https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96349
Bug ID: 96349
Summary: [10/11 Regression] ICE: SSA corruption (Unable to
coalesce ssa_names 2 and 3 which are marked as MUST
COALESCE.) [in fail_abnormal_edge_coalesce]
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Keywords: ice-on-valid-code
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: asolokha at gmx dot com
Target Milestone: ---
gcc-11.0.0-alpha20200726 snapshot (g:39ddfef9a5c24acf6412236f52f6716c8e0ebc9e)
ICEs when compiling the following testcase w/ -O3:
void __attribute__ ((returns_twice))
gr (void);
void
ib (void);
void
zg (void);
void
yw (int uz)
{
gr ();
for (;;)
if (uz != 0)
{
uz = 0;
ib ();
}
else
zg ();
}
% gcc-11.0.0 -O3 -c kl7mlgao.c
Unable to coalesce ssa_names 2 and 3 which are marked as MUST COALESCE.
uz_2(ab) and uz_3(ab)
during RTL pass: expand
kl7mlgao.c: In function 'yw':
kl7mlgao.c:11:1: internal compiler error: SSA corruption
11 | yw (int uz)
| ^~
0xedadfa fail_abnormal_edge_coalesce
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20200726/work/gcc-11-20200726/gcc/tree-ssa-coalesce.c:1003
0xedadfa coalesce_partitions
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20200726/work/gcc-11-20200726/gcc/tree-ssa-coalesce.c:1425
0xedadfa coalesce_ssa_name(_var_map*)
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20200726/work/gcc-11-20200726/gcc/tree-ssa-coalesce.c:1755
0xe78937 remove_ssa_form
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20200726/work/gcc-11-20200726/gcc/tree-outof-ssa.c:1065
0xe78937 rewrite_out_of_ssa(ssaexpand*)
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20200726/work/gcc-11-20200726/gcc/tree-outof-ssa.c:1323
0x912f80 execute
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20200726/work/gcc-11-20200726/gcc/cfgexpand.c:6377
