+/*
+ * PicoDrive
+ * (C) notaz, 2006
+ *
+ * This work is licensed under the terms of MAME license.
+ * See COPYING file in the top-level directory.
+ */
+
@ this is a rewrite of MAME's ym2612 code, in particular this is only the main sample-generatin loop.
@ it does not seem to give much performance increase (if any at all), so don't use it if it causes trouble.
@ - notaz, 2006
.equiv EG_TIMER_OVERFLOW, (3*(1<<EG_SH)) @ envelope generator timer overflows every 3 samples (on real chip)
.equiv LFO_SH, 25 /* 7.25 fixed point (LFO calculations) */
-.equiv ENV_QUIET, (2*13*256/8)/2
+.equiv ENV_QUIET, (2*13*256/8)
+.text
+.align 2
@ r5=slot, r1=eg_cnt, trashes: r0,r2,r3
@ writes output to routp, but only if vol_out changes
.macro update_eg_phase_slot slot
- ldrb r2, [r5,#0x17] @ state
- mov r3, #1 @ 1ci
- cmp r2, #1
- blt 5f @ EG_OFF
- beq 3f @ EG_REL
- cmp r2, #3
- blt 2f @ EG_SUS
- beq 1f @ EG_DEC
-
-0: @ EG_ATT
- ldr r2, [r5,#0x20] @ eg_pack_ar (1ci)
- mov r0, r2, lsr #24
+ ldrb r2, [r5,#0x17] @ state
+ add r3, r5, #0x1c
+ tst r2, r2
+ beq 0f @ EG_OFF
+
+ ldr r2, [r3, r2, lsl #2] @ pack
+ mov r3, #1
+ mov r0, r2, lsr #24 @ shift
mov r3, r3, lsl r0
sub r3, r3, #1
- tst r1, r3
- bne 5f @ do smth for tl problem (set on init?)
- mov r3, r1, lsr r0
- ldrh r0, [r5,#0x1a] @ volume, unsigned (0-1023)
- and r3, r3, #7
- add r3, r3, r3, lsl #1
- mov r3, r2, lsr r3
- and r3, r3, #7 @ shift for eg_inc calculation
- mvn r2, r0
- mov r2, r2, lsl r3
- add r0, r0, r2, asr #5
- cmp r0, #0 @ if (volume <= MIN_ATT_INDEX)
- movle r3, #EG_DEC
- strleb r3, [r5,#0x17] @ state
- movle r0, #0
- b 4f
-1: @ EG_DEC
- ldr r2, [r5,#0x24] @ eg_pack_d1r (1ci)
- mov r0, r2, lsr #24
- mov r3, r3, lsl r0
- sub r3, r3, #1
tst r1, r3
- bne 5f @ do smth for tl problem (set on init?)
+ bne 0f @ no volume change
+
mov r3, r1, lsr r0
- ldrh r0, [r5,#0x1a] @ volume
and r3, r3, #7
add r3, r3, r3, lsl #1
mov r3, r2, lsr r3
- and r3, r3, #7 @ shift for eg_inc calculation
+ and r3, r3, #7 @ eg_inc_val shift, may be 0
+ ldrb r2, [r5,#0x17] @ state
+ ldrh r0, [r5,#0x1a] @ volume, unsigned (0-1023)
+
+ cmp r2, #4 @ EG_ATT
+ beq 4f
+ cmp r2, #2
mov r2, #1
- mov r3, r2, lsl r3
+ mov r2, r2, lsl r3
+ mov r2, r2, lsr #1 @ eg_inc_val
+ add r0, r0, r2
+ blt 1f @ EG_REL
+ beq 2f @ EG_SUS
+
+3: @ EG_DEC
ldr r2, [r5,#0x1c] @ sl (can be 16bit?)
- add r0, r0, r3, asr #1
+ mov r3, #EG_SUS
cmp r0, r2 @ if ( volume >= (INT32) SLOT->sl )
- movge r3, #EG_SUS
strgeb r3, [r5,#0x17] @ state
- b 4f
+ b 10f
+
+4: @ EG_ATT
+ subs r3, r3, #1 @ eg_inc_val_shift - 1
+ mov r2, #0
+ mvnpl r2, r0
+ mov r2, r2, lsl r3
+ add r0, r0, r2, asr #4
+ cmp r0, #0 @ if (volume <= MIN_ATT_INDEX)
+ movle r3, #EG_DEC
+ strleb r3, [r5,#0x17] @ state
+ movle r0, #0
+ b 10f
2: @ EG_SUS
- ldr r2, [r5,#0x28] @ eg_pack_d2r (1ci)
- mov r0, r2, lsr #24
- mov r3, r3, lsl r0
- sub r3, r3, #1
- tst r1, r3
- bne 5f @ do smth for tl problem (set on init?)
