X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Fcmm%2FCmmProcPoint.hs;h=aa0ef01d37fbd8575749da759f19e18c23ea4d57;hb=7b2ac617ee9e54ee4e4c413a13085d9bda548d14;hp=fe64608022fb1ab3ea450a35975ff27063a0918a;hpb=55f8b001f06d0a2a1e9b0e84cbaa5f2f109270df;p=ghc-hetmet.git

diff --git a/compiler/cmm/CmmProcPoint.hs b/compiler/cmm/CmmProcPoint.hs
index fe64608..aa0ef01 100644
--- a/compiler/cmm/CmmProcPoint.hs
+++ b/compiler/cmm/CmmProcPoint.hs
@@ -1,9 +1,17 @@
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
+-- for details
+
 module CmmProcPoint (
   calculateProcPoints
   ) where
 
 #include "HsVersions.h"
 
+import BlockId
 import Cmm
 import CmmBrokenBlock
 import Dataflow
@@ -79,8 +87,12 @@ calculateNewProcPoints  owners block =
           where
             parent_owners = lookupWithDefaultUFM owners emptyUniqSet parent_id
             child_owners = lookupWithDefaultUFM owners emptyUniqSet child_id
-            needs_proc_point = not $ isEmptyUniqSet $
-                               child_owners `minusUniqSet` parent_owners
+            needs_proc_point =
+                -- only if parent isn't dead
+                (not $ isEmptyUniqSet parent_owners) &&
+                -- and only if child has more owners than parent
+                (not $ isEmptyUniqSet $
+                     child_owners `minusUniqSet` parent_owners)
 
 calculateOwnership :: BlockEnv BrokenBlock
                    -> UniqSet BlockId