GCC-14 build is failing due to pytorch/third_party/fbgemm/src/UtilsAvx512.cc:970:35: error: ‘r’ may be used uninitialized [-Werror=maybe-uninitialized]

[anmyachev]

Logs:

pytorch/third_party/fbgemm/src/UtilsAvx512.cc:970:35: error: ‘r’ may be used uninitialized [-Werror=maybe-uninitialized]
  970 |   d[0] = _mm512_permutex2var_epi32(r[0], index1, r[1]);
      |          ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~

pytorch/third_party/fbgemm/src/UtilsAvx512.cc:922:11: note: ‘r’ declared here
  922 |   __m512i r[2], d[2];
      |           ^

Initially found in intel/intel-xpu-backend-for-triton#2897.

This is not a blocker, but I think it is easy to fix and this report can help gradually prepare for the new GCC release.

[cheezeburglar]

FWIW reproduced on trunk gcc and (slowly) reducing a testcase to report

[q10]

This is being worked on at pytorch/pytorch#129358