Renames the assembler* files.

src/assembler.h

-//===- subzero/src/assembler.h - Integrated assembler -----------*- C++ -*-===//
-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-//
-// Modified by the Subzero authors.
-//
-//===----------------------------------------------------------------------===//
-//
-//                        The Subzero Code Generator
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file declares the Assembler base class.  Instructions are assembled
-// by architecture-specific assemblers that derive from this base class.
-// This base class manages buffers and fixups for emitting code, etc.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef SUBZERO_SRC_ASSEMBLER_H
-#define SUBZERO_SRC_ASSEMBLER_H
-
-#include "IceDefs.h"
-#include "IceFixups.h"
-
-namespace Ice {
-
-// Assembler buffers are used to emit binary code. They grow on demand.
-class AssemblerBuffer {
-  AssemblerBuffer(const AssemblerBuffer &) = delete;
-  AssemblerBuffer &operator=(const AssemblerBuffer &) = delete;
-
-public:
-  AssemblerBuffer(Assembler &);
-  ~AssemblerBuffer();
-
-  // Basic support for emitting, loading, and storing.
-  template <typename T> void Emit(T value) {
-    assert(HasEnsuredCapacity());
-    *reinterpret_cast<T *>(cursor_) = value;
-    cursor_ += sizeof(T);
-  }
-
-  template <typename T> T Load(intptr_t position) const {
-    assert(position >= 0 &&
-           position <= (Size() - static_cast<intptr_t>(sizeof(T))));
-    return *reinterpret_cast<T *>(contents_ + position);
-  }
-
-  template <typename T> void Store(intptr_t position, T value) {
-    assert(position >= 0 &&
-           position <= (Size() - static_cast<intptr_t>(sizeof(T))));
-    *reinterpret_cast<T *>(contents_ + position) = value;
-  }
-
-  // Emit a fixup at the current location.
-  void EmitFixup(AssemblerFixup *fixup) { fixup->set_position(Size()); }
-
-  // Get the size of the emitted code.
-  intptr_t Size() const { return cursor_ - contents_; }
-  uintptr_t contents() const { return contents_; }
-
-// To emit an instruction to the assembler buffer, the EnsureCapacity helper
-// must be used to guarantee that the underlying data area is big enough to
-// hold the emitted instruction. Usage:
-//
-//     AssemblerBuffer buffer;
-//     AssemblerBuffer::EnsureCapacity ensured(&buffer);
-//     ... emit bytes for single instruction ...
-
-#ifndef NDEBUG
-  class EnsureCapacity {
-    EnsureCapacity(const EnsureCapacity &) = delete;
-    EnsureCapacity &operator=(const EnsureCapacity &) = delete;
-
-  public:
-    explicit EnsureCapacity(AssemblerBuffer *buffer);
-    ~EnsureCapacity();
-
-  private:
-    AssemblerBuffer *buffer_;
-    intptr_t gap_;
-
-    intptr_t ComputeGap() { return buffer_->Capacity() - buffer_->Size(); }
-  };
-
-  bool has_ensured_capacity_;
-  bool HasEnsuredCapacity() const { return has_ensured_capacity_; }
-#else  // NDEBUG
-  class EnsureCapacity {
-    EnsureCapacity(const EnsureCapacity &) = delete;
-    EnsureCapacity &operator=(const EnsureCapacity &) = delete;
-
-  public:
-    explicit EnsureCapacity(AssemblerBuffer *buffer) {
-      if (buffer->cursor() >= buffer->limit())
-        buffer->ExtendCapacity();
-    }
-  };
-
-  // When building the C++ tests, assertion code is enabled. To allow
-  // asserting that the user of the assembler buffer has ensured the
-  // capacity needed for emitting, we add a dummy method in non-debug mode.
-  bool HasEnsuredCapacity() const { return true; }
-#endif // NDEBUG
-
-  // Returns the position in the instruction stream.
-  intptr_t GetPosition() const { return cursor_ - contents_; }
-
-  // Create and track a fixup in the current function.
-  AssemblerFixup *createFixup(FixupKind Kind, const Constant *Value);
-
-  const FixupRefList &fixups() const { return fixups_; }
-
-  void setSize(intptr_t NewSize) {
-    assert(NewSize <= Size());
-    cursor_ = contents_ + NewSize;
-  }
-
-private:
-  // The limit is set to kMinimumGap bytes before the end of the data area.
-  // This leaves enough space for the longest possible instruction and allows
-  // for a single, fast space check per instruction.
