Let BumpPtrAllocator lazily allocate the first slab.

We have some code in llvm and clang where a BumpPtrAllocator is declared in a
class but never used in the common case. Stop wasting memory there.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101130 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Benjamin Kramer 2010-04-13 14:41:51 +00:00
parent d5e624027a
commit 5e6a705985

View File

@ -23,9 +23,7 @@ namespace llvm {
BumpPtrAllocator::BumpPtrAllocator(size_t size, size_t threshold,
SlabAllocator &allocator)
: SlabSize(size), SizeThreshold(threshold), Allocator(allocator),
CurSlab(0), BytesAllocated(0) {
StartNewSlab();
}
CurSlab(0), BytesAllocated(0) { }
BumpPtrAllocator::~BumpPtrAllocator() {
DeallocateSlabs(CurSlab);
@ -72,6 +70,8 @@ void BumpPtrAllocator::DeallocateSlabs(MemSlab *Slab) {
/// 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) // Start a new slab if we didn't allocate one already.
StartNewSlab();
DeallocateSlabs(CurSlab->NextPtr);
CurSlab->NextPtr = 0;
CurPtr = (char*)(CurSlab + 1);
@ -81,6 +81,9 @@ void BumpPtrAllocator::Reset() {
/// 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;