fix sub-core operand collector dispatch rr

1 files changed, 10 insertions, 34 deletions

diff --git a/src/gpgpu-sim/shader.h b/src/gpgpu-sim/shader.h
index c3e6f93..deea1c9 100644
--- a/src/gpgpu-sim/shader.h
+++ b/src/gpgpu-sim/shader.h
@@ -956,41 +956,19 @@ class opndcoll_rfu_t {  // operand collector based register file unit
     void init(bool sub_core_model, unsigned num_warp_scheds) {
       m_sub_core_model = sub_core_model;
       m_num_warp_scheds = num_warp_scheds;
-      if (m_sub_core_model) {
-        m_last_cu_set = new unsigned(m_num_warp_scheds);
-        for (unsigned i = 0; i < m_num_warp_scheds; i++)
-        {
-          m_last_cu_set[i] = i * m_num_collectors / m_num_warp_scheds;
-        }
-      }
-      
     }
 
     collector_unit_t *find_ready() {
-      if (m_sub_core_model) {
-        assert(m_num_collectors % m_num_warp_scheds == 0 &&
-                 m_num_collectors >= m_num_warp_scheds);
-        unsigned cusPerSched = m_num_collectors / m_num_warp_scheds;
-        for (unsigned i = 0; i < m_num_warp_scheds; i++) {
-          unsigned cuLowerBound = i * cusPerSched;
-          unsigned cuUpperBound = cuLowerBound + cusPerSched;
-          assert(0 <= cuLowerBound && cuUpperBound <= m_num_collectors);
-          assert(cuLowerBound <= m_last_cu_set[i] && m_last_cu_set[i] <= cuUpperBound);
-          for (unsigned j = cuLowerBound; j < cuUpperBound; j++) {
-            unsigned c = cuLowerBound + (m_last_cu_set[i] + j + 1) % cusPerSched;
-            if ((*m_collector_units)[c].ready()) {
-            m_last_cu_set[i] = c;
-            return &((*m_collector_units)[c]);
-            }
-          }
-        }
-      } else {
-        for (unsigned n = 0; n < m_num_collectors; n++) {
-          unsigned c = (m_last_cu + n + 1) % m_num_collectors;
-          if ((*m_collector_units)[c].ready()) {
-            m_last_cu = c;
-            return &((*m_collector_units)[c]);
-          }
+      // With sub-core enabled round robin starts with the next cu assigned to a
+      // different sub-core than the one that dispatched last
+      unsigned cusPerSched = m_num_collectors / m_num_warp_scheds;
+      unsigned rr_increment = m_sub_core_model ?
+                              cusPerSched - (m_last_cu % cusPerSched) : 1;
+      for (unsigned n = 0; n < m_num_collectors; n++) {
+        unsigned c = (m_last_cu + n + rr_increment) % m_num_collectors;
+        if ((*m_collector_units)[c].ready()) {
+          m_last_cu = c;
+          return &((*m_collector_units)[c]);
         }
       }
       return NULL;
@@ -1000,9 +978,7 @@ class opndcoll_rfu_t {  // operand collector based register file unit
     unsigned m_num_collectors;
     std::vector<collector_unit_t> *m_collector_units;
     unsigned m_last_cu;  // dispatch ready cu's rr
-    unsigned *m_last_cu_set;
     unsigned m_next_cu;  // for initialization
-
     bool m_sub_core_model;
     unsigned m_num_warp_scheds;
   };