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			121 lines
		
	
	
	
		
			3.6 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			121 lines
		
	
	
	
		
			3.6 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| // Copyright 2014 Dolphin Emulator Project
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| // Licensed under GPLv2+
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| // Refer to the license.txt file included.
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| 
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| #pragma once
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| 
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| #include <cstddef>
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| #include <vector>
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| 
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| #include "Common/Assert.h"
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| #include "Common/CommonTypes.h"
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| #include "Common/MemoryUtil.h"
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| 
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| namespace Common
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| {
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| // Everything that needs to generate code should inherit from this.
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| // You get memory management for free, plus, you can use all emitter functions without
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| // having to prefix them with gen-> or something similar.
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| // Example implementation:
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| // class JIT : public CodeBlock<ARMXEmitter> {}
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| template <class T>
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| class CodeBlock : public T
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| {
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| private:
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|   // A privately used function to set the executable RAM space to something invalid.
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|   // For debugging usefulness it should be used to set the RAM to a host specific breakpoint
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|   // instruction
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|   virtual void PoisonMemory() = 0;
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| 
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| protected:
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|   u8* region = nullptr;
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|   // Size of region we can use.
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|   size_t region_size = 0;
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|   // Original size of the region we allocated.
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|   size_t total_region_size = 0;
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| 
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|   bool m_is_child = false;
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|   std::vector<CodeBlock*> m_children;
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| 
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| public:
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|   CodeBlock() = default;
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|   virtual ~CodeBlock()
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|   {
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|     if (region)
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|       FreeCodeSpace();
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|   }
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|   CodeBlock(const CodeBlock&) = delete;
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|   CodeBlock& operator=(const CodeBlock&) = delete;
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|   CodeBlock(CodeBlock&&) = delete;
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|   CodeBlock& operator=(CodeBlock&&) = delete;
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| 
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|   // Call this before you generate any code.
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|   void AllocCodeSpace(size_t size)
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|   {
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|     region_size = size;
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|     total_region_size = size;
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|     region = static_cast<u8*>(Common::AllocateExecutableMemory(total_region_size));
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|     T::SetCodePtr(region);
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|   }
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| 
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|   // Always clear code space with breakpoints, so that if someone accidentally executes
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|   // uninitialized, it just breaks into the debugger.
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|   void ClearCodeSpace()
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|   {
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|     PoisonMemory();
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|     ResetCodePtr();
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|   }
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| 
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|   // Call this when shutting down. Don't rely on the destructor, even though it'll do the job.
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|   void FreeCodeSpace()
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|   {
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|     ASSERT(!m_is_child);
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|     Common::FreeMemoryPages(region, total_region_size);
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|     region = nullptr;
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|     region_size = 0;
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|     total_region_size = 0;
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|     for (CodeBlock* child : m_children)
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|     {
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|       child->region = nullptr;
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|       child->region_size = 0;
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|       child->total_region_size = 0;
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|     }
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|   }
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| 
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|   bool IsInSpace(const u8* ptr) const { return ptr >= region && ptr < (region + region_size); }
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|   // Cannot currently be undone. Will write protect the entire code region.
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|   // Start over if you need to change the code (call FreeCodeSpace(), AllocCodeSpace()).
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|   void WriteProtect() { Common::WriteProtectMemory(region, region_size, true); }
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|   void ResetCodePtr() { T::SetCodePtr(region); }
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|   size_t GetSpaceLeft() const
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|   {
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|     ASSERT(static_cast<size_t>(T::GetCodePtr() - region) < region_size);
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|     return region_size - (T::GetCodePtr() - region);
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|   }
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| 
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|   bool IsAlmostFull() const
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|   {
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|     // This should be bigger than the biggest block ever.
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|     return GetSpaceLeft() < 0x10000;
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|   }
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| 
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|   bool HasChildren() const { return region_size != total_region_size; }
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|   u8* AllocChildCodeSpace(size_t child_size)
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|   {
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|     ASSERT_MSG(DYNA_REC, child_size < GetSpaceLeft(), "Insufficient space for child allocation.");
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|     u8* child_region = region + region_size - child_size;
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|     region_size -= child_size;
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|     return child_region;
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|   }
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|   void AddChildCodeSpace(CodeBlock* child, size_t child_size)
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|   {
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|     u8* child_region = AllocChildCodeSpace(child_size);
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|     child->m_is_child = true;
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|     child->region = child_region;
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|     child->region_size = child_size;
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|     child->total_region_size = child_size;
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|     child->ResetCodePtr();
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|     m_children.emplace_back(child);
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|   }
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| };
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| }  // namespace Common
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