| Re: [eigen] Alignment issues |
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- To: eigen <eigen@xxxxxxxxxxxxxxxxxxx>
- Subject: Re: [eigen] Alignment issues
- From: Gael Guennebaud <gael.guennebaud@xxxxxxxxx>
- Date: Fri, 14 Feb 2014 11:05:30 +0100
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> In your test program, requesting an alignment of 128 bytes is asking for troubles. The standard only guarantees support for alignment up
> to alignof(std::max_align_t), which on OS X 64bits is 16. However, an unsupported alignment requirement should trigger a compile-time
> error, so this actually sounds like a bug in clang. Since you’re using version 3.3 and alignment support was introduced right in that version,
> it could be. But are you using truly clang 3.3 or are you using the 3.3svn shipped with Xcode 5?
I tried with:
* clang version 3.3 (tags/RELEASE_33/final) [from macport]
* Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn) [from xcode]
* g++-mp-4.8 (MacPorts gcc48 4.8.2_0) 4.8.2
and got same behaviors.
Note that we do not only need 16bytes alignement but also 32 bytes for AVX.
gael
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>
> Nicola
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>
>