Re: [Qemu-devel] [PATCH 1/2] cutils: remove one unnecessary pointer operation

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Wei Yang (richardw.yang@linux.intel.com) wrote:
> Since we will not operate on the next address pointed by out, it is not
> necessary to do addition on it.
> 
> After removing the operation, the function size reduced 16/18 bytes.

For me with a -O3 it didn't make any difference - the compiler was
already smart enough to spot it, but it is correct.


Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
> ---
>  util/cutils.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/util/cutils.c b/util/cutils.c
> index 9aacc422ca..1933a68da5 100644
> --- a/util/cutils.c
> +++ b/util/cutils.c
> @@ -754,11 +754,11 @@ int uleb128_encode_small(uint8_t *out, uint32_t n)
>  {
>      g_assert(n <= 0x3fff);
>      if (n < 0x80) {
> -        *out++ = n;
> +        *out = n;
>          return 1;
>      } else {
>          *out++ = (n & 0x7f) | 0x80;
> -        *out++ = n >> 7;
> +        *out = n >> 7;
>          return 2;
>      }
>  }
> @@ -766,7 +766,7 @@ int uleb128_encode_small(uint8_t *out, uint32_t n)
>  int uleb128_decode_small(const uint8_t *in, uint32_t *n)
>  {
>      if (!(*in & 0x80)) {
> -        *n = *in++;
> +        *n = *in;
>          return 1;
>      } else {
>          *n = *in++ & 0x7f;
> @@ -774,7 +774,7 @@ int uleb128_decode_small(const uint8_t *in, uint32_t *n)
>          if (*in & 0x80) {
>              return -1;
>          }
> -        *n |= *in++ << 7;
> +        *n |= *in << 7;
>          return 2;
>      }
>  }
> -- 
> 2.19.1
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK