This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [patch] more bitmap obstacks
On Sat, Aug 18, 2012 at 9:01 AM, Tobias Burnus <burnus@net-b.de> wrote:
> Steven Bosscher wrote:
>>
>> This reduces peak memory usage for the small test case of PR54146
>> Bootstrapped&tested on x86_64-unknown-linux-gnu. OK for trunk?
>
>
> I think it's your patch which breaks bootstrapping here:
>
> Checking multilib configuration for libgcc...
> ...
> checking for suffix of object files... configure: error: in
> `/projects/tob/gcc-git/gcc-build/x86_64-unknown-linux-gnu/libgcc':
> configure: error: cannot compute suffix of object files: cannot compile
>
> conftest.c: In Function »main«:
> conftest.c:7:1: internal compiler error: segmentation fault
> }
> ^
>
> Program received signal SIGSEGV, Segmentation fault.
> 0x00000000005bfa40 in bitmap_obstack_free (map=0x18693a0) at
> /projects/tob/gcc-git/gcc/gcc/bitmap.c:388
> 388 map->first = (bitmap_element *) map->obstack->heads;
> (gdb) p map->obstack
> $1 = (bitmap_obstack *) 0x9090909090909090
>
> Thus, your patch assumes that malloc returns nullified memory, but e.g. with
> MALLOC_PERTURB_ set, that's not the case.
If my patch broke this, it was broken before also. I only added a few
more bitmap obstacks, but there were lots of existing ones before the
patch.
Can you file a big report with a test case and instructions to
reproduce, so that I can have a look?
Ciao!
Steven