src/org/ibex/nestedvm/ClassFileCompiler.java

   1 package org.ibex.nestedvm;
   2
   3 import java.io.*;
   4 import org.ibex.nestedvm.util.*;
   5
   6 import org.apache.bcel.generic.*;
   7
   8 // FEATURE: Use BCEL to do peephole optimization
   9 // FEATURE: Special mode to support single-precision only - regs are floats not ints
  10
  11 /* FEATURE: Span large binaries across several classfiles
  12  * We should be able to do this with no performance penalty
  13  * Every method in the inner classes is static and takes the main class as an arg
  14  * This makes them look just like methods in the main class because arg1 gets loaded into
  15  * local register 0
  16  */
  17
  18 /* FEATURE: smarter with local regs
  19  * Be even smarter with the use of local registers. We need to only load fields into
  20  * local regs when they are actually used and only write to fields if the regs could have
  21  * changed. This should allow us to put more regs in local vars. Right now putting all used
  22  * regs local vars makes code like this slower.
  23  *
  24  * void work(int a, int b) {
  25  *    if(a == b) {
  26  *       fast path
  27  *       return;
  28  *    }
  29  *    real work
  30  * }
  31  * Because all the regs used in "real work" are loaded/restored even for fast path
  32  */
  33
  34
  35 public class ClassFileCompiler extends Compiler implements org.apache.bcel.Constants  {
  36     /** The stream to write the compiled output to */
  37     private OutputStream os;
  38     private PrintStream warn = System.err;
  39
  40     private ClassGen cl;
  41     private ConstantPoolGen cp;
  42     private InstructionList clinitExtras = new InstructionList();
  43     private InstructionList initExtras = new InstructionList();
  44     private InstructionFactory fac;
  45
  46     // Handy wrappers around the BCEL functions
  47     private InstructionList insnList;
  48     private void selectMethod(MethodGen m) { insnList = m.getInstructionList();    }
  49     private void selectList(InstructionList l) { insnList = l; }
  50     private InstructionHandle a(Instruction i) { return insnList.append(i); }
  51     private BranchHandle a(BranchInstruction i) { return insnList.append(i); }
  52     private InstructionHandle a(InstructionList l) { return insnList.append(l); }
  53     private InstructionHandle a(CompoundInstruction c) { return insnList.append(c); }
  54
  55     // This works around a bug in InstructionList
  56     // FEATURE: fix this in bcel, send them a patch, etc
  57     private static class FixedInstructionList extends InstructionList {
  58         public void move(InstructionHandle start, InstructionHandle end, InstructionHandle target) {
  59             InstructionHandle extra = target != null && target == getEnd() ? append(InstructionConstants.NOP) : null;
  60             super.move(start,end,target);
  61             if(extra != null) try { delete(extra); } catch (TargetLostException e) { /* won't happen */ }
  62         }
  63     }
  64
  65     private MethodGen newMethod(int flags, Type ret, Type[] args, String name) {
  66         return new MethodGen(flags,ret,args,null,name,fullClassName,new FixedInstructionList(),cp);
  67     }
  68
  69     public ClassFileCompiler(String path, String className, OutputStream os) throws IOException { this(new Seekable.File(path),className,os); }
  70     public ClassFileCompiler(Seekable binary, String className, OutputStream os) throws IOException {
  71         super(binary,className);
  72         this.os = os;
  73     }
  74
  75     public void setWarnWriter(PrintStream warn) { this.warn = warn; }
  76
  77     protected void _go() throws Exn, IOException {
  78         if(lessConstants) throw new Exn("ClassFileCompiler doesn't support -o lessconstants");
  79         if(!pruneCases) throw new Exn("-o prunecases MUST be enabled for ClassFileCompiler");
  80
  81         // Class
  82         cl = new ClassGen(fullClassName,runtimeClass,source,ACC_SUPER|ACC_PUBLIC|ACC_FINAL,null);
  83         cp = cl.getConstantPool();
  84         fac = new InstructionFactory(cl,cp);
  85
  86         // Fields
  87         cl.addField(new FieldGen(ACC_PRIVATE,Type.INT,"pc",cp).getField());
  88         for(int i=1;i<32;i++)
  89             cl.addField(new FieldGen(ACC_PRIVATE,Type.INT,"r"+i,cp).getField());
  90         for(int i=0;i<32;i++)
  91             cl.addField(new FieldGen(ACC_PRIVATE,Type.INT,"f"+i,cp).getField());
  92
  93         cl.addField(new FieldGen(ACC_PRIVATE,Type.INT,"hi",cp).getField());
  94         cl.addField(new FieldGen(ACC_PRIVATE,Type.INT,"lo",cp).getField());
  95         cl.addField(new FieldGen(ACC_PRIVATE,Type.INT,"fcsr",cp).getField());
  96
  97         if(onePage) {
  98             cl.addField(new FieldGen(ACC_PRIVATE|ACC_FINAL,new ArrayType(Type.INT,1),"page",cp).getField());
  99
 100             selectList(initExtras);
 101             a(InstructionConstants.ALOAD_0);
 102             a(InstructionConstants.DUP);
 103             a(fac.createFieldAccess(fullClassName,"readPages",new ArrayType(Type.INT, 2), GETFIELD));
 104             pushConst(0);
 105             a(InstructionConstants.AALOAD);
 106             a(fac.createFieldAccess(fullClassName,"page",new ArrayType(Type.INT,1), PUTFIELD));
 107         }
 108
 109         if(supportCall)
 110             cl.addField(new FieldGen(ACC_PRIVATE|ACC_STATIC|ACC_FINAL,Type.getType("L"+hashClass.replace('.','/')+";"),"symbols",cp).getField());
 111
 112         int highestAddr = 0;
 113
 114         for(int i=0;i<elf.sheaders.length;i++) {
 115             ELF.SHeader sheader = elf.sheaders[i];
 116             String name = sheader.name;
 117             // if this section doesn't get loaded into our address space don't worry about it
 118             if(sheader.addr == 0x0) continue;
 119
 120             highestAddr = Math.max(highestAddr, sheader.addr + sheader.size);
 121
 122             if(name.equals(".text"))
 123                 emitText(sheader.addr, new DataInputStream(sheader.getInputStream()),sheader.size);
 124             else if(name.equals(".data") || name.equals(".sdata") || name.equals(".rodata") || name.equals(".ctors") || name.equals(".dtors"))
 125                 emitData(sheader.addr, new DataInputStream(sheader.getInputStream()), sheader.size,name.equals(".rodata"));
 126             else if(name.equals(".bss") || name.equals(".sbss"))
 127                 emitBSS(sheader.addr,sheader.size);
 128             else
 129                 throw new Exn("Unknown segment: " + name);
 130         }
 131
 132         ELF.SHeader text = elf.sectionWithName(".text");
 133
 134         // Trampoline
 135         MethodGen tramp = newMethod(ACC_PRIVATE,Type.VOID, Type.NO_ARGS, "trampoline");
 136         tramp.addException("org.ibex.nestedvm.Runtime$ExecutionException");
 137         selectMethod(tramp);
 138
 139         InstructionHandle start = a(InstructionConstants.ALOAD_0);
 140         a(fac.createFieldAccess(fullClassName,"state",Type.INT, GETFIELD));
 141         pushConst(Runtime.RUNNING);
 142         BranchInstruction stateCheck =  InstructionFactory.createBranchInstruction(IF_ICMPNE,null);
 143         a(stateCheck);
 144         a(InstructionConstants.ALOAD_0);
 145         a(InstructionConstants.ALOAD_0);
 146         a(fac.createFieldAccess(fullClassName,"pc",Type.INT, GETFIELD));
 147         pushConst(methodShift);
 148         a(InstructionConstants.IUSHR);
 149
 150         int beg = text.addr >>> methodShift;
 151         int end = ((text.addr + text.size) >>> methodShift);
 152
 153         // This data is redundant but BCEL wants it
 154         int[] matches = new int[end-beg];
 155         for(int i=beg;i<end;i++)  matches[i-beg] = i;
 156         TABLESWITCH ts = new TABLESWITCH(matches,new InstructionHandle[matches.length],null);
 157         a(ts);
 158         for(int n=beg;n<end;n++){
 159             InstructionHandle h = a(fac.createInvoke(fullClassName,"run_"+toHex(n<<methodShift),Type.VOID,Type.NO_ARGS,INVOKESPECIAL));
 160             a(InstructionFactory.createBranchInstruction(GOTO,start));
 161             ts.setTarget(n-beg,h);
 162         }
 163
 164         ts.setTarget(a(InstructionConstants.POP)); // default case
 165         a(fac.createNew("org.ibex.nestedvm.Runtime$ExecutionException"));
 166         a(InstructionConstants.DUP);
 167         a(fac.createNew("java.lang.StringBuffer"));
 168         a(InstructionConstants.DUP);
 169         a(new PUSH(cp,"Jumped to invalid address in trampoline (r2: "));
 170         a(fac.createInvoke("java.lang.StringBuffer","<init>",Type.VOID,new Type[]{Type.STRING},INVOKESPECIAL));
 171         a(InstructionConstants.ALOAD_0);
 172         a(fac.createFieldAccess(fullClassName,"r2",Type.INT, GETFIELD));
 173         a(fac.createInvoke("java.lang.StringBuffer","append",Type.STRINGBUFFER,new Type[]{Type.INT},INVOKEVIRTUAL));
 174         a(new PUSH(cp," pc:"));
 175         a(fac.createInvoke("java.lang.StringBuffer","append",Type.STRINGBUFFER,new Type[]{Type.STRING},INVOKEVIRTUAL));
 176         a(InstructionConstants.ALOAD_0);
 177         a(fac.createFieldAccess(fullClassName,"pc",Type.INT, GETFIELD));
 178         a(fac.createInvoke("java.lang.StringBuffer","append",Type.STRINGBUFFER,new Type[]{Type.INT},INVOKEVIRTUAL));
 179         a(new PUSH(cp,')'));
 180         a(fac.createInvoke("java.lang.StringBuffer","append",Type.STRINGBUFFER,new Type[]{Type.CHAR},INVOKEVIRTUAL));
 181         a(fac.createInvoke("java.lang.StringBuffer","toString",Type.STRING,Type.NO_ARGS,INVOKEVIRTUAL));
 182         a(fac.createInvoke("org.ibex.nestedvm.Runtime$ExecutionException","<init>",Type.VOID,new Type[]{Type.STRING},INVOKESPECIAL));
 183         a(InstructionConstants.ATHROW);
 184
 185         stateCheck.setTarget(a(InstructionConstants.RETURN));
 186
 187         tramp.setMaxStack();
 188         tramp.setMaxLocals();
 189         try {
 190             cl.addMethod(tramp.getMethod());
 191         } catch(ClassGenException e) {
 192             e.printStackTrace(warn);
 193             throw new Exn("Generation of the trampoline method failed. Try increasing maxInsnPerMethod");
 194         }
 195
 196         addConstReturnMethod("gp",gp.addr);
 197         addConstReturnMethod("entryPoint",elf.header.entry);
 198         addConstReturnMethod("heapStart",highestAddr);
 199
 200         if(userInfo != null) {
 201             addConstReturnMethod("userInfoBase",userInfo.addr);
 202             addConstReturnMethod("userInfoSize",userInfo.size);
 203         }
 204
 205         // FEATURE: Allow specification of memory size at runtime (numpages)
 206         // Constructor
 207         MethodGen init = newMethod(ACC_PUBLIC,Type.VOID, Type.NO_ARGS, "<init>");
 208         selectMethod(init);
 209         a(InstructionConstants.ALOAD_0);
 210         pushConst(pageSize);
 211         pushConst(totalPages);
 212         a(fac.createInvoke(runtimeClass,"<init>",Type.VOID,new Type[]{Type.INT,Type.INT},INVOKESPECIAL));
 213
 214         a(initExtras);
 215
 216         a(InstructionConstants.RETURN);
 217
 218         init.setMaxLocals();
 219         init.setMaxStack();
 220         cl.addMethod(init.getMethod());
 221
 222
 223         MethodGen clinit = newMethod(ACC_PRIVATE|ACC_STATIC,Type.VOID, Type.NO_ARGS, "<clinit>");
 224         selectMethod(clinit);
 225         a(clinitExtras);
 226
 227         if(supportCall) {
 228             a(fac.createNew(hashClass));
 229             a(InstructionConstants.DUP);
 230             a(InstructionConstants.DUP);
 231             a(fac.createInvoke(hashClass,"<init>",Type.VOID,Type.NO_ARGS,INVOKESPECIAL));
 232             a(fac.createFieldAccess(fullClassName,"symbols",Type.getType("L"+hashClass.replace('.','/')+";"), PUTSTATIC));
