--- a/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/ClassReader.java	Thu Dec 08 16:52:38 2016 -0800
+++ b/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/ClassReader.java	Fri Dec 09 18:06:48 2016 +0100
@@ -2479,7 +2479,7 @@
                     ? parameterNameIndices[index] : 0);
             Name name = nameIdx == 0 ? names.empty : readName(nameIdx);
             paramNames = paramNames.prepend(name);
-            index += Code.width(t);
+            index += sawMethodParameters ? 1 : Code.width(t);
         }
         sym.savedParameterNames = paramNames.reverse();
     }

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javac/T8170667/ParameterProcessor.java	Fri Dec 09 18:06:48 2016 +0100
@@ -0,0 +1,94 @@
+/*
+ * Copyright 2016 Google Inc. 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.
+ *
+ * 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.
+ */
+
+import static java.util.stream.Collectors.toCollection;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Set;
+import javax.annotation.processing.RoundEnvironment;
+import javax.annotation.processing.SupportedAnnotationTypes;
+import javax.lang.model.element.Element;
+import javax.lang.model.element.ExecutableElement;
+import javax.lang.model.element.TypeElement;
+import javax.tools.Diagnostic.Kind;
+
+/*
+ * @test
+ * @bug 8170667
+ * @summary ClassReader assigns method parameters from MethodParameters incorrectly when long/double
+ * parameters are present
+ * @library /tools/javac/lib
+ * @modules java.compiler
+ *          jdk.compiler
+ * @compile -parameters ParameterProcessor.java
+ * @compile/process -proc:only -processor ParameterProcessor ParameterProcessor
+ */
+@SupportedAnnotationTypes("ParameterProcessor.ParameterNames")
+public class ParameterProcessor extends JavacTestingAbstractProcessor {
+
+    @Retention(RetentionPolicy.RUNTIME)
+    @Target(ElementType.METHOD)
+    @interface ParameterNames {
+        String[] value() default {};
+    }
+
+    @ParameterProcessor.ParameterNames({"a", "b", "c"})
+    void f(int a, int b, int c) {}
+
+    @ParameterProcessor.ParameterNames({"d", "e", "f"})
+    void g(int d, long e, int f) {}
+
+    @ParameterProcessor.ParameterNames({"g", "h", "i", "j"})
+    void h(int g, double h, int i, int j) {}
+
+    @Override
+    public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
+        for (Element element : roundEnv.getElementsAnnotatedWith(ParameterNames.class)) {
+            ParameterNames names = element.getAnnotation(ParameterNames.class);
+            if (names == null) {
+                continue;
+            }
+            List<String> expected = Arrays.asList(names.value());
+            List<String> actual =
+                    ((ExecutableElement) element)
+                            .getParameters()
+                            .stream()
+                            .map(p -> p.getSimpleName().toString())
+                            .collect(toCollection(ArrayList::new));
+            if (!expected.equals(actual)) {
+                String message =
+                        String.format(
+                                "bad parameter names for %s#%s; expected: %s, was: %s",
+                                element, element, expected, actual);
+                messager.printMessage(Kind.ERROR, message);
+            }
+        }
+        return false;
+    }
+}