On October 16, 2017 7:38:50 AM GMT+02:00, Sandra Loosemore <san...@codesourcery.com> wrote: >This patch is a first cut at solving the problem discussed in this >thread > >https://gcc.gnu.org/ml/gcc/2017-10/msg00016.html > >where I have some nios2 backend patches in my queue that need a way of >knowing whether the split1 pass has run yet. There seemed to be >agreement that a general way to query the pass manager for this >information would be useful. > >The approach I took here is to add a new counter field, so that I can >do >the test I want with > > opt_pass *split1_pass = g->get_passes ()->get_pass_split_all_insns (); > if (current_pass->pass_number > split1_pass->pass_number) > ... > >Well, mostly. :-P There are some gotchas. > >* TARGET_ASM_OUTPUT_MI_THUNK is called outside the pass manager (so >current_pass is NULL) and on many targets this hook is implemented by >setting reload_completed to 1, generating some RTL, and invoking some >passes directly to emit code. > >* modulo-sched.c also plays tricks with setting reload_completed to >pretend to be something it's not. > >* Possibly other places? E.g. I'm not familiar with how plugins work. > >For my purposes it's good enough to check reload_completed before the >test in the code snippet above, but trying to determine whether a >particular post-reload pass has run won't work. So this isn't as >general as it ought to be, at least not until we get rid of the >reload_completed hackery. > >Since this patch isn't useful without something that uses the pass >counters, I tested it on nios2-linux-gnu with my not-yet-posted patch >set, by wiring it up in parallel with my previously-implemented >solution >of adding a target-specific pass to set a flag, with various assertions > >to check for consistency. I also had some temporary debugging code in >there at one point to print the pass numbers. > >WDYT? Is this the right direction? I'm somewhat worried that we're >getting late in stage 1 and I'd really like to finish up my nios2 >patches; so if getting this right looks like a tar pit, I think I >should >probably stick with my previous implementation for now.
I missed the post of why you need to know this. But as you noticed we're using reload_completed for similar purpose. There's also the possibility of setting/adding a pass property that split could provide and which you could query. We're using this to signal the various different lowering stages in GIMPLE for example. Richard. > >-Sandra