Merge jdk17

src/hotspot/cpu/x86/x86_32.ad

@@ -11539,7 +11539,7 @@ instruct rep_stos(eCXRegI cnt, eDIRegP base, regD tmp, eAXRegI zero, Universe du
 %}
 
 // Small ClearArray AVX512 non-constant length.
-instruct rep_stos_evex(eCXRegI cnt, eDIRegP base, regD tmp, kReg ktmp, eAXRegI zero, Universe dummy, eFlagsReg cr) %{
+instruct rep_stos_evex(eCXRegI cnt, eDIRegP base, legRegD tmp, kReg ktmp, eAXRegI zero, Universe dummy, eFlagsReg cr) %{
   predicate(!((ClearArrayNode*)n)->is_large() && (UseAVX > 2));
   match(Set dummy (ClearArray cnt base));
   ins_cost(125);
@@ -11650,7 +11650,7 @@ instruct rep_stos_large(eCXRegI cnt, eDIRegP base, regD tmp, eAXRegI zero, Unive
 %}
 
 // Large ClearArray AVX512.
-instruct rep_stos_large_evex(eCXRegI cnt, eDIRegP base, regD tmp, kReg ktmp, eAXRegI zero, Universe dummy, eFlagsReg cr) %{
+instruct rep_stos_large_evex(eCXRegI cnt, eDIRegP base, legRegD tmp, kReg ktmp, eAXRegI zero, Universe dummy, eFlagsReg cr) %{
   predicate((UseAVX > 2) && ((ClearArrayNode*)n)->is_large());
   match(Set dummy (ClearArray cnt base));
   effect(USE_KILL cnt, USE_KILL base, TEMP tmp, TEMP ktmp, KILL zero, KILL cr);

src/hotspot/cpu/x86/x86_64.ad

@@ -11100,7 +11100,7 @@ instruct rep_stos(rcx_RegL cnt, rdi_RegP base, regD tmp, rax_RegI zero,
 %}
 
 // Small ClearArray AVX512 non-constant length.
-instruct rep_stos_evex(rcx_RegL cnt, rdi_RegP base, regD tmp, kReg ktmp, rax_RegI zero,
+instruct rep_stos_evex(rcx_RegL cnt, rdi_RegP base, legRegD tmp, kReg ktmp, rax_RegI zero,
                        Universe dummy, rFlagsReg cr)
 %{
   predicate(!((ClearArrayNode*)n)->is_large() && (UseAVX > 2));
@@ -11212,7 +11212,7 @@ instruct rep_stos_large(rcx_RegL cnt, rdi_RegP base, regD tmp, rax_RegI zero,
 %}
 
 // Large ClearArray AVX512.
-instruct rep_stos_large_evex(rcx_RegL cnt, rdi_RegP base, regD tmp, kReg ktmp, rax_RegI zero,
+instruct rep_stos_large_evex(rcx_RegL cnt, rdi_RegP base, legRegD tmp, kReg ktmp, rax_RegI zero,
                              Universe dummy, rFlagsReg cr)
 %{
   predicate((UseAVX > 2) && ((ClearArrayNode*)n)->is_large());

src/hotspot/share/opto/callnode.cpp

@@ -1411,8 +1411,14 @@ Node *SafePointNode::Ideal(PhaseGVN *phase, bool can_reshape) {
 Node* SafePointNode::Identity(PhaseGVN* phase) {
 
   // If you have back to back safepoints, remove one
-  if( in(TypeFunc::Control)->is_SafePoint() )
-    return in(TypeFunc::Control);
+  if (in(TypeFunc::Control)->is_SafePoint()) {
+    Node* out_c = unique_ctrl_out();
+    // This can be the safepoint of an outer strip mined loop if the inner loop's backedge was removed. Replacing the
+    // outer loop's safepoint could confuse removal of the outer loop.
+    if (out_c != NULL && !out_c->is_OuterStripMinedLoopEnd()) {
+      return in(TypeFunc::Control);
+    }
+  }
 
   // Transforming long counted loops requires a safepoint node. Do not
   // eliminate a safepoint until loop opts are over.

src/java.base/share/classes/java/io/ByteArrayInputStream.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1994, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1994, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -156,6 +156,10 @@ public synchronized int read() {
      * {@code b[off+k-1]} in the manner performed by {@code System.arraycopy}.
      * The value {@code k} is added into {@code pos} and {@code k} is returned.
      * <p>
+     * Unlike the {@link InputStream#read(byte[],int,int) overridden method}
+     * of {@code InputStream}, this method returns {@code -1} instead of zero
+     * if the end of the stream has been reached and {@code len == 0}.
+     * <p>
      * This {@code read} method cannot block.
      *
      * @param   b     the buffer into which the data is read.

