I’m trying to write a simple x86-64 assembly program (AT&T syntax) to calculate the sum of a float array and print the result using printf. Here’s my code:

asm
.section .data
msg: .asciz "Result is: %fn"
n: .int 5
a: .float 1.1, 2.2, 3.3, 4.4, 5.5
res: .float 0

.section .text
.globl main
main:
    xor %ecx, %ecx
    movss res, %xmm0
    mov n, %ebx
    
    while:
        cmp %ebx, %ecx
        je end_while
        
        addss a(,%ecx, 4) , %xmm0
        inc %ecx
        jmp while
        
    end_while:
    
    mov $msg, %rdi
    mov $0, %eax
    call printf
    
    call exit

Problem: When I run this program, I get a Segmentation fault (core dumped) error. I suspect there’s something wrong with how I’m using the printf function, but I’m not sure where the issue is.

Am I using the printf function correctly in this context?
Is there something wrong with the way I access the float array (addss a(,%ecx,4), %xmm0)?
Any help or guidance would be greatly appreciated!