Merge pull request #5121 from MerryMage/children-happen

Jit64: Merge memory allocations into a single allocation

1 files changed, 35 insertions, 22 deletions

diff --git a/Source/Core/Common/CodeBlock.h b/Source/Core/Common/CodeBlock.h
index 28a4919e66..9c3da1058b 100644
--- a/Source/Core/Common/CodeBlock.h
+++ b/Source/Core/Common/CodeBlock.h
@@ -5,6 +5,7 @@
 #pragma once
 
 #include <cstddef>
+#include <vector>
 
 #include "Common/Assert.h"
 #include "Common/CommonTypes.h"
@@ -27,12 +28,13 @@ private:
 
 protected:
   u8* region = nullptr;
+  // Size of region we can use.
   size_t region_size = 0;
-  size_t parent_region_size = 0;
+  // Original size of the region we allocated.
+  size_t total_region_size = 0;
 
-  bool m_has_child = false;
   bool m_is_child = false;
-  CodeBlock* m_child = nullptr;
+  std::vector<CodeBlock*> m_children;
 
 public:
   virtual ~CodeBlock()
@@ -42,16 +44,17 @@ public:
   }
 
   // Call this before you generate any code.
-  virtual void AllocCodeSpace(size_t size, bool need_low = true)
+  void AllocCodeSpace(size_t size, bool need_low = true)
   {
     region_size = size;
-    region = static_cast<u8*>(Common::AllocateExecutableMemory(region_size, need_low));
+    total_region_size = size;
+    region = static_cast<u8*>(Common::AllocateExecutableMemory(total_region_size, need_low));
     T::SetCodePtr(region);
   }
 
   // Always clear code space with breakpoints, so that if someone accidentally executes
   // uninitialized, it just breaks into the debugger.
-  virtual void ClearCodeSpace()
+  void ClearCodeSpace()
   {
     PoisonMemory();
     ResetCodePtr();
@@ -60,14 +63,16 @@ public:
   // Call this when shutting down. Don't rely on the destructor, even though it'll do the job.
   void FreeCodeSpace()
   {
-    Common::FreeMemoryPages(region, region_size);
+    _assert_(!m_is_child);
+    Common::FreeMemoryPages(region, total_region_size);
     region = nullptr;
     region_size = 0;
-    parent_region_size = 0;
-    if (m_has_child)
+    total_region_size = 0;
+    for (CodeBlock* child : m_children)
     {
-      m_child->region = nullptr;
-      m_child->region_size = 0;
+      child->region = nullptr;
+      child->region_size = 0;
+      child->total_region_size = 0;
     }
   }
 
@@ -78,7 +83,8 @@ public:
   void ResetCodePtr() { T::SetCodePtr(region); }
   size_t GetSpaceLeft() const
   {
-    return (m_has_child ? parent_region_size : region_size) - (T::GetCodePtr() - region);
+    _assert_(static_cast<size_t>(T::GetCodePtr() - region) < region_size);
+    return region_size - (T::GetCodePtr() - region);
   }
 
   bool IsAlmostFull() const
@@ -86,16 +92,23 @@ public:
     // This should be bigger than the biggest block ever.
     return GetSpaceLeft() < 0x10000;
   }
-  void AddChildCodeSpace(CodeBlock* child, size_t size)
+
+  bool HasChildren() const { return region_size != total_region_size; }
+  u8* AllocChildCodeSpace(size_t child_size)
+  {
+    _assert_msg_(DYNA_REG, child_size < GetSpaceLeft(), "Insufficient space for child allocation.");
+    u8* child_region = region + region_size - child_size;
+    region_size -= child_size;
+    return child_region;
+  }
+  void AddChildCodeSpace(CodeBlock* child, size_t child_size)
   {
-    _assert_msg_(DYNA_REC, !m_has_child, "Already have a child! Can't have another!");
-    m_child = child;
-    m_has_child = true;
-    m_child->m_is_child = true;
-    u8* child_region = region + region_size - size;
-    m_child->region = child_region;
-    m_child->region_size = size;
-    m_child->ResetCodePtr();
-    parent_region_size = region_size - size;
+    u8* child_region = AllocChildCodeSpace(child_size);
+    child->m_is_child = true;
+    child->region = child_region;
+    child->region_size = child_size;
+    child->total_region_size = child_size;
+    child->ResetCodePtr();
+    m_children.emplace_back(child);
   }
 };