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Diffstat (limited to 'include/llvm/MC/MCLinkerOptimizationHint.h')
| -rw-r--r-- | include/llvm/MC/MCLinkerOptimizationHint.h | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/include/llvm/MC/MCLinkerOptimizationHint.h b/include/llvm/MC/MCLinkerOptimizationHint.h new file mode 100644 index 0000000..3b0d933 --- /dev/null +++ b/include/llvm/MC/MCLinkerOptimizationHint.h @@ -0,0 +1,194 @@ +//===- MCLinkerOptimizationHint.h - LOH interface ---------------*- C++ -*-===// +// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file declares some helpers classes to handle Linker Optimization Hint +// (LOH). +// +// FIXME: LOH interface supports only MachO format at the moment. +//===----------------------------------------------------------------------===// + +#ifndef LLVM_MC_MCLINKEROPTIMIZATIONHINT_H +#define LLVM_MC_MCLINKEROPTIMIZATIONHINT_H + +#include "llvm/ADT/SmallVector.h" +#include "llvm/ADT/StringSwitch.h" +#include "llvm/ADT/StringRef.h" +#include "llvm/MC/MCMachObjectWriter.h" +#include "llvm/Support/raw_ostream.h" + +namespace llvm { + +// Forward declarations. +class MCAsmLayout; +class MCSymbol; + +/// Linker Optimization Hint Type. +enum MCLOHType { + MCLOH_AdrpAdrp = 0x1u, ///< Adrp xY, _v1@PAGE -> Adrp xY, _v2@PAGE. + MCLOH_AdrpLdr = 0x2u, ///< Adrp _v@PAGE -> Ldr _v@PAGEOFF. + MCLOH_AdrpAddLdr = 0x3u, ///< Adrp _v@PAGE -> Add _v@PAGEOFF -> Ldr. + MCLOH_AdrpLdrGotLdr = 0x4u, ///< Adrp _v@GOTPAGE -> Ldr _v@GOTPAGEOFF -> Ldr. + MCLOH_AdrpAddStr = 0x5u, ///< Adrp _v@PAGE -> Add _v@PAGEOFF -> Str. + MCLOH_AdrpLdrGotStr = 0x6u, ///< Adrp _v@GOTPAGE -> Ldr _v@GOTPAGEOFF -> Str. + MCLOH_AdrpAdd = 0x7u, ///< Adrp _v@PAGE -> Add _v@PAGEOFF. + MCLOH_AdrpLdrGot = 0x8u ///< Adrp _v@GOTPAGE -> Ldr _v@GOTPAGEOFF. +}; + +static inline StringRef MCLOHDirectiveName() { + return StringRef(".loh"); +} + +static inline bool isValidMCLOHType(MCLOHType Kind) { + return Kind >= MCLOH_AdrpAdrp && Kind <= MCLOH_AdrpLdrGot; +} + +static inline int MCLOHNameToId(StringRef Name) { +#define MCLOHCaseNameToId(Name) .Case(#Name, MCLOH_ ## Name) + return StringSwitch<int>(Name) + MCLOHCaseNameToId(AdrpAdrp) + MCLOHCaseNameToId(AdrpLdr) + MCLOHCaseNameToId(AdrpAddLdr) + MCLOHCaseNameToId(AdrpLdrGotLdr) + MCLOHCaseNameToId(AdrpAddStr) + MCLOHCaseNameToId(AdrpLdrGotStr) + MCLOHCaseNameToId(AdrpAdd) + MCLOHCaseNameToId(AdrpLdrGot) + .Default(-1); +} + +static inline StringRef MCLOHIdToName(MCLOHType Kind) { +#define MCLOHCaseIdToName(Name) case MCLOH_ ## Name: return StringRef(#Name); + switch (Kind) { + MCLOHCaseIdToName(AdrpAdrp); + MCLOHCaseIdToName(AdrpLdr); + MCLOHCaseIdToName(AdrpAddLdr); + MCLOHCaseIdToName(AdrpLdrGotLdr); + MCLOHCaseIdToName(AdrpAddStr); + MCLOHCaseIdToName(AdrpLdrGotStr); + MCLOHCaseIdToName(AdrpAdd); + MCLOHCaseIdToName(AdrpLdrGot); + } + return StringRef(); +} + +static inline int MCLOHIdToNbArgs(MCLOHType Kind) { + switch (Kind) { + // LOH with two arguments + case MCLOH_AdrpAdrp: + case MCLOH_AdrpLdr: + case MCLOH_AdrpAdd: + case MCLOH_AdrpLdrGot: + return 2; + // LOH with three arguments + case MCLOH_AdrpAddLdr: + case MCLOH_AdrpLdrGotLdr: + case MCLOH_AdrpAddStr: + case MCLOH_AdrpLdrGotStr: + return 3; + } + return -1; +} + +/// Store Linker Optimization Hint information (LOH). +class MCLOHDirective { + MCLOHType Kind; + + /// Arguments of this directive. Order matters. + SmallVector<MCSymbol *, 3> Args; + + /// Emit this directive in @p OutStream using the information available + /// in the given @p ObjWriter and @p Layout to get the address of the + /// arguments within the object file. + void Emit_impl(raw_ostream &OutStream, const MachObjectWriter &ObjWriter, + const MCAsmLayout &Layout) const; + +public: + typedef SmallVectorImpl<MCSymbol *> LOHArgs; + + MCLOHDirective(MCLOHType Kind, const LOHArgs &Args) + : Kind(Kind), Args(Args.begin(), Args.end()) { + assert(isValidMCLOHType(Kind) && "Invalid LOH directive type!"); + } + + MCLOHType getKind() const { return Kind; } + + const LOHArgs &getArgs() const { return Args; } + + /// Emit this directive as: + /// <kind, numArgs, addr1, ..., addrN> + void Emit(MachObjectWriter &ObjWriter, const MCAsmLayout &Layout) const { + raw_ostream &OutStream = ObjWriter.getStream(); + Emit_impl(OutStream, ObjWriter, Layout); + } + + /// Get the size in bytes of this directive if emitted in @p ObjWriter with + /// the given @p Layout. + uint64_t getEmitSize(const MachObjectWriter &ObjWriter, + const MCAsmLayout &Layout) const { + std::string Buffer; + raw_string_ostream OutStream(Buffer); + Emit_impl(OutStream, ObjWriter, Layout); + return OutStream.tell(); + } +}; + +class MCLOHContainer { + /// Keep track of the emit size of all the LOHs. + mutable uint64_t EmitSize; + + /// Keep track of all LOH directives. + SmallVector<MCLOHDirective, 32> Directives; + +public: + typedef SmallVectorImpl<MCLOHDirective> LOHDirectives; + + MCLOHContainer() : EmitSize(0) {}; + + /// Const accessor to the directives. + const LOHDirectives &getDirectives() const { + return Directives; + } + + /// Add the directive of the given kind @p Kind with the given arguments + /// @p Args to the container. + void addDirective(MCLOHType Kind, const MCLOHDirective::LOHArgs &Args) { + Directives.push_back(MCLOHDirective(Kind, Args)); + } + + /// Get the size of the directives if emitted. + uint64_t getEmitSize(const MachObjectWriter &ObjWriter, + const MCAsmLayout &Layout) const { + if (!EmitSize) { + for (const MCLOHDirective &D : Directives) + EmitSize += D.getEmitSize(ObjWriter, Layout); + } + return EmitSize; + } + + /// Emit all Linker Optimization Hint in one big table. + /// Each line of the table is emitted by LOHDirective::Emit. + void Emit(MachObjectWriter &ObjWriter, const MCAsmLayout &Layout) const { + for (const MCLOHDirective &D : Directives) + D.Emit(ObjWriter, Layout); + } + + void reset() { + Directives.clear(); + EmitSize = 0; + } +}; + +// Add types for specialized template using MCSymbol. +typedef MCLOHDirective::LOHArgs MCLOHArgs; +typedef MCLOHContainer::LOHDirectives MCLOHDirectives; + +} // end namespace llvm + +#endif |