virtual void EmitHandlerData();
79 virtual void EmitSetFP(unsigned NewFpReg,
80 unsigned NewSpReg,
81 int64_t Offset = 0);
82 virtual void EmitPad(int64_t Offset);
83 virtual void EmitRegSave(const SmallVectorImpl<unsigned> &RegList,
84 bool isVector);
85
Peter Collingbourne2f495b92013-04-17 21:18:16 +000086 virtual void ChangeSection(const MCSection *Section,
87 const MCExpr *Subsection) {
Tim Northover5cc3dc82012-12-07 16:50:23 +000088 // We have to keep track of the mapping symbol state of any sections we
89 // use. Each one should start off as EMS_None, which is provided as the
90 // default constructor by DenseMap::lookup.
Peter Collingbourne2f495b92013-04-17 21:18:16 +000091 LastMappingSymbols[getPreviousSection().first] = LastEMS;
Tim Northover5cc3dc82012-12-07 16:50:23 +000092 LastEMS = LastMappingSymbols.lookup(Section);
93
Peter Collingbourne2f495b92013-04-17 21:18:16 +000094 MCELFStreamer::ChangeSection(Section, Subsection);
Tim Northover5cc3dc82012-12-07 16:50:23 +000095 }
96
97 /// This function is the one used to emit instruction data into the ELF
98 /// streamer. We override it to add the appropriate mapping symbol if
99 /// necessary.
100 virtual void EmitInstruction(const MCInst& Inst) {
101 if (IsThumb)
102 EmitThumbMappingSymbol();
103 else
104 EmitARMMappingSymbol();
105
106 MCELFStreamer::EmitInstruction(Inst);
107 }
108
109 /// This is one of the functions used to emit data into an ELF section, so the
110 /// ARM streamer overrides it to add the appropriate mapping symbol ($d) if
111 /// necessary.
Rafael Espindola64e1af82013-07-02 15:49:13 +0000112 virtual void EmitBytes(StringRef Data) {
Tim Northover5cc3dc82012-12-07 16:50:23 +0000113 EmitDataMappingSymbol();
Rafael Espindola64e1af82013-07-02 15:49:13 +0000114 MCELFStreamer::EmitBytes(Data);
Tim Northover5cc3dc82012-12-07 16:50:23 +0000115 }
116
117 /// This is one of the functions used to emit data into an ELF section, so the
118 /// ARM streamer overrides it to add the appropriate mapping symbol ($d) if
119 /// necessary.
Rafael Espindola64e1af82013-07-02 15:49:13 +0000120 virtual void EmitValueImpl(const MCExpr *Value, unsigned Size) {
Tim Northover5cc3dc82012-12-07 16:50:23 +0000121 EmitDataMappingSymbol();
Rafael Espindola64e1af82013-07-02 15:49:13 +0000122 MCELFStreamer::EmitValueImpl(Value, Size);
Tim Northover5cc3dc82012-12-07 16:50:23 +0000123 }
124
125 virtual void EmitAssemblerFlag(MCAssemblerFlag Flag) {
126 MCELFStreamer::EmitAssemblerFlag(Flag);
127
128 switch (Flag) {
129 case MCAF_SyntaxUnified:
130 return; // no-op here.
