On Wed, Sep 28, 2011 at 5:49 AM, Andi Kleen <a...@firstfloor.org> wrote: > From: Andi Kleen <a...@linux.intel.com> > > I had some trouble with random build failures in a large LTO project > and it turned out to be random seed collisions in a highly parallel build > (thanks to Honza for suggesting that) > > There were multiple problems: > - The way to generate the random seed is not very random (milliseconds time > plus pid) > and prone to collisions on highly parallel builds > - It's only 32bit > - Several users take the existing ascii seed and re-CRC32 it again, which > doesn't exactly improve it. > > This patch changes that to: > - Always use 64bit seeds as numbers (no re-crcing) > - Change all users to use HOST_WIDE_INT > - When the user specifies a random seed it's still crc32ed, but only in > this case. > > Passes bootstrap + testsuite on x86_64-linux. > > gcc/cp: > > 2011-09-26 Andi Kleen <a...@linux.intel.com> > > * repo.c (finish_repo): Use HOST_WIDE_INT_PRINT_HEX_PURE. > > gcc/: > > 2011-09-26 Andi Kleen <a...@linux.intel.com> > > * hwint.h (HOST_WIDE_INT_PRINT_HEX_PURE): Add. > * lto-streamer.c (lto_get_section_name): Remove crc32_string. > Handle numerical random seed. > * lto-streamer.h (lto_file_decl_data): Change id to unsigned > HOST_WIDE_INT. > * toplev.c (random_seed): Add. > (init_random_seed): Change for numerical random seed. > (get_random_seed): Return as HOST_WIDE_INT. > (set_random_seed): Crc32 existing string. > * toplev.h (get_random_seed): Change to numercal return. > * tree.c (get_file_function_name): Remove CRC. Handle numerical random > seed. > > gcc/lto/: > > 2011-09-26 Andi Kleen <a...@linux.intel.com> > > * lto.c (lto_resolution_read): Remove id dumping. > (lto_section_with_id): Turn id HOST_WIDE_ID. > (create_subid_section_table): Dito.
This patch caused: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50568 -- H.J.
