[gcc r12-5092] [Ada] Use predefined equality for arrays inside records

[gcc r12-5092] [Ada] Use predefined equality for arrays inside records

[Pierre-Marie de Rodat]

https://gcc.gnu.org/g:0c66423ac99a0cbdb87b8019b7d5da3931b50045

commit r12-5092-g0c66423ac99a0cbdb87b8019b7d5da3931b50045
Author: Piotr Trojanek <trojanek@adacore.com>
Date:   Sun Oct 31 20:52:04 2021 +0100

    [Ada] Use predefined equality for arrays inside records
    
    gcc/ada/
    
            * exp_ch4.adb (Expand_Composite_Equality): Handle arrays inside
            records just like scalars; only records inside records need
            dedicated handling.

Diff:
---
 gcc/ada/exp_ch4.adb | 70 ++---------------------------------------------------
 1 file changed, 2 insertions(+), 68 deletions(-)

diff --git a/gcc/ada/exp_ch4.adb b/gcc/ada/exp_ch4.adb
index 8fb0424f274..7e250014379 100644
--- a/gcc/ada/exp_ch4.adb
+++ b/gcc/ada/exp_ch4.adb
@@ -2475,75 +2475,9 @@ package body Exp_Ch4 is
          Full_Type := Underlying_Type (Full_Type);
       end if;
 
-      --  Case of array types
-
-      if Is_Array_Type (Full_Type) then
-
-         --  If the operand is an elementary type other than a floating-point
-         --  type, then we can simply use the built-in block bitwise equality,
-         --  since the predefined equality operators always apply and bitwise
-         --  equality is fine for all these cases.
-
-         if Is_Elementary_Type (Component_Type (Full_Type))
-           and then not Is_Floating_Point_Type (Component_Type (Full_Type))
-         then
-            return Make_Op_Eq (Loc, Left_Opnd => Lhs, Right_Opnd => Rhs);
-
-         --  For composite component types, and floating-point types, use the
-         --  expansion. This deals with tagged component types (where we use
-         --  the applicable equality routine) and floating-point (where we
-         --  need to worry about negative zeroes), and also the case of any
-         --  composite type recursively containing such fields.
-
-         else
-            declare
-               Comp_Typ : Entity_Id;
-               Hi       : Node_Id;
-               Indx     : Node_Id;
-               Ityp     : Entity_Id;
-               Lo       : Node_Id;
-
-            begin
-               --  Do the comparison in the type (or its full view) and not in
-               --  its unconstrained base type, because the latter operation is
-               --  more complex and would also require an unchecked conversion.
-
-               if Is_Private_Type (Typ) then
-                  Comp_Typ := Underlying_Type (Typ);
-               else
-                  Comp_Typ := Typ;
-               end if;
-
-               --  Except for the case where the bounds of the type depend on a
-               --  discriminant, or else we would run into scoping issues.
-
-               Indx := First_Index (Comp_Typ);
-               while Present (Indx) loop
-                  Ityp := Etype (Indx);
-
-                  Lo := Type_Low_Bound (Ityp);
-                  Hi := Type_High_Bound (Ityp);
-
-                  if (Nkind (Lo) = N_Identifier
-                       and then Ekind (Entity (Lo)) = E_Discriminant)
-                    or else
-                     (Nkind (Hi) = N_Identifier
-                       and then Ekind (Entity (Hi)) = E_Discriminant)
-                  then
-                     Comp_Typ := Full_Type;
-                     exit;
-                  end if;
-
-                  Next_Index (Indx);
-               end loop;
-
-               return Expand_Array_Equality (Nod, Lhs, Rhs, Bodies, Comp_Typ);
-            end;
-         end if;
-
       --  Case of tagged record types
 
-      elsif Is_Tagged_Type (Full_Type) then
+      if Is_Tagged_Type (Full_Type) then
          Eq_Op := Find_Primitive_Eq (Typ);
          pragma Assert (Present (Eq_Op));
 
@@ -2734,7 +2668,7 @@ package body Exp_Ch4 is
             return Expand_Record_Equality (Nod, Full_Type, Lhs, Rhs, Bodies);
          end if;
 
-      --  Non-composite types (always use predefined equality)
+      --  Case of non-record types (always use predefined equality)
 
       else
          return Make_Op_Eq (Loc, Left_Opnd => Lhs, Right_Opnd => Rhs);