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     public static final int OFFSET_LITERAL      = OFFSET_COUNT;
  27     public static final int WIDTH_LITERAL       = WIDTH_COUNT+WIDTH_DEST_ADDR;
  28
  29     /** get the bits describing this box's location on the DESTINATION HORN */
  30     protected abstract long getDestAddr(Destination box);
  31
  32     /** get the bits describing this box's location on the INSTRUCTION HORN */
  33     protected abstract long getBoxInstAddr(Pump box);
  34
  35     /** given an INSTRUCTION HORN address, retrieve the corresponding Pump object */
  36     protected abstract Pump getBoxByInstAddr(long dest);
  37
  38     /** given a DESTINATION HORN address, retrieve the corresponding Pump object */
  39     protected abstract Destination getDestByAddr(long dest);
  40
  41     /** read a machine-formatted instruction from a file (into a Java object) */
  42     public Instruction readInstruction(DataInputStream is) throws IOException {
  43         long inst = 0;
  44         try {
  45             inst = (inst << 8) | (is.readByte() & 0xff);
  46             inst = (inst << 8) | (is.readByte() & 0xff);
  47             inst = (inst << 8) | (is.readByte() & 0xff);
  48             inst = (inst << 8) | (is.readByte() & 0xff);
  49             inst = (inst << 8) | (is.readByte() & 0xff);
  50             inst = (inst << 8) | (is.readByte() & 0xff);
  51             return readInstruction(inst);
  52         } catch (EOFException eof) {
  53             return null;
  54         }
  55     }
  56
  57     public Instruction readInstruction(long instr) {
  58         long inst = instr;
  59         switch((int)getField(WIDTH_WORD-1, WIDTH_WORD-2, inst)) {
  60             case 0: {
  61                 Pump name           = getBoxByInstAddr(getIntField(OFFSET_PUMP_ADDR+WIDTH_PUMP_ADDR-1, OFFSET_PUMP_ADDR, inst));
  62                 Destination dest    = getDestByAddr   (getIntField(OFFSET_DEST+WIDTH_DEST_ADDR-1,      OFFSET_DEST,      inst));
  63                 int count           = getIntField(                 OFFSET_COUNT+WIDTH_COUNT-1,         OFFSET_COUNT,     inst);
  64                 boolean tokenIn     = getBit(OFFSET_TI, instr);
  65                 boolean dataIn      = getBit(OFFSET_DI, instr);
  66                 boolean latch       = getBit(OFFSET_DL, instr);
  67                 boolean dataOut     = getBit(OFFSET_DO, instr);
  68                 boolean tokenOut    = getBit(OFFSET_TO, instr);
  69                 boolean requeue     = getBit(OFFSET_RQ, instr);
  70                 boolean dataOutDest = dataOut && tokenOut;
  71                 boolean isLiteral   = tokenIn && tokenOut && !dataOutDest;
  72                 if (isLiteral)
  73                     return new Instruction.LocalLiteral(name, getIntField(OFFSET_LITERAL+WIDTH_LITERAL-1, OFFSET_LITERAL, inst));
  74                 if (latch & !dataIn) return new Instruction.Kill(name, count, tokenIn);
  75                 return new Instruction.Executable(name, dest, count, tokenIn, dataIn, latch, dataOutDest,
  76                                                   dataOut, tokenOut, requeue);
  77             }
  78                 /*
  79             case 1: {
  80                 Destination name = getDestByAddr(getField(WIDTH_WORD-3, WIDTH_WORD-3-WIDTH_DEST_ADDR+1, inst));
  81                 long offset      = getSignedField(WIDTH_WORD-3-WIDTH_DEST_ADDR, WIDTH_CODEBAG_SIZE, instr);
  82                 long size        = getSignedField(WIDTH_CODEBAG_SIZE-1,        0,                 instr);
  83                 return new Instruction.Literal.CodeBagDescriptor(name, offset, size);
  84             }
