[unix-history] / usr / src / usr.bin / f77 / libF77 / traper_.c

/*
char id_traper[] = "@(#)traper_.c	1.1";
 * Arrange to trap integer overflow & floating underflow.
 * Full of Magic! DON'T CHANGE ANYTHING !!
 *
 * To use from f77:
 *	integer oldmsk, traper
 *	oldmsk = traper (mask)
 * where:
 *	mask = 1 to trap integer overflow
 *	mask = 2 to trap floating underflow
 *	mask = 3 to trap both
 *	These 2 bits will be set into the PSW.
 *	The old state will be returned.
 */

long traper_(msk)
long	*msk;
{
	int	old = 0;
#if	vax
#define IOV_MASK	0140
	int	**s = &msk;
	int	psw;

	s -= 5;
	psw = (int)*s;
	old = (psw & IOV_MASK) >> 5;
	psw = (psw & ~IOV_MASK) | ((*msk << 5) & IOV_MASK);
	*s = (int *)psw;
#endif	vax
	return((long)old);
}
Commit	Line	Data
2d8189f2 DW	1	/*
	2	char id_traper[] = "@(#)traper_.c 1.1";
	3	* Arrange to trap integer overflow & floating underflow.
	4	* Full of Magic! DON'T CHANGE ANYTHING !!
	5	*
	6	* To use from f77:
	7	* integer oldmsk, traper
	8	* oldmsk = traper (mask)
	9	* where:
	10	* mask = 1 to trap integer overflow
	11	* mask = 2 to trap floating underflow
	12	* mask = 3 to trap both
	13	* These 2 bits will be set into the PSW.
	14	* The old state will be returned.
	15	*/
	16
	17	long traper_(msk)
	18	long *msk;
	19	{
	20	int old = 0;
	21	#if vax
	22	#define IOV_MASK 0140
	23	int **s = &msk;
	24	int psw;
	25
	26	s -= 5;
	27	psw = (int)*s;
	28	old = (psw & IOV_MASK) >> 5;
	29	psw = (psw & ~IOV_MASK) \| ((*msk << 5) & IOV_MASK);
	30	s = (int )psw;
	31	#endif vax
	32	return((long)old);
	33	}