Re: [PATCH 4/4] Implement hierarchical discriminators for AutoFDO

[Kugan Vivekanandarajah]

Hi Honza,

> On 12 Dec 2025, at 9:04 am, Kugan Vivekanandarajah <kvivekana...@nvidia.com> 
> wrote
> How about going with  something like:
> copyid_base = allocate_copyid_base (loc, base_discriminator);
> This should have global context and allocate new copyid_base for each call 
> without any of the defines we have now.
> This would still have issue for LTO where any copyid_base generated in LTRANS 
> will have conflict unless we generate this
> in WPA and stream. What do you think?

Here is the implementation (just the patch 1 or the infrastructure). Do you 
prefer this?

Using this API, we would assign copy_id like:
+      gimple *nloop_last = last_nondebug_stmt (nloop->header);
+      location_t nloop_loc
+               = nloop_last ? gimple_location (nloop_last) : UNKNOWN_LOCATION;
+      if (nloop_loc != UNKNOWN_LOCATION)
+       {        
+         unsigned int nloop_copyid = allocate_copyid_base (nloop_loc, 1);
+         assign_discriminators_to_loop (nloop, 0, nloop_copyid);
+       }


I will post the series based on this if you prefer this.

Thanks,
Kugan

0001-Autofdo-V3-Add-hierarchical-discriminator-support.patch
Description: 0001-Autofdo-V3-Add-hierarchical-discriminator-support.patch