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OpenBLAS Example

OpenBLAS Overview

OpenBLAS is an optimized BLAS computation library released under the BSD license. BLAS (Basic Linear Algebra Subprograms) is an API standard for numerical libraries that provide basic linear-algebra operations such as vector and matrix multiplication. OpenBLAS is one concrete implementation of the BLAS standard.

In K230 RTOS SDK, a prebuilt OpenBLAS library is already included under:

src/rtsmart/libs/openblas/

Users can directly link against this static library when building their own applications.

Build Examples

This section explains how to build executables by using the prebuilt OpenBLAS static library in the SDK. The SDK provides four example programs under:

src/rtsmart/examples/3rd-party/openblas/

Code Structure

openblas_cblas_saxpy
openblas_cblas_sgemm
openblas_cblas_sger
openblas_fortran_dgemm
CMakeLists.txt
build_app.sh
cmake/

Firmware Build

If you want the examples to be built into the firmware, run make menuconfig from the K230 RTOS SDK root and enable:

RT-Smart UserSpace Examples Configuration
-> Enable build 3rd-party examples
-> Enable Build OpenBlas Sample Programs

The examples will be placed under sdcard/app/examples/3rd-party/openblas in the firmware image.

Example Build

If you only want to build the OpenBLAS example programs, enter:

src/rtsmart/examples/3rd-party/openblas

and run:

./build_app.sh

After a successful build, the k230_bin directory contains the compiled elf files and related test files.

Run Examples

openblas_cblas_saxpy

This sample implements:

y = alpha * x + y

Representative result:

This is the result:
4 7 11 14
This is the reference:
4 7 11 14
{Test PASS}.

openblas_cblas_sgemm

This sample implements:

C = alpha * A * B + beta * C

Representative result:

This is the result:
7 10 15 22
This is the reference:
7 10 15 22
{Test PASS}.

openblas_cblas_sger

This sample implements:

A = alpha * x * y^T + beta * A

Representative result:

This is the result:
20 40 10 20 30 60
This is the reference:
20 40 10 20 30 60
{Test PASS}.

openblas_fortran_dgemm

This sample demonstrates the Fortran-interface dgemm flow.

Representative result:

m=2,n=3,k=4,alpha=1.200000,beta=0.001000,sizeofc=6
This is matrix A
...
This is the result:
16.801 18.002 18.003 16.801 15.602 22.803
This is the reference:
16.801 18.002 18.003 16.801 15.602 22.803
{Test PASS}.