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authorBALATON Zoltan <balaton@eik.bme.hu>2020-06-24 18:42:18 +0200
committerGerd Hoffmann <kraxel@redhat.com>2020-06-30 22:50:04 +0200
commit9982c605a71bffd4c52c111b5c79e2060953a762 (patch)
tree73ef2a7b035df327d229b5b593da1dcfc1898824 /hw/display
parentd8327a68694e49d7d125b5dbe4eeaaf9695cbb73 (diff)
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sm501: Fix and optimize overlap check
When doing reverse blit we need to check if source and dest overlap but it is not trivial due to possible different base and pitch of source and dest. Do rectangle overlap if base and pitch match, otherwise just check if memory area containing the rects overlaps so rects could possibly overlap. Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu> Message-Id: <20200624164737.A941374633D@zero.eik.bme.hu> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Diffstat (limited to 'hw/display')
-rw-r--r--hw/display/sm501.c26
1 files changed, 16 insertions, 10 deletions
diff --git a/hw/display/sm501.c b/hw/display/sm501.c
index 2db347d..9cccc68 100644
--- a/hw/display/sm501.c
+++ b/hw/display/sm501.c
@@ -690,6 +690,7 @@ static void sm501_2d_operation(SM501State *s)
unsigned int dst_pitch = (s->twoD_pitch >> 16) & 0x1FFF;
int crt = (s->dc_crt_control & SM501_DC_CRT_CONTROL_SEL) ? 1 : 0;
int fb_len = get_width(s, crt) * get_height(s, crt) * get_bpp(s, crt);
+ bool overlap = false;
if ((s->twoD_stretch >> 16) & 0xF) {
qemu_log_mask(LOG_UNIMP, "sm501: only XY addressing is supported.\n");
@@ -784,16 +785,21 @@ static void sm501_2d_operation(SM501State *s)
ldn_he_p(&s->local_mem[src_base + si], bypp));
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);
- se = sb + width + height * (width + src_pitch);
- db = dst_base + dst_x + dst_y * (width + dst_pitch);
- de = db + width + height * (width + dst_pitch);
- if (rtl && ((db >= sb && db <= se) || (de >= sb && de <= se))) {
- /* regions may overlap: copy via temporary */
- int llb = width * bypp;
- int tmp_stride = DIV_ROUND_UP(llb, sizeof(uint32_t));
+ /* If reverse blit do simple check for overlaps */
+ if (rtl && src_base == dst_base && src_pitch == dst_pitch) {
+ overlap = (src_x < dst_x + width && src_x + width > dst_x &&
+ src_y < dst_y + height && src_y + height > dst_y);
+ } else if (rtl) {
+ unsigned int sb, se, db, de;
+ sb = src_base + (src_x + src_y * src_pitch) * bypp;
+ se = sb + (width + (height - 1) * src_pitch) * bypp;
+ db = dst_base + (dst_x + dst_y * dst_pitch) * bypp;
+ de = db + (width + (height - 1) * dst_pitch) * bypp;
+ overlap = (db < se && sb < de);
+ }
+ if (overlap) {
+ /* pixman can't do reverse blit: copy via temporary */
+ int tmp_stride = DIV_ROUND_UP(width * bypp, sizeof(uint32_t));
uint32_t *tmp = tmp_buf;
if (tmp_stride * sizeof(uint32_t) * height > sizeof(tmp_buf)) {