//===----------------------------------------------------------------------===//
#include "llvm/Support/Allocator.h"
-#include "llvm/System/DataTypes.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/DataTypes.h"
+#include "llvm/Support/Memory.h"
#include "llvm/Support/Recycler.h"
#include "llvm/Support/raw_ostream.h"
-#include "llvm/System/Memory.h"
#include <cstring>
namespace llvm {
BumpPtrAllocator::BumpPtrAllocator(size_t size, size_t threshold,
SlabAllocator &allocator)
- : SlabSize(size), SizeThreshold(threshold), Allocator(allocator),
- CurSlab(0), BytesAllocated(0) {
- StartNewSlab();
-}
+ : SlabSize(size), SizeThreshold(std::min(size, threshold)),
+ Allocator(allocator), CurSlab(0), BytesAllocated(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() {
+ // If we allocated a big number of slabs already it's likely that we're going
+ // to allocate more. Increase slab size to reduce mallocs and possibly memory
+ // overhead. The factors are chosen conservatively to avoid overallocation.
+ if (BytesAllocated >= SlabSize * 128)
+ SlabSize *= 2;
+
MemSlab *NewSlab = Allocator.Allocate(SlabSize);
NewSlab->NextPtr = CurSlab;
CurSlab = NewSlab;
/// 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;
}
/// 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;
// 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;
}
Ptr = AlignPtr((char*)(NewSlab + 1), Alignment);
assert((uintptr_t)Ptr + Size <= (uintptr_t)NewSlab + NewSlab->Size);
+ __msan_allocated_memory(Ptr, Size);
return Ptr;
}
Ptr = AlignPtr(CurPtr, Alignment);
CurPtr = Ptr + Size;
assert(CurPtr <= End && "Unable to allocate memory!");
+ __msan_allocated_memory(Ptr, Size);
return Ptr;
}
return NumSlabs;
}
+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 {
unsigned NumSlabs = 0;
size_t TotalMemory = 0;