 233             ELF.Symbol[] symbols = elf.getSymtab().symbols;
 234             for(int i=0;i<symbols.length;i++) {
 235                 ELF.Symbol s = symbols[i];
 236                 if(s.type == ELF.Symbol.STT_FUNC && s.binding == ELF.Symbol.STB_GLOBAL && (s.name.equals("_call_helper") || !s.name.startsWith("_"))) {
 237                     a(InstructionConstants.DUP);
 238                     a(new PUSH(cp,s.name));
 239                     a(fac.createNew("java.lang.Integer"));
 240                     a(InstructionConstants.DUP);
 241                     a(new PUSH(cp,s.addr));
 242                     a(fac.createInvoke("java.lang.Integer","<init>",Type.VOID,new Type[]{Type.INT},INVOKESPECIAL));
 243                     a(fac.createInvoke(hashClass,"put",Type.OBJECT,new Type[]{Type.OBJECT,Type.OBJECT},INVOKEVIRTUAL));
 244                     a(InstructionConstants.POP);
 245                 }
 246             }
 247             a(InstructionConstants.POP);
 248         }
 249
 250         a(InstructionConstants.RETURN);
 251         clinit.setMaxLocals();
 252         clinit.setMaxStack();
 253         cl.addMethod(clinit.getMethod());
 254
 255         if(supportCall) {
 256             MethodGen lookupSymbol = newMethod(ACC_PROTECTED,Type.INT,new Type[]{Type.STRING},"lookupSymbol");
 257             selectMethod(lookupSymbol);
 258             a(fac.createFieldAccess(fullClassName,"symbols",Type.getType("L"+hashClass.replace('.','/')+";"), GETSTATIC));
 259             a(InstructionConstants.ALOAD_1);
 260             a(fac.createInvoke(hashClass,"get",Type.OBJECT,new Type[]{Type.OBJECT},INVOKEVIRTUAL));
 261             a(InstructionConstants.DUP);
 262             BranchHandle bh = a(InstructionFactory.createBranchInstruction(IFNULL,null));
 263             a(fac.createCheckCast(new ObjectType("java.lang.Integer")));
 264             a(fac.createInvoke("java.lang.Integer","intValue",Type.INT,Type.NO_ARGS,INVOKEVIRTUAL));
 265             a(InstructionConstants.IRETURN);
 266             bh.setTarget(a(InstructionConstants.ICONST_M1));
 267             a(InstructionConstants.IRETURN);
 268             lookupSymbol.setMaxLocals();
 269             lookupSymbol.setMaxStack();
 270             cl.addMethod(lookupSymbol.getMethod());
 271         }
 272
 273         MethodGen setCPUState = newMethod(ACC_PROTECTED,Type.VOID,new Type[]{Type.getType("Lorg/ibex/nestedvm/Runtime$CPUState;")},"setCPUState");
 274         selectMethod(setCPUState);
 275         a(InstructionConstants.ALOAD_1);
 276         a(fac.createFieldAccess("org.ibex.nestedvm.Runtime$CPUState","r",new ArrayType(Type.INT,1),GETFIELD));
 277         a(InstructionConstants.ASTORE_2);
 278         for(int i=1;i<32;i++) {
 279             a(InstructionConstants.ALOAD_0);
 280             a(InstructionConstants.ALOAD_2);
 281             pushConst(i);
 282             a(InstructionConstants.IALOAD);
 283             a(fac.createFieldAccess(fullClassName,"r"+i,Type.INT, PUTFIELD));
 284         }
 285         a(InstructionConstants.ALOAD_1);
 286         a(fac.createFieldAccess("org.ibex.nestedvm.Runtime$CPUState","f",new ArrayType(Type.INT,1),GETFIELD));
 287         a(InstructionConstants.ASTORE_2);
 288         for(int i=0;i<32;i++) {
 289             a(InstructionConstants.ALOAD_0);
 290             a(InstructionConstants.ALOAD_2);
 291             pushConst(i);
 292             a(InstructionConstants.IALOAD);
 293             a(fac.createFieldAccess(fullClassName,"f"+i,Type.INT, PUTFIELD));
 294         }
 295         a(InstructionConstants.ALOAD_0);
 296         a(InstructionConstants.ALOAD_1);
 297         a(fac.createFieldAccess("org.ibex.nestedvm.Runtime$CPUState","hi",Type.INT,GETFIELD));
 298         a(fac.createFieldAccess(fullClassName,"hi",Type.INT, PUTFIELD));
 299         a(InstructionConstants.ALOAD_0);
 300         a(InstructionConstants.ALOAD_1);
 301         a(fac.createFieldAccess("org.ibex.nestedvm.Runtime$CPUState","lo",Type.INT,GETFIELD));
 302         a(fac.createFieldAccess(fullClassName,"lo",Type.INT, PUTFIELD));
 303         a(InstructionConstants.ALOAD_0);
 304         a(InstructionConstants.ALOAD_1);
 305         a(fac.createFieldAccess("org.ibex.nestedvm.Runtime$CPUState","fcsr",Type.INT,GETFIELD));
 306         a(fac.createFieldAccess(fullClassName,"fcsr",Type.INT, PUTFIELD));
 307         a(InstructionConstants.ALOAD_0);
 308         a(InstructionConstants.ALOAD_1);
 309         a(fac.createFieldAccess("org.ibex.nestedvm.Runtime$CPUState","pc",Type.INT,GETFIELD));
 310         a(fac.createFieldAccess(fullClassName,"pc",Type.INT, PUTFIELD));
 311
 312         a(InstructionConstants.RETURN);
 313         setCPUState.setMaxLocals();
 314         setCPUState.setMaxStack();
 315         cl.addMethod(setCPUState.getMethod());
 316
 317         MethodGen getCPUState = newMethod(ACC_PROTECTED,Type.VOID,new Type[]{Type.getType("Lorg/ibex/nestedvm/Runtime$CPUState;")},"getCPUState");
 318         selectMethod(getCPUState);
 319         a(InstructionConstants.ALOAD_1);
 320         a(fac.createFieldAccess("org.ibex.nestedvm.Runtime$CPUState","r",new ArrayType(Type.INT,1),GETFIELD));
 321         a(InstructionConstants.ASTORE_2);
 322         for(int i=1;i<32;i++) {
 323             a(InstructionConstants.ALOAD_2);
 324             pushConst(i);
 325             a(InstructionConstants.ALOAD_0);
 326             a(fac.createFieldAccess(fullClassName,"r"+i,Type.INT, GETFIELD));
 327             a(InstructionConstants.IASTORE);
 328         }
 329
 330         a(InstructionConstants.ALOAD_1);
 331         a(fac.createFieldAccess("org.ibex.nestedvm.Runtime$CPUState","f",new ArrayType(Type.INT,1),GETFIELD));
 332         a(InstructionConstants.ASTORE_2);
 333         for(int i=0;i<32;i++) {
 334             a(InstructionConstants.ALOAD_2);
 335             pushConst(i);
 336             a(InstructionConstants.ALOAD_0);
 337             a(fac.createFieldAccess(fullClassName,"f"+i,Type.INT, GETFIELD));
 338             a(InstructionConstants.IASTORE);
 339         }
 340         a(InstructionConstants.ALOAD_1);
 341         a(InstructionConstants.ALOAD_0);
 342         a(fac.createFieldAccess(fullClassName,"hi",Type.INT, GETFIELD));
 343         a(fac.createFieldAccess("org.ibex.nestedvm.Runtime$CPUState","hi",Type.INT,PUTFIELD));
 344         a(InstructionConstants.ALOAD_1);
 345         a(InstructionConstants.ALOAD_0);
 346         a(fac.createFieldAccess(fullClassName,"lo",Type.INT, GETFIELD));
 347         a(fac.createFieldAccess("org.ibex.nestedvm.Runtime$CPUState","lo",Type.INT,PUTFIELD));
 348         a(InstructionConstants.ALOAD_1);
 349         a(InstructionConstants.ALOAD_0);
 350         a(fac.createFieldAccess(fullClassName,"fcsr",Type.INT, GETFIELD));
 351         a(fac.createFieldAccess("org.ibex.nestedvm.Runtime$CPUState","fcsr",Type.INT,PUTFIELD));
 352         a(InstructionConstants.ALOAD_1);
 353         a(InstructionConstants.ALOAD_0);
 354         a(fac.createFieldAccess(fullClassName,"pc",Type.INT, GETFIELD));
 355         a(fac.createFieldAccess("org.ibex.nestedvm.Runtime$CPUState","pc",Type.INT,PUTFIELD));
 356
 357         a(InstructionConstants.RETURN);
 358         getCPUState.setMaxLocals();
 359         getCPUState.setMaxStack();
 360         cl.addMethod(getCPUState.getMethod());
 361
 362
 363         // FEATURE: Catch RuntimeException and turn it into a fault exception
 364         MethodGen execute = newMethod(ACC_PROTECTED,Type.VOID,Type.NO_ARGS,"_execute");
 365         selectMethod(execute);
 366         a(InstructionConstants.ALOAD_0);
 367         a(fac.createInvoke(fullClassName,"trampoline",Type.VOID,Type.NO_ARGS,INVOKESPECIAL));
 368         a(InstructionConstants.RETURN);
 369         execute.setMaxLocals();
 370         execute.setMaxStack();
 371         cl.addMethod(execute.getMethod());
 372
 373
 374         MethodGen main = newMethod(ACC_STATIC|ACC_PUBLIC,Type.VOID,new Type[]{new ArrayType(Type.STRING,1)},"main");
 375         selectMethod(main);
 376         a(fac.createNew(fullClassName));
 377         a(InstructionConstants.DUP);
 378         a(fac.createInvoke(fullClassName,"<init>",Type.VOID,Type.NO_ARGS,INVOKESPECIAL));
 379         a(new PUSH(cp,fullClassName));
 380         a(InstructionConstants.ALOAD_0);
 381         if(unixRuntime)
 382             a(fac.createInvoke("org.ibex.nestedvm.UnixRuntime","runAndExec",Type.INT,
 383                     new Type[]{Type.getType("Lorg/ibex/nestedvm/UnixRuntime;"),Type.STRING,new ArrayType(Type.STRING,1)},
 384                     INVOKESTATIC));
 385         else
 386                     a(fac.createInvoke(fullClassName,"run",Type.INT,new Type[]{Type.STRING,new ArrayType(Type.STRING,1)},INVOKEVIRTUAL));
 387         a(fac.createInvoke("java.lang.System","exit",Type.VOID,new Type[]{Type.INT},INVOKESTATIC));
 388         a(InstructionConstants.RETURN);
 389         main.setMaxLocals();
 390         main.setMaxStack();
 391         cl.addMethod(main.getMethod());
 392
 393         cl.getJavaClass().dump(os);
 394     }
 395
 396     private void addConstReturnMethod(String name, int val) {
 397             MethodGen method = newMethod(ACC_PROTECTED,Type.INT, Type.NO_ARGS,name);
 398         selectMethod(method);
 399         pushConst(val);
 400         a(InstructionConstants.IRETURN);
 401         method.setMaxLocals();
 402         method.setMaxStack();
 403         cl.addMethod(method.getMethod());
 404     }
 405
 406     private static int initDataCount;
 407     private void emitData(int addr, DataInputStream dis, int size, boolean readOnly) throws Exn,IOException {
 408         if((addr&3)!=0 || (size&3)!=0) throw new Exn("Data section on weird boundaries");
 409         int last = addr + size;
 410         while(addr < last) {
 411             int segSize = Math.min(size,28000); // must be a multiple of 56
 412             StringBuffer sb = new StringBuffer();
 413             for(int i=0;i<segSize;i+=7) {
 414                 long l = 0;
 415                 for(int j=0;j<7;j++) {
 416                     l <<= 8;
 417                     byte b = (i+j < size) ? dis.readByte() : 1;
 418                     l |= (b & 0xffL);
 419                 }
 420                 for(int j=0;j<8;j++)
 421                     sb.append((char) ((l>>>(7*(7-j)))&0x7f));
 422             }
 423             String fieldname =  "_data" + (++initDataCount);
 424             cl.addField(new FieldGen(ACC_PRIVATE|ACC_STATIC|ACC_FINAL,new ArrayType(Type.INT,1),fieldname,cp).getField());
 425
 426             selectList(clinitExtras);
 427             a(new PUSH(cp,sb.toString()));
 428             a(new PUSH(cp,segSize/4));
 429             a(fac.createInvoke("org.ibex.nestedvm.Runtime","decodeData",new ArrayType(Type.INT,1),new Type[]{Type.STRING,Type.INT},INVOKESTATIC));
 430             a(fac.createPutStatic(fullClassName,fieldname,new ArrayType(Type.INT,1)));
 431
 432             selectList(initExtras);
 433             a(InstructionConstants.ALOAD_0);
 434             a(fac.createGetStatic(fullClassName,fieldname,new ArrayType(Type.INT,1)));
 435             a(new PUSH(cp,addr));
 436             a(new PUSH(cp,readOnly));
 437             a(fac.createInvoke(fullClassName,"initPages",Type.VOID,new Type[]{new ArrayType(Type.INT,1),Type.INT,Type.BOOLEAN},INVOKEVIRTUAL));
 438
 439             addr += segSize;
 440             size -= segSize;
 441         }
 442         dis.close();
 443     }
 444
 445     private void emitBSS(int addr, int size) throws Exn {
 446         if((addr&3)!=0) throw new Exn("BSS section on weird boundaries");
 447         size = (size+3)&~3;
 448         int count = size/4;
 449         selectList(initExtras);
 450         a(InstructionConstants.ALOAD_0);
 451         a(new PUSH(cp,addr));
 452         a(new PUSH(cp,count));
