Work around lack of saving volatile registers from unsafe foreign calls.

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

diff --git a/compiler/cmm/OldCmm.hs b/compiler/cmm/OldCmm.hs
index 57d458c..f5c0817 100644 (file)
--- a/compiler/cmm/OldCmm.hs
+++ b/compiler/cmm/OldCmm.hs
@@ -144,12 +144,14 @@ data CmmStmt      -- Old-style
   | CmmStore CmmExpr CmmExpr     -- Assign to memory location.  Size is
                                  -- given by cmmExprType of the rhs.
 
-  | CmmCall                     -- A call (forign, native or primitive), with 
+  | CmmCall                     -- A call (foreign, native or primitive), with 
      CmmCallTarget
      HintedCmmFormals           -- zero or more results
      HintedCmmActuals           -- zero or more arguments
      CmmSafety                  -- whether to build a continuation
      CmmReturnInfo
+  -- Some care is necessary when handling the arguments of these, see
+  -- [Register parameter passing] and the hack in cmm/CmmOpt.hs
 
   | CmmBranch BlockId             -- branch to another BB in this fn