mach/6800/as/mach5.c

   1 /*
   2  * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
   3  * See the copyright notice in the ACK home directory, in the file "Copyright".
   4  */
   5 #define RCSID5 "$Id: mach5.c,v 3.3 1994/06/24 12:55:23 ceriel Exp $"
   6
   7 /*
   8  * Motorola 6800 special routines
   9  */
  10
  11 branch(opc,exp) register opc; expr_t exp; {
  12         register sm, dist;
  13         int saving;
  14
  15         dist = exp.val - (DOTVAL + 2);
  16         if (pass == PASS_2 && dist > 0 && !(exp.typ & S_DOT))
  17                 dist -= DOTGAIN;
  18         sm = fitb(dist);
  19         if ((exp.typ & ~S_DOT) != DOTTYP)
  20                 sm = 0;
  21         if (opc == 0x8D || opc == 0x20)
  22                 saving = 1;
  23         else
  24                 saving = 3;
  25         if (small(sm,saving)) {
  26                 emit1(opc);
  27                 emit1(dist);
  28         } else {
  29                 if (opc == 0x8D)                /* bsr */
  30                         emit1(0xBD);            /* jsr */
  31                 else {
  32                         if (opc != 0x20) {      /* bra */
  33
  34                                         /* reverse condition : */
  35
  36                                 emit1(opc ^ 1);
  37                                 emit1(3);
  38                         }
  39                         emit1(0x7E);            /* jmp */
  40                 }
  41 #ifdef RELOCATION
  42                 newrelo(exp.typ, RELO2 | RELBR);
  43 #endif
  44                 emit2(exp.val);
  45         }
  46 }