[Bug target/100354] New: [9 regression] aarch64: non-deligitimized UNSPEC UNSPEC_TLS (76) found in variable location

[nsz at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100354

            Bug ID: 100354
           Summary: [9 regression] aarch64: non-deligitimized UNSPEC
                    UNSPEC_TLS (76) found in variable location
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: nsz at gcc dot gnu.org
  Target Milestone: ---

i see this note/warning a lot during an aarch64 glibc build
since gcc-9, it seems to require -O -g, and seems to be
harmless wrt code generation, just annoying.

$ cat bug.c
struct s {
  void *p;
  int n;
};

void foo(struct s *x)
{
  void *p = __builtin_thread_pointer();
  if (x->p != p)
    x->p = p;
  x->n++;
}

$ aarch64-none-linux-gnu-gcc -S -O1 -g bug.c
bug.c: In function ‘foo’:
bug.c:6:6: note: non-delegitimized UNSPEC UNSPEC_TLS (76) found in variable
location
    6 | void foo(struct s *x)
      |      ^~~


may be related to bug 89006