[PATCH 2/4] EXA/evergreen/ni: optimize non-overlapping Copy

[Michel Dänzer]

On Mon, 2013-07-22 at 06:06 +0200, Grigori Goronzy wrote:
> In case dst and src rectangles of a Copy operation in the same surface
> don't overlap, it is safe to skip the scratch surface. This is a
> common case.
> ---
>  src/evergreen_exa.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/src/evergreen_exa.c b/src/evergreen_exa.c
> index 86f455d..2cdce0f 100644
> --- a/src/evergreen_exa.c
> +++ b/src/evergreen_exa.c
> @@ -575,7 +575,12 @@ EVERGREENCopy(PixmapPtr pDst,
>      if (accel_state->vsync)
>  	RADEONVlineHelperSet(pScrn, dstX, dstY, dstX + w, dstY + h);
>  
> -    if (accel_state->same_surface && accel_state->copy_area) {
> +    if (accel_state->same_surface &&
> +	    (srcX + w <= dstX || dstX + w <= srcX || srcY + h <= dstY || dstY + h <= srcY)) {
> +	EVERGREENDoPrepareCopy(pScrn);
> +	EVERGREENAppendCopyVertex(pScrn, srcX, srcY, dstX, dstY, w, h);
> +	EVERGREENDoCopyVline(pDst);
> +    } else if (accel_state->same_surface && accel_state->copy_area) {
>  	uint32_t orig_dst_domain = accel_state->dst_obj.domain;
>  	uint32_t orig_src_domain = accel_state->src_obj[0].domain;
>  	uint32_t orig_src_tiling_flags = accel_state->src_obj[0].tiling_flags;

This looks a bit weird. EVERGREENCopy() may be called any number of
times between calls to EVERGREENPrepareCopy() and EVERGREENDoneCopy(),
and the source and destination rectangles may or may not overlap for
each call. Does this change handle arbitrary transitions between the
overlapping and non-overlapping case correctly?

Also, I think you might get even more gains by not allocating a
temporary BO at all when none of the rectangles overlap.


-- 
Earthling Michel Dänzer           |                   http://www.amd.com
Libre software enthusiast         |          Debian, X and DRI developer