#include <cstring>
using namespace llvm;
-TargetAsmInfo::TargetAsmInfo(const TargetMachine &tm)
-: TM(tm) {
+TargetAsmInfo::TargetAsmInfo(const TargetMachine &tm) : TM(tm) {
BSSSection = "\t.bss";
BSSSection_ = 0;
ReadOnlySection = 0;
- SmallDataSection = 0;
- SmallBSSSection = 0;
- SmallRODataSection = 0;
TLSDataSection = 0;
TLSBSSSection = 0;
ZeroFillDirective = 0;
SeparatorChar = ';';
CommentColumn = 60;
CommentString = "#";
+ FirstOperandColumn = 0;
+ MaxOperandLength = 0;
GlobalPrefix = "";
PrivateGlobalPrefix = ".";
- LessPrivateGlobalPrefix = "";
+ LinkerPrivateGlobalPrefix = "";
JumpTableSpecialLabelPrefix = 0;
GlobalVarAddrPrefix = "";
GlobalVarAddrSuffix = "";
}
static bool isSuitableForBSS(const GlobalVariable *GV) {
- if (!GV->hasInitializer())
- return true;
-
// Leave constant zeros in readonly constant sections, so they can be shared
Constant *C = GV->getInitializer();
return (C->isNullValue() && !GV->isConstant() && !NoZerosInBSS);
return true;
// Another possibility: [1 x i8] zeroinitializer
- if (isa<ConstantAggregateZero>(C)) {
- if (const ArrayType *Ty = dyn_cast<ArrayType>(C->getType())) {
+ if (isa<ConstantAggregateZero>(C))
+ if (const ArrayType *Ty = dyn_cast<ArrayType>(C->getType()))
return (Ty->getElementType() == Type::Int8Ty &&
Ty->getNumElements() == 1);
- }
- }
return false;
}
-unsigned TargetAsmInfo::RelocBehaviour() const {
- // By default - all relocations in PIC mode would force symbol to be
- // placed in r/w section.
- return (TM.getRelocationModel() != Reloc::Static ?
- Reloc::LocalOrGlobal : Reloc::None);
+static unsigned SectionFlagsForGlobal(const GlobalValue *GV,
+ SectionKind::Kind Kind) {
+ unsigned Flags = SectionFlags::None;
+
+ // Decode flags from global itself.
+ switch (Kind) {
+ case SectionKind::Text:
+ Flags |= SectionFlags::Code;
+ break;
+ case SectionKind::ThreadData:
+ case SectionKind::ThreadBSS:
+ Flags |= SectionFlags::TLS;
+ // FALLS THROUGH
+ case SectionKind::Data:
+ case SectionKind::DataRel:
+ case SectionKind::DataRelLocal:
+ case SectionKind::DataRelRO:
+ case SectionKind::DataRelROLocal:
+ case SectionKind::BSS:
+ Flags |= SectionFlags::Writeable;
+ break;
+ case SectionKind::ROData:
+ case SectionKind::RODataMergeStr:
+ case SectionKind::RODataMergeConst:
+ // No additional flags here
+ break;
+ default:
+ llvm_unreachable("Unexpected section kind!");
+ }
+
+ if (GV->isWeakForLinker())
+ Flags |= SectionFlags::Linkonce;
+
+ return Flags;
}
-SectionKind::Kind
-TargetAsmInfo::SectionKindForGlobal(const GlobalValue *GV) const {
+static SectionKind::Kind SectionKindForGlobal(const GlobalValue *GV,
+ Reloc::Model ReloModel) {
// Early exit - functions should be always in text sections.
- if (isa<Function>(GV))
+ const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
+ if (GVar == 0)
return SectionKind::Text;
- const GlobalVariable* GVar = dyn_cast<GlobalVariable>(GV);
bool isThreadLocal = GVar->isThreadLocal();
- assert(GVar && "Invalid global value for section selection");
-
- if (isSuitableForBSS(GVar)) {
- // Variable can be easily put to BSS section.
- return (isThreadLocal ? SectionKind::ThreadBSS : SectionKind::BSS);
- } else if (GVar->isConstant() && !isThreadLocal) {
- // Now we know, that varible has initializer and it is constant. We need to
- // check its initializer to decide, which section to output it into. Also
- // note, there is no thread-local r/o section.
- Constant *C = GVar->getInitializer();
- if (C->ContainsRelocations(Reloc::LocalOrGlobal)) {
- // Decide, whether it is still possible to put symbol into r/o section.
