[Mesa-dev] [PATCH 01/12] intel: Conditionally compile mcs-related code for i965 only.

[Ian Romanick]

On 05/21/2013 04:52 PM, Paul Berry wrote:
> This patch ifdefs out intel_mipmap_tree::mcs_mt when building the i915
> (pre-Gen4) driver (MCS buffers aren't supported until Gen7, so there
> is no need for this field in the i915 driver).  This should make it a
> bit easier to implement fast color clears without undue risk to i915.

We have a bunch of other fields like this (e.g., hiz_mt).  Should we 
have done this with those fields, or is this case different?

> ---
>   src/mesa/drivers/dri/intel/intel_mipmap_tree.c | 8 +++++++-
>   src/mesa/drivers/dri/intel/intel_mipmap_tree.h | 2 ++
>   2 files changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/src/mesa/drivers/dri/intel/intel_mipmap_tree.c b/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
> index 2dfa787..ad9e2b3 100644
> --- a/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
> +++ b/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
> @@ -624,7 +624,9 @@ intel_miptree_release(struct intel_mipmap_tree **mt)
>         intel_region_release(&((*mt)->region));
>         intel_miptree_release(&(*mt)->stencil_mt);
>         intel_miptree_release(&(*mt)->hiz_mt);
> +#ifndef I915
>         intel_miptree_release(&(*mt)->mcs_mt);
> +#endif
>         intel_miptree_release(&(*mt)->singlesample_mt);
>         intel_resolve_map_clear(&(*mt)->hiz_map);
>
> @@ -963,8 +965,11 @@ intel_miptree_alloc_mcs(struct intel_context *intel,
>                           struct intel_mipmap_tree *mt,
>                           GLuint num_samples)
>   {
> -   assert(mt->mcs_mt == NULL);
>      assert(intel->gen >= 7); /* MCS only used on Gen7+ */
> +#ifdef I915
> +   return false;

       return NULL;

since this function returns 'struct intel_mipmap_tree*'.

> +#else
> +   assert(mt->mcs_mt == NULL);
>
>      /* Choose the correct format for the MCS buffer.  All that really matters
>       * is that we allocate the right buffer size, since we'll always be
> @@ -1021,6 +1026,7 @@ intel_miptree_alloc_mcs(struct intel_context *intel,
>      intel_miptree_unmap_raw(intel, mt->mcs_mt);
>
>      return mt->mcs_mt;
> +#endif
>   }
>
>   /**
> diff --git a/src/mesa/drivers/dri/intel/intel_mipmap_tree.h b/src/mesa/drivers/dri/intel/intel_mipmap_tree.h
> index b7376e0..0ec3c5e 100644
> --- a/src/mesa/drivers/dri/intel/intel_mipmap_tree.h
> +++ b/src/mesa/drivers/dri/intel/intel_mipmap_tree.h
> @@ -373,6 +373,7 @@ struct intel_mipmap_tree
>       */
>      struct intel_mipmap_tree *stencil_mt;
>
> +#ifndef I915
>      /**
>       * \brief MCS miptree for multisampled textures.
>       *
> @@ -381,6 +382,7 @@ struct intel_mipmap_tree
>       * (INTEL_MSAA_FORMAT_CMS).
>       */
>      struct intel_mipmap_tree *mcs_mt;
> +#endif
>
>      /* These are also refcounted:
>       */
>