llvm-6502/lib/MC/MCSymbol.cpp
Pete Cooper f89e1bdc1a Pack MCSymbol::Flags in to the bitfield with other members. NFC.
All file formats only needed 16-bits right now which is enough to fit
in to the padding with other fields.

This reduces the size of MCSymbol to 24-bytes on a 64-bit system.  The
layout is now

   0 | class llvm::MCSymbol
   0 |   class llvm::PointerIntPair SectionOrFragmentAndHasName
   0 |     intptr_t Value
     |   [sizeof=8, dsize=8, align=8
     |    nvsize=8, nvalign=8]

   8 |   unsigned int IsTemporary
   8 |   unsigned int IsRedefinable
   8 |   unsigned int IsUsed
   8 |   _Bool IsRegistered
   8 |   unsigned int IsExternal
   8 |   unsigned int IsPrivateExtern
   8 |   unsigned int Kind
   9 |   unsigned int IsUsedInReloc
   9 |   unsigned int SymbolContents
   9 |   unsigned int CommonAlignLog2
  10 |   uint32_t Flags
  12 |   uint32_t Index
  16 |   union
  16 |     uint64_t Offset
  16 |     uint64_t CommonSize
  16 |     const class llvm::MCExpr * Value
     |   [sizeof=8, dsize=8, align=8
     |    nvsize=8, nvalign=8]

     | [sizeof=24, dsize=24, align=8
     |  nvsize=24, nvalign=8]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241196 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-01 21:57:51 +00:00

82 lines
2.8 KiB
C++

//===- lib/MC/MCSymbol.cpp - MCSymbol implementation ----------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
// Sentinel value for the absolute pseudo section.
MCSection *MCSymbol::AbsolutePseudoSection = reinterpret_cast<MCSection *>(1);
const unsigned MCSymbol::NumCommonAlignmentBits;
const unsigned MCSymbol::NumFlagsBits;
void *MCSymbol::operator new(size_t s, const StringMapEntry<bool> *Name,
MCContext &Ctx) {
// We may need more space for a Name to account for alignment. So allocate
// space for the storage type and not the name pointer.
size_t Size = s + (Name ? sizeof(NameEntryStorageTy) : 0);
// For safety, ensure that the alignment of a pointer is enough for an
// MCSymbol. This also ensures we don't need padding between the name and
// symbol.
static_assert((unsigned)AlignOf<MCSymbol>::Alignment <=
AlignOf<NameEntryStorageTy>::Alignment,
"Bad alignment of MCSymbol");
void *Storage = Ctx.allocate(Size, alignOf<NameEntryStorageTy>());
NameEntryStorageTy *Start = static_cast<NameEntryStorageTy*>(Storage);
NameEntryStorageTy *End = Start + (Name ? 1 : 0);
return End;
}
void MCSymbol::setVariableValue(const MCExpr *Value) {
assert(!IsUsed && "Cannot set a variable that has already been used.");
assert(Value && "Invalid variable value!");
assert((SymbolContents == SymContentsUnset ||
SymbolContents == SymContentsVariable) &&
"Cannot give common/offset symbol a variable value");
this->Value = Value;
SymbolContents = SymContentsVariable;
setUndefined();
}
void MCSymbol::print(raw_ostream &OS, const MCAsmInfo *MAI) const {
// The name for this MCSymbol is required to be a valid target name. However,
// some targets support quoting names with funny characters. If the name
// contains a funny character, then print it quoted.
StringRef Name = getName();
if (!MAI || MAI->isValidUnquotedName(Name)) {
OS << Name;
return;
}
if (MAI && !MAI->supportsNameQuoting())
report_fatal_error("Symbol name with unsupported characters");
OS << '"';
for (char C : Name) {
if (C == '\n')
OS << "\\n";
else if (C == '"')
OS << "\\\"";
else
OS << C;
}
OS << '"';
}
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
void MCSymbol::dump() const { dbgs() << *this; }
#endif