ack/mach/proto/fp/shifter.c

/*
  (c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
  See the copyright notice in the ACK home directory, in the file "Copyright".
*/

/* $Header$ */

# include "adder.h"

b64_sft(e1,n)
B64	*e1;
int	n;
{
	if (n >= 32) {
		e1->l_32 = e1->h_32;
		e1->h_32 = 0;
		n -= 32;
	}
	if (n > 0) {
		e1->l_32 = (e1->l_32 >> n) | (e1->h_32 << (32 - n));
		e1->h_32 >>= n;
		return;
	}
	n = -n;
	if (n >= 32) {
		e1->h_32 = e1->l_32;
		e1->l_32 = 0;
		n -= 32;
	}
	if (n > 0) {
		e1->h_32 = (e1->h_32 << n) | (e1->l_32 >> (32 - n));
		e1->l_32 <<= n;
	}
}

b64_lsft(e1)
B64	*e1;
{
	/*	shift left 1 bit */
	e1->h_32 <<= 1;
	if (e1->l_32 & 0x80000000L) e1->h_32 |= 1;
	e1->l_32 <<= 1;
}

b64_rsft(e1)
B64	*e1;
{
	/*	shift right 1 bit */
	e1->l_32 >>= 1;
	if (e1->h_32 & 1) e1->l_32 |= 0x80000000L;
	e1->h_32 >>= 1;
}