cmd/compile: use expandable columns in ssa.html?

[josharian]

As the number of SSA passes has grown, ssa.html has gotten wider and thus harder to navigate. I'd like to float the idea of having the initial display show just a few columns, with the others be expandable stubs (with names). As to the initial list of columns, maybe something like: start, after early deadcode, after opt, after lower, after late deadcode, after regalloc, genssa.

There's also the question of whether this can be reasonably implemented in standalone javascript, a question about which I know little.

Opinions?

cc @dr2chase @randall77 @cherrymui

[randall77]

Yes, please. It is not possible that your javascript knowledge is less than mine.

[ysmolski]

@josharian is it okay when you reload ssa.html [in a browser] you would get to default state of collapsed columns?

[josharian]

Yes. It’d be nice to do some saved local state or query params, but as a first pass, I think always reverting to the default is fine. In the normal case I imagine the reader will be interested in one or two columns at most, so restoring state manually isn’t that big a deal.

[gopherbot]

Change https://golang.org/cl/117275 mentions this issue: cmd/compile: use expandable columns in ssa.html

[ysmolski]

In case if you want to give a feedback without downloading the patch above:

The vertical text (a column) can be expanded by clicking on it. If you want something else, just let me know.

I would be glad to help because I learned a thing or two about SSA while making the change. Also I would like to implement some of the TODOs buired in ssa.go regarding graphic representation (nodes->ssa?) or maybe just dumping the log from ssa to the ssa.html, so file can be shared as standalone piece. /cc @josharian

EDITED: typos and formatting