Re: [PATCH v6 26/30] tcg/loongarch64: Implement tcg_target_init

[Philippe Mathieu-Daudé]

On 9/25/21 19:30, 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 | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)

> +static void tcg_target_init(TCGContext *s)
> +{
> +    tcg_target_available_regs[TCG_TYPE_I32] = ALL_GENERAL_REGS;
> +    tcg_target_available_regs[TCG_TYPE_I64] = ALL_GENERAL_REGS;
> +
> +    tcg_target_call_clobber_regs = ALL_GENERAL_REGS;

If you plan to add support for vector registers later, I think it is
safer to start today with:

       tcg_target_call_clobber_regs = -1ull;

> +    tcg_regset_reset_reg(tcg_target_call_clobber_regs, TCG_REG_S0);
> +    tcg_regset_reset_reg(tcg_target_call_clobber_regs, TCG_REG_S1);
> +    tcg_regset_reset_reg(tcg_target_call_clobber_regs, TCG_REG_S2);
> +    tcg_regset_reset_reg(tcg_target_call_clobber_regs, TCG_REG_S3);
> +    tcg_regset_reset_reg(tcg_target_call_clobber_regs, TCG_REG_S4);
> +    tcg_regset_reset_reg(tcg_target_call_clobber_regs, TCG_REG_S5);
> +    tcg_regset_reset_reg(tcg_target_call_clobber_regs, TCG_REG_S6);
> +    tcg_regset_reset_reg(tcg_target_call_clobber_regs, TCG_REG_S7);
> +    tcg_regset_reset_reg(tcg_target_call_clobber_regs, TCG_REG_S8);
> +    tcg_regset_reset_reg(tcg_target_call_clobber_regs, TCG_REG_S9);
> +
> +    s->reserved_regs = 0;
> +    tcg_regset_set_reg(s->reserved_regs, TCG_REG_ZERO);
> +    tcg_regset_set_reg(s->reserved_regs, TCG_REG_TMP0);
> +    tcg_regset_set_reg(s->reserved_regs, TCG_REG_TMP1);
> +    tcg_regset_set_reg(s->reserved_regs, TCG_REG_TMP2);
> +    tcg_regset_set_reg(s->reserved_regs, TCG_REG_SP);
> +    tcg_regset_set_reg(s->reserved_regs, TCG_REG_TP);
> +    tcg_regset_set_reg(s->reserved_regs, TCG_REG_RESERVED);
> +}
> 

Conditional on using -1 to initialize:
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>