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101 lines
1.4 KiB

CODE32
EXPORT |CrcUpdateT4@16|
AREA |.text|, CODE, ARM
MACRO
CRC32_STEP_1
ldrb r4, [r1], #1
subs r2, r2, #1
eor r4, r4, r0
and r4, r4, #0xFF
ldr r4, [r3, +r4, lsl #2]
eor r0, r4, r0, lsr #8
MEND
MACRO
CRC32_STEP_4 $STREAM_WORD
eor r7, r7, r8
eor r7, r7, r9
eor r0, r0, r7
eor r0, r0, $STREAM_WORD
ldr $STREAM_WORD, [r1], #4
and r7, r0, #0xFF
and r8, r0, #0xFF00
and r9, r0, #0xFF0000
and r0, r0, #0xFF000000
ldr r7, [r6, +r7, lsl #2]
ldr r8, [r5, +r8, lsr #6]
ldr r9, [r4, +r9, lsr #14]
ldr r0, [r3, +r0, lsr #22]
MEND
|CrcUpdateT4@16| PROC
stmdb sp!, {r4-r11, lr}
cmp r2, #0
beq |$fin|
|$v1|
tst r1, #7
beq |$v2|
CRC32_STEP_1
bne |$v1|
|$v2|
cmp r2, #16
blo |$v3|
ldr r10, [r1], #4
ldr r11, [r1], #4
add r4, r3, #0x400
add r5, r3, #0x800
add r6, r3, #0xC00
mov r7, #0
mov r8, #0
mov r9, #0
sub r2, r2, #16
|$loop|
; pld [r1, #0x40]
CRC32_STEP_4 r10
CRC32_STEP_4 r11
subs r2, r2, #8
bhs |$loop|
sub r1, r1, #8
add r2, r2, #16
eor r7, r7, r8
eor r7, r7, r9
eor r0, r0, r7
|$v3|
cmp r2, #0
beq |$fin|
|$v4|
CRC32_STEP_1
bne |$v4|
|$fin|
ldmia sp!, {r4-r11, pc}
|CrcUpdateT4@16| ENDP
END