X-Git-Url: http://git.megacz.com/?p=org.ibex.classgen.git;a=blobdiff_plain;f=src%2Forg%2Fibex%2Fclassgen%2FJSSA.java;h=2fc521ace03c227e2eec2ee45040f42d2af51988;hp=6cf8d07edb613141ffc76006ea96593d6edaeca2;hb=7b7d64efd6761d48aabe652945e907e9309bccd0;hpb=9271b834f0f1ca988f0374cad6a8cc0cce274ee0

diff --git a/src/org/ibex/classgen/JSSA.java b/src/org/ibex/classgen/JSSA.java
index 6cf8d07..2fc521a 100644
--- a/src/org/ibex/classgen/JSSA.java
+++ b/src/org/ibex/classgen/JSSA.java
@@ -13,29 +13,51 @@ public class JSSA extends MethodGen implements CGConst {
     
     public JSSA(Type.Class c, DataInput in, ConstantPool cp) throws IOException {
         super(c, in, cp);
-        local = new Expr[maxLocals];
-        stack = new Expr[maxStack];
-        int n=0;
-        if (!isStatic())
-            local[n++] = new Argument("this",method.getDeclaringClass());
-        for(int i=0;i<this.method.getNumArgs(); i++)
-            local[n++] = new Argument("arg"+i, this.method.getArgType(i));
+        sp = 0;
+        stacks = new Phi[size()][];
+        locals = new Phi[size()][];
         for(int i=0; i<size(); i++) {
-            int    op  = get(i);
-            Object arg = getArg(i);
+            int n = 0;
+            locals[i] = new Phi[maxLocals];
+            for(int j=0; j<locals[i].length; j++) locals[i][j] = new Phi();
+            if (i==0) {
+                if (!isStatic()) locals[i][n++].merge(new Argument("this",method.getDeclaringClass()));
+                for(int j=0;j<this.method.getNumArgs(); j++) locals[i][n++].merge(new Argument("arg"+j,this.method.getArgType(j)));
+            }
+        }
+
+        stack = new Phi[maxStack];
+        branchTo(0);
+        for(pc=0; pc<size(); pc++) {
+            int    op  = get(pc);
+            Object arg = getArg(pc);
             try {
                 Object o = addOp(op, arg);
                 if (o != null) {
                     ops[numOps] = o;
-                    ofs[numOps++] = i;
+                    ofs[numOps++] = pc;
                 }
+                if (o!=null && o instanceof Branch) ((Branch)o).branchTo();
+                if (o==null || (!(o instanceof Branch))) branchTo(pc+1);
             } catch(RuntimeException e) {
-                System.err.println("Had a problem at PC: " + i + " of " + method);
+                System.err.println("Had a problem at PC: " + pc + " of " + method);
                 e.printStackTrace();
                 throw new IOException("invalid class file");
             }
         }
     }
+
+    public void branchTo(int newPC) {
+        System.out.println("!!!branchTo("+newPC+")!!!");
+        if (stacks[newPC] == null) {
+            stacks[newPC] = new Phi[sp];
+            for(int i=0; i<sp; i++) stacks[newPC][i] = new Phi();
+        }
+        if (stacks[newPC].length != sp)
+            throw new IllegalArgumentException("stack depth disagreement: " + sp + " " + stacks[newPC].length);
+        for(int i=0; i<stacks[newPC].length; i++) stacks[newPC][i].merge(stack[i]);
+        for(int i=0; i<maxLocals; i++) locals[newPC][i].merge(locals[pc][i]);
+    }
     
     private Object[] ops = new Object[65535];
     private int[] ofs = new int[65535];
@@ -44,25 +66,26 @@ public class JSSA extends MethodGen implements CGConst {
     // Instance Data; used ONLY during constructor; then thrown away /////////////////////////////////////////////////
 
     /** this models the JVM locals; it is only used for unwinding stack-ops into an SSA-tree, then thrown away */
-    private final Expr[] local;
+    private final Phi[][] locals;
     
     /** this models the JVM stack; it is only used for unwinding stack-ops into an SSA-tree, then thrown away */
-    private final Expr[] stack;
+    private final Phi[][] stacks;
+    private final Phi[] stack;
 
