* [Bug c/49379] warning from Mac OS X linker alignment lost for -ftree-vectorize optimization
2011-06-12 2:25 [Bug c/49379] New: warning from Mac OS X linker alignment lost for -ftree-vectorize optimization nenad at intrepid dot com
@ 2011-06-12 2:26 ` nenad at intrepid dot com
2011-06-12 11:43 ` rguenth at gcc dot gnu.org
` (6 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: nenad at intrepid dot com @ 2011-06-12 2:26 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49379
--- Comment #1 from Nenad Vukicevic <nenad at intrepid dot com> 2011-06-12 02:26:32 UTC ---
Created attachment 24495
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24495
Sample code for MAc OS X linker warning
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug c/49379] warning from Mac OS X linker alignment lost for -ftree-vectorize optimization
2011-06-12 2:25 [Bug c/49379] New: warning from Mac OS X linker alignment lost for -ftree-vectorize optimization nenad at intrepid dot com
2011-06-12 2:26 ` [Bug c/49379] " nenad at intrepid dot com
@ 2011-06-12 11:43 ` rguenth at gcc dot gnu.org
2011-06-12 12:44 ` dominiq at lps dot ens.fr
` (5 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: rguenth at gcc dot gnu.org @ 2011-06-12 11:43 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49379
--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-06-12 11:42:57 UTC ---
You should probably report this to Apple instead.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug c/49379] warning from Mac OS X linker alignment lost for -ftree-vectorize optimization
2011-06-12 2:25 [Bug c/49379] New: warning from Mac OS X linker alignment lost for -ftree-vectorize optimization nenad at intrepid dot com
2011-06-12 2:26 ` [Bug c/49379] " nenad at intrepid dot com
2011-06-12 11:43 ` rguenth at gcc dot gnu.org
@ 2011-06-12 12:44 ` dominiq at lps dot ens.fr
2011-06-12 13:07 ` gary at intrepid dot com
` (4 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: dominiq at lps dot ens.fr @ 2011-06-12 12:44 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49379
Dominique d'Humieres <dominiq at lps dot ens.fr> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2011.06.12 12:43:18
Ever Confirmed|0 |1
--- Comment #3 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2011-06-12 12:43:18 UTC ---
Confirmed on x86_64-apple-darwin10
@(#)PROGRAM:ld PROJECT:ld64-97.17
llvm version 2.9svn, from Apple Clang 1.7 (build 77)
and powerpc-apple-darwin9.8.0
@(#)PROGRAM:ld PROJECT:ld64-85.2.1
for trunk and gcc 4.5.2, but not for 4.4.4.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug c/49379] warning from Mac OS X linker alignment lost for -ftree-vectorize optimization
2011-06-12 2:25 [Bug c/49379] New: warning from Mac OS X linker alignment lost for -ftree-vectorize optimization nenad at intrepid dot com
` (2 preceding siblings ...)
2011-06-12 12:44 ` dominiq at lps dot ens.fr
@ 2011-06-12 13:07 ` gary at intrepid dot com
2011-06-29 4:20 ` PHHargrove at lbl dot gov
` (3 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: gary at intrepid dot com @ 2011-06-12 13:07 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49379
--- Comment #4 from Gary Funck <gary at intrepid dot com> 2011-06-12 13:04:59 UTC ---
We think that this issue is related to an optimization that increases the
alignment of common symbols that have the potential to improve vectorization.
We didn't run a reghunt, but it looks like this may have been the update that
initially implemented the alignment change.
r120576 | hubicka | 2007-01-08 03:13:14 -0800 (Mon, 08 Jan 2007) | 23 lines
[...]
* tree-vectorizer.c (increase_alignment): Move here from cgraphunit.c
(gate_increase_alignment): New function.
(pass_ipa_increase_alignment): New pass.
