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Comment by abductee_hg

7 years ago

as long as basic things like __alignment__ are still fundamentally broken I simply do not care about the syntax. (I mean it doesn't get anything more basic than this, no?)

3 comments

abductee_hg

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edflsafoiewq  7 years ago

What's wrong with alignment?

  • abductee_hg  7 years ago

    well there is this: #ifdef _MSC_VER __declspec( align(16) ) struct float4 { float v[4]; }; #else struct float4 { float v[4]; } __attribute__ ((aligned(16))); #endif

    but the main problem ist tthat alignment is _not_ part of the typing system. ( alignas vs alignof )

    butt, to put it more general: 90% of your performance is in memory access and compilers are rubbish optimizing those, they are however getting increasingly good at the 10%. see also https://www.youtube.com/watch?v=rX0ItVEVjHc for realworld examples/exploration

    • account42  7 years ago

      > well there is this: #ifdef _MSC_VER __declspec( align(16) ) struct float4 { float v[4]; }; #else struct float4 { float v[4]; } __attribute__ ((aligned(16))); #endif

      I don't understand what you are trying to say here? Why not just use

          struct alignas(16) float4 { float v[4]; };

      You can even put both __declspec( align(16) ) and __attribute__ ((aligned(16))) in the same place if you want to have a fallback for older compilers.