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/*

 *      install --- add a symbol to the table

 */

install(str,val)

char    *str;

int     val;

{

        struct link *lp;

 struct nlist *np,*p,*backp;

 struct nlist *lookup();

 int     i;

 char *LastChar();      /* ver TER_2.0 */

 if( !alpha(*str) ){

  error("Illegal Symbol Name");

  return(NO);

  }

 if( (np = lookup(str)) != NULL ){

  if (*LastChar(str) == '@') {  /* redefinable symbol  ver TER_2.0 */

        np->def = val;          /* redefined */

        return(YES);

        }

  if( Pass==2 ){

   np->def2 = 2;        /* defined for this pass=Pass  ver TER_2.0 */

   if( np->def == val )

    return(YES);

   else{

    error("Phasing Error");

    return(NO);

    }

   }

  error("Symbol Redefined");

  return(NO);

  }

 /* enter new symbol */

#ifdef DEBUG

 printf("Installing %s as %d\n",str,val);

#endif

 np = (struct nlist *) alloc(sizeof(struct nlist));

 if( np == (struct nlist *)ERR ){

  error("Symbol table full");

  return(NO);

  }

 np->name = alloc(strlen(str)+1);

 if( np->name == (char *)ERR ){

  error("Symbol table full");

  return(NO);

  }

 strcpy(np->name,str);

 np->def = val;

 np->def2 = 1;  /* defined for this pass=Pass  ver TER_2.0 */

 np->Lnext = NULL;

        np->Rnext = NULL;

           lp = (struct link *) alloc(sizeof(struct link));

           np->L_list = lp;

           lp->L_num = Line_num;

           lp->next = NULL;

        p = root;

          backp = NULL;

           while (p != NULL)

            {

              backp = p;

              i = strcmp (str,p->name);

               if (i<0)

                   p=p->Lnext;

                  else p=p->Rnext;

            }

          if (backp == NULL)

              root = np;

             else if (strcmp(str,backp->name)<0)

                  backp->Lnext = np;

                 else backp->Rnext = np;

          return (YES);

}

/*

 *      lookup --- find string in symbol table

 */

struct nlist *

lookup(name)

char    *name;

{

 struct nlist *np;

 int     i;

 char   *c;     /* ver TER_2.0 */

 c = name;      /* copy symbol pointer */

 while(alphan(*c))      /* search for end of symbol */

  c++;  /* next char */

 *c = EOS;      /* disconnect anything after for good compare */

                /* end of mods for ver TER_2.0 */

        np = root;      /* and now go on and look for symbol */

         while (np != NULL)

          {

            i = strcmp(name,np->name);

             if (i == 0)

               {

                 Last_sym = np->def;

                 return (np);

               }

             else if (i < 0)

                 np = np->Lnext;

                else np = np->Rnext;

          }

      Last_sym = 0;

/*      if (Pass == 2)

        error ("symbol Undefined on pass 2"); */

                /* commented out ver TER_2.0 2 Jul 89 */

                /* function used in IFD */

        return (NULL);

}

#define NMNE (sizeof(table)/ sizeof(struct oper))

#define NPSE (sizeof(pseudo)/ sizeof(struct oper))

/*

 *      mne_look --- mnemonic lookup

 *

 *      Return pointer to an oper structure if found.

 *      Searches both the machine mnemonic table and the pseudo table.

 */

struct oper *

mne_look(str)

char    *str;

{

 struct oper *low,*high,*mid;

 int     cond;

 /* Search machine mnemonics first */

 low =  &table[0];

 high = &table[ NMNE-1 ];

 while (low <= high){

  mid = low + (high-low)/2;

  if( ( cond = strcmp(str,mid->mnemonic)) < 0)

   high = mid - 1;

  else if (cond > 0)

   low = mid + 1;

  else

   return(mid);

 }

 /* Check for pseudo ops */

 low =  &pseudo[0];

 high = &pseudo[ NPSE-1 ];

 while (low <= high){

  mid = low + (high-low)/2;

  if( ( cond = strcmp(str,mid->mnemonic)) < 0)

   high = mid - 1;

  else if (cond > 0)

   low = mid + 1;

  else

   return(mid);

 }

 return(NULL);

}