src/edu/berkeley/fleet/ies44/InstructionEncoder.java

   1 package edu.berkeley.fleet.ies44;
   2 import edu.berkeley.fleet.api.*;
   3 import edu.berkeley.fleet.*;
   4 import java.io.*;
   5 import static edu.berkeley.fleet.ies44.BitManipulations.*;
   6
   7 public abstract class InstructionEncoder {
   8
   9     public static final int WIDTH_WORD          = 37;   /* word width */
  10     public static final int WIDTH_CODEBAG_SIZE  = 6;
  11     public static final int WIDTH_PUMP_ADDR     = 11;
  12     public static final int WIDTH_DEST_ADDR     = 11;
  13     public static final int WIDTH_COUNT         = 7;
  14
  15     public static final int OFFSET_COUNT        = 0;
  16     public static final int OFFSET_DEST         = OFFSET_COUNT+WIDTH_COUNT;
  17     public static final int OFFSET_CONTROL      = OFFSET_DEST+WIDTH_DEST_ADDR;
  18     public static final int OFFSET_RQ           = OFFSET_CONTROL+0;
  19     public static final int OFFSET_TO           = OFFSET_CONTROL+1;
  20     public static final int OFFSET_DO           = OFFSET_CONTROL+2;
  21     public static final int OFFSET_DL           = OFFSET_CONTROL+3;
  22     public static final int OFFSET_DI           = OFFSET_CONTROL+4;
  23     public static final int OFFSET_TI           = OFFSET_CONTROL+5;
  24     public static final int OFFSET_PUMP_ADDR    = OFFSET_TI+1;
  25
  26     /** get the bits describing this box's location on the DESTINATION HORN */
  27     protected abstract long getDestAddr(Destination box);
  28
  29     /** get the bits describing this box's location on the INSTRUCTION HORN */
  30     protected abstract long getBoxInstAddr(Pump box);
  31
  32     /** given an INSTRUCTION HORN address, retrieve the corresponding Pump object */
  33     protected abstract Pump getBoxByInstAddr(long dest);
  34
  35     /** given a DESTINATION HORN address, retrieve the corresponding Pump object */
  36     protected abstract Destination getDestByAddr(long dest);
  37
  38     /** read a machine-formatted instruction from a file (into a Java object) */
  39     public Instruction readInstruction(DataInputStream is) throws IOException {
  40         long inst = 0;
  41         try {
  42             inst = (inst << 8) | (is.readByte() & 0xff);
  43             inst = (inst << 8) | (is.readByte() & 0xff);
  44             inst = (inst << 8) | (is.readByte() & 0xff);
  45             inst = (inst << 8) | (is.readByte() & 0xff);
  46             inst = (inst << 8) | (is.readByte() & 0xff);
  47             inst = (inst << 8) | (is.readByte() & 0xff);
  48             return readInstruction(inst);
  49         } catch (EOFException eof) {
  50             return null;
  51         }
  52     }
  53
  54     public Instruction readInstruction(long instr) {
  55         long inst = instr;
  56         switch((int)getField(WIDTH_WORD-1, WIDTH_WORD-2, inst)) {
  57             case 0: {
  58                 Pump name    = getBoxByInstAddr(getIntField(OFFSET_PUMP_ADDR+WIDTH_PUMP_ADDR-1, OFFSET_PUMP_ADDR, inst));
  59                 Destination dest = getDestByAddr   (getIntField(OFFSET_DEST+WIDTH_DEST_ADDR-1,      OFFSET_DEST,      inst));
  60                 int count        = getIntField(                 OFFSET_COUNT+WIDTH_COUNT-1,         OFFSET_COUNT,     inst);
  61                 boolean tokenIn     = getBit(OFFSET_TI, instr);
  62                 boolean dataIn      = getBit(OFFSET_DI, instr);
  63                 boolean latch       = getBit(OFFSET_DL, instr);
  64                 boolean dataOut     = getBit(OFFSET_DO, instr);
  65                 boolean tokenOut    = getBit(OFFSET_TO, instr);
  66                 boolean requeue     = getBit(OFFSET_RQ, instr);
  67                 boolean dataOutDest = dataOut && tokenOut;
  68                 if (latch & !dataIn) return new Instruction.Kill(name, count, tokenIn);
  69                 return new Instruction.Executable(name, dest, count, tokenIn, dataIn, latch, dataOutDest,
  70                                                   dataOut, tokenOut, requeue);
  71             }
  72
  73             case 1: {
  74                 Destination name = getDestByAddr(getField(WIDTH_WORD-3, WIDTH_WORD-3-WIDTH_DEST_ADDR+1, inst));
  75                 long offset = getSignedField(WIDTH_WORD-3-WIDTH_DEST_ADDR, WIDTH_CODEBAG_SIZE, instr);
