Keep Touch'd variables live through the back end

[ghc-hetmet.git] / compiler / cmm / Cmm.hs

diff --git a/compiler/cmm/Cmm.hs b/compiler/cmm/Cmm.hs
index 383ed06..c48269e 100644 (file)
--- a/compiler/cmm/Cmm.hs
+++ b/compiler/cmm/Cmm.hs
@@ -174,7 +174,9 @@ data ClosureTypeInfo
   | ThunkInfo  ClosureLayout C_SRT
   | ThunkSelectorInfo SelectorOffset C_SRT
   | ContInfo
-      [Maybe LocalReg]  -- stack layout
+      [Maybe LocalReg]  -- Stack layout: Just x, an item x
+                        --               Nothing: a 1-word gap
+                       -- Start of list is the *young* end
       C_SRT
 
 data CmmReturnInfo = CmmMayReturn
@@ -382,6 +384,7 @@ data CallishMachOp
   | MO_F32_Exp
   | MO_F32_Sqrt
   | MO_WriteBarrier
+  | MO_Touch         -- Keep variables live (when using interior pointers)
   deriving (Eq, Show)
 
 pprCallishMachOp :: CallishMachOp -> SDoc