src/org/xwt/mips/Compiler.java

   1 // Copyright 2004 Adam Megacz, see the COPYING file for licensing [GPL]
   2 package org.xwt.mips;
   3
   4 import java.util.*;
   5 import java.io.*;
   6
   7 // FEATURE: progress indicator
   8 // FEATURE: emit bytecode rather than .java code (for on-the-fly classloading without javac present in "real" JVMs
   9
  10 public class Compiler implements Registers {
  11
  12     private static StringBuffer runs = new StringBuffer();
  13     private static StringBuffer inits = new StringBuffer();
  14
  15     private static PrintStream out = System.out;
  16
  17     private static int indent;
  18     private static String indents[] = new String[16];
  19     static { String s=""; for(int i=0;i<indents.length;i++,s=s+"    ") indents[i] = s; }
  20     private static final void p() { out.println(); }
  21     private static final void p(String s) { out.println(indents[indent] + s); }
  22
  23     // FEATURE: This should probably provide some detail about where the excpetion happened (address, line numbers, etc)
  24     private static class CompilationException extends Exception { public CompilationException(String s) { super(s); } }
  25
  26     // Set this to true to enable fast memory access
  27     // When this is enabled a Java RuntimeException will be thrown when a page fault occures. When it is disabled
  28     // a FaultException will be throw which is easier to catch and deal with, however. as the name implies, this is slower
  29     private static boolean fastMem = true;
  30
  31     // log_2 of the maximum bytes per method
  32     // NOTE: This value can be much higher without breaking the classfile
  33     // specs (around 1024) but Hotstop seems to do much better with smaller
  34     // methods.
  35     private static int LOG_MAX_BYTES_PER_METHOD = 9;
  36     private static int MAX_BYTES_PER_METHOD = 512;
  37
  38     // Store frequently used registers in local variables
  39     // Unfortunately this doesn't seem to speed things up much
  40     private static String[] freqRegs = { /*"r2", "r29", "r3", "r16", "r5", "r17", "r6", "r18", "r4", "r31", "r19"*/ };
  41
  42     // True to try to determine which case statement are needed and only include them
  43     private static boolean pruneCases = true;
  44
  45     // True to insert some code in the output to help diagnore compiler problems
  46     private final static boolean debugCompiler = false;
  47
  48     // True to print various statistics about the compilation
  49     private final static boolean printStats = true;
  50
  51     public static void main(String[] s) throws Exception {
  52
  53         if (s.length != 2) {
  54             System.err.println("usage: java " + Compiler.class.getName() + " <classname> <binary.mips>");
  55             System.exit(1);
  56         }
  57
  58         String packageName = null;
  59         String className = s[0];
  60         if (s[0].indexOf('.') != -1) {
  61             packageName = s[0].substring(0, s[0].lastIndexOf('.'));
  62             className = s[0].substring(s[0].lastIndexOf('.') + 1);
  63         }
  64
  65         ELF elf = new ELF(s[1]);
  66         if(elf.header.type != ELF.ELFHeader.ET_EXEC) throw new IOException("Binary is not an executable");
  67         if(elf.header.machine != ELF.ELFHeader.EM_MIPS) throw new IOException("Binary is not for the MIPS I Architecture");
  68
  69         p("// This file was generated by MipsToJava");
  70         if (packageName != null) p("package " + packageName + ";");
  71         p("public class " + className + " extends org.xwt.mips.Runtime {");
  72         p("");
  73         p("    // program counter");
  74         p("    private int pc = 0;");
  75         if(debugCompiler)
  76             p("    private int lastPC = 0;");
  77         p("");
  78         p("    // General Purpose registers");
  79         p("    private final static int r0 = 0;");
  80         p("    int r1 = 0, r2 = 0, r3 = 0, r4 = 0, r5 = 0, r6 = 0, r7 = 0,");
  81         p("        r8 = 0, r9 = 0, r10 = 0, r11 = 0, r12 = 0, r13 = 0, r14 = 0, r15 = 0,");
  82         p("        r16 = 0, r17 = 0, r18 = 0, r19 = 0, r20 = 0, r21 = 0, r22 = 0, r23 = 0,");
  83         p("        r24 = 0, r25 = 0, r26 = 0, r27 = 0, r28 = 0, r29 = 0, r30 = 0, r31 = 0,");
  84         p("        hi = 0, lo = 0;");
  85         p("    // FP registers");
  86         p("    private int f0 = 0, f1 = 0, f2 = 0, f3 = 0, f4 = 0, f5 = 0, f6 = 0, f7 = 0,");
  87         p("        f8 = 0, f9 = 0, f10 = 0, f11 = 0, f12 = 0, f13 = 0, f14 = 0, f15 = 0,");
  88         p("        f16 = 0, f17 = 0, f18 = 0, f19 = 0, f20 = 0, f21 = 0, f22 = 0, f23 = 0,");
  89         p("        f24 = 0, f25 = 0, f26 = 0, f27 = 0, f28 = 0, f29 = 0, f30 = 0, f31 = 0;");
  90         p("    // FP Control Register");
  91         p("    private int fcsr = 0;");
  92         p("");
  93         indent++;
  94         // These should all be inlind by javac
  95         p("private final void setFC(boolean b) { fcsr = (fcsr&~0x800000) | (b ? 0x800000 : 0x000000); }");
  96         p("private final int roundingMode() { return fcsr & 3; /* bits 0-1 */ }");
  97         indent--;
  98
  99         Set jumpableAddresses = null;
 100         if(pruneCases) {
 101             // Find all possible branches
 102             jumpableAddresses = new HashSet();
 103
 104             jumpableAddresses.add(new Integer(elf.header.entry));
 105
 106             ELF.SHeader text = elf.sectionWithName(".text");
 107             if(text == null) throw new Error("No .text segment");
 108             findBranchesInText(text.addr,new DataInputStream(text.getInputStream()),text.size,jumpableAddresses);
 109
 110             findBranchesInSymtab(elf.getSymtab(),jumpableAddresses);
 111
 112             for(int i=0;i<elf.sheaders.length;i++) {
 113                 ELF.SHeader sheader = elf.sheaders[i];
 114                 String name = sheader.name;
 115                 // if this section doesn't get loaded into our address space don't worry about it
 116                 if(sheader.addr == 0x0) continue;
 117                 if(name.equals(".data") || name.equals(".sdata") || name.equals(".rodata") || name.equals(".ctors") || name.equals(".dtors"))
 118                     findBranchesInData(new DataInputStream(sheader.getInputStream()),sheader.size,jumpableAddresses,text.addr,text.addr+text.size);
 119             }
 120         }
 121
 122         // Generate main body functions
