[Bug c/123455] New: wrong code at -Os with asm goto

[jiangchangwu at smail dot nju.edu.cn via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123455

            Bug ID: 123455
           Summary: wrong code at -Os with asm goto
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jiangchangwu at smail dot nju.edu.cn
  Target Milestone: ---

This code returns 139 at -Os and returns 0 at -O0/1/2/3:

void abort();
void b(int c) {
  if (0 == c)
    __asm__ goto("jmp *%0" ::"r"(&&a) : : a);
  __asm__ goto("" : : : : d);
a:
  __asm__ goto("" : : : : d);
d:
  if (c)
    abort();
}
int main() { b(0); }


Compiler Explorer: https://godbolt.org/z/r65n4jc5a