From 85affe995e9620d96be34c8a4cf195e2a8a977e7 Mon Sep 17 00:00:00 2001
From: degasus <wickmarkus@web.de>
Date: Sat, 6 Aug 2016 14:15:11 +0200
Subject: [PATCH] JitCache: Do not use block 0.

This ID is reserved for invalid blocks. So this block can't be invalidated.
---
 Source/Core/Core/PowerPC/JitCommon/JitCache.cpp | 6 +++---
 Source/Core/Core/PowerPC/JitCommon/JitCache.h   | 3 ++-
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/Source/Core/Core/PowerPC/JitCommon/JitCache.cpp b/Source/Core/Core/PowerPC/JitCommon/JitCache.cpp
index d3c0be127b..6f345b9636 100644
--- a/Source/Core/Core/PowerPC/JitCommon/JitCache.cpp
+++ b/Source/Core/Core/PowerPC/JitCommon/JitCache.cpp
@@ -42,7 +42,7 @@ void JitBaseBlockCache::Init()
 
 void JitBaseBlockCache::Shutdown()
 {
-  num_blocks = 0;
+  num_blocks = 1;
 
   JitRegister::Shutdown();
 }
@@ -59,7 +59,7 @@ void JitBaseBlockCache::Clear()
 #endif
   jit->js.fifoWriteAddresses.clear();
   jit->js.pairedQuantizeAddresses.clear();
-  for (int i = 0; i < num_blocks; i++)
+  for (int i = 1; i < num_blocks; i++)
   {
     DestroyBlock(i, false);
   }
@@ -68,7 +68,7 @@ void JitBaseBlockCache::Clear()
 
   valid_block.ClearAll();
 
-  num_blocks = 0;
+  num_blocks = 1;
   blocks[0].msrBits = 0xFFFFFFFF;
   blocks[0].invalid = true;
 }
diff --git a/Source/Core/Core/PowerPC/JitCommon/JitCache.h b/Source/Core/Core/PowerPC/JitCommon/JitCache.h
index aeae78e696..842e723ee9 100644
--- a/Source/Core/Core/PowerPC/JitCommon/JitCache.h
+++ b/Source/Core/Core/PowerPC/JitCommon/JitCache.h
@@ -114,6 +114,7 @@ public:
 
 private:
   // We store the metadata of all blocks in a linear way within this array.
+  // Note: blocks[0] must not be used as it is referenced as invalid block in iCache.
   std::array<JitBlock, MAX_NUM_BLOCKS> blocks;  // number -> JitBlock
   int num_blocks;
 
@@ -152,7 +153,7 @@ private:
   virtual void WriteLinkBlock(const JitBlock::LinkData& source, const JitBlock* dest) = 0;
   virtual void WriteDestroyBlock(const JitBlock& block) {}
 public:
-  JitBaseBlockCache() : num_blocks(0) {}
+  JitBaseBlockCache() : num_blocks(1) {}
   virtual ~JitBaseBlockCache() {}
   int AllocateBlock(u32 em_address);
   void FinalizeBlock(int block_num, bool block_link, const u8* code_ptr);