 453         a(fac.createInvoke(fullClassName,"clearPages",Type.VOID,new Type[]{Type.INT,Type.INT},INVOKEVIRTUAL));
 454     }
 455
 456     // method state info
 457     private boolean textDone;
 458     private int startOfMethod = 0;
 459     private int endOfMethod = 0;
 460     private boolean unreachable = false;
 461     private InstructionHandle[] jumpHandles;
 462     private InstructionHandle defaultHandle;
 463     private InstructionHandle returnHandle;
 464     private InstructionHandle realStart;
 465     private MethodGen curMethod;
 466
 467     private boolean jumpable(int addr) { return jumpableAddresses.contains(new Integer(addr)); }
 468
 469     private void emitText(int addr, DataInputStream dis, int size) throws Exn,IOException {
 470         if(textDone) throw new Exn("Multiple text segments");
 471         textDone = true;
 472
 473         if((addr&3)!=0 || (size&3)!=0) throw new Exn("Section on weird boundaries");
 474         int count = size/4;
 475         int insn,nextInsn=-1;
 476         boolean skipNext = true;
 477
 478         for(int i=0;i<count;i++,addr+=4) {
 479             insn = skipNext ? dis.readInt() : nextInsn;
 480             nextInsn = (i == count-1) ? -1 : dis.readInt();
 481             if(addr >= endOfMethod) { endMethod(addr); startMethod(addr); }
 482             if(jumpHandles[(addr-startOfMethod)/4] != null) {
 483                 // Move the fake jump target to the current location
 484                 insnList.move(jumpHandles[(addr-startOfMethod)/4],insnList.getEnd());
 485                 unreachable = false;
 486             } else if(unreachable) {
 487                 continue;
 488             }
 489             try {
 490                 skipNext = emitInstruction(addr,insn,nextInsn);
 491             } catch(RuntimeException e) {
 492                 warn.println("Exception at " + toHex(addr));
 493                 throw e;
 494             }
 495             if(skipNext) { addr+=4; i++; }
 496         }
 497         endMethod(0);
 498         dis.close();
 499     }
 500
 501     private void startMethod(int first) {
 502         startOfMethod = first & methodMask;
 503         endOfMethod = startOfMethod + maxBytesPerMethod;
 504         curMethod = newMethod(ACC_PRIVATE,Type.VOID,Type.NO_ARGS,"run_" + toHex(startOfMethod));
 505         selectMethod(curMethod);
 506
 507         int[] buf = new int[maxBytesPerMethod/4];
 508         jumpHandles = new InstructionHandle[maxBytesPerMethod/4];
 509         int n=0;
 510         for(int addr=first;addr<endOfMethod;addr+=4) {
 511             if(jumpable(addr)) {
 512                 buf[n++] = addr;
 513                 // append NOPs for GOTO jumps (these will be moved to the correct location later)
 514                 jumpHandles[(addr-startOfMethod)/4] = a(InstructionConstants.NOP);
 515             }
 516         }
 517
 518         // append NOP for default case (throw exn) (this will be moved later)
 519         defaultHandle = a(InstructionConstants.NOP);
 520         returnHandle = a(InstructionConstants.NOP);
 521
 522         int[] matches = new int[n];
 523         System.arraycopy(buf,0,matches,0,n);
 524         InstructionHandle[] targets = new InstructionHandle[n];
 525         for(int i=0;i<matches.length;i++)
 526             targets[i] = jumpHandles[(matches[i]-startOfMethod)/4];
 527
 528
 529         // First instruction of the actual method - everything above this should be removed
 530         // before we get to the end
 531         realStart = a(InstructionConstants.NOP);
 532
 533         if(onePage) {
 534             a(InstructionConstants.ALOAD_0);
 535             a(fac.createFieldAccess(fullClassName,"page",new ArrayType(Type.INT,1), GETFIELD));
 536             a(InstructionConstants.ASTORE_2);
 537         } else {
 538             a(InstructionConstants.ALOAD_0);
 539             a(fac.createFieldAccess(fullClassName,"readPages",new ArrayType(Type.INT,2), GETFIELD));
 540             a(InstructionConstants.ASTORE_2);
 541             a(InstructionConstants.ALOAD_0);
 542             a(fac.createFieldAccess(fullClassName,"writePages",new ArrayType(Type.INT,2), GETFIELD));
 543             a(InstructionFactory.createStore(Type.OBJECT,3));
 544         }
 545
 546         LOOKUPSWITCH initialSwitch = new LOOKUPSWITCH(matches,targets,defaultHandle);
 547         a(InstructionConstants.ALOAD_0);
 548         a(fac.createFieldAccess(fullClassName,"pc",Type.INT, GETFIELD));
 549         a(initialSwitch);
 550     }
 551
 552     private void endMethod(int firstAddrOfNext) {
 553         if(startOfMethod == 0) return;
 554
 555         if(!unreachable) {
 556             preSetPC();
 557             pushConst(firstAddrOfNext);
 558             setPC();
 559             // mark the start of the next method as jumpable
 560             jumpableAddresses.add(new Integer(firstAddrOfNext));
 561         }
 562
 563         insnList.move(returnHandle,insnList.getEnd());
 564         fixupRegs();
 565         a(InstructionConstants.RETURN);
 566
 567         // move the default jump target (lookupswitch) to before the throw
 568         insnList.move(defaultHandle,insnList.getEnd());
 569         if(debugCompiler) {
 570             a(fac.createNew("org.ibex.nestedvm.Runtime$ExecutionException"));
 571             a(InstructionConstants.DUP);
 572             a(fac.createNew("java.lang.StringBuffer"));
 573             a(InstructionConstants.DUP);
 574             a(new PUSH(cp,"Jumped to invalid address: "));
 575             a(fac.createInvoke("java.lang.StringBuffer","<init>",Type.VOID,new Type[]{Type.STRING},INVOKESPECIAL));
 576             a(InstructionConstants.ALOAD_0);
 577             a(fac.createFieldAccess(fullClassName,"pc",Type.INT, GETFIELD));
 578             a(fac.createInvoke("java.lang.StringBuffer","append",Type.STRINGBUFFER,new Type[]{Type.INT},INVOKEVIRTUAL));
 579             a(fac.createInvoke("java.lang.StringBuffer","toString",Type.STRING,Type.NO_ARGS,INVOKEVIRTUAL));
 580             a(fac.createInvoke("org.ibex.nestedvm.Runtime$ExecutionException","<init>",Type.VOID,new Type[]{Type.STRING},INVOKESPECIAL));
 581             a(InstructionConstants.ATHROW);
 582         } else {
 583             a(fac.createNew("org.ibex.nestedvm.Runtime$ExecutionException"));
 584             a(InstructionConstants.DUP);
 585             a(new PUSH(cp,"Jumped to invalid address"));
 586             a(fac.createInvoke("org.ibex.nestedvm.Runtime$ExecutionException","<init>",Type.VOID,new Type[]{Type.STRING},INVOKESPECIAL));
 587             a(InstructionConstants.ATHROW);
 588         }
 589
 590         if(insnList.getStart() != realStart) {
 591             System.err.println(insnList);
 592             throw new Error("A jumpHandle wasn't moved into place");
 593         }
 594
 595         curMethod.removeNOPs();
 596         curMethod.setMaxLocals();
 597         curMethod.setMaxStack();
 598
 599         cl.addMethod(curMethod.getMethod());
 600
 601         endOfMethod = startOfMethod = 0;
 602     }
 603
 604
 605     private void leaveMethod() {
 606         a(InstructionFactory.createBranchInstruction(GOTO,returnHandle));
 607     }
 608
 609     private void branch(int pc, int target) {
 610         if((pc&methodMask) == (target&methodMask)) {
 611             a(InstructionFactory.createBranchInstruction(GOTO,jumpHandles[(target-startOfMethod)/4]));
 612         } else {
 613             preSetPC();
 614             pushConst(target);
 615             setPC();
 616             leaveMethod();
 617         }
 618     }
 619
 620     // This assumes everything needed by ifInsn is already on the stack
 621     private boolean doIfInstruction(short op, int pc, int target, int nextInsn) throws Exn {
 622         emitInstruction(-1,nextInsn,-1); // delay slot
 623         BranchHandle h;
 624         IfInstruction ifInsn = (IfInstruction) InstructionFactory.createBranchInstruction(op,null);
 625         if((target&methodMask) == (pc&methodMask)) {
 626             h = a(ifInsn);
 627             h.setTarget(jumpHandles[(target-startOfMethod)/4]);
 628         } else {
 629             h = a(ifInsn.negate());
 630             branch(pc,target);
 631             h.setTarget(a(InstructionConstants.NOP));
 632         }
 633         if(!jumpable(pc+4)) return true; // done - skip it
 634
 635         //System.err.println("Delay slot is jumpable - This code is untested + " + toHex(nextInsn));
 636         if(pc+4==endOfMethod) {
 637             // the delay slot is at the start of the next method
 638             jumpableAddresses.add(new Integer(pc+8)); // make the 2nd insn of the next method jumpable
 639             branch(pc,pc+8); // jump over it
 640             //System.err.println("delay slot: " + toHex(pc+8));
 641             unreachable = true;
 642             return false; // we still need to output it
 643         } else {
 644             //System.err.println("jumped over delay slot: " + toHex(pc+4));
 645             // add another copy and jump over
 646             h = a(InstructionFactory.createBranchInstruction(GOTO,null));
 647             insnList.move(jumpHandles[(pc+4-startOfMethod)/4],insnList.getEnd());
 648             emitInstruction(-1,nextInsn,-1); // delay slot
 649             h.setTarget(a(InstructionConstants.NOP));
 650             return true;
 651         }
 652     }
 653
 654     private boolean emitInstruction(int pc, int insn, int nextInsn) throws Exn {
 655         if(insn == -1) throw new Exn("insn is -1");
 656
 657         int op = (insn >>> 26) & 0xff;                 // bits 26-31
 658         int rs = (insn >>> 21) & 0x1f;                 // bits 21-25
 659         int rt = (insn >>> 16) & 0x1f;                 // bits 16-20
 660         int ft = (insn >>> 16) & 0x1f;
 661         int rd = (insn >>> 11) & 0x1f;                 // bits 11-15
 662         int fs = (insn >>> 11) & 0x1f;
 663         int shamt = (insn >>> 6) & 0x1f;               // bits 6-10
 664         int fd = (insn >>> 6) & 0x1f;
 665         int subcode = insn & 0x3f;                     // bits 0-5
 666         int breakCode = (insn >>> 6) & 0xfffff;         // bits 6-20
 667
 668         int jumpTarget = (insn & 0x03ffffff);          // bits 0-25
 669         int unsignedImmediate = insn & 0xffff;
 670         int signedImmediate = (insn << 16) >> 16;
 671         int branchTarget = signedImmediate;
 672
 673         // temporaries
 674         BranchHandle b1,b2;
 675
 676         switch(op) {
 677         case 0: {
 678             switch(subcode) {
 679             case 0: // SLL
 680                 if(insn == 0) break;
 681                 preSetReg(R+rd);
 682                 pushRegWZ(R+rt);
 683                 pushConst(shamt);
 684                 a(InstructionConstants.ISHL);
 685                 setReg();
 686                 break;
 687             case 2: // SRL
 688                 preSetReg(R+rd);
 689                 pushRegWZ(R+rt);
 690                 pushConst(shamt);
 691                 a(InstructionConstants.IUSHR);
 692                 setReg();
 693                 break;
 694             case 3: // SRA
 695                 preSetReg(R+rd);
 696                 pushRegWZ(R+rt);
 697                 pushConst(shamt);
 698                 a(InstructionConstants.ISHR);
 699                 setReg();
 700                 break;
 701             case 4: // SLLV
 702                 preSetReg(R+rd);
 703                 pushRegWZ(R+rt);
 704                 pushRegWZ(R+rs);
 705                 a(InstructionConstants.ISHL);
 706                 setReg();
 707                 break;
 708             case 6: // SRLV
 709                 preSetReg(R+rd);
 710                 pushRegWZ(R+rt);
 711                 pushRegWZ(R+rs);
 712                 a(InstructionConstants.IUSHR);
