[Bug target/125396] New: [16/17 Regression] ICE at -O1/2/3 during RTL pass: expand

[xxs_chy at outlook dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125396

            Bug ID: 125396
           Summary: [16/17 Regression] ICE at -O1/2/3 during RTL pass:
                    expand
           Product: gcc
           Version: 17.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: xxs_chy at outlook dot com
  Target Milestone: ---

Reproducer: https://godbolt.org/z/s3TY49Ka9
Testcase:
#include <setjmp.h>
#include <stdint.h>
int8_t g7;
_Bool g13, g26;
jmp_buf g32;
void f8()
{
    int32_t arr1[2];
    _Bool c2, c4;
    int16_t v6;
    _Bool arr9[1];
    int32_t sj12;
    int32_t sj14;
lbl_br1:
    if (g13) goto lbl_br3;
    if (c4)
    {
        c4 = 0;
        goto lbl_br6;
    }
    switch (v6)
    case 1:
        c4 = arr9;
    sj14 = setjmp(g32);
    g13 = sj12;
lbl_br3:
    arr1[0] = 0;
    sj12 = setjmp(g32);
    c2 = g7;
    g26 = 5;
    if (c2) __builtin_unreachable();
lbl_br6:
    sj12 = arr1[0];
    arr1[0] = 9;
    if (g26) f8();
    goto lbl_br1;
}

Dump at -O1/2/3:
Unable to coalesce ssa_names 35 and 43 which are marked as MUST COALESCE.
arr1$0_35(ab) and  arr1$0_43(ab)
during RTL pass: expand
<source>: In function 'f8':
<source>:6:6: internal compiler error: SSA corruption
    6 | void f8()
      |      ^~
0x2067238 diagnostics::context::diagnostic_impl(rich_location*,
diagnostics::metadata const*, diagnostics::option_id, char const*,
__va_list_tag (*) [1], diagnostics::kind)
        ???:0
0x206052b internal_error(char const*, ...)
        ???:0
0xfafc04 coalesce_ssa_name(_var_map*)
        ???:0
0xf48081 rewrite_out_of_ssa(ssaexpand*)
        ???:0