Re: [PATCH v3 0/1] MR3546: gdiplus: move pointer calculation outside inner loop for alpha_blend_bmp_pixels

[Nikolay Sivov (＠nsivov)]

On Fri Aug 11 08:34:38 2023 +0000, Bartosz Kosiorek wrote:
> In previous implementation we calculated `src_color` position every time
> (in `for (x` loop):
>         for (x=0; x<src_width; x++)
>         {
>             ARGB dst_color, src_color;
>             src_color = ((ARGB*)(src + src_stride * y))[x];
>
> With new implementation we are calculating `src_color` position only
> once (outside `x` loop), and we just iterating the `src_color++`:
>         ARGB *src_color = ((ARGB*)(src + src_stride * y));
>         for (x=0; x<src_width; x++)
>         {
> ...
>             src_color++;
>         }
>
> It is faster (avoiding not needed multiplications), especially for wide images.

I asked because usually claiming something is faster also needs some performance numbers.