Example #1
0
  /** Runs BLOAT on a method. */
  public static void bloatMethod(final MethodEditor m, final BloatContext context) {
    try {
      if (Main.COMPACT_ARRAY_INIT) {
        // Compact the initialization of arrays of the basic types by
        // putting the values of the array into a string in the constant
        // pool. The initialization code is replaced with a loop that
        // loads the array from the string in the constant pool.

        if (Main.TRACE) {
          System.out.println("  Compacting Arrays: " + Main.dateFormat.format(new Date()));
        }

        CompactArrayInitializer.transform(m);

        if (Main.DEBUG) {
          System.out.println("---------- After compaction:");
          m.print(System.out);
          System.out.println("---------- end print");
        }
      }

      FlowGraph cfg; // The control flow graph for a method

      if (Main.TRACE) {
        System.out.println("  Constructing CFG: " + Main.dateFormat.format(new Date()));
      }

      try {
        // Construct the control flow graph for method m
        cfg = new FlowGraph(m);
      } catch (final ClassFormatException ex) {
        System.err.println(ex.getMessage());
        context.release(m.methodInfo());
        return;
      }

      // We separate out initialization since before this the FlowGraph
      // more exactly represents the input program.
      cfg.initialize();

      if (Main.TRACE) {
        System.out.println("  Transforming to SSA: " + Main.dateFormat.format(new Date()));
      }

      SSA.transform(cfg);

      if (FlowGraph.DEBUG) {
        System.out.println("---------- After SSA:");
        cfg.print(System.out);
        System.out.println("---------- end print");
      }

      if (Main.DEBUG) {
        cfg.visit(new VerifyCFG(false));
      }

      if (!Tree.USE_STACK) {
        // Do copy propagation and value numbering first to get rid of
        // all the extra copies inserted for dups. If they're left in,
        // it really slows down value numbering.
        if (Main.PROP) {
          if (Main.DEBUG) {
            System.out.println("-----Before Copy Propagation-----");
          }

          if (Main.TRACE) {
            System.out.println("  Copy propagation: " + Main.dateFormat.format(new Date()));
          }

          final ExprPropagation copy = new ExprPropagation(cfg);
          copy.transform();

          if (Main.DEBUG) {
            cfg.visit(new VerifyCFG(false));
          }

          if (Main.DEBUG) {
            System.out.println("------After Copy Propagation-----");
            cfg.print(System.out);
          }
        }
      }

      DeadCodeElimination dce = null;

      if (Main.DCE) {

        if (Main.TRACE) {
          System.out.println("  Dead Code Elimination: " + Main.dateFormat.format(new Date()));
        }

        if (Main.DEBUG) {
          System.out.println("---Before Dead Code Elimination--");
        }

        dce = new DeadCodeElimination(cfg);
        dce.transform();

        if (Main.DEBUG) {
          cfg.visit(new VerifyCFG(false));
        }

        if (Main.DEBUG) {
          System.out.println("---After Dead Code Elimination---");
          cfg.print(System.out);
        }
      }

      if (Main.INFER) {

        if (Main.DEBUG) {
          System.out.println("---------Doing type inference--------");
        }

        if (Main.TRACE) {
          System.out.println("  Type Inferencing: " + Main.dateFormat.format(new Date()));
        }

        TypeInference.transform(cfg, context.getHierarchy());
      }

      if (Main.NUMBER) {

        if (Main.TRACE) {
          System.out.println("  Value Numbering: " + Main.dateFormat.format(new Date()));
        }

        if (Main.DEBUG) {
          System.out.println("--------Doing value numbering--------");
        }

        (new ValueNumbering()).transform(cfg);
      }

      if (Main.FOLD) {
        if (Main.DEBUG) {
          System.out.println("--------Before Value Folding---------");
        }

        if (Main.TRACE) {
          System.out.println("  Value Folding: " + Main.dateFormat.format(new Date()));
        }

        (new ValueFolding()).transform(cfg);

        if (Main.DEBUG) {
          cfg.visit(new VerifyCFG());
        }

        if (Main.DEBUG) {
          System.out.println("---------After Value Folding---------");
          cfg.print(System.out);
        }
      }

      if (Main.PRE) {
        if (Main.DEBUG) {
          System.out.println("-------------Before SSAPRE-----------");
        }

        if (Main.TRACE) {
          System.out.println("  SSAPRE: " + Main.dateFormat.format(new Date()));
        }

        final SSAPRE pre = new SSAPRE(cfg, context);
        pre.transform();

        if (Main.DEBUG) {
          cfg.visit(new VerifyCFG());
        }

        if (Main.DEBUG) {
          System.out.println("-------------After SSAPRE------------");
          cfg.print(System.out);
        }
      }

      if (Main.FOLD) {
        if (Main.DEBUG) {
          System.out.println("--------Before Value Folding---------");
        }

        if (Main.TRACE) {
          System.out.println("  Value Folding: " + Main.dateFormat.format(new Date()));
        }

