From 6847bbf7cefcebfeed6ec29fa139efcb3ce20be4 Mon Sep 17 00:00:00 2001
From: Mitch Hayenga <mitch.hayenga@arm.com>
Date: Wed, 29 Oct 2014 23:18:26 -0500
Subject: [PATCH] cpu: Add drain check functionality to IEW

IEW did not check the instQueue and memDepUnit to ensure
they were drained.  This caused issues when drainSanityCheck()
did check those structures after asserting IEW was drained.
---
 src/cpu/o3/iew_impl.hh          |  2 +-
 src/cpu/o3/inst_queue.hh        |  3 +++
 src/cpu/o3/inst_queue_impl.hh   | 11 +++++++++++
 src/cpu/o3/mem_dep_unit.hh      |  3 +++
 src/cpu/o3/mem_dep_unit_impl.hh | 13 +++++++++++++
 5 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/src/cpu/o3/iew_impl.hh b/src/cpu/o3/iew_impl.hh
index 448be3a74..bf44fb9f2 100644
--- a/src/cpu/o3/iew_impl.hh
+++ b/src/cpu/o3/iew_impl.hh
@@ -381,7 +381,7 @@ template <class Impl>
 bool
 DefaultIEW<Impl>::isDrained() const
 {
-    bool drained(ldstQueue.isDrained());
+    bool drained = ldstQueue.isDrained() && instQueue.isDrained();
 
     for (ThreadID tid = 0; tid < numThreads; tid++) {
         if (!insts[tid].empty()) {
diff --git a/src/cpu/o3/inst_queue.hh b/src/cpu/o3/inst_queue.hh
index d59d5281b..c6c55d08a 100644
--- a/src/cpu/o3/inst_queue.hh
+++ b/src/cpu/o3/inst_queue.hh
@@ -145,6 +145,9 @@ class InstructionQueue
     /** Sets the global time buffer. */
     void setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr);
 
+    /** Determine if we are drained. */
+    bool isDrained() const;
+
     /** Perform sanity checks after a drain. */
     void drainSanityCheck() const;
 
diff --git a/src/cpu/o3/inst_queue_impl.hh b/src/cpu/o3/inst_queue_impl.hh
index 0caee41ed..6a76b49d0 100644
--- a/src/cpu/o3/inst_queue_impl.hh
+++ b/src/cpu/o3/inst_queue_impl.hh
@@ -440,6 +440,17 @@ InstructionQueue<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr)
     fromCommit = timeBuffer->getWire(-commitToIEWDelay);
 }
 
+template <class Impl>
+bool
+InstructionQueue<Impl>::isDrained() const
+{
+    bool drained = dependGraph.empty() && instsToExecute.empty();
+    for (ThreadID tid = 0; tid < numThreads; ++tid)
+        drained = drained && memDepUnit[tid].isDrained();
+
+    return drained;
+}
+
 template <class Impl>
 void
 InstructionQueue<Impl>::drainSanityCheck() const
diff --git a/src/cpu/o3/mem_dep_unit.hh b/src/cpu/o3/mem_dep_unit.hh
index 3cc1d88fe..c2c411fe4 100644
--- a/src/cpu/o3/mem_dep_unit.hh
+++ b/src/cpu/o3/mem_dep_unit.hh
@@ -104,6 +104,9 @@ class MemDepUnit
     /** Registers statistics. */
     void regStats();
 
+    /** Determine if we are drained. */
+    bool isDrained() const;
+
     /** Perform sanity checks after a drain. */
     void drainSanityCheck() const;
 
diff --git a/src/cpu/o3/mem_dep_unit_impl.hh b/src/cpu/o3/mem_dep_unit_impl.hh
index 6684e4ff0..376198fc1 100644
--- a/src/cpu/o3/mem_dep_unit_impl.hh
+++ b/src/cpu/o3/mem_dep_unit_impl.hh
@@ -127,6 +127,19 @@ MemDepUnit<MemDepPred, Impl>::regStats()
         .desc("Number of conflicting stores.");
 }
 
+template <class MemDepPred, class Impl>
+bool
+MemDepUnit<MemDepPred, Impl>::isDrained() const
+{
+    bool drained = instsToReplay.empty()
+                 && memDepHash.empty()
+                 && instsToReplay.empty();
+    for (int i = 0; i < Impl::MaxThreads; ++i)
+        drained = drained && instList[i].empty();
+
+    return drained;
+}
+
 template <class MemDepPred, class Impl>
 void
 MemDepUnit<MemDepPred, Impl>::drainSanityCheck() const
-- 
2.30.2