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8332528: Generate code in SwitchBootstraps.generateTypeSwitch that require fewer adaptations

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Reviewed-by: liach, jlahoda
This commit is contained in:
Claes Redestad 2024-05-23 12:26:19 +00:00
parent b890336e11
commit 2581935b47
4 changed files with 150 additions and 39 deletions
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84
src/java.base/share/classes/java/lang/runtime/SwitchBootstraps.java
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@ -26,6 +26,7 @@
package java.lang.runtime;
import java.lang.Enum.EnumDesc;
import java.lang.classfile.ClassBuilder;
import java.lang.classfile.CodeBuilder;
import java.lang.constant.ClassDesc;
import java.lang.constant.ConstantDesc;
@ -48,6 +49,8 @@ import jdk.internal.access.SharedSecrets;
import java.lang.classfile.ClassFile;
import java.lang.classfile.Label;
import java.lang.classfile.instruction.SwitchCase;
import jdk.internal.constant.ReferenceClassDescImpl;
import jdk.internal.misc.PreviewFeatures;
import jdk.internal.vm.annotation.Stable;
@ -74,28 +77,38 @@ public class SwitchBootstraps {
private static final MethodHandles.Lookup LOOKUP = MethodHandles.lookup();
private static final boolean previewEnabled = PreviewFeatures.isEnabled();
private static final MethodHandle NULL_CHECK;
private static final MethodHandle IS_ZERO;
private static final MethodHandle CHECK_INDEX;
private static final MethodHandle MAPPED_ENUM_LOOKUP;
private static final MethodType TYPES_SWITCH_TYPE = MethodType.methodType(int.class,
Object.class,
int.class,
BiPredicate.class,
List.class);
private static final MethodTypeDesc TYPES_SWITCH_DESCRIPTOR =
MethodTypeDesc.ofDescriptor("(Ljava/lang/Object;ILjava/util/function/BiPredicate;Ljava/util/List;)I");
private static final MethodTypeDesc CHECK_INDEX_DESCRIPTOR =
MethodTypeDesc.ofDescriptor("(II)I");
static {
try {
NULL_CHECK = LOOKUP.findStatic(Objects.class, "isNull",
MethodType.methodType(boolean.class, Object.class));
IS_ZERO = LOOKUP.findStatic(SwitchBootstraps.class, "isZero",
MethodType.methodType(boolean.class, int.class));
CHECK_INDEX = LOOKUP.findStatic(Objects.class, "checkIndex",
MethodType.methodType(int.class, int.class, int.class));
MAPPED_ENUM_LOOKUP = LOOKUP.findStatic(SwitchBootstraps.class, "mappedEnumLookup",
MethodType.methodType(int.class, Enum.class, MethodHandles.Lookup.class,
Class.class, EnumDesc[].class, EnumMap.class));
}
catch (ReflectiveOperationException e) {
throw new ExceptionInInitializerError(e);
private static final ClassDesc CD_Objects = ReferenceClassDescImpl.ofValidated("Ljava/util/Objects;");
private static class StaticHolders {
private static final MethodHandle NULL_CHECK;
private static final MethodHandle IS_ZERO;
private static final MethodHandle MAPPED_ENUM_LOOKUP;
static {
try {
NULL_CHECK = LOOKUP.findStatic(Objects.class, "isNull",
MethodType.methodType(boolean.class, Object.class));
IS_ZERO = LOOKUP.findStatic(SwitchBootstraps.class, "isZero",
MethodType.methodType(boolean.class, int.class));
MAPPED_ENUM_LOOKUP = LOOKUP.findStatic(SwitchBootstraps.class, "mappedEnumLookup",
MethodType.methodType(int.class, Enum.class, MethodHandles.Lookup.class,
Class.class, EnumDesc[].class, EnumMap.class));
}
catch (ReflectiveOperationException e) {
throw new ExceptionInInitializerError(e);
}
}
}
@ -163,14 +176,13 @@ public class SwitchBootstraps {
|| (!invocationType.returnType().equals(int.class))
|| !invocationType.parameterType(1).equals(int.class))
throw new IllegalArgumentException("Illegal invocation type " + invocationType);
