1 //===-- X86TargetAsmInfo.cpp - X86 asm properties ---------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains the declarations of the X86TargetAsmInfo properties.
12 //===----------------------------------------------------------------------===//
14 #include "X86TargetAsmInfo.h"
15 #include "X86TargetMachine.h"
16 #include "X86Subtarget.h"
17 #include "llvm/DerivedTypes.h"
18 #include "llvm/InlineAsm.h"
19 #include "llvm/Instructions.h"
20 #include "llvm/Intrinsics.h"
21 #include "llvm/Module.h"
22 #include "llvm/ADT/StringExtras.h"
23 #include "llvm/Support/Dwarf.h"
26 using namespace llvm::dwarf;
28 static const char *const x86_asm_table[] = {
40 X86TargetAsmInfo::X86TargetAsmInfo(const X86TargetMachine &TM) {
41 const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
44 // FIXME - Should be simplified.
46 AsmTransCBE = x86_asm_table;
48 switch (Subtarget->TargetType) {
49 case X86Subtarget::isDarwin:
50 AlignmentIsInBytes = false;
51 TextAlignFillValue = 0x90;
53 if (!Subtarget->is64Bit())
54 Data64bitsDirective = 0; // we can't emit a 64-bit unit
55 ZeroDirective = "\t.space\t"; // ".space N" emits N zeros.
56 PrivateGlobalPrefix = "L"; // Marker for constant pool idxs
57 BSSSection = 0; // no BSS section.
58 ZeroFillDirective = "\t.zerofill\t"; // Uses .zerofill
59 ConstantPoolSection = "\t.const\n";
60 JumpTableDataSection = "\t.const\n";
61 CStringSection = "\t.cstring";
62 FourByteConstantSection = "\t.literal4\n";
63 EightByteConstantSection = "\t.literal8\n";
64 if (Subtarget->is64Bit())
65 SixteenByteConstantSection = "\t.literal16\n";
66 ReadOnlySection = "\t.const\n";
67 LCOMMDirective = "\t.lcomm\t";
68 SwitchToSectionDirective = "\t.section ";
69 StringConstantPrefix = "\1LC";
70 COMMDirectiveTakesAlignment = false;
71 HasDotTypeDotSizeDirective = false;
72 if (TM.getRelocationModel() == Reloc::Static) {
73 StaticCtorsSection = ".constructor";
74 StaticDtorsSection = ".destructor";
76 StaticCtorsSection = ".mod_init_func";
77 StaticDtorsSection = ".mod_term_func";
79 if (Subtarget->is64Bit()) {
80 PersonalityPrefix = "";
81 PersonalitySuffix = "+4@GOTPCREL";
83 PersonalityPrefix = "L";
84 PersonalitySuffix = "$non_lazy_ptr";
86 NeedsIndirectEncoding = true;
87 InlineAsmStart = "## InlineAsm Start";
88 InlineAsmEnd = "## InlineAsm End";
90 SetDirective = "\t.set";
92 UsedDirective = "\t.no_dead_strip\t";
93 WeakDefDirective = "\t.weak_definition ";
94 WeakRefDirective = "\t.weak_reference ";
95 HiddenDirective = "\t.private_extern ";
96 ProtectedDirective = "\t.globl\t";
98 // In non-PIC modes, emit a special label before jump tables so that the
99 // linker can perform more accurate dead code stripping.
100 if (TM.getRelocationModel() != Reloc::PIC_) {
101 // Emit a local label that is preserved until the linker runs.
