--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/agent/src/share/classes/sun/jvm/hotspot/asm/sparc/InstructionDecoder.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,80 @@
+/*
+ * 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.*;
+
+// basic instruction decoder class
+abstract class InstructionDecoder implements /* imports */ SPARCOpcodes , RTLDataTypes, RTLOperations {
+    // some general utility functions - for format 2, 3 & 3A instructions
+
+    static int extractSignedIntFromNBits(int value, int num_bits) {
+        return (value << (32 - num_bits)) >> (32 - num_bits);
+    }
+
+    // "rs1"
+    static int getSourceRegister1(int instruction) {
+        return (instruction & RS1_MASK) >>> RS1_START_BIT;
+    }
+
+    // "rs2"
+    static int getSourceRegister2(int instruction) {
+        return (instruction & RS2_MASK);
+    }
+
+    // "rd"
+    static int getDestinationRegister(int instruction) {
+        return (instruction & RD_MASK) >>> RD_START_BIT;
+    }
+
+    static int getConditionCode(int instruction) {
+        return (instruction & CONDITION_CODE_MASK) >>> CONDITION_CODE_START_BIT;
+    }
+
+    // "i" bit - used to indicate whether second component in an indirect
+    // address is immediate value or a register. (format 3 & 3A).
+
+    static boolean isIBitSet(int instruction) {
+        return (instruction & I_MASK) != 0;
+    }
+
+    static ImmediateOrRegister getOperand2(int instruction) {
+        boolean iBit = isIBitSet(instruction);
+        ImmediateOrRegister operand2 = null;
+        if (iBit) {
+           operand2 = new Immediate(new Short((short)extractSignedIntFromNBits(instruction, 13)));
+        } else {
+           operand2 = SPARCRegisters.getRegister(getSourceRegister2(instruction));
+        }
+        return operand2;
+    }
+
+    // "opf" - floating point operation code.
+    static int getOpf(int instruction) {
+        return (instruction & OPF_MASK) >>> OPF_START_BIT;
+    }
+
+    abstract Instruction decode(int instruction, SPARCInstructionFactory factory);
+}