From 0cba96ba6a5d7a4dab2a63b14149c49dfbfbb3bc Mon Sep 17 00:00:00 2001
From: Gabe Black <gblack@eecs.umich.edu>
Date: Sat, 26 May 2012 13:44:46 -0700
Subject: CPU: Merge the predecoder and decoder.

These classes are always used together, and merging them will give the ISAs
more flexibility in how they cache things and manage the process.

--HG--
rename : src/arch/x86/predecoder_tables.cc => src/arch/x86/decoder_tables.cc
---
 src/cpu/simple/atomic.cc |  4 ++--
 src/cpu/simple/base.cc   | 23 ++++++++++++-----------
 src/cpu/simple/base.hh   |  6 ------
 3 files changed, 14 insertions(+), 19 deletions(-)

(limited to 'src/cpu/simple')

diff --git a/src/cpu/simple/atomic.cc b/src/cpu/simple/atomic.cc
index 87f41a721..f12c2c174 100644
--- a/src/cpu/simple/atomic.cc
+++ b/src/cpu/simple/atomic.cc
@@ -465,12 +465,12 @@ AtomicSimpleCPU::tick()
             dcache_access = false; // assume no dcache access
 
             if (needToFetch) {
-                // This is commented out because the predecoder would act like
+                // This is commented out because the decoder would act like
                 // a tiny cache otherwise. It wouldn't be flushed when needed
                 // like the I cache. It should be flushed, and when that works
                 // this code should be uncommented.
                 //Fetch more instruction memory if necessary
-                //if(predecoder.needMoreBytes())
+                //if(decoder.needMoreBytes())
                 //{
                     icache_access = true;
                     Packet ifetch_pkt = Packet(&ifetch_req, MemCmd::ReadReq);
diff --git a/src/cpu/simple/base.cc b/src/cpu/simple/base.cc
index ca4090870..bdc4b0f44 100644
--- a/src/cpu/simple/base.cc
+++ b/src/cpu/simple/base.cc
@@ -85,7 +85,7 @@ using namespace std;
 using namespace TheISA;
 
 BaseSimpleCPU::BaseSimpleCPU(BaseSimpleCPUParams *p)
-    : BaseCPU(p), traceData(NULL), thread(NULL), predecoder(NULL)
+    : BaseCPU(p), traceData(NULL), thread(NULL)
 {
     if (FullSystem)
         thread = new SimpleThread(this, 0, p->system, p->itb, p->dtb);
@@ -332,7 +332,7 @@ BaseSimpleCPU::checkForInterrupts()
             fetchOffset = 0;
             interrupts->updateIntrInfo(tc);
             interrupt->invoke(tc);
-            predecoder.reset();
+            thread->decoder.reset();
         }
     }
 }
@@ -378,23 +378,24 @@ BaseSimpleCPU::preExecute()
         //We're not in the middle of a macro instruction
         StaticInstPtr instPtr = NULL;
 
+        TheISA::Decoder *decoder = &(thread->decoder);
+
         //Predecode, ie bundle up an ExtMachInst
         //This should go away once the constructor can be set up properly
-        predecoder.setTC(thread->getTC());
+        decoder->setTC(thread->getTC());
         //If more fetch data is needed, pass it in.
         Addr fetchPC = (pcState.instAddr() & PCMask) + fetchOffset;
-        //if(predecoder.needMoreBytes())
-            predecoder.moreBytes(pcState, fetchPC, inst);
+        //if(decoder->needMoreBytes())
+            decoder->moreBytes(pcState, fetchPC, inst);
         //else
-        //    predecoder.process();
+        //    decoder->process();
 
-        //If an instruction is ready, decode it. Otherwise, we'll have to
+        //Decode an instruction if one is ready. Otherwise, we'll have to
         //fetch beyond the MachInst at the current pc.
-        if (predecoder.extMachInstReady()) {
+        instPtr = decoder->decode(pcState);
+        if (instPtr) {
             stayAtPC = false;
-            ExtMachInst machInst = predecoder.getExtMachInst(pcState);
             thread->pcState(pcState);
-            instPtr = thread->decoder.decode(machInst, pcState.instAddr());
         } else {
             stayAtPC = true;
             fetchOffset += sizeof(MachInst);
@@ -505,7 +506,7 @@ BaseSimpleCPU::advancePC(Fault fault)
     if (fault != NoFault) {
         curMacroStaticInst = StaticInst::nullStaticInstPtr;
         fault->invoke(tc, curStaticInst);
-        predecoder.reset();
+        thread->decoder.reset();
     } else {
         if (curStaticInst) {
             if (curStaticInst->isLastMicroop())
diff --git a/src/cpu/simple/base.hh b/src/cpu/simple/base.hh
index 34b039fc0..9bf144326 100644
--- a/src/cpu/simple/base.hh
+++ b/src/cpu/simple/base.hh
@@ -45,8 +45,6 @@
 #ifndef __CPU_SIMPLE_BASE_HH__
 #define __CPU_SIMPLE_BASE_HH__
 
-#include "arch/decoder.hh"
-#include "arch/predecoder.hh"
 #include "base/statistics.hh"
 #include "config/the_isa.hh"
 #include "cpu/base.hh"
@@ -71,7 +69,6 @@ namespace TheISA
 {
     class DTB;
     class ITB;
-    class Predecoder;
 }
 
 namespace Trace {
@@ -154,9 +151,6 @@ class BaseSimpleCPU : public BaseCPU
     // current instruction
     TheISA::MachInst inst;
 
-    // The predecoder
-    TheISA::Predecoder predecoder;
-
     StaticInstPtr curStaticInst;
     StaticInstPtr curMacroStaticInst;
 
-- 
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