We've determined: (1) the vanilla GNU/Linux linker doesn't complain, (2) the
installed (Apple) GCC compiler likely pre-dates the change above.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug c/49379] warning from Mac OS X linker alignment lost for -ftree-vectorize optimization
2011-06-12 2:25 [Bug c/49379] New: warning from Mac OS X linker alignment lost for -ftree-vectorize optimization nenad at intrepid dot com
` (3 preceding siblings ...)
2011-06-12 13:07 ` gary at intrepid dot com
@ 2011-06-29 4:20 ` PHHargrove at lbl dot gov
2011-06-29 5:28 ` PHHargrove at lbl dot gov
` (2 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: PHHargrove at lbl dot gov @ 2011-06-29 4:20 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49379
--- Comment #5 from Paul H. Hargrove <PHHargrove at lbl dot gov> 2011-06-29 04:20:13 UTC ---
Created attachment 24629
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24629
Second (non Apple) reproducer for bug 49379
This attachment is a simple 3-file reproducer for this bug on x86-64/Linux (no
Apple linker involved):
As seen by Gary the -fno-tree-vectorize flag eliminates an alignment warning
from the linker that is otherwise present at -O3 (or with explicit
"-ftree-vectorize at -O1 and -O2):
$ tar xfvj bug49379-2.tar.bz2
bug49379-2.h
bug49379-2_aux.c
bug49379-2_main.c
$ /tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc/xgcc
-B/tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc -O3 bug49379-2_main.c
bug49379-2_aux.c
/usr/bin/ld: Warning: alignment 4 of symbol `flag' in /tmp/ccwZjyV0.o is
smaller than 16 in /tmp/ccYSRWEX.o
$ /tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc/xgcc
-B/tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc -O3
-fno-tree-vectorize bug49379-2_main.c bug49379-2_aux.c
$ /tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc/xgcc
-B/tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc -O2 -ftree-vectorize
bug49379-2_main.c bug49379-2_aux.c
/usr/bin/ld: Warning: alignment 4 of symbol `flag' in /tmp/ccSN6r8r.o is
smaller than 16 in /tmp/cc7JOniC.o
$ /tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc/xgcc
-B/tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc -O1 -ftree-vectorize
bug49379-2_main.c bug49379-2_aux.c
/usr/bin/ld: Warning: alignment 4 of symbol `flag' in /tmp/ccw0AZs5.o is
smaller than 16 in /tmp/ccRVugJ6.o
$ /tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc/xgcc -v
Using built-in specs.
COLLECT_GCC=/tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc/xgcc
Target: x86_64-unknown-linux-gnu
Configured with: ./configure --enable-languages=c
--with-mpc=/usr/common/ftg/gcc/common/
Thread model: posix
gcc version 4.7.0 20110625 (experimental) (GCC)
$ ld --version
GNU ld version 2.17.50.0.6-14.el5 20061020
Copyright 2005 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License. This program has absolutely no warranty.
$ uname -a
Linux tesla 2.6.18-194.17.1.el5 #1 SMP Wed Sep 29 12:09:22 EDT 2010 x86_64
x86_64 x86_64 GNU/Linux
$ cat /etc/redhat-release
Scientific Linux SL release 5.5 (Boron)
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug c/49379] warning from Mac OS X linker alignment lost for -ftree-vectorize optimization
2011-06-12 2:25 [Bug c/49379] New: warning from Mac OS X linker alignment lost for -ftree-vectorize optimization nenad at intrepid dot com
` (4 preceding siblings ...)