- mov r3, r1, lsr r0
- ldrh r0, [r5,#0x1a] @ volume
- and r3, r3, #7
- add r3, r3, r3, lsl #1
- mov r3, r2, lsr r3
- and r3, r3, #7 @ shift for eg_inc calculation
- mov r2, #1
- mov r3, r2, lsl r3
- add r0, r0, r3, asr #1
mov r2, #1024
sub r2, r2, #1 @ r2 = MAX_ATT_INDEX
cmp r0, r2 @ if ( volume >= MAX_ATT_INDEX )
movge r0, r2
- b 4f
+ b 10f
-3: @ EG_REL
- ldr r2, [r5,#0x2c] @ eg_pack_rr (1ci)
- mov r0, r2, lsr #24
- mov r3, r3, lsl r0
- sub r3, r3, #1
- tst r1, r3
- bne 5f @ do smth for tl problem (set on init?)
- mov r3, r1, lsr r0
- ldrh r0, [r5,#0x1a] @ volume
- and r3, r3, #7
- add r3, r3, r3, lsl #1
- mov r3, r2, lsr r3
- and r3, r3, #7 @ shift for eg_inc calculation
- mov r2, #1
- mov r3, r2, lsl r3
- add r0, r0, r3, asr #1
+1: @ EG_REL
mov r2, #1024
sub r2, r2, #1 @ r2 = MAX_ATT_INDEX
cmp r0, r2 @ if ( volume >= MAX_ATT_INDEX )
movge r3, #EG_OFF
strgeb r3, [r5,#0x17] @ state
-4:
+10: @ finish
ldrh r3, [r5,#0x18] @ tl
strh r0, [r5,#0x1a] @ volume
.if \slot == SLOT1
orr r7, r0, r7, lsr #16
.endif
-5:
+0: @ EG_OFF
.endm
tstne r12, #(1<<(\slot+8))
.if \slot == SLOT1
mov r1, r6, lsl #16
- mov r1, r1, lsr #17
+ mov r1, r1, lsr #16
.elseif \slot == SLOT2
- mov r1, r6, lsr #17
+ mov r1, r6, lsr #16
.elseif \slot == SLOT3
mov r1, r7, lsl #16
- mov r1, r1, lsr #17
+ mov r1, r1, lsr #16
.elseif \slot == SLOT4
- mov r1, r7, lsr #17
+ mov r1, r7, lsr #16
.endif
andne r2, r12, #0xc0
movne r2, r2, lsr #6
addne r2, r2, #24
addne r1, r1, r12, lsr r2
+ bic r1, r1, #1
.endm
+@ \r=sin/result, r1=env, r3=ym_tl_tab
.macro lookup_tl r
tst \r, #0x100
eorne \r, \r, #0xff @ if (sin & 0x100) sin = 0xff - (sin&0xff);
tst \r, #0x200
and \r, \r, #0xff
- orr \r, \r, r1, lsl #8
+ orr \r, \r, r1, lsl #7
mov \r, \r, lsl #1
ldrh \r, [r3, \r] @ 2ci if ne
rsbne \r, \r, #0
make_eg_out SLOT3
cmp r1, #ENV_QUIET
ldr r2, [lr, #0x38] @ mem (for future)
- movcs r0, r2
+ mov r0, #0
bcs 0f
- ldr r0, [lr, #0x18] @ 1ci
+ ldr r0, [lr, #0x18] @ phase3
mov r0, r0, lsr #16
lookup_tl r0 @ r0=c2
cmp r1, #ENV_QUIET
movcs r2, #0
bcs 2f
- ldr r2, [lr, #0x14]
+ ldr r2, [lr, #0x14] @ phase2
mov r5, r10, lsr #17
add r2, r5, r2, lsr #16
lookup_tl r2 @ r2=mem
2:
- str r2, [lr, #0x38] @ mem
+ str r2, [lr, #0x38] @ mem
.endm
movne r0, r0, asr #16
movne r0, r0, lsl r2
- ldr r2, [lr, #0x10]
+ ldr r2, [lr, #0x10] @ phase1
+ add r0, r0, r2
mov r0, r0, lsr #16
- add r0, r0, r2, lsr #16
lookup_tl r0
mov r10,r10,lsl #16 @ ct->op1_out <<= 16;
mov r0, r0, lsl #16
crl_loop_lfo:
add r0, lr, #0x30
ldmia r0, {r1,r2}
+
+ subs r4, r4, #0x100
+ bmi crl_loop_end
+
add r2, r2, r1
str r2, [lr, #0x30]
+
@ r12=lfo_ampm[31:16], r1=lfo_cnt_old, r2=lfo_cnt
advance_lfo_m
+ add r4, r4, #0x100
+
crl_loop:
subs r4, r4, #0x100
bmi crl_loop_end
crl_algo7:
upd_algo7_m
- .pool
crl_algo_done:
crl_loop_end:
+@ stmia lr, {r6,r7} @ save volumes (for debug)
str r8, [lr, #0x44] @ eg_timer
str r12, [lr, #0x4c] @ pack (for lfo_ampm)
str r4, [lr, #0x50] @ was_update
.pool
+@ vim:filetype=armasm
notaz.gp2x.de / picodrive.git / blobdiff