HD200 - use line transfers in lcd_grey_data. This gives ~25% speedup.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@26856 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Marcin Bukat 2010-06-15 10:41:43 +00:00
parent 518d3fcc77
commit a316ebe65b

View file

@ -125,16 +125,26 @@ lcd_mono_data:
.type lcd_grey_data,@function
lcd_grey_data:
lea.l (-6*4, %sp), %sp
movem.l %d2-%d5/%a2-%a3, (%sp)
movem.l (6*4+4, %sp), %a0-%a2 /* values, phases, length */
lea.l (-8*4, %sp), %sp
movem.l %d2-%d7/%a2-%a3, (%sp) /* save some registers */
movem.l (8*4+4, %sp), %a0-%a2 /* values, phases, length */
add.l %a2, %a2
lea.l (%a1, %a2.l*4), %a2 /* end address */
lea.l LCD_BASE_ADDRESS+2, %a3 /* LCD data port address */
moveq.l #24, %d4 /* shift count */
move.l #0x204081, %d5 /* bit shuffle factor */
.ph_loop:
moveq.l #12, %d2
add.l %a1, %d2
and.l #0xfffffff0, %d2 /* first line bound */
cmp.l %d2, %a2 /* end address lower than first line bound? */
bhs.s 1f
move.l %a2, %d2 /* -> adjust end address of head loop */
1:
cmp.l %a1, %d2
bls.s .g_head_tail_end
.g_head_tail:
movem.l (%a1), %d0-%d1 /* fetch 8 pixel phases */
move.l %d0, %d2
@ -159,11 +169,71 @@ lcd_grey_data:
addq.l #8, %a1
move.w %d2, (%a3) /* transfer second LCD byte */
cmp.l %a2, %a1
bls.s .ph_loop
movem.l (%sp), %d2-%d5/%a2-%a3
lea.l (6*4, %sp), %sp
.g_head_tail_end:
cmp.l %a1, %a2
bls.w .g_end
lea.l (-8, %a2), %a2
cmp.l %a1, %a2
bls.s .g_line_end
.g_line_loop:
/* loop that utilize line transfers */
movem.l (%a1), %d0-%d3 /* fetch 2 * 8 pixels phases */
move.l %d0, %d6
and.l #0x80808080, %d6 /* %d6 = 0.......1.......2.......3....... */
eor.l %d6, %d0
add.l (%a0)+, %d0 /* add values to first 4 phases */
move.l %d1, %d7
and.l #0x80808080, %d7 /* %d7 = 4.......5.......6.......7....... */
eor.l %d7, %d1
add.l (%a0)+, %d1 /* add values to second 4 phases */
lsr.l #4, %d7 /* %d7 = ....4.......5.......6.......7... */
or.l %d7, %d6 /* %d6 = 0...4...1...5...2...6...3...7... */
mulu.l %d5, %d6 /* %d6 = 01234567123.567.23..67..3...7... */
not.l %d6 /* negate bits */
lsr.l %d4, %d6 /* %d6 = ........................01234567 */
move.w %d6, (%a3) /* transfer first LCD byte */
move.w %d6, (%a3) /* transfer second LCD byte */
move.l %d2, %d6
and.l #0x80808080, %d6 /* %d6 = 0.......1.......2.......3....... */
eor.l %d6, %d2
add.l (%a0)+, %d2 /* add values to first 4 phases */
move.l %d3, %d7
and.l #0x80808080, %d7 /* %d7 = 4.......5.......6.......7....... */
eor.l %d7, %d3
add.l (%a0)+, %d3 /* add values to second 4 phases */
lsr.l #4, %d7 /* %d7 = ....4.......5.......6.......7... */
or.l %d7, %d6 /* %d6 = 0...4...1...5...2...6...3...7... */
mulu.l %d5, %d6 /* %d6 = 01234567123.567.23..67..3...7... */
not.l %d6 /* negate bits */
lsr.l %d4, %d6 /* %d6 = ........................01234567 */
move.w %d6, (%a3) /* transfer first LCD byte */
move.w %d6, (%a3) /* transfer second LCD byte */
movem.l %d0-%d3, (%a1) /* store 2 * 8 new pixel phases */
lea.l (16, %a1), %a1 /* advance pointer */
cmp.l %a2, %a1
bls.s .g_line_loop
.g_line_end:
lea.l (8, %a2), %a2
cmp.l %a1, %a2
bls.s .g_end
bra.w .g_head_tail
.g_end:
movem.l (%sp), %d2-%d7/%a2-%a3
lea.l (8*4, %sp), %sp
rts
.grey_end:
.size lcd_grey_data,.grey_end-lcd_grey_data