--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/PrimitiveValueProfile.java	Fri Oct 24 22:50:04 2014 +0100
@@ -0,0 +1,224 @@
+/*
+ * Copyright (c) 2014, 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.utilities;
+
+import java.util.*;
+
+import com.oracle.truffle.api.*;
+import com.oracle.truffle.api.CompilerDirectives.CompilationFinal;
+
+/**
+ * Represents a {@link ValueProfile} that speculates on the primitive equality or object identity of
+ * values.
+ * <p>
+ * Note that for {code float} and {@code double} values we compare primitive equality via
+ * {@link Float#floatToRawIntBits} and {@link Double#doubleToRawLongBits}, so that for example
+ * {@code -0.0} is not considered the same as {@code 0.0}, even though primitive equality would
+ * normally say that it was.
+ */
+public class PrimitiveValueProfile extends ValueProfile {
+
+    private static final Object UNINITIALIZED = new Object();
+    private static final Object GENERIC = new Object();
+
+    @CompilationFinal private Object cachedValue = UNINITIALIZED;
+
+    PrimitiveValueProfile() {
+    }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public Object profile(Object value) {
+        if (cachedValue != GENERIC) {
+            if (cachedValue instanceof Byte && value instanceof Byte && (byte) cachedValue == (byte) value) {
+                return cachedValue;
+            } else if (cachedValue instanceof Short && value instanceof Short && (short) cachedValue == (short) value) {
+                return cachedValue;
+            } else if (cachedValue instanceof Integer && value instanceof Integer && (int) cachedValue == (int) value) {
+                return cachedValue;
+            } else if (cachedValue instanceof Long && value instanceof Long && (long) cachedValue == (long) value) {
+                return cachedValue;
+            } else if (cachedValue instanceof Float && value instanceof Float && exactCompare((float) cachedValue, (float) value)) {
+                return cachedValue;
+            } else if (cachedValue instanceof Double && value instanceof Double && exactCompare((double) cachedValue, (double) value)) {
+                return cachedValue;
+            } else if (cachedValue instanceof Boolean && value instanceof Boolean && (boolean) cachedValue == (boolean) value) {
+                return cachedValue;
+            } else if (cachedValue instanceof Character && value instanceof Character && (char) cachedValue == (char) value) {
+                return cachedValue;
+            } else if (cachedValue == value) {
+                return cachedValue;
+            } else {
+                cacheMiss(value);
+            }
+        }
+        return value;
+    }
+
+    public byte profile(byte value) {
+        if (cachedValue != GENERIC) {
+            if (cachedValue instanceof Byte && (byte) cachedValue == value) {
+                return (byte) cachedValue;
+            } else {
+                cacheMiss(value);
+            }
+        }
+        return value;
+    }
+
+    public short profile(short value) {
+        if (cachedValue != GENERIC) {
+            if (cachedValue instanceof Short && (short) cachedValue == value) {
+                return (short) cachedValue;
+            } else {
+                cacheMiss(value);
+            }
+        }
+        return value;
+    }
+
+    public int profile(int value) {
+        if (cachedValue != GENERIC) {
+            if (cachedValue instanceof Integer && (int) cachedValue == value) {
+                return (int) cachedValue;
+            } else {
+                cacheMiss(value);
+            }
+        }
+        return value;
+    }
+
+    public long profile(long value) {
+        if (cachedValue != GENERIC) {
+            if (cachedValue instanceof Long && (long) cachedValue == value) {
+                return (long) cachedValue;
+            } else {
+                cacheMiss(value);
+            }
+        }
+        return value;
+    }
+
+    public float profile(float value) {
+        if (cachedValue != GENERIC) {
+            if (cachedValue instanceof Float && exactCompare((float) cachedValue, value)) {
+                return (float) cachedValue;
+            } else {
+                cacheMiss(value);
+            }
+        }
+        return value;
+    }
+
+    public double profile(double value) {
+        if (cachedValue != GENERIC) {
+            if (cachedValue instanceof Double && exactCompare((double) cachedValue, value)) {
+                return (double) cachedValue;
+            } else {
+                cacheMiss(value);
+            }
+        }
+        return value;
+    }
+
+    public boolean profile(boolean value) {
+        if (cachedValue != GENERIC) {
+            if (cachedValue instanceof Boolean && (boolean) cachedValue == value) {
+                return (boolean) cachedValue;
+            } else {
+                cacheMiss(value);
+            }
+        }
+        return value;
+    }
+
+    public char profile(char value) {
+        if (cachedValue != GENERIC) {
+            if (cachedValue instanceof Character && (char) cachedValue == value) {
+                return (char) cachedValue;
+            } else {
+                cacheMiss(value);
+            }
+        }
+        return value;
+    }
+
+    public boolean isGeneric() {
+        return getCachedValue() == GENERIC;
+    }
+
+    public boolean isUninitialized() {
+        return getCachedValue() == UNINITIALIZED;
+    }
+
+    public Object getCachedValue() {
+        return cachedValue;
+    }
+
+    @Override
+    public String toString() {
+        return String.format("%s(%s)@%x", getClass().getSimpleName(), formatValue(), hashCode());
+    }
+
+    private void cacheMiss(Object value) {
+        CompilerDirectives.transferToInterpreterAndInvalidate();
+        if (cachedValue == UNINITIALIZED) {
+            cachedValue = value;
+        } else {
+            cachedValue = GENERIC;
+        }
+    }
+
+    public static boolean exactCompare(float a, float b) {
+        /*
+         * -0.0 == 0.0, but you can tell the difference through other means, so we need to
+         * differentiate.
+         */
+        return Float.floatToRawIntBits(a) == Float.floatToRawIntBits(b);
+    }
+
+    public static boolean exactCompare(double a, double b) {
+        /*
+         * -0.0 == 0.0, but you can tell the difference through other means, so we need to
+         * differentiate.
+         */
+        return Double.doubleToRawLongBits(a) == Double.doubleToRawLongBits(b);
+    }
+
+    private String formatValue() {
+        if (cachedValue == null) {
+            return "null";
+        } else if (cachedValue == UNINITIALIZED) {
+            return "uninitialized";
+        } else if (cachedValue == GENERIC) {
+            return "generic";
+        } else if (cachedValue instanceof Byte || cachedValue instanceof Short || cachedValue instanceof Integer || cachedValue instanceof Long || cachedValue instanceof Float ||
+                        cachedValue instanceof Double || cachedValue instanceof Boolean || cachedValue instanceof Character) {
+            return String.format("%s=%s", cachedValue.getClass().getSimpleName(), cachedValue);
+        } else {
+            return String.format("%s@%x", cachedValue.getClass().getSimpleName(), Objects.hash(cachedValue));
+        }
+    }
+}