Calculate cpu usage in MCycles/sec

Here is the script to calculate cpu usage in MCycles per second.
The cpu speed is 222MHz as an example, processing data rate is 44100, each block has 8192 samples, and the total calls to foo is 532.

#!/bin/bash

rate=44100
blksize=8192
cpu=222
call=532

# the following val is got from gprof as percentage cpu time, 30.11%.
pcpu_foo=30.11

duration=`echo "scale=4; $blksize * $call / $rate" | bc`
echo "duration: " $duration

secs_foo=`echo "scale=4; $duration * $pcpu_foo /100" | bc` 
echo "secs_foo " $secs_foo

blksecs_foo=`echo "scale=4; $secs_foo/$call"|bc`
echo "blocksecs_foo" $blksecs_foo

cpu_foo=`echo "scale=4; $cpu * $rate / $blksize * $blksecs_foo"|bc`
echo "cpu_foo " $cpu_foo " MCycle/sec"