102 JumpTableSpecialLabelPrefix = "l";
105 SupportsDebugInformation = true;
107 DwarfAbbrevSection = ".section __DWARF,__debug_abbrev,regular,debug";
108 DwarfInfoSection = ".section __DWARF,__debug_info,regular,debug";
109 DwarfLineSection = ".section __DWARF,__debug_line,regular,debug";
110 DwarfFrameSection = ".section __DWARF,__debug_frame,regular,debug";
111 DwarfPubNamesSection = ".section __DWARF,__debug_pubnames,regular,debug";
112 DwarfPubTypesSection = ".section __DWARF,__debug_pubtypes,regular,debug";
113 DwarfStrSection = ".section __DWARF,__debug_str,regular,debug";
114 DwarfLocSection = ".section __DWARF,__debug_loc,regular,debug";
115 DwarfARangesSection = ".section __DWARF,__debug_aranges,regular,debug";
116 DwarfRangesSection = ".section __DWARF,__debug_ranges,regular,debug";
117 DwarfMacInfoSection = ".section __DWARF,__debug_macinfo,regular,debug";
119 // Exceptions handling
120 SupportsExceptionHandling = true;
121 GlobalEHDirective = "\t.globl\t";
122 SupportsWeakOmittedEHFrame = false;
123 AbsoluteEHSectionOffsets = false;
124 DwarfEHFrameSection =
125 ".section __TEXT,__eh_frame,coalesced,no_toc+strip_static_syms+live_support";
126 DwarfExceptionSection = ".section __DATA,__gcc_except_tab";
129 case X86Subtarget::isELF:
130 ReadOnlySection = "\t.section\t.rodata";
131 FourByteConstantSection = "\t.section\t.rodata.cst4,\"aM\",@progbits,4";
132 EightByteConstantSection = "\t.section\t.rodata.cst8,\"aM\",@progbits,8";
133 SixteenByteConstantSection = "\t.section\t.rodata.cst16,\"aM\",@progbits,16";
134 CStringSection = "\t.section\t.rodata.str1.1,\"aMS\",@progbits,1";
135 PrivateGlobalPrefix = ".L";
136 WeakRefDirective = "\t.weak\t";
137 SetDirective = "\t.set\t";
140 // Set up DWARF directives
141 HasLEB128 = true; // Target asm supports leb128 directives (little-endian)
144 AbsoluteDebugSectionOffsets = true;
145 SupportsDebugInformation = true;
146 DwarfAbbrevSection = "\t.section\t.debug_abbrev,\"\",@progbits";
147 DwarfInfoSection = "\t.section\t.debug_info,\"\",@progbits";
148 DwarfLineSection = "\t.section\t.debug_line,\"\",@progbits";
149 DwarfFrameSection = "\t.section\t.debug_frame,\"\",@progbits";
150 DwarfPubNamesSection ="\t.section\t.debug_pubnames,\"\",@progbits";
151 DwarfPubTypesSection ="\t.section\t.debug_pubtypes,\"\",@progbits";
152 DwarfStrSection = "\t.section\t.debug_str,\"\",@progbits";
153 DwarfLocSection = "\t.section\t.debug_loc,\"\",@progbits";
154 DwarfARangesSection = "\t.section\t.debug_aranges,\"\",@progbits";
155 DwarfRangesSection = "\t.section\t.debug_ranges,\"\",@progbits";
156 DwarfMacInfoSection = "\t.section\t.debug_macinfo,\"\",@progbits";
158 // Exceptions handling
159 if (!Subtarget->is64Bit())
160 SupportsExceptionHandling = true;
161 AbsoluteEHSectionOffsets = false;
162 DwarfEHFrameSection = "\t.section\t.eh_frame,\"aw\",@progbits";
163 DwarfExceptionSection = "\t.section\t.gcc_except_table,\"a\",@progbits";
166 case X86Subtarget::isCygwin:
167 case X86Subtarget::isMingw:
169 LCOMMDirective = "\t.lcomm\t";
170 COMMDirectiveTakesAlignment = false;
171 HasDotTypeDotSizeDirective = false;
172 StaticCtorsSection = "\t.section .ctors,\"aw\"";
173 StaticDtorsSection = "\t.section .dtors,\"aw\"";
174 HiddenDirective = NULL;
175 PrivateGlobalPrefix = "L"; // Prefix for private global symbols
