Re: gcc-2.95.2-51 is buggy
Hello all, I have used patch from GCC-PATCHES list posted by Bernd Schmidt . Because of high importance I am forwarding this patch to Linux-Kernel. Patch seems to solve problem. I have added warning print for case of problem, to find which parts of Linux kernel could be affected by this GCC bug. There are results: linux-2.4.0-test10-pre? compiled for K7 make[2]: Entering directory `/usr/src/linux-2.4.0-t9/fs' gcc -D__KERNEL__ -I/usr/src/linux-2.4.0-t9/include -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer -pipe -mpreferred-stack-boundary=2 -march=i686 -malign-functions=4 -fno-strict-aliasing-c -o block_dev.o block_dev.c block_dev.c: In function `block_read': block_dev.c:311: warning: possible original gcc 2.95.2 error c/877 make[2]: Entering directory `/usr/src/linux-2.4.0-t9/ipc' gcc -D__KERNEL__ -I/usr/src/linux-2.4.0-t9/include -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer -pipe -mpreferred-stack-boundary=2 -march=i686 -malign-functions=4 -fno-strict-aliasing-c -o msg.o msg.c msg.c: In function `sys_msgctl': msg.c:576: warning: possible original gcc 2.95.2 error c/877 gcc -D__KERNEL__ -I/usr/src/linux-2.4.0-t9/include -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer -pipe -mpreferred-stack-boundary=2 -march=i686 -malign-functions=4 -fno-strict-aliasing-c -o sem.o sem.c I have run same compilation for 2.2.15 kernel compiled for K6 make[2]: Entering directory `/usr/src/linux-2.2.15/fs' block_dev.c: In function `block_read': block_dev.c:304: warning: possible original gcc 2.95.2 error c/877 I hope that my mail is not only waste of your time. These possible wrong compiled files could be sources of other false kernel related bugs. If you have interest I will to try to compile 2.2.x and 2.4.0-x kernels for bare i586 to find more such problematic places. Best wishes Pavel Pisa PS: For faster response CC any reply directly to my address, please. - To: aeb at cwi dot nl Subject: Re: c/877: gcc 2.95.2 generates incorrect code on i386 From: Bernd Schmidt Date: Fri, 24 Nov 2000 15:40:05 + (GMT) cc: gcc-gnats at gcc dot gnu dot org, gcc-prs at gcc dot gnu dot org, gcc-bugs at gcc dot gnu dot org, gcc-patches at gcc dot gnu dot org On 24 Nov 2000 [EMAIL PROTECTED] wrote: > >Synopsis: gcc 2.95.2 generates incorrect code on i386 > It seems that a variable length shift of a long long > is miscompiled. This causes Linux kernel bugs. This is (as usual) a bug in reload. We have two insns: (insn 69 67 70 (set (reg:QI 46) (subreg:QI (reg:SI 43) 0)) (insn 70 69 72 (set (reg:DI 44) (ashiftrt:DI (reg:DI 44) (reg:QI 46))) (expr_list:REG_DEAD 46) Neither reg 46 nor reg 44 gets a hard register. While processing insn 70, reload decides that it will need reg 2 (%cl) for reg 46, and reg 3/4 (%ebx/%esi) for reg 44. It also notices that the value of reg 44 is already available in reg 1/2 (%edx/%ecx), so it can avoid loading it from the stack and instead use reg 1/2 as overriding input. It then notices that reg 46 dies in insn 70 and is set in insn 69, so it would be possible simply to replace the destination of insn 69 with the reload reg (%cl). The problem is that by changing insn 69 to store into %cl, the input override for the other reload gets clobbered. Oops. The function reload_reg_free_for_value_p doesn't test for this case. I'm currently bootstrapping