llvm-6502/include/llvm/Support/Allocator.h
2009-03-10 23:48:49 +00:00

92 lines
2.5 KiB
C++

//===--- Allocator.h - Simple memory allocation abstraction -----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the MallocAllocator and BumpPtrAllocator interfaces.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_ALLOCATOR_H
#define LLVM_SUPPORT_ALLOCATOR_H
#include "llvm/Support/AlignOf.h"
#include <cstdlib>
namespace llvm {
class MallocAllocator {
public:
MallocAllocator() {}
~MallocAllocator() {}
void Reset() {}
void *Allocate(size_t Size, size_t /*Alignment*/) { return malloc(Size); }
template <typename T>
T *Allocate() { return static_cast<T*>(malloc(sizeof(T))); }
template <typename T>
T *Allocate(size_t Num) {
return static_cast<T*>(malloc(sizeof(T)*Num));
}
void Deallocate(const void *Ptr) { free(const_cast<void*>(Ptr)); }
void PrintStats() const {}
};
/// BumpPtrAllocator - This allocator is useful for containers that need very
/// simple memory allocation strategies. In particular, this just keeps
/// allocating memory, and never deletes it until the entire block is dead. This
/// makes allocation speedy, but must only be used when the trade-off is ok.
class BumpPtrAllocator {
BumpPtrAllocator(const BumpPtrAllocator &); // do not implement
void operator=(const BumpPtrAllocator &); // do not implement
void *TheMemory;
public:
BumpPtrAllocator();
~BumpPtrAllocator();
void Reset();
void *Allocate(size_t Size, size_t Alignment);
/// Allocate space, but do not construct, one object.
///
template <typename T>
T *Allocate() {
return static_cast<T*>(Allocate(sizeof(T),AlignOf<T>::Alignment));
}
/// Allocate space for an array of objects. This does not construct the
/// objects though.
template <typename T>
T *Allocate(size_t Num) {
return static_cast<T*>(Allocate(Num * sizeof(T), AlignOf<T>::Alignment));
}
/// Allocate space for a specific count of elements and with a specified
/// alignment.
template <typename T>
T *Allocate(size_t Num, size_t Alignment) {
// Round EltSize up to the specified alignment.
size_t EltSize = (sizeof(T)+Alignment-1)&(-Alignment);
return static_cast<T*>(Allocate(Num * EltSize, Alignment));
}
void Deallocate(const void * /*Ptr*/) {}
void PrintStats() const;
};
} // end namespace llvm
#endif