From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
 id 2AFEB3857820; Tue, 25 May 2021 08:20:20 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 2AFEB3857820
From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/100727] [12 Regression] Recent change to
 WITH_SIZE_EXPR handling breaks mn10300-elf
Date: Tue, 25 May 2021 08:20:19 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: tree-optimization
X-Bugzilla-Version: 12.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: rguenth at gcc dot gnu.org
X-Bugzilla-Status: ASSIGNED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: rguenth at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 12.0
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-100727-4-oosn1STbCi@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-100727-4@http.gcc.gnu.org/bugzilla/>
References: <bug-100727-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-BeenThere: gcc-bugs@gcc.gnu.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Gcc-bugs mailing list <gcc-bugs.gcc.gnu.org>
List-Unsubscribe: <https://gcc.gnu.org/mailman/options/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=unsubscribe>
List-Archive: <https://gcc.gnu.org/pipermail/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-request@gcc.gnu.org?subject=help>
List-Subscribe: <https://gcc.gnu.org/mailman/listinfo/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Tue, 25 May 2021 08:20:20 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D100727

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
So it's fixed with

diff --git a/gcc/calls.c b/gcc/calls.c
index f3da1839dc5..74a5070605e 100644
--- a/gcc/calls.c
+++ b/gcc/calls.c
@@ -2397,6 +2397,7 @@ initialize_argument_information (int num_actuals
ATTRIBUTE_UNUSED,
             already in memory, instead of making a copy.  Likewise if we w=
ant
             to make the copy in the callee instead of the caller.  */
          if ((call_from_thunk_p || callee_copies)
+             && TREE_CODE (args[i].tree_value) !=3D WITH_SIZE_EXPR
              && (base =3D get_base_address (args[i].tree_value))
              && TREE_CODE (base) !=3D SSA_NAME
              && (!DECL_P (base) || MEM_P (DECL_RTL (base))))

where the get_base_address change lets WITH_SIZE_EXPR through now but not
before.  The only obvious followon difference is that we then do

              mark_addressable (args[i].tree_value);
...
              args[i].tree_value =3D build_fold_addr_expr_loc (loc,
                                                         args[i].tree_value=
);
              type =3D TREE_TYPE (args[i].tree_value);

unchanged is that we pass the argument by reference and that the target
requests callee_copies.

Now, this is variadic args, so maybe the callee_copies thing doesn't apply
and/or the varargs setup code now is inconsistent - in the end it's an
ABI change.

So given get_base_address only ever returned NULL for WITH_SIZE_EXPR
and clearly the !base check switches between ABIs we have to make the
WITH_SIZE_EXPR check explicit.

I'm also testing the additional (but then not needed)

diff --git a/gcc/gimple-expr.c b/gcc/gimple-expr.c
index b8c732b632a..c3211795d33 100644
--- a/gcc/gimple-expr.c
+++ b/gcc/gimple-expr.c
@@ -900,6 +900,8 @@ flush_mark_addressable_queue ()
 void
 mark_addressable (tree x)
 {
+  if (TREE_CODE (x) =3D=3D WITH_SIZE_EXPR)
+    x =3D TREE_OPERAND (x, 0);
   while (handled_component_p (x))
     x =3D TREE_OPERAND (x, 0);
   if (TREE_CODE (x) =3D=3D MEM_REF=