tcg: Introduce byte pointer arithmetic helpers

TCGv_i32 tcg_const_local_i32(int32_t val);

TCGv_i64 tcg_const_local_i64(int64_t val);

/**

 * tcg_ptr_byte_diff

 * @a, @b: addresses to be differenced

 *

 * There are many places within the TCG backends where we need a byte

 * difference between two pointers.  While this can be accomplished

 * with local casting, it's easy to get wrong -- especially if one is

 * concerned with the signedness of the result.

 *

 * This version relies on GCC's void pointer arithmetic to get the

 * correct result.

 */

static inline ptrdiff_t tcg_ptr_byte_diff(void *a, void *b)

{

    return a - b;

}

/**

 * tcg_pcrel_diff

 * @s: the tcg context

 * @target: address of the target

 *

 * Produce a pc-relative difference, from the current code_ptr

 * to the destination address.

 */

static inline ptrdiff_t tcg_pcrel_diff(TCGContext *s, void *target)

{

    return tcg_ptr_byte_diff(target, s->code_ptr);

}

/**

 * tcg_current_code_size

 * @s: the tcg context

 *

 * Compute the current code size within the translation block.

 * This is used to fill in qemu's data structures for goto_tb.

 */

static inline size_t tcg_current_code_size(TCGContext *s)

{

    return tcg_ptr_byte_diff(s->code_ptr, s->code_buf);

}

/**

 * tcg_qemu_tb_exec:

 * @env: CPUArchState * for the CPU