function result = perf ()

result = struct ('name', {}, 't_est', {}, 't_mad', {});

warning off;
if exist('OCTAVE_VERSION') == 0
    maxNumCompThreads(1);
end

result(end+1) = timeit ('doubleForLoop/1', @doubleForLoop_nonasgn1, 1);  
result(end+1) = timeit ('doubleForLoop/a=1', @doubleForLoop_aequal1, 1);
result(end+1) = timeit ('doubleForLoop/a=b', @doubleForLoop_aequalb, 1, 1);
result(end+1) = timeit ('doubleForLoop/a=a+b', @doubleForLoop_aplusb, 1, 1);
result(end+1) = timeit ('doubleForLoop/a=sin(b*i)', @doubleForLoop_asinbi, 2);

result(end+1) = timeit ('vectorOfSquares', @vectorOfSquares, 100, 1e3);

% mandelbrot
assert (sum (sum (mandelperf (true))) == 14791)
result(end+1) = timeit('mandel', @mandelperf, true);

% recursive fib
assert((fib (20)) == 6765)
result(end+1) = timeit('fib', @fib, 20);

% parse int
result(end+1) = timeit('parse_int', @parseintperf, 1000);

% numeric vector quicksort
assert(issorted(sortperf(5000)))
result(end+1) = timeit('quicksort', @sortperf, 5000);

% slow pi series
s = pisum (true);
assert (abs (s - 1.644834071848065) < 1e-12);
result(end+1) = timeit('pi_sum', @pisum, true);

% random matrix statistics
result(end+1) = timeit('rand_mat_stat', @randmatstat, 1000);

% largish random number gen & matmul
result(end+1) = timeit('rand_mat_mul', @randmatmul, 1000);

% printf
printfd(1)
result(end+1) = timeit('printfd', @printfd, 100000);

end


function result = timeit (name, func, varargin)

lang = 'matlab';
if exist('OCTAVE_VERSION') ~= 0
    lang = 'octave';
end

nexpt = 20;
t = zeros (nexpt, 1);

for i = 1:nexpt
    tic(); func(varargin{:}); t(i) = toc();    
end

t = t * 1000;

t_est = median (t);
t_mad = mean (abs (t - t_est));
fprintf ('%s, %s, %.2f ms  [%.2f]\n', lang, name, t_est, t_mad);

result.name = name;
result.t_est = t_est;
result.t_mad = t_mad;

end


function a = doubleForLoop_aplusb (a, b)

for i = 1:400,
    for j = 1:400,
        a = a + b;
    end
end

end


function a = doubleForLoop_aequalb (a, b)

for i = 1:600,
    for j = 1:600,
        a = b;
    end
end

end


function a = doubleForLoop_aequal1 (a)

for i = 1:1000,
    for j = 1:1000,
        a = 1;
    end
end

end


function a = doubleForLoop_nonasgn1 (ignored)

for i = 1:800,
    for j = 1:800,
        1;
    end
end

end


function a = doubleForLoop_asinbi (b)

for i = 1:200,
    for j = 1:200,
        a = sin (b * j);
    end
end

end


function vectorOfSquares (nrep, n)

for r = 1:nrep
    x = zeros (1, n);
    for i = 1:n
        x(i) = i * i;
    end
end

end


function sum = pisum(ignore)
sum = 0.0;
for j=1:500
    sum = 0.0;
    for k=1:10000
        sum = sum + 1.0/(k*k);
    end
end
end


function n = parseintperf(t)
for i = 1:t
    n = randi([0,2^32-1],1,'uint32');
    s = dec2hex(n);
    m = hex2dec(s);
    assert(m == n);
end
end


function M = mandelperf (ignore)

rr = linspace (-2.0, 0.5, 26);
ii = linspace (-1.0, 1.0, 21);
M = zeros (length (rr), length (ii));
count = 1;
for r = rr
    for i = ii
        M(count) = mandel(complex(r,i));
        count = count + 1;
    end
end
end

function n = mandel(z)
c = z;
for n=0:79
    if abs(z)>2
        return
    end
    z = z^2+c;
end
n = 80;
end


function b = qsort(a)
b = qsort_kernel(a, 1, length(a));
end

function a = qsort_kernel(a, lo, hi)
i = lo;
j = hi;
while i < hi
    pivot = a(floor((lo+hi)/2));
    while i <= j
        while a(i) < pivot, i = i + 1; end
        while a(j) > pivot, j = j - 1; end
        if i <= j
            t = a(i);
            a(i) = a(j);
            a(j) = t;
            i = i + 1;
            j = j - 1;
        end
    end
    if lo < j; a=qsort_kernel(a, lo, j); end
    lo = i;
    j = hi;
end
end

function v = sortperf(n)
v = rand(n,1);
v = qsort(v);
end


function s = pisumvec(ignore)
a = [1:10000]
for j=1:500
    s = sum( 1./(a.^2));
end
end


function [s1, s2] = randmatstat(t)
n=5;
v = zeros(t,1);
w = zeros(t,1);
for i=1:t
    a = randn(n, n);
    b = randn(n, n);
    c = randn(n, n);
    d = randn(n, n);
    P = [a b c d];
    Q = [a b;c d];
    v(i) = trace((P.'*P)^4);
    w(i) = trace((Q.'*Q)^4);
end
s1 = std(v)/mean(v);
s2 = std(w)/mean(w);
end

function t = mytranspose(x)
[m, n] = size(x);
t = zeros(n, m);
for i=1:n
    for j=1:m
        t(i,j) = x(j,i);
    end
end
end

function X = randmatmul(n)
X = rand(n,n)*rand(n,n);
end

function printfd(n)
f = fopen('/dev/null','w');
for i = 1:n
    fprintf(f, '%d %d\n', i, i);
end
fclose(f);
end