[PATCH vkd3d 1/5] vkd3d-shader/hlsl: Allocate textures for SM4.

[Matteo Bruni]

On Tue, Oct 12, 2021 at 4:59 AM Zebediah Figura <zfigura at codeweavers.com> wrote:
>
> Signed-off-by: Zebediah Figura <zfigura at codeweavers.com>
> ---
>  libs/vkd3d-shader/hlsl_codegen.c | 63 ++++++++++++++++++++++++++++++++
>  1 file changed, 63 insertions(+)
>
> diff --git a/libs/vkd3d-shader/hlsl_codegen.c b/libs/vkd3d-shader/hlsl_codegen.c
> index 00fe76b2f..bf93a03df 100644
> --- a/libs/vkd3d-shader/hlsl_codegen.c
> +++ b/libs/vkd3d-shader/hlsl_codegen.c
> @@ -1197,6 +1197,64 @@ static void allocate_buffers(struct hlsl_ctx *ctx)
>      }
>  }
>
> +static const struct hlsl_ir_var *get_reserved_texture(struct hlsl_ctx *ctx, uint32_t index)
> +{
> +    const struct hlsl_ir_var *var;
> +
> +    LIST_FOR_EACH_ENTRY(var, &ctx->extern_vars, const struct hlsl_ir_var, extern_entry)
> +    {
> +        if (var->has_resource_access && var->reg_reservation.type == 't' && var->reg_reservation.index == index)
> +            return var;
> +    }
> +    return NULL;
> +}
> +
> +static void allocate_textures(struct hlsl_ctx *ctx)
> +{
> +    struct hlsl_ir_var *var;
> +    uint32_t index = 0;
> +
> +    LIST_FOR_EACH_ENTRY(var, &ctx->extern_vars, struct hlsl_ir_var, extern_entry)
> +    {
> +        if (!var->has_resource_access || var->data_type->type != HLSL_CLASS_OBJECT
> +                || var->data_type->base_type != HLSL_TYPE_TEXTURE)
> +            continue;
> +
> +        if (var->reg_reservation.type == 't')
> +        {
> +            const struct hlsl_ir_var *reserved_texture = get_reserved_texture(ctx, var->reg_reservation.index);
> +
> +            if (reserved_texture && reserved_texture != var)
> +            {
> +                hlsl_error(ctx, var->loc, VKD3D_SHADER_ERROR_HLSL_OVERLAPPING_RESERVATIONS,
> +                        "Multiple textures bound to t%u.", var->reg_reservation.index);
> +                hlsl_note(ctx, reserved_texture->loc, VKD3D_SHADER_LOG_ERROR,
> +                        "Texture '%s' is already bound to t%u.", reserved_texture->name,
> +                        var->reg_reservation.index);
> +            }
> +
> +            var->reg.id = var->reg_reservation.index;
> +            var->reg.allocated = true;
> +            TRACE("Allocated reserved %s to t%u.\n", var->name, index);
> +        }
> +        else if (!var->reg_reservation.type)
> +        {
> +            while (get_reserved_texture(ctx, index))
> +                ++index;
> +
> +            var->reg.id = index;
> +            var->reg.allocated = true;
> +            TRACE("Allocated %s to t%u.\n", var->name, index);
> +            ++index;
> +        }
> +        else
> +        {
> +            hlsl_error(ctx, var->loc, VKD3D_SHADER_ERROR_HLSL_INVALID_RESERVATION,
> +                    "Textures must be bound to register type 't'.");
> +        }
> +    }
> +}

The reservation lookup seems... suboptimal. It's not new (it's
basically the same as what we do for buffers already) and probably
there won't be that many extern variables in the usual cases, so maybe
this is not going to be an issue in practice. It does kind of raise a
red flag for me though...
I guess let's keep this in mind if we ever happen to encounter
performance issues.