[Bug fortran/106565] Using a transposed matrix in matmul (GCC-10.3.0) is very slow

[quanhua.liu at noaa dot gov via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106565

--- Comment #4 from Quanhua Liu <quanhua.liu at noaa dot gov> ---
Using 
gfortran -O3 -fexternal-blas -L/..... -lblas testmatrixCal.f90
time a.out  1
real:  6.14 (s)
time a.out  2
real: 5.41

It is 6 times slower than
  BB = transpose(B)
  C = matmul(A, BB)

ifort doesn't have the problem.