Changeset 142 for trunk/modules/vci_mem_cache_v4

Timestamp:

Mar 17, 2011, 2:32:38 PM (14 years ago)

Author:

guthmull

Message:

Eviction can now be random. Unselected by default.

File:

• trunk/modules/vci_mem_cache_v4/caba/source/include/mem_cache_directory_v4.h (modified) (4 diffs)

trunk/modules/vci_mem_cache_v4/caba/source/include/mem_cache_directory_v4.h

@@ -8 +8 @@
 
 #define L1_MULTI_CACHE      1
+//#define RANDOM_EVICTION
 
 namespace soclib { namespace caba {
@@ -189 +190 @@
     size_t                                      m_words;
     size_t                                      m_width;
+    uint32_t                lfsr;
 
     // the directory & lru tables
@@ -205 +207 @@
       m_words = words;
       m_width = address_width;
+      lfsr = -1;
 
       m_dir_tab = new DirectoryEntry*[sets];
@@ -324 +327 @@
         }
       }
+
+#ifdef RANDOM_EVICTION
+      lfsr = (lfsr >> 1) ^ ((-(lfsr & 1)) & 0xd0000001);
+      way = lfsr % m_ways;
+      return DirectoryEntry(m_dir_tab[set][way]);
+#endif
+
       for(size_t i=0; i<m_ways; i++){
         if(!(m_lru_tab[set][i].recent) && !(m_dir_tab[set][i].lock)){