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* [Bug c/38616]  New: Wrong code when -O3 or -O2 used
@ 2008-12-24 11:53 socketpair at gmail dot com
  2008-12-24 13:28 ` [Bug c/38616] " socketpair at gmail dot com
                   ` (12 more replies)
  0 siblings, 13 replies; 14+ messages in thread
From: socketpair at gmail dot com @ 2008-12-24 11:53 UTC (permalink / raw)
  To: gcc-bugs

I'm using generic Ubuntu Intrepid desktop i386 system.
My program:
--------------------
#include <stdio.h> 

int main (void)
{
  char buffer[1024]="";
  sprintf (buffer, "%s", "1234567890abcdefghijklmno");
  printf ("%s\n", buffer);
  return 0;
}
----------
It will print '12345678' if -O2 or -O3 is used. If no optimizations used, it
print full string as in source. If I replace 'char buffer[1024]="";'  with
'char buffer[1024];'  it will work just fine with any optimizations. WTF?
------
mmarkk@mmarkk-desktop:~$ LANG=C gcc -O2 -v zzz2.c
Using built-in specs.
Target: i486-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 4.3.2-1ubuntu11'
--with-bugurl=file:///usr/share/doc/gcc-4.3/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --enable-shared
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --enable-nls --with-gxx-include-dir=/usr/include/c++/4.3
--program-suffix=-4.3 --enable-clocale=gnu --enable-libstdcxx-debug
--enable-objc-gc --enable-mpfr --enable-targets=all --enable-checking=release
--build=i486-linux-gnu --host=i486-linux-gnu --target=i486-linux-gnu
Thread model: posix
gcc version 4.3.2 (Ubuntu 4.3.2-1ubuntu11) 
COLLECT_GCC_OPTIONS='-O2' '-v' '-mtune=generic'
 /usr/lib/gcc/i486-linux-gnu/4.3.2/cc1 -quiet -v zzz2.c -D_FORTIFY_SOURCE=2
-quiet -dumpbase zzz2.c -mtune=generic -auxbase zzz2 -O2 -version
-fstack-protector -o /tmp/ccxjcnkd.s
ignoring nonexistent directory "/usr/local/include/i486-linux-gnu"
ignoring nonexistent directory "/usr/local/include"
ignoring nonexistent directory
"/usr/lib/gcc/i486-linux-gnu/4.3.2/../../../../i486-linux-gnu/include"
ignoring nonexistent directory "/usr/include/i486-linux-gnu"
#include "..." search starts here:
#include <...> search starts here:
 /usr/lib/gcc/i486-linux-gnu/4.3.2/include
 /usr/lib/gcc/i486-linux-gnu/4.3.2/include-fixed
 /usr/include
End of search list.
GNU C (Ubuntu 4.3.2-1ubuntu11) version 4.3.2 (i486-linux-gnu)
        compiled by GNU C version 4.3.2, GMP version 4.2.2, MPFR version 2.3.2.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: fbed29247d8ae538bfd0dd565a17225f
COLLECT_GCC_OPTIONS='-O2' '-v' '-mtune=generic'
 as -V -Qy -o /tmp/ccy32lKh.o /tmp/ccxjcnkd.s
GNU assembler version 2.18.93 (i486-linux-gnu) using BFD version (GNU Binutils
for Ubuntu) 2.18.93.20081009
COMPILER_PATH=/usr/lib/gcc/i486-linux-gnu/4.3.2/:/usr/lib/gcc/i486-linux-gnu/4.3.2/:/usr/lib/gcc/i486-linux-gnu/:/usr/lib/gcc/i486-linux-gnu/4.3.2/:/usr/lib/gcc/i486-linux-gnu/:/usr/lib/gcc/i486-linux-gnu/4.3.2/:/usr/lib/gcc/i486-linux-gnu/
LIBRARY_PATH=/usr/lib/gcc/i486-linux-gnu/4.3.2/:/usr/lib/gcc/i486-linux-gnu/4.3.2/:/usr/lib/gcc/i486-linux-gnu/4.3.2/../../../../lib/:/lib/../lib/:/usr/lib/../lib/:/usr/lib/gcc/i486-linux-gnu/4.3.2/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-O2' '-v' '-mtune=generic'
 /usr/lib/gcc/i486-linux-gnu/4.3.2/collect2 --eh-frame-hdr -m elf_i386
--hash-style=both -dynamic-linker /lib/ld-linux.so.2 -z relro
/usr/lib/gcc/i486-linux-gnu/4.3.2/../../../../lib/crt1.o
/usr/lib/gcc/i486-linux-gnu/4.3.2/../../../../lib/crti.o
/usr/lib/gcc/i486-linux-gnu/4.3.2/crtbegin.o
-L/usr/lib/gcc/i486-linux-gnu/4.3.2 -L/usr/lib/gcc/i486-linux-gnu/4.3.2
-L/usr/lib/gcc/i486-linux-gnu/4.3.2/../../../../lib -L/lib/../lib
-L/usr/lib/../lib -L/usr/lib/gcc/i486-linux-gnu/4.3.2/../../.. /tmp/ccy32lKh.o
-lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s
--no-as-needed /usr/lib/gcc/i486-linux-gnu/4.3.2/crtend.o
/usr/lib/gcc/i486-linux-gnu/4.3.2/../../../../lib/crtn.o


-- 
           Summary: Wrong code when -O3 or -O2 used
           Product: gcc
           Version: 4.3.2
            Status: UNCONFIRMED
          Severity: critical
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: socketpair at gmail dot com
 GCC build triplet: i386
  GCC host triplet: i386
GCC target triplet: i386


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38616


^ permalink raw reply	[flat|nested] 14+ messages in thread
end of thread, other threads:[~2009-01-18 22:06 UTC | newest]

Thread overview: 14+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2008-12-24 11:53 [Bug c/38616] New: Wrong code when -O3 or -O2 used socketpair at gmail dot com
2008-12-24 13:28 ` [Bug c/38616] " socketpair at gmail dot com
2008-12-24 13:35 ` socketpair at gmail dot com
2008-12-24 13:41 ` socketpair at gmail dot com
2008-12-24 13:59 ` [Bug middle-end/38616] [4.3 only] Wrong code when -O3 or -O2 -fstack-protector used pinskia at gcc dot gnu dot org
2008-12-24 15:23 ` socketpair at gmail dot com
2008-12-24 15:29 ` socketpair at gmail dot com
2008-12-29 20:39 ` [Bug middle-end/38616] [4.3 Regression] " rguenth at gcc dot gnu dot org
2009-01-11 17:29 ` doko at gcc dot gnu dot org
2009-01-11 17:38 ` doko at gcc dot gnu dot org
2009-01-14 19:18 ` danglin at gcc dot gnu dot org
2009-01-14 19:24 ` pinskia at gcc dot gnu dot org
2009-01-18 17:08 ` hjl dot tools at gmail dot com
2009-01-18 22:06 ` hjl dot tools at gmail dot com

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