building libjvm with -Os for space optimization - was : RE: RFR: 8234525: enable link-time section-gc for linux s390x to remove unused code

[Baesken, Matthias]

Hi August , thanks for pointing to your webpage,  very interesting !  

We did our builds+tests/benchmarks  with  gcc  7.4.0   , what compiler+version did you use?

Probably I should look a bit more into Dacapo (we used that one in the past too sometimes).

Best regards, Matthias


> 
> I published some benchmarks of OpenJDK on Mac with Ofast and O3 [1].
> Some microbenchmarks like Netty’s HttpObjectEncoder experienced >100%
> speedup with O3, and the more real-world Dacapo suite was ~15%
> improvement over O2 (which is exactly the same as Os). I did include a few
> other flags, however the speedup was primarily due to optimization level.
> 
> Building with Os is the old wisdom. It used to be the case that many programs
> would be faster with the smaller binary size, but this is almost never the case
> nowadays.
> 
> - August
> 
> [1]: http://august.nagro.us/optimized-openjdk.html