From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-462118-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 16488 invoked by alias); 19 Sep 2014 14:10:38 -0000
Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Id: <gcc-bugs.gcc.gnu.org>
List-Archive: <http://gcc.gnu.org/ml/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-help@gcc.gnu.org>
Sender: gcc-bugs-owner@gcc.gnu.org
Received: (qmail 16417 invoked by uid 48); 19 Sep 2014 14:10:34 -0000
From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/58192] G++ emits incorrect code when passing enum classes as function parameters
Date: Fri, 19 Sep 2014 14:10:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c++
X-Bugzilla-Version: 4.8.1
X-Bugzilla-Keywords: wrong-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: jakub at gcc dot gnu.org
X-Bugzilla-Status: NEW
X-Bugzilla-Priority: P2
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags:
X-Bugzilla-Changed-Fields:
Message-ID: <bug-58192-4-aPHAhjmIvA@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-58192-4@http.gcc.gnu.org/bugzilla/>
References: <bug-58192-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-SW-Source: 2014-09/txt/msg01952.txt.bz2

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58192

--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
When I compile:
#ifdef CHAR
typedef unsigned char Foo;
#else
enum class Foo : unsigned char { FOO };
#endif
unsigned int v1, v2;

__attribute__((noinline, noclone)) static void
foo (Foo a)
{
  v1 = (unsigned int) a;
}

__attribute__((noinline, noclone)) void
bar (Foo a)
{
  v2 = (unsigned int) a;
}

void
baz (unsigned int a)
{
  foo ((Foo) a);
  bar ((Foo) a);
}

with -DCHAR vs. -UCHAR, there is a difference visible already in *.original
dump:
 <<cleanup_point <<< Unknown tree: expr_stmt
-  foo ((int) (Foo) a) >>>>>;
+  foo ((Foo) a) >>>>>;
 <<cleanup_point <<< Unknown tree: expr_stmt
-  bar ((int) (Foo) a) >>>>>;
+  bar ((Foo) a) >>>>>;
i.e. there is explicit zero-extension for integral types smaller than int in
the IL (i.e. for the -DCHAR) case, but nothing like that for the enum class
with underlying type smaller than int.  And presumably the middle-end and
backends rely on this.