[Shader JIT] Add caching

src/core/PICA/shader_unit.cpp

@@ -1,4 +1,5 @@
 #include "PICA/shader_unit.hpp"
+#include "cityhash.hpp"
 
 void ShaderUnit::reset() {
 	vs.reset();
@@ -30,4 +31,29 @@ void PICAShader::reset() {
 	addrRegister.x() = 0;
 	addrRegister.y() = 0;
 	loopCounter = 0;
+
+	codeHashDirty = true;
+	opdescHashDirty = true;
+}
+
+PICAShader::Hash PICAShader::getCodeHash() {
+	// Hash the code again if the code changed
+	if (codeHashDirty) {
+		codeHashDirty = false;
+		lastCodeHash = CityHash::CityHash64((const char*)&loadedShader[0], loadedShader.size() * sizeof(loadedShader[0]));
+	}
+
+	// Return the code hash
+	return lastCodeHash;
+}
+
+PICAShader::Hash PICAShader::getOpdescHash() {
+	// Hash the code again if the operand descriptors changed
+	if (opdescHashDirty) {
+		opdescHashDirty = false;
+		lastOpdescHash = CityHash::CityHash64((const char*)&operandDescriptors[0], operandDescriptors.size() * sizeof(operandDescriptors[0]));
+	}
+
+	// Return the code hash
+	return lastOpdescHash;
 }