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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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package org.graalvm.compiler.nodes.graphbuilderconf;

import static jdk.vm.ci.meta.DeoptimizationAction.InvalidateReprofile;
import static jdk.vm.ci.meta.DeoptimizationReason.NullCheckException;
import static org.graalvm.compiler.core.common.type.StampFactory.objectNonNull;

import org.graalvm.compiler.bytecode.Bytecode;
import org.graalvm.compiler.bytecode.BytecodeProvider;
import org.graalvm.compiler.core.common.type.AbstractPointerStamp;
import org.graalvm.compiler.core.common.type.ObjectStamp;
import org.graalvm.compiler.core.common.type.Stamp;
import org.graalvm.compiler.core.common.type.StampFactory;
import org.graalvm.compiler.core.common.type.StampPair;
import org.graalvm.compiler.nodes.AbstractMergeNode;
import org.graalvm.compiler.nodes.CallTargetNode;
import org.graalvm.compiler.nodes.CallTargetNode.InvokeKind;
import org.graalvm.compiler.nodes.ConstantNode;
import org.graalvm.compiler.nodes.FixedGuardNode;
import org.graalvm.compiler.nodes.LogicNode;
import org.graalvm.compiler.nodes.NodeView;
import org.graalvm.compiler.nodes.PiNode;
import org.graalvm.compiler.nodes.StateSplit;
import org.graalvm.compiler.nodes.ValueNode;
import org.graalvm.compiler.nodes.calc.IsNullNode;
import org.graalvm.compiler.nodes.calc.NarrowNode;
import org.graalvm.compiler.nodes.calc.SignExtendNode;
import org.graalvm.compiler.nodes.calc.ZeroExtendNode;
import org.graalvm.compiler.nodes.type.StampTool;

import jdk.vm.ci.code.BailoutException;
import jdk.vm.ci.meta.Assumptions;
import jdk.vm.ci.meta.DeoptimizationAction;
import jdk.vm.ci.meta.DeoptimizationReason;
import jdk.vm.ci.meta.JavaKind;
import jdk.vm.ci.meta.JavaType;
import jdk.vm.ci.meta.ResolvedJavaMethod;

Used by a GraphBuilderPlugin to interface with an object that parses the bytecode of a single method as part of building a graph . /**
 * Used by a {@link GraphBuilderPlugin} to interface with an object that parses the bytecode of a
 * single {@linkplain #getMethod() method} as part of building a {@linkplain #getGraph() graph} .
 */
public interface GraphBuilderContext extends GraphBuilderTool {

    
Pushes a given value to the frame state stack using an explicit kind. This should be used when value.getJavaKind() is different from the kind that the bytecode instruction currently being parsed pushes to the stack. 
Params:
kind – the kind to use when type checking this operation
value – the value to push to the stack. The value must already have been appended./**
     * Pushes a given value to the frame state stack using an explicit kind. This should be used
     * when {@code value.getJavaKind()} is different from the kind that the bytecode instruction
     * currently being parsed pushes to the stack.
     *
     * @param kind the kind to use when type checking this operation
     * @param value the value to push to the stack. The value must already have been
     *            {@linkplain #append(ValueNode) appended}.
     */
    void push(JavaKind kind, ValueNode value);

    
Adds a node to the graph. If the node is in the graph, returns immediately. If the node is a StateSplit with a null frame state, the frame state is initialized. 
Params:
value – the value to add to the graph and push to the stack. The value.getJavaKind() kind is used when type checking this operation.
Returns:
a node equivalent to value in the graph/**
     * Adds a node to the graph. If the node is in the graph, returns immediately. If the node is a
     * {@link StateSplit} with a null {@linkplain StateSplit#stateAfter() frame state}, the frame
     * state is initialized.
     *
     * @param value the value to add to the graph and push to the stack. The
     *            {@code value.getJavaKind()} kind is used when type checking this operation.
     * @return a node equivalent to {@code value} in the graph
     */
    default <T extends ValueNode> T add(T value) {
        if (value.graph() != null) {
            assert !(value instanceof StateSplit) || ((StateSplit) value).stateAfter() != null;
            return value;
        }
        return GraphBuilderContextUtil.setStateAfterIfNecessary(this, append(value));
    }

