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mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-12-24 06:30:19 +00:00
llvm-6502/include/llvm/MC/MCAsmLayout.h
Rafael Espindola 4f4363a490 Layout each section independently. With the testcase in PR8711:
before:
        4 assembler - Number of assembler layout and relaxation steps
    78563 assembler - Number of emitted assembler fragments
  8693904 assembler - Number of emitted object file bytes
   271223 assembler - Number of evaluated fixups
330771677 assembler - Number of fragment layouts
     5958 assembler - Number of relaxed instructions
  2508361 mcexpr    - Number of MCExpr evaluations

real	0m26.123s
user	0m25.694s
sys	0m0.388s

after:

      4 assembler - Number of assembler layout and relaxation steps
  78563 assembler - Number of emitted assembler fragments
8693904 assembler - Number of emitted object file bytes
 271223 assembler - Number of evaluated fixups
 231507 assembler - Number of fragment layouts
   5958 assembler - Number of relaxed instructions
2508361 mcexpr    - Number of MCExpr evaluations

real	0m2.500s
user	0m2.113s
sys	0m0.273s

And yes, the outputs are identical :-)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121207 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-07 23:32:26 +00:00

109 lines
3.6 KiB
C++

//===- MCAsmLayout.h - Assembly Layout Object -------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_MC_MCASMLAYOUT_H
#define LLVM_MC_MCASMLAYOUT_H
#include "llvm/ADT/SmallVector.h"
namespace llvm {
class MCAssembler;
class MCFragment;
class MCSectionData;
class MCSymbolData;
/// Encapsulates the layout of an assembly file at a particular point in time.
///
/// Assembly may requiring compute multiple layouts for a particular assembly
/// file as part of the relaxation process. This class encapsulates the layout
/// at a single point in time in such a way that it is always possible to
/// efficiently compute the exact addresses of any symbol in the assembly file,
/// even during the relaxation process.
class MCAsmLayout {
public:
typedef llvm::SmallVectorImpl<MCSectionData*>::const_iterator const_iterator;
typedef llvm::SmallVectorImpl<MCSectionData*>::iterator iterator;
private:
MCAssembler &Assembler;
/// List of sections in layout order.
llvm::SmallVector<MCSectionData*, 16> SectionOrder;
/// The last fragment which was layed out, or 0 if nothing has been layed
/// out. Fragments are always layed out in order, so all fragments with a
/// lower ordinal will be up to date.
mutable DenseMap<const MCSectionData*, MCFragment *> LastValidFragment;
/// \brief Make sure that the layout for the given fragment is valid, lazily
/// computing it if necessary.
void EnsureValid(const MCFragment *F) const;
bool isFragmentUpToDate(const MCFragment *F) const;
public:
MCAsmLayout(MCAssembler &_Assembler);
/// Get the assembler object this is a layout for.
MCAssembler &getAssembler() const { return Assembler; }
/// \brief Invalidate all following fragments because a fragment has been resized. The
/// fragments size should have already been updated.
void Invalidate(MCFragment *F);
/// \brief Perform layout for a single fragment, assuming that the previous
/// fragment has already been layed out correctly, and the parent section has
/// been initialized.
void LayoutFragment(MCFragment *Fragment);
/// @name Section Access (in layout order)
/// @{
llvm::SmallVectorImpl<MCSectionData*> &getSectionOrder() {
return SectionOrder;
}
const llvm::SmallVectorImpl<MCSectionData*> &getSectionOrder() const {
return SectionOrder;
}
/// @}
/// @name Fragment Layout Data
/// @{
/// \brief Get the effective size of the given fragment, as computed in the
/// current layout.
uint64_t getFragmentEffectiveSize(const MCFragment *F) const;
/// \brief Get the offset of the given fragment inside its containing section.
uint64_t getFragmentOffset(const MCFragment *F) const;
/// @}
/// @name Utility Functions
/// @{
/// \brief Get the address space size of the given section, as it effects
/// layout. This may differ from the size reported by \see getSectionSize() by
/// not including section tail padding.
uint64_t getSectionAddressSize(const MCSectionData *SD) const;
/// \brief Get the data size of the given section, as emitted to the object
/// file. This may include additional padding, or be 0 for virtual sections.
uint64_t getSectionFileSize(const MCSectionData *SD) const;
/// \brief Get the offset of the given symbol, as computed in the current
/// layout.
uint64_t getSymbolOffset(const MCSymbolData *SD) const;
/// @}
};
} // end namespace llvm
#endif