8348570: CTW: Expose the code hidden by uncommon traps

Reviewed-by: kvn, thartmann

Author: shipilev

test/hotspot/jtreg/testlibrary/ctw/src/sun/hotspot/tools/ctw/Compiler.java

@@ -72,13 +72,27 @@ public static long getMethodCount() {
     public static void compileClass(Class<?> aClass, long id, Executor executor) {
         Objects.requireNonNull(aClass);
         Objects.requireNonNull(executor);
-        ConstantPool constantPool = SharedSecrets.getJavaLangAccess().
-                getConstantPool(aClass);
+
+        // Initialize all constant pool entries, if requested.
         if (Utils.COMPILE_THE_WORLD_PRELOAD_CLASSES) {
+            ConstantPool constantPool = SharedSecrets.getJavaLangAccess().getConstantPool(aClass);
             preloadClasses(aClass.getName(), id, constantPool);
         }
+
+        // Make sure the class is initialized.
         UNSAFE.ensureClassInitialized(aClass);
         compileClinit(aClass, id);
+
+        // Populate profile for all methods to expand the scope of
+        // compiler optimizations. Do this before compilations start.
+        for (Executable e : aClass.getDeclaredConstructors()) {
+            WHITE_BOX.markMethodProfiled(e);
+        }
+        for (Executable e : aClass.getDeclaredMethods()) {
+            WHITE_BOX.markMethodProfiled(e);
+        }
+
+        // Now schedule the compilations.
         long methodCount = 0;
         for (Executable e : aClass.getDeclaredConstructors()) {
             ++methodCount;

test/hotspot/jtreg/testlibrary/ctw/src/sun/hotspot/tools/ctw/CtwRunner.java

@@ -279,6 +279,7 @@ private String[] cmd(long classStart, long classStop) {
                 "-Xbatch",
                 "-XX:-ShowMessageBoxOnError",
                 "-XX:+UnlockDiagnosticVMOptions",
+                "-XX:+UnlockExperimentalVMOptions",
                 // redirect VM output to cerr so it won't collide w/ ctw output
                 "-XX:+DisplayVMOutputToStderr",
                 // define phase start
@@ -299,6 +300,11 @@ private String[] cmd(long classStart, long classStop) {
                 String.format("-XX:ReplayDataFile=replay_%s_%%p.log", phase),
                 // MethodHandle MUST NOT be compiled
                 "-XX:CompileCommand=exclude,java/lang/invoke/MethodHandle.*",
+                // CTW does not have good execution profile info, which would uncommon-trap
+                // a lot of branches/calls that are presumed to be never executed.
+                // Expand the optimization scope by disallowing most traps.
+                "-XX:PerMethodTrapLimit=0",
+                "-XX:PerMethodSpecTrapLimit=0",
                 "-XX:+IgnoreUnrecognizedVMOptions",
                 // Do not pay extra zapping cost for explicit GC invocations
                 "-XX:-ZapUnusedHeapArea",