Re: [PATCH] Simplify the implementation of ios_mask functions.

[Egeyar Bagcioglu]

Hi John!

It looks good to me. Thanks! The patch will still need to be reviewer by 
a global reviewer though.

Regards
Egeyar


On 12/21/19 6:16 PM, John Darrington wrote:
> ---
>   ChangeLog |  5 +++++
>   src/ios.c | 72 +++++++++------------------------------------------------------
>   2 files changed, 15 insertions(+), 62 deletions(-)
>
> diff --git a/ChangeLog b/ChangeLog
> index 6640c2b..7fd81a1 100644
> --- a/ChangeLog
> +++ b/ChangeLog
> @@ -5,6 +5,11 @@
>         * src/pk-cmd.c (pk_cmd_exec_1): fix memory leak of filename
>         * src/pk-cmd.c (null_cmd): properly initialize struct
>   
> +2019-12-15 John Darrington <address@hidden>
> +
> +       *src/ios.c (ios_mask_last_byte) simplify
> +       *src/ios.c (ios_mask_first_byte) simplify
> +
>   2019-12-16  Jose E. Marchesi  <address@hidden>
>   
>   	* src/pkl-asm.pks (atrim): The mka instruction expects the type of
> diff --git a/src/ios.c b/src/ios.c
> index a96e349..757ada3 100644
> --- a/src/ios.c
> +++ b/src/ios.c
> @@ -23,6 +23,7 @@
>   #include <unistd.h>
>   #include <stdio.h>
>   #include <assert.h>
> +#include <limits.h>
>   #define _(str) gettext (str)
>   #include <streq.h>
>   
> @@ -310,72 +311,19 @@ ios_map (ios_map_fn cb, void *data)
>       (*cb) (io, data);
>   }
>   
> -inline static void
> -ios_mask_first_byte(uint64_t *byte, int significant_bits)
> +/* Set all except the lowest SIGNIFICANT_BITS of VALUE to zero.  */
> +static inline void
> +ios_mask_first_byte (uint64_t *value, int significant_bits)
>   {
> -  switch (significant_bits)
> -    {
> -    case 1:
> -      *byte &= (char) 0x01;
> -      return;
> -    case 2:
> -      *byte &= (char) 0x03;
> -      return;
> -    case 3:
> -      *byte &= (char) 0x07;
> -      return;
> -    case 4:
> -      *byte &= (char) 0x0f;
> -      return;
> -    case 5:
> -      *byte &= (char) 0x1f;
> -      return;
> -    case 6:
> -      *byte &= (char) 0x3f;
> -      return;
> -    case 7:
> -      *byte &= (char) 0x7f;
> -      return;
> -    case 8:
> -      return;
> -    default:
> -      assert (0);
> -      return;
> -    }
> +  *value &= 0xFFU >> (CHAR_BIT - significant_bits);
>   }
>   
> -inline static void
> -ios_mask_last_byte(uint64_t *byte, int significant_bits)
> +/* Set all except the highest SIGNIFICANT_BITS of the lowest
> +   significant byte of VALUE to zero.  */
> +static inline void
> +ios_mask_last_byte (uint64_t *value, int significant_bits)
>   {
> -  switch (significant_bits)
> -    {
> -    case 1:
> -      *byte &= (char) 0x80;
> -      return;
> -    case 2:
> -      *byte &= (char) 0xc0;
> -      return;
> -    case 3:
> -      *byte &= (char) 0xe0;
> -      return;
> -    case 4:
> -      *byte &= (char) 0xf0;
> -      return;
> -    case 5:
> -      *byte &= (char) 0xf8;
> -      return;
> -    case 6:
> -      *byte &= (char) 0xfc;
> -      return;
> -    case 7:
> -      *byte &= (char) 0xfe;
> -      return;
> -    case 8:
> -      return;
> -    default:
> -      assert (0);
> -      return;
> -    }
> +  *value &= 0xFFU << (CHAR_BIT - significant_bits);
>   }
>   
>   static inline int