 713                 setReg();
 714                 break;
 715             case 7: // SRAV
 716                 preSetReg(R+rd);
 717                 pushRegWZ(R+rt);
 718                 pushRegWZ(R+rs);
 719                 a(InstructionConstants.ISHR);
 720                 setReg();
 721                 break;
 722             case 8: // JR
 723                 if(pc == -1) throw new Exn("pc modifying insn in delay slot");
 724                 emitInstruction(-1,nextInsn,-1);
 725                 preSetPC();
 726                 pushRegWZ(R+rs);
 727                 setPC();
 728                 leaveMethod();
 729                 unreachable = true;
 730                 break;
 731             case 9: // JALR
 732                 if(pc == -1) throw new Exn("pc modifying insn in delay slot");
 733                 emitInstruction(-1,nextInsn,-1);
 734                 preSetPC();
 735                 pushRegWZ(R+rs);
 736                 setPC();
 737
 738                 preSetReg(R+RA);
 739                 pushConst(pc+8);
 740                 setReg();
 741                 leaveMethod();
 742                 unreachable = true;
 743                 break;
 744             case 12: // SYSCALL
 745                 preSetPC();
 746                 pushConst(pc);
 747                 setPC();
 748
 749                 restoreChangedRegs();
 750
 751                 preSetReg(R+V0);
 752                 a(InstructionConstants.ALOAD_0);
 753                 pushRegZ(R+V0);
 754                 pushRegZ(R+A0);
 755                 pushRegZ(R+A1);
 756                 pushRegZ(R+A2);
 757                 pushRegZ(R+A3);
 758                 a(fac.createInvoke(fullClassName,"syscall",Type.INT,new Type[]{Type.INT,Type.INT,Type.INT,Type.INT,Type.INT},INVOKEVIRTUAL));
 759                 setReg();
 760
 761                 a(InstructionConstants.ALOAD_0);
 762                 a(fac.createFieldAccess(fullClassName,"state",Type.INT, GETFIELD));
 763                 pushConst(Runtime.RUNNING);
 764                 b1 = a(InstructionFactory.createBranchInstruction(IF_ICMPEQ,null));
 765                 preSetPC();
 766                 pushConst(pc+4);
 767                 setPC();
 768                 leaveMethod();
 769                 b1.setTarget(a(InstructionConstants.NOP));
 770
 771                 break;
 772             case 13: // BREAK
 773                 a(fac.createNew("org.ibex.nestedvm.Runtime$ExecutionException"));
 774                 a(InstructionConstants.DUP);
 775                 a(new PUSH(cp,"BREAK Code " + toHex(breakCode)));
 776                 a(fac.createInvoke("org.ibex.nestedvm.Runtime$ExecutionException","<init>",Type.VOID,new Type[]{Type.STRING},INVOKESPECIAL));
 777                 a(InstructionConstants.ATHROW);
 778                 unreachable = true;
 779                 break;
 780             case 16: // MFHI
 781                 preSetReg(R+rd);
 782                 pushReg(HI);
 783                 setReg();
 784                 break;
 785             case 17: // MTHI
 786                 preSetReg(HI);
 787                 pushRegZ(R+rs);
 788                 setReg();
 789                 break;
 790             case 18: // MFLO
 791                 preSetReg(R+rd);
 792                 pushReg(LO);
 793                 setReg();
 794                 break;
 795             case 19: // MTLO
 796                 preSetReg(LO);
 797                 pushRegZ(R+rs);
 798                 setReg();
 799                 break;
 800             case 24: // MULT
 801                 pushRegWZ(R+rs);
 802                 a(InstructionConstants.I2L);
 803                 pushRegWZ(R+rt);
 804                 a(InstructionConstants.I2L);
 805                 a(InstructionConstants.LMUL);
 806                 a(InstructionConstants.DUP2);
 807
 808                 a(InstructionConstants.L2I);
 809                 if(preSetReg(LO))
 810                     a(InstructionConstants.SWAP);
 811                 setReg();
 812
 813                 pushConst(32);
 814                 a(InstructionConstants.LUSHR);
 815                 a(InstructionConstants.L2I);
 816                 if(preSetReg(HI))
 817                     a(InstructionConstants.SWAP);
 818                 setReg();
 819
 820                 break;
 821             case 25: // MULTU
 822                 pushRegWZ(R+rs);
 823                 a(InstructionConstants.I2L);
 824                 pushConst(0xffffffffL);
 825                 a(InstructionConstants.LAND);
 826                 pushRegWZ(R+rt);
 827                 a(InstructionConstants.I2L);
 828                 pushConst(0xffffffffL);
 829                 a(InstructionConstants.LAND);
 830                 a(InstructionConstants.LMUL);
 831                 a(InstructionConstants.DUP2);
 832
 833                 a(InstructionConstants.L2I);
 834                 if(preSetReg(LO))
 835                     a(InstructionConstants.SWAP);
 836                 setReg();
 837
 838                 pushConst(32);
 839                 a(InstructionConstants.LUSHR);
 840                 a(InstructionConstants.L2I);
 841                 if(preSetReg(HI))
 842                     a(InstructionConstants.SWAP);
 843                 setReg();
 844
 845                 break;
 846             case 26: // DIV
 847                 pushRegWZ(R+rs);
 848                 pushRegWZ(R+rt);
 849                 a(InstructionConstants.DUP2);
 850
 851                 a(InstructionConstants.IDIV);
 852                 if(preSetReg(LO))
 853                     a(InstructionConstants.SWAP);
 854                 setReg();
 855
 856                 a(InstructionConstants.IREM);
 857                 if(preSetReg(HI))
 858                     a(InstructionConstants.SWAP);
 859                 setReg();
 860
 861                 break;
 862             case 27: { // DIVU
 863                 pushRegWZ(R+rt);
 864                 a(InstructionConstants.DUP);
 865                 setTmp();
 866                 b1 = a(InstructionFactory.createBranchInstruction(IFEQ,null));
 867
 868                 pushRegWZ(R+rs);
 869                 a(InstructionConstants.I2L);
 870                 pushConst(0xffffffffL);
 871                 a(InstructionConstants.LAND);
 872                 a(InstructionConstants.DUP2);
 873                 pushTmp();
 874                 a(InstructionConstants.I2L);
 875                 pushConst(0xffffffffL);
 876
 877                 a(InstructionConstants.LAND);
 878                 a(InstructionConstants.DUP2_X2);
 879                 a(InstructionConstants.LDIV);
 880
 881                 a(InstructionConstants.L2I);
 882                 if(preSetReg(LO))
 883                     a(InstructionConstants.SWAP);
 884                 setReg();
 885
 886                 a(InstructionConstants.LREM);
 887                 a(InstructionConstants.L2I);
 888                 if(preSetReg(HI))
 889                     a(InstructionConstants.SWAP);
 890                 setReg();
 891
 892                 b1.setTarget(a(InstructionConstants.NOP));
 893
 894                 break;
 895             }
 896             case 32: // ADD
 897                 throw new Exn("ADD (add with oveflow trap) not suported");
 898             case 33: // ADDU
 899                    preSetReg(R+rd);
 900                 if(rt != 0 && rs != 0) {
 901                     pushReg(R+rs);
 902                     pushReg(R+rt);
 903                     a(InstructionConstants.IADD);
 904                 } else if(rs != 0) {
 905                     pushReg(R+rs);
 906                 } else {
 907                     pushRegZ(R+rt);
 908                 }
 909                 setReg();
 910                 break;
 911             case 34: // SUB
 912                 throw new Exn("SUB (add with oveflow trap) not suported");
 913             case 35: // SUBU
 914                 preSetReg(R+rd);
 915                 if(rt != 0 && rs != 0) {
 916                     pushReg(R+rs);
 917                     pushReg(R+rt);
 918                     a(InstructionConstants.ISUB);
 919                 } else if(rt != 0) {
 920                     pushReg(R+rt);
 921                     a(InstructionConstants.INEG);
 922                 } else {
 923                     pushRegZ(R+rs);
 924                 }
 925                 setReg();
 926                 break;
 927             case 36: // AND
 928                 preSetReg(R+rd);
 929                 pushRegWZ(R+rs);
 930                 pushRegWZ(R+rt);
 931                 a(InstructionConstants.IAND);
 932                 setReg();
 933                 break;
 934             case 37: // OR
 935                 preSetReg(R+rd);
 936                 pushRegWZ(R+rs);
 937                 pushRegWZ(R+rt);
 938                 a(InstructionConstants.IOR);
 939                 setReg();
 940                 break;
 941             case 38: // XOR
 942                 preSetReg(R+rd);
 943                 pushRegWZ(R+rs);
 944                 pushRegWZ(R+rt);
 945                 a(InstructionConstants.IXOR);
 946                 setReg();
 947                 break;
 948             case 39: // NOR
 949                 preSetReg(R+rd);
 950                 if(rs != 0 || rt != 0) {
 951                     if(rs != 0 && rt != 0) {
 952                         pushReg(R+rs);
 953                         pushReg(R+rt);
 954                         a(InstructionConstants.IOR);
 955                     } else if(rs != 0) {
 956                         pushReg(R+rs);
 957                     } else {
 958                         pushReg(R+rt);
 959                     }
 960                     a(InstructionConstants.ICONST_M1);
 961                     a(InstructionConstants.IXOR);
 962                 } else {
 963                     pushConst(-1);
 964                 }
 965                 setReg();
 966                 break;
 967             case 42: // SLT
 968                 preSetReg(R+rd);
 969                 if(rs != rt) {
 970                     pushRegZ(R+rs);
 971                     pushRegZ(R+rt);
 972                     b1 = a(InstructionFactory.createBranchInstruction(IF_ICMPLT,null));
 973                     a(InstructionConstants.ICONST_0);
 974                     b2 = a(InstructionFactory.createBranchInstruction(GOTO,null));
 975                     b1.setTarget(a(InstructionConstants.ICONST_1));
 976                     b2.setTarget(a(InstructionConstants.NOP));
 977                 } else {
 978                     pushConst(0);
 979                 }
 980                 setReg();
 981                 break;
 982             case 43: // SLTU
 983                 preSetReg(R+rd);
 984                 if(rs != rt) {
 985                     if(rs != 0) {
 986                         pushReg(R+rs);
 987                         a(InstructionConstants.I2L);
 988                         pushConst(0xffffffffL);
 989                         a(InstructionConstants.LAND);
 990                         pushReg(R+rt);
 991                         a(InstructionConstants.I2L);
 992                         pushConst(0xffffffffL);
 993                         a(InstructionConstants.LAND);
 994                         a(InstructionConstants.LCMP);
 995                         b1 = a(InstructionFactory.createBranchInstruction(IFLT,null));
 996                     } else {
 997                         pushReg(R+rt);
 998                         b1 = a(InstructionFactory.createBranchInstruction(IFNE,null));
 999                     }
1000                     a(InstructionConstants.ICONST_0);
1001                     b2 = a(InstructionFactory.createBranchInstruction(GOTO,null));
1002                     b1.setTarget(a(InstructionConstants.ICONST_1));
1003                     b2.setTarget(a(InstructionConstants.NOP));
1004                 } else {
1005                     pushConst(0);
1006                 }
1007                 setReg();
1008                 break;
1009             default:
1010                 throw new RuntimeException("Illegal instruction 0/" + subcode);
1011             }
1012             break;
1013         }
1014         case 1: {
1015             switch(rt) {
1016             case 0: // BLTZ
1017                 if(pc == -1) throw new Exn("pc modifying insn in delay slot");
1018                 pushRegWZ(R+rs);
1019                 return doIfInstruction(IFLT,pc,pc+branchTarget*4+4,nextInsn);
1020             case 1: // BGEZ
1021                 if(pc == -1) throw new Exn("pc modifying insn in delay slot");
1022                 pushRegWZ(R+rs);
1023                 return doIfInstruction(IFGE,pc,pc+branchTarget*4+4,nextInsn);
1024             case 16: // BLTZAL
1025                 if(pc == -1) throw new Exn("pc modifying insn in delay slot");
1026                 pushRegWZ(R+rs);
1027                 b1 = a(InstructionFactory.createBranchInstruction(IFGE,null));
1028                 emitInstruction(-1,nextInsn,-1);
1029                 preSetReg(R+RA);
1030                 pushConst(pc+8);
1031                 setReg();
1032                 branch(pc,pc+branchTarget*4+4);
1033                 b1.setTarget(a(InstructionConstants.NOP));
1034                 break;
1035             case 17: // BGEZAL
1036                 if(pc == -1) throw new Exn("pc modifying insn in delay slot");
1037                 b1 = null;
1038                 if(rs != 0) { // r0 is always >= 0
1039                     pushRegWZ(R+rs);
1040                     b1 = a(InstructionFactory.createBranchInstruction(IFLT,null));
1041                 }
1042                 emitInstruction(-1,nextInsn,-1);
1043                 preSetReg(R+RA);
1044                 pushConst(pc+8);
1045                 setReg();
1046                 branch(pc,pc+branchTarget*4+4);
1047                 if(b1 != null) b1.setTarget(a(InstructionConstants.NOP));
1048                 if(b1 == null) unreachable = true;
1049                 break;
1050             default:
1051                 throw new RuntimeException("Illegal Instruction 1/" + rt);
1052             }
1053             break;
1054         }
1055         case 2: { // J
1056             if(pc == -1) throw new Exn("pc modifying insn in delay slot");
1057             emitInstruction(-1,nextInsn,-1);
1058             branch(pc,(pc&0xf0000000)|(jumpTarget << 2));
1059             unreachable = true;
1060             break;
1061         }
1062         case 3: { // JAL
1063             if(pc == -1) throw new Exn("pc modifying insn in delay slot");
1064             int target = (pc&0xf0000000)|(jumpTarget << 2);
1065             emitInstruction(-1,nextInsn,-1);
1066             if(optimizedMemcpy && (target == memcpy || target == memset)) {
1067                 a(InstructionConstants.ALOAD_0);
1068                 pushRegZ(R+4);
1069                 pushRegZ(R+5);
1070                 pushRegZ(R+6);
1071                 a(fac.createInvoke(fullClassName,target==memcpy ? "memcpy" : "memset", Type.VOID, new Type[]{Type.INT,Type.INT,Type.INT},INVOKEVIRTUAL));
1072                 preSetReg(R+2);
1073                 pushReg(R+4);
1074                 setReg();
1075                 branch(pc,pc+8);
1076             } else {
1077                 preSetReg(R+RA);
1078                 pushConst(pc+8);
1079                 setReg();
1080                 branch(pc, target);
1081             }
1082             unreachable = true;
1083             break;
1084         }
1085         case 4: // BEQ
1086             if(pc == -1) throw new Exn("pc modifying insn in delay slot");
1087             if(rs == rt) {
1088                 emitInstruction(-1,nextInsn,-1);
1089                 branch(pc,pc+branchTarget*4+4);
1090                 unreachable = true;
1091             } else if(rs == 0 || rt == 0) {
1092                 pushReg(rt == 0 ? R+rs : R+rt);
1093                 return doIfInstruction(IFEQ,pc,pc+branchTarget*4+4,nextInsn);
1094             } else {
1095                 pushReg(R+rs);
1096                 pushReg(R+rt);
1097                 return doIfInstruction(IF_ICMPEQ,pc,pc+branchTarget*4+4,nextInsn);
1098             }
1099             break;
1100         case 5: // BNE
1101             if(pc == -1) throw new Exn("pc modifying insn in delay slot");
1102             pushRegWZ(R+rs);
1103             if(rt == 0) {
1104                 return doIfInstruction(IFNE,pc,pc+branchTarget*4+4,nextInsn);
1105             } else {
1106                 pushReg(R+rt);
1107                 return doIfInstruction(IF_ICMPNE,pc,pc+branchTarget*4+4,nextInsn);
1108             }
1109         case 6: //BLEZ
1110             if(pc == -1) throw new Exn("pc modifying insn in delay slot");
1111             pushRegWZ(R+rs);
1112             return doIfInstruction(IFLE,pc,pc+branchTarget*4+4,nextInsn);
1113         case 7: //BGTZ
1114             if(pc == -1) throw new Exn("pc modifying insn in delay slot");
1115             pushRegWZ(R+rs);
1116             return doIfInstruction(IFGT,pc,pc+branchTarget*4+4,nextInsn);
1117         case 8: // ADDI
1118             throw new Exn("ADDI (add immediate with oveflow trap) not suported");
1119         case 9: // ADDIU
1120             preSetReg(R+rt);
1121             addiu(rs,signedImmediate);
1122             setReg();
1123             break;
1124         case 10: // SLTI
1125             preSetReg(R+rt);
1126             pushRegWZ(R+rs);
1127             pushConst(signedImmediate);
1128             b1 = a(InstructionFactory.createBranchInstruction(IF_ICMPLT,null));
1129             a(InstructionConstants.ICONST_0);
1130             b2 = a(InstructionFactory.createBranchInstruction(GOTO,null));
1131             b1.setTarget(a(InstructionConstants.ICONST_1));
1132             b2.setTarget(a(InstructionConstants.NOP));
1133             setReg();
1134             break;
1135         case 11: // SLTIU
1136             preSetReg(R+rt);
1137             pushRegWZ(R+rs);
1138             a(InstructionConstants.I2L);
1139             pushConst(0xffffffffL);
1140             a(InstructionConstants.LAND);
1141             pushConst((long)unsignedImmediate);
1142             a(InstructionConstants.LCMP);
1143
1144             b1 = a(InstructionFactory.createBranchInstruction(IFLT,null));
1145             a(InstructionConstants.ICONST_0);
1146             b2 = a(InstructionFactory.createBranchInstruction(GOTO,null));
1147             b1.setTarget(a(InstructionConstants.ICONST_1));
1148             b2.setTarget(a(InstructionConstants.NOP));
1149
1150             setReg();
1151             break;
1152         case 12: // ANDI
1153             preSetReg(R+rt);
1154             pushRegWZ(R+rs);
1155             pushConst(unsignedImmediate);
1156             a(InstructionConstants.IAND);
1157             setReg();
1158             break;
1159         case 13: // ORI
1160             preSetReg(R+rt);
1161             if(rs != 0 && unsignedImmediate != 0) {
1162                 pushReg(R+rs);
1163                 pushConst(unsignedImmediate);
1164                 a(InstructionConstants.IOR);
1165             } else if(rs != 0){
1166                 pushReg(R+rs);
1167             } else {
1168                 pushConst(unsignedImmediate);
1169             }
1170             setReg();
1171             break;
1172         case 14: // XORI
1173             preSetReg(R+rt);
1174             pushRegWZ(R+rs);
1175             pushConst(unsignedImmediate);
1176             a(InstructionConstants.IXOR);
1177             setReg();
1178             break;
1179         case 15: // LUI
1180             preSetReg(R+rt);
1181             pushConst(unsignedImmediate << 16);
1182             setReg();
1183             break;
1184         case 16:
1185             throw new Exn("TLB/Exception support not implemented");
1186         case 17: { // FPU
1187             switch(rs) {
1188             case 0: // MFC.1
1189                 preSetReg(R+rt);
1190                 pushReg(F+rd);
1191                 setReg();
1192                 break;
1193             case 2: // CFC.1
1194                 if(fs != 31) throw new Exn("FCR " + fs + " unavailable");
1195                 preSetReg(R+rt);
1196                 pushReg(FCSR);
1197                 setReg();
1198                 break;
1199             case 4: // MTC.1
1200                 preSetReg(F+rd);
1201                 if(rt != 0)
1202                     pushReg(R+rt);
1203                 else
1204                     pushConst(0);
1205                 setReg();
1206                 break;
1207             case 6: // CTC.1
1208                 if(fs != 31) throw new Exn("FCR " + fs + " unavailable");
1209                 preSetReg(FCSR);
1210                 pushReg(R+rt);
1211                 setReg();
1212                 break;
1213             case 8: {// BC1F, BC1T
1214                 pushReg(FCSR);
1215                 pushConst(0x800000);
1216                 a(InstructionConstants.IAND);
1217                 return doIfInstruction(((insn>>>16)&1) == 0 ? IFEQ : IFNE,pc,pc+branchTarget*4+4,nextInsn);
1218             }
1219             case 16:
1220             case 17:
1221             { // Single/Double math
1222                 boolean d = rs == 17;
1223                 switch(subcode) {
1224                 case 0: // ADD.X
1225                     preSetDouble(F+fd,d);
1226                     pushDouble(F+fs,d);
1227                     pushDouble(F+ft,d);
1228                     a(d ? InstructionConstants.DADD : InstructionConstants.FADD);
1229                     setDouble(d);
1230                     break;
1231                 case 1: // SUB.X
1232                     preSetDouble(F+fd,d);
1233                     pushDouble(F+fs,d);
1234                     pushDouble(F+ft,d);
1235                     a(d ? InstructionConstants.DSUB : InstructionConstants.FSUB);
1236                     setDouble(d);
1237                     break;
1238                 case 2: // MUL.X
1239                     preSetDouble(F+fd,d);
1240                     pushDouble(F+fs,d);
1241                     pushDouble(F+ft,d);
1242                     a(d ? InstructionConstants.DMUL : InstructionConstants.FMUL);
1243                     setDouble(d);
1244                     break;
1245                 case 3: // DIV.X
1246                     preSetDouble(F+fd,d);
1247                     pushDouble(F+fs,d);
1248                     pushDouble(F+ft,d);
1249                     a(d ? InstructionConstants.DDIV : InstructionConstants.FDIV);
1250                     setDouble(d);
1251                     break;
1252                 case 5: // ABS.X
1253                     preSetDouble(F+fd,d);
1254                     // NOTE: We can't use fneg/dneg here since they'll turn +0.0 into -0.0
1255
1256                     pushDouble(F+fs,d);
1257                     a(d ? InstructionConstants.DUP2 : InstructionConstants.DUP);
1258                     a(d ? InstructionConstants.DCONST_0 : InstructionConstants.FCONST_0);
1259                     a(d ? InstructionConstants.DCMPG : InstructionConstants.FCMPG);
1260
1261                     b1 = a(InstructionFactory.createBranchInstruction(IFGT,null));
1262                     a(d ? InstructionConstants.DCONST_0 : InstructionConstants.FCONST_0);
1263                     if(d) {
1264                         a(InstructionConstants.DUP2_X2);
1265                         a(InstructionConstants.POP2);
1266                     } else {
1267                         a(InstructionConstants.POP);
1268                     }
1269                     a(InstructionConstants.DSUB);
1270
1271                     b1.setTarget(setDouble(d));
