src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.hotspot.lir.test/src/org/graalvm/compiler/hotspot/lir/test/MitigateExceedingMaxOopMapStackOffsetTest.java
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package org.graalvm.compiler.hotspot.lir.test;
import java.util.ArrayList;
import java.util.List;
import org.graalvm.compiler.core.common.LIRKind;
import org.graalvm.compiler.hotspot.HotSpotBackend;
import org.graalvm.compiler.lir.VirtualStackSlot;
import org.graalvm.compiler.lir.framemap.FrameMapBuilder;
import org.graalvm.compiler.lir.gen.LIRGeneratorTool;
import org.graalvm.compiler.lir.jtt.LIRTest;
import org.graalvm.compiler.lir.jtt.LIRTestSpecification;
import org.graalvm.compiler.lir.stackslotalloc.LSStackSlotAllocator;
import org.graalvm.compiler.nodes.SafepointNode;
import org.graalvm.compiler.nodes.graphbuilderconf.GraphBuilderConfiguration;
import org.graalvm.compiler.nodes.graphbuilderconf.GraphBuilderContext;
import org.graalvm.compiler.nodes.graphbuilderconf.InvocationPlugin;
import org.junit.Assume;
import org.junit.Test;
import jdk.vm.ci.meta.AllocatableValue;
import jdk.vm.ci.meta.JavaConstant;
import jdk.vm.ci.meta.ResolvedJavaMethod;
/**
* Tests the mitigation against overflowing the max size limit for a HotSpot OopMap. The mitigation
* works by {@link LSStackSlotAllocator} placing reference typed stack slots at lower offsets.
*/
public class MitigateExceedingMaxOopMapStackOffsetTest extends LIRTest {
/**
* Allocate stacks slots and initializes those at an odd index with a reference constant and
* those at an even index with a primitive constant.
*/
private static class WriteStackValues extends LIRTestSpecification {
private final JavaConstant objectConstant;
private final JavaConstant primitiveConstant;
WriteStackValues(JavaConstant objectConstant, JavaConstant primitiveConstant) {
this.objectConstant = objectConstant;
this.primitiveConstant = primitiveConstant;
}
@Override
public void generate(LIRGeneratorTool gen) {
FrameMapBuilder frameMapBuilder = gen.getResult().getFrameMapBuilder();
LIRKind objectLirKind = LIRKind.reference(gen.target().arch.getPlatformKind(objectConstant.getJavaKind()));
LIRKind primitiveLirKind = LIRKind.value(gen.target().arch.getPlatformKind(primitiveConstant.getJavaKind()));
int numSlots = numPrimitiveSlots + numReferenceSlots;
List<AllocatableValue> slotList = new ArrayList<>(numSlots);
// Place reference slots at top and bottom of virtual frame
// with primitive slots in the middle. This tests that slot
// partitioning works.
AllocatableValue srcObject = gen.emitLoadConstant(objectLirKind, objectConstant);
for (int i = 0; i < numReferenceSlots / 2; i++) {
VirtualStackSlot slot = frameMapBuilder.allocateSpillSlot(objectLirKind);
slotList.add(slot);
gen.emitMove(slot, srcObject);
}
AllocatableValue srcPrimitive = gen.emitLoadConstant(objectLirKind, primitiveConstant);
for (int i = 0; i < numPrimitiveSlots; i++) {
VirtualStackSlot slot = frameMapBuilder.allocateSpillSlot(primitiveLirKind);
slotList.add(slot);
gen.emitMove(slot, srcPrimitive);
}
for (int i = numReferenceSlots / 2; i < numReferenceSlots; i++) {
VirtualStackSlot slot = frameMapBuilder.allocateSpillSlot(objectLirKind);
slotList.add(slot);
gen.emitMove(slot, srcObject);
}
slots = slotList.toArray(new AllocatableValue[slotList.size()]);
}
}
/**
* Read stacks slots and move their content into a blackhole.
*/
private static class ReadStackValues extends LIRTestSpecification {
ReadStackValues() {
}
@Override
public void generate(LIRGeneratorTool gen) {
for (int i = 0; i < slots.length; i++) {
gen.emitBlackhole(gen.emitMove(slots[i]));
}
}
}
@Override
protected GraphBuilderConfiguration editGraphBuilderConfiguration(GraphBuilderConfiguration conf) {
InvocationPlugin safepointPlugin = new InvocationPlugin() {
@Override
public boolean apply(GraphBuilderContext b, ResolvedJavaMethod targetMethod, Receiver receiver) {
b.add(new SafepointNode());
return true;
}
};
conf.getPlugins().getInvocationPlugins().register(safepointPlugin, getClass(), "safepoint");
return super.editGraphBuilderConfiguration(conf);
}
/*
* Safepoint Snippet
*/
private static void safepoint() {
}
private static int numPrimitiveSlots;
private static int numReferenceSlots;
private static AllocatableValue[] slots;
private static final LIRTestSpecification readStackValues = new ReadStackValues();
@SuppressWarnings("unused")
@LIRIntrinsic
public static void instrinsic(LIRTestSpecification spec) {
}
private static final LIRTestSpecification writeStackValues = new WriteStackValues(JavaConstant.NULL_POINTER, JavaConstant.LONG_0);
public void testStackObjects() {
instrinsic(writeStackValues);
safepoint();
instrinsic(readStackValues);
}
@Test
public void runStackObjects() {
int max = ((HotSpotBackend) getBackend()).getRuntime().getVMConfig().maxOopMapStackOffset;
Assume.assumeFalse("no limit on oop map size", max == Integer.MAX_VALUE);
numPrimitiveSlots = (max / 8) * 2;
numReferenceSlots = (max / 8) - 100; // Should be enough margin for all platforms
runTest("testStackObjects");
}
}