Re: [PATCHES] fix for strict-alias warnings

"Andrew Dunstan" <andrew(at)dunslane(dot)net> writes:
> I was inder the impression, perhaps incorrectly, the casting the pointers to
> (void *) would inhibit the compiler from making any assumptions about what
> it pointed to, and hence inhibit bad effects from those assumptions. The
> only way to know would be to examine the assembler output, I suppose. The
> alternative is that it would merely inhibit the compiler from issuing a
> warning and mask a bad effect. That would be nasty

IIUC the issue is whether the compiler might incorrectly rearrange the
order of operations based on the assumption that two pointers point
to different storage (when in fact they point to the same storage).
I don't see what about introducing "(void *)" would be likely to keep
the compiler from making such assumptions --- you'll still have the same
two pointers and the exact same sequence of operations. Accordingly,
I think it's very likely that the so-far-proposed patches are indeed
masking the symptom and not solving the real problem.

regards, tom lane