[gcc(refs/users/mikael/heads/pr121185_v01)] fortran: Generate array reallocation out of loops

[Mikael Morin via Gcc-cvs]

https://gcc.gnu.org/g:6a9def148bccfca1388c7b45b3c46589c40c8f04

commit 6a9def148bccfca1388c7b45b3c46589c40c8f04
Author: Mikael Morin <mik...@gcc.gnu.org>
Date:   Tue Jul 15 09:58:26 2025 +0200

    fortran: Generate array reallocation out of loops
    
    Generate the array reallocation on assignment code before entering the
    scalarization loops.  This doesn't move the generated code itself,
    which was already put before the outermost loop, but only changes the
    current scope at the time the code is generated.  This is a prerequisite
    for a followup patch that makes the reallocation code create new
    variables.  Without this change the new variables would be declared in
    the innermost loop body and couldn't be used outside of it.
    
    gcc/fortran/ChangeLog:
    
            * trans-expr.cc (gfc_trans_assignment_1): Generate array
            reallocation code before entering the scalarisation loops.

Diff:
---
 gcc/fortran/trans-expr.cc | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/gcc/fortran/trans-expr.cc b/gcc/fortran/trans-expr.cc
index 3e0d763d2fb0..760c8c4e72bd 100644
--- a/gcc/fortran/trans-expr.cc
+++ b/gcc/fortran/trans-expr.cc
@@ -12943,6 +12943,7 @@ gfc_trans_assignment_1 (gfc_expr * expr1, gfc_expr * 
expr2, bool init_flag,
       rhs_caf_attr = gfc_caf_attr (expr2, false, &rhs_refs_comp);
     }
 
+  tree reallocation = NULL_TREE;
   if (lss != gfc_ss_terminator)
     {
       /* The assignment needs scalarization.  */
@@ -13011,6 +13012,15 @@ gfc_trans_assignment_1 (gfc_expr * expr1, gfc_expr * 
expr2, bool init_flag,
          ompws_flags |= OMPWS_SCALARIZER_WS | OMPWS_SCALARIZER_BODY;
        }
 
+      /* F2003: Allocate or reallocate lhs of allocatable array.  */
+      if (realloc_flag)
+       {
+         realloc_lhs_warning (expr1->ts.type, true, &expr1->where);
+         ompws_flags &= ~OMPWS_SCALARIZER_WS;
+         reallocation = gfc_alloc_allocatable_for_assignment (&loop, expr1,
+                                                              expr2);
+       }
+
       /* Start the scalarized loop body.  */
       gfc_start_scalarized_body (&loop, &body);
     }
@@ -13319,15 +13329,8 @@ gfc_trans_assignment_1 (gfc_expr * expr1, gfc_expr * 
expr2, bool init_flag,
          gfc_add_expr_to_block (&body, tmp);
        }
 
-      /* F2003: Allocate or reallocate lhs of allocatable array.  */
-      if (realloc_flag)
-       {
-         realloc_lhs_warning (expr1->ts.type, true, &expr1->where);
-         ompws_flags &= ~OMPWS_SCALARIZER_WS;
-         tmp = gfc_alloc_allocatable_for_assignment (&loop, expr1, expr2);
-         if (tmp != NULL_TREE)
-           gfc_add_expr_to_block (&loop.code[expr1->rank - 1], tmp);
-       }
+      if (reallocation != NULL_TREE)
+       gfc_add_expr_to_block (&loop.code[loop.dimen - 1], reallocation);
 
       if (maybe_workshare)
        ompws_flags &= ~OMPWS_SCALARIZER_BODY;