veloz

README

veloz

Veloz is a high-performance SIMD-accelerated library for ASCII and UTF-8 string operations in Go. It provides fast validation and case-insensitive string matching, leveraging SIMD instructions on supported architectures for significant performance improvements over standard library implementations.

While amd64 SIMD optimizations are becoming common in the Go ecosystem, arm64 (NEON) support is often overlooked. Veloz focuses on providing first-class SIMD acceleration for arm64, making it ideal for deployment on ARM-based servers like AWS Graviton, Apple Silicon, and other ARM platforms.

Another motivation for veloz is maintainability. Many Go packages rely on hand-rolled assembly for performance-critical code, which is notoriously difficult to maintain, debug, and extend. By writing SIMD implementations in C and transpiling them to Go assembly using gocc, veloz keeps the source code readable and maintainable while still delivering native performance.

Features

• High-speed ASCII string validation
• Case-insensitive ASCII string comparison (EqualFold)
• Case-insensitive ASCII substring search (IndexFold)
• Fast UTF-8 validation
• SIMD support for amd64 (AVX2, SSE4.1) and arm64 (NEON)
• Pure Go fallback for other architectures

Installation

To install the library, use go get:

go get github.com/mhr3/veloz

Usage

ASCII Operations

The ascii package provides functions for validating and searching ASCII strings:

package main

import (
    "fmt"

    "github.com/mhr3/veloz/ascii"
)

func main() {
    // Check if a string contains only ASCII characters
    fmt.Println(ascii.ValidString("Hello, World!"))  // true
    fmt.Println(ascii.ValidString("Hello, 世界!"))   // false

    // Case-insensitive string comparison
    fmt.Println(ascii.EqualFold("Hello", "HELLO"))   // true
    fmt.Println(ascii.EqualFold("Hello", "World"))   // false

    // Case-insensitive substring search
    fmt.Println(ascii.IndexFold("Hello, World!", "WORLD"))  // 7
    fmt.Println(ascii.IndexFold("Hello, World!", "foo"))    // -1
}

UTF-8 Validation

The utf8 package provides fast UTF-8 string validation:

package main

import (
    "fmt"

    "github.com/mhr3/veloz/utf8"
)

func main() {
    // Validate UTF-8 strings
    fmt.Println(utf8.ValidString("Hello, 世界!"))           // true
    fmt.Println(utf8.ValidString("Valid UTF-8 string"))    // true
    fmt.Println(utf8.ValidString(string([]byte{0xff})))    // false (invalid UTF-8)
}

Benchmarks

Function	CPU	naive (MB/s)	veloz (MB/s)	Speedup
ascii.ValidString	AMD Zen 3	8,715	117,592	13.5x
ascii.EqualFold	AMD Zen 3	5,333	32,775	6.1x
ascii.IndexFold	AMD Zen 3	5,828	19,372	3.3x
ascii.IndexAny	AMD Zen 3	1,716	8,775	5.1x
utf8.ValidString	AMD Zen 3	1,184	11,291	9.5x
ascii.ValidString	Graviton 2	4,902	33,642	6.9x
ascii.EqualFold	Graviton 2	3,017	10,848	3.6x
ascii.IndexFold	Graviton 2	2,728	8,431	3.1x
ascii.IndexAny	Graviton 2	698	9,488	13.6x
utf8.ValidString	Graviton 2	618	3,091	5.0x
ascii.ValidString	Apple M2	12,256	89,227	7.3x
ascii.EqualFold	Apple M2	2,336	21,254	9.1x
ascii.IndexFold	Apple M2	7,117	29,046	4.1x
ascii.IndexAny	Apple M2	1,950	28,527	14.6x
utf8.ValidString	Apple M2	1,673	10,014	6.0x