[nnc] Allow 1 ulp tolerance in log approximation (#52165)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/52165
Apparently bitwise identicality is too high a bar (I'm seeing
differences at this level depending on the HW platform, e.g.,
Broadwell is bitwise accurate but Skylake is 1ulp off). But anyways
VML is accurate to 1 ulp, so let's allow that.
ghstack-source-id: 121815001
Test Plan: test_approx
Reviewed By: asuhan
Differential Revision: D26408079
fbshipit-source-id: 46cbd1487c72ae7bc40567f2f72ed2b919707d0d
