tcg/tcg.h:Define type and accessor macros for TCG variables. TCG variables are the inputs and outputs of TCG ops, as described in tcg/README. Target CPU front-end code uses these types to deal with TCG variables as it emits TCG code via the tcg_gen_* functions. They come in several flavours: * TCGv_i32 : 32 bit integer type * TCGv_i64 : 64 bit integer type * TCGv_ptr : a host pointer type * TCGv_vec : a host vector type; the exact size is not exposed to the CPU front-end code. * TCGv : an integer type the same size as target_ulong (an alias for either TCGv_i32 or TCGv_i64) The compiler's type checking will complain if you mix them up and pass the wrong sized TCGv to a function. Users of tcg_gen_* don't need to know about any of the internal details of these, and should treat them as opaque types. You won't be able to look inside them in a debugger either. Internal implementation details follow: Note that there is no definition of the structs TCGv_i32_d etc anywhere. This is deliberate, because the values we store in variables of type TCGv_i32 are not really pointers-to-structures. They're just small integers, but keeping them in pointer types like this means that the compiler will complain if you accidentally pass a TCGv_i32 to a function which takes a TCGv_i64, and so on. Only the internals of TCG need to care about the actual contents of the types.tcg/optimize.cstatic TCGArg do_constant_folding_2(TCGOpcode op, TCGArg x, TCGArg y){ uint64_t l64, h64; switch (op) { CASE_OP_32_64(add): return x + y; CASE_OP_32_64(sub): return x - y; CASE_OP_32_64(mul): return x * y; CASE_OP_32_64(and): return x & y; CASE_OP_32_64(or): return x | y; CASE_OP_32_64(xor): return x ^ y; case INDEX_op_shl_i32: return (uint32_t)x << (y & 31);可以看到TCGV就是普通的運算元