Timing the Linear Equations Routines

The linear equation timing program is found in LAPACK/TIMING/LIN and the input files are in LAPACK/TIMING. Three input files are provided in each data type for timing the linear equation routines, one for square matrices, one for band matrices, and one for rectangular matrices. The small data sets for the REAL version are stime_small.in, sband_small.in, and stime2_small.in, respectively, and the large data sets are stime_large.in, sband_large.in, and stime2_large.in.

The timing program for the least squares routines uses special instrumented versions of the LAPACK routines to time individual sections of the code. The first step in compiling the timing program is therefore to make a library of the instrumented routines.

a)

To make a library of the instrumented LAPACK routines, first go to LAPACK/TIMING/LIN/LINSRC and type make followed by the data types desired, as in the examples of Section 5.3. The library of instrumented code is created in LAPACK/TIMING/LIN/linsrc_PLAT.a, where PLAT is the user-defined architecture suffix specified in the file LAPACK/make.inc.

b)

To make the linear equation timing programs, go to LAPACK/TIMING/LIN and type make followed by the data types desired, as in the examples in Section 5.3. The executable files are called xlintims, xlintimc, xlintimd, and xlintimz and are created in LAPACK/TIMING.

c)

Go to LAPACK/TIMING and make any necessary modifications to the input files. You may need to set the minimum time a subroutine will be timed to a positive value, or to restrict the size of the tests if you are using a computer with performance in between that of a workstation and that of a supercomputer. The computational requirements can be cut in half by using only one value of LDA. If it is necessary to also reduce the matrix sizes or the values of the blocksize, corresponding changes should be made to the BLAS input files (see Section 6.7.2).

d)

Run the programs for each data type you are using. For the REAL version, the commands for the small data sets are

• xlintims < stime_small.in > stime_small.out
• xlintims < sband_small.in > sband_small.out
• xlintims < stime2_small.in > stime2_small.out

or the commands for the large data sets are

• xlintims < stime_large.in > stime_large.out
• xlintims < sband_large.in > sband_large.out
• xlintims < stime2_large.in > stime2_large.out

Similar commands should be used for the other data types.