https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82276
Bug ID: 82276
Summary: -O2: ICE: SSA corruption during RTL pass: expand; at
tree-ssa-coalesce.c:1010
Product: gcc
Version: c++-concepts
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: ivo.raisr at oracle dot com
Target Milestone: ---
With gcc 8.0 (SVN revision 252973 from 2017-09-19) we hit internal compiler
error:
Unable to coalesce ssa_names 8 and 28 which are marked as MUST COALESCE.
f_8(ab) and f_28(ab)
during RTL pass: expand
reduced-2.c:12:6: internal compiler error: SSA corruption
void c(void) {
^
0xe23c9c fail_abnormal_edge_coalesce
../../gcc-trunk/gcc/tree-ssa-coalesce.c:1010
0xe23c9c coalesce_partitions
../../gcc-trunk/gcc/tree-ssa-coalesce.c:1399
0xe23c9c coalesce_ssa_name()
../../gcc-trunk/gcc/tree-ssa-coalesce.c:1886
0xdc997b remove_ssa_form
../../gcc-trunk/gcc/tree-outof-ssa.c:948
0xdc997b rewrite_out_of_ssa(ssaexpand*)
../../gcc-trunk/gcc/tree-outof-ssa.c:1172
0x992a90 execute
../../gcc-trunk/gcc/cfgexpand.c:6164
Full pre-processed source is not publicly available but it is the same one as
for bug #82244.
C-reduce was able to produce "reduced-2.bare.c" which I slightly reformatted to
make it more readable: "reduced-2.c". Both files attached.
Reproduce as:
$ gcc -c reduced-2.c -O2