     /** JVM stack pointer */
+    private int pc = 0;
     private int sp = 0;
-    
-    private Expr push(Expr e) {
-        if (sp == stack.length) {
-            for(int i=0;i<stack.length;i++) System.err.println("Stack " + i + ": " + stack[i]);
-            throw new IllegalStateException("stack overflow (" + stack.length + ")");
-        }
+
+    private void push(Expr e) {
         if (e.getType() == Type.VOID) throw new IllegalArgumentException("can't push a void");
-        return stack[sp++] = e;
+        if (stack[sp] == null) stack[sp] = new Phi();
+        stack[sp++].merge(e);
     }
     private Expr pop() {
-        if (sp == 0) throw new IllegalStateException("stack underflow");
-        return stack[--sp];
+        Expr ret = stack[sp-1];
+        stack[sp-1] = null;
+        sp--;
+        return ret;
     }
     
     private Op seqPush(Expr e) {
@@ -107,34 +130,89 @@ public class JSSA extends MethodGen implements CGConst {
         /** every JSSA.Expr either remembers its type _OR_ knows how to figure it out (the latter is preferred to eliminate
          *  redundant information that could possibly "disagree" with itself -- this happened a LOT in Soot) */
         public abstract Type getType();
-        
-        public final String toString() { return exprToString(this); }
-        public String _toString() { return super.toString(); } // Adam is going to hate me for this (yes; why is this here?)
+        public String _toString() { return super.toString(); }
+        public String toString() { return _toString(); } /*
+            String s = (String)bindingMap.get(this);
+            if (s != null) return s;
+            String prefix;
+            if (getType() == Type.VOID) return _toString();
+            else if (getType() == Type.DOUBLE || getType() == Type.FLOAT) prefix = "f";
+            else if (getType().isPrimitive()) prefix = "i";
+            else if (getType().isArray()) prefix = "a";
+            else prefix = "o";
+            s = prefix + (nextVar++);
+            bindingMap.put(this,s);
+            return "(" + s + " = " + _toString() + ")";
+            }*/
     }
 
     /**
-     *  A "nondeterministic merge" -- for example when the first instruction in a loop reads from a local which could have been
-     *  written to either by some instruction at the end of the previous iteration of the loop or by some instruction before
+     *  A "nondeterministic merge" -- for example when the first
+     *  instruction in a loop reads from a local which could have been
+     *  written to either by some instruction at the end of the
+     *  previous iteration of the loop or by some instruction before
      *  the loop (on the first iteration).
+     *
+     *  Note that Phi's are *mutable*.  This means that when one Phi
+     *  holds a reference to another, updates to the referenced Phi
+     *  are "seen" by the other Phi.  This prevents us from having to
+     *  repeat loops to propagate the Phis.
      */
     public class Phi extends Expr {
-        private final Expr[] inputs;
-        public Phi(Expr[] inputs) {
-            this.inputs = new Expr[inputs.length];
-            System.arraycopy(inputs, 0, this.inputs, 0, inputs.length);
+        Expr[] inputs;
+        public Phi(Expr[] inputs) { this.inputs = inputs; }
+        public Phi() { this.inputs = new Expr[0]; }
+        public Phi(Expr e1) {
+            this.inputs = new Expr[1];
+            inputs[0] = e1;
+        }
+        public Phi(Expr e1, Expr e2) {
+            this.inputs = new Expr[2];
+            inputs[0] = e1;
+            inputs[1] = e2;
+        }
+        public void merge(Expr e) {
+            if (e==this) return;
+            for(int i=0; i<inputs.length; i++) if (inputs[i]==e) return;
+            Expr[] newinputs = new Expr[inputs.length + 1];
+            System.arraycopy(inputs, 0, newinputs, 0, inputs.length);
+            newinputs[newinputs.length-1] = e;
+            inputs = newinputs;
+        }
+        public String toString() {
+            if (inputs.length == 1) return inputs[0].toString();
+            StringBuffer ret = new StringBuffer();
+            int count = 0;
+            for(int i=0; i<inputs.length; i++) {
+                String s = inputs[i].toString().trim();
+                if (s.length() == 0) continue;
+                count++;
+                ret.append(s);
+                ret.append(" ");
+            }
+            if (count == 0) return "";
+            if (count == 1) return ret.toString().trim();
+            return "{{ " + ret.toString() + "}}";
+            //return "{"+ret+"}";
         }
         public Type getType() {
+            if (inputs.length == 0) return null;
             // sanity check
             Type t = inputs[0].getType();
 
             // FIXME: actually this should check type-unifiability... fe, the "type of null" unifies with any Type.Ref
-            for(int i=1; i<inputs.length; i++)
+            for(int i=1; i<inputs.length; i++) {
+                if (t==null) { t = inputs[i].getType(); continue; }
+                if (inputs[i].getType() == null) continue;
                 if (inputs[i].getType() != t)
-                    throw new Error("Phi node with disagreeing types!  Crisis!");
+                    throw new Error("Phi node with disagreeing types: " + t + " " + inputs[i].getType() +"\n  Crisis!");
+            }
             return t;
         }
     }
 
