Re: [PATCH 3/5] wined3d: Optimize scanning changed shader constants in wined3d_device_apply_stateblock().

[Matteo Bruni]

On Tue, Feb 11, 2020 at 5:33 PM Henri Verbeet  wrote:
> On Mon, 10 Feb 2020 at 23:06, Matteo Bruni  wrote:
> > +typedef HRESULT (CDECL *wined3d_device_shader_constant_setter)(struct wined3d_device *device,
> > -
> >    unsigned int start_idx, unsigned int count, const void *constants);
> > -
> >
> > +static void device_apply_shader_constants(struct wined3d_device *device,
> > -
> >    const struct wined3d_stateblock_state *state,
> > -
> >    DWORD *bitmap, unsigned int bit_count, const void *data, unsigned int stride,
> > -
> >    wined3d_device_shader_constant_setter shader_constant_setter)
> >
> > +{
> > - const unsigned int word_bit_count = sizeof(DWORD) * CHAR_BIT;
> > - unsigned int i, j, idx, start, last;
> > - const BYTE *byte_data = data;
> > - DWORD map;
> > -
> > - start = last = ~0u;
> > - for (i = 0; i < (bit_count + word_bit_count - 1) / word_bit_count; ++i)
> > - {
> > -
> >    map = bitmap[i];
> > -
> > -
> >    if (map == ~0u)
> > -
> >    {
> > -
> >        if (last != ~0u && last != i * word_bit_count - 1)
> > -
> >        {
> > -
> >            shader_constant_setter(device, start, last - start + 1, &byte_data[start * stride]);
> > -
> >            start = i * word_bit_count;
> > -
> >        }
> > -
> >        if (start == ~0u)
> > -
> >            start = i * word_bit_count;
> > -
> >        last = i * word_bit_count + word_bit_count - 1;
> > -
> >        continue;
> > -
> >    }
> > -
> >    while (map)
> > -
> >    {
> > -
> >        j = wined3d_bit_scan(&map);
> > -
> >        idx = i * word_bit_count + j;
> > -
> > -
> >        if (start == ~0u)
> > -
> >        {
> > -
> >            start = last = idx;
> > -
> >        }
> > -
> >        else if (last != idx - 1)
> > -
> >        {
> > -
> >            shader_constant_setter(device, start, last - start + 1, &byte_data[start * stride]);
> > -
> >            start = last = idx;
> > -
> >        }
> > -
> >        else
> > -
> >        {
> > -
> >            last = idx;
> > -
> >        }
> > -
> >    }
> > - }
> > - if (start != ~0u)
> > -
> >    shader_constant_setter(device, start, last - start + 1, &byte_data[start * stride]);
> >
> > +}
> > -
>
> This looks like it's a fair bit more complicated than it needs to be.
> I think the primitives you want are something like the following:
> unsigned int wined3d_bitmap_ffs(uint32_t *bitmap, unsigned int
>
> start, unsigned int count);
>     unsigned int wined3d_bitmap_ffz(uint32_t *bitmap, unsigned int
> start, unsigned int count);
>
> and then you can extract the ranges relatively trivially.

Oh, interesting. I'll update the patch along those lines and see what
the end result looks like.