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[Bug c++/68484] _mm_storel_epi64((__m128i *)x, m); does nothing if "x" is a "volatile" ptr
- From: "glisse at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Mon, 23 Nov 2015 08:01:06 +0000
- Subject: [Bug c++/68484] _mm_storel_epi64((__m128i *)x, m); does nothing if "x" is a "volatile" ptr
- Auto-submitted: auto-generated
- References: <bug-68484-4 at http dot gcc dot gnu dot org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68484
--- Comment #3 from Marc Glisse <glisse at gcc dot gnu.org> ---
(In reply to Vladimir Sedach from comment #2)
> It is not just about "long long".
It isn't about long long at all, it is about whether your code is valid. In
your latest example, you are casting an int* to a float*, that's pretty much
the definition of an aliasing violation.
The types __m128 etc are documented as allowing aliasing, but I don't think
that extends to other operands of the intrinsics.