    
Adds a node and its inputs to the graph. If the node is in the graph, returns immediately. If the node is a StateSplit with a null frame state , the frame state is initialized. 
Params:
value – the value to add to the graph and push to the stack. The value.getJavaKind() kind is used when type checking this operation.
Returns:
a node equivalent to value in the graph/**
     * Adds a node and its inputs to the graph. If the node is in the graph, returns immediately. If
     * the node is a {@link StateSplit} with a null {@linkplain StateSplit#stateAfter() frame state}
     * , the frame state is initialized.
     *
     * @param value the value to add to the graph and push to the stack. The
     *            {@code value.getJavaKind()} kind is used when type checking this operation.
     * @return a node equivalent to {@code value} in the graph
     */
    default <T extends ValueNode> T addWithInputs(T value) {
        if (value.graph() != null) {
            assert !(value instanceof StateSplit) || ((StateSplit) value).stateAfter() != null;
            return value;
        }
        return GraphBuilderContextUtil.setStateAfterIfNecessary(this, append(value));
    }

    default ValueNode addNonNullCast(ValueNode value) {
        AbstractPointerStamp valueStamp = (AbstractPointerStamp) value.stamp(NodeView.DEFAULT);
        if (valueStamp.nonNull()) {
            return value;
        } else {
            LogicNode isNull = add(IsNullNode.create(value));
            FixedGuardNode fixedGuard = add(new FixedGuardNode(isNull, DeoptimizationReason.NullCheckException, DeoptimizationAction.None, true));
            Stamp newStamp = valueStamp.improveWith(StampFactory.objectNonNull());
            return add(PiNode.create(value, newStamp, fixedGuard));
        }
    }

    
Adds a node with a non-void kind to the graph, pushes it to the stack. If the returned node is a StateSplit with a null frame state, the frame state is initialized. 
Params:
kind – the kind to use when type checking this operation
value – the value to add to the graph and push to the stack
Returns:
a node equivalent to value in the graph/**
     * Adds a node with a non-void kind to the graph, pushes it to the stack. If the returned node
     * is a {@link StateSplit} with a null {@linkplain StateSplit#stateAfter() frame state}, the
     * frame state is initialized.
     *
     * @param kind the kind to use when type checking this operation
     * @param value the value to add to the graph and push to the stack
     * @return a node equivalent to {@code value} in the graph
     */
    default <T extends ValueNode> T addPush(JavaKind kind, T value) {
        T equivalentValue = value.graph() != null ? value : append(value);
        push(kind, equivalentValue);
        return GraphBuilderContextUtil.setStateAfterIfNecessary(this, equivalentValue);
    }

    
Handles an invocation that a plugin determines can replace the original invocation (i.e., the
one for which the plugin was applied). This applies all standard graph builder processing to
the replaced invocation including applying any relevant plugins.
Params:
invokeKind – the kind of the replacement invocation
targetMethod – the target of the replacement invocation
args – the arguments to the replacement invocation
forceInlineEverything – specifies if all invocations encountered in the scope of
           handling the replaced invoke are to be force inlined/**
     * Handles an invocation that a plugin determines can replace the original invocation (i.e., the
     * one for which the plugin was applied). This applies all standard graph builder processing to
     * the replaced invocation including applying any relevant plugins.
     *
     * @param invokeKind the kind of the replacement invocation
     * @param targetMethod the target of the replacement invocation
     * @param args the arguments to the replacement invocation
     * @param forceInlineEverything specifies if all invocations encountered in the scope of
     *            handling the replaced invoke are to be force inlined
     */
    void handleReplacedInvoke(InvokeKind invokeKind, ResolvedJavaMethod targetMethod, ValueNode[] args, boolean forceInlineEverything);

    void handleReplacedInvoke(CallTargetNode callTarget, JavaKind resultType);

