usr/src/sys/tahoe/align/Aadwc.c

/*-
 * Copyright (c) 1986 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Computer Consoles Inc.
 *
 * %sccs.include.redist.c%
 *
 *      @(#)Aadwc.c     7.1 (Berkeley) %G%
 */

#include "align.h"
adwc(infop)     process_info *infop;
/*
/*      Add with carry.
/*      Note : the play with 'tmp' just before the 'asm' line makes
/*              sure that when the adwc opcode is executed, the current
/*              carry in psl is the same as the 'offending' process'.
/*              Don't change unless you know exactly what you're doing.
/*
/*****************************/
{
        register        long    Register_12;    /* Has to be first reg ! */
        register        long    Register_11;
        register        long    Register_10;
        register        long    tmp;

        Register_12 = operand(infop,0)->data;
        Register_11 = operand(infop,1)->data;
        if (carry)      /* If process' carry set */
                tmp = -1;
        else tmp = 0;
        tmp++;          /* 0 => carry set.  1 => carry clear */

        Register_10=psl;
        Set_psl(r10);   /* restore the user psl */
        asm("   adwc    r11,r12");
        asm("   movpsl  r11");
        New_cc (Register_11);

        write_back(infop, Register_12, operand(infop,1) );
}