Question

:96: Error: `(%rax,%edx,4)' is not a valid base/index expression

:97: Error: `-4(%rax,%edx,4)' is not a valid base/index expression

101: Error: `(%rax,%edx,4)' is not a valid base/index expression

102: Error: `-4(%rax,%edx,4)' is not a valid base/index expression

i get these error messages not sure how to fix it this is my code

                 "movl        $0, %6\n"
     line96      "start:        \n\t"
     line97      "movl        (%1,%3,4),%4\n\t"       
                 "movl        -4(%1, %3, 4), %5\n\t"  
             "cmpl        %4, %5\n\t"    
    line 101     "jle             next\n\t"
     line102     xchgl        %4, %5\n\t"               
                 "movl        %4, (%1, %3, 4)\n\t"        
                 "movl        %5, -4(%1, %3, 4)\n\t"        
                 "movl        $1, %6\n\t"

… my code is long so i did not want to post the whole code but i am doing a bubble sort in asm ,, when i compile i get the above error messages am not quite sure how to fix it … if any one could explain to what is wrong will be helpful .. thanks .. sorry if the format is a bit untidy am new to this ..

Answer 1

You’ve incorrectly use indirect addressing.

It is incorrectly use ax:dx pair as base pointers with displacement. Refer to this and this for examples.