/* rabadr.c */

/*
 *  Copyright (C) 1989-2009  Alan R. Baldwin
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *
 * Alan R. Baldwin
 * 721 Berkeley St.
 * Kent, Ohio  44240
 * 
 * ported to the Rabbit2000 by
 * Ulrich Raich and Razaq Ijoduola
 * PS Division
 * CERN
 * CH-1211 Geneva-23
 * email: Ulrich dot Raich at cern dot ch
 */

/*
 * Extensions: P. Felber
 *
 * Altered by Leland Morrison to support rabbit 2000 
 *   and rabbit 4000 instruction sets (2011)
 */

#include "asxxxx.h"
#include "rab.h"

/*
 * Read an address specifier. Pack the
 * address information into the supplied
 * `expr' structure. Return the mode of
 * the address.
 *
 * This addr(esp) routine performs the following addressing decoding:
 *
 *      address         mode            flag            addr            base
 *      #n              S_IMMED         0               n               NULL
 *      label           s_type          ----            s_addr          s_area
 *      [REG]           S_IND+icode     0               0               NULL
 *      [label]         S_INDM          ----            s_addr          s_area
 *      offset[REG]     S_IND+icode     ----            offset          ----
 */
int
addr(esp)
struct expr *esp;
{
        int c, mode, indx;

        if ((c = getnb()) == '#') {
                expr(esp, 0);
                esp->e_mode = S_IMMED;
#if 0
                /* ljm - leading digit is used for offset for dd(ix|iy|sp) */
        } else if ((c == '-') || ((c >= '0') && (c <= '9'))) {
          unget(c);
          expr(esp, 0);
          esp->e_mode = S_IMMED;
#endif
        } else
        if (c == LFIND) {
          /* ljm comment -
           *      '(' number ')'   
           *  or  '(' register=[hl,ix,iy,sp,bc,de] ')'
           *     ref to memory, scan the next 'symbol' to see if
           *     it is a register or an absolute address
           */
                if ((indx = admode(R8)) != 0) {
                        mode = S_INDB;
                } else
                if ((indx = admode(R8X)) != 0) {
                        mode = S_R8X;
                        aerr();
                } else
                if ((indx = admode(R16X)) != 0) {
                        mode = S_R16X;
                        aerr();
                } else
                if ((indx = admode(R16)) != 0) {
                        mode = S_INDR;
                } else {
                        mode = S_INDM;
                        expr(esp, 0);
                        esp->e_mode = mode;
                }
                if (indx) {
                        esp->e_mode = (mode + indx)&0xFF;
                        esp->e_base.e_ap = NULL;
                }
                /* ljm comment -
                 *   flag an error if the closing paren is absent
                 */
                if ((c = getnb()) != RTIND) {
                        qerr();
                }
        } else {
                unget(c);
          /* ljm -
           *   cases:
           *     register
           *     symbol
           *     symbol(register)
           *     number
           *     number(register)
           *
           * scan the list(s) of registers to see if the
           * name matches the name of one of the processor
           * registers
           */
                if ((indx = admode(R8)) != 0) {
                        mode = S_R8;
                } else
                if ((indx = admode(R8X)) != 0) {
                        mode = S_R8X;
                } else
                if ((indx = admode(R16X)) != 0) {
                        mode = S_R16X;
                } else
                if ((indx = admode(R16)) != 0) {
                        mode = S_R16;
                } else
                if ((indx = admode(R32_JKHL)) != 0) {
                        mode = S_R32_JKHL;
                } else
                if ((indx = admode(R32_BCDE)) != 0) {
                        mode = S_R32_BCDE;
                } else
                if ((indx = admode(RXPC)) != 0) {
                        mode = S_RXPC;
                } else {
                        mode = S_USER;
                        expr(esp, 0);
                        esp->e_mode = mode;
                }
                if (indx) {
                        esp->e_addr = indx&0xFF;
                        esp->e_mode = mode;
                        esp->e_base.e_ap = NULL;
                }
                if ((c = getnb()) == LFIND) {
                        indx = admode(R16);
                        if ((indx&0xFF)==IX || (indx&0xFF)==IY ||
                            (indx&0xFF)==SP)
                        {
                          esp->e_mode = S_INDR + (indx&0xFF);
                        } else if ( (indx&0xFF)==HL ) {
                          esp->e_mode = S_IDHL_OFFSET;
                        } else {
                                aerr();
                        }
                        if ((c = getnb()) != RTIND)
                                qerr();
                } else {
                        unget(c);
                }
        }
        return (esp->e_mode);
}

