gemmt fills output matrix in wrong corner for upper row-major #4905
Description
In function cblas_?gemmt, if I pass CblasRowMajor + CblasUplo to MKL's function with that name, the output ends up being filled in the upper corner (in row-major order), but in OpenBLAS's version of cblas_?gemmt, the output ends up being filled in the lower corner instead.
Example code:
#include <iostream>
#include "cblas.h"
extern "C" void cblas_dgemmt(OPENBLAS_CONST enum CBLAS_ORDER Order, OPENBLAS_CONST enum CBLAS_UPLO Uplo, OPENBLAS_CONST enum CBLAS_TRANSPOSE TransA, OPENBLAS_CONST enum CBLAS_TRANSPOSE TransB, OPENBLAS_CONST blasint M, OPENBLAS_CONST blasint K,
OPENBLAS_CONST double alpha, OPENBLAS_CONST double *A, OPENBLAS_CONST blasint lda, OPENBLAS_CONST double *B, OPENBLAS_CONST blasint ldb, OPENBLAS_CONST double beta, double *C, OPENBLAS_CONST blasint ldc);
int main()
{
const double A[] = {
2., 3.,
0., 4.
};
double B[4] = {0.};
cblas_dgemmt(
CblasRowMajor, CblasUpper, CblasTrans, CblasNoTrans,
2, 2,
1., A, 2,
A, 2,
0., B, 2
);
std::cout << "B:" << std::endl;
std::cout << "[ " << B[0] << ", " << B[1] << "]" << std::endl;
std::cout << "[ " << B[2] << ", " << B[3] << "]" << std::endl;
return 0;
}If I run the example with OpenBLAS, the output is:
B:
[ 4, 0]
[ 6, 25]
Whereas with MKL, the output is:
B:
[ 4, 6]
[ 0, 25]
Version: OpenBLAS 0.3.28, OpenMP variant, installed from source.