A series of Javascript puzzles helpful for understanding the underlying implementation of V8 engine.
Please follow the instructions from the official site.
Note that if you want to inspect generated assembly code don't forget to add disassembler=on option
By default, you will find the d8 shell's binary at ./out/[your_architecture_or_mode]/d8 and it will be convenient to add it to your bash's PATH.
After installation successfully, executing a Javascript file using d8 is as easy as:
$ d8 mytest.js
C1visualizer is a visualization tool originally developed for JVM's internal structure, but it can also process Crankshaft's IR. Extremely useful! Simply download and use it.
You can generate the output of Crankshaft's Hydrogen IR (HIR) and visualize it in C1visualizer. For example:
$ d8 --trace_hydrogen --trace_phase=Z mytest.js
Thus, a CFG(control flow graph) file hydrogen.cfg will be generated. (Of course, your JS code should at least be 'hot' enough to be processed by Crankshaft, instead of full-codegen only)
Then after executing the c1visualizer program and seeing the GUI, you can open that file by "[File] > [Open Compiled Methods...]".
Select any loaded method's "Z_Code generation", right click on it and choose "Open Control Flow Graph", then the graph will be visualized at right side. Further click any node in the graph and its corresponding HIR code and LIR code will be shown at bottom. More information and easier to read than assembly code!
For each puzzle, several Javascript files and their corresponding CFG files are provided for comparison.
To test which JS file runs faster in V8, simply execute it by
$ d8 puzzle_A.js
and a number indicating how long it takes (in ms) to finish running this file will be printed on console.
Furthermore, to check what actually happened underlying you can dive into the CFG files in ./hydrogen/ folder.