reference Swish implementation (#40150)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/40150
added a skeleton for a Swish implementation using fakelowp
this implementation is as precise as it gets since it uses computation in fp32 as a reference
-simplified the test since this is a linear sweep, no need to randomize it
-modified the domain to ensure that 0 is always covered
Test Plan: ran this test against the lowered swish implementation and found that the interpolation domain should be [-21,12] to cover even the smallest value in the Y domain
Reviewed By: venkatacrc
Differential Revision: D22025105
fbshipit-source-id: dd8561243182c359003b4370ce2312f607d964c9
