From 69f2911e04ffb1b19eef1fafb8c040af271f656e Mon Sep 17 00:00:00 2001
From: Tor Aamodt <aamodt@ece.ubc.ca>
Date: Thu, 15 Jul 2010 18:09:46 -0800
Subject: creating branch for adding support for CUDA 3.x and Fermi

[git-p4: depot-paths = "//depot/gpgpu_sim_research/fermi/distribution/": change = 6829]
---
 src/intersim/islip.cpp | 185 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 185 insertions(+)
 create mode 100644 src/intersim/islip.cpp

(limited to 'src/intersim/islip.cpp')

diff --git a/src/intersim/islip.cpp b/src/intersim/islip.cpp
new file mode 100644
index 0000000..1aafacc
--- /dev/null
+++ b/src/intersim/islip.cpp
@@ -0,0 +1,185 @@
+#include "booksim.hpp"
+#include <iostream>
+
+#include "islip.hpp"
+#include "random_utils.hpp"
+
+//#define DEBUG_ISLIP
+
+iSLIP_Sparse::iSLIP_Sparse( const Configuration &config,
+                            Module *parent, const string& name,
+                            int inputs, int outputs ) :
+SparseAllocator( config, parent, name, inputs, outputs )
+{
+   _iSLIP_iter = config.GetInt( "alloc_iters" );
+
+   _grants = new int [_outputs];
+   _gptrs  = new int [_outputs];
+   _aptrs  = new int [_inputs];
+
+   for ( int i = 0; i < _inputs; ++i ) {
+      _aptrs[i] = 0;
+   }
+   for ( int j = 0; j < _outputs; ++j ) {
+      _gptrs[j] = 0;
+   }
+}
+
+iSLIP_Sparse::~iSLIP_Sparse( )
+{
+   delete [] _grants;
+   delete [] _gptrs;
+   delete [] _aptrs;
+}
+
+void iSLIP_Sparse::Allocate( )
+{
+   int input;
+   int output;
+
+   int input_offset;
+   int output_offset;
+
+   list<sRequest>::iterator p;
+   bool wrapped;
+
+   _ClearMatching( );
+
+   for ( int iter = 0; iter < _iSLIP_iter; ++iter ) {
+      // Grant phase
+
+      for ( output = 0; output < _outputs; ++output ) {
+         _grants[output] = -1;
+
+         // Skip loop if there are no requests
+         // or the output is already matched
+         if ( ( _out_req[output].empty( ) ) ||
+              ( _outmatch[output] != -1 ) ) {
+            continue;
+         }
+
+         // A round-robin arbiter between input requests
+         input_offset = _gptrs[output];
+
+         p = _out_req[output].begin( );
+         while ( ( p != _out_req[output].end( ) ) &&
+                 ( p->port < input_offset ) ) {
+            p++;
+         }
+
+         wrapped = false;
+         while ( (!wrapped) || ( p->port < input_offset ) ) {
+            if ( p == _out_req[output].end( ) ) {
+               if ( wrapped ) {
+                  break;
+               }
+               // p is valid here because empty lists
+               // are skipped (above)
+               p = _out_req[output].begin( );
+               wrapped = true;
+            }
+
+            input = p->port;
+
+            // we know the output is free (above) and
+            // if the input is free, grant request
+            if ( _inmatch[input] == -1 ) {
+               _grants[output] = input;
+               break;
+            }
+
+            p++;
+         }      
+      }
+
+#ifdef DEBUG_ISLIP
+      cout << "grants: ";
+      for ( int i = 0; i < _outputs; ++i ) {
+         cout << _grants[i] << " ";
+      }
+      cout << endl;
+
+      cout << "aptrs: ";
+      for ( int i = 0; i < _inputs; ++i ) {
+         cout << _aptrs[i] << " ";
+      }
+      cout << endl;
+#endif
+
+      // Accept phase
+
+      for ( input = 0; input < _inputs; ++input ) {
+
+         if ( _in_req[input].empty( ) ) {
+            continue;
+         }
+
+         // A round-robin arbiter between output grants
+         output_offset = _aptrs[input];
+
+         p = _in_req[input].begin( );
+         while ( ( p != _in_req[input].end( ) ) &&
+                 ( p->port < output_offset ) ) {
+            p++;
+         }
+
+         wrapped = false;
+         int flag ;
+         if ( p != _in_req[input].end( ) ) {
+            flag= (p->port < output_offset) ;
+         } else {
+            flag = true;
+         }
+         while ( (!wrapped) || (flag) ) {
+            if ( p == _in_req[input].end( ) ) {
+               if ( wrapped ) {
+                  break;
+               }
+               // p is valid here because empty lists
+               // are skipped (above)
+               p = _in_req[input].begin( );
+               wrapped = true;
+            }
+
+            output = p->port;
+
+            // we know the output is free (above) and
+            // if the input is free, grant request
+            if ( _grants[output] == input ) {
+               // Accept
+               _inmatch[input]   = output;
+               _outmatch[output] = input;
+
+               // Only update pointers if accepted during the 1st iteration
+               if ( iter == 0 ) {
+                  _gptrs[output] = ( input + 1 ) % _inputs;
+                  _aptrs[input]  = ( output + 1 ) % _outputs;
+               }
+
+               break;
+            }
+
+            p++;
+            if ( p != _in_req[input].end( ) ) {
+               flag= (p->port < output_offset) ;
+            } else {
+               flag = true;
+            }
+         } 
+      }
+   }
+
+#ifdef DEBUG_ISLIP
+   cout << "input match: ";
+   for ( int i = 0; i < _inputs; ++i ) {
+      cout << _inmatch[i] << " ";
+   }
+   cout << endl;
+
+   cout << "output match: ";
+   for ( int j = 0; j < _outputs; ++j ) {
+      cout << _outmatch[j] << " ";
+   }
+   cout << endl;
+#endif
+}
-- 
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