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diff --git a/contrib/llvm/lib/Target/Hexagon/HexagonTargetObjectFile.cpp b/contrib/llvm/lib/Target/Hexagon/HexagonTargetObjectFile.cpp
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+//===-- HexagonTargetObjectFile.cpp ---------------------------------------===//
+//
+// 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 HexagonTargetAsmInfo properties.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "hexagon-sdata"
+
+#include "HexagonTargetObjectFile.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/BinaryFormat/ELF.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/GlobalObject.h"
+#include "llvm/IR/GlobalValue.h"
+#include "llvm/IR/GlobalVariable.h"
+#include "llvm/IR/Type.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/SectionKind.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetMachine.h"
+
+using namespace llvm;
+
+static cl::opt<unsigned> SmallDataThreshold("hexagon-small-data-threshold",
+ cl::init(8), cl::Hidden,
+ cl::desc("The maximum size of an object in the sdata section"));
+
+static cl::opt<bool> NoSmallDataSorting("mno-sort-sda", cl::init(false),
+ cl::Hidden, cl::desc("Disable small data sections sorting"));
+
+static cl::opt<bool> StaticsInSData("hexagon-statics-in-small-data",
+ cl::init(false), cl::Hidden, cl::ZeroOrMore,
+ cl::desc("Allow static variables in .sdata"));
+
+static cl::opt<bool> TraceGVPlacement("trace-gv-placement",
+ cl::Hidden, cl::init(false),
+ cl::desc("Trace global value placement"));
+
+// TraceGVPlacement controls messages for all builds. For builds with assertions
+// (debug or release), messages are also controlled by the usual debug flags
+// (e.g. -debug and -debug-only=globallayout)
+#define TRACE_TO(s, X) s << X
+#ifdef NDEBUG
+#define TRACE(X) \
+ do { \
+ if (TraceGVPlacement) { \
+ TRACE_TO(errs(), X); \
+ } \
+ } while (false)
+#else
+#define TRACE(X) \
+ do { \
+ if (TraceGVPlacement) { \
+ TRACE_TO(errs(), X); \
+ } else { \
+ DEBUG(TRACE_TO(dbgs(), X)); \
+ } \
+ } while (false)
+#endif
+
+// Returns true if the section name is such that the symbol will be put
+// in a small data section.
+// For instance, global variables with section attributes such as ".sdata"
+// ".sdata.*", ".sbss", and ".sbss.*" will go into small data.
+static bool isSmallDataSection(StringRef Sec) {
+ // sectionName is either ".sdata" or ".sbss". Looking for an exact match
+ // obviates the need for checks for section names such as ".sdatafoo".
+ if (Sec.equals(".sdata") || Sec.equals(".sbss") || Sec.equals(".scommon"))
+ return true;
+ // If either ".sdata." or ".sbss." is a substring of the section name
+ // then put the symbol in small data.