- unsigned Reloc = RelocBehaviour();
-
- // We already did a query for 'all' relocs, thus - early exits.
- if (Reloc == Reloc::LocalOrGlobal)
- return SectionKind::Data;
- else if (Reloc == Reloc::None)
- return SectionKind::ROData;
- else {
- // Ok, target wants something funny. Honour it.
- return (C->ContainsRelocations(Reloc) ?
- SectionKind::Data : SectionKind::ROData);
- }
- } else {
- // Check, if initializer is a null-terminated string
+
+ // Variable can be easily put to BSS section.
+ if (isSuitableForBSS(GVar))
+ return isThreadLocal ? SectionKind::ThreadBSS : SectionKind::BSS;
+
+ // If this is thread-local, put it in the general "thread_data" section.
+ if (isThreadLocal)
+ return SectionKind::ThreadData;
+
+ Constant *C = GVar->getInitializer();
+
+ // If the global is marked constant, we can put it into a mergable section,
+ // a mergable string section, or general .data if it contains relocations.
+ if (GVar->isConstant()) {
+ // If the initializer for the global contains something that requires a
+ // relocation, then we may have to drop this into a wriable data section
+ // even though it is marked const.
+ switch (C->getRelocationInfo()) {
+ default: llvm_unreachable("unknown relocation info kind");
+ case Constant::NoRelocation:
+ // If initializer is a null-terminated string, put it in a "cstring"
+ // section if the target has it.
if (isConstantString(C))
return SectionKind::RODataMergeStr;
- else
- return SectionKind::RODataMergeConst;
+
+ // Otherwise, just drop it into a mergable constant section.
+ return SectionKind::RODataMergeConst;
+
+ case Constant::LocalRelocation:
+ // In static relocation model, the linker will resolve all addresses, so
+ // the relocation entries will actually be constants by the time the app
+ // starts up.
+ if (ReloModel == Reloc::Static)
+ return SectionKind::ROData;
+
+ // Otherwise, the dynamic linker needs to fix it up, put it in the
+ // writable data.rel.local section.
+ return SectionKind::DataRelROLocal;
+
+ case Constant::GlobalRelocations:
+ // In static relocation model, the linker will resolve all addresses, so
+ // the relocation entries will actually be constants by the time the app
+ // starts up.
+ if (ReloModel == Reloc::Static)
+ return SectionKind::ROData;
+
+ // Otherwise, the dynamic linker needs to fix it up, put it in the
+ // writable data.rel section.
+ return SectionKind::DataRelRO;
}
}
- // Variable either is not constant or thread-local - output to data section.
- return (isThreadLocal ? SectionKind::ThreadData : SectionKind::Data);
+ // Okay, this isn't a constant. If the initializer for the global is going
+ // to require a runtime relocation by the dynamic linker, put it into a more
+ // specific section to improve startup time of the app. This coalesces these
+ // globals together onto fewer pages, improving the locality of the dynamic
+ // linker.
+ if (ReloModel == Reloc::Static)
+ return SectionKind::Data;
+
+ switch (C->getRelocationInfo()) {
+ default: llvm_unreachable("unknown relocation info kind");
+ case Constant::NoRelocation: return SectionKind::Data;
+ case Constant::LocalRelocation: return SectionKind::DataRelLocal;
+ case Constant::GlobalRelocations: return SectionKind::DataRel;
+ }
}
-unsigned
-TargetAsmInfo::SectionFlagsForGlobal(const GlobalValue *GV,
- const char* Name) const {
- unsigned Flags = SectionFlags::None;
- // Decode flags from global itself.
- if (GV) {
- SectionKind::Kind Kind = SectionKindForGlobal(GV);
- switch (Kind) {
- case SectionKind::Text:
- Flags |= SectionFlags::Code;
- break;
- case SectionKind::ThreadData:
- case SectionKind::ThreadBSS:
- Flags |= SectionFlags::TLS;
- // FALLS THROUGH
- case SectionKind::Data:
- case SectionKind::DataRel:
- case SectionKind::DataRelLocal:
- case SectionKind::DataRelRO:
- case SectionKind::DataRelROLocal:
- case SectionKind::BSS:
- Flags |= SectionFlags::Writeable;
- break;
- case SectionKind::ROData:
- case SectionKind::RODataMergeStr:
- case SectionKind::RODataMergeConst:
- // No additional flags here
- break;
- case SectionKind::SmallData:
- case SectionKind::SmallBSS:
- Flags |= SectionFlags::Writeable;
- // FALLS THROUGH
- case SectionKind::SmallROData:
- Flags |= SectionFlags::Small;
- break;
- default:
- llvm_unreachable("Unexpected section kind!");
- }
+const Section *TargetAsmInfo::SectionForGlobal(const GlobalValue *GV) const {
+ SectionKind::Kind Kind = SectionKindForGlobal(GV, TM.getRelocationModel());
- if (GV->isWeakForLinker())
- Flags |= SectionFlags::Linkonce;
- }
-
- // Add flags from sections, if any.
