sse2neon

A C/C++ header file that converts Intel SSE intrinsics to Arm/Aarch64 NEON intrinsics.

Introduction

sse2neon is a translator of Intel SSE (Streaming SIMD Extensions) intrinsics to Arm NEON, shortening the time needed to get an Arm working program that then can be used to extract profiles and to identify hot paths in the code. The header file sse2neon.h contains several of the functions provided by Intel intrinsic headers such as <xmmintrin.h>, only implemented with NEON-based counterparts to produce the exact semantics of the intrinsics.

Mapping and Coverage

Header file	Extension
<mmintrin.h>	MMX
<xmmintrin.h>	SSE
<emmintrin.h>	SSE2
<pmmintrin.h>	SSE3
<tmmintrin.h>	SSSE3
<smmintrin.h>	SSE4.1
<nmmintrin.h>	SSE4.2
<wmmintrin.h>	AES

sse2neon aims to support SSE, SSE2, SSE3, SSSE3, SSE4.1, SSE4.2 and AES extension.

In order to deliver NEON-equivalent intrinsics for all SSE intrinsics used widely, please be aware that some SSE intrinsics exist a direct mapping with a concrete NEON-equivalent intrinsic. However, others lack of 1-to-1 mapping, that means the equivalents are implemented using several NEON intrinsics.

For example, SSE intrinsic _mm_loadu_si128 has a direct NEON mapping (vld1q_s32), but SSE intrinsic _mm_maddubs_epi16 has to be implemented with 13+ NEON instructions.

Usage

• Put the file sse2neon.h in to your source code directory.

• Locate the following SSE header files included in the code:

#include <xmmintrin.h>
#include <emmintrin.h>

{p,t,s,n,w}mmintrin.h should be replaceable, but the coverage of these extensions might be limited though.

• Replace them with:

#include "sse2neon.h"

• Explicitly specify platform-specific options to gcc/clang compilers.
  • On ARMv8-A targets, you should specify the following compiler option: (Remove crypto and/or crc if your architecture does not support cryptographic and/or CRC32 extensions)

  -march=armv8-a+fp+simd+crypto+crc

  • On ARMv7-A targets, you need to append the following compiler option:

  -mfpu=neon

Compile-time Configurations

Considering the balance between correctness and performance, sse2neon recognizes the following compile-time configurations:

• SSE2NEON_PRECISE_MINMAX: Enable precise implementation of _mm_min_ps and _mm_max_ps. If you need consistent results such as NaN special cases, enable it.
• SSE2NEON_PRECISE_DIV: Enable precise implementation of _mm_rcp_ps and _mm_div_ps by additional Netwon-Raphson iteration for accuracy.
• SSE2NEON_PRECISE_SQRT: Enable precise implementation of _mm_sqrt_ps and _mm_rsqrt_ps by additional Netwon-Raphson iteration for accuracy.
• SSE2NEON_PRECISE_DP: Enable precise implementation of _mm_dp_pd. When the conditional bit is not set, the corresponding multiplication would not be executed.

The above are turned off by default, and you should define the corresponding macro(s) as 1 before including sse2neon.h if you need the precise implementations.

Run Built-in Test Suite

sse2neon provides a unified interface for developing test cases. These test cases are located in tests directory, and the input data is specified at runtime. Use the following commands to perform test cases:

$ make check

You can specify GNU toolchain for cross compilation as well. QEMU should be installed in advance.

$ make CROSS_COMPILE=aarch64-linux-gnu- check # ARMv8-A

or

$ make CROSS_COMPILE=arm-linux-gnueabihf- check # ARMv7-A

Check the details via Test Suite for SSE2NEON.

Adoptions

Here is a partial list of open source projects that have adopted sse2neon for Arm/Aarch64 support.