with the patch below; I'll check it in (along with a testcase) once that finishes. It won't apply cleanly to 2.95, but it should be quite easy to figure out how to apply it. This is an obvious candidate should we decide to make a 2.95.3 release. (As a side note, this bug has nothing to do with the fact that there's a long long shift in this testcase, although I think I've noticed a bunch of potential bugs related to multiword values in the reload inheritance code while looking at this testcase...) Bernd * reload1.c (conflicts_with_override): New function. (emit_input_reload_insns): Use it to tighten test for validity of substituting into output of previous insn. Index: reload1.c === RCS file: /cvs/gcc/egcs/gcc/reload1.c,v retrieving revision 1.241 diff -u -p -r1.241 reload1.c --- reload1.c 2000/11/14 10:23:37 1.241 +++ reload1.c 2000/11/24 15:11:43 @@ -417,6 +417,7 @@ static int reload_reg_reaches_end_p PARA enum reload_type)); static int allocate_reload_reg PARAMS ((struct insn_chain *, int, int)); +static int conflicts_with_override PARAMS ((rtx)); static void failed_reload PARAMS ((rtx, int)); static int set_reload_reg PARAMS ((int, int)); static void choose_reload_regs_initPARAMS ((struct insn_chain *, rtx *)); @@ -4882,6
Re: gcc-2.95.2-51 is buggy
On Sun, 26 Nov 2000 16:33:25 Olaf Dietsche wrote: > > A simple `gcc -march=i686' or `gcc -mpentiumpro' does fix it as > well. So, if you configure your kernel with `CONFIG_M686=y' the problem > should be gone. > That does not work for 2.2 kernels. Always compile for -m486. To use the -march flag you need to modify arch/i386/kernel/Makefile. Patch follows: = PATCH patch-gcc-arch: --- linux-2.2.17/arch/i386/Makefile.origWed Nov 22 20:42:49 2000 +++ linux-2.2.17/arch/i386/Makefile Wed Nov 22 20:44:40 2000 @@ -24,23 +24,23 @@ CFLAGS := $(CFLAGS) $(CFLAGS_PIPE) $(CFLAGS_NSR) ifdef CONFIG_M386 -CFLAGS := $(CFLAGS) -m386 -DCPU=386 +CFLAGS := $(CFLAGS) -march=i386 -DCPU=386 endif ifdef CONFIG_M486 -CFLAGS := $(CFLAGS) -m486 -DCPU=486 +CFLAGS := $(CFLAGS) -march=i486 -DCPU=486 endif ifdef CONFIG_M586 -CFLAGS := $(CFLAGS) -m486 -malign-loops=2 -malign-jumps=2 -malign-functions=2 -DCPU=586 +CFLAGS := $(CFLAGS) -march=i586 -malign-loops=2 -malign-jumps=2 -malign-functions=2 -DCPU=586 endif ifdef CONFIG_M586TSC -CFLAGS := $(CFLAGS) -m486 -malign-loops=2 -malign-jumps=2 -malign-functions=2 -DCPU=586 +CFLAGS := $(CFLAGS) -march=i586 -malign-loops=2 -malign-jumps=2 -malign-functions=2 -DCPU=586 endif ifdef CONFIG_M686 -CFLAGS := $(CFLAGS) -m486 -malign-loops=2 -malign-jumps=2 -malign-functions=2 -DCPU=686 +CFLAGS := $(CFLAGS) -march=i686 -malign-loops=2 -malign-jumps=2 -malign-functions=2 -DCPU=686 endif HEAD := arch/i386/kernel/head.o arch/i386/kernel/init_task.o -- Juan Antonio Magallon Lacarta #> cd /pub mailto:[EMAIL PROTECTED] #> more beer Linux 2.2.18-pre23-vm #3 SMP Wed Nov 22 22:33:53 CET 2000 i686 unknown - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
Re: gcc-2.95.2-51 is buggy
Mike Castle writes: > Btw, was this ever tested on other arch's? I don't remember seeing > anything come across this list. Well, I've tested it on egcs-1.1.2 and RH's gcc 2.96 on ARM, both of which appear ok. _ |_| - ---+---+- | | Russell King[EMAIL PROTECTED] --- --- | | | | http://www.arm.linux.org.uk/personal/aboutme.html / / | | +-+-+ --- -+- / | THE developer of ARM Linux |+| /|\ / | | | --- | +-+-+ - /\\\ | - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
