-qessl

The -qessl option for Fortran compiles directs the compiler to substitute the much faster routines from the Engineering and Scientific Subroutine Library (ESSL) for their equivalent Fortran 90 intrinsic procedures when it is safe to do so. Both 32 and 64 bit datatypes are supported. In addition to -qessl, at least one of these other options must be specified for this optimization to take effect: -qsmp, -qipa , -qhot, -O3, -O4, or -O5.

In addition to -qessl, either -lessl or -lesslsmp must be specified at link time. If -lessl is specified the single threaded versions from the ESSL library will be used. If -lesslsmp is specified, the multi-threaded versions will be used. Codes linked with -lesslsmp will be run with OMP_NUM_THREADS user threads or with one user threads per processor if this environment variable has not been set.