stats: update stats for mmap() change.

[gem5.git] / src / arch / arm / decoder.cc

diff --git a/src/arch/arm/decoder.cc b/src/arch/arm/decoder.cc
index be46ff5404a9e72c7a6b20190c3d7f0772e499fd..1502b061ff54c680d3756820c991c1bcc0bac672 100644 (file)
--- a/src/arch/arm/decoder.cc
+++ b/src/arch/arm/decoder.cc
@@ -1,5 +1,17 @@
 /*
- * Copyright (c) 2011 Google
+ * 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.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -30,9 +42,150 @@
 
 #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 "debug/Decoder.hh"
+
 namespace ArmISA
 {
 
-DecodeCache Decoder::defaultCache;
+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()
+{
+    // emi is typically ready, with some caveats below...
+    instDone = true;
+
+    if (!emi.thumb) {
+        emi.instBits = data;
+        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 {
+        uint16_t word = (data >> (offset * 8));
+        if (bigThumb) {
+            // A 32 bit thumb inst is half collected.
+            emi.instBits = emi.instBits | word;
+            bigThumb = false;
+            consumeBytes(2);
+            DPRINTF(Decoder, "Second half of 32 bit Thumb: %#x.\n",
+                    emi.instBits);
+        } else {
+            uint16_t highBits = word & 0xF800;
+            if (highBits == 0xE800 || highBits == 0xF000 ||
+                    highBits == 0xF800) {
+                // The start of a 32 bit thumb inst.
+                emi.bigThumb = 1;
+                if (offset == 0) {
+                    // We've got the whole thing.
+                    emi.instBits = (data >> 16) | (data << 16);
+                    DPRINTF(Decoder, "All of 32 bit Thumb: %#x.\n",
+                            emi.instBits);
+                    consumeBytes(4);
+                } else {
+                    // We only have the first half word.
+                    DPRINTF(Decoder,
+                            "First half of 32 bit Thumb.\n");
+                    emi.instBits = (uint32_t)word << 16;
+                    bigThumb = true;
+                    consumeBytes(2);
+                    // emi not ready yet.
+                    instDone = false;
+                }
+            } else {
+                // A 16 bit thumb inst.
+                consumeBytes(2);
+                emi.instBits = word;
+                // Set the condition code field artificially.
+                emi.condCode = COND_UC;
+                DPRINTF(Decoder, "16 bit Thumb: %#x.\n",
+                        emi.instBits);
+                if (bits(word, 15, 8) == 0xbf &&
+                        bits(word, 3, 0) != 0x0) {
+                    foundIt = true;
+                    itBits = bits(word, 7, 0);
+                    DPRINTF(Decoder,
+                            "IT detected, cond = %#x, mask = %#x\n",
+                            itBits.cond, itBits.mask);
+                }
+            }
+        }
+    }
+}
+
+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());
+}
 
 }