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simd directives #6

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lucaparisi91 opened this issue Jun 26, 2024 · 1 comment
Open

simd directives #6

lucaparisi91 opened this issue Jun 26, 2024 · 1 comment
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What does #pragma omp simd actually do on the GPU ?
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lucaparisi91 commented Jul 15, 2024 •
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NVidia GPUs can have vectorized instructions of length 2 or 4 . This is different from SIMT parallelism. The instruction will operate on 2(4) x 32 threads in a warp .
It looks like some old versions of CCE interprets simd as simt , and the value is required to use all threads in a warp.
That is not the case for new versions of cce . At the moment most compilers seem to ignore the simd directive.

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