+    public Phi phi(Expr e) { return e instanceof Phi ? ((Phi)e) : new Phi(e); }
+
     public class Argument extends Expr {
         public final String name;
         public final Type t;
@@ -143,7 +221,9 @@ public class JSSA extends MethodGen implements CGConst {
         public Type getType() { return t; }
     }
     
-    // Unary Operations
+
+    // Unary Operations //////////////////////////////////////////////////////////////////////////////
+    
     public class Not extends Expr {
         public final Expr e;
         public Not(Expr e) {
@@ -163,6 +243,7 @@ public class JSSA extends MethodGen implements CGConst {
         public Type getType() { return e.getType(); }
         public String _toString() { return "- (" + e + ")"; }
     }
+
     
     // Binary Operations //////////////////////////////////////////////////////////////////////////////
 
@@ -172,7 +253,7 @@ public class JSSA extends MethodGen implements CGConst {
         private final String show;
         public BinExpr(Expr e1, Expr e2, String show) { this.e1 = e1; this.e2 = e2; this.show = show; }
         public String _toString() {
-            // FEATURE: should we be doing some precedence stuff here? probably no worth it for debugging output
+            // FEATURE: should we be doing some precedence stuff here? probably not worth it for debugging output
             return "(" + e1 + show + e2 + ")";
         }
     }
@@ -186,9 +267,9 @@ public class JSSA extends MethodGen implements CGConst {
         public Eq(Expr e1, Expr e2) {
             super(e1, e2, "=="); 
             if (e1.getType().isPrimitive() != e2.getType().isPrimitive())
-                throw new IllegalArgumentException("type mismatch");
+                throw new IllegalArgumentException("type mismatch: " + e1.getType() + " and " + e2.getType());
             if (e1.getType().isPrimitive() && e1.getType() != e2.getType())
-                throw new IllegalArgumentException("type mismatch");            
+                throw new IllegalArgumentException("type mismatch: " + e1.getType() + " and " + e2.getType());
             // FEATURE: Check if we can compare these classes
         }
     }
@@ -205,6 +286,7 @@ public class JSSA extends MethodGen implements CGConst {
     public class Lt extends PrimitiveComparison { public Lt(Expr e1, Expr e2) { super(e1, e2, "<"); } }
     public class Ge extends PrimitiveComparison { public Ge(Expr e1, Expr e2) { super(e1, e2, ">="); } }
     public class Le extends PrimitiveComparison { public Le(Expr e1, Expr e2) { super(e1, e2, "<="); } }
+
     
 
     // Math Operations //////////////////////////////////////////////////////////////////////////////
@@ -212,7 +294,8 @@ public class JSSA extends MethodGen implements CGConst {
     public class BinMath extends BinExpr {
         public BinMath(Expr e1, Expr e2, String show) {
             super(e2, e1, show); 
-            if (e1.getType() != e2.getType()) throw new IllegalArgumentException("types disagree");
+            if (e1.getType() != null && e2.getType() != null && e1.getType() != e2.getType())
+                throw new IllegalArgumentException("types disagree");
         }
         public Type getType() { return e1.getType(); }
     }
@@ -265,7 +348,24 @@ public class JSSA extends MethodGen implements CGConst {
         public Type getType() { return Type.BOOLEAN; }
     }
 
