llvm-6502/include/llvm/MC/MCLinkerOptimizationHint.h
Jim Grosbach 398f175c45 MC: Tidy up LOH naming a bit. NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238800 91177308-0d34-0410-b5e6-96231b3b80d8
2015-06-01 23:55:06 +00:00

206 lines
6.2 KiB
C++

//===- 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/StringRef.h"
#include "llvm/ADT/StringSwitch.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(unsigned 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 {
class raw_counting_ostream : public raw_ostream {
uint64_t Count;
void write_impl(const char *, size_t size) override { Count += size; }
uint64_t current_pos() const override { return Count; }
public:
raw_counting_ostream() : Count(0) {}
~raw_counting_ostream() override { flush(); }
};
raw_counting_ostream OutStream;
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