> On Sun, 22 Jun 2025, Jan Hubicka wrote:
>
> > Hi,
> > auto-fdo is currently confused by a fact that all inlined functions get
> > locators with 0 discriminator, so it is not bale to distinguish multiple
> > inlined calls from single line.
> >
> > Discriminator is lost by calling LOCATION_LOCUS before copying it from
> > former call statement. I believe this is only intended to drop block
> > annotations.
> >
> > Bootstrapped/regtested x86_64-linux, OK?
> >
> > gcc/ChangeLog:
> >
> > * tree-inline.cc (expand_call_inline): Preserve discriminator.
> >
> > diff --git a/gcc/tree-inline.cc b/gcc/tree-inline.cc
> > index dee2dfc2620..fa2641780a5 100644
> > --- a/gcc/tree-inline.cc
> > +++ b/gcc/tree-inline.cc
> > @@ -5014,6 +5014,9 @@ expand_call_inline (basic_block bb, gimple *stmt,
> > copy_body_data *id,
> > /* We do want to assign a not UNKNOWN_LOCATION BLOCK_SOURCE_LOCATION
> > to make inlined_function_outer_scope_p return true on this BLOCK.
> > */
> > location_t loc = LOCATION_LOCUS (gimple_location (stmt));
> > + if (loc != UNKNOWN_LOCATION)
> > + loc = location_with_discriminator
> > + (loc, get_discriminator_from_loc (gimple_location (stmt)));
>
> So this doesn't preserve the discriminator on UNKNOWN_LOCATION? Don't
> you maybe want
>
> if (has_discriminator (gimple_location (stmt)))
> loc = location_with_discriminator (loc, get_disc....
>
> ? Also ...
>
> > if (loc == UNKNOWN_LOCATION)
> > loc = LOCATION_LOCUS (DECL_SOURCE_LOCATION (fn));
> > if (loc == UNKNOWN_LOCATION)
>
> ... these no longer trigger when there's a discriminator, but we do
> want a != UNKNOWN_LOCATION LOCATION_LOCUS as the comment says. So
> better apply the discriminator last?
That is why I checked for loc != UNKNOWN_LOCATION. I did not expect
UNKNOWN_LOCATION to have discriminators. What they are good for?
I am re-testing the change as suggested. I will commit it if tesitng
succeds (I am in China with somewhat limited SSH access and I would like
the lnt testers to pick that change soon, so I know what benchmarks I
need to analyze for afdo regressions.)
Thanks,
Honza
gcc/ChangeLog:
* tree-inline.cc (expand_call_inline): Copy discriminators.
diff --git a/gcc/tree-inline.cc b/gcc/tree-inline.cc
index dee2dfc2620..7e0ac698e5e 100644
--- a/gcc/tree-inline.cc
+++ b/gcc/tree-inline.cc
@@ -5018,6 +5018,9 @@ expand_call_inline (basic_block bb, gimple *stmt,
copy_body_data *id,
loc = LOCATION_LOCUS (DECL_SOURCE_LOCATION (fn));
if (loc == UNKNOWN_LOCATION)
loc = BUILTINS_LOCATION;
+ if (has_discriminator (gimple_location (stmt)))
+ loc = location_with_discriminator
+ (loc, get_discriminator_from_loc (gimple_location (stmt)));
id->block = make_node (BLOCK);
BLOCK_ABSTRACT_ORIGIN (id->block) = DECL_ORIGIN (fn);
BLOCK_SOURCE_LOCATION (id->block) = loc;
