[Bug middle-end/68392] New: ICE: SIGSEGV in update_uses (fwprop.c:896) with -fno-checking

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68392

            Bug ID: 68392
           Summary: ICE: SIGSEGV in update_uses (fwprop.c:896) with
                    -fno-checking
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz
  Target Milestone: ---

Created attachment 36743
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36743&action=edit
reduced testcase

Compiler output:
$ aarch64-unknown-linux-gnu-gcc -O -fno-checking testcase.c -wrapper
valgrind,-q,--num-callers=40
==16356== Invalid read of size 8
==16356==    at 0x111163A: sparseset_bit_p (sparseset.h:143)
==16356==    by 0x111163A: update_uses (fwprop.c:896)
==16356==    by 0x111163A: update_df(rtx_insn*, rtx_def*) (fwprop.c:919)
==16356==    by 0x11127FC: try_fwprop_subst(df_ref_d*, rtx_def**, rtx_def*,
rtx_insn*, bool) (fwprop.c:1007)
==16356==    by 0x1112F2A: forward_propagate_and_simplify (fwprop.c:1321)
==16356==    by 0x1112F2A: forward_propagate_into(df_ref_d*) (fwprop.c:1374)
==16356==    by 0x1113C24: fwprop (fwprop.c:1457)
==16356==    by 0x1113C24: (anonymous
namespace)::pass_rtl_fwprop::execute(function*) (fwprop.c:1490)
==16356==    by 0xA29FF7: execute_one_pass(opt_pass*) (passes.c:2325)
==16356==    by 0xA2A597: execute_pass_list_1(opt_pass*) (passes.c:2398)
==16356==    by 0xA2A5A9: execute_pass_list_1(opt_pass*) (passes.c:2399)
==16356==    by 0xA2A5F4: execute_pass_list(function*, opt_pass*)
(passes.c:2409)
==16356==    by 0x703593: cgraph_node::expand() (cgraphunit.c:1965)
==16356==    by 0x704E95: expand_all_functions (cgraphunit.c:2101)
==16356==    by 0x704E95: symbol_table::compile() (cgraphunit.c:2450)
==16356==    by 0x706D85: symbol_table::finalize_compilation_unit()
(cgraphunit.c:2540)
==16356==    by 0xB2A1D3: compile_file() (toplev.c:489)
==16356==    by 0x56C7BD: do_compile (toplev.c:1951)
==16356==    by 0x56C7BD: toplev::main(int, char**) (toplev.c:2058)
==16356==    by 0x56E576: main (main.c:39)
==16356==  Address 0x18 is not stack'd, malloc'd or (recently) free'd
==16356== 
testcase.c: In function 'foo':
testcase.c:8:1: internal compiler error: Segmentation fault
 }
 ^

Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

$ aarch64-unknown-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/mnt/svn/gcc-trunk/binary-latest-aarch64/bin/aarch64-unknown-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/mnt/svn/gcc-trunk/binary-230409-checking-release-nographite-aarch64/libexec/gcc/aarch64-unknown-linux-gnu/6.0.0/lto-wrapper
Target: aarch64-unknown-linux-gnu
Configured with: /mnt/svn/gcc-trunk//configure --enable-checking=release
--enable-languages=c,c++
--prefix=/mnt/svn/gcc-trunk/binary-230409-checking-release-nographite-aarch64/
--without-cloog --without-ppl --without-isl --host=x86_64-pc-linux-gnu
--target=aarch64-unknown-linux-gnu --build=x86_64-pc-linux-gnu
--with-sysroot=/home/aarch64-chroot
--with-as=/usr/libexec/gcc/aarch64-unknown-linux-gnu/as
--with-ld=/usr/libexec/gcc/aarch64-unknown-linux-gnu/ld
Thread model: posix
gcc version 6.0.0 20151116 (experimental) (GCC) 


I don't have any other recent GCC by hand than this aarch64 crosscompiler,
configured with --enable-checking=yes,rtl,df

Tested revisions:
r230409 - ICE