176 WeakRefDirective = "\t.weak\t";
177 SetDirective = "\t.set\t";
179 // Set up DWARF directives
180 HasLEB128 = true; // Target asm supports leb128 directives (little-endian)
181 AbsoluteDebugSectionOffsets = true;
182 AbsoluteEHSectionOffsets = false;
183 SupportsDebugInformation = true;
184 DwarfSectionOffsetDirective = "\t.secrel32\t";
185 DwarfAbbrevSection = "\t.section\t.debug_abbrev,\"dr\"";
186 DwarfInfoSection = "\t.section\t.debug_info,\"dr\"";
187 DwarfLineSection = "\t.section\t.debug_line,\"dr\"";
188 DwarfFrameSection = "\t.section\t.debug_frame,\"dr\"";
189 DwarfPubNamesSection ="\t.section\t.debug_pubnames,\"dr\"";
190 DwarfPubTypesSection ="\t.section\t.debug_pubtypes,\"dr\"";
191 DwarfStrSection = "\t.section\t.debug_str,\"dr\"";
192 DwarfLocSection = "\t.section\t.debug_loc,\"dr\"";
193 DwarfARangesSection = "\t.section\t.debug_aranges,\"dr\"";
194 DwarfRangesSection = "\t.section\t.debug_ranges,\"dr\"";
195 DwarfMacInfoSection = "\t.section\t.debug_macinfo,\"dr\"";
198 case X86Subtarget::isWindows:
200 HasDotTypeDotSizeDirective = false;
206 if (Subtarget->isFlavorIntel()) {
210 PrivateGlobalPrefix = "$";
211 AlignDirective = "\talign\t";
212 ZeroDirective = "\tdb\t";
213 ZeroDirectiveSuffix = " dup(0)";
214 AsciiDirective = "\tdb\t";
216 Data8bitsDirective = "\tdb\t";
217 Data16bitsDirective = "\tdw\t";
218 Data32bitsDirective = "\tdd\t";
219 Data64bitsDirective = "\tdq\t";
220 HasDotTypeDotSizeDirective = false;
222 TextSection = "_text";
223 DataSection = "_data";
224 JumpTableDataSection = NULL;
225 SwitchToSectionDirective = "";
226 TextSectionStartSuffix = "\tsegment 'CODE'";
227 DataSectionStartSuffix = "\tsegment 'DATA'";
228 SectionEndDirectiveSuffix = "\tends\n";
231 // On Linux we must declare when we can use a non-executable stack.
232 if (Subtarget->isLinux())
233 NonexecutableStackDirective = "\t.section\t.note.GNU-stack,\"\",@progbits";
235 AssemblerDialect = Subtarget->getAsmFlavor();
238 bool X86TargetAsmInfo::LowerToBSwap(CallInst *CI) const {
239 // FIXME: this should verify that we are targetting a 486 or better. If not,
240 // we will turn this bswap into something that will be lowered to logical ops
241 // instead of emitting the bswap asm. For now, we don't support 486 or lower
242 // so don't worry about this.
244 // Verify this is a simple bswap.
245 if (CI->getNumOperands() != 2 ||
246 CI->getType() != CI->getOperand(1)->getType() ||
247 !CI->getType()->isInteger())
250 const IntegerType *Ty = dyn_cast<IntegerType>(CI->getType());
251 if (!Ty || Ty->getBitWidth() % 16 != 0)
254 // Okay, we can do this xform, do so now.
255 const Type *Tys[] = { Ty };
256 Module *M = CI->getParent()->getParent()->getParent();
257 Constant *Int = Intrinsic::getDeclaration(M, Intrinsic::bswap, Tys, 1);
259 Value *Op = CI->getOperand(1);
260 Op = CallInst::Create(Int, Op, CI->getName(), CI);
262 CI->replaceAllUsesWith(Op);
263 CI->eraseFromParent();
268 bool X86TargetAsmInfo::ExpandInlineAsm(CallInst *CI) const {
269 InlineAsm *IA = cast<InlineAsm>(CI->getCalledValue());
270 std::vector<InlineAsm::ConstraintInfo> Constraints = IA->ParseConstraints();
272 std::string AsmStr = IA->getAsmString();
274 // TODO: should remove alternatives from the asmstring: "foo {a|b}" -> "foo a"
275 std::vector<std::string> AsmPieces;
