//===-- X86TargetAsmInfo.cpp - X86 asm properties ---------------*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file contains the declarations of the X86TargetAsmInfo properties. // //===----------------------------------------------------------------------===// #include "X86TargetAsmInfo.h" #include "X86TargetMachine.h" #include "X86Subtarget.h" #include "llvm/DerivedTypes.h" #include "llvm/InlineAsm.h" #include "llvm/Instructions.h" #include "llvm/Intrinsics.h" #include "llvm/Module.h" #include "llvm/ADT/StringExtras.h" #include "llvm/Support/Dwarf.h" using namespace llvm; using namespace llvm::dwarf; static const char *const x86_asm_table[] = { "{si}", "S", "{di}", "D", "{ax}", "a", "{cx}", "c", "{memory}", "memory", "{flags}", "", "{dirflag}", "", "{fpsr}", "", "{cc}", "cc", 0,0}; X86TargetAsmInfo::X86TargetAsmInfo(const X86TargetMachine &TM) { const X86Subtarget *Subtarget = &TM.getSubtarget(); X86TM = &TM; AsmTransCBE = x86_asm_table; AssemblerDialect = Subtarget->getAsmFlavor(); } bool X86TargetAsmInfo::LowerToBSwap(CallInst *CI) const { // FIXME: this should verify that we are targetting a 486 or better. If not, // we will turn this bswap into something that will be lowered to logical ops // instead of emitting the bswap asm. For now, we don't support 486 or lower // so don't worry about this. // Verify this is a simple bswap. if (CI->getNumOperands() != 2 || CI->getType() != CI->getOperand(1)->getType() || !CI->getType()->isInteger()) return false; const IntegerType *Ty = dyn_cast(CI->getType()); if (!Ty || Ty->getBitWidth() % 16 != 0) return false; // Okay, we can do this xform, do so now. const Type *Tys[] = { Ty }; Module *M = CI->getParent()->getParent()->getParent(); Constant *Int = Intrinsic::getDeclaration(M, Intrinsic::bswap, Tys, 1); Value *Op = CI->getOperand(1); Op = CallInst::Create(Int, Op, CI->getName(), CI); CI->replaceAllUsesWith(Op); CI->eraseFromParent(); return true; } bool X86TargetAsmInfo::ExpandInlineAsm(CallInst *CI) const { InlineAsm *IA = cast(CI->getCalledValue()); std::vector Constraints = IA->ParseConstraints(); std::string AsmStr = IA->getAsmString(); // TODO: should remove alternatives from the asmstring: "foo {a|b}" -> "foo a" std::vector AsmPieces; SplitString(AsmStr, AsmPieces, "\n"); // ; as separator? switch (AsmPieces.size()) { default: return false; case 1: AsmStr = AsmPieces[0]; AsmPieces.clear(); SplitString(AsmStr, AsmPieces, " \t"); // Split with whitespace. // bswap $0 if (AsmPieces.size() == 2 && AsmPieces[0] == "bswap" && AsmPieces[1] == "$0") { // No need to check constraints, nothing other than the equivalent of // "=r,0" would be valid here. return LowerToBSwap(CI); } break; case 3: if (CI->getType() == Type::Int64Ty && Constraints.size() >= 2 && Constraints[0].Codes.size() == 1 && Constraints[0].Codes[0] == "A" && Constraints[1].Codes.size() == 1 && Constraints[1].Codes[0] == "0") { // bswap %eax / bswap %edx / xchgl %eax, %edx -> llvm.bswap.i64 std::vector Words; SplitString(AsmPieces[0], Words, " \t"); if (Words.size() == 2 && Words[0] == "bswap" && Words[1] == "%eax") { Words.clear(); SplitString(AsmPieces[1], Words, " \t"); if (Words.size() == 2 && Words[0] == "bswap" && Words[1] == "%edx") { Words.clear(); SplitString(AsmPieces[2], Words, " \t,"); if (Words.size() == 3 && Words[0] == "xchgl" && Words[1] == "%eax" && Words[2] == "%edx") { return