 123         int highestAddr = 0;
 124         indent=1;
 125         for(int i=0;i<elf.sheaders.length;i++) {
 126             ELF.SHeader sheader = elf.sheaders[i];
 127             String name = sheader.name;
 128             // if this section doesn't get loaded into our address space don't worry about it
 129             if(sheader.addr == 0x0) continue;
 130
 131             highestAddr = Math.max(highestAddr, sheader.addr + sheader.size);
 132
 133             if(name.equals(".text")) {
 134                 emitText(sheader.addr, new DataInputStream(sheader.getInputStream()),sheader.size,jumpableAddresses);
 135                 endMethod(nextEmitTextAddr);
 136             } else if(name.equals(".data") || name.equals(".sdata") || name.equals(".rodata") || name.equals(".ctors") || name.equals(".dtors")) {
 137                 emitData(sheader.addr, new DataInputStream(sheader.getInputStream()), sheader.size,name.equals(".rodata"));
 138             } else if(name.equals(".bss") || name.equals(".sbss")) {
 139                 if(sheader.entsize != 0) throw new CompilationException("bss segment has data!");
 140                 emitBSS(sheader.addr,sheader.size);
 141             } else {
 142                 throw new CompilationException("Unknown segment: " + name);
 143             }
 144         }
 145         indent = 0;
 146
 147         p("    public " + className + "() throws FaultException {");
 148         if(fastMem) {
 149             p("        super(false); // don't allow empty pages");
 150             p("        if(PAGE_SIZE != " + toHex(Runtime.PAGE_SIZE) + ") throw new Error(\"Runtime.PAGE_SIZE mismatch\");");
 151         } else {
 152             p("        super(true); // allow empty pages");
 153         }
 154         p("        // init data");
 155         p("        entryPoint = " + toHex(elf.header.entry) + ";");
 156         p(inits.toString());
 157         p("        brk = (" + toHex(highestAddr) + "+PAGE_SIZE-1) >>> PAGE_SHIFT;");
 158         p("        state = INITIALIZED;");
 159         p("    }");
 160         p("");
 161         p();
 162         p("    public static void main(String[] javaArgs) throws Exception {");
 163         p("        String[] args = new String[javaArgs.length+1];");
 164         p("        System.arraycopy(javaArgs,0,args,1,javaArgs.length);");
 165         p("        args[0] = \"" + className + "\";");
 166         p("        " + className + " me = new " + className + "();");
 167         p("        // User data");
 168         p("        int addr = me.sbrk(PAGE_SIZE);");
 169         p("        for(int i=0;i<10;i++) {");
 170         p("            String s = \"User Info item: \" + (i+1) + \"\\0\";");
 171         p("            byte[] b = s.getBytes(\"US-ASCII\");");
 172         p("            me.copyout(b,addr,b.length);");
 173         p("            me.setUserInfo(i,addr);");
 174         p("            addr += b.length;");
 175         p("        }");
 176         p("        // End user data");
 177         p("        int status = me.run(args);");
 178         p("        System.err.println(\"Exit status: \" + status);");
 179         p("        System.exit(status);");
 180         p("        }");
 181         p();
 182         p("    protected void _start(int pc) {");
 183         p("        // set the stack pointer");
 184                 p("        r26 = STUFF_BASE;");
 185                 p("        r27 = PAGE_SIZE;");
 186         p("        r29 = INITIAL_SP;");
 187         p("        // set the \"return address\" from _start to point at the \"magic exit address\" (0xdeadbeef)");
 188         p("        r31 = 0xdeadbeef;");
 189         p("        this.pc = pc;");
 190         p("    }");
 191
 192         p();
 193         p("    protected void _execute() throws ExecutionException { trampoline(); }");
 194         p();
 195         p("    private final void trampoline() throws ExecutionException {");
 196         p("        boolean finished = false;");
 197         p("        while(!finished) {");
 198         p("            switch(this.pc >> " + LOG_MAX_BYTES_PER_METHOD + ") {");
 199         p(runs.toString());
 200         p("                default: throw new Error(\"invalid address 0x\" + Long.toString(this.pc&0xffffffffL,16));");
 201         p("            }");
 202         p("        }");
 203         p("    }");
 204         p("}");
 205     }
 206
 207     private static int startOfMethod = 0;
 208     private static int endOfMethod = 0;
 209
 210     private static void startMethod(int addr) {
 211         addr &= ~(MAX_BYTES_PER_METHOD-1);
 212         endOfMethod= addr + MAX_BYTES_PER_METHOD;
 213         String methodName = "run_" + Long.toString(addr & 0xffffffffL, 16);
 214         runs.append(indents[4] + "case " + toHex(addr>>LOG_MAX_BYTES_PER_METHOD) + ": finished = !" + methodName + "(); break;\n");
 215         p("private final boolean " + methodName + "() throws ExecutionException { /"+"* " + toHex(addr) + " - " + toHex(endOfMethod) + " *" + "/");
 216         indent++;
 217         p("int addr, tmp;");
 218         for(int i=0;i<freqRegs.length;i++)
 219             p("int " + freqRegs[i] + " = this." + freqRegs[i] + ";");
 220         p("for(;;) {");
 221         indent++;
 222         p("switch(pc>>2) {");
 223         indent++;
 224         startOfMethod = addr;
 225
 226     }
 227     private static void endMethod() { endMethod(endOfMethod); }
 228     private static void endMethod(int lastAddr) {
 229         if(startOfMethod == 0) return;
 230         // This isn't strictly necessary; its just here to work around unreachable code errors
 231         p("case " + toHex(lastAddr>>2) + ":");
 232         indent++;
 233         p("pc=" + toHex(lastAddr) + ";");
 234         leaveMethod();
 235         indent--;
 236         if(debugCompiler)
 237             p("default: throw new Error(\"invalid address 0x\" + Long.toString(pc&0xffffffffL,16)  + \" (got here from 0x\" + Long.toString(lastPC&0xffffffffL,16)+\")\");");
 238         else
 239             p("default: throw new Error(\"invalid address 0x\" + Long.toString(pc&0xffffffffL,16));");
 240         indent--;
 241         p("}"); // end switch
 242         p("/* NOT REACHED */");
 243         indent--;
 244         p("}"); // end for
 245         indent--;
 246         p("}"); // end method
 247         endOfMethod = 0;
 248     }
 249
 250     private static void branch(int pc, int target) {
 251         if(debugCompiler)
 252             p("lastPC = " + toHex(pc) + ";");
