Subversion Repositories lxp32

/*

 * This test calculates a CRC-32 checksum of a small byte array

 * CRC32("123456789")=0xCBF43926

 */

        lc r100, 0x10000000 // test result output pointer

        lc r101, halt

        lc r102, failure

        lc r16, 0x10000004 // output pointer

        lc r17, 0xFFFFFFFF // initial CRC value

        lc r18, 0xEDB88320 // polynom

        lc r19, data // input pointer

        lc r32, byte_loop

        lc r33, bit_loop

        lc r34, dont_xor

        mov r20, 0 // byte counter

byte_loop:

        lub r0, r19

        mov r21, 0 // bit counter

bit_loop:

        and r1, r0, 1

        and r2, r17, 1

        sru r17, r17, 1

        xor r3, r1, r2

        cjmpe r34, r3, 0

        xor r17, r17, r18

dont_xor:

        sru r0, r0, 1

        add r21, r21, 1

        cjmpul r33, r21, 8

        add r19, r19, 1

        add r20, r20, 1

        cjmpul r32, r20, 9

        not r17, r17

        sw r16, r17

        lc r0, 0xCBF43926

        cjmpne r102, r0, r17

        sw r100, 1

        jmp r101

failure:

        sw r100, 2

halt:

        hlt

        jmp r101

data:

        .byte "123456789"