[commit: ghc] master: comment (7db26e0)

[Simon Marlow]

Repository : ssh://darcs.haskell.org//srv/darcs/ghc

On branch  : master

http://hackage.haskell.org/trac/ghc/changeset/7db26e00a945532e2ab6be50a8ffe43a6a5917a8

>---------------------------------------------------------------

commit 7db26e00a945532e2ab6be50a8ffe43a6a5917a8
Author: Simon Marlow <marlowsd at gmail.com>
Date:   Fri Aug 3 16:38:01 2012 +0100

    comment

>---------------------------------------------------------------

 compiler/cmm/CmmOpt.hs |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/compiler/cmm/CmmOpt.hs b/compiler/cmm/CmmOpt.hs
index 2e3da5c..09cbf50 100644
--- a/compiler/cmm/CmmOpt.hs
+++ b/compiler/cmm/CmmOpt.hs
@@ -605,6 +605,11 @@ cmmMachOpFoldM platform mop [x, (CmmLit (CmmInt n _))]
                 Just (cmmMachOpFold platform (MO_S_Shr rep) [x3, CmmLit (CmmInt p rep)])
         _ -> Nothing
 
+-- ToDo (#7116): optimise floating-point multiplication, e.g. x*2.0 -> x+x
+-- Unfortunately this needs a unique supply because x might not be a
+-- register.  See #2253 (program 6) for an example.
+
+
 -- Anything else is just too hard.
 
 cmmMachOpFoldM _ _ _ = Nothing