@@ -1,5 +1,9 @@
2010-09-09 Sebastian Pop <firstname.lastname@example.org>
+ * graphite-flattening.c: Fix comments.
+2010-09-09 Sebastian Pop <email@example.com>
* Makefile.in (OBJS-common): Add graphite-flattening.o.
(graphite-flattening.o): New rule.
* common.opt (floop-flatten): New flag.
@@ -55,6 +55,12 @@ along with GCC; see the file COPYING3. If not see
then apply on the full loop body, without needing the outer-loop
+ The loop flattening pass that has been described in a very Fortran
+ specific way in the 1992 paper by Reinhard von Hanxleden and Ken
+ Kennedy: "Relaxing SIMD Control Flow Constraints using Loop
+ Transformations" available from
The canonical example is as follows: suppose that we have a loop
nest with known iteration counts
@@ -95,11 +101,11 @@ along with GCC; see the file COPYING3. If not see
- For an arbitrarily complex loop nests the algorithm proceeds in two
+ For an arbitrarily complex loop nest the algorithm proceeds in two
steps. First, the LST is flattened by removing the loops structure
and by inserting the statements in the order they appear in
depth-first order. Then, the scattering of each statement is
- transformed such that it
+ transformed accordingly.
Supposing that the original program is represented by the following