  85                 */
  86             case 2: {
  87                 Destination name = getDestByAddr(getField(WIDTH_WORD-3, WIDTH_WORD-3-WIDTH_PUMP_ADDR+1, inst));
  88                 return new Instruction.Literal.Absolute(name, getSignedField(WIDTH_WORD-3-WIDTH_PUMP_ADDR, 0, instr));
  89             }
  90
  91             case 3: {
  92                 Destination name = getDestByAddr(getField(WIDTH_WORD-3, WIDTH_WORD-3-WIDTH_PUMP_ADDR+1, inst));
  93                 return new Instruction.Literal.Relative(name, getSignedField(WIDTH_WORD-3-WIDTH_PUMP_ADDR, 0, instr));
  94             }
  95
  96         }
  97         return null;
  98
  99     }
 100
 101     public long writeInstruction(Instruction d) {
 102         long instr = 0;
 103
 104         // Kill is encoded as Execute with the illegal combination (Latch & ~DataIn)
 105         if (d instanceof Instruction.Kill) {
 106             Instruction.Kill k = (Instruction.Kill)d;
 107             d = new Instruction.Executable(k.pump, null, k.count, k.killOnlyStandingInstructions,
 108                                            false, true, false, false, false, false);
 109         }
 110
 111         if (d instanceof Instruction.Literal.CodeBagDescriptor) {
 112             Instruction.Literal.CodeBagDescriptor lc = (Instruction.Literal.CodeBagDescriptor)d;
 113             d = new Instruction.LocalLiteral(lc.pump, ((lc.offset << WIDTH_CODEBAG_SIZE)) | lc.size);
 114         }
 115
 116         if (d instanceof Instruction.LocalLiteral) {
 117             Instruction.LocalLiteral inst = (Instruction.LocalLiteral)d;
 118             if (inst.pump != null) {
 119                 instr |= putField(OFFSET_PUMP_ADDR+WIDTH_PUMP_ADDR-1, OFFSET_PUMP_ADDR,   getBoxInstAddr(inst.pump));
 120                 instr |= putField(OFFSET_TI,                          OFFSET_TI,          1);
 121                 instr |= putField(OFFSET_TO,                          OFFSET_TO,          1);
 122                 instr |= putField(OFFSET_LITERAL+WIDTH_LITERAL-1, OFFSET_LITERAL,         inst.literal);
 123             } else {
 124                 instr = inst.literal;
 125             }
 126
 127         } else if (d instanceof Instruction.Executable) {
 128             Instruction.Executable inst = (Instruction.Executable)d;
 129             instr |= putField(OFFSET_PUMP_ADDR+WIDTH_PUMP_ADDR-1, OFFSET_PUMP_ADDR,   getBoxInstAddr(inst.pump));
 130             instr |= putField(OFFSET_DEST+WIDTH_DEST_ADDR-1,      OFFSET_DEST,        inst.dest==null?0:getDestAddr(inst.dest));
 131             instr |= putField(OFFSET_COUNT+WIDTH_COUNT-1,         OFFSET_COUNT,       inst.count);
 132             instr |= putField(OFFSET_TI,                          OFFSET_TI,          inst.tokenIn?1:0);
 133             instr |= putField(OFFSET_DI,                          OFFSET_DI,          inst.dataIn?1:0);
 134             instr |= putField(OFFSET_DL,                          OFFSET_DL,          inst.latch?1:0);
 135             instr |= putField(OFFSET_DO,                          OFFSET_DO,          (inst.dataOutDest||inst.dataOut)?1:0);
 136             instr |= putField(OFFSET_TO,                          OFFSET_TO,          (inst.dataOutDest||inst.tokenOut)?1:0);
 137             instr |= putField(OFFSET_RQ,                          OFFSET_RQ,          inst.requeue?1:0);
 138
 139         }
 140         return instr;
 141     }
 142
 143     public void writeInstruction(DataOutputStream os, Instruction d) throws IOException {
 144         long instr = writeInstruction(d);
 145         for(int i=5; i>=0; i--)
 146             os.write(getIntField(i*8+7, i*8, instr));
 147    }
 148
 149 }