Add a benchmark for the Lengauer-Tarjan dominator tree algorithm

[samolisov]

Issue: #383

[samolisov]

I use numerous small test cases (10-14 vertices) from the dominator_tree_test.cpp test as well as a 10x times larger example - a CFG from a real code (up to 200 vertices).

Unfortunately, I'm not familiar with a CMake-based infrastructure (if any exists at all) to build and test the boost.graph library. This is why I've added a short instruction how to compile the benchmark directly into the dominator_tree_benchmark.cpp source file.

On my machine (64 X 1792.7 MHz CPU s with almost zero Load Average) the report is the following (we may use it as a base-line for issue #383):

Running ./dominator_tree_benchmark
Run on (64 X 1792.7 MHz CPU s)
CPU Caches:
  L1 Data 32 KiB (x32)
  L1 Instruction 32 KiB (x32)
  L2 Unified 512 KiB (x32)
  L3 Unified 16384 KiB (x8)
Load Average: 0.00, 0.01, 0.00
----------------------------------------------------------------------------------
Benchmark                                        Time             CPU   Iterations
----------------------------------------------------------------------------------
Tarjan's paper (vertex list)                  1545 ns         1545 ns       453859
Tarjan's paper  (vertex vector)               1519 ns         1519 ns       461328
Appel. fig. 19.8 (vertex list)                1587 ns         1587 ns       439286
Appel. fig. 19.8  (vertex vector)             1489 ns         1488 ns       473160
Muchnick. fig. 8.18 (vertex list)              870 ns          870 ns       805296
Muchnick. fig. 8.18  (vertex vector)           847 ns          847 ns       833885
Cytron's paper, fig. 9 (vertex list)          1812 ns         1812 ns       391492
Cytron's paper, fig. 9  (vertex vector)       1651 ns         1651 ns       421622
From a code, 186 BBs (vertex list)           22388 ns        22386 ns        29279
From a code, 186 BBs (vertex vector)         19391 ns        19389 ns        35854

After replacing std::deque with std::vector as it was suggested by @jeremy-murphy, the numbers are the following:

----------------------------------------------------------------------------------
Benchmark                                        Time             CPU   Iterations
----------------------------------------------------------------------------------
Tarjan's paper (vertex list)                   944 ns          944 ns       747521
Tarjan's paper  (vertex vector)                852 ns          852 ns       822843
Appel. fig. 19.8 (vertex list)                 956 ns          956 ns       729393
Appel. fig. 19.8  (vertex vector)              865 ns          865 ns       807835
Muchnick. fig. 8.18 (vertex list)              560 ns          560 ns      1252412
Muchnick. fig. 8.18  (vertex vector)           543 ns          543 ns      1306887
Cytron's paper, fig. 9 (vertex list)          1164 ns         1164 ns       602748
Cytron's paper, fig. 9  (vertex vector)       1054 ns         1054 ns       666930
From a code, 186 BBs (vertex list)           12750 ns        12749 ns        55535
From a code, 186 BBs (vertex vector)         11284 ns        11283 ns        62585

(I checked for From a code, 186 BBs (vertex vector), std::vector wins about 40%, not so bad!)

[samolisov]

@jeremy-murphy Could you have a look? Unfortunately, I'm not able to edit the Reviewers list.

[jeremy-murphy]

I have an improvement to the CMake build in a PR of my own, so I'll try to merge that ASAP. After that's merged it will be easier to incorporate your benchmark.
As a rule, I want to separate tests and benchmarks physically, but I haven't decided exactly how yet.