• Aaru Data Preservation Suite is a fully-featured software package to preserve all storage media from the very old to the cutting edge, as well as to give detailed information about any supported image file (whether from Aaru or not) and to extract the files from those images.
• aether-game-utils is a collection of cross platform utilities for quickly creating small game prototypes in C++.
• Apache Doris is a Massively Parallel Processing (MPP) based interactive SQL data warehousing for reporting and analysis.
• Apache Impala is a lightning-fast, distributed SQL queries for petabytes of data stored in Apache Hadoop clusters.
• Apache Kudu completes Hadoop's storage layer to enable fast analytics on fast data.
• ART is an implementation in OCaml of Adaptive Radix Tree (ART).
• Async is a set of c++ primitives that allows efficient and rapid development in C++17 on GNU/Linux systems.
• avec is a little library for using SIMD instructions on both x86 and Arm.
• BEAGLE is a high-performance library that can perform the core calculations at the heart of most Bayesian and Maximum Likelihood phylogenetics packages.
• BitMagic implements compressed bit-vectors and containers (vectors) based on ideas of bit-slicing transform and Rank-Select compression, offering sets of method to architect your applications to use HPC techniques to save memory (thus be able to fit more data in one compute unit) and improve storage and traffic patterns when storing data vectors and models in files or object stores.
• bipartite_motif_finder as known as BMF (Bipartite Motif Finder) is an open source tool for finding co-occurences of sequence motifs in genomic sequences.
• Blender is the free and open source 3D creation suite, supporting the entirety of the 3D pipeline.
• Boo is a cross-platform windowing and event manager similar to SDL or SFML, with additional 3D rendering functionality.
• CARTA is a new visualization tool designed for viewing radio astronomy images in CASA, FITS, MIRIAD, and HDF5 formats (using the IDIA custom schema for HDF5).
• Catcoon is a feedforward neural network implementation in C.
• compute-runtime, the Intel Graphics Compute Runtime for oneAPI Level Zero and OpenCL Driver, provides compute API support (Level Zero, OpenCL) for Intel graphics hardware architectures (HD Graphics, Xe).
• Cog is a free and open source audio player for macOS.
• dab-cmdline provides entries for the functionality to handle Digital audio broadcasting (DAB)/DAB+ through some simple calls.
• DISTRHO is an open-source project for Cross-Platform Audio Plugins.
• EDGE is an advanced OpenGL source port spawned from the DOOM engine, with focus on easy development and expansion for modders and end-users.
• Embree a collection of high-performance ray tracing kernels. Its target users are graphics application engineers who want to improve the performance of their photo-realistic rendering application by leveraging Embree's performance-optimized ray tracing kernels.
• emp-tool aims to provide a benchmark for secure computation and allowing other researchers to experiment and extend.
• FoundationDB is a distributed database designed to handle large volumes of structured data across clusters of commodity servers.
• iqtree2 is an efficient and versatile stochastic implementation to infer phylogenetic trees by maximum likelihood.
• IResearch is a cross-platform, high-performance document oriented search engine library written entirely in C++ with the focus on a pluggability of different ranking/similarity models.
• kram is a wrapper to several popular encoders to and from PNG/KTX files with LDR/HDR and BC/ASTC/ETC2.
• libscapi stands for the "Secure Computation API", providing reliable, efficient, and highly flexible cryptographic infrastructure.
• libmatoya is a cross-platform application development library, providing various features such as common cryptography tasks.
• Madronalib enables efficient audio DSP on SIMD processors with readable and brief C++ code.
• minimap2 is a versatile sequence alignment program that aligns DNA or mRNA sequences against a large reference database.
• MMseqs2 (Many-against-Many sequence searching) is a software suite to search and cluster huge protein and nucleotide sequence sets.
• MRIcroGL is a cross-platform tool for viewing NIfTI, DICOM, MGH, MHD, NRRD, AFNI format medical images.
• N2 is an approximate nearest neighborhoods algorithm library written in C++, providing a much faster search speed than other implementations when modeling large dataset.
• nanors is a tiny, performant implementation of Reed-Solomon codes, capable of reaching multi-gigabit speeds on a single core.
• niimath is a general image calculator with superior performance.
• NVIDIA GameWorks has been already used in a lot of games. These repositories are public on GitHub.
• ofxNDI is an openFrameworks addon to allow sending and receiving images over a network using the NewTek Network Device Protocol.
• OGRE is a scene-oriented, flexible 3D engine written in C++ designed to make it easier and more intuitive for developers to produce games and demos utilising 3D hardware.
• Olive is a free non-linear video editor for Windows, macOS, and Linux.
• OpenXRay is an improved version of the X-Ray engine, used in world famous S.T.A.L.K.E.R. game series by GSC Game World.
• parallel-n64 is an optimized/rewritten Nintendo 64 emulator made specifically for Libretro.
• PFFFT does 1D Fast Fourier Transforms, of single precision real and complex vectors.
• PlutoSDR Firmware is the customized firmware for the PlutoSDR that can be used to introduce fundamentals of Software Defined Radio (SDR) or Radio Frequency (RF) or Communications as advanced topics in electrical engineering in a self or instructor lead setting.
• Pygame is cross-platform and designed to make it easy to write multimedia software, such as games, in Python.
• RPCS3 is the world's first free and open-source PlayStation 3 emulator/debugger, written in C++.
• simd_utils is a header-only library implementing common mathematical functions using SIMD intrinsics.
• SMhasher provides comprehensive Hash function quality and speed tests.
• Spack is a multi-platform package manager that builds and installs multiple versions and configurations of software.
• srsLTE is an open source SDR LTE software suite.
• Surge is an open source digital synthesizer.
• XMRig is an open source CPU miner for Monero cryptocurrency.

Related Projects

• SIMDe: fast and portable implementations of SIMD intrinsics on hardware which doesn't natively support them, such as calling SSE functions on ARM.
• CatBoost's sse2neon
• ARM_NEON_2_x86_SSE
• AvxToNeon
• sse2rvv: C header file that converts Intel SSE intrinsics to RISC-V Vector intrinsic.
• sse2msa: A C/C++ header file that converts Intel SSE intrinsics to MIPS/MIPS64 MSA intrinsics.
• POWER/PowerPC support for GCC contains a series of headers simplifying porting x86_64 code that makes explicit use of Intel intrinsics to powerpc64le (pure little-endian mode that has been introduced with the POWER8).
  • implementation: xmmintrin.h, emmintrin.h, pmmintrin.h, tmmintrin.h, smmintrin.h

Reference

• Intel Intrinsics Guide
• Arm Neon Intrinsics Reference
• Neon Programmer's Guide for Armv8-A
• NEON Programmer's Guide
• qemu/target/i386/ops_sse.h: Comprehensive SSE instruction emulation in C. Ideal for semantic checks.
• Porting Takua Renderer to 64-bit ARM- Part 1
• Porting Takua Renderer to 64-bit ARM- Part 2
• Comparing SIMD on x86-64 and arm64
• Getting started with AWS Graviton

Licensing

sse2neon is freely redistributable under the MIT License.