/* This file is in the public domain. */

#define NEED_EXTERN
#include "instrtbl.h"

#include "pdp11.h"
#include "disas.h"
#include "deftbl.h"

static int adjust_adjacent(int dtx, INSTR_OPS opfwant)
{
 int dtx2;

 for (dtx2=dtx;(dtx2>=0)&&(instr_defs[dtx2].value==instr_defs[dtx].value);dtx2--) if (instr_defs[dtx2].ops_format == opfwant) return(dtx2);
 for (dtx2=dtx;(dtx2<instr_def_n)&&(instr_defs[dtx2].value==instr_defs[dtx].value);dtx2++) if (instr_defs[dtx2].ops_format == opfwant) return(dtx2);
 bugchk("adjust_adjacent can't find it");
}

static int disas_r(int rno)
{
 static const char *rnames[] = { "r0", "r1", "r2", "r3", "r4", "r5", "sp", "pc" };

 put_s(rnames[rno&7]);
 return(strlen(rnames[rno&7]));
}

static int disas_g(int op, word *pcp)
{
 int n;

 n = 0;
 switch (op & 070)
  { case 000:
       n += disas_r(op);
       break;
    case 010:
       put('(');
       n ++;
       n += disas_r(op);
       put(')');
       n ++;
       break;
    case 020:
       if ((op & 7) == 7)
	{ put('#');
	  n ++;
	  put_6(fetchword(*pcp,MMAN_ISPACE));
	  n += 6;
	  *pcp = (*pcp + 2) & 0xffff;
	}
       else
	{ put('(');
	  n ++;
	  n += disas_r(op);
	  put_s(")+");
	  n += 2;
	}
       break;
    case 030:
       if ((op & 7) == 7)
	{ put_s("@#");
	  n += 2;
	  put_6(fetchword(*pcp,MMAN_ISPACE));
	  n += 6;
	  *pcp = (*pcp + 2) & 0xffff;
	}
       else
	{ put_s("@(");
	  n += 2;
	  n += disas_r(op);
	  put_s(")+");
	  n += 2;
	}
       break;
    case 040:
       put_s("-(");
       n += 2;
       n += disas_r(op);
       put(')');
       n ++;
       break;
    case 050:
       put_s("@-(");
       n += 3;
       n += disas_r(op);
       put(')');
       n ++;
       break;
    case 060:
       if ((op & 7) == 7)
	{ put_6(fetchword(*pcp,MMAN_ISPACE)+2+*pcp);
	  n += 6;
	  *pcp = (*pcp + 2) & 0xffff;
	}
       else
	{ put_6(fetchword(*pcp,MMAN_ISPACE));
	  n += 6;
	  *pcp = (*pcp + 2) & 0xffff;
	  put('(');
	  n ++;
	  n += disas_r(op);
	  put(')');
	  n ++;
	}
       break;
    case 070:
       if ((op & 7) == 7)
	{ put('@');
	  n ++;
	  put_6(fetchword(*pcp,MMAN_ISPACE)+2+*pcp);
	  n += 6;
	  *pcp = (*pcp + 2) & 0xffff;
	}
       else
	{ put('@');
	  n ++;
	  put_6(fetchword(*pcp,MMAN_ISPACE));
	  n += 6;
	  *pcp = (*pcp + 2) & 0xffff;
	  put('(');
	  n ++;
	  n += disas_r(op);
	  put(')');
	  n ++;
	}
       break;
  }
 return(n);
}

static int disas_fr(int rno)
{
 static const char *rnames[] = { "f0", "f1", "f2", "f3", "f4", "f5", "?f6?", "?f7?" };

 put_s(rnames[rno&7]);
 return(strlen(rnames[rno&7]));
}

static int disas_f(int op, word *pcp)
{
 int n;