1272
1273                     break;
1274                 case 6: // MOV.X
1275                     preSetReg(F+fd);
1276                     pushReg(F+fs);
1277                     setReg();
1278
1279                     preSetReg(F+fd+1);
1280                     pushReg(F+fs+1);
1281                     setReg();
1282
1283                     break;
1284                 case 7: // NEG.X
1285                     preSetDouble(F+fd,d);
1286                     pushDouble(F+fs,d);
1287                     a(d ? InstructionConstants.DNEG : InstructionConstants.FNEG);
1288                     setDouble(d);
1289                     break;
1290                 case 32: // CVT.S.X
1291                     preSetFloat(F+fd);
1292                     pushDouble(F+fd,d);
1293                     if(d) a(InstructionConstants.D2F);
1294                     setFloat();
1295                     break;
1296                 case 33: // CVT.D.X
1297                     preSetDouble(F+fd);
1298                     pushDouble(F+fd,d);
1299                     if(!d) a(InstructionConstants.F2D);
1300                     setDouble();
1301                     break;
1302                 case 36: { // CVT.W.D
1303                     int[] matches = new int[4];
1304                     for(int i=0;i<4;i++) matches[i] = i;
1305
1306                     TABLESWITCH ts = new  TABLESWITCH(matches,new InstructionHandle[4], null);
1307
1308                     preSetReg(F+fd);
1309                     pushDouble(F+fs,d);
1310                     pushReg(FCSR);
1311                     a(InstructionConstants.ICONST_3);
1312                     a(InstructionConstants.IAND);
1313                     a(ts);
1314
1315                     // Round towards plus infinity
1316                     ts.setTarget(2,a(InstructionConstants.NOP));
1317                     if(!d) a(InstructionConstants.F2D); // Ugh.. java.lang.Math doesn't have a float ceil/floor
1318                     a(fac.createInvoke("java.lang.Math","ceil",Type.DOUBLE,new Type[]{Type.DOUBLE},INVOKESTATIC));
1319                     if(!d) a(InstructionConstants.D2F);
1320                     b1 = a(InstructionFactory.createBranchInstruction(GOTO,null));
1321
1322                     // Round to nearest
1323                     ts.setTarget(0,d ? pushConst(0.5d) : pushConst(0.5f));
1324                     a(d ? InstructionConstants.DADD : InstructionConstants.FADD);
1325                     // fall through
1326
1327                     // Round towards minus infinity
1328                     ts.setTarget(3,a(InstructionConstants.NOP));
1329                     if(!d) a(InstructionConstants.F2D);
1330                     a(fac.createInvoke("java.lang.Math","floor",Type.DOUBLE,new Type[]{Type.DOUBLE},INVOKESTATIC));
1331                     if(!d) a(InstructionConstants.D2F);
1332
1333                     InstructionHandle h = a(d ? InstructionConstants.D2I : InstructionConstants.F2I);
1334                     setReg();
1335
1336                     ts.setTarget(1,h);
1337                     ts.setTarget(h);
1338                     b1.setTarget(h);
1339
1340                     break;
1341                 }
1342                 case 50: // C.EQ.D
1343                 case 60: // C.LT.D
1344                 case 62: // C.LE.D
1345                     preSetReg(FCSR);
1346                     pushReg(FCSR);
1347                     pushConst(~0x800000);
1348                     a(InstructionConstants.IAND);
1349                     pushDouble(F+fs,d);
1350                     pushDouble(F+ft,d);
1351                     a(d ? InstructionConstants.DCMPG : InstructionConstants.FCMPG);
1352                     switch(subcode) {
1353                         case 50: b1 = a(InstructionFactory.createBranchInstruction(IFEQ,null)); break;
1354                         case 60: b1 = a(InstructionFactory.createBranchInstruction(IFLT,null)); break;
1355                         case 62: b1 = a(InstructionFactory.createBranchInstruction(IFLE,null)); break;
1356                         default: b1 = null;
1357                     }
1358
1359                     pushConst(0x000000);
1360                     b2 = a(InstructionFactory.createBranchInstruction(GOTO,null));
1361                     b1.setTarget(pushConst(0x800000));
1362                     b2.setTarget(a(InstructionConstants.IOR));
1363                     setReg();
1364                     break;
1365                 default: throw new Exn("Invalid Instruction 17/" + rs + "/" + subcode);
1366                 }
1367                 break;
1368             }
1369             case 20: { // Integer
1370                 switch(subcode) {
1371                 case 32: // CVT.S.W
1372                     preSetFloat(F+fd);
1373                     pushReg(F+fs);
1374                     a(InstructionConstants.I2F);
1375                     setFloat();
1376                     break;
1377                 case 33: // CVT.D.W
1378                     preSetDouble(F+fd);
1379                     pushReg(F+fs);
1380                     a(InstructionConstants.I2D);
1381                     setDouble();
1382                     break;
1383                 default: throw new Exn("Invalid Instruction 17/" + rs + "/" + subcode);
1384                 }
1385                 break;
1386             }
1387             default:
1388                 throw new Exn("Invalid Instruction 17/" + rs);
1389             }
1390             break;
1391         }
1392         case 18: case 19:
1393             throw new Exn("coprocessor 2 and 3 instructions not available");
1394         case 32: { // LB
1395             preSetReg(R+rt);
1396             addiu(R+rs,signedImmediate);
1397             setTmp();
1398             preMemRead();
1399             pushTmp();
1400             memRead(true);
1401             pushTmp();
1402
1403             a(InstructionConstants.ICONST_M1);
1404             a(InstructionConstants.IXOR);
1405             a(InstructionConstants.ICONST_3);
1406             a(InstructionConstants.IAND);
1407             a(InstructionConstants.ICONST_3);
1408             a(InstructionConstants.ISHL);
1409             a(InstructionConstants.IUSHR);
1410             a(InstructionConstants.I2B);
1411             setReg();
1412             break;
1413         }
1414         case 33: { // LH
1415             preSetReg(R+rt);
1416             addiu(R+rs,signedImmediate);
1417             setTmp();
1418             preMemRead();
1419             pushTmp();
1420             memRead(true);
1421             pushTmp();
1422
1423             a(InstructionConstants.ICONST_M1);
1424             a(InstructionConstants.IXOR);
1425             a(InstructionConstants.ICONST_2);
1426             a(InstructionConstants.IAND);
1427             a(InstructionConstants.ICONST_3);
1428             a(InstructionConstants.ISHL);
1429             a(InstructionConstants.IUSHR);
1430             a(InstructionConstants.I2S);
1431             setReg();
1432             break;
1433         }
1434         case 34: { // LWL;
1435             preSetReg(R+rt);
1436             addiu(R+rs,signedImmediate);
1437             setTmp(); // addr
1438
1439             pushRegWZ(R+rt);
1440             pushConst(0x00ffffff);
1441             pushTmp();
1442
1443             a(InstructionConstants.ICONST_M1);
1444             a(InstructionConstants.IXOR);
1445             a(InstructionConstants.ICONST_3);
1446             a(InstructionConstants.IAND);
1447             a(InstructionConstants.ICONST_3);
1448             a(InstructionConstants.ISHL);
1449             a(InstructionConstants.IUSHR);
1450             a(InstructionConstants.IAND);
1451
1452             preMemRead();
1453             pushTmp();
1454             memRead(true);
1455             pushTmp();
1456
1457             a(InstructionConstants.ICONST_3);
1458             a(InstructionConstants.IAND);
1459             a(InstructionConstants.ICONST_3);
1460             a(InstructionConstants.ISHL);
1461             a(InstructionConstants.ISHL);
1462             a(InstructionConstants.IOR);
1463
1464             setReg();
1465
1466             break;
1467
1468         }
1469         case 35: // LW
1470             preSetReg(R+rt);
1471             memRead(R+rs,signedImmediate);
1472             setReg();
1473             break;
1474         case 36: { // LBU
1475             preSetReg(R+rt);
1476             addiu(R+rs,signedImmediate);
1477             setTmp();
1478             preMemRead();
1479             pushTmp();
1480             memRead(true);
1481             pushTmp();
1482
1483             a(InstructionConstants.ICONST_M1);
1484             a(InstructionConstants.IXOR);
1485             a(InstructionConstants.ICONST_3);
1486             a(InstructionConstants.IAND);
1487             a(InstructionConstants.ICONST_3);
1488             a(InstructionConstants.ISHL);
1489             a(InstructionConstants.IUSHR);
1490             pushConst(0xff);
1491             a(InstructionConstants.IAND);
1492             setReg();
1493             break;
1494         }
1495         case 37: { // LHU
1496             preSetReg(R+rt);
1497             addiu(R+rs,signedImmediate);
1498             setTmp();
1499             preMemRead();
1500             pushTmp();
1501             memRead(true);
1502             pushTmp();
1503
1504             a(InstructionConstants.ICONST_M1);
1505             a(InstructionConstants.IXOR);
1506             a(InstructionConstants.ICONST_2);
1507             a(InstructionConstants.IAND);
1508             a(InstructionConstants.ICONST_3);
1509             a(InstructionConstants.ISHL);
1510             a(InstructionConstants.IUSHR);
1511
1512             // chars are unsigend so this works
1513             a(InstructionConstants.I2C);
1514             setReg();
1515             break;
1516         }
1517         case 38: { // LWR
1518             preSetReg(R+rt);
1519             addiu(R+rs,signedImmediate);
1520             setTmp(); // addr
1521
1522             pushRegWZ(R+rt);
1523             pushConst(0xffffff00);
1524             pushTmp();
1525
1526             a(InstructionConstants.ICONST_3);
1527             a(InstructionConstants.IAND);
1528             a(InstructionConstants.ICONST_3);
1529             a(InstructionConstants.ISHL);
1530             a(InstructionConstants.ISHL);
1531             a(InstructionConstants.IAND);
1532
1533             preMemRead();
1534             pushTmp();
1535             memRead(true);
1536             pushTmp();
1537
1538             a(InstructionConstants.ICONST_M1);
1539             a(InstructionConstants.IXOR);
1540             a(InstructionConstants.ICONST_3);
1541             a(InstructionConstants.IAND);
1542             a(InstructionConstants.ICONST_3);
1543             a(InstructionConstants.ISHL);
1544             a(InstructionConstants.IUSHR);
1545             a(InstructionConstants.IOR);
1546
1547
1548             setReg();
1549             break;
1550         }
1551         case 40: { // SB
1552             addiu(R+rs,signedImmediate);
1553             setTmp(); // addr
1554
1555             // FEATURE: DO the preMemRead(true) thing for the rest of the S* instructions
1556             preMemRead(true);
1557             pushTmp();
1558             memRead(true);
1559
1560             pushConst(0xff000000);
1561             pushTmp();
1562
1563             a(InstructionConstants.ICONST_3);
1564             a(InstructionConstants.IAND);
1565             a(InstructionConstants.ICONST_3);
1566             a(InstructionConstants.ISHL);
1567             a(InstructionConstants.IUSHR);
1568             a(InstructionConstants.ICONST_M1);
1569             a(InstructionConstants.IXOR);
1570             a(InstructionConstants.IAND);
1571
1572             if(rt != 0) {
