flops.c is a C program which attempts to estimate your system's floating-
point 'MFLOPS' rating for the FADD, FSUB, FMUL, and FDIV operations based on
specific 'instruction mixes' (discussed below).  The program provides an
estimate of PEAK MFLOPS performance by making maximal use of register
variables with minimal interaction with main memory.  The execution loops
are all small so that they will fit in any cache.  The flops.c execution
modules include various percent weightings of FDIV's (from 0% to 25% FDIV's)
so that the range of performance can be obtained when using FDIV's.  FDIV's,
being computationally more intensive than FADD's or FMUL's, can impact
performance considerably on some systems.

WWW: http://performance.netlib.org/performance/html/flops.html