> I think this program should not terminate at all because i will
> always be one greater than oldi.
> I think gcc3.0 has a problem with no optimization then but since
> there is later version that works gcc 3.1.1, upgrade.
>
> Thanks,
> Andrew Pinski
>
Agreed. Infact it doesn't terminate on all the systems I've tried (3).
But for the sake of presenting a test case :)
---
Test System: Dell XPS-T 450Mhz PIII (Debian testing/unstable)
---
Reading specs from /usr/lib/gcc-lib/i386-linux/3.0.4/specs
Configured with: ../src/configure -v --enable-languages=c,c++,java,f77,objc
--prefix=/usr --infodir=/share/info --mandir=/share/man --enable-shared
--with-gnu-as --with-gnu-ld --with-system-zlib --enable-long-long --enable-nls
--without-included-gettext --disable-checking --enable-threads=posix
--enable-java-gc=boehm --with-cpp-install-dir=bin --enable-objc-gc i386-linux
Thread model: posix
gcc version 3.0.4
---
[EMAIL PROTECTED]:~$ cat test.c
main() {
int i=0;
int oldi=0;;
while(++i>oldi) oldi=i;
return oldi;
}
[EMAIL PROTECTED]:~$ gcc-3.0 -O0 -o test test.c
[EMAIL PROTECTED]:~$ ./test
(Attach gdb, look at stuff, it's not stopping) ^C
[EMAIL PROTECTED]:~$ gcc-3.0 -o test test.c
[EMAIL PROTECTED]:~$ ./test
(Attach gdb, look at stuff, it's not stopping) ^C
---
Maybe you've been bad to your gcc ;)
In the optimized case (-O9) I see:
080483f8 <main>:
80483f8: 55 push %ebp
80483f9: 89 e5 mov %esp,%ebp
80483fb: 83 ec 08 sub $0x8,%esp
80483fe: 83 e4 f0 and $0xfffffff0,%esp
8048401: 8d 76 00 lea 0x0(%esi),%esi
8048404: eb fe jmp 8048404 <main+0xc>
8048406: 90 nop
8048407: 90 nop
Which never terminates... and gcc knew it.
If there were some examples of gcc-3.0 mucking
up optimizations... this isn't it.
c.