  76                 long size   = getSignedField(WIDTH_CODEBAG_SIZE-1,        0,                 instr);
  77                 return new Instruction.Literal.CodeBagDescriptor(name, offset, size);
  78             }
  79
  80             case 2: {
  81                 Destination name = getDestByAddr(getField(WIDTH_WORD-3, WIDTH_WORD-3-WIDTH_PUMP_ADDR+1, inst));
  82                 return new Instruction.Literal.Absolute(name, getSignedField(WIDTH_WORD-3-WIDTH_PUMP_ADDR, 0, instr));
  83             }
  84
  85             case 3: {
  86                 Destination name = getDestByAddr(getField(WIDTH_WORD-3, WIDTH_WORD-3-WIDTH_PUMP_ADDR+1, inst));
  87                 return new Instruction.Literal.Relative(name, getSignedField(WIDTH_WORD-3-WIDTH_PUMP_ADDR, 0, instr));
  88             }
  89
  90         }
  91         return null;
  92
  93     }
  94
  95     public long writeInstruction(Instruction d) {
  96         long instr = 0;
  97
  98         // Kill is encoded as Execute with the illegal combination (Latch & ~DataIn)
  99         if (d instanceof Instruction.Kill) {
 100             Instruction.Kill k = (Instruction.Kill)d;
 101             d = new Instruction.Executable(k.pump, null, k.count, k.killOnlyStandingInstructions,
 102                                            false, true, false, false, false, false);
 103         }
 104
 105         if (d instanceof Instruction.Executable) {
 106             Instruction.Executable inst = (Instruction.Executable)d;
 107             instr |= putField(OFFSET_PUMP_ADDR+WIDTH_PUMP_ADDR-1, OFFSET_PUMP_ADDR,   getBoxInstAddr(inst.pump));
 108             instr |= putField(OFFSET_DEST+WIDTH_DEST_ADDR-1,      OFFSET_DEST,        inst.dest==null?0:getDestAddr(inst.dest));
 109             instr |= putField(OFFSET_COUNT+WIDTH_COUNT-1,         OFFSET_COUNT,       inst.count);
 110             instr |= putField(OFFSET_TI,                          OFFSET_TI,          inst.tokenIn?1:0);
 111             instr |= putField(OFFSET_DI,                          OFFSET_DI,          inst.dataIn?1:0);
 112             instr |= putField(OFFSET_DL,                          OFFSET_DL,          inst.latch?1:0);
 113             instr |= putField(OFFSET_DO,                          OFFSET_DO,          (inst.dataOutDest||inst.dataOut)?1:0);
 114             instr |= putField(OFFSET_TO,                          OFFSET_TO,          (inst.dataOutDest||inst.tokenOut)?1:0);
 115             instr |= putField(OFFSET_RQ,                          OFFSET_RQ,          inst.requeue?1:0);
 116
 117         } else if (d instanceof Instruction.Literal.CodeBagDescriptor) {
 118             Instruction.Literal.CodeBagDescriptor lc = (Instruction.Literal.CodeBagDescriptor)d;
 119             instr = putField(WIDTH_WORD-1, WIDTH_WORD-2, 1);
 120             if (lc.dest != null) instr |= putField(WIDTH_WORD-3, WIDTH_WORD-3-WIDTH_DEST_ADDR+1, getDestAddr(lc.dest));
 121             instr |= putSignedField(WIDTH_WORD-3-WIDTH_DEST_ADDR, WIDTH_CODEBAG_SIZE, lc.offset);
 122             instr |= putField(WIDTH_CODEBAG_SIZE-1,        0,                 lc.size);
 123
 124         } else if (d instanceof Instruction.Literal.Absolute) {
 125             Instruction.Literal.Absolute ld = (Instruction.Literal.Absolute)d;
 126             instr = putField(WIDTH_WORD-1, WIDTH_WORD-2, 2);
 127             instr |= putField(WIDTH_WORD-3, WIDTH_WORD-3-WIDTH_DEST_ADDR+1, getDestAddr(ld.dest));
 128             instr |= putSignedField(WIDTH_WORD-3-WIDTH_DEST_ADDR, 0, ld.value);
 129
 130         } else if (d instanceof Instruction.Literal.Relative) {
 131             Instruction.Literal.Relative lr = (Instruction.Literal.Relative)d;
 132             instr = putField(WIDTH_WORD-1, WIDTH_WORD-2, 3);
 133             instr |= putField(WIDTH_WORD-3, WIDTH_WORD-3-WIDTH_DEST_ADDR+1, getDestAddr(lr.dest));
 134             instr |= putSignedField(WIDTH_WORD-3-WIDTH_DEST_ADDR, 0, lr.offset);
 135
 136         }
 137         return instr;
 138     }
 139
 140     public void writeInstruction(DataOutputStream os, Instruction d) throws IOException {
 141         long instr = writeInstruction(d);
 142         for(int i=5; i>=0; i--)
 143             os.write(getIntField(i*8+7, i*8, instr));
 144    }
 145
 146 }