stack frame align to different size?

It's a simple test. A similar topic has been discussed in Stack allocation, padding, and alignment but when i compile the following two source code i have conflicting results.

 #include <stdio.h>
 //first source code
    void haha()
    {
      printf("HI");
    }
    int main()
    {
      int b = 2;
      b = b << 1;
      haha();
      //printf("n = %d",b);
      return 0;
    }

---

 #include <stdio.h>
     //second source code
void haha3()
{
  int c,a,b;
  c=a+b;
} 
void haha2()
{
  int c,a,b;
  c=a+b;
  haha3();
}
int main()
{
  int b = 2;
  b = b << 1;
  haha2();
  //printf("n = %d",b);
  return 0;
}

For the first source code i got the assembly code:

haha:
    pushl   %ebp
    movl    %esp, %ebp
    subl    $24, %esp
    movl    $.LC0, %eax
    movl    %eax, (%esp)
    call    printf
    leave
    ret
    .size   haha, .-haha
.globl main
    .type   main, @function
main:
    pushl   %ebp
    movl    %esp, %ebp
    andl    $-16, %esp
    subl    $16, %esp
    movl    $2, 12(%esp)
    sall    12(%esp)
    call    haha
    movl    $0, %eax
    leave
    ret

For the second source code i got the assembly code:

haha3:
    pushl   %ebp
    movl    %esp, %ebp
    subl    $16, %esp
    movl    -4(%ebp), %eax
    movl    -8(%ebp), %edx
    leal    (%edx,%eax), %eax
    movl    %eax, -12(%ebp)
    leave
    ret
    .size   haha3, .-haha3
.globl haha2
    .type   haha2, @function
haha2:
    pushl   %ebp
    movl    %esp, %ebp
    subl    $16, %esp
    movl    -4(%ebp), %eax
    movl    -8(%ebp), %edx
    leal    (%edx,%eax), %eax
    movl    %eax, -12(%ebp)
    call    haha3
    leave
    ret
    .size   haha2, .-haha2
.globl main
    .type   main, @function
main:
    pushl   %ebp
    movl    %esp, %ebp
    subl    $16, %esp
    movl    $2, -4(%ebp)
    sall    -4(%ebp)
    call    haha2
    movl    $0, %eax
    leave
    ret

My question is why the stack frame of the first code aligns to 24(subl $24, %esp) and the second aligns to 16(subl $16, %esp)? It's said in Stack allocation, padding, and alignment the SSEx family of instructions REQUIRES packed 128-bit vectors to be aligned to 16 bytes. So, I expect the stack frame of the first code has a subl $32, %esp and subl $16, %esp for the second one, or subl $24, %esp for the first and subl $8, %esp for the second because of the leave and ret reserved 8 bytes as it said. However, the fact is the first code use 'subl $24, %esp' and the second use 'subl $16, %esp' Thank you for your interest.

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