 253         p("pc=" + toHex(target) + ";");
 254         if((pc>>LOG_MAX_BYTES_PER_METHOD) == (target>>LOG_MAX_BYTES_PER_METHOD))
 255             p("continue;");
 256         else
 257             leaveMethod();
 258     }
 259
 260     private static void leaveMethod() { leaveMethod(true); }
 261     private static void leaveMethod(boolean cont) {
 262         for(int i=0;i<freqRegs.length;i++)
 263             p("this." + freqRegs[i] + " = " + freqRegs[i] + ";");
 264         p("return " + (cont?"true":"false") + ";");
 265     }
 266
 267     private static int nextEmitTextAddr = -1;
 268     private static void emitText(int addr, DataInputStream dis, int size, Set jumpableAddresses) throws CompilationException,IOException {
 269         if(addr < nextEmitTextAddr) throw new CompilationException("Out of order sections");
 270         if((addr&3)!=0 || (size&3)!=0) throw new CompilationException("Section on weird boundaries");
 271         int count = size/4;
 272         int nextInsn = dis.readInt();
 273         if(nextInsn == -1) throw new Error("Actually read -1 at " + toHex(addr));
 274         int insn;
 275
 276         for(int i=0;i<count;i++,addr+=4) {
 277             insn = nextInsn;
 278             nextInsn = (i == count-1) ? -1 : dis.readInt();
 279             if(addr >= endOfMethod) { endMethod(); startMethod(addr); }
 280             if(jumpableAddresses==null || addr == startOfMethod || jumpableAddresses.contains(new Integer(addr))) {
 281                 p("case " + toHex(addr>>2) + ":");
 282                 unreachable = false;
 283             } else if(unreachable) {
 284                 continue;
 285             } else if(debugCompiler) {
 286                 p("/" + "* pc = " + toHex(addr) + "*" + "/");
 287             }
 288             indent++;
 289             emitInstruction(addr,insn,nextInsn);
 290             indent--;
 291         }
 292         nextEmitTextAddr = addr;
 293         dis.close();
 294     }
 295
 296     private static int initDataCount = 0;
 297     private static void emitData(int addr, DataInputStream dis, int size, boolean readOnly) throws CompilationException,IOException {
 298         if((addr&3)!=0 || (size&3)!=0) throw new CompilationException("Section on weird boundaries");
 299         int count = size/4;
 300         String varname =  "_data" + (++initDataCount);
 301         p("private final static int[] " + varname +  " = {");
 302         indent++;
 303         for(int i=0;i<count;) {
 304             StringBuffer sb = new StringBuffer();
 305             for(int j=0;j<8 && i<count;j++,i++) {
 306                 sb.append(toHex8(dis.readInt()));
 307                 if(i!=count-1) sb.append(",");
 308             }
 309             p(sb.toString());
 310         }
 311         indent--;
 312         p("};");
 313         inits.append(indents[2] + "initPages(" + varname + "," + toHex(addr) + "," + (readOnly?"true":"false") + ");\n");
 314         dis.close();
 315     }
 316
 317     private static int initBSSCount = 0;
 318     private static void emitBSS(int addr, int size) throws CompilationException,IOException {
 319         if((addr&3)!=0 || (size&3)!=0) throw new CompilationException("Section on weird boundaries");
 320         int count = size/4;
 321         inits.append(indents[2] + "clearPages(" + toHex(addr) + "," + toHex(count) + ");\n");
 322     }
 323
 324     private static void findBranchesInSymtab(ELF.Symtab symtab, Set jumps) {
 325         ELF.Symbol[] symbols = symtab.symbols;
 326         int n=0;
 327         for(int i=0;i<symbols.length;i++) {
 328             ELF.Symbol s = symbols[i];
 329             if(s.type == ELF.Symbol.STT_FUNC) {
 330                 //System.err.println("Adding symbol: " + s.name + " at " + toHex(s.addr));
 331                 if(jumps.add(new Integer(s.addr))) n++;
 332             }
 333         }
 334         if(printStats) System.err.println("Found " + n + " additional possible branch targets in Symtab");
 335     }
 336
 337     private static void findBranchesInText(int addr, DataInputStream dis, int size, Set jumps) throws IOException {
 338         int count = size/4;
 339         int pc = addr;
 340         int n=0;
 341
 342         for(int i=0;i<count;i++,pc+=4) {
 343             int insn = dis.readInt();
 344             int op = (insn >>> 26) & 0xff;
 345             int rs = (insn >>> 21) & 0x1f;
 346             int rt = (insn >>> 16) & 0x1f;
 347             int signedImmediate = (insn << 16) >> 16;
 348             int branchTarget = signedImmediate;
 349             int jumpTarget = (insn & 0x03ffffff);
 350             int subcode = insn & 0x3f;
 351
 352             switch(op) {
 353                 case 0:
 354                     switch(subcode) {
 355                         case 9: // JALR
 356                             if(jumps.add(new Integer(pc+8))) n++; // return address
 357                             break;
 358                         case 12: // SYSCALL
 359                             if(jumps.add(new Integer(pc+4))) n++;
 360                             break;
 361                     }
 362                     break;
 363                 case 1:
 364                     switch(rt) {
 365                         case 16: // BLTZAL
 366                         case 17: // BGTZAL
 367                             if(jumps.add(new Integer(pc+8))) n++; // return address
 368                             // fall through
 369                         case 0: // BLTZ
 370                         case 1: // BGEZ
 371                             if(jumps.add(new Integer(pc+branchTarget*4+4))) n++;
 372                             break;
 373                     }
 374                     break;
 375                 case 3: // JAL
 376                     if(jumps.add(new Integer(pc+8))) n++; // return address
 377                     // fall through
 378                 case 2: // J
 379                     if(jumps.add(new Integer((pc&0xf0000000)|(jumpTarget << 2)))) n++;
 380                     break;
 381                 case 4: // BEQ
 382                 case 5: // BNE
 383                 case 6: // BLEZ
 384                 case 7: // BGTZ
 385                     if(jumps.add(new Integer(pc+branchTarget*4+4))) n++;
 386                     break;
 387                 case 17: // FPU Instructions
 388                     switch(rs) {
 389                         case 8: // BC1F, BC1T
 390                             if(jumps.add(new Integer(pc+branchTarget*4+4))) n++;
