--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/Compiler.java	Fri Sep 26 18:47:20 2014 +0200
+++ b/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/Compiler.java	Mon Sep 29 14:39:58 2014 -0700
@@ -32,7 +32,6 @@
 import static jdk.nashorn.internal.codegen.CompilerConstants.THIS;
 import static jdk.nashorn.internal.codegen.CompilerConstants.VARARGS;
 import static jdk.nashorn.internal.runtime.logging.DebugLogger.quote;
-
 import java.io.File;
 import java.lang.invoke.MethodType;
 import java.util.Arrays;
@@ -154,6 +153,13 @@
     private RecompilableScriptFunctionData compiledFunction;
 
     /**
+     * Most compile unit names are longer than the default StringBuilder buffer,
+     * worth startup performance when massive class generation is going on to increase
+     * this
+     */
+    private static final int COMPILE_UNIT_NAME_BUFFER_SIZE = 32;
+
+    /**
      * Compilation phases that a compilation goes through
      */
     public static class CompilationPhases implements Iterable<CompilationPhase> {
@@ -631,7 +637,8 @@
     }
 
     String nextCompileUnitName() {
-        final StringBuilder sb = new StringBuilder(firstCompileUnitName);
+        final StringBuilder sb = new StringBuilder(COMPILE_UNIT_NAME_BUFFER_SIZE);
+        sb.append(firstCompileUnitName);
         final int cuid = nextCompileUnitId.getAndIncrement();
         if (cuid > 0) {
             sb.append("$cu").append(cuid);

--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/Label.java	Fri Sep 26 18:47:20 2014 +0200
+++ b/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/Label.java	Mon Sep 29 14:39:58 2014 -0700
@@ -590,8 +590,13 @@
         return label.getOffset() > other.label.getOffset();
     }
 
+    private String str;
+
     @Override
     public String toString() {
-        return name + '_' + id;
+        if (str == null) {
+            str = name + '_' + id;
+        }
+        return str;
     }
 }

--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/MethodEmitter.java	Fri Sep 26 18:47:20 2014 +0200
+++ b/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/MethodEmitter.java	Mon Sep 29 14:39:58 2014 -0700
@@ -2576,12 +2576,55 @@
      *
      * @param args debug information to print
      */
+    @SuppressWarnings("unused")
     private void debug(final Object... args) {
         if (debug) {
             debug(30, args);
         }
     }
 
+    private void debug(final String arg) {
+        if (debug) {
+            debug(30, arg);
+        }
+    }
+
+    private void debug(final Object arg0, final Object arg1) {
+        if (debug) {
+            debug(30, new Object[] { arg0, arg1 });
+        }
+    }
+
+    private void debug(final Object arg0, final Object arg1, final Object arg2) {
+        if (debug) {
+            debug(30, new Object[] { arg0, arg1, arg2 });
+        }
+    }
+
+    private void debug(final Object arg0, final Object arg1, final Object arg2, final Object arg3) {
+        if (debug) {
+            debug(30, new Object[] { arg0, arg1, arg2, arg3 });
+        }
+    }
+
+    private void debug(final Object arg0, final Object arg1, final Object arg2, final Object arg3, final Object arg4) {
+        if (debug) {
+            debug(30, new Object[] { arg0, arg1, arg2, arg3, arg4 });
+        }
+    }
+
+    private void debug(final Object arg0, final Object arg1, final Object arg2, final Object arg3, final Object arg4, final Object arg5) {
+        if (debug) {
+            debug(30, new Object[] { arg0, arg1, arg2, arg3, arg4, arg5 });
+        }
+    }
+
+    private void debug(final Object arg0, final Object arg1, final Object arg2, final Object arg3, final Object arg4, final Object arg5, final Object arg6) {
+        if (debug) {
+            debug(30, new Object[] { arg0, arg1, arg2, arg3, arg4, arg5, arg6 });
+        }
+    }
+
     /**
      * Debug function that outputs generated bytecode and stack contents
      * for a label - indentation is currently the only thing that differs

--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/types/Type.java	Fri Sep 26 18:47:20 2014 +0200
+++ b/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/codegen/types/Type.java	Mon Sep 29 14:39:58 2014 -0700
@@ -54,8 +54,10 @@
 import java.lang.invoke.MethodHandle;
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.MethodType;
+import java.util.Collections;
 import java.util.Map;
 import java.util.TreeMap;
+import java.util.WeakHashMap;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import jdk.internal.org.objectweb.asm.Handle;
@@ -103,6 +105,16 @@
     /** The class for this type */
     private final Class<?> clazz;
 
+    /**
+     * Cache for internal types - this is a query that requires complex stringbuilding inside
+     * ASM and it saves startup time to cache the type mappings
+     */
+    private static final Map<Class<?>, jdk.internal.org.objectweb.asm.Type> INTERNAL_TYPE_CACHE =
+            Collections.synchronizedMap(new WeakHashMap<Class<?>, jdk.internal.org.objectweb.asm.Type>());
+
+    /** Internal ASM type for this Type - computed once at construction */
+    private final jdk.internal.org.objectweb.asm.Type internalType;
+
     /** Weights are used to decide which types are "wider" than other types */
     protected static final int MIN_WEIGHT = -1;
 