131 case MCAF_Code16:
132 IsThumb = true;
133 return; // Change to Thumb mode
134 case MCAF_Code32:
135 IsThumb = false;
136 return; // Change to ARM mode
137 case MCAF_Code64:
138 return;
139 case MCAF_SubsectionsViaSymbols:
140 return;
141 }
142 }
143
Chandler Carruthde093ef2013-01-31 23:29:57 +0000144 static bool classof(const MCStreamer *S) {
145 return S->getKind() == SK_ARMELFStreamer;
146 }
147
Tim Northover5cc3dc82012-12-07 16:50:23 +0000148private:
149 enum ElfMappingSymbol {
150 EMS_None,
151 EMS_ARM,
152 EMS_Thumb,
153 EMS_Data
154 };
155
156 void EmitDataMappingSymbol() {
157 if (LastEMS == EMS_Data) return;
158 EmitMappingSymbol("$d");
159 LastEMS = EMS_Data;
160 }
161
162 void EmitThumbMappingSymbol() {
163 if (LastEMS == EMS_Thumb) return;
164 EmitMappingSymbol("$t");
165 LastEMS = EMS_Thumb;
166 }
167
168 void EmitARMMappingSymbol() {
169 if (LastEMS == EMS_ARM) return;
170 EmitMappingSymbol("$a");
171 LastEMS = EMS_ARM;
172 }
173
174 void EmitMappingSymbol(StringRef Name) {
175 MCSymbol *Start = getContext().CreateTempSymbol();
176 EmitLabel(Start);
177
Chandler Carruth1d94e932012-12-08 03:10:14 +0000178 MCSymbol *Symbol =
Benjamin Kramerf242d8c2012-12-08 10:45:24 +0000179 getContext().GetOrCreateSymbol(Name + "." +
180 Twine(MappingSymbolCounter++));
Tim Northover5cc3dc82012-12-07 16:50:23 +0000181
182 MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Symbol);
183 MCELF::SetType(SD, ELF::STT_NOTYPE);
184 MCELF::SetBinding(SD, ELF::STB_LOCAL);
185 SD.setExternal(false);
Peter Collingbourne2f495b92013-04-17 21:18:16 +0000186 Symbol->setSection(*getCurrentSection().first);
Tim Northover5cc3dc82012-12-07 16:50:23 +0000187
188 const MCExpr *Value = MCSymbolRefExpr::Create(Start, getContext());
189 Symbol->setVariableValue(Value);
190 }
191
192 void EmitThumbFunc(MCSymbol *Func) {
193 // FIXME: Anything needed here to flag the function as thumb?
194
195 getAssembler().setIsThumbFunc(Func);
196
197 MCSymbolData &SD = getAssembler().getOrCreateSymbolData(*Func);
198 SD.setFlags(SD.getFlags() | ELF_Other_ThumbFunc);
199 }
200
Logan Chien2bcc42c2013-01-30 15:39:04 +0000201 // Helper functions for ARM exception handling directives
202 void Reset();
203
204 void EmitPersonalityFixup(StringRef Name);
Logan Chien325823a2013-06-09 12:22:30 +0000205 void FlushPendingOffset();
Logan Chienc931fce2013-07-02 12:43:27 +0000206 void FlushUnwindOpcodes(bool NoHandlerData);
Logan Chien2bcc42c2013-01-30 15:39:04 +0000207
208 void SwitchToEHSection(const char *Prefix, unsigned Type, unsigned Flags,
209 SectionKind Kind, const MCSymbol &Fn);
210 void SwitchToExTabSection(const MCSymbol &FnStart);
211 void SwitchToExIdxSection(const MCSymbol &FnStart);
Tim Northover5cc3dc82012-12-07 16:50:23 +0000212
213 bool IsThumb;
214 int64_t MappingSymbolCounter;
215
216 DenseMap<const MCSection *, ElfMappingSymbol> LastMappingSymbols;
217 ElfMappingSymbol LastEMS;
218
Logan Chien2bcc42c2013-01-30 15:39:04 +0000219 // ARM Exception Handling Frame Information
220 MCSymbol *ExTab;
221 MCSymbol *FnStart;
222 const MCSymbol *Personality;
Logan Chien325823a2013-06-09 12:22:30 +0000223 unsigned PersonalityIndex;
224 unsigned FPReg; // Frame pointer register
225 int64_t FPOffset; // Offset: (final frame pointer) - (initial $sp)
