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Verify FAILED in multi-rank runs: Revision history

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28 June 2026

  • curprev 04:0404:04, 28 June 2026 SanzSkuy talk contribs 9,261 bytes +9,261 Created page with "This page documents a correctness bug in the MPI × OpenCL matmul cluster where multi-rank runs produced zeroed output elements, the investigation that isolated it, and the fix. It also records three secondary issues found along the way. '''TL;DR''': The OpenCL kernel maps NDRange dimension 0 to the matrix ''row'' and dimension 1 to the ''column'', but the host launch code set the global work size as <code>{cols, rows}</code> — the two were swapped. Square m..."