Factor Language Blog

V8 is, of course, Google’s new, much-hyped JavaScript VM. It combines a simple JIT with inline caching, and along with SquirrelFish, it promises to take JavaScript performance to the next level.

Factor does not do inline caching (although this is planned), however the language itself is more static and the compiler performs more advanced optimizations than the V8 JIT. So I thought it would be interesting to see how these two approaches to dynamic language implementation stack up.

I compiled the V8 trunk today on my Intel Core 2 Duo. Factor is of course the latest Factor from git.

I chose the following benchmarks from the language shootout:

• spectral-norm
• binary-trees
• fasta
• nsieve
• nsieve-bits
• partial-sums

Unfortunately, I couldn’t get reverse-complement or a few others to work in V8, because they use the readline() function which does not appear to exist. It would have been interesting to compare more benchmarks.

I got the JavaScript versions from the shootout website; the Factor versions are in the Factor repository.

I ran the V8 benchmarks from the command line, like so,
./shell foo.js
And I ran the Factor benchmarks from within the Factor environment.

Without further ado, and without any attempt at post-mortem or analysis, here are the results. All running times are in seconds:

Benchmark:	Factor	V8
binary-trees	3.1	3.8
fasta	8.9	12
nsieve	0.6	1.3
nsieve-bits	1.5	6.9
partial-sums	2.6	2.3
spectral-norm	29	85