226 int64_t SPOffset; // Offset: (final $sp) - (initial $sp)
227 int64_t PendingOffset; // Offset: (final $sp) - (emitted $sp)
Logan Chiend8bb4b72013-04-16 12:02:21 +0000228 bool UsedFP;
Logan Chien2bcc42c2013-01-30 15:39:04 +0000229 bool CantUnwind;
Logan Chien325823a2013-06-09 12:22:30 +0000230 SmallVector<uint8_t, 64> Opcodes;
Logan Chiend8bb4b72013-04-16 12:02:21 +0000231 UnwindOpcodeAssembler UnwindOpAsm;
Tim Northover5cc3dc82012-12-07 16:50:23 +0000232};
Logan Chiend8bb4b72013-04-16 12:02:21 +0000233} // end anonymous namespace
Tim Northover5cc3dc82012-12-07 16:50:23 +0000234
Logan Chien2bcc42c2013-01-30 15:39:04 +0000235inline void ARMELFStreamer::SwitchToEHSection(const char *Prefix,
236 unsigned Type,
237 unsigned Flags,
238 SectionKind Kind,
239 const MCSymbol &Fn) {
240 const MCSectionELF &FnSection =
241 static_cast<const MCSectionELF &>(Fn.getSection());
242
243 // Create the name for new section
244 StringRef FnSecName(FnSection.getSectionName());
245 SmallString<128> EHSecName(Prefix);
246 if (FnSecName != ".text") {
247 EHSecName += FnSecName;
248 }
249
250 // Get .ARM.extab or .ARM.exidx section
251 const MCSectionELF *EHSection = NULL;
252 if (const MCSymbol *Group = FnSection.getGroup()) {
253 EHSection = getContext().getELFSection(
254 EHSecName, Type, Flags | ELF::SHF_GROUP, Kind,
255 FnSection.getEntrySize(), Group->getName());
256 } else {
257 EHSection = getContext().getELFSection(EHSecName, Type, Flags, Kind);
258 }
Logan Chiend8bb4b72013-04-16 12:02:21 +0000259 assert(EHSection && "Failed to get the required EH section");
Logan Chien2bcc42c2013-01-30 15:39:04 +0000260
261 // Switch to .ARM.extab or .ARM.exidx section
262 SwitchSection(EHSection);
263 EmitCodeAlignment(4, 0);
264}
265
266inline void ARMELFStreamer::SwitchToExTabSection(const MCSymbol &FnStart) {
267 SwitchToEHSection(".ARM.extab",
268 ELF::SHT_PROGBITS,
269 ELF::SHF_ALLOC,
270 SectionKind::getDataRel(),
271 FnStart);
272}
273
274inline void ARMELFStreamer::SwitchToExIdxSection(const MCSymbol &FnStart) {
275 SwitchToEHSection(".ARM.exidx",
276 ELF::SHT_ARM_EXIDX,
277 ELF::SHF_ALLOC | ELF::SHF_LINK_ORDER,
278 SectionKind::getDataRel(),
279 FnStart);
280}
281
282void ARMELFStreamer::Reset() {
283 ExTab = NULL;
284 FnStart = NULL;
285 Personality = NULL;
Logan Chien325823a2013-06-09 12:22:30 +0000286 PersonalityIndex = NUM_PERSONALITY_INDEX;
287 FPReg = ARM::SP;
Logan Chiend8bb4b72013-04-16 12:02:21 +0000288 FPOffset = 0;
289 SPOffset = 0;
Logan Chien325823a2013-06-09 12:22:30 +0000290 PendingOffset = 0;
Logan Chiend8bb4b72013-04-16 12:02:21 +0000291 UsedFP = false;
Logan Chien2bcc42c2013-01-30 15:39:04 +0000292 CantUnwind = false;
Logan Chiend8bb4b72013-04-16 12:02:21 +0000293
Logan Chien325823a2013-06-09 12:22:30 +0000294 Opcodes.clear();
Logan Chiend8bb4b72013-04-16 12:02:21 +0000295 UnwindOpAsm.Reset();
Logan Chien2bcc42c2013-01-30 15:39:04 +0000296}
297
298// Add the R_ARM_NONE fixup at the same position
299void ARMELFStreamer::EmitPersonalityFixup(StringRef Name) {
300 const MCSymbol *PersonalitySym = getContext().GetOrCreateSymbol(Name);
301
302 const MCSymbolRefExpr *PersonalityRef =
303 MCSymbolRefExpr::Create(PersonalitySym,
304 MCSymbolRefExpr::VK_ARM_NONE,
305 getContext());
306
307 AddValueSymbols(PersonalityRef);
