com.oracle.truffle.api.utilities

Class ConditionProfile

java.lang.Object

com.oracle.truffle.api.nodes.NodeCloneable

com.oracle.truffle.api.utilities.ConditionProfile

All Implemented Interfaces:

java.lang.Cloneable

Direct Known Subclasses:

BinaryConditionProfile, CountingConditionProfile

public abstract class ConditionProfile
extends NodeCloneable

Abstract utility class to speculate on conditions. Condition profiles are intended to be used as part of if conditions. Example usage:

 private final ConditionProfile zero = ConditionProfile.createBinaryProfile();
 
 int value = ...;
 if (zero.profile(value == 0)) {
   return 0;
 } else {
   return value;
 }

 

All instances of ConditionProfile (and subclasses) must be held in final fields for compiler optimizations to take effect.

See Also:

createCountingProfile(), createBinaryProfile()

Constructor Summary

Constructors

Constructor and Description
ConditionProfile()

Method Summary

Methods

Modifier and Type	Method and Description
static ConditionProfile	createBinaryProfile() Returns a ConditionProfile that speculates on conditions to be never true or to be never false.
static ConditionProfile	createCountingProfile() Returns a ConditionProfile that speculates on conditions to be never true or to be never false.
abstract boolean	profile(boolean value)

Methods inherited from class com.oracle.truffle.api.nodes.NodeCloneable

clone

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ConditionProfile

public ConditionProfile()

Method Detail

profile

public abstract boolean profile(boolean value)

createCountingProfile

public static ConditionProfile createCountingProfile()

Returns a ConditionProfile that speculates on conditions to be never true or to be never false. Additionally to a binary profile this method returns a condition profile that also counts the number of times the condition was true and false. This information is reported to the underlying optimization system using CompilerDirectives.injectBranchProbability(double, boolean). Condition profiles are intended to be used as part of if conditions.

See Also:

ConditionProfile, createBinaryProfile()

createBinaryProfile

public static ConditionProfile createBinaryProfile()

Returns a ConditionProfile that speculates on conditions to be never true or to be never false. Condition profiles are intended to be used as part of if conditions.

See Also:

ConditionProfile, createCountingProfile()