The result would not be correct if, on input, |x->neg != 0| or |y->neg != 0|. Change-Id: I645566a78c2e18e42492fbfca1df17baa05240f7 Reviewed-on: https://boringssl-review.googlesource.com/7587 Reviewed-by: David Benjamin <davidben@google.com>kris/onging/CECPQ3_patch15