    
Intrinsifies an invocation of a given method by inlining the bytecodes of a given
substitution method.
Params:
bytecodeProvider – used to get the bytecodes to parse for the substitution method
targetMethod – the method being intrinsified
substitute – the intrinsic implementation
receiver – the receiver, or null for static methods
argsIncludingReceiver – the arguments with which to inline the invocation
Returns:
whether the intrinsification was successful/**
     * Intrinsifies an invocation of a given method by inlining the bytecodes of a given
     * substitution method.
     *
     * @param bytecodeProvider used to get the bytecodes to parse for the substitution method
     * @param targetMethod the method being intrinsified
     * @param substitute the intrinsic implementation
     * @param receiver the receiver, or null for static methods
     * @param argsIncludingReceiver the arguments with which to inline the invocation
     *
     * @return whether the intrinsification was successful
     */
    boolean intrinsify(BytecodeProvider bytecodeProvider, ResolvedJavaMethod targetMethod, ResolvedJavaMethod substitute, InvocationPlugin.Receiver receiver, ValueNode[] argsIncludingReceiver);

    
Creates a snap shot of the current frame state with the BCI of the instruction after the one currently being parsed and assigns it to a given side
effect node. 
Params:
sideEffect – a side effect node just appended to the graph/**
     * Creates a snap shot of the current frame state with the BCI of the instruction after the one
     * currently being parsed and assigns it to a given {@linkplain StateSplit#hasSideEffect() side
     * effect} node.
     *
     * @param sideEffect a side effect node just appended to the graph
     */
    void setStateAfter(StateSplit sideEffect);

    
Gets the parsing context for the method that inlines the method being parsed by this context.
/**
     * Gets the parsing context for the method that inlines the method being parsed by this context.
     */
    GraphBuilderContext getParent();

    
Gets the first ancestor parsing context that is not parsing a 
intrinsic. /**
     * Gets the first ancestor parsing context that is not parsing a {@linkplain #parsingIntrinsic()
     * intrinsic}.
     */
    default GraphBuilderContext getNonIntrinsicAncestor() {
        GraphBuilderContext ancestor = getParent();
        while (ancestor != null && ancestor.parsingIntrinsic()) {
            ancestor = ancestor.getParent();
        }
        return ancestor;
    }

    
Gets the code being parsed.
/**
     * Gets the code being parsed.
     */
    Bytecode getCode();

    
Gets the method being parsed by this context.
/**
     * Gets the method being parsed by this context.
     */
    ResolvedJavaMethod getMethod();

    
Gets the index of the bytecode instruction currently being parsed.
/**
     * Gets the index of the bytecode instruction currently being parsed.
     */
    int bci();

    
Gets the kind of invocation currently being parsed.
/**
     * Gets the kind of invocation currently being parsed.
     */
    InvokeKind getInvokeKind();

    
Gets the return type of the invocation currently being parsed.
/**
     * Gets the return type of the invocation currently being parsed.
     */
    JavaType getInvokeReturnType();

    default StampPair getInvokeReturnStamp(Assumptions assumptions) {
        JavaType returnType = getInvokeReturnType();
        return StampFactory.forDeclaredType(assumptions, returnType, false);
    }

    
Gets the inline depth of this context. A return value of 0 implies that this is the context
for the parse root.
/**
     * Gets the inline depth of this context. A return value of 0 implies that this is the context
     * for the parse root.
     */
    default int getDepth() {
        GraphBuilderContext parent = getParent();
        int result = 0;
        while (parent != null) {
            result++;
            parent = parent.getParent();
        }
        return result;
    }

    
Determines if this parsing context is within the bytecode of an intrinsic or a method inlined
by an intrinsic.
/**
     * Determines if this parsing context is within the bytecode of an intrinsic or a method inlined
     * by an intrinsic.
     */
    @Override
    default boolean parsingIntrinsic() {
        return getIntrinsic() != null;
    }

