Files
regorus/mimalloc/mimalloc-sys/mimalloc/include/mimalloc-new-delete.h
Anand Krishnamoorthi 2a0b4ae6b5 feat! Mimalloc as the default allocator (#434)
This change integrates mimalloc as the default memory allocator for Regorus,
delivering significant performance improvements across all evaluation modes
and language bindings.

Technical Implementation:
- Build mimalloc in vendored mode from C sources (following QSharp approach)
- Implement GlobalAlloc trait for seamless Rust integration
- Add optional 'mimalloc' feature flag for conditional compilation
- Add comprehensive ACI benchmarks to measure evaluation performance

Performance Impact:

Rust Engine Evaluation:
- Single-threaded: ~29% improvement (423 vs 328 Kelem/s)
- Multi-threaded: Better scaling with reduced thread contention
- Fresh engines: ~24% improvement (56 vs 45 Kelem/s)

Rust Compiled Policy Evaluation:
- Single-threaded: ~41% improvement (426 vs 303 Kelem/s)
- Multi-threaded: Improved allocation efficiency under contention
- Fresh compilation: ~26% improvement (53 vs 42 Kelem/s)

C# FFI Bindings:
- Engine evaluation: ~27% improvement (279 vs 219 Kelem/s)
- Compiled policies: ~29% improvement (273 vs 211 Kelem/s)
- Better threading characteristics through improved underlying allocation

Key Benefits:
- Reduced allocation-related contention in multi-threaded scenarios
- More consistent performance across different thread counts
- Improved memory allocation efficiency for both native Rust and FFI workloads
- Better scaling characteristics for production deployments

The mimalloc integration provides substantial performance gains while
maintaining full compatibility with existing code through feature flags.

Reference: QSharp allocator implementation
(https://github.com/microsoft/qsharp/tree/main/source/allocator)

Fixes #297

Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>
2025-08-25 15:01:38 -05:00

67 lines
3.9 KiB
C++

/* ----------------------------------------------------------------------------
Copyright (c) 2018-2020 Microsoft Research, Daan Leijen
This is free software; you can redistribute it and/or modify it under the
terms of the MIT license. A copy of the license can be found in the file
"LICENSE" at the root of this distribution.
-----------------------------------------------------------------------------*/
#pragma once
#ifndef MIMALLOC_NEW_DELETE_H
#define MIMALLOC_NEW_DELETE_H
// ----------------------------------------------------------------------------
// This header provides convenient overrides for the new and
// delete operations in C++.
//
// This header should be included in only one source file!
//
// On Windows, or when linking dynamically with mimalloc, these
// can be more performant than the standard new-delete operations.
// See <https://en.cppreference.com/w/cpp/memory/new/operator_new>
// ---------------------------------------------------------------------------
#if defined(__cplusplus)
#include <new>
#include <mimalloc.h>
#if defined(_MSC_VER) && defined(_Ret_notnull_) && defined(_Post_writable_byte_size_)
// stay consistent with VCRT definitions
#define mi_decl_new(n) mi_decl_nodiscard mi_decl_restrict _Ret_notnull_ _Post_writable_byte_size_(n)
#define mi_decl_new_nothrow(n) mi_decl_nodiscard mi_decl_restrict _Ret_maybenull_ _Success_(return != NULL) _Post_writable_byte_size_(n)
#else
#define mi_decl_new(n) mi_decl_nodiscard mi_decl_restrict
#define mi_decl_new_nothrow(n) mi_decl_nodiscard mi_decl_restrict
#endif
void operator delete(void* p) noexcept { mi_free(p); };
void operator delete[](void* p) noexcept { mi_free(p); };
void operator delete (void* p, const std::nothrow_t&) noexcept { mi_free(p); }
void operator delete[](void* p, const std::nothrow_t&) noexcept { mi_free(p); }
mi_decl_new(n) void* operator new(std::size_t n) noexcept(false) { return mi_new(n); }
mi_decl_new(n) void* operator new[](std::size_t n) noexcept(false) { return mi_new(n); }
mi_decl_new_nothrow(n) void* operator new (std::size_t n, const std::nothrow_t& tag) noexcept { (void)(tag); return mi_new_nothrow(n); }
mi_decl_new_nothrow(n) void* operator new[](std::size_t n, const std::nothrow_t& tag) noexcept { (void)(tag); return mi_new_nothrow(n); }
#if (__cplusplus >= 201402L || _MSC_VER >= 1916)
void operator delete (void* p, std::size_t n) noexcept { mi_free_size(p,n); };
void operator delete[](void* p, std::size_t n) noexcept { mi_free_size(p,n); };
#endif
#if (__cplusplus > 201402L || defined(__cpp_aligned_new))
void operator delete (void* p, std::align_val_t al) noexcept { mi_free_aligned(p, static_cast<size_t>(al)); }
void operator delete[](void* p, std::align_val_t al) noexcept { mi_free_aligned(p, static_cast<size_t>(al)); }
void operator delete (void* p, std::size_t n, std::align_val_t al) noexcept { mi_free_size_aligned(p, n, static_cast<size_t>(al)); };
void operator delete[](void* p, std::size_t n, std::align_val_t al) noexcept { mi_free_size_aligned(p, n, static_cast<size_t>(al)); };
void operator delete (void* p, std::align_val_t al, const std::nothrow_t&) noexcept { mi_free_aligned(p, static_cast<size_t>(al)); }
void operator delete[](void* p, std::align_val_t al, const std::nothrow_t&) noexcept { mi_free_aligned(p, static_cast<size_t>(al)); }
void* operator new (std::size_t n, std::align_val_t al) noexcept(false) { return mi_new_aligned(n, static_cast<size_t>(al)); }
void* operator new[](std::size_t n, std::align_val_t al) noexcept(false) { return mi_new_aligned(n, static_cast<size_t>(al)); }
void* operator new (std::size_t n, std::align_val_t al, const std::nothrow_t&) noexcept { return mi_new_aligned_nothrow(n, static_cast<size_t>(al)); }
void* operator new[](std::size_t n, std::align_val_t al, const std::nothrow_t&) noexcept { return mi_new_aligned_nothrow(n, static_cast<size_t>(al)); }
#endif
#endif
#endif // MIMALLOC_NEW_DELETE_H