308 MCDataFragment *DF = getOrCreateDataFragment();
309 DF->getFixups().push_back(
310 MCFixup::Create(DF->getContents().size(), PersonalityRef,
311 MCFixup::getKindForSize(4, false)));
312}
313
314void ARMELFStreamer::EmitFnStart() {
315 assert(FnStart == 0);
316 FnStart = getContext().CreateTempSymbol();
317 EmitLabel(FnStart);
318}
319
320void ARMELFStreamer::EmitFnEnd() {
321 assert(FnStart && ".fnstart must preceeds .fnend");
322
323 // Emit unwind opcodes if there is no .handlerdata directive
Logan Chien4ea23b52013-05-10 16:17:24 +0000324 if (!ExTab && !CantUnwind)
325 FlushUnwindOpcodes(true);
Logan Chien2bcc42c2013-01-30 15:39:04 +0000326
327 // Emit the exception index table entry
328 SwitchToExIdxSection(*FnStart);
329
Logan Chiend8bb4b72013-04-16 12:02:21 +0000330 if (PersonalityIndex < NUM_PERSONALITY_INDEX)
331 EmitPersonalityFixup(GetAEABIUnwindPersonalityName(PersonalityIndex));
Logan Chien2bcc42c2013-01-30 15:39:04 +0000332
333 const MCSymbolRefExpr *FnStartRef =
334 MCSymbolRefExpr::Create(FnStart,
335 MCSymbolRefExpr::VK_ARM_PREL31,
336 getContext());
337
Rafael Espindola64e1af82013-07-02 15:49:13 +0000338 EmitValue(FnStartRef, 4);
Logan Chien2bcc42c2013-01-30 15:39:04 +0000339
340 if (CantUnwind) {
Rafael Espindola64e1af82013-07-02 15:49:13 +0000341 EmitIntValue(EXIDX_CANTUNWIND, 4);
Logan Chiend8bb4b72013-04-16 12:02:21 +0000342 } else if (ExTab) {
343 // Emit a reference to the unwind opcodes in the ".ARM.extab" section.
Logan Chien2bcc42c2013-01-30 15:39:04 +0000344 const MCSymbolRefExpr *ExTabEntryRef =
345 MCSymbolRefExpr::Create(ExTab,
346 MCSymbolRefExpr::VK_ARM_PREL31,
347 getContext());
Rafael Espindola64e1af82013-07-02 15:49:13 +0000348 EmitValue(ExTabEntryRef, 4);
Logan Chiend8bb4b72013-04-16 12:02:21 +0000349 } else {
350 // For the __aeabi_unwind_cpp_pr0, we have to emit the unwind opcodes in
351 // the second word of exception index table entry. The size of the unwind
352 // opcodes should always be 4 bytes.
353 assert(PersonalityIndex == AEABI_UNWIND_CPP_PR0 &&
354 "Compact model must use __aeabi_cpp_unwind_pr0 as personality");
Logan Chien325823a2013-06-09 12:22:30 +0000355 assert(Opcodes.size() == 4u &&
Logan Chiend8bb4b72013-04-16 12:02:21 +0000356 "Unwind opcode size for __aeabi_cpp_unwind_pr0 must be equal to 4");
Logan Chien325823a2013-06-09 12:22:30 +0000357 EmitBytes(StringRef(reinterpret_cast<const char*>(Opcodes.data()),
Rafael Espindola64e1af82013-07-02 15:49:13 +0000358 Opcodes.size()));
Logan Chien2bcc42c2013-01-30 15:39:04 +0000359 }
360
Logan Chien4ea23b52013-05-10 16:17:24 +0000361 // Switch to the section containing FnStart
362 SwitchSection(&FnStart->getSection());
363
Logan Chien2bcc42c2013-01-30 15:39:04 +0000364 // Clean exception handling frame information
365 Reset();
366}
367
368void ARMELFStreamer::EmitCantUnwind() {
369 CantUnwind = true;
370}
371
Logan Chien325823a2013-06-09 12:22:30 +0000372void ARMELFStreamer::FlushPendingOffset() {
373 if (PendingOffset != 0) {
374 UnwindOpAsm.EmitSPOffset(-PendingOffset);
375 PendingOffset = 0;
376 }
377}
378
Logan Chienc931fce2013-07-02 12:43:27 +0000379void ARMELFStreamer::FlushUnwindOpcodes(bool NoHandlerData) {
Logan Chien325823a2013-06-09 12:22:30 +0000380 // Emit the unwind opcode to restore $sp.
