I just tried enabling JIT on my php8 with the following two lines:
bench.php went from 0.232 to 0.074 (ran multiple times, both varied by ±0.002 at most).
I know it’s not representative of real-world code, but I wasn’t expecting anywhere near that level of improvement.
I’ll add some more numbers when I’ve run some tests in my own codebase.
Without opcache and JIT
With opcache, but without JIT
With opcache and JIT
This is the result of testing these with hyperfine. The times are a little higher because they include starting php when ran this way.
Running Psalm on itself (a real-world code use-case):
./psalm --no-diff
PHP 7.4: 12.25 seconds
PHP 8.0: 12.22 seconds
PHP 8.0 with JIT: 11.89 seconds
Running Psalm on itself without cache (less of a real-world use-case, though sometimes CI won’t use cache) :
./psalm --no-cache
PHP 7.4: 16.00 seconds
PHP 8.0: 16.46 seconds
PHP 8.0 with JIT: 15.25 seconds
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