src/java.base/share/classes/java/lang/runtime/SwitchBootstraps.java

@@ -26,12 +26,11 @@
 package java.lang.runtime;
 
 import java.lang.invoke.CallSite;
+import java.lang.invoke.ConstantBootstraps;
 import java.lang.invoke.ConstantCallSite;
 import java.lang.invoke.MethodHandle;
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.MethodType;
-import java.util.Arrays;
-import java.util.Objects;
 import java.util.stream.Stream;
 
 import jdk.internal.javac.PreviewFeature;
@@ -53,12 +52,15 @@ private SwitchBootstraps() {}
 
     private static final MethodHandles.Lookup LOOKUP = MethodHandles.lookup();
 
-    private static final MethodHandle DO_SWITCH;
+    private static final MethodHandle DO_TYPE_SWITCH;
+    private static final MethodHandle DO_ENUM_SWITCH;
 
     static {
         try {
-            DO_SWITCH = LOOKUP.findStatic(SwitchBootstraps.class, "doSwitch",
+            DO_TYPE_SWITCH = LOOKUP.findStatic(SwitchBootstraps.class, "doTypeSwitch",
                                            MethodType.methodType(int.class, Object.class, int.class, Object[].class));
+            DO_ENUM_SWITCH = LOOKUP.findStatic(SwitchBootstraps.class, "doEnumSwitch",
+                                           MethodType.methodType(int.class, Enum.class, int.class, Object[].class));
         }
         catch (ReflectiveOperationException e) {
             throw new ExceptionInInitializerError(e);
@@ -108,14 +110,13 @@ private SwitchBootstraps() {}
      * second parameter of type {@code int} and with {@code int} as its return type,
      * or if {@code labels} contains an element that is not of type {@code String},
      * {@code Integer} or {@code Class}.
-     * @throws Throwable if there is any error linking the call site
      * @jvms 4.4.6 The CONSTANT_NameAndType_info Structure
      * @jvms 4.4.10 The CONSTANT_Dynamic_info and CONSTANT_InvokeDynamic_info Structures
      */
     public static CallSite typeSwitch(MethodHandles.Lookup lookup,
                                       String invocationName,
                                       MethodType invocationType,
-                                      Object... labels) throws Throwable {
+                                      Object... labels) {
         if (invocationType.parameterCount() != 2
             || (!invocationType.returnType().equals(int.class))
             || invocationType.parameterType(0).isPrimitive()
@@ -126,7 +127,7 @@ public static CallSite typeSwitch(MethodHandles.Lookup lookup,
         labels = labels.clone();
         Stream.of(labels).forEach(SwitchBootstraps::verifyLabel);
 
-        MethodHandle target = MethodHandles.insertArguments(DO_SWITCH, 2, (Object) labels);
+        MethodHandle target = MethodHandles.insertArguments(DO_TYPE_SWITCH, 2, (Object) labels);
         return new ConstantCallSite(target);
     }
 
@@ -142,7 +143,7 @@ private static void verifyLabel(Object label) {
         }
     }
 
-    private static int doSwitch(Object target, int startIndex, Object[] labels) {
+    private static int doTypeSwitch(Object target, int startIndex, Object[] labels) {
         if (target == null)
             return -1;
 
@@ -167,4 +168,124 @@ private static int doSwitch(Object target, int startIndex, Object[] labels) {
         return labels.length;
     }
 