        (new ValueFolding()).transform(cfg);

        if (Main.DEBUG) {
          cfg.visit(new VerifyCFG());
        }

        if (Main.DEBUG) {
          System.out.println("---------After Value Folding---------");
          cfg.print(System.out);
        }
      }

      if (Main.PROP) {
        if (Main.DEBUG) {
          System.out.println("-------Before Copy Propagation-------");
        }

        if (Main.TRACE) {
          System.out.println("  Copy Propagation " + Main.dateFormat.format(new Date()));
        }

        final ExprPropagation copy = new ExprPropagation(cfg);
        copy.transform();

        if (Main.DEBUG) {
          cfg.visit(new VerifyCFG());
        }

        if (Main.DEBUG) {
          System.out.println("--------After Copy Propagation-------");
          cfg.print(System.out);
        }
      }

      // make sure we've done at least one thing since the last DCE
      if (Main.DCE && (Main.INFER || Main.NUMBER || Main.FOLD || Main.PRE || Main.PROP)) {
        if (Main.DEBUG) {
          System.out.println("-----Before Dead Code Elimination----");
        }

        if (Main.TRACE) {
          System.out.println("  Dead Code Elimination: " + Main.dateFormat.format(new Date()));
        }

        dce = new DeadCodeElimination(cfg);
        dce.transform();

        if (Main.DEBUG) {
          cfg.visit(new VerifyCFG());
        }

        if (Main.DEBUG) {
          System.out.println("-----After Dead Code Elimination-----");
          cfg.print(System.out);
        }
      }

      if (Main.PERSIST) {
        (new PersistentCheckElimination()).transform(cfg);
      }

      if (Main.DIVA) {
        if (Main.DEBUG) {
          System.out.println("-----Before DIVA------");
        }

        if (Main.TRACE) {
          System.out.println("  DIVA: " + Main.dateFormat.format(new Date()));
        }

        (new InductionVarAnalyzer()).transform(cfg);

        if (Main.DEBUG) {
          System.out.println("-----After DIVA-----");
          cfg.print(System.out);
        }
      }

      /*
       * if (STACK_ALLOC) { if (DEBUG) {
       * System.out.println("------------Before StackPRE----------"); }
       *
       * StackPRE pre = new StackPRE(cfg); pre.transform();
       *
       * if (DEBUG) { cfg.visit(new VerifyCFG()); }
       *
       * if (DEBUG) { System.out.println("------------After
       * StackPRE-----------"); cfg.print(System.out); } }
       */

      // Do the new stack optimization
      if (Main.OPT_STACK_2) {

        if (Main.TRACE) {
          System.out.println("  New stack optimization: " + Main.dateFormat.format(new Date()));
        }

        // generate code without doing liveness or register allocation
        final CodeGenerator codegen = new CodeGenerator(m);
        codegen.replacePhis(cfg);
        m.clearCode2();
        cfg.visit(codegen);
        // do stack optimization on the bytecode

        final StackOpt so = new StackOpt();
        so.transform(m);

        // convert it back to a cfg
        cfg = new FlowGraph(m);
        cfg.initialize();

        // convert it back to SSA
        SSA.transform(cfg);

        // do more dead code elimination (eliminate stores)
        dce = new DeadCodeElimination(cfg);
        dce.transform();
      }

      if (Main.TRACE) {
        System.out.println("  Register allocation: " + Main.dateFormat.format(new Date()));
      }

      if (Main.VERIFY) {
        try {
          cfg.visit(new VerifyCFG());
        } catch (final IllegalArgumentException ee) {
          System.out.println(
              " NOTE: CFG did not verify while "
                  + "bloating "
                  + m.name()
                  + " after all optimizations. Exception: "
                  + ee);
        }
      }

      // We're all done performing optimizations. Let's generate some code
      // and go home.

