Mercurial > hg > truffle
diff truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/profiles/FloatValueProfile.java @ 22501:a63bda98cfdb
Extract profiles into separate package. Add isProfilingEnabled in TruffleRuntime to disable profiling in the default runtime; Add low overhead profiles for primitives; Add LoopConditionProfile; Profile footprint/threadsafety improvements; Make toString implementations more consistent; Greatly enhanced javadoc documentation for profiles; Deprecate old profiles
author | Christian Humer <christian.humer@oracle.com> |
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date | Wed, 16 Dec 2015 16:38:13 +0100 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/profiles/FloatValueProfile.java Wed Dec 16 16:38:13 2015 +0100 @@ -0,0 +1,159 @@ +/* + * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. Oracle designates this + * particular file as subject to the "Classpath" exception as provided + * by Oracle in the LICENSE file that accompanied this code. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * 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. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + */ +package com.oracle.truffle.api.profiles; + +import com.oracle.truffle.api.CompilerDirectives; +import com.oracle.truffle.api.CompilerDirectives.CompilationFinal; +import com.oracle.truffle.api.Truffle; + +/** + * <p> + * Specialized value profile to capture certain properties of <code>float</code> 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. + * </p> + * + * <p> + * <b> Usage example: </b> + * + * <pre> + * class SampleNode extends Node { + * + * final FloatValueProfile profile = FloatValueProfile.createRawIdentityProfile(); + * + * float execute(float input) { + * float profiledValue = profile.profile(input); + * // compiler may know now more about profiledValue + * return profiledValue; + * } + * } + * </pre> + * <p> + * + * + * {@inheritDoc} + * + * @see #createRawIdentityProfile() + * @see ValueProfile + */ +public abstract class FloatValueProfile extends Profile { + + FloatValueProfile() { + } + + public abstract float profile(float value); + + /** + * Returns a value profile that profiles the exact value of a <code>float</code> using + * {@link Float#floatToRawIntBits(float)}. + * + * @see IntValueProfile + */ + public static FloatValueProfile createRawIdentityProfile() { + if (Truffle.getRuntime().isProfilingEnabled()) { + return Enabled.create(); + } else { + return Disabled.INSTANCE; + } + } + + static final class Enabled extends FloatValueProfile { + + private static final byte UNINITIALIZED = 0; + private static final byte SPECIALIZED = 1; + private static final byte GENERIC = 2; + + @CompilationFinal private float cachedValue; + @CompilationFinal private int cachedRawValue; + @CompilationFinal private byte state = 0; + + @Override + public float profile(float value) { + byte localState = this.state; + if (localState != GENERIC) { + if (localState == SPECIALIZED) { + if (cachedRawValue == Float.floatToRawIntBits(value)) { + return cachedValue; + } + } + CompilerDirectives.transferToInterpreterAndInvalidate(); + if (localState == UNINITIALIZED) { + this.cachedValue = value; + this.cachedRawValue = Float.floatToRawIntBits(value); + this.state = SPECIALIZED; + } else { + this.state = GENERIC; + } + } + return value; + } + + boolean isGeneric() { + return state == GENERIC; + } + + boolean isUninitialized() { + return state == UNINITIALIZED; + } + + float getCachedValue() { + return cachedValue; + } + + @Override + public String toString() { + return toString(FloatValueProfile.class, state == UNINITIALIZED, state == GENERIC, // + String.format("value == (float)%s (raw %h)", cachedValue, cachedRawValue)); + } + + /* Needed for lazy class loading. */ + static FloatValueProfile create() { + return new Enabled(); + } + } + + static final class Disabled extends FloatValueProfile { + + static final FloatValueProfile INSTANCE = new Disabled(); + + @Override + protected Object clone() { + return INSTANCE; + } + + @Override + public float profile(float value) { + return value; + } + + @Override + public String toString() { + return toStringDisabled(FloatValueProfile.class); + } + + } +}