http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55875
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-01-04
12:24:12 UTC ---
ssa name _12
type long unsigned int
base 4294967295
step 1
ssa name _13
type long unsigned int
base 34359738360
step 8
ssa name _14
type const struct A *
base a_4 + 34359738360
step 8
base object (void *) a_4
all look wrong to me, it ignores the wrapping in the narrower type.
OT, I wonder why number of iterations analysis doesn't figure out smaller
number:
Analyzing # of iterations of loop 1
exit condition [1, + , 1] < (unsigned int) n_5
bounds on difference of bases: 0 ... 4294967294
result:
# of iterations (unsigned int) n_5 + 4294967295, bounded by 4294967294
The loop condition is:
i_18 = i_21 + 1;
if (i_18 < _20)
and _20 is:
_20 = (unsigned int) n_5;
where
short unsigned int n;
thus, I'd thought we should figure out from that that i_18 will be at most
0xffff (highest possible n_5 is 0xffff).
But that is 4.9 material likely, while the ivopts? bug is a severe 4.8 issue.