      // Perform liveness analysis of variables in the method.
      // Assign local variables ("registers") to expression values.
      final Liveness liveness = new Liveness(cfg);
      final RegisterAllocator alloc = new RegisterAllocator(cfg, liveness);

      // Gather information which can be used to optimize use of the stack
      if (CodeGenerator.OPT_STACK) {
        if (Main.TRACE) {
          System.out.println("  Old stack optimization: " + Main.dateFormat.format(new Date()));
        }
        StackOptimizer.optimizeCFG(cfg);
      }

      if (Main.TRACE) {
        System.out.println("  Code Generation: " + Main.dateFormat.format(new Date()));
      }

      // Start the code generation process.
      final CodeGenerator codegen = new CodeGenerator(m);
      codegen.replacePhis(cfg);

      if (Main.DEBUG) {
        System.out.println("After fixing Phis------------------------");
        cfg.print(System.out);
        System.out.println("End print--------------------------------");
      }

      codegen.simplifyControlFlow(cfg);
      codegen.allocReturnAddresses(cfg, alloc);

      if (Main.DEBUG) {
        System.out.println("After removing empty blocks--------------");
        cfg.print(System.out);
        System.out.println("End print--------------------------------");
      }

      // Clear the old contents of the bytecode store and generate new
      // code.
      // Code is generated using a visitor pattern on the CFG.
      m.clearCode();
      cfg.visit(codegen);

      Peephole.transform(m);

      // Commit any changes that have been made to the method
      context.commit(m.methodInfo());

    } catch (final Exception ex99) {
      final String msg =
          "** Exception while optimizing "
              + m.name()
              + m.type()
              + " of class "
              + m.declaringClass().name();
      System.err.println(msg);
      System.err.println(ex99.getMessage());
      ex99.printStackTrace(System.err);
      System.exit(1);
    }
  }
  /**
   * Performs intraprocedural BLOAT on a program's live methods.
   *
   * @param liveMethods Should be alphabetized. This way we can commit a class once we've BLOATed
   *     all of its methods.
   */
  private static void intraBloat(final Collection liveMethods, final BloatContext context) {

    ClassEditor prevClass = null;
    final Iterator iter = liveMethods.iterator();
    for (int count = 0; iter.hasNext(); count++) {
      MethodEditor live = null;
      ClassEditor ce = null; // Hack to make sure commit happens
      try {
        live = context.editMethod((MemberRef) iter.next());
        ce = context.editClass(live.declaringClass().classInfo());

      } catch (final NoSuchMethodException ex3) {
        BloatBenchmark.err.println("** Could not find method " + ex3.getMessage());
        System.exit(1);
      }

      /* So we can skip classes or packages */
      final String name = ce.type().className();
      final String qual = ce.type().qualifier() + "/*";
      boolean skip = false;
      for (int i = 0; i < BloatBenchmark.SKIP.size(); i++) {
        final String pkg = (String) BloatBenchmark.SKIP.get(i);

        if (name.equals(pkg) || qual.equals(pkg)) {
          skip = true;
          break;
        }
      }

      if (context.ignoreMethod(live.memberRef()) || skip) {
        // Don't display ignored methods, it's misleading.
        context.release(live.methodInfo());
        continue;
      }

      final Runtime runtime = Runtime.getRuntime();
      runtime.gc();

      final Date start = new Date();
      BloatBenchmark.tr(
          "  " + count + ") " + live.declaringClass().name() + "." + live.name() + live.type());
      BloatBenchmark.tr("    Start: " + start);

      try {
        EDU.purdue.cs.bloat.optimize.Main.TRACE = BloatBenchmark.TRACE;
        if (!BloatBenchmark.VERIFY) {
          EDU.purdue.cs.bloat.optimize.Main.VERIFY = false;
        }
        EDU.purdue.cs.bloat.optimize.Main.bloatMethod(live, context);

      } catch (final Exception oops) {
        BloatBenchmark.err.println("******************************************");
        BloatBenchmark.err.println(
            "Exception while BLOATing "
                + live.declaringClass().name()
                + "."
                + live.name()
                + live.type());
        BloatBenchmark.err.println(oops.getMessage());
        oops.printStackTrace(System.err);
        BloatBenchmark.err.println("******************************************");
      }

      // Commit here in an attempt to conserve memory
      context.commit(live.methodInfo());
      context.release(live.methodInfo());

      if (prevClass == null) {
        prevClass = ce;

      } else if (!prevClass.equals(ce)) {
        // We've finished BLOATed the methods for prevClass, commit
        // prevClass and move on
        BloatBenchmark.tr(prevClass.type() + " != " + ce.type());
        context.commit(prevClass.classInfo());
        context.release(prevClass.classInfo());
        // context.commitDirty();
        // tr(context.toString());
        prevClass = ce;

      } else {
        context.release(ce.classInfo());
      }

      final Date end = new Date();
      BloatBenchmark.tr("    Ellapsed time: " + (end.getTime() - start.getTime()) + " ms");
    }

    context.commitDirty();
  }