+ return Sec.find(".sdata.") != StringRef::npos ||
+ Sec.find(".sbss.") != StringRef::npos ||
+ Sec.find(".scommon.") != StringRef::npos;
+}
+
+static const char *getSectionSuffixForSize(unsigned Size) {
+ switch (Size) {
+ default:
+ return "";
+ case 1:
+ return ".1";
+ case 2:
+ return ".2";
+ case 4:
+ return ".4";
+ case 8:
+ return ".8";
+ }
+}
+
+void HexagonTargetObjectFile::Initialize(MCContext &Ctx,
+ const TargetMachine &TM) {
+ TargetLoweringObjectFileELF::Initialize(Ctx, TM);
+ InitializeELF(TM.Options.UseInitArray);
+
+ SmallDataSection =
+ getContext().getELFSection(".sdata", ELF::SHT_PROGBITS,
+ ELF::SHF_WRITE | ELF::SHF_ALLOC |
+ ELF::SHF_HEX_GPREL);
+ SmallBSSSection =
+ getContext().getELFSection(".sbss", ELF::SHT_NOBITS,
+ ELF::SHF_WRITE | ELF::SHF_ALLOC |
+ ELF::SHF_HEX_GPREL);
+}
+
+MCSection *HexagonTargetObjectFile::SelectSectionForGlobal(
+ const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
+ TRACE("[SelectSectionForGlobal] GO(" << GO->getName() << ") ");
+ TRACE("input section(" << GO->getSection() << ") ");
+
+ TRACE((GO->hasPrivateLinkage() ? "private_linkage " : "")
+ << (GO->hasLocalLinkage() ? "local_linkage " : "")
+ << (GO->hasInternalLinkage() ? "internal " : "")
+ << (GO->hasExternalLinkage() ? "external " : "")
+ << (GO->hasCommonLinkage() ? "common_linkage " : "")
+ << (GO->hasCommonLinkage() ? "common " : "" )
+ << (Kind.isCommon() ? "kind_common " : "" )
+ << (Kind.isBSS() ? "kind_bss " : "" )
+ << (Kind.isBSSLocal() ? "kind_bss_local " : "" ));
+
+ if (isGlobalInSmallSection(GO, TM))
+ return selectSmallSectionForGlobal(GO, Kind, TM);
+
+ if (Kind.isCommon()) {
+ // This is purely for LTO+Linker Script because commons don't really have a
+ // section. However, the BitcodeSectionWriter pass will query for the
+ // sections of commons (and the linker expects us to know their section) so
+ // we'll return one here.
+ return BSSSection;
+ }
+
+ TRACE("default_ELF_section\n");
+ // Otherwise, we work the same as ELF.
+ return TargetLoweringObjectFileELF::SelectSectionForGlobal(GO, Kind, TM);
+}
+
+MCSection *HexagonTargetObjectFile::getExplicitSectionGlobal(
+ const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
+ TRACE("[getExplicitSectionGlobal] GO(" << GO->getName() << ") from("
+ << GO->getSection() << ") ");
+ TRACE((GO->hasPrivateLinkage() ? "private_linkage " : "")
+ << (GO->hasLocalLinkage() ? "local_linkage " : "")
+ << (GO->hasInternalLinkage() ? "internal " : "")
+ << (GO->hasExternalLinkage() ? "external " : "")
+ << (GO->hasCommonLinkage() ? "common_linkage " : "")
+ << (GO->hasCommonLinkage() ? "common " : "" )
+ << (Kind.isCommon() ? "kind_common " : "" )
+ << (Kind.isBSS() ? "kind_bss " : "" )
+ << (Kind.isBSSLocal() ? "kind_bss_local " : "" ));
+
+ if (GO->hasSection()) {
+ StringRef Section = GO->getSection();
+ if (Section.find(".access.text.group") != StringRef::npos)
+ return getContext().getELFSection(GO->getSection(), ELF::SHT_PROGBITS,
+ ELF::SHF_ALLOC | ELF::SHF_EXECINSTR);
+ if (Section.find(".access.data.group") != StringRef::npos)
+ return getContext().getELFSection(GO->getSection(), ELF::SHT_PROGBITS,
+ ELF::SHF_WRITE | ELF::SHF_ALLOC);
+ }
+
+ if (isGlobalInSmallSection(GO, TM))
+ return selectSmallSectionForGlobal(GO, Kind, TM);
+
+ // Otherwise, we work the same as ELF.
+ TRACE("default_ELF_section\n");
+ return TargetLoweringObjectFileELF::getExplicitSectionGlobal(GO, Kind, TM);
+}
+
+/// Return true if this global value should be placed into small data/bss
+/// section.
+bool HexagonTargetObjectFile::isGlobalInSmallSection(const GlobalObject *GO,
+ const TargetMachine &TM) const {
+ // Only global variables, not functions.
+ DEBUG(dbgs() << "Checking if value is in small-data, -G"
+ << SmallDataThreshold << ": \"" << GO->getName() << "\": ");
+ const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GO);
+ if (!GVar) {
+ DEBUG(dbgs() << "no, not a global variable\n");
+ return false;
+ }
+
+ // Globals with external linkage that have an original section set must be
+ // emitted to that section, regardless of whether we would put them into
+ // small data or not. This is how we can support mixing -G0/-G8 in LTO.
