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Optimization part 2 (-~4000 on first frame)
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@ADM228
ADM228 committed Jan 9, 2024
1 parent fcd00c2 commit edc3ea9
Showing 1 changed file with 74 additions and 54 deletions.
128 changes: 74 additions & 54 deletions source/sound/SNESFM.asm
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Original file line number Diff line number Diff line change
Expand Up @@ -156,8 +156,9 @@ Documentation:
; $A | | | | Data transfer finished
; $F | | | | What?
; Sound engine documentation:
; Channel flags: n00afoir
; Channel flags: n0Iafoir
; n - sample number (0 or 1)
; I - whether it is the first frame of an instrument (stops from parsing instrument data on that frame)
; a - whether to disable the attack
; f - whether to reset the instrument
; o - in real channels: whether the channel is overridden by a virtual channel
Expand Down Expand Up @@ -201,11 +202,9 @@ InternalDefines:
CH1_PITCHBEND_POINTER = $08C4
CH1_COUNTERS_DIRECTION = $08C7
;Pointers for temporary <-> permanent storage transfers
CHTEMP_POINTER_0 = $20
CHTEMP_POINTER_2 = $30
CHTEMP_POINTER_3 = $38

CH1_POINTER_0 = $0800
CH1_POINTER_2 = $0880
CH1_POINTER_3 = $08C0

Expand Down Expand Up @@ -263,12 +262,7 @@ InternalDefines:

CHTEMP_SONG_POINTER_L = $20
CHTEMP_SONG_POINTER_H = $21
CHTEMP_REF0_POINTER_L = $22
CHTEMP_REF0_POINTER_H = $23
CHTEMP_INSTRUMENT_INDEX = $24
CHTEMP_INSTRUMENT_TYPE = $25
CHTEMP_SAMPLE_POINTER_L = $26
CHTEMP_SAMPLE_POINTER_H = $27
CHTEMP_INSTRUMENT_TYPE = $25

;$2B and $2C will be used by pitchbend
CHTEMP_FLAGS = $2F
Expand Down Expand Up @@ -935,6 +929,7 @@ namespace ParseSongData
Start:
ReadByte:
MOV Y, #$00
Y00ReadByte: ; Use if Y and X not modified
MOV A, (CHTEMP_SONG_POINTER_L)+Y
; If the opcode >= $80, then it's either an instrument change or a waiting opcode
Expand All @@ -961,10 +956,11 @@ namespace ParseSongData
AND A, #$7F
LSR A
BCC WaitCmd
MOV CHTEMP_INSTRUMENT_INDEX, A
MOV !TEMP_VALUE, A
MOV A, CHTEMP_INSTRUMENT_SECTION_HIGHBITS
AND A, #$C0
TSET CHTEMP_INSTRUMENT_INDEX, A
OR A, !TEMP_VALUE
MOV CH1_INSTRUMENT_INDEX+X, A
CALL CallInstrumentParser
JMP ReadByte

Expand All @@ -975,7 +971,7 @@ namespace ParseSongData
;DEC A
MOV CH1_SONG_COUNTER+X, A
BBS0 CHTEMP_FLAGS, DecrementReference
BCC ReadByte ; C still in effect since the ADC, indicates that the driver is REALLY falling behind
BCC Y00ReadByte ; C still in effect since the ADC, indicates that the driver is REALLY falling behind
RET

Inst_Section_HighBits:
Expand All @@ -984,12 +980,13 @@ namespace ParseSongData
BBC2 !TEMP_VALUE, Inst_HighBits ; If it is setting the high bits, call the right routine
AND CHTEMP_INSTRUMENT_SECTION_HIGHBITS, #$FC
-- TSET CHTEMP_INSTRUMENT_SECTION_HIGHBITS, A
JMP ReadByte
JMP Y00ReadByte

Note:
MOV A, !TEMP_VALUE
MOV CH1_NOTE+X, A
BBS4 CHTEMP_FLAGS, PitchUpdate
BBS5 CHTEMP_FLAGS, PitchUpdate
; Retrigger
MOV $F2, #$5C ; Key off the needed channel
MOV $F3, !CHANNEL_BITMASK ;__
Expand Down Expand Up @@ -1034,8 +1031,10 @@ namespace ParseSongData

; Return from reference
CLR0 CHTEMP_FLAGS
MOV CHTEMP_SONG_POINTER_L, CHTEMP_REF0_POINTER_L
MOV CHTEMP_SONG_POINTER_H, CHTEMP_REF0_POINTER_H
MOV A, CH1_REF0_POINTER_H+X
MOV Y, A
MOV A, CH1_REF0_POINTER_L+X
MOVW CHTEMP_SONG_POINTER_L, YA
MOV A, CH1_SONG_COUNTER+X
BMI - ; Indicates that the driver is really falling behind
Expand Down Expand Up @@ -1093,12 +1092,7 @@ namespace ParseSongData
MOV CHTEMP_COUNTERS_HALT, Y
MOV CHTEMP_COUNTERS_DIRECTION, Y
CALL SPC_ParseInstrumentData_Start
CLRC
ADC CHTEMP_INSTRUMENT_TYPE_COUNTER, !TIMER_VALUE
ADC CHTEMP_ENVELOPE_COUNTER, !TIMER_VALUE
ADC CHTEMP_SAMPLE_POINTER_COUNTER, !TIMER_VALUE
ADC CHTEMP_ARPEGGIO_COUNTER, !TIMER_VALUE
ADC CHTEMP_PITCHBEND_COUNTER, !TIMER_VALUE
SET5 CHTEMP_FLAGS

