http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51885
Manuel López-Ibáñez <manu at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |manu at gcc dot gnu.org
--- Comment #3 from Manuel López-Ibáñez <manu at gcc dot gnu.org> 2012-01-18
10:02:04 UTC ---
(In reply to comment #2)
> The reinterpret_cast definitely results in undefined behaviour, because it
> accesses the float objects through a different type, violating [basic.lval]/10
>
> And indeed, -fno-strict-aliasing makes the problem go away.
It definitely does not make the problem go away, it merely hides it. The
undefined behavior does not disappear just by using command-line options.
On the other hand, is it possible to cast a float pointer to a uint32 pointer
and use it for anything that does not invoke undefined behaviour?
GCC gives a warning with -Wstrict-aliasing=1 but no with other levels.
