Merge branch 'v2.3' into v2.4

src/tools/OpenMP.h

@@ -57,8 +57,8 @@ unsigned OpenMP::getGoodNumThreads(const T*x,unsigned n) {
 // to cache line boundary
   unsigned m=n*sizeof(T)/(2*getCachelineSize());
   unsigned numThreads=getNumThreads();
-  if(m>numThreads) m=numThreads;
-  if(m==0) m=1;
+  if(m>=numThreads) m=numThreads;
+  else m=1;
   return m;
 }