/*
* Copyright (c) 2014, 2020, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* The Universal Permissive License (UPL), Version 1.0
*
* Subject to the condition set forth below, permission is hereby granted to any
* person obtaining a copy of this software, associated documentation and/or
* data (collectively the "Software"), free of charge and under any and all
* copyright rights in the Software, and any and all patent rights owned or
* freely licensable by each licensor hereunder covering either (i) the
* unmodified Software as contributed to or provided by such licensor, or (ii)
* the Larger Works (as defined below), to deal in both
*
* (a) the Software, and
*
* (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
* one is included with the Software each a "Larger Work" to which the Software
* is contributed by such licensors),
*
* without restriction, including without limitation the rights to copy, create
* derivative works of, display, perform, and distribute the Software and make,
* use, sell, offer for sale, import, export, have made, and have sold the
* Software and the Larger Work(s), and to sublicense the foregoing rights on
* either these or other terms.
*
* This license is subject to the following condition:
*
* The above copyright notice and either this complete permission notice or at a
* minimum a reference to the UPL must be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package com.oracle.truffle.api.profiles;
import com.oracle.truffle.api.CompilerDirectives;
import com.oracle.truffle.api.CompilerDirectives.CompilationFinal;
ConditionProfiles are useful to profile the outcome of conditions.
Usage example:
class AbsoluteNode extends Node {
final ConditionProfile greaterZeroProfile = ConditionProfile.create{Binary,Counting}Profile();
void execute(int value) {
if (greaterZeroProfile.profile(value >= 0)) {
return value;
} else {
return -value;
}
}
}
{@inheritDoc}
See Also: Since: 0.10
/**
* <p>
* ConditionProfiles are useful to profile the outcome of conditions.
* </p>
*
* <p>
* <b> Usage example: </b>
*
* <pre>
* class AbsoluteNode extends Node {
*
* final ConditionProfile greaterZeroProfile = ConditionProfile.create{Binary,Counting}Profile();
*
* void execute(int value) {
* if (greaterZeroProfile.profile(value >= 0)) {
* return value;
* } else {
* return -value;
* }
* }
* }
* </pre>
*
* {@inheritDoc}
*
* @see #createBinaryProfile()
* @see #createCountingProfile()
* @see LoopConditionProfile
* @since 0.10
*/
public abstract class ConditionProfile extends Profile {
ConditionProfile() {
}
Since: 0.10
/** @since 0.10 */
public abstract boolean profile(boolean value);
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: Since: 0.10
/**
* Returns a {@link ConditionProfile} that speculates on conditions to be never
* <code>true</code> or to be never <code>false</code>. 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
* {@link CompilerDirectives#injectBranchProbability(double, boolean)}. Condition profiles are
* intended to be used as part of if conditions.
*
* @see ConditionProfile
* @see #createBinaryProfile()
* @since 0.10
*/
public static ConditionProfile createCountingProfile() {
if (Profile.isProfilingEnabled()) {
return Counting.createLazyLoadClass();
} else {
return Disabled.INSTANCE;
}
}
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: Since: 0.10
/**
* Returns a {@link ConditionProfile} that speculates on conditions to be never
* <code>true</code> or to be never <code>false</code>. Condition profiles are intended to be
* used as part of if conditions.
*
* @see ConditionProfile
* @see ConditionProfile#createCountingProfile()
* @since 0.10
*/
public static ConditionProfile createBinaryProfile() {
if (Profile.isProfilingEnabled()) {
return Binary.createLazyLoadClass();
} else {
return Disabled.INSTANCE;
}
}
Creates a binary ConditionProfile using createBinaryProfile(). This is a convenience method so it can be used as @Cached ConditionProfile myProfile instead of the much longer @Cached("createBinaryProfile()") ConditionProfile myProfile. Since: 20.2
/**
* Creates a binary ConditionProfile using {@link #createBinaryProfile()}. This is a convenience
* method so it can be used as {@code @Cached ConditionProfile myProfile} instead of the much
* longer {@code @Cached("createBinaryProfile()") ConditionProfile myProfile}.