RET

Expand All @@ -1125,37 +1119,45 @@ namespace ParseSongData
ReferenceSet:
MOV X, !BACKUP_X

MOV CHTEMP_REF0_POINTER_L, CHTEMP_SONG_POINTER_L
MOV CHTEMP_REF0_POINTER_H, CHTEMP_SONG_POINTER_H

MOV A, (CHTEMP_REF0_POINTER_L)+Y
INCW CHTEMP_REF0_POINTER_L
MOV A, (CHTEMP_SONG_POINTER_L)+Y
INCW CHTEMP_SONG_POINTER_L
MOV CH1_REF0_COUNTER+X, A
SET0 CHTEMP_FLAGS

MOV A, (CHTEMP_REF0_POINTER_L)+Y ; Y assumed to be 0
INCW CHTEMP_REF0_POINTER_L
MOV CHTEMP_SONG_POINTER_L, A
MOV A, (CHTEMP_SONG_POINTER_L)+Y ; Y assumed to be 0
INCW CHTEMP_SONG_POINTER_L
PUSH A

MOV A, (CHTEMP_REF0_POINTER_L)+Y ; Y still assumed to be 0
INCW CHTEMP_REF0_POINTER_L
MOV CHTEMP_SONG_POINTER_H, A
MOV A, (CHTEMP_SONG_POINTER_L)+Y ; Y still assumed to be 0
INCW CHTEMP_SONG_POINTER_L
MOV Y, A ; The high byte, for YA

MOV A, CHTEMP_SONG_POINTER_L
MOV CH1_REF0_POINTER_L+X, A
MOV A, CHTEMP_SONG_POINTER_H
MOV CH1_REF0_POINTER_H+X, A

POP A
MOVW CHTEMP_SONG_POINTER_L, YA

JMP ReadByte

ReferenceRepeat:
MOV A, (CHTEMP_SONG_POINTER_L)+Y
CLRC
ADC A, #$04 ;__ 3 bytes of parameters + 1 byte for this opcode
ADC A, #$05 ;__ 3 bytes of parameters + 1 byte for this opcode
MOV !TEMP_POINTER0_L, A ; Neither of these instructions
MOV !TEMP_POINTER0_H, Y ;__ affect carry
ADC !TEMP_POINTER0_H, #$00

MOV X, !BACKUP_X
INCW CHTEMP_SONG_POINTER_L
MOVW YA, CHTEMP_SONG_POINTER_L
MOVW CHTEMP_REF0_POINTER_L, YA
INCW CHTEMP_REF0_POINTER_L
MOV CH1_REF0_POINTER_L+X, A
MOV A, Y
MOV CH1_REF0_POINTER_H+X, A
MOV A, CHTEMP_SONG_POINTER_L ; The high byte is correct but the low one got corrupted

SUBW YA, !TEMP_POINTER0_L ; Get address of last
MOVW !TEMP_POINTER0_L, YA ;__ reference opcode's parameters
Expand All @@ -1165,6 +1167,7 @@ namespace ParseSongData
MOV A, (!TEMP_POINTER0_L)+Y
MOV CH1_REF0_COUNTER+X, A
INC Y

SET0 CHTEMP_FLAGS

MOV A, (!TEMP_POINTER0_L)+Y
Expand Down Expand Up @@ -1212,8 +1215,6 @@ MainLoop:

MOV X, #$08
-:
MOV A, CH1_POINTER_0-1+Y
MOV CHTEMP_POINTER_0-1+X, A
MOV A, CH1_POINTER_2-1+Y
MOV CHTEMP_POINTER_2-1+X, A
MOV A, CH1_POINTER_3-1+Y
Expand All @@ -1225,6 +1226,12 @@ MainLoop:
; Special cases (will become the main)
MOV A, CH1_FLAGS+Y
MOV CHTEMP_FLAGS, A
MOV A, CH1_SONG_POINTER_L+Y
MOV CHTEMP_SONG_POINTER_L, A
MOV A, CH1_SONG_POINTER_H+Y
MOV CHTEMP_SONG_POINTER_H, A
MOV A, CH1_INSTRUMENT_TYPE+Y
MOV CHTEMP_INSTRUMENT_TYPE, A

MOV A, Y ; Saves 2 cycles compared
MOV X, A ;__ to PUSH X : POP X
Expand Down Expand Up @@ -1269,8 +1276,6 @@ MainLoop:

