C++ Headers Not Found with pip install on MSYS2/Mingw64 for OpenBLAS

C++ Headers Not Found: Installing MSYS2/Mingw64 OpenBLAS

In this article, we will discuss how to install OpenBLAS on MSYS2/Mingw64 for C++ development. This is especially useful when you encounter errors such as "C++ headers not found" while trying to compile a C++ program that requires OpenBLAS.

Prerequisites

Before we begin, it is assumed that you have already installed MSYS2/Mingw64 on your system. If you haven't, you can download it from the official website here.

It is also assumed that you have a C++ compiler installed on your system. If you don't have one, you can install the mingw-w64-x86_64-gcc package using the pacman package manager.

Installing OpenBLAS

To install OpenBLAS on MSYS2/Mingw64, open the MSYS2 terminal and run the following command:

pacman -S mingw-w64-x86_64-openblas

This will install the OpenBLAS library for 64-bit Windows systems.

Using OpenBLAS in Your C++ Program

Once you have installed OpenBLAS, you can use it in your C++ program by linking it during the compilation process. Here's an example:

#include 
#include 

int main() {
    double A[6] = {1.0, 2.0, 3.0, 4.0, 5.0, 6.0};
    double B[6] = {1.0, 2.0, 3.0, 4.0, 5.0, 6.0};
    double C[6] = {0.0, 0.0, 0.0, 0.0, 0.0, 0.0};

    cblas_dgemm(CblasRowMajor, CblasNoTrans, CblasNoTrans, 2, 3, 3, 1.0, A, 3, B, 3, 0.0, C, 3);

    for (int i = 0; i < 6; i++) {
        std::cout << C[i] << " ";
    }

    return 0;
}

This program uses the cblas_dgemm() function from the OpenBLAS library to perform a matrix multiplication. To compile this program, you can use the following command:

g++ -o my_program my_program.cpp -I/usr/include/openblas -L/usr/lib/openblas -lopenblas

This command includes the OpenBLAS header files using the -I flag, links the OpenBLAS library using the -L and -l flags, and specifies the output file name using the -o flag.

• Installing OpenBLAS on MSYS2/Mingw64 can be done using the pacman package manager.
• To use OpenBLAS in your C++ program, you need to include its header files and link its library during the compilation process.
• Here are some references that you might find helpful:

• MSYS2 Official Website
• OpenBLAS Official Website
• GCC Compiler Documentation

Note: This article is intended to provide a focused discussion on installing OpenBLAS on MSYS2/Mingw64 for C++ development. It is not intended to cover all the details of C++ programming or OpenBLAS usage. For more in-depth information, please refer to the official documentation and resources.