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oot/asm/mio0.s
Tharo 7334ffa373
Improve the state of handwritten assembly files (#865)
* Format all handwritten asm and document some

* Use c preprocessor for constants

* Fix

* Fix PI_STATUS_ERROR, some label improvements

* Avoid hi/lo for constants

* Some more comments

* Properly mark functions as functions and their sizes

* Fix merge

* Improvements

* Review suggestions, rework procedure start/end macros to be more like libreultra

* Move IPL3 symbol definitions into ipl3.s

* Fix undefined_syms, add include and language guards to asm.h and fix the comment in gbi.h

* Consistent hex capitalization, add some MIPS builtin defines to CC_CHECK to behave properly

* Add -no-pad-sections assembler option and clean up alignment in gu files and bzero

* Further suggestions and improvements

* Matrix conversion function clarifications

* Fix passing AVOID_UB to gcc

* Suggestions

* Suggestions, global interrupt mask improvements

* Further suggestions, interrupt mask comments

* Comments fixes, rdb.h

* Switch from # comments to // comments, remove unnecesary .set gp=64 directives

* Further review suggestions

* Missed one
2022-05-01 01:03:22 +02:00

65 lines
1.6 KiB
ArmAsm

#include "ultra64/asm.h"
.set noat
.set noreorder
.section .text
.balign 16
/**
* void Mio0_Decompress(void* src, void* dst);
*
* Decompress Mio0 chunk
*/
LEAF(Mio0_Decompress)
lw $a3, 8($a0) // compressed offset
lw $t9, 0xC($a0) // uncompressed offset
lw $t8, 4($a0) // decompressed length
add $a3, $a3, $a0 // compressed start
add $t9, $t9, $a0 // uncompressed start
move $a2, $zero // 0
addi $a0, $a0, 0x10 // move past header
add $t8, $t8, $a1 // dst + decompressed length = end
mainloop:
bnez $a2, 1f
nop
lw $t0, ($a0)
li $a2, 32
addi $a0, $a0, 4
1:
slt $t1, $t0, $zero
beqz $t1, read_comp
nop
lb $t2, ($t9) // read 1 byte from uncompressed data
addi $t9, $t9, 1 // advance uncompressed start
addi $a1, $a1, 1
b next_iter
sb $t2, -1($a1) // store uncompressed byte
read_comp:
lhu $t2, ($a3) // read 2 bytes from compressed data
addi $a3, $a3, 2 // advance compressed start
srl $t3, $t2, 0xC
andi $t2, $t2, 0xFFF
beqz $t3, 3f
sub $t1, $a1, $t2
addi $t3, $t3, 2
2:
lb $t2, -1($t1)
addi $t3, $t3, -1
addi $t1, $t1, 1
addi $a1, $a1, 1
bnez $t3, 2b
sb $t2, -1($a1)
next_iter:
sll $t0, $t0, 1
bne $a1, $t8, mainloop // continue until decompressed length is reached
addi $a2, $a2, -1
jr $ra
nop
3:
lbu $t3, ($t9)
addi $t9, $t9, 1
b 2b
addi $t3, $t3, 0x12
END(Mio0_Decompress)