- if (Name && *Name) {
+ // Select section name.
+ if (GV->hasSection()) {
+ // If the target has special section hacks for specifically named globals,
+ // return them now.
+ if (const Section *TS = getSpecialCasedSectionGlobals(GV, Kind))
+ return TS;
+
+ // Honour section already set, if any.
+ unsigned Flags = SectionFlagsForGlobal(GV, Kind);
+
+ // This is an explicitly named section.
Flags |= SectionFlags::Named;
-
- // Some lame default implementation based on some magic section names.
- if (strncmp(Name, ".gnu.linkonce.b.", 16) == 0 ||
- strncmp(Name, ".llvm.linkonce.b.", 17) == 0 ||
- strncmp(Name, ".gnu.linkonce.sb.", 17) == 0 ||
- strncmp(Name, ".llvm.linkonce.sb.", 18) == 0)
- Flags |= SectionFlags::BSS;
- else if (strcmp(Name, ".tdata") == 0 ||
- strncmp(Name, ".tdata.", 7) == 0 ||
- strncmp(Name, ".gnu.linkonce.td.", 17) == 0 ||
- strncmp(Name, ".llvm.linkonce.td.", 18) == 0)
- Flags |= SectionFlags::TLS;
- else if (strcmp(Name, ".tbss") == 0 ||
- strncmp(Name, ".tbss.", 6) == 0 ||
- strncmp(Name, ".gnu.linkonce.tb.", 17) == 0 ||
- strncmp(Name, ".llvm.linkonce.tb.", 18) == 0)
- Flags |= SectionFlags::BSS | SectionFlags::TLS;
+
+ // If the target has magic semantics for certain section names, make sure to
+ // pick up the flags. This allows the user to write things with attribute
+ // section and still get the appropriate section flags printed.
+ Flags |= getFlagsForNamedSection(GV->getSection().c_str());
+
+ return getNamedSection(GV->getSection().c_str(), Flags);
}
- return Flags;
-}
+ // If this global is linkonce/weak and the target handles this by emitting it
+ // into a 'uniqued' section name, create and return the section now.
+ if (GV->isWeakForLinker()) {
+ if (const char *Prefix = getSectionPrefixForUniqueGlobal(Kind)) {
+ unsigned Flags = SectionFlagsForGlobal(GV, Kind);
-const Section*
-TargetAsmInfo::SectionForGlobal(const GlobalValue *GV) const {
- const Section* S;
- // Select section name
- if (GV->hasSection()) {
- // Honour section already set, if any
- unsigned Flags = SectionFlagsForGlobal(GV,
- GV->getSection().c_str());
- S = getNamedSection(GV->getSection().c_str(), Flags);
- } else {
- // Use default section depending on the 'type' of global
- S = SelectSectionForGlobal(GV);
+ // FIXME: Use mangler interface (PR4584).
+ std::string Name = Prefix+GV->getNameStr();
+ return getNamedSection(Name.c_str(), Flags);
+ }
}
-
- return S;
+
+ // Use default section depending on the 'type' of global
+ return SelectSectionForGlobal(GV, Kind);
}
// Lame default implementation. Calculate the section name for global.
