Skip to content

Commit

Permalink
Use pre-clamped LUT for IMA indices
Browse files Browse the repository at this point in the history
  • Loading branch information
@viciious
viciious committed Jul 23, 2023
1 parent 8cad241 commit 91f350a
Showing 1 changed file with 101 additions and 37 deletions.
138 changes: 101 additions & 37 deletions sh2_mixer.s
View file
Original file line number Diff line number Diff line change
Expand Up @@ -253,16 +253,11 @@ mix4_loop:
5:
/* step_index += index_table[nibble] */
mov.l _index_table,r1
mov.b @(r0,r1),r1
add r2,r2 /* index *= 2 */
shll2 r2 /* index *= 4 */
add r2,r0
mov.b @(r0,r1),r2
extu.w r12,r12 /* clear upper word for step_index */
add r1,r2 /* step_index += index_table[nibble] */

/* clamp to 0:88 */
cmp/pz r2
bf/s 6f
mov #88,r1
cmp/gt r1,r2
bt/s 7f
shll16 r2
or r2,r12 /* r12 is step_index : predictor again */

Expand Down Expand Up @@ -326,14 +321,8 @@ mix4_exit:
3:
bra 5b
mov r1,r12 /* clamp sample to 32767 */
6:
bra mix4_gets
mov #0,r2 /* clamp step_index to 0 */
7:
mov #88,r2 /* clamp step_index to 88 */
shll16 r2
bra mix4_gets
or r2,r12 /* r12 is step_index : predictor again */
nop

! void S_PaintChannel4IMA2x(void *channel, int16_t *buffer, int32_t cnt, int32_t scale);
! On entry: r4 = channel pointer
Expand Down Expand Up @@ -447,16 +436,11 @@ mix4_loop2x:
5:
/* step_index += index_table[nibble] */
mov.l _index_table,r1
mov.b @(r0,r1),r1
add r2,r2 /* index *= 2 */
shll2 r2 /* index *= 4 */
add r2,r0
mov.b @(r0,r1),r2
extu.w r12,r12 /* clear upper word for step_index */
add r1,r2 /* step_index += index_table[nibble] */

/* clamp to 0:88 */
cmp/pz r2
bf/s 6f
mov #88,r1
cmp/gt r1,r2
bt/s 7f
shll16 r2
or r2,r12 /* r12 is step_index : predictor again */

Expand Down Expand Up @@ -527,15 +511,8 @@ mix4_exit2x:
3:
bra 5b
mov r1,r12 /* clamp sample to 32767 */
6:
bra mix4_gets2x
mov #0,r2 /* clamp step_index to 0 */
7:
mov #88,r2 /* clamp step_index to 88 */
shll16 r2
bra mix4_gets2x
or r2,r12 /* r12 is step_index : predictor again */

nop

.align 4

Expand All @@ -557,8 +534,95 @@ step_table:
.word 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899
.word 15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794
.word 32767


.global index_table
index_table:
.byte -1, -1, -1, -1, 2, 4, 6, 8
.byte -1, -1, -1, -1, 2, 4, 6, 8