MOV X, #$08
-:
MOV A, CHTEMP_POINTER_0-1+X
MOV CH1_POINTER_0-1-8+Y, A
MOV A, CHTEMP_POINTER_2-1+X
MOV CH1_POINTER_2-1-8+Y, A
MOV A, CHTEMP_POINTER_3-1+X
Expand All @@ -1280,6 +1285,12 @@ MainLoop:
BNE -
MOV A, CHTEMP_FLAGS
MOV CH1_FLAGS-8+Y, A
MOV A, CHTEMP_SONG_POINTER_L
MOV CH1_SONG_POINTER_L-8+Y, A
MOV A, CHTEMP_SONG_POINTER_H
MOV CH1_SONG_POINTER_H-8+Y, A
MOV A, CHTEMP_INSTRUMENT_TYPE
MOV CH1_INSTRUMENT_TYPE-8+Y, A

MOV A, Y ; Saves 8 cycles compared to PUSH X : POP X : MOV A, X
.GoToNextChannel:
Expand All @@ -1295,11 +1306,18 @@ MainLoop:

namespace ParseInstrumentData
Start:
BBS5 CHTEMP_FLAGS, OneOff
BBC1 CHTEMP_FLAGS, Load
RET

OneOff:
CLR5 CHTEMP_FLAGS
RET

Load:
MOV Y, CHTEMP_INSTRUMENT_INDEX
MOV X, !BACKUP_X
MOV A, CH1_INSTRUMENT_INDEX+X
MOV Y, A
MOV A, InstrumentPtrLo+Y
MOV !TEMP_POINTER0_L, A
MOV A, InstrumentPtrHi+Y
Expand Down Expand Up @@ -1478,7 +1496,7 @@ namespace ParseInstrumentData
%realChannelWrite() ;__
RET
UpdateSamplePointer:

MOV X, !BACKUP_X ;__
BBS3 CHTEMP_INSTRUMENT_TYPE, + ;__ If sample index is used,
MOV A, (!TEMP_POINTER1_L)+Y ;
MOV Y, A ;
Expand All @@ -1490,30 +1508,32 @@ namespace ParseInstrumentData
AND A, #$40 ;
OR A, $EF ;
TCALL 15 ;
MOVW CHTEMP_SAMPLE_POINTER_L, YA ;
MOV Y, #$00 ;
JMP ++ ;__
MOVW !TEMP_POINTER1_L, YA ;
MOV CH1_SAMPLE_POINTER_L+X, A ;
MOV A, Y ;
MOV CH1_SAMPLE_POINTER_H+X, A ;
JMP updatePointer ;__
+ MOV A, (!TEMP_POINTER1_L)+Y ;
MOV CHTEMP_SAMPLE_POINTER_L, A ; If no, just blatantly
PUSH A ; If no, just blatantly
INCW !TEMP_POINTER1_L ; Load sample pointer into memory
MOV A, (!TEMP_POINTER1_L)+Y ;
MOV CHTEMP_SAMPLE_POINTER_H, A ;__
++:
MOV X, !BACKUP_X ;__
MOV Y, A ;
POP A ;
MOVW !TEMP_POINTER1_L, YA ;__
updatePointer:
BBS7 CHTEMP_FLAGS, updatePointer_1 ; If the currently playing sample is 1, update sample 0
.0:
MOV A, CHTEMP_SAMPLE_POINTER_H ; Check if the high byte is the same
MOV A, !TEMP_POINTER1_H ; Check if the high byte is the same
CMP A, $0203+X ;__
BNE updatePointer_0_withRestart ;
MOV A, CHTEMP_SAMPLE_POINTER_L ; If yes, update only the low byte of the sample pointer
MOV A, !TEMP_POINTER1_L ; If yes, update only the low byte of the sample pointer
MOV $0202+X, A ;__
POP X
RET
..withRestart:
MOV $0207+X, A ; If high byte is different,
MOV A, CHTEMP_SAMPLE_POINTER_L ; Update sample 1 loop pointer
MOV A, !TEMP_POINTER1_L ; Update sample 1 loop pointer
MOV $0206+X, A ;__
MOV A, #$C0 ;
MOV $0204+X, A ; Reset sample 1 start pointer to blank sample
Expand All @@ -1533,17 +1553,17 @@ namespace ParseInstrumentData


.1:
MOV A, CHTEMP_SAMPLE_POINTER_H ; Check if high byte is the same
MOV A, !TEMP_POINTER1_H ; Check if high byte is the same
CMP A, $0207+X ;__
BNE updatePointer_1_withRestart ;
MOV A, CHTEMP_SAMPLE_POINTER_L ; If yes, update only the low byte of the sample pointer
MOV A, !TEMP_POINTER1_L ; If yes, update only the low byte of the sample pointer
MOV $0206+X, A ;__
POP X
RET
..withRestart:
MOV $0203+X, A ; If high byte is different,
MOV A, CHTEMP_SAMPLE_POINTER_L ; Update sample 1 loop pointer
MOV A, !TEMP_POINTER1_L ; Update sample 1 loop pointer
MOV $0202+X, A ;__
MOV A, #$C0 ;
MOV $0200+X, A ; Reset sample 1 start pointer to blank sample
Expand Down

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