const Section*
-TargetAsmInfo::SelectSectionForGlobal(const GlobalValue *GV) const {
- SectionKind::Kind Kind = SectionKindForGlobal(GV);
-
- if (GV->isWeakForLinker()) {
- std::string Name = UniqueSectionForGlobal(GV, Kind);
- unsigned Flags = SectionFlagsForGlobal(GV, Name.c_str());
- return getNamedSection(Name.c_str(), Flags);
- } else {
- if (Kind == SectionKind::Text)
- return getTextSection();
- else if (isBSS(Kind) && getBSSSection_())
- return getBSSSection_();
- else if (getReadOnlySection() && SectionKind::isReadOnly(Kind))
- return getReadOnlySection();
- }
+TargetAsmInfo::SelectSectionForGlobal(const GlobalValue *GV,
+ SectionKind::Kind Kind) const {
+ if (Kind == SectionKind::Text)
+ return getTextSection();
+
+ if (isBSS(Kind))
+ if (const Section *S = getBSSSection_())
+ return S;
+
+ if (SectionKind::isReadOnly(Kind))
+ if (const Section *S = getReadOnlySection())
+ return S;
return getDataSection();
}
-// Lame default implementation. Calculate the section name for machine const.
-const Section*
-TargetAsmInfo::SelectSectionForMachineConst(const Type *Ty) const {
+/// getSectionForMergableConstant - Given a mergable constant with the
+/// specified size and relocation information, return a section that it
+/// should be placed in.
+const Section *
+TargetAsmInfo::getSectionForMergableConstant(uint64_t Size,
+ unsigned ReloInfo) const {
// FIXME: Support data.rel stuff someday
+ // Lame default implementation. Calculate the section name for machine const.
return getDataSection();
}
-std::string
-TargetAsmInfo::UniqueSectionForGlobal(const GlobalValue* GV,
- SectionKind::Kind Kind) const {
+
+
+
+const char *
+TargetAsmInfo::getSectionPrefixForUniqueGlobal(SectionKind::Kind Kind) const {
switch (Kind) {
- case SectionKind::Text:
- return ".gnu.linkonce.t." + GV->getName();
- case SectionKind::Data:
- return ".gnu.linkonce.d." + GV->getName();
- case SectionKind::DataRel:
- return ".gnu.linkonce.d.rel" + GV->getName();
- case SectionKind::DataRelLocal:
- return ".gnu.linkonce.d.rel.local" + GV->getName();
- case SectionKind::DataRelRO:
- return ".gnu.linkonce.d.rel.ro" + GV->getName();
- case SectionKind::DataRelROLocal:
- return ".gnu.linkonce.d.rel.ro.local" + GV->getName();
- case SectionKind::SmallData:
- return ".gnu.linkonce.s." + GV->getName();
- case SectionKind::BSS:
- return ".gnu.linkonce.b." + GV->getName();
- case SectionKind::SmallBSS:
- return ".gnu.linkonce.sb." + GV->getName();
- case SectionKind::ROData:
- case SectionKind::RODataMergeConst:
- case SectionKind::RODataMergeStr:
- return ".gnu.linkonce.r." + GV->getName();
- case SectionKind::SmallROData:
- return ".gnu.linkonce.s2." + GV->getName();
- case SectionKind::ThreadData:
- return ".gnu.linkonce.td." + GV->getName();
- case SectionKind::ThreadBSS:
- return ".gnu.linkonce.tb." + GV->getName();
- default:
- llvm_unreachable("Unknown section kind");
+ default: llvm_unreachable("Unknown section kind");
+ case SectionKind::Text: return ".gnu.linkonce.t.";
+ case SectionKind::Data: return ".gnu.linkonce.d.";
+ case SectionKind::DataRel: return ".gnu.linkonce.d.rel.";
+ case SectionKind::DataRelLocal: return ".gnu.linkonce.d.rel.local.";
+ case SectionKind::DataRelRO: return ".gnu.linkonce.d.rel.ro.";
+ case SectionKind::DataRelROLocal: return ".gnu.linkonce.d.rel.ro.local.";
+ case SectionKind::BSS: return ".gnu.linkonce.b.";
+ case SectionKind::ROData:
+ case SectionKind::RODataMergeConst:
+ case SectionKind::RODataMergeStr: return ".gnu.linkonce.r.";
+ case SectionKind::ThreadData: return ".gnu.linkonce.td.";
+ case SectionKind::ThreadBSS: return ".gnu.linkonce.tb.";
}
- return NULL;
}
-const Section*
-TargetAsmInfo::getNamedSection(const char *Name, unsigned Flags,
- bool Override) const {
- Section& S = Sections[Name];
+const Section *TargetAsmInfo::getNamedSection(const char *Name, unsigned Flags,
+ bool Override) const {
+ Section &S = Sections[Name];
// This is newly-created section, set it up properly.
if (S.Flags == SectionFlags::Invalid || Override) {
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