When implementing an infinite loop, is there a difference in using while(1) vs for(;;) vs goto (in C)?

Question

When implementing an infinite loop, is there a difference in using while(1) vs for(;;) vs goto?

Thanks, Chenz

Answer 1

I just compared the unoptimized assembler output of gcc:

# cat while.c 
int main() {
    while(1) {};
    return 0;
}

# cat forloop.c 
int main() {
    for (;;) { };
    return 0;
}

Make assembler output:

# gcc -S while.c 
# gcc -S forloop.c 

Compare assembler files:

# diff forloop.s while.s
1c1
<   .file   "forloop.c"
---
>   .file   "while.c"

As you can see there are no significant differences. Here is the output

# cat while.s 
    .file   "while.c"
    .text
.globl main
    .type   main, @function
main:
    pushl   %ebp
    movl    %esp, %ebp
.L2:
    jmp .L2                    # this is the loop in both cases
    .size   main, .-main
    .ident  "GCC: (GNU) 4.4.3"
    .section    .note.GNU-stack,"",@progbits

While this is not a technical proof that they are the same, I'd say it is in 99.9% of the cases.