Reorganisation of the source tree

Most of the other users of the fptools build system have migrated to
Cabal, and with the move to darcs we can now flatten the source tree
without losing history, so here goes.

The main change is that the ghc/ subdir is gone, and most of what it
contained is now at the top level.  The build system now makes no
pretense at being multi-project, it is just the GHC build system.

No doubt this will break many things, and there will be a period of
instability while we fix the dependencies.  A straightforward build
should work, but I haven't yet fixed binary/source distributions.
Changes to the Building Guide will follow, too.

1 files changed, 14 insertions, 0 deletions

diff --git a/rts/gmp/mpn/cray/README b/rts/gmp/mpn/cray/README
new file mode 100644
index 0000000000..8195c67e21
--- /dev/null
+++ b/rts/gmp/mpn/cray/README
@@ -0,0 +1,14 @@
+The (poorly optimized) code in this directory was originally written for a
+j90 system, but finished on a c90.  It should work on all Cray vector
+computers.  For the T3E and T3D systems, the `alpha' subdirectory at the
+same level as the directory containing this file, is much better.
+
+* `+' seems to be faster than `|' when combining carries.
+
+* It is possible that the best multiply performance would be achived by
+  storing only 24 bits per element, and using lazy carry propagation.  Before
+  calling i24mult, full carry propagation would be needed.
+
+* Supply tasking versions of the C loops.
+
+