1573                 pushReg(R+rt);
1574                 pushConst(0xff);
1575                 a(InstructionConstants.IAND);
1576             } else {
1577                 pushConst(0);
1578             }
1579             pushTmp();
1580
1581             a(InstructionConstants.ICONST_M1);
1582             a(InstructionConstants.IXOR);
1583             a(InstructionConstants.ICONST_3);
1584             a(InstructionConstants.IAND);
1585             a(InstructionConstants.ICONST_3);
1586             a(InstructionConstants.ISHL);
1587             a(InstructionConstants.ISHL);
1588             a(InstructionConstants.IOR);
1589
1590             memWrite();
1591
1592             break;
1593         }
1594         case 41: { // SH
1595             preMemWrite1();
1596
1597             addiu(R+rs,signedImmediate);
1598
1599             a(InstructionConstants.DUP);
1600             setTmp(); // addr
1601
1602             preMemWrite2(true);
1603
1604             preMemRead();
1605             pushTmp();
1606             memRead(true);
1607
1608             pushConst(0xffff);
1609             pushTmp();
1610
1611             a(InstructionConstants.ICONST_2);
1612             a(InstructionConstants.IAND);
1613             a(InstructionConstants.ICONST_3);
1614             a(InstructionConstants.ISHL);
1615             a(InstructionConstants.ISHL);
1616             a(InstructionConstants.IAND);
1617
1618             if(rt != 0) {
1619                 pushReg(R+rt);
1620                 pushConst(0xffff);
1621                 a(InstructionConstants.IAND);
1622             } else {
1623                 pushConst(0);
1624             }
1625             pushTmp();
1626
1627             a(InstructionConstants.ICONST_M1);
1628             a(InstructionConstants.IXOR);
1629             a(InstructionConstants.ICONST_2);
1630             a(InstructionConstants.IAND);
1631             a(InstructionConstants.ICONST_3);
1632             a(InstructionConstants.ISHL);
1633             a(InstructionConstants.ISHL);
1634             a(InstructionConstants.IOR);
1635
1636             memWrite();
1637
1638             break;
1639         }
1640         case 42: { // SWL
1641             preMemWrite1();
1642
1643             addiu(R+rs,signedImmediate);
1644             a(InstructionConstants.DUP);
1645             setTmp(); // addr
1646
1647             preMemWrite2(true);
1648
1649             preMemRead();
1650             pushTmp();
1651             memRead(true);
1652
1653             pushConst(0xffffff00);
1654             pushTmp();
1655
1656             a(InstructionConstants.ICONST_M1);
1657             a(InstructionConstants.IXOR);
1658             a(InstructionConstants.ICONST_3);
1659             a(InstructionConstants.IAND);
1660             a(InstructionConstants.ICONST_3);
1661             a(InstructionConstants.ISHL);
1662             a(InstructionConstants.ISHL);
1663             a(InstructionConstants.IAND);
1664
1665             pushRegWZ(R+rt);
1666             pushTmp();
1667
1668             a(InstructionConstants.ICONST_3);
1669             a(InstructionConstants.IAND);
1670             a(InstructionConstants.ICONST_3);
1671             a(InstructionConstants.ISHL);
1672             a(InstructionConstants.IUSHR);
1673             a(InstructionConstants.IOR);
1674
1675             memWrite();
1676             break;
1677
1678         }
1679         case 43: // SW
1680             preMemWrite1();
1681             preMemWrite2(R+rs,signedImmediate);
1682             pushRegZ(R+rt);
1683             memWrite();
1684             break;
1685         case 46: { // SWR
1686             preMemWrite1();
1687
1688             addiu(R+rs,signedImmediate);
1689             a(InstructionConstants.DUP);
1690             setTmp(); // addr
1691
1692             preMemWrite2(true);
1693
1694             preMemRead();
1695             pushTmp();
1696             memRead(true);
1697
1698             pushConst(0x00ffffff);
1699             pushTmp();
1700
1701             a(InstructionConstants.ICONST_3);
1702             a(InstructionConstants.IAND);
1703             a(InstructionConstants.ICONST_3);
1704             a(InstructionConstants.ISHL);
1705             a(InstructionConstants.IUSHR);
1706             a(InstructionConstants.IAND);
1707
1708             pushRegWZ(R+rt);
1709             pushTmp();
1710
1711             a(InstructionConstants.ICONST_M1);
1712             a(InstructionConstants.IXOR);
1713             a(InstructionConstants.ICONST_3);
1714             a(InstructionConstants.IAND);
1715             a(InstructionConstants.ICONST_3);
1716             a(InstructionConstants.ISHL);
1717             a(InstructionConstants.ISHL);
1718             a(InstructionConstants.IOR);
1719
1720             memWrite();
1721             break;
1722         }
1723         // FEATURE: This need to be atomic if we ever support threads (see SWC0/SC)
1724         case 48: // LWC0/LL
1725             preSetReg(R+rt);
1726             memRead(R+rs,signedImmediate);
1727             setReg();
1728             break;
1729
1730         case 49: // LWC1
1731             preSetReg(F+rt);
1732             memRead(R+rs,signedImmediate);
1733             setReg();
1734             break;
1735
1736         /* FEATURE: This needs to fail (set rt to 0) if the memory location was modified
1737          * between the LL and SC if we every support threads.
1738          */
1739         case 56: // SWC0/SC
1740             preSetReg(R+rt);
1741             preMemWrite1();
1742             preMemWrite2(R+rs,signedImmediate);
1743             pushReg(R+rt);
1744             memWrite();
1745             pushConst(1);
1746             setReg();
1747             break;
1748
1749         case 57: // SWC1
1750             preMemWrite1();
1751             preMemWrite2(R+rs,signedImmediate);
1752             pushReg(F+rt);
1753             memWrite();
1754             break;
1755         default:
1756             throw new Exn("Invalid Instruction: " + op + " at " + toHex(pc));
1757         }
1758         return false;
1759     }
1760
1761     // Helper functions for emitText
1762
1763     private static final int R = 0;
1764     private static final int F = 32;
1765     private static final int HI = 64;
1766     private static final int LO = 65;
1767     private static final int FCSR = 66;
1768     private static final int REG_COUNT=67;
1769
1770     private int[] regLocalMapping = new int[REG_COUNT];
1771     private int[] regLocalReadCount = new int[REG_COUNT];
1772     private int[] regLocalWriteCount = new int[REG_COUNT];
1773     private int nextAvailLocal;
1774
1775     private int getLocalForReg(int reg) {
1776         if(regLocalMapping[reg] != 0) return regLocalMapping[reg];
1777         if(nextAvailLocal == 0) nextAvailLocal = onePage ? 3 : 4;
1778         regLocalMapping[reg] = nextAvailLocal++;
1779         return regLocalMapping[reg];
1780     }
1781
1782     private void fixupRegs() {
1783         InstructionHandle prev = realStart;
1784         for(int i=0;i<REG_COUNT;i++) {
1785             if(regLocalMapping[i] == 0) continue;
1786
1787             prev = insnList.append(prev,InstructionConstants.ALOAD_0);
1788             prev = insnList.append(prev,fac.createFieldAccess(fullClassName,regField(i),Type.INT, GETFIELD));
1789             prev = insnList.append(prev,InstructionFactory.createStore(Type.INT,regLocalMapping[i]));
1790
1791             if(regLocalWriteCount[i] > 0) {
1792                 a(InstructionConstants.ALOAD_0);
1793                 a(InstructionFactory.createLoad(Type.INT,regLocalMapping[i]));
1794                 a(fac.createFieldAccess(fullClassName,regField(i),Type.INT, PUTFIELD));
1795             }
1796
1797             regLocalMapping[i] = regLocalReadCount[i] = regLocalWriteCount[i] = 0;
1798         }
1799         nextAvailLocal = 0;
1800     }
1801
1802     private void restoreChangedRegs() {
1803         for(int i=0;i<REG_COUNT;i++) {
1804             if(regLocalWriteCount[i] > 0) {
1805                 a(InstructionConstants.ALOAD_0);
1806                 a(InstructionFactory.createLoad(Type.INT,regLocalMapping[i]));
1807                 a(fac.createFieldAccess(fullClassName,regField(i),Type.INT, PUTFIELD));
1808             }
1809         }
1810     }
1811
1812     private String regField(int reg) {
1813         String field;
1814         switch(reg) {
1815             case HI: field = "hi"; break;
1816             case LO: field = "lo"; break;
1817             case FCSR: field = "fcsr"; break;
1818             default:
1819                 if(reg > R && reg < R+32) field="r"+(reg-R);
1820                 else if(reg >= F && reg < F+32) field="f"+(reg-F);
1821                 else throw new IllegalArgumentException(""+reg);
1822         }
1823         return field;
1824     }
1825
1826     private boolean doLocal(int reg) {
1827         //return false;
1828         return reg == R+2 || reg == R+3 || reg == R+4 || reg == R+29;
1829     }
1830
1831     private InstructionHandle pushRegWZ(int reg) {
1832         if(reg == R+0) {
1833             warn.println("Warning: Pushing r0!");
1834             new Exception().printStackTrace(warn);
1835         }
1836         return pushRegZ(reg);
1837     }
1838
1839     private InstructionHandle pushRegZ(int reg) {
1840         if(reg == R+0) return pushConst(0);
1841         else return pushReg(reg);
1842     }
1843
1844
1845     private InstructionHandle pushReg(int reg) {
1846         InstructionHandle h;
1847         if(doLocal(reg)) {
1848             regLocalReadCount[reg]++;
1849             h = a(InstructionFactory.createLoad(Type.INT,getLocalForReg(reg)));
1850         } else {
1851             h = a(InstructionConstants.ALOAD_0);
1852             a(fac.createFieldAccess(fullClassName,regField(reg),Type.INT, GETFIELD));
1853         }
1854         return h;
1855     }
1856
1857     private int preSetRegStackPos;
1858     private int[] preSetRegStack = new int[8];
1859
1860     // This can push ONE or ZERO words to the stack. If it pushed one it returns true
1861     private boolean preSetReg(int reg) {
1862         regField(reg); // just to check for validity
1863         preSetRegStack[preSetRegStackPos] = reg;
1864         preSetRegStackPos++;
1865         if(doLocal(reg)) {
1866             return false;
1867         } else {
1868             a(InstructionConstants.ALOAD_0);
1869             return true;
1870         }
1871     }
1872
1873     private InstructionHandle setReg() {
1874         if(preSetRegStackPos==0) throw new RuntimeException("didn't do preSetReg");
1875         preSetRegStackPos--;
1876         int reg = preSetRegStack[preSetRegStackPos];
1877         InstructionHandle h;
1878         if(doLocal(reg)) {
1879             h = a(InstructionFactory.createStore(Type.INT,getLocalForReg(reg)));
1880             regLocalWriteCount[reg]++;
1881         } else {
1882             h = a(fac.createFieldAccess(fullClassName,regField(reg),Type.INT, PUTFIELD));
1883         }
1884         return h;
1885     }
1886
1887     private InstructionHandle preSetPC() { return a(InstructionConstants.ALOAD_0); }
1888     private InstructionHandle setPC() { return a(fac.createFieldAccess(fullClassName,"pc",Type.INT, PUTFIELD)); }
1889
1890     //unused - private InstructionHandle pushFloat(int reg) throws CompilationException { return pushDouble(reg,false); }
1891     //unused - private InstructionHandle pushDouble(int reg) throws CompilationException { return pushDouble(reg,true); }
1892     private InstructionHandle pushDouble(int reg, boolean d) throws Exn {
1893         if(reg < F || reg >= F+32) throw new IllegalArgumentException(""+reg);
1894         InstructionHandle h;
1895         if(d) {
1896             if(reg == F+31) throw new Exn("Tried to use a double in f31");
1897             h = pushReg(reg+1);