276 SplitString(AsmStr, AsmPieces, "\n"); // ; as separator?
278 switch (AsmPieces.size()) {
279 default: return false;
281 AsmStr = AsmPieces[0];
283 SplitString(AsmStr, AsmPieces, " \t"); // Split with whitespace.
286 if (AsmPieces.size() == 2 &&
287 AsmPieces[0] == "bswap" && AsmPieces[1] == "$0") {
288 // No need to check constraints, nothing other than the equivalent of
289 // "=r,0" would be valid here.
290 return LowerToBSwap(CI);
294 if (CI->getType() == Type::Int64Ty && Constraints.size() >= 2 &&
295 Constraints[0].Codes.size() == 1 && Constraints[0].Codes[0] == "A" &&
296 Constraints[1].Codes.size() == 1 && Constraints[1].Codes[0] == "0") {
297 // bswap %eax / bswap %edx / xchgl %eax, %edx -> llvm.bswap.i64
298 std::vector<std::string> Words;
299 SplitString(AsmPieces[0], Words, " \t");
300 if (Words.size() == 2 && Words[0] == "bswap" && Words[1] == "%eax") {
302 SplitString(AsmPieces[1], Words, " \t");
303 if (Words.size() == 2 && Words[0] == "bswap" && Words[1] == "%edx") {
305 SplitString(AsmPieces[2], Words, " \t,");
306 if (Words.size() == 3 && Words[0] == "xchgl" && Words[1] == "%eax" &&
307 Words[2] == "%edx") {
308 return LowerToBSwap(CI);
318 /// PreferredEHDataFormat - This hook allows the target to select data
319 /// format used for encoding pointers in exception handling data. Reason is
320 /// 0 for data, 1 for code labels, 2 for function pointers. Global is true
321 /// if the symbol can be relocated.
322 unsigned X86TargetAsmInfo::PreferredEHDataFormat(DwarfEncoding::Target Reason,
324 const X86Subtarget *Subtarget = &X86TM->getSubtarget<X86Subtarget>();
326 switch (Subtarget->TargetType) {
327 case X86Subtarget::isDarwin:
328 if (Reason == DwarfEncoding::Functions && Global)
329 return (DW_EH_PE_pcrel | DW_EH_PE_indirect | DW_EH_PE_sdata4);
330 else if (Reason == DwarfEncoding::CodeLabels || !Global)
331 return DW_EH_PE_pcrel;
333 return DW_EH_PE_absptr;
335 case X86Subtarget::isELF:
336 case X86Subtarget::isCygwin:
337 case X86Subtarget::isMingw: {
338 CodeModel::Model CM = X86TM->getCodeModel();
340 if (X86TM->getRelocationModel() == Reloc::PIC_) {
343 if (!Subtarget->is64Bit())
344 // 32 bit targets always encode pointers as 4 bytes
345 Format = DW_EH_PE_sdata4;
347 // 64 bit targets encode pointers in 4 bytes iff:
348 // - code model is small OR
349 // - code model is medium and we're emitting externally visible symbols
350 // or any code symbols
351 if (CM == CodeModel::Small ||
352 (CM == CodeModel::Medium && (Global ||
353 Reason != DwarfEncoding::Data)))
354 Format = DW_EH_PE_sdata4;
356 Format = DW_EH_PE_sdata8;
360 Format |= DW_EH_PE_indirect;
362 return (Format | DW_EH_PE_pcrel);
364 if (Subtarget->is64Bit() &&
365 (CM == CodeModel::Small ||
366 (CM == CodeModel::Medium && Reason != DwarfEncoding::Data)))
367 return DW_EH_PE_udata4;
369 return DW_EH_PE_absptr;
374 return TargetAsmInfo::PreferredEHDataFormat(Reason, Global);
378 std::string X86TargetAsmInfo::UniqueSectionForGlobal(const GlobalValue* GV,
379 SectionKind::Kind kind) const {
380 const X86Subtarget *Subtarget = &X86TM->getSubtarget<X86Subtarget>();
382 switch (Subtarget->TargetType) {
383 case X86Subtarget::isDarwin:
384 if (kind == SectionKind::Text)