.byte 0, 0, 0, 0, 2, 4, 6, 8
.byte 0, 0, 0, 0, 3, 5, 7, 9
.byte 1, 1, 1, 1, 4, 6, 8, 10
.byte 2, 2, 2, 2, 5, 7, 9, 11
.byte 3, 3, 3, 3, 6, 8, 10, 12
.byte 4, 4, 4, 4, 7, 9, 11, 13
.byte 5, 5, 5, 5, 8, 10, 12, 14
.byte 6, 6, 6, 6, 9, 11, 13, 15
.byte 7, 7, 7, 7, 10, 12, 14, 16
.byte 8, 8, 8, 8, 11, 13, 15, 17
.byte 9, 9, 9, 9, 12, 14, 16, 18
.byte 10, 10, 10, 10, 13, 15, 17, 19
.byte 11, 11, 11, 11, 14, 16, 18, 20
.byte 12, 12, 12, 12, 15, 17, 19, 21
.byte 13, 13, 13, 13, 16, 18, 20, 22
.byte 14, 14, 14, 14, 17, 19, 21, 23
.byte 15, 15, 15, 15, 18, 20, 22, 24
.byte 16, 16, 16, 16, 19, 21, 23, 25
.byte 17, 17, 17, 17, 20, 22, 24, 26
.byte 18, 18, 18, 18, 21, 23, 25, 27
.byte 19, 19, 19, 19, 22, 24, 26, 28
.byte 20, 20, 20, 20, 23, 25, 27, 29
.byte 21, 21, 21, 21, 24, 26, 28, 30
.byte 22, 22, 22, 22, 25, 27, 29, 31
.byte 23, 23, 23, 23, 26, 28, 30, 32
.byte 24, 24, 24, 24, 27, 29, 31, 33
.byte 25, 25, 25, 25, 28, 30, 32, 34
.byte 26, 26, 26, 26, 29, 31, 33, 35
.byte 27, 27, 27, 27, 30, 32, 34, 36
.byte 28, 28, 28, 28, 31, 33, 35, 37
.byte 29, 29, 29, 29, 32, 34, 36, 38
.byte 30, 30, 30, 30, 33, 35, 37, 39
.byte 31, 31, 31, 31, 34, 36, 38, 40
.byte 32, 32, 32, 32, 35, 37, 39, 41
.byte 33, 33, 33, 33, 36, 38, 40, 42
.byte 34, 34, 34, 34, 37, 39, 41, 43
.byte 35, 35, 35, 35, 38, 40, 42, 44
.byte 36, 36, 36, 36, 39, 41, 43, 45
.byte 37, 37, 37, 37, 40, 42, 44, 46
.byte 38, 38, 38, 38, 41, 43, 45, 47
.byte 39, 39, 39, 39, 42, 44, 46, 48
.byte 40, 40, 40, 40, 43, 45, 47, 49
.byte 41, 41, 41, 41, 44, 46, 48, 50
.byte 42, 42, 42, 42, 45, 47, 49, 51
.byte 43, 43, 43, 43, 46, 48, 50, 52
.byte 44, 44, 44, 44, 47, 49, 51, 53
.byte 45, 45, 45, 45, 48, 50, 52, 54
.byte 46, 46, 46, 46, 49, 51, 53, 55
.byte 47, 47, 47, 47, 50, 52, 54, 56
.byte 48, 48, 48, 48, 51, 53, 55, 57
.byte 49, 49, 49, 49, 52, 54, 56, 58
.byte 50, 50, 50, 50, 53, 55, 57, 59
.byte 51, 51, 51, 51, 54, 56, 58, 60
.byte 52, 52, 52, 52, 55, 57, 59, 61
.byte 53, 53, 53, 53, 56, 58, 60, 62
.byte 54, 54, 54, 54, 57, 59, 61, 63
.byte 55, 55, 55, 55, 58, 60, 62, 64
.byte 56, 56, 56, 56, 59, 61, 63, 65
.byte 57, 57, 57, 57, 60, 62, 64, 66
.byte 58, 58, 58, 58, 61, 63, 65, 67
.byte 59, 59, 59, 59, 62, 64, 66, 68
.byte 60, 60, 60, 60, 63, 65, 67, 69
.byte 61, 61, 61, 61, 64, 66, 68, 70
.byte 62, 62, 62, 62, 65, 67, 69, 71
.byte 63, 63, 63, 63, 66, 68, 70, 72
.byte 64, 64, 64, 64, 67, 69, 71, 73
.byte 65, 65, 65, 65, 68, 70, 72, 74
.byte 66, 66, 66, 66, 69, 71, 73, 75
.byte 67, 67, 67, 67, 70, 72, 74, 76
.byte 68, 68, 68, 68, 71, 73, 75, 77
.byte 69, 69, 69, 69, 72, 74, 76, 78
.byte 70, 70, 70, 70, 73, 75, 77, 79
.byte 71, 71, 71, 71, 74, 76, 78, 80
.byte 72, 72, 72, 72, 75, 77, 79, 81
.byte 73, 73, 73, 73, 76, 78, 80, 82
.byte 74, 74, 74, 74, 77, 79, 81, 83
.byte 75, 75, 75, 75, 78, 80, 82, 84
.byte 76, 76, 76, 76, 79, 81, 83, 85
.byte 77, 77, 77, 77, 80, 82, 84, 86
.byte 78, 78, 78, 78, 81, 83, 85, 87
.byte 79, 79, 79, 79, 82, 84, 86, 88
.byte 80, 80, 80, 80, 83, 85, 87, 88
.byte 81, 81, 81, 81, 84, 86, 88, 88
.byte 82, 82, 82, 82, 85, 87, 88, 88
.byte 83, 83, 83, 83, 86, 88, 88, 88
.byte 84, 84, 84, 84, 87, 88, 88, 88
.byte 85, 85, 85, 85, 88, 88, 88, 88
.byte 86, 86, 86, 86, 88, 88, 88, 88
.byte 87, 87, 87, 87, 88, 88, 88, 88

0 comments on commit 91f350a

Please sign in to comment.