Re: gcc-2.95.2-51 is buggy
On Sun, Nov 26, 2000 at 04:33:25PM +0100, Olaf Dietsche wrote: > A simple `gcc -march=i686' or `gcc -mpentiumpro' does fix it as > well. So, if you configure your kernel with `CONFIG_M686=y' the problem > should be gone. Btw, was this ever tested on other arch's? I don't remember seeing anything come across this list. mrc -- Mike Castle Life is like a clock: You can work constantly [EMAIL PROTECTED] and be right all the time, or not work at all www.netcom.com/~dalgoda/ and be right at least twice a day. -- mrc We are all of us living in the shadow of Manhattan. -- Watchmen - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
Re: gcc-2.95.2-51 is buggy
On 26 Nov 2000, Olaf Dietsche wrote: > A simple `gcc -march=i686' or `gcc -mpentiumpro' does fix it as > well. So, if you configure your kernel with `CONFIG_M686=y' the > problem should be gone. Except for the fact that it'll no longer boot on Pentiums and 486es ;) Rik -- Hollywood goes for world dumbination, Trailer at 11. http://www.surriel.com/ http://www.conectiva.com/ http://distro.conectiva.com.br/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
Re: gcc-2.95.2-51 is buggy
Rik van Riel <[EMAIL PROTECTED]> writes: > On Sat, 25 Nov 2000, Andries Brouwer wrote: > > On Sat, Nov 25, 2000 at 03:26:15PM -0200, Rik van Riel wrote: > > > > > The gcc-2.95.2-6cl from Conectiva 6.0 is buggy too. > > > > Yes. Probably you have seen it by now, but the difference between > > good and bad versions of gcc-2.95.2 did not lie in the applied patches, > > but was the difference between compilation for 686 or 386. > > It is not your (SuSE's, Debian's) fault. A fix already exists. > > Indeed, this should be fixed soon. > > I'm sure a simple 'apt-get upgrade' will install a new > gcc RPM on my workstation soon ;) A simple `gcc -march=i686' or `gcc -mpentiumpro' does fix it as well. So, if you configure your kernel with `CONFIG_M686=y' the problem should be gone. Regards, Olaf. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
Re: gcc-2.95.2-51 is buggy
On Sat, 25 Nov 2000, Andries Brouwer wrote: > On Sat, Nov 25, 2000 at 03:26:15PM -0200, Rik van Riel wrote: > > > The gcc-2.95.2-6cl from Conectiva 6.0 is buggy too. > > Yes. Probably you have seen it by now, but the difference between > good and bad versions of gcc-2.95.2 did not lie in the applied patches, > but was the difference between compilation for 686 or 386. > It is not your (SuSE's, Debian's) fault. A fix already exists. Indeed, this should be fixed soon. I'm sure a simple 'apt-get upgrade' will install a new gcc RPM on my workstation soon ;) cheers, Rik -- Hollywood goes for world dumbination, Trailer at 11. http://www.conectiva.com/ http://www.surriel.com/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
Re: gcc-2.95.2-51 is buggy
On Sat, Nov 25, 2000 at 03:26:15PM -0200, Rik van Riel wrote: > The gcc-2.95.2-6cl from Conectiva 6.0 is buggy too. Yes. Probably you have seen it by now, but the difference between good and bad versions of gcc-2.95.2 did not lie in the applied patches, but was the difference between compilation for 686 or 386. It is not your (SuSE's, Debian's) fault. A fix already exists. Andries - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
