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Extract to macros

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This commit is contained in:
Gwilym Inzani 2023-07-14 23:02:41 +01:00
parent fc4632ca8a
commit eb8cb667c1
1 changed files with 20 additions and 7 deletions
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27
agb/src/sound/mixer/mixer.s
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@ -12,7 +12,14 @@ agb_arm_func \fn_name
push {{r4-r8}} push {{r4-r8}}
ldr r7, [sp, #20] @ load the right channel modification amount into r7 ldr r7, [sp, #20] @ load the right channel modification amount into r7
ldr r8, [sp, #24] @ load the buffer size into r8 ldr r8, [sp, #24] @ load the buffer size into r8
movs r8, r8 @ check that the buffer size isn't 0
bne 1f
pop {{r4-r8}}
bx lr
1:
cmp r7, r3 @ check if left and right channel need the same modifications cmp r7, r3 @ check if left and right channel need the same modifications
beq 3f @ same modification beq 3f @ same modification
@ -22,8 +29,7 @@ agb_arm_func \fn_name
mov r5, #0 @ current index we're reading from mov r5, #0 @ current index we're reading from
1: .macro add_one_sample
.rept 4
add r4, r0, r5, asr #8 @ calculate the address of the next read from the sound buffer add r4, r0, r5, asr #8 @ calculate the address of the next read from the sound buffer
ldrsb r6, [r4] @ load the current sound sample to r6 ldrsb r6, [r4] @ load the current sound sample to r6
add r5, r5, r2 @ calculate the position to read the next sample from add r5, r5, r2 @ calculate the position to read the next sample from
@ -36,8 +42,12 @@ agb_arm_func \fn_name
.endif .endif
str r4, [r1], #4 @ store the new value, and increment the pointer str r4, [r1], #4 @ store the new value, and increment the pointer
.endm
1:
.rept 4
add_one_sample
.endr .endr
.purgem add_one_sample
subs r8, r8, #4 @ loop counter subs r8, r8, #4 @ loop counter
bne 1b @ jump back if we're done with the loop bne 1b @ jump back if we're done with the loop
@ -63,13 +73,11 @@ agb_arm_func \fn_name
mov r5, #0 @ current index we're reading from mov r5, #0 @ current index we're reading from
1: .macro add_one_sample_same_modification
.rept 4
add r4, r0, r5, asr #8 @ calculate the address of the next read from the sound buffer add r4, r0, r5, asr #8 @ calculate the address of the next read from the sound buffer
ldrsb r6, [r4] @ load the current sound sample to r6 ldrsb r6, [r4] @ load the current sound sample to r6
add r5, r5, r2 @ calculate the position to read the next sample from add r5, r5, r2 @ calculate the position to read the next sample from
lsl r6, r6, #16 lsl r6, r6, #16
orr r6, r6, lsr #16 orr r6, r6, lsr #16
@ -81,7 +89,12 @@ agb_arm_func \fn_name
.endif .endif
str r4, [r1], #4 @ store the new value, and increment the pointer str r4, [r1], #4 @ store the new value, and increment the pointer
.endm
1:
.rept 4
add_one_sample_same_modification
.endr .endr
.purgem add_one_sample_same_modification
subs r8, r8, #4 @ loop counter subs r8, r8, #4 @ loop counter
bne 1b @ jump back if we're done with the loop bne 1b @ jump back if we're done with the loop