[lazarus] An overflow problem

[Michael Van Canneyt]

On Fri, 17 Dec 1999, Veselic wrote:

> Dear fpk friends,
> 
> I noticed two overflow cases where my fpk (on PC-Linux),
> performed less satisfactory than expected and in particular
> less satisfactory than GNU pascal in the same environment:
> 
> Case 1. The program
> 
> program test2(input,output);
> var 
>      b,c:single;
> begin {main}
> c := 1e+33; 
> c := sqr(c);
> b := c - c;
> writeln(b,' ',c);
> end.
> 
> was normally compiled and upon execution produced
> 
> Run time error  200 at 0x0804F02F
>   0xBFFFF894
>   0x080480A4
>   0x00000000
> 
> On the other hand, after compiling the same with GNU pascal,
> the execution yielded
> 
>  NaN  Inf 
> 
> as expected.
> 
> Case 2. The program
> 
> program test1(input,output);
> var 
>      c:single;
> begin {main}
> c := sqr(1e+33);
> writeln(c);
> end.
> 
> the compiler produced the message
> Target OS: Linux for i386
> Compiling test1.p
> Assembling test1
> Linking test1
> FPE error inside compiler
> 
> and the execution yielded a curious output
> 
>  4.357678781E-34   
> 
> Again, GNU pascal gave
> 
>  Inf       
> 
> Question: Can one teach freepascal to make equally friendly
> outputs in such cases?

I will add it next week. 

Michael.