-    public class Throw extends Op {
+    public class Branch extends Op {
+        Expr destination = null;
+        public Branch(Expr destination) { this.destination = destination; }
+        public Branch(MethodGen.Switch s) { /* FIXME */ }
+        public Branch() { }
+        public void branchTo() { if (destination != null) branchTo(destination); }
+        private void branchTo(Expr e) {
+            if (e instanceof Phi) {
+                Phi phi = (Phi)e;
+                for(int i=0; i<phi.inputs.length; i++) branchTo(phi.inputs[i]);
+            } else if (e instanceof Label) {
+                JSSA.this.branchTo(((Label)e).pc);
+            } else {
+                throw new IllegalArgumentException("can't branch to a " + e.getClass());
+            }
+        }
+    }
+    public class Throw extends Branch {
         public final Expr e;
         public Throw(Expr e) {
             if (!e.getType().isRef()) throw new IllegalArgumentException("can't throw a non ref");
@@ -273,24 +373,44 @@ public class JSSA extends MethodGen implements CGConst {
             this.e = e; 
         }
     }
-
-    public class Branch extends Op {
-        public Branch(Expr condition, Object destination) { }
-        public Branch(Label destination) { }
-        public Branch(MethodGen.Switch s) { }
-        public Branch() { }
+    public class Return extends Branch {
+        final Expr e;
+        public Return() { this(VOID_EXPR); }
+        public Return(Expr e) {
+            this.e = e; 
+            if (Type.unify(method.getReturnType(),e.getType()) != method.getReturnType())
+               throw new IllegalArgumentException("type mismatch");
+        }
+        public String toString() { return e.getType() == Type.VOID ? "return" : ("return "+e.toString()); }
+    }
+    public class Goto extends Branch {
+        public Goto(Expr destination) { super(destination); }
+        public String toString() { return "goto " + destination; }
+    }
+    public class RET extends Branch {
+        public RET(Expr destination) { super(destination); }
+        public String toString() { return "retsub [" + destination + "]"; }
+    }
+    public class JSR extends Branch {
+        public JSR(Expr destination) { super(destination); }
+        public String toString() { return "callsub " + destination; }
+    }
+    public class If extends Branch {
+        Expr condition = null;
+        public If(Expr condition, Expr destination) { super(destination); this.condition = condition; }
+        public String toString() { return "if (" + condition + ") goto " + destination; }
+        public void branchTo() {
+            if (condition != null) JSSA.this.branchTo(pc+1);
+            super.branchTo();
+        }
     }
-    public class Goto extends Branch { }
-    public class RET extends Branch { }
-    public class JSR extends Branch { public JSR(Label l) { super(l); } }
-    public class If extends Branch { }
 
     /** represents a "returnaddr" pushed onto the stack */
     public class Label extends Expr {
-        public final Op op;
+        public int pc;
+        public Label(int i) { this.pc = i; }
         public Type getType() { throw new Error("attempted to call getType() on a Label"); }
-        public Label(Op op) { this.op = op; }
-        public Label(int i) { this.op = null; /* FIXME */ }
+        public String toString() { return "<<label " + pc + ">>"; }
     }
 
     public class New extends Expr {
@@ -320,17 +440,6 @@ public class JSSA extends MethodGen implements CGConst {
         }
     }
     
-    public class Return extends Op {
-        final Expr e;
-        public Return() { this(VOID_EXPR); }
-        public Return(Expr e) {
-            this.e = e; 
-            if (Type.unify(method.getReturnType(),e.getType()) != method.getReturnType())
-               throw new IllegalArgumentException("type mismatch");
-        }
-        public String toString() { return e.getType() == Type.VOID ? "return" : ("return "+e.toString()); }
-    }
-
     /** GETFIELD and GETSTATIC */
     public class Get extends Expr {
         final Type.Class.Field f;
@@ -434,7 +543,7 @@ public class JSSA extends MethodGen implements CGConst {
         private final Object o;
         public Constant(int i) { this(new Integer(i)); }
         public Constant(Object o) { this.o = o; }
-        public String _toString() { return o == null ? "null" : o instanceof String ? "\"" + o + "\"" : o.toString(); }
+        public String toString() { return o == null ? "null" : o instanceof String ? "\"" + o + "\"" : o.toString(); }
         public Type getType() {
             if (o == null) return Type.NULL;
             if (o instanceof Byte) return Type.BYTE;
@@ -469,6 +578,8 @@ public class JSSA extends MethodGen implements CGConst {
             i1 = p.i1;
             i2 = p.i2;
         }
+        if (arg instanceof Number) i1 = ((Integer)arg).intValue();
+        Label label = (arg instanceof Label) ? (Label)arg : null;
         switch(op) {
 
