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authorGabe Black <gblack@eecs.umich.edu>2007-03-15 02:47:42 +0000
committerGabe Black <gblack@eecs.umich.edu>2007-03-15 02:47:42 +0000
commita2b56088fb4d12aee73ecfeaba88cfa46f98567e (patch)
tree7c6787e2757e9e5d047a3b6cec1b71b4eef915f1 /src/cpu/simple/atomic.cc
parentce18d900a17cdda2cc041b51c56e6c84fb155331 (diff)
downloadgem5-a2b56088fb4d12aee73ecfeaba88cfa46f98567e.tar.xz
Make the predecoder an object with it's own switched header file. Start adding predecoding functionality to x86.
src/arch/SConscript: src/arch/alpha/utility.hh: src/arch/mips/utility.hh: src/arch/sparc/utility.hh: src/cpu/base.hh: src/cpu/o3/fetch.hh: src/cpu/o3/fetch_impl.hh: src/cpu/simple/atomic.cc: src/cpu/simple/base.cc: src/cpu/simple/base.hh: src/cpu/static_inst.hh: src/arch/alpha/predecoder.hh: src/arch/mips/predecoder.hh: src/arch/sparc/predecoder.hh: Make the predecoder an object with it's own switched header file. --HG-- extra : convert_revision : 77206e29089130e86b97164c30022a062699ba86
Diffstat (limited to 'src/cpu/simple/atomic.cc')
-rw-r--r--src/cpu/simple/atomic.cc32
1 files changed, 22 insertions, 10 deletions
diff --git a/src/cpu/simple/atomic.cc b/src/cpu/simple/atomic.cc
index df7e780e6..0361db012 100644
--- a/src/cpu/simple/atomic.cc
+++ b/src/cpu/simple/atomic.cc
@@ -500,17 +500,28 @@ AtomicSimpleCPU::tick()
Fault fault = setupFetchRequest(ifetch_req);
if (fault == NoFault) {
- ifetch_pkt->reinitFromRequest();
+ Tick icache_latency = 0;
+ bool icache_access = false;
+ dcache_access = false; // assume no dcache access
- Tick icache_latency = icachePort.sendAtomic(ifetch_pkt);
- // ifetch_req is initialized to read the instruction directly
- // into the CPU object's inst field.
+ //Fetch more instruction memory if necessary
+ if(predecoder.needMoreBytes())
+ {
+ icache_access = true;
+ ifetch_pkt->reinitFromRequest();
+
+ icache_latency = icachePort.sendAtomic(ifetch_pkt);
+ // ifetch_req is initialized to read the instruction directly
+ // into the CPU object's inst field.
+ }
- dcache_access = false; // assume no dcache access
preExecute();
- fault = curStaticInst->execute(this, traceData);
- postExecute();
+ if(curStaticInst)
+ {
+ fault = curStaticInst->execute(this, traceData);
+ postExecute();
+ }
// @todo remove me after debugging with legion done
if (curStaticInst && (!curStaticInst->isMicroOp() ||
@@ -518,7 +529,8 @@ AtomicSimpleCPU::tick()
instCnt++;
if (simulate_stalls) {
- Tick icache_stall = icache_latency - cycles(1);
+ Tick icache_stall =
+ icache_access ? icache_latency - cycles(1) : 0;
Tick dcache_stall =
dcache_access ? dcache_latency - cycles(1) : 0;
Tick stall_cycles = (icache_stall + dcache_stall) / cycles(1);
@@ -529,8 +541,8 @@ AtomicSimpleCPU::tick()
}
}
-
- advancePC(fault);
+ if(predecoder.needMoreBytes())
+ advancePC(fault);
}
if (_status != Idle)