README.md

matmul - Generalized Matrix-Matrix-Multiplication (GEMM) Library with C Interface

This repository contains multiple sequential and parallel implementations of the generalized matrix-matrix-multiplication GEMM (C = alpha * A * B + beta * C). Single and double precision values are supported (compile-time decision).

Software License

matmul is licensed under LGPLv3 or later.

Available Implementations

• Sequential

  • Basic (3 nested loops ijk)
  • Basic Algorithm with a Single Optimization:
    • Pointer Instead of Index
    • restrict for Input Pointers
    • Loop Reordering (ikj)
    • Index Precalculation
    • Loop Unrolling (4, 8, 16)
    • Loop Blocking/Tiling
  • With Multiple Optimizations
    • restrict + Loop Reordering + Blocking
    • restrict + Loop Reordering
  • Strassen algorithm

• Parallel

  • OpenMP 2.0
    • guided schedule
    • static schedule
    • Offload to Intel XeonPhi
    • Strassen Algorithm
  • OpenMP 3.0
    • static schedule + loop collapsing
  • OpenMP 4.0
    • target + teams + distribute + parallel for host and device
  • OpenACC
  • CUDA Native Implementation
    • fixed block size
      • 2D static shared memory
      • 1D static shared memory
      • 1D extern shared memory
    • dynamic block size
      • 1D extern shared memory
        • with memory copy
        • without memory copy
  • alpaka
    • Sequential
    • CUDA
      • with memory copy
      • without memory copy
    • OpenMP 2.0 (Host only)
    • OpenMP 4.0 (Host only)
    • std::thread
    • Boost.Fiber
  • BLAS
    • MKL
    • MKL Offload to Intel XeonPhi
    • cuBLAS2
      • with memory copy
      • without memory copy
  • MPI
    • Cannon Algorithm
      • Optimized Sequential per Node
        • Blocking Communication
        • Non-Blocking Communication
      • MKL per Node
      • cuBLAS2 per Node
    • DNS
      • Optimized Sequential per Node