https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107898
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed| |2022-11-29
Component|tree-optimization |c
Ever confirmed|0 |1
CC| |aldyh at gcc dot gnu.org,
| |mpolacek at gcc dot gnu.org
Status|UNCONFIRMED |NEW
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.
(gdb) up
#1 0x00000000019f5fed in irange::irange_intersect (this=0x7fffffffc500, r=...)
at /home/rguenther/src/trunk/gcc/value-range.cc:2559
2559 gcc_checking_assert (undefined_p () || r.undefined_p ()
(gdb) l
2554
2555 bool
2556 irange::irange_intersect (const irange &r)
2557 {
2558 gcc_checking_assert (!legacy_mode_p () && !r.legacy_mode_p ());
2559 gcc_checking_assert (undefined_p () || r.undefined_p ()
2560 || range_compatible_p (type (), r.type ()));
2561
2562 if (undefined_p ())
2563 return false;
(gdb) p debug (r)
[irange] long unsigned int [5001, +INF]
$1 = void
(gdb) p debug (*this)
[irange] unsigned int [1, +INF]
and we invoke this from
#4 0x0000000002bf496d in alloca_call_type (stmt=<gimple_call 0x7ffff631c120>,
is_vla=false)
at /home/rguenther/src/trunk/gcc/gimple-ssa-warn-alloca.cc:228
(gdb) l
223 // The invalid bits are anything outside of [0, MAX_SIZE].
224 int_range<2> invalid_range (build_int_cst (size_type_node, 0),
225 build_int_cst (size_type_node,
max_size),
226 VR_ANTI_RANGE);
227
228 r.intersect (invalid_range);
229 if (r.undefined_p ())
230 return alloca_type_and_limit (ALLOCA_OK);
and the issue is that the argument of the 'alloca' call is of type
unsigned int due to the "parsing" error with -fpreprocessed. The C frontend
again makes 'alloca' built-in with a mismatched prototype here.
I'm not sure why we have to require compatible ranges on intersection
of irange though? Since we don't have anti-ranges there's no implicit
min/max of types involved here, only symbolics (if they could creep in)
would make things difficult. There's
if (varying_p ())
{
operator= (r);
return true;
}
that would require range "conversion" (we don't want to change the type
of 'this') and all the ::to_wide would instead require ::to_widest.
Anyway, it's easy to "fix" the Walloca pass here.
Unfortunately there's no conversion operator or operator> for irange,
we just want to ask if (r > max_size) (and have max_size converted to
the type of r with saturation).
