> Hi Honza,
>
> Thanks for the review.
>
> > On 13 Jan 2026, at 7:53 pm, Jan Hubicka <[email protected]> wrote:
> >
> > External email: Use caution opening links or attachments
> >
> >
> >> I would like to again ping the patch posted in
> >> https://gcc.gnu.org/pipermail/gcc-patches/2025-November/700704.html
> >>
> >> Add hierarchical discriminator support for loop unrolling.
> >> Assigns multiplicity and copyid discriminators to distinguish unrolled
> >> iterations.
> >>
> >> gcc/ChangeLog:
> >>
> >> * cfgloopmanip.cc (duplicate_loop_body_to_header_edge): Assign
> >> hierarchical discriminators for loop unrolling.
> >> * cfgloopmanip.h (DLTHE_RECORD_HIERARCHICAL_DISCRIMINATOR): New
> >> flag.
> >> * tree-ssa-loop-ivcanon.cc (try_unroll_loop_completely): Pass flag
> >> to enable hierarchical discriminator assignment.
> >> (try_peel_loop): Likewise.
> >>
> >> gcc/testsuite/ChangeLog:
> >>
> >> * gcc.dg/hierarchical-discriminator-unroll.c: New test.
> >
> > + unsigned int loop_copyid_base = 0;
> > + if (current_ir_type () == IR_GIMPLE)
> > + {
> > ..
> > + }
> > + else
> > + {
> > + /* For RTL, try to find an instruction with a valid location.
> > + Be defensive to avoid crashes on invalid/corrupted insns. */
> > + rtx_insn *insn = BB_END (loop->header);
> > + while (insn && insn != BB_HEAD (loop->header))
> > + {
> > + /* Only check location if this is a valid insn. */
> > + if (INSN_P (insn))
> > + {
> > + location_t loc = INSN_LOCATION (insn);
> > + if (loc != UNKNOWN_LOCATION)
> > + {
> > + loop_loc = get_pure_location (loc);
> > + break;
> > + }
> > + }
> > + insn = PREV_INSN (insn);
> > + }
> > + }
> > +
> > ...
> > + if (current_ir_type () == IR_GIMPLE)
> > + {
> > ....
> > + }
> > + else
> > + {
> > + /* Only assign discriminators if we successfully allocated
> > + a copyid base. */
> > + if (loop_copyid_base > 0)
> >
> > This will never be true. But I think the copyid allocation can work
> > both on RTL and Gimple. You will need to support initializing the
> > allocator at RTL level too if necessary, but both is just a siple walk
> > of a function body.
>
> Fixed this.
>
>
> Is this OK?
OK,
Thanks!
Honza
>
> Thanks,
> Kugan
>
>
> >
> >
> > Honza
>
