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+// -*- mode:c++ -*-
+
+// Copyright (c) 2003-2006 The Regents of The University of Michigan
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met: redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer;
+// redistributions in binary form must reproduce the above copyright
+// notice, this list of conditions and the following disclaimer in the
+// documentation and/or other materials provided with the distribution;
+// neither the name of the copyright holders nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Authors: Korey Sewell
+
+////////////////////////////////////////////////////////////////////
+//
+// Nop
+//
+
+output header {{
+ /**
+ * Static instruction class for no-ops. This is a leaf class.
+ */
+ class Nop : public MipsStaticInst
+ {
+ /// Disassembly of original instruction.
+ const std::string originalDisassembly;
+
+ public:
+ /// Constructor
+ Nop(const std::string _originalDisassembly, MachInst _machInst)
+ : MipsStaticInst("nop", _machInst, No_OpClass),
+ originalDisassembly(_originalDisassembly)
+ {
+ flags[IsNop] = true;
+ }
+
+ ~Nop() { }
+
+ std::string
+ generateDisassembly(Addr pc, const SymbolTable *symtab) const;
+
+ %(BasicExecDeclare)s
+ };
+}};
+
+output decoder {{
+ std::string Nop::generateDisassembly(Addr pc,
+ const SymbolTable *symtab) const
+ {
+ return csprintf("%-10s %s", "nop", originalDisassembly);
+ }
+
+ /// Helper function for decoding nops. Substitute Nop object
+ /// for original inst passed in as arg (and delete latter).
+ inline
+ MipsStaticInst *
+ makeNop(MipsStaticInst *inst)
+ {
+ MipsStaticInst *nop = new Nop(inst->disassemble(0), inst->machInst);
+ delete inst;
+ return nop;
+ }
+}};
+
+output exec {{
+ Fault
+ Nop::execute(%(CPU_exec_context)s *, Trace::InstRecord *) const
+ {
+ return NoFault;
+ }
+}};
+
+// integer & FP operate instructions use RT as dest, so check for
+// RT == 0 to detect nops
+def template OperateNopCheckDecode {{
+ {
+ MipsStaticInst *i = new %(class_name)s(machInst);
+
+ //if (RD == 0) {
+ // i = makeNop(i);
+ //}
+
+ return i;
+ }
+}};
+
+
+// Like BasicOperate format, but generates NOP if RC/FC == 31
+def format BasicOperateWithNopCheck(code, *opt_args) {{
+ iop = InstObjParams(name, Name, 'MipsStaticInst', CodeBlock(code),
+ opt_args)
+ header_output = BasicDeclare.subst(iop)
+ decoder_output = BasicConstructor.subst(iop)
+ decode_block = OperateNopCheckDecode.subst(iop)
+ exec_output = BasicExecute.subst(iop)
+}};
+
+def format Nop() {{
+ decode_block = 'return new Nop(\"\",machInst);\n'
+}};
+