#
# The point of this is not to test the efficiency of the algorithm,
# but to see how fast the client can crank out lots and lots and lots
# of function calls and many many many evaluation switches.
#
# The point of fib vs. fibb is to demonstrate how a little bit of
# care in coding can make a big difference in performance.
#
# These functions are considered to be "frozen".  Dont you dare change
# them under penalty of death, for that will foul up the long term
# comparisons that we're trying to test!
#
# All of the times here are for my 486DX2/66, running FreeBSD 2.2
#

load utime
^set max_recur 1000

alias fib {
	if ([$0]==0) { @ function_return = 0} {
		if ([$0]==1) { @ function_return = 1} {
			@ function_return = fib(${[$0]-1}) + fib(${[$0]-2})
		}
	}
}

alias fibb {
	@function_return=[$0]>1?fibb(${[$0]-1})+fibb(${[$0]-2}):[$0]?1:0
}

alias fibbb {
	@ [$0] > 1 ? {
		@ :x1 = [$0], x1--, :x2 = x1, x2--
		return ${fibbb($x1)+fibbb($x2)}
	} : { return $0 }
}

alias fib2 {
	@ start = utime()
	eval echo $fib(20)
	echo Total time = $utime_sub($utime() $start)
}

# (epic3.000 - 53 s), (epic3.004 - 45 s), (epic4pre0.020 - 37 s)
alias fib3 {
	@ start = utime()
	eval echo $fibb(20)
	echo Total time = $utime_sub($utime() $start)
}

# (epic3.000 - 198 s), (epic3.004 - 180 s), (epic4pre0.020 - 144 s)
alias fib4 {
	@ start = utime()
	eval echo $fib(22)
	echo Total time = $utime_sub($utime() $start)
}

alias fib4b {
	@ start = utime()
	eval echo $fibbb(22)
	echo Total time = $utime_sub($utime() $start)
}


# (epic3.000 - 141 s), (epic3.004 - 117 s), (epic4pre0.020 - 96 s)
alias fib5 {
	@ start = utime()
	eval echo $fibb(22)
	echo Total time = $utime_sub($utime() $start)
}

alias fib6 {
	@ start = utime()
	eval echo $fib(6)
	echo Total time = $utime_sub($utime() $start)
}

alias fib7 {
	@ start = utime()
	eval echo $fibb(6)
	echo Total time = $utime_sub($utime() $start)
}