https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104947
Bug ID: 104947
Summary: ICE: SSA corruption (Unable to coalesce ssa_names 5
and 11 which are marked as MUST COALESCE.)
Product: gcc
Version: 12.0
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 12.0.1 20220313 snapshot (g:7e28750395889d16a9cba49cd5935ced7dc00ce8) ICEs
when compiling the following testcase w/ -O2 -fno-tree-dce -fno-tree-dse:
int n;
__attribute__ ((returns_twice)) void
foo (void);
void
bar (void);
void
quux (int x)
{
if (x)
++x;
else
{
if (n)
{
x = 1;
foo ();
}
else
bar ();
if (n)
{
++x;
++n;
}
}
}
% gcc-12.0.1 -O2 -fno-tree-dce -fno-tree-dse -c ehpnzg5r.c
Unable to coalesce ssa_names 5 and 11 which are marked as MUST COALESCE.
x_5(ab) and x_11(D)(ab)
during RTL pass: expand
ehpnzg5r.c: In function 'quux':
ehpnzg5r.c:10:1: internal compiler error: SSA corruption
10 | quux (int x)
| ^~~~
0xff74bb fail_abnormal_edge_coalesce
/var/tmp/portage/sys-devel/gcc-12.0.1_p20220313/work/gcc-12-20220313/gcc/tree-ssa-coalesce.cc:1003
0xff74bb coalesce_partitions
/var/tmp/portage/sys-devel/gcc-12.0.1_p20220313/work/gcc-12-20220313/gcc/tree-ssa-coalesce.cc:1425
0xff74bb coalesce_ssa_name(_var_map*)
/var/tmp/portage/sys-devel/gcc-12.0.1_p20220313/work/gcc-12-20220313/gcc/tree-ssa-coalesce.cc:1755
0xf89ef1 remove_ssa_form
/var/tmp/portage/sys-devel/gcc-12.0.1_p20220313/work/gcc-12-20220313/gcc/tree-outof-ssa.cc:1065
0xf89ef1 rewrite_out_of_ssa(ssaexpand*)
/var/tmp/portage/sys-devel/gcc-12.0.1_p20220313/work/gcc-12-20220313/gcc/tree-outof-ssa.cc:1323
0x9d9d56 execute
/var/tmp/portage/sys-devel/gcc-12.0.1_p20220313/work/gcc-12-20220313/gcc/cfgexpand.cc:6585
