On March 21, 2014 9:30:25 PM CET, Jakub Jelinek <ja...@redhat.com> wrote:
>Hi!
>
>--with-build-config=bootstrap-ubsan on i686-linux showed
>most often these two issues.
>
>The first one is that 32-bit signed time_t is multiplied by 1000, which
>overflows the int type. The result is then cast to unsigned, so even
>on
>64-bit hosts we don't care about the upper bits.
>
>The other change fixes a badly written portable rotate, which was
>shitfing
>up (correctly) by 0 for i == 0, but for all other i values was shifting
>up
>64-bit value by 64.
>
>Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK.
Thanks,
Richard.
>2014-03-21 Jakub Jelinek <ja...@redhat.com>
>
> * toplev.c (init_local_tick): Avoid signed integer multiplication
> overflow.
> * genautomata.c (reserv_sets_hash_value): Fix rotate idiom, avoid
> shift by first operand's bitsize.
>
>--- gcc/toplev.c.jj 2014-01-08 10:23:22.000000000 +0100
>+++ gcc/toplev.c 2014-03-21 11:32:25.929893013 +0100
>@@ -261,7 +261,7 @@ init_local_tick (void)
> struct timeval tv;
>
> gettimeofday (&tv, NULL);
>- local_tick = tv.tv_sec * 1000 + tv.tv_usec / 1000;
>+ local_tick = (unsigned) tv.tv_sec * 1000 + tv.tv_usec / 1000;
> }
> #else
> {
>--- gcc/genautomata.c.jj 2014-02-12 08:33:34.000000000 +0100
>+++ gcc/genautomata.c 2014-03-21 12:01:14.245727924 +0100
>@@ -3494,7 +3494,7 @@ reserv_sets_hash_value (reserv_sets_t re
> {
> reservs_num--;
> hash_value += ((*reserv_ptr >> i)
>- | (*reserv_ptr << ((sizeof (set_el_t) * CHAR_BIT) & -i)));
>+ | (*reserv_ptr << (((sizeof (set_el_t) * CHAR_BIT) - 1) &
>-i)));
> i++;
> if (i == sizeof (set_el_t) * CHAR_BIT)
> i = 0;
>
> Jakub