Re: gcc-2.95.2-51 is buggy
On Sat, Nov 25, 2000 at 03:26:15PM -0200, Rik van Riel wrote: Rik, We refuse to use it here at present. Builds from it have a lot of problems, for some reason. Andre is looking into it more deeply than I, but I agree with your assessment. Jeff > On Fri, 24 Nov 2000, Neil Brown wrote: > > On Friday November 24, [EMAIL PROTECTED] wrote: > > > >> ... RedHat's GCC snapshot "2.96" handles this case just fine. > > > > > > > Now, if you can isolate the relevant part of the diff between > > > > 2.95.2 and RH 2.96... > > > > > > Maybe I have to be more precise in the statement "gcc 2.95.2 is buggy". > > [image from FTP site not buggy] > > > > This is from a SuSE distribution, I forget which, not very recent. > > > Revised summary: gcc-2.95.2-51 from SuSE is buggy. > > > > Ditto for gcc-2.95.2-13 from Debian (potato). It exhibits the > > same bug. Debian applies a total of 49 patches to gcc and the > > libraries. > > The gcc-2.95.2-6cl from Conectiva 6.0 is buggy too. > > (and the ISO images haven't even been available for > one week yet ... *sigh*) > > regards, > > Rik > -- > Hollywood goes for world dumbination, > Trailer at 11. > > http://www.conectiva.com/ http://www.surriel.com/ > > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to [EMAIL PROTECTED] > Please read the FAQ at http://www.tux.org/lkml/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
Re: gcc-2.95.2-51 is buggy
On Fri, 24 Nov 2000, Neil Brown wrote: > On Friday November 24, [EMAIL PROTECTED] wrote: > > >> ... RedHat's GCC snapshot "2.96" handles this case just fine. > > > > > Now, if you can isolate the relevant part of the diff between > > > 2.95.2 and RH 2.96... > > > > Maybe I have to be more precise in the statement "gcc 2.95.2 is buggy". [image from FTP site not buggy] > > This is from a SuSE distribution, I forget which, not very recent. > > Revised summary: gcc-2.95.2-51 from SuSE is buggy. > > Ditto for gcc-2.95.2-13 from Debian (potato). It exhibits the > same bug. Debian applies a total of 49 patches to gcc and the > libraries. The gcc-2.95.2-6cl from Conectiva 6.0 is buggy too. (and the ISO images haven't even been available for one week yet ... *sigh*) regards, Rik -- Hollywood goes for world dumbination, Trailer at 11. http://www.conectiva.com/ http://www.surriel.com/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
Re: gcc-2.95.2-51 is buggy
[EMAIL PROTECTED] wrote: > > > so the reason why it did not show up in the gcc you picked up from > > ftp.gnu.org is that you have compiled it so that it defaults to -mcpu=i686 > > Yes, you are right. > > So 2.95.2 fails for i386, i486, i586 and does not fail for i686. > RedHat 7.0's gcc 2.96 and kgcc do not seem to exhibit this problem: me2v@reliant tmp $ gcc -v Reading specs from /usr/lib/gcc-lib/i386-redhat-linux/2.96/specs gcc version 2.96 2731 (Red Hat Linux 7.0) me2v@reliant tmp $ kgcc -v Reading specs from /usr/lib/gcc-lib/i386-glibc21-linux/egcs-2.91.66/specs gcc version egcs-2.91.66 19990314/Linux (egcs-1.1.2 release) me2v@reliant tmp $ gcc -O2 -o bug bug.c ; ./bug 0x0 me2v@reliant tmp $ gcc -o bug bug.c ; ./bug 0x0 me2v@reliant tmp $ kgcc -O2 -o bug bug.c ; ./bug 0x0 me2v@reliant tmp $ kgcc -o bug bug.c ; ./bug 0x0 -- Matthew Vanecek perl -e 'print $i=pack(c5,(41*2),sqrt(7056),(unpack(c,H)-2),oct(115),10);' For 93 million miles, there is nothing between the sun and my shadow except me. I'm always getting in the way of something... - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
