+ | StCall (Either FastString StixExpr) -- Left: static, Right: dynamic
+ CCallConv PrimRep [StixExpr]
+
+
+-- What's the PrimRep of the value denoted by this StixExpr?
+repOfStixExpr :: StixExpr -> PrimRep
+repOfStixExpr (StInt _) = IntRep
+repOfStixExpr (StFloat _) = FloatRep
+repOfStixExpr (StDouble _) = DoubleRep
+repOfStixExpr (StString _) = PtrRep
+repOfStixExpr (StCLbl _) = PtrRep
+repOfStixExpr (StReg reg) = repOfStixReg reg
+repOfStixExpr (StIndex _ _ _) = PtrRep
+repOfStixExpr (StInd rep _) = rep
+repOfStixExpr (StCall target conv retrep args) = retrep
+repOfStixExpr (StMachOp mop args) = resultRepOfMachOp mop