https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96818
Aldy Hernandez <aldyh at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jason at redhat dot com,
| |law at gcc dot gnu.org,
| |rguenth at gcc dot gnu.org
Depends on| |87798
--- Comment #3 from Aldy Hernandez <aldyh at gcc dot gnu.org> ---
[Could other gimple experts pontificate here?]
This is caused by the problem reported in PR87798.
We have a switch_stmt with a control variable of type int:
int _6;
...
_6 = _5 & 255;
switch (_6) <default: <L7> [33.33%], case 0: <L3> [33.33%], case 1: <L6>
[33.33%]>
But the cases are unsigned char:
(gdb) p debug_tree(case_high)
<integer_cst 0x7fffea8bd870 type <integer_type 0x7fffea76e348 unsigned char>
constant 1>
This is causing us to intersect incompatible ranges:
(gdb) p debug (range_of_op)
int [0, 255]
$21 = void
(gdb) p debug (label_range)
unsigned char [0, 1]
$22 = void
(gdb)
Are incompatible switch operands and labels valid gimple? I would say no.
This look like a latent bug.
FWIW, the reason this was working before was because the original code used
tree_int_cst_compare which upgrades everything to a widest_int before doing the
comparison:
inline int
tree_int_cst_compare (const_tree t1, const_tree t2)
{
return wi::cmps (wi::to_widest (t1), wi::to_widest (t2));
}
I could hack around it, but would rather we fix the underlying problem.
Is this valid gimple or not?
Thanks.
Referenced Bugs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87798
[Bug 87798] EH lowering is creating a gimple_switch statement with
type-incompatible index and case labels
