From 60dba3fba4d6012acb1afd15e9712c02b9c76e48 Mon Sep 17 00:00:00 2001
From: henry <Henry Weller h.weller@opencfd.co.uk>
Date: Fri, 30 Jan 2009 15:02:00 +0000
Subject: [PATCH] Improved the test for the pow-of-2 constraint from Mark's
 recommendation.

---
 src/randomProcesses/fft/fft.C | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/randomProcesses/fft/fft.C b/src/randomProcesses/fft/fft.C
index 660079d6bf..67d13fd04d 100644
--- a/src/randomProcesses/fft/fft.C
+++ b/src/randomProcesses/fft/fft.C
@@ -48,8 +48,9 @@ void fft::transform
 {
     forAll(nn, idim)
     {
-        scalar pow2 = log(scalar(nn[idim]))/log(scalar(2));
-        if ((pow2 - int(pow2 + 0.5)) > SMALL)
+        // Check for power of two
+        unsigned int dimCount = nn[idim];
+        if (!dimCount || (dimCount & (dimCount - 1)))
         {
             FatalErrorIn
             (