[Bug rtl-optimization/78596] New: combine.c:12561:14: runtime error: left shift of negative value -9

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78596

            Bug ID: 78596
           Summary: combine.c:12561:14: runtime error: left shift of
                    negative value -9
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: trippels at gcc dot gnu.org
  Target Milestone: ---

markus@x4 mplayer % cat demux_mkv.i
extern void fn2();
void fn1() {
  int a = fn1, b = 8;
  if (a > 18446744073709551615UL - b)
    fn2();
}

markus@x4 mplayer % UBSAN_OPTIONS=print_stacktrace=1
/var/tmp/gcc_ubsan/usr/local/bin/gcc -w -O2 -c demux_mkv.i
../../gcc/gcc/combine.c:12561:14: runtime error: left shift of negative value
-9
    #0 0x361d796 in simplify_comparison ../../gcc/gcc/combine.c:12561
    #1 0x3620ed6 in simplify_set ../../gcc/gcc/combine.c:6652
    #2 0x3627f5f in combine_simplify_rtx ../../gcc/gcc/combine.c:6187
    #3 0x3632a35 in subst ../../gcc/gcc/combine.c:5487
    #4 0x3641bd4 in try_combine ../../gcc/gcc/combine.c:3269
    #5 0x36561b7 in combine_instructions ../../gcc/gcc/combine.c:1265
    #6 0x36561b7 in rest_of_handle_combine ../../gcc/gcc/combine.c:14581
    #7 0x36561b7 in execute ../../gcc/gcc/combine.c:14626
    #8 0x195ad78 in execute_one_pass(opt_pass*) ../../gcc/gcc/passes.c:2370
    #9 0x195cc0b in execute_pass_list_1 ../../gcc/gcc/passes.c:2459
    #10 0x195cc34 in execute_pass_list_1 ../../gcc/gcc/passes.c:2460
    #11 0x195ccc4 in execute_pass_list(function*, opt_pass*)
../../gcc/gcc/passes.c:2470
    #12 0xc75e4b in cgraph_node::expand() ../../gcc/gcc/cgraphunit.c:2001
    #13 0xc7b35a in expand_all_functions ../../gcc/gcc/cgraphunit.c:2137
    #14 0xc7b35a in symbol_table::compile() ../../gcc/gcc/cgraphunit.c:2494
    #15 0xc85517 in symbol_table::compile() ../../gcc/gcc/cgraphunit.c:2587
    #16 0xc85517 in symbol_table::finalize_compilation_unit()
../../gcc/gcc/cgraphunit.c:2584
    #17 0x1d3ead0 in compile_file ../../gcc/gcc/toplev.c:488
    #18 0x629a34 in do_compile ../../gcc/gcc/toplev.c:1983
    #19 0x629a34 in toplev::main(int, char**) ../../gcc/gcc/toplev.c:2117
    #20 0x62c066 in main ../../gcc/gcc/main.c:39
    #21 0x7f40bae26310 in __libc_start_main ../csu/libc-start.c:286
    #22 0x62c489 in _start
(/var/tmp/gcc_ubsan/usr/local/libexec/gcc/x86_64-pc-linux-gnu/7.0.0/cc1+0x62c489)