 391                             break;
 392                     }
 393                     break;
 394             }
 395         }
 396         dis.close();
 397         if(printStats) System.err.println("Found " + n + " additional possible branch targets in Text segment");
 398     }
 399
 400     private static void findBranchesInData(DataInputStream dis, int size, Set jumps, int textStart, int textEnd) throws IOException {
 401         int count = size/4;
 402         int n=0;
 403         for(int i=0;i<count;i++) {
 404             int word = dis.readInt();
 405             if((word&3)==0 && word >= textStart && word < textEnd) {
 406                 if(jumps.add(new Integer(word))) n++;
 407             }
 408         }
 409         dis.close();
 410         if(n>0 && printStats) System.err.println("Found " + n + " additional possible branch targets in Data segment");
 411     }
 412
 413     private static boolean unreachable = false;
 414
 415     private static void emitInstruction(int pc, int insn, int nextInsn) throws IOException,CompilationException {
 416         if(insn == -1) throw new Error("insn is -1");
 417
 418         int op = (insn >>> 26) & 0xff;                 // bits 26-31
 419         int rs = (insn >>> 21) & 0x1f;                 // bits 21-25
 420         int rt = (insn >>> 16) & 0x1f;                 // bits 16-20
 421         int ft = (insn >>> 16) & 0x1f;
 422         int rd = (insn >>> 11) & 0x1f;                 // bits 11-15
 423         int fs = (insn >>> 11) & 0x1f;
 424         int shamt = (insn >>> 6) & 0x1f;               // bits 6-10
 425         int fd = (insn >>> 6) & 0x1f;
 426         int subcode = insn & 0x3f;                     // bits 0-5
 427
 428         int jumpTarget = (insn & 0x03ffffff);          // bits 0-25
 429         int unsignedImmediate = insn & 0xffff;
 430         int signedImmediate = (insn << 16) >> 16;
 431         int branchTarget = signedImmediate;
 432
 433         int tmp, addr; // temporaries
 434
 435         //if(pc%64==0) p("System.err.println(\"Executing: " + toHex(pc) + "\");");
 436         //p("/" + "*" + (pc == -1 ? "Delay Slot"  : toHex(pc)) + " *" + "/ ");
 437         if(pc==-1) p("/" + "* Next insn is delay slot *" + "/ ");
 438
 439         switch(op) {
 440             case 0: {
 441                 switch(subcode) {
 442                     case 0: // SLL
 443                         if(insn == 0)
 444                             p("/* NOOP */");
 445                         else
 446                             p( "r"+rd+" = r"+rt+" << "+shamt+";");
 447                         break;
 448                     case 2: // SRL
 449                         p( "r"+rd+" = r"+rt+" >>> "+shamt+";");
 450                         break;
 451                     case 3: // SRA
 452                         p( "r"+rd+" = r"+rt+" >> "+shamt+";");
 453                         break;
 454                     case 4: // SLLV
 455                         p( "r"+rd+" = r"+rt+" << (r"+rs+"&0x1f);");
 456                         break;
 457                     case 6: // SRLV
 458                         p( "r"+rd+" = r"+rt+" >>> (r"+rs+"&0x1f);");
 459                         break;
 460                     case 7: // SRAV
 461                         p( "r"+rd+" = r"+rt+" >> (r"+rs+"&0x1f);");
 462                         break;
 463                     case 8: // JR
 464                         if(pc == -1) throw new Error("pc modifying insn in delay slot");
 465                         emitInstruction(-1,nextInsn,-1);
 466                         if(debugCompiler) p("lastPC = " + toHex(pc) + ";");
 467                         p("pc=r" + rs + ";");
 468                         leaveMethod();
 469                         unreachable = true;
 470                         break;
 471                     case 9: // JALR
 472                         if(pc == -1) throw new Error("pc modifying insn in delay slot");
 473                         emitInstruction(-1,nextInsn,-1);
 474                         if(debugCompiler) p("lastPC = " + toHex(pc) + ";");
 475                         p("pc=r" + rs + ";");
 476                         p("r" + RA + "=" + toHex(pc+8 /*skip this insn and delay slot*/) + ";");
 477                         leaveMethod();
 478                         unreachable = true;
 479                         break;
 480                     case 12: // SYSCALL
 481                         p( "r"+V0+" = syscall(r"+V0+",r"+A0+",r"+A1+",r"+A2+",r"+A3+");");
 482                         p("if (state != RUNNING) {");
 483                             indent++;
 484                             p("pc = " + toHex(pc+4) + ";");
 485                             leaveMethod(false);
 486                             indent--;
 487                         p("}");
 488                         break;
 489                     case 13: // BREAK
 490                         p( "throw new ExecutionException(\"Break\");");
 491                         break;
 492                     case 16: // MFHI
 493                         p( "r"+rd+" = hi;");
 494                         break;
 495                     case 17: // MTHI
 496                         p( "hi = r"+rs+";");
 497                         break;
 498                     case 18: // MFLO
 499                         p( "r"+rd+" = lo;");
 500                         break;
 501                     case 19: // MTLO
 502                         p( "lo = r"+rs+";");
 503                         break;
 504                     case 24: // MULT
 505                         p( "{ long hilo = (long)(r"+rs+") * ((long)r"+rt+"); " +
 506                              "hi = (int) (hilo >>> 32); " +
 507                              "lo = (int) hilo; }");
 508                         break;
 509                     case 25: // MULTU
 510                         p( "{ long hilo = (r"+rs+" & 0xffffffffL) * (r"+rt+" & 0xffffffffL); " +
 511                              "hi = (int) (hilo >>> 32); " +
 512                              "lo = (int) hilo; } ");
 513                         break;
 514                     case 26: // DIV
 515                         p( "hi = r"+rs+"%r"+rt+"; lo = r"+rs+"/r"+rt+";");
 516                         break;
 517                     case 27: // DIVU
 518                         p( "hi = (int)((r"+rs+" & 0xffffffffL) % (r"+rt+" & 0xffffffffL)); " +
 519                              "lo = (int)((r"+rs+" & 0xffffffffL) / (r"+rt+" & 0xffffffffL));");
 520                         break;
