[PATCH vkd3d 5/5] vkd3d-shader: Allocate constant buffers.

[Zebediah Figura (she/her)]

On 6/28/21 4:40 AM, Matteo Bruni wrote:
> On Thu, Jun 24, 2021 at 7:15 AM Zebediah Figura <zfigura at codeweavers.com> wrote:
>>
>> Signed-off-by: Zebediah Figura <zfigura at codeweavers.com>
>> ---
>>   libs/vkd3d-shader/hlsl.c                 |  21 +++--
>>   libs/vkd3d-shader/hlsl.h                 |   5 ++
>>   libs/vkd3d-shader/hlsl_codegen.c         | 101 +++++++++++++++++++++++
>>   libs/vkd3d-shader/vkd3d_shader_private.h |   2 +
>>   4 files changed, 121 insertions(+), 8 deletions(-)
> 
>> diff --git a/libs/vkd3d-shader/hlsl_codegen.c b/libs/vkd3d-shader/hlsl_codegen.c
>> index 2768f8ac..6336ddfc 100644
>> --- a/libs/vkd3d-shader/hlsl_codegen.c
>> +++ b/libs/vkd3d-shader/hlsl_codegen.c
>> @@ -1115,6 +1115,105 @@ static void allocate_semantic_registers(struct hlsl_ctx *ctx)
>>       }
>>   }
>>
>> +static const struct hlsl_buffer *get_reserved_buffer(struct hlsl_ctx *ctx, uint32_t index)
>> +{
>> +    const struct hlsl_buffer *buffer;
>> +
>> +    LIST_FOR_EACH_ENTRY(buffer, &ctx->buffers, const struct hlsl_buffer, entry)
>> +    {
>> +        if (buffer->used_size && buffer->reservation.type == 'b' && buffer->reservation.index == index)
>> +            return buffer;
>> +    }
>> +    return NULL;
>> +}
>> +
>> +static void calculate_buffer_offset(struct hlsl_ir_var *var)
>> +{
>> +    struct hlsl_buffer *buffer = var->buffer;
>> +
>> +    buffer->size = hlsl_type_get_sm4_offset(var->data_type, buffer->size);
>> +
>> +    var->buffer_offset = buffer->size;
>> +    TRACE("Allocated buffer offset %u to %s.\n", var->buffer_offset, var->name);
>> +    buffer->size += var->data_type->reg_size;
>> +    if (var->last_read)
>> +        buffer->used_size = buffer->size;
>> +}
>> +
>> +static void allocate_buffers(struct hlsl_ctx *ctx)
>> +{
>> +    struct hlsl_buffer *buffer, *params_buffer;
>> +    struct hlsl_ir_var *var;
>> +    uint32_t index = 0;
>> +
>> +    if (!(params_buffer = hlsl_new_buffer(ctx, HLSL_BUFFER_CONSTANT,
>> +            hlsl_strdup(ctx, "$Params"), NULL, ctx->location)))
>> +        return;
>> +
>> +    /* The $Globals and $Params buffers should be allocated first, before all
>> +     * explicit buffers. */
>> +    list_remove(&params_buffer->entry);
>> +    list_add_head(&ctx->buffers, &params_buffer->entry);
>> +    list_remove(&ctx->globals_buffer->entry);
>> +    list_add_head(&ctx->buffers, &ctx->globals_buffer->entry);
> 
> I find the split in the creation of $Globals and $Params a tiny bit
> annoying. Right now $Globals is created in hlsl_ctx_init() (which also
> means that there should be no need to explicitly put it at the top of
> the buffers list here AFAIU) while $Params is created right here,
> after parsing. If the point is just to make sure that $Params is the
> second buffer in the list, list_add_after() should make it a bit more
> compact and explicit. In theory you could add an assert() if you want
> to make sure that $Globals is at the head of the list, although
> probably it would be even better if both these special buffers were
> created together, in the same place.
> Unless I'm missing something?
> 

I forgot that list_add_after() exists :-/

Anyway, I think the only reason I didn't bother with creating the same 
place is that $Params isn't needed (and in fact can't be used) until 
codegen, and so I'd save a bit of space in hlsl_ctx.