+ if (GVar->hasSection()) {
+ bool IsSmall = isSmallDataSection(GVar->getSection());
+ DEBUG(dbgs() << (IsSmall ? "yes" : "no") << ", has section: "
+ << GVar->getSection() << '\n');
+ return IsSmall;
+ }
+
+ if (GVar->isConstant()) {
+ DEBUG(dbgs() << "no, is a constant\n");
+ return false;
+ }
+
+ bool IsLocal = GVar->hasLocalLinkage();
+ if (!StaticsInSData && IsLocal) {
+ DEBUG(dbgs() << "no, is static\n");
+ return false;
+ }
+
+ Type *GType = GVar->getType();
+ if (PointerType *PT = dyn_cast<PointerType>(GType))
+ GType = PT->getElementType();
+
+ if (isa<ArrayType>(GType)) {
+ DEBUG(dbgs() << "no, is an array\n");
+ return false;
+ }
+
+ // If the type is a struct with no body provided, treat is conservatively.
+ // There cannot be actual definitions of object of such a type in this CU
+ // (only references), so assuming that they are not in sdata is safe. If
+ // these objects end up in the sdata, the references will still be valid.
+ if (StructType *ST = dyn_cast<StructType>(GType)) {
+ if (ST->isOpaque()) {
+ DEBUG(dbgs() << "no, has opaque type\n");
+ return false;
+ }
+ }
+
+ unsigned Size = GVar->getParent()->getDataLayout().getTypeAllocSize(GType);
+ if (Size == 0) {
+ DEBUG(dbgs() << "no, has size 0\n");
+ return false;
+ }
+ if (Size > SmallDataThreshold) {
+ DEBUG(dbgs() << "no, size exceeds sdata threshold: " << Size << '\n');
+ return false;
+ }
+
+ DEBUG(dbgs() << "yes\n");
+ return true;
+}
+
+bool HexagonTargetObjectFile::isSmallDataEnabled() const {
+ return SmallDataThreshold > 0;
+}
+
+unsigned HexagonTargetObjectFile::getSmallDataSize() const {
+ return SmallDataThreshold;
+}
+
+/// Descends any type down to "elementary" components,
+/// discovering the smallest addressable one.
+/// If zero is returned, declaration will not be modified.
+unsigned HexagonTargetObjectFile::getSmallestAddressableSize(const Type *Ty,
+ const GlobalValue *GV, const TargetMachine &TM) const {
+ // Assign the smallest element access size to the highest
+ // value which assembler can handle.
+ unsigned SmallestElement = 8;
+
+ if (!Ty)
+ return 0;
+ switch (Ty->getTypeID()) {
+ case Type::StructTyID: {
+ const StructType *STy = cast<const StructType>(Ty);
+ for (auto &E : STy->elements()) {
+ unsigned AtomicSize = getSmallestAddressableSize(E, GV, TM);
+ if (AtomicSize < SmallestElement)
+ SmallestElement = AtomicSize;
+ }
+ return (STy->getNumElements() == 0) ? 0 : SmallestElement;
+ }
+ case Type::ArrayTyID: {
+ const ArrayType *ATy = cast<const ArrayType>(Ty);
+ return getSmallestAddressableSize(ATy->getElementType(), GV, TM);
+ }
+ case Type::VectorTyID: {
+ const VectorType *PTy = cast<const VectorType>(Ty);
+ return getSmallestAddressableSize(PTy->getElementType(), GV, TM);
+ }
+ case Type::PointerTyID:
+ case Type::HalfTyID:
+ case Type::FloatTyID:
+ case Type::DoubleTyID:
+ case Type::IntegerTyID: {
+ const DataLayout &DL = GV->getParent()->getDataLayout();
+ // It is unfortunate that DL's function take non-const Type*.
