http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55094
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2012-11-13
CC| |jakub at gcc dot gnu.org,
| |rth at gcc dot gnu.org,
| |vmakarov at gcc dot gnu.org
Ever Confirmed|0 |1
--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-11-13
14:31:11 UTC ---
Doesn't ICE on the trunk anymore since LRA merge, apparently because LRA
decides for some reason to use frame pointer anyway, despite
-fomit-frame-pointer -Os.
CCing Vlad to see why. Apparently it happens in:
665 if (ep->from_rtx == XEXP (x, 0)
666 || (ep->to_rtx == XEXP (x, 0)
667 && ep->to_rtx != hard_frame_pointer_rtx))
668 setup_can_eliminate (ep, false);
where ep->from_rtx is (frame), ep->to_rtx is (sp) and x is (pre_dec:SI
(reg/f:SI 7 sp)).
Is that intentional?
Anyway, testcase that also ICEs on 4.7 branch is e.g.
extern int puts (const char *);
int x;
int
main (int argc, char **argv)
{
if (argc)
{
puts (argv[0]);
x = 1;
__builtin_unreachable ();
}
x = 1;
__builtin_unreachable ();
}
with the same options - similar reason, crossjumping during jump2 crossjumps
bbs with different ARGS_SIZE final depth. For noreturn calls we've handled it
by adding REG_ARGS_SIZE note on the noreturn call I think, for unconditional
TRAP_IF we perhaps could do the same, but not sure what we can do for
__builtin_unreachable which expands to nothing..., with no outgoing edge from
the bb at all.
