Performance

[Konstantin8105]

In according to tool go tool trace for transpiling file shell.c from sqlite:

Now, c2go use only one core for transpiling.(on picture more core - it is GC working).

Problem

Need to add concurrency if possible.

[Konstantin8105]

For function main.convertLinesToNodes possible.

[Konstantin8105]

For regexp : https://github.com/opennota/re2dfa

[elliotchance]

This is great information. One of the biggest performance improvements was made by you with caching the regex's. Parallelising convertLinesToNodes would be difficult because it builds a tree.

My first thought is that it would have to be a two stage process:

1. The tree is built to a very shallow depth (like max 3 nodes deep).
2. Iterating the leaf nodes and scheduling the rest of the children to be processed on an independent Go routine.

Ideally in a pool since there would be lots of small jobs.

[Konstantin8105]

Now, on my laptop:

$ time c2go transpile sqlite3.c
real	1m0.523s
user	1m22.988s
sys	0m2.048s

[Konstantin8105]

Function main.convertLinesToNodes easy to parallelize, because it not a tree - it is parsing each element of slice. Now, I check concerrency of that function and time of transpilig going down from 60 sec to 45 sec. Preliminary 25%.
But function main.buildTree is a tree and that function is difficult for parallelization.

[Konstantin8105]

After create a parallell covertLinesToNodes: