https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96326
Martin Liška <marxin at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |marxin at gcc dot gnu.org,
| |rguenth at gcc dot gnu.org,
| |rsandifo at gcc dot gnu.org
Last reconfirmed| |2020-07-27
Summary|Incorrect loop optimization |[10/11 Regression]
|at -O3 |Incorrect loop optimization
| |at -O3 since
| |r10-4803-g8489e1f45b50600c
Status|UNCONFIRMED |NEW
Ever confirmed|0 |1
--- Comment #3 from Martin Liška <marxin at gcc dot gnu.org> ---
Started with r10-4803-g8489e1f45b50600c. I see:
$ gcc pr96326.c -fsanitize=undefined && ./a.out
pr96326.c:11:23: runtime error: store to misaligned address 0x7fffffffe263 for
type 'long unsigned int', which requires 8 byte alignment
0x7fffffffe263: note: pointer points here
00 61 62 63 00 00 00 00 00 e0 69 61 f7 ff 7f 00 00 29 00 00 00 00 00 00 00
88 ff ff ff ff ff ff
^
pr96326.c:16:23: runtime error: store to misaligned address 0x7fffffffe26c for
type 'long unsigned int', which requires 8 byte alignment
0x7fffffffe26c: note: pointer points here
63 61 62 63 00 00 00 00 29 00 00 00 00 00 00 00 88 ff ff ff ff ff ff ff 40
6a 61 f7 ff 7f 00 00
^
68
and ASAN returns a different value:
$ gcc pr96326.c -fsanitize=address && ./a.out
70
Same for clang:
$ clang pr96326.c -fsanitize=address && ./a.out
70
So I bet the test-case must be invalid?
