[Bug c++/112780] New: ICE: symtab_node::verify failed: "Two symbols with same comdat_group are not linked by the same_comdat_group list." with -mlong-double-128

["zsojka at seznam dot cz" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112780

            Bug ID: 112780
           Summary: ICE: symtab_node::verify failed: "Two symbols with
                    same comdat_group are not linked by the
                    same_comdat_group list." with -mlong-double-128
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: c++
          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 56726
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=56726&action=edit
reduced testcase

Compiler output:
$ x86_64-pc-linux-gnu-gcc -mlong-double-128 testcase.C
testcase.C:10:32: error: Two symbols with same comdat_group are not linked by
the same_comdat_group list.
   10 | template void foo(__float128 t);
      |                                ^
_Z3fooIgEvT_/7 (void foo(T) [with T = __float128])
  Type: function definition analyzed
  Visibility: forced_by_abi semantic_interposition no_reorder public weak
comdat comdat_group:_Z3fooIgEvT_ one_only
  previous sharing asm name: 6
  References: 
  Referring: 
  Function flags: body
  Called by: 
  Calls: 
_Z3fooIgEvT_/6 (void foo(T) [with T = long double])
  Type: function definition analyzed
  Visibility: forced_by_abi semantic_interposition no_reorder public weak
comdat comdat_group:_Z3fooIgEvT_ one_only
  next sharing asm name: 7
  References: 
  Referring: 
  Function flags: body
  Called by: 
  Calls: 
testcase.C:10:32: internal compiler error: symtab_node::verify failed
0x12953f1 symtab_node::verify_symtab_nodes()
        /repo/gcc-trunk/gcc/symtab.cc:1412
0x12aacf0 symtab_node::checking_verify_symtab_nodes()
        /repo/gcc-trunk/gcc/cgraph.h:686
0x12aacf0 symbol_table::compile()
        /repo/gcc-trunk/gcc/cgraphunit.cc:2314
0x12ada77 symbol_table::compile()
        /repo/gcc-trunk/gcc/cgraphunit.cc:2311
0x12ada77 symbol_table::finalize_compilation_unit()
        /repo/gcc-trunk/gcc/cgraphunit.cc:2583
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-r14-5986-20231129235555-g8315f998659-checking-yes-rtl-df-extra-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/14.0.0/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
--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-r14-5986-20231129235555-g8315f998659-checking-yes-rtl-df-extra-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 14.0.0 20231130 (experimental) (GCC)