381 if (UsedFP) {
Bill Wendlingbc07a892013-06-18 07:20:20 +0000382 const MCRegisterInfo *MRI = getContext().getRegisterInfo();
Logan Chien325823a2013-06-09 12:22:30 +0000383 int64_t LastRegSaveSPOffset = SPOffset - PendingOffset;
384 UnwindOpAsm.EmitSPOffset(LastRegSaveSPOffset - FPOffset);
Bill Wendlingbc07a892013-06-18 07:20:20 +0000385 UnwindOpAsm.EmitSetSP(MRI->getEncodingValue(FPReg));
Logan Chien325823a2013-06-09 12:22:30 +0000386 } else {
387 FlushPendingOffset();
388 }
389
390 // Finalize the unwind opcode sequence
391 UnwindOpAsm.Finalize(PersonalityIndex, Opcodes);
Logan Chien4ea23b52013-05-10 16:17:24 +0000392
393 // For compact model 0, we have to emit the unwind opcodes in the .ARM.exidx
394 // section. Thus, we don't have to create an entry in the .ARM.extab
395 // section.
Logan Chienc931fce2013-07-02 12:43:27 +0000396 if (NoHandlerData && PersonalityIndex == AEABI_UNWIND_CPP_PR0)
Logan Chien4ea23b52013-05-10 16:17:24 +0000397 return;
398
399 // Switch to .ARM.extab section.
Logan Chien2bcc42c2013-01-30 15:39:04 +0000400 SwitchToExTabSection(*FnStart);
401
402 // Create .ARM.extab label for offset in .ARM.exidx
403 assert(!ExTab);
404 ExTab = getContext().CreateTempSymbol();
405 EmitLabel(ExTab);
406
Logan Chien4ea23b52013-05-10 16:17:24 +0000407 // Emit personality
408 if (Personality) {
409 const MCSymbolRefExpr *PersonalityRef =
410 MCSymbolRefExpr::Create(Personality,
411 MCSymbolRefExpr::VK_ARM_PREL31,
412 getContext());
Logan Chien2bcc42c2013-01-30 15:39:04 +0000413
Rafael Espindola64e1af82013-07-02 15:49:13 +0000414 EmitValue(PersonalityRef, 4);
Logan Chien4ea23b52013-05-10 16:17:24 +0000415 }
Logan Chien2bcc42c2013-01-30 15:39:04 +0000416
417 // Emit unwind opcodes
Logan Chien325823a2013-06-09 12:22:30 +0000418 EmitBytes(StringRef(reinterpret_cast<const char *>(Opcodes.data()),
Rafael Espindola64e1af82013-07-02 15:49:13 +0000419 Opcodes.size()));
Logan Chienc931fce2013-07-02 12:43:27 +0000420
421 // According to ARM EHABI section 9.2, if the __aeabi_unwind_cpp_pr1() or
422 // __aeabi_unwind_cpp_pr2() is used, then the handler data must be emitted
423 // after the unwind opcodes. The handler data consists of several 32-bit
424 // words, and should be terminated by zero.
425 //
426 // In case that the .handlerdata directive is not specified by the
427 // programmer, we should emit zero to terminate the handler data.
