[PATCH 1/3] fortran: Generate array reallocation out of loops

[Mikael Morin]

From: Mikael Morin <mik...@gcc.gnu.org>

Regression tested on x86_64-pc-linux-gnu.
OK for master?

-- >8 --

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.
---
 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 3e0d763d2fb..760c8c4e72b 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;
-- 
2.47.2