Load the target of a dynamic foreign call into a temporary

Fixes ffi011(opt) on x86_64.  I don't know why this has only just
appeared today, it's apparently been broken for some time.

diff --git a/compiler/codeGen/CgForeignCall.hs b/compiler/codeGen/CgForeignCall.hs
index e66e1b8..822a043 100644 (file)
--- a/compiler/codeGen/CgForeignCall.hs
+++ b/compiler/codeGen/CgForeignCall.hs
@@ -110,13 +110,14 @@ emitForeignCall' safety results target args vols
   | otherwise = do
     id <- newTemp wordRep
     temp_args <- load_args_into_temps args
+    temp_target <- load_target_into_temp target
     emitSaveThreadState
     stmtC (CmmCall (CmmForeignCall suspendThread CCallConv) 
                        [(id,PtrHint)]
                        [ (CmmReg (CmmGlobal BaseReg), PtrHint) ] 
                        vols
                        )
-    stmtC (CmmCall target results temp_args vols)
+    stmtC (CmmCall temp_target results temp_args vols)
     stmtC (CmmCall (CmmForeignCall resumeThread CCallConv) 
                        [ (CmmGlobal BaseReg, PtrHint) ]
                                -- Assign the result to BaseReg: we
@@ -139,16 +140,25 @@ resumeThread  = CmmLit (CmmLabel (mkRtsCodeLabel SLIT("resumeThread")))
 --
 -- This is a HACK; really it should be done in the back end, but
 -- it's easier to generate the temporaries here.
-load_args_into_temps args = mapM maybe_assignTemp args
+load_args_into_temps = mapM arg_assign_temp
+  where arg_assign_temp (e,hint) = do
+          tmp <- maybe_assign_temp e
+          return (tmp,hint)
        
-maybe_assignTemp (e, hint)
-  | hasNoGlobalRegs e = return (e, hint)
+load_target_into_temp (CmmForeignCall expr conv) = do 
+  tmp <- maybe_assign_temp expr
+  return (CmmForeignCall tmp conv)
+load_target_info_temp other_target =
+  return other_target
+
+maybe_assign_temp e
+  | hasNoGlobalRegs e = return e
   | otherwise          = do 
        -- don't use assignTemp, it uses its own notion of "trivial"
        -- expressions, which are wrong here
        reg <- newTemp (cmmExprRep e)
        stmtC (CmmAssign reg e)
-       return (CmmReg reg, hint)
+       return (CmmReg reg)
 
 -- -----------------------------------------------------------------------------
 -- Save/restore the thread state in the TSO