Bench optimized builds

[oyvindln]

Looking at this repo and rustc-benchmarks, it doesn't look like there is any benchmarks done of optimized/release mode builds. (Or am I missing something?)

Wouldn't it make sense to check the performance of this as well?

[Mark-Simulacrum]

We don't check compile times on release benchmarks currently. I don't think our current infrastructure can really support that (it'd take too long for most of these) but I'd be willing to look at options if we wanted it. cc @alexcrichton @nikomatsakis @aturon -- do we want this?

[alexcrichton]

Seems desirable to me! We probably don't want to double all our collected benchmarks but we can select a few "LLVM stressors" and see what optimized build times look like.

[Mark-Simulacrum]

@aturon Could you suggest someone (@nikomatsakis?) to find or select a few LLVM stressing benchmarks to enable release mode on? We can then add those.

[alexcrichton]

I'd imagine we already have some great candidates -- regex, syntex_syntax, tokio-webpush, etc.

[Mark-Simulacrum]

Let's promote the (newer) incremental regex. We can also promote tokio webpush, syntex_syntax will take too long I think. Marking for impl period, happy to mentor.

[michaelwoerister]

+1 for also testing optimized builds of regex.

[oyvindln]

If there is some mentoring available, I can have a go at this one.

[Mark-Simulacrum]

Sure! You can look at how #151 was implemented, and you'd probably add --release to the cargo rustc invocations. Let's call it regex-opt-version and copy both regex-0.1.80 and regex.0.1.30 over. Let me know if you'd like further assistance!