> Thank you Honza for the review > > > The default value was tuned according to the target applications - large > applications that benefit from the higher size. This results in majority of > the target applications not needing param adjustment. I see ~5-10% > improvement for the current default over a lower value. > > The adjustment I made here was for additional build time improvement > specifically for GCC bootstrap with the intention that the target > applications can use the pass without needing it.
I see that 5-10% improvement is quite important for the specific use-case. It is kind of unfortunate that we need to tune the parameter so high. Is it something that can be fixed by better code placement across adjacent partitions (which can be acomplished by tp_first_run machinery and also your new numbered textsubsections) or is it really about late IPA optimizations (such as register alloation) being important and ltrans partition being in a way? I think we should go with reasonable defaults (which does not bow up build times) in GCC, so perhaps param should be lowered by default to what we need for bootstrap and have the target app to bump it up in its config. Hozna
