On Sat, 6 Jun 2020 at 20:22, BALATON Zoltan <bala...@eik.bme.hu> wrote:
>
> Some guests do 1x1 blits which is faster to do directly than calling a
> function for it so avoid overhead in this case.
How much does the performance improve by ?
> Signed-off-by: BALATON Zoltan <bala...@eik.bme.hu>
> ---
> hw/display/sm501.c | 40 +++++++++++++++++++++++++++++++++++++---
> 1 file changed, 37 insertions(+), 3 deletions(-)
>
> diff --git a/hw/display/sm501.c b/hw/display/sm501.c
> index 3397ca9fbf..59693fbb5c 100644
> --- a/hw/display/sm501.c
> +++ b/hw/display/sm501.c
> @@ -793,6 +793,25 @@ static void sm501_2d_operation(SM501State *s)
> src_x == dst_x && src_y == dst_y) {
> break;
> }
> + /* Some clients also do 1 pixel blits, avoid overhead for these
> */
> + if (width == 1 && height == 1) {
> + unsigned int si = (src_x + src_y * src_pitch) * (1 <<
> format);
> + unsigned int di = (dst_x + dst_y * dst_pitch) * (1 <<
> format);
> + switch (format) {
> + case 0:
> + s->local_mem[dst_base + di] = s->local_mem[src_base +
> si];
> + break;
> + case 1:
> + *(uint16_t *)&s->local_mem[dst_base + di] =
> + *(uint16_t *)&s->local_mem[src_base +
> si];
> + break;
> + case 2:
> + *(uint32_t *)&s->local_mem[dst_base + di] =
> + *(uint32_t *)&s->local_mem[src_base +
> si];
> + break;
> + }
You could write this more compactly as
stn_he_p(&s->local_mem[dst_base + di], 1 << format,
ldn_he_p(&s->local_mem[src_base + si], 1
<< format));
(which handles the length-cases for you and also doesn't rely on
casting a uint8_t* giving you something correctly aligned for a
wider access).
> + break;
> + }
> /* Check for overlaps, this could be made more exact */
> uint32_t sb, se, db, de;
> sb = src_base + src_x + src_y * (width + src_pitch);
> @@ -841,9 +860,24 @@ static void sm501_2d_operation(SM501State *s)
> color = cpu_to_le16(color);
> }
>
> - pixman_fill((uint32_t *)&s->local_mem[dst_base],
> - dst_pitch * (1 << format) / sizeof(uint32_t),
> - 8 * (1 << format), dst_x, dst_y, width, height, color);
> + if (width == 1 && height == 1) {
> + unsigned int i = (dst_x + dst_y * dst_pitch) * (1 << format);
> + switch (format) {
> + case 0:
> + s->local_mem[dst_base + i] = color & 0xff;
> + break;
> + case 1:
> + *(uint16_t *)&s->local_mem[dst_base + i] = color & 0xffff;
> + break;
> + case 2:
> + *(uint32_t *)&s->local_mem[dst_base + i] = color;
> + break;
> + }
stn_he_p(&s->local_mem[dst_base + i], 1 << format, color);
> + } else {
> + pixman_fill((uint32_t *)&s->local_mem[dst_base],
> + dst_pitch * (1 << format) / sizeof(uint32_t),
> + 8 * (1 << format), dst_x, dst_y, width, height,
> color);
> + }
> break;
> }
> default:
thanks
-- PMM