Re: gcc-2.95.2-51 is buggy
On Fri, 24 Nov 2000, Jakub Jelinek wrote: >so the reason why it did not show up in the gcc you picked up from >ftp.gnu.org is that you have compiled it so that it defaults to -mcpu=i686 >where the bug does not show up. Indeed. I just ran some tests, and I can confirm that gcc 2.95.2 vanilla exhibits the bug when compiled and run for i486 or i585, but not i686. /Mikael - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
Re: gcc-2.95.2-51 is buggy
> so the reason why it did not show up in the gcc you picked up from > ftp.gnu.org is that you have compiled it so that it defaults to -mcpu=i686 Yes, you are right. So 2.95.2 fails for i386, i486, i586 and does not fail for i686. Andries - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
Re: gcc-2.95.2-51 is buggy
> > Reading specs from /usr/lib/gcc-lib/i486-suse-linux/2.95.2/specs > > gcc version 2.95.2 19991024 (release) > > % /usr/bin/gcc -Wall -O2 -o bug bug.c; ./bug > > 0x8480 > > % /usr/gcc/aeb/bin/gcc -v > > Reading specs from /usr/gcc/aeb/lib/gcc-lib/i686-pc-linux-gnu/2.95.2/specs > > gcc version 2.95.2 19991024 (release) > > % /usr/gcc/aeb/bin/gcc -Wall -O2 -o nobug bug.c; ./nobug > > 0x0 > > > > So, not all versions of gcc 2.95.2 are equal. > > Interesting. Plain vanilla 2.95.2 from ftp.gnu.org exhibits the same > bug on an BSDI2.1 i386 system. > > defiant ~/tmp$ gcc -v > Reading specs from /usr/local/gnu/lib/gcc-lib/i386-pc-bsdi2.1/2.95.2/specs > gcc version 2.95.2 19991024 (release) > defiant ~/tmp$ gcc -O2 -o bug bug.c; ./bug > 0x480 > > Ion > Don't know if anyone else has noticed this but from what I've seen posted it appears, unless I missed something, the gcc 2.95.2s that have exibited the bug were compiled for a 386 or a 486 while the one on which it worked was a 686. Perhaps the bug only appears on certain gcc configurations. Either the build configuration or the default optimization method(s), if I remember correctly gcc optimizes for the platform (i.e. i386, i486, i586, etc) it was configured for by default. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
Re: gcc-2.95.2-51 is buggy
On Fri, Nov 24, 2000 at 06:20:33AM +0100, [EMAIL PROTECTED] wrote: > >> ... RedHat's GCC snapshot "2.96" handles this case just fine. > > > Now, if you can isolate the relevant part of the diff between > > 2.95.2 and RH 2.96... > > Maybe I have to be more precise in the statement "gcc 2.95.2 is buggy". > > I just installed gcc 2.95.2 freshly ftp'ed from ftp.gnu.org, and > > % /usr/bin/gcc -v > Reading specs from /usr/lib/gcc-lib/i486-suse-linux/2.95.2/specs > gcc version 2.95.2 19991024 (release) > % /usr/bin/gcc -Wall -O2 -o bug bug.c; ./bug > 0x8480 > % /usr/gcc/aeb/bin/gcc -v > Reading specs from /usr/gcc/aeb/lib/gcc-lib/i686-pc-linux-gnu/2.95.2/specs > gcc version 2.95.2 19991024 (release) > % /usr/gcc/aeb/bin/gcc -Wall -O2 -o nobug bug.c; ./nobug > 0x0 > > So, not all versions of gcc 2.95.2 are equal. I believe all 2.95.2's are equal in this, I think the fact that it gives 0 in the nobug case is some other reason: $ for i in gcc kgcc '/usr/src/gcc-trunk/obj/gcc/xgcc -B /usr/src/gcc-trunk/obj/gcc/' '/usr/src/gcc-2.95.2/obj/gcc/xgcc -B /usr/src/gcc-2.95.2/obj/gcc/'; do $i -v; for j in -mcpu=i386 -mcpu=i586 -mcpu=i686; do $i $j -O2 -o aeb aeb.c; echo -n "$i $j "; ./aeb; done; done Reading specs from /usr/lib/gcc-lib/i386-redhat-linux/2.96/specs gcc version 2.96 2731 (Red Hat Linux 7.0) gcc -mcpu=i386 0x0 gcc -mcpu=i586 0x0 gcc -mcpu=i686 0x0 Reading specs from /usr/lib/gcc-lib/i386-glibc21-linux/egcs-2.91.66/specs gcc version egcs-2.91.66 19990314/Linux (egcs-1.1.2 release) kgcc -mcpu=i386 0x0 kgcc -mcpu=i586 0x0 kgcc -mcpu=i686 0x0 Reading specs from /usr/src/gcc-trunk/obj/gcc/specs Configured with: gcc version 2.97 20001120 (experimental) /usr/src/gcc-trunk/obj/gcc/xgcc -B /usr/src/gcc-trunk/obj/gcc/ -mcpu=i386 0x0 /usr/src/gcc-trunk/obj/gcc/xgcc -B /usr/src/gcc-trunk/obj/gcc/ -mcpu=i586 0x0 /usr/src/gcc-trunk/obj/gcc/xgcc -B /usr/src/gcc-trunk/obj/gcc/ -mcpu=i686 0x0 Reading specs from /usr/src/gcc-2.95.2/obj/gcc/specs gcc version 2.95.2 19991024 (release) /usr/src/gcc-2.95.2/obj/gcc/xgcc -B /usr/src/gcc-2.95.2/obj/gcc/ -mcpu=i386 0x8480 /usr/src/gcc-2.95.2/obj/gcc/xgcc -B /usr/src/gcc-2.95.2/obj/gcc/ -mcpu=i586 0x8480 /usr/src/gcc-2.95.2/obj/gcc/xgcc -B /usr/src/gcc-2.95.2/obj/gcc/ -mcpu=i686 0x0 so the reason why it did not show up in the gcc you picked up from ftp.gnu.org is that you have compiled it so that it defaults to -mcpu=i686 where the bug does not show up. Jakub - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
Re: gcc-2.95.2-51 is buggy
On Fri, 24 Nov 2000 06:20:33 +0100 (MET), [EMAIL PROTECTED] wrote: > Reading specs from /usr/lib/gcc-lib/i486-suse-linux/2.95.2/specs > gcc version 2.95.2 19991024 (release) > % /usr/bin/gcc -Wall -O2 -o bug bug.c; ./bug > 0x8480 > % /usr/gcc/aeb/bin/gcc -v > Reading specs from /usr/gcc/aeb/lib/gcc-lib/i686-pc-linux-gnu/2.95.2/specs > gcc version 2.95.2 19991024 (release) > % /usr/gcc/aeb/bin/gcc -Wall -O2 -o nobug bug.c; ./nobug > 0x0 > > So, not all versions of gcc 2.95.2 are equal. Interesting. Plain vanilla 2.95.2 from ftp.gnu.org exhibits the same bug on an BSDI2.1 i386 system. defiant ~/tmp$ gcc -v Reading specs from /usr/local/gnu/lib/gcc-lib/i386-pc-bsdi2.1/2.95.2/specs gcc version 2.95.2 19991024 (release) defiant ~/tmp$ gcc -O2 -o bug bug.c; ./bug 0x480 Ion -- It is better to keep your mouth shut and be thought a fool, than to open it and remove all doubt. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
Re: gcc-2.95.2-51 is buggy
[EMAIL PROTECTED] wrote:
> % /usr/gcc/aeb/bin/gcc -v
> Reading specs from
> /usr/gcc/aeb/lib/gcc-lib/i686-pc-linux-gnu/2.95.2/specs
> gcc version 2.95.2 19991024 (release)gcc version 2.95.2 19991024 (release)
> % /usr/gcc/aeb/bin/gcc -Wall -O2 -o nobug bug.c; ./nobug
> 0x0
Interesting. On a Slackware 7.1 recently upgraded to glibc 2.2
(and where gcc 2.95.2 from ftp.gnu.org was built because 2.2
requires this version) I get:
% gcc -Wall -O2 -o bug bug.c
% ./bug
0x8480
% egcs-2.91.66 -Wall -O2 -o bug bug.c
% ./bug
0x0
% gcc -Wall -O -o bug bug.c
% ./bug
0x0
% gcc -v
Reading specs from
/usr/lib/gcc-lib/i386-slackware-linux/2.95.2/specs
gcc version 2.95.2 19991024 (release)
% egcs-2.91.66 -v
Reading specs from
/usr/lib/gcc-lib/i386-slackware-linux/egcs-2.91.66/specs
gcc version egcs-2.91.66 19990314/Linux (egcs-1.1.2 release)
Slackware's -current tree was upgraded to glibc 2.2 and gcc
2.95.2, but I built them myself.
