[Bug rtl-optimization/105376] New: ICE: in decimal_to_decnumber, at dfp.cc:134 with _Decimal128 at -O -g

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105376

            Bug ID: 105376
           Summary: ICE: in decimal_to_decnumber, at dfp.cc:134 with
                    _Decimal128 at -O -g
           Product: gcc
           Version: 12.0
            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

Created attachment 52868
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52868&action=edit
reduced testcase

Compiler output:
$ x86_64-pc-linux-gnu-gcc -O -g testcase.c 
during RTL pass: final
testcase.c: In function 'foo':
testcase.c:6:1: internal compiler error: in decimal_to_decnumber, at dfp.cc:134
    6 | }
      | ^
0x22f0853 decimal_to_decnumber
        /repo/gcc-trunk/gcc/dfp.cc:134
0x22f0adf encode_decimal128(real_format const*, long*, real_value const*)
        /repo/gcc-trunk/gcc/dfp.cc:269
0x12e6585 real_to_target(long*, real_value const*, format_helper)
        /repo/gcc-trunk/gcc/real.cc:2838
0xf1d9b3 insert_float
        /repo/gcc-trunk/gcc/dwarf2out.cc:20173
0xf560d6 mem_loc_descriptor(rtx_def*, machine_mode, machine_mode,
var_init_status)
        /repo/gcc-trunk/gcc/dwarf2out.cc:16654
0xf5642e mem_loc_descriptor(rtx_def*, machine_mode, machine_mode,
var_init_status)
        /repo/gcc-trunk/gcc/dwarf2out.cc:16481
0xf563c9 mem_loc_descriptor(rtx_def*, machine_mode, machine_mode,
var_init_status)
        /repo/gcc-trunk/gcc/dwarf2out.cc:16470
0xf5b30a loc_descriptor
        /repo/gcc-trunk/gcc/dwarf2out.cc:17357
0xf5b70a dw_loc_list_1
        /repo/gcc-trunk/gcc/dwarf2out.cc:17460
0xf5bc59 dw_loc_list
        /repo/gcc-trunk/gcc/dwarf2out.cc:17743
0xf51819 loc_list_from_tree_1
        /repo/gcc-trunk/gcc/dwarf2out.cc:18939
0xf6198d loc_list_from_tree
        /repo/gcc-trunk/gcc/dwarf2out.cc:19642
0xf6198d add_location_or_const_value_attribute
        /repo/gcc-trunk/gcc/dwarf2out.cc:20861
0xf61ca7 gen_formal_parameter_die
        /repo/gcc-trunk/gcc/dwarf2out.cc:22966
0xf44425 gen_subprogram_die
        /repo/gcc-trunk/gcc/dwarf2out.cc:23978
0xf4911c gen_decl_die
        /repo/gcc-trunk/gcc/dwarf2out.cc:26977
0xf4a12b dwarf2out_decl
        /repo/gcc-trunk/gcc/dwarf2out.cc:27555
0xf4a5de dwarf2out_function_decl
        /repo/gcc-trunk/gcc/dwarf2out.cc:27570
0xfd16e2 rest_of_handle_final
        /repo/gcc-trunk/gcc/final.cc:4321
0xfd16e2 execute
        /repo/gcc-trunk/gcc/final.cc:4363
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
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-r12-8242-20220425114659-gf0e170f72f8-checking-yes-rtl-df-extra-nobootstrap-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/12.0.1/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
--disable-bootstrap --with-cloog --with-ppl --with-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-r12-8242-20220425114659-gf0e170f72f8-checking-yes-rtl-df-extra-nobootstrap-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 12.0.1 20220425 (experimental) (GCC)