tree 8762e1cb2221920ff7a70eb7dfd96acae07127c9
parent 97873ea658fa6a7979980b3dcb785085a49db917
author Tobias Schlüter <tobias@lp-research.com> 1612003721 +0900
committer Tobias Schlüter <Ruediger.Knippel@googlemail.com> 1612016347 +0900

Use portable expression for constant 2/sqrt(pi)

M_2_SQRTPI is not part of standard C++, replace it with an
equivalent expression.  gcc immediately folds this and thus
generates the same code even at -O0.

Change-Id: I5d38e67a4508c1d43a1a8e5f1639f2243cdb143e