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Re: gcc-2.95.2-51 is buggy
On Fri, 24 Nov 2000, Neil Brown wrote: > Ditto for gcc-2.95.2-13 from Debian (potato). It exhibits the same > bug. > Debian applies a total of 49 patches to gcc and the libraries. > > I am tempted to write a little script which discards the patches one > by one and re-builds and re-tests each time, and leave it going all > night but I'm not sure if I actually will. Not all of them are applied on x86: % cat stamps/02-patch-stamp-*|less bootstrap patches applied. cpp-dos-newlines patches applied. cpp-macro-doc patches applied. gcc-cvs-updates-2220 patches applied. gcc-default-arch patches applied. gcc-empty-struct-init patches applied. gcc-manpage patches applied. gcc-pointer-arith patches applied. gcj-debian-policy patches applied. gcj-vs-iconv patches applied. gpc-2.95 patches applied. gpc-updates patches applied. libg++-update patches applied. libobjc patches applied. libstdc++-bastring patches applied. libstdc++-out-of-mem patches applied. libstdc++-wall3 patches applied. libstdc++-wstring patches applied. reporting patches applied. And only 4 have any chance to be relevant: gcc-cvs-updates-2220, gcc-default-arch, gcc-empty-struct-init. Unfortunately, the first one is ~100Kb worth of changes. Hmmm... After some cleaning the whole thing boils down to 11Kb. And I seriously suspect that relevant bits are in cse.c, loop.c or toplev.c, with the first two being the most likely candidates (all coming from the -cvs-updates-2220)... - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
Re: gcc-2.95.2-51 is buggy
On Friday November 24, [EMAIL PROTECTED] wrote: > >> ... RedHat's GCC snapshot "2.96" handles this case just fine. > > > Now, if you can isolate the relevant part of the diff between > > 2.95.2 and RH 2.96... > > Maybe I have to be more precise in the statement "gcc 2.95.2 is buggy". > > I just installed gcc 2.95.2 freshly ftp'ed from ftp.gnu.org, and > ... > > So, not all versions of gcc 2.95.2 are equal. > > % rpm -qf /usr/bin/gcc > gcc-2.95.2-51 > > This is from a SuSE distribution, I forget which, not very recent. > Revised summary: gcc-2.95.2-51 from SuSE is buggy. Ditto for gcc-2.95.2-13 from Debian (potato). It exhibits the same bug. Debian applies a total of 49 patches to gcc and the libraries. I am tempted to write a little script which discards the patches one by one and re-builds and re-tests each time, and leave it going all night but I'm not sure if I actually will. NeilBrown > > Andries > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to [EMAIL PROTECTED] > Please read the FAQ at http://www.tux.org/lkml/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
gcc-2.95.2-51 is buggy
>> ... RedHat's GCC snapshot "2.96" handles this case just fine. > Now, if you can isolate the relevant part of the diff between > 2.95.2 and RH 2.96... Maybe I have to be more precise in the statement "gcc 2.95.2 is buggy". I just installed gcc 2.95.2 freshly ftp'ed from ftp.gnu.org, and % /usr/bin/gcc -v Reading specs from /usr/lib/gcc-lib/i486-suse-linux/2.95.2/specs gcc version 2.95.2 19991024 (release) % /usr/bin/gcc -Wall -O2 -o bug bug.c; ./bug 0x8480 % /usr/gcc/aeb/bin/gcc -v Reading specs from /usr/gcc/aeb/lib/gcc-lib/i686-pc-linux-gnu/2.95.2/specs gcc version 2.95.2 19991024 (release) % /usr/gcc/aeb/bin/gcc -Wall -O2 -o nobug bug.c; ./nobug 0x0 So, not all versions of gcc 2.95.2 are equal. % rpm -qf /usr/bin/gcc gcc-2.95.2-51 This is from a SuSE distribution, I forget which, not very recent. Revised summary: gcc-2.95.2-51 from SuSE is buggy. Andries - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
