Jens Johansen
2849d34c7c
The RegEx engine in the VM was updated in
e443b89f23 which caused the analyzer
analyzing the CFE to use ~150 mio instructions more.
Part of this was an increased cost in ignore comment processing which
relied on regex. Using regex before the updated engine made
`processPrecedingComments` have a cost of ~240 mio instructions,
updating the regex engine took that to ~264 mio instructions.
This CL gets rid of the regex and takes the cost of
`processPrecedingComments` to ~74.4 mio instructions a saving of about
189 mio instructions (all then analyzing the CFE and looking at output
from `valgrind --tool=callgrind`).
Benchmarking with `perf stat` with normal GC gives:
```
task-clock:u: -2.1760% +/- 1.6063% (-265608341.80 +/- 196062087.98) (12206056036.20 -> 11940447694.40)
page-faults:u: 0.2301% +/- 0.0313% (448.20 +/- 60.88) (194764.60 -> 195212.80)
cycles:u: -2.2906% +/- 1.6090% (-1180119481.60 +/- 828994273.75) (51521138476.00 -> 50341018994.40)
instructions:u: -0.3325% +/- 0.0032% (-196547942.60 +/- 1874215.18) (59120651337.60 -> 58924103395.00)
seconds time elapsed: -2.1715% +/- 1.6011% (-0.27 +/- 0.20) (12.21 -> 11.95)
seconds user: -2.2487% +/- 1.7816% (-0.27 +/- 0.21) (11.87 -> 11.60)
Comparing GC data:
'No' GC change.
```
Note that it must push the GC - the savings isn't really 2% in time.
And with GC disabled:
```
instructions:u: -0.4562% +/- 0.0029% (-185499444.00 +/- 1189012.77) (40663084597.80 -> 40477585153.80)
```
So here a saving of ~185 mio which fits okay with the data from
valgrind.
Change-Id: Ib203baeac6a93f5e37c737080fed342dbd0740a7
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/487021
Commit-Queue: Jens Johansen <jensj@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>
analysis_server
A long-running process that provides analysis results to other tools.
The analysis server is designed to provide on-going analysis of one or more code bases as those code bases are changing.
Using the server
The analysis server is not intended to be used stand-alone, and therefore does not have a human-friendly user interface.
Clients (typically tools, such as an editor) are expected to run the analysis
server in a separate process and communicate with it using a JSON protocol. The
original protocol is specified in the file analysis_server/doc/api.html
and Language Server Protocol support is documented in
tool/lsp_spec/README.md.
Features and bugs
Please file feature requests and bugs at the issue tracker.