/*
+ * Copyright (c) 2012-2014 ARM Limited
+ * 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.
+ *
* Copyright (c) 2012 Google
* All rights reserved.
*
*/
#include "arch/arm/decoder.hh"
+
+#include "arch/arm/isa.hh"
#include "arch/arm/isa_traits.hh"
#include "arch/arm/utility.hh"
#include "base/trace.hh"
-#include "cpu/thread_context.hh"
#include "debug/Decoder.hh"
namespace ArmISA
GenericISA::BasicDecodeCache Decoder::defaultCache;
+Decoder::Decoder(ISA* isa)
+ : data(0), fpscrLen(0), fpscrStride(0), decoderFlavour(isa
+ ? isa->decoderFlavour()
+ : Enums::Generic)
+{
+ reset();
+}
+
+void
+Decoder::reset()
+{
+ bigThumb = false;
+ offset = 0;
+ emi = 0;
+ instDone = false;
+ outOfBytes = true;
+ foundIt = false;
+}
+
void
Decoder::process()
{
if (!emi.thumb) {
emi.instBits = data;
- emi.sevenAndFour = bits(data, 7) && bits(data, 4);
- emi.isMisc = (bits(data, 24, 23) == 0x2 &&
- bits(data, 20) == 0);
+ if (!emi.aarch64) {
+ emi.sevenAndFour = bits(data, 7) && bits(data, 4);
+ emi.isMisc = (bits(data, 24, 23) == 0x2 &&
+ bits(data, 20) == 0);
+ }
consumeBytes(4);
DPRINTF(Decoder, "Arm inst: %#x.\n", (uint64_t)emi);
} else {
}
}
-//Use this to give data to the decoder. This should be used
-//when there is control flow.
+void
+Decoder::consumeBytes(int numBytes)
+{
+ offset += numBytes;
+ assert(offset <= sizeof(MachInst) || emi.decoderFault);
+ if (offset == sizeof(MachInst))
+ outOfBytes = true;
+}
+
void
Decoder::moreBytes(const PCState &pc, Addr fetchPC, MachInst inst)
{
data = inst;
offset = (fetchPC >= pc.instAddr()) ? 0 : pc.instAddr() - fetchPC;
emi.thumb = pc.thumb();
+ emi.aarch64 = pc.aarch64();
emi.fpscrLen = fpscrLen;
emi.fpscrStride = fpscrStride;
+ const Addr alignment(pc.thumb() ? 0x1 : 0x3);
+ emi.decoderFault = static_cast<uint8_t>(
+ pc.instAddr() & alignment ? DecoderFault::UNALIGNED : DecoderFault::OK);
+
outOfBytes = false;
process();
}
+StaticInstPtr
+Decoder::decode(ArmISA::PCState &pc)
+{
+ if (!instDone)
+ return NULL;
+
+ const int inst_size((!emi.thumb || emi.bigThumb) ? 4 : 2);
+ ExtMachInst this_emi(emi);
+
+ pc.npc(pc.pc() + inst_size);
+ if (foundIt)
+ pc.nextItstate(itBits);
+ this_emi.itstate = pc.itstate();
+ pc.size(inst_size);
+
+ emi = 0;
+ instDone = false;
+ foundIt = false;
+
+ return decode(this_emi, pc.instAddr());
+}
+
}