how to test jsengine in firefox with the affiliate js files in firefox source code?

Question

I have built the spidermonkey from source successfully ，all that I am confused is how can I test its performance？ Fortunaly, I see many test js files in the /js/src/tests folder in FFsource code, so, can I take adventage of these test files? And how ?

Answer 1

Those tests are reference tests for correctness purposes. Performance tests you'll generally run yourself along these lines:

$ cat test.js 
var accum = 1;
for (let i = 0; i < 1000000000; ++i) accum = accum * 1.0000001 + 1;
print(accum);
$ ./js -m -n -b test.js 
2.6881041239718265e+50
runtime = 7313.683 ms

Make sure you're running an optimized build and be sure to turn on the JIT flags.