2011-06-29 4:20 ` PHHargrove at lbl dot gov
@ 2011-06-29 5:28 ` PHHargrove at lbl dot gov
2011-06-29 17:08 ` d.g.gorbachev at gmail dot com
2014-11-19 23:40 ` [Bug tree-optimization/49379] warning from linker: " egall at gwmail dot gwu.edu
7 siblings, 0 replies; 9+ messages in thread
From: PHHargrove at lbl dot gov @ 2011-06-29 5:28 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49379
Paul H. Hargrove <PHHargrove at lbl dot gov> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |PHHargrove at lbl dot gov
--- Comment #6 from Paul H. Hargrove <PHHargrove at lbl dot gov> 2011-06-29 05:27:36 UTC ---
Following up on my previous comment, I've repeated the experiment w/ a system
with more recent binutils. The result is the same:
$ /tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc/xgcc
-B/tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc -O3 bug49379-2_main.c
bug49379-2_aux.c
/usr/bin/ld: Warning: alignment 4 of symbol `flag' in /tmp/ccIvQMTp.o is
smaller than 16 in /tmp/ccP5ZCFr.o
$ /tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc/xgcc
-B/tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc -O3
-fno-tree-vectorize bug49379-2_main.c bug49379-2_aux.c
$ ld --version
GNU ld (GNU Binutils for Ubuntu) 2.20
Copyright 2009 Free Software Foundation, Inc.
This program is free software; you may redistribute it under the terms of
the GNU General Public License version 3 or (at your option) a later version.
This program has absolutely no warranty.
$ uname -a
Linux ftg4 2.6.31-16-generic #53-Ubuntu SMP Tue Dec 8 04:02:15 UTC 2009 x86_64
GNU/Linux
$ cat /etc/*release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=9.10
DISTRIB_CODENAME=karmic
DISTRIB_DESCRIPTION="Ubuntu 9.10"
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug c/49379] warning from Mac OS X linker alignment lost for -ftree-vectorize optimization
2011-06-12 2:25 [Bug c/49379] New: warning from Mac OS X linker alignment lost for -ftree-vectorize optimization nenad at intrepid dot com
` (5 preceding siblings ...)
2011-06-29 5:28 ` PHHargrove at lbl dot gov
@ 2011-06-29 17:08 ` d.g.gorbachev at gmail dot com
2014-11-19 23:40 ` [Bug tree-optimization/49379] warning from linker: " egall at gwmail dot gwu.edu
7 siblings, 0 replies; 9+ messages in thread
From: d.g.gorbachev at gmail dot com @ 2011-06-29 17:08 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49379
--- Comment #7 from Dmitry Gorbachev <d.g.gorbachev at gmail dot com> 2011-06-29 17:07:50 UTC ---
See also bug 48127.
^ permalink raw reply [flat|nested] 9+ messages in thread
* [Bug tree-optimization/49379] warning from linker: alignment lost for -ftree-vectorize optimization
2011-06-12 2:25 [Bug c/49379] New: warning from Mac OS X linker alignment lost for -ftree-vectorize optimization nenad at intrepid dot com
` (6 preceding siblings ...)
2011-06-29 17:08 ` d.g.gorbachev at gmail dot com
@ 2014-11-19 23:40 ` egall at gwmail dot gwu.edu
7 siblings, 0 replies; 9+ messages in thread
From: egall at gwmail dot gwu.edu @ 2014-11-19 23:40 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=49379
Eric Gallager <egall at gwmail dot gwu.edu> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |egall at gwmail dot gwu.edu
--- Comment #8 from Eric Gallager <egall at gwmail dot gwu.edu> ---
(In reply to Dominique d'Humieres from comment #3)
> Confirmed on x86_64-apple-darwin10
>
> @(#)PROGRAM:ld PROJECT:ld64-97.17
> llvm version 2.9svn, from Apple Clang 1.7 (build 77)
>
> and powerpc-apple-darwin9.8.0
>
> @(#)PROGRAM:ld PROJECT:ld64-85.2.1
>
It looks like Apple has removed the warning since then;
searching opensource.apple.com for the warning string in the OP shows that the
most recent time it appeared was around line 246 of
ld64/ld64-127.2/src/ld/SymbolTable.cpp.
Looking around the same place in my copy of the ld64-136 sources, the warning
is now no longer anywhere to be found around there.
Still, I suppose, though, if other linkers still print similar warnings, the
underlying issue must still remain then...
^ permalink raw reply [flat|nested] 9+ messages in thread