[Bug rtl-optimization/82881] New: [8 Regression] ICE: in df_compact_blocks, at df-core.c:1729 with -freorder-blocks-algorithm=simple

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82881

            Bug ID: 82881
           Summary: [8 Regression] ICE: in df_compact_blocks, at
                    df-core.c:1729 with -freorder-blocks-algorithm=simple
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu

Created attachment 42558
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=42558&action=edit
reduced testcase

Compiler output:
$ x86_64-pc-linux-gnu-gcc -O2 -freorder-blocks-algorithm=simple testcase.c 
during RTL pass: bbro
testcase.c: In function 'foo':
testcase.c:7:1: internal compiler error: in df_compact_blocks, at
df-core.c:1729
 }
 ^
0x8a6b3f df_compact_blocks()
        /repo/gcc-trunk/gcc/df-core.c:1729
0x1543a45 compact_blocks()
        /repo/gcc-trunk/gcc/cfg.c:160
0x153c150 reorder_basic_blocks
        /repo/gcc-trunk/gcc/bb-reorder.c:2502
0x153c150 execute
        /repo/gcc-trunk/gcc/bb-reorder.c:2592
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.

$ x86_64-pc-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-amd64/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-254487-checking-yes-rtl-df-extra-nographite-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/8.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--without-cloog --without-ppl --without-isl --build=x86_64-pc-linux-gnu
--host=x86_64-pc-linux-gnu --target=x86_64-pc-linux-gnu
--with-ld=/usr/bin/x86_64-pc-linux-gnu-ld
--with-as=/usr/bin/x86_64-pc-linux-gnu-as --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-254487-checking-yes-rtl-df-extra-nographite-amd64
Thread model: posix
gcc version 8.0.0 20171107 (experimental) (GCC)