Improve categorization code by jumping over blocks of same types.

openjdk-bots · Jul 28, 2022 · cf5f4a0 · cf5f4a0
1 parent 796eea4
commit cf5f4a0
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Showing 2 changed files with 30 additions and 18 deletions.
diff --git a/src/java.base/share/classes/java/lang/runtime/SwitchBootstraps.java b/src/java.base/share/classes/java/lang/runtime/SwitchBootstraps.java
@@ -43,6 +43,7 @@
 import java.security.PrivilegedAction;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.LinkedHashSet;
 import java.util.List;
@@ -318,18 +319,27 @@ private static Class<?> generateInnerClass(MethodHandles.Lookup caller, Object[]
         } else {
             mv.visitVarInsn(ILOAD, 1);
             Label dflt = new Label();
-            record Element(Label label, Class<?> clazz) {}
+            record Element(Label label, Class<?> clazz, Label falseTarget) {}
             List<Element> cases = new ArrayList<Element>();
-            for (Object o : labels) {
-                cases.add(new Element(new Label(), (Class<?>) o));
+            Class<?> lastClass = null;
+            Label lastClassLabel = dflt;
+            for (int i = labels.length - 1; i >= 0; i--) {
+                Class<?> label = (Class<?>) labels[i];
+                Element currentElement = new Element(new Label(), label, lastClassLabel);
+                cases.add(currentElement);
+                if (lastClass != label) {
+                    lastClassLabel = currentElement.label();
+                }
+                lastClass = label;
             }
+            Collections.reverse(cases);
             mv.visitTableSwitchInsn(0, labels.length - 1, dflt, cases.stream().map(e -> e.label()).toArray(s -> new Label[s]));
             for (int idx = 0; idx < cases.size(); idx++) {
                 Element element = cases.get(idx);
                 mv.visitLabel(element.label());
                 mv.visitVarInsn(ALOAD, 0);
                 mv.visitTypeInsn(INSTANCEOF, element.clazz().getName().replace('.', '/'));
-                mv.visitJumpInsn(IFEQ, idx + 1 < cases.size() ? cases.get(idx + 1).label() : dflt);
+                mv.visitJumpInsn(IFEQ, element.falseTarget());
                 mv.iconst(idx);
                 mv.visitInsn(IRETURN);
             }
@@ -347,19 +357,21 @@ record Element(Label label, Class<?> clazz) {}
 
         final byte[] classBytes = cw.toByteArray();
         // If requested, dump out to a file for debugging purposes
-//        var dumper = ProxyClassesDumper.getInstance("/tmp/classes/classes");
-//        if (dumper != null) {
-//            AccessController.doPrivileged(new PrivilegedAction<>() {
-//                @Override
-//                public Void run() {
-//                    dumper.dumpClass("foobar", classBytes);
-//                    return null;
-//                }
-//            }, null,
-//            new FilePermission("<<ALL FILES>>", "read, write"),
-//            // createDirectories may need it
-//            new PropertyPermission("user.dir", "read"));
-//        }
+        if (false) {
+            var dumper = ProxyClassesDumper.getInstance("/tmp/classes/classes");
+            if (dumper != null) {
+                AccessController.doPrivileged(new PrivilegedAction<>() {
+                    @Override
+                    public Void run() {
+                        dumper.dumpClass("foobar", classBytes);
+                        return null;
+                    }
+                }, null,
+                new FilePermission("<<ALL FILES>>", "read, write"),
+                // createDirectories may need it
+                new PropertyPermission("user.dir", "read"));
+            }
+        }
         try {
             // this class is linked at the indy callsite; so define a hidden nestmate
             MethodHandles.Lookup lookup;

diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/TransPatterns.java b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/TransPatterns.java
@@ -657,7 +657,7 @@ JCNewClass makeNewClass(Type ctype, List<JCExpression> args) {
         return tree;
     }
 
-    public List<JCCase> processCases(JCTree currentSwitch, List<JCCase> inputCases) {
+    protected List<JCCase> processCases(JCTree currentSwitch, List<JCCase> inputCases) {
         interface AccummulatorResolver {
             public void resolve(VarSymbol commonBinding, JCExpression commonNestedExpression, VarSymbol commonNestedBinding);
         }