algorithm - Find longest alternating string of 1's and 0's -

i learning bitwise operations in assembly. in terms of bitwise operations, quite forward find longest string of 0's or 1's, how find longest string of alternating 1's , 0's.

i thought similar first 2 in sense need right shift , appropriate operation, , repeat until had 0's, couldn't figure out solution. ideas on do?

thanks!

edit

some examples: 101101010001 has string of 6 alternating 1s , 0s. number 1010 has string of 4 consecutive 1s , 0s. don't care alternating strings of 0's , 1's, 0101, 2 because of 10 in middle of it

the architecture i'm using arm a9 processor

here tried

.text .global _start _start:  mov r5, #0//store final result mov r6, #0 mov r2 , #0 mov r7, #0 ldr r3 , =test_num  ones: ldr r1, [r3]  //load data word r1      mov r0, #0      // r0 hold result loop: cmp r1, #0     //loop until data contains no more ones     beq next     lsr r2, r1, #1  //perform shift, followed ,     xor r1, r1, r2     add r0, #1      // count number of iterations     b loop next: cmp r5, r0 //     movle  r5, r0     b end end:   b end  test_num: .word 0x1fffffff, 0x7fffffff .end  

this logic can use getting longest alternating bit pattern:

int last_bit = num & 1; int count = 1; int bit_at_pos;    //holds lsb num = num >> 1; int longest = 1;  while(num > 0){     bit_at_pos = num & 1;     if(bit_at_pos == 1 - last_bit){  //checks if bit alternate last bit or not.         count++;         }else{         if(longest < count) longest = count;         count = 1;     }     last_bit = bit_at_pos;     num = num >> 1; } // longest answer