From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-470562-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 23638 invoked by alias); 13 Dec 2014 21:12:41 -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 23608 invoked by uid 48); 13 Dec 2014 21:12:36 -0000
From: "gcc at breakpoint dot cc" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug rtl-optimization/64294] invalid code, zero check gets optimized away
Date: Sat, 13 Dec 2014 21:12:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: rtl-optimization
X-Bugzilla-Version: 4.9.2
X-Bugzilla-Keywords:
X-Bugzilla-Severity: normal
X-Bugzilla-Who: gcc at breakpoint dot cc
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags:
X-Bugzilla-Changed-Fields: bug_status resolution
Message-ID: <bug-64294-4-eimneMYxpX@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-64294-4@http.gcc.gnu.org/bugzilla/>
References: <bug-64294-4@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: 2014-12/txt/msg01569.txt.bz2

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64294

Sebastian Andrzej Siewior <gcc at breakpoint dot cc> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |UNCONFIRMED
         Resolution|INVALID                     |---

--- Comment #5 from Sebastian Andrzej Siewior <gcc at breakpoint dot cc> ---
I re-open it. This time I attached the whole .i twice:
- "macro" contains the second CLI_ISCONTAINED() invocation as a macro
- "static" contains the second CLI_ISCONTAINED() as a static function

The first one (macro) segfaults, the second one (static) works as a expected. 
The only obvious change I made in the static version is that the size argument
is not signed but unsigned. Changing the type of sb_size to signed int results
in the segfault again.

I saw this problem with gcc-4.8 and 4.9. gcc 4.7 seems not to miss compile it.

Comparing the disassemble between those two .i I see:

- macro
+ static
 <label>:
-       8b 44 24 44             mov    0x44(%esp),%eax
-       89 c1                   mov    %eax,%ecx
+       8b 44 24 20             mov    0x20(%esp),%eax
+       85 c0                   test   %eax,%eax
+       0f 84 8c fb ff ff       je     3f0 <petite_inflate2x_1to9+0x3f0>
+       8b 4c 24 58             mov    0x58(%esp),%ecx
+       8b 44 24 20             mov    0x20(%esp),%eax

For me as a no-compiler guy it looks like the zero check has been removed
because for 
some reason the size argument has to be != 0.

I'm not sure if this is related but #26763 fixed a problem with the same macro.

Sebastian