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package jdk.vm.ci.meta;

Manages unique deoptimization reasons. Reasons are embedded in compiled code and can be
invalidated at run time. Subsequent compilations then should not speculate again on such
invalidated reasons to avoid repeated deoptimization.
All methods of this interface are called by the compiler. There is no need for API to register
failed speculations during deoptimization, since every VM has different needs there.
/**
 * Manages unique deoptimization reasons. Reasons are embedded in compiled code and can be
 * invalidated at run time. Subsequent compilations then should not speculate again on such
 * invalidated reasons to avoid repeated deoptimization.
 *
 * All methods of this interface are called by the compiler. There is no need for API to register
 * failed speculations during deoptimization, since every VM has different needs there.
 */
public interface SpeculationLog {

    
Marker interface for speculation objects that can be added to the speculation log.
/**
     * Marker interface for speculation objects that can be added to the speculation log.
     */
    public interface SpeculationReason {
    }

    
Must be called before compilation, i.e., before a compiler calls maySpeculate. /**
     * Must be called before compilation, i.e., before a compiler calls {@link #maySpeculate}.
     */
    void collectFailedSpeculations();

    
If this method returns true, the compiler is allowed to speculate with the given reason. /**
     * If this method returns true, the compiler is allowed to {@link #speculate} with the given
     * reason.
     */
    boolean maySpeculate(SpeculationReason reason);

    
Registers a speculation that was performed by the compiler.
Returns:
A compiler constant encapsulating the provided reason. It is usually passed as an
        argument to the deoptimization function./**
     * Registers a speculation that was performed by the compiler.
     *
     * @return A compiler constant encapsulating the provided reason. It is usually passed as an
     *         argument to the deoptimization function.
     */
    JavaConstant speculate(SpeculationReason reason);

    
Returns if this log has speculations.
Returns:
true if there are speculations, false otherwise/**
     * Returns if this log has speculations.
     *
     * @return true if there are speculations, false otherwise
     */
    boolean hasSpeculations();
}