[Spice-devel] [PATCH spice-common] quic: Remove some too strict asserts in hot paths

[Frediano Ziglio]

ping

> 
> Some assert in the code are doing some paranoid test and in code
> paths quite hot.
> The encoding time is reduced by 30-50% while the decoding time
> is reduced by a 20-30%.
> 
> Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> ---
>  common/quic.c             | 20 ++++++++++++++------
>  common/quic_family_tmpl.c |  4 +++-
>  2 files changed, 17 insertions(+), 7 deletions(-)
> 
> diff --git a/common/quic.c b/common/quic.c
> index 12e9b0b..c9c9df4 100644
> --- a/common/quic.c
> +++ b/common/quic.c
> @@ -409,8 +409,10 @@ static inline void encode(Encoder *encoder, unsigned int
> word, unsigned int len)
>  {
>      int delta;
>  
> -    spice_assert(len > 0 && len < 32);
> -    spice_assert(!(word & ~bppmask[len]));
> +    if (spice_extra_checks) {
> +        spice_assert(len > 0 && len < 32);
> +        spice_assert(!(word & ~bppmask[len]));
> +    }
>      if ((delta = ((int)encoder->io_available_bits - len)) >= 0) {
>          encoder->io_available_bits = delta;
>          encoder->io_word |= word << encoder->io_available_bits;
> @@ -422,8 +424,10 @@ static inline void encode(Encoder *encoder, unsigned int
> word, unsigned int len)
>      encoder->io_available_bits = 32 - delta;
>      encoder->io_word = word << encoder->io_available_bits;
>  
> -    spice_assert(encoder->io_available_bits < 32);
> -    spice_assert((encoder->io_word & bppmask[encoder->io_available_bits]) ==
> 0);
> +    if (spice_extra_checks) {
> +        spice_assert(encoder->io_available_bits < 32);
> +        spice_assert((encoder->io_word &
> bppmask[encoder->io_available_bits]) == 0);
> +    }
>  }
>  
>  static inline void encode_32(Encoder *encoder, unsigned int word)
> @@ -456,7 +460,9 @@ static inline void read_io_word(Encoder *encoder)
>          __read_io_word_ptr(encoder); //disable inline optimizations
>          return;
>      }
> -    spice_assert(encoder->io_now < encoder->io_end);
> +    if (spice_extra_checks) {
> +        spice_assert(encoder->io_now < encoder->io_end);
> +    }
>      encoder->io_next_word = GUINT32_FROM_LE(*(encoder->io_now++));
>  }
>  
> @@ -464,7 +470,9 @@ static inline void decode_eatbits(Encoder *encoder, int
> len)
>  {
>      int delta;
>  
> -    spice_assert(len > 0 && len < 32);
> +    if (spice_extra_checks) {
> +        spice_assert(len > 0 && len < 32);
> +    }
>      encoder->io_word <<= len;
>  
>      if ((delta = ((int)encoder->io_available_bits - len)) >= 0) {
> diff --git a/common/quic_family_tmpl.c b/common/quic_family_tmpl.c
> index 9450f44..cda15bd 100644
> --- a/common/quic_family_tmpl.c
> +++ b/common/quic_family_tmpl.c
> @@ -105,7 +105,9 @@ static void FNAME(update_model)(CommonState *state,
> s_bucket * const bucket,
>  
>  static s_bucket *FNAME(find_bucket)(Channel *channel, const unsigned int
>  val)
>  {
> -    spice_assert(val < (0x1U << BPC));
> +    if (spice_extra_checks) {
> +        spice_assert(val < (0x1U << BPC));
> +    }
>  
>      return channel->_buckets_ptrs[val];
>  }