+-- -----------------------------------------------------------------------------
+-- caller-save registers
+
+-- Here we generate the sequence of saves/restores required around a
+-- foreign call instruction.
+
+callerSaveVolatileRegs :: Maybe [GlobalReg] -> ([CmmStmt], [CmmStmt])
+callerSaveVolatileRegs vols = (caller_save, caller_load)
+ where
+ caller_save = foldr ($!) [] (map callerSaveGlobalReg regs_to_save)
+ caller_load = foldr ($!) [] (map callerRestoreGlobalReg regs_to_save)
+
+ system_regs = [Sp,SpLim,Hp,HpLim,CurrentTSO,CurrentNursery,
+ {-SparkHd,SparkTl,SparkBase,SparkLim,-}BaseReg ]
+
+ regs_to_save = system_regs ++ vol_list
+
+ vol_list = case vols of Nothing -> []; Just regs -> regs
+
+ callerSaveGlobalReg reg next
+ | callerSaves reg =
+ CmmStore (get_GlobalReg_addr reg)
+ (CmmReg (CmmGlobal reg)) : next
+ | otherwise = next
+
+ callerRestoreGlobalReg reg next
+ | callerSaves reg =
+ CmmAssign (CmmGlobal reg)
+ (CmmLoad (get_GlobalReg_addr reg) (globalRegRep reg))
+ : next
+ | otherwise = next
+
+