Module simd 

SIMD (Single Instruction Multiple Data) optimizations for performance-critical operations

This module provides SIMD-accelerated implementations of raster operations, statistics, resampling, and mathematical functions. It uses architecture-specific intrinsics (std::arch) with runtime CPU feature detection and graceful scalar fallback.

Architecture Support

• aarch64: NEON (128-bit, baseline on all aarch64 CPUs)
• x86-64: SSE2 (baseline), AVX2 (runtime detected), AVX-512 (runtime detected)
• Other: Scalar fallback with auto-vectorization hints

Runtime Detection

On x86-64, the module uses is_x86_feature_detected! to select the best available instruction set at runtime. On aarch64, NEON is always available as part of the base architecture. See detect module for details.

Performance

Expected speedups over scalar implementations:

• Raster operations: 2-8x (element-wise ops, min/max, thresholds)
• Statistics: 4-8x (sum, mean, histograms)
• Resampling: 2-4x (bilinear, bicubic interpolation)
• Math functions: 3-6x (sqrt, log, exp, trig)

Usage

Enable SIMD optimizations with the simd feature (enabled by default):

[dependencies]
oxigdal-algorithms = { version = "0.1", features = ["simd"] }

Example

use oxigdal_algorithms::simd::raster::add_f32;

let a = vec![1.0_f32; 1000];
let b = vec![2.0_f32; 1000];
let mut result = vec![0.0_f32; 1000];

// Automatically uses best available SIMD instruction set
add_f32(&a, &b, &mut result);

assert_eq!(result[0], 3.0);

Safety

All public SIMD operations are safe. Unsafe intrinsics are encapsulated internally with proper bounds checking, alignment handling, and error propagation. Pure Rust implementation (no C/Fortran dependencies).

Modules

colorspace

SIMD-accelerated color space conversions

cost_distance_simd

SIMD-accelerated cost-distance and path analysis operations

detect

Runtime SIMD capability detection

filters

SIMD-accelerated convolution filters for image processing

focal_simd

SIMD-accelerated focal (neighborhood) statistics operations

histogram

SIMD-accelerated histogram computation

hydrology_simd

SIMD-accelerated hydrology analysis operations

math

SIMD-accelerated mathematical operations

morphology

SIMD-accelerated morphological operations

platform

Platform-specific SIMD configuration (compile-time constants)

projection

SIMD-accelerated coordinate transformations

raster

SIMD-accelerated raster operations

resampling

SIMD-accelerated resampling operations

statistics

SIMD-accelerated statistical operations

terrain_simd

SIMD-accelerated terrain analysis operations

texture_simd

SIMD-accelerated texture analysis using Gray-Level Co-occurrence Matrix (GLCM)

threshold

SIMD-accelerated thresholding operations

util

Utilities for working with SIMD operations