com.oracle.truffle.api.profiles.IntValueProfile Maven / Gradle / Ivy
Show all versions of truffle-api Show documentation
/*
* Copyright (c) 2015, 2021, 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;
/**
*
* Specialized value profile to capture certain properties of int runtime values. Value
* profiles require a runtime check in their initialized state to verify their profiled assumption.
* Value profiles are limited to capture monomorphic profiles only. This means that if two or more
* values are profiled within a single profile then the profile has no effect. If the value
* assumption is invalidated in compiled code then it is invalidated.
*
*
*
* Usage example:
*
*
* class SampleNode extends Node {
*
* final IntValueProfile profile = IntValueProfile.createIdentityProfile();
*
* int execute(int input) {
* int profiledValue = profile.profile(input);
* // compiler may know now more about profiledValue
* return profiledValue;
* }
* }
*
*
*
*
* {@inheritDoc}
*
* @see #createIdentityProfile()
* @see ValueProfile
* @since 0.10
*/
public final class IntValueProfile extends Profile {
private static final IntValueProfile DISABLED;
static {
IntValueProfile profile = new IntValueProfile();
profile.disable();
DISABLED = profile;
}
private static final byte UNINITIALIZED = 0;
private static final byte SPECIALIZED = 1;
private static final byte GENERIC = 2;
@CompilationFinal private int cachedValue;
@CompilationFinal private byte state = UNINITIALIZED;
IntValueProfile() {
}
/** @since 0.10 */
public int profile(int value) {
byte localState = this.state;
if (localState != GENERIC) {
if (localState == SPECIALIZED) {
int v = cachedValue;
if (v == value) {
return v;
}
}
CompilerDirectives.transferToInterpreterAndInvalidate();
if (localState == UNINITIALIZED) {
this.cachedValue = value;
this.state = SPECIALIZED;
} else {
this.state = GENERIC;
}
}
return value;
}
boolean isGeneric() {
return state == GENERIC;
}
boolean isUninitialized() {
return state == UNINITIALIZED;
}
int getCachedValue() {
return cachedValue;
}
/**
* {@inheritDoc}
*
* @since 22.1
*/
@Override
public void disable() {
this.state = GENERIC;
}
/**
* {@inheritDoc}
*
* @since 22.1
*/
@Override
public void reset() {
this.state = UNINITIALIZED;
}
/**
* {@inheritDoc}
*
* @since 22.1
*/
@Override
public String toString() {
return toString(IntValueProfile.class, isUninitialized(), isGeneric(), //
String.format("value == (int)%s", cachedValue));
}
/**
* Returns a value profile that profiles the exact value of an int.
*
* @see IntValueProfile
* @since 0.10
*/
public static IntValueProfile createIdentityProfile() {
return create();
}
/**
* Returns a value profile that profiles the exact value of an int.
*
* @see IntValueProfile
* @since 22.1
*/
public static IntValueProfile create() {
if (Profile.isProfilingEnabled()) {
return new IntValueProfile();
} else {
return DISABLED;
}
}
/**
* Returns the uncached version of the profile. The uncached version of a profile does nothing.
*
* @since 19.0
*/
public static IntValueProfile getUncached() {
return DISABLED;
}
}