3 files changed, 31 insertions, 12 deletions

diff --git a/src/cpu/trace/TraceCPU.py b/src/cpu/trace/TraceCPU.py
index e1c02ae63..bbce9c0ad 100644
--- a/src/cpu/trace/TraceCPU.py
+++ b/src/cpu/trace/TraceCPU.py
@@ -1,4 +1,4 @@
-# Copyright (c) 2013 - 2015 ARM Limited
+# Copyright (c) 2013 - 2016 ARM Limited
 # All rights reserved.
 #
 # The license below extends only to copyright in the software and shall
@@ -69,3 +69,9 @@ class TraceCPU(BaseCPU):
     sizeLoadBuffer = Param.Unsigned(16, "Number of entries in the load buffer")
     sizeROB =  Param.Unsigned(40, "Number of entries in the re-order buffer")
 
+    # Frequency multiplier used to effectively scale the Trace CPU frequency
+    # either up or down. Note that the Trace CPU's clock domain must also be
+    # changed when frequency is scaled. A default value of 1.0 means the same
+    # frequency as was used for generating the traces.
+    freqMultiplier = Param.Float(1.0, "Multiplier scale the Trace CPU "\
+                                 "frequency up or down")
diff --git a/src/cpu/trace/trace_cpu.cc b/src/cpu/trace/trace_cpu.cc
index e81a79818..42620a177 100644
--- a/src/cpu/trace/trace_cpu.cc
+++ b/src/cpu/trace/trace_cpu.cc
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013 - 2015 ARM Limited
+ * Copyright (c) 2013 - 2016 ARM Limited
  * All rights reserved
  *
  * The license below extends only to copyright in the software and shall
@@ -56,8 +56,7 @@ TraceCPU::TraceCPU(TraceCPUParams *params)
         dataTraceFile(params->dataTraceFile),
         icacheGen(*this, ".iside", icachePort, instMasterID, instTraceFile),
         dcacheGen(*this, ".dside", dcachePort, dataMasterID, dataTraceFile,
-                    params->sizeROB, params->sizeStoreBuffer,
-                    params->sizeLoadBuffer),
+                  params),
         icacheNextEvent(this),
         dcacheNextEvent(this),
         oneTraceComplete(false),
@@ -1225,8 +1224,11 @@ TraceCPU::DcachePort::recvReqRetry()
     owner->dcacheRetryRecvd();
 }
 
-TraceCPU::ElasticDataGen::InputStream::InputStream(const std::string& filename)
+TraceCPU::ElasticDataGen::InputStream::InputStream(
+    const std::string& filename,
+    const double time_multiplier)
     : trace(filename),
+      timeMultiplier(time_multiplier),
       microOpCount(0)
 {
     // Create a protobuf message for the header and read it from the stream
@@ -1259,7 +1261,8 @@ TraceCPU::ElasticDataGen::InputStream::read(GraphNode* element)
         // Required fields
         element->seqNum = pkt_msg.seq_num();
         element->type = pkt_msg.type();
-        element->compDelay = pkt_msg.comp_delay();
+        // Scale the compute delay to effectively scale the Trace CPU frequency
+        element->compDelay = pkt_msg.comp_delay() * timeMultiplier;
 
         // Repeated field robDepList
         element->clearRobDep();
diff --git a/src/cpu/trace/trace_cpu.hh b/src/cpu/trace/trace_cpu.hh
index bb59c3fab..2c7168d51 100644
--- a/src/cpu/trace/trace_cpu.hh
+++ b/src/cpu/trace/trace_cpu.hh
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013 - 2015 ARM Limited
+ * Copyright (c) 2013 - 2016 ARM Limited
  * All rights reserved
  *
  * The license below extends only to copyright in the software and shall
@@ -795,6 +795,14 @@ class TraceCPU : public BaseCPU
             /** Input file stream for the protobuf trace */
             ProtoInputStream trace;
 
+            /**
+             * A multiplier for the compute delays in the trace to modulate
+             * the Trace CPU frequency either up or down. The Trace CPU's
+             * clock domain frequency must also be set to match the expected
+             * result of frequency scaling.
+             */
+            const double timeMultiplier;
+
             /** Count of committed ops read from trace plus the filtered ops */
             uint64_t microOpCount;
 
@@ -809,8 +817,10 @@ class TraceCPU : public BaseCPU
              * Create a trace input stream for a given file name.
              *
              * @param filename Path to the file to read from
+             * @param time_multiplier used to scale the compute delays
              */
-            InputStream(const std::string& filename);
+            InputStream(const std::string& filename,
+                        const double time_multiplier);
 
             /**
              * Reset the stream such that it can be played once
@@ -840,19 +850,19 @@ class TraceCPU : public BaseCPU
         /* Constructor */
         ElasticDataGen(TraceCPU& _owner, const std::string& _name,
                    MasterPort& _port, MasterID master_id,
-                   const std::string& trace_file, uint16_t max_rob,
-                   uint16_t max_stores, uint16_t max_loads)
+                   const std::string& trace_file, TraceCPUParams *params)
             : owner(_owner),
               port(_port),
               masterID(master_id),
-              trace(trace_file),
+              trace(trace_file, 1.0 / params->freqMultiplier),
               genName(owner.name() + ".elastic" + _name),
               retryPkt(nullptr),
               traceComplete(false),
               nextRead(false),
               execComplete(false),
               windowSize(trace.getWindowSize()),
-              hwResource(max_rob, max_stores, max_loads)
+              hwResource(params->sizeROB, params->sizeStoreBuffer,
+                         params->sizeLoadBuffer)
         {
             DPRINTF(TraceCPUData, "Window size in the trace is %d.\n",
                     windowSize);