So... I'm compiling into assembler, with gcc -S -O2 -m32:

void h(int y){int x; x=y+1; f(y); f(2); }

And it gives me the following:

.file   "sample.c"
.text
.p2align 4,,15
.globl h
.type   h, @function
 h:
pushl   %ebp
movl    %esp, %ebp
subl    $24, %esp
movl    8(%ebp), %eax
movl    %eax, (%esp)
call    f
movl    $2, 8(%ebp)
leave
jmp f
.size   h, .-h
.ident  "GCC: (GNU) 4.4.3 20100127 (Red Hat 4.4.3-4)"
.section    .note.GNU-stack,"",@progbits

Now I know what pushl and movel: they store the current frame pointer onto the stack and then set the value of the frame pointer register to the value of the Stack Pointer.

But I have no idea what the subl $24, %esp is. Thanks!