From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-175869-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 24503 invoked by alias); 7 Feb 2006 08:23:50 -0000
Received: (qmail 24481 invoked by uid 48); 7 Feb 2006 08:23:47 -0000
Date: Tue, 07 Feb 2006 08:23:00 -0000
Message-ID: <20060207082347.24480.qmail@sourceware.org>
X-Bugzilla-Reason: CC
References: <bug-15792-6528@http.gcc.gnu.org/bugzilla/>
Subject: [Bug rtl-optimization/15792] missed subreg optimization
In-Reply-To: <bug-15792-6528@http.gcc.gnu.org/bugzilla/>
Reply-To: gcc-bugzilla@gcc.gnu.org
To: gcc-bugs@gcc.gnu.org
From: "ian at airs dot com" <gcc-bugzilla@gcc.gnu.org>
Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
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
X-SW-Source: 2006-02/txt/msg00615.txt.bz2
List-Id: <gcc-bugs.sourceware.org>



------- Comment #9 from ian at airs dot com  2006-02-07 08:23 -------
I now have a reasonably simple reload patch which eliminates the unnecessary
move.  For the test case in comment #4, I get this code with -O2
-momit-leaf-frame-pointer:

foo:
        movl    12(%esp), %eax
        movl    16(%esp), %edx
        addl    4(%esp), %eax
        adcl    8(%esp), %edx
        orl     %eax, %edx
        jne     .L7
        rep ; ret
        .p2align 4,,7
.L7:
        jmp     gh


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15792