    
Gets the intrinsic of the current parsing context or null if not parsing an intrinsic. /**
     * Gets the intrinsic of the current parsing context or {@code null} if not
     * {@link #parsingIntrinsic() parsing an intrinsic}.
     */
    IntrinsicContext getIntrinsic();

    BailoutException bailout(String string);

    default ValueNode nullCheckedValue(ValueNode value) {
        return nullCheckedValue(value, InvalidateReprofile);
    }

    
Gets a version of a given value that has a 
non-null stamp. /**
     * Gets a version of a given value that has a {@linkplain StampTool#isPointerNonNull(ValueNode)
     * non-null} stamp.
     */
    default ValueNode nullCheckedValue(ValueNode value, DeoptimizationAction action) {
        if (!StampTool.isPointerNonNull(value)) {
            LogicNode condition = getGraph().unique(IsNullNode.create(value));
            ObjectStamp receiverStamp = (ObjectStamp) value.stamp(NodeView.DEFAULT);
            Stamp stamp = receiverStamp.join(objectNonNull());
            FixedGuardNode fixedGuard = append(new FixedGuardNode(condition, NullCheckException, action, true));
            ValueNode nonNullReceiver = getGraph().addOrUniqueWithInputs(PiNode.create(value, stamp, fixedGuard));
            // TODO: Propogating the non-null into the frame state would
            // remove subsequent null-checks on the same value. However,
            // it currently causes an assertion failure when merging states.
            //
            // frameState.replace(value, nonNullReceiver);
            return nonNullReceiver;
        }
        return value;
    }

    @SuppressWarnings("unused")
    default void notifyReplacedCall(ResolvedJavaMethod targetMethod, ConstantNode node) {

    }

    
Interface whose instances hold inlining information about the current context, in a wider sense. The wider sense in this case concerns graph building approaches that don't necessarily keep a chain of GraphBuilderContext instances normally available through GraphBuilderContext.getParent(). Examples of such approaches are partial evaluation and incremental inlining. /**
     * Interface whose instances hold inlining information about the current context, in a wider
     * sense. The wider sense in this case concerns graph building approaches that don't necessarily
     * keep a chain of {@link GraphBuilderContext} instances normally available through
     * {@linkplain #getParent()}. Examples of such approaches are partial evaluation and incremental
     * inlining.
     */
    interface ExternalInliningContext {
        int getInlinedDepth();
    }

    default ExternalInliningContext getExternalInliningContext() {
        return null;
    }

    
Adds masking to a given subword value according to a given {@Link JavaKind}, such that the
masked value falls in the range of the given kind. In the cases where the given kind is not a
subword kind, the input value is returned immediately.
Params:
value – the value to be masked
kind – the kind that specifies the range of the masked value
Returns:
the masked value/**
     * Adds masking to a given subword value according to a given {@Link JavaKind}, such that the
     * masked value falls in the range of the given kind. In the cases where the given kind is not a
     * subword kind, the input value is returned immediately.
     *
     * @param value the value to be masked
     * @param kind the kind that specifies the range of the masked value
     * @return the masked value
     */
    default ValueNode maskSubWordValue(ValueNode value, JavaKind kind) {
        if (kind == kind.getStackKind()) {
            return value;
        }
        // Subword value
        ValueNode narrow = append(NarrowNode.create(value, kind.getBitCount(), NodeView.DEFAULT));
        if (kind.isUnsigned()) {
            return append(ZeroExtendNode.create(narrow, 32, NodeView.DEFAULT));
        } else {
            return append(SignExtendNode.create(narrow, 32, NodeView.DEFAULT));
        }
    }
}

class GraphBuilderContextUtil {
    static <T extends ValueNode> T setStateAfterIfNecessary(GraphBuilderContext b, T value) {
        if (value instanceof StateSplit) {
            StateSplit stateSplit = (StateSplit) value;
            if (stateSplit.stateAfter() == null && (stateSplit.hasSideEffect() || stateSplit instanceof AbstractMergeNode)) {
                b.setStateAfter(stateSplit);
            }
        }
        return value;
    }
}