eliminate FE_INVALID exceptions related to fp16 conversion (#20390)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/20390
duc0 Ngo implemented observing floating point exceptions but there were a couple of places where we have "benign" floating point exceptions leading to false positives. This diff eliminates one source of such false positives, namely using _mm256_cvtph_ps and _mm256_cvtps_ph for partially uninitialized array for the remainder loop.
Reviewed By: hx89
Differential Revision: D15307358
fbshipit-source-id: 38f57dfdd90c70bc693292d2f9c33c7ba558e2c9
