labneura2 0.1.8

SIMD-accelerated tensor operations for neural networks

LabNeura

High-performance C++ tensor library with Python bindings, featuring hardware-accelerated SIMD operations optimized for modern CPUs. Supports AVX2 (x86_64), NEON (ARM64/Apple Silicon), and provides mixed-precision computation with optional INT8 quantization.

🚀 Features

Hardware Acceleration

• Multi-backend Architecture: Runtime detection and selection of optimal SIMD backend
  • AVX2 Backend: 8-wide FP32 or 32-wide INT8 vectorization on Intel/AMD x86_64 CPUs
  • NEON Backend: 4-wide FP32 or 16-wide INT8 vectorization on Apple Silicon (M1/M2/M3/M4) and ARM64
  • Generic Backend: Portable fallback for all architectures
• Automatic Backend Selection: Detects CPU capabilities at runtime using detect_backend()
• Compile-time Optimization: CMake detects hardware and enables appropriate compiler flags

Tensor Operations

• Mixed-Precision Support: FP32 (32-bit float), INT8 (8-bit quantized), with future support for FP64, FP16, INT32, INT16
• In-place Operations: add_inplace(), mul_inplace(), sub_inplace() for memory efficiency
• Immutable Operations: add() returns new tensors without modifying originals
• Quantization: Built-in INT8 quantization with 4x memory reduction

Python Integration

• Easy Installation: pip install labneura2 (PyPI package name, import as labneura)
• pybind11 Bindings: Zero-copy data access between C++ and Python
• NumPy Compatible: Seamless integration with NumPy workflows

📦 Installation

Python Package (Recommended)

pip install labneura2

Note: The PyPI package is named labneura2, but you import it as labneura:

import labneura  # Import statement

Build from Source

Prerequisites

• CMake >= 3.14
• C++17 compatible compiler (Clang, GCC, MSVC)
• Python 3.9+ (for Python bindings)
• pybind11 >= 3.0.1

C++ Library

mkdir build && cd build
cmake .. -DCMAKE_BUILD_TYPE=Release
cmake --build . --config Release
cmake --install .

Python Bindings

cd python
pip install .

For development with coverage:

LABNEURA_COVERAGE=1 pip install -e .

🎯 Quick Start

Python Usage

import labneura

# Detect available backend
print(f"Using backend: {labneura.detect_backend()}")  # "AVX2", "NEON", or "GENERIC"

# FP32 operations
t1 = labneura.Tensor([1.0, 2.0, 3.0, 4.0], labneura.QuantizationMode.FP32)
t2 = labneura.Tensor([0.5, 0.5, 0.5, 0.5], labneura.QuantizationMode.FP32)

# In-place addition (modifies t1)
t1.add_inplace(t2)
print(t1.data_fp32())  # [1.5, 2.5, 3.5, 4.5]

# Non-destructive addition (returns new tensor)
t3 = t1.add(t2)

# Other operations
t1.mul_inplace(t2)  # Element-wise multiplication
t1.sub_inplace(t2)  # Element-wise subtraction

# INT8 quantization for memory efficiency
t_int8 = labneura.Tensor([10, 20, 30, 40], labneura.QuantizationMode.INT8)
print(t_int8.data_int8())  # [10, 20, 30, 40]

C++ Usage

#include "labneura/tensor.h"
#include "labneura/backends/backend_factory.h"
#include <iostream>

int main() {
    // Detect backend at runtime
    std::cout << "Backend: " << labneura::detect_backend() << std::endl;
    
    // Create tensors
    std::vector<float> data1 = {1.0f, 2.0f, 3.0f, 4.0f};
    std::vector<float> data2 = {0.5f, 0.5f, 0.5f, 0.5f};
    
    labneura::Tensor t1(data1, labneura::QuantizationMode::FP32);
    labneura::Tensor t2(data2, labneura::QuantizationMode::FP32);
    
    // In-place operations
    t1.add_inplace(t2);
    
    // Access data
    const float* result = t1.data_fp32();
    for (size_t i = 0; i < t1.size(); ++i) {
        std::cout << result[i] << " ";
    }
    
    return 0;
}

Compile:

g++ -std=c++17 -O3 -mavx2 main.cpp -I/path/to/labneura/include -L/path/to/labneura/lib -llabneura

⚡ Performance

LabNeura delivers SIMD-accelerated performance competitive with or exceeding NumPy through hardware-specific optimizations:

Benchmarks (Apple M1)

Backend: NEON
Size: 1,000,000 elements, 100 iterations
FP32 Addition: 2500 M ops/sec
INT8 Addition: 5000 M ops/sec (4x throughput due to wider vectors)

Run Benchmarks

python examples/benchmark_numpy.py

Performance Characteristics

• NEON (ARM64): Processes 4 FP32 or 16 INT8 elements per instruction
• AVX2 (x86_64): Processes 8 FP32 or 32 INT8 elements per instruction
• Memory Efficiency: INT8 mode uses 4x less memory, improving cache utilization
• Zero Threading Overhead: Single-threaded SIMD maximizes per-core performance