 521                     case 32: // ADD
 522                         throw new CompilationException("ADD (add with oveflow trap) not suported");
 523                         /*This must trap on overflow
 524                         p( "r"+rd+" = r"+rs+" + r"+rt+";");
 525                         break;*/
 526                     case 33: // ADDU
 527                         p( "r"+rd+" = r"+rs+" + r"+rt+";");
 528                         break;
 529                     case 34: // SUB
 530                         throw new CompilationException("SUB (add with oveflow trap) not suported");
 531                         /*This must trap on overflow
 532                         p( "r"+rd+" = r"+rs+" - r"+rt+";");
 533                         break;*/
 534                     case 35: // SUBU
 535                         p( "r"+rd+" = r"+rs+" - r"+rt+";");
 536                         break;
 537                     case 36: // AND
 538                         p( "r"+rd+" = r"+rs+" & r"+rt+";");
 539                         break;
 540                     case 37: // OR
 541                         p( "r"+rd+" = r"+rs+" | r"+rt+";");
 542                         break;
 543                     case 38: // XOR
 544                         p( "r"+rd+" = r"+rs+" ^ r"+rt+";");
 545                         break;
 546                     case 39: // NOR
 547                         p( "r"+rd+" = ~(r"+rs+" | r"+rt+");");
 548                         break;
 549                     case 42: // SLT
 550                         p( "r"+rd+" = r"+rs+" < r"+rt+" ? 1 : 0;");
 551                         break;
 552                     case 43: // SLTU
 553                         p( "r"+rd+" = ((r"+rs+" & 0xffffffffL) < (r"+rt+" & 0xffffffffL)) ? 1 : 0;");
 554                         break;
 555                     default:
 556                         throw new RuntimeException("Illegal instruction 0/" + subcode);
 557                 }
 558                 break;
 559             }
 560             case 1: {
 561                 switch(rt) {
 562                     case 0: // BLTZ
 563                         if(pc == -1) throw new Error("pc modifying insn in delay slot");
 564                         p("if(r" + rs + " < 0) {");
 565                             indent++;
 566                             emitInstruction(-1,nextInsn,-1);
 567                             branch(pc,pc+branchTarget*4+4);
 568                             indent--;
 569                         p("}");
 570                         break;
 571                     case 1: // BGEZ
 572                         if(pc == -1) throw new Error("pc modifying insn in delay slot");
 573                         p("if(r" + rs + " >= 0) {");
 574                             indent++;
 575                             emitInstruction(-1,nextInsn,-1);
 576                             branch(pc,pc+branchTarget*4+4);
 577                             indent--;
 578                         p("}");
 579                         break;
 580                     case 16: // BLTZAL
 581                         if(pc == -1) throw new Error("pc modifying insn in delay slot");
 582                         p("if(r" + rs + " < 0) {");
 583                             indent++;
 584                             emitInstruction(-1,nextInsn,-1);
 585                             p("r" + RA + "=" + toHex(pc+8 /*skip this insn and delay slot*/) + ";");
 586                             branch(pc,pc+branchTarget*4+4);
 587                             indent--;
 588                         p("}");
 589                         break;
 590                     case 17: // BGEZAL
 591                         if(pc == -1) throw new Error("pc modifying insn in delay slot");
 592                         p("if(r" + rs + " >= 0) {");
 593                             indent++;
 594                             emitInstruction(-1,nextInsn,-1);
 595                             p("r" + RA + "=" + toHex(pc+8 /*skip this insn and delay slot*/) + ";");
 596                             branch(pc,pc+branchTarget*4+4);
 597                             indent--;
 598                         p("}");
 599                         break;
 600                     default:
 601                         throw new RuntimeException("Illegal Instruction 1/" + rt);
 602                 }
 603                 break;
 604             }
 605             case 2: { // J
 606                 if(pc == -1) throw new Error("pc modifying insn in delay slot");
 607                 emitInstruction(-1,nextInsn,-1);
 608                 branch(pc,(pc&0xf0000000)|(jumpTarget << 2));
 609                 unreachable = true;
 610                 break;
 611             }
 612             case 3: { // JAL
 613                 if(pc == -1) throw new Error("pc modifying insn in delay slot");
 614                 emitInstruction(-1,nextInsn,-1);
 615                 p("r" + RA + "=" + toHex(pc+8 /*skip this insn and delay slot*/) + ";");
 616                 branch(pc, (pc&0xf0000000)|(jumpTarget << 2));
 617                 unreachable = true;
 618                 break;
 619             }
 620             case 4: // BEQ
 621                 if(pc == -1) throw new Error("pc modifying insn in delay slot");
 622                 p("// BEQ");
 623                 p("if(r" + rs + " == r" + rt + ") {");
 624                     indent++;
 625                     emitInstruction(-1,nextInsn,-1);
 626                     branch(pc,pc+branchTarget*4+4);
 627                     indent--;
 628                 p("}");
 629                 break;
 630             case 5: // BNE
 631                 if(pc == -1) throw new Error("pc modifying insn in delay slot");
 632                 p("if(r" + rs + " != r" + rt + ") {");
 633                     indent++;
 634                     emitInstruction(-1,nextInsn,-1);
 635                     branch(pc,pc+branchTarget*4+4);
 636                     indent--;
 637                 p("}");
 638                 break;
 639             case 6: //BLEZ
 640                 if(pc == -1) throw new Error("pc modifying insn in delay slot");
 641                 p("if(r" + rs + " <= 0) {");
 642                     indent++;
 643                     emitInstruction(-1,nextInsn,-1);
 644                     branch(pc,pc+branchTarget*4+4);
 645                     indent--;
 646                 p("}");
 647                 break;
 648             case 7: //BGTZ
 649                 if(pc == -1) throw new Error("pc modifying insn in delay slot");
