[Allocator] Lift the slab size and size threshold into template

parameters rather than runtime parameters.

There is only one user of these parameters and they are compile time for
that user. Making these compile time seems to better reflect their
intended usage as well.

llvm-svn: 205143

2 files changed, 20 insertions, 135 deletions

diff --git a/llvm/lib/ExecutionEngine/JIT/JITMemoryManager.cpp b/llvm/lib/ExecutionEngine/JIT/JITMemoryManager.cpp
index 1cfed2803b3..0d1ea0263c7 100644
--- a/llvm/lib/ExecutionEngine/JIT/JITMemoryManager.cpp
+++ b/llvm/lib/ExecutionEngine/JIT/JITMemoryManager.cpp
@@ -314,8 +314,8 @@ namespace {
     // confuse them with the blocks of memory described above.
     std::vector<sys::MemoryBlock> CodeSlabs;
     JITSlabAllocator BumpSlabAllocator;
-    BumpPtrAllocator StubAllocator;
-    BumpPtrAllocator DataAllocator;
+    BumpPtrAllocatorImpl<DefaultSlabSize, DefaultSizeThreshold> StubAllocator;
+    BumpPtrAllocatorImpl<DefaultSlabSize, DefaultSizeThreshold> DataAllocator;
 
     // Circular list of free blocks.
     FreeRangeHeader *FreeMemoryList;
@@ -590,8 +590,8 @@ DefaultJITMemoryManager::DefaultJITMemoryManager()
 #endif
     LastSlab(0, 0),
     BumpSlabAllocator(*this),
-    StubAllocator(DefaultSlabSize, DefaultSizeThreshold, BumpSlabAllocator),
-    DataAllocator(DefaultSlabSize, DefaultSizeThreshold, BumpSlabAllocator) {
+    StubAllocator(BumpSlabAllocator),
+    DataAllocator(BumpSlabAllocator) {
 
   // Allocate space for code.
   sys::MemoryBlock MemBlock = allocateNewSlab(DefaultCodeSlabSize);
diff --git a/llvm/lib/Support/Allocator.cpp b/llvm/lib/Support/Allocator.cpp
index c5ad50b39b9..7e177481cb5 100644
--- a/llvm/lib/Support/Allocator.cpp
+++ b/llvm/lib/Support/Allocator.cpp
@@ -21,130 +21,22 @@
 
 namespace llvm {
 
-BumpPtrAllocator::BumpPtrAllocator(size_t size, size_t threshold,
-                                   SlabAllocator &allocator)
-    : SlabSize(size), SizeThreshold(std::min(size, threshold)),
-      Allocator(allocator), CurSlab(0), BytesAllocated(0), NumSlabs(0) {}
-
-BumpPtrAllocator::BumpPtrAllocator(size_t size, size_t threshold)
-    : SlabSize(size), SizeThreshold(std::min(size, threshold)),
-      Allocator(DefaultSlabAllocator), CurSlab(0), BytesAllocated(0),
-      NumSlabs(0) {}
-
-BumpPtrAllocator::~BumpPtrAllocator() {
-  DeallocateSlabs(CurSlab);
-}
-
-/// StartNewSlab - Allocate a new slab and move the bump pointers over into
-/// the new slab.  Modifies CurPtr and End.
-void BumpPtrAllocator::StartNewSlab() {
-  ++NumSlabs;
-  // Scale the actual allocated slab size based on the number of slabs
-  // allocated. Every 128 slabs allocated, we double the allocated size to
-  // reduce allocation frequency, but saturate at multiplying the slab size by
-  // 2^30.
-  // FIXME: Currently, this count includes special slabs for objects above the
-  // size threshold. That will be fixed in a subsequent commit to make the
-  // growth even more predictable.
-  size_t AllocatedSlabSize =
-      SlabSize * (1 << std::min<size_t>(30, NumSlabs / 128));
-
-  MemSlab *NewSlab = Allocator.Allocate(AllocatedSlabSize);
-  NewSlab->NextPtr = CurSlab;
-  CurSlab = NewSlab;
-  CurPtr = (char*)(CurSlab + 1);
-  End = ((char*)CurSlab) + CurSlab->Size;
-}
+SlabAllocator::~SlabAllocator() { }
 
-/// DeallocateSlabs - Deallocate all memory slabs after and including this
-/// one.
-void BumpPtrAllocator::DeallocateSlabs(MemSlab *Slab) {
-  while (Slab) {
-    MemSlab *NextSlab = Slab->NextPtr;
-#ifndef NDEBUG
-    // Poison the memory so stale pointers crash sooner.  Note we must
-    // preserve the Size and NextPtr fields at the beginning.
-    sys::Memory::setRangeWritable(Slab + 1, Slab->Size - sizeof(MemSlab));
-    memset(Slab + 1, 0xCD, Slab->Size - sizeof(MemSlab));
-#endif
-    Allocator.Deallocate(Slab);
-    Slab = NextSlab;
-    --NumSlabs;
-  }
-}
+MallocSlabAllocator::~MallocSlabAllocator() { }
 
