[commit: ghc] wip/T13861: add TODOs (6d30495)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : wip/T13861
Link       : http://ghc.haskell.org/trac/ghc/changeset/6d3049543ed9bb684b0c207aaf877502676516cb/ghc

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

commit 6d3049543ed9bb684b0c207aaf877502676516cb
Author: Gabor Greif <ggreif at gmail.com>
Date:   Mon Jul 31 12:04:07 2017 +0200

    add TODOs


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

6d3049543ed9bb684b0c207aaf877502676516cb
 compiler/simplStg/StgCse.hs | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/compiler/simplStg/StgCse.hs b/compiler/simplStg/StgCse.hs
index 1b98265..3b989a0 100644
--- a/compiler/simplStg/StgCse.hs
+++ b/compiler/simplStg/StgCse.hs
@@ -13,6 +13,12 @@ There are two types of common code occurrences that we aim for, see
 note [Case 1: CSEing allocated closures] and
 note [Case 2: CSEing case binders] below.
 
+TODOs:
+- rerun occurrence analysis
+- dumping of STG misses binder
+- does not look up in scope to find low-hanging fruit
+- can we dedup info tables for representationally equal data constructors?
+
 
 Note [Case 1: CSEing allocated closures]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -203,9 +209,9 @@ envLookup dataCon args env = lookupTM (dataCon, args') (ce_conAppMap env)
 
 addDataCon :: OutId -> LaxDataCon -> [OutStgArg] -> CseEnv -> CseEnv
 -- do not bother with nullary data constructors, they are static anyways
---addDataCon bndr dataCon [] env = env { ce_conAppMap = new_env }
---  where new_env = alterTM (dataCon, []) (\case Nothing -> pure bndr; p -> p) (ce_conAppMap env)
-addDataCon _ _ [] env = env
+addDataCon bndr dataCon [] env = env { ce_conAppMap = new_env }
+  where new_env = alterTM (dataCon, []) (\case Nothing -> pure bndr; p -> p) (ce_conAppMap env)
+--addDataCon _ _ [] env = env
 addDataCon bndr dataCon args env = env { ce_conAppMap = new_env }
   where
     new_env = insertTM (dataCon, args) bndr (ce_conAppMap env)