/*
 * Enter admode() to search a specific addressing mode table
 * for a match. Return the addressing value on a match or
 * zero for no match.
 */
int
admode(sp)
struct adsym *sp;
{
        char *ptr;
        int i;
        char *ips;

        ips = ip;
        unget(getnb());

        i = 0;
        while ( *(ptr = &sp[i].a_str[0]) ) {
                if (srch(ptr)) {
                        return(sp[i].a_val);
                }
                i++;
        }
        ip = ips;
        return(0);
}

/*
 *      srch --- does string match ?
 */
int
srch(str)
char *str;
{
        char *ptr;
        ptr = ip;

        while (*ptr && *str) {
                if (ccase[*ptr & 0x007F] != ccase[*str & 0x007F])
                        break;
                ptr++;
                str++;
        }
        if (ccase[*ptr & 0x007F] == ccase[*str  & 0x007F]) {
                ip = ptr;
                return(1);
        }

        if (!*str) {
                if (!(ctype[*ptr & 0x007F] & LTR16)) {
                        ip = ptr;
                        return(1);
                }
        }
        return(0);
}

/*
 * Registers
 */

struct  adsym   R8[] = {
    {   "b",    B|0400  },
    {   "c",    C|0400  },
    {   "d",    D|0400  },
    {   "e",    E|0400  },
    {   "h",    H|0400  },
    {   "l",    L|0400  },
    {   "a",    A|0400  },
    {   "",     0000    }
};

struct  adsym   R8X[] = {
    {   "eir",  EIR|0400},
    {   "iir",  IIR|0400},
    {   "",     0000    }
};

struct  adsym   R8IP[] = {
    {   "ip",   IP|0400 },
    {   "",     0000    }
};

struct  adsym   R16[] = {
    {   "bc",   BC|0400 },
    {   "de",   DE|0400 },
    {   "hl",   HL|0400 },
    {   "sp",   SP|0400 },
    {   "ix",   IX|0400 },
    {   "iy",   IY|0400 },
    {   "",     0000    }
};

struct  adsym   R16X[] = {
    {   "af'",  AF|0400 },      /* af' must be first !!! */
    {   "af",   AF|0400 },
    {   "",     0000    }
};

struct  adsym   R32_BCDE[] = {
  {   "bcde",   BCDE|0400 },
  {   "",       0000      }
};

struct  adsym   R32_JKHL[] = {
  {   "jkhl",   JKHL|0400 },
  {   "",       0000      }
};

struct  adsym   RXPC[] = {
  {   "xpc",    1|0400  },
  {   "",       0000    }
};

/*
 * Conditional definitions
 */

struct  adsym   CND[] = {
    {   "NZ",   NZ|0400 },
    {   "Z",    Z |0400 },
    {   "NC",   NC|0400 },
    {   "C",    CS|0400 },
    {   "LZ",   PO|0400 },
    {   "LO",   PE|0400 },
    {   "P",    P |0400 },
    {   "M",    M |0400 },
    {   "",     0000    }
};

struct  adsym   ALT_CND[] = {
    {   "GT",   CC_GT|0400  },
    {   "GTU",  CC_GTU|0400 },
    {   "LT",   CC_LT|0400  },
    {   "V",    CC_V |0400  },
    {   "NZ",   CC_NZ|0400  },
    {   "Z",    CC_Z |0400  },
    {   "NC",   CC_NC|0400  },
    {   "C",    CC_C |0400  },
    {   "",     0000        }
};