             case NOP: return null;
@@ -483,20 +594,25 @@ public class JSSA extends MethodGen implements CGConst {
             case ICONST_3:                                                             push(new Constant(3));    return null;
             case ICONST_4:                                                             push(new Constant(4));    return null;
             case ICONST_5:                                                             push(new Constant(5));    return null;
-            case ILOAD:    case LLOAD:    case FLOAD:    case DLOAD:    case ALOAD:    push(local[i1]);          return null;
-            case ILOAD_0:  case LLOAD_0:  case FLOAD_0:  case DLOAD_0:  case ALOAD_0:  push(local[0]);           return null;
-            case ILOAD_1:  case LLOAD_1:  case FLOAD_1:  case DLOAD_1:  case ALOAD_1:  push(local[1]);           return null;
-            case ALOAD_2:  case DLOAD_2:  case FLOAD_2:  case LLOAD_2:  case ILOAD_2:  push(local[2]);           return null;
-            case ILOAD_3:  case LLOAD_3:  case FLOAD_3:  case DLOAD_3:  case ALOAD_3:  push(local[3]);           return null;
-            case ISTORE:   case LSTORE:   case FSTORE:   case DSTORE:   case ASTORE:   local[i1] = pop();        return null;
-            case ISTORE_0: case LSTORE_0: case FSTORE_0: case DSTORE_0: case ASTORE_0: local[0]  = pop();        return null;
-            case ISTORE_1: case LSTORE_1: case FSTORE_1: case DSTORE_1: case ASTORE_1: local[1]  = pop();        return null;
-            case ASTORE_2: case DSTORE_2: case FSTORE_2: case LSTORE_2: case ISTORE_2: local[2]  = pop();        return null;
-            case ISTORE_3: case LSTORE_3: case FSTORE_3: case DSTORE_3: case ASTORE_3: local[3]  = pop();        return null;
+            case ILOAD:    case LLOAD:    case FLOAD:    case DLOAD:    case ALOAD:    push(locals[pc][i1]);     return null;
+            case ILOAD_0:  case LLOAD_0:  case FLOAD_0:  case DLOAD_0:  case ALOAD_0:  push(locals[pc][0]);      return null;
+            case ILOAD_1:  case LLOAD_1:  case FLOAD_1:  case DLOAD_1:  case ALOAD_1:  push(locals[pc][1]);      return null;
+            case ALOAD_2:  case DLOAD_2:  case FLOAD_2:  case LLOAD_2:  case ILOAD_2:  push(locals[pc][2]);      return null;
+            case ILOAD_3:  case LLOAD_3:  case FLOAD_3:  case DLOAD_3:  case ALOAD_3:  push(locals[pc][3]);      return null;
+            case ISTORE:   case LSTORE:   case FSTORE:   case DSTORE:   case ASTORE:
+                locals[pc+1][i1].merge(pop()); return null;
+            case ISTORE_0: case LSTORE_0: case FSTORE_0: case DSTORE_0: case ASTORE_0:
+                locals[pc+1][0].merge(pop()); return null;
+            case ISTORE_1: case LSTORE_1: case FSTORE_1: case DSTORE_1: case ASTORE_1:
+                locals[pc+1][1].merge(pop()); return null;
+            case ASTORE_2: case DSTORE_2: case FSTORE_2: case LSTORE_2: case ISTORE_2:
+                locals[pc+1][2].merge(pop()); return null;
+            case ISTORE_3: case LSTORE_3: case FSTORE_3: case DSTORE_3: case ASTORE_3:
+                locals[pc+1][3].merge(pop()); return null;
             case POP:                                                                  pop();                    return null;
             case POP2:                                                                 pop(); pop();             return null;
-            case DUP:                                                                  push(stack[sp-1]);        return null;
-            case DUP2:                                                     push(stack[sp-2]); push(stack[sp-2]); return null;
+            case DUP:   push(stack[sp-1]);                  return null;
+            case DUP2:  push(stack[sp-2]); push(stack[sp-1]); return null;
 
                 // Conversions //////////////////////////////////////////////////////////////////////////////
 
@@ -526,31 +642,31 @@ public class JSSA extends MethodGen implements CGConst {
             case IAND: case LAND:                       push(new And(pop(), pop()));  return null;
             case IOR:  case LOR:                        push(new Or(pop(), pop()));   return null;
             case IXOR: case LXOR:                       push(new Xor(pop(), pop()));  return null;
-            case IINC:                                  return local[i1] = new Add(local[i1], new Constant(i2));
+            case IINC:                                  return locals[pc+1][i1] = phi(new Add(locals[pc][i1], new Constant(i2)));
 
                 // Control and branching //////////////////////////////////////////////////////////////////////////////
 
