Copyright (C) 1994, Digital Equipment Corp.File: Abs.m3 Last Modified On Tue May 3 16:28:46 PDT 1994 By kalsow Modified On Sat Dec 8 00:46:53 1990 By muller
MODULE; IMPORT CG, CallExpr, Expr, ExprRep, Type, Procedure, Error; IMPORT Target, TInt, Int, Reel, LReel, EReel, IntegerExpr, ReelExpr; VAR Z: CallExpr.MethodList; PROCEDURE Abs TypeOf (ce: CallExpr.T): Type.T = BEGIN RETURN Type.Base (Expr.TypeOf (ce.args[0])); END TypeOf; PROCEDURECheck (ce: CallExpr.T; VAR cs: Expr.CheckState) = VAR t := TypeOf (ce); BEGIN ce.type := t; IF (t = Int.T) THEN INC (cs.int_ops); ELSIF (t = Reel.T) OR (t = LReel.T) OR (t = EReel.T) THEN INC (cs.fp_ops); ELSE Error.Msg ("ABS: wrong argument type"); END; END Check; PROCEDURECompile (ce: CallExpr.T) = VAR e := ce.args[0]; BEGIN Expr.Compile (e); CG.Abs (Type.CGType (Expr.TypeOf (e))); END Compile; PROCEDUREFold (ce: CallExpr.T): Expr.T = VAR e, x: Expr.T; i, j: Target.Int; BEGIN e := Expr.ConstValue (ce.args[0]); IF (e = NIL) THEN RETURN NIL; ELSIF IntegerExpr.Split (e, i) THEN IF TInt.LT (i, TInt.Zero) THEN IF NOT TInt.Subtract (TInt.Zero, i, j) THEN RETURN NIL END; e := IntegerExpr.New (j); END; RETURN e; ELSIF ReelExpr.Abs (e, x) THEN RETURN x; ELSE RETURN NIL; END; END Fold; PROCEDUREInitialize () = BEGIN Z := CallExpr.NewMethodList (1, 1, TRUE, FALSE, TRUE, NIL, TypeOf, CallExpr.NotAddressable, Check, CallExpr.PrepArgs, Compile, CallExpr.NoLValue, CallExpr.NoLValue, CallExpr.NotBoolean, CallExpr.NotBoolean, Fold, CallExpr.IsNever, (* writable *) CallExpr.IsNever, (* designator *) CallExpr.NotWritable (* noteWriter *)); Procedure.Define ("ABS", Z, TRUE); END Initialize; BEGIN END Abs.