gdb opaque symbol resolution turned off

When inter-procedural-analysis optimization (compiler flag) is enabled, the struct debug symbols (opaque-symbol-resolution) does not work. Any one knows why? Is it possible to have this optimization enabled but not lose this convenient debug capability?

typedef struct mystruct {
  int a;
  char b;
} mystruct_t;

Without ipa enabled,

(gdb) p /x global_var
$1 = {a = 0xdeadbeef, b = 0xa}

With ipa enabled,

(gdb) p /x global_var
$1 = 0xdeadbeef