Subversion Repositories eco32

/*

 * instr.c -- instruction encoding

 */

#include "common.h"

#include "stdarg.h"

#include "romlib.h"

#include "instr.h"

/*

 * This is the ECO32 machine instruction set.

 * The table below needs no particular order

 * and may have gaps in the instruction encoding.

 */

Instr instrTbl[] = {

  { "add",   FORMAT_RRY, OP_ADD  },

  { "sub",   FORMAT_RRY, OP_SUB  },

  { "mul",   FORMAT_RRY, OP_MUL  },

  { "mulu",  FORMAT_RRX, OP_MULU },

  { "div",   FORMAT_RRY, OP_DIV  },

  { "divu",  FORMAT_RRX, OP_DIVU },

  { "rem",   FORMAT_RRY, OP_REM  },

  { "remu",  FORMAT_RRX, OP_REMU },

  { "and",   FORMAT_RRX, OP_AND  },

  { "or",    FORMAT_RRX, OP_OR   },

  { "xor",   FORMAT_RRX, OP_XOR  },

  { "xnor",  FORMAT_RRX, OP_XNOR },

  { "sll",   FORMAT_RRX, OP_SLL  },

  { "slr",   FORMAT_RRX, OP_SLR  },

  { "sar",   FORMAT_RRX, OP_SAR  },

  { "ldhi",  FORMAT_RHH, OP_LDHI },

  { "beq",   FORMAT_RRB, OP_BEQ  },

  { "bne",   FORMAT_RRB, OP_BNE  },

  { "ble",   FORMAT_RRB, OP_BLE  },

  { "bleu",  FORMAT_RRB, OP_BLEU },

  { "blt",   FORMAT_RRB, OP_BLT  },

  { "bltu",  FORMAT_RRB, OP_BLTU },

  { "bge",   FORMAT_RRB, OP_BGE  },

  { "bgeu",  FORMAT_RRB, OP_BGEU },

  { "bgt",   FORMAT_RRB, OP_BGT  },

  { "bgtu",  FORMAT_RRB, OP_BGTU },

  { "j",     FORMAT_J,   OP_J    },

  { "jr",    FORMAT_JR,  OP_JR   },

  { "jal",   FORMAT_J,   OP_JAL  },

  { "jalr",  FORMAT_JR,  OP_JALR },

  { "trap",  FORMAT_N,   OP_TRAP },

  { "rfx",   FORMAT_N,   OP_RFX  },

  { "ldw",   FORMAT_RRS, OP_LDW  },

  { "ldh",   FORMAT_RRS, OP_LDH  },

  { "ldhu",  FORMAT_RRS, OP_LDHU },

  { "ldb",   FORMAT_RRS, OP_LDB  },

  { "ldbu",  FORMAT_RRS, OP_LDBU },

  { "stw",   FORMAT_RRS, OP_STW  },

  { "sth",   FORMAT_RRS, OP_STH  },

  { "stb",   FORMAT_RRS, OP_STB  },

  { "mvfs",  FORMAT_RH,  OP_MVFS },

  { "mvts",  FORMAT_RH,  OP_MVTS },

  { "tbs",   FORMAT_N,   OP_TBS  },

  { "tbwr",  FORMAT_N,   OP_TBWR },

  { "tbri",  FORMAT_N,   OP_TBRI },

  { "tbwi",  FORMAT_N,   OP_TBWI }

};

Instr *instrCodeTbl[64];

static int instrCompare(const void *instr1, const void *instr2) {

  return strcmp(((Instr *) instr1)->name, ((Instr *) instr2)->name);

}

void initInstrTable(void) {

  int i;

  /* first sort instruction table alphabetically */

  qsort(instrTbl, sizeof(instrTbl)/sizeof(instrTbl[0]),

        sizeof(instrTbl[0]), instrCompare);

  /* then initialize instruction code table */

  for (i = 0; i < 64; i++) {

    instrCodeTbl[i] = NULL;

  }

  for (i = 0; i < sizeof(instrTbl)/sizeof(instrTbl[0]); i++) {

    instrCodeTbl[instrTbl[i].opcode] = &instrTbl[i];

    if (instrTbl[i].format == FORMAT_RRX ||

        instrTbl[i].format == FORMAT_RRY) {

      /* enter the immediate variant of this instruction also */

      instrCodeTbl[instrTbl[i].opcode + 1] = &instrTbl[i];

    }

  }

}

Instr *lookupInstr(char *name) {

  int lo, hi, tst;

  int res;

  lo = 0;

  hi = sizeof(instrTbl) / sizeof(instrTbl[0]) - 1;

  while (lo <= hi) {

    tst = (lo + hi) / 2;

    res = strcmp(instrTbl[tst].name, name);

    if (res == 0) {

      return &instrTbl[tst];

    }

    if (res < 0) {

      lo = tst + 1;

    } else {

      hi = tst - 1;

    }

  }

  return NULL;

}