Re: [Qemu-devel] [PATCH v13 11/12] qemu/bitops.h: Add extract8 and extract16

[Philippe Mathieu-Daudé]

On 5/16/19 7:52 AM, Yoshinori Sato wrote:
> Signed-off-by: Yoshinori Sato <address@hidden>
> Reviewed-by: Richard Henderson <address@hidden>
> ---
>  include/qemu/bitops.h | 38 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 38 insertions(+)
> 
> diff --git a/include/qemu/bitops.h b/include/qemu/bitops.h
> index 3f0926cf40..764f9d1ea0 100644
> --- a/include/qemu/bitops.h
> +++ b/include/qemu/bitops.h
> @@ -301,6 +301,44 @@ static inline uint32_t extract32(uint32_t value, int 
> start, int length)
>  }
>  
>  /**
> + * extract8:
> + * @value: the value to extract the bit field from
> + * @start: the lowest bit in the bit field (numbered from 0)
> + * @length: the length of the bit field
> + *
> + * Extract from the 8 bit input @value the bit field specified by the
> + * @start and @length parameters, and return it. The bit field must
> + * lie entirely within the 8 bit word. It is valid to request that
> + * all 8 bits are returned (ie @length 8 and @start 0).
> + *
> + * Returns: the value of the bit field extracted from the input value.
> + */
> +static inline uint8_t extract8(uint8_t value, int start, int length)
> +{
> +    assert(start >= 0 && length > 0 && length <= 8 - start);
> +    return extract32(value, start, length);
> +}
> +
> +/**
> + * extract16:
> + * @value: the value to extract the bit field from
> + * @start: the lowest bit in the bit field (numbered from 0)
> + * @length: the length of the bit field
> + *
> + * Extract from the 16 bit input @value the bit field specified by the
> + * @start and @length parameters, and return it. The bit field must
> + * lie entirely within the 16 bit word. It is valid to request that
> + * all 16 bits are returned (ie @length 16 and @start 0).
> + *
> + * Returns: the value of the bit field extracted from the input value.
> + */
> +static inline uint16_t extract16(uint16_t value, int start, int length)
> +{
> +    assert(start >= 0 && length > 0 && length <= 16 - start);
> +    return extract32(value, start, length);
> +}
> +
> +/**
>   * extract64:
>   * @value: the value to extract the bit field from
>   * @start: the lowest bit in the bit field (numbered from 0)
> 

Reviewed-by: Philippe Mathieu-Daudé <address@hidden>