1*48081Sbostic(*
2*48081Sbostic * Copyright (c) 1980 The Regents of the University of California.
3*48081Sbostic * All rights reserved.
4*48081Sbostic *
5*48081Sbostic * %sccs.include.redist.c%
6*48081Sbostic *
7*48081Sbostic *	@(#)overflow.p	5.1 (Berkeley) 04/16/91
8*48081Sbostic *)
9*48081Sbostic
10*48081Sbosticprogram fpexceptions(input,output);
11*48081Sbostic    type
12*48081Sbostic	fperrorkind = ( fperrorfirst,
13*48081Sbostic			overflow,underflow,divideby0,domain,
14*48081Sbostic			fperrolast );
15*48081Sbostic    var
16*48081Sbostic	request : fperrorkind;
17*48081Sbostic    procedure genoverflow;
18*48081Sbostic	var
19*48081Sbostic	    i : integer;
20*48081Sbostic	    r : real;
21*48081Sbostic	begin
22*48081Sbostic	    r := 2.0;
23*48081Sbostic	    for i := 1 to 1000 do begin
24*48081Sbostic		r := r * r;
25*48081Sbostic	    end;
26*48081Sbostic	    writeln('this machine handles more than 2^1000');
27*48081Sbostic	end;
28*48081Sbostic    procedure genunderflow;
29*48081Sbostic	var
30*48081Sbostic	    i : integer;
31*48081Sbostic	    r : real;
32*48081Sbostic	begin
33*48081Sbostic	    r := 0.5;
34*48081Sbostic	    for i := 1 to 1000 do begin
35*48081Sbostic		r := r * r;
36*48081Sbostic	    end;
37*48081Sbostic	    writeln('this machine handles more than 2^-1000');
38*48081Sbostic	end;
39*48081Sbostic    procedure gendivideby0;
40*48081Sbostic	var
41*48081Sbostic	    r : real;
42*48081Sbostic	begin
43*48081Sbostic	    r := 17.0;
44*48081Sbostic	    r := r - r;		{should be 0.0}
45*48081Sbostic	    r := 17.0 / r;
46*48081Sbostic	    writeln('i wonder what r is?', r);
47*48081Sbostic	end;
48*48081Sbostic    procedure gendomain;
49*48081Sbostic	var
50*48081Sbostic	    r : real;
51*48081Sbostic	begin
52*48081Sbostic	    r := -17.0;
53*48081Sbostic	    r := sqrt(r);
54*48081Sbostic	    writeln('i wonder what r is?', r);
55*48081Sbostic	end;
56*48081Sbostic    begin
57*48081Sbostic	write('which do you want (');
58*48081Sbostic	for request := succ(fperrorfirst) to pred(fperrolast) do begin
59*48081Sbostic		{this isn't standard pascal.}
60*48081Sbostic	    write( ' ', request);
61*48081Sbostic	end;
62*48081Sbostic	write(' ): ');
63*48081Sbostic	    {neither is this, but it sure is convenient.}
64*48081Sbostic	readln(request);
65*48081Sbostic	if request in [overflow,underflow,divideby0,domain] then begin
66*48081Sbostic	    writeln('one ', request, ' coming right down');
67*48081Sbostic	    case request of
68*48081Sbostic		overflow:	genoverflow;
69*48081Sbostic		underflow:	genunderflow;
70*48081Sbostic		divideby0:	gendivideby0;
71*48081Sbostic		domain:	gendomain;
72*48081Sbostic	    end;
73*48081Sbostic	end else begin
74*48081Sbostic		{default:}
75*48081Sbostic	    writeln('oh, never mind');
76*48081Sbostic	end;
77*48081Sbostic    end.
78*48081Sbostic
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