 650                 p("if(r" + rs + " > 0) {");
 651                     indent++;
 652                     emitInstruction(-1,nextInsn,-1);
 653                     branch(pc,pc+branchTarget*4+4);
 654                     indent--;
 655                 p("}");
 656                 break;
 657             case 8: // ADDI
 658                 p( "r"+rt+" = r"+rs+" + "+signedImmediate +";");
 659                 break;
 660             case 9: // ADDIU
 661                 p( "r"+rt+" = r"+rs+" + "+signedImmediate+";");
 662                 break;
 663             case 10: // SLTI
 664                 p( "r"+rt+" = r"+rs+" < "+signedImmediate+" ? 1 : 0;");
 665                 break;
 666             case 11: // SLTIU
 667                 p( "r"+rt+" = (r"+rs+"&0xffffffffL) < ("+unsignedImmediate+"&0xffffffffL) ? 1 : 0;");
 668                 break;
 669             case 12: // ANDI
 670                 p( "r"+rt+" = r"+rs+" & "+unsignedImmediate+";");
 671                 break;
 672             case 13: // ORI
 673                 p( "r"+rt+" = r"+rs+" | "+unsignedImmediate+";");
 674                 break;
 675             case 14: // XORI
 676                 p( "r"+rt+" = r"+rs+" ^ "+unsignedImmediate+";");
 677                 break;
 678             case 15: // LUI
 679                 p( "r"+rt+" = "+unsignedImmediate+" << 16;");
 680                 break;
 681             case 16:
 682                 throw new CompilationException("TLB/Exception support not implemented");
 683             case 17: { // FPU
 684                 switch(rs) {
 685                     case 0: // MFC.1
 686                         p( "r"+rt+" = f"+rd+";");
 687                         break;
 688                     case 2: // CFC.1
 689                         if(fs != 31) throw new CompilationException("FCR " + fs + " unavailable");
 690                         p( "r"+rt+" = fcsr;");
 691                         break;
 692                     case 4: // MTC.1
 693                         p( "f"+rd+" = r"+rt+";");
 694                         break;
 695                     case 6: // CTC.1
 696                         if(fs != 31) throw new CompilationException("FCR " + fs + " unavailable");
 697                         p( "fcsr = r"+rt+";");
 698                         break;
 699                     case 8: {// BC1F, BC1T
 700                         tmp = (insn>>>16)&1;
 701                         p("//BC1F, BC1T");
 702                         p("if(((fcsr&0x800000)!=0) == (" + tmp + "!=0)) {");
 703                             indent++;
 704                             emitInstruction(-1,nextInsn,-1);
 705                             branch(pc,pc+branchTarget*4+4);
 706                             indent--;
 707                         p("}");
 708                         break;
 709                     }
 710                     case 16: {  // Single
 711                         switch(subcode) {
 712                             case 0: // ADD.S
 713                                 p(setFloat(fd,getFloat(fs)+"+"+getFloat(ft)));
 714                                 break;
 715                             case 1: // SUB.S
 716                                 p(setFloat(fd,getFloat(fs)+"-"+getFloat(ft)));
 717                                 break;
 718                             case 2: // MUL.S
 719                                 p(setFloat(fd,getFloat(fs)+"*"+getFloat(ft)));
 720                                 break;
 721                             case 3: // DIV.S
 722                                 p(setFloat(fd,getFloat(fs)+"/"+getFloat(ft)));
 723                                 break;
 724                             case 5: // ABS.S
 725                                 p(setFloat(fd,"Math.abs("+getFloat(fs)+")"));
 726                                 break;
 727                             case 6: // MOV.S
 728                                 p("f"+fd+" = f"+fs+"; // MOV.S");
 729                                 break;
 730                             case 7: // NEG.S
 731                                 p(setFloat(fd,"-"+getFloat(fs))); // FEATURE: just flip the sign bit
 732                                 break;
 733                             case 33: // CVT.D.S
 734                                 p(setDouble(fd,"(float)"+getFloat(fs)));
 735                                 break;
 736                             case 36: // CVT.W.D
 737                                 p("// CVT.W.D");
 738                                 p("switch(roundingMode()) {");
 739                                     indent++;
 740                                     p("case 0: f"+fd+" = (int)Math.floor("+getFloat(fs)+"+0.5); break; // Round to nearest");
 741                                     p("case 1: f"+fd+" = (int)"+getFloat(fs)+"; break; // Round towards zero");
 742                                     p("case 2: f"+fd+" = (int)Math.ceil("+getFloat(fs)+"); break; // Round towards plus infinity");
 743                                     p("case 3: f"+fd+" = (int)Math.floor("+getFloat(fs)+"); break; // Round towards minus infinity");
 744                                     indent--;
 745                                 p("}");
 746                                 break;
 747                             case 50: // C.EQ.D
 748                                 p("setFC("+getFloat(fs)+"=="+getFloat(ft)+");"); // FEATURE: just compare the ints, be sure things are normalized
 749                                 break;
 750                             case 60: // C.LT.D
 751                                 p("setFC("+getFloat(fs)+"<"+getFloat(ft)+");");
 752                                 break;
 753                             case 62: // C.LE.D
 754                                 p("setFC("+getFloat(fs)+"<="+getFloat(ft)+");");
 755                                 break;
 756                             default: throw new CompilationException("Invalid Instruction 17/" + rs + "/" + subcode);
 757                         }
 758                         break;
 759                     }
 760                     case 17: { // Double
 761                         switch(subcode) {
 762                             case 0: // ADD.D
 763                                 p(setDouble(fd,getDouble(fs)+"+"+getDouble(ft)));
 764                                 break;
 765                             case 1: // SUB.D
 766                                 p(setDouble(fd,getDouble(fs)+"-"+getDouble(ft)));
