[Bug target/108267] New: [13 Regression] Bootstrap failure on aarch64-linux since r13-4953

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108267

            Bug ID: 108267
           Summary: [13 Regression] Bootstrap failure on aarch64-linux
                    since r13-4953
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jakub at gcc dot gnu.org
  Target Milestone: ---

My aarch64 bootstrap fails with:
../../../libgcc/unwind-dw2.c: In function 'init_dwarf_reg_size_table':
../../../libgcc/unwind-dw2.c:1334:3: error: this operation requires the SVE ISA
extension
 1334 |   __builtin_init_dwarf_reg_size_table (dwarf_reg_size_table);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../../libgcc/unwind-dw2.c:1334:3: note: you can enable SVE using the
command-line option '-march', or by using the 'target' attribute or pragma
../../../libgcc/unwind-dw2.c:1334: confused by earlier errors, bailing out

Trying to compile even simple:
static unsigned char dwarf_reg_size_table[__LIBGCC_DWARF_FRAME_REGISTERS__+1];

void
foo (void)
{
  __builtin_init_dwarf_reg_size_table (dwarf_reg_size_table);
}
with -O2 -nostdinc -fbuilding-libgcc before that change used to give different
results between when SVE was on and when it wasn't (v0 .. v31 registers get
dwarf_reg_size_table[32 .. 63] = 8 when unwind-dw2.o is compiled without SVE
and
result of cntd with it (it isn't clear to me how this is supposed to work
because clearly unwind-dw2.o compiled with SVE can't be used on CPUs without
SVE), but now
it just ICEs without SVE:
./cc1 -quiet -O2 -nostdinc a.c -fbuilding-libgcc -o a.s2
a.c: In function ‘foo’:
a.c:6:3: error: this operation requires the SVE ISA extension
    6 |   __builtin_init_dwarf_reg_size_table (dwarf_reg_size_table);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.c:6:3: note: you can enable SVE using the command-line option ‘-march’, or by
using the ‘target’ attribute or pragma
during RTL pass: expand
a.c:6:3: internal compiler error: Segmentation fault
0x1567ab0 crash_signal
        ../../gcc/toplev.cc:314
0xdc56ff single_set(rtx_insn const*)
        ../../gcc/rtl.h:3594
0xfd150c emit_move_insn(rtx_def*, rtx_def*)
        ../../gcc/expr.cc:4345
0xf9f8b6 force_reg(machine_mode, rtx_def*)
        ../../gcc/explow.cc:688
0x23040e7 gen_movqi(rtx_def*, rtx_def*)
        ../../gcc/config/aarch64/aarch64.md:1207
0xe02abe rtx_insn* insn_gen_fn::operator()<rtx_def*, rtx_def*>(rtx_def*,
rtx_def*) const
        ../../gcc/recog.h:407
0xfd09c1 emit_move_insn_1(rtx_def*, rtx_def*)
        ../../gcc/expr.cc:4172
0xfd14e5 emit_move_insn(rtx_def*, rtx_def*)
        ../../gcc/expr.cc:4342
0xef7e00 expand_builtin_init_dwarf_reg_sizes(tree_node*)
        ../../gcc/dwarf2cfi.cc:380