On Sat, Oct 16, 2021 at 8:46 AM Richard Biener via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> On October 16, 2021 2:47:51 PM GMT+02:00, Jan Hubicka via Gcc-patches
> <gcc-patches@gcc.gnu.org> wrote:
> >Hi,
> >while updating compute_points_to_sets I missed that the code not only
> >sets the nonlocal/escaped flags but also initializes pt. With my
> >previous change if uses_global_memory is false pt is not updated
> >correctly which may lead to wrong code.
> >
> >This is fixed by the following patch I comitted to avoid strange
> >misoptimizations.
> >
> >Bootstrapped/regtested x86_64-linux and also tested with LTO.
This caused:
FAIL: gfortran.dg/deferred_type_param_6.f90 -O1 execution test
on Linux/x86-64. -march=cascadelake may be needed to reproduce it.
> OK.
>
> Richard.
>
> >Honza
> >
> >gcc/ChangeLog:
> >
> > PR tree-optimization/102720
> > * tree-ssa-structalias.c (compute_points_to_sets): Fix producing
> > of call used and clobbered sets.
> >
> >diff --git a/gcc/tree-ssa-structalias.c b/gcc/tree-ssa-structalias.c
> >index 6f12a66ee0d..2e6513bb72a 100644
> >--- a/gcc/tree-ssa-structalias.c
> >+++ b/gcc/tree-ssa-structalias.c
> >@@ -7541,17 +7541,18 @@ compute_points_to_sets (void)
> > determine_global_memory_access (stmt, NULL,
> > &reads_global_memory,
> > &uses_global_memory);
> >- if (!uses_global_memory)
> >- ;
> >- else if ((vi = lookup_call_use_vi (stmt)) != NULL)
> >+ if ((vi = lookup_call_use_vi (stmt)) != NULL)
> > {
> > *pt = find_what_var_points_to (cfun->decl, vi);
> > /* Escaped (and thus nonlocal) variables are always
> > implicitly used by calls. */
> > /* ??? ESCAPED can be empty even though NONLOCAL
> > always escaped. */
> >- pt->nonlocal = uses_global_memory;
> >- pt->escaped = uses_global_memory;
> >+ if (uses_global_memory)
> >+ {
> >+ pt->nonlocal = uses_global_memory;
> >+ pt->escaped = uses_global_memory;
> >+ }
> > }
> > else if (uses_global_memory)
> > {
> >@@ -7572,17 +7573,18 @@ compute_points_to_sets (void)
> > determine_global_memory_access (stmt, &writes_global_memory,
> > NULL, NULL);
> >
> >- if (!writes_global_memory)
> >- ;
> >- else if ((vi = lookup_call_clobber_vi (stmt)) != NULL)
> >+ if ((vi = lookup_call_clobber_vi (stmt)) != NULL)
> > {
> > *pt = find_what_var_points_to (cfun->decl, vi);
> > /* Escaped (and thus nonlocal) variables are always
> > implicitly clobbered by calls. */
> > /* ??? ESCAPED can be empty even though NONLOCAL
> > always escaped. */
> >- pt->nonlocal = writes_global_memory;
> >- pt->escaped = writes_global_memory;
> >+ if (writes_global_memory)
> >+ {
> >+ pt->nonlocal = writes_global_memory;
> >+ pt->escaped = writes_global_memory;
> >+ }
> > }
> > else if (writes_global_memory)
> > {
>
--
H.J.
