From 7f49fe9feb174d34efc2a011bad79b38522a360b Mon Sep 17 00:00:00 2001
From: Dongdong Li <qqlddg@gmail.com>
Date: Thu, 8 Aug 2013 00:15:58 -0800
Subject: Intesim2 Integration Details: See Review 80001
 https://gpgpu-sim-code-review.appspot.com/80001/

[git-p4: depot-paths = "//depot/gpgpu_sim_research/fermi/distribution/": change = 16747]
---
 src/intersim2/arbiters/prio_arb.cpp | 160 ++++++++++++++++++++++++++++++++++++
 1 file changed, 160 insertions(+)
 create mode 100644 src/intersim2/arbiters/prio_arb.cpp

(limited to 'src/intersim2/arbiters/prio_arb.cpp')

diff --git a/src/intersim2/arbiters/prio_arb.cpp b/src/intersim2/arbiters/prio_arb.cpp
new file mode 100644
index 0000000..9de2bc2
--- /dev/null
+++ b/src/intersim2/arbiters/prio_arb.cpp
@@ -0,0 +1,160 @@
+// $Id: prio_arb.cpp 5188 2012-08-30 00:31:31Z dub $
+
+/*
+ Copyright (c) 2007-2012, Trustees of The Leland Stanford Junior University
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ Redistributions of source code must retain the above copyright notice, this 
+ list of conditions and the following disclaimer.
+ Redistributions in binary form must reproduce the above copyright notice, this
+ list of conditions and the following disclaimer in the documentation and/or
+ other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#include "booksim.hpp"
+#include <cassert>
+
+#include "prio_arb.hpp"
+
+
+PriorityArbiter::PriorityArbiter( const Configuration &config,
+				  Module *parent, const string& name,
+				  int inputs ) 
+: Module( parent, name ), _rr_ptr(0), _inputs( inputs )
+{
+
+}
+
+void PriorityArbiter::Clear( )
+{
+  _requests.clear( );
+}
+
+void PriorityArbiter::AddRequest( int in, int label, int pri )
+{
+  sRequest r;
+  list<sRequest>::iterator insert_point;
+
+  r.in = in; r.label = label; r.pri = pri;
+
+  insert_point = _requests.begin( );
+  while( ( insert_point != _requests.end( ) ) &&
+	 ( insert_point->in < in ) ) {
+    insert_point++;
+  }
+
+  bool del = false;
+  bool add = true;
+
+  // For consistant behavior, delete the existing request
+  // if it is for the same input and has a higher
+  // priority
+
+  if ( ( insert_point != _requests.end( ) ) &&
+       ( insert_point->in == in ) ) {
+    if ( insert_point->pri < pri ) {
+      del = true;
+    } else {
+      add = false;
+    }
+  }
+
+  if ( add ) {
+    _requests.insert( insert_point, r );
+  }
+
+  if ( del ) {
+    _requests.erase( insert_point );
+  }
+}
+
+void PriorityArbiter::RemoveRequest( int in, int label )
+{
+  list<sRequest>::iterator erase_point;
+
+  erase_point = _requests.begin( );
+  while( ( erase_point != _requests.end( ) ) &&
+	 ( erase_point->in < in ) ) {
+    erase_point++;
+  }
+
+  assert( erase_point != _requests.end( ) );
+  _requests.erase( erase_point );
+}
+
+int PriorityArbiter::Match( ) const
+{
+  return _match;
+}
+
+void PriorityArbiter::Arbitrate( )
+{
+  list<sRequest>::iterator p;
+
+  int max_index, max_pri;
+  bool wrapped;
+
+  //MERGENOTE
+  //booksim does not have this if statement
+  //as far as I can tell they are identical in function 
+  if ( _requests.begin( ) != _requests.end( ) ) {
+    // A round-robin arbiter between input requests
+    p = _requests.begin( );
+    while( ( p != _requests.end( ) ) &&
+	   ( p->in < _rr_ptr ) ) {
+      p++;
+    }
+    
+    max_index = -1;
+    max_pri   = 0;
+    
+    wrapped = false;
+    while( (!wrapped) || ( p->in < _rr_ptr ) ) {
+      if ( p == _requests.end( ) ) {
+	if ( wrapped ) { break; }
+	// p is valid here because empty lists
+	// are skipped (above)
+	p = _requests.begin( );
+	wrapped = true;
+      }
+      
+      // check if request is the highest priority so far
+      if ( ( p->pri > max_pri ) || ( max_index == -1 ) ) {
+	max_pri   = p->pri;
+	max_index = p->in;
+      }
+      
+      p++;
+    }   
+
+    _match = max_index; // -1 for no match
+    if ( _match != -1 ) { 
+      _rr_ptr = ( _match + 1 ) % _inputs;
+    }
+    
+  } else {
+    _match = -1;
+  }
+}
+
+//MERGENOTE
+//added update function to priorityarbiter
+
+void PriorityArbiter::Update( )
+{
+  _rr_ptr = ( _rr_ptr + 1 ) % _inputs;
+}
-- 
cgit v1.3