🏗️ Architecture

Backend Selection Hierarchy

Runtime Detection → Best Available Backend
1. Check AVX2 support (x86_64) → AVX2Backend
2. Check NEON support (ARM64) → NEONBackend
3. Fallback → GenericBackend

Directory Structure

LabNeura/
├── include/labneura/          # Public C++ headers
│   ├── tensor.h               # Main Tensor API
│   ├── types.hpp              # Type definitions
│   └── backends/              # Backend interfaces
│       ├── base.h             # TensorBackend abstract base
│       ├── avx2.h             # AVX2 SIMD backend
│       ├── neon.h             # NEON SIMD backend
│       ├── generic.h          # Portable fallback
│       ├── backend_factory.h  # Factory + detect_backend()
│       └── cpu_features.h     # Runtime CPU feature detection
├── src/labneura/              # Implementation
│   ├── tensor.cpp             # Tensor class implementation
│   └── backends/*.cpp         # Backend implementations
├── python/                    # Python bindings
│   ├── labneura_py.cpp        # pybind11 bindings
│   └── setup.py               # Python package config
├── examples/                  # Usage examples
│   ├── main.cpp               # C++ example
│   ├── test_tensor.py         # Python example
│   └── benchmark_numpy.py     # Performance comparison
├── tests/                     # Test suite
├── CMakeLists.txt             # CMake build configuration
└── Makefile                   # Build automation

🧪 Testing

Run Tests

# Python tests
pytest tests/

# Specific test files
pytest tests/test_tensor_ops.py
pytest tests/test_quantization.py

# With coverage
pytest --cov=labneura tests/

Run Examples

# C++ example
./build/labneura_example

# Python examples
python examples/test_tensor.py
python examples/benchmark_numpy.py

🛠️ Development

Build Commands

# Clean build
make clean

# Build Python package
make build

# Install locally
make install

# Run tests
make test

# Build distribution packages
make build-dist

# Publish to TestPyPI
TEST_PYPI_TOKEN=pypi-... make publish-testpypi

# Publish to PyPI
PYPI_TOKEN=pypi-... make publish

Build Flags

# Enable AVX2 (x86_64)
cmake .. -DCMAKE_CXX_FLAGS="-mavx2"

# Enable LLVM coverage
LABNEURA_COVERAGE=1 cmake ..

# Release build with optimizations
cmake .. -DCMAKE_BUILD_TYPE=Release

📊 Implementation Details

SIMD Optimization

AVX2 Backend (x86_64)

• Register Width: 256 bits
• FP32: Processes 8 floats per instruction (_mm256_add_ps, _mm256_mul_ps)
• INT8: Processes 32 bytes per instruction (_mm256_add_epi8)
• Alignment: Pads arrays to 8-element boundaries

NEON Backend (ARM64/Apple Silicon)

• Register Width: 128 bits
• FP32: Processes 4 floats per instruction (vaddq_f32, vmulq_f32)
• INT8: Processes 16 bytes per instruction (vaddq_s8)
• Alignment: Pads arrays to 4-element boundaries
• Optimization: Single-threaded design maximizes instruction-level parallelism

Quantization Strategy

• INT8 Mode: Stores data as 8-bit signed integers (-128 to 127)
• Memory Reduction: 4x smaller than FP32 (1 byte vs 4 bytes per element)
• Saturation Arithmetic: Prevents overflow by clamping to [-128, 127]
• Use Cases: Neural network inference, mobile deployment

Backend Detection

// Runtime detection in backend_factory.cpp
std::string detect_backend() {
    if (cpu_supports_avx2()) return "AVX2";
    if (cpu_supports_neon()) return "NEON";
    return "GENERIC";
}

CPU feature detection uses:

• x86_64: __builtin_cpu_supports("avx2")
• ARM64: Compile-time __ARM_NEON macro (NEON is mandatory on ARMv8)

🌐 Publishing

Package Names

• PyPI Name: labneura2 (install with pip install labneura2)
• Python Module: labneura (import with import labneura)
• GitHub: https://github.com/gokatharun/LabNeura

CI/CD Pipeline

GitHub Actions workflow automates:

1. Build distribution packages
2. Run test suite
3. Publish to TestPyPI (manual trigger)
4. Publish to PyPI (on release tags)

📝 License

MIT License - see LICENSE file for details.

🤝 Contributing

Contributions welcome! Please:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit changes (git commit -m 'Add amazing feature')
4. Push to branch (git push origin feature/amazing-feature)
5. Open a Pull Request

📮 Support

• Issues: https://github.com/gokatharun/LabNeura/issues
• Discussions: https://github.com/gokatharun/LabNeura/discussions

🙏 Acknowledgments

Built with:

• pybind11 - Seamless Python/C++ bindings
• CMake - Cross-platform build system
• SIMD intrinsics: Intel AVX2, ARM NEON

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Author: LabNeura Contributors
Version: 0.1.2
Python: 3.9+ | C++: 17+ | Platforms: macOS (Apple Silicon & Intel), Linux (x86_64, ARM64)