BSD 4_1_snap release

[unix-history] / usr / src / cmd / pi / tmps.c

/* Copyright (c) 1979 Regents of the University of California */

static char sccsid[] = "@(#)tmps.c 1.5 6/1/81";

#include "whoami.h"
#include "0.h"
#ifdef PC
#   include "pc.h"
#endif PC

/*
* This routine defines the register allocation strategy
* All temporaries are allocated here, and this routines decides
* where they are to be put.
*/
#ifdef PC
#ifdef VAX
#    define MAXREGS 6
#    define MINREGSIZE 4
#    define MAXREGSIZE 4
#    define FIRSTREG 6
#else
#ifdef PDP11
#    define MAXREGS 3
#    define MINREGSIZE 2
#    define MAXREGSIZE 2
#    define FIRSTREG 2
#else
#    define MAXREGS 0
#    define MINREGSIZE 0
#    define MAXREGSIZE 0
#    define FIRSTREG 0
#endif PDP11
#endif VAX
#endif PC

/*
* allocate runtime temporary variables
*/
struct nl *
tmpalloc(size, type, mode)
       long size;
       struct nl *type;
       int mode;
{
       register struct om *op = &sizes[ cbn ];
       register int offset;
       register struct nl      *nlp;

#       ifdef PC
           if (mode == REGOK && size >= MINREGSIZE && size <= MAXREGSIZE &&
               op->curtmps.reg_off < MAXREGS) {
                   offset = op->curtmps.reg_off++;
                   if ( offset > op->reg_max ) {
                           op->reg_max = offset;
                   }
                   nlp = defnl( 0 , VAR , type , offset + FIRSTREG );
                   nlp -> extra_flags = NLOCAL | NREGVAR;
                   return nlp;
           }
#       endif PC
       offset = op->curtmps.om_off -= leven( size );
       if ( offset < op->om_max ) {
               op->om_max = offset;
       }
       nlp = defnl( 0 , VAR , type , offset );
#       ifdef PC
           nlp -> extra_flags = NLOCAL;
           putlbracket( ftnno , -offset );
#       endif PC
       return nlp;
}
\f
/*
* deallocate runtime temporary variables
*/
tmpfree(restore)
       register struct tmps *restore;
{
       register struct om *op = &sizes[ cbn ];

#       ifdef PC
           if (restore->reg_off < op->curtmps.reg_off) {
                   op->curtmps.reg_off = restore->reg_off;
           }
#       endif PC
       if (restore->om_off > op->curtmps.om_off) {
               op->curtmps.om_off = restore->om_off;
#               ifdef PC
                   putlbracket( ftnno , -restore->om_off );
#               endif PC
       }
}
\f
#ifdef PC
#ifdef VAX
/*
* create a save mask for registers which have been used
* in this level
*/
savmask()
{
       int mask;
       int i;

       mask = RSAVEMASK;
       if (opt('t'))
               mask |= RUNCHECK;
       for (i = 0; i <= sizes[ cbn ].reg_max; i++)
               mask |= 1 << (FIRSTREG + i);
       return mask;
}
#endif VAX
#endif PC