Import LLVM, at r72732.

1 files changed, 141 insertions, 0 deletions

diff --git a/lib/Support/Allocator.cpp b/lib/Support/Allocator.cpp
new file mode 100644
index 0000000..db0d8f3
--- /dev/null
+++ b/lib/Support/Allocator.cpp
@@ -0,0 +1,141 @@
+//===--- Allocator.cpp - Simple memory allocation abstraction -------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the BumpPtrAllocator interface.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/Allocator.h"
+#include "llvm/Support/Recycler.h"
+#include "llvm/Support/DataTypes.h"
+#include "llvm/Support/Streams.h"
+#include <ostream>
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// MemRegion class implementation
+//===----------------------------------------------------------------------===//
+
+namespace {
+/// MemRegion - This is one chunk of the BumpPtrAllocator.
+class MemRegion {
+  unsigned RegionSize;
+  MemRegion *Next;
+  char *NextPtr;
+public:
+  void Init(unsigned size, unsigned Alignment, MemRegion *next) {
+    RegionSize = size;
+    Next = next;
+    NextPtr = (char*)(this+1);
+    
+    // Align NextPtr.
+    NextPtr = (char*)((intptr_t)(NextPtr+Alignment-1) &
+                      ~(intptr_t)(Alignment-1));
+  }
+  
+  const MemRegion *getNext() const { return Next; }
+  unsigned getNumBytesAllocated() const {
+    return NextPtr-(const char*)this;
+  }
+  
+  /// Allocate - Allocate and return at least the specified number of bytes.
+  ///
+  void *Allocate(size_t AllocSize, size_t Alignment, MemRegion **RegPtr) {
+    
+    char* Result = (char*) (((uintptr_t) (NextPtr+Alignment-1)) 
+                            & ~((uintptr_t) Alignment-1));
+
+    // Speculate the new value of NextPtr.
+    char* NextPtrTmp = Result + AllocSize;
+    
+    // If we are still within the current region, return Result.
+    if (unsigned (NextPtrTmp - (char*) this) <= RegionSize) {
+      NextPtr = NextPtrTmp;
+      return Result;
+    }
+    
+    // Otherwise, we have to allocate a new chunk.  Create one twice as big as
+    // this one.
+    MemRegion *NewRegion = (MemRegion *)malloc(RegionSize*2);
+    NewRegion->Init(RegionSize*2, Alignment, this);
+
+    // Update the current "first region" pointer  to point to the new region.
+    *RegPtr = NewRegion;
+    
+    // Try allocating from it now.
+    return NewRegion->Allocate(AllocSize, Alignment, RegPtr);
+  }
+  
+  /// Deallocate - Recursively release all memory for this and its next regions
+  /// to the system.
+  void Deallocate() {
+    MemRegion *next = Next;
+    free(this);
+    if (next)
+      next->Deallocate();
+  }
+
+  /// DeallocateAllButLast - Recursively release all memory for this and its
+  /// next regions to the system stopping at the last region in the list.
+  /// Returns the pointer to the last region.
+  MemRegion *DeallocateAllButLast() {
+    MemRegion *next = Next;
+    if (!next)
+      return this;
+    free(this);
+    return next->DeallocateAllButLast();
+  }
+};
+}
+
+//===----------------------------------------------------------------------===//
+// BumpPtrAllocator class implementation
+//===----------------------------------------------------------------------===//
+
+BumpPtrAllocator::BumpPtrAllocator() {
+  TheMemory = malloc(4096);
+  ((MemRegion*)TheMemory)->Init(4096, 1, 0);
+}
+
+BumpPtrAllocator::~BumpPtrAllocator() {
+  ((MemRegion*)TheMemory)->Deallocate();
+}
+
+void BumpPtrAllocator::Reset() {
+  MemRegion *MRP = (MemRegion*)TheMemory;
+  MRP = MRP->DeallocateAllButLast();
+  MRP->Init(4096, 1, 0);
+  TheMemory = MRP;
+}
+
+void *BumpPtrAllocator::Allocate(size_t Size, size_t Align) {
+  MemRegion *MRP = (MemRegion*)TheMemory;
+  void *Ptr = MRP->Allocate(Size, Align, &MRP);
+  TheMemory = MRP;
+  return Ptr;
+}
+
+void BumpPtrAllocator::PrintStats() const {
+  unsigned BytesUsed = 0;
+  unsigned NumRegions = 0;
+  const MemRegion *R = (MemRegion*)TheMemory;
+  for (; R; R = R->getNext(), ++NumRegions)
+    BytesUsed += R->getNumBytesAllocated();
+
+  cerr << "\nNumber of memory regions: " << NumRegions << "\n";
+  cerr << "Bytes allocated: " << BytesUsed << "\n";
+}
+
+void llvm::PrintRecyclerStats(size_t Size,
+                              size_t Align,
+                              size_t FreeListSize) {
+  cerr << "Recycler element size: " << Size << '\n';
+  cerr << "Recycler element alignment: " << Align << '\n';
+  cerr << "Number of elements free for recycling: " << FreeListSize << '\n';
+}