LowerToBSwap(CI); } } } } break; } return false; } X86DarwinTargetAsmInfo::X86DarwinTargetAsmInfo(const X86TargetMachine &TM): X86TargetAsmInfo(TM) { bool is64Bit = X86TM->getSubtarget().is64Bit(); AlignmentIsInBytes = false; TextAlignFillValue = 0x90; GlobalPrefix = "_"; if (!is64Bit) Data64bitsDirective = 0; // we can't emit a 64-bit unit ZeroDirective = "\t.space\t"; // ".space N" emits N zeros. PrivateGlobalPrefix = "L"; // Marker for constant pool idxs BSSSection = 0; // no BSS section. ZeroFillDirective = "\t.zerofill\t"; // Uses .zerofill ConstantPoolSection = "\t.const\n"; JumpTableDataSection = "\t.const\n"; CStringSection = "\t.cstring"; CStringSection_ = getUnnamedSection("\t.cstring", SectionFlags::Mergeable | SectionFlags::Strings); FourByteConstantSection = "\t.literal4\n"; FourByteConstantSection_ = getUnnamedSection("\t.literal4\n", SectionFlags::Mergeable); EightByteConstantSection_ = getUnnamedSection("\t.literal8\n", SectionFlags::Mergeable); // FIXME: Why don't always use this section? if (is64Bit) { SixteenByteConstantSection = "\t.literal16\n"; SixteenByteConstantSection_ = getUnnamedSection("\t.literal16\n", SectionFlags::Mergeable); } ReadOnlySection = "\t.const\n"; ReadOnlySection_ = getUnnamedSection("\t.const\n", SectionFlags::None); // FIXME: These should be named sections, really. TextCoalSection = getUnnamedSection(".section __TEXT,__textcoal_nt,coalesced,pure_instructions", SectionFlags::Code); ConstDataCoalSection = getUnnamedSection(".section __DATA,__const_coal,coalesced", SectionFlags::None); ConstDataSection = getUnnamedSection(".const_data", SectionFlags::None); DataCoalSection = getUnnamedSection(".section __DATA,__datacoal_nt,coalesced", SectionFlags::Writeable); LCOMMDirective = "\t.lcomm\t"; SwitchToSectionDirective = "\t.section "; StringConstantPrefix = "\1LC"; COMMDirectiveTakesAlignment = false; HasDotTypeDotSizeDirective = false; if (TM.getRelocationModel() == Reloc::Static) { StaticCtorsSection = ".constructor"; StaticDtorsSection = ".destructor"; } else { StaticCtorsSection = ".mod_init_func"; StaticDtorsSection = ".mod_term_func"; } if (is64Bit) { PersonalityPrefix = ""; PersonalitySuffix = "+4@GOTPCREL"; } else { PersonalityPrefix = "L"; PersonalitySuffix = "$non_lazy_ptr"; } NeedsIndirectEncoding = true; InlineAsmStart = "## InlineAsm Start"; InlineAsmEnd = "## InlineAsm End"; CommentString = "##"; SetDirective = "\t.set"; PCSymbol = "."; UsedDirective = "\t.no_dead_strip\t"; WeakDefDirective = "\t.weak_definition "; WeakRefDirective = "\t.weak_reference "; HiddenDirective = "\t.private_extern "; ProtectedDirective = "\t.globl\t"; // In non-PIC modes, emit a special label before jump tables so that the // linker can perform more accurate dead code stripping. if (TM.getRelocationModel() != Reloc::PIC_) { // Emit a local label that is preserved until the linker runs. JumpTableSpecialLabelPrefix = "l"; } SupportsDebugInformation = true; NeedsSet = true; DwarfAbbrevSection = ".section __DWARF,__debug_abbrev,regular,debug"; DwarfInfoSection = ".section __DWARF,__debug_info,regular,debug"; DwarfLineSection = ".section __DWARF,__debug_line,regular,debug"; DwarfFrameSection = ".section __DWARF,__debug_frame,regular,debug"; DwarfPubNamesSection = ".section __DWARF,__debug_pubnames,regular,debug"; DwarfPubTypesSection = ".section __DWARF,__debug_pubtypes,regular,debug"; DwarfStrSection = ".section __DWARF,__debug_str,regular,debug"; DwarfLocSection = ".section __DWARF,__debug_loc,regular,debug"; DwarfARangesSection = ".section __DWARF,__debug_aranges,regular,debug"; DwarfRangesSection = ".section __DWARF,__debug_ranges,regular,debug"; DwarfMacInfoSection = ".section __DWARF,__debug_macinfo,regular,debug"; // Exceptions handling SupportsExceptionHandling = true; GlobalEHDirective = "\t.globl\t"; SupportsWeakOmittedEHFrame = false; AbsoluteEHSectionOffsets = false; DwarfEHFrameSection = ".section __TEXT,__eh_frame,coalesced,no_toc+strip_static_syms+live_support"; DwarfExceptionSection = ".section __DATA,__gcc_except_tab"; } unsigned X86DarwinTargetAsmInfo::PreferredEHDataFormat(DwarfEncoding::Target Reason, bool Global) const { if (Reason == DwarfEncoding::Functions && Global) return (DW_EH_PE_pcrel | DW_EH_PE_indirect | DW_EH_PE_sdata4); else if (Reason == DwarfEncoding::CodeLabels || !Global) return DW_EH_PE_pcrel; else return DW_EH_PE_absptr; } const Section* X86DarwinTargetAsmInfo::SelectSectionForGlobal(const GlobalValue *GV) const { SectionKind::Kind Kind = SectionKindForGlobal(GV); bool isWeak = GV->isWeakForLinker(); switch (Kind) { case SectionKind::Text: if (isWeak) return TextCoalSection; else return getTextSection_(); case SectionKind::Data: case SectionKind::ThreadData: case SectionKind::BSS: case SectionKind::ThreadBSS: if (cast(GV)->isConstant()) return (isWeak ? ConstDataCoalSection : ConstDataSection); else return (isWeak ? DataCoalSection : getDataSection_()); case SectionKind::ROData: return (isWeak ? ConstDataCoalSection : getReadOnlySection_()); case SectionKind::RODataMergeStr: return (isWeak ? ConstDataCoalSection : MergeableStringSection(cast(GV))); case SectionKind::RODataMergeConst: return (isWeak ? ConstDataCoalSection: MergeableConstSection(cast(GV))); default: assert(0 && "Unsuported section kind for global"); } // FIXME: Do we have any extra special weird cases? } const Section* X86DarwinTargetAsmInfo::MergeableStringSection(const GlobalVariable *GV) const { const TargetData *TD = X86TM->getTargetData(); Constant *C = cast(GV)->getInitializer(); const Type *Type = cast(C)->getType()->getElementType(); unsigned Size = TD->getABITypeSize(Type); if (Size) { const TargetData *TD = X86TM->getTargetData(); unsigned Align = TD->getPreferredAlignment(GV); if (Align <= 32) return getCStringSection_(); } return getReadOnlySection_(); } const Section* X86DarwinTargetAsmInfo::MergeableConstSection(const GlobalVariable *GV) const { const TargetData *TD = X86TM->getTargetData(); Constant *C = cast(GV)->getInitializer(); unsigned Size = TD->getABITypeSize(C->getType()); if (Size == 4) return FourByteConstantSection_; else if (Size == 8) return EightByteConstantSection_; else if (Size == 16 && X86TM->getSubtarget().is64Bit()) return SixteenByteConstantSection_; return getReadOnlySection_(); } std::string X86DarwinTargetAsmInfo::UniqueSectionForGlobal(const GlobalValue* GV, SectionKind::Kind kind) const { assert(0 && "Darwin does not use unique sections"); return ""; } X86ELFTargetAsmInfo::X86ELFTargetAsmInfo(const X86TargetMachine &TM): X86TargetAsmInfo(TM) { bool is64Bit = X86TM->getSubtarget().is64Bit(); TextSection_ = getUnnamedSection("\t.text", SectionFlags::Code); DataSection_ = getUnnamedSection("\t.data", SectionFlags::Writeable); BSSSection_ = getUnnamedSection("\t.bss", SectionFlags::Writeable | SectionFlags::BSS); ReadOnlySection_ = getNamedSection("\t.rodata", SectionFlags::None); TLSDataSection_ = getNamedSection("\t.tdata", SectionFlags::Writeable | SectionFlags::TLS); TLSBSSSection_ = getNamedSection("\t.tbss", SectionFlags::Writeable | SectionFlags::TLS | SectionFlags::BSS); ReadOnlySection = ".rodata"; FourByteConstantSection = "\t.section\t.rodata.cst4,\"aM\",@progbits,4"; EightByteConstantSection = "\t.section\t.rodata.cst8,\"aM\",@progbits,8"; SixteenByteConstantSection = "\t.section\t.rodata.cst16,\"aM\",@progbits,16"; CStringSection = ".rodata.str"; PrivateGlobalPrefix = ".L"; WeakRefDirective = "\t.weak\t"; SetDirective = "\t.set\t"; PCSymbol = "."; // Set up DWARF directives HasLEB128 = true; // Target asm supports leb128 directives (little-endian) // Debug Information AbsoluteDebugSectionOffsets = true; SupportsDebugInformation = true; DwarfAbbrevSection = "\t.section\t.debug_abbrev,\"\",@progbits"; DwarfInfoSection = "\t.section\t.debug_info,\"\",@progbits"; DwarfLineSection = "\t.section\t.debug_line,\"\",@progbits"; DwarfFrameSection = "\t.section\t.debug_frame,\"\",@progbits"; DwarfPubNamesSection ="\t.section\t.debug_pubnames,\"\",@progbits"; DwarfPubTypesSection ="\t.section\t.debug_pubtypes,\"\",@progbits"; DwarfStrSection = "\t.section\t.debug_str,\"\",@progbits"; DwarfLocSection = "\t.section\t.debug_loc,\"\",@progbits"; DwarfARangesSection = "\t.section\t.debug_aranges,\"\",@progbits"; DwarfRangesSection = "\t.section\t.debug_ranges,\"\",@progbits"; DwarfMacInfoSection = "\t.section\t.debug_macinfo,\"\",@progbits"; // Exceptions handling if (!is64Bit) SupportsExceptionHandling = true; AbsoluteEHSectionOffsets = false; DwarfEHFrameSection = "\t.section\t.eh_frame,\"aw\",@progbits"; DwarfExceptionSection = "\t.section\t.gcc_except_table,\"a\",@progbits"; // On Linux we must declare when we can use a non-executable stack. if (X86TM->getSubtarget().isLinux()) NonexecutableStackDirective = "\t.section\t.note.GNU-stack,\"\",@progbits"; } unsigned X86ELFTargetAsmInfo::PreferredEHDataFormat(DwarfEncoding::Target Reason, bool Global) const { CodeModel::Model CM = X86TM->getCodeModel(); bool is64Bit = X86TM->getSubtarget().is64Bit(); if (X86TM->getRelocationModel() == Reloc::PIC_) { unsigned Format = 0; if (!is64Bit) // 32 bit targets always encode pointers as 4 bytes Format = DW_EH_PE_sdata4; else { // 64 bit targets encode pointers in 4 bytes iff: // - code model is small OR // - code model is medium and we're emitting externally visible symbols // or any code symbols if (CM == CodeModel::Small || (CM == CodeModel::Medium && (Global || Reason != DwarfEncoding::Data))) Format = DW_EH_PE_sdata4; else Format = DW_EH_PE_sdata8; } if (Global) Format |= DW_EH_PE_indirect; return (Format | DW_EH_PE_pcrel); } else { if (is64Bit && (CM == CodeModel::Small || (CM == CodeModel::Medium && Reason != DwarfEncoding::Data))) return DW_EH_PE_udata4; else return DW_EH_PE_absptr; } } const Section* X86ELFTargetAsmInfo::SelectSectionForGlobal(const GlobalValue *GV) const { SectionKind::Kind Kind = SectionKindForGlobal(GV); if (const Function *F = dyn_cast(GV)) { switch (F->getLinkage()) { default: assert(0 && "Unknown linkage type!"); case Function::InternalLinkage: case Function::DLLExportLinkage: case Function::ExternalLinkage: return getTextSection_(); case Function::WeakLinkage: case Function::LinkOnceLinkage: std::string Name = UniqueSectionForGlobal(GV, Kind); unsigned Flags = SectionFlagsForGlobal(GV, Name.c_str()); return getNamedSection(Name.c_str(), Flags); } } else if (const GlobalVariable *GVar = dyn_cast(GV)) { if (GVar->isWeakForLinker()) { std::string Name = UniqueSectionForGlobal(GVar, Kind); unsigned Flags = SectionFlagsForGlobal(GVar, Name.c_str()); return getNamedSection(Name.c_str(), Flags); } else { switch (Kind) { case SectionKind::Data: return getDataSection_(); case SectionKind::BSS: // ELF targets usually have BSS sections return getBSSSection_(); case SectionKind::ROData: return getReadOnlySection_(); case SectionKind::RODataMergeStr: return MergeableStringSection(GVar); case SectionKind::RODataMergeConst: return MergeableConstSection(GVar); case SectionKind::ThreadData: // ELF targets usually support TLS stuff return getTLSDataSection_(); case SectionKind::ThreadBSS: return getTLSBSSSection_(); default: assert(0 && "Unsuported section kind for global"); } } } else assert(0 && "Unsupported global"); } const Section* X86ELFTargetAsmInfo::MergeableConstSection(const GlobalVariable *GV) const { const TargetData *TD = X86TM->getTargetData(); Constant *C = cast(GV)->getInitializer(); const Type *Type = C->getType(); // FIXME: string here is temporary, until stuff will fully land in. // We cannot use {Four,Eight,Sixteen}ByteConstantSection here, since it's // currently directly used by asmprinter. unsigned Size = TD->getABITypeSize(Type); if (Size == 4 || Size == 8 || Size == 16) { std::string Name = ".rodata.cst" + utostr(Size); return getNamedSection(Name.c_str(), SectionFlags::setEntitySize(SectionFlags::Mergeable, Size)); } return getReadOnlySection_(); } const Section* X86ELFTargetAsmInfo::MergeableStringSection(const GlobalVariable *GV) const { const TargetData *TD = X86TM->getTargetData(); Constant *C = cast(GV)->getInitializer(); const ConstantArray *CVA = cast(C); const Type *Type = CVA->getType()->getElementType(); unsigned Size = TD->getABITypeSize(Type); if (Size <= 16) { // We also need alignment here const TargetData *TD = X86TM->getTargetData(); unsigned Align = TD->getPreferredAlignment(GV); if (Align < Size) Align = Size; std::string Name = getCStringSection() + utostr(Size) + '.' + utostr(Align); unsigned Flags = SectionFlags::setEntitySize(SectionFlags::Mergeable | SectionFlags::Strings, Size); return getNamedSection(Name.c_str(), Flags); } return getReadOnlySection_(); } std::string X86ELFTargetAsmInfo::PrintSectionFlags(unsigned flags) const { std::string Flags = ",\""; if (!(flags & SectionFlags::Debug)) Flags += 'a'; if (flags & SectionFlags::Code) Flags += 'x'; if (flags & SectionFlags::Writeable) Flags += 'w'; if (flags & SectionFlags::Mergeable) Flags += 'M'; if (flags & SectionFlags::Strings) Flags += 'S'; if (flags & SectionFlags::TLS) Flags += 'T'; Flags += "\""; // FIXME: There can be exceptions here if (flags & SectionFlags::BSS) Flags += ",@nobits"; else Flags += ",@progbits"; if (unsigned entitySize = SectionFlags::getEntitySize(flags)) Flags += "," + utostr(entitySize); return Flags; } X86COFFTargetAsmInfo::X86COFFTargetAsmInfo(const X86TargetMachine &TM): X86TargetAsmInfo(TM) { GlobalPrefix = "_"; LCOMMDirective = "\t.lcomm\t"; COMMDirectiveTakesAlignment = false; HasDotTypeDotSizeDirective = false; StaticCtorsSection = "\t.section .ctors,\"aw\""; StaticDtorsSection = "\t.section .dtors,\"aw\""; HiddenDirective = NULL; PrivateGlobalPrefix = "L"; // Prefix for private global symbols WeakRefDirective = "\t.weak\t"; SetDirective = "\t.set\t"; // Set up DWARF directives HasLEB128 = true; // Target asm supports leb128 directives (little-endian) AbsoluteDebugSectionOffsets = true; AbsoluteEHSectionOffsets = false; SupportsDebugInformation = true; DwarfSectionOffsetDirective = "\t.secrel32\t"; DwarfAbbrevSection = "\t.section\t.debug_abbrev,\"dr\""; DwarfInfoSection = "\t.section\t.debug_info,\"dr\""; DwarfLineSection = "\t.section\t.debug_line,\"dr\""; DwarfFrameSection = "\t.section\t.debug_frame,\"dr\""; DwarfPubNamesSection ="\t.section\t.debug_pubnames,\"dr\""; DwarfPubTypesSection ="\t.section\t.debug_pubtypes,\"dr\""; DwarfStrSection = "\t.section\t.debug_str,\"dr\""; DwarfLocSection = "\t.section\t.debug_loc,\"dr\""; DwarfARangesSection = "\t.section\t.debug_aranges,\"dr\""; DwarfRangesSection = "\t.section\t.debug_ranges,\"dr\""; DwarfMacInfoSection = "\t.section\t.debug_macinfo,\"dr\""; } unsigned X86COFFTargetAsmInfo::PreferredEHDataFormat(DwarfEncoding::Target Reason, bool Global) const { CodeModel::Model CM = X86TM->getCodeModel(); bool is64Bit = X86TM->getSubtarget().is64Bit(); if (X86TM->getRelocationModel() == Reloc::PIC_) { unsigned Format = 0; if (!is64Bit) // 32 bit targets always encode pointers as 4 bytes Format = DW_EH_PE_sdata4; else { // 64 bit targets encode pointers in 4 bytes iff: // - code model is small OR // - code model is medium and we're emitting externally visible symbols // or any code symbols if (CM == CodeModel::Small || (CM == CodeModel::Medium && (Global || Reason != DwarfEncoding::Data))) Format = DW_EH_PE_sdata4; else Format = DW_EH_PE_sdata8; } if (Global) Format |= DW_EH_PE_indirect; return (Format | DW_EH_PE_pcrel); } else { if (is64Bit && (CM == CodeModel::Small || (CM == CodeModel::Medium && Reason != DwarfEncoding::Data))) return DW_EH_PE_udata4; else return DW_EH_PE_absptr; } } std::string X86COFFTargetAsmInfo::UniqueSectionForGlobal(const GlobalValue* GV, SectionKind::Kind kind) const { switch (kind) { case SectionKind::Text: return ".text$linkonce" + GV->getName(); case SectionKind::Data: case SectionKind::BSS: case SectionKind::ThreadData: case SectionKind::ThreadBSS: return ".data$linkonce" + GV->getName(); case SectionKind::ROData: case SectionKind::RODataMergeConst: case SectionKind::RODataMergeStr: return ".rdata$linkonce" + GV->getName(); default: assert(0 && "Unknown section kind"); } } std::string X86COFFTargetAsmInfo::PrintSectionFlags(unsigned flags) const { std::string Flags = ",\""; if (flags & SectionFlags::Code) Flags += 'x'; if (flags & SectionFlags::Writeable) Flags += 'w'; Flags += "\""; return Flags; } X86WinTargetAsmInfo::X86WinTargetAsmInfo(const X86TargetMachine &TM): X86TargetAsmInfo(TM) { GlobalPrefix = "_"; CommentString = ";"; PrivateGlobalPrefix = "$"; AlignDirective = "\talign\t"; ZeroDirective = "\tdb\t"; ZeroDirectiveSuffix = " dup(0)"; AsciiDirective = "\tdb\t"; AscizDirective = 0; Data8bitsDirective = "\tdb\t"; Data16bitsDirective = "\tdw\t"; Data32bitsDirective = "\tdd\t"; Data64bitsDirective = "\tdq\t"; HasDotTypeDotSizeDirective = false; TextSection = "_text"; DataSection = "_data"; JumpTableDataSection = NULL; SwitchToSectionDirective = ""; TextSectionStartSuffix = "\tsegment 'CODE'"; DataSectionStartSuffix = "\tsegment 'DATA'"; SectionEndDirectiveSuffix = "\tends\n"; }