mach/proto/cg/move.c

   1 #ifndef NORCSID
   2 static char rcsid[] = "$Id: move.c,v 2.5 1994/06/24 13:23:53 ceriel Exp $";
   3 #endif
   4
   5 #include "assert.h"
   6 #include "param.h"
   7 #include "tables.h"
   8 #include "types.h"
   9 #include <cg_pattern.h>
  10 #include "data.h"
  11 #include "result.h"
  12 #include "extern.h"
  13
  14 /*
  15  * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
  16  * See the copyright notice in the ACK home directory, in the file "Copyright".
  17  *
  18  * Author: Hans van Staveren
  19  */
  20
  21 unsigned costcalc();
  22
  23 move(tp1,tp2,ply,toplevel,maxcost) token_p tp1,tp2; unsigned maxcost; {
  24         register move_p mp;
  25         register unsigned t;
  26         register struct reginfo *rp;
  27         tkdef_p tdp;
  28         int i;
  29         unsigned codegen();
  30
  31         if (eqtoken(tp1,tp2))
  32                 return(0);
  33         if (tp2->t_token == -1) {
  34                 if (tp1->t_token == -1) {
  35                         if (eqtoken(&machregs[tp1->t_att[0].ar].r_contents,
  36                                     &machregs[tp2->t_att[0].ar].r_contents) &&
  37                               machregs[tp1->t_att[0].ar].r_contents.t_token!=0)
  38                                 return(0);
  39                         if (tp1->t_att[0].ar!=1) { /* COCO reg; tmp kludge */
  40                                 erasereg(tp2->t_att[0].ar);
  41                                 machregs[tp2->t_att[0].ar].r_contents =
  42                                   machregs[tp1->t_att[0].ar].r_contents ;
  43                         } else
  44                                 machregs[tp1->t_att[0].ar].r_contents =
  45                                   machregs[tp2->t_att[0].ar].r_contents ;
  46                 } else {
  47                         if (eqtoken(&machregs[tp2->t_att[0].ar].r_contents,tp1))
  48                                 return(0);
  49                         erasereg(tp2->t_att[0].ar);
  50                         machregs[tp2->t_att[0].ar].r_contents = *tp1;
  51                 }
  52                 for (rp=machregs;rp<machregs+NREGS;rp++) {
  53                         if (rp->r_contents.t_token == 0)
  54                                 continue;
  55                         assert(rp->r_contents.t_token > 0);
  56                         tdp = &tokens[rp->r_contents.t_token];
  57                         for (i=0;i<TOKENSIZE;i++)
  58                                 if (tdp->t_type[i] == EV_REG &&
  59                                     clash(rp->r_contents.t_att[i].ar,tp2->t_att[0].ar)) {
  60                                         erasereg((int)(rp-machregs));
  61                                         break;
  62                                 }
  63                 }
  64         } else if (tp1->t_token == -1) {
  65                 if (eqtoken(tp2,&machregs[tp1->t_att[0].ar].r_contents))
  66                         return(0);
  67                 machregs[tp1->t_att[0].ar].r_contents = *tp2;
  68         }
  69         /*
  70          * If we arrive here the move must really be executed
  71          */
  72         for (mp=moves;mp<moves+NMOVES;mp++) {
  73                 if (!match(tp1,&machsets[mp->m_set1],mp->m_expr1))
  74                         continue;
  75                 if (match(tp2,&machsets[mp->m_set2],mp->m_expr2))
  76                         break;
  77                 /*
  78                  * Correct move rule is found
  79                  */
  80         }
  81         assert(mp<moves+NMOVES);
  82         /*
  83          * To get correct interpretation of things like %[1]
  84          * in move code we stack tp2 and tp1. This little trick
  85          * saves a lot of testing in other places.
  86          */
  87
  88         if (mp->m_cindex!=0) {
  89                 fakestack[stackheight] = *tp2;
  90                 fakestack[stackheight+1] = *tp1;
  91                 stackheight += 2;
  92                 t = codegen(&coderules[mp->m_cindex],ply,toplevel,maxcost,0);
  93                 if (t <= maxcost)
  94                         t += costcalc(mp->m_cost);
  95                 stackheight -= 2;
  96         } else {
  97                 t = 0;
  98         }
  99         return(t);
 100 }