From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-371375-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 5315 invoked by alias); 20 Oct 2011 11:07:32 -0000
Received: (qmail 5304 invoked by uid 22791); 20 Oct 2011 11:07:30 -0000
X-SWARE-Spam-Status: No, hits=-2.8 required=5.0	tests=ALL_TRUSTED,AWL,BAYES_00,TW_CP,TW_DR
X-Spam-Check-By: sourceware.org
Received: from localhost (HELO gcc.gnu.org) (127.0.0.1)    by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 20 Oct 2011 11:07:14 +0000
From: "sebastian.huber@embedded-brains.de" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/50106] [ARM] Wrong code with -march=armv5t -mthumb -Os
Date: Thu, 20 Oct 2011 11:07:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: target
X-Bugzilla-Keywords: wrong-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: sebastian.huber@embedded-brains.de
X-Bugzilla-Status: RESOLVED
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: ramana at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 4.6.2
X-Bugzilla-Changed-Fields:
Message-ID: <bug-50106-4-2TFTCOcBoA@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-50106-4@http.gcc.gnu.org/bugzilla/>
References: <bug-50106-4@http.gcc.gnu.org/bugzilla/>
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
Content-Type: text/plain; charset="UTF-8"
MIME-Version: 1.0
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
X-SW-Source: 2011-10/txt/msg02119.txt.bz2

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50106

--- Comment #11 from Sebastian Huber <sebastian.huber@embedded-brains.de> 2011-10-20 11:07:09 UTC ---
Thank you very much.  With this change the GCC 4.6.2-RC-20111019 produces now
correct code in this case.

I know understand why the unused volatile registers are saved and restored. 
This is to get rid of the arithmetic stack adjustments.

--- test.Os.GCC-4.5.s   2011-10-20 13:04:15.384638860 +0200
+++ test.Os.GCC-4.6.s   2011-10-20 13:04:15.396639237 +0200
@@ -17,32 +17,29 @@
        .thumb_func
        .type   _GetIDS, %function
 _GetIDS:
-       push    {lr}
-       ldr     r2, .L4
-       sub     sp, sp, #12
-       ldr     r2, [r2]
-       mov     r3, r0
+       push    {r0, r1, r2, lr}
+       ldr     r3, .L4
        ldr     r1, .L4+4
-       add     r0, sp, #4
-       cmp     r3, r2
+       ldr     r3, [r3]
+       cmp     r0, r3
        bge     .L2
-       lsl     r3, r3, #1
-       add     r1, r1, r3
+       lsl     r0, r0, #1
+       add     r1, r1, r0
 .L2:
        mov     r2, #2
+       add     r0, sp, #4
        bl      memcpy
        add     r3, sp, #4
        ldrb    r0, [r3, #1]
        ldrb    r2, [r3]
        lsl     r0, r0, #8
-       add     sp, sp, #12
-       orr     r0, r0, r2
+       orr     r0, r2
        @ sp needed for prologue
-       pop     {pc}
+       pop     {r1, r2, r3, pc}
 .L5:
        .align  2
 .L4:
        .word   _LIST_SIZE
        .word   _List
        .size   _GetIDS, .-_GetIDS
-       .ident  "GCC: (GNU) 4.5.4 20111013 (prerelease)"
+       .ident  "GCC: (GNU) 4.6.2 20111019 (prerelease)"