/* Tutorial 4 - mul_add, C++ version Builds and compiles the following function: int mul_add(int x, int y, int z) { return x * y + z; } Differs from Tutorial 3 in that this version is written in C++. */ #include #include class mul_add_function : public jit_function { public: mul_add_function(jit_context& context) : jit_function(context) { create(); set_recompilable(); } virtual void build(); protected: virtual jit_type_t create_signature(); }; jit_type_t mul_add_function::create_signature() { // Return type, followed by three parameters, terminated with "end_params". return signature_helper (jit_type_int, jit_type_int, jit_type_int, jit_type_int, end_params); } void mul_add_function::build() { printf("Compiling mul_add on demand\n"); jit_value x = get_param(0); jit_value y = get_param(1); jit_value z = get_param(2); insn_return(x * y + z); } int main(int argc, char **argv) { jit_int arg1, arg2, arg3; void *args[3]; jit_int result; // Create a context to hold the JIT's primary state. jit_context context; // Create the function object. mul_add_function mul_add(context); // Execute the function and print the result. This will arrange // to call "mul_add_function::build" to build the function's body. arg1 = 3; arg2 = 5; arg3 = 2; args[0] = &arg1; args[1] = &arg2; args[2] = &arg3; mul_add.apply(args, &result); printf("mul_add(3, 5, 2) = %d\n", (int)result); // Execute the function again, to demonstrate that the // on-demand compiler is not invoked a second time. arg1 = 13; arg2 = 5; arg3 = 7; args[0] = &arg1; args[1] = &arg2; args[2] = &arg3; mul_add.apply(args, &result); printf("mul_add(13, 5, 7) = %d\n", (int)result); // Force the function to be recompiled. mul_add.build_start(); mul_add.build(); mul_add.compile(); mul_add.build_end(); // Execute the function a third time, after it is recompiled. arg1 = 2; arg2 = 18; arg3 = -3; args[0] = &arg1; args[1] = &arg2; args[2] = &arg3; mul_add.apply(args, &result); printf("mul_add(2, 18, -3) = %d\n", (int)result); /* Finished */ return 0; }