[pypy-issue] Issue #2502: Recipes for a loop with a lot of small functions (splitting long traces?) (pypy/pypy)

[Shunning Jiang]

New issue 2502: Recipes for a loop with a lot of small functions (splitting long traces?)
https://bitbucket.org/pypy/pypy/issues/2502/recipes-for-a-loop-with-a-lot-of-small

Shunning Jiang:

I'm dealing a big loop that is expected to execute for 10M-1B iterations. Inside the iteration I will have 500 functions. Inside each function there is not much work going on, basically 5-10 lines of calculations or for i in xrange(2) small loops.

I wonder if there is a way to write code differently to avoid generating too long traces.

```
#!python
for i in xrange(1000000000):
  func1()
  func2()
  func3()
  func4()
  func5()
  func6()
  func7()
  func8()
  ...
  func500()
```

The speedup of pypy over cpython is negligible. I looked at jit log and found that there are too many (~100) trace too long aborts. Is there anyway to still get high performance (or let the performance scale with the number of functions) in this case?

Thanks!