[patch] Fix PR fortran/72743

[Chung-Lin Tang]

Hi Richard, Martin,
this issue is actually sort of like PR 70856, basically the same ICE
after IPA-ICF, due to DECL_PT_UIDs not consistent after reaching for the
ultimate_alias_target().

The reason this wasn't covered by the PR70856 fix is that, in this case,
the DECL_PT_UID was not set in original->decl, evading the condition, and
hence the the merged alias doesn't have DECL_PT_UID set, and causes the
ICE in the second round of IPA-PTA (under -fopenacc).

My fix is to simply remove the DECL_PT_UID_SET_P (original->decl) guard,
and allow the DECL_PT_UID to be set using the DECL_UID in this case.

Does this fix make sense?
Testing does show no regressions, and the PR testcase ICE is fixed.

Thanks,
Chung-Lin

        PR fortran/72743
        * ipa-icf.c (sem_variable::merge): Remove guard condition for
        setting DECL_PT_UID (alias->decl).

        testsuite/
        * gfortran.dg/goacc/pr72743.f90: New test.



Index: ipa-icf.c
===================================================================
--- ipa-icf.c   (revision 239624)
+++ ipa-icf.c   (working copy)
@@ -2258,8 +2258,7 @@ sem_variable::merge (sem_item *alias_item)
 
       varpool_node::create_alias (alias_var->decl, decl);
       alias->resolve_alias (original);
-      if (DECL_PT_UID_SET_P (original->decl))
-       SET_DECL_PT_UID (alias->decl, DECL_PT_UID (original->decl));
+      SET_DECL_PT_UID (alias->decl, DECL_PT_UID (original->decl));
 
       if (dump_file)
        fprintf (dump_file, "Unified; Variable alias has been created.\n\n");
Index: testsuite/gfortran.dg/goacc/pr72743.f90
===================================================================
--- testsuite/gfortran.dg/goacc/pr72743.f90     (revision 0)
+++ testsuite/gfortran.dg/goacc/pr72743.f90     (revision 0)
@@ -0,0 +1,15 @@
+! { dg-do compile }
+! { dg-additional-options "-O2" }
+
+program p
+   integer, parameter :: n = 8
+   integer :: i, z(n)
+   z = [(i, i=1,n)]
+   print *, z
+end
+subroutine s
+   integer, parameter :: n = 8
+   integer :: i, z(n)
+   z = [(i, i=1,n)]
+   print *, z
+end