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[Bug target/42779] [C++0x] Variadic templates + lambdas = extremely poor code quality, __m128i and aliasing sucks
- From: "hjl dot tools at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 17 Jan 2010 22:11:33 -0000
- Subject: [Bug target/42779] [C++0x] Variadic templates + lambdas = extremely poor code quality, __m128i and aliasing sucks
- References: <bug-42779-17090@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #10 from hjl dot tools at gmail dot com 2010-01-17 22:11 -------
(In reply to comment #7)
> Btw, if you know more about data types than nothing then do not use the
> __m128* types for data but build your vector types yourself with an
> appropriate base type like
>
> typedef T m128T __attribute__((__vector_size__(16)));
It isn't a bad idea.
> It seems that the Intel intrinsics API at no point follows type-based
> aliasing rules (they even have vectors of characters, so restricting
> types based on possible data types is not going to work out).
>
That is true.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42779