+    /**
+     * Bootstrap method for linking an {@code invokedynamic} call site that
+     * implements a {@code switch} on a target of an enum type. The static
+     * arguments are used to encode the case labels associated to the switch
+     * construct, where each label can be encoded in two ways:
+     * <ul>
+     *   <li>as a {@code String} value, which represents the name of
+     *       the enum constant associated with the label</li>
+     *   <li>as a {@code Class} value, which represents the enum type
+     *       associated with a type test pattern</li>
+     * </ul>
+     * <p>
+     * The returned {@code CallSite}'s method handle will have
+     * a return type of {@code int} and accepts two parameters: the first argument
+     * will be an {@code Enum} instance ({@code target}) and the second
+     * will be {@code int} ({@code restart}).
+     * <p>
+     * If the {@code target} is {@code null}, then the method of the call site
+     * returns {@literal -1}.
+     * <p>
+     * If the {@code target} is not {@code null}, then the method of the call site
+     * returns the index of the first element in the {@code labels} array starting from
+     * the {@code restart} index matching one of the following conditions:
+     * <ul>
+     *   <li>the element is of type {@code Class} that is assignable
+     *       from the target's class; or</li>
+     *   <li>the element is of type {@code String} and equals to the target
+     *       enum constant's {@link Enum#name()}.</li>
+     * </ul>
+     * <p>
+     * If no element in the {@code labels} array matches the target, then
+     * the method of the call site return the length of the {@code labels} array.
+     *
+     * @param lookup Represents a lookup context with the accessibility
+     *               privileges of the caller. When used with {@code invokedynamic},
+     *               this is stacked automatically by the VM.
+     * @param invocationName unused
+     * @param invocationType The invocation type of the {@code CallSite} with two parameters,
+     *                       an enum type, an {@code int}, and {@code int} as a return type.
+     * @param labels case labels - {@code String} constants and {@code Class} instances,
+     *               in any combination
+     * @return a {@code CallSite} returning the first matching element as described above
+     *
+     * @throws NullPointerException if any argument is {@code null}
+     * @throws IllegalArgumentException if any element in the labels array is null, if the
+     * invocation type is not a method type whose first parameter type is an enum type,
+     * second parameter of type {@code int} and whose return type is {@code int},
+     * or if {@code labels} contains an element that is not of type {@code String} or
+     * {@code Class} of the target enum type.
+     * @jvms 4.4.6 The CONSTANT_NameAndType_info Structure
+     * @jvms 4.4.10 The CONSTANT_Dynamic_info and CONSTANT_InvokeDynamic_info Structures
+     */
+    public static CallSite enumSwitch(MethodHandles.Lookup lookup,
+                                      String invocationName,
+                                      MethodType invocationType,
+                                      Object... labels) {
+        if (invocationType.parameterCount() != 2
+            || (!invocationType.returnType().equals(int.class))
+            || invocationType.parameterType(0).isPrimitive()
+            || !invocationType.parameterType(0).isEnum()
+            || !invocationType.parameterType(1).equals(int.class))
+            throw new IllegalArgumentException("Illegal invocation type " + invocationType);
+        requireNonNull(labels);
+
+        labels = labels.clone();
+
+        Class<?> enumClass = invocationType.parameterType(0);
+        labels = Stream.of(labels).map(l -> convertEnumConstants(lookup, enumClass, l)).toArray();
+
+        MethodHandle target =
+                MethodHandles.insertArguments(DO_ENUM_SWITCH, 2, (Object) labels);
+        target = target.asType(invocationType);
+
+        return new ConstantCallSite(target);
+    }
+
+    private static <E extends Enum<E>> Object convertEnumConstants(MethodHandles.Lookup lookup, Class<?> enumClassTemplate, Object label) {
+        if (label == null) {
+            throw new IllegalArgumentException("null label found");
+        }
+        Class<?> labelClass = label.getClass();
+        if (labelClass == Class.class) {
+            if (label != enumClassTemplate) {
+                throw new IllegalArgumentException("the Class label: " + label +
+                                                   ", expected the provided enum class: " + enumClassTemplate);
+            }
+            return label;
+        } else if (labelClass == String.class) {
+            @SuppressWarnings("unchecked")
+            Class<E> enumClass = (Class<E>) enumClassTemplate;
+            try {
+                return ConstantBootstraps.enumConstant(lookup, (String) label, enumClass);
+            } catch (IllegalArgumentException ex) {
+                return null;
+            }
+        } else {
+            throw new IllegalArgumentException("label with illegal type found: " + labelClass +
+                                               ", expected label of type either String or Class");
+        }
+    }
+
+    private static int doEnumSwitch(Enum<?> target, int startIndex, Object[] labels) {
+        if (target == null)
+            return -1;
+
+        // Dumbest possible strategy
+        Class<?> targetClass = target.getClass();
+        for (int i = startIndex; i < labels.length; i++) {
+            Object label = labels[i];
+            if (label instanceof Class<?> c) {
+                if (c.isAssignableFrom(targetClass))
+                    return i;
+            } else if (label == target) {
+                return i;
+            }
+        }
+
+        return labels.length;
+    }
+
 }

src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Flow.java

@@ -664,7 +664,11 @@ public void visitSwitch(JCSwitch tree) {
             ListBuffer<PendingExit> prevPendingExits = pendingExits;
             pendingExits = new ListBuffer<>();
             scan(tree.selector);
-            Set<Symbol> constants = tree.patternSwitch ? new HashSet<>() : null;
+            boolean exhaustiveSwitch = tree.patternSwitch ||
+                                       tree.cases.stream()
+                                                 .flatMap(c -> c.labels.stream())
+                                                 .anyMatch(l -> TreeInfo.isNull(l));
+            Set<Symbol> constants = exhaustiveSwitch ? new HashSet<>() : null;
             for (List<JCCase> l = tree.cases; l.nonEmpty(); l = l.tail) {
                 alive = Liveness.ALIVE;
                 JCCase c = l.head;
@@ -686,7 +690,7 @@ public void visitSwitch(JCSwitch tree) {
                                 l.tail.head.pos(),
                                 Warnings.PossibleFallThroughIntoCase);
             }
-            if (!tree.hasTotalPattern && tree.patternSwitch &&
+            if (!tree.hasTotalPattern && exhaustiveSwitch &&
                 !TreeInfo.isErrorEnumSwitch(tree.selector, tree.cases) &&
                 (constants == null || !isExhaustive(tree.selector.type, constants))) {
                 log.error(tree, Errors.NotExhaustiveStatement);