2. pyatomic_msc.h:974-978 — _Py_atomic_store_uint_release broken on ARM64

  static inline void
  _Py_atomic_store_uint_release(unsigned int *obj, unsigned int value)
  {
      *(volatile unsigned int *)obj = value;
  }

  This is placed among the relaxed stores and uses only a volatile store. On x86/x64, volatile stores have release semantics, so this happens to work. But on ARM64, volatile accesses are only relaxed
  (as stated in the file's header comment). Every other _release function in this file (e.g., _Py_atomic_store_int_release at line 1057, _Py_atomic_store_uint32_release at line 1108) properly uses
  __stlr32 on ARM64. This function is missing the #if/#elif ARM64 branch.

  3. pyatomic_gcc.h — Missing _Py_atomic_store_uint_release

  Both pyatomic_std.h (line 1035) and pyatomic_msc.h (line 975) define _Py_atomic_store_uint_release, but pyatomic_gcc.h does not. If any code calls it when compiled with GCC/Clang, it would fail to
  link/compile.

  4. pyatomic.h:75-76 — Incorrect pseudo-code comment

  def _Py_atomic_store_ptr_release(obj):
      return obj  # release

  This is documented as a one-arg function that returns a value, but it's actually a two-arg store (like the real declaration at line 518). Should be:
  def _Py_atomic_store_ptr_release(obj, value):
      obj = value  # release