[Shader JIT] Add caching

include/PICA/dynapica/shader_rec.hpp

@@ -1,22 +1,35 @@
 #pragma once
 #include "PICA/shader.hpp"
 
+#if defined(PANDA3DS_DYNAPICA_SUPPORTED) && defined(PANDA3DS_X64_HOST)
+#define PANDA3DS_SHADER_JIT_SUPPORTED
+#include <unordered_map>
+#endif
+
 class ShaderJIT {
+#ifdef PANDA3DS_SHADER_JIT_SUPPORTED
+	using Hash = PICAShader::Hash;
+	using ShaderCache = std::unordered_map<Hash, int>;
+
+	ShaderCache cache;
 	void compileShader(PICAShader& shaderUnit);
+#endif
 
 public:
-#if defined(PANDA3DS_DYNAPICA_SUPPORTED) && defined(PANDA3DS_X64_HOST)
-	#define PANDA3DS_SHADER_JIT_SUPPORTED
-
+#ifdef PANDA3DS_SHADER_JIT_SUPPORTED
 	// Call this before starting to process a batch of vertices
 	// This will read the PICA config (uploaded shader and shader operand descriptors) and search if we've already compiled this shader
 	// If yes, it sets it as the active shader. if not, then it compiles it, adds it to the cache, and sets it as active,
 	void prepare(PICAShader& shaderUnit);
+	void reset();
+
 	static constexpr bool isAvailable() { return true; }
 #else
 	void prepare(PICAShader& shaderUnit) {
 		Helpers::panic("Vertex Loader JIT: Tried to load vertices with JIT on platform that does not support vertex loader jit");
 	}
+
+	void reset() {}
 	static constexpr bool isAvailable() { return false; }
 #endif
 

include/PICA/gpu.hpp

@@ -16,6 +16,8 @@ class GPU {
 
 	Memory& mem;
 	ShaderUnit shaderUnit;
+	ShaderJIT shaderJIT; // Doesn't do anything if JIT is disabled or not supported
+
 	u8* vram = nullptr;
 	MAKE_LOG_FUNCTION(log, gpuLogger)
 

include/PICA/shader.hpp

@@ -89,6 +89,17 @@ protected:
 	std::array<CallInfo, 4> callInfo;
 	ShaderType type;
 
+	// We use a hashmap for matching 3DS shaders to their equivalent compiled code in our shader cache in the shader JIT
+	// We choose our hash type to be a 64-bit integer by default, as the collision chance is very tiny and generating it is decently optimal
+	// Ideally we want to be able to support multiple different types of hash depending on compilation settings, but let's get this working first
+	using Hash = u64;
+
+	Hash lastCodeHash = 0; // Last hash computed for the shader code (Used for the JIT caching mechanism)
+	Hash lastOpdescHash = 0;  // Last hash computed for the operand descriptors (Also used for the JIT)
+
+	bool codeHashDirty = false;
+	bool opdescHashDirty = false;
+
 	friend class ShaderJIT;
 
 private:
@@ -204,11 +215,15 @@ public:
 		if (bufferIndex >= 4095) Helpers::panic("o no, shader upload overflew");
 		bufferedShader[bufferIndex++] = word;
 		bufferIndex &= 0xfff;
+
+		codeHashDirty = true; // Signal the JIT if necessary that the program hash has potentially changed
 	}
 
 	void uploadDescriptor(u32 word) {
 		operandDescriptors[opDescriptorIndex++] = word;
 		opDescriptorIndex &= 0x7f;
+
+		opdescHashDirty = true; // Signal the JIT if necessary that the program hash has potentially changed
 	}
 
 	void setFloatUniformIndex(u32 word) {
@@ -250,4 +265,7 @@ public:
 
 	void run();
 	void reset();
+
+	Hash getCodeHash();
+	Hash getOpdescHash();
 };