[gcc r15-3656] fortran: Remove useless nested end of scalarization chain handling

[Mikael Morin]

https://gcc.gnu.org/g:d204bee388d74a6895da15a1027a64a8c4ea4fbb

commit r15-3656-gd204bee388d74a6895da15a1027a64a8c4ea4fbb
Author: Mikael Morin <mikael@gcc.gnu.org>
Date:   Sun Jul 7 11:00:51 2024 +0200

    fortran: Remove useless nested end of scalarization chain handling
    
    Remove the special handling of end of nested scalarization chains, which
    advanced the chain to an element of a parent chain when the current one
    was reaching its end.
    
    That handling was superfluous as nested chains correspond to nested
    scalarizations of subexpressions and the scalarizations don't extend beyond
    their associated subexpression and don't use any scalarisation element from
    the parent expression.
    
    No change of behaviour, as the GFC_SE struct is supposed to be in its final
    state anyway when the last element from the chain has been consumed.
    
    gcc/fortran/ChangeLog:
    
            * trans-expr.cc (gfc_advance_se_ss_chain): Don't use an element
            from the parent scalarization chain when the current chain reaches
            its end.

Diff:
---
 gcc/fortran/trans-expr.cc | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/gcc/fortran/trans-expr.cc b/gcc/fortran/trans-expr.cc
index f1dfac4a2be8..07e28a9f7a8d 100644
--- a/gcc/fortran/trans-expr.cc
+++ b/gcc/fortran/trans-expr.cc
@@ -2044,7 +2044,6 @@ void
 gfc_advance_se_ss_chain (gfc_se * se)
 {
   gfc_se *p;
-  gfc_ss *ss;
 
   gcc_assert (se != NULL && se->ss != NULL && se->ss != gfc_ss_terminator);
 
@@ -2056,15 +2055,7 @@ gfc_advance_se_ss_chain (gfc_se * se)
       gcc_assert (p->parent == NULL || p->parent->ss == p->ss
 		  || p->parent->ss->nested_ss == p->ss);
 
-      /* If we were in a nested loop, the next scalarized expression can be
-	 on the parent ss' next pointer.  Thus we should not take the next
-	 pointer blindly, but rather go up one nest level as long as next
-	 is the end of chain.  */
-      ss = p->ss;
-      while (ss->next == gfc_ss_terminator && ss->parent != NULL)
-	ss = ss->parent;
-
-      p->ss = ss->next;
+      p->ss = p->ss->next;
 
       p = p->parent;
     }