1 files changed, 100 insertions, 0 deletions

diff --git a/Asm/arm/7zCrcOpt.asm b/Asm/arm/7zCrcOpt.asm
new file mode 100644
index 0000000..6001d8e
--- /dev/null
+++ b/Asm/arm/7zCrcOpt.asm
@@ -0,0 +1,100 @@
+        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