Re: [PATCH] tcg: Fix do_nonatomic_op_* vs signed operations

[LIU Zhiwei]

On 2020/7/2 0:56, Richard Henderson wrote:
> The smin/smax/umin/umax operations require the operands to be
> properly sign extended.  Do not drop the MO_SIGN bit from the
> load, and additionally extend the val input.
>
> Reported-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   tcg/tcg-op.c | 10 ++++++----
>   1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c
> index e60b74fb82..4b8a473fad 100644
> --- a/tcg/tcg-op.c
> +++ b/tcg/tcg-op.c
> @@ -3189,8 +3189,9 @@ static void do_nonatomic_op_i32(TCGv_i32 ret, TCGv addr, 
> TCGv_i32 val,
>   
>       memop = tcg_canonicalize_memop(memop, 0, 0);
>   
> -    tcg_gen_qemu_ld_i32(t1, addr, idx, memop & ~MO_SIGN);
> -    gen(t2, t1, val);
> +    tcg_gen_qemu_ld_i32(t1, addr, idx, memop);
> +    tcg_gen_ext_i32(t2, val, memop);
> +    gen(t2, t1, t2);
>       tcg_gen_qemu_st_i32(t2, addr, idx, memop);
>   
>       tcg_gen_ext_i32(ret, (new_val ? t2 : t1), memop);
> @@ -3232,8 +3233,9 @@ static void do_nonatomic_op_i64(TCGv_i64 ret, TCGv addr, 
> TCGv_i64 val,
>   
>       memop = tcg_canonicalize_memop(memop, 1, 0);
>   
> -    tcg_gen_qemu_ld_i64(t1, addr, idx, memop & ~MO_SIGN);
> -    gen(t2, t1, val);
> +    tcg_gen_qemu_ld_i64(t1, addr, idx, memop);
> +    tcg_gen_ext_i64(t2, val, memop);
> +    gen(t2, t1, t2);
>       tcg_gen_qemu_st_i64(t2, addr, idx, memop);
>   
>       tcg_gen_ext_i64(ret, (new_val ? t2 : t1), memop);

Reviewed-by: LIU Zhiwei <zhiwei_liu@c-sky.com>

Zhiwei