+\begin{description}
+
+\item[loop unrolling]{
+ is a loop transformation.
+ Unrolling a loop by a factor of $n$ consists in the substitution of a loop
+ body by itself, replicated $n$ times. A prelude and/or postlude are
+ added to preserve the number of iteration.}
+
+\item[loop fusion]{
+ is a loop transformation that replaces two loops by a single loops whose
+ body is the concatenation of the bodies of the two initial loops.}
+
+\item[loop tiling]{
+ is a loop nest transformation that changes the loop execution order
+ through a partitions of the iteration space into
+ chunks, so that the iteration is performed over each chunk and in the
+ chunks.}
+
+\item[loop interchange]{is a loop transformation that permutes two
+ loops from a loop nest.}
+
+\item[loop unswitching]{is a loop transformation that replaces a
+ loop containing a test independent from the loop execution by a test
+ containing the loop without the test in both true and false branch.}
+
+\item[loop normalization]{is a loop transformation that changes
+ the loop initial increment value or the loop range to enforce certain values,
+ generally 1.}
+
+\end{description}
+