 n = 0;
 switch (op & 070)
  { case 000:
       n += disas_fr(op);
       break;
    case 010:
       put('(');
       n ++;
       n += disas_r(op);
       put(')');
       n ++;
       break;
    case 020:
       if ((op & 7) == 7)
	{ put_s("#0x");
	  n += 3;
	  if (fps & FPS_FD)
	   { unsigned long int fl;
	     unsigned long int fh;
	     fl = 0xffff && (unsigned long int) fetchword(*pcp,MMAN_ISPACE);
	     *pcp = (*pcp + 2) & 0xffff;
	     fl |= (0xffff && (unsigned long int) fetchword(*pcp,MMAN_ISPACE)) << 16;
	     *pcp = (*pcp + 2) & 0xffff;
	     fh = 0xffff && (unsigned long int) fetchword(*pcp,MMAN_ISPACE);
	     *pcp = (*pcp + 2) & 0xffff;
	     fh |= (0xffff && (unsigned long int) fetchword(*pcp,MMAN_ISPACE)) << 16;
	     *pcp = (*pcp + 2) & 0xffff;
	     put_x8(fh);
	     put_x8(fl);
	     n += 16;
	   }
	  else
	   { unsigned long int f;
	     f = 0xffff && (unsigned long int) fetchword(*pcp,MMAN_ISPACE);
	     *pcp = (*pcp + 2) & 0xffff;
	     f |= (0xffff && (unsigned long int) fetchword(*pcp,MMAN_ISPACE)) << 16;
	     *pcp = (*pcp + 2) & 0xffff;
	     put_x8(f);
	     n += 8;
	   }
	}
       else
	{ put('(');
	  n ++;
	  n += disas_r(op);
	  put_s(")+");
	  n += 2;
	}
       break;
    case 030:
       if ((op & 7) == 7)
	{ put_s("@#");
	  n += 2;
	  put_6(fetchword(*pcp,MMAN_ISPACE));
	  n += 6;
	  *pcp = (*pcp + 2) & 0xffff;
	}
       else
	{ put_s("@(");
	  n += 2;
	  n += disas_r(op);
	  put_s(")+");
	  n += 2;
	}
       break;
    case 040:
       put_s("-(");
       n += 2;
       n += disas_r(op);
       put(')');
       n ++;
       break;
    case 050:
       put_s("@-(");
       n += 3;
       n += disas_r(op);
       put(')');
       n ++;
       break;
    case 060:
       if ((op & 7) == 7)
	{ put_6(fetchword(*pcp,MMAN_ISPACE)+2+*pcp);
	  n += 6;
	  *pcp = (*pcp + 2) & 0xffff;
	}
       else
	{ put_6(fetchword(*pcp,MMAN_ISPACE));
	  n += 6;
	  *pcp = (*pcp + 2) & 0xffff;
	  put('(');
	  n ++;
	  n += disas_r(op);
	  put(')');
	  n ++;
	}
       break;
    case 070:
       if ((op & 7) == 7)
	{ put('@');
	  n ++;
	  put_6(fetchword(*pcp,MMAN_ISPACE)+2+*pcp);
	  n += 6;
	  *pcp = (*pcp + 2) & 0xffff;
	}
       else
	{ put('@');
	  n ++;
	  put_6(fetchword(*pcp,MMAN_ISPACE));
	  n += 6;
	  *pcp = (*pcp + 2) & 0xffff;
	  put('(');
	  n ++;
	  n += disas_r(op);
	  put(')');
	  n ++;
	}
       break;
  }
 return(n);
}

int disas(word addr)
{
 word inst;
 int dtx;
 int i;
 word pctemp;
 word a;
 int nw;