-            case IFNULL:                                return new Branch(new Eq(pop(), new Constant(null)), new Label(i1));
-            case IFNONNULL:                             return new Branch(new Not(new Eq(pop(),new Constant(null))),new Label(i1));
-            case IFEQ:                                  return new Branch(    new Eq(new Constant(0), pop()),  arg);
-            case IFNE:                                  return new Branch(new Not(new Eq(new Constant(0), pop())), arg);
-            case IFLT:                                  return new Branch(    new Lt(new Constant(0), pop()),  arg);
-            case IFGE:                                  return new Branch(new Not(new Lt(new Constant(0), pop())), arg);
-            case IFGT:                                  return new Branch(    new Gt(new Constant(0), pop()),  arg);
-            case IFLE:                                  return new Branch(new Not(new Gt(new Constant(0), pop())), arg);
-            case IF_ICMPEQ:                             return new Branch(    new Eq(pop(), pop()),  arg);
-            case IF_ICMPNE:                             return new Branch(new Not(new Eq(pop(), pop())), arg);
-            case IF_ICMPLT:                             return new Branch(    new Lt(pop(), pop()),  arg);
-            case IF_ICMPGE:                             return new Branch(new Not(new Lt(pop(), pop())), arg);
-            case IF_ICMPGT:                             return new Branch(    new Gt(pop(), pop()),  arg);
-            case IF_ICMPLE:                             return new Branch(new Not(new Gt(pop(), pop())), arg);
-            case IF_ACMPEQ:                             return new Branch(    new Eq(pop(), pop()),  arg);
-            case IF_ACMPNE:                             return new Branch(new Not(new Eq(pop(), pop())), arg);
-            case ATHROW:                                return new Throw(pop());
-            case GOTO:                                  return new Branch(new Label(i1));
-            case JSR:                                   return new JSR(new Label(i1));
-            case RET:                                   return new RET();
-            case RETURN:                                return new Return();
+            case IFNULL:                                return new If(new Eq(pop(), new Constant(null)), new Label(i1));
+            case IFNONNULL:                             return new If(new Not(new Eq(pop(),new Constant(null))),new Label(i1));
+            case IFEQ:                                  return new If(    new Eq(new Constant(0), pop()), new Label(i1));
+            case IFNE:                                  return new If(new Not(new Eq(new Constant(0), pop())), new Label(i1));
+            case IFLT:                                  return new If(    new Lt(new Constant(0), pop()), new Label(i1));
+            case IFGE:                                  return new If(new Not(new Lt(new Constant(0), pop())), new Label(i1));
+            case IFGT:                                  return new If(    new Gt(new Constant(0), pop()), new Label(i1));
+            case IFLE:                                  return new If(new Not(new Gt(new Constant(0), pop())), new Label(i1));
+            case IF_ICMPEQ:                             return new If(    new Eq(pop(), pop()), new Label(i1));
+            case IF_ICMPNE:                             return new If(new Not(new Eq(pop(), pop())), new Label(i1));
+            case IF_ICMPLT:                             return new If(    new Lt(pop(), pop()), new Label(i1));
+            case IF_ICMPGE:                             return new If(new Not(new Lt(pop(), pop())), new Label(i1));
+            case IF_ICMPGT:                             return new If(    new Gt(pop(), pop()), new Label(i1));
+            case IF_ICMPLE:                             return new If(new Not(new Gt(pop(), pop())), new Label(i1));
+            case IF_ACMPEQ:                             return new If(    new Eq(pop(), pop()), new Label(i1));
+            case IF_ACMPNE:                             return new If(new Not(new Eq(pop(), pop())), new Label(i1));
+            case ATHROW:                                                       return new Throw(pop());
+            case GOTO:                                                         return new Goto(locals[pc][i1]);
+            case JSR:                                   push(new Label(pc));   return new JSR(new Label(i1));
+            case RET:                                                          return new RET(pop());
+            case RETURN:                                                       return new Return();
             case IRETURN: case LRETURN: case FRETURN: case DRETURN: case ARETURN:
                 return new Return(pop());
 
@@ -671,20 +787,6 @@ public class JSSA extends MethodGen implements CGConst {
     
     private Map bindingMap;
     private int nextVar;
-    String exprToString(Expr e) {
-        if (e instanceof Constant) return e._toString();
-        String s = (String)bindingMap.get(e);
-        if (s != null) return s;
-        String prefix;
-        if (e.getType() == Type.VOID) return e._toString();
-        else if (e.getType() == Type.DOUBLE || e.getType() == Type.FLOAT) prefix = "f";
-        else if (e.getType().isPrimitive()) prefix = "i";
-        else if (e.getType().isArray()) prefix = "a";
-        else prefix = "o";
-        s = prefix + (nextVar++);
-        bindingMap.put(e,s);
-        return "(" + s + " = " + e._toString() + ")";
-    }
     
     public static void main(String[] args) throws Exception {
         InputStream is = Class.forName(args[0]).getClassLoader().getResourceAsStream(args[0].replace('.', '/')+".class");