428 if (NoHandlerData && !Personality)
429 EmitIntValue(0, 4);
Logan Chien2bcc42c2013-01-30 15:39:04 +0000430}
431
Logan Chien4ea23b52013-05-10 16:17:24 +0000432void ARMELFStreamer::EmitHandlerData() {
433 FlushUnwindOpcodes(false);
434}
435
Logan Chien2bcc42c2013-01-30 15:39:04 +0000436void ARMELFStreamer::EmitPersonality(const MCSymbol *Per) {
437 Personality = Per;
Logan Chiend8bb4b72013-04-16 12:02:21 +0000438 UnwindOpAsm.setPersonality(Per);
Logan Chien2bcc42c2013-01-30 15:39:04 +0000439}
440
Logan Chiend8bb4b72013-04-16 12:02:21 +0000441void ARMELFStreamer::EmitSetFP(unsigned NewFPReg,
442 unsigned NewSPReg,
Logan Chien2bcc42c2013-01-30 15:39:04 +0000443 int64_t Offset) {
Logan Chien325823a2013-06-09 12:22:30 +0000444 assert((NewSPReg == ARM::SP || NewSPReg == FPReg) &&
Logan Chiend8bb4b72013-04-16 12:02:21 +0000445 "the operand of .setfp directive should be either $sp or $fp");
446
447 UsedFP = true;
Logan Chien325823a2013-06-09 12:22:30 +0000448 FPReg = NewFPReg;
449
450 if (NewSPReg == ARM::SP)
451 FPOffset = SPOffset + Offset;
452 else
453 FPOffset += Offset;
Logan Chien2bcc42c2013-01-30 15:39:04 +0000454}
455
456void ARMELFStreamer::EmitPad(int64_t Offset) {
Logan Chien325823a2013-06-09 12:22:30 +0000457 // Track the change of the $sp offset
458 SPOffset -= Offset;
459
460 // To squash multiple .pad directives, we should delay the unwind opcode
461 // until the .save, .vsave, .handlerdata, or .fnend directives.
462 PendingOffset -= Offset;
Logan Chien2bcc42c2013-01-30 15:39:04 +0000463}
464
465void ARMELFStreamer::EmitRegSave(const SmallVectorImpl<unsigned> &RegList,
466 bool IsVector) {
Logan Chien325823a2013-06-09 12:22:30 +0000467 // Collect the registers in the register list
468 unsigned Count = 0;
469 uint32_t Mask = 0;
Bill Wendlingbc07a892013-06-18 07:20:20 +0000470 const MCRegisterInfo *MRI = getContext().getRegisterInfo();
Logan Chiend8bb4b72013-04-16 12:02:21 +0000471 for (size_t i = 0; i < RegList.size(); ++i) {
Bill Wendlingbc07a892013-06-18 07:20:20 +0000472 unsigned Reg = MRI->getEncodingValue(RegList[i]);
Aaron Ballmanab1d27e2013-06-10 16:45:40 +0000473 assert(Reg < (IsVector ? 32U : 16U) && "Register out of range");
Logan Chien325823a2013-06-09 12:22:30 +0000474 unsigned Bit = (1u << Reg);
475 if ((Mask & Bit) == 0) {
476 Mask |= Bit;
477 ++Count;
478 }
Logan Chiend8bb4b72013-04-16 12:02:21 +0000479 }
Logan Chien325823a2013-06-09 12:22:30 +0000480
481 // Track the change the $sp offset: For the .save directive, the
482 // corresponding push instruction will decrease the $sp by (4 * Count).
483 // For the .vsave directive, the corresponding vpush instruction will
484 // decrease $sp by (8 * Count).
485 SPOffset -= Count * (IsVector ? 8 : 4);
486
487 // Emit the opcode
488 FlushPendingOffset();
489 if (IsVector)
490 UnwindOpAsm.EmitVFPRegSave(Mask);
491 else
492 UnwindOpAsm.EmitRegSave(Mask);
Logan Chien2bcc42c2013-01-30 15:39:04 +0000493}
494
Tim Northover5cc3dc82012-12-07 16:50:23 +0000495namespace llvm {
496 MCELFStreamer* createARMELFStreamer(MCContext &Context, MCAsmBackend &TAB,
497 raw_ostream &OS, MCCodeEmitter *Emitter,
498 bool RelaxAll, bool NoExecStack,
499 bool IsThumb) {
500 ARMELFStreamer *S = new ARMELFStreamer(Context, TAB, OS, Emitter, IsThumb);
501 if (RelaxAll)
502 S->getAssembler().setRelaxAll(true);
503 if (NoExecStack)
504 S->getAssembler().setNoExecStack(true);
505 return S;
506 }
507
508}
509
510