+ return DL.getTypeAllocSize(const_cast<Type*>(Ty));
+ }
+ case Type::FunctionTyID:
+ case Type::VoidTyID:
+ case Type::X86_FP80TyID:
+ case Type::FP128TyID:
+ case Type::PPC_FP128TyID:
+ case Type::LabelTyID:
+ case Type::MetadataTyID:
+ case Type::X86_MMXTyID:
+ case Type::TokenTyID:
+ return 0;
+ }
+
+ return 0;
+}
+
+MCSection *HexagonTargetObjectFile::selectSmallSectionForGlobal(
+ const GlobalObject *GO, SectionKind Kind, const TargetMachine &TM) const {
+ const Type *GTy = GO->getType()->getElementType();
+ unsigned Size = getSmallestAddressableSize(GTy, GO, TM);
+
+ // If we have -ffunction-section or -fdata-section then we should emit the
+ // global value to a unique section specifically for it... even for sdata.
+ bool EmitUniquedSection = TM.getDataSections();
+
+ TRACE("Small data. Size(" << Size << ")");
+ // Handle Small Section classification here.
+ if (Kind.isBSS() || Kind.isBSSLocal()) {
+ // If -mno-sort-sda is not set, find out smallest accessible entity in
+ // declaration and add it to the section name string.
+ // Note. It does not track the actual usage of the value, only its de-
+ // claration. Also, compiler adds explicit pad fields to some struct
+ // declarations - they are currently counted towards smallest addres-
+ // sable entity.
+ if (NoSmallDataSorting) {
+ TRACE(" default sbss\n");
+ return SmallBSSSection;
+ }
+
+ StringRef Prefix(".sbss");
+ SmallString<128> Name(Prefix);
+ Name.append(getSectionSuffixForSize(Size));
+
+ if (EmitUniquedSection) {
+ Name.append(".");
+ Name.append(GO->getName());
+ }
+ TRACE(" unique sbss(" << Name << ")\n");
+ return getContext().getELFSection(Name.str(), ELF::SHT_NOBITS,
+ ELF::SHF_WRITE | ELF::SHF_ALLOC | ELF::SHF_HEX_GPREL);
+ }
+
+ if (Kind.isCommon()) {
+ // This is purely for LTO+Linker Script because commons don't really have a
+ // section. However, the BitcodeSectionWriter pass will query for the
+ // sections of commons (and the linker expects us to know their section) so
+ // we'll return one here.
+ if (NoSmallDataSorting)
+ return BSSSection;
+
+ Twine Name = Twine(".scommon") + getSectionSuffixForSize(Size);
+ TRACE(" small COMMON (" << Name << ")\n");
+
+ return getContext().getELFSection(Name.str(), ELF::SHT_NOBITS,
+ ELF::SHF_WRITE | ELF::SHF_ALLOC |
+ ELF::SHF_HEX_GPREL);
+ }
+
+ // We could have changed sdata object to a constant... in this
+ // case the Kind could be wrong for it.
+ if (Kind.isMergeableConst()) {
+ TRACE(" const_object_as_data ");
+ const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GO);
+ if (GVar->hasSection() && isSmallDataSection(GVar->getSection()))
+ Kind = SectionKind::getData();
+ }
+
+ if (Kind.isData()) {
+ if (NoSmallDataSorting) {
+ TRACE(" default sdata\n");
+ return SmallDataSection;
+ }
+
+ StringRef Prefix(".sdata");
+ SmallString<128> Name(Prefix);
+ Name.append(getSectionSuffixForSize(Size));
+
+ if (EmitUniquedSection) {
+ Name.append(".");
+ Name.append(GO->getName());
+ }
+ TRACE(" unique sdata(" << Name << ")\n");
+ return getContext().getELFSection(Name.str(), ELF::SHT_PROGBITS,
+ ELF::SHF_WRITE | ELF::SHF_ALLOC | ELF::SHF_HEX_GPREL);
+ }
+
+ TRACE("default ELF section\n");
+ // Otherwise, we work the same as ELF.
+ return TargetLoweringObjectFileELF::SelectSectionForGlobal(GO, Kind, TM);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2025-11-04 06:52:40 +0000