[Speed] perf 0.9.4 released

[Victor Stinner]

Hi,

I released the version 0.9.4 of my Python perf module:

* Add --compare-to option to the Runner CLI
* compare_to command: Add --table option to render a table

http://perf.readthedocs.io/en/latest/

I used the --table feature to write this FASTCALL microbenchmarks article:
https://haypo.github.io/fastcall-microbenchmarks.html

Example:

+---------------------+---------+------------------------------+
| Benchmark           | 3.5     | 3.7                          |
+=====================+=========+==============================+
| struct.pack("i", 1) | 105 ns  | 77.6 ns: 1.36x faster (-26%) |
+---------------------+---------+------------------------------+
| getattr(1, "real")  | 79.4 ns | 64.4 ns: 1.23x faster (-19%) |
+---------------------+---------+------------------------------+

Use --quiet for smaller table.

The --compare-to command is the generalization to any perf script of
the existing perf timeit --compare-to option, to quickly compare two
Python binaries.

Example with timeit (because I'm too lazy to write a perf script!):
---
$ ./python -m perf timeit 'int(0)' --duplicate=100 --compare-to
../master-ref/python -p3
/home/haypo/prog/bench_python/master-ref/python: .... 112 ns +- 1 ns
/home/haypo/prog/bench_python/master/python: .... 108 ns +- 1 ns

Median +- std dev: [/home/haypo/prog/bench_python/master-ref/python]
112 ns +- 1 ns -> [/home/haypo/prog/bench_python/master/python] 108 ns
+- 1 ns: 1.04x faster (-3%)
----

Hum, I should write an option to allow to specify the name of python
binaries, to replace [/home/haypo/prog/bench_python/master-ref/python]
just with [ref].

Victor