-/// Reset - Deallocate all but the current slab and reset the current pointer
-/// to the beginning of it, freeing all memory allocated so far.
-void BumpPtrAllocator::Reset() {
-  if (!CurSlab)
-    return;
-  DeallocateSlabs(CurSlab->NextPtr);
-  CurSlab->NextPtr = 0;
-  CurPtr = (char*)(CurSlab + 1);
-  End = ((char*)CurSlab) + CurSlab->Size;
-  BytesAllocated = 0;
+MemSlab *MallocSlabAllocator::Allocate(size_t Size) {
+  MemSlab *Slab = (MemSlab*)Allocator.Allocate(Size, 0);
+  Slab->Size = Size;
+  Slab->NextPtr = 0;
+  return Slab;
 }
 
-/// Allocate - Allocate space at the specified alignment.
-///
-void *BumpPtrAllocator::Allocate(size_t Size, size_t Alignment) {
-  if (!CurSlab) // Start a new slab if we haven't allocated one already.
-    StartNewSlab();
-
-  // Keep track of how many bytes we've allocated.
-  BytesAllocated += Size;
-
-  // 0-byte alignment means 1-byte alignment.
-  if (Alignment == 0) Alignment = 1;
-
-  // Allocate the aligned space, going forwards from CurPtr.
-  char *Ptr = alignPtr(CurPtr, Alignment);
-
-  // Check if we can hold it.
-  if (Ptr + Size <= End) {
-    CurPtr = Ptr + Size;
-    // Update the allocation point of this memory block in MemorySanitizer.
-    // Without this, MemorySanitizer messages for values originated from here
-    // will point to the allocation of the entire slab.
-    __msan_allocated_memory(Ptr, Size);
-    return Ptr;
-  }
-
-  // If Size is really big, allocate a separate slab for it.
-  size_t PaddedSize = Size + sizeof(MemSlab) + Alignment - 1;
-  if (PaddedSize > SizeThreshold) {
-    ++NumSlabs;
-    MemSlab *NewSlab = Allocator.Allocate(PaddedSize);
-
-    // Put the new slab after the current slab, since we are not allocating
-    // into it.
-    NewSlab->NextPtr = CurSlab->NextPtr;
-    CurSlab->NextPtr = NewSlab;
-
-    Ptr = alignPtr((char*)(NewSlab + 1), Alignment);
-    assert((uintptr_t)Ptr + Size <= (uintptr_t)NewSlab + NewSlab->Size);
-    __msan_allocated_memory(Ptr, Size);
-    return Ptr;
-  }
-
-  // Otherwise, start a new slab and try again.
-  StartNewSlab();
-  Ptr = alignPtr(CurPtr, Alignment);
-  CurPtr = Ptr + Size;
-  assert(CurPtr <= End && "Unable to allocate memory!");
-  __msan_allocated_memory(Ptr, Size);
-  return Ptr;
+void MallocSlabAllocator::Deallocate(MemSlab *Slab) {
+  Allocator.Deallocate(Slab);
 }
 
-size_t BumpPtrAllocator::getTotalMemory() const {
-  size_t TotalMemory = 0;
-  for (MemSlab *Slab = CurSlab; Slab != 0; Slab = Slab->NextPtr) {
-    TotalMemory += Slab->Size;
-  }
-  return TotalMemory;
-}
-  
-void BumpPtrAllocator::PrintStats() const {
+void BumpPtrAllocatorBase::PrintStats() const {
   unsigned NumSlabs = 0;
   size_t TotalMemory = 0;
   for (MemSlab *Slab = CurSlab; Slab != 0; Slab = Slab->NextPtr) {
@@ -159,19 +51,12 @@ void BumpPtrAllocator::PrintStats() const {
          << " (includes alignment, etc)\n";
 }
 
-SlabAllocator::~SlabAllocator() { }
-
-MallocSlabAllocator::~MallocSlabAllocator() { }
-
-MemSlab *MallocSlabAllocator::Allocate(size_t Size) {
-  MemSlab *Slab = (MemSlab*)Allocator.Allocate(Size, 0);
-  Slab->Size = Size;
-  Slab->NextPtr = 0;
-  return Slab;
-}
-
-void MallocSlabAllocator::Deallocate(MemSlab *Slab) {
-  Allocator.Deallocate(Slab);
+size_t BumpPtrAllocatorBase::getTotalMemory() const {
+  size_t TotalMemory = 0;
+  for (MemSlab *Slab = CurSlab; Slab != 0; Slab = Slab->NextPtr) {
+    TotalMemory += Slab->Size;
+  }
+  return TotalMemory;
 }
 
 void PrintRecyclerStats(size_t Size,