X86: On a bad microopc, return a microop that returns a fault that panics.

This way a bad micropc will have to get all the way to commit before killing
the simulation. This accounts for misspeculated branches.

src/arch/x86/SConscript

@@ -46,6 +46,7 @@ if env['TARGET_ISA'] == 'x86':
     Source('cpuid.cc')
     Source('emulenv.cc')
     Source('faults.cc')
+    Source('insts/badmicroop.cc')
     Source('insts/microfpop.cc')
     Source('insts/microldstop.cc')
     Source('insts/micromediaop.cc')

src/arch/x86/insts/badmicroop.cc

@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2011 Advanced Micro Devices
+ * All rights reserved.
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder.  You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
+ * 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: Gabe Black
+ */
+
+#include "arch/x86/insts/badmicroop.hh"
+#include "arch/x86/isa_traits.hh"
+#include "arch/x86/decoder.hh"
+
+namespace X86ISA
+{
+
+// This microop needs to be allocated on the heap even though it could
+// theoretically be statically allocated. The reference counted pointer would
+// try to delete the static memory when it was destructed.
+const StaticInstPtr badMicroop =
+    new X86ISAInst::MicroPanic(NoopMachInst, "BAD",
+        StaticInst::IsMicroop | StaticInst::IsLastMicroop,
+        "Invalid microop!", 0);
+
+} // namespace X86ISA

src/arch/x86/insts/badmicroop.hh

@@ -0,0 +1,52 @@
+/*
+ * Copyright (c) 2011 Advanced Micro Devices
+ * All rights reserved.
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder.  You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
+ * 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: Gabe Black
+ */
+
+#ifndef __ARCH_X86_INSTS_BADMICROOP_HH__
+#define __ARCH_X86_INSTS_BADMICROOP_HH__
+
+class StaticInstPtr;
+
+namespace X86ISA
+{
+
+extern const StaticInstPtr badMicroop;
+
+} // namespace X86ISA
+
+#endif //__ARCH_X86_INSTS_BADMICROOP_HH__

src/arch/x86/insts/macroop.hh

@@ -41,6 +41,7 @@
 #define __ARCH_X86_INSTS_MACROOP_HH__
 
 #include "arch/x86/emulenv.hh"
+#include "arch/x86/insts/badmicroop.hh"
 #include "arch/x86/types.hh"
 #include "arch/x86/insts/static_inst.hh"
 
@@ -76,8 +77,10 @@ class MacroopBase : public X86StaticInst
     StaticInstPtr
     fetchMicroop(MicroPC microPC) const
     {
-        assert(microPC < numMicroops);
-        return microops[microPC];
+        if (microPC >= numMicroops)
+            return badMicroop;
+        else
+            return microops[microPC];
     }
 
     std::string

src/arch/x86/microcode_rom.hh

@@ -32,6 +32,7 @@
 #define __ARCH_X86_MICROCODE_ROM_HH__
 
 #include "arch/x86/emulenv.hh"
+#include "arch/x86/insts/badmicroop.hh"
 #include "cpu/static_inst.hh"
 
 namespace X86ISAInst
@@ -60,8 +61,10 @@ namespace X86ISAInst
         fetchMicroop(MicroPC microPC, StaticInstPtr curMacroop)
         {
             microPC = normalMicroPC(microPC);
-            assert(microPC < numMicroops);
-            return genFuncs[microPC](curMacroop);
+            if (microPC >= numMicroops)
+                return X86ISA::badMicroop;
+            else
+                return genFuncs[microPC](curMacroop);
         }
     };
 }