Set Voice Release Shift

0001b828: 3c028003 lui r2,0x8003
0001b82c: 8c42ad44 lw r2,-0x52bc(r2)                Voice 0...23 registers
0001b830: 00042100 sll r4,r4,0x04
0001b834: 00822021 addu r4,r4,r2
0001b838: 9482000a lhu r2,0x000a(r4)                upper halfword of Voice 0..23 Attack/Decay/Sustain/Release
0001b83c: 27bdfff8 addiu r29,r29,0xfff8
0001b840: 3042ffc0 andi r2,r2,0xffc0
0001b844: 00451025 or r2,r2,r5                      set Release Shift to param 2
0001b848: a482000a sh r2,0x000a(r4)
0001b84c: 34020001 ori r2,r0,0x0001
0001b850: afa20004 sw r2,0x0004(r29)
0001b854: afa00000 sw r0,0x0000(r29)
0001b858: 08006e24 j 0x0001b890
0001b85c: 00000000 nop
0001b860: 8fa30004 lw r3,0x0004(r29)                code below achieves... nothing.
0001b864: 00000000 nop
0001b868: 00031040 sll r2,r3,0x01
0001b86c: 00431021 addu r2,r2,r3
0001b870: 00021080 sll r2,r2,0x02
0001b874: 00431021 addu r2,r2,r3
0001b878: afa20004 sw r2,0x0004(r29)
0001b87c: 8fa20000 lw r2,0x0000(r29)
0001b880: 00000000 nop
0001b884: 24420001 addiu r2,r2,0x0001
0001b888: afa20000 sw r2,0x0000(r29)
0001b88c: 8fa20000 lw r2,0x0000(r29)
0001b890: 8fa20000 lw r2,0x0000(r29)
0001b894: 00000000 nop
0001b898: 28420002 slti r2,r2,0x0002
0001b89c: 1440fff0 bne r2,r0,0x0001b860
0001b8a0: 00000000 nop
0001b8a4: 27bd0008 addiu r29,r29,0x0008
0001b8a8: 03e00008 jr r31
0001b8ac: 00000000 nop