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Re: Aliasing brokenness (Was: Re: [patch RFC] SH: Use FRAME_GROWS_DOWNWARD)
Andreas Schwab wrote:
Gabriel Dos Reis <email@example.com> writes:
Is the conclusion that a presence of "potentially unused" union that
contains two structures with the same prefix destroys non-aliasing
IMHO the third example in 18.104.22.168 gives a strong hint at that. AFAIU the
second fragment becomes valid as soon as declaration of the union is moved
before function f.
I think it's hard to read 22.214.171.124 to say anything other than that the
mere visibilty implies that sturctures contained in the union with
common initial sequences may alias. I don't particularly like that
rule, but I think that's what it says.