1898             a(InstructionConstants.I2L);
1899             pushConst(32);
1900             a(InstructionConstants.LSHL);
1901             pushReg(reg);
1902             a(InstructionConstants.I2L);
1903             pushConst(0xffffffffL);
1904             a(InstructionConstants.LAND);
1905             a(InstructionConstants.LOR);
1906             //p("invokestatic java/lang/Double/longBitsToDouble(J)D");
1907             a(fac.createInvoke("java.lang.Double","longBitsToDouble",Type.DOUBLE,new Type[]{Type.LONG},INVOKESTATIC));
1908         } else {
1909             h = pushReg(reg);
1910             a(fac.createInvoke("java.lang.Float","intBitsToFloat",Type.FLOAT,new Type[]{Type.INT},INVOKESTATIC));
1911         }
1912         return h;
1913     }
1914
1915     private void preSetFloat(int reg) { preSetDouble(reg,false); }
1916     private void preSetDouble(int reg) { preSetDouble(reg,true); }
1917     private void preSetDouble(int reg, boolean d) { preSetReg(reg); }
1918
1919     private InstructionHandle setFloat() throws Exn { return setDouble(false); }
1920     private InstructionHandle setDouble() throws Exn { return setDouble(true); }
1921     private InstructionHandle setDouble(boolean d) throws Exn {
1922         int reg = preSetRegStack[preSetRegStackPos-1];
1923         if(reg < F || reg >= F+32) throw new IllegalArgumentException(""+reg);
1924         //p("invokestatic java/lang/Double/doubleToLongBits(D)J");
1925         InstructionHandle h;
1926         if(d) {
1927             if(reg == F+31) throw new Exn("Tried to use a double in f31");
1928             h = a(fac.createInvoke("java.lang.Double","doubleToLongBits",Type.LONG,new Type[]{Type.DOUBLE},INVOKESTATIC));
1929             a(InstructionConstants.DUP2);
1930             pushConst(32);
1931             a(InstructionConstants.LUSHR);
1932             a(InstructionConstants.L2I);
1933             if(preSetReg(reg+1))
1934                 a(InstructionConstants.SWAP);
1935             setReg();
1936             a(InstructionConstants.L2I);
1937             setReg(); // preSetReg was already done for this by preSetDouble
1938         } else {
1939             h = a(fac.createInvoke("java.lang.Float","floatToRawIntBits",Type.INT,new Type[]{Type.FLOAT},INVOKESTATIC));
1940             setReg();
1941         }
1942         return h;
1943     }
1944
1945     private InstructionHandle pushConst(int n) {
1946         if(n >= 0 && n <= 5) {
1947             switch(n) {
1948                 case 0: return a(InstructionConstants.ICONST_0);
1949                 case 1: return a(InstructionConstants.ICONST_1);
1950                 case 2: return a(InstructionConstants.ICONST_2);
1951                 case 3: return a(InstructionConstants.ICONST_3);
1952                 case 4: return a(InstructionConstants.ICONST_4);
1953                 case 5: return a(InstructionConstants.ICONST_5);
1954                 default: return null;
1955             }
1956         } else if(n == -1) {
1957             return a(InstructionConstants.ICONST_M1);
1958         } else if(n >= -128 && n <= 127) {
1959             return a(new BIPUSH((byte) n));
1960         } else if(n >= -32768 && n <= 32767) {
1961             return a(new SIPUSH((short) n));
1962         } else {
1963             return a(new PUSH(cp,n));
1964         }
1965     }
1966
1967     private InstructionHandle pushConst(long l) { return a(new PUSH(cp,l)); }
1968     private InstructionHandle pushConst(float f) { return a(new PUSH(cp,f)); }
1969     private InstructionHandle pushConst(double d) { return a(new PUSH(cp,d)); }
1970
1971     private void pushTmp() { a(InstructionConstants.ILOAD_1); }
1972     private void setTmp() { a(InstructionConstants.ISTORE_1); }
1973
1974     private void addiu(int reg, int offset) {
1975         if(reg != R+0 && offset != 0) {
1976             pushReg(reg);
1977             pushConst(offset);
1978             a(InstructionConstants.IADD);
1979         } else if(reg != R+0) {
1980             pushReg(reg);
1981         } else {
1982             pushConst(offset);
1983         }
1984     }
1985     private int memWriteStage;
1986     private void preMemWrite1() {
1987         if(memWriteStage!=0) throw new Error("pending preMemWrite1/2");
1988         memWriteStage=1;
1989         if(onePage)
1990             a(InstructionConstants.ALOAD_2);
1991         else if(fastMem)
1992             a(InstructionFactory.createLoad(Type.OBJECT,3));
1993         else
1994             a(InstructionConstants.ALOAD_0);
1995     }
1996
1997     private void preMemWrite2(int reg, int offset) {
1998         addiu(reg,offset);
1999         preMemWrite2();
2000     }
2001
2002     private void preMemWrite2() { preMemWrite2(false); }
2003     private void preMemWrite2(boolean addrInTmp) {
2004         if(memWriteStage!=1) throw new Error("pending preMemWrite2 or no preMemWrite1");
2005         memWriteStage=2;
2006
2007         if(nullPointerCheck) {
2008             a(InstructionConstants.DUP);
2009             a(InstructionConstants.ALOAD_0);
2010             a(InstructionConstants.SWAP);
2011             a(fac.createInvoke(fullClassName,"nullPointerCheck",Type.VOID,new Type[]{Type.INT},INVOKEVIRTUAL));
2012         }
2013
2014         if(onePage) {
2015             a(InstructionConstants.ICONST_2);
2016             a(InstructionConstants.IUSHR);
2017         } else if(fastMem) {
2018             if(!addrInTmp)
2019                 a(InstructionConstants.DUP_X1);
2020             pushConst(pageShift);
2021             a(InstructionConstants.IUSHR);
2022             a(InstructionConstants.AALOAD);
2023             if(addrInTmp)
2024                 pushTmp();
2025             else
2026                 a(InstructionConstants.SWAP);
2027             a(InstructionConstants.ICONST_2);
2028             a(InstructionConstants.IUSHR);
2029             pushConst((pageSize>>2)-1);
2030             a(InstructionConstants.IAND);
2031         }
2032     }
2033
2034     // pops an address and value off the stack, sets *addr to value
2035     private void memWrite() {
2036         if(memWriteStage!=2) throw new Error("didn't do preMemWrite1 or preMemWrite2");
2037         memWriteStage=0;
2038
2039         if(onePage) {
2040             a(InstructionConstants.IASTORE);
2041         } else if(fastMem) {
2042             a(InstructionConstants.IASTORE);
2043         } else {
2044             a(fac.createInvoke(fullClassName,"unsafeMemWrite",Type.VOID,new Type[]{Type.INT,Type.INT},INVOKEVIRTUAL));
2045         }
2046
2047     }
2048
2049     // reads the word at r[reg]+offset
2050     private void memRead(int reg, int offset) {
2051         preMemRead();
2052         addiu(reg,offset);
2053         memRead();
2054     }
2055
2056     private boolean didPreMemRead;
2057     private boolean preMemReadDoPreWrite;
2058
2059     private void preMemRead() { preMemRead(false); }
2060     private void preMemRead(boolean preWrite) {
2061         if(didPreMemRead) throw new Error("pending preMemRead");
2062         didPreMemRead = true;
2063         preMemReadDoPreWrite = preWrite;
2064         if(onePage)
2065             a(InstructionConstants.ALOAD_2);
2066         else if(fastMem)
2067             a(InstructionFactory.createLoad(Type.OBJECT,preWrite ? 3 : 2));
2068         else
2069             a(InstructionConstants.ALOAD_0);
2070     }
2071     // memRead pops an address off the stack, reads the value at that addr, and pushed the value
2072     // preMemRead MUST be called BEFORE the addresses is pushed
2073     private void memRead() { memRead(false); }
2074
2075     private void memRead(boolean addrInTmp) {
2076         if(!didPreMemRead) throw new Error("didn't do preMemRead");
2077         didPreMemRead = false;
2078         if(preMemReadDoPreWrite)
2079             memWriteStage=2;
2080
2081         if(nullPointerCheck) {
2082             a(InstructionConstants.DUP);
2083             a(InstructionConstants.ALOAD_0);
2084             a(InstructionConstants.SWAP);
2085             a(fac.createInvoke(fullClassName,"nullPointerCheck",Type.VOID,new Type[]{Type.INT},INVOKEVIRTUAL));
2086         }
2087
2088         if(onePage) {
2089             // p(target + "= page[(" + addr + ")>>>2];");
2090             a(InstructionConstants.ICONST_2);
2091             a(InstructionConstants.IUSHR);
2092             if(preMemReadDoPreWrite)
2093                 a(InstructionConstants.DUP2);
2094             a(InstructionConstants.IALOAD);
2095         } else if(fastMem) {
2096             //p(target  + " = readPages[("+addr+")>>>"+pageShift+"][(("+addr+")>>>2)&"+toHex((pageSize>>2)-1)+"];");
2097
2098             if(!addrInTmp)
2099                 a(InstructionConstants.DUP_X1);
2100             pushConst(pageShift);
2101             a(InstructionConstants.IUSHR);
2102             a(InstructionConstants.AALOAD);
2103             if(addrInTmp)
2104                 pushTmp();
2105             else
2106                 a(InstructionConstants.SWAP);
2107             a(InstructionConstants.ICONST_2);
2108             a(InstructionConstants.IUSHR);
2109             pushConst((pageSize>>2)-1);
2110             a(InstructionConstants.IAND);
2111             if(preMemReadDoPreWrite)
2112                 a(InstructionConstants.DUP2);
2113             a(InstructionConstants.IALOAD);
2114
2115         } else {
2116             if(preMemReadDoPreWrite)
2117                 a(InstructionConstants.DUP2);
2118             a(fac.createInvoke(fullClassName,"unsafeMemWrite",Type.INT,new Type[]{Type.INT},INVOKEVIRTUAL));
2119         }
2120     }
2121
2122
2123     // This might come in handy for something else
2124     /*private boolean touchesReg(int insn, int reg) {
2125         if((reg < R+0 || reg >= R+32) && reg != FCSR) throw new IllegalArgumentException(""+reg);
2126         if(reg == R+0) return false; // r0 is never modified
2127         int op = (insn >>> 26) & 0xff;                 // bits 26-31
2128         int subcode = insn & 0x3f;                     // bits 0-5
2129         int rd = (insn >>> 11) & 0x1f;                 // bits 11-15
2130         int rt = (insn >>> 16) & 0x1f;                 // bits 16-20
2131         int rs = (insn >>> 21) & 0x1f;                 // bits 21-25
2132
2133         switch(op) {
2134         case 0:
2135             if(subcode >= 0 && subcode <= 7) return reg == R+rd; // Shift ops
2136             if(subcode >= 32 && subcode <= 43) return reg == R+rd; // Other math ops
2137             if(subcode >= 24 && subcode <= 27) return reg == HI || reg == LO; // MULT/DIV
2138             break;
2139         case 13: return false; // BREAK
2140         case 17:
2141             switch(rs) {
2142                 case 0: return reg == R+rt; // MFC.1
2143                 case 2: return reg == R+rt; // CFC.1
2144                 case 4: return false; // MTC.1
2145                 case 6: return false; // CTC.1
2146                 case 16: // Single
2147                 case 17: // Double
2148                     if(subcode == 50 || subcode == 60 || subcode == 62) return reg == FCSR;
2149                     return false; // everything else just touches f0-f31
2150                 case 20: return false; // Integer - just touches f0-f31
2151             }
2152             break;
2153         default:
2154             if(op >= 8 && op <= 15) return reg == R+rt; // XXXI instructions
2155             if(op >= 40 && op <= 46) return false; // Memory WRITE ops
2156             if(op == 49) return reg == F+rt; // LWC1
2157             if(op == 57) return false; // SWC1
2158             break;
2159         }
2160         warn.println("Unknown instruction in touchesReg()- assuming it modifies all regs " + op + " " + subcode);
2161         new Exception().fillInStackTrace().printStackTrace(warn);
2162         return true;
2163     }*/
2164 }