requireNonNull(labels);
Stream.of(labels).forEach(l -> verifyLabel(l, selectorType));
for (Object l : labels) { // implicit null-check
verifyLabel(l, selectorType);
}
MethodHandle target = generateTypeSwitch(lookup, selectorType, labels);
target = withIndexCheck(target, labels.length);
return new ConstantCallSite(target);
}
@ -282,18 +294,17 @@ public class SwitchBootstraps {
//else if (idx == 0) return mappingArray[selector.ordinal()]; //mapping array created lazily
//else return "typeSwitch(labels)"
MethodHandle body =
MethodHandles.guardWithTest(MethodHandles.dropArguments(NULL_CHECK, 0, int.class),
MethodHandles.guardWithTest(MethodHandles.dropArguments(StaticHolders.NULL_CHECK, 0, int.class),
MethodHandles.dropArguments(MethodHandles.constant(int.class, -1), 0, int.class, Object.class),
MethodHandles.guardWithTest(MethodHandles.dropArguments(IS_ZERO, 1, Object.class),
MethodHandles.guardWithTest(MethodHandles.dropArguments(StaticHolders.IS_ZERO, 1, Object.class),
generateTypeSwitch(lookup, invocationType.parameterType(0), labels),
MethodHandles.insertArguments(MAPPED_ENUM_LOOKUP, 1, lookup, enumClass, labels, new EnumMap())));
MethodHandles.insertArguments(StaticHolders.MAPPED_ENUM_LOOKUP, 1, lookup, enumClass, labels, new EnumMap())));
target = MethodHandles.permuteArguments(body, MethodType.methodType(int.class, Object.class, int.class), 1, 0);
} else {
target = generateTypeSwitch(lookup, invocationType.parameterType(0), labels);
}
target = target.asType(invocationType);
target = withIndexCheck(target, labels.length);
return new ConstantCallSite(target);
}
@ -339,12 +350,6 @@ public class SwitchBootstraps {
return enumMap.map[value.ordinal()];
}
private static MethodHandle withIndexCheck(MethodHandle target, int labelsCount) {
MethodHandle checkIndex = MethodHandles.insertArguments(CHECK_INDEX, 1, labelsCount + 1);
return MethodHandles.filterArguments(target, 1, checkIndex);
}
private static final class ResolvedEnumLabels implements BiPredicate<Integer, Object> {
private final MethodHandles.Lookup lookup;
@ -407,6 +412,11 @@ public class SwitchBootstraps {
int EXTRA_CLASS_LABELS = 3;
return cb -> {
// Objects.checkIndex(RESTART_IDX, labelConstants + 1)
cb.iload(RESTART_IDX);
cb.loadConstant(labelConstants.length + 1);
cb.invokestatic(CD_Objects, "checkIndex", CHECK_INDEX_DESCRIPTOR);
cb.pop();
cb.aload(SELECTOR_OBJ);
Label nonNullLabel = cb.newLabel();
cb.if_nonnull(nonNullLabel);
@ -621,7 +631,7 @@ public class SwitchBootstraps {
List<EnumDesc<?>> enumDescs = new ArrayList<>();
List<Class<?>> extraClassLabels = new ArrayList<>();
byte[] classBytes = ClassFile.of().build(ClassDesc.of(typeSwitchClassName(caller.lookupClass())),
byte[] classBytes = ClassFile.of().build(ReferenceClassDescImpl.ofValidatedBinaryName(typeSwitchClassName(caller.lookupClass())),
clb -> {
clb.withFlags(AccessFlag.FINAL, AccessFlag.SUPER, AccessFlag.SYNTHETIC)
.withMethodBody("typeSwitch",
@ -636,12 +646,8 @@ public class SwitchBootstraps {
lookup = caller.defineHiddenClass(classBytes, true, NESTMATE, STRONG);
MethodHandle typeSwitch = lookup.findStatic(lookup.lookupClass(),
"typeSwitch",
MethodType.methodType(int.class,
Object.class,
int.class,
BiPredicate.class,
List.class));
typeSwitch = MethodHandles.insertArguments(typeSwitch, 2, new ResolvedEnumLabels(caller, enumDescs.toArray(EnumDesc[]::new)),
TYPES_SWITCH_TYPE);
typeSwitch = MethodHandles.insertArguments(typeSwitch, 2, new ResolvedEnumLabels(caller, enumDescs.toArray(new EnumDesc<?>[0])),
List.copyOf(extraClassLabels));
typeSwitch = MethodHandles.explicitCastArguments(typeSwitch,
MethodType.methodType(int.class,