Smaller & faster grey blitting on greyscale ipods, based on an idea by Mike Sevakis. ISR speedup on all greyscale iPods except Mini 2nd Gen is ~10%. No speedup on the latter, because the serial transfer is the limiting factor.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@26422 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Jens Arnold 2010-05-30 22:24:50 +00:00
parent 839057733f
commit 7a1aca46a3

View file

@ -201,8 +201,8 @@ lcd_mono_data:
*
* Register usage:
* r3/r4 - current block of phases
* r5/r6 - current block of values
* r7 - lcd data accumulator
* r5/r6 - lcd data accumulators
* r6/r7 - current block of values
* r12 - phase signs mask
* lr - lcd bridge address
*/
@ -216,63 +216,52 @@ lcd_grey_data:
.greyloop:
ldmia r1, {r3-r4} /* Fetch 8 pixel phases */
ldmia r0!, {r5-r6} /* Fetch 8 pixel values */
#ifdef IPOD_MINI2G /* Serial bridge mode */
mov r7, #0x760000
tst r3, #0x80
orreq r7, r7, #0xc000
tst r3, #0x8000
orreq r7, r7, #0x3000
tst r3, #0x800000
orreq r7, r7, #0x0c00
tst r3, #0x80000000
orreq r7, r7, #0x0300
bic r5, r12, r3 /* r5 = 0.......1.......2.......3....... */
orr r5, r5, r5, lsr #10 /* r5 = 0.......1.0.....2.1.....3.2..... */
orr r5, r5, r5, lsr #10 /* r5 = 0.......1.0.....2.1.0...3.2.1... */
orr r5, r5, r5, lsr #10 /* r5 = 0.......1.0.....2.1.0...3.2.1.0. */
orr r5, r5, r5, lsr #1 /* r5 = 00......1100....221100..33221100 */
bic r3, r3, r12
add r3, r3, r5
#else /* Parallel bridge mode */
mov r7, #0
tst r3, #0x80
orreq r7, r7, #0xc0
tst r3, #0x8000
orreq r7, r7, #0x30
tst r3, #0x800000
orreq r7, r7, #0x0c
tst r3, #0x80000000
orreq r7, r7, #0x03
bic r3, r3, r12
add r3, r3, r5
#ifndef IPOD_MINI2G /* 8 bit parallel bridge mode */
1:
ldr r5, [lr]
tst r5, #LCD1_BUSY_MASK
ldr r6, [lr]
tst r6, #LCD1_BUSY_MASK
bne 1b
str r7, [lr, #0x10]
mov r7, #0
str r5, [lr, #0x10]
#endif
tst r4, #0x80
orreq r7, r7, #0xc0
tst r4, #0x8000
orreq r7, r7, #0x30
tst r4, #0x800000
orreq r7, r7, #0x0c
tst r4, #0x80000000
orreq r7, r7, #0x03
bic r4, r4, r12
add r4, r4, r6
ldmia r0!, {r6-r7} /* Fetch 8 pixel values */
add r3, r3, r6
bic r6, r12, r4 /* r6 = 4.......5.......6.......7....... */
orr r6, r6, r6, lsr #10 /* r6 = 4.......5.4.....6.5.....7.6..... */
orr r6, r6, r6, lsr #10 /* r6 = 4.......5.4.....6.5.4...7.6.5... */
orr r6, r6, r6, lsr #10 /* r6 = 4.......5.4.....6.5.4...7.6.5.4. */
orr r6, r6, r6, lsr #1 /* r6 = 44......5544....665544..77665544 */
bic r4, r4, r12
add r4, r4, r7
stmia r1!, {r3-r4}
#ifdef IPOD_MINI2G /* 16 bit serial bridge mode */
and r5, r5, #0xff /* r5 = ........................33221100 */
and r6, r6, #0xff /* r6 = ........................77665544 */
orr r5, r5, r6, lsl #8 /* r5 = ................7766554433221100 */
orr r5, r5, #0x760000 /* data marker */
#endif
1:
ldr r5, [lr]
tst r5, #LCD1_BUSY_MASK
ldr r7, [lr]
tst r7, #LCD1_BUSY_MASK
bne 1b
#ifdef IPOD_MINI2G
str r7, [lr, #0x08]
str r5, [lr, #0x08]
#else
str r7, [lr, #0x10]
str r6, [lr, #0x10]
#endif
subs r2, r2, #1