 767                                 break;
 768                             case 2: // MUL.D
 769                                 p(setDouble(fd,getDouble(fs)+"*"+getDouble(ft)));
 770                                 break;
 771                             case 3: // DIV.D
 772                                 p(setDouble(fd,getDouble(fs)+"/"+getDouble(ft)));
 773                                 break;
 774                             case 5: // ABS.D
 775                                 p(setDouble(fd,"Math.abs("+getDouble(fs)+")"));
 776                                 break;
 777                             case 6: // MOV.D
 778                                 p("f"+fd+" = f"+fs+";");
 779                                 p("f"+(fd+1)+" = f"+(fs+1)+";");
 780                                 break;
 781                             case 7: // NEG.D
 782                                 p(setDouble(fd,"-"+getDouble(fs))); // FEATURE: just flip the sign bit
 783                                 break;
 784                             case 32: // CVT.S.D
 785                                 p(setFloat(fd,"(float)"+getDouble(fs)));
 786                                 break;
 787                             case 36: // CVT.W.D
 788                                 p("// CVT.W.D");
 789                                 p("switch(roundingMode()) {");
 790                                     indent++;
 791                                     p("case 0: f"+fd+" = (int)Math.floor("+getDouble(fs)+"+0.5); break; // Round to nearest");
 792                                     p("case 1: f"+fd+" = (int)"+getDouble(fs)+"; break; // Round towards zero");
 793                                     p("case 2: f"+fd+" = (int)Math.ceil("+getDouble(fs)+"); break; // Round towards plus infinity");
 794                                     p("case 3: f"+fd+" = (int)Math.floor("+getDouble(fs)+"); break; // Round towards minus infinity");
 795                                     indent--;
 796                                 p("}");
 797                                 break;
 798                             case 50: // C.EQ.D
 799                                 p("setFC("+getDouble(fs)+"=="+getDouble(ft)+");"); // FEATURE: just compare the ints, be sure things are normalized
 800                                 break;
 801                             case 60: // C.LT.D
 802                                 p("setFC("+getDouble(fs)+"<"+getDouble(ft)+");");
 803                                 break;
 804                             case 62: // C.LE.D
 805                                 p("setFC("+getDouble(fs)+"<="+getDouble(ft)+");");
 806                                 break;
 807                             default: throw new CompilationException("Invalid Instruction 17/" + rs + "/" + subcode);
 808                         }
 809                         break;
 810                     }
 811                     case 20: { // Integer
 812                         switch(subcode) {
 813                             case 32: // CVT.S.W
 814                                 p(" // CVS.S.W");
 815                                 p(setFloat(fd,"((float)f"+fs+")"));
 816                                 break;
 817                             case 33: // CVT.D.W
 818                                 p("// CVT.D.W");
 819                                 p(setDouble(fd,"((double)f"+fs+")"));
 820                                 break;
 821                             default: throw new CompilationException("Invalid Instruction 17/" + rs + "/" + subcode);
 822                         }
 823                         break;
 824                     }
 825                     default:
 826                         throw new CompilationException("Invalid Instruction 17/" + rs);
 827                 }
 828                 break;
 829             }
 830             case 18: case 19:
 831                 throw new CompilationException("coprocessor 2 and 3 instructions not available");
 832             case 32: { // LB
 833                 p("addr=r" + rs +"+"+signedImmediate + ";");
 834                 memRead("addr&~3","tmp");
 835                 p("switch(addr&3) {");
 836                     indent++;
 837                     p("case 0: tmp = (tmp>>>24)&0xff; break;");
 838                     p("case 1: tmp = (tmp>>>16)&0xff; break;");
 839                     p("case 2: tmp = (tmp>>> 8)&0xff; break;");
 840                     p("case 3: tmp = (tmp>>> 0)&0xff; break;");
 841                     indent--;
 842                 p("}");
 843                 p("if((tmp&0x80)!=0) tmp |= 0xffffff00; // sign extend");
 844                 p("r"+rt+" = tmp;");
 845                 break;
 846             }
 847             case 33: { // LH
 848                 p("addr=r" + rs +"+"+signedImmediate + ";");
 849                 memRead("addr&~3","tmp");
 850                 p("switch(addr&2) {");
 851                     indent++;
 852                     p("case 0: tmp = (tmp>>>16)&0xffff; break;");
 853                     p("case 2: tmp = (tmp>>> 0)&0xffff; break;");
 854                     indent--;
 855                 p("}");
 856                 p("if((tmp&0x8000)!=0) tmp |= 0xffff0000; // sign extend");
 857                 p("r"+rt+" = tmp;");
 858                 break;
 859             }
 860             case 34: { // LWL;
 861                 p("addr=r" + rs +"+"+signedImmediate + ";");
 862                 memRead("addr&~3","tmp");
 863                 p("switch(addr&3) {");
 864                     indent++;
 865                     p("case 0: r"+rt+" = (r"+rt+"&0x00000000)|(tmp<< 0); break;");
 866                     p("case 1: r"+rt+" = (r"+rt+"&0x000000ff)|(tmp<< 8); break;");
 867                     p("case 2: r"+rt+" = (r"+rt+"&0x0000ffff)|(tmp<<16); break;");
 868                     p("case 3: r"+rt+" = (r"+rt+"&0x00ffffff)|(tmp<<24); break;");
 869                     indent--;
 870                 p("}");
 871                 break;
 872             }
 873             case 35: // LW
 874                 memRead("r" + rs +"+"+signedImmediate,"r"+rt);
 875                 break;
 876             case 36: { // LBU
 877                 p("addr=r" + rs +"+"+signedImmediate + ";");
 878                 memRead("addr&~3","tmp");
 879                 p("switch(addr&3) {");
 880                     indent++;
 881                     p("case 0: r"+rt+" = (tmp>>>24)&0xff; break;");
 882                     p("case 1: r"+rt+" = (tmp>>>16)&0xff; break;");
