X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FsimplCore%2FCSE.lhs;h=11eec3e684b6d64214c55eb561adc646ffd3e2ca;hb=de905f504a3e129e2c4a1906d7e0a26e36cd6c4b;hp=e7dd2175235cf3e5adeea63940bd039d4af7cba2;hpb=1ee8a6f6cf3c06e3651438720333612a70348091;p=ghc-hetmet.git

diff --git a/compiler/simplCore/CSE.lhs b/compiler/simplCore/CSE.lhs
index e7dd217..11eec3e 100644
--- a/compiler/simplCore/CSE.lhs
+++ b/compiler/simplCore/CSE.lhs
@@ -19,6 +19,7 @@ import CoreSyn
 import VarEnv	
 import CoreLint		( showPass, endPass )
 import Outputable
+import StaticFlags	( opt_PprStyle_Debug )
 import BasicTypes	( isAlwaysActive )
 import Util		( mapAccumL, lengthExceeds )
 import UniqFM
@@ -314,11 +315,14 @@ addCSEnvItem env expr expr' | exprIsBig expr = env
 extendCSEnv (CS cs in_scope sub) expr expr'
   = CS (addToUFM_C combine cs hash [(expr, expr')]) in_scope sub
   where
-    hash   = hashExpr expr
-    combine old new = WARN( result `lengthExceeds` 4, text "extendCSEnv: long list:" <+> ppr result )
-		      result
-		    where
-		      result = new ++ old
+    hash = hashExpr expr
+    combine old new 
+	= WARN( result `lengthExceeds` 4, short_msg $$ nest 2 long_msg ) result
+	where
+	  result = new ++ old
+	  short_msg = ptext SLIT("extendCSEnv: long list, length") <+> int (length result)
+	  long_msg | opt_PprStyle_Debug = (text "hash code" <+> text (show hash)) $$ ppr result 
+		   | otherwise	        = empty
 
 lookupSubst (CS _ _ sub) x = case lookupVarEnv sub x of
 			       Just y  -> y