Path: utzoo!attcan!uunet!mcsun!hp4nl!tuegate.tue.nl!al.ele.tue.nl!jos
From: jos@ele.tue.nl (Jos van Eijndhoven)
Newsgroups: comp.sys.apollo
Subject: BUG in cc int>double type conversion !!!!!
Keywords: bug cc double type conversion
Message-ID: <538@al.ele.tue.nl>
Date: 7 Aug 90 13:12:48 GMT
Sender: jos@ele.tue.nl (Jos van Eijndhoven)
Organization: Eindhoven University of Technology, The Netherlands
Lines: 35

I just discovered a bug in the apollo 10.2 C compiler on a DN3000,
regarding int to double type conversion between two fields in a union.
The problem is shown by the following tiny program:

/****** show cc bug in union type conversion *****/
#include <stdio.h>
main()
{	union
	{	int i;
		double f;
	} val;
	double f;

	val.i = 1;

	f = (double)(val.i);
	val.f = (double)(val.i);
	printf("f = %g, val.f = %g\n", f, val.f);
}
/**************************************************/

The program will print two different values!!!
Changing the order of int and double in the union doesn't help.
Changing the union to a struct removes the error.

I am severely hindered by this bug in a larger program.
Is this problem known already, and if so is there a patch available?
Does anybody know an easy way to circumvent the problem?

Any help appreciated,

Jos van Eijndhoven
Eindhoven University of Technology
The Netherlands
jos@es.ele.tue.nl