Re: [PATCH v3 07/30] tcg/loongarch64: Implement necessary relocation operations

[Philippe Mathieu-Daudé]

On 9/22/21 20:09, WANG Xuerui wrote:
> Signed-off-by: WANG Xuerui <git@xen0n.name>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   tcg/loongarch64/tcg-target.c.inc | 66 ++++++++++++++++++++++++++++++++
>   1 file changed, 66 insertions(+)

> +/* Field Sk16, shifted right by 2; suitable for conditional jumps */
> +#define R_LOONGARCH_BR_SK16     256
> +/* Field Sd10k16, shifted right by 2; suitable for B and BL */
> +#define R_LOONGARCH_BR_SD10K16  257
> +
> +static bool reloc_br_sk16(tcg_insn_unit *src_rw, const tcg_insn_unit *target)
> +{
> +    const tcg_insn_unit *src_rx = tcg_splitwx_to_rx(src_rw);
> +    intptr_t offset = (intptr_t)target - (intptr_t)src_rx;
> +
> +    tcg_debug_assert((offset & 3) == 0);
> +    offset >>= 2;
> +    if (offset == sextreg(offset, 0, 16)) {
> +        *src_rw |= (offset << 10) & 0x3fffc00;

Alternatively easier to read:

           *src_rw = deposit64(*src_rw , 10, 16, offset);

> +        return true;
> +    }
> +
> +    return false;
> +}