-  static const intptr_t kMinimumGap = 32;
-
-  uintptr_t contents_;
-  uintptr_t cursor_;
-  uintptr_t limit_;
-  Assembler &assembler_;
-  // List of pool-allocated fixups relative to the current function.
-  FixupRefList fixups_;
-
-  uintptr_t cursor() const { return cursor_; }
-  uintptr_t limit() const { return limit_; }
-  intptr_t Capacity() const {
-    assert(limit_ >= contents_);
-    return (limit_ - contents_) + kMinimumGap;
-  }
-
-  // Compute the limit based on the data area and the capacity. See
-  // description of kMinimumGap for the reasoning behind the value.
-  static uintptr_t ComputeLimit(uintptr_t data, intptr_t capacity) {
-    return data + capacity - kMinimumGap;
-  }
-
-  void ExtendCapacity();
-};
-
-class Assembler {
-  Assembler(const Assembler &) = delete;
-  Assembler &operator=(const Assembler &) = delete;
-
-public:
-  Assembler()
-      : FunctionName(""), IsInternal(false), Preliminary(false),
-        buffer_(*this) {}
-  virtual ~Assembler() {}
-
-  // Allocate a chunk of bytes using the per-Assembler allocator.
-  uintptr_t AllocateBytes(size_t bytes) {
-    // For now, alignment is not related to NaCl bundle alignment, since
-    // the buffer's GetPosition is relative to the base. So NaCl bundle
-    // alignment checks can be relative to that base. Later, the buffer
-    // will be copied out to a ".text" section (or an in memory-buffer
-    // that can be mprotect'ed with executable permission), and that
-    // second buffer should be aligned for NaCl.
-    const size_t Alignment = 16;
-    return reinterpret_cast<uintptr_t>(Allocator.Allocate(bytes, Alignment));
-  }
-
-  // Allocate data of type T using the per-Assembler allocator.
-  template <typename T> T *Allocate() { return Allocator.Allocate<T>(); }
-
-  // Align the tail end of the function to the required target alignment.
-  virtual void alignFunction() = 0;
-
-  // Add nop padding of a particular width to the current bundle.
-  virtual void padWithNop(intptr_t Padding) = 0;
-
-  virtual SizeT getBundleAlignLog2Bytes() const = 0;
-
-  virtual const char *getNonExecPadDirective() const = 0;
-  virtual llvm::ArrayRef<uint8_t> getNonExecBundlePadding() const = 0;
-
-  // Mark the current text location as the start of a CFG node
-  // (represented by NodeNumber).
-  virtual void BindCfgNodeLabel(SizeT NodeNumber) = 0;
-
-  virtual bool fixupIsPCRel(FixupKind Kind) const = 0;
-
-  // Return a view of all the bytes of code for the current function.
-  llvm::StringRef getBufferView() const;
-
-  const FixupRefList &fixups() const { return buffer_.fixups(); }
-
-  AssemblerFixup *createFixup(FixupKind Kind, const Constant *Value) {
-    return buffer_.createFixup(Kind, Value);
-  }
-
-  void emitIASBytes(GlobalContext *Ctx) const;
-  bool getInternal() const { return IsInternal; }
-  void setInternal(bool Internal) { IsInternal = Internal; }
-  const IceString &getFunctionName() { return FunctionName; }
-  void setFunctionName(const IceString &NewName) { FunctionName = NewName; }
-  intptr_t getBufferSize() const { return buffer_.Size(); }
-  // Roll back to a (smaller) size.
-  void setBufferSize(intptr_t NewSize) { buffer_.setSize(NewSize); }
-  void setPreliminary(bool Value) { Preliminary = Value; }
-  bool getPreliminary() const { return Preliminary; }
-
-private:
-  ArenaAllocator<32 * 1024> Allocator;
-  // FunctionName and IsInternal are transferred from the original Cfg
-  // object, since the Cfg object may be deleted by the time the
-  // assembler buffer is emitted.
-  IceString FunctionName;
-  bool IsInternal;
-  // Preliminary indicates whether a preliminary pass is being made
-  // for calculating bundle padding (Preliminary=true), versus the
-  // final pass where all changes to label bindings, label links, and
-  // relocation fixups are fully committed (Preliminary=false).
-  bool Preliminary;
-
-protected:
-  AssemblerBuffer buffer_;
-};
-
-} // end of namespace Ice
-
-#endif // SUBZERO_SRC_ASSEMBLER_H_