 put_6(addr);
 put_s(": ");
 inst = fetchword(addr,MMAN_ISPACE);
 dtx = get_deftbl(inst);
 pctemp = (addr + 2) & 0xffff;
 if (dtx == DEF_UNUSED)
  { put_s(".word   ");
    put_6(inst);
  }
 else
  { switch (instr_defs[dtx].ops_format)
     { case OPS_F0:
	  if (fps & FPS_FD) dtx = adjust_adjacent(dtx,OPS_D0);
	  break;
       case OPS_FA6_F0:
	  if (fps & FPS_FD) dtx = adjust_adjacent(dtx,OPS_FA6_D0);
	  break;
       case OPS_F0_FA6:
	  if (fps & FPS_FD) dtx = adjust_adjacent(dtx,OPS_D0_FA6);
	  break;
       case OPS_D0:
	  if (! (fps & FPS_FD)) dtx = adjust_adjacent(dtx,OPS_F0);
	  break;
       case OPS_FA6_D0:
	  if (! (fps & FPS_FD)) dtx = adjust_adjacent(dtx,OPS_FA6_F0);
	  break;
       case OPS_D0_FA6:
	  if (! (fps & FPS_FD)) dtx = adjust_adjacent(dtx,OPS_F0_FA6);
	  break;
       default:
	  break;
     }
    put_s(instr_defs[dtx].name);
    for (i=strlen(instr_defs[dtx].name);i<8;i++) put(' ');
    nw = 0;
    switch (instr_defs[dtx].ops_format)
     { case OPS_NONE:
	  break;
       case OPS_G0:
	  nw += disas_g(inst,&pctemp);
	  break;
       case OPS_R0:
	  nw += disas_r(inst);
	  break;
       case OPS_O30:
	  put('0'+(inst&7));
	  nw ++;
	  break;
       case OPS_B80:
	  put_6(pctemp+((inst&0xff)<<1)+((inst&0x80)?0xfe00:0));
	  nw += 6;
	  break;
       case OPS_R6_G0:
	  nw += disas_r(inst>>6);
	  put(',');
	  nw ++;
	  nw += disas_g(inst,&pctemp);
	  break;
       case OPS_G0_R6:
	  nw += disas_g(inst,&pctemp);
	  put(',');
	  nw ++;
	  nw += disas_r(inst>>6);
	  break;
       case OPS_G6_G0:
	  nw += disas_g(inst>>6,&pctemp);
	  put(',');
	  nw ++;
	  nw += disas_g(inst,&pctemp);
	  break;
       case OPS_R6_B60:
	  nw += disas_r(inst>>6);
	  put(',');
	  nw ++;
	  put_6(pctemp-((inst&077)<<1));
	  nw += 6;
	  break;
       case OPS_O80:
	  put_3(inst);
	  nw += 3;
	  break;
       case OPS_O60:
	  put_2(inst);
	  nw += 2;
	  break;
       case OPS_F0:
       case OPS_D0:
	  nw += disas_f(inst,&pctemp);
	  break;
       case OPS_FA6_F0:
       case OPS_FA6_D0:
	  nw += disas_fr((inst>>6)&3);
	  put(',');
	  nw ++;
	  nw += disas_f(inst,&pctemp);
	  break;
       case OPS_F0_FA6:
       case OPS_D0_FA6:
	  nw += disas_f(inst,&pctemp);
	  put(',');
	  nw ++;
	  nw += disas_fr((inst>>6)&3);
	  break;
       case OPS_FA6_G0:
	  nw += disas_fr((inst>>6)&3);
	  put(',');
	  nw ++;
	  nw += disas_g(inst,&pctemp);
	  break;
       case OPS_G0_FA6:
	  nw += disas_g(inst,&pctemp);
	  put(',');
	  nw ++;
	  nw += disas_fr((inst>>6)&3);
	  break;
       default:
	  bugchk("bad ops_format %d",(int)instr_defs[dtx].ops_format);
	  break;
     }
    put(' ');
    nw ++;
    for (;nw<24;nw++) put(' ');
    for (;nw%8;nw++) put(' ');
    for (a=addr;a!=pctemp;a=(a+2)&0xffff)
     { put((a==addr)?'[':' ');
       put_6(fetchword(a,MMAN_ISPACE));
     }
    put(']');
  }
 return((pctemp-addr)&0xffff);
}