@@ -121,12 +133,13 @@
      * @param slots       how many bytecode slots the type takes up
      */
     Type(final String name, final Class<?> clazz, final int weight, final int slots) {
-        this.name       = name;
-        this.clazz      = clazz;
-        this.descriptor = jdk.internal.org.objectweb.asm.Type.getDescriptor(clazz);
-        this.weight     = weight;
+        this.name         = name;
+        this.clazz        = clazz;
+        this.descriptor   = jdk.internal.org.objectweb.asm.Type.getDescriptor(clazz);
+        this.weight       = weight;
         assert weight >= MIN_WEIGHT && weight <= MAX_WEIGHT : "illegal type weight: " + weight;
-        this.slots      = slots;
+        this.slots        = slots;
+        this.internalType = getInternalType(clazz);
     }
 
     /**
@@ -356,11 +369,22 @@
     }
 
     private jdk.internal.org.objectweb.asm.Type getInternalType() {
-        return jdk.internal.org.objectweb.asm.Type.getType(getTypeClass());
+        return internalType;
+    }
+
+    private static jdk.internal.org.objectweb.asm.Type lookupInternalType(final Class<?> type) {
+        final Map<Class<?>, jdk.internal.org.objectweb.asm.Type> cache = INTERNAL_TYPE_CACHE;
+        jdk.internal.org.objectweb.asm.Type itype = cache.get(type);
+        if (itype != null) {
+            return itype;
+        }
+        itype = jdk.internal.org.objectweb.asm.Type.getType(type);
+        cache.put(type, itype);
+        return itype;
     }
 
     private static jdk.internal.org.objectweb.asm.Type getInternalType(final Class<?> type) {
-        return jdk.internal.org.objectweb.asm.Type.getType(type);
+        return lookupInternalType(type);
     }
 
     static void invokestatic(final MethodVisitor method, final Call call) {

--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/parser/AbstractParser.java	Fri Sep 26 18:47:20 2014 +0200
+++ b/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/parser/AbstractParser.java	Mon Sep 29 14:39:58 2014 -0700
@@ -30,7 +30,6 @@
 import static jdk.nashorn.internal.parser.TokenType.EOF;
 import static jdk.nashorn.internal.parser.TokenType.EOL;
 import static jdk.nashorn.internal.parser.TokenType.IDENT;
-
 import java.util.HashMap;
 import java.util.Map;
 import jdk.nashorn.internal.ir.IdentNode;

--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/RecompilableScriptFunctionData.java	Fri Sep 26 18:47:20 2014 +0200
+++ b/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/RecompilableScriptFunctionData.java	Mon Sep 29 14:39:58 2014 -0700
@@ -589,7 +589,9 @@
     }
 
     MethodHandle lookupCodeMethod(final Class<?> codeClass, final MethodType targetType) {
-        log.info("Looking up ", DebugLogger.quote(name), " type=", targetType);
+        if (log.isEnabled()) {
+            log.info("Looking up ", DebugLogger.quote(name), " type=", targetType);
+        }
         return MH.findStatic(LOOKUP, codeClass, functionName, targetType);
     }
 

--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/regexp/RegExpFactory.java	Fri Sep 26 18:47:20 2014 +0200
+++ b/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/regexp/RegExpFactory.java	Mon Sep 29 14:39:58 2014 -0700
@@ -25,6 +25,9 @@
 
 package jdk.nashorn.internal.runtime.regexp;
 
+import java.util.Collections;
+import java.util.Set;
+import java.util.WeakHashMap;
 import jdk.nashorn.internal.runtime.ParserException;
 import jdk.nashorn.internal.runtime.options.Options;
 
@@ -39,6 +42,15 @@
     private final static String JDK  = "jdk";
     private final static String JONI = "joni";
 
+    /** Weak cache of already validated regexps - when reparsing, we don't, for example
+     *  need to recompile (reverify) all regexps that have previously been parsed by this
+     *  RegExpFactory in a previous compilation. This saves significant time in e.g. avatar
+     *  startup */
+    private static final Set<String> VALID_CACHE_SET =
+            Collections.newSetFromMap(
+                    Collections.synchronizedMap(
+                            new WeakHashMap<String, Boolean>()));
+
     static {
         final String impl = Options.getStringProperty("nashorn.regexp.impl", JONI);
         switch (impl) {
@@ -88,7 +100,9 @@
      */
     // @SuppressWarnings({"unused"})
     public static void validate(final String pattern, final String flags) throws ParserException {
-        instance.compile(pattern, flags);
+        if (VALID_CACHE_SET.add(pattern + flags)) {
+            instance.compile(pattern, flags);
+        }
     }
 
     /**