llvm-project/libcxx/benchmarks/allocation.bench.cpp

136 lines
3.5 KiB
C++

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "benchmark/benchmark.h"
#include <new>
#include <vector>
#include <cassert>
struct PointerList {
PointerList* Next = nullptr;
};
struct MallocWrapper {
__attribute__((always_inline))
static void* Allocate(size_t N) {
return std::malloc(N);
}
__attribute__((always_inline))
static void Deallocate(void* P, size_t) {
std::free(P);
}
};
struct NewWrapper {
__attribute__((always_inline))
static void* Allocate(size_t N) {
return ::operator new(N);
}
__attribute__((always_inline))
static void Deallocate(void* P, size_t) {
::operator delete(P);
}
};
struct BuiltinNewWrapper {
__attribute__((always_inline))
static void* Allocate(size_t N) {
return __builtin_operator_new(N);
}
__attribute__((always_inline))
static void Deallocate(void* P, size_t) {
__builtin_operator_delete(P);
}
};
struct BuiltinSizedNewWrapper {
__attribute__((always_inline))
static void* Allocate(size_t N) {
return __builtin_operator_new(N);
}
__attribute__((always_inline))
static void Deallocate(void* P, size_t N) {
__builtin_operator_delete(P, N);
}
};
template <class AllocWrapper>
static void BM_AllocateAndDeallocate(benchmark::State& st) {
const size_t alloc_size = st.range(0);
while (st.KeepRunning()) {
void* p = AllocWrapper::Allocate(alloc_size);
benchmark::DoNotOptimize(p);
AllocWrapper::Deallocate(p, alloc_size);
}
}
template <class AllocWrapper>
static void BM_AllocateOnly(benchmark::State& st) {
const size_t alloc_size = st.range(0);
PointerList *Start = nullptr;
while (st.KeepRunning()) {
PointerList* p = (PointerList*)AllocWrapper::Allocate(alloc_size);
benchmark::DoNotOptimize(p);
p->Next = Start;
Start = p;
}
PointerList *Next = Start;
while (Next) {
PointerList *Tmp = Next;
Next = Tmp->Next;
AllocWrapper::Deallocate(Tmp, alloc_size);
}
}
template <class AllocWrapper>
static void BM_DeallocateOnly(benchmark::State& st) {
const size_t alloc_size = st.range(0);
const auto NumAllocs = st.max_iterations;
std::vector<void*> Pointers(NumAllocs);
for (auto& p : Pointers) {
p = AllocWrapper::Allocate(alloc_size);
}
void** Data = Pointers.data();
void** const End = Pointers.data() + Pointers.size();
while (st.KeepRunning()) {
AllocWrapper::Deallocate(*Data, alloc_size);
Data += 1;
}
assert(Data == End);
}
static int RegisterAllocBenchmarks() {
using FnType = void(*)(benchmark::State&);
struct {
const char* name;
FnType func;
} TestCases[] = {
{"BM_Malloc", &BM_AllocateAndDeallocate<MallocWrapper>},
{"BM_New", &BM_AllocateAndDeallocate<NewWrapper>},
{"BM_BuiltinNewDelete", BM_AllocateAndDeallocate<BuiltinNewWrapper>},
{"BM_BuiltinSizedNewDelete", BM_AllocateAndDeallocate<BuiltinSizedNewWrapper>},
{"BM_BuiltinNewAllocateOnly", BM_AllocateOnly<BuiltinSizedNewWrapper>},
{"BM_BuiltinNewSizedDeallocateOnly", BM_DeallocateOnly<BuiltinSizedNewWrapper>},
};
for (auto TC : TestCases) {
benchmark::RegisterBenchmark(TC.name, TC.func)->Range(16, 4096 * 2);
}
return 0;
}
int Sink = RegisterAllocBenchmarks();
BENCHMARK_MAIN();