variables and stack space question

["Hudak, Tyler" <Tyler dot Hudak at roadway dot com>]

Hello,

  I'm confused on how stack space for variables are handlted.  In the
function
foo, a 5-byte string, buf2, is created.  I would expect the stack to
only be subtracted 8 bytes to make room for this, but when I generate
the assembly output for it (with gcc -s), 24 bytes are subtracted on
the stack.  Why so much?  Does this have to do with alignment?  If so,
where can I find more information on this.  Thanks.  If you need to
know, I'm running RH 7.1 on a P3 with gcc 2.96.

Tyler

prog.c:

void foo (int a, int b, int c)
{
  char buf2[5];
}

void main()
{
  foo(1,2,3);
}

prog.asm:

	.file	"ex1.c"
	.version	"01.01"
gcc2_compiled.:
.text
	.align 4
.globl foo
	.type	 foo,@function
foo:
	pushl	%ebp
	movl	%esp, %ebp
	subl	$24, %esp    <-----------  space on stack for buf2 created
here
	leave
	ret
.Lfe1:
	.size	 foo,.Lfe1-foo
	.align 4
.globl main
	.type	 main,@function
main:
	pushl	%ebp
	movl	%esp, %ebp
	subl	$8, %esp
	subl	$4, %esp
	pushl	$3
	pushl	$2
	pushl	$1
	call	foo
	addl	$16, %esp
	leave
	ret
.Lfe2:
	.size	 main,.Lfe2-main
	.ident	"GCC: (GNU) 2.96 20000731 (Red Hat Linux 7.1 2.96-81)"