*
* @since 20.2
*/
public static ConditionProfile create() {
return createBinaryProfile();
}
Returns the uncached version of the profile. The uncached version of a profile does nothing.
Since: 19.0
/**
* Returns the uncached version of the profile. The uncached version of a profile does nothing.
*
* @since 19.0
*/
public static ConditionProfile getUncached() {
return Disabled.INSTANCE;
}
static final class Disabled extends ConditionProfile {
static final ConditionProfile INSTANCE = new Disabled();
@Override
protected Object clone() {
return INSTANCE;
}
@Override
public boolean profile(boolean value) {
return value;
}
@Override
public String toString() {
return toStringDisabled(ConditionProfile.class);
}
}
static final class Counting extends ConditionProfile {
@CompilationFinal private int trueCount;
@CompilationFinal private int falseCount;
A constant holding the maximum value an int can have, 230-1. The sum
of the true and false count must not overflow. This constant is used to check whether one
of the counts does not exceed the required maximum value.
/**
* A constant holding the maximum value an {@code int} can have, 2<sup>30</sup>-1. The sum
* of the true and false count must not overflow. This constant is used to check whether one
* of the counts does not exceed the required maximum value.
*/
public static final int MAX_VALUE = 0x3fffffff;
Counting() {
}
@Override
public boolean profile(boolean value) {
// locals required to guarantee no overflow in multi-threaded environments
int t = trueCount;
int f = falseCount;
boolean val = value;
if (val) {
if (t == 0) {
CompilerDirectives.transferToInterpreterAndInvalidate();
}
if (f == 0) {
// Make this branch fold during PE
val = true;
}
if (CompilerDirectives.inInterpreter()) {
if (t < MAX_VALUE) {
trueCount = t + 1;
}
}
} else {
if (f == 0) {
CompilerDirectives.transferToInterpreterAndInvalidate();
}
if (t == 0) {
// Make this branch fold during PE
val = false;
}
if (CompilerDirectives.inInterpreter()) {
if (f < MAX_VALUE) {
falseCount = f + 1;
}
}
}
if (CompilerDirectives.inInterpreter()) {
// no branch probability calculation in the interpreter
return val;
} else {
int sum = t + f;
return CompilerDirectives.injectBranchProbability((double) t / (double) sum, val);
}
}
int getTrueCount() {
return trueCount;
}
int getFalseCount() {
return falseCount;
}
@Override
public String toString() {
int t = trueCount;
int f = falseCount;
int sum = t + f;
String details = String.format("trueProbability=%s (trueCount=%s, falseCount=%s)", (double) t / (double) sum, t, f);
return toString(ConditionProfile.class, sum == 0, false, details);
}
/* Needed for lazy class loading. */
static ConditionProfile createLazyLoadClass() {
return new Counting();
}
}
Utility class to speculate 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: - createBinaryProfile.createBinaryProfile()
/**
* Utility class to speculate on conditions to be never true or to be never false. Condition
* profiles are intended to be used as part of if conditions.
*
* @see ConditionProfile#createBinaryProfile()
*/
static final class Binary extends ConditionProfile {
@CompilationFinal private boolean wasTrue;
@CompilationFinal private boolean wasFalse;
Binary() {
}
@Override
public boolean profile(boolean value) {
if (value) {
if (!wasTrue) {
CompilerDirectives.transferToInterpreterAndInvalidate();
wasTrue = true;
}
return true;
} else {
if (!wasFalse) {
CompilerDirectives.transferToInterpreterAndInvalidate();
wasFalse = true;
}
return false;
}
}
boolean wasTrue() {
return wasTrue;
}
boolean wasFalse() {
return wasFalse;
}
@Override
public String toString() {
return String.format("%s(wasTrue=%s, wasFalse=%s)@%x", getClass().getSimpleName(), wasTrue, wasFalse, hashCode());
}
/* Needed for lazy class loading. */
static ConditionProfile createLazyLoadClass() {
return new Binary();
}
}
}