Strange warning...

[Hal Murray]

Anybody understand this one?

That's running on a Pi 1, with -O3
  cc (Raspbian 6.3.0-18+rpi1+deb9u1) 6.3.0 20170516
  Raspbian GNU/Linux 9 (stretch) 9.13
No warning with -O1

../../ntpd/ntp_util.c:566:2: warning: dereferencing type-punned pointer 
will break strict-aliasing rules [-Wstrict-aliasing]

        refid_t refid = *(const uint32_t*)rbufp->pkt.refid;


-- 
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