Merge pull request #10935 from Pokechu22/icache-dont-save-lookup-table

PPCCache: Stop storing lookup table in savestates

Source/Core/Core/PowerPC/PPCCache.cpp

@@ -204,13 +204,53 @@ u32 InstructionCache::ReadInstruction(u32 addr)
 
 void InstructionCache::DoState(PointerWrap& p)
 {
+  if (p.IsReadMode())
+  {
+    // Clear valid parts of the lookup tables (this is done instead of using fill(0xff) to avoid
+    // loading the entire 4MB of tables into cache)
+    for (u32 set = 0; set < ICACHE_SETS; set++)
+    {
+      for (u32 way = 0; way < ICACHE_WAYS; way++)
+      {
+        if ((valid[set] & (1 << way)) != 0)
+        {
+          const u32 addr = (tags[set][way] << 12) | (set << 5);
+          if (addr & ICACHE_VMEM_BIT)
+            lookup_table_vmem[(addr >> 5) & 0xfffff] = 0xff;
+          else if (addr & ICACHE_EXRAM_BIT)
+            lookup_table_ex[(addr >> 5) & 0x1fffff] = 0xff;
+          else
+            lookup_table[(addr >> 5) & 0xfffff] = 0xff;
+        }
+      }
+    }
+  }
+
   p.DoArray(data);
   p.DoArray(tags);
   p.DoArray(plru);
   p.DoArray(valid);
-  p.DoArray(lookup_table);
-  p.DoArray(lookup_table_ex);
-  p.DoArray(lookup_table_vmem);
+
+  if (p.IsReadMode())
+  {
+    // Recompute lookup tables
+    for (u32 set = 0; set < ICACHE_SETS; set++)
+    {
+      for (u32 way = 0; way < ICACHE_WAYS; way++)
+      {
+        if ((valid[set] & (1 << way)) != 0)
+        {
+          const u32 addr = (tags[set][way] << 12) | (set << 5);
+          if (addr & ICACHE_VMEM_BIT)
+            lookup_table_vmem[(addr >> 5) & 0xfffff] = way;
+          else if (addr & ICACHE_EXRAM_BIT)
+            lookup_table_ex[(addr >> 5) & 0x1fffff] = way;
+          else
+            lookup_table[(addr >> 5) & 0xfffff] = way;
+        }
+      }
+    }
+  }
 }
 
 void InstructionCache::RefreshConfig()

Source/Core/Core/PowerPC/PPCCache.h

@@ -27,6 +27,8 @@ struct InstructionCache
   std::array<u32, ICACHE_SETS> plru{};
   std::array<u32, ICACHE_SETS> valid{};
 
+  // Note: This is only for performance purposes; this same data could be computed at runtime
+  // from the tags and valid fields (and that's how it's done on the actual cache)
   std::array<u8, 1 << 20> lookup_table{};
   std::array<u8, 1 << 21> lookup_table_ex{};
   std::array<u8, 1 << 20> lookup_table_vmem{};

Source/Core/Core/State.cpp

@@ -74,7 +74,7 @@ static std::recursive_mutex g_save_thread_mutex;
 static std::thread g_save_thread;
 
 // Don't forget to increase this after doing changes on the savestate system
-constexpr u32 STATE_VERSION = 146;  // Last changed in PR 10883
+constexpr u32 STATE_VERSION = 147;  // Last changed in PR 10935
 
 // Maps savestate versions to Dolphin versions.
 // Versions after 42 don't need to be added to this list,