From: David Wells <wellsd2@rpi.edu>
Date: Sat, 29 Aug 2015 17:33:54 +0000 (-0400)
Subject: Compute powers of -1 by checking exponent parity.
X-Git-Tag: v8.4.0-rc2~521^2~1
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0c6450f69b1c9a0e99d0e34968342d05b8a99882;p=dealii.git

Compute powers of -1 by checking exponent parity.
---

diff --git a/source/base/polynomials_bernstein.cc b/source/base/polynomials_bernstein.cc
index c9c3e8849b..942d3e9314 100644
--- a/source/base/polynomials_bernstein.cc
+++ b/source/base/polynomials_bernstein.cc
@@ -18,7 +18,7 @@ namespace Binomial
     std::vector<number> coeff(n + 1, number(0.0));
     for (unsigned int i = k; i < n + 1; ++i)
       {
-        coeff[i] = pow(number(-1), number(i - k))
+        coeff[i] = ((i - k) % 2 == 0 ? 1 : -1)
                    * boost::math::binomial_coefficient<number>(n, i)
                    * boost::math::binomial_coefficient<number>(i, k);
       }