[Ada] Fix PR ada/83535

[Eric Botcazou]

This is a regression recently introduced on the mainline: the compiler doesn't 
use the specified size to access an atomic variable with an address clause.

Tested on x86_64-suse-linux, applied on the mainline.


2017-12-21  Eric Botcazou  <ebotca...@adacore.com>

        * gcc-interface/decl.c (gnat_to_gnu_entity) <E_Variable>: Always take
        into account the Esize if it is known.


2017-12-21  Eric Botcazou  <ebotca...@adacore.com>

        * gnat.dg/atomic9.adb: New test.

-- 
Eric Botcazou
Index: gcc-interface/decl.c
===================================================================
--- gcc-interface/decl.c	(revision 255854)
+++ gcc-interface/decl.c	(working copy)
@@ -723,7 +723,7 @@ gnat_to_gnu_entity (Entity_Id gnat_entit
 				      TYPE_ALIGN (gnu_type));
 
 	/* Likewise, if a size is specified, use it if valid.  */
-	if (Known_Esize (gnat_entity) && No (Address_Clause (gnat_entity)))
+	if (Known_Esize (gnat_entity))
 	  gnu_size
 	    = validate_size (Esize (gnat_entity), gnu_type, gnat_entity,
 			     VAR_DECL, false, Has_Size_Clause (gnat_entity));

-- { dg-do compile }
-- { dg-options "-fdump-tree-gimple" }

with Interfaces;

procedure Atomic9 is

   Register : Interfaces.Unsigned_32;

   type Interrupt_ID is range 0 .. 44;

   procedure Trigger_Interrupt (IRQ : Interrupt_ID) is
      NVIC_STIR : Interrupt_ID
      with
        Import,
        Atomic,
        Size    => 32,
        Address => Register'Address;

   begin
      NVIC_STIR := IRQ;
   end Trigger_Interrupt;

begin
   Register := 16#ffff_ffff#;
   Trigger_Interrupt (1);
end;

-- { dg-final { scan-tree-dump "atomic_store_4" "gimple" } }