 883                     p("case 2: r"+rt+" = (tmp>>> 8)&0xff; break;");
 884                     p("case 3: r"+rt+" = (tmp>>> 0)&0xff; break;");
 885                     indent--;
 886                 p("}");
 887                 break;
 888             }
 889             case 37: { // LHU
 890                 p("addr=r" + rs +"+"+signedImmediate + ";");
 891                 memRead("addr&~3","tmp");
 892                 p("switch(addr&2) {");
 893                     indent++;
 894                     p("case 0: r"+rt+" = (tmp>>>16)&0xffff; break;");
 895                     p("case 2: r"+rt+" = (tmp>>> 0)&0xffff; break;");
 896                     indent--;
 897                 p("}");
 898                 break;
 899             }
 900             case 38: { // LWR
 901                 p("addr=r" + rs +"+"+signedImmediate + ";");
 902                 memRead("addr&~3","tmp");
 903                 p("switch(addr&3) {");
 904                     indent++;
 905                     p("case 0: r"+rt+" = (r"+rt+"&0xffffff00)|(tmp>>>24); break;");
 906                     p("case 1: r"+rt+" = (r"+rt+"&0xffff0000)|(tmp>>>16); break;");
 907                     p("case 2: r"+rt+" = (r"+rt+"&0xff000000)|(tmp>>> 8); break;");
 908                     p("case 3: r"+rt+" = (r"+rt+"&0x00000000)|(tmp>>> 0); break;");
 909                     indent--;
 910                 p("}");
 911                 break;
 912             }
 913             case 40: { // SB
 914                 p("// SB");
 915                 p("addr=r" + rs +"+"+signedImmediate + ";");
 916                 memRead("addr&~3","tmp");
 917                 p("switch(addr&3) {");
 918                     indent++;
 919                     p("case 0: tmp = (tmp&0x00ffffff) | ((r"+rt+"&0xff)<<24); break;");
 920                     p("case 1: tmp = (tmp&0xff00ffff) | ((r"+rt+"&0xff)<<16); break;");
 921                     p("case 2: tmp = (tmp&0xffff00ff) | ((r"+rt+"&0xff)<< 8); break;");
 922                     p("case 3: tmp = (tmp&0xffffff00) | ((r"+rt+"&0xff)<< 0); break;");
 923                     indent--;
 924                 p("}");
 925                 memWrite("addr&~3","tmp");
 926                 break;
 927             }
 928             case 41: { // SH
 929                 p("// SH");
 930                 p("addr=r" + rs +"+"+signedImmediate + ";");
 931                 memRead("addr&~3","tmp");
 932                 p("switch(addr&2) {");
 933                     indent++;
 934                     p("case 0: tmp = (tmp&0x0000ffff) | ((r"+rt+"&0xffff)<<16); break;");
 935                     p("case 2: tmp = (tmp&0xffff0000) | ((r"+rt+"&0xffff)<< 0); break;");
 936                     indent--;
 937                 p("}");
 938                 memWrite("addr&~3","tmp");
 939                 break;
 940             }
 941             case 42: { // SWL
 942                 p(" // SWL");
 943                 p("addr=r" + rs +"+"+signedImmediate + ";");
 944                 memRead("addr&~3","tmp");
 945                 p("switch(addr&3) {");
 946                     indent++;
 947                     p("case 0: tmp=(tmp&0x00000000)|(r"+rt+">>> 0); break;");
 948                     p("case 1: tmp=(tmp&0xff000000)|(r"+rt+">>> 8); break;");
 949                     p("case 2: tmp=(tmp&0xffff0000)|(r"+rt+">>>16); break;");
 950                     p("case 3: tmp=(tmp&0xffffff00)|(r"+rt+">>>24); break;");
 951                     indent--;
 952                 p("}");
 953                 memWrite("addr&~3","tmp");
 954                 break;
 955             }
 956             case 43: // SW
 957                 memWrite("r"+rs+"+"+signedImmediate,"r" + rt);
 958                 break;
 959             case 46: { // SWR
 960                 p(" // SWR");
 961                 p("addr=r" + rs +"+"+signedImmediate + ";");
 962                 memRead("addr&~3","tmp");
 963                 p("switch(addr&3) {");
 964                     indent++;
 965                     p("case 0: tmp=(tmp&0x00ffffff)|(r"+rt+"<<24); break;");
 966                     p("case 1: tmp=(tmp&0x0000ffff)|(r"+rt+"<<16); break;");
 967                     p("case 2: tmp=(tmp&0x000000ff)|(r"+rt+"<< 8); break;");
 968                     p("case 3: tmp=(tmp&0x00000000)|(r"+rt+"<< 0); break;");
 969                     indent--;
 970                 p("}");
 971                 memWrite("addr&~3","tmp");
 972                 break;
 973             }
 974             case 49: // LWC1
 975                 memRead("r"+rs+"+"+signedImmediate,"f"+rt);
 976                 break;
 977             case 57: // SWC1
 978                 memWrite("r"+rs+"+"+signedImmediate,"f"+rt);
 979                 break;
 980             default:
 981                 throw new CompilationException("Invalid Instruction: " + op + " at " + toHex(pc));
 982         }
 983     }
 984
 985     private static void memWrite(String addr, String target) {
 986         if(fastMem)
 987             p("writePages[("+addr+")>>>"+Runtime.PAGE_SHIFT+"][(("+addr+")>>>2)&"+toHex(Runtime.PAGE_WORDS-1)+"] = " + target + ";");
 988         else
 989             p("memWrite(" + addr + "," + target + ");");
 990
 991     }
 992
 993     private static void memRead(String addr, String target) {
 994         if(fastMem)
 995             p(target  + " = readPages[("+addr+")>>>"+Runtime.PAGE_SHIFT+"][(("+addr+")>>>2)&"+toHex(Runtime.PAGE_WORDS-1)+"];");
 996         else
 997             p(target + " = memRead(" + addr + ");");
 998     }
 999
1000     private static String getFloat(int r) { return "(Float.intBitsToFloat(f"+r+"))"; }
1001     private static String getDouble(int r) {
1002         return "(Double.longBitsToDouble(((f"+(r+1)+"&0xffffffffL) << 32) | (f"+r+"&0xffffffffL)))";
1003     }
1004     private static String setFloat(int r, String expr) { return "f"+r+"=Float.floatToRawIntBits("+expr+");"; }
1005     private static String setDouble(int r, String expr) {
1006         return "{ long l = Double.doubleToLongBits("+expr+"); "+
1007             "f"+(r+1)+" = (int)(l >>> 32); f"+r+" = (int)l; }";
1008     }
1009
1010     private final static String toHex(int n) { return "0x" + Long.toString(n & 0xffffffffL, 16); }
1011     private final static String toHex8(int n) {
1012         String s = Long.toString(n & 0xffffffffL, 16);
1013         StringBuffer sb = new StringBuffer("0x");
1014         for(int i=8-s.length();i>0;i--) sb.append('0');
1015         sb.append(s);
1016         return sb.toString();
1017     }
1018 }
1019