--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/agent/src/share/classes/sun/jvm/hotspot/asm/sparc/RegisterDecoder.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,85 @@
+/*
+ * Copyright 2002 Sun Microsystems, 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+package sun.jvm.hotspot.asm.sparc;
+
+import sun.jvm.hotspot.asm.RTLDataTypes;
+
+class RegisterDecoder implements /* imports */ RTLDataTypes {
+    // refer to page 40 - section 5.1.4.1 - Floating-point Register Number Encoding
+    private static SPARCFloatRegister decodeDouble(int num) {
+        // 6 bit double precision registers are encoded in 5 bits as
+        // b<4> b<3> b<2> b<1> b<5>.
+
+        boolean lsb = (0x1 & num) != 0;
+        if (lsb)
+            num |= 0x20;  // 10000b
+
+        if ((num % 2) != 0)
+            return null;
+
+        return SPARCFloatRegisters.getRegister(num);
+    }
+
+    private static SPARCFloatRegister decodeQuad(int num) {
+        // 6 bit quad precision registers are encoded in 5 bits as
+        // b<4> b<3> b<2> 0 b<5>
+
+        boolean lsb = (0x1 & num) != 0;
+        if (lsb)
+            num |= 0x20; // 10000b
+
+        if ((num % 4) != 0)
+            return null;
+
+        return SPARCFloatRegisters.getRegister(num);
+    }
+
+    static SPARCRegister decode(int dataType, int regNum) {
+        regNum &= 0x1F; // mask out all but lsb 5 bits
+        SPARCRegister result = null;
+        switch (dataType) {
+            case RTLDT_FL_SINGLE:
+                result = SPARCFloatRegisters.getRegister(regNum);
+                break;
+
+            case RTLDT_FL_DOUBLE:
+                result = decodeDouble(regNum);
+                break;
+
+            case RTLDT_FL_QUAD:
+                result = decodeQuad(regNum);
+                break;
+
+            case RTLDT_UNKNOWN:
+                result = null;
+                break;
+
+            default: // some integer register
+                result = SPARCRegisters.getRegister(regNum);
+                break;
+        }
+        return result;
+    }
+}