/*
 * Copyright 1988 by the Massachusetts Institute of Technology.
 *
 * For copying and distribution information,
 * please see the file <mit-cpyright.h>.
 *
 * This file contains a generation routine for source code
 * implementing the final permutation of the DES.
 */

#include <afsconfig.h>
#include <afs/param.h>

RCSID
    ("$Header: /cvs/openafs/src/des/make_fp.c,v 1.6 2003/07/15 23:15:00 shadow Exp $");

#include <mit-cpyright.h>
#include <stdio.h>
#include <des.h>
#include "des_internal.h"
#include "des_prototypes.h"

#define WANT_FP_TABLE
#include "tables.h"

void
gen(FILE * stream)
{
    register int i;

    /* clear the output */
    fprintf(stream, "    L2 = 0; R2 = 0;\n");

    /*
     *  NOTE: As part of the final permutation, we also have to adjust
     *  for host bit order via "swap_bit_pos_0()".  Since L2,R2 are
     *  the output from this, we adjust the bit positions written into
     *  L2,R2.
     */

#define SWAP(i,j) \
    swap_long_bytes_bit_number(swap_bit_pos_0_to_ansi((unsigned)i)-j)

    /* first setup FP */
    fprintf(stream, "/* FP operations */\n/* first left to left */\n");

    /* first list mapping from left to left */
    for (i = 0; i <= 31; i++)
	if (FP[i] < 32)
	    test_set(stream, "L1", FP[i], "L2", SWAP(i, 0));

    /* now mapping from right to left */
    fprintf(stream, "\n\n/* now from right to left */\n");
    for (i = 0; i <= 31; i++)
	if (FP[i] >= 32)
	    test_set(stream, "R1", FP[i] - 32, "L2", SWAP(i, 0));

    fprintf(stream, "\n/* now from left to right */\n");

    /*  list mapping from left to right */
    for (i = 32; i <= 63; i++)
	if (FP[i] < 32)
	    test_set(stream, "L1", FP[i], "R2", SWAP(i, 32));

    /* now mapping from right to right */
    fprintf(stream, "\n/* last from right to right */\n");
    for (i = 32; i <= 63; i++)
	if (FP[i] >= 32)
	    test_set(stream, "R1", FP[i] - 32, "R2", SWAP(i, 32));
}
