X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Fcmm%2FCmmExpr.hs;fp=compiler%2Fcmm%2FCmmExpr.hs;h=1769a01466c4f6a1205fc5d0c5f315493506aabf;hb=bbd857519eb2960476ef67b935a632983f2d84f6;hp=983a232e1704c1a5f0f267f104fb207f01438207;hpb=b2acf7a7179f08f7e4099799180017825154567d;p=ghc-hetmet.git

diff --git a/compiler/cmm/CmmExpr.hs b/compiler/cmm/CmmExpr.hs
index 983a232..1769a01 100644
--- a/compiler/cmm/CmmExpr.hs
+++ b/compiler/cmm/CmmExpr.hs
@@ -5,7 +5,7 @@ module CmmExpr
     , CmmLit(..), cmmLitRep
     , LocalReg(..), localRegRep, localRegGCFollow, GCKind(..)
     , GlobalReg(..), globalRegRep, spReg, hpReg, spLimReg, nodeReg, node
-    , UserOfLocalRegs, foldRegsUsed
+    , UserOfLocalRegs, foldRegsUsed, filterRegsUsed
     , RegSet, emptyRegSet, elemRegSet, extendRegSet, deleteFromRegSet, mkRegSet
             , plusRegSet, minusRegSet, timesRegSet
     )
@@ -112,6 +112,11 @@ timesRegSet      = intersectUniqSets
 class UserOfLocalRegs a where
   foldRegsUsed :: (b -> LocalReg -> b) -> b -> a -> b
 
+filterRegsUsed :: UserOfLocalRegs e => (LocalReg -> Bool) -> e -> RegSet
+filterRegsUsed p e =
+    foldRegsUsed (\regs r -> if p r then extendRegSet regs r else regs)
+                 emptyRegSet e
+
 instance UserOfLocalRegs CmmReg where
     foldRegsUsed f z (CmmLocal reg) = f z reg
     foldRegsUsed _ z (CmmGlobal _)  = z