385 return "__TEXT,__textcoal_nt,coalesced,pure_instructions";
387 return "__DATA,__datacoal_nt,coalesced";
388 case X86Subtarget::isCygwin:
389 case X86Subtarget::isMingw:
391 case SectionKind::Text:
392 return ".text$linkonce" + GV->getName();
393 case SectionKind::Data:
394 case SectionKind::BSS:
395 case SectionKind::ThreadData:
396 case SectionKind::ThreadBSS:
397 return ".data$linkonce" + GV->getName();
398 case SectionKind::ROData:
399 case SectionKind::RODataMergeConst:
400 case SectionKind::RODataMergeStr:
401 return ".rdata$linkonce" + GV->getName();
403 assert(0 && "Unknown section kind");
405 case X86Subtarget::isELF:
406 return TargetAsmInfo::UniqueSectionForGlobal(GV, kind);
413 std::string X86TargetAsmInfo::SectionForGlobal(const GlobalValue *GV) const {
414 SectionKind::Kind kind = SectionKindForGlobal(GV);
415 unsigned flags = SectionFlagsForGlobal(GV, GV->getSection().c_str());
418 // FIXME: Should we use some hashing based on section name and just check
420 // FIXME: It seems, that Darwin uses much more sections.
422 // Select section name
423 if (GV->hasSection()) {
424 // Honour section already set, if any
425 Name = GV->getSection();
427 // Use default section depending on the 'type' of global
428 if (const Function *F = dyn_cast<Function>(GV)) {
429 switch (F->getLinkage()) {
430 default: assert(0 && "Unknown linkage type!");
431 case Function::InternalLinkage:
432 case Function::DLLExportLinkage:
433 case Function::ExternalLinkage:
436 case Function::WeakLinkage:
437 case Function::LinkOnceLinkage:
438 Name = UniqueSectionForGlobal(F, kind);
441 } else if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV)) {
442 if (GVar->hasCommonLinkage() ||
443 GVar->hasLinkOnceLinkage() ||
444 GVar->hasWeakLinkage())
445 Name = UniqueSectionForGlobal(GVar, kind);
448 case SectionKind::Data:
451 case SectionKind::BSS:
452 Name = (BSSSection ? BSSSection : DataSection);
454 case SectionKind::ROData:
455 case SectionKind::RODataMergeStr:
456 case SectionKind::RODataMergeConst:
460 case SectionKind::ThreadData:
461 Name = (TLSDataSection ? TLSDataSection : DataSection);
463 case SectionKind::ThreadBSS:
464 Name = (TLSBSSSection ? TLSBSSSection : DataSection);
466 assert(0 && "Unsuported section kind for global");
470 assert(0 && "Unsupported global");
473 Name += PrintSectionFlags(flags);
477 std::string X86TargetAsmInfo::PrintSectionFlags(unsigned flags) const {
478 const X86Subtarget *Subtarget = &X86TM->getSubtarget<X86Subtarget>();
480 std::string Flags = "";
482 // Add all special flags, etc
483 switch (Subtarget->TargetType) {
484 case X86Subtarget::isELF:
487 if (!(flags & SectionFlags::Debug))
489 if (flags & SectionFlags::Code)
491 if (flags & SectionFlags::Writeable)
493 if (flags & SectionFlags::Mergeable)
495 if (flags & SectionFlags::Strings)
497 if (flags & SectionFlags::TLS)
502 // FIXME: There can be exceptions here
503 if (flags & SectionFlags::BSS)
506 Flags += ",@progbits";
508 // FIXME: entity size for mergeable sections
510 case X86Subtarget::isCygwin:
511 case X86Subtarget::isMingw:
514 if (flags & SectionFlags::Code)
516 if (flags